DK2478163T3

DK2478163T3 - Indstøbelig Fixing rail

Info

Publication number: DK2478163T3
Application number: DK10762610.3T
Authority: DK
Inventors: Ulrich Birnbaum; Holger Basche; Markus Heudorfer; Denis Novokshanov
Original assignee: Hilti Ag
Priority date: 2009-09-17
Filing date: 2010-08-25
Publication date: 2014-02-24
Also published as: DE102009041654A1; PL2478163T3; EP2478163B1; ES2446357T3; WO2011032810A1; EP2478163A1; CN102597383A; PT2478163E; CN102597383B

Description

The invention relates to an embeddable anchor rail of the type specified in the preamble of Claim 1.

For producing flexible fastening points in a cast structural member, for example one made of concrete, anchor rails of this kind are first placed in the formwork for the structural member, for example a wall or ceiling, and become embedded in this when the structural member is poured. Fastening elements are directly secured to the anchor rails by means of rail nuts, rear engagement components or hammer-head bolts. Loads are transferred into the cured structural member via the rail geometry and the anchor elements. DE 35 31 998 A1 discloses an embeddable anchor rail comprising a rail body and attached anchor elements. The rail body has a rectangular receiving space which extends in longitudinal direction of the rail body and is accessible via an assembly opening delimited by flanges, said receiving space being delimited laterally by side walls located opposite one another and by a rear wall located opposite the assembly opening. The side walls form a right angle with a plane spanned by the assembly opening.

In addition to tensile forces acting on an anchor rail embedded in the structural member, these acting perpendicular to the plane spanned by the assembly opening and being simply directed via the anchor elements into the structural member, the anchor rail is also subjected to transverse forces or, in the case of loads acting diagonally on the anchor rail, to transverse force components which act in a plane spanned by the assembly opening.

It is a disadvantage of the known approach that, particularly when the anchor rail is placed in a peripheral region of the structural member, a failure crack occurs under transverse loading which, proceeding from the point where the side wall merges into the rear wall, extends diagonally to the edge of the structural member and results in a correspondingly large piece (lump) of the structural member breaking away.

Other anchor rails for concrete are disclosed in GB 1 020 471 A, US 3 156 450 A, US 1 502 766 A, US 1 260 331 A, US 1 710 422 A, GB 892 555 A, US 3 364 641 A and US 3 375 623 A. These known anchor rails have projections or edges on the outside of the rail body.

It is the objective of the invention to produce an embeddable anchor rail which has an improved load-bearing capacity in respect of transverse forces.

This objective is achieved by the features of the independent claim. Further advantageous developments are described in the subclaims.

According to the invention, crack initiator means are provided on at least one of the side walls.

When the anchor rail is placed close to an edge and subjected to transverse forces, instead of one crack occurring in the structural member, said crack initiator means result in two cracks being produced which do not intersect and thus do not affect one another. Moreover, the crack initiator means provided on the at least one side wall ensure a controlled development of the first crack and thus also of the second crack. Due to the first crack formation being different from the second crack formation, two independent breakout cones are produced. As regards the second crack (failure crack), the location of the critical pressure resultant is moved away from the surface into the structural member by a distance defined by the crack initiator means. In this way, with a breakout in the region close to the edge of the structural member, a larger area of fracture is formed than is the case with an anchor rail where only one crack is formed under transverse loading. Consequently, with the same loading, the anchor rail according to the invention can be placed closer to the edge of the structural member, that is to say at the same distance from the edge, a greater transverse force can be applied to the embedded anchor rail.

At the same time, due to the defined development of the cracks, crack propagation, caused, for example, by the material properties of the structural member or anchor rail, by the distance of the embedded anchor rail from the edge of the structural member or by lack of precision during installation, is reduced.

Both of the side walls located opposite one another are advantageously provided with crack initiator means, so that when the anchor rail is positioned in the structural member no particular orientation of same in respect of the edge of the structural member has to be considered. With such a configuration of the anchor rail, identical crack initiator means are advantageously formed on the side walls.

The assembly opening preferably extends along a plane and the crack initiator means are located at a distance from said plane which corresponds to a maximum of 0.75 times the overall height of the rail body. Thus, according to the loads to be expected, desirable crack formations develop which are optimum in terms of the load-bearing capacity, as a result of which, with the same transverse force, the anchor rail can be positioned closer to the edge of the structural member than with known solutions, that is to say at the same distance from the edge, the anchor rail has a greater load-bearing capacity in respect of transverse forces.

