Drive-in anchor and anchor assembly having at least one such drive-in anchor

Abstract

The invention relates to a drive-in anchor and an anchor assembly having at least one such drive-in anchor, wherein the drive-in anchor is equipped with a shaft and a head integrally formed at one end thereof, the shaft having at least one anchoring portion which extends at least over a sub-region of the shaft length in which the drive-in anchor is to be secured in an anchor opening in an object, the anchoring portion being designed in the manner of a thread and having at least one thread turn with a rounded flank crest portion.

Description

[0001] DRIVE-IN ANCHOR AND FASTENING ARRANGEMENT WITH AT LEAST ONE SUCH DRIVE-IN ANCHOR

[0002] The invention relates to a drive-in fastener and a fastening arrangement formed by at least one such drive-in fastener connecting objects, such as planks for scaffolding.

[0003] Drive-in fasteners are fasteners that are fixed into a substrate by means of a blow, for example, with a hammer or a suitable power tool. If a connection between two or more objects is to be detachable, screw fasteners are used instead of drive-in fasteners. An example of a detachable connection between two objects is the connection of walkways in scaffolding construction, as described in EP 2 642 045 B1. These walkways are made of profiled metal sheets. For slip resistance, they are designed with perforations arranged in a grid pattern, with the edges of the perforations being crimped or beaded to form collars projecting from the plank's surface.The raised, flanged end faces of the perforation area, which extend away from the flat surface of such a walkway, constitute the walkable and, due to this design of the perforation edges, slip-resistant walking surface. The collar formation is oriented in the opposite direction to adjacent openings. Therefore, there are openings where the raised collars point upwards from the walking surface and others where they point downwards. To connect two such walkways, two walkways are arranged in an overlap, with at least one opening in the overlap, where the upper walkway has a downward-facing flange, aligns with one of the lower walkways. A screw fastener serves to hold the two walkways together.This fastener is screwed into place through the aligned fastener openings, with the collar of the opening providing the material against which the thread engages. To ensure a secure connection between two walkways joined by such a fastener, the thread must dig into the wall of the hole formed by the collar, as expansion due to the structural stiffening caused by the collar is not possible, at least not with the available force. A screwdriver is required to screw in the fasteners. When erecting a scaffold with such walkways, numerous overlapping arrangements as described above must be created. Due to the large number of fasteners required, this process is relatively time-consuming.

[0004] Based on this discussed state of the art, the invention therefore aims to propose a fastener, for example for forming a previously described overlap arrangement, which in principle can not only be used for other purposes, but with which the creation of an overlap arrangement described above can be carried out more quickly.

[0005] This problem is solved according to the invention by a drive-in fastener with a shaft and a head integrally formed at one end thereof, wherein the shaft has at least one anchoring section extending at least over a portion of its length in which the drive-in fastener is to be secured in a fastener opening of an object, the anchoring section being designed in the manner of a thread, the at least one thread of which has a rounded flank apex. According to the invention, a drive-in fastener is provided instead of a screw fastener, which necessarily requires a screw tool, to create a fastening arrangement. To establish the connection, it is simply driven into the aligned fastener openings of the objects to be joined.To achieve the necessary retention functionality, the drive-in fastener has a threaded section extending at least over a portion of its length, serving as an anchoring section to be secured in a fastener opening. The diameter of the anchoring section is larger than the inner diameter of the fastener opening in which the drive-in fastener is to be anchored. The fastener opening of the object in which the drive-in fastener is to be anchored is designed, with respect to its inner diameter relative to the core of the anchoring section, such that the hole edge, or parts thereof, engages between adjacent thread sections after the anchoring section is driven into this fastener opening. This creates an effective pull-out resistance.A special feature of the thread in the anchoring section is that at least one thread has a rounded flank apex. This facilitates driving the fastener into the opening and the subsequent widening of the opening, so that at least one section, for example, an edge of the widened hole rim area, engages with a snap-fit ​​between two adjacent thread sections, utilizing the material elasticity of the hole rim area. The hole rim area of ​​such a fastener is typically formed by a metal sheet whose rim area lacks end-end stiffening structures, such as a crimp. This design gives the thread a convex appearance. Such a drive-in fastener can easily be installed with a hammer blow or a suitable power tool.Due to its threaded anchoring section, the connection created with the drive-in fastener can be easily disassembled. The threaded anchoring section then serves as the unscrewing mechanism. The rounded flank apex is also advantageous for loosening, as such a drive-in fastener can generally be unscrewed from the aligned fastener opening(s) without tools. Typically, such a drive-in fastener is designed with a head featuring a rotating contour for engaging a tool. This allows the drive-in fastener to be loosened or loosened, if necessary, with a tool.

