FIXING SYSTEM WITH THREADED STUD

Abstract

The invention relates mainly to a fastening system (1) comprising a fastening piece (2) and an arming piece (11), which fastening system (1) is actuable between a positioning position around the stud (34) in which the arming piece (11) holds four tabs (7, 9) of a fastening piece (2) in their constrained position, and a tensioned fastening position to the stud (34) in which the arming piece (11) is connected to the fastening piece (2) when the four tabs (7, 9) are in a free position.

Description

TECHNICAL FIELD

[0001] The invention falls within the field of fasteners, and relates more particularly to a system for fastening to a threaded stud, particularly suitable for mounting a panel on an automobile body. PRIOR ART AND DISADVANTAGES OF PRIOR ART

[0002] As is known, the fixing of panels to automobile-type chassis is carried out by positioning the panel against the chassis, which chassis includes projecting threaded studs which pass through holes made in the panel, then screwing bolts into them to fix the panel against the chassis without any mechanical play remaining.

[0003] These screw-on fasteners are often tedious for an operator, in addition to taking a lot of time.

[0004] One-piece clips are known that can be snapped onto a threaded stud. This avoids the need to rotate a bolt. However, these clips are adapted to a particular type of threaded stud, and the operator must exert significant force on the clip to secure and lock it around the stud.

[0005] Also known from publication FR3091909 is a part for fixing to a threaded stud projecting from a base comprising a fixing part provided with several curved claws whose ends are intended to be inserted into the thread of a stud, and a covering part intended to cover the fixing part by exerting a force on the claws: this force deforms the claws which will consolidate the embedding of the ends of the claws in the thread and generate a tension force against the base.

[0006] However, the tension force generated by the fastener against the base after fastening depends greatly on the installation effort provided by the operator. OBJECTIVE OF THE INVENTION

[0007] The invention therefore aims to propose a fixing system for a threaded stud projecting from a base, the installation of which is carried out in an ergonomic and reproducible manner. STATEMENT OF THE INVENTION

[0008] To this end, the invention relates to a system for fixing to a threaded stud projecting from a base, for example a motor vehicle chassis, comprising: a) a fixing part comprising: i) a base provided with a through hole intended to receive the threaded stud, ii) two opposite claws each comprising a free end for cooperating with the thread of the stud, which free ends of the two claws are opposite each other on either side of the hole, and iii) two tension tabs projecting from two second opposite edges of the base distinct from the first edges, which tension tabs are elastically deformable between a free position in which the base is non-planar and a stressed position in which the base is planar; b) a part for arming the fixing part comprising: i) an orifice intended to receive the threaded stud, and ii) means for locking the tension tabs of the fixing part in the stressed position;which fixing system is operable between a position of installation around the stud in which the arming part maintains the tabs of the fixing part in their constrained position, and a position of fixing under tension to the stud.;