The crack initiator means are preferably formed by reducing the material in certain areas of the at least one side wall, thus forming a flexible joint in the corresponding side wall of the rail body. When a load is applied to the anchor rail, deflecting forces are generated as a result of this joint, which act on the structural member and initiate a crack due to the cleavage effect produced. The material reduction is, for example, provided on one or both sides of the corresponding side wall of the rail body. With a bilateral arrangement, the material reductions are advantageously symmetrical to one another and are advantageously identical in form. The material is, for example, directly reinforced [sic], during shaping of the rail body, e.g. in a rolling process, in respect of the portion of material which in the final state constitutes the corresponding side wall.

In an alternative embodiment or in addition, the crack initiator means are formed by reinforcing the material in certain areas of the at least one side wall, a notch effect being produced in the material of the structural member in the region of the crack initiator means. This notch effect is particularly advantageous in terms of initiating cracks in brittle materials, such as concrete. It is particularly advantageous if the material reinforcement is triangular in cross-section, so that its apex defines the starting point of the first crack. The material reinforcement is, for example, provided on one or both sides of the corresponding side wall of the rail body. With a bilateral arrangement, the material reinforcements are advantageously symmetrical to one another and are advantageously identical in form. The material is, for example, directly reinforced, during shaping of the rail body, e.g. in a rolling process, in respect of the portion of material which in the final state constitutes the corresponding side wall. Alternatively, a separate profile, for example, having an appropriate configuration of the cross-section is attached by material technology to the corresponding side wall, e.g. by welding or soldering.

Furthermore, differently formed crack initiator means can also be provided on the side walls of a rail body. Moreover, one type of crack initiator means can be provided on the sides of the side walls facing the receiving space and another type of crack initiator means can be provided on the sides of the side walls facing away from the receiving space.

The crack initiator means are preferably provided on the side of the at least one side wall facing away from the receiving space of the rail body, this on the one hand ensuring an advantageous notch effect in the material of the structural member and thus an advantageously defined development of the first crack, and on the other hand ensuring that the receiving space of the rail body is not restricted by inward-projecting elements when it comes to installing fasteners for example.

In an alternative embodiment, the crack initiator means are formed by varying the wall thickness of the at least one side wall, resulting in a crack-initiating joint advantageously being formed in the region of the side wall with the least wall thickness. Due to the variation in the wall thickness over the extent of the corresponding side wall, the flow of force can be controlled in such a way that, upon deformation of the rail body under load, locally increased pressures occur in the structural member and initiate the first crack. Furthermore, the material of the rail body in respect of transverse and tensile loading can thus be optimally utilized. The variation of the wall thickness of the corresponding side wall can also be combined with a different type of crack initiator means so as further to influence initiation of the first crack. The variation in the wall thickness of the at least one side wall is, for example, directly produced during shaping of the rail body, e.g. in a rolling process, in respect of the portion of material which in the final state constitutes the corresponding side wall.

In a further alternative embodiment, the crack initiator means consist of a comer formed on the side of the at least one side wall facing away from the receiving space of the rail body, said comer being formed by a first wall portion of the at least one side wall and a second wall portion of the at least one side wall, the first wall portion and the second wall portion each forming a different angle with the plane spanned by the assembly opening. Due to the deflecting forces produced on loading of the anchor rail, in addition to the notch effect there is a cleavage effect as a result of the corner, which intensifies the crack-initiating effect.

The first, internal angle of the first wall portion of the at least one side wall adjoining the flanges of the assembly opening corresponds to 75° to 135°, as a result of which an advantageous notch effect and cleavage effect, produced by the deflecting forces, are combined and have a crack-initiating effect. Furthermore, this inclination of the first wall portion of the corresponding side wall results in an advantageous load-bearing behaviour of the anchor rail, so that simple optimization of the wall thicknesses of the rail body is possible, which leads to advantageous savings in terms of the material used when manufacturing the rail body and thus the anchor rail.

