[0001] The present invention relates to a roof window frame having top, bottom and side
parts surrounding an opening, which side parts are made up as a sandwich construction
comprising a first insulating member secured to a first supporting member on a side
opposite the opening.
[0002] Attics and lofts are increasingly being used for living, which requires installation
of roof windows. With increasing prices of energy there is a growing demand for energy
saving solutions for roof windows, and various solutions have been proposed in recent
years.
[0003] EP-A1-0679773 discloses a window frame according to the preamble of claim 1.
[0004] A frame box for roof windows is the subject of
EP-B1-0 679 773. This frame box comprises a window frame, which carries the window sash, and a window
frame carrier, which carries the window frame and is insertable in the roof. The carrier
is a sandwich construction made up of heat insulating material with a supporting member.
This construction is depicted in Fig. 2 and will be described in more detail with
reference to the drawing. It is found, however, that the insulating property of the
frame is mediocre.
[0005] US patent no. 6,263,624 discloses a skylight assembly comprising a curb of a plastic sheet material. The
sheet further extends to form an integral surrounding flashing portion. Strips of
rigid foam insulation material are adhesively attached to the inner peripheral portions
of the curb, and wood trim strips are adhesively attached to the inner peripheral
portions of the foam strips. This construction is a light-weight dome type of skylight
without a separate frame, and is hence not suited for roof windows.
[0006] A further example of related art is
WO-A1-98/31896, which relates to an insulation and installation frame for a roof window. An embodiment
comprises insulating frame elements provided with reinforcing and supporting strips.
A conventional roof window frame can be installed on the installation frame, whereby
installation of the roof window is facilitated and insulation of the window construction
in the installed position is improved. However, the installation frame is somewhat
delicate, and in addition relatively bulky, so there is a risk that the installation
frame will be damaged, thereby increasing the cost and time necessary for handling
and installation of the frame.
[0007] Another insulation and installation frame is described in
EP-A1-1 061 199. This document relates to an insulating installation frame for a roof window, where
the frame is made up of insulating elements. The installation frame is adapted for
attachment to a roof construction, and will provide a seat for the roof window for
installation of the roof window. This insulation and installation frame is delicate
and subject to damage.
[0008] Although these known constructions are all steps in the right direction, they all
have some drawbacks and they appear as half measures resulting in sub-optimization
of the insulating properties.
[0009] It is an object of the present invention to provide a roof window frame with improved
insulating properties.
[0010] To meet this object, the roof window frame outlined in the introduction comprises
all features of claim 1. The second supporting member makes it possible to provide
an integral, self-supporting window frame with improved insulating properties. Hereby
a separate insulating and installation frame is not needed, and hence installation
of the window frame is facilitated. The window frame can be produced cost efficiently
in an automated process to be ready for installation in one operation. Further the
resulting integral window frame is also relatively robust compared to the relatively
delicate insulating and installation frames discussed above.
[0011] According to the invention, the second supporting member of the roof window frame,
in a mounted position of the frame, is arranged exterior to a building in which the
roof window frame is mounted. By arranging the second supporting member, which will
typically be made of a material having poor insulating properties, in a region exterior
to the building, i.e. remote from the warm interior of the building, the second supporting
member will only have a very limited effect on the insulating properties of the window
frame. Further the amount of insulating material may be increased in regions that
affect the insulating properties of the window frame.
[0012] The second supporting member may be made from any suitable high-strength material,
e.g. plastics or reinforced plastics, but it is presently preferred that the second
supporting member is made of metal, such as a U-shaped steel profile, which will provide
a relatively cheap and high-strength member. The U-shape inherently provides favourable
strength properties and further allows hinges etc. to be accommodated within the supporting
member. Moreover the U-shaped profile provides outer surfaces for attachment of mounting
brackets and the like. Alternatively the second supporting member may be massive or
for example L-shaped, although such embodiments presently are considered to be less
than optimum. The second supporting member will allow the dimension of the first supporting
member to be reduced, thereby reducing the effect of heat conduction through the first
supporting member, so the effect of the second supporting member as a thermal bridge
is reduced. Further the second supporting member will relieve the first supporting
member, whereby alternative materials can be used for the first supporting member,
e.g. materials of reduced strength and low thermal conductivity, thereby improving
the insulating properties of the window frame construction.
[0013] To further increase the insulating capabilities of the roof window frame the first
supporting member may, on a side facing the opening, carry a second insulating member.
The second insulating member may also provide be considered as trim, and may further
provide an abutment face for a lining.