[0009] The fixing system may also include the following optional features considered in isolation or in all possible technical combinations: The fixing part comprises two embedding tabs projecting from two first opposite edges of the base and mechanically connected to the two respective cooperation claws, which embedding tabs are elastically deformable between a free embedding position of the free ends of the claws in the thread of the stud and a constrained position of separation of said free ends of the claws from the thread of the stud. The arming part comprises means for locking in the constrained position of the embedding tabs of the fixing part. The fixing system is actuable between the position of installation around the stud in which the arming part holds the four tabs of the fixing part in their constrained position, and the position of attachment under tension to the stud.The arming part comprises means for connection to the fixing part when the embedding tabs and the tension tabs of the fixing part are in the free position, the fixing system being in its tensioned fixing position to the stud. Each embedding tab of the fixing part comprises a window for cooperation with the arming part by its connection means. The window is delimited by an upper portion for cooperation with the arming part by its locking means in the constrained position of the embedding tab in question. The window is delimited by an opposite lower portion from which the claw in question projects. The free end of each claw is concave.Each claw comprises a planar main body and in that the free end of each claw is inclined relative to an extension plane of the body of the claw, the directions of inclination of the free ends of the two respective claws being opposite. Each tension tab of the fixing part comprises a main body for deforming the base and a free end portion for cooperating with the fixing part: a) by the locking means provided on the arming part when the tension tab is in the constrained position and, b) by the connecting means provided on the arming part when the tension tab is in its free position. The base is curved when the tension tabs are in their free position.The connecting means and the locking means of the embedding tabs are formed by two opposite projecting stops each comprising: a) a surface for retaining the embedding tab considered in its free position forming connecting means, and b) a locking shoulder provided on an inclined surface for receiving the upper portion of the embedding tab considered in its constrained position.The connecting means and the locking means of the tension tabs are formed by two opposite hollow members each comprising: a) a housing for locking the free end portion of the tension tab considered in its constrained position, and b) a grooved portion forming connecting means and comprising a groove for housing the main body of the tension tab and two retaining edges of the free end portion of the tension tab arranged on either side of the groove when said tension tab is in its free position. The locking housing provided in each hollow member of the arming part is delimited by an inclined surface for receiving the free end portion of the tension tab.The fixing system comprises a panel-connecting element intended to be fixed to the base, which element comprises a main body, panel-connecting tabs and a housing for the fixing and arming parts connected together. The fixing part comprises legs for connecting to the connecting element, at least one end portion of each connecting leg facing a lower face of the main body.

[0010] The invention also relates to a method of installing a panel against a base with at least one fixing system as described previously to a threaded stud projecting from said base, which method comprises the successive steps of: a) Positioning the panel against the base, the stud passing through the panel through an orifice made in said panel; b) Positioning the fixing system around the stud, the tabs of the fixing part being in the constrained position and the base being flat; c) Translation of the fixing system in its constrained position along the threaded stud until the base comes into contact with the panel; d) Translational movement of the arming part in the direction of the panel relative to the fixing part in contact with the panel, the tabs being in their constrained position;(e) Concomitant release of the tabs and actuation of the fixing part towards its free fixing position around the stud, during which the free ends of the claws engage in the thread of the stud and during which the base passes from its flat position to its non-flat position by exerting a force against the panel directed perpendicular to said base to eliminate any mechanical play between the fixing part, the panel and the base.; PRESENTATION OF FIGURES

[0011] Other characteristics and advantages of the invention will emerge clearly from the description given below, for information purposes only and in no way limiting, with reference to the appended figures: [ Fig. 1 ] There figure 1 represents a perspective view of the fastening system of the invention, which system is armed and pre-mounted on a panel; [ Fig. 2 ] There figure 2 represents a perspective view of the fastening system of the invention, which system is free; [ Fig. 3 ] There figure 3 represents a perspective view of a fixing part of the fixing system of the figure 1 , which part is in a free, unconstrained position; [ Fig. 4 ] There figure 4 illustrates a side view of the attachment part of the figure 3 in free position; [ Fig. 5 ] There figure 5 illustrates a side view of the attachment part of the figure 3 in a constrained position. DETAILED DESCRIPTION OF THE INVENTION

[0012] It is first of all specified that in the figures, the same references designate the same elements regardless of the figure in which they appear and regardless of the form of representation of these elements. Similarly, if elements are not specifically referenced in one of the figures, their references can be easily found by referring to another figure.

[0013] It is also specified that the figures essentially represent one embodiment of the subject of the invention but that there may be other embodiments which meet the definition of the invention.

[0014] The invention relates to a fixing system 1 by snap-fastening to a threaded stud 34, and finds its application in the field of fixing industrial parts, and in particular in the field of fixing accessories to a chassis 42 or an automobile body.

[0015] In reference to the figures 1 à 5 , the fixing system 1 of the invention comprises a fixing part 2 to the threaded stud 34 and a part 11 for arming said fixing part 2.

[0016] The fixing part 2, made of metallic material, typically steel, will now be described. This part is particularly visible in the free, unconstrained position on the figures 2 And 4 , and in the constrained position armed on the figure 5 .