With this embodiment of the anchor rail, the first angle advantageously corresponds to 90° to 120°, as a result of which the force is substantially directed into the stmctural member in the region of the first wall portion of the side wall. This force acts in direction of the surface of the stmctural member, which, under transverse load, leads to an earlier development of the first crack and thus a quick release of the portion of the stmctural member close to the surface.

The second, internal angle of the second wall portion of the at least one side wall adjoining the first wall portion preferably corresponds to 20° to 70°, the angle being selected according to the main load of the anchor rail. For example, in the case of an anchor rail for producing fastening points for curtain-type cladding panels (curtain wall applications), a second angle in a flatter range, starting from 20°, is preferably selected. An anchor rail of this type has a great load-bearing capacity in respect of the transverse force usually occurring with this application. With an anchor rail for producing fastening points for central suspensions for example, such as suspensions for wire installations and the like, a second angle in a steeper range, around 70°, is preferably selected. Such an anchor rail has a great load-bearing capacity in respect of the tensile force usually occurring with this application.

Since, in practice, different loads combine in respect of the anchor rail, a force resultant occurs which can advantageously be diverted into the substrate by an anchor rail with a second wall portion of the side wall which forms a second angle of 40° to 50° with the plane spanned by the assembly opening. Such an anchor rail can be used universally.

The first wall portions and/or the second wall portions of the side walls located opposite one another preferably form the same first and second angles respectively with the plane spanned by the assembly opening, as a result of which the receiving space and thus the rail body has a substantially symmetrical configuration.

In an alternative embodiment, for example for specific applications in which the occurring forces are to be diverted via specially formed rail bodies, the first wall portions and/or the second wall portions can be oriented differently in respect of the plane spanned by the assembly opening. Furthermore, the wall portions, and in particular the first wall portions of the side walls lying opposite one another, can be inclined relative to the plane spanned by the assembly opening as well as extending parallel to one another. Thus the region of the receiving space adjacent to the assembly opening has a substantially diamond-shaped configuration.

The rail body is preferably made in one piece, which makes this easy to manufacture and facilitates a good deflection of the occurring forces by the rail body. The rail body is preferably made of a flat base material, for example a steel strip. It is particularly advantageous if the rail body is made the appropriate shape in a rolling process. Depending on the type and configuration of the crack initiator means, these can, for example, be formed in the base material during the rolling process.

The wall portions of the side walls preferably extend linearly, which ensures a simple manufacture of the anchor rail and in particular of the rail body.

As an alternative to the wall portions extending linearly, at least the second wall portion of one of the side walls can also extend along a curve, as a result of which the flow of force in the rail body can further be optimized for deflection of the force into the structural member via the anchor element. It is particularly advantageous if the second wall portion runs along a circular arc. In this context, the inclination of a curved wall portion is determined by the inclination of a tangent line through the middle point of the circular arc. This tangent line forms an angle with the plane spanned by the assembly opening which, depending on the wall portion concerned, corresponds to the first or the second angle.

For securing the anchor elements, screw threads are advantageously provided on the rail body, in which the corresponding anchor element is screwed down. Due to this method of securing the anchor elements, the rail body can be made separate from the anchor elements, and the anchor element can simply be attached in a further production step. Thus, the anchor rail, compared with anchor rails with the anchor elements directly mounted, has a significantly smaller transport volume, which, particularly in the case of global production of the rail body and anchor elements, or specifically of the anchor rails, considerably reduces transport costs. Furthermore, differently configured anchor elements can simply be fixed as needed to one type of rail body. The anchor element can advantageously be secured in the assembled position on the rail body using safety means, such as, for example, an additional element or by caulking. The screw thread is advantageously an internal thread provided in a through hole, for example, on the rail body, into which the anchor element provided with an external thread can be screwed. Alternatively, the thread on the rail body takes the form of an external thread and the thread on the anchor element is a correspondingly formed internal thread, which can be brought into engagement with the external thread on the rail body.

An additional component, such as a rivet nut, is advantageously provided on the rail body, said component being provided with the thread for fixing the anchor elements and being fixed in advance in a punched hole made in the rail body. The term “rivet nut” in this context means a rivet, of which the free end inserted through the punched hole is widened or flanged for fixing the rivet nut to the rail body, and which has an internal threaded portion as fixing means for securing the anchor elements to the rail body. The screw thread advantageously takes the form of an internal threaded portion which is provided in a bore advantageously extending right through the rivet nut. The rivet nut is advantageously located in the receiving space and advantageously fully surrounds the free edges of the punched hole from the outside so as to ensure protection against corrosion of the free edges of a hole punched in a corrosion-proof rail body.