[0014] In an embodiment the roof window frame further comprises a slat arranged interior
to the first insulating member to facilitate aesthetical building-in of the window
frame, e.g. by plaster.
[0015] The present invention also relates to a method for manufacturing the window frame
outlined above. The method comprises the steps of providing a set of first supporting
members, and assembling the first supporting members to sub-frame of first supporting
members surrounding an opening, providing a set of second supporting members at a
side of the first supporting members opposite the opening and at the outer side of
the frame in a frame region, which is the mounted state of the frame on a roof construction
of a building is situated exterior to the building along a substantial part of side
parts of the window frame, and providing first insulating members at a side of the
first supporting members opposite the opening.
[0016] In an easily automated embodiment, the step of providing first insulating members
is performed by placing the sub-frame in a mould and foam moulding in-situ. This embodiment
will especially be advantageous when manufacturing the window frame in relatively
large numbers, as the production time per unit can be low, and the cost per unit hence
also low. Furthermore a consistent quality can easily be achieved.
[0017] In an alternative embodiment, the first insulating members are cut in shape and attached
to the first supporting member. This embodiment is particularly attractive when manufacturing
relatively small numbers of window frames, as the cost of production tooling is small.
[0018] According to an embodiment, the first insulating members are made of polyurethane
foam having a density in the range of 100-150 kg/m
3, which is found to provide advantageous results with regard to insulating properties
and this material is easy to use in the production.
[0019] In an embodiment a film is provided to the outer surface of the first insulating
members to protect the surface of the first insulating members, although it may be
superfluous depending on the material of the first insulating members and the environment
in which the window frame is installed. If provided, the film would protect the first
insulating members from exposure to e.g. moisture, and hence reduce the risk of deterioration
of the first insulating members. Further the film would encapsulate the first insulating
members and reduce the risk of release of any potentially harmful particles, such
as fibres.
[0020] In the following the invention will be described in more detail by way of example
and with reference to the accompanying drawing, in which:
Fig. 1 is a perspective view of a roof window,
Fig. 2 is a cross-sectional view of a prior art installation frame,
Fig. 3 is a cross-sectional view of a side part of an embodiment of a window frame
according to the invention,
Fig. 4 is a cross-sectional view corresponding to Fig. 3 of an alternative embodiment
of the invention,
Fig. 5 is a cross-sectional view of a side part according to another embodiment,
Fig. 6 is a cross-sectional view of a bottom part of a frame according to the invention,
Fig. 7 is a cross-sectional view of a top part,
Fig. 8 is a cross-sectional view of a side part, and
Fig. 9 is a cross-sectional view similar to Fig. 8 with isotherms plotted through
the side part.
[0021] A roof window is illustrated in perspective in Fig. 1. The roof window comprises
a frame 1 and a sash 11 provided with a pane 13.
[0022] A prior art window construction is illustrated in Fig. 2, which is a cross-sectional
view of a side of the prior art window construction known from
EP-B1-0 679 773. This prior art construction comprises a mounting frame 140, which is a sandwich
construction comprising a supporting member 103 and an insulating member 104. The
mounting frame 140 is secured to the roof rafter 143 by means of a screw 130. The
supporting member 103 of the mounting frame 140 is provided with a step 141 for supporting
a window frame 102. The window frame 102 is secured to the mounting frame 140 by a
screw 109, and a lining 120 is provided.
[0023] A window frame construction according to an embodiment of the invention can be seen
in the cross-sectional view of Fig. 3 and 4. The window frame 1 side part is a sandwich
construction comprising a first insulating member 4 attached to a first supporting
member 3. Commonly the window frame side parts are loaded more than the top and bottom
frame parts, and further the space available for insulating material at the side parts
is relatively restricted compared to the situation at the top and bottom parts, and
hence the side parts normally have the greatest influence on the overall insulating
property of the window frame.
[0024] The first insulating member 4 is arranged to a side of the first supporting member
3 opposite the window frame opening. Typically the first insulating member 4 consists
of a foam material, such as polyurethane foam. Polyurethane foam having a density
of 110-120 kg/m
3 was used with favourable result in a prototype of the invention. The skilled person
will however appreciate that other suitable materials for the first insulating member
include common insulating materials, such as stone wool, glass wool or the like. For
the first supporting member 3, it is presently preferred to use plywood, which is
a suitably strong and relatively cheap material, although other materials could be
envisaged, such as plastic materials, wood, fibre board etc. A board of plywood having
a thickness of approximately 6-7 mm and a height of for example approximately 150
mm will normally provide a first supporting member 3 of sufficient thickness.
