Connecting material

Abstract

To improve locking of a connecting member for being pressed in or embedded in a component, in the component.SOLUTION: In a connecting member having a shaft for being pressed in or embedded in a component, the shaft extends along a center longitudinal axis of the connecting member, in which the shaft is provided with ribs extending in a radial direction with respect to the shaft, and the shaft, at least partially, has a multi-leaf shaped cross-section. The circumference of the multi-leaf shaped cross-section is convexly curved over the entire length thereof and arranged between a circumscribed circle and an inscribed circle and further has regions with a larger radius and regions with smaller radius when observed from the radial direction. In the connecting member, an angular position of the regions with smaller radius and the regions with larger radius changes along the shaft when viewed along the center longitudinal axis.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a connecting element having a shaft for press-fitting or embedding into a component, the shaft extending along a central longitudinal axis of the connecting element, in which the shaft has ribs extending radially relative to the shaft and in which the shaft has at least a sectionally multilobed cross-section, in which the periphery of the multilobed cross-section is convexly curved over its entire length, in particular located between the circumscribing circle and the inscribing circle, and has, viewed in the radial direction, regions with a larger radius or smaller curvature and regions with a smaller radius or larger curvature. Summary of the Invention [Problem to be solved by the invention]

[0002] The present invention seeks to improve upon a fastening member for press-fitting or embedding into a component with respect to locking therein. [Means for solving the problem]

[0003] To this end, a connecting element having the features of claim 1 is provided according to the invention. A connecting element with a shaft for press-fitting or embedding into a component, the shaft extending along the central longitudinal axis of the connecting element, the shaft having ribs extending radially relative to the shaft, and the shaft having at least partially a multilobed cross section, the periphery of the multilobed cross section being curved, in particular convexly, over its entire length, in particular located between the circumscribing circle and the inscribing circle, and having, viewed radially, areas with a larger radius or smaller curvature and areas with a smaller radius or larger curvature, the angular positions of the areas with the smaller radius and the areas with the larger radius changing along the shaft, viewed along the central longitudinal axis. In other words, viewed over the length of the shaft, the multilobed cross section of the shaft is twisted, whereby the areas with smaller radii, which extend to the circumscribing circle of the multilobed cross section, viewed along the central longitudinal axis of the shaft, are displaced with respect to each other. The outwardly projecting areas with smaller radii are primarily responsible for locking the connecting element in the component. When the connecting element is pressed or embedded in the component, the radially projecting areas with smaller radii can be made not to overlap or align in projection or along the central longitudinal axis. This allows higher pull-out forces to be obtained. This is particularly advantageous when the connecting element according to the invention is pressed in, since the areas with smaller radii of the individual ribs of the shaft have at least partially different angular positions. The effect that occurs in conventional connecting elements, that these projecting areas with smaller radii push the material of the component radially apart, which material is no longer available for the subsequent locking of the ribs, does not occur in the connecting element according to the invention. Indeed, it is observed that when conventional connecting elements are pressed into aluminum for pressing in, the material flows very little into the transverse knurls, but is mostly just sheared off and pushed out. Thereby, only the first transverse knurl pitch, which is located at the front of the shaft, is covered with material of the component, so that the pulling force is relatively small.Furthermore, the pull-out force of conventional fasteners for press-in depends to a large extent on the tolerances of the core bore. According to the invention, the multilobed cross section of the shaft is twisted along the shaft axis, for example in a spiral shape. As a result, the high points of the knurls, which are formed by the areas of the cross section with smaller radii, are no longer aligned. As a result, the knurls or transverse knurls located further back can still absorb the material that has not yet been pushed out. As a result, the total filling of the knurls or ribs and therefore the pull-out force when pressing or embedding into the component can be significantly improved. This is especially the case when the component is made of aluminum or plastic. The ratio of the smaller radius to the larger radius varies with the dimensions of the shaft and thus with the maximum transverse dimension.

[0004] In a development of the invention, the angular positions of the region with the smaller radius and the region with the larger radius vary by a constant amount per unit length along the shaft.

[0005] In this way, a helical rotation of the lobe-shaped cross section of the shaft is produced, which has a constant pitch.

[0006] In a development of the invention, the multilobal cross section has n regions with smaller radii and the angular position varies by an angle of 360° / n along the complete length of the shaft.

[0007] In this way, it is possible that along the complete length of the shaft there are no areas with smaller radii, as a result of which particularly high pull-out forces and therefore very secure locking of the coupling element are obtained.

[0008] In a development of the invention, along the length of the shaft there are alternating regions having different multilobal cross sections.

[0009] In a development of the invention, regions having a circular cross section alternate with regions having a multilobal cross section along the length of the shaft.

[0010] In a development of the invention, within a section of the shaft having a multilobal cross section, the shaft has a multilobal cross section at each point of this section.

[0011] In this case, both the outer shape of the shaft and the core diameter of the shaft are formed in a multi-lobe shape. In this way, a shaft having ribs can be stably formed.

[0012] In a development of the invention, in a section of the shaft having a multilobal cross section, at each angular position about the central longitudinal axis, the cross section of the shaft has a wavy outer contour.

[0013] The wavy outer contour in the cutting plane containing the central longitudinal axis provides a secure locking of the connecting element in the surrounding material. This is achieved according to the invention over the entire circumference of the connecting element. Preferably, in this cutting plane, an imaginary line joining the lowest point between the two ribs or the point closest to the central longitudinal axis also runs wavy likewise.

