Mounting bracket for connecting a window or door frame to an opening

Abstract

 A mounting bracket (1,20,60,70) suitable for connecting a fixed frame (50a,50b,50c,50d) of a window assembly to an opening in a wall, said fixed frame being of the type with a groove (51) arranged along at least a portion of the outer periphery of the fixed frame, said mounting bracket comprising least a first flange (6) and a second flange (7) which protrude from the bracket, said flanges are arranged one on each side of a first axis (C) which is parallel to an axis which is perpendicular to the plane of the window and one on each side of a first plane (A) which is parallel to the plane of the window and where the first flange (6) is in contact with at least a portion of a first inner side of said groove (51) and the second flange (7) is in contact with at least a portion of a second inner side of said groove (51) which is opposite the first inner side of said groove. Said contact between the flanges and the inner sides of the groove when seen in a cross section taken along a plane which is perpendicular to the longitudinal axis of the groove, forms a path of contact, the angle between the average tangent of the path of contact and the plane of the window assembly being less than 80°, preferably less than 60°, and most preferably being less than 40°.

Description

[0001] The current invention relates to a mounting bracket which is suitable for connecting a fixed frame of a window assembly to an opening in a wall. The fixed frame is of the type which has a groove arranged along at least a portion of its outer periphery and arranged such that the longitudinal axis of the groove is parallel with the plane of the window assembly. The mounting bracket comprises a first area which is arranged to be fastened to the fixed frame and a second area which is arranged to be fastened to said opening when window assembly is mounted in the opening. The first area comprises at least a first flange and a second flange which protrude from the first area. When the bracket is mounted on the fixed frame, the flanges protrude from the first area on the side of said mounting bracket which is facing the fixed frame and are arranged one on each side of a first axis which is parallel to an axis which is perpendicular to the plane of the window and one on each side of a first plane which is parallel to the plane of the window. The first flange is in contact with at least a portion of a first inner side of said groove and the second flange is in contact with at least a portion of a second inner side of said groove which is opposite the first inner side of said groove

[0002] It should be noted that in the description the focus is on window assemblies, however it should be clear to the person skilled in the art that the mounting bracket of the invention can also be used to mount door frames in wall openings.

[0003] In the current specification, the term "groove" should be understood as a longitudinal recess having an essentially constant cross section taken along a plane which is perpendicular to the longitudinal axis of the groove. The term "flange" should be understood as an element which protrudes from the main body portion of the bracket and having a surface which can press up against the inner side of the groove. In the context of the current specification, the flange could take many forms, both straight, curved, asymmetric, symmetric, etc.

Description of related art

[0004] Mounting brackets for mounting a window or door assembly in a wall opening are known in many different forms. Many brackets are attached to the fixed frame of the window or door assembly via screws/nails and also fixed to the wall opening via screws/nails. An example of this type of bracket is shown in DK 176245 B1 (Friis).

[0005] Lately many window and door assemblies have been manufactured from composite materials and metal. In these types of materials, it is often possible to form a track in a portion of the fixed frame which has two flanges. Many brackets have therefore been disclosed which can engage with the flanges of such a track. Some examples of such brackets are disclosed in DE 6913297 (Schenning), EP 1 806 469 A2 (Fuchs), EP 1 688 577 A2 (Mallebay) and GB 2 291 455 A (Wilson).

[0006] A problem with the first type of bracket is that it can be difficult to mount the bracket on the window frame since the person mounting the bracket has to hold the bracket in one hand while fastening the bracket to the window with the screws/nails. This can be a complicated procedure especially if the window needs to be stabilized during the mounting as well.

[0007] The second type of bracket discussed above is only suitable for use with frames having a track with two flanges which the bracket can engage. However, for frames which are made of wood, the brackets can't be used since it is not possible to make thin and strong flanges in a wooden frame which would be suitable for the known types of brackets. Furthermore, certain types of composite materials are very strong, but are also very brittle. In these types of materials, it is also not possible to make thin flanges which will be robust enough to be used together with such brackets.

[0008] Another example of a known bracket is disclosed in DE 30 39 484 A1 (Schwarzer). This bracket is used on wooden frames. A tooth on the bracket is arranged in a groove in the frame. The bracket is then rotated 90° and the tooth is forced into the sides of the groove. However, this type of bracket creates quite a bit of damage on the frame due to the large tooth which needs to cut into the frame. This can weaken the frame. Furthermore, this type of bracket can't be used together with composite frames. Another problem with this type of bracket is that over time, the tooth will press itself more and more into the groove and the frame will become loose.