The invention is described in greater detail below with the aid of working examples which are illustrated as follows:

Fig. 1 is a side view of a first working example of an anchor rail;

Fig. 2 is a cross-section through the anchor rail according to line II-II in Fig. 1;

Fig. 3 is a cross-section similar to Fig. 2 of a second working example of an anchor rail; Fig. 4 is a cross-section similar to Fig. 2 of a third working example of an anchor rail; and Fig. 5 is a cross-section similar to Fig. 2 of a fourth working example of an anchor rail; Fig. 6 is an enlarged detailed section of a variant of the crack initiator means;

Fig. 7 is an enlarged detailed section of another variant of the crack initiator means; and Fig. 8 is a cross-section of an anchor rail embedded in the structural member.

The same parts are basically provided with the same reference numerals in the drawings.

The embeddable anchor rail 11 shown in Figs. 1 and 2 comprises a rail body 12 and attached anchor elements 21.

The rail body 12 has a space 13 extending in longitudinal direction of the rail body 12 for receiving a fastening element 6, which is secured to the anchor rail 11 via a rear engagement component as fastener 7. The receiving space 13 can be accessed via an assembly opening 15 delimited by flanges 14 and is laterally delimited by side walls lying opposite one another and facing one another. Each of the side walls 16 has a first wall portion 17 adjoining the flanges 14, which forms a first, internal angle (alpha) with the plane E spanned by the assembly opening 15, and a second wall portion 18 adjoining the first wall portion 17, which forms a second angle (beta) with the plane E spanned by the assembly opening 15. The first angle (alpha) is larger than the second angle (beta). In this working example, the first angle (alpha) corresponds to 115°. In this working example, the second angle (beta) corresponds to 45°. The two side walls 16 are identical in form and in each case the first wall portion 17 and the second wall portion 18 form the same angles with the plane E spanned by the assembly opening 15. The rail body 12 is thus symmetrical in form.

For an advantageous transmission of forces from the anchor rail 11 into the structural member, the rail body 12 has a width B in the region of the assembly opening 15 which corresponds to 1.1 times to 1.65 times the overall height H of the rail body 12. In this example, the corresponding width B of the rail body 12 corresponds to 1.3 times the overall height H of the rail body 12.

In the drawings, for purposes of illustration and clarification as to which angle of the first and second wall portions 17 and 18 is being referred to in this context, the plane spanned by the assembly opening 15 has been extended beyond the rail body 12.

Provided in the region of the rail body 12 lying opposite the assembly opening 15 there is a rear wall 19, which linearly connects the second wall portions 18 of the side walls 16. The anchor elements 21 are advantageously secured to said rear wall 19. Owing to the trapezoidal area of the receiving space 13 formed next to the rear wall 19, additional space is created for receiving fastening elements for securing the anchor elements 21 to the rail body 12. Thus any intrusion into the space provided for the fasteners 7 of the fastening elements 6 as a result of fixing elements for the anchor elements 21 possibly protruding into the receiving space 13 can be avoided.

Crack initiator means are provided on both side walls 16, the crack initiator means being located at a distance A from the plane E spanned by the assembly opening 15 which corresponds to a maximum of 0.75 times and in this example 0.55 times the overall height H of the rail body 12.

The crack initiator means 26 are in each case formed by a comer 27 located on the side of the corresponding side wall 16 facing away from the receiving space 13 of the rail body 12. The corner 27 corresponds to the junction between the first wall portion 17 and the second wall portion 18 of the corresponding side wall 16.

The anchor rail 31 according to Fig. 3 has a rail body 32 with a rectangular cross-section. The receiving space 33 of the rail body 32 has a right-angled area for receiving conventional fasteners such as are already available on the market. The rail body 32 has a width B, which corresponds to 1.35 times the overall height H of the rail body 32. As crack initiator means 46, there is an outward-projecting material reinforcement 47, taking the form of a protuberance, on each side wall 36 on its side facing away from the receiving space 33, and in addition there is also a material reduction 48, taking the form of a recess, located on the inside of each side wall 36 facing the receiving space 33. The crack initiator means 46 are located on the rail body 32 at a distance A from the plane E spanned by the assembly opening 35 which corresponds to 0.45 times the overall height H of the rail body 32.