[0025] The frame 1 further comprises an outwardly open U-shaped steel profile doing duty
as a second supporting member 5 attached to the first supporting member 3. The second
supporting member 5 is the primary supporting member of the frame 1 at the side parts
and is arranged at the outer side of the frame in a frame region, which in the mounted
state of the frame on a roof construction of a building is situated exterior to the
building. The second supporting members extend for a substantial length of the side
parts, such as at least 50% of the length of the side parts, at least 80%, or even
100%. The relative length of the second supporting member can be chosen dependent
on the size and load of the window frame, as a large window frame carrying a heavy
window sash will normally require a large relative length of the second supporting
member, whereas a small window frame carrying a light window sash may require only
a small relative length of the second supporting member. Suitable dimensions of the
U-shaped profile made of 2 mm steel plate is a height of approximately 60 mm and a
width of approximately 25-27 mm.
[0026] The second supporting member 5 can be used for anchoring of mounting brackets (not
shown) for installation to a roof structure of a building. The cavity 7 of the second
supporting member 5 can advantageously accommodate a pivot hinge (not shown) for a
moveable window sash.
[0027] On the side of the first supporting member 3 facing the opening of the window frame
1, the first supporting member 3 carries a second insulating member 2. The second
insulating member 2 may be a board of wood as illustrated in Fig. 3 or alternatively
a board comprising a hard outer shell 9 of a plastic material, such as high density
polyurethane, filled with an insulating core 10 of low density polyurethane foam.
Common to the embodiments of the insulating member 2 illustrated in Fig. 3 and 4 is
that the member 2 comprises a groove 8 adapted for receiving a key of a lining for
the opening.
[0028] As illustrated a slat 6 may be arranged to the interior side of the frame 1 at the
first insulating member 4 to provide a suitable surface for plaster, if considered
necessary or convenient.
[0029] Fig. 5 illustrates a similar, but slightly different embodiment of the frame 1 in
a cross-sectional view of a side part thereof. The frame 1 is shown with a sash 11
carrying an insulating pane 13 covering the opening 12 of the frame 1. A collar 14
is provided for connection to an underroof. A covering 15 is arranged to cover the
outer surface of the sash 11 and frame 1.
[0030] A bottom part of the frame 1 and sash 11 is seen in cross-sectional view in Fig.
6. The bottom part comprises a first insulating member 4, a first supporting member
3 and a second insulating member 2. A second supporting member will normally not be
necessary to provide a frame bottom part of sufficient strength, but can of course
be provided if it is considered convenient. The bottom part may be provided as a massive
part or a sort of sandwich construction as illustrated.
[0031] A top part of the frame 1 and sash 11 is seen in cross-section in Fig. 7. The top
part comprises a first insulating member 4, a first supporting member 3 and a second
insulating member 2. A second supporting member will normally not be necessary to
provide a frame top part of sufficient strength, but can of course be provided if
it is considered convenient. The top part may be provided as a massive part or a sort
of sandwich construction as illustrated. A housing 14 for a roller shutter 15 may
be integrated at the frame top part, and a guiding rail 16 may be arranged for guiding
the roller shutter 15. Such a roller shutter 15 may be provided initially or be retrofitted
to an installed window.
[0032] Fig. 8 is a cross-sectional view of a side part of a window frame 1. The second supporting
member 5 may accommodate a spring 18 serving as lifting assistance means for the sash.
The spring 18 is well protected in the U-shaped steel profile, and hidden, so the
spring 18 does not negatively affect the appearance of the window.
[0033] A plot of isotherms 17 in a cross-sectional view of a side part of the window can
be seen in Fig. 9. It is evident to the skilled person that the isotherms 17 follow
advantageous paths. The second supporting member 5 is positioned in an exterior region
of the frame 1, i.e. a relatively cold region of the construction, and hence the relatively
poor insulating properties of the second supporting member 5 does not influence the
insulating properties of the window construction negatively in any serious degree.
This is illustrated by the relatively smooth course of the isotherms in the first
insulating member 4.
1. A window frame (1) for an opening roof-window to be mounted substantially in plane
with a roof, said frame having top, bottom and side parts surrounding an opening,
which side parts are made up as a sandwich construction comprising a first insulating
member (4) secured to a first supporting member (3) on a side opposite the opening,
the first supporting member (3) being secured to a second supporting member (5) along
a substantial length of the side parts, characterized in that the second supporting member is arranged at a side of the first supporting members
opposite the opening and at the outer side of the frame in a frame region, which in
the mounted state of the frame on a roof construction of a building is situated exterior
to the building.
