Patent Description:
In the field of installation parts, the use of mounting rails and anchoring elements in fastening assemblies is widespread and well known. Mounting rails are channel shaped profiled section elements having flanges defining a longitudinal slot between them. A particular type of mounting rail is known in the field as a "strut rail", which is a mounting rail having generally a C-shaped cross section, wherein the flanges are folded inwardly such that the edges of the flanges are facing the bottom of the rail.

The <CIT> shows a fastening assembly for use with mounting rails. This known fastening assembly includes a metal washer element, a plastic support and a metal anchoring element. The metal anchoring element is formed as an oblong nut with a threaded bore in the centre. On a top side of the oblong nut, grooves are formed which extend in the transverse direction. This is typical for channel fasteners which are used in combination with strut rails. The edges of the respective flanges of the strut rail are in a mounted state received in the respective grooves on the upper side of the nut.

<CIT> shows another fastening assembly for use with a strut rail. This known fastening assembly comprises an anchoring element, a washer and a threaded stud portion connected to the anchoring element and extending through a bore in the washer. A threaded nut is screwed on the threaded stud and a biasing member, e.g. a coil spring, is arranged around the stud between the washer and the nut. In a preliminary mounting state, the spring biases the anchoring element against the flanges. The anchoring element has parallel grooves in which protrusions are formed which are adapted to cut into the flange edges to improve the grip. A similar anchoring element is shown in <CIT>.

In <CIT> is shown a mounting rail having a toothing provided on the flange edges and an anchoring element which has toothing zones extending in the transverse direction of the anchoring element at a top side to cooperate with the toothing provided on the edge of the flanges.

The most oblong anchoring elements are inserted through the slot of the rail profile with their longer sides parallel to the rail's flanges, then turned clockwise around the axis defined by the threaded hole or stud until their shorter sides block further rotation by engaging the inner wall of the rail profile as is for example illustrated in <CIT> or <CIT>.

Mounting rail profiles, and also the so-called strut rail profiles, are to a great extent standardized. They have a set of outer dimensions which are fixed, irrespective of the material thickness used. Moreover, the width of the longitudinal slot in the rail profile is also fixed irrespective of the material thickness.

However, in practise the strut rail profile can be produced in several material thicknesses. The difference in material thickness, combined with a set of fixed outer dimensions causes a variance in the space inside the profile. This variance is furthermore influenced by production tolerances.

The variance in available space causes the anchoring element to be positioned slightly different in profiles with different wall thicknesses. This may cause a misalignment of the toothing on the top surface of the anchoring element and the inwardly folded flanges. Especially with mounting rail profiles wherein the flanges are provided with toothing, the grip between the anchoring element and the flanges of the mounting rail, i.e. the resistance against sliding of the anchoring element in the longitudinal direction of the mounting rail, may be significantly reduced by the mentioned misalignment.

The invention has for an object to provide an anchoring element which removes or at least mitigates the above-mentioned problem.

This object is achieved by an anchoring element according to claim <NUM>.

According to the invention the anchoring element has toothings having teeth which are curved having a radius of curvature substantially parallel to the top surface of the anchoring element. The curvature of the teeth, preferably in combination with a wider track of teeth, ensures that respective of the relative orientation of the anchoring element in a rail profile, the teeth always align with the teeth on the rail profile.

In a possible embodiment the teeth have a convex side and a concave side, wherein the convex side faces one of the longitudinal sides of the anchoring element, and the concave side faces the other longitudinal side of the anchoring element. The teeth of the respective toothings may be facing with their convex side in opposite directions. Alternatively, it is also foreseen that the teeth of the respective toothings are facing with their convex side in the same direction. Both the alternatives provide a good grip of the anchoring element on the flanges of the rail profile.

In a possible embodiment the anchoring element according to the invention may be provided with a threaded bore in the centre. However, in another possible embodiment a fastener rod is fixedly connected to the anchoring element. The fastener rod may be threaded rod.

In a possible embodiment of the anchoring element the longitudinal sides are straight and mutually parallel. Preferably the transverse sides extend under an angle smaller than <NUM>° with respect to the longitudinal sides. The transverse sides may have a curved portion and a straight portion.

The invention also relates to a fastening assembly comprising an anchoring element as described in the above and furthermore comprising a washer and an intermediate part interconnecting the anchoring element and the washer.

In a possible embodiment the intermediate part is a part made of plastic.

In a further embodiment the intermediate part comprises spring members allowing to hold the fastening unit on the mounting rail in a preliminary mounting state.

The invention also relates to a fastening assembly comprising an anchoring element as described in the above and furthermore comprising a fastener rod connected to the anchoring element.

The invention also relates to the use of an anchoring element as described in the above for mounting an object to a mounting rail,.

