SPACER

Description

[0001] The invention relates to a spacer fastener for fastening an outer shell of a building to a substructure.

[0002] Generic spacer fasteners for fastening outer shells to a substructure are known, for example from EP 3 415 773 A1. The outer shell is held between the head and a thread under the head. A sealing element is arranged between the head and the outer shell, which is usually arranged as a sealing washer between the head of the spacer fastener and the outer shell. When installed, the hole in the outer shell through which the spacer fastener passes is sealed. The outer shells are usually thicker than 0.35 mm, in particular between 0.4 mm and 1.0 mm. The outer shells can be cover sheets of a sandwich element, a trapezoidal sheet or similar. The space between the outer shell and the substructure can also be provided with an insulating material.

[0003] The purpose of such spacer fasteners is to fix the outer shell at a predetermined distance from the substructure with as little tension as possible.

[0004] Since the insulation material is flexible, this can result in, for example, high wind pressure on the outer shell or settlement or creep processes in the insulation material, which can lead to the sealing of the outer shell suffering as the pitch of the underhead thread increases, particularly in the case of a spacer fastener with a single-start underhead thread.

[0005] As an improvement, EP 3 415 773 A1 proposed that the underhead thread be designed as a short, multi-start thread section with a large pitch, in particular a pitch that is greater than the pitch in the anchoring section. The runouts of the individual threads of the double-start thread create two support points that reduce the tendency of the outer shell to tilt relative to the head and thus improve sealing. However, this leads to a spreading due to the larger pitch of the underhead thread. Furthermore, manufacturing is complex because the underhead area must be upset to ensure sufficient material is available for the double-start thread.

[0006] The object of the invention is to provide a spacer fastener which can be easily produced in a pressing and rolling process and in which the sealing of the passage point in the outer shell through which the spacer fastener is inserted is improved.

[0007] In a known manner, a spacer fastener for the spaced attachment of an outer shell to a substructure comprises a head and an adjoining shaft. The shaft ends in a point, in particular a hole-forming point, and carries an anchoring thread for tensile-resistant anchoring in the substructure.

[0008] The shaft has a subhead thread closest to the head, with a thread-free shaft section located between the subhead thread and the first anchoring thread, with the subhead thread running out close to the head and having a subhead thread pitch.

[0009] The underhead thread forms a support point AU at the thread runout.

[0010] According to the invention, in addition to the underhead thread, at least one support element is formed at a circumferential distance from the thread runout of the underhead thread. The support element forms a support point for an outer shell located between the head and the underhead thread.

[0011] The support element is arranged at a distance in the axial direction from the underhead thread, namely from the area of ​​the underhead thread which overlaps with the support element in the plan view.

[0012] Furthermore, the distance from the head to the support element's contact point is defined as the support element distance DS. According to the invention, the support element distance DS is greater than the distance resulting from the difference between the distance of the runout of the underhead thread and a tolerance dimension DD. The tolerance dimension DD is at most 15%, preferably at most 10%, of the outer diameter of the underhead thread.

[0013] For example, the maximum distance between the thread runout and the support point of the support element for common spacer fasteners is about 0.5 mm.

[0014] In particular, the distance between the end of the underhead thread and the head corresponds to the support element distance DS. This allows the outer shell to be supported orthogonally to the screw axis. The support element according to the invention provides an additional support point for the outer shell in addition to the end of the underhead thread, so that the tilting of the outer shell can be kept within narrow limits.

[0015] In this way, the outer shell can be lifted over the underhead thread when screwing in the underhead thread and then held clamped between the head or a sealing washer and the underhead thread.

[0016] The support element, which is circumferentially spaced from the underhead thread, reduces the tendency of the outer shell to tilt relative to the head and thus relative to the sealing element when pressure is applied to the outer shell, ensuring that the sealing element's contact pressure remains evenly distributed. In this way, the support element and the end of the underhead thread form a support level that is almost orthogonal to the screw axis.

[0017] Further according to the invention, the support element extends, when viewed from above, in the circumferential direction over an angle of extension which is less than 150°.

[0018] The angular distance between the thread runout and the beginning of the support element is preferably more than 50°. This allows the design of the support element, particularly with regard to its cross-sectional shape, to be largely independent of the design of the underhead thread.

[0019] Due to the circumferential spacing of the support element from the underhead thread and the circumferential extension of the support element over only a small extension angle, the support element according to the invention can provide a support point, whereby only relatively little material has to be displaced.

[0020] This allows for simplified manufacturing, as the shaft material in the area of ​​the underhead thread needs to be upset only slightly, preferably by less than 10% of the blank diameter, or even not at all, before rolling, while the core diameter of the underhead thread can still correspond to that of the anchoring section. This simplifies the pressing process.