[0014] In a development of the invention, within a section of the shaft having a multilobal cross section, the profile depth of the ribs varies by up to 50%.

[0015] In this way, it is possible to ensure that the connecting member is securely held in the pressed-in state.

[0016] In a development of the invention, within a section of the shaft having a multilobal cross section, the profile depth of the ribs varies by a maximum of 10%, in particular the profile depth is constant.

[0017] Such slight variations in profile depth or a constant profile depth provide a secure retention of the coupling member in the press fit condition.

[0018] In a development of the invention, the cross section is formed as a constant width figure.

[0019] Thereby, the transverse dimension, measured in the radial direction, of the multilobed cross section is always equal regardless of the angular position, which facilitates the formation of the connecting member by the rolling tools, in particular the rolling jaws.

[0020] In a development of the invention, the cross section has three regions with a smaller radius or greater curvature and three regions with a larger radius or smaller curvature.

[0021] Viewed circumferentially, the cross section thus has three outwardly projecting regions, i.e. regions with smaller radii or greater curvatures, the vertices of which lie on the circumscribing circle, and three regions with larger radii or smaller curvatures, the vertices of which lie on the inscribing circle. The regions with smaller and larger radii are uniformly spaced apart from one another. Cross sections of this kind can be produced cost-effectively with high precision and in large quantities using rolling methods, in particular with rolling jaws.

[0022] In a development of the invention, the periphery of the cross section is formed continuously without corners.

[0023] This also facilitates the formation of the coupling member according to the present invention.

[0024] In a development of the invention, the ribs extend at least partially in the circumferential direction.

[0025] The circumferential ribs allow a high and sufficient press-in force to be achieved.

[0026] In a development of the invention, the angular position of the areas with smaller radii or larger curvature and the areas with larger radii or smaller curvature varies, viewed in the longitudinal direction of the shaft, by approximately 10° to 40° in each rib.

[0027] In this way, after about 10 ribs, a complete revolution of the angular position of the smaller and larger radius regions can be obtained, whereby high pull-out forces can be obtained even if the shaft of the coupling member is relatively short. The angular position of the smaller and larger radius regions can vary from about 10° to even 40° per millimeter of shaft length.

[0028] In a development of the invention, the ribs extend at least partially in the axial direction.

[0029] Axially extending ribs are used to provide positive prevention of rotation of the coupling member within the component.

[0030] In a development of the invention, the ribs extend circumferentially over at least a partial region of the length of the shaft, and the ribs extend axially over at least a partial region of the length of the shaft.

[0031] In this way, a very secure locking of the connecting element is achieved both in the circumferential direction and in the longitudinal direction of the shaft, whereby the partial regions with axially extending ribs or the partial regions with circumferential ribs can have a multilobed cross-section and varying angular positions of the regions with smaller radii or larger curvatures and the regions with larger radii or smaller curvatures, or both the partial regions with circumferential ribs and the partial regions with axial ribs can have correspondingly multilobed cross-sections.

[0032] In a development of the invention, the ribs extend circumferentially over at least a partial region of the length of the shaft, and the angular positions of the regions with smaller radii or larger curvatures and the regions with larger radii or smaller curvatures vary alternately in a positive and negative direction, starting from the first rib.

[0033] In this case, the direction of change of the angular position can change from rib to rib, or it is also possible, for example, for several ribs to be changed in a positive direction in succession and then for one or several ribs to be changed in a negative direction. By alternating the direction of change of the angular position, it is possible to completely avoid alignment of the areas with the largest and smallest radii over the length of the shaft, or to adjust it so that alignment occurs again only after a relatively large number of ribs, thereby increasing the pull-out force of the connection according to the invention.

[0034] In a development of the invention, the angular positions of the areas with smaller and larger radii vary clockwise and / or counterclockwise, viewed along the central longitudinal axis.

[0035] In a development of the invention, the connecting member is at least partially made of steel, aluminum, copper or brass.

[0036] Further characteristics and advantages of the invention emerge from the claims and the following description of preferred embodiments of the invention in conjunction with the drawings, in which the individual features of the various embodiments shown and described can be combined with one another in any manner without departing from the scope of the invention, and this also applies to combinations of individual features without individual features being described and shown in conjunction with other individual features.

[0037] In the drawings: [Brief description of the drawings]

