Corner bracket, a bracket system, use of such a corner bracket, a window mounting collar and a window mounting system

A corner bracket for assembly of two boards of a window mounting collar into a collar corner and for affixing said window mounting collar to an exterior face of a building façade so as to surround a window opening, said corner bracket; comprising two holding plates and two base arms, all four adapted for extending in planes parallel with and having back surfaces abutting the exterior face of the building façade in an affixed position of the collar. The bracket further comprises two flanges and two abutment plates adapted to extend away from said exterior face in an affixed position of the collar. Each abutment plate is positioned at a mutual distance from and in parallel with an associated said flange, each abutment plate being connected to the associated said flange via an associated said holding plate; so as to be able to hold said boards together to form said window collar corner, each board being received between a respective flange and its associated abutment plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase under 35. U.S.C. §371 of International Application PCT/DK2014/050202, filed Jul. 4, 2014, which claims priority to European Application No. 13175272.7, filed Jul. 5, 2013. The disclosures of the above-described applications are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

This invention relates in a first aspect to a corner bracket for assembly of two boards of a window mounting collar into a collar corner and for affixing said window mounting collar to an exterior face of a building façade so as to surround a window opening. The invention also relates in a second aspect to a bracket set comprising a corner bracket, in a third aspect to use of a corner bracket, in a third aspect to a window mounting collar, and in a fourth aspect to a window mounting system.

BACKGROUND OF THE INVENTION

When building façades are insulated with external wall insulation, the window frames of the building can act as a thermal bridge, because the window frames are generally not covered by the external wall insulation. Heat can, therefore, escape from the building by passing from the building interior through the building wall, into the window frame and to the exterior of the building. Such thermal bridges can undermine the benefit of the new insulation.

In order to reduce the thermal bridging effect of the window frames, the windows are often replaced when the external wall insulation is installed. The new windows are often shifted outwards and arranged so that they are in line with the new façade front. This reduces thermal bridging by preventing contact between the window frame and the building wall itself.

However, in order to fix the new windows in place securely, in particular so that the building meets fire regulations, it is often necessary to fix the window in its new position with brackets, which are attached to the window frame at one end and the reveal or window opening in the building wall at the other. In order to provide sufficient support for the window frame, these brackets must be very strong. They are, therefore, generally metal brackets which form a thermal bridge between the window frame and the building wall. Furthermore, since the brackets are attached to the reveal of the building wall, it is necessary to remove the existing window frame before installing the new window frame. This is undesirable, because it leaves the building open to the elements for a period of time. That is particularly problematic when the building remains occupied during the installation process, as is often the case.

DE 20 2008 016 538 U1 discloses an assembly for installation into an opening in a building wall, which includes a facing frame, made from thermally insulating material, which is secured to a frame arranged in the opening of the building wall. The window frame is mounted within the insulating frame.

The insulating frame is attached to the frame arranged in the opening of the building wall. There is also no separation between the plane of the face of the building façade and the window frame. These features make installation of a new window impossible before the existing window is removed.

DE 20 2006 000 4425 describes a frame assembly for sealing a building opening such as a window or door, which comprises a prefabricated insulation system that is integrally joined to a window frame. Brackets are used to fix the window frame itself to the building wall. In this system, the window frame is attached directly to the building wall. Therefore, although installation is quick, a thermal bridge is formed. This system also appears to prevent installation of a new window before the existing window has been removed.

DE 299 05 365 U1 describes a prefabricated thermal insulating element to be placed in the opening in a façade-insulating layer that is aligned with an opening in the building wall. The prefabricated element has a reveal element formed from a thermal insulating material that is attached to a window frame. When the prefabricated element is installed, the window frame sits within the opening of the building wall. This positioning of the window frame makes it impossible to install the prefabricated element before any existing window has been removed.

On the above background the present invention relates in a first aspect to a corner bracket for assembly of two boards of a window mounting collar into a collar corner and for affixing said window mounting collar to an exterior face of a building façade so as to surround a window opening.

Assembly and mounting of the above described window mounting collar on an exterior face of a building façade presents a number of challenges. First, it is desirable to be able to attach the boards to each other to form the collar, either before or during affixing of the collar to the exterior face of the building façade. Further, affixation should be sufficiently strong, and affixing of the boards to each other should preferably be independent from the specific material of the boards, for example from whether it is possible to attach screws to the boards. For example man-made vitreous fibre boards, e.g. mineral wool fibre boards, will not always be able to provide satisfactory affixation of e.g. screws screwed into the boards. Moreover, freedom regarding spacial dimensions of the boards is of value to make in situ adjustment of the dimensions possible. Finally, insulation abilities of the resultant construction are of importance.

SUMMARY OF THE INVENTION

In view of the above the object of the present invention is providing a solution for cheap and effective assembly of a window mounting collar and mounting of this on an exterior face of a building façade.

