EP0466609A1 - Tool for placing insertable clamps - Google Patents

Abstract

The invention relates to a tool for placing insertable clamps on metal sheets to be assembled. The tool comprises a fixed cylindrical sheath (2) interacting with the body (11) of the clamp and a screwing sleeve (4) accommodated in the said sheath and capable of interacting with the control nut (13) of the displaceable mechanism of the said clamp. Moreover, the tool advantageously comprises an intermediate coupling piece (5) capable of being linked in rotation and in translation with the said control nut (13), via an engagement link (5D), and with the said screwing sleeve, via a dog clutch link (5A, 4C). <IMAGE>

Description

The present invention relates to a tool for laying pinning staples on sheets, plates or the like to be assembled.

Before carrying out the final assembly of sheets, for example by riveting, one generally proceeds to a temporary assembly of said sheets by means of pinning staples passing through facing holes made in the sheets. This assembly process is particularly used in the aeronautical field.

• un corps pourvu d'une face d'appui susceptible de venir au contact de la face avant de l'empilage de tôles à assembler ;
• au moins un élément allongé, destiné à traverser des trous en regard ménagés dans les tôles et pourvu d'un bec d'accrochage susceptible de s'appliquer contre la face arrière dudit empilage de tôles ; et
• un mécanisme déplaçable par rapport au corps, comprenant une tige filetée, qui est disposée coaxialement audit corps et dont une des extrémités est prolongée par ledit élément allongé, et un écrou de commande dudit mécanisme monté sur ladite tige au voisinage de son autre extrémité, un ressort de compression étant disposé autour de la tige entre ledit corps et ledit écrou.

Generally, the pinning staples are of the type comprising:

• a body provided with a bearing face capable of coming into contact with the front face of the stack of sheets to be assembled;
• at least one elongated element intended to pass through facing holes made in the sheets and provided with a hooking spout capable of being applied against the rear face of said stack of sheets; and
• a mechanism displaceable relative to the body, comprising a threaded rod, which is arranged coaxially with said body and one of the ends of which is extended by said elongated element, and a control nut of said mechanism mounted on said rod near its other end, a compression spring being disposed around the rod between said body and said nut.

The tools usually used for these pinning staples comprise a fixed cylindrical sheath capable of cooperating with the body of said staple to immobilize it in rotation and a screw sleeve housed in the sheath and capable of being driven in rotation by the one of its ends, while its another end cooperates with the control nut of the mechanism of said clip.

Thus, when said tool is mounted on a motor device, such as a screwdriver-unscrewer, the nut of the staple driven in rotation by the screwing sleeve pulls on the threaded rod so that the hooking spout of the elongated element and the bearing face of the body of the clip apply respectively against the rear and front faces of the stack of sheets to be assembled, and then compresses the spring so as to exert a clamping force pressing said sheets against each other.

Furthermore, it is known that, in particular in the aeronautical field, more or less viscous and generally polymerizable interposition products are applied between the various sheets to be assembled, such as resins and sealants, serving mainly to provide protection against corrosion. and / or a sealing barrier.

Consequently, the fluidity of the interposing product necessitates applying to the sheets to be assembled, throughout the polymerization period, a relatively low clamping force (of the order of 20 to 40 DaN depending on the diameters of the staples), precisely controlled.

However, with the usual screwdrivers on which the tools described above are mounted, the clamping force applied to the sheets by the staples is generally too imprecise and greater due to the low mounting torque required in this specific application, compared to the ranges working of these screwdrivers, so that the thickness of each layer of resin is unevenly distributed, the resin having, by elsewhere, tendency to flow by the external edges of the sheets, as well as by the edges delimiting the holes.

The object of the present invention is to remedy these drawbacks and relates to a tool for fitting pinning staples onto sheets, the design of which makes it possible to respect and provide an appropriate and constant clamping force on the stacking of sheets to be assembled without deforming them.