[0017] The fixing part 2 extends along a longitudinal axis and comprises a base 3 of generally rectangular shape, which base 3 comprises an internal face and an opposite external face. The base 3 comprises at its center a frustoconical central portion 45 projecting from the internal face of the base 3 and which comprises at its center a cylindrical through-orifice 4 through which the threaded stud 34 is intended to be housed therein. The through-orifice 4 has a diameter greater than the diameter of the threaded stud 34.

[0018] The fixing part 2 further comprises two opposite embedding tabs 7, projecting from two opposite longitudinal edges 8 of the internal face of the base 3. These embedding tabs 7 are elastically deformable and are actuable between a free embedding position and a constrained - or armed - position. The transition from the free position to the constrained position is done by separating the distal ends of said embedding tabs 7.

[0019] Each embedding tab 7 comprises a window 15 delimited by a lower portion 17 secured to the edge in question 8 of the base 3, and an opposite upper portion 16. The upper portion 16 also extends in a plane secant relative to an extension plane of the rest of the embedding tab 7.

[0020] The fixing part 2 also comprises two opposite claws 5 each comprising a main planar body 19 which extends from the lower portion 17 of the considered embedding tab 7, and a distal free end 6 for cooperation with the thread 35 of the stud 34. The free ends 6 of the two respective claws 5 are opposite each other, on either side of the through-hole 4. To ensure a larger surface area for cooperation of the free end 6 of each claw 5 with the thread 35 of the stud 34, said free end 6 of each claw 5 has a concave shape. In other words, the concave shape of the free end 6 of each claw 5 makes it possible to ensure linear contact between said free end 6 and the threaded stud 34.

[0021] Furthermore, the free end 6 of each claw 5 has the same orientation as that of the thread 35 of the stud 34. For example, if the stud has a lying thread, the main body 19 and the free end 6 of each claw 5 extend in the same plane. If the stud 34 has a triangular thread 35, like that shown in the figure 1 , then the free end 6 of the claw 5 is inclined relative to an extension plane of the claw 5, so as to allow insertion of the entire free end 6 of the claw 5 into the thread 35 of the stud 34. In the case of a fixing part 2 adapted to a triangular thread 35, the directions of inclination of the free ends 6 of the two respective claws 5 are opposite.

[0022] The claws 5 are mechanically connected to the embedding tabs 7. Thus, when the embedding tabs 7 are in their free position, the claws 5 are configured to embed themselves in the thread 35 of the stud 34. Conversely, when the embedding tabs 7 are in their constrained position, the claws 5 are in a position of disengagement of their free ends 6 from the thread 35 of the stud 34. Indeed, the passage from the free position to the constrained position of the embedding tabs 7 causes the distal free ends 6 of the facing claws 5 to move apart from each other.

[0023] The fixing part 2 also comprises two opposite tension tabs 9, projecting from two opposite transverse edges 10 of the internal face of the base 3. The tension tabs 9 are elastically deformable by bringing together the distal free ends 21 of said tension tabs 9. They are thus actuable between a free position in which the base 3 of the fixing part 2 is not flat and a constrained - or armed - position in which the base 3 is flat ( figure 5 ).

[0024] More particularly, when the tension tabs 9 are in their free position, the opposite external face of the base 3 of the fixing part 2 has a concave curved profile. Alternatively, when the tension tabs 9 are in their free position, the external face of the base 3 has a broken line-shaped profile (see figure 4 ), with a flat central zone and two inclined extreme zones, the angle between the central zone and the extreme zone considered being less than 180° at the level of the external face of the base 3 of the fixing part 2.

[0025] In order to adjust and limit the force required to move the tension tabs 9 from their free position to their armed position, U-shaped through grooves 46 may be provided in the base 3 of the fixing part 2.

[0026] Each tension tab 9 further has the shape of a T and comprises a main body 20 projecting from the base 3 of the fixing part 2 and a free end portion 21 forming the distal end which extends perpendicular to said main body 20, that is to say parallel to the longitudinal axis. The free end portion 21 further extends in a plane secant to a plane of extension of the remainder of the tension tab 9.