With the first aspect of the invention this object is met by providing a corner bracket comprising:

two holding plates and two base arms, all four adapted for extending in planes parallel with and having back surfaces abutting the exterior face of the building façade in an affixed position of the collar, the two base arms each being adapted for receiving a fixation member for insertion therethrough and into the building façade such as to fixate the collar to the façade;

a flange arm comprising two flanges adapted to extend away from said exterior face in the affixed position of the collar, each flange having a proximal end configured to be proximal and a distal end configured to be distal to the exterior face in the affixed position of the collar, each flange further having an attaching edge extending from the proximal end to the distal end, the attaching edges of the flanges being attached to each other along at least a part of the attaching edges, the flanges extending at a mutual angle such as to form a flange corner at said attaching edges, the flange corner being adapted to be positioned in an inner corner formed between the two boards in the affixed position of the collar;

two abutment plates adapted to extend away from said exterior face in the affixed position of the collar, each abutment plate having a proximal end configured to be proximal and a distal end configured to be distal to the exterior face in the affixed position of the collar, each abutment plate being adapted to abut a respective outer surface of the two boards in the affixed position of the collar; and

each abutment plate being positioned at a mutual distance from and in parallel with an associated said flange, each abutment plate being connected to the associated said flange via an associated said holding plate;

so as to be able to hold said boards together to form said window collar corner, each board being received between a respective flange and its associated abutment plate.

Thus, according to the first aspect of the invention two boards of a window mounting collar may be brought together and preliminarily retained in a collar corner of the collar between the respective associated abutment plates and flanges of the corner bracket. This reduces work time and provides for easier and quicker assembly of the boards. In this context it is possible to provide pretension in the corner bracket material at one or more of the distal ends of the abutment plates and flanges, forcing the abutment plate and associated flange towards each other for better preliminary attachment. Such pretension can in principle be strong enough to provide permanent retention of the boards.

After preliminarily retaining the boards between the plates and the associated flanges, the boards may then be permanently attached to each other by a separate attachment means such as a screw or bolt inserted through the respective associated flanges and plates and through the associated board. Hereby, the attachment means need not be able to firmly grip the material of the boards since the respective associated abutment plates and flanges will be able to retain the boards to the corner bracket by means of pressure exerted on the board by means of for example a bolt head on the one side of the board and an associated nut on the other side.

Mutual attachment of the flanges along the attaching edges provides increased rigidity of the corner bracket in the direction of the flange planes. This is important to ensure that the corner bracket is strong enough to withstand forces not only from gravity of collar, window and/or insulation plates positioned around the collar, but especially also from wind forces acting on the collar after mounting thereof. Also, the attaching edges provide an inner flange corner, which enables or improves guided abutment of the boards against this corner.

Since the corner bracket need not be attached to or be in contact with the boards at or near the outer surface, i.e. the surface of the boards positioned co-planarly with and at a distance from the façade, it is possible to reduce thermal bridging between the façade and the outside.

In an embodiment of the first aspect of the invention said two abutment plates of the corner bracket are positioned at a distance from each other. Preferably, each abutment plate does not extend beyond a plane in which its non-associated flange extends.

In the first aspect of the invention the flanges are directly attached to each other. Thereby, it is not necessary for the abutment plates to be attached to each other for the corner bracket to be held together. The distance between the two abutment plates of the corner bracket enables the corner bracket to be manufactured as one integral piece by punching it out from a single sheet of plate metal (or like material), thereby avoiding a time-consuming assembly process of several parts to form the corner bracket. Accordingly, in a preferred embodiment the corner bracket is obtainable by a process of punching one single work-piece out from a single sheet of plate metal and folding or bending the work-piece into shape. It should be noted that it is alternatively possible to for example cast or mould the bracket in one integral piece to avoid assembly of the bracket. To this end the corner bracket may be manufactured from metal or a plastic material.

In another embodiment said two flanges of the corner bracket extend in respective planes forming a mutual angle of 60-120°, preferably 80-100°, more preferred approximately 90°, and/or said two abutment plates extend in respective planes forming a mutual angle of 60-120°, preferably 80-100°, more preferred approximately 90°, and/or each associated abutment plate and flange extend in parallel planes. Furthermore, each associated holding plate and flange extend in respective planes forming a mutual angle between approximately 60-120°, preferably 80-100°, more preferred approximately 90°, and/or each associated holding plate and abutment plate extend in respective planes forming a mutual angle between approximately 60-120°, preferably 80-100°, more preferred approximately 90°. By providing the corner bracket with angle dimensions close to right angles, an approximately rectangular window mounting collar may be provided that may be attached to the exterior face of a plane building façade, surrounding a window, such that a regular rectangular window frame can be positioned inside said collar. However, the corner bracket may be configured to match windows, collars or facades of other shapes and sizes, such as triangular windows and collars, where the angles may be 60° or less, or pentagonal windows and collars, where the angles may be larger than 90°.