• un corps pourvu d'une face d'appui susceptible de venir au contact de la face avant de l'empilage de tôles à assembler ;
• au moins un élément allongé, destiné à traverser des trous en regard ménagés dans les tôles et pourvu d'un bec d'accrochage susceptible de s'appliquer contre la face arrière dudit empilage de tôles ; et
• un mécanisme déplaçable par rapport au corps, comprenant une tige filetée, qui est disposée coaxialement audit corps et dont une des extrémités est prolongée par ledit élément allongé, et un écrou de commande dudit mécanisme monté au voisinage de l'autre extrémité de la tige, un ressort de compression étant disposé autour de la tige entre ledit corps et ledit écrou, et ledit outil comprenant :
• un fourreau cylindrique fixe susceptible de coopérer avec le corps de ladite agrafe pour l'immobiliser en rotation ; et
  - un manchon de vissage logé dans ledit fourreau et susceptible d'être entraîné en rotation par l'une de ses extrémités, tandis que son autre extrémité est susceptible de coopérer avec ledit écrou de commande, est remarquable selon l'invention en ce qu'il comprend, de plus, une pièce de couplage intermédiaire susceptible d'être liée en rotation et en translation avec ledit écrou de commande d'une part, et avec ledit manchon de vissage d'autre part, de façon que, lorsque la face d'appui du corps de l'agrafe et le bec d'accrochage de l'élément allongé sont au contact de l'empilage de tôles après que ladite tige filetée a été tirée axialement par la rotation dudit écrou, ladite pièce de couplage se désengage progressivement dudit manchon de vissage rotatif, en étant entraînée par le déplacement alors hélicoïdal dudit écrou par rapport à la tige, d'une course correspondant à la course de compression préétablie dudit ressort.

To this end, the tool for laying pinning staples on sheets or the like to be assembled, said staples comprising:

• a body provided with a bearing face capable of coming into contact with the front face of the stack of sheets to be assembled;
• at least one elongated element intended to pass through facing holes made in the sheets and provided with a hooking spout capable of being applied against the rear face of said stack of sheets; and
• a mechanism movable relative to the body, comprising a threaded rod, which is arranged coaxially with said body and one of the ends of which is extended by said elongated element, and a control nut for said mechanism mounted in the vicinity of the other end of the rod, a compression spring being disposed around the rod between said body and said nut, and said tool comprising:
• a fixed cylindrical sheath capable of cooperating with the body of said clip to immobilize it in rotation; and
  - a screwing sleeve housed in said sheath and capable of being rotated by one of its ends, while its other end is capable of cooperating with said control nut, is remarkable according to the invention in that it also includes an intermediate coupling piece capable of to be linked in rotation and in translation with said control nut on the one hand, and with said screwing sleeve on the other hand, so that when the bearing face of the body of the clip and the spout d attachment of the elongated element is in contact with the stack of sheets after said threaded rod has been pulled axially by the rotation of said nut, said coupling piece gradually disengages from said rotary screw sleeve, being driven by displacement then helical of said nut relative to the rod, of a stroke corresponding to the predetermined compression stroke of said spring.

Thus, it is certain that the clamping force to be applied to the stacking of the sheets, between which the polymerizable resin is interposed, is correct, since it corresponds to the determined compression stroke of the spring, representative of the force of tightening to be applied, the compression stroke of said spring being substantially identical to the disengagement stroke of the intermediate coupling piece with said screw sleeve. In this way, the clamping force on each of the pinning staples used to assemble the sheets is identical. Depending on the desired clamping force, a compression spring with an appropriate stiffness will be used.

Preferably, the intermediate coupling piece is housed in a movable manner in said sheath and has a hollow cylindrical shape.

According to another characteristic of said tool, said intermediate coupling piece is linked to said screwing sleeve by a link of the spigot type.

In this case, the compression stroke of said spring, which is a function of the clamping force to be applied to said sheets, corresponds substantially to the disengagement stroke of said swivel link between the intermediate coupling piece and the screw sleeve.

In a preferred embodiment, said spigot link is defined by at least one diametrical groove, formed in the end face of said coupling piece, and by a diametrical tongue, formed in projection in the corresponding end face of said screw sleeve and capable of engaging in the diametrical groove of said coupling piece.

It is thus noted the simplicity of realization of said spigot connection, as well as its operating reliability in use. The disengagement stroke of said link, from which the compression stroke of the spring is determined, then corresponds to the height of the tongue which cooperates with the groove, or vice versa, to the depth of the groove.