The rail body 52 of the anchor rail 51 shown in Fig. 4 has side walls 56, the first wall portion 57 forming a first angle (alpha) of 90° with the plane E spanned by the assembly opening 55 and the second wall portion 58 forming a second angle (beta) of 40° with the plane E spanned by the assembly opening 55. The second wall portion 58 extends along a circular arc and thus along a curved path. The second angle (beta) which the second wall portion 58 forms with the plane E spanned by the assembly opening 55 is determined by the tangent line 60 in the middle point of the circular arc. The second wall portions 58 of the side walls 56 are directly connected, thus this anchor rail 51 does not comprise a rail body 52 with a rear wall. The rail body 52 has a width B which corresponds to 1.5 times the overall height H of the rail body 52. The anchor elements 61 are fixed in an area where the two second wall portions 58 merge into one another.

As crack initiator means 66, outward-projecting material reinforcements 67 are provided on the second wall portions 58 of the side walls 56, said reinforcements 67 being triangular in cross-section and being provided on the side of the side wall 56 facing away from the receiving space 53. The crack initiator means 66 are made in one piece with the rail body 52, for example in a rolling process or a forming process. The crack initiator means 66 are located on the rail body 52 at a distance A from the plane E spanned by the assembly opening 55 which corresponds to 0.7 times the overall height H of the rail body 52.

The anchor rail 71 shown in Fig. 5 has side walls 76, the first wall portion 77 forming a first angle (alpha) of 100° with the plane E spanned by the assembly opening 75 and the second wall portion 78 forming a second angle (beta) of 50° with the plane E spanned by the assembly opening 75. In the region of the rail body 72 lying opposite the assembly opening 75, a rear wall 79 is provided, which connects the second wall portions 78 of the side walls 76. The first wall portions 77 have a varying wall thickness Wl, which, in this example, diminishes progressively from the flanges 74 in direction of the second wall portions 78. The second wall portions 78 likewise have a varying wall thickness W2, which in this example increases progressively from the rear wall 79 in direction of the first wall portions 77.

The rear wall 79 has a portion which extends outwards relative to the receiving space 73 and is provided with a punched hole in which a rivet nut 80 is fixed. The rivet nut 80 is located in the receiving space 73 and completely surrounds the edges of the punched hole from the outside. The rivet nut 80, as fixing element for an anchor element 81, has a bore with an internally threaded portion, into which an anchor element 81 having an externally threaded portion can be screwed for securing it to the rail body 72.

As crack initiator means 86, the anchor rail 71 has a corner 87 on each side wall 76 on its side facing away from the receiving space 73 of the rail body 72. In each case, this corner 87 corresponds to the junction between the first wall portion 77 and the second wall portion 78 of the corresponding side wall 76. In addition, because of the variation in the wall thicknesses of the side walls 76, the crack-producing effect of the crack initiator means 86 is intensified, that is to say optimized. The crack initiator means 86 are located on the rail body 72 at a distance A from the plane E spanned by the assembly opening 75 which corresponds to 0.4 times the overall height H of the rail body 72.

The flanges 74 of the assembly opening 75 are swaged to produce a material reinforcement along the assembly opening and thus strengthen the rail body in certain areas. Each swaged flange 74 of the assembly opening 75 has, at its free end, a height extending in direction of the receiving space 73 which diminishes in direction of the adjacent side wall 76 down to the actual material thickness of the rail body 72 to form an enlarged stop face extending in the form of a ramp for a fastener of a fastening element.

The cutaway portion of the side wall 96 shown in Fig. 6 has a material reduction 107 on one side, forming crack initiator means 106. A variant is represented in broken lines, which provides for a second material reduction 108 which is located on the side wall 96 opposite the first material reduction 107. The first material reduction 107, or else the first material reduction 107 and the second material reduction 108, form a flexible joint in the side wall 96 which has a crack-initiating effect when the anchor rail is under load.

In the case of the cutaway portion of the side wall 116 shown in Fig. 7, a material reinforcement 127 is provided on one side for the forming of crack initiator means 126. A variant is shown here in broken lines which provides for a second material reinforcement 128 which is located on the side wall 116 opposite the first material reinforcement 127. The first material reinforcement 127, or else the first material reinforcement 127 and the second material reinforcement 128, likewise form a joint in the side wall 116 which has a crack-initiating effect when the anchor rail is under load.