In another embodiment each of said base arms are formed as an extension of the associated said holding plate, each base arm extending away from a plane of the associated said abutment plate so that the associated fixation member can be inserted through the base arm when the two boards are positioned to be held between the respective flanges and abutment plates, and/or at least one of said base arms comprises a receiving aperture for receiving the fixation member therethrough. By providing the corner bracket with base arms as described above it is possible to affix the corner bracket to the exterior face of the building façade, both with or without the two boards positioned between the respective flanges and abutment plates, thus facilitating the possibility of providing collars already assembled with corner brackets mounted to the boards at each corner of the collar, ready for affixing on the exterior face at delivery. Furthermore, the corner bracket may be attached to the exterior face of the building facade to achieve the advantages therewith as explained above.

Each base arm and each associated abutment plate or associated flange may extend in respective planes forming a mutual angle between approximately 60-120°, preferably 80-100°, more preferred approximately 90°. With angle dimensions as described above, an approximately plane back surface of the corner bracket is provided, which may be adapted to abut a plane of the exterior face, such as to create greater stability and strength.

In another embodiment each of said base arms is obtainable by punching it out from an associated one of said abutment plates and folding or bending it into position. This makes it possible to manufacture the base arms integral with the associated abutment plates, thereby avoiding time-consuming assembly of several parts.

In another embodiment at least one of each associated abutment plate and flange comprises at least one retention aperture positioned for receiving a preferably oblong retention member, such as a screw or a bolt, inserted through the associated abutment plate, through the board to be positioned between the associated abutment plate and flange, and through the associated flange so as to press the board in between the associated abutment plate and flange to retain the board, the abutment plate and flange being pulled against each other by means of the retention member. The screw or bolt may at one end comprise a head with a nut or the like screwed upon the opposite end of the screw or bolt such as to provide oppositely directed forces by the head and the nut, respectively, on each side of the board to be retained between the respective flange and associated abutment plate. The at least one retention aperture may be one or more slots or holes, preferably with several apertures positioned to make it easier to match retention member with retention aperture at an end of the retention member first inserted into the retention aperture, i.e. when the retention member comes out of the board on the opposite side of the board. By pressing the board in between the associated abutment plate and flange to retain the board by means of the retention member the respective associated abutment plates and flanges will be able to retain each of the two boards to the corner bracket independent of whether or not the specific material of the boards allows for firm attachment of the retention member, such as a screw, to the board itself. This allows for use of for example boards manufactured from man-made vitreous fibre, e.g. mineral wool fibre, with the associated advantages thereof.

However, if the boards are formed from material in which it is possible to sufficiently firmly attach screws or like retention members, it may also be possible to affix the boards to the bracket corner by inserting the retention member such that it does not extend fully through the board, thereby not connecting the associated abutment plate and flange.

In an embodiment of the first aspect of the invention the corner bracket further comprises two boards of a window mounting collar assembled to form a collar corner by means of the corner bracket, said two boards being held together by the corner bracket to form said collar corner, each board being received between a respective flange and its associated abutment plate, wherein each board has an outer board surface, which is adapted to be parallel with and to face away from the exterior face of the façade in the affixed position of the collar, each flange and associated abutment plate being in contact with an associated one of said two boards, the distal end of each flange and/or of each abutment plate being positioned at a distance from the outer board surface of its associated board of 10% to 150%, preferably 25% to 75%, more preferred approximately 50%, of a length of the respective flange or abutment plate. This distance between the distal end of the flanges and abutment plates from the outer board surface minimizes the corner bracket's thermal bridging between the surroundings and the exterior face of the façade.

In the second aspect of the present invention the above object is met by providing a bracket set, which comprises a corner bracket according to the first aspect of the invention as well as one or two further, different brackets. By providing different bracket types, where each bracket is formed from the same base bracket shape, a more cost-effective and simple production is facilitated. Each bracket may for example be punched out in the same pattern from a sheet of plate metal after which further punching or different folding procedure may result in the different brackets. Each bracket of the bracket set may thus be produced in very much the same process, thereby to a large extent avoiding different process steps.

Furthermore, by providing the bracket set, it is possible to not only assemble the collar by using the corner brackets, but also to provide additional support and rigidity along the boards. The joining bracket also provides for the possibility of assembling two boards at their respective ends along a side of the mounting collar, thereby making it possible to use more of the board material when the boards are provided in standard lengths. This material would otherwise need to be disposed of.

In the third aspect of the invention the above object is met by providing use of a corner bracket according to the first aspect of the invention for holding together two boards of a window mounting collar to form a window mounting collar corner, each board being received between a respective flange and its associated abutment plate and attached by means of a preferably oblong retention member inserted through the respective flange, the respective board and the abutment plate associated with said respective flange, and further for affixing said window mounting collar to an exterior face of a building façade so as to surround a window opening, the two base arms each receiving a preferably oblong fixation member for insertion therethrough and into the building façade such as to fixate the window mounting collar to the façade.