[0021] The short support element, measured in the circumferential direction, also enables good passage of the outer shell between the support element and the underhead thread, even with a low thread pitch of the underhead thread.

[0022] According to a preferred embodiment, the pitch of the underhead thread corresponds to the pitch of the anchoring thread.

[0023] The same pitch means that the feed rate in the substructure and the feed rate in the outer shell in engagement with the underhead thread are the same.

[0024] This prevents the outer shell and the substructure from moving apart during the screwing process, i.e., spreading apart, as would be the case with a larger pitch of the underhead thread. This is particularly advantageous when working with sandwich elements where the outer shell is bonded to insulation.

[0025] According to a further advantageous embodiment of the invention, the support element can have flanks similar to those of a thread. This allows for particularly good shaping of the support element during the thread rolling process.

[0026] In the case of an asymmetrical design of the underhead thread, the flank facing the head, called the load flank, can have a flank angle that is smaller than the flank angle of the flank opposite the load flank.

[0027] For example, the load flank of the underhead thread can have a flank angle of 10° relative to the perpendicular to the screw axis, and the flank opposite the load flank can have an angle of 35°. The small flank angle of the load flank ensures a good contact surface for the outer shell. The flanks of the support element can be designed analogously to those of the underhead thread.

[0028] Particularly in the case of spacer fasteners intended for use in a metal substructure, the same pitch of the underhead thread and the anchoring thread results in the underhead thread also having a relatively small pitch corresponding to the anchoring thread.

[0029] Particularly with regard to a low pitch of the underhead thread, the thread flanks of the support element can be designed in such a way that they have different cross-sectional shapes.

[0030] In particular, the support element can have a cross-sectional shape that is mirror-inverted to the cross-sectional shape of the underhead thread.

[0031] For example, the load flank of the underhead thread can be arranged at a flank angle of 10° relative to the orthogonal to the screw axis, and the flank of the support element opposite the load flank can have the same angle as the load flank of the underhead thread, i.e., also an angle of 10°. The other flank can also enclose the same angle with the orthogonal, for example, 35°.

[0032] This design allows for the largest possible clearance height in the axial direction between the support element and the underhead thread with a small thread pitch.

[0033] This is particularly true for spacer fasteners that have a ratio Q1 = DK / DA between 0.6 and 0.8 and a ratio Q2 = PU / DA between 0.25 and 0.35.

[0034] As a result, even with a small pitch, the underhead thread can be easily passed through an outer shell with a usual material thickness of more than 0.35 mm, in particular of approximately 0.5 mm, since the passage of the outer shell between the underhead thread and the support element is not obstructed.

[0035] The thread crest angle between the flanks is preferably greater than 40°. This applies to the support element and the anchoring thread, as well as to the underhead thread. This facilitates thread production during the thread rolling process.

[0036] The support element has a rise along its circumference that is smaller than the pitch of the sub-head thread. This allows the support surface for the outer shell to be enlarged, especially with a large pitch of the sub-head thread, without the minimum axial distance between the sub-head thread and the support element becoming too small, and thus preferably remains greater than 0.35 mm between the adjacent thread structures.

[0037] The anchoring thread can be used in such a way that it is either screwed to the substructure or forms a positive connection with the substructure in the extension direction.

[0038] The support element is preferably designed such that the axial distance to the underhead thread decreases in the direction of the head.

[0039] Preferably, the flank facing the head at the beginning of the support element is located below the point, i.e. further away from the head, at which the flank of the under-head thread facing the head has the smallest distance from the head.

[0040] This makes it easier to guide the outer shell along the underhead thread.

[0041] The support element, with its flank facing the head, further approaches the head in its further course, preferably until it has a distance from the head that is less than or equal to the distance of the flank of the underhead thread from the head at the thread runout of the underhead thread.

[0042] The approach is preferably continuous, particularly preferably with a pitch angle of less than 45°, in particular less than 30°. This prevents scraping of the support element after the underhead thread is screwed through the outer shell and the support element is to pass through the outer shell.

[0043] The support element has a location or area with a minimum distance from the head. This location or area is preferably located opposite the location or area of ​​the sub-head thread with the minimum distance from the head in a top view. The angular distance is approximately 180°.

[0044] The angular distance is chosen to be as large as possible up to approximately 180°, but can be smaller due to the minimum distance that the lower flank must maintain from the underhead thread.

[0045] For example, with a slight gradient, the angular distance can be as high as 112.5°, with the support element already starting at an angular distance of 60°.