[0038] [Figure 1] 1 is a side view of a coupling member according to the present invention based on a first embodiment. FIG. [Diagram 2] FIG. 2 is a front view of the connecting member of FIG. [Diagram 3] 2 is a cross-sectional view showing a cutting plane AA in FIG. 1. [Figure 4] FIG. 2 is a cross-sectional view showing plane BB of FIG. [Diagram 5] 2 is a perspective view showing the connecting member of FIG. 1 obliquely from above. FIG. [Figure 6] FIG. 13 is a side view of a coupling member according to the present invention, according to another embodiment. [Figure 7] 7 is a perspective view showing the connecting member of FIG. 6 from diagonally above. [Figure 8] FIG. 11 is a perspective view showing a connecting member according to another embodiment of the present invention from obliquely above. [Figure 9] FIG. 9 is a side view of the coupling member of FIG. 8. [Figure 10] FIG. 9 is a front view of the coupling member of FIG. 8. [Figure 11] 10 is a cross-sectional view taken along the cutting plane AA of FIG. 9. [Figure 12] 10 is a cross-sectional view taken along the cutting plane BB in FIG. 9. [Figure 13] 10 is a cross-sectional view taken along cutting plane CC in FIG. 9. [Figure 14] FIG. 11 is a perspective view showing a connecting member according to another embodiment of the present invention, viewed obliquely from the rear. [Figure 15] FIG. 15 is a side view of the coupling member of FIG. 14. [Figure 16] 16 is a cross-sectional view showing a cutting plane AA in FIG. 15. [Figure 17] 4A-4D diagrammatically show sections of a circumferential development of another embodiment of a coupling member according to the invention; [Figure 18] 13A-B diagrammatically show sections of a circumferential development of a coupling member according to another embodiment; [Figure 19] 13A-B diagrammatically illustrate a circumferential deployment of a coupling member according to another embodiment of the invention; [Figure 20] 4 shows a coupling member according to another embodiment of the invention from below. [Figure 21] 21 is a cross-sectional view showing a cutting plane AA in FIG. 20. [Figure 22] 21 is a cross-sectional view showing a cutting plane BB in FIG. 20. [Figure 23] 21 is a cross-sectional view showing a cutting plane CC in FIG. 20. [Figure 24] FIG. 21 is a side view of the coupling member of FIG. 20. [Diagram 25] 25 is a cross-sectional view showing a cutting plane AA in FIG. 24. [Figure 26] 25 is a cross-sectional view showing a cutting plane BB in FIG. 24. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] FIG. 1 shows a coupling element 10 according to the invention according to a first embodiment. The coupling element 10 is intended to be pressed or embedded into a component (not shown) and has a shaft 12, which extends along a central longitudinal axis 14 of the coupling element 10. At the end of the shaft 12, shown on the left in FIG. 1, a head 16 of the coupling element 10 is provided, which has a larger diameter than the shaft 12. The head 16 is formed in a disk shape. The head 16 can have a driving shape on its side shown on the left in FIG. 1, but usually the head 16 does not have a driving shape, since the coupling element 10 is intended to be pressed or embedded into a component.

[0040] The shaft 12 has a frusto-conical taper 18 at the end shown on the right in FIG. 1, which facilitates insertion into the core hole.

[0041] The shaft 12 has a number of radially extending ribs 20. The ribs 20 extend in the circumferential direction and, as can be seen in FIG. 1, each have a triangular cross section. The height of the ribs, measured along the central longitudinal axis 14, is equal for all ribs. The ribs 20 are each formed in a frustoconical shape, with the side with the smaller diameter of each rib 20 facing the free end 18 of the shaft 12 and thus in the direction of the press-in of the connecting element 10. The frustoconical section of each rib 20 is joined towards the head 16 by a significantly shorter section, which is approximately perpendicular to the central longitudinal axis 14 and in which the diameter reduction takes place. The diameter of the end of each rib located to the left in FIG. 1 and the diameter of the end of each rib 20 located to the right are approximately equal. As a result, the shaft 12 as a whole has a sawtooth outer contour in the region of the ribs 20. As a result, the shaft 12 is pressed into the core bore of the component. In contrast, pulling the shaft 12 out of the core hole of the component is significantly more difficult due to the sawtooth form of the outer contour of the shaft 12 with the ribs 20. This is because when pulling the coupling part 10 out of the core hole, and thus to the left in FIG. 1, the ribs 20 sink into the material of the wall of the core hole that surrounds them.

[0042] FIG. 2 shows the front side of the connecting element 10 of FIG. 1, with the view in FIG. 2 directed towards the frustoconically tapered end 18 of the shaft 12. As can be seen in this view, the cross section of the shaft 12 is not circular, but multilobed with three outwardly projecting regions and three regions connecting the outwardly projecting regions. A cross section of this kind can also be called trilobal. The cross section of the shaft 12 has a periphery with three regions 22 having a smaller radius or a larger curvature, evenly spaced apart by 120° from one another. These regions 22 having smaller radii form radially projecting regions around the cross section of the shaft 12. Between the regions 22 having smaller radii are arranged regions 24 having respectively larger diameters or smaller curvatures, which are necessarily also equally spaced apart from one another, in particular at an angle of 120° from one another. These regions 24 having larger radii connect the outwardly projecting regions 22 having smaller radii. The periphery of the cross-section of shaft 12 is contiguous, convexly curved and has no corners or edges. The periphery of shaft 12 as seen in Figure 2 corresponds to the cross-section in the region of section plane AA in Figure 1.

[0043] In FIG. 1, the apex of the area 22 with a smaller radius in each rib 20 is indicated diagrammatically by means of a bar. It is recognized that the area with a smaller radius changes its angular position in the longitudinal direction of the shaft 12, and therefore in the direction of the central longitudinal axis 14. From the head 16 to the end 18 of the shaft 12, the cross section of the shaft 12 with each rib 20 is rotated clockwise little by little. The areas with a smaller radius 22 are thus arranged such that a line drawn through the areas with a smaller radius 22 forms a spiral around the shaft 12, as can be seen from FIG. 1. This occurs because, from rib 20 to rib 20, the angular position of the areas with a smaller radius 22, and therefore also the angular position of the areas with a larger radius 24, changes by a certain amount.

[0044] Figure 3 shows a cross-sectional view of the cutting plane AA of Figure 1. It will be seen that the regions 22 having smaller radii are spaced apart at an angle of 120° with respect to one another, and that the region 22 having smaller radii shown on the left of Figure 3 has an angle of 0° with respect to the horizontally extending axis.

