EP1146973B1 - Method for deforming a tube in the proximity of one of its ends and tool therefor - Google Patents

Abstract

The invention concerns a method comprising the following steps: placing a tube (6) in an opening matrix (2) having an impression (22) corresponding to the desired final external shape; inserting the end (16) of the tube into a cavity (12) of a shaping component (26), said cavity having a base (32), a side wall with adapted shape, and an opening (30) opposite the base (32); pressing the end (16) of the tube against the base (32) of the cavity (12), leaving a clearance between the opening of the cavity and the matrix; applying an essentially axial force on the end (16) of the tube, the zone of application of the force rotating about a longitudinal axis (14) of the tube thereby causing gradual deformation of the tube; withdrawing the end of the deformed tube outside the cavity (12) of the shaping component and outside the matrix (2).

Description

The present invention relates to a method of deformation of a tube near one of its ends, especially for making a tight fitting for rigid tubes. The invention also relates to a tool used in such a process.

The process in question here must make it possible to carry out the deformation of a tube to make a fitting of the type shown in FIG. 2 of document DE-195 26 316 C2 or even in the document DE-197 57 946 A1. In these two documents, there is a rigid pipe connection. A nut is fitted on the tube to be connected. The end of the tube to be connected is introduced into a male part of the fitting which has on the one hand a thread on its outer surface corresponding to the thread of the nut and on the other hand inside a tapered bore. The tube is deformed outward to achieve a stop to limit the insertion length of the tube to be connected in the male part. Once the end of the tube fitted into the part male, the nut is screwed onto the corresponding thread when coming support directly or indirectly on the deformation of the rigid tube to connected.

The documents cited do not indicate how the tube deformation. It is in fact known to place the end of the tube at deform in a matrix and come to push on the free end of the tube in order to deform the wall of it and push the material forming this tube in a housing provided for this purpose in the matrix.

One drawback of this device is that it requires the use a heavy machine that can exert significant efforts. Furthermore, it a large amount of energy is required to deform the tube.

Another disadvantage of this production method is that it breaks the fibers of the metal forming the tube to be connected. At the level of deformation, this tube is therefore weakened.

For other types of fittings, for which the deformation of the tube is carried out immediately at the end of the tube to be connected, it is known to achieve a deformation of the tube by rolling. The patent EP-O 381 603 B1 describes such a method of producing a connector. This process respects the fibers of the metal and consumes less energy but does not allow for a connection such as those revealed in document DE-197 57 946 A1.

The object of the present invention is therefore to provide a method allowing a tube to be deformed at a distance from its free end without the weaken.

To this end, it proposes a method of deformation of a tube having a longitudinal axis, close to its end, in which the tube is placed in an opening matrix having an imprint corresponding to the desired final external shape, a free end of the tube sticking out of the matrix.

• introduction de l'extrémité du tube dépassant de la matrice dans une cavité d'une pièce de forme, cette cavité présentant un fond, une paroi latérale de forme adaptée au tube et à la déformation souhaitée, ainsi qu'une ouverture opposée au fond,
• appui de l'extrémité du tube contre le fond de la cavité, un jeu subsistant entre l'ouverture de la cavité et la matrice,
• application d'une force essentiellement axiale sur l'extrémité du tube par l'intermédiaire de la pièce de forme, la zone d'application de la force tournant autour de l'axe longitudinal du tube provoquant ainsi une déformation progressive du tube,
• retrait de l'extrémité du tube déformé hors de la cavité de la pièce de forme et hors de la matrice.

According to the invention, this method also comprises the following steps:

• introduction of the end of the tube projecting from the matrix into a cavity of a shaped part, this cavity having a bottom, a lateral wall of a shape adapted to the tube and to the desired deformation, as well as an opening opposite the bottom,
• support of the end of the tube against the bottom of the cavity, a clearance remaining between the opening of the cavity and the matrix,
• application of an essentially axial force to the end of the tube by means of the shaping part, the zone of application of the force rotating around the longitudinal axis of the tube thus causing progressive deformation of the tube,
• removal of the end of the deformed tube from the cavity of the shaped part and from the die.

The fact that the force making the deformation is not not applied simultaneously to the entire periphery of the tube allows gradually deform the tube without breaking the metal fibers constituting this tube. As the tube is introduced into a cavity, the deformation is controlled. By adapting the shape of this cavity, it is possible to leave part of the tube without deformation over a length predetermined from its free end.