Such use simplifies both collar assembly and mounting process as the collar assembly can be combined with the process of affixing the boards of the collar to the corner bracket. This can be done both prior to, during or after the corner bracket is affixed to the exterior face of the building façade.

In the fourth aspect of the invention the above object is met by providing a window mounting collar having at least one inside face, at least one outside face, a first open end and a second open end and comprising a corner bracket according to the first aspect of the invention.

This window mounting collar may be affixed to the exterior face to surround a window and may be adapted to receive the window through the first or second open end, the window further being received by the at least one inside face of the collar.

The window mounting collar may be made using boards of any suitable material, such as plywood, cement or similar common building materials. However according to an embodiment at least one of the boards comprises or is manufactured from man-made vitreous fibre material. Such boards have a number of advantages in this context, such as resistance to deterioration from rot, fungus etc, superior fire rating, superior thermal conductivity, and relatively low weight.

In the fifth aspect of the present invention the above object is met by providing a window mounting system comprising a building façade having an interior face and an exterior face and comprising a window opening and a window mounting collar according to the fourth aspect of the invention, the window mounting collar preferably comprising two side boards, an upper cross board and a lower cross board, each having an inside face and an outside face, wherein at least one and preferably each side board is joined orthogonally to the upper and lower cross boards by means of a corner bracket according to the first aspect of the invention.

Since the collar is affixed directly to the exterior face opposed to the inside of the window opening, the process of moving the window from an original position to a position in the collar, may be performed without first having to remove the window to attach the collar, thereby providing for a quicker and easier assembly, see also the remarks described above in the disclosure of the background of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

InFIG. 1, a window mounting collar1is shown before installation on a building façade. The mounting collar1comprises two side boards2, an upper cross board3and a lower cross board4, each having an inside face2a,3a,4aand an outside face2b,3b,4b, wherein each side board2is joined orthogonally to the upper and lower cross boards3,4. The mounting collar has a first open end5, which, when installed, faces the exterior face of the building façade. The second open end6of the mounting collar1receives a window frame, which can be installed either before the mounting collar is affixed to the building façade or after the mounting collar has been affixed to the building façade.

In the embodiment shown, the two side boards2, the upper cross board3and the lower cross board4are each formed from three layers of man-made vitreous fibre boards, each layer comprising man-made vitreous fibres and binder.

Preferably, each board has a bending strength of at least 7 N/m2 and a point load resistance of at least 500 kN.

The board preferably has a thermal conductivity, measured in a direction from the first end to the second of the collar, of below 0.150 W/m·K, preferably below 0.100 W/m·K. The thermal conductivity of the board, measured in a direction from its inside face to its outside face, is preferably below 0.150 W/m·K, more preferably below 0.100 W/m·K. The thermal conductivity of the board, measured in a direction from its inside face to its outside face, is often lower than the thermal conductivity, measured in a direction from the first end to the second of the collar. Most preferably, the thermal conductivity of the board, measured in a direction from its inside face to its outside face, is below 0.075 W/m·K.

In one embodiment, the board comprises man-made vitreous fibres and binder and has a density of at least 150 kg/m3. Such compressed man-made vitreous fibre boards generally have sufficient rigidity and strength to support window frames without the use of additional brackets attaching the window frame to the building façade directly. It is preferred that the material has a density of at least 200 or at least 300 kg/m3. Usually, the density is less than 600 kg/m3, preferably less than 500 kg/m3.

Particularly suitable man-made vitreous fibre boards are produced according to the method described in WO2011/012712. Preferably, the boards comprise from 1% to 20% binder and from 80 to 99% man-made vitreous fibres.

Compressed man-made vitreous fibre boards have the additional benefit that they are fire-proof. In a preferred embodiment, the man-made vitreous fibre boards are layered to form the sides of the mounting collar. Where at least two man-made vitreous fibre boards are layered at their large surfaces, the bending strength of the mounting frame can be improved, thereby improving the stability of the system.

Alternatively, the mounting collar can be formed from polymeric foam, for example polyurethane foam.

In a further embodiment, the mounting collar is formed from a polymeric foam composite material comprising a polymeric foam and man-made vitreous fibres, wherein at least 50% by weight of the man-made vitreous fibres present in the polymeric foam composite material have a length less than 100 micrometers. Such a polymeric foam composite is discussed in our co-pending application PCT/EP2012/066196.

Attached to the mounting collar1, on its outside faces2b,3b,4b, are brackets7. In the embodiment shown, the brackets7are L-shaped brackets, which are positioned on the outside faces of the mounting collar adjacent to its first open end5.

FIG. 2shows the mounting collar1in place on a building façade8, as part of a complete window mounting system. Brackets7affix the mounting collar1to the exterior face of the building façade8. A window frame9is mounted in the mounting collar such that there is a separation d shown inFIG. 3of at least 10 mm between the window frame9and the plane of the exterior face of the building façade8. The window frame9surrounds a window sash10and window panes11. External wall insulation12not shown on one side of the mounting collar is positioned around the outside of the mounting collar1and affixed to the building façade8. The external wall insulation12has the same depth as the mounting collar1, so the window frame9is arranged to be flush with the outer surface of the external wall insulation12.

