EP2999571B1 - Device for applying temporary fasteners - Google Patents

Description

The present invention relates to a device for fixing fasteners, in particular temporary fasteners of the pinning fastener type.

In the aeronautical industry, prior to final assembly of sheets or the like, it is known to temporarily assemble the sheets by means of staples inserted into through holes.

• un corps pourvu d'une face d'appui susceptible de venir au contact d'une face avant des structures à assembler,
• au moins une pince destinée à traverser les perçages et pourvue d'un bec d'accrochage susceptible de s'appliquer contre une face arrière des structures à assembler,
• un mécanisme déplaçable par rapport au corps, le mécanisme comprenant une tige filetée disposée coaxialement au corps, une extrémité de la tige étant prolongée par la pince, le mécanisme comprenant en outre un écrou de commande monté sur une autre extrémité de la tige.

Such staples, for example described in the document GB2126146 or the document EP0336808 , typically include:

• a body provided with a bearing face capable of coming into contact with a front face of the structures to be assembled,
• at least one clamp intended to pass through the bores and provided with a catching nose which can be applied against a rear face of the structures to be assembled,
• a mechanism movable relative to the body, the mechanism comprising a threaded rod disposed coaxially with the body, one end of the rod being extended by the clamp, the mechanism further comprising a control nut mounted on another end of the rod.

• un premier fourreau cylindrique qui immobilise en translation le corps d'une agrafe après son insertion,
• un deuxième fourreau cylindrique logé dans le premier fourreau, permettant de bloquer en rotation le corps de l'agrafe,
• un troisième fourreau cylindrique logé dans le deuxième fourreau, le troisième fourreau étant entraîné en rotation par l'appareil moteur, une extrémité du troisième fourreau entraînant en rotation l'écrou de commande de l'agrafe.

These staples are generally placed on the sheets using a screwdriver / stripper-type motor apparatus, provided with a laying device comprising:

• a first cylindrical sleeve that immobilizes in translation the body of a staple after insertion,
• a second cylindrical sleeve housed in the first sleeve, for locking the body of the clip in rotation,
• a third cylindrical sleeve housed in the second sleeve, the third sleeve being rotated by the motor apparatus, one end of the third sleeve rotating the control nut of the clip.

Such a laying device is described in particular in the document EP0466609 .

Driven in rotation, the nut moves in translation the threaded rod of the staple, so that the catching nose and the bearing surface of the body respectively apply to the rear and front faces of the stacked sheets. A determined tightening torque is generally applied to the staple during its installation.

The second and third sleeves of the laying device are provided with means for driving / locking in rotation, respectively of the body and the nut of the clip. When the body or the nut has a polygonal section, these drive / locking means may be formed by a complementary shape impression.

On the other hand, when the body or the nut has a circular section, it is advisable to use a wedge-type drive system, like a roller cage. Such a roller cage system is described in particular in the document EP0466609 .

The roller cage is typically installed free to rotate in a housing of polygonal section, whose sides cooperate with the rollers during operation of the laying device.

However, depending on the angular position of the rollers relative to the panels, problems may arise during the installation of the temporary fasteners. Improper positioning may induce excessive friction, which disturbs the installation of the fasteners and / or causes damage to the control nut.

In the case of manual stapling, the operators are able to handle the laying device wisely in order to circumvent these problems. However, in automatic use, laying robots currently do not have such skills.

It is therefore necessary to avoid, in the laying device, a bad positioning of the roller cage at the time of the insertion of a temporary attachment into the device.

The present invention aims to solve this problem by providing the laying device with an optimal positioning means of the roller cage.