Various means can be envisaged to exert a force locally on the tube by turning around its axis. We can by example consider having a pressure roller acting on a wall of the part of the form part by rolling on this wall and describing a circle around the axis of the tube to be deformed.

In an advantageous embodiment of the method according to the invention, the shaped part is for example integrated into a tool having a longitudinal axis inclined relative to the axis of the tube and substantially intersecting with the latter, and the essentially axial force is exerted on the end of the tube by rotating the tool, the latter then being animated an orbital movement relative to the axis of the tube, and by approximation tool and die simultaneously.

In this embodiment, the angle of inclination between the axis of revolution of the cavity and the axis of the tube is preferably between 2 and 5 degrees.

It is also possible to provide that a nose of a snap, intended for come to bear on the inner wall of the tube to be deformed is introduced in the latter when the end of the tube is introduced into the cavity of the tool. The inside of the tube is then shaped at the same time that we distort this tube.

In another embodiment of a method according to the invention, the shaped part is placed on the end of the tube of such so that the longitudinal axis of the cavity corresponds substantially to the axis longitudinal of the tube, and an external tool comes to bear on one face of the piece of shape opposite to the face in which the cavity is made.

In this case, the external tool is advantageously a tool axis inclined relative to the longitudinal axis of the tube and this tool is animated of an orbital movement with respect to the longitudinal axis of the tube combined with a translation towards the matrix.

The present invention also relates to a tool for setting work of a deformation process according to the invention. This tool presents itself in the form of a substantially cylindrical part, at the end of which is made an open cavity, having an axis of revolution and having a bottom substantially arranged in a transverse plane thus that a conical zone close to the bottom and narrowing away from this latest. The cavity has for example on the side of its open side a second conical zone, connecting to the first and widening towards the open side.

To make a rib, or an annular bead, on the outer surface of the tube to be deformed, the cavity advantageously has an annular groove. Similarly, to make an annular groove on the outer surface of the tube to be deformed, the cavity advantageously has an annular rib.

Another type of tool that can be used to implement a method according to the invention comprises a substantially cylindrical part, at the end of which is formed an open cavity, having an axis of revolution and having a bottom substantially arranged in a plane transverse as well as a conical zone close to the bottom and it comprises also a nose piece mounted pivoting relative to an axis transverse of the cavity. This snap nose allows shaping of the tube from the inside during the deformation.

In an advantageous embodiment of this type of tool, the cavity is made in a tubular part in which comes to take places the nose of the head, the bottom of the cavity being formed by the base of the snap, these two parts being mounted in a shaped housing substantially cylindrical circular, having a bottom and open to the opposite end.

Figures 1 à 4 représentent de manière schématique quatre étapes d'un procédé pour déformer un tube à proximité de l'une de ses extrémités,

Figure 5 est une vue en coupe montrant un raccord obtenu lors de la déformation illustrée sur les figures 1 à 4,

Figure 6 est une vue correspondante à la figure 4 pour un procédé identique utilisant un outil différent,

Figure 7 est une vue en coupe montrant un raccord utilisant un tube tel que représenté déformé sur la figure 6,

Figure 8 est une vue correspondant à la figure 4 pour une autre variante de réalisation,

Figure 9 est une vue en coupe d'un raccord obtenu avec un tube tel que représenté sur la figure 8,

Figures 10 à 13 sont des vues montrant une variante d'un procédé selon l'invention,

Figure 14 est une vue en coupe montrant un raccord obtenu avec un tube déformé par le procédé illustré sur les figures 10 à 13,

Figure 15 montre à échelle agrandie une variante de réalisation de l'outil représenté sur les figures 10 à 13, et

Figure 16 est une vue correspondante à la figure 15 pour une autre variante de réalisation d'un outil selon l'invention.

In any case, the invention will be clearly understood with the aid of the description which follows, with reference to the appended schematic drawing, representing by way of nonlimiting examples several alternative embodiments of a method according to the invention and several tools implemented in these variants.