[0027] Finally, the fixing part 2 comprises four transverse connecting legs 32 projecting from the tops of the base 3, perpendicular to the opposite longitudinal edges 8 of said base 3.

[0028] The arming part 11, preferably made of plastic or composite material and assembled to the fixing part, will now be described.

[0029] The arming part 11 is at least partly housed in a space delimited by the four tabs 7, 9 of the fixing part 2, and extends along a second longitudinal axis which coincides with the longitudinal axis of the fixing part 2.

[0030] The arming part 11 comprises a main body 36 with a rectangular section in which a through hole 14 is provided for receiving the threaded stud 34. The hole 14 shown in the figures 1 et 2 has a rectangular section shape, but any section shape is possible without departing from the scope of the invention provided that the orifice 14 allows the threaded stud 34 to be housed. The two orifices 4, 14 respectively of the fixing part 2 and of the arming part 11 extend along the same axis perpendicular to the longitudinal axis and to a transverse axis of the fixing system, which axis will be referred to hereinafter as the vertical axis.

[0031] The main body 36 of the arming part 11 comprises an upper face, an opposite lower face facing the base of the fixing part, and four lateral faces 37, 38 including two longitudinal lateral faces 37 and two transverse lateral faces 38.

[0032] The arming part 11 comprises means 23 for locking the embedding tabs 7 in the constrained position, means 22 for locking the tension tabs 9 in the constrained position, and means 12, 13 for connecting to the fixing part 2 when the embedding tabs 7 and tension tabs 9 are in their free position.

[0033] In reference to the figure 2 , the structure of the arming part 11 forming the connecting means 12, 13 and locking means 22, 23 will be described.

[0034] The arming part 11 comprises two opposite hollow members 25 respectively secured to the two opposite transverse side walls 38 of the main body 36 of the arming part 11. Each hollow member 25 comprises a grooved portion 13 - which forms the connecting means of the fixing part 2 when the tensioning tabs 9 and embedding tabs 7 are in the free position - comprising a longitudinal housing groove 26 of the main body 20 of the tensioning tab in question 9 and two longitudinal retaining edges 27 of the free end portion 21 of the tensioning tab 9, which longitudinal retaining edges 27 extend on either side of the housing groove 26.

[0035] The longitudinal retaining edges 27 project from the considered transverse lateral wall 38 of the main body 36 of the arming part 11. The width of the housing groove 26 is greater than or equal to the width of the main body 20 of the considered tension tab 9, and less than the width (i.e. a dimension perpendicular to the longitudinal axis) of the free end portion 21 of said tension tab 9. Furthermore, the longitudinal retaining edges 27 extend obliquely relative to the considered transverse lateral face 38 of the main body 36 of the arming part 11 and in the direction of the lower face of said main body 36. By obliquely, is meant a direction of extension of the retaining edges 27 which is neither parallel nor perpendicular to the considered transverse lateral face 38. Finally, each grooved portion 13 comprises a transverse edge 39 forming the distal end of the hollow member 25.

[0036] Thus, each housing groove 26 is delimited by the transverse side wall considered 38 of the main body 36 of the arming part 11, by the two longitudinal retaining edges 27 and by the distal end transverse edge 39.

[0037] Each hollow member 25 further comprises a housing 22 for the free end portion 21 of the tension tab 9 - which forms the locking means in the constrained position of the tension tab considered 9 - which extends between the transverse side wall considered 38 and the housing groove 26 of the grooved portion 13. This locking housing 22 for the free end portion 21 of the tension tab 9 extends in a transverse direction and has a width greater than or equal to the transverse dimension of the free end portion 21 of the tension tab 9. In addition, each locking housing 22 is delimited by two inclined receiving surfaces 28 for the free end portion 21 of the tension tab 9, formed in the walls of the respective longitudinal retaining edges 27 on either side of the housing groove 26.Thus, the surface contact between the free end 21 of the tension tab considered 9 and the inclined receiving surfaces 28 is maximized, which improves the locking in the constrained position of the tension tab 9. Furthermore, these inclined surfaces 28 each extend to two respective shoulders (not shown) formed in the walls of the respective longitudinal retaining edges 27 on either side of the housing groove 26. These shoulders make it possible to retain the reinforced fixing part (2) in the reinforcement part (11).