The invention will be further explained in the following detailed description with reference to the drawing, wherein:.

<FIG> show an anchoring element <NUM>. The anchoring element <NUM> has an oblong body <NUM> that is made of strip metal, e.g. steel. The oblong body <NUM> has two opposite longer longitudinal sides <NUM> and two shorter transversal sides <NUM>. The body <NUM> has a top surface <NUM> and a bottom surface <NUM>.

The longitudinal sides <NUM> are straight and mutually parallel. The transversal sides <NUM> have a curved portion 4A and a straight portion 4B. The straight portion 4B of the transversal sides <NUM> extends under an angle smaller than <NUM>° with respect to the longitudinal side <NUM> adjoining it, in the embodiment shown in <FIG> an angle of about <NUM>°.

In the embodiment seen in <FIG> a central bore <NUM> is provided which extends from the top surface <NUM> to the bottom surface <NUM>. The central bore <NUM> is provided with a female thread such that anchoring element <NUM> has the function of a nut which can cooperate with a threaded rod or bolt. In the relevant technical field this kind of anchoring element is sometimes called a "slidenut".

In the top surface two toothings <NUM> are provided. The toothings <NUM> each comprises a series of teeth <NUM>, which series of teeth <NUM> extends substantially rectilinear in the transverse direction of the anchoring element <NUM> from one longitudinal side <NUM> to the opposite longitudinal side <NUM>. The series of teeth <NUM> extend parallel to each other and the distance between them is adapted to the distance between the flanges of a mounting rail as will be become clear further below.

Each tooth <NUM> has a curved shape as is best visible in top elevational view of <FIG>. The radius of curvature is substantially parallel to the top surface <NUM> of the anchoring element <NUM>. The curvature provides the tooth a convex side 9A and a concave side 9B. The convex side 9A is facing one longitudinal side <NUM> of the anchoring element <NUM> and the concave side 9B is facing the opposite longitudinal side <NUM> of the anchoring element <NUM>. In the embodiment shown in <FIG>, the curvatures of the teeth <NUM> of the different toothings <NUM> are opposite, i.e. the teeth <NUM> of one toothing <NUM> have their convex side 9A facing to the opposite longitudinal side <NUM> as the other toothing <NUM>. This is clearly visible in <FIG>.

Another embodiment of anchoring element is shown in <FIG> and is indicated by reference numeral <NUM>. In this embodiment, the toothings are indicated by reference numeral <NUM> and the teeth are indicated by reference numerals <NUM>. Also, in this embodiment the teeth <NUM> are curved and their convex side is indicated by reference numeral 109A and the concave side is indicated by reference numeral 109B. The curvatures of the teeth <NUM> of the different toothings <NUM> are in the same direction in this embodiment, i.e. the teeth <NUM> of one toothing <NUM> have their convex side 109A facing to the same longitudinal side <NUM> as the teeth <NUM> of the other toothing <NUM>. This is clearly visible in <FIG>. For the rest the anchoring element <NUM> can be the same as the anchoring element <NUM> and for a description of the other features is referred to the description associated with <FIG>.

In <FIG> is illustrated an anchoring element <NUM>, <NUM> which is arranged in a mounting rail <NUM>. The mounting rail <NUM> comprises a rail profile having a generally C-shaped cross section. The mounting rail <NUM> is a so called "strut rail" having a bottom <NUM>, two lateral walls <NUM> extending from the bottom and an upper side comprising two flanges <NUM>, which extend from the lateral walls <NUM> towards each other and which define a longitudinal slot <NUM> between them. Typical for a "strut rail" is that the flanges <NUM> are folded inwardly such that the edges <NUM> of the flanges <NUM> are facing the bottom <NUM> of the rail <NUM>. The edges <NUM> are provided with toothing <NUM>. Such a strut rail <NUM> is generally made of metal, in particular steel.

During installation of the anchoring element <NUM>, <NUM> in the rail <NUM>, the longitudinal sides <NUM> of the anchoring element <NUM>, <NUM> are aligned with the longitudinal slot <NUM> of the mounting rail <NUM>. This allows introduction of the anchoring element <NUM>, <NUM> into the mounting rail <NUM> through the longitudinal slot <NUM>. After introduction of the anchoring element <NUM>, <NUM> through the longitudinal slot <NUM>, thus when the anchoring element has moved beyond the edges <NUM> of the flanges <NUM>, the anchoring element <NUM>, <NUM> can be rotated clockwise to a mounted state around a rotation axis, which is in this embodiment coinciding with the centre axis of the threaded bore <NUM>. By this rotation the longitudinal sides <NUM> of the anchoring element <NUM>, <NUM> are misaligned with the longitudinal slot <NUM> such that the respective toothings <NUM>, <NUM> of the anchoring element <NUM>, <NUM> engage the edge <NUM> of the respective flanges <NUM> of the mounting rail <NUM>,<NUM> and mesh with the toothing <NUM> on the respective edges <NUM>. This mounted state is shown in <FIG>.