FIGS. 1 to 4 schematically represent four steps of a method for deforming a tube near one of its ends,

FIG. 5 is a sectional view showing a connection obtained during the deformation illustrated in FIGS. 1 to 4,

FIG. 6 is a view corresponding to FIG. 4 for an identical process using a different tool,

FIG. 7 is a sectional view showing a connector using a tube as shown deformed in FIG. 6,

FIG. 8 is a view corresponding to FIG. 4 for another alternative embodiment,

FIG. 9 is a sectional view of a fitting obtained with a tube as shown in FIG. 8,

Figures 10 to 13 are views showing a variant of a method according to the invention,

FIG. 14 is a sectional view showing a connection obtained with a tube deformed by the method illustrated in FIGS. 10 to 13,

FIG. 15 shows on an enlarged scale an alternative embodiment of the tool shown in FIGS. 10 to 13, and

Figure 16 is a view corresponding to Figure 15 for another alternative embodiment of a tool according to the invention.

Figures 1 to 4 show an opening matrix 2 with two jaws 4. Between these two jaws, comes to take places a tube 6. This tube is arranged so that a free end of it protrudes out of the matrix 2. We also recognize on these Figures a tool 8 having a front face 10 in which is made a cavity 12.

The tube 6 is a circular cylindrical metal tube. he has a longitudinal axis of symmetry 14.

The matrix 2 is intended to hold the tube 6 during its deformation and it also partly determines the shape of the tube deformed. The two jaws 4 forming the matrix 2 are supported one towards each other by means not shown and known to the person skilled in the art job. In this way, they tighten and hold the tube 6 in square. A free end 16 of the tube 6 protrudes from the matrix 2. The tube 6 will be deformed at the level where tube 6 exits the matrix 2.

The jaws 4 have a corresponding recess 18 substantially on the outer surface of the tube to be deformed. The dimensions of this recess 18 are adapted to allow excellent tightening of the tube 6. At the face 20 of the matrix from which the free end 16 of the tube protrudes, an additional groove 22 is made in each jaw 4. The shape of this groove 22 is adapted to the deformation that one wishes to achieve.

The tool 8 has a pin 24 at the end of which is fixed a shaped part 26. The cavity 12 is produced in the part of shape 26. The pin 24 and the shape piece 26 are two pieces of substantially cylindrical circular outer shell and have each a common axis of revolution 28. This axis 28 intersects with the axis 14 of the tube and is inclined relative to the latter about 4 °.

The cavity 12 has an opening 30 at the face frontal 10. Opposite the opening 30, the cavity 12 has a bottom 32 substantially transverse to the axis 28. On the side of the bottom 32, the cavity 12 has a frustoconical surface 34. This truncated cone narrowing towards the opening 30. Before this opening 30, the surface of the cavity 12 widens again. The cavity 12 therefore has a narrowing 36. This widening of the cavity 12 on the side of the opening 30 is in the form of two frustoconical zones with angles of different cones.

Figure 1 shows only the different objects work for the implementation of a method according to the invention. On the face 2, as can easily be seen, a relative displacement between the tool and the matrix has occurred. We assume here that the matrix 2 is fixed while the tool 8 can move in translation in a direction parallel to the axis 14 of the tube 6. Thus, the tool 8 has approached the die 2 and the free end 16 of the tube 6 enters the cavity 12 of the shaped part 26. The tool 8 is then rotated around the axis 14 of the tube. This tool is then animated by an orbital movement relative to the tube 6. The axis 28 of the tool is then driven so as to describe a cone around the axis 16 of the tube 2. This rotational movement is combined with the translational movement according to the direction determined by the axis 14 of the tube 6. The tool holder allowing the drive of the tool 8 is not shown in the drawing. Such a tool holder is known to those skilled in the art. We can use a machine here same type of bolt as described in the document FR-2 660 219.

During the approximation of the tool 8 towards the matrix 2, I free end 16 of the tube abuts against the bottom 32 of the cavity 12. The depth of the cavity 12 and the length of the tube projecting out of the matrix are such that, when the end 16 of the tube abuts against the bottom 32 of the cavity, there is still a space between the face front 10 of the tool and the face 20 of the die. The tool continues to be trained in its orbital movement and in its movement of translation to cause deformation of the tube 6. Thanks to the combination of these two movements, the tool 8 exerts on the tube 6, in particular on its free end 16, a substantially axial force. This force is not exerted on the entire periphery of the tube but locally. The area of application of this force rotates with the tool 8. We therefore have a force which moves around the periphery of the tube. This allows for a "gentle" deformation which does not abrupt the material of which the tube and does not break the fibers of the metal.