[0038] The arming part 11 further comprises two opposite stops 24 which project from the opposite longitudinal lateral faces 37 of the main body 36 of said arming part 11. These stops 24 form locking beaks of the embedding tabs 7 in their constrained position.

[0039] Each stop 24 comprises an upper connecting surface 12 which extends perpendicularly from the longitudinal lateral face considered 37 of the main body 36 of the arming part 11. This upper surface forms the connecting means of the fixing part 2 when the tensioning tabs 9 and embedding tabs 7 are in the free position.

[0040] The stop 24 also comprises an inclined locking surface 47 towards the lower face of the main body 36 of the arming part 11 and which extends from the upper face 12 of the stop 24, so that the stop has a triangular profile.

[0041] A locking shoulder 23 is provided in this inclined surface 47 and which forms the locking means of the embedding tab considered 7 in its constrained position. The lateral surface 43 of the shoulder 23 is parallel to the upper portion 16 of the embedding tab considered 7 in the constrained position, so that the surface contact between the upper portion 16 of the embedding tab considered 7 and the lateral surface 43 of the shoulder 23 is maximized, which improves the locking in the constrained position of the embedding tab 7.

[0042] The attachment to a threaded stud 34 of the attachment system 1 will now be described.

[0043] Before use, the fixing system 1 is armed, that is to say that the embedding tabs 7 and tension tabs 8 are in their armed position, in other words under stress, as shown in the figure 1 .

[0044] The two embedding tabs 7 are held in constraint by the stops 24 - or locking beaks - of the arming part 11: the upper cooperation portion 16 of each embedding tab 7 cooperates with the shoulder 23 of the stop considered 24 of the arming part 11. This has the effect of separating the embedding tabs 7 in a transverse direction, and concomitantly of separating the distal free ends 6 of the two claws 5 so that they are disengaged from the thread 35 of the stud 34. In this way the fixing part 2, when the embedding tabs 7 are armed, can slide without resistance along the threaded stud 34.

[0045] The two tension tabs 9 are also kept under stress by being housed in the locking housings 22 of the hollow members 25. The arming part 11 tends under these conditions to bring the free ends 21 of the tension tabs 9 together, which has the effect of deforming the base 3 of the fixing part 2, and more precisely of flattening said base 3.

[0046] When an operator installs the fixing system 1 around the stud 34, he grasps the arming part 11 and inserts the stud 34 into the two through holes 4, 14 respectively of the fixing part 2 and of the arming part 11.

[0047] Advantageously, the arming part 11 comprises two opposite flexible tabs (not shown) which project from the internal face of the orifice 14 of the main body 36 of said arming part 11, each extending to a distal free end, which distal ends are opposite each other. The distance between the two flexible tabs is less than the diameter of the stud 34, so that when the stud 34 is inserted into the orifices 4, 14 of the arming system 1 in the armed position, the claws 5 of the fixing part 2 are disengaged from the thread 35 of the stud 34 but the flexible tabs of the arming part 11 are in contact against the stud 34, which ensures that the fixing system 1 is held around the stud 34.The resistance force exerted by these flexible tabs is low, i.e. less than 20 newtons, which offers the double advantage of allowing pre-installation of the fixing system 1 around the stud 34 before final fixing, while allowing the operator to remove the fixing system 1 from the stud 34 while still armed.

[0048] To install the fixing system 1, the operator then moves the fixing system 1 around the stud 34 until the external face of the base 3 of the fixing part 2 comes into contact with the surface from which the stud 34 projects, for example the frame 42. Alternatively, when the operation aims to press a panel 41 against the base 42, the operator moves the fixing system 1 around the stud 34 until the external face of the base 3 of the fixing part 2 comes into contact with the panel 41.