[0046] The underhead thread preferably tapers abruptly. This improves the load-bearing capacity in conjunction with the support element.

[0047] The smallest distance between the underhead thread and the support element is greater than half the pitch but smaller than the pitch.

[0048] Further advantages, features and possible applications of the present invention will become apparent from the following description in conjunction with the embodiments shown in the drawings.

[0049] In the drawing means: Fig. 1a a view of a spacer fastener according to the invention; Fig. 1b a view of the head area of ​​a spacer fastener according to the invention; Fig. 2a a detailed view of the lower head area of ​​the spacer fastener from Fig. 1 ; Fig. 2b cross-sectional view of the Fig.1 ; Fig. 3a a cross-sectional view of the underhead thread of the Fig. 1 ; Fig. 3b cross-sectional view of the support element of the Fig. 1 ; Fig. 4a a view of the head region of a further embodiment of a spacer fastener according to the invention; Fig. 4b a cross-sectional view of the Fig. 4a and Fig. 5 a view of the head region of a further embodiment of a spacer fastener according to the invention.

[0050] Fig. 1a shows a side view of a spacer fastener 10 according to the invention, with a head 12 and a shaft 13, which here, for example, ends in a drill bit. The shaft 13 has a subhead thread 14 with the outer diameter DA and an anchoring thread with the outer diameter DV. In the present embodiment, the outer diameter DA is slightly larger than DV. The difference can therefore preferably be less than 10%. However, the outer diameters DA and DV can also preferably be the same.

[0051] The pitch of the underhead thread PU and the anchoring thread PV are also the same, which has the advantage that the outer shell and substructure are not necessarily moved relative to each other during the screwing process if the substructure and outer shell are simultaneously engaged with the spacer fastener 10.

[0052] Between the anchoring thread 18 and the underhead thread 14 there is, as is usual with spacer fasteners, a thread-free section 17.

[0053] In this embodiment, the ratio Q1 = DK / DA is 0.67 and Q2 = PU / DA is 0.29. As can be seen from Q2, the underhead thread has a relatively low pitch PU. Since the pitch of the underhead thread 14 corresponds to the pitch of the anchoring thread 18, such a spacer fastener 10 is particularly suitable for use in a metal substructure.

[0054] The spacer fastener 10 according to the invention has a support element 16 according to the invention in the area of ​​the outlet of the underhead thread 14 facing the head 12. This is shown in the detailed view of the Fig. 1b described in more detail.

[0055] The spacer fastener 10 shown connects a substructure 22 and an outer shell 20. An insulating material can be inserted between the substructure 22 and the outer shell 20.

[0056] Fig. 1b shows the head portion of a spacer fastener 10 according to the invention. This has a head 12 provided with drive features, to which a shaft 13 is connected. The shaft 13 has a subhead thread 14.

[0057] A support element 16 is formed on the shaft 13 next to the underhead thread. The support element 16 is arranged at a distance from the thread runout of the underhead thread 14.

[0058] The support element 16 also extends over an extension angle of 125°, as shown in Fig. 2b can be seen, so that the support points formed by the thread runout of the underhead thread and the support element are arranged at a distance from each other.

[0059] Fig. 2a shows a detailed view of the underhead area of ​​the spacer fastener from Fig. 1 in a position rotated by a quarter turn.

[0060] Fig. 2a shows the support point AS on the support element 16, at which the support element 16 has its minimum distance DS from the head 12. The underhead thread 14 ends abruptly at its end point 15. At this point, the underhead thread 14 has a distance DU from the head 12.

[0061] According to the invention, the support element 16 begins with its load flank, viewed in the axial direction, below the support point AU of the underhead thread 14, which here corresponds to the load flank at the thread runout of the underhead thread 14.

[0062] The start of the support element is located at a distance D Sstart from the head. Thus, the distance DU is smaller than the distance D Sstart .

[0063] This ensures that the support element 16 can grip softly under the outer shell 20 when screwing in the spacer fastener 10, thus preventing destruction of the support element during screwing in.

[0064] Furthermore, the tolerance dimension DD is shown, which amounts to a maximum of 15%, preferably a maximum of 10%, of the outer diameter DA of the underhead thread. The support point AS is preferably located at the same distance from the head as the support point AU of the underhead thread, but can also be located at a distance from the support point AU of the underhead thread 14 in the direction of the head, within the tolerance dimension DD. Relative to the distance from the head, the distance of the support point AS is greater than or equal to the difference between the distance of the support point AU and the tolerance distance DD.

[0065] This keeps the tilting of the outer shell within narrow limits.