Summary of the invention

[0009] It is therefore one aspect of the current invention to provide a mounting bracket as mentioned in the opening paragraph which is better than the mounting brackets known in the art.

[0010] This aspect is provided by a mounting bracket according to the opening paragraph where the contact between the flanges and the inner sides of the groove when seen in a cross section taken along a plane which is perpendicular to the longitudinal axis of the groove, forms a path of contact, the angle between the average tangent of the path of contact and the plane of the window assembly being less than 80°, preferably less than 60°, and most preferably being less than 40°. In this way, it is possible to distribute the forces which are applied to the groove in the frame by the flanges of the bracket over a larger area. It is also possible to build the groove without thin flanges. This makes it possible to use the bracket in softer materials such as wood and less robust materials such as fiberglass.

[0011] Additional features of the invention are described in the dependent claims and the details and advantages of the different features are discussed in the description.

[0012] It should be emphasized that the term "comprises/comprising/comprised of" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0013] For example, in the embodiments shown in the figures, there are two distinct flanges. But it could also be imagined that each flange could be made up of a number of smaller flanges, rods, columns, flaps, etc... Together, they form a surface which can press up against the side of the groove. Also, it should be understood that the two flanges could be joined together such that they are integrally formed, but still act as two flanges which each press up against the sides of the groove.

Brief description of the drawings

[0014] In the following, the invention will be described in greater detail with reference to embodiments shown by the enclosed figures. It should be emphasized that the embodiments shown are used for example purposes only and should not be used to limit the scope of the invention.

[0015] Figures 1-5 show a top perspective view, a bottom perspective view, a top view, a side view and a bottom view respectively of a first embodiment of a left hand (when seen from the inside of the window) mounting bracket according to the invention.

[0016] Figures 6-7 show a top perspective view and a bottom perspective view respectively of a first embodiment of a right hand (when seen from the inside of the window) mounting bracket according to the invention.

[0017] Figures 8-9 show two different perspective views of a window assembly comprising a bracket according to figures 1-5 mounted on the left side of the window assembly and a bracket according to figures 6-7 mounted on the right side of the window assembly.

Figure 10 shows a left side view of the window assembly shown in figures 8-9.

Figure 11 shows a right side view of the window assembly shown in figures 8-9.

Figure 12 shows a top view of the window assembly shown in figures 8-9.

Figure 13 shows a detail left side view of the connection between the bracket and the window frame of the window assembly shown in figures 8-9.

Figure 14 shows a detail right side view of the connection between the bracket and the window frame of the window assembly shown in figures 8-9.

Figure 15 shows a detail top view of the connection between the left hand bracket and the window frame of the window assembly shown in figures 8-9.

Figure 16 shows a detail top view of the connection between the right hand bracket and the window frame of the window assembly shown in figures 8-9.

Figures 17-21 show a top perspective view, a bottom perspective view, a top view, a side view and a bottom view respectively of a second embodiment of a left hand (when seen from the inside of the window) mounting bracket according to the invention.

Figures 22-24 show a top perspective view, a top view in the mounted position and a top view in a mounting position respectively of a third embodiment of a left hand (when seen from the inside of the window) mounting bracket according to the invention.

Figure 25-27 show top views of a fourth embodiment of a bracket, showing an engagement element in three different positions.

Detailed description of the embodiments

[0018] The mounting bracket 1 shown in figures 1-5 is a mounting bracket for mounting a window assembly in an opening in a wall. Figures 11-19 show details of how the mounting bracket achieves this purpose. Figures 11-19 will be described in more detail later on in this specification.

[0019] The mounting bracket of figures 1-5 is a left hand bracket. That is to say, the bracket is design to be mounted on the left hand side of a window assembly when the window is seen from the inside. It should be noted that the bracket can also be mounted on the right hand side of a window assembly, but will not have the same effect. We will return to this feature later on in this specification.