[0049] By the pressure force exerted by the operator on the upper face of the arming part 11, the latter continues its translational movement towards the chassis 42 while the fixing part 2 remains immobile, the base being in abutment against the panel: there is therefore a relative translational movement of the arming part 11 with respect to the fixing part 2. The necessary force to be exerted by the operator to ensure the translation of the arming part 11 with respect to the fixing part 2 is relatively low, between 30 and 50 newtons.

[0050] This relative movement causes, concomitantly, on the one hand the displacement of the distal end parts 21 of the tension tabs 9 out of the locking housings 22, and on the other hand the disengagement of the upper portions 16 of the embedding tabs 7 out of the shoulders 23 formed in the locking stops 24 of the arming part 11.

[0051] The four tabs 7, 9 of the fixing part 2 then pass simultaneously from their armed position to their free position: the main body 20 of each tension tab 9 is found in the housing groove 26 of the arming part 11, while the upper portion 16 of each embedding tab 7 comes opposite the upper connecting surface 12 of the stop 24. This passage from the constrained position to the free position of the tabs 7, 9 is sudden - a few hundredths of a second - and produces a characteristic sound perfectly recognizable by the operator installing the fixing system 1, which indicates to him that the fixing part 2 has been actuated to its free position and that it is in place around the threaded stud 34.

[0052] Furthermore, the upper part 21 of each tension tab 9 is retained in the housing groove 26 by the distal end 39 of the grooved portion 13 while the stops 24 of the arming part 11 are housed in the windows 15 of the embedding tabs 7, which ensures the connection between the fixing part 2 to the arming part 11 while ensuring the free movement of the arming part 11 relative to the fixing part 2. The fixing system 1 is then in a position of fixing under tension to the stud 34, as shown in the figure 2 .

[0053] Indeed, when the four tabs 7, 9 move from the armed position to the free position, the free ends 6 of the claws 5 of the fixing part 2 engage in the thread 35 of the stud 34 while the base 3 of the fixing part 2 returns to its non-planar free position by exerting a pressing force against the frame 42 and the panel 41. This exerted force, which is greater than or equal to 50 newtons, makes it possible to eliminate any mechanical play between the panel 41, the frame 42 and the fixing system 2. Furthermore, the force exerted by the fixing part 2 against the frame 42 and the panel 41 depends on the material of the fixing part 2 and the shape of said fixing part 2.Thus, if all the fixing parts 2 of several fixing systems 1 are identical, then the forces exerted by these fixing parts 2 against the panel 41 and the frame 42 from which the studs 34 protrude are all identical, which ensures reproducible installation of the fixing systems 1 around the studs 34.

[0054] The fastening system 1 installed around the stud 34 is designed to resist tearing, in particular a pulling force directed in the opposite direction to the force of pressing the fastening part 1 against the chassis 42. The tearing resistance of the fastening part 1 fixed to the threaded stud 34 is at least equal to 600 newtons.

[0055] Advantageously, the fixing system 1 absorbs the separation stresses by deformation of the fixing part 2. This deformation of the fixing part 2 tends to bring the distal ends 6 of the cooperation claws 5 closer together, causing an increase in the bearing force of said distal ends 6 of the claws 5 against the thread 35 of the stud 34. Thus, a force exerted on the fixing system 1 aimed at moving said fixing system 1 away from the frame 42 will tend on the contrary to reinforce the fixing of the fixing system 1 around the threaded stud 34, provided that this separation force remains less than the force necessary for tearing.

[0056] In any event, the fixing system 1 installed around the stud 34 is easily removable, in particular on a stud 34 with triangular thread 35, because the operator simply has to unscrew the fixing system 1 in the conventional manner like a conventional nut.

[0057] Finally, to allow the pre-assembly of the fixing system 1 on a panel 41, said fixing system 1 comprises a connecting part 30 to said panel 41 which will now be described, mainly with reference to the figure 1 .