[0006] Since this drive-in fastener is set with a hammer blow, fastening arrangements in which at least two objects are connected to each other by means of one or more such drive-in fasteners can be created much faster than was conventionally possible with screw fasteners.

[0007] According to a preferred embodiment, the curvature of the flank apex is curved at least in a central flank apex section with a constant radius, this curvature extending from the apex to both sides over at least 30° and not more than 70°. An extension of 40° to 55° is considered particularly advantageous. This curved flank apex section preferably transitions directly, or via an intervening short, straight, inclined flank section, into a base section curved in the opposite direction. The radius of curvature of the base section is significantly smaller than that of the flank apex section. It is typically 3 to 7 times smaller. The base sections of two adjacent threads can transition directly into one another.It is also quite possible to design the thread in which the base sections of adjacent thread sections merge into one another via a short, straight shaft section that forms the core of the anchoring section. In a preferred design, the different curvature between the flank apex sections and the base sections is achieved such that the width of a thread at its transition to adjacent base sections is greater than the span of the adjacent base sections.

[0008] According to an advantageous embodiment, the thread of the anchoring section is single-start. The thread pitch is typically less than 10° and is particularly between 2° and 5°. For a drive-in fastener of nominal size 8 (8 mm diameter), the pitch in one embodiment is approximately 2 mm.

[0009] The threaded anchoring section can extend substantially or entirely along the length of the shaft. It is also possible to design the drive-in fastener in which the anchoring section is limited to a portion of the shaft's length, while the remaining portion is unthreaded. Furthermore, the shaft may have multiple anchoring sections in addition to its single anchoring section, or, besides its at least one anchoring section, one or more sections with a different, possibly also threaded, structure. Typically, the head molded onto the shaft extends radially beyond the shaft's maximum diameter. This is advantageous when the underside of the head is intended to act against the surface of a first object to be joined to a second.

[0010] To facilitate the location of the aligned fastener penetrations, such a drive-in fastener preferably has a locating tip that tapers towards its insertion end. This tip is typically rounded in a carpel-like shape at its end. Adjoining this section is a section with a frustoconical outer surface, which in turn transitions into the core diameter of the shaft and, if the anchoring section is directly adjacent to the locating tip, into its core diameter.

[0011] The invention is described below with reference to an exemplary embodiment and the accompanying figures. These show:

[0012] Fig. 1: A side view of a device according to the invention

[0013] Drive-in fasteners,

[0014] Fig. 2: an enlarged view of the impact side

[0015] End area of ​​the drive-in fastener of Fig. 1 and

[0016] Fig. 3: a fastening arrangement for connecting two

[0017] objects using a drive-in fastener as shown in Figs. 1 and 2.

[0018] A drive-in fastener 1 comprises a shaft 2 with a head 3 integrally formed at one end. The head 3 of the illustrated embodiment has a rotational engagement contour 4 (shown in dashed lines). The underside 5 of the head 3, facing the shaft 2, serves as a support against the surface of a first object through which the drive-in fastener 1 penetrates in a fastening arrangement. The shaft 2 has a prong 6, which is formed by a cap-shaped end tip 7 and an integrally formed section 8 with a frustoconical outer surface. The prong 6 transitions into a threaded anchoring section 9. This section serves to secure the drive-in fastener 1 in a fastener opening of an object. The thread in the anchoring section 9 is single-start and features rounded flank apex.In the illustrated embodiment, the anchoring section 9 ends shortly before the head 3 or its underside 5, starting from the finding tip 6.