FIG. 3shows a section through the system ofFIG. 2, viewed from above. The side boards2of the mounting collar1are affixed to the exterior face13of the building façade8. The side boards2extend perpendicularly outwards from the building façade8. L-shaped brackets7have two perpendicular arms, one of which is attached to an outside face2bof the mounting collar1, the other of which is attached to the exterior face13of the building façade8. The separation d between the window frame9and the plane of the exterior face13of the façade allows the mounting collar1to be fitted when an existing window is still present in the window opening14. External wall insulation12is present on either side of the mounting frame1. The mounting collar1extends away from the building façade8by the same distance as the depth of the external wall insulation12. Means for attaching the window frame9to the mounting collar1are not shown, but could, for example, be screws passing through the window frame9and into the mounting collar1.

FIGS. 4aand 4bshow a corner system that may be used with the window mounting collar1according toFIG. 1and comprising two boards1aand1bof the window mounting collar1assembled to form a collar corner by means of a corner bracket denoted0. The window mounting collar could be in the form of that shown inFIG. 1. The corner bracket0comprises a bracket part15with two base arms16in the form of plates and flange arm17, which comprises two abutment plates17a,17bthat are substantially perpendicular to each other and are joined at one edge. The two abutment plates17a,17bextend away from the exterior face of the facade8in the affixed position of the collar1. Each abutment plate17a,17bhas an end proximal and an end distal to the exterior face of the facade8in the affixed position of the collar1. Each abutment plate17a,17babuts a respective outer surface of the two boards1a,1b. In the embodiment ofFIGS. 4aand 4bthe two abutment plates17a,17bare attached to each other along a mutual attachment edge.

The two base arms16extend in planes parallel with the exterior face of the building façade in the affixed position of the collar1. The two base arms16further have back surfaces for abutting the exterior face and are each provided with five fixation member holes or receiving apertures18for receiving fixation members (not shown), such as screws, therethrough and into the building façade such as to fixate the collar1to the façade. The second arm17of the bracket part15extends away from the exterior face of the building façade8along two of the outside faces2b,3bof the boards1a,1b, respectively, of the mounting collar1.

Holding part19has an attachment arm20and two holding plates21a,21bformed as two connected parts of one single plate positioned at an outer surface of the two boards1a,1b. The holding plates21a,21bextend in planes parallel with and are positioned at a distance from the exterior face of the building façade8in the affixed position of the collar1. The attachment arm20is in the form of two substantially orthogonal plates20a,20b, attached to each other at one edge, and each attached to the holding plate21at one end. The holding plate21is L-shaped to match the shape of the corner of the mounting collar1and has two flanges22that are perpendicular to each other and perpendicular to the holding plate21. The flanges22extend away from the exterior face of the facade8in the affixed position of the collar1to be attached to respective edges of the holding plates21a,21bpositioned opposite to the edges attached to the plates20a,20bof the attachment arm20. The flanges22lie against two adjoining inside faces2a,3aof the respective boards1a,1bof the mounting collar1. Each flange22has an end proximal to and an end distal to the exterior face of the facade8in the affixed position of the collar1. The flanges22extend at a mutual angle of about 90° such as to fit snugly into an inner corner formed between the two boards1a,1b.

Each abutment plate17a,17bis positioned at a mutual distance from and in parallel with an associated of the two flanges22. This distance is established as corresponding to the thickness of the boards1a,1bsince the associated flange22and abutment plate17a,17bare positioned on each side of the respective board1a,1b. Each abutment plate17a,17bis connected to the associated of the flanges22via an associated of the holding plates21b,21a, respectively. Each abutment plate17a,17bextends in this embodiment beyond a plane in which its non-associated flange22extends; for example, the abutment plate17aextends farther in the left direction ofFIG. 4athan to the plane in which the lowermost flange (which abuts the holding plate21a) extends. The plane, in which the lowermost flange (which abuts the holding plate21a) extends, extends along the inside face2aof board1a. Each associated abutment plate17a,17band flange22extend in parallel planes. Each of the base arms16are positioned at a distance from the associated holding plate17a,17b.

Hereby, the two boards1a,1bare held together by the corner bracket0to form the window collar corner, each board1a,1bbeing received between a flange21a,21band its associated abutment plate17b,17a, respectively.

Since the holding plates21a,21bare attached along outer edges to the plates20a,20b, respectively, the corner bracket is in this embodiment not directly obtainable by a process of punching one single work-piece out from a single sheet of plate metal and folding or bending the work-piece into shape.

In the corner bracket shown inFIGS. 4aand 4bthe two flanges22extend in respective planes forming an angle between them of approximately 90°, and the two abutment plates17a,17bextend in respective planes forming a mutual angle of 90°. Each associated holding plate21a,21band flange22extend in respective planes forming an angle of approximately 90°, and each associated holding plate21a,21band abutment plate17b,17a, respectively, extend in respective planes forming an angle of approximately 90°.