In addition, the outer contour of said tongue and the inner contour of said groove have trapezoidal shapes complementary to each other. The engagement of the tongue in the groove is thus easily effected by cooperation of their respective inclined edges.

According to another characteristic of the invention, the connection between said intermediate coupling piece and said nut of the control mechanism of said clip is preferably carried out by engagement of said nut in the end of the coupling piece, opposite to its other end linked to said screw sleeve.

In a preferred embodiment, said connection is defined by a polygonal imprint, which is formed in the corresponding end of said coupling piece and into which is likely to introduce the nut, of similar section, of said control mechanism of said clip.

In an alternative embodiment, said engagement link can be defined by a roller cage regularly distributed around it, which is arranged in the coupling part by being linked thereto and which is capable of surrounding said control nut. said clip, said rollers arranged parallel to the coupling piece applying radially against said control nut.

This variant embodiment of said connection is particularly suitable when the external contour of said clip control nut is circular, the rollers effectively holding said nut.

The roller cage can be driven by the coupling part thanks to a polygonal imprint formed therein and cooperating by its sides with the rollers, and all of said rollers are surrounded at their ends, linked to opposite flanges of the cage, by elastic rings. Thanks to these, the rollers are pressed radially against the external contour of said nut, so that the coupling piece can move helically with said nut, during compression of said spring.

The figures of the appended drawing will make it clear how the invention can be implemented. In these figures, identical references designate similar elements.

Figure 1 is an axial sectional view of the tool according to the invention, which is mounted on a motor device, such as a screwdriver-unscrewer, and in which is arranged a pinning staple intended to temporarily assemble sheets .

Figures 2, 3 and 4 are respectively cross-sectional views of the tool along lines II-II, III-III and IV-IV of Figure 1.

FIG. 5 is an exploded perspective view showing the connection of the spike type between the intermediate coupling part and the screw sleeve of said tool.

FIG. 6 represents an axial section of said tool, similar to FIG. 1, in the position for which the hooking spouts and the bearing face of the clip, under the action of said tool, are in contact with the faces of stacking of sheets, the intermediate coupling part being linked to said screwing sleeve of the tool and to said nut, in this case hexagonal, of the control mechanism of said clip.

FIG. 7 illustrates, still in axial section, the tightening of the sheets by the clip under the action of the compression of said spring, the coupling part of said tool being disengaged from the screwing sleeve.

Figures 8 and 9 are respectively side and end views of a roller cage intended to be arranged between the coupling piece and the clip control nut, especially when the outer contour of said nut is circular.

Figure 10 is a partial view similar to Figure 1 showing the engagement of the nut in the roller cage.

FIG. 11 is a sectional view along the line XI-XI of FIG. 10.

Referring to Figure 1, the tool 1 according to the invention allows in particular the installation of pinning staples 10 on sheets in order to temporarily assemble them. Two sheets 20 and 21 to be assembled have been shown in this exemplary embodiment, between which is placed a polymerizable resin 22.

To automate the assembly process and, subsequently, the disassembly of the staples, the tool 1 is mounted on a motor device 30, such as a screwdriver-unscrewer. In the figure, the tool 1 is fixed to the device 30, while a pinning clip 10 is mounted in said tool.

Prior to the description of said tool, the pinning staple 10 comprises, in known manner, a hollow body 11 terminated at one of its ends by a bearing face 11A from which a rod 11B is extended, integral with the support face 11A. This is intended to bear against the front face 20A of the stack of sheets 20, 21 to be assembled. The other end of the body 11 has a head 11C, the section of which is for example hexagonal.

Furthermore, the clip 10 is provided with a movable mechanism comprising a threaded rod 12, arranged coaxially inside the body 11, and a control nut 13 mounted on the rod and having, in this case, an external contour. hexagonal. More in particular, the nut 13 is located in the vicinity of one 12A of the ends of the threaded rod which ends in a head, while the other end of the threaded rod 12, not visible in the figures, is extended by two elongated elements, such as elastic blades 14 respectively provided at their free ends with opposite hooking nozzles 14A. These blades 14 pass through the bearing face 11A of the body and are arranged respectively on either side of the rod 11B. Thanks to the shape and elasticity of the blades, the spouts 14A are spontaneously in contact with one another when the rod 11B is not disposed between them, as illustrated in FIG. 1. On this one , it can be seen that the blades 14 are introduced into aligned through holes 20B and 21B, respectively formed in the sheets 20 and 21.