More specifically, the present invention relates to a fastening tool, said tool comprising: a sheath disposed along a main axis, said sheath providing a cylindrical inner housing of polygonal base, developing along the main axis; a roller cage received in said cylindrical housing, said cage comprising: a substantially circular base cylindrical support disposed along the main axis, an external lateral surface of said support being substantially tangential to side faces of the polygonal base cylindrical housing; rollers disposed on the periphery of the support, each roller being rotatable relative to said support along an axis parallel to the main axis; a compression spring exerting on the rollers a radial force towards the main axis; the cage being configured so that each roller is housed at an edge of the cylindrical housing of the sleeve; the support of the cage being able to pivot along the main axis inside said cylindrical housing. The laying tool further comprises a return element, connected on the one hand to a roller of the cage and on the other hand to the sheath, said return element tending to bring the rollers of the cage opposite the edges of the housing cylindrical sheath.

Preferably, the return element is a torsion spring.

Thus, although the roller cage rotates in its housing during the installation of the staples, the return element brings the cage back to its optimum position at the end of the installation.

In the context of the invention, the term "tool" is understood as a complete laying device, or as a part of said device, such as a drive key of the control nut.

Preferably, the tool is intended for the installation of temporary fasteners comprising: a longitudinal body provided with a front face, at least one clamp emerging from said front face, a threaded rod coaxial with the body and movable in translation along said axis, a end of the rod being extended by the clamp, a control nut mounted on another end of the rod.

Such an installation tool can also be adapted to install a cylindrical outer form of assembly nut, as well as any fastener incorporating such a nut.

According to one embodiment of the invention, the nut is of circular section and the tool is configured so that the nut can be inserted into the roller cage, an outer lateral surface of the nut then coming into contact shingles. In this embodiment, the tool is for example a drive key of the nut.

Preferably, another element of the tool or of the complete laying device comprises a retaining means in rotation of the longitudinal body.

According to another embodiment of the invention, the longitudinal body has a circular end of section and the tool is configured so that said end can be inserted into the roller cage, an outer lateral surface of said end then coming to contact of pebbles. In this embodiment, the tool is for example a front part, or nose, of a screwdriver / unscrewing device.

Preferably, another element of the tool or of the complete laying device comprises means for driving the nut in rotation.

• Figure 1 : une vue en coupe axiale d'un dispositif de pose d'une agrafe selon un mode de réalisation de l'invention ;
• Figure 2 : une vue éclatée d'une partie d'un dispositif de pose selon un mode de réalisation de l'invention ;
• Figures 3A et 3B : des vues partielles en coupe transversale du dispositif de la figure 1 ;
• Figure 4 : une vue partielle, en coupe axiale, d'un dispositif de pose d'une agrafe selon un autre mode de réalisation de l'invention.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These are given as an indication and in no way limitative of the invention. The figures show:

• Figure 1 : an axial sectional view of a staple laying device according to one embodiment of the invention;
• Figure 2 an exploded view of a part of a laying device according to one embodiment of the invention;
• Figures 3A and 3B : partial cross-sectional views of the device of the figure 1 ;
• Figure 4 : a partial view, in axial section, of a device for placing a clip according to another embodiment of the invention.

The figure 1 is a schematic sectional view of a device 10 for laying a pinning clip 50.

The clip 50 comprises a body 51, substantially cylindrical and arranged along an axis 11. The body 51 is provided with a front face 52 of support, capable of coming into contact with a face of elements to be assembled, such that pierced sheets.

The clip 50 also comprises two elongate half-pliers 53, each provided with a hooking nose 54 capable of being applied against another face of the sheets to be assembled, through the aligned bores of the sheets.

The clip 50 further comprises a threaded rod 55 disposed along the axis 11 and movable relative to the body 51. One end of the rod is attached to the two half-clips 53. A control nut 57 is mounted on the thread of said rod.

Furthermore, a compression spring 58 is disposed around the rod 55 along the axis 11, between the nut 57 and an end 59 of the body 51, opposite the bearing face 52.

The laying device 10 comprises a first cylindrical sheath 12 arranged along the axis 11. The first sheath 12 delimits a first internal cavity in which is disposed along the axis 11 a second sheath 13.

The translation of the body of the staple 50 in the direction of the bearing face 52 is blocked by the first sleeve 12, coming into axial abutment against the end 59 of the body 51.