[0020] The bracket 1 is formed from a plate like material such as metal sheet which is stamped and bent into the proper shape. The bracket comprises an elongated body portion 2. In order to make the body portion stiff, ribs 3 are formed along the longitudinal axis of the body portion. The bracket has a first area 4 which is connected to the window frame when the bracket is mounted on a window frame and a second area 5 which is connected to the wall opening when the bracket is connected to a wall opening. At the second area 5 there are a number of holes through which screws and/or other types of fasteners can be mounted to fasten the bracket to the wall opening.

[0021] At the first area 4, the bracket comprises two flanges 6, 7 which protrude from the first area on the side of the bracket which will be facing the window frame when the bracket is mounted on a window frame. As it can be seen from the figures, the flanges are formed by making a C-shaped cut in the material of the bracket at the first area and then bending the flange up. The flanges in this particular embodiment are essentially rectangular planar flanges. The flanges are arranged one on each side of the centre axis C of the bracket and one on each side a plane A which is parallel to the plane of the window assembly. It should be mentioned that in this particular embodiment, the centre axis of the bracket is aligned with an axis which is perpendicular to the plane of the window assembly.

[0022] The flanges are arranged such that the plane of the flange is arranged at an angle to the plane of the window assembly. In the current example, the two flanges are each angled the same amount from the plane of the window assembly, but in opposite directions. This can be seen when looking at the flanges from the side of the bracket (see figure 4), where it can be see that the flanges form a V shape with respect to each other. In order to strengthen the flanges, against forces which attempt to bend the flanges, a support rib 8 has been formed in the centre of each flange.

[0023] The flanges have also been formed with three protrusions 9, 10, 11 extending from the ends of each of the flanges. The protrusions extend in a direction which is perpendicular to the plane of the window assembly when the bracket is mounted on the window frame. As can be seen from especially figures 3 and 5, there is one large protrusion 9 near the side of the bracket when seen from the top or bottom, and two smaller protrusions 10,11 near the centre of the bracket when seen from the top or bottom.

[0024] The bracket also comprises two holes 12 in the first area of the bracket. These holes can be used for screws which can further fasten the bracket to the window frame if it is necessary. It can also be seen from the figures that the bracket at the first area of the bracket has been formed into a box like structure. This gives extra strength to the bracket.

[0025] The mounting bracket 20 shown in figures 6-7 is the mirror image of the bracket shown in figures 1-5 and is therefore designed to be mounted on the right hand side of a window assembly when the window is seen from the inside. The bracket of figures 6-7 won't be described in detail, but the reader is referred to the description of the bracket in figures 1-5. The reference numerals on figures 6-7 are the same reference numerals that are used in figures 1-5.

[0026] Figures 8-16 show different views of how the brackets 1, 20 are attached to a window frame 50. The window frame 50 is comprised of four wooden frame elements 50a, 50b, 50c, 50d. A groove 51 is arranged along the periphery of the window frame of two of the frame elements 50a, 50c. In many cases, a groove will be formed around all four frame elements. The groove of the current embodiment is a dovetail groove. By dovetail groove, is meant a groove which is narrower at its entrance than in its interior.

[0027] A left hand bracket 1 is mounted on the left hand side of the window frame when seen from the inside of the window and a right hand bracket 20 is mounted on the right hand side of the window frame when seen from inside the window. The left hand bracket 1 is shown in a position just before it is fastened to the frame and the right hand bracket 20 is shown after it has been fastened to the frame.

[0028] As can be seen from the figure, see especially figures 10 and 13, the left hand bracket is rotated clockwise about 20 degrees from the horizontal. In this position, it can be seen that the maximum distance between the flanges 7 and protrusions 9,10,11 in the direction which is perpendicular to the plane of the window assembly is less than when the bracket is rotated into the horizontal position. The horizontal position is shown in figures 11 and 14. This is especially clear when comparing figures 16 and 17. When the bracket is rotated, it is possible to insert the flanges of the bracket into the groove in the frame. When the flanges have been inserted as shown in figures 16 and 18, the bracket can be rotated, back into the horizontal position. In this way, the flanges are pressed up against the inner sides of the groove and the protrusions are pressed into the wooden material of the frame. In this way, the protrusions "bite" into the frame and hold the bracket fastened to the frame.

[0029] In addition, the protrusions have the effect of increasing the friction between the bracket and the frame in the direction which is parallel to the longitudinal axis of the groove. This allows the bracket to support a portion of the window's own weight when the window is mounted in the window opening. If enough brackets are used with respect to the weight of the window, it is possible to eliminate the need for brackets mounted at the base of the window.

