CENTERING DEVICE, MOUNTING ARRANGEMENT AND THEIR USE

Description

[0001] The present invention relates to a centering device used to position a fastener, such as a self-drilling screw or a drill bit, at a predefined location within a hole or slot. The centering device is integral, meaning it forms part of the component that is to be fastened to a substructure or other structural element by means of a fastener.

[0002] Furthermore, a fastening arrangement consisting of a component with a centering device and fastener is described. BACKGROUND

[0003] In the construction industry today, functional building envelopes are created, particularly in office and commercial buildings, which must meet high standards in terms of safety, transparency, insulation, as well as design and maintainability. Especially with sophisticated architecture, the technical fastening of facade elements must be carried out in such a way that the overall appearance of the building is not negatively affected.

[0004] The human eye is capable of detecting individual, incorrectly installed facade panels as deviations from the pattern on an evenly clad facade. Avoiding this places high demands on the quality of the installation. At the same time, however, it must be taken into account that, due to the different thermal stresses on the facade panels and the supporting substructure, fastening solely with fixed points is not possible.

[0005] Especially with narrow joints between facade panels, deviations of just a millimeter can become problematic. Such a difference can be caused, for example, by an installer not positioning a fastener with pinpoint accuracy. When tightening the screw, it's quite possible that the facade panel is pulled or pushed slightly in a certain direction at the fastening point. If the fastener is a self-tapping screw engaging in a metal or wooden substructure, subsequent corrections are very difficult and expensive to implement. STATE OF THE ART

[0006] There are several approaches in the prior art to solving this problem. For example, drilling jigs, as described in DE 200 08 638 U1, are known. These consist of a guide unit for a drill bit in the form of a hollow cylinder with a conical point at its end facing the drilling side. The cone is placed onto a through-hole in the component to be fastened. This through-hole has a diameter larger than the hole to be drilled. A disadvantage, particularly for the application mentioned above, is that the setting process requires pre-drilling the substructure and the use of an additional tool. Alternatively, EP 3 960 963 and 3 564 464 describe centering sleeves that can be attached to a self-drilling screw and provide centering during the critical time period until the tip of the screw has sunk into the material.

[0007] With centering sleeves designed in this way, there is a residual risk that sleeve fragments may become trapped in the borehole. This can occur particularly if the screw has a high feed rate during installation and / or the sleeve fragments cannot be ejected laterally quickly enough. Especially when a self-drilling screw equipped in this way is to be installed in a recess, such centering sleeves may be unsuitable.

[0008] Document US 2010 / 088988 A1 describes plastic facade elements that can be attached directly to a substrate, for example, with a nail. For this purpose, a series of openings, designed as elongated slots, are provided in the edge area of ​​the facade element. A thin layer of material narrows the slots into elongated openings that serve as a centering aid. At a defined point, the elongated opening can be widened or narrowed, or a mark can be applied, to indicate the preferred insertion point for the fastener.

[0009] A centering device according to the preamble of claim 1 is known from US 2012 / 266545 A1.

[0010] The present invention therefore aims to avoid the disadvantages of the prior art, in particular to enable safe and simple assembly of components of the described type and to allow a centered and guided placement of a fastener. DESCRIPTION OF THE INVENTION

[0011] For the purposes of this invention, a fastening point is understood to be an opening in a component through which a fastener can be inserted. This fastener, after the setting process is complete, holds the component in a defined position on a substrate or substructure. A fastening point can be either a fixed point or a sliding point. Specifically, in the case of a sliding point, such as an elongated hole, the component can move within certain limits along the longitudinal axis defined by the opening. Functionally similar fastening points with structural differences or variations are also included.

[0012] Specifically, the problem is solved by a centering device at the mounting point of a component according to the features of the independent device claim. The dependent features describe useful variants and further developments of the invention.

[0013] The present invention describes a centering device suitable and designed for guiding a fastener or drill bit during the setting process. The centering device is arranged in or on a through-opening of a component, the through-opening constituting a fastening point of the component. The component is a substantially flat, plate-shaped metal part with a front and a back. These two define, at least in the region of the fastening point, two substantially parallel planes with a distance S between them. The fastening point thus represents a through-opening in the component between the front and back. In particular, the component can be a tab or a bracket that is attached on one side to a facade element and on the other side to a substructure. However, the functionality and benefits of a centering device described herein are not limited to this application.

[0014] The centering device is positioned in or near the plane of the back side within the through-hole. The front side refers to the side of the component facing the installer during the installation process, while the back side faces the substructure to which the component is to be attached.