There is also provided between the control nut 13 and the body 11, a compression spring 15 which is shown in the relaxed state in FIG. 1 and which makes it possible to provide, when it is compressed, an appropriate clamping force. , as a function of its compression stroke, on the stack of sheets to be assembled, as will be seen with reference to FIG. 7.

FIG. 1 shows the potential compression stroke C of the spring 15 which is between a washer 13A, associated with the nut 13 and against which one end of said spring is applied, and the end face 17A of a spacer 17 mounted on the threaded rod 12 of the movable mechanism. The spacer 17 is provided with an external annular shoulder 17B in the vicinity of its other end 17C, against which the other end of the spring is applied and which is in abutment against the end 11C of the body 11. It is thus possible to adjust easily the compression stroke of the spring 15 as a function of its stiffness and, therefore, the clamping force at apply to the stack of sheets to be assembled. Furthermore, the spacer 17 also serves as a guide for the spring 15.

In the embodiment illustrated in FIG. 1, the tool 1 comprises a first hollow cylindrical sheath 2, one end of which 2A is screwed onto the fixed end piece 31 of the motor device 30. At least one radial screw 2B immobilizes the first sheath 2 at the end piece 31. The other end 2C of the sheath 2 has a 2D transverse imprint advantageously of hexagonal section, corresponding to that 11C formed on the body 11 of the clip. The cooperation of the 2D imprint of the sleeve 2 with the imprint 11C of the body 11 is illustrated in particular with regard to FIG. 2, the body 11 of the pinning clip 10 thus being immobilized in rotation by the sleeve 2 of the tool linked to the fixed end piece of the motor unit 30.

The tool 1 also includes a second cylindrical protective sheath 3 which concentrically surrounds the first sheath 2. This second sheath 3 is fixed to the first sheath 2 by radial screws 3A. Inside the first cylindrical sheath 2 is housed a screw sleeve 4 of cylindrical shape. The end 4A of the sleeve 4 is extended by a splined shaft 4B which engages, as shown in FIG. 1, in a bore of corresponding section 32 formed in the rotary drive shaft 33 of the device 30.

According to the invention, the tool 1 further comprises an intermediate coupling part 5 capable of being linked in rotation and in translation to the control nut 13 of the movable mechanism of the clip on the one hand, and to the screw sleeve 4, on the other hand.

As shown in FIG. 1, the intermediate coupling part 5 has a hollow cylindrical shape and is arranged inside the first sleeve 2.

In a preferred embodiment, the intermediate coupling part 5 is associated with the screwing sleeve by a connection of the spike type illustrated with reference to FIGS. 1, 4 and 5. For this, the spike connection is defined by a diametrical groove 5A, formed in the corresponding end face 5B of the part 5, and by a diametrical tongue 4C protruding in the end face 4D of the screw sleeve, opposite the splined shaft 4B. Advantageously, the profile of the tongue 4C and that of the groove 5A have trapezoidal shapes complementary to each other. In this way, the engagement of the tongue 4C by its inclined lateral edges 4E in the inclined lateral edges 5C of the groove 5A is carried out easily, without difficulty. Also, in Figure 1, there is shown the distance h corresponding to the engagement of the diametrical tongue 4C in the groove 5A. This distance h corresponds substantially to the desired compression stroke C of said spring.

Furthermore, with particular reference to FIGS. 1 and 3, the connection of the intermediate coupling part 5 with the hexagonal control nut 13 of said movable mechanism of the clip 10 is effected by engagement and it is produced by an imprint hexagonal 5D formed in the end face 5E of said part 5, opposite to that provided with the diametrical groove 5A.