[0030] It can also be seen from figure 16 that the flanges press up against the inner sides of the groove. The contact between the inner sides of the groove and the flanges, is spread out over an area. When seen in a cross section taken along a plane which is perpendicular to the longitudinal axis of the groove, the contact occurs along a contact path. As can be seen from the figures, this contact path assumes an angle to the plane of the window assembly which is quite small. In the prior art where the bracket engages with flanges on the frame profile, the path of contact is usually arranged at an angle of 90° to the plane of the window assembly. In this way, one ends up with thin flanges if the frame profile thickness is to be minimized. However, by arranging the contact path at a smaller angle to the plane of the window assembly, the contact area can be increased and the forces on the frame minimized. It should also be noted that if the contact path were curved, then according to the invention, the average of the tangent of the contact path would be at an angle of less than 90° to the plane of the window assembly.

[0031] The design of the flanges which presses against opposite inner sides of the groove, also has the effect of securing the bracket in the groove such that the frame cannot move relative to the bracket in the direction which is perpendicular to the plane of the window. This ensures that the bracket can support the window when it is exposed to wind loads.

[0032] It can also be mentioned that when a left hand bracket is mounted on the left hand side of the window, the weight of the window will cause the protrusions to be forced deeper into the wood of the frame. This would also make it possible to fasten the bracket to the wall opening at its second end with a single bolt because the bracket would be able to support a moment at the interface between the groove and the bracket. However, this would cause large moments to be applied to the groove in the frame. If the frame was not strong enough, the bracket could damage the frame. Therefore, in most cases, two screws would be used to fasten the bracket to the wall opening. In this way, the bracket acts as a beam solidly connected to the wall opening and most of the moments would be applied to the wall opening.

[0033] If the left hand bracket were mounted on the right hand side of the window, then the weight of the window would cause the protrusions to withdraw from the wood. However, it could be mentioned that when the left hand bracket is mounted on the right hand side of the window, then the bracket would hold itself in position due to gravity, before the protrusions have been forced into the wood of the frame. Therefore, in embodiments which don't have protrusions which bite into the frame, it might be desirable to use a left hand bracket on the right hand side of the frame in order to ease mounting of the brackets on the frame.

[0034] In the above example, the brackets have been mounted to the left and right hand sides of the window. However, within the scope of the invention, it could also be advantageous to mount the brackets to the top and/or bottom of the window. For example, when a side hung window is attached to a wall opening, there are loads in the frame which run sideways due to the moment applied by the window sash on the window frame. In this case, a bracket according to the current invention could be mounted on the top of the frame to support the forces which are present in the top and bottom frame members.

[0035] For example, if the window assembly shown in figure 8 where a side hung window where a window sash was hinged on the right hand side of the window when looking out of the window, there would be forces which would cause the window frame to want to rotated counter clockwise when looking out the window. In this case, a left hand bracket could be mounted to the top frame element and/or a left hand bracket could be mounted to the bottom frame element. It should be noted that figure 8 shows top and bottom frame elements without a groove, however, a groove could be added if brackets were to be added to the top and/or bottom frame element.

[0036] The second embodiment of a bracket 60 shown in figures 17-21 is almost identical to the bracket 1 shown in figures 1-5. It is also a left hand bracket. The major differences between the bracket 60 of figures 17-21 and the bracket 1 of figures 1-5 is that the flanges 6,7 have two smaller support ribs 61,62 instead of one larger support rib 8 and there is only one protrusion 63,64 per flange instead of three as in the previous embodiment. It can also be seen that the protrusion 63 which is arranged at the top of the bracket when the bracket is mounted on the frame, is formed to provide more support to the protrusion with a curved portion 65 below the protrusion. In this way, the protrusion is strengthened. This allows the protrusion to bear more load in a direction which is parallel to the longitudinal axis of the groove.

