FR2762882A1 - Threaded fastener for components attached to plastics support - Google Patents

Abstract

The fastener comprises two basically flat plates (2, 3) linked by a flexible portion (4) which allows them to be set at an open angle prior to use and parallel to one another in the operational position. The fastener has a spacer in the form of a collar (13) which holds the two plates at an appropriate distance from one another after fitting to a plastics support (25), and a second collar (14), of smaller diameter, which receives the threaded portion of the screw (31). The corners of the upper plate can be bent over to grip the support and a variant of the design can incorporate a third panel and an additional collar.

Description

 The present invention relates to a tapped fixing element of an improved type, particularly suitable for tightening, by coupling with a corresponding screw, various components on a plastic support element, without risk of damaging the latter and providing at the same time time a high tightening torque for the screw.

Problems linked to the coupling of various components on supports made of rigid polymeric materials
(so-called plastic materials), tightened by groups of metal screws, as is the case, for example, in the mounting of motor vehicle floors, are known.

 In particular, metallic threaded elements are known which consist of a small deformable metallic spring, substantially U-shaped, the opposite ends of which are defined by two plates each provided with through holes: once the spring has been snapped onto a plastic support , at one of these holes, so that the holes of the plates and that of the support are aligned, the connection of the support with any component is carried out simply by inserting a screw in the housing defined by the cited holes .

 This type of tapped element is not without its drawbacks: indeed, if a high tightening torque is applied, this tightening operation can cause damage to the plastic support, while a limited tightening torque may not be effective in coupling components; moreover, because of the particular deformation behavior of polymer materials, the initial tightening torque can decrease over time, as a result of creep phenomena, according to which, once the desired torque has been reached, the coupling can be loosen in time.

 One possible solution to these problems lies in the use of metal spacers to be placed between the plates of the deformable spring, inside the hole of the support. It is however obvious that this solution involves the use of an additional separate component, with the consequence of increasing the complexity and the cost of the assembly operations.

 The object of the present invention is to provide a threaded fixing element for blocking by means of a corresponding, metric or self-tapping screw, various components on a plastic support, which does not have the aforementioned drawbacks, and which, in particular, guarantees a high tightening torque without risk of damage to the coupled components, and which at the same time is simple and economical to produce and practical in use.

 In accordance with the aim defined above, there is therefore provided a threaded fixing element for coupling with a corresponding screw, comprising a first plate and a second substantially flat plate and a deformable connection portion, making these plates integral with the one from the other, in a substantially opposite position, along corresponding sides thereof, the first and second plates being respectively provided with a first hole and a second through hole for the insertion of the screw, the deformable connecting portion being able to selectively support the plates in a first operational, mounting position, in which the plates are at a first predetermined angle relative to one another, and in a second operational position, of use, in which the plates are at a second predetermined angle relative to each other, because operated in that it further comprises spacing means making it possible to maintain the plates, after they have been brought into the second operational position, at a predetermined distance and making it possible to prevent a greater approach of these , the spacing means being in one piece with the first plate.

 In particular, the spacing means comprise at least one first collar, substantially cylindrical, delimiting the first hole and extending perpendicularly, in overhang, from a first face of the first plate, facing the second plate, the first collar having an end edge, opposite to an edge connecting to the first plate, capable of cooperating by application against an abutment surface of the second plate, facing the first plate.

 The threaded fastening element according to the invention is therefore particularly suitable for carrying out the fixing of various components on supports made of polymer material: in fact, although of a simple and economical production and of practical use, the invention is at the same time extremely effective in guaranteeing a high tightening torque, without causing damage to the assembled components, not even when these are made of polymer materials. In addition, the tightening torque is ensured over time without the collapsing phenomena of the plastic material causing a loosening of the tightening itself.

 The specific function of the threaded fastening element according to the invention is in fact to guarantee a high and stable tightening torque, obtained by means of the collar interposed between the plates, with their spacing function, which not only prevents excessive deformation of the polymer support during tightening (and therefore without damage), but also prevents subsequent phenomena of "creep" which affect this support from causing loosening of the tightening.