[0045] FIG. 4 shows a cross-section in the cutting plane BB of FIG. 1. The cutting plane BB is located at a distance of 5xP from the cutting plane AA, thus at a distance of 5 times the height of each rib 20. As can be seen in FIG. 4, the area 22 with the smaller radius, which was still located to the left in FIG. 3, is now located rotated downwards by an angle A, which is approximately 50° in the embodiment shown. In FIG. 4, the angular positions of the areas 22 in the cutting plane AA, still taken from FIG. 3, are seen by the black areas. Starting from the cutting plane AA of FIG. 1, the angular positions of the areas 22 with the smaller radius and the areas 24 with the larger radius thus change by 10° in the direction of the head 16 in each rib 20. After five ribs and in the cutting plane BB, the angular positions of the areas 22 with the smaller radius and the areas 24 with the larger radius are then rotated counterclockwise by 50° compared to their angular positions in the cutting plane AA. This results in a helical rotation of the multi-lobed cross section of the ribs 20 over the entire length of the shaft 12, or a twisting of the multi-lobed cross section over the length of the shaft 12.

[0046] Figure 5 shows a top perspective view of the coupling member 10 of Figure 1. The apexes of the regions 22 having smaller radii are again indicated by bars in the individual ribs 20, and the helical twist of the multilobed cross section of the ribs 20 is discernible when viewed over the entire length of the shaft 12 as a whole.

[0047] 6 illustrates a coupling member 30 according to another embodiment of the present invention. Coupling member 30 has a shaft 32 that extends along central longitudinal axis 14 between frusto-conical end 18 and head 16. Shaft 32 has two partial sections 34 and 36.

[0048] In the partial section 34, which extends starting from the head 16, a number of circumferentially extending ribs 20 are provided, as in the coupling element 10 of FIG. 1. In the partial section 34, the shaft 32 is formed identically to the shaft 12 of the coupling element 10 of FIG. 1. The individual ribs 20 each have a multilobed cross section with three areas 22 with a smaller radius and three areas 24 with a larger radius, and the angular positions of the areas 22 with smaller radius and the areas 24 with larger radius vary in the longitudinal direction of the shaft 32. This can be seen in FIG. 6 by the areas 22 with smaller radius marked with a bar.

[0049] However, the partial section 34 of the shaft 32 has only nine ribs 20 adjacent to one another and then transitions to a partial section 36 in which axially extending ribs 40 are provided. The ribs 40 each have a triangular cross section. The cross section of the shaft 32 in the partial section 36 is generally circular. The outer edges of the ribs 40, which extend parallel to the central longitudinal axis 14, therefore all lie on a circle centered about the central longitudinal axis 14.

[0050] Within the scope of the present invention, the cross section of the shaft 32 can also be formed multilobately in the partial section 36 by several regions with smaller radii and several regions with larger radii. In that case, the angular position of the regions with smaller and larger radii can be constant, so that the shaft is formed multilobately and cylindrically in the partial section 36. Alternatively, the angular position of the regions with smaller and larger radii can also vary in the longitudinal direction of the shaft 32 in the partial section 326. Preferably, the angular change of the regions with smaller and larger radii is between 10° and 40°, in particular between 10° and 20°, per millimeter length of the shaft 32.

[0051] 6 to the left of the head 16, the connecting member 30 is provided with a threaded bolt 42. After the connecting member 30 has been pressed or embedded into the component, the other component can be fixed to the threaded bolt 42 and can be fixed on the threaded bolt 42, for example by means of a nut.

[0052] After shaft 32 of coupling member 30 is press-fit or embedded into a component, partial section 36 of shaft 32 provides resistance to rotation of coupling member 30 about central longitudinal axis 14. Partial section 34 of shaft 32 provides resistance to pull-out along central longitudinal axis 14, and thus to the left in FIG. 6, as described with coupling member 10 of FIG.

[0053] Figure 7 shows the connecting element 30 of Figure 6 in a perspective view from obliquely above. The threaded bolt 42 is only diagrammatically shown in Figure 7. The position of the smaller radius areas 22 on the shaft 32, and in particular in the partial section 34, can be seen. The smaller radius areas 22 of the individual ribs 20 are not aligned with one another but are arranged displaced with respect to one another in the longitudinal direction of the shaft 32.

[0054] 8 shows a coupling element 50 according to another embodiment of the invention in a perspective view from above. The coupling element 50 has a shaft 52 with a number of circumferentially extending ribs 20. The cross section of the ribs 20 corresponds to the cross section already described with reference to FIG. 1. As a result, the shaft 52 as a whole has a sawtooth profile.

[0055] The coupling member 50 has a head 16 and a free end 18 formed in a frusto-conical shape.

[0056] The individual ribs 20 are formed identically, as explained with reference to Figures 1 to 5. However, unlike the connecting member 10 of Figure 1, the angular positions of the smaller diameter regions 22 and the larger diameter regions 24 in each rib 20 are different in the connecting member 50 of Figure 8. This can already be seen in Figure 8 by the arrangement of the bars in each rib 20, which mark the position of the apex of the smaller diameter regions 22.