[0066] The Fig. 2b shows a cross-sectional view of the Fig.1 , which is rotated. The underhead thread ends abruptly at its end point 15, which simultaneously forms the support point AU of the underhead thread 14.

[0067] The beginning of the support element 14 is spaced counterclockwise from the end point 15 at an angular distance beta. In this case, beta is 60°, since a larger distance is not possible with the underhead thread while still maintaining the minimum distance H between the support element 16 and the underhead thread 14. The support element 16 extends over an extension angle gamma. This is 125° here. Over this length, the support element 16 can be easily manufactured by rolling.

[0068] The angular distance alpha is the angular distance between the support point AU of the underhead thread 14 and the support point AS of the support element 16. Although the angular distance alpha is only approximately 122° instead of the desired 180°, this can only be achieved for the existing thread pitch because the cross-sectional shapes of the support element 16 and the underhead thread 14 are matched to each other. This is shown in the Figuren 3a und 3b described in more detail.

[0069] The underhead thread has a cross-sectional shape as shown in Fig. 3a and the support element has a cross-sectional shape as shown in Fig. 3b is shown.

[0070] The two cross-sectional shapes are identical in their flank angles, but mirrored on the orthogonal.

[0071] This shows Fig. 3a A section of the cross-section of the underhead thread 14, which forms a load flank angle phi_1 with the plane E, which is orthogonal to the screw center axis A. The flank opposite the load flank encloses a flank angle of phi_2 with the plane E. Preferably, phi_1 is selected to be smaller than phi_2 for the underhead thread. Thus, in the case of the spacer fastener according to the invention, phi_1 is 10° and phi_2 is 35°.

[0072] Fig. 3b shows a section of the cross-sectional shape of the support element 16, which accordingly has a load flank angle of sigma_1 and a flank angle of sigma_2 opposite the load flank.

[0073] In this way, the flanks opposite the support element 16 and the underhead thread 14 are formed with a small flank angle phi_1 and sigma_2, so that an improved clearance height H is present at the core diameter between the underhead thread and the support element 16.

[0074] The position of the thread crest of the underhead thread runout and the radially outermost point of the support element 16 is preferably located approximately in the same plane orthogonal to the screw center axis.

[0075] In this design with the same thread pitch and correspondingly thin sheet thickness, a double-start thread would result in the distance between the two threads being too small for the support element to pass through the outer shell without a thread being formed into the outer shell.

[0076] However, the support element according to the invention provides a support with the necessary clearance height without the support element and the underhead thread coming too close to each other in their course and thus hindering the passage through the outer shell.

[0077] The distance between the point of the load flank of the underhead thread closest to the head and that of the support element can be kept small due to the choice of the cross-sectional shape of the support element, so that the tendency to tip is significantly reduced even at high wind pressure.

[0078] Due to the circumferential distance between the underhead thread and the support element, a simpler geometry change and offset between the underhead thread and the support element can be carried out than would be the case with a continuous thread.

[0079] Fig. 4a shows a further embodiment of a spacer fastener 30 according to the invention, in a similar embodiment as Fig. 1 , wherein the support element 36 and the underhead thread 34 are also asymmetrical and mirrored. In the Fig. 3 In the illustrated embodiment, the ratio Q2 is approximately 0.4, where Q1 corresponds to the Fig. 1 Such a ratio is particularly suitable for screwing into a wooden substructure.

[0080] Fig. 4b shows the sectional view IVB-IVB, in which it is clearly visible that the extension of the support element 16 takes place over the same extension angle gamma, but the position differs from the embodiment according to Fig. 1 Since in the case of the spacer fastener 30 the pitch of the underhead thread PU is greater than in the version according to Fig.1 , the support element 36 can be spaced further from the support point AU of the underhead thread and still provide a sufficient clearance height H.

[0081] The angular distance between the support point AU of the underhead thread and the support point AS of the support thread is 180°. Since the underhead thread 34 ends abruptly at the support point, the angular distance beta between the end of the underhead thread and the beginning of the support element is 117.5°.

[0082] Fig. 5 shows a further embodiment of a spacer fastener 40 according to the invention, which has a Q2 ratio of approximately 0.65. Such a design of the underhead thread 44 corresponds to an anchoring thread that is preferably suitable for fastening in a concrete part.

[0083] In this embodiment, the cross-sectional shape for the support element 46 and the underhead thread 44 is the same, in particular as shown in Fig. 3a is shown. Due to the relatively large pitch with regard to the usual sheet thicknesses of outer shells, the small flank angle of the load flank can also be maintained in the support element 46, while still ensuring a sufficient clearance height H between the underhead thread 44 and the support element 46.