Various other characteristics and advantages of the invention will emerge from the detailed description which follows. Embodiments of the invention are shown by way of non-limiting examples with reference to the accompanying drawings in which
Figure 1 is a sectional view of a threaded fastener according to the invention;
Figure 2 is a perspective view of the threaded fastener of Figure 1, ready for mounting on a plastic panel;
Figure 3 is a sectional view of the threaded fastener of Figure 1, shown in use;
Figure 4 is a sectional view of a possible variant of the threaded fastening element of Figure 1;
Figure 5 is a perspective view of the variant of Figure 4, shown with its mounting tool;
Figure 6 is a sectional view of another variant of the threaded fastener of Figure 1;
Figure 7 is a perspective view of the threaded fastener of Figure 6, ready for mounting on a plastic panel; and
Figure 8 is a sectional view of the threaded fastener of Figure 6, shown in use.

 With reference to FIGS. 1 and 2, a threaded fastening element 1 comprises two substantially flat plates 2 and 3 and a deformable connecting portion 4 which assembles the plates 2, 3 to each other, in a substantially facing position. opposite.

 The plates 2, 3 can be produced in any shape and dimensions, depending on the specific application: in the nonlimiting example illustrated, the plates 2, 3 are substantially rectangular and are joined to one another by the connecting portion 4, along corresponding sides 5, 6.

 The connecting portion 4 can also be produced in various forms: for example, as illustrated in FIGS. 1 and 2, it is constituted by a wall 7 substantially perpendicular to the plate 3 and having a predetermined inclination relative to the plate 2 .

 In the nonlimiting example illustrated, the portion 4 is further provided, in line with a connection profile to the wafer 2, a through slot 8, of rectangular section, with its long sides parallel to the side 5 of the wafer 2, on which the slot 8 partially extends; the slot 8 therefore defines, on the connecting portion 4, two straps 9, 10, arranged on respective sides of the slot. The slot 8 is essentially a discharge element which has the function, as explained below, of promoting the deformation of the connecting portion 4 and, in particular, of the straps 9, 10; this function can obviously be provided by discharge elements formed on the portion 4, different from that described, for example by a plurality of through holes.

 The plates 2, 3 are provided with through holes 11, 12 corresponding, substantially circular, and respective cylindrical collars 13, 14 delimiting the holes 11, 12 respectively; the collar 13 extends perpendicularly in overhang from a face 15 of the plate 2, facing the plate 3, and has a connecting edge 16 to the plate 2 and an end edge 17, opposite the previous one; similarly, the cylindrical collar 14 delimiting the hole 12 extends perpendicularly in overhang, from a face 18 of the plate 3 opposite to a face 19, facing the plate 2.

 The plate 3 is further provided, on the side opposite to the connecting portion 4, with an edge 20 which is inclined at a predetermined angle relative to the plate 3, in the direction opposite to the plate 2. According to a preferred embodiment, the plate 2 is provided, at the angles of one side 21 of the plate 2, opposite to the side 5 thereof, of two small teeth 22, 23 which extend from the face 15 of the wafer 2 in the direction of the wafer 3. On the other hand, according to a possible variant, the teeth 22, 23 can also be eliminated.

 With particular reference to FIG. 2, the plates 2, 3, assembled reciprocally by the connecting portion 4, are inclined relative to each other by a predetermined angle; the connection portion 4 therefore supports the plates 2 and 3 in a first operational mounting position 1, in which the predetermined angle according to which the plates 2, 3 are held by the connection portion 4, is such that between the edge end 17 of the collar 13 and the plate 3, there is sufficient clearance to allow the insertion therein of an element 25 having a thickness substantially equal to the axial extension of the collar 13.

 As indicated above, the present invention is particularly suitable for tightening a generic component on a support made of polymer (plastic) material; Without losing its general character, the description which follows therefore considers the element made of a polymer material; the element 25, which can be of any shape, comprises in particular a substantially planar portion 26 provided with a through hole 27, of a diameter making it possible to receive the collar 13 inside.

 According to a preferred embodiment, the threaded fastening element 1 is made of a folded and cut metal sheet, and the collars 13, 14 are defined by corresponding pressed and semi-cut portions of the plates 2 and 3. The teeth 22 , 23 can in this case be produced by simple folding of the angles on the side 21 of the plate 2. Preferably, the threaded fastening element 1 is made of non-hardened zinc-plated steel and, consequently, it has a deformation behavior essentially plastic.