[0057] 9 shows a side view of the coupling member 50 of FIG. 8, and FIG. 10 shows a front view of the coupling member 50 of FIG. 9, therefore from the right in FIG. 9. In the coupling member 50 of FIGS. 8 to 10, the angular positions of the area 22 with a smaller diameter and the area 24 with a larger diameter change from rib 20 to rib 20, partly in a clockwise direction and partly in a counterclockwise direction. FIG. 11 shows a cross section of the section plane AA of FIG. 9. In FIG. 11, the angular positions of the area 22 with a smaller diameter and the area 24 with a larger diameter can be seen in the first rib 20 (see FIG. 9), which continues directly into the frustoconical end 18 in the direction towards the head 16. The area 22 with a smaller diameter, shown on the left in FIG. 11, is located on a horizontal line.

[0058] Figure 12 shows a cross section of the cutting plane BB in Figure 9. Figure 12 thus shows the angular position of the smaller diameter region 22 and the larger diameter region 24 of the fifth rib 20 starting from the frustoconical end 18. It will be appreciated that the smaller diameter region 22, located to the left in Figure 12, is rotated clockwise by an angle AR with respect to a horizontal line.

[0059] Figure 13 shows a cross section of the cutting plane CC in Figure 9 and thereby illustrates the angular position of the smaller diameter region 22 and the larger diameter region 24 of the sixth rib 20 of the shaft 52, starting from the frustoconical end 18. From Figure 13 it can be seen that the smaller diameter region 22, located to the left of Figure 13, is rotated counterclockwise by an angle AL with respect to a horizontal line.

[0060] Thus, the angular positions of the smaller diameter region 22 and the larger diameter region 24 change partly in the clockwise or negative rotation direction and partly in the counterclockwise or negative rotation direction when viewed in the longitudinal direction of the shaft 52. As a result, the smaller diameter regions 22 can only align with one another in the radially extending individual ribs 20 after a relatively large number of ribs or overlap one another in the projection. This can further improve the pull-out force of the coupling member 50.

[0061] In FIG. 9, it can be seen that, with the position of the smaller diameter region 22 suggested by the bars in each rib 20, starting from the frustoconical end 18, the angular position of the region 22 is first changed in a clockwise direction between the first rib 20 and the second rib 20, but then changed in a clockwise direction again from the second rib to the third rib.

[0062] Further detailed description of possible varying orientations and arrangements of smaller diameter region 22 and larger diameter region 24 along the shaft of the coupling member is provided below with reference to FIGS.

[0063] Figure 14 shows a perspective view of another connecting element 70 according to the invention. The connecting element 70 has a shaft 72 with two partial sections 74 and 76. In the partial section 74 the ribs 20 are arranged circumferentially, in the partial section 76 the ribs 40 run axially. A head 78 is continuous with the partial section 76. The connecting element 70 is provided with a through hole or through opening 80, see also figure 16. The connecting element 70 can be recessed or pressed into a component, the through hole 80 providing a core hole into which, for example, another component can be inserted or into which a fixing screw can be screwed.

[0064] Figure 15 shows a side view of the coupling element 70 of Figure 14. A total of five ribs 20 are arranged one after the other in the partial section 74 of the shaft 72j, which are formed like the ribs 20 of the coupling element 10 of Figure 1 and therefore will not be described further. The areas 22 with smaller radii of the circumference of the shaft 22 in the area of ​​the individual ribs 20 are again indicated by bars in Figure 15. It can be seen that the positions of the areas 22 with smaller radii, and therefore also the positions of the areas with larger radii, vary clockwise from rib 20 to rib 20.

[0065] In the partial section 76, which is located between the end of the partial section 74 and the head 16, the axially extending rib 40 is arranged. However, the cross section of the shaft 72 in the partial section 76 is likewise formed multilobed and has three areas with a smaller radius and three areas 24 with a larger radius. In the representation of FIG. 15, the area 22 with the smaller radius faces the viewer. In the partial section 76, the shaft 72 thus also has a multilobed cross section. This makes it possible to strengthen the fixation of the coupling member 70 against rotation about its central longitudinal axis.

[0066] FIG. 16 shows a cross section along the cutting plane AA in FIG.

[0067] Fig. 17 shows diagrammatically a portion of the circumferential development of a coupling element according to the invention, in which the change or rotation of the angular position of the areas with smaller radii or larger curvature and the areas with larger radii or smaller curvature is performed in the clockwise direction along the shaft. Each row of the development then shows the circumferentially extending ribs 20, and the apexes of the areas with smaller radii 22 are shown by means of vertical bars. It can be seen from Fig. 17 that the angular position of the areas with smaller radii 22 changes by a constant amount from rib to rib. This results in a helical arrangement of the apexes of the areas with smaller radii 22, as seen along the shaft of the coupling element, similar to that described with the aid of Fig. 1.

[0068] Figure 18 is a representation similar to that of Figure 17. It shows a counterclockwise change or rotation of the angular position of the smaller radius region 22, with a constant change in angular position from rib 20 to rib 20. In this type of embodiment, too, there is a helical series of smaller radius regions 22 over the length of the shaft of the coupling member, as has already been illustrated in the figures.

[0069] Figure 19 shows a schematic representation of a portion of the circumferential development of a coupling member according to the invention, in a representation comparable to Figures 17 and 18. Figure 19 is used to explain the change or rotation of the angular position of the area 22 with the smaller radius and the area 24 with the larger radius in different directions, thus in the clockwise and counterclockwise directions.

[0070] In Fig. 19, a first rib 20 is shown at the free end of the shaft of the coupling member, which, in comparison with Fig. 9, is the first rib 20 following the frustoconical end 18 shown on the right of Fig. 9. This rib 20 has a region 22 with a smaller radius, located in the center of Fig. 90. The region 22 with a smaller radius, e.g. at the apex, can also be referred to as a high point of the multilobed cross section.