[0019] The design of the anchoring section 9 is explained below with reference to the enlarged view of the same in Fig. 2. The curved flank apex of the thread of the anchoring section 9 is located in a flank apex section 10, which extends symmetrically to the flank apex over approximately 120° and, in the illustrated embodiment, over 60°. This flank apex section 10 transitions into a oppositely curved base section 11, almost directly in the illustrated embodiment. Only a very short, straight section separates the flank section 10 from the base section 11. The base section 11 transitions into the base section 11 of the adjacent thread section via an interposed, also short, straight intermediate section 12.This intermediate section 12 is cylindrical and defines the core diameter of the shaft 2 in its anchoring section 9. In the illustrated embodiment, the flank height corresponds to approximately 10% of the core diameter. In the illustrated embodiment, the drive-in fastener 1 is of nominal size 8 (core diameter 8 mm). The flank height is therefore approximately 0.8 mm. The helix angle 13, which the thread has relative to the perpendicular to the longitudinal axis L, is approximately 5° in the illustrated embodiment, corresponding to a pitch of approximately 2 mm.

[0020] Due to the different radii of curvature in the flank apex section 10 and the adjacent base sections 11, the longitudinal axial extent of the flank apex sections 10 is significantly greater than the distance between the flank apex sections 10 of two adjacent thread sections in the illustrated embodiment. In the illustrated embodiment, this longitudinal extent of the flank apex sections 10 is approximately 2 to 2.5 times greater than the distance between the flank apex sections 10 of two adjacent thread sections.

[0021] Fig. 3 shows an example of a fastening arrangement 14 in which two walkways 15, 15.1, as examples of objects to be connected, are joined together by a drive-in fastener 1. The two walkways 15, 15.1 are spaced apart from each other, with the upper walkway 15 being supported on the lower walkway 15.1 by its end-bent legs. These legs, as well as the corresponding legs of the lower walkway 15.1, are not shown in Fig. 3. Only the walkways are visible, which are spaced apart from each other due to the support arrangement described above.

[0022] Each walkway 15, 15.1 has fastener openings 16, 16.1 arranged in a grid pattern, each positioned between two anti-slip structures that point upwards from the walkway surface. The fastener openings 16, 16.1 are punched-out openings in the walkway surface 17, 17.1. The shaft 2 of the drive-in fastener 1, which passes through the two fastener openings 16, 16.1 aligned with each other, is driven into or through them with a hammer blow. The inner diameter of the fastener opening 16, 16.1 is slightly smaller than the diameter of the shaft 2 in its anchoring section 9, but larger than the core diameter. By driving the drive-in fastener 1 into the fastener opening 16, 16.1, the hole edge area of ​​the fastener opening 16, 16.1 is elastically widened slightly, so that when the drive-in fastener 1 is driven in, it is as shown in Fig.3. The hole edge is visibly engaged in the space between two thread sections. These widened hole edge areas act like barbs against a pull-out force. The rounded flank apex sections 10 ensure a gradual widening of the hole edge areas, thus preventing the risk of tearing.

[0023] If the two running boards 15, 15.1 are to be separated, the drive-in fastener 1 can be easily unscrewed from the fastener openings 16, 16.1 due to the threaded design of the anchoring section. This is generally possible without the use of a tool. A tool can be used to initially loosen the drive-in fastener 1 by applying pressure to the rotary drive 4 of the head 3.

[0024] Such a drive-in fastener 1 can also be used to connect two different objects, provided that the object located furthest from the head 3 of the drive-in fastener 1 has at least one suitable fastener opening. The object furthest from the head 3 of the drive-in fastener 1 can also be a retaining element, in whose fastener opening the anchoring section 9 of the drive-in fastener 1 is fixed or is fixed. Such a retaining element can, for example, be a sheet metal section that forms the clamping abutment in the manner of a nut.