[0058] This connecting piece 30 comprises an annular wall 44 whose internal diameter allows the passage of the arming piece 11 and the embedding tabs 7 and tension tabs 9 of the fixing piece 2, but not the connecting legs 32 which are opposite a lower face of this annular wall 44.

[0059] The connecting piece 30 further comprises a cylindrical wall 40 which projects from the lower face of the annular wall 44, and a plurality of deformable snap-fastening tabs 33 which extend from the free edge of the cylindrical wall 40.

[0060] This connecting piece 30 makes it possible to pre-assemble the fixing system 1 on the panel 41 by placing the fixing 2 and arming 11 parts assembled together against the panel 41, so that the orifices 4, 14 of the fixing 2 and arming 11 parts of the fixing system 1 are opposite a through orifice 49 made in the panel 41. The connecting piece 30 is then fixed to the panel 41 by snap-fastening the snap-fastening tabs 33 into through recesses 48 provided for this purpose and made in the panel 41 ( figure 1 ).

[0061] According to an alternative embodiment not shown, the connecting piece 30 comprises two opposite tabs which extend from the free edge of the cylindrical wall 40 perpendicular to the latter, which tabs allow sliding mounting in a groove provided in the panel 41.

[0062] The assembly between the fixing 2 and arming 11 parts are thus retained by the connecting part 30, and the distance separating two opposite connecting legs 32 of the fixing part 2 being less than the internal diameter of the orifice 31 of the connecting part 30, there is a displacement clearance of this assembly to facilitate the positioning of the fixing system 1 opposite the stud 34 during installation.

[0063] Particularly advantageously, the invention provides a fastening panel 41 to a plurality of studs 34 projecting from a vehicle chassis 42, which panel 41 comprises a plurality of pre-assembled fastening systems 1. The mounting of a plurality of fastening systems 1 concomitantly is then made possible. The fastening to the studs 34 is not only easier, reproducible, but also faster.

Claims

1. A fixing system (1) for a threaded stud (34) projecting from a base, for example a motor vehicle chassis, comprising: a) a fixing part (2) comprising: i) a base (3) provided with a through-hole (4) intended to receive the threaded stud (34), ii) two opposite claws (5) each comprising a free end (6) for cooperating with the thread (35) of the stud (34), which free ends (6) of the two claws (5) are opposite each other on either side of the hole (4), and iii) two tension tabs (9) projecting from two second opposite edges (10) of the base distinct from the first edges (8), which tension tabs (9) are elastically deformable between a free position in which the base (3) is non-planar and a constrained position in which the base (3) is planar;b) an arming part (11) of the fixing part (2) comprising: i) an orifice (14) intended to receive the threaded stud (34), and ii) means for locking in the stressed position (22) the tension tabs (9) of the fixing part (2); which fixing system (1) is actuable between a position of installation around the stud (34) in which the arming part (11) maintains the tabs (9) of the fixing part (2) in their stressed position, and a position of fixing under tension to the stud (34).; 2. System according to the preceding claim, characterized in that: a) The fixing part (2) comprises two embedding tabs (7) projecting from two first opposite edges (8) of the base (3) and mechanically connected to the two respective cooperation claws (5), which embedding tabs (7) are elastically deformable between a free embedding position of the free ends (6) of the claws (5) in the thread (35) of the stud (34) and a constrained position of separation of said free ends (6) of the claws (5) from the thread (35) of the stud (34), and in that b) The arming part (11) comprises means for locking in the constrained position (23) the embedding tabs (7) of the fixing part (2); which fixing system (1) is operable between the position of installation around the stud (34) in which the arming part (11) holds the four tabs (7, 9) of the fixing part (2) in their constrained position, and the position of fixing under tension to the stud (34).

3. System according to the preceding claim, characterized in that the arming part (11) comprises connecting means (12, 13) to the fixing part (2) when the embedding tabs (7) and the tension tabs (9) of the fixing part (2) are in the free position, the fixing system (1) being in its fixing position under tension to the stud (34).