The abutment plates17a,17beach comprises a slit extending along the respective abutment plates17a,17bfor receiving screws inserted into the respective boards1a,1b. To this end the boards1a,1bmay be manufactured from wood.

FIG. 5shows a window mounting collar, for the sake of convenience also denoted1, according to the fourth aspect of the present invention and mounted in place on an exterior face of a building façade8, the collar1forming part of a complete window mounting system surrounding a window opening14. Four corner brackets100, each according to the first aspect of the invention, one holding bracket200and one joining bracket300affix the mounting collar1to the exterior face of the building façade8.

Features of the corner bracket100, holding bracket200and joining bracket300, which are similar or like in function to the associated features of the bracket0inFIGS. 4aand 4b, are referred to herein with reference numbers with100,200and300added, respectively.

The brackets100,200,300specifically retain four boards1a,1b,1c,1dof the collar1between respective abutment plates117a,117b,217,317a,317band associated flanges122a,122b,222,322a,322b, respectively, of the brackets100,200,300as shown inFIGS. 6-9. Note that a further, similar joining bracket (not shown) may be positioned oppositely on the board1c, and a further, similar holding bracket or joining bracket may be positioned oppositely on the board1d. Generally, the number of corner brackets, holding brackets and joining brackets may vary depending on window size, number of boards, collar dimensions etc.

InFIG. 5the base arms116a,116b,216,316a,316bof the corner brackets100, holding bracket200and joining bracket300are visible on an outside of the upper1band the left1aboard of the collar1. The base arms116a,116b,216,316a,316blie parallel with and abut the building façade8. Similarly the abutment plates117a,117b,217,317a,317bof the corner brackets100, holding bracket200and joining bracket300are visible on an outside of the upper1band the left1aboard of the collar1. The abutment plates117a,117b,217,317a,317blie parallel with and abut an associated board1a,1b,1c,1dof the window mounting collar1.

InFIG. 5an inside of a flange arm180of a corner bracket100is visible at the inside bottom right corner of the collar1. The flange arm180comprises two flanges122a,122b.

Similar to the embodiment of the window mounting system as shown inFIG. 2, external wall insulation (not shown inFIG. 5) may be positioned around the outside of the mounting collar1and affixed to the building façade8. The external wall insulation may have the same depth as the mounting collar1, e.g. 300 mm, so that a window frame may be arranged to approximately be flush with an outer surface of the external wall insulation.

FIGS. 6a, 6band 6cshow one of the corner brackets100for assembly of two respective boards1a,1b;1b,1c;1c,1d;1d,1aof the window mounting collar1ofFIG. 5into a collar corner and for affixing the window mounting collar1to the exterior face of the building façade8so as to surround the window opening. The corner bracket100is symmetrical so as to be divided into a first bracket part100aand a second bracket part100b, which is formed similar to the first bracket part100a, but symmetrically over a symmetry plane. The bracket part100acomprises one holding plate121a, one associated base arm116a, one associated abutment plate117aand one associated flange122a. The bracket part100bsimilarly comprises one holding plate121bone associated base arm116b, one associated abutment plate117band one associated flange122b.

Generally, in the context of the present specification it is noted that the term “associated” when used in relation to the abutment plate, flange, holding plate and base arm of the corner bracket should be understood as “forming part of the same of the two bracket parts”. The “associated board” is equivalently the board positioned between a abutment plate and associated flange of a corner bracket.

Each holding plate121a,121band its associated base arm116a,116b, respectively, extend in planes parallel with and having back surfaces abutting the exterior face of the building facade8.

The base arms116a,116bare formed as respective extensions of their associated holding plate121a;121b, extending away from a plane of the associated said holding plate121a;121b. Each holding plate121a,121bis at one edge attached to the associated base arm116a,116b. The base arms116a,116bhave a width (defined as the direction extending along a longitudinal direction of the associated board) somewhat smaller than the width of the holding plates121a,121b, and extend away from the holding plate121a,121b. The base arms116a,116bfurther each comprise one elongated, approximately elliptical receiving aperture118a,118bpositioned approximately at the centre of the respective base arm116a,116bin the width direction, and extending in the same direction as the respective base arm116a,116b. The receiving apertures118a,118breceives a fixation member in the form of a screw or bolt therethrough and into the building façade8, such as to fixate the collar1to the façade8when the board is positioned to be held between the associated flange122a;122band abutment plate117a;117b.

Each abutment plate117a,117bextends approximately perpendicularly away from its associated holding plate121a,121band base arm116a,116b. Each abutment plate117a,117bcomprise a proximal end147a,147bconfigured to be proximal and a distal end157a,157bconfigured to be distal to the exterior face of the façade8in the affixed position of the collar1. Each abutment plate117a,117bis connected at its proximal end147a,147b, respectively, to the associated holding plate121a,121band associated base arm116a,116bat a line dividing the associated holding plate121a,121band the associated base arm116a,116b. Each abutment plate117a,117bis adapted to abut a respective outer surface of the associated board1a,1b,1c,1din the affixed position of the collar1.