The second sleeve 13 is configured to cooperate with the end 59 to immobilize the body 51 in rotation along the axis 11. The end 59 has for example a section of hexagonal shape; near an axial opening 20, the second sleeve 13 has an inner wall 14 of complementary shape to this section.

The second sleeve defines a second internal cavity, in which the end 59 of the body 51 is inserted, while the rest of the body emerges outside the device 10 through the axial opening 20.

The laying device 10 further comprises a sleeve 15, housed in the second internal cavity. The sleeve 15 is movable in rotation and in translation in said second internal cavity along the axis 11.

The sleeve 15 forms a third internal cavity 17, open at both ends of the sleeve along the axis 11. A portion of the cavity 17 forms a housing 18, whose lateral wall is cylindrical with a polygonal base, developing along the axis 11 The housing 18 has for example a twelve-sided lateral surface, that is to say a section forming a regular dodecagon.

The housing 18 receives a roll cage 19, the operation of which will be detailed below.

An end 21 of the cavity 17 receives a drive shaft 22 intended to be connected to an output shaft of a screwing / unscrewing device. The sleeve 15 is movable in translation along the axis 11 relative to the shaft 22, which is fixed in translation relative to the first sleeve 12. A compression spring 23, housed in the end 21 of the cavity 17 and pressed against the shaft 22, tends to bring the sleeve 15 towards the opening 20.

The shaft 22 can rotate the sleeve 15, along the axis 11, by means of a pin 24.

The figure 2 shows an exploded view of a sleeve 15 similar to the sleeve 15 of the figure 1 . The reference numbers are kept in relation to the figure 1 .

The sleeve 15, or drive key, comprises a sleeve 16 disposed along a main axis 11, said sleeve providing an internal cavity. A portion of said internal cavity forms a housing 18, cylindrical polygonal base, developing along the axis 11. As in the case of the figure 1 , the polygonal base is for example a regular dodecagon.

On the figure 2 , there is also a transverse perforation 25 of the sleeve 16, intended to receive the pin 24 described above.

The cylindrical housing 18 receives a cage 19 with rollers. Said cage is formed of a ring 30 and an elastic ring 31, arranged along the axis 11 and connected by spacers 32. The ring 30, the ring 31 and the spacers 32 form a cylindrical support 33 of base substantially circular. The support 33 is configured so that the spacers 32 are substantially tangent to side faces 26 of the housing 18.

The cage 19 further comprises rollers 34 disposed on the periphery of the support 33, between the spacers 32. Each roller 34 is rotatable relative to the support 33 along an axis 35 parallel to the main axis 11. In the example of the figure 2 the rollers 34 are distributed over six axes 35, arranged around the axis 11 in a regular hexagon.

Furthermore, the cage 19 comprises a compression spring 36 disposed around the spacers and rollers. The spring 36 exerts on the rollers 34 a radial force towards the axis 11.

When the staple 50 is inserted into the device 10 for its installation (see figure 1 ), the control nut 57, of circular section, is housed in the roll cage 19 of the sleeve. The spring 36 allows the rollers 34 to be pressed radially against the lateral surface of the nut 57. When the sleeve 16 is rotated by the shaft 22, the side faces 26, or sides of the housing 18 cooperate with the rollers 34 , which themselves cooperate with the lateral surface of the nut 57. The nut is rotated by wedging the rollers 34 between the panels 26 and said nut.

The Figures 3A and 3B show cross-sectional views of the drive key 15 into which the staple 50 is inserted. The cutting plane passes through the roller cage 19 and the nut 57.

The figure 3A shows the drive key 15 in a configuration before screwing / unscrewing, allowing proper installation of the staple 50. Inset, a detailed view of a roller 34 is shown.

In the configuration of the figure 3A each of the rollers 34 is opposite an edge 27 delimiting two lateral panels 26 of the housing 18. More specifically, each axis 35 of rotation of a roller is included in a plane passing through the main axis 11 and by a ridge 27.