The depth of the imprint 5D corresponds substantially to the height of the control nut 13. In addition, the trapezoidal shape of the tongue 4C allows, during its engagement in the groove 5A, to maintain the control nut 13 in abutment against the bottom of the hexagonal imprint 5D.

In the position illustrated in FIG. 1, the tool 1 is mounted on the motor device 30, the splined shaft 4B of the screw sleeve 4 being engaged in the rotary drive shaft 33 of the device, while that the nut 13 of the movable mechanism of the clip and the head 11C of its body 11 are respectively received in the imprint 5D of the intermediate coupling piece 5 and in the imprint 2D of the cylindrical sleeve 2. The elastic blades 14 of the clip 10 are introduced into the holes 20B and 21B of the stack of sheets to be assembled, so that the bearing face 11A of the body 11 of the clip is in abutment against the front face 20A of the stack of sheets 20, 21.

When the drive shaft 33 of the device is rotated, the intermediate coupling part 5 is simultaneously driven in rotation by the screwing sleeve 4 integral in rotation with the shaft 33, via the connection choppy. The control nut 13 of the movable mechanism of the clip 10 is in turn driven in rotation by virtue of the imprint 5D of the part 5, causing the translational displacement of the threaded rod 12 which is thus pulled, up to that the hooking spouts 14A of the elastic blades 14, linked to the threaded rod 12, are applied against the rear face 21A of the stack of sheets.

FIG. 6 illustrates this position, the hooking spouts 14A deviating from one another by means of the rod 11B, secured to the fixed body 11.

At this stage, with reference to FIG. 7, the screwing continues and, as the threaded rod 12 cannot then move, the control nut 13 moves, helically, relative to the rod 12, driving with it the intermediate coupling piece 5 thanks to the hexagonal imprint 5D.

Simultaneously, the part 5, driven by the nut, gradually disengages from the screwing sleeve 4, the diametrical groove 5A of the chuck link moving away from the drive tongue 4C as the displacement of the nut. The washer 13A of the nut 13 then compresses the spring 15, which thus provides a force proportional to its compression stroke C , representative of the desired clamping force to be applied to the stack of sheets so that the resin 22 is pressed properly.

The compression stroke of the spring 15 is a function of the clearance height between the groove of the part 5 and the tongue of the sleeve 4, so that, when the distance h of separation of the faces 5B and 4D is reached, the coupling part is no longer driven by the rotary sleeve 4, the spring no longer being compressed. Simultaneously with the uncoupling of the spigot link, the washer 13A of the nut 13 abuts against the end face 17A of the spacer 17. This allows precise compression of the spring 15 and prevents the helical displacement of the coupling part 5, due to its inertia, by stopping it.

Thanks to the tool according to the invention, the clamping force applied to the stack of sheets to be assembled, between which there is polymerizable resin, is precise and corresponds to the compression stroke of said spring, itself defined by the distance h to decouple the chuck connection.

Subsequent unscrewing of the clip can be carried out using the same screwdriver provided with a change of direction of rotation.

Indeed, the slight axial thrust exerted by the operator on the screwdriver to obtain the engagement of the nut in part 5 is enough to push it back slightly and to engage the screwing sleeve 4 in part 5 by the chuck link for unscrewing the clip.

In an alternative embodiment, the engagement link between the intermediate coupling part 5 and the control nut 13 ′ of the staple mechanism is effected by means of a roller cage 40, in particular when the external contour of the nut is circular.

In FIGS. 8 and 9, the roller cage 40 comprises two identical flanges 41 in the form of a crown, spaced parallel to one another by spacers 42 regularly distributed six in number. Between the spacers 42 are provided rollers 43, six in number, the ends 43A of which engage respectively in the flanges 41. In particular, FIG. 9 shows the position of the rollers relative to the flanges, which rollers will allow the connection between the coupling part and the nut of the control mechanism.

Furthermore, the ends 43A of the rollers are respectively surrounded by elastic rings which thus tend to press said rollers radially towards the inside of the cage.

In FIGS. 10 and 11, the roller cage 40 is housed in a polygonal cavity 5D ′ formed in the coupling part 5 of said tool while being held there axially by an annular retaining ring 45.