In the embodiment ofFIG. 6ato 6ceach abutment plate117a,117bdoes not extend beyond a plane in which its non-associated flange122b,122a, respectively, extends. The abutment plate117awith which the flange122bis not associated is referred to as the non-associated abutment plate thereof. Similarly, the abutment plate117bwith which the flange122ais not associated is denoted the non-associated abutment plate thereof.

Each abutment plate117a,117bfurther comprises two retention apertures130a,130bpositioned for receiving an oblong retention member (not shown) in the form of a screw or a bolt inserted through the associated abutment plate117a,117b, through the board1a,1b,1c,1dto be positioned between the associated abutment plate117a,117band flange122a,122b, and through the associated flange122a,122b. Hereby, the board may be pressed in between the associated abutment plate117a,117band flange122a,122bto retain the board, the abutment plate117a,117band flange122a,122bbeing pulled against each other by means of the retention member. The abutment plate117a,117badditionally comprises a cut-out140a,140bextending from its proximal end towards its distal end, which provides for the base arm116a,116bto be folded into position, see further below regarding manufacture of the brackets according to the invention.

Each flange122a,122bextends approximately perpendicularly away from its associated holding plate121a,121b, and is positioned at a mutual distance from and in parallel with its associated abutment plate117a,117b. Each flange122a,122bhas a proximal end142a,142bconfigured to be proximal, and a distal end152a,152bconfigured to be distal to the associated holding plate121a,121b. The flange122a,122bis attached at one edge at its proximal end to an edge of its associated holding plate121a,121b. The flange122a,122bis wider than its associated holding plate121a,121b.

Finally, the bracket parts100a,100bare connected via flange arm180comprising the two flanges122aand122b. Each flange122a,122bhas an attaching edge123a,123b, respectively, extending from the proximal end142a,142bto the distal end152a,152b. The attaching edges123a,123bare attached to each other along the entire part of the attaching edges123a,123b, but may in other embodiments extend only along part of the edges123a,123b. For example one or more discontinuations could be provided between the ends142a,152a;152a,152b, respectively, the ends being attached to each other, which can save bracket material. The flanges122a,122bextend approximately perpendicularly to each other, forming an inner flange corner supporting the inner faces of the associated two boards, for example1a,1b, in the affixed position of the boards.

The symmetry plane dividing the corner bracket100into the two bracket parts100a,100bextends through the attaching edges123a,123bof the flanges122aand122b.

InFIG. 5associated pairs of the boards1a,1b,1c,1dare received between a respective flange122a,122band an associated abutment plate117a,117bof each corner bracket100. Each board1a,1b,1c,1dhas an outer board surface, which is parallel with and faces away from the exterior face of the façade8. Each flange122a,122band associated abutment plate117a,117bare thus in contact with an associated one of the boards1a,1b,1c,1d, the distal end152a,152b,157a,157bof each flange122a,122band/or of each abutment plate117a,117bbeing positioned at a distance from the outer board surface of its associated board1a,1b,1c,1d. The respective distal ends152a,152b,157a,157bof the flanges122a,122band abutment plates117a,117bare positioned at a distance from the outer board surface of the associated board1a,1b,1c,1dof approximately 200 mm, i.e. about 50% of a length measured in the depth direction of the collar1of the respective flange122a,122bor abutment plate117a,177b.

Note that according to the invention the bracket parts100aand100bneed not necessarily be similar, and the holding plates121a,121b, base arms116a,116b, abutment plates117a,117bor flanges122a,122bmay be of respective different shapes or sizes. For example the length of abutment plates117a,117band flanges122a,122b, respectively, may be different from each other.

FIG. 7shows a top view of a work-piece W punched out from one single sheet of plate metal. The work-piece W is subsequently folded or bent into the corner bracket100ofFIG. 6a. The folding lines are shown with dashed lines. All foldings are by approximately 90°. Similarly, the holding bracket200ofFIG. 8and joining bracket300ofFIG. 9are manufactured by punching out from a single sheet of plate metal.

FIG. 8shows the holding bracket200shaped like the corner bracket100ofFIGS. 5a, 5band 5c, but with the difference that it comprises only one single associated abutment plate217and flange222, one associated holding plate221and one associated base arm216. The holding bracket200may be manufactured by cutting along the attaching edges123a,123bof the corner bracket100to separate the two flanges122a,122b. The holding bracket is thus adapted to hold a board1a,1b,1c,1dto the exterior face of the façade8anywhere along the boards.