[0071] Starting from this first rib 20, the angular position of the region 22 then changes clockwise to the next rib. Thus, in FIG. 19, the region 22 of the second rib is located to the right of the region 22 of the first rib. But in the following ribs, the change in angular position takes place counterclockwise and in particular by the same angle relative to the angular position of the region 22 in the first rib as the angle from the first rib 20 to the second rib 20. Thus, in the third rib in FIG. 19, the region 22 is shown to the left of the region 22 in the first rib. In the fourth rib, the change in angular position again takes place clockwise, in particular by the same angle relative to the angular position in the second rib. In the fifth rib, the change in angular position again takes place counterclockwise, in particular by the same angle relative to the position in the third rib.

[0072] Looking along the shaft (see also FIG. 9), the regions 22 with smaller radii are found in the even-numbered ribs, thus in the second, fourth, sixth, eighth and tenth ribs. A spiral shape is created which runs clockwise around the shaft. In contrast, in the odd-numbered ribs, thus in the third, fifth, seventh, ninth and eleventh, the regions 22 with smaller radii are located on a spiral which rotates counterclockwise along the shaft.

[0073] From FIG. 19 it can further be seen that in the twelfth rib 20 the area 22 with the smaller radius and the area 24 with the larger radius again reach the same position as in the first rib.

[0074] 19, it can be clearly seen that the areas 22 with smaller radii or the high points of the cross-section of the multi-lobed shape only align or overlap in projection after the twelfth rib, so that all the ribs can be securely inserted into the material of the core hole, pressed or embedded therein, and a very secure locking with a very high pull-out force is obtained.

[0075] 20 shows from below another connecting element 10 according to the invention. The connecting element 10 is substantially identical to the connecting element 10 of FIG. 1, whereby minor differences will be explained with the aid of FIG.

[0076] It is easy to see the head 16 and the shaft 12, which is formed in a multilobed shape in cross section, with a frustoconical taper 18. In FIG. 20, three cutting planes AA, BB and CC are shown, which run parallel to and each contain the central longitudinal axis 14 (see also FIG. 1) and are therefore oriented radially. The cutting planes AA, BB and CC are each disposed at a different angle. Between the cutting planes AA and CC there is an angle of 120°. Between the cutting planes AA and BB there is an angle of 60°. Between the cutting planes BB and CC there is also an angle of 60°. The multilobal cross section of shaft 12 has three regions of smaller radius or greater curvature, each uniformly spaced apart by 120° from one another, with the regions of larger radius or lesser curvature, respectively, disposed between the regions of smaller radius, also uniformly spaced apart from one another, such that the cross section between cutting planes AA and CC is repeated three times around the entire circumference of shaft 12. Therefore, for ease of viewing, only three cutting planes AA, BB and CC are drawn.

[0077] 21 is a partial representation of a cross-sectional view of the cutting plane AA. It will be appreciated that the shaft 12 presents a corrugated outer profile in the cutting plane AA. It will further be appreciated that the profile depth of the ribs 20 varies slightly along the length of the shaft 12. Within the scope of the present invention, the profile depth of the ribs 20 varies by no more than 50%. In the illustrated embodiment, the profile depth of the ribs 20 varies by no more than 10%.

[0078] Figure 22 shows a cross section of the section plane BB of Figure 20. In this section plane, too, the shaft 12 has a wavy outer profile. It will be appreciated that in this section plane, too, the profile depth of the ribs 20 varies only slightly over the length of the shaft 12, varying by a maximum of about 10% in the embodiment shown.

[0079] Figure 23 shows a cross-section of cutting plane CC of Figure 20. Cutting plane CC is spaced 120° from cutting plane AA about central longitudinal axis 14, so that the cross-section of cutting plane CC corresponds to the cross-section of cutting plane AA. Also in cutting plane CC, shaft 12 has a wavy outer contour, and the profile height of ribs 20 varies only slightly over the length of the shaft.

[0080] With the aid of Figures 20 to 23, it is also seen that the shaft 12 has a multilobal cross section at each point. Both the outer diameter of the shaft and the core diameter of the shaft between the ribs 20 are each formed multilobal. This can be seen in the corrugations of the outer contour of the shaft 12 in Figures 21, 22 and 23, and also in the imaginary joining lines of the valleys between the ribs 20, which are then also corrugated. This inner dashed line joining the wave troughs between the ribs 20 represents the core diameter. With the aid of Figures 21 to 23, it is well seen that both the outer diameter and the core diameter of the shaft 12 show a multilobal progression. The outer diameter or outer contour is indicated by the imaginary dashed lines joining the wave crests and thus the outer sections of the ribs to one another, as indicated in Figures 21, 22 and 23.

[0081] Figure 24 shows a side view of the coupling member of Figure 20. The head 16 and the shaft 12 with the rib 20 and the frustoconical taper 18 can be seen. The coupling member 10 of Figure 24 is configured identically to the coupling member 10 of Figure 1, except that the distance between the rib 20 closest to the head 16 and the head 16 is smaller. The parts of the coupling member 10 which are configured identically to the coupling member of the figure are therefore not described anew and bear the same reference numbers.