The anchoring element <NUM>, <NUM> will in general not be used as a separate part, but will for instance be part of a fastening assembly <NUM> furthermore comprising a washer <NUM> and an intermediate part <NUM> interconnecting the anchoring element <NUM>, <NUM> and the washer <NUM>, as is for example shown in <FIG>. The intermediate part <NUM> in this example is an integrally formed plastic part which has a bottom support <NUM> that carries the metal anchoring element <NUM>, <NUM>, and furthermore includes a head portion <NUM> that is connected to the washer <NUM>. Two opposite spring elements <NUM> surrounding the washer <NUM> element are connected to the head portion <NUM> and are adapted to engage flanges <NUM> of the mounting rail <NUM>. This fastener assembly <NUM> allows the anchoring element to be introduced in the rail <NUM> via the longitudinal slot <NUM> as was described in the above. Subsequently by turning of the fastener assembly <NUM> clockwise, the anchoring element <NUM>, <NUM> extends at an angle relative to the longitudinal slot <NUM>, such that the flanges <NUM> of the mounting rail <NUM> are accommodated in spaces between the washer element <NUM> and longitudinal end portions of the anchoring element <NUM>, <NUM>. In this position the spring elements <NUM> engage the upper side of the flanges <NUM> of the mounting rail <NUM> and bias the fastening assembly <NUM> upwards such that the toothings <NUM>, <NUM> of the anchoring element <NUM>, <NUM> are pulled in engagement with the flanges <NUM> of the mounting rail <NUM>. In particular the toothings <NUM> on flange edges mesh with the toothings <NUM>, <NUM> in the top surface <NUM> of the anchoring element <NUM>, <NUM>. In this state the fastening assembly is in a preliminary mounting state, in which it is held stationary on the mounting rail <NUM> by the spring force of the spring elements <NUM>. By pushing the washer down the toothings <NUM>, <NUM> can be decoupled from the toothings <NUM> on the flange edges <NUM> and the fastening assembly <NUM> is allowed to be moved along the mounting rail <NUM> towards its desired position. When the fastening assembly <NUM> is in its desired position, the anchoring element <NUM>, <NUM> and the washer element <NUM> can be tensioned towards each other by means of a male fastening element such as a threaded rod (not shown) screwed in the threaded bore <NUM> in the anchoring element <NUM>, <NUM> and a nut (not shown) engaging the washer element <NUM>. The flanges <NUM> of the mounting rail <NUM> are thereby clamped between the longitudinal end portions, in particular the toothings <NUM>, <NUM> formed therein, of the anchoring element <NUM>, <NUM> and the washer element <NUM> in order to fix the fastening assembly <NUM> to the mounting rail <NUM>.

As is for example shown in <FIG>, the anchoring element <NUM>, <NUM> may also be part of a fastening assembly in which a threaded rod <NUM> is connected to the anchoring element <NUM>, <NUM>. It is even possible that the anchoring element is embodied as a bolt head wherein it is fixed as a sort of hammerhead to a (threaded) shank.

Also other fastening assemblies than the examples mentioned above are possible.

The advantage of an anchoring element <NUM>, <NUM> according to the invention is illustrated in <FIG>. In <FIG> is shown a rail <NUM> which has the same outer dimensions, but is made of steel sheet with a thickness of <NUM>,<NUM>, <NUM>,<NUM>, <NUM>,<NUM> and <NUM>,<NUM>, respectively. As a consequence, the rails <NUM> shown in <FIG> have a decreasing internal space and a thicker flange edge <NUM> seen from <FIG>.

Claim 1:
Anchoring element (<NUM>, <NUM>) for anchoring a fastening assembly (<NUM>) to a C-shaped mounting rail (<NUM>), the anchoring element (<NUM>, <NUM>) comprising an oblong metal body having opposite longer longitudinal sides (<NUM>) and opposite shorter transversal sides (<NUM>), and having a top surface (<NUM>), wherein a pair of parallel toothings (<NUM>, <NUM>) is formed in the top surface (<NUM>), said toothings (<NUM>, <NUM>) extending substantially straight from one of the longitudinal sides (<NUM>) to the other one of the longitudinal sides (<NUM>), characterised in that each of the toothings (<NUM>, <NUM>) has teeth (<NUM>, <NUM>) which are curved having a radius of curvature substantially parallel to the top surface (<NUM>) of the anchoring element (<NUM>, <NUM>).