The frustoconical zone 34 of the cavity 12 is such that, during the rotation of the tool 8, the free end 16 of the tube 6 is not deformed. The deformation of the tube 6 begins at the narrowing 36 of the cavity. The tool 8 pushes the material of the tube 6 into the groove 22 made in the jaws 4. At the same time, the part of the cavity finding between the narrowing 36 and the opening 30 comes to shape the outside of the tube to give it the desired shape. As shown in FIG. 4, the tool 8 abuts against the face 20 of the matrix 2. The deformation of the tube is completed. The free end 16 is then removed from the tube out of the cavity 12 and the jaws are opened 4. The tube is thus released.

Figure 5 shows a fitting made with the deformed tube through the process illustrated in Figures 1 to 4. We recognize in this fitting the deformed tube 6, a nut 38, a threaded nipple 40 having an inner conical surface 42, as well as a seal 44. These different parts are known to those skilled in the art and are standardized. They don't are therefore not described in detail here. The outer bead 46 which has been obtained by pushing the tube back into the groove 22 of the jaws 4 serves as stop at the bottom of the nut 38. The area formed from the outside by the piece of form 26 serves to support the seal 44. The latter bears on the face frontal of the nipple 40.

Figure 6 shows a variant of the tool 8. Thus, it is possible to deform the tube 6.lci differently, in the area of the cavity included between the opening 30 and the narrowing 36, the cavity has a rib annular 48 which is intended to produce a groove 50 on the outer surface of the tube 6. This groove 50 is intended to receive an O-ring 52. The tube deformation process is identical to that described above. There is therefore only shown in the drawing one step of this process. corresponding to the step shown in Figure 4.

Likewise in FIG. 8, a step in the process is shown. deformation corresponding to the step shown in Figure 4. Here, the area of the cavity between the narrowing 36 and the opening 30 comprises an annular groove 54. This groove 54 makes it possible to produce at the level of the outer surface of the tube a second bead 56. As shown in Figure 9, so we find the first bead 46 and the second bead 56. This second bead 56 is situated at the level of the conical surface 42 of the nipple 40. Between the two beads 46 and 56 is placed the O-ring 52. A seal is therefore produced here at the conical surface 42.

Figures 10 to 13 illustrate a variant of the deformation described with reference to Figures 1 to 4. As can be seen in these figures, the tool used here is very different from the tools represented on Figures 1 to 4, 6 and 8. In principle, there is a shaped part 126 in which is formed a cavity 112. In the center of the cavity 112 however, there is a nose piece of 158 mounted pivoting around a transverse axis 160. The form part 126 and the nose of the head 158 are mounted in a housing formed in a support 162. This support is itself mounted on a spindle 124. The spindle 124 and the support 162 have a common axis of revolution 128. On the side of the matrix 2, we finds the same elements. The only difference noted on the Figures 10 to 13 at the level of the matrix relates to the groove 22 which has a slightly different shape. As for the process described previously, the axis 14 of the tube 6 is intersecting with the axis 128 of the tool and the angle formed between axis 14 and axis 128 is approximately 4 °.

The deformation process is as follows here.

During a first step, represented in FIG. 10, the tool approaches the matrix 2. It then presents a movement of translation in the direction given by the axis 14 of the tube 6. During this moving closer, the tool can also be animated with a orbital motion as described above. Tool axis 128 then describes a cone around the axis 14 of the tube. As shown in Figure 10, the nose of the snap rests against the inner wall of the tube 6. The edge of the nose of this dowel is rounded so as to facilitate its introduction into the tube 6. When the approximation movement continuous, the nose of nose 158 rotates around its axis 160 and returns in the tube 6. The contact surface between the shaped part 126 and the base of the nose piece 158 is substantially spherical. Spring 164 keeps the shaped piece pressed against the nose of the head.

Once the snap nose has been inserted into tube 6 as shown in Figure 11, the movement of the tool closer to the matrix continues, a wall of tube 6 then abuts against the bottom of the cavity 112. Here, the bottom of the cavity 112 is formed by the base of the nose of snap-button 158. This is shown in Figure 12. The movement of approximation of the tool combined with its orbital movement continues. We then, as explained above, applying a force substantially axial on the free end of the tube. This force is exerted from in a localized manner, the application area rotating at the periphery of the tube. However, here we have, in addition to the deformation by the outer wall, a shaping of the inside of the tube thanks to the nose bolt. Of this way, it is possible to precisely control the thickness of the tube in the deformed area.

