SPACING FASTENER

Abstract

A spacing fastener comprises a head and a shaft adjoining the head and ending with a tip. The shaft comprises an anchoring screw thread, an under-head screw thread closest to and ending near the head, and a non-threaded shaft portion therebetween. A support element at a distance circumferentially from the screw-thread end of under-head screw thread forms contact point (Au) therewith. In the region overlapping with under-head screw thread in top view, the support element is spaced apart therefrom and forms a contact point (As) for an outer shell lying between the head and under-head screw thread. The distance of contact point (As) from the head is greater than or equal to difference between the distance of contact point (Au) from the head and a tolerance distance of at most 15% of the major diameter of the under-head screw thread. The support element extends lengthwise over less than 150?.

Claims

1-15. (canceled)

16. A spacing fastener (10, 30, 40) for fastening an outer shell (20) to a substructure, comprising a head (12), and a shaft adjoining the head (12) and ending in a tip, wherein the shaft bears an anchoring screw thread for tension-resistant anchoring in the substructure, and comprises an under-head screw thread (14) closest to the head; there is a non-threaded shaft portion (17) between the under-head screw thread (14, 34, 44) and the anchoring screw thread (18); the under-head screw thread (14, 34, 44) ends close to the head (12) and comprises an under-head screw thread pitch (P.sub.U), wherein, in addition to the under-head screw thread (14, 34, 44), a support element (16) is formed at a distance, in the circumferential direction, from the screw thread end of the under-head screw thread (14, 34, 44), which under-head screw thread (14, 34, 44) forms a contact point (A.sub.U), the support element is spaced apart from the under-head screw thread in the region in which the support element overlaps with the under-head screw thread in a top view, wherein the support element (16) forms a contact point (A.sub.S) for an outer shell (20) located between the head (12) and the under-head screw thread (14, 34, 44), the distance of the contact point (A.sub.S) 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 (A.sub.U) of the under-head screw thread (14, 34, 44) from the head and a tolerance distance DD, which is at most 15% of the outside diameter (D.sub.A) of the under-head screw thread (14, 34, 44), and the length of the support element extends over an angular extent (gamma) which is less than 150?.

17. The spacing fastener according to claim 16, wherein the beginning of the support element (16, 36, 46) is located at a greater distance from the head than the contact point (A.sub.U) of the under-head screw thread (14, 34, 44).

18. The spacing fastener according to claim 16, wherein the under-head screw thread (14, 34, 44) is a single-start thread.

19. The spacing fastener according to claim 16, wherein the pitch (P.sub.U) of the under-head screw thread (14, 34, 44) is greater than the rise in the support element (16, 36, 46).

20. The spacing fastener according to claim 16, wherein the under-head screw thread (14, 34, 44) ends abruptly.

21. The spacing fastener according to claim 16, wherein the angular distance (alpha) between the contact point (A.sub.S) of the support element (16, 36, 46) and the contact point (A.sub.U) of the under-head screw thread (14, 34, 44) is between 110? and 190?.

22. The spacing fastener according to claim 16, wherein the angular distance (beta) between the end of the under-head screw thread (14, 34, 44) and the beginning of the support element (16, 36, 46) is between 50? and 150?.

23. The spacing fastener according to claim 16, wherein the minimum distance of the support element (16, 36, 46) from the under-head screw thread in the region in which the support element overlaps with the under-head screw thread in top view defines a clearance height (H) which is greater than 0.4 mm.

24. The spacing fastener according to claim 16, wherein the support element (34) has two flanks.

25. The spacing fastener according to claim 24, wherein the tip angle of the support element (16, 36, 46) corresponds to that of the under-head screw thread (14).

26. The spacing fastener according to claim 24, wherein the flank of the support element (16, 36) facing the screw tip forms an angle (sigma_2) with the plane (E), which is orthogonal to the screw axis (A), which angle is smaller than the angle (phi_2) of the flank of the under-head screw thread facing the screw tip.

27. The spacing fastener according to claim 16, wherein the flank of the under-head screw thread (16, 36) facing the screw tip forms an angle (phi_2) with the plane (E), which is orthogonal to the screw axis (A), which angle is greater than the angle (phi_1) of the flank of the under-head screw thread facing the screw tip.

28. The spacing fastener according to claim 24, wherein the support element (16, 36) has a cross-section which corresponds to the cross-section of the under-head screw thread (14, 34) mirrored at the plane (E) which is orthogonal to the screw axis.

29. The spacing fastener according to claim 16, wherein the anchoring screw thread has the same pitch as the under-head screw thread (14, 34, 44).

30. An assembly, comprising a substructure, the spacing fastener as described in claim 16, wherein the spacing fastener is anchored in the substructure, wherein an outer shell is held in place between the head and the under-head screw thread, with the thickness of the outer shell being less than the minimum axial distance between the support element and the under-head screw thread.