[0084] The short and spaced support element allows a spacer fastener 40 with improved sealing effect to be easily produced with the same core diameter and a consistent blank diameter throughout. Alternatively, if the underhead thread 44 is to have a larger outer diameter than the anchoring thread, only a slight upsetting of the underhead area is necessary before rolling.

[0085] In the execution according to Fig. 5 the support point AS of the support thread and the support point AU of the underhead thread have the same distance from the head.

[0086] The angular distances and the extension angle correspond to those of the Fig. 4b .

Claims

1. Spacing fastener (10, 30, 40) for fastening an outer shell (20) to a substructure, which spacing fastener (10, 30, 40) has a head (12) and an adjoining shank that ends in a tip, which shank has an anchoring thread for anchoring it in the substructure in a pull-out resistant manner, and which shank has an under head thread (14) closest to the head, with a non-threaded shank portion (17) being located between the under head thread (14, 34, 44) and the anchoring thread (18), which under head thread (14, 34, 44) ends close to the head (12) and has an under head thread pitch (PU), characterized in that, in addition to the under head thread (14, 34, 44), a support element (16) is formed which is spaced at a distance, in the circumferential direction, from the screw thread end of the under head thread (14, 34, 44), which under head thread (14, 34, 44) forms a contact point (AU), which support element is spaced apart from the under head thread in the region in which the support element overlaps with the under head thread as viewed from above, which support element (16) forms a contact point (AS) for an outer shell (20) located between the head (12) and the under head thread (14, 34, 44), wherein the distance of the contact point (AS) of the support element (16, 36, 46) from the head is greater than or equal to the difference between the distance of the contact point (AU) of the under head thread (14, 34, 44) from the head and a tolerance distance DD, which is at most 15% of the outer diameter (DA) of the under head thread (14, 34, 44), with the length of the support element extending over an angular extent (gamma) that is less than 150°.

2. Spacing fastener according to claim 1, characterized in that, at its start, the support element (16, 36, 46) is at a greater distance from the head than the contact point (AU) of the under head thread (14, 34, 44).

3. Spacing fastener according to any one of claims 1 or 2 above, characterized in that the under head thread (14, 34, 44) is a single-start thread.

4. Spacing fastener according to any one of claims 1 to 3 above, characterized in that the pitch (PU) of the under head thread (14, 34, 44) is greater than the rise in the support element (16, 36, 46).

5. Spacing fastener according to any one of the preceding claims, characterized in that the under head thread (14, 34, 44) ends abruptly.

6. Spacing fastener according to any one of the preceding claims, characterized in that the angular distance (alpha) between the contact point (AS) of the support element (16, 36, 46) and the contact point (AU) of the under head thread (14, 34, 44) is between 110° and 190°.

7. Spacing fastener according to any one of the preceding claims, characterized in that the angular distance (beta) between the end of the under head thread (14, 34, 44) and the start of the support element (16, 36, 46) is between 50° and 150°.

8. Spacing fastener according to any one of the preceding claims, characterized in that the minimum distance of the support element (16, 36, 46) from the under head thread in the region in which the support element overlaps with the under head thread as viewed from above defines a passage height (H) which is greater than 0.4 mm.

9. Spacing fastener according to any one of the preceding claims, characterized in that said support element (34) has two flanks.

10. Spacing fastener according to claim 9, characterized in that the tip angle of the support element (16, 36, 46) corresponds to that of the under head thread (14).

11. Spacing fastener according to any one of claims 9 or 10 above, characterized in that the flank of the support element (16, 36) facing the screw tip forms an angle (sigma_2) with the plane (E) that is orthogonal to the screw axis (A), which angle is smaller than the angle (phi_2) of the flank of the under head thread facing the screw tip.

12. Spacing fastener according to any one of the preceding claims, characterized in that the flank of the under head thread (16, 36) facing the screw tip forms an angle (phi_2) with the plane (E) that is orthogonal to the screw axis (A), which angle is greater than the angle (phi_1) of the flank of the under head thread facing the screw tip.

13. Spacing fastener according to any one of claims 9 to 12 above, characterized in that the cross-section of the support element (16, 36) corresponds to the cross-section of the under head thread (14, 34) mirrored about the plane (E) that is orthogonal to the screw axis.

14. Spacing fastener according to any one of the preceding claims, characterized in that the anchoring thread has the same pitch as the under head thread (14, 34, 44).

15. Assembly comprising a substructure, a spacing fastener of the type specified in any one of the preceding claims which is anchored in the substructure, wherein an outer shell is held in place between the head and the under head thread, with the thickness of the outer shell being less than the minimum axial distance between the support element and the under head thread.