4. System (1) according to claim 2 or 3, characterized in that each embedding tab (7) of the fixing part (2) comprises a window (15) for cooperation with the arming part (11) by its connecting means (12).

5. System (1) according to the preceding claim, characterized in that the window (15) is delimited by an upper portion (16) cooperating with the arming part (11) by its locking means in the constrained position (23) of the embedding tab considered (7).

6. System (1) according to claim 4 or 5, characterized in thatthe window (15) is delimited by an opposite lower portion (17) from which the claw in question (5) projects.

7. System (1) according to any one of claims 1 to 6, characterized in that the free end (6) of each claw (5) is concave.

8. System (1) according to any one of the preceding claims, characterized in that each claw (5) comprises a flat main body (19) and in that the free end (6) of each claw (5) is inclined relative to an extension plane of the body (19) of the claw (5), the directions of inclination of the free ends (6) of the two respective claws (5) being opposite.

9. System (1) according to any one of the preceding claims, characterized in thateach tension tab (9) of the fixing part (2) comprises a main body (20) for deforming the base (3) and a free end portion (21) for cooperating with the fixing part (11): a) by the locking means (22) provided on the arming part (11) when the tension tab (9) is in the constrained position and, b) by the connecting means (13) provided on the arming part (11) when the tension tab (9) is in its free position.

10. System (1) according to any one of the preceding claims, characterized in that the base (3) is curved when the tension tabs (9) are in their free position.

11. System (1) according to any one of claims 3 to 10, characterized in that: a) The connecting means (12) and the locking means (23) of the embedding tabs (7) are formed by two opposite projecting stops (24) each comprising: i) a retaining surface (12) of the embedding tab in question (7) in its free position forming connecting means (12), and ii) a locking shoulder (23) provided on an inclined surface for receiving the upper portion (16) of the embedding tab in question (7) in its constrained position;b) The connecting means (13) and the locking means (22) of the tension tabs (9) are formed by two opposite hollow members (25) each comprising: i) a locking housing (22) of the free end portion of the tension tab considered (9) in its constrained position, and ii) a grooved portion forming connecting means (13) and comprising a housing groove (26) of the main body (20) of the tension tab (9) and two retaining edges (27) of the free end portion (21) of the tension tab (9) arranged on either side of the groove (26) when said tension tab (9) is in its free position.; 12. System (1) according to the preceding claim, characterized in that the locking housing (22) provided in each hollow member (25) of the arming part (11) is delimited by an inclined receiving surface (28) of the free end portion (21) of the tensioning tab (9).

13. System (1) according to any one of the preceding claims, characterized in that it comprises a connecting element (29) to a panel (41) intended to be fixed to the base, which element (29) comprises a main body (30), fixing lugs (33) to the panel (41) and a housing (31) of the fixing (2) and arming (11) parts connected together.

14. System (1) according to the preceding claim, characterized in that the fixing part (2) comprises connecting legs (32) to the connecting element (29), at least one end portion of each connecting leg (32) being opposite a lower face of the main body (30).

15. Method for installing a panel against a base with at least one fixing system (1) according to any one of claims 2 to 14 to a threaded stud (34) projecting from said base, which method comprises the successive steps of: a) Placing the panel against the base, the stud (34) passing through the panel through an orifice provided in said panel; b) Placing the fixing system (1) around the stud (34), the tabs (7, 9) of the fixing part (2) being in the constrained position and the base (3) being flat; c) Translating the fixing system (1) into its constrained position along the threaded stud (34) until the base (3) is brought into contact with the panel; d) Translational movement of the arming part (11) in the direction of the panel relative to the fixing part (2) in contact with the panel, the tabs (7, 9) being in their constrained position;e) Concomitant release of the tabs (7, 9) and actuation of the fixing part (2) towards its free fixing position around the stud (34), during which the free ends (6) of the claws (5) engage in the thread (35) of the stud (34) and during which the base (3) passes from its flat position to its non-flat position by exerting a stress against the panel directed perpendicular to said base (3) to eliminate any mechanical play between the fixing part (2), the panel and the base.;