Description

[0049] Additional advantages, features and possible applications of the present invention will be apparent from the description which follows, in which reference is made to the embodiments illustrated in the drawings.

[0050] In the drawings,

[0051] FIG. 1a is a view of a spacing fastener according to the invention;

[0052] FIG. 1b is a view of the head area of a spacing fastener according to the invention;

[0053] FIG. 2a is a detailed view of the lower head area of the spacing fastener of FIG. 1;

[0054] FIG. 2b is a cross-sectional view of FIG. 1;

[0055] FIG. 3a is a cross-sectional view of the under-head screw thread of FIG. 1;

[0056] FIG. 3b is a cross-sectional view of the support element of FIG. 1;

[0057] FIG. 4a is a view of the head area of another embodiment of a spacing fastener according to the invention;

[0058] FIG. 4b is a cross-sectional view of FIG. 4a; and

[0059] FIG. 5 is a view of the head area of yet another embodiment of a spacing fastener according to the invention.

[0060] FIG. 1a is a side view of a spacing fastener 10 according to the invention, with a head 12 and a shaft 13, which latter in this example terminates in a drill tip. The shaft 13 has an under-head screw thread 14 of an outer diameter D.sub.A, and an anchoring screw thread of an outer diameter D.sub.V. In the present embodiment, the outer diameter D.sub.A is slightly larger than D.sub.V. The difference can therefore also preferably be less than 10%. More preferably, however, the outer diameters D.sub.A and D.sub.V can also be the same.

[0061] The pitch each of the under-head screw thread P.sub.U and of the anchoring screw thread P.sub.V 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 made to engage with the spacing fastener 10 at the same time.

[0062] Between the anchoring screw thread 18 and the under-head screw thread 14 there is a non-threaded section 17, as is common for spacing fasteners.

[0063] In this example, the ratio Q1=D.sub.K/D.sub.A is 0.67, and Q2=P.sub.U/D.sub.A is 0.29. As can be seen from Q2, the under-head screw thread has a relatively small pitch P.sub.U. As the pitch of the under-head screw thread 14 corresponds to the pitch of the anchoring screw thread 18, this type of spacing fastener 10 is particularly suitable for use in a metal substructure.

[0064] The spacing fastener 10 according to the invention has a support element 16 according to the invention in the area of the outlet of the under-head screw thread 14 facing the head 12. This is illustrated in more detail in the detail view of FIG. 1b.

[0065] The distance fastener 10 shown there connects a substructure 22 to an outer shell 20. An insulating material can be inserted between the substructure 22 and the outer shell 20.

[0066] FIG. 1b shows the head area of a spacing fastener 10 according to the invention. The fastener has a head 12 with drive features, which is connected to a shaft 13. The shaft 13 has an under-head screw thread 14.

[0067] In addition to the under-head screw thread, a support element 16 is formed on the shaft 13. The support element 16 is arranged at a distance from the thread runout of the under-head screw thread 14.

[0068] The support element 16 also extends over an angular extent of 125?, as can be seen in FIG. 2b, so that the contact points formed by the thread runout of the under-head screw thread and the support element are arranged at a distance from each other.

[0069] FIG. 2a is a detailed view of the under-head area of the spacing fastener of FIG. 1, in a position rotated by a quarter turn.

[0070] Seen in FIG. 2a is the contact point A.sub.S on the support element 16, at which the support element 16 is at its minimum distance D.sub.S from the head 12. The under-head screw thread 14 runs out abruptly at its end point 15. At this point, the under-head screw thread 14 is at a distance D.sub.U from the head 12.

[0071] According to the invention, the load flank of the support element 16 begins below the contact point A.sub.U of the under-head screw thread 14 as viewed in the axial direction, which in this case corresponds to the load flank at the thread runout of the under-head screw thread 14.

[0072] The beginning of the support element is at a distance D.sub.Sstart from the head. The distance D.sub.u is therefore smaller than the distance D.sub.Sstart.

[0073] This ensures that the support element 16 can grip softly under the outer shell 20 as the spacing fastener 10 is being screwed in, which prevents the support element from being destroyed in the screw-in process.

[0074] Furthermore, the tolerance distance D.sub.D, which is at most 15%, preferably at most 10%, of the outer diameter D.sub.A of the under-head screw thread, is shown. The contact point A.sub.S is preferably located at the same distance from the head as the contact point A.sub.U of the under-head screw thread, but can also be at a distance from the contact point A.sub.U of the under-head screw thread 14 in the direction of the head within the tolerance distance D.sub.D. In relation to the distance from the head, the distance of the contact point A.sub.S is greater than or equal to the difference between the distance of the contact point A.sub.U and the tolerance distance D.sub.D.