[0015] A centering device essentially consists of a collar and connecting elements between the collar and the edge of the through-hole. The collar's shape can be described as essentially flat and ring-shaped, and it is formed from the component's metal. The collar may, but does not necessarily have to, bead-shaped in the sense that it is thicker than the connecting elements. The central opening of the collar forms a centering seat for a fastener during its installation. The term "ring-shaped" here does not necessarily refer to a perfect circle, but can also encompass a somewhat irregularly shaped structure with a closed edge and a central opening, as long as it functionally fulfills the criteria described here.

[0016] The collar is connected to the edge of the through-opening at the attachment point via at least one web, a plurality of webs, or a connecting surface. The web and connecting surface constitute the connecting elements; the collar is thus held in the through-opening by the webs or the connecting surface. This defines a target position of the collar relative to the edge of the through-opening.

[0017] One characteristic here is that the material thickness h of the bridge(s), collar, or connecting surface is significantly less than the thickness S of the metal part in the area around the opening. Mathematically, this means h << S. The material thickness is determined, as is common knowledge, by the colloquial definition of material thickness. As mentioned above, the collar and connecting elements can have different thicknesses locally, but the aforementioned condition remains fulfilled.

[0018] The collar, web(s), or connecting surface is preferably integrally formed, i.e., connected to the metal part or component itself, without any additional, inserted, clamped, or pressed-in components. Most preferably, the through-hole, collar, and web(s) or connecting surface are produced from the component itself by single- or multi-stage stamping and forming processes. This also ensures that the centering device is permanently attached to the component.

[0019] A useful value for the thickness h of a collar or fastener is less than 1 mm, preferably 0.2 to 0.5 mm. The inner diameter of the central opening of the (essentially) annular collar is between 1.5 and 2.5 mm. The nominal diameter of a suitable fastener or drill bit would be between 2.5 and approximately 4 mm, thus always larger than the central opening of the collar. By appropriate scaling and adjusting the thickness h, the functionality can also be extended to larger diameters. Centering is achieved when the collar provides support during the initial twisting motion and prevents the tip of the drill bit or fastener from slipping. Experience has shown that the collar or centering device becomes obsolete as soon as the drill bit / fastener engages centrally in the material of the substructure.

[0020] Experts know that, for example, in facade construction, different facade panels require different fastening methods. Not only the weight per panel plays a role, but also its size, the specified grid of the substructure, and, furthermore, safety and building regulations, which in turn are based on calculated wind loads and temperature fluctuations. These specifications, plus the number of brackets per panel and the number of fasteners per bracket, determine the dimensions of the fasteners, including their length, diameter, and thread. This also determines the number of fixed and sliding points.

[0021] The centering device described here is designed for single use: The material thickness is chosen so that the centering device is destroyed during the setting process and ejected from the opening, e.g., through the fastener's thread. Depending on the application, design, and material thickness, however, the centering device material can also be forced radially outward, compacted there, and remain in the through-hole. This may, under certain circumstances, result in a clamping fit rather than a purely form-fit connection of the fastener in the through-hole.

[0022] Functionally, it is of secondary importance whether the fastener has a drill point, a displacement point, or a classic screw point. The function of centering by the collar remains fundamentally the same. As is obvious to a professional, the parameters "thickness h of the collar" and "diameter of the central opening of the collar" can be adjusted to the intended application. Thus, fasteners with diameters of 4 mm, 6 mm, or more are also conceivable, which can be guided by appropriate centering devices. A linear scaling of the material thicknesses of the collar or the webs is not necessary because the initial insertion of the fastener is not done with the full diameter but with the tip, and the centering device only plays a role for this initial moment.

[0023] The installation process involves an installer providing a component with a suitable centering device, an appropriately sized fastener, and a substructure. They will fix the component to a predetermined position on the substructure – either manually or using mechanical aids. Then, using a suitable tool, they can position the fastener so that its tip is located in the central opening of the collar.

[0024] It is a common observation in any conventional fastening process that excessive initial pressure on the fastener, and thus on the substructure, is counterproductive because it increases the tendency of the drill bit or fastener to deflect laterally. Unforeseeable factors such as the surface condition of the substructure (notches), an imperfect drill bit or fastener tip, or an angled approach all play a role. The present invention minimizes or eliminates these factors by forcefully guiding the fastener during the crucial initial moments of the fastening process. The design described above, made of material only millimeters thick, may appear flimsy, but it is advantageous. An excessively thick collar could unnecessarily disrupt the main fastening process, and too much material in the through-hole can be undesirable.