The circular nut 13 ′ of said clip control mechanism, shown in FIGS. 10 and 11, is inserted into the internal cylindrical contour delimited by the six rollers 43, which, under the action of the elastic rings 44, s 'apply radially by one of their longitudinal generatrices against the cylindrical contour of the nut 13'. The polygonal imprint 5D ′ of the part 5 is capable of cooperating, by its sides, with the rollers 43 during the screwing or unscrewing operation of the clip. Thus, the connection between the part 5 and the nut 13 ′, by means of the roller cage 40, is effectively ensured and it allows the coupling part 5 to be driven helically with the nut 13 ′ When this compresses the spring 15.

Claims (10)

Tool for laying pinning staples on sheets or the like to be assembled, said staples comprising: - A body (11) provided with a bearing face capable of coming into contact with the front face of the stack of sheets to be assembled; - At least one elongated element (14) intended to pass through facing holes made in the sheets and provided with a hooking spout (14A) capable of being applied against the rear face of said stack of sheets; and - a mechanism movable relative to the body, comprising a threaded rod (12), which is arranged coaxially with said body and one end of which is extended by said elongated member, and a control nut (13) of said mechanism mounted on said rod at near its other end, a compression spring (15) being arranged around the rod between said body and said nut, and said tool comprising: - A fixed cylindrical sheath (2) capable of cooperating with the body (11) of said clip to immobilize it in rotation; and a screwing sleeve (4) housed in said sleeve and capable of being driven in rotation by one of its ends, while its other end is capable of cooperating with said control nut, characterized in that said tool further comprises an intermediate coupling piece (5) capable of being linked in rotation and in translation with said control nut (13) on the one hand, and with said screwing sleeve (4 ) on the other hand, so that when the bearing face (11A) of the body (11) of the staple and the hooking beak (14A) of the elongated element (14) are in contact with the stacking of sheets after said rod threaded (12) has been pulled axially by the rotation of said nut, said coupling piece (5) gradually disengages from said rotary screw sleeve (4), being driven by the then helical movement of said nut (13) relative to the rod (12), of a stroke corresponding to the preset compression stroke of said spring. Tool according to claim 1,
characterized in that said intermediate coupling part (5) is housed, in a movable manner, in said sheath (2) and has a hollow cylindrical shape. Tool according to one of claims 1 or 2,
characterized in that said intermediate coupling piece (5) is connected to said screwing sleeve (4) by a link of the spigot type. Tool according to claim 3,
characterized in that the compression stroke of said spring (15), which is a function of the clamping force to be applied to said sheets, corresponds substantially to the disengagement race of said spigot link between the intermediate coupling piece (5) and the screw sleeve (4). Tool according to one of claims 3 or 4,
characterized in that said spigot connection is defined by at least one diametral groove (5A), formed in the end face of said coupling piece (5), and by a diametrical tongue (4C), protruding in the corresponding end face of said screw sleeve (4) and capable of engaging in the diametrical groove of said coupling piece. Tool according to claim 5,
characterized in that the outer contour of said tongue (4C) and the inner contour of said groove (5A) have trapezoidal shapes complementary to each other. Tool according to any one of the preceding claims 1 to 6,
characterized in that the connection between said intermediate coupling piece (5) and said nut (13) of the control mechanism of said clip is effected by engagement of said nut in the end of the coupling piece, opposite its other end linked to said screw sleeve. Tool according to claim 7,
characterized in that said engagement link is defined by a polygonal imprint (5D), which is formed in the corresponding end of said coupling piece (5) and into which the nut (13) can be introduced, of similar section, of said control mechanism of said clip. Tool according to claim 7,
characterized in that said engagement connection is defined by a roller cage (40) regularly distributed around it, which is arranged in the coupling part (5) by being linked thereto and which is capable of surrounding said nut control (13 ′) of said clip, said rollers (43) arranged parallel to the coupling piece applying radially against said control nut (13 ′). Tool according to claim 9,
characterized in that the roller cage (40) is driven by said coupling piece (5) by an imprint polygonal (5D ′), formed therein and cooperating by its sides with said rollers, and all of said rollers are surrounded at their ends (43A) linked to opposite flanges (41) of said cage by elastic rings ( 44).

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