[0037] The third embodiment of a bracket 70 shown in figures 22-24 is very similar to the bracket 1 shown in figures 1-5 and is also a left hand bracket. Please note that the elongated body portion of the bracket is not shown in figures 22-24 in order to simplify the figures. The major differences between the bracket 70 of figures 22-24 and the bracket 1 of figures 1-5 is that the instead of having bent up metal flanges as in figures 1-5, the "flanges" 6,7 of the third embodiment are two surfaces of a single solid protrusion 71. The solid protrusion 71, has two flat surfaces 6,7 which will engage with the inner sides 74 of the groove when the bracket is rotated into place. On the side of the flanges 6,7 there is a curved surface 72,73. This curved surface helps in pressing the bracket into the groove when the solid protrusion 71 is made slightly larger than the groove. This allows the protrusion 71 to securely wedge in place in the groove.

[0038] We note that in the current embodiment, the surfaces 6,7 are shown as being flat and smooth. However, it could be imagined that the surfaces 6,7 are provided with small protrusions or other friction enhancing means in order to more securely grip onto the inner sides of the groove.

[0039] The fourth embodiment of a bracket shown in figures 25-27 is very similar to the bracket shown in figure 22-24, but in order to simplify the figures, only the solid protrusion 81, the inner sides 82 of the groove and the longitudinal axis L of the bracket are shown in the figures. in the figures. The main body of the protrusion 82 is formed as a protrusion having a generally oval shape. On either side of the major axis of the oval protrusion, flanges 6,7 are arranged.

[0040] When the bracket is to be mounted in place, the solid protrusion is inserted into the groove as shown in figure 25 with the longitudinal axis of the bracket at around 80 degrees to the plane which is perpendicular to the longitudinal axis of the groove. In this position, the dimension of the solid protrusion perpendicular to the groove is less than the width of the groove. When the bracket is rotated clockwise in the figures the oval protrusion wedges into the groove. When the major axis of the oval is perpendicular to the longitudinal axis of the groove, see figure 26, the oval disk slightly deforms the groove because the width of the oval protrusion at the major axis is slightly larger than the width of the groove. When the bracket is further rotated, the groove springs back because the major dimension of the oval has been passed. A slight rotation more and the flanges come into contact with the sides of the groove, see figure 27. In this way, the solid protrusion is held firmly in the groove and can't fall out. When the bracket is to be removed, the bracket must be forcefully rotated in order to rotate the major dimension of the oval protrusion past the inner sides of the groove.

[0041] In this way, the solid protrusion 81 is formed such that it has a position in which is locked in place and can only be removed by the application of a certain amount of force. This self locking action can be attributed to the fact that the distance from the centre of the protrusion to the perimeter of the solid protrusion has at least four peaks, instead of just two as would be the case with a simple oval. In the embodiment shown, along the direction of rotation, the first peak is slightly lower than the second peak.

[0042] As mentioned previously the embodiments shown in the figures have only shown a limited number of different embodiments which are covered by the scope of the invention. The person skilled in the art will be able to develop other embodiments based on the teachings of the current invention.

[0043] For example, in the embodiments shown, the groove has been a dovetail groove. However, the invention will also cover grooves having a square cross section for example. In this case, the flanges could be made spring loaded so that they are firmly pressed against the sides of the groove when the bracket is mounted on the groove.

[0044] Another example is that the embodiments shown in the figures all have protrusions which act as large hooks which press into the material of the frame. However embodiments of brackets which don't have such large hook like protrusions could also be imagined. For example one could imagine small protrusions in the main body of the flange which could press out and dig into the sides of the groove.

[0045] If the brackets should be used together with a frame material other than wood, for example fibreglass or metal, large protrusions which dig into the material will not be the best solution. However, in this case, other types of friction inducing means could be used to allow the bracket to support vertical loads. For example, one could use glue or other type of adhesive. One could also imagine that a number of recesses were formed in the sides of the groove of the frame element, with which a large protrusion could engage when mounted on the frame.

[0046] It can also be mentioned that the current embodiments are all elongated, however, the bracket could have another form than elongated. For example, the bracket could be square or triangular. In addition, the flanges have all been shown as flat planar flanges. however, it could also be imagined that the flanges were curved and that the inner sides of the groove were curved a similar amount.

[0047] It should also be mentioned that the current embodiment has been related to a window having a window frame with four frame elements. However, the brackets can also be used to mount a door in a wall opening. As will be known to the person skilled in the art, door frames are typically comprised of two side frame elements (jamb), a top frame element (head) and a bottom frame element (threshold). In the most common cases, the bracket according to the invention will be mounted to the left and right side frame elements (jamb). In many cases, the top and side frame elements will be identical and will have a groove at their outer side, whereas the bottom frame element will be different and not have a groove on its outer side.