[0082] In figure 24 two cutting planes AA and BB are drawn in. The cutting plane AA extends through the point of taper 18 with the largest diameter, which in its outer dimension corresponds to the outer dimension of rib 20, but is rotated with respect to the remaining rib 20 about its central longitudinal axis, as already explained.

[0083] The cutting plane BB extends through the valley between the point of the taper 18 with the largest diameter and the rib 20 following the taper 18 in the direction of the head 16. In the cutting plane BB, the progression of the core diameter or the transverse dimension of the shaft between two ribs 20 is thus recognized. In this case, the dimension of the shaft 12 in the cutting plane BB corresponds in size to the dimension of the shaft between two ribs 20 in each case. However, as explained, the cross-section in the cutting plane BB is rotated about the central longitudinal axis 14 with respect to the cross-section between any two ribs 20.

[0084] Figure 25 shows a cross-section in the cutting plane AA in Figure 24. The view is directed in the taper direction of the taper 18. With this view direction, only the outer diameter or the largest transverse dimension of the taper 18 is recognized, and therefore this position of the cutting plane AA is selected. In Figure 25, it is recognized that the cross-section in the cutting plane AA is multi-lobed. This is recognized by means of the solid lines in Figure 25. All ribs have this kind of multi-lobed cross-section as shown in Figure 25, only the angular position around the central axis 14 varies, as explained in detail above.

[0085] Additionally, in Fig. 25, an imaginary envelope circle 80 is drawn, which is drawn using a dashed line. Further, an imaginary fence or inscribed circle 82 is shown, which is also indicated by a dashed line. As already explained, three regions with larger radii and smaller curvatures touch the envelope circle 80 at intervals of 120° about the central longitudinal axis, and three regions with smaller radii and larger curvatures touch the fence or inscribed circle 82.

[0086] FIG. 26 shows a cross section in the cutting plane BB in FIG. 24. With the aid of FIGS. 25 and 26, it can be seen that the shaft 12 has a multi-lobed shape, both between the ribs 20 and at the highest points of the ribs 20, respectively. In FIG. 26, the outer contour of the taper 18 can also be seen at the point where it has its greatest transverse dimension. This is shown using a solid circle 84. The outer contour in the cutting plane BB is shown by a solid line 86. From FIG. 26, it can be seen that the profile depth, and therefore the distance between the lines 86 and 84 in the radial direction starting from the central longitudinal axis 14, varies only slightly around the circumference of the shaft 12. In the embodiment shown, the profile depth varies by only about 10%.

[0087] 26, it will also be appreciated that the angular location of the maximum lateral dimension in cutting plane BB and thus the angle of the maximum lateral dimension in cutting plane AA varies between lines 86 and 84. In line 84, and thus in the cross section in cutting plane AA, the maximum lateral dimension is located vertically above the central longitudinal axis, whereas in line 86 the maximum lateral dimension is displaced slightly to the left, or counterclockwise. As previously explained, the angular location of the maximum lateral dimension of rib 20 varies from rib to rib. The present disclosure also includes the following aspects. [Aspect 1] A coupling member having a shaft for press-fitting or embedding into a component, the shaft extending along a central longitudinal axis of the coupling member, the shaft having ribs extending radially relative to the shaft, the shaft having an at least partially multilobal cross-section, the periphery of the multilobal cross-section being convexly curved along its entire length and having, viewed radially, regions of greater radius or lesser curvature and regions of lesser radius or greater curvature, A coupling member characterized in that, as viewed along a central longitudinal axis, the angular positions of the areas having smaller radii or larger curvatures and areas having larger radii or smaller curvatures vary along the shaft. [Aspect 2] 2. The coupling member of claim 1, wherein the angular positions of the regions having a smaller radius or larger curvature and the regions having a larger radius or smaller curvature vary by a constant amount per unit length along the shaft. [Aspect 3] the multilobal cross-section has n regions with smaller radii or greater curvatures; and the angular position varies by an angle of 360 degrees / n along the complete length of the shaft; 3. The coupling member according to claim 1 or 2, Aspect 4 4. The coupling member of at least one of the preceding aspects, wherein the shaft has alternating regions having different lobular cross-sections along its length. Aspect 5 5. The coupling member according to at least one of the preceding aspects, wherein, along the length of the shaft, regions having a circular cross-section alternate with regions having a multi-lobed cross-section. Aspect 6 A coupling member according to any one of aspects 1 to 5, wherein within a section of the shaft having a multilobal cross-section, at each location in the section, the shaft has a multilobal cross-section. Aspect 7 7. The coupling member of any one of aspects 1 to 6, wherein within a section of the shaft having a multilobal cross-section, at each angular position about the central longitudinal axis, a cross-section of the shaft shows a corrugated outer contour, and in the cross-section, an imaginary line joining the lowest points between two ribs extends in the corrugation. Aspect 8 8. A coupling member according to any one of the preceding aspects, wherein the profile depth of the ribs varies by up to 50% within the section of the shaft having a multilobal cross-section. Aspect 9 A coupling member according to any one of the preceding aspects, characterized in that within the section of the shaft having a multilobal cross-section, the profile depth of the ribs varies by a maximum of 10%, in particular is constant. Aspect 10 10. A coupling member according to any one of the preceding aspects, wherein the cross section is formed as a constant width figure. Aspect 11 11. A coupling member according to any one of the preceding aspects, wherein the cross-section has three regions having a smaller radius or greater curvature and three regions having a larger radius or smaller curvature. Aspect 12 12. A coupling member according to any one of the preceding aspects, wherein the periphery of the cross section is formed continuously without corners. Aspect 13 13. A coupling member according to any one of the preceding aspects, wherein the rib extends, at least partially, in a circumferential direction. Aspect 14 8. The coupling member of claim 7, wherein the angular positions of the regions having smaller radii or larger curvature and the regions having larger radii or smaller curvature vary from 10° to 40° in each rib, as viewed in the longitudinal direction of the shaft. Aspect 15 15. A coupling member according to any one of the preceding aspects, wherein the ribs extend at least partially in the axial direction. Aspect 16 a rib extends circumferentially over at least a portion of the length of the shaft; and The ribs extend axially over at least a portion of the length of the shaft. 16. A coupling member according to any one of the preceding aspects, characterized in that Aspect 17 a rib extends circumferentially over at least a portion of the length of the shaft; and the angular positions of the areas having smaller radii or larger curvatures and areas having larger radii or smaller curvatures vary in alternating positive and negative directions starting from the first rib, 17. The coupling member according to at least one of the preceding aspects, Aspect 18 18. A coupling member according to any one of the preceding aspects, characterized in that the angular positions of the regions with smaller radii or larger curvatures and the regions with larger radii or smaller curvatures vary from 10 degrees to 40 degrees, in particular from 10 degrees to 20 degrees, per millimeter length of the shaft, in particular within a partial section (36) of the shaft (32) having an axially extending rib (40). Aspect 19 13. The coupling member of claim 11 or 12, wherein the angular positions of the regions having smaller radii or larger curvature and the regions having larger radii or smaller curvature vary in a clockwise and / or counterclockwise direction when viewed along the central longitudinal axis. Aspect 20 20. The coupling member according to at least one of the preceding aspects, wherein the coupling member is at least partially formed from steel, aluminum, copper, or brass.