The housing 18 comprising twelve sections 26 and twelve edges 27, one edge in two is opposite a roller 34. There is a clearance 40 between each roller 34 and the edge 27 vis-à-vis. This configuration of the cage 19 allows the drive key 15 to exert on the nut 57 an optimal effort during screwing.

The figure 3B shows the drive key 15 in another configuration before screwing / unscrewing, this configuration being unfavorable to the correct installation of the staple 50. In this configuration, the rollers 34 are offset with respect to the edges 27. Each roller 34 is in contact with a single pan 26 of housing 18, without play.

In the devices of the prior art, the roller cage is free to rotate along the main axis in the housing of polygonal section. It is therefore possible that the cage is in the configuration of the figure 3B when inserting a control nut.

Such a configuration induces excessive forces during the installation of the staple 50. In the case where the device 10 exerts insufficient effort on the key 15, the drive of the rotating nut is defective. In the event of greater forces exerted by the device 10, the nut 57 can be damaged by the friction of the rollers 34.

The present invention thus includes a means of bringing the rollers back into the position of the figure 3A before any insertion of a temporary fixation into the roller cage.

In the example of the figure 2 this means is embodied by a torsion spring 37. The spring 37 has the shape of a wire wound along the axis 11. A first end 38 of the spring 37 is connected to a roller 34 of the cage 19. A second end 39 of the spring 37 is connected to the sheath 16. The end 39 is for example housed in a radial notch (not shown) formed on an inner surface of the sheath.

The spring 37 tends to place the rollers 34 of the cage 19 in the configuration shown in FIG. figure 3A said rollers being opposite an edge 27.

When a screwing / unscrewing torque is applied to the wrench 15, a deformation of the spring 37 takes place by inertia of the cage 19, ensuring the drive in rotation of the nut 57. When stopping the screwing / unscrewing , the spring 37 rotates the cage 19 to return it to its initial configuration, as represented in FIG. figure 3A .

Thus, before any insertion of a staple 50 into the device 10 of the figure 1 , the position of the cage 19 in the key 15 is necessarily optimal at the installation of said staple.

The figure 4 represents a detailed view of an alternative embodiment of the invention. More specifically, the figure 4 represents a detailed view of a staple 50 'similar to the staple 50 shown in FIG. figure 1 inserted in a laying device 10 'similar to the device 10 of the figure 1 . The references of the elements common with those of the figure 1 are preserved below.

A difference between the staple 50 'and the staple 50 of the figure 1 is the shape of a control nut 57 ', similar to the nut 57. More specifically, the nut 57' has a hexagonal and non-circular section.

On the figure 4 , the nut 57 'is housed in a sleeve 15' similar to the sleeve 15. More specifically, the sleeve 15 'has a housing 18' whose shape is complementary to that of the nut 57 '. The housing 18 'therefore has a cylindrical shape of hexagonal base. During the rotation of the sleeve 15 ', the surface of the housing 18' cooperates directly with the nut 57 'to drive it in rotation.

Another difference between the staple 50 'and the staple 50 is the shape of an end 59' of the body 51. In the example of the figure 4 , the end 59 'has a circular section, unlike the hexagonal shape of the end 59 of the figure 1 .

As in the example of figure 1 a second sleeve 13 'of the device 10' cooperates with the end 59 'to immobilize the body 51 in rotation along the axis 11. Near an axial opening, the second sheath 13 'has an internal housing 14', of the same shape as housing 18 of Figures 1 and 2 . This housing 14 'contains a roller cage 19, identical to that described above in support of Figures 1 and 2 .

The other elements of the device 10 'and the staple 50' are identical to those of the device 10 and the staple 50 shown in FIG. figure 1 .

During the rotational drive of the nut 57 ', the end 59' of the body 51 is locked in rotation by wedging the rollers of the cage 19 against the sides of the inner housing 14 ', in a manner identical to that described herein. -above. The nut 57 'can then move along the threaded rod 55 for the installation of the staple 50'.