[0025] The invention has been described with reference to exemplary embodiments. Without leaving the scope of protection described by the applicable claims, numerous further possibilities arise for the person skilled in the art.

[0026] embodiments to realize the inventive idea, without these needing to be explained in more detail within the scope of these remarks.

[0027] REFERENCE SYMBOL LIST Drive-in fastener Shank Head Rotating drive contour Washer Finding tip Tip Section Anchoring section Flank apex section Base section Intermediate section Pitch angle Fastening arrangement , 15.1 Running board , 16.1 Fastener opening , 17.1 Running surface

Claims

REQUIREMENTS 1. Drive-in fastener (1) with a shaft (2) and with a head (3) formed on it at one end, wherein the shaft (2) has at least one anchoring section (9) extending at least over a partial region of its length in which the drive-in fastener (1) is to be fixed in a fastener opening (16, 16.1) of an object (15, 15.1) and formed in the manner of a thread, the at least one thread of which has a rounded flank apex section (10).

2. Drive-in fastener according to claim 1, characterized in that the radius of curvature of the flank apex section (10) is designed with a constant radius and extends from the apex over at least 30° and typically not more than 70°, in particular over 40 to 45° in both directions.

3. Drive-in fastener according to claim 1 or 2, characterized in that the curved flank apex section (10) transitions directly or by means of an intermediate short, non-curved flank section inclined relative to the longitudinal axis of the shaft (2) into a base section (11) curved in the opposite direction.

4. Impact fastener according to claim 3, characterized in that the radius of curvature of the base section (11) is smaller, in particular 3 to 7 times smaller, than the radius of curvature of the flank apex section (10).

5. Drive-in fastener according to claim 3 or 4, characterized in that the base sections (11) of adjacent Thread sections transition directly into one another or via an interposed, uncurved section.

6. Drive-in fastener according to one of claims 1 to 5, characterized in that the thread in the anchoring section (9) of the shaft (2) is single-start.

7. Drive-in fastener according to one of claims 1 to 6, characterized in that the thread in the anchoring section (9) has a pitch of less than 10°, in particular between 2° and 6°.

8. Drive-in fastener according to one of claims 1 to 7, characterized in that the head (3) formed on the shaft (2) extends beyond the maximum diameter of the shaft (2) in a radial direction.

9. Impact fastener according to one of claims 1 to 8, characterized in that the head (3) formed on the shaft (2) is equipped with a rotary drive contour (4) for attaching a tool.

10. Drive-in fastener according to one of claims 1 to 9, characterized in that the drive-in fastener (1) has a finding tip (6) with a rounded end at its end of the shaft (2) opposite the head (3).

11. Drive-in fastener according to claim 10, characterized in that a section (8) with a frustoconical outer surface is provided between the finding tip (6) and the anchoring section (9) of the shaft (2).

12. Drive-in fastener according to one of claims 1 to 11, characterized in that the threaded anchoring section (9) extends substantially over the entire length of the shaft (2).

13. Fastening arrangement (14) with at least two objects (15, 15.1) to be fastened to one another, each of which has at least one fastener opening (16.1) for the passage of a drive-in fastener (1) according to one of claims 1 to 12, the fastener opening (16.1) of the object (15.1) located furthest from the head (3) of the drive-in fastener (1) having a material thickness in the hole edge region of the fastener opening (16.1) that is less than the distance between two adjacent flank vertices of the anchoring section (9) of the drive-in fastener (1) and a hole diameter that is smaller than the outer diameter of the shaft (2) in its anchoring section (9) but larger than the core diameter of the shaft (2) in the anchoring section (9) or this corresponds, and wherein the hole edge area of ​​this fastener penetration (16.1) is elastically and / or plastically widened by driving the drive-in fastener (1 ) with its anchoring section (9) into this fastener opening (16.1 ).

14. Fastening arrangement according to claim 12, characterized in that the two objects to be connected to each other in the fastening arrangement (14) are metal walkways (15, 15.1 ), for example for scaffolding, stage construction or the like.

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