The present invention relates to a mounting bracket for connecting a roof penetrating structure, such as a roof window, to a roof structure, said bracket comprising a first leg intended to be connected to a frame of the roof penetrating structure and joined with a second leg intended to be connected to the roof structure, said legs being joined in a joint section and being arranged in intersecting planes that are substantially perpendicular to each other, and said bracket further comprising one or more frame engagement members projecting from the plane of the first leg in the opposite direction of the second leg and substantially parallel to the plane of the second leg. During mounting the frame engagement members are inserted in one or more grooves in the frame or forces into the material of the frame. Such a mounting bracket is known from PL-B1-195393. This bracket however suffers from the disadvantage that the connection provided between the roof penetrating structure and the roof structure is not always sufficiently strong, particularly under the influence of irregular external loads caused for example by natural forces such as heavy winds or even earth quakes or when a person working on the roof incidentally steps up on the window.

It is therefore the object of the invention to provide a mounting bracket with which a connection with increased strength and stiffness can be achieved. This is met by a bracket, where the frame engagement members are arranged at the end of the first leg, which is distal to the second leg. This location of the engagement members means that they come into engagement with the frame of the roof penetrating structure at higher level in relation to the roof surface, thus hindering the frame member in question in turning about its own length axis.

The frame engagement members may be attached to the first leg by welding or the like, but are preferably formed by angled parts of the first leg. When forming the bracket from sheet metal, this could for instance be achieved by making an incision in the material at the edge of the first leg and bending down the distal corners of the first leg. Alternatively, a U- or V-shaped cut in the face of the first leg will allow a flap of material to be bend out for the formation of the frame engagement member. Brackets of the type described in the above Polish publication are marketed in a version, where the frame engagement members consist of material that is cut loose from the edge of the first leg before bending so that they remain in plane with the second leg. This constitutes a very efficient method of manufacture, but the removal of mate- rial from the first leg adjacent to the joint with the second leg causes a weakening of the bracket, particularly as regards torsion. It is therefore preferred, that the first leg is substantially rectangular with the frame engagement members projecting from an edge thereof.

It is, however, to be noted that removal of material at the distal edge of the first leg will not have the same impact on strength and stiffness as the removal of material at the joint between the first and second legs. Embodiments according to the present invention, where the frame engagement members are made by bending out material from the first leg will therefore not be subject to the same reduction of strength and stiffness as mentioned above for the prior art bracket.

To further increase the strength and stiffness of the connection between the roof penetrating structure and the roof structure, a bracket according to a preferred embodiment of the invention further comprises a lath engagement member arranged at the second leg and projecting in a direction substantially parallel to the plane of the first leg in the opposite direction of the first leg. This lath engagement member may be brought into contact with the side of the lath facing the frame thus hindering the bracket from rotating about the length axis of the lath. Alternatively, the lath engagement member may be forced into the material of the lath or inserted in a groove therein.

As for the frame engagement members, the lath engagement member may be formed by an angled section of the second leg, which may for example be a part of the second leg, which has been partially loosened and bent out. To achieve optimum strength and stiffness, the engagement members are preferably of a blunt shape, but if intending to force them into the material of the frame and/or lath, a pointed shape may be appropriate. An even further increase of the strength and stiffness of the bracket is achieved when reinforcement is provided at the joint between the first and second leg, so as to hinder a deformation changing the angle between them. This may be achieved by making the material thicker at the joint, but in a preferred embodiment the reinforcement is in the form of ridges extending between the first and second leg in the space between them. The ridges may for example be in the form of flange-like webs attached by welding or gluing, but may also be formed by pressing up elongate bumps in a sheet material.

In a preferred embodiment, the joint section between the first leg and the second leg is shaped as an inclined section with respect to the said intersecting planes, preferably at an angle of 45 degrees and having an extent in the interval of 1/6 - 1/3 of the length of either one of the said two legs. This shape provides strength and stiffness and allows the bracket to reach further away from the frame of the roof pene- trating structure.

In the above, the bracket has been described as being made from sheet metal by bending the respective parts of the bracket in relation to each other, possibly in combination with pressing. It is, however, to be understood that similar brackets may be achieved by moulding or the like, in which case the bending action will not be necessary. Similarly it is to be understood, that the bracket need not be made from metal, but could also be made from plastics and composite materials.

An embodiment of the invention will now be described in closer detail with reference to the drawing, in which: Fig. 1 is a perspective view of a mounting bracket seen from above,

Fig. 2 is a perspective view of a mounting bracket seen from below,

Fig. 3 is a cross sectional view of a mounting bracket attached to a roof lath and to the lowermost frame member of a roof window, and Fig. 4 is a cross sectional view of a mounting bracket attached to a roof lath and to the uppermost frame member of a roof window.