 Due to the material from which the threaded fastening element 1 is made and the special construction geometry thereof, the connecting portion 4 is plastically deformable under the action of an appropriate tool, for example pliers, and is therefore capable of selectively supporting the plates 2, 3, not only in the operational mounting position 1a already described, in which the plates 2, 3 are at a first predetermined angle relative to one another (as shown in Figures 1 and 2), but also in a second operational position 1b (Figure 3), in use, in which the pads 2, 3 are located at a predetermined angle relative to one another.

 In fact, with reference also to FIG. 3, the threaded fixing element 1 can be used to effect the fixing of a generic component 30 on the element 25, by means of a screw 31; when the flat portion 26 of the element 25 is inserted between the plates 2, 3, still in the mounting position la (FIG. 2) and when the collar 13 is disposed in line with the hole 27 in the element 25, the threaded fastening element 1 is closed, for example by using an appropriate tool, known and not shown for simplicity, such as pliers, so as to plastically deform the connecting portion 4 and, in particular, the straps 9, 10 and so as to bring the plates 2, 3 into the operational position of use 1b (FIG. 3), in which the collar 13 is inserted in the hole 27.

 In the position of use 1b, the plates 2, 3 are arranged substantially parallel to each other, the collar 13 is interposed between the plates 2, 3 substantially perpendicular thereto and the through holes ll and 12 are substantially aligned with each other and with the collar 13, so as to define therewith a single housing 33 for the pass-through insertion of the screw 31.

 The deformation of the deformable connecting portion 4, obtained by the action of the cited external tool, therefore tends to bring the plates 2, 3 closer to one another, but is limited by the presence of the collar 13 between those -this ; in fact, when the end edge 17 of the collar 13 cooperates by application against an abutment surface on the face 19 of the wafer 3, it prevents further advancement of the wafers 2, 3 and, therefore, possible damage to the item 25.

 According to the present invention therefore, the threaded fastening element 1 comprises spacing means capable of holding the plates 2 and 3, brought into the operational position of use 1b, at a predetermined distance and of preventing their greater coming together. ; in particular, in the example described here, these spacing means consist of the cylindrical collar 13 and are therefore produced in one piece with the plate 2.

 The closing of the threaded fastening element 1 being carried out, that is to say the connecting portion 4 being deformed so as to bring the plates 2, 3 into the position of use 1b, the component 30 can be fixed , in known manner, on the element 25, by means of the screw 31 and possibly using a socket 34.

 In the example illustrated, the screw 31 is of the self-tapping type, but it is preferred to use a collar 4 already pre-tapped; more precisely, various solutions are possible: for example, one can use a collar 14 already tapped for a metric screw, or one can tighten the screw 31 with an appropriate nut. In each case, the collar 14 is capable of receiving inside, by screwing, the screw 31, but it is also obvious that this function can be ensured, as a variant or in combination, by the collar 13.

 The presence of the teeth 22, 23, which at the time of closing of the threaded fastening element 1, penetrate into the plastic element 25, allows the effective angular blocking of the threaded element 1 on this same plastic element 25; on the contrary, in the case where the plastic element 25 has a thickness less than the axial extension of the collar 13, there is consequently an axial clearance between the plates 2, 3 of the threaded fixing element 1 and the element plastic 25; the teeth 22, 23, extending in a cantilever direction substantially parallel to the collar 13, come anyway to bear on the plastic element 25, compensating for this play and avoiding possible consecutive vibrations.

 With reference to FIGS. 4 and 5, in which details similar or identical to those already described are designated by the same references, 50 indicates a possible variant of the threaded fastening element according to the invention.

 Like the threaded fixing element 1, the element 50 comprises two plates 2, 3, assembled to each other in position substantially opposite by a deformable connecting portion 4 and provided with collars 13, 14 respective. In the example illustrated, the through slot 8, formed in the connecting portion 4 and defining the straps 9, 10, extends partially, not only on the plate 2, but also on the plate 3.

The threaded fastening element 50, like the element 1 described above, is preferably made from a folded and cut metal sheet and the collars 13, 14 are defined by corresponding stamped and semi-cut portions of the plates 2, 3; in this case, however, a hardened and zinc-plated steel is effectively used, so that the connecting portion 4 is elastically deformable.