2. A roof window frame (1) according to claim 1, wherein the second supporting member
(5) of the roof window frame (1) is arranged so that, in a mounted position of the
frame, it will be located exterior to a building in which the roof window frame (1)
is mounted.
3. A roof window frame (1) according to claim 1 or 2, wherein the second supporting member
(5) is made of metal, such as a U-shaped steel profile.
4. A roof window frame (1) according to any of the claims above, wherein the first supporting
member (3), on a side facing the opening, carries a second insulating member (2).
5. A roof window frame (1) according to any of the claims above, further comprising a
slat (6) arranged interior to the first insulating member (4).
6. A method for manufacturing a window frame for an opening roof-window to be mounted
substantially ins plane with a roof according to any of the claims above,
characterized in that the method comprises the steps of providing a set of first supporting members, and
assembling the first supporting members to sub-frame of first supporting members surrounding
an opening,
providing a set of second supporting members at a side of the first supporting members
opposite the opening and at the outer side of the frame in a frame region, which in
the mounted state of the frame on a roof construction of a building is situated exterior
to the building along a substantial part of side parts of the window frame, and
providing first insulating members at a side of the first supporting members opposite
the opening.
7. A method according to claim 6, wherein the step of providing first insulating members
is performed by placing the sub-frame in a mould and foam moulding in-situ.
8. A method according to claim 6, wherein the first insulating members are cut in shape
and attached to the first supporting member.
9. A method according to any of the claims 6-8, wherein the first insulating members
are made of polyurethane foam having a density in the range of 100-150 kg/m3.
10. A method according to any of the claims 6-9, wherein a film is provided to the outer
surface of the first insulating members.
1. Fensterrahmen (1) für ein öffenbares Dachfenster, der dazu bestimmt ist, im Wesentlichen
in einer Ebene mit einem Dach montiert zu werden, wobei der Rahmen einen Oberteil,
einen Unterteil und Seitenteile aufweist, die eine Öffnung umgeben, wobei die Seitenteile
aus einer Sandwichkonstruktion bestehen, die einen ersten Isolierteil (4) umfasst,
der mit einem ersten Tragteil (3) auf einer Seite, gegenüber der Öffnung, verbunden
ist, wobei der erste Tragteil (3) mit einem zweiten Tragteil (5) über eine wesentliche
Länge der Seitenteile verbunden ist, dadurch gekennzeichnet, dass der zweite Tragteil auf einer Seite des ersten Tragteils angeordnet ist, die der
Öffnung gegenüber liegt und auf der Außenseite des Rahmens in einem Rahmenbereich
liegt, der, im montiertem Zustand des Rahmens, auf einer Dachkonstruktion eines Gebäudes
außerhalb des Gebäudes liegt.
2. Ein Dachfensterrahmen (1) entsprechend dem Anspruch 1, wobei der zweite Tragteil (5)
des Dachfensterrahmens (1) so ausgebildet ist, dass er, in montierter Position des
Rahmens, außerhalb des Gebäudes, an dem der Dachfensterrahmen (1) montiert ist, liegt.
3. Dachfensterrahmen (1) nach Anspruch 1 oder 2, wobei der zweite Tragteil (5) aus Metall,
beispielsweise einem U-förmigen Stahlprofil, besteht.
4. Dachfensterrahmen (1) nach einem der voranstehenden Ansprüche, wobei der erste Tragteil
(3) an einer Seite, die zur Öffnung gerichtete ist, einen zweiten Isolierteil (2)
trägt.
5. Dachfensterrahmen (1) nach einem der voranstehenden Ansprüche, weiters umfassend eine
Leiste (6), die innerhalb bezüglich des ersten Isolierteils (4) angeordnet ist.
6. Verfahren zur Herstellung eines Fensterrahmens für die Öffnung eines Dachfensters,
der im Wesentlichen in einer Ebene mit dem Dach montiert werden soll, entsprechend
einem der obenstehenden Ansprüche, dadurch gekennzeichnet, dass das Verfahren die Schritte umfasst, einen Satz von ersten Tragteilen anzubringen
und die ersten Tragteile zu einem Hilfsrahmen aus ersten Tragteilen zusammen zu bauen,
der die Öffnung umgibt, dann das Anbringen von zweiten Tragteilen auf einer Seite
der ersten Tragteile, die der Öffnung gegenüber liegt und auf der Außenseite des Rahmens
in einem Rahmenbereich liegt, der im montiertem Zustand des Rahmens auf einer Dachkonstruktion
eines Gebäudes außerhalb des Gebäudes zu liegen kommt, und das Verbinden entlang eines
wesentlichen Teils der Seitenteile des Dachrahmens und schließlich das Anbringen von
ersten Isolierteilen auf einer Seite der ersten Tragteile gegenüber der Öffnung.