Claims

1. A coupling member having a shaft for press-fitting or embedding into a component, the shaft extending along a central longitudinal axis of the coupling member, the shaft having ribs extending radially relative to the shaft, the shaft having an at least partially multilobal cross-section, the periphery of the multilobal cross-section being convexly curved along its entire length and having, viewed radially, regions of greater radius or lesser curvature and regions of lesser radius or greater curvature, A coupling member characterized in that, as viewed along a central longitudinal axis, the angular positions of the areas having smaller radii or larger curvatures and areas having larger radii or smaller curvatures vary along the shaft.

2. 2. The coupling member of claim 1, wherein the angular positions of the regions having smaller radii or larger curvatures and the regions having larger radii or smaller curvatures vary by a constant amount per unit length along the shaft.

3. 3. A coupling member according to claim 1 or 2, characterized in that, viewed along the length of the shaft, there are alternating regions having different lobate cross sections.

4. 4. A coupling member according to claim 1, characterized in that, viewed along the length of the shaft, regions having a circular cross section alternate with regions having a multilobal cross section.

5. A coupling member according to any one of claims 1 to 4, characterized in that within the section of the shaft having a multilobal cross-section, the shaft has a multilobal cross-section at each point of the section.

6. 6. A coupling member according to claim 1, characterized in that in a section of the shaft having a multilobal cross section, at each angular position about the central longitudinal axis, a cut-away view of the shaft shows a corrugated outer contour, and in the cut-away view, an imaginary line joining the lowest points between two ribs extends along the corrugations.

7. 7. A coupling member according to any one of claims 1 to 6, characterized in that within the section of the shaft having a multilobal cross section, the profile depth of the ribs varies by up to 50%.

8. 8. A coupling member according to any one of the preceding claims, characterized in that within the section of the shaft having a multilobal cross section, the profile depth of the ribs varies by a maximum of 10%.

9. 9. A coupling member according to claim 1, characterized in that the cross-section has three regions with a smaller radius or greater curvature and three regions with a larger radius or smaller curvature.

10. 10. A connecting element according to claim 1, characterized in that the periphery of the cross section is formed continuously without corners.

11. 11. A coupling element according to any one of the preceding claims, characterized in that the ribs extend, at least partially, in the circumferential direction.

12. 7. The coupling member of claim 6, wherein the angular positions of the areas of smaller radius or larger curvature and the areas of larger radius or smaller curvature vary circumferentially at each rib from 10° to 40° as viewed in the longitudinal direction of the shaft.

13. 13. A coupling member according to any one of the preceding claims, characterized in that the ribs extend at least partially in the axial direction.

14. a rib extends circumferentially over at least a portion of the length of the shaft; and The ribs extend axially over at least a portion of the length of the shaft. A coupling member according to any one of the preceding claims.

15. a rib extends circumferentially over at least a portion of the length of the shaft; and the angular positions of the areas having smaller radii or larger curvatures and areas having larger radii or smaller curvatures vary in alternating positive and negative directions starting from the first rib; A coupling member according to at least one of the preceding claims.

16. 16. A coupling member according to any one of claims 1 to 15, characterized in that the angular positions of areas having smaller radii or larger curvatures and areas having larger radii or smaller curvatures vary from 10 degrees to 40 degrees per millimetre length of the shaft.

17. 11. A coupling member according to claim 9 or 10, characterized in that the angular positions of the areas with smaller radii or larger curvature and the areas with larger radii or smaller curvature vary in a clockwise and / or counterclockwise direction when viewed along the central longitudinal axis.

18. 18. The coupling element according to claim 1, characterized in that the coupling element is at least partially made of steel, aluminum, copper or brass.

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