 An end portion 51 of the plate 3, opposite the deformable connecting portion 4 and obtained by L-shaped folding of the plate 3, extends perpendicularly in cantilever from the plate 3 on the opposite side to the plate 2, and is provided with two housings 52, 53 for the insertion of respective teeth 54, 55 of a spacing tool 56, essentially known and shown only schematically in FIG. 5, for simplicity . The teeth 54, 55 are carried integrally by a first arm 57 of the tool 56, while a second arm 58 of the latter is provided with another tooth 59, capable of catching the end edge 17 of the necklace 13; the tool 56 is shaped so that its two arms 57, 58 are capable of being separated from one another.

 The element 50 is therefore, at rest, in the configuration illustrated in FIGS. 4 and 5, in which the deformable connecting portion 4 supports the plates 2, 3 in a position slightly spaced from one another relative to a position of use in which the plates 2, 3 are substantially parallel and which, although not shown for simplicity, is quite similar to the corresponding position of use of the element 1 shown in FIG. 3.

Alternatively, the pads 2, 3 may actually be in a position which substantially coincides with the position of use.

 For mounting the threaded fastening element 50 on an element 25, for example of polymer material, provided with a through hole 27, the appropriate spacing tool 56 is introduced with its own teeth 54, 55 into the housings 52, 53 corresponding to the tapped fixing element 50, while its tooth 59, introduced through the collar 13, is brought to engage with the end edge 17 of the latter.

 The end edge 17 of the collar 13 and the housings 52, 53 therefore constitute gripping means disposed respectively integral with the plates 2 and 3 and capable of cooperating with the spacing tool 56, to bring the plates 2, 3 into a separated position (corresponding to the mounting position described with reference to the threaded fastening element 1).

 This separated position, authorized by the elastic deformability of the connecting portion 4, is capable of defining between the end edge 17 of the collar 13 and the plate 3, sufficient play to allow the insertion therein of the element 25. When the collar 13, whose axial extension is substantially equal to the thickness of the element 25, has been arranged, as already described, in line with the hole 27, and if the tool d is released 'spacing 56, the connecting portion 4 tends to replace the plates 2, 3, by clicking in the rest position, by exerting an elastic return action and thus allowing the insertion of the collar 13 in the hole 27; at this time, the insertion of a screw, in the same manner as described above, allows the final tightening of the threaded element 50 and the fixing of various components on the element 25, always by interposition between the plates 2, 3 of the spacer collar 13, which prevents excessive approximation thereof, even when the screw is tightly tightened.

 With reference to FIGS. 6 to 8, in which details similar or identical to those already exposed are indicated by the same references, 60 designates another variant of the threaded fastening element according to the invention, which further comprises a third substantially cylindrical collar 61, which extends perpendicularly in overhang from a face 62 of the plate 2, opposite to the face 15 facing the plate 3. The collar 61 is substantially coaxial with the collar 13 and defines, with the latter, the hole 11. The threaded fastening element 60 is for the rest completely similar to the element 1 described above.

 If, as is preferable, the threaded fastening element 60 is made of a folded and cut metal sheet, the collar 61 is also defined, like the collars 13, 14, by a stamped and semi-cut portion of the plates 2, 3; in particular, the third collar 61 is carried by a half 63 of the plate 2 folded back at 1800, to define the face 62 of the plate itself.

In the example shown, the collar 61 is capable of receiving inside, by screwing, the self-tapping screw 31.

 As is evident from FIG. 8, the third collar 61 performs a function equivalent to that of the collar 14 in variants 1 and 50, while the collar 14 now has the function of replacing any socket applied to the component 30 to be fixed and is particularly suitable for making couplings with possibilities of relative rotation between the component 30 and the element 25. The collar 13, inserted between the plates 2, 3, always has the function of a spacer between the pads, preventing their excessive approximation even in the case of a tightly tightened screw 31.

 Finally, to the threaded fastening element described above can be made other modifications and variants without departing from the scope of the present invention.

 For example, the plates 2 and 3 can each be provided with a plurality of holes, so as to be able to receive an equivalent number of screws.