[0025] In a further interpretation and in the terminology of the claims, the invention permits a fastening arrangement comprising a component with a fastening point and a centering device, as described above. It further includes a fastener, wherein the fastener essentially comprises a head with a force application, a lower head section, a threaded shank section, and a tip area. The tip area can be designed as a drill tip, a displacement tip, or a self-tapping tip.

[0026] The lower head section has a diameter DU dimensioned such that, after the setting process is complete, this lower head section forms a positive fit in the component's through-hole in at least one direction. In other words, the precise setting process ensured by the centering device will locate the fastener relative to the edge of the through-hole such that the lower head section contacts the edge at at least one point (or line) and positively restricts the component's movement at that point towards the fastener, preventing any subsequent slippage of the component in that direction after the setting process. Any clamping of the component by the head is not considered here.

[0027] If a fastener of the type described here—that is, with a lower head section whose diameter is larger than that of the threaded section (shank section with thread)—were used with a component without a centering device, the setting process could begin too close to the edge of the through-hole, and the threaded section could touch the wall of the through-hole. Inevitably, as soon as the setting process reaches the transition to the lower head section, the fastener would experience a force perpendicular to the direction of rotation. This would lead to displacement of the component, tilting of the fastener, or damage to the component. The centering device, on the other hand, ensures that the load-bearing lower head section is precisely positioned as a bearing surface for the wall of the through-hole in the component.

[0028] If the through-hole is a slot, the diameter DU of the underhead section can be selected to correspond to the diameter perpendicular to the slot's longitudinal axis (plus / minus manufacturing tolerance). If the centering device is also positioned centrally within the slot's transverse diameter, the fastener is positioned precisely so that the underhead section aligns with the slot opening without altering the component's predetermined position. Traditional fastening methods tend to center the component, whereas this method achieves the opposite. With such a slot, a sliding point is created along the slot's longitudinal axis, while a positive fit in the predetermined position is maintained perpendicular to it.

[0029] If a classic round hole is used with a centering device according to the invention, the positive locking is achieved in all directions of the fastening plane (clamping by the screw head normal to this plane is not taken into account).

[0030] The component, especially when designed as a fastening bracket for facade construction, is preferably manufactured in aluminum. Alternatively, it can also be produced in steel using stamping and forming processes. Finally, a version in plastic is also conceivable, particularly fiber-reinforced plastic using injection molding. In this case, the component, including the through-hole and centering device, would be manufactured as a single unit.

[0031] Alternatively, the invention can also be described as the use of a centering device, as explained in detail above, to guide a fastener or a drill bit during its setting process. When using a suitably designed fastener, a fastening arrangement is achieved as described above. SHORT DESCRIPTION OF THE FIGURES

[0032] Figure 1 Shows component 100 with various attachment points in an oblique view and side view. Figure 2 shows three exemplary designs of through openings with centering devices Figure 3 shows a fastener as a self-drilling screw with a lower head section suitable for an embodiment of a fastening point. Figure 4 shows a fastening arrangement DESCRIPTION OF THE FIGURES

[0033] Figure 1Figure 100 shows a component with various fastening points in a slanted view on the left and a side view on the right. Specifically, the component is designed as a tab that can connect a facade element to a substructure; see also... Figure 4 The metal part is shown as a flat component 100, here with a crank, which has an elongated hole and a round bore, each with a centering device 200, on its upper third (in the drawing). Below this is a "classic" elongated hole. The left element of the drawing shows the front 120. The two openings 140 each form a fixing point 110. The design as an elongated hole with a centering device 200 allows for a sliding point, while the right round hole forms a fixed point.

[0034] The centering device 200 in the left elongated hole is countersunk, shown in the plane of the back side 130. The thickness of the metal part is denoted by S. In the right-hand illustration of Figure 1, S' indicates the thickness of the metal part at the opposite ("lower") end. We have described component 100 as a substantially flat, plate-shaped metal part, as is known and common for the described application. Some variation (even local variation) in the thickness of the material (S') is not unusual.

[0035] We have described the openings 140 as through-holes because they provide passage for the fastener 300. However, the centering device is shown at the bottom of the opening (viewed from the front) or in the plane of the rear 130 of component 100; it partially obstructs the through-hole 140. Nevertheless, this does not make the opening 140 a blind hole.

[0036] The in Figure 1The cranked version shown on the right in side view exhibits an offset of the lower part of component 100 relative to the upper part by the distance V. This offset is not essential to the invention in the illustrated embodiment, but rather a design feature.

[0037] Figure 2 shows three exemplary designs of through openings with centering devices, which are referred to below as left, right and bottom.