FIG. 9shows a joining bracket300shaped like the corner bracket100, but with the difference that an angle between planes in which the flanges322a,322bextend is approximately 180°. Hereby, the abutment plates317a,317band flanges322a,322bextend in a mutual plane, so that the joining bracket300may be used to join two board pieces of one collar board1a,1b,1c,1dextending in a mutual longitudinal direction. Each board1a,1b,1c,1dmay thus be received between a respective flange322a,322band its associated abutment plate317a,317bof said joining bracket300, see further below. The joining bracket300can be manufactured by avoiding the folding along the attaching edges123a,123bof the corner bracket100as shown inFIG. 6a. The joining bracket300can also be used as a holding bracket, i.e. without joining two board pieces.

The window frame is mounted in the mounting collar and can be fixed in place by conventional means. For example, screws could be inserted through the window frame and into the mounting collar. If the material of mounting collar allows the screws to be pulled out too easily, it may be necessary to arrange a plate at the outside face of the mounting collar. A screw can then be inserted through the window frame, through the mounting collar and through the plate to provide a firmer connection. However, if external wall insulation is already in place, then positioning of a plate at the outside face of the mounting collar can be difficult.

Therefore, it has been found to be particularly advantageous to use a frame mounting clip to mount the window frame in the mounting collar. The frame mounting clip has a base plate and first and second side plates extending from opposite ends of the base plate, substantially perpendicular to the base plate and substantially parallel to each other. The clip can be arranged on the mounting collar at its second end such that the first side plate abuts an inside face of the mounting collar and the second side plate abuts an outside face of the mounting collar. In order to mount the window frame in place, a screw is inserted through the window frame, the first side plate of the mounting clip, through the window mounting collar and through the second side plate of the mounting clip.

This clip allows for a stronger attachment of the window frame to the mounting collar and allows for easy positioning of the clip because the base plate of the mounting clip is always easily accessible, even when external wall insulation is in place surrounding the mounting collar.

The clip can be made of any suitable material with sufficient rigidity and strength and that can accept screws. The clip could, for example, be made of metal. However, materials with a lower thermal conductivity are preferred. In one embodiment, the first and second side plates of the clip each comprise a pre-bored hole to accept a screw.FIG. 10shows an example of a mounting clip system. The mounting clip23has a base plate24and first and second side plates25,26extending from opposite ends of the base plate24. The clip23is shown arranged on the mounting collar1at its second end6such that the first side plate25abuts an inside face2aof the mounting collar1and the second side plate26abuts an outside face2bof the mounting collar1. The first side plate25of the window mounting clip23is shaped as a wedge, having a thickness at its end furthest from the base plate24that is greater than the thickness of the first side plate25of the window mounting clip23at its end that is adjoined to the base plate24.

When assembling the collar1ofFIG. 5, first the boards1a,1b,1c,1dare cut (e.g. sawed) out from longer board members. If this results in surplus board pieces, examples of surplus board pieces shown as board pieces1eand1finFIG. 5, of too short lengths, these may be further cut to appropriate sizes to be joined by means of one or more joining brackets300to form a resultant board, in the example ofFIG. 5board1b, of suitable length. The boards may alternatively be manufactured from the factory in suitable lengths so as to avoid the sawing operation.

Two respective of the boards1a,1b,1c,1dof the collar1are subsequently positioned between abutment plate117a,177band associated flange122a,122b, respectively, of a first corner bracket100to be preliminary retained to the corner bracket100between the abutment plates117a,177band the associated flanges122a,122b. The associated board1a,1b,1c,1dis then permanently retained by means of oblong retention members in the form of bolts (not shown) inserted through the retention apertures130a,130bof the abutment plates117a,117b, through the associated board1a,1b,1c,1d, and through further, associated retention apertures (not shown) of flanges122a,122b. Hereby, the two associated boards1a,1b,1c,1dare positioned in the bracket100as shown inFIG. 5, the boards1a,1b,1c,1dforming a collar corner of the collar1. This procedure is subsequently performed with each corner bracket of the collar1, thereby resulting in a finished collar1as shown inFIG. 5. The boards may alternatively be inserted preliminarily in all the collar corners before permanent retention is achieved by means of the bolts. One or more holding brackets200are before or after attachment of the corner brackets100attached to the boards1a,1b,1c,1dto further attach the boards1a,1b,1c,1dto the façade8. Screws or bolts are inserted through receiving apertures18,118a,118b,218,318a,318binto the façade8to affix the collar1to the façade8; this may be done before, during or after assembly of the collar1.

In the embodiment shown the mounting clip23forms one part of a clip system. The clip system comprises the mounting clip23and a separate plate27. The face of the first side plate25of the mounting clip that faces away from the second side plate has ridges28. The peaks of the ridges are substantially parallel to the base plate24of the clip. The clip system also comprises a separate plate27having ridges29on one of its faces that are adapted to cooperate with the ridges28on the first side plate25of the mounting clip. A window frame not shown can be set in place by positioning the window frame in the mounting collar1and then pushing the separate plates27in between the window frame and the mounting clip23. The frame is then fixed in place with screws.