Claims (14)

 1. Tapped fixing element (1) for coupling with a corresponding screw (31), comprising a first substantially flat plate (2) and a second plate (3) and a deformable connection portion (4), making these plates (2, 3) integral with one another, in a substantially opposite position, along corresponding sides (5, 6) thereof, the first and second plates being respectively provided with '' a first hole (11) and a second through hole (12) for the insertion of the screw (31), the deformable connection portion (4) being able to selectively support the plates (2, 3) in a first operational position (la), for mounting, in which the plates (2, 3) are at a first predetermined angle relative to each other, and in a second operational position (lb), for use, in which the plates (2, 3) lie at a second predetermined angle, one with respect to to the other, characterized in that it further comprises spacing means (13) making it possible to maintain the plates (2, 3), after they have been brought into the second operational position (lb), a predetermined distance and making it possible to prevent a later approaching of these, the spacing means (13) being in one piece with the first plate (2).  2. tapped fixing element according to claim 1, characterized in that the spacing means comprise at least a first collar (13), substantially cylindrical, delimiting the first hole (11) and extending perpendicularly, in door-to - false, from a first face (15) of the first plate (2), facing the second plate (3), the first collar (13) having an end edge (17), opposite to a connecting edge (16) to the first plate (2), capable of cooperating by application against a stop surface  (19) of the second plate (3), facing the first plate (2).  3. tapped fixing element according to any one of claims 1 and 2, characterized in that the second plate (3) is provided with at least one second collar  (14), substantially cylindrical, delimiting the second hole  (12) and extending perpendicularly, in overhang, from a face (18) of the second plate (3) opposite the abutment surface (19) thereof.  4. tapped fastening element according to any one of claims 2 and 3, characterized in that in the operational position of use (lb), the pads  (2, 3) are arranged substantially parallel to each other, the first collar (13) being placed between the plates  (2, 3), substantially perpendicular thereto, the first and second through holes (11, 12) being substantially aligned with each other and with the first collar  (13), so as to define a single seat (33) for the pass-through insertion of the screw (31).  5. tapped fixing element according to any one of claims 2 to 4, characterized in that the second plate (3) is further provided, on a side opposite to the deformable connection portion (4), with an edge (20) folded in the opposite direction to the first plate (2).  6. tapped fixing element according to any one of claims 2 to 5, characterized in that the portion  (4) of connection is plastically deformable, the first predetermined angle at which the plates are located  (2, 3) in the mounting position (la) being as it defines between the edge (17) of the end of the first collar  (13) and the second plate (3), a clearance allowing the insertion therein of an element (25) of thickness substantially equal to the axial extension of the first collar  (13).  7. tapped fixing element according to any one of claims 2 to 5, characterized in that the portion  (4) of connection is elastically deformable and is shaped so as to support, at rest, the plates  (2, 3) substantially in the position of use (lb), or in a position slightly offset from the position of use.  8. tapped fixing element according to claim 7, characterized in that it comprises gripping means (17, 52, 53), arranged integral with the two plates (2, 3) and capable of cooperating with a tool  (56) of external spacing, the portion (4) of elastically deformable connection being capable of allowing a spacing between the plates (2, 3), so as to define between the edge (17) of the end of the first collar  (13) and the second plate (3), a clearance allowing the insertion therein of an element (25) of thickness substantially equal to the axial extension of the first collar (13).  9. tapped fixing element according to claim 8, characterized in that the gripping means comprise the end edge (17) of the first collar (13) and at least one housing (52, 53) for the insertion of a respective tooth (54, 55) of the spacer tool (56), the housing (52, 53) being arranged in line with an end portion (51) of the second plate (3), opposite to the deformable and folded L-shaped connecting portion (4) on the side opposite to the first plate (2).  10. Tapped fixing element according to any one of claims 3 to 9, characterized in that it is made of a folded and cut metal sheet and in that the first collar (13) and the second collar (14) are defined by corresponding pressed and semi-cut portions of, respectively, the first plate (2) and the second plate (3).  11. tapped fixing element according to claim 10, characterized in that the second collar (14) is capable of receiving inside, by screwing, the screw (31).  12. Tapped fastening element according to claim 6 or 7, characterized in that the first plate (2) is provided with a third substantially cylindrical collar (61), extending perpendicularly in overhang from a second face (62) of the first plate  (2), opposite the first face (15), substantially coaxial with the first collar (13) and defining the first hole (11) with the latter.  13. Tapped fastening element according to claim 12, characterized in that it is produced in a folded and cut metal sheet, the collars (13, 14, 61) being defined by stamped and semi-cut portions corresponding to the plates ( 2, 3), the third necklace  (61) being carried by one half (63) of the first plate (2) folded back at 1800 to define the second face  (62) of the first plate (2).  14. tapped fixing element according to claim 13, characterized in that the third collar (61) is capable of receiving inside, by screwing, the screw (31)