In Fig. 8, the anchor rail 31 is shown in the embedded state, located close to the edge 9 of the cast structural member 8. When transverse loading of the anchor rail 31 occurs in a direction 131 extending parallel to the plane E spanned by the assembly opening 35, a first crack 132 is produced by the crack initiator means 46 provided on the side wall 36. To begin with, a first break 133 occurs in the structural member 8 as a result of this first crack 132. With additional or continued transverse loading, the point of application of the force resultant is moved away from the surface 10 into the structural member so that the second crack 134 (failure crack) develops lower down in the structural member. The first crack 132 and the second crack 134 do not overlap or intersect.

Another variant is shown in broken lines in Fig. 8 with an anchor rail 11 having a cross-section according to Fig. 2. The comer 27 as crack initiator means 26 of the anchor rail 11 produces, under transverse loading, a first crack 142, which develops earlier than that produced by the crack initiator means 46 of the anchor rail 31 and produces a significantly smaller break 143 in the stmctural member. The position of the second crack (failure crack) occurring when the anchor rail 11 is under transverse loading substantially corresponds to that of the second crack 134 produced by the anchor rail 31.

Claims

A moldable anchor rail with a rail member (12; 32; 52; 72) having a receiving space (13; 33; 53; 73) extending in the length of the rail member (12; 32; 52; 72) to a fastener (6) accessible via a mounting aperture (15; 35; 55; 75) bounded by edges (14; 74) and confined to the side by opposite side walls (16; 36; 56; 76 ) facing each other and having anchor members (21; 61; 81) attachable to the rail body (12; 32; 52; 72), characterized in that a crack initiator means (26; 46; 66; 86) is provided. ; 106; 126) on at least one of the sidewalls (16; 36; 56; 76).

Anchor rail according to claim 1, characterized in that the mounting opening (15; 35; 55; 75) extends along a plane (E) and the crack initiator means is located at a distance (A) from this plane (E), which maximum distance corresponds to 0.75 times the total height (H) of the rail body (12; 32; 52; 72).

Anchor rail according to claim 1 or 2, characterized in that the crack initiator means (46; 106) is formed by a material reduction (48; 107, 108) provided regionally in the at least one side wall (36; 96).

Anchor rail according to one of claims 1 to 3, characterized in that the crack initiator means (46; 66; 126) is formed by a material reinforcement (47; 67; 127, 128) provided regionally in the at least one side wall (36; 56, 116).

Anchor rail according to one of claims 1 to 4, characterized in that the crack initiator means (26; 46; 66; 86; 107, 108; 127, 128) is provided on the side of the at least one side wall (16; 36; 56; 76; 106; 116), facing away from the recording space (13; 33; 53; 73) of the rail body (12; 32; 52; 72).

Anchor rail according to claim 1 or 2, characterized in that the crack initiator means (86) is formed by a variation of the wall thickness (W1, W2) of the at least one side wall (76).

Anchor rail according to claim 1 or 2, characterized in that the crack initiator means (16; 86) is a rim (27; 87) on the side of the at least one side wall (16; 76) that faces away from the rail body (12; 72). ) recording space (13; 73) formed by a first wall section (17; 77) of the at least one side wall (16; 76) and a second wall section (18; 78) of the at least one side wall (16; 76), wherein the first wall section (17; 77) and the second wall section (18; 78) each with respect to a plane (E) extending along the mounting opening (15; 75) constitute different angles (Alpha, Beta) therewith. .

Anchor rail according to claim 7, characterized in that the first, internal angle (Alpha) of the first adjoins the wall portions (17; 77) of the at least one side wall (17; 77) of the mounting opening (15; 75) 16; 76) corresponds to 75 ° to 135 °, preferably 90 ° to 120 °.

Anchor rail according to claim 7 or 8, characterized in that the second, internal angle (Beta) of the second, adjoining the wall portion (18; 78) of the at least one side wall (16; 76) corresponds to 20 ° to 70 °, preferably 40 ° to 50 °.

Anchor rail according to one of claims 1 to 9, characterized in that the rail body (12; 32; 52; 72) is integral.