Once the deformation has been carried out, the tool moves away from the matrix and the jaws 4 of the latter are open in order to release the tube deformed. This tube is then used to make for example a connection such as shown in Figure 14. Here we find a nut 138 coming in taken on a threaded nipple 140. Of course, the nut 138 is mounted on the tube 6 before the deformation of the latter. In this connection, we notice that the tube 6 also has a bead 146 against which comes support the bottom of the nut 138. At the level of this bead 146, note that the tube has an extra thickness which could be achieved thanks on the nose of a snap 158.

Figure 15 shows in more detail and on an enlarged scale a alternative embodiment of a tool that can be used in the process illustrated in Figures 10 to 13. Here we find a piece of form 126 and a nose of snap 158. These two parts are housed in a room support 162. The latter is mounted at the end of a spindle 124. In rest position, this assembly has an axis of revolution 128.

The nose piece has a rounded base 166 dish. The support piece 162 is in the form of a pot. The flat bottom 166 of the nose of snap rests against the interior bottom of the support piece 162. The base of the nose piece 158 carries a frustoconical projection extending the along axis 128 (in the rest position of the assembly). This projection frustoconical carries at its end an annular rib whose shape is adapted to the desired shaping of the interior of the tube 6. At the passage between the base of the nose and the frustoconical projection, finds the axis 160 of articulation of the nose of nose. This axis is transverse relative to the axis 128 of the tool.

The form part 126 is here a tubular part. She comes cover, like a ring, the nose of the head 158. At at the base of the nose piece, the shaped part 126 is in contact. The contact surface is a substantially spherical surface. This surface allows the snap nose to pivot without inducing pivoting of the piece of form 126. At the level of the frustoconical projection of the nose of snap, a clearance remains between the nose of the snap and the workpiece. This game is intended to allow the passage of the wall of the tube 6 to be deformed. The outer surface of the shaped part 126 is substantially cylindrical circular. It comes to marry the inner wall of the support piece 162 in pot shape. An elastic ring 168 keeps the assembly formed by the nose of the nose 158 and the ring 126 in the support part 162.

Figure 16 shows a variant of a tool that can be used to deform the tube 6 near its free end 16. Here, the matrix 2 remains unchanged. It has two jaws 4, one face 20 from which protrudes the tube 6 to be deformed, and a housing for receive the tube. Grooves 22 are also provided to allow the deformation of the wall of the tube.

Here, the tool is produced in two separate parts: a socket form 226 and an inclined flat head 270.

The shaped part 126 has the shape of a closed socket at one of its ends. This shaped part therefore has a cavity 212. This cavity is of a shape adapted to the tube and to the deformation desired tube. The shaped part 226 has an axis of revolution. When the shaped part is placed on the free end 16 of the tube 6. This axis of revolution coincides with the axis 14 of the tube. On the side opposite the face into which the cavity 212 opens, the shaped part has a flat transverse bottom 272.

The inclined flat head has a pin 224 of axis 228. This axis 228 intersects with the axis 14 of the tube and is inclined by relation to this axis. At the end of the pin 224, is mounted a head snap 274 having a conical face 276 flattened conical. The angle of cone is such that the front face has an edge 278 perpendicular to axis 14 of the tube.

To achieve the deformation of the tube, the form part 226 is placed on the free end of the tube 6. This shaped part can be connected to matrix 2. This link allows displacement in translation along the axis 14 of the form piece 226. The free end of the tube 16 comes to bear at the bottom of the cavity 212 of the shaped part 226. The inclined flat dowel is driven by an orbital movement. His axis 228 therefore describes a cone around axis 14. This chisel 270 is also driven in a translational movement in the given direction by the axis 14 towards the matrix 2. The bolt 270 presses by its face frontal 276 on the bottom 272 of the form piece 226. During this movement, there is always an edge 278 in contact with the bottom 272 of the form part 226. This contact line rotates around the axis 14. The snap 270 exerts on the workpiece 226 a force substantially axial. This force is fully transmitted to tube 16. It is located at the angular position of the edge 278 which is in contact with the background 272. During the orbital motion of the snap 270, the area of force application moves on the periphery of the free end of the tube. Once the desired deformation has been achieved, the dowel is removed and the form part 226 and the deformed tube is released by opening the die 2.