A mounting bracket 1 according to the invention is shown in Fig. 1. It comprises a first leg 2 and a second leg 3 arranged substantially perpendicularly to each other. An inclined section 4 interconnects the two legs 2,3 at angles of approximately 45 degrees in relation thereto.

At the distal end 21 of the first leg 2, two projections 22 are provided. In the present embodiment, the bracket is made from sheet metal and the projections are provided as bend over pieces of material. It is, however, also possible to make the bracket by moulding in which case the projections may be of a slightly different configuration. Projections may also be attached subsequently by welding, gluing or by mechanical means, e.g. as click-in members. The bracket displayed in Figs. 1 and 2 are made from sheet metal and to minimise loss of material, the material needed for the projections on the first leg of one bracket is taken from the corners 31 of the second leg of another.

Here, the first and second legs 2, 3 are depicted as being almost square and of approximately the same size, but it is be understood that these dimension may vary depending on the loads to be carried, the number of brackets used, the mutual positions of the brackets in relation to the structure to be mounted etc.

The projections 22 on the first leg 2 is intended for being in- serted in a groove 71 in a frame member 72, 73 of a roof penetrating structure such as a roof window, solar collector or the like as depicted in Figs. 3 and 4, thus functioning as frame engagement members. It is, however, also possible to do without the groove, in which case the projections are simply forced into the frame material. The projections may then be pointed and/or sharpened (not shown).

Both legs 2, 3 are provided with holes 5 for screws or like fastenings means (not shown). In the present case two holes are provided in the first leg and three in the second leg, but a different number of holes may of course be employed. Similarly, the legs may in stead be provided with tooth-like projections corresponding to those on toothed plate connectors, in which case the holes and separate fastening means may be dispensed with. Alternatively, the frame member 72, 73 and bracket 1 may be provided with mating halves of a hook-and-loop type or snap fastener type system (not shown) for interconnection.

At the inclined section 4, material has been pressed up into two bumps 41, extending crosswise to the inclined section. These bumps increases the torsional rigidity of the bracket in a very cost efficient manner, but it is of course also possible to provided regular web flanges (not shown), particularly if making the bracket by moulding.

In a preferred embodiment of the invention, a lug 6 has been cut out in the second leg 3 and bend down, so that it projects blow the second leg. This lug is intended to abut on a roof lath 8 or the like in the mounted state of the bracket as may be seen in Figs. 3 and 4. In Fig. 3 the bracket 1 is attached to the lower horizontal frame member 72 of a roof window with the projecting frame engagement members 22 close to the top of the frame member. This gives a very good hold of the frame, as the frame member is supported almost over its entire height, thus effectively preventing it from tilting by rotation about its length axis.

At the top of the window the first leg 2 of the bracket 1 covers only little more than half of the height of the upper horizontal frame member 73 as may be seen in Fig. 4, but this is counterbalanced by the fact that the load on the upper half of the uppermost frame member is relatively limited.

As may also be seen from Figs. 3 and 4 the second leg 3 of the mounting bracket and the lug 6 forms an angle, which spans the upper corner 81 of the lath 8 facing the frame 72, 73. In this way the rotation about the length-wise edge of the lath represented by the corner 81, which can occur when a bracket with no lug is insufficiently fastened to the lath, is effectively prevented.

The bracket 1 thus being securely fastened to the lath 8 leaves only a single possibility of deformation of the interconnection between the lath 8 and the frame 72, 73, namely a deformation of the bracket it- self. This risk is, however, reduced by the bracket being provided with the inclined section 4 and the bumps 41.

Thus, means has been provided for increasing the strength and stiffness of the connection at all possible points. The inclined section 4 of the bracket has the additional advantage of allowing a greater distance d between the lath 8 and the frame 72, 73, than when using a bracket without an inclined section. This increased distance gives room for increased amounts of insulation material and may facilitate the mounting of lining panels etc. Here, the inclined section constitutes about 1/4 of the length of the legs 2,3, but this dimension may vary. Usually, however, the extent of the inclined section will be in the interval of 1/6 - 1/3 of the length of the legs.

In the above the mounting bracket according to the invention has been described on the basis of a single embodiment depicted in the drawing. It is, however, to be understood that this embodiment is in no way limiting on the scope of the invention as defined in the appended claims. For example, it will be apparent to skilled persons that the number of projecting frame engagement members may vary and that holes, bumps and lugs may also vary in number or be left out entirely.