[0038] The illustration on the left shows a through-hole 140 as an elongated slot with a single, centrally arranged centering device 200. The collar 210 is designed as an irregularly shaped ring around the central opening 220, which transitions on two opposite sides into webs 230, 235, which in turn transition into the longitudinal sides of the elongated slot. The illustration "below" shows a variant of an elongated slot, in which the collar 210 is connected to the edge of the elongated slot only on one side via a web 230.

[0039] The illustration on the right shows an embodiment of a centering device 200 with a round hole as a through-opening 140. The collar 210 around the central opening 220 seamlessly transitions into the connecting surface 240, which connects the collar 210 to the edge of the through-opening 140. AK denotes half the diameter of the through-opening 140. This diameter corresponds approximately to the diameter DU of the lower head section of the fastener 300, with appropriately designed tolerances to achieve a snug fit.

[0040] Figure 3Figure 1 shows a fastener 300 as a self-drilling screw with a drill point 360. The essential components, shown in the figure from top to bottom, are the head 310 with a countersunk force engagement 315, the underhead section 320 with diameter DU, a short unthreaded shank section 330, a threaded shank section (340), and a tip section 350 with the drill point 360. The nominal diameter DN of the fastener is measured as usual via the thread crests; the diameter of the drill point DS is known to be smaller than DU to allow for the thread-forming properties of section 340. Overall, DS < DN < DU.

[0041] The type of force application 315 is selected by the specialist according to the requirements and his expertise.

[0042] A threadless shank section 330 is preferred; with appropriate dimensioning of the substructure, it allows the thread to penetrate a load-bearing plate of the substructure, and this load-bearing plate to lie within the area of ​​section 330. This prevents the opening created by the fastener (self-tapping screw) from being torn out by the fastener's thread when the fastener is overtightened during the setting process, which can severely impair the pull-out forces of the fastening arrangement. The thread 340 can be single-start or double-start.

[0043] Figure 4 Figure 400 shows a fastening arrangement with a facade element 420 to which a component 100 – here designed as a tab – is attached. The component 100 can be screwed to the substructure 410 using the fastener 300. Pre-drilling the substructure 420 is analogous when using a fastener 300. Figure 3Not necessary. If a purely thread-forming, non-self-drilling fastener is to be used, a centering device according to the present invention can also serve a drill bit to create a precisely positioned opening.

Claims

1. Centering device (200) for guiding a fastener (300) or a drill during the setting process, comprising a component (100) having at least one fastening point (110), wherein the component (100) is a substantially flat, plate-shaped metal part with a front side (120) and a rear side (130) that define two substantially parallel planes spaced apart by a distance S, at least in the region of the fastening point; wherein the fastening point (110) represents a through-hole (140) in the component between the front side (120) and the rear side (130), wherein the centering device (200) is arranged in or near the plane of the rear side (130) in the through-hole (140) and comprises a collar (210) and connecting elements between the collar and the edge of the through-hole, wherein - the collar (210) has a substantially flat to bead-shaped, annular shape and is formed from the metal of the component, - wherein the central opening (220) of the collar (210) forms a centering seat for a fastener (300) or drill during the setting process; - and the collar is connected to the edge of the through-hole (140) of the fastening point (110) via at least one web (230, 235) or connecting surface (240) as connecting elements; characterized in that the h << S applies to the material thickness h of the web(s) (230, 235), the collar (210) and the solid surface (240).

2. Centering device (200) according to claim 1, characterized in that its collar (210) and web(s) (230, 235) or connecting surface (240) are integrally formed without additional, inserted, clamped, or pressed-in components.

3. Centering device (200) according to claims 1-2, characterized in that the through-hole (140) of the fastening point (110), the collar and web(s) or the connecting surface (240) are produced from the component (100) itself by means of one or more stages of punching and forming steps.

4. Centering device (200) according to claims 1-3, characterized in that, measured in the direction of the specified setting process, the thickness of the collar is less than 1 mm, preferably 0.2 to 0.5 mm.

5. Centering device (200) according to claims 1-4, characterized in that the inner diameter of the central opening 220 of the annular collar (210) is between 1.5 and 2.5 mm.

6. Fastening assembly (400) consisting of a component (100) with a fastening point (110) with a centering device (200) according to claims 1 to 5 and a fastener (300), wherein the fastener (300) substantially comprises a head (310) with a force application point (315), an underhead section (320), a threaded shaft section (340) and a tip area (350), characterized in that the fastener (300) has a diameter DU in the underhead section (320) which is dimensioned such that, after completion of the setting process, this underhead section forms a positive connection in at least one direction in the through-hole (140) of the component (100).

7. Use of a centering device (200) according to claims 1-5 for guiding a fastener (300) or a drill during its setting process to produce a fastening assembly according to claim 6.