For reasons identical to those described above, an optimal installation of the staple 50 'requires that the cage 19 of the figure 4 is in the configuration shown in the figure 3A before insertion of the end 59 'of the body 51, which then takes the place of the nut 57. The cage 19 of the figure 4 therefore includes a spring 37 identical to that described above, said spring ensuring the return of the cage 19 in its optimal configuration at the end of the installation of the staple 50 '.

It is also possible to envisage a staple comprising a circular nut 57 and a circular end 59 'to the body 51. In this case, it is possible to combine the examples of the figures 1 and 4 , so that said nut 57 and said end 59 'each cooperate with a roller cage 19 as described above, each cage returning to its initial position after installation, using a torsion spring.

Although the biasing element of the invention has been described in the examples as being formed by a torsion spring, it will be understood that this example is not restrictive. Any equivalent means for bringing the rollers of the cage opposite the edges of the cylindrical housing of the sheath is included in the invention.

Claims (7)

1. A tool (10, 15, 10', 13') for installing fasteners (50, 50'), said tool comprising:

   - a sheath (16, 13') disposed along a main axis (11), said sheath containing a cylindrical internal housing (18, 14') with a polygonal base, extending along the main axis.

   - a roller cage (19) accommodated within said cylindrical housing, said cage comprising:

   - a cylindrical support (33) with a substantially circular base, disposed along the main axis, an external lateral surface (32) of said support being substantially tangent to lateral surfaces (26) of the cylindrical housing with a polygonal base.

   - rollers (34) disposed on the perimeter of the support, each roller being able to rotate with respect to said support around an axis (35) parallel to the main axis.

   - a compressing spring (36) exerting a radial force on the rollers in the direction of the main axis,

   the cage being configured such that each roller is housed in an edge (27) of the cylindrical housing of the sheath,
   the support of the cage being able to pivot along the main axis within said cylindrical housing,
   the tool being characterized in that it comprises a retaining member (37), connected to a roller of the cage and to the sheath, said retaining member tending to bring the rollers of the cage to face the edges of the cylindrical housing of the sheath.
2. A tool for installing fasteners according to claim 1, wherein the retaining member is a torsion spring (37), one end (38) of said spring being connected to a roller of the cage, another end (39) of said spring being connected to the sheath.
3. A tool (10, 15) according to claim 1 or claim 2, intended for installing temporary fasteners (50) comprising:

   - a longitudinal body (51) with a front face (52),

   - at least one clip (53) emerging from said front face,

   - a threaded rod (55) coaxial to the body and movable along said axis, one end of the rod being extended by the clip,

   - a control nut (57) mounted on another end of the rod, said nut being of circular exterior cross-section,

   said tool being configured so that the nut can be inserted into the roller cage, whereupon an external lateral surface of the nut comes in contact with the rollers.
4. A tool (10) according to claim 3, such that the sheath (16) is inserted into an outer envelope (13) disposed along the main axis, said envelope comprising a means (14) of keeping the longitudinal bodies of the temporary fasteners from rotating when the nut is rotated around the main axis.
5. A tool according to claim 4, such that the sheath is connected to a means (22, 24) of rotation around the main axis.
6. A tool (10', 13') according to claim 1 or claim 2, intended for installing temporary fasteners (50') comprising:

   - a longitudinal body (51) provided with a front face, said body having an end (59') with a circular cross-section,

   - at least one clip emerging from said front face,

   - a threaded rod (55) coaxial to the body and movable along said axis, one end of the rod being extended by the clip,

   - a control nut (57') mounted on another end of the rod,

   said tool being configured so that said end (59') of the longitudinal body can be inserted into the roller cage, whereupon an external lateral surface of said end comes in contact with the rollers.
7. A tool according to claim 6, further comprising a sleeve (15') inserted into the sheath (13') and disposed along the main axis, said sleeve comprising a means (18') of rotating the nut (57') of the temporary fasteners around the main axis.

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