Claims

1. A mounting bracket (1;20;60;70) suitable for connecting a fixed frame (50a,50b,50c,50d) of a window assembly to an opening in a wall, said fixed frame being of the type with a groove (51) arranged along at least a portion of the outer periphery of the fixed frame and arranged such that the longitudinal axis of the groove is parallel with the plane of the window assembly, said mounting bracket comprising a first area (4) which is arranged to be fastened to the fixed frame and a second area (5) which is arranged to be fastened to said opening when window assembly is mounted in the opening, and where said first area comprises at least a first flange (6) and a second flange (7) which protrude from the first area, said bracket being arranged such that when said bracket is mounted on the fixed frame, the flanges protrude from the first area on the side of said mounting bracket which is facing the fixed frame, said flanges are arranged one on each side of a first axis (C) which is parallel to an axis which is perpendicular to the plane of the window and one on each side of a first plane (A) which is parallel to the plane of the window and where the first flange is in contact with at least a portion of a first inner side of said groove and the second flange is in contact with at least a portion of a second inner side of said groove which is opposite the first inner side of said groove characterized in that the contact between the flanges and the inner sides of the groove when seen in a cross section taken along a plane which is perpendicular to the longitudinal axis of the groove, forms a path of contact, the angle between the average tangent of the path of contact and the plane of the window assembly being less than 80°, preferably less than 60°, and most preferably being less than 40°.

2. A mounting bracket (1;20;60;70) according to claim 1, characterized in that at least one of the flanges (6,7) is arranged such that the flange's dimension which is parallel to the longitudinal axis of the groove to which the bracket is connected when the bracket is connected to the frame is greater than the flange's dimension which is perpendicular to said longitudinal axis of the groove (51).

3. A mounting bracket (1;20;60) according to claim 1 or 2, characterized in that the mounting bracket is formed from a metal plate element (2) and that the flanges (6,7) are stamped and bent away from the plane of the bracket.

4. A mounting bracket (1;20;60) according to any one of claims 1-3, characterized in that at least one flange (6,7) has a friction enhancing element (9,10,11; 63,64) which is arranged to increase the friction between the flange and the side of the groove (51) which the flange is in contact with when said bracket is mounted on the frame, the friction being increased in the direction which is parallel to the longitudinal axis of the groove.

5. A mounting bracket (1;20;60) according to claim 4, characterized in that the friction enhancing element (9,10,11; 63,64) is a protrusion which is attached to the flange and which protrudes from said flange in a direction having a component which is perpendicular to the plane of the window when the bracket is mounted on the frame (50), said protrusion being arranged to protrude into a recess in the inner side of the groove (51) of the frame element when the bracket is mounted on the frame.

6. A mounting bracket (1;20;60;70) according to any one of claims 1-5, characterized in that flanges (6,7) are arranged such that when the bracket is held such that the first axis (C) is at an angle to the axis which is perpendicular to the plane of the window structure, the maximum distance between the flanges in a direction which is perpendicular to the plane of the window structure is less than when the bracket is held such that the first axis is parallel with the axis which is perpendicular to the window structure.

7. A window structure which is suitable for being mounted in a window opening, said window structure comprising a window frame (50) being of the type with a groove (51) arranged along at least a portion of the outer periphery of the window frame and arranged such that the longitudinal axis of the groove is parallel with the plane of the window structure and where said window structure comprises at least one mounting bracket (1 ;20;60;70) according to any one of claims 1-6.

8. A window structure according to claim 7, characterized in that the groove (51) in the window frame (50) is a dovetail groove and that the two flanges (6,7) are arranged such that when the bracket is mounted on the window frame the outer surfaces of the flanges presses up against the inner sides of the dovetail groove.

9. A window structure according to claim 7 or 8, characterized in that the window frame (50) comprises a wooden portion and that the groove (51) is placed in the wooden portion of the window frame.

10. A window structure according to claim 5 and 9 , characterized in that the protrusion (9; 63,64) is in the form of a hook which cuts into the wooden portion of the window frame (50) when the mounting bracket (1 ;20;60) is mounted on the window frame.

Drawing