[0075] This keeps the tilting of the outer shell within narrow limits.

[0076] FIG. 2b is a cross-sectional view of FIG. 1, which is rotated. The under-head screw thread ends abruptly at its end point 15, which also forms the contact point A.sub.U of the under-head screw thread 14.

[0077] Starting from the end point 15, the beginning of the support element 14 is spaced counterclockwise at an angular distance beta. In the present case, beta is 60?, because a larger distance is not possible with the under-head screw thread which would still allow the minimum distance H between the support element 16 and the under-head screw thread 14 to be maintained. The support element 16 extends over an angular extent gamma. This is 125? in this case. This length allows the support element 16 to be easily produced by rolling.

[0078] The angular distance alpha is the angular distance between the contact point A.sub.U of the under-head screw thread 14 and the contact point A.sub.S of the support element 16. Although the angular distance alpha here is only around 122?, instead of the desired value of 180?, this can only be achieved for the present thread pitch because the cross-sectional shapes of the support element 16 and the under-head screw thread 14 are matched to each other. This is illustrated in more detail in FIGS. 3a and 3b.

[0079] The under-head screw 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.

[0080] The two cross-sectional shapes have identical flank angles, but are mirrored at the orthogonal.

[0081] FIG. 3a shows part of the cross-section of the under-head screw 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 includes a flank angle of phi_2 with the plane E. Preferably, phi_1 is selected to be smaller than phi_2 for the under-head screw thread. In the case of the spacing fastener according to the invention, phi_1 is 10? and phi_2 is 35?.

[0082] FIG. 3b shows part 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.

[0083] In this way, the opposing flanks on the support element 16 and on the under-head screw thread 14 are formed with a small flank angle phi_1 and sigma_2, so that there is an improved clearance height H at the core diameter between the under-head screw thread and the support element 16.

[0084] The position of the threaded tip of the under-head screw thread runout and of the radially outermost point of the support element 16 is preferably in approximately the same plane orthogonal to the screw center axis.

[0085] In this design with the same thread pitch and correspondingly thin sheet thickness, a double 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 in the outer shell.

[0086] However, the support element according to the invention provides a support with the necessary clearance height without the support element and the under-head screw thread coming too close to each other in their course and thus hindering the passage through the outer shell.

[0087] The distance between the point of the load flank of the under-head screw thread that is 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 tilting tendency is significantly reduced even under high wind pressure.

[0088] The circumferential distance between the under-head screw thread and the support element makes it easier to change the geometry and offset between the under-head screw thread and the support element than would be the case with a continuous thread.

[0089] FIG. 4a is a view of another embodiment of a spacing fastener 30 according to the invention, of a design similar to that of FIG. 1, in which the support element 36 and the under-head screw thread 34 are also asymmetrical and mirrored. In the embodiment of FIG. 3, the ratio Q2 is approximately 0.4, with Q1 corresponding to that of FIG. 1. Such a ratio is particularly suitable for screwing into a wooden substructure.

[0090] FIG. 4b is the sectional view IVB-IVB, in which it is clearly seen that the support element 16 extends over the same angular extent gamma, but the position differs from the embodiment of FIG. 1. Because the pitch of the under-head screw thread P.sub.U is higher in the case of the spacing fastener 30 than in the embodiment of FIG. 1, the support element 36 can be spaced further away from the contact point A.sub.U of the under-head screw thread and still provide a sufficient clearance height H.

[0091] The angular distance between the contact point A.sub.U of the under-head screw thread and the contact point of the support thread A.sub.S is 180? in this case. Because the under-head screw thread 34 ends abruptly at the contact point, the angular distance beta between the end of the under-head screw thread and the beginning of the support element is 117.5?.

[0092] The view of FIG. 5 is another embodiment of a spacing fastener 40 according to the invention, which fastener has a ratio of Q2 of approximately 0.65. Such a design of the under-head screw thread 44 corresponds to an anchoring screw thread, which is preferably suitable for fastening in a concrete component.

[0093] In this embodiment example, the cross-sectional shape is the same for the support element 46 and for the under-head screw thread 44, in particular as seen in FIG. 3a. Owing to the rather 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 under-head screw thread 44 and the support element 46.

[0094] Thanks to the nevertheless short and spaced support element, a spacing fastener 40 with an improved sealing effect can easily be produced with the same core diameter and the same tube diameter throughout. Alternatively, if the under-head screw thread 44 is to have a larger outer diameter than the anchoring screw thread, only a slight upsetting of the under-head area is necessary before rolling.

[0095] In the embodiment illustrated in FIG. 5, the contact point A.sub.S of the support screw thread and the contact point A.sub.U of the under-head screw thread are spaced at the same distance from the head.

[0096] The angular distances and the angular extent correspond to those of FIG. 4b.