All the methods described above make it possible to deform a tube near its free end. These processes are processes economical because the energy used to deform a tube is lower than the energy used by the methods of the prior art allowing to carry out such a deformation. In addition, these processes allow to deform a metal tube without breaking the fibers of the metal. Therefore, at the level of the deformation the tube does not present any weakness. The strength and rigidity of the tube remain constant throughout its length.

It goes without saying that the invention is not limited to processes described above by way of nonlimiting examples, or to the tools described therein also by way of nonlimiting examples; on the contrary it embraces all variants within the scope of the claims below.

Claims (12)

1. Method for deformation, in the vicinity of its end (16), of a pipe (6) having a longitudinal axis (14), wherein the pipe (6) is put into place in a die (2) which can be opened, having a recess (22) corresponding to the final outer shape required, a free end (16) of the pipe extending outside the die (2), characterised in that it additionally comprises the following steps:

   introduction of the end (16) of the pipe which extends from the die (2) into a cavity (12;112;212) into a form part (26;126;226), this cavity having a base (32), a lateral wall with a shape which is adapted to the pipe and to the deformation required, as well as an opening (30) opposite the base (32);

   support of the end of the pipe (16) against the base (32) of the cavity (12;112;212), play existing between the opening in the cavity and the die;

   application of substantially axial force on the end (16) of the pipe by means of the form part (26;126;226), the area of application of the force revolving around the longitudinal axis (14) of the pipe, thus giving rise to progressive deformation of the pipe; and

   withdrawal of the end of the deformed pipe from the cavity (12;112;212) in the form part and from the die (2).
2. Method for deformation according to claim 1, characterised in that the form part (26;126) is integrated with a tool (8) with a longitudinal axis (28;128) which is inclined relative to the axis of the pipe and substantially intersects the latter, and in that the substantially axial force is exerted on the end of the pipe by rotation of the tool, the latter thus being driven by orbital movement relative to the axis (14) of the pipe, and by simultaneous bringing together of the tool (8) and the die (2).
3. Method for deformation according to claim 2, characterised in that the angle of inclination between the axis (28;128) of revolution of the cavity and the axis (14) of the pipe is between 2 and 5°.
4. Method for deformation according to claim 2 or claim 3, characterised in that a nose of a riveting head (158) which is designed to be supported on the inner wall of the pipe (6) to be deformed is introduced into the latter when the end (16) of the pipe is introduced into the cavity (112) in the tool.
5. Method for deformation according to claim 1, characterised in that the form part (226) is placed on the end (16) of the pipe, such that the longitudinal axis of the cavity (212) corresponds substantially to the longitudinal axis (14) of the pipe, and in that an external tool (270) is supported on a surface (272) of the form part (226) opposite the surface in which the cavity (212) is provided.
6. Method for deformation according to claim 5, characterised in that the external tool is a tool (270) with an axis (228) which is inclined relative to the longitudinal axis (14) of the pipe, and in that this tool is driven by orbital movement relative to the longitudinal axis of the pipe, combined with translation towards the die (2).
7. Tool (8) for implementation of a method for deformation according to any one of claims 1 to 3, characterised in that it is in the form of a substantially cylindrical part, at the end of which there is provided an open cavity (12) with an axis of revolution (28), and comprising a base (32) which is disposed substantially on a transverse plane, as well as a conical area (34) which is in the vicinity of the base (32) and narrows as it extends away from the latter.
8. Tool according to claim 7, characterised in that, on its open side (10), the cavity (12) has a second conical area, which is connected to the first area, and widens towards the open side (10).
9. Tool according to claim 7 or claim 8, characterised in that the cavity (12) has an annular groove (54).
10. Tool according to any one of claims 7 to 9, characterised in that the cavity (12) has an annular rib (48).
11. Tool for implementation of a method for deformation according to claim 4, characterised in that it comprises a substantially cylindrical part, at the end of which there is provided an open cavity (112) which has an axis of revolution (128) and comprises a base which is disposed substantially on a transverse plane, as well as a conical area in the vicinity of the base, and in that it also comprises a nose of a riveting head (158) which is fitted such as to pivot relative to a transverse axis (160) of the cavity.
12. Tool according to claim 11, characterised in that the cavity is provided in a tubular part (126) in which the nose of the riveting head (158) is placed, the base of the cavity being formed by the base of the riveting head, these two parts being fitted in a receptacle with a substantially circular cylindrical shape, which has a base and is open at the opposite end.

Images