7. Verfahren nach Anspruch 6, worin der Schritt des Anbringens von Isolierteilen durch
Platzieren des Hilfsrahmens in einer Form und in-situ Aufschäumen erfolgt.
8. Verfahren nach Anspruch 6, wobei die ersten Isolierteile in Form geschnitten und an
den ersten Tragteilen befestigt werden.
9. Verfahren nach einem der Ansprüche 6 bis 8, wobei die ersten Isolierteile aus Polyurethanschaum
mit einer Dichte im Bereich von 100 - 150 kg/m3 bestehen.
10. Verfahren nach einem der Ansprüche 6 bis 9, wobei ein Film auf der äußeren Oberfläche
der ersten Isolierteile vorgesehen ist.
1. Cadre de fenêtre (1) pour une fenêtre de toit ouvrante destiné à être monté essentiellement
dans le plan d'un toit, ledit cadre comportant des parties supérieure, inférieure
et latérales entourant une ouverture, lesquelles parties latérales sont fabriquées
sous la forme d'une construction en sandwich comprenant un premier élément isolant
(4) fixé à un premier élément de support (3) sur un côté opposé à l'ouverture, le
premier élément de support (3) étant fixé à un second élément de support (5) sur une
longueur importante des parties latérales, caractérisé en ce que le second élément de support est agencé au niveau d'un côté des premiers éléments
de support opposé à l'ouverture et au niveau du côté extérieur du cadre dans une zone
de cadre, laquelle, lorsque le cadre est monté sur une construction de toit d'un bâtiment,
est située à l'extérieur du bâtiment.
2. Cadre de fenêtre de toit (1) selon la revendication 1, dans lequel le second élément
de support (5) du cadre de fenêtre de toit (1) est agencé de sorte que, dans la position
montée du cadre, il sera placé à l'extérieur d'un bâtiment dans lequel le cadre de
fenêtre de toit (1) est monté.
3. Cadre de fenêtre de toit (1) selon la revendication 1 ou 2, dans lequel le second
élément de support (5) est constitué de métal, tel qu'un profilé en acier configuré
en U.
4. Cadre de fenêtre de toit (1) selon l'une quelconque des revendications précédentes,
dans lequel le premier élément de support (3), sur un côté faisant face à l'ouverture,
supporte un second élément isolant 2.
5. Cadre de fenêtre de toit (1) selon l'un quelconque des revendications précédentes,
comprenant, de plus, une latte (6) disposée à l'intérieur sur le premier élément isolant
(4).
6. Procédé de fabrication d'un cadre de fenêtre pour une fenêtre de toit ouvrante en
vue d'être monté essentiellement dans le plan d'un toit selon l'une quelconque des
revendications précédentes,
caractérisé en ce que le procédé comporte les étapes consistant à :
fournir un ensemble de premiers éléments de support, et à assembler les premiers éléments
de support selon une sous-structure de cadre faite des premiers éléments de support
entourant une ouverture,
fournir un ensemble de seconds éléments de support au niveau d'un côté des premiers
éléments de support opposé à l'ouverture et au niveau du côté extérieur du cadre dans
une zone du cadre, qui, lorsque le cadre est monté sur une construction de toit d'un
bâtiment, est située à l'extérieur du bâtiment le long d'une partie importante des
parties latérales du cadre de fenêtre, et
fournir des premiers éléments isolants au niveau d'un côté des premiers éléments de
support opposé à l'ouverture.
7. Procédé selon la revendication 6, dans lequel l'étape consistant à fournir des premiers
éléments isolants est exécutée en plaçant la sous-structure de cadre dans un moule
et à faire un moulage par expansion in situ.
8. Procédé selon la revendication 6 dans lequel les premiers éléments isolants sont découpés
à la forme et fixés au premier élément de support.
9. Procédé selon l'une quelconque des revendications 6 à 8, dans lequel les premiers
éléments isolants sont constitués de mousse de polyuréthanne ayant une densité se
situant dans la plage de 100 à 150 kg/m3.
10. Procédé selon l'une quelconque des revendications 6 à 9, dans lequel un film est fourni
sur la surface extérieure des premiers éléments isolants.