Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: A thermally broken frame The following statement is a full description of this invention, including the best method of performing it known to us: 2 A thermally broken frame Field of the invention The invention relates to thermally broken frames for supporting panel structures. The invention will be described with reference primarily to aluminium window frames, 5 although it will be appreciated that the invention also has application to frames for supporting other panel-like structures such as doors, shutters or the like, and frames made of other materials which may need to be thermally broken to reduce heat transfer from outside to inside (or vice-versa). Background of the invention 10 Windows frames are frequently supplied to the building sites as preassembled units. These preassembled units include a frame by which the window is mountable to the wall studs or other structural member of the building. The frame will support one or more sashes carrying a pane of glass. It is desirable to minimise the heat transfer through the window. For this purpose 15 windows are sometimes "double glazed" to reduce heat transfer through the pane portion of the window. Heat transfer through the frame portion of the window is also a problem. Aluminium is the most popular material used in Australian window frames. Aluminium outperforms alternative materials in this role in most respects but has the significant drawback of a 20 relatively high thermal conductivity. In cold climates, such as much of Europe "thermally broken" aluminium window frames are popular. Such window frames include an inner aluminium frame portion which is exposed to the inside of the building and an outer aluminium frame which is exposed to the outside of the building. These frame portions are structurally connected and 25 thermally isolated from each other by a plurality of polyamide strips. The polyamide strips, often called "dog-bones" in the field due to their cross sectional shape are 3 crimped into place in respective channels formed within the frame portions. The positioning of the strips varies from design to design but in common arrangements are often aligned with each other in a plane parallel to the pane of glass and spaced apart from each other in this plane throughout the thickness of the frame. 5 The spacing of the polyamide strips, increases the strength of the frame but places limitations on the thickness of the frame, which impinges on the area of the pane and is aesthetically undesirable. Following this "European approach" the aluminium window frame is typically fastened directly to the studs (or other structural members of the building) through the metal 10 frame portions using screws and the like. In Australia preassembled windows are mostly supplied with a timber reveal. The reveal is formed by the addition of an externally mounted timber frame surrounding the aluminium frame. The timber frame projects a short distance, say 100mm, from the indoor side of the aluminium frame. Such windows are typically installed using fasteners 15 such as screws or nails passing through the wooden reveal and into the studs (or other structural component) of the building. The use of such a reveal provides an aesthetically pleasing result desirable in the Australian market. Windows and doors with sliding panels present particular problems in relation to reducing heat transfer through the frame. Such windows typically include a frame 20 defining a pair of parallel inwardly facing channels about the periphery of the frame, a fixed panel is mounted within one of the channels, and a moveable panel mounted is slideably mounted within the other of the channels. Conventional practice dictates that such a frame can be thermally broken along the base portion of each channel using a pair of vertically spaced strips in the manner 25 described above for the single panel window. As a result, such a frame typically includes 3 aluminium extrusions and 4 polyamide strips. In addition to the need to thermally break the frame of the panel must also be thermally broken. According to 4 conventional practice panel frame would also include polyamide strip forming the thermal break. It is desirable to reduce the dimension of the frame and sash in directions parallel to the plane of the panel, to reduce the amount of material used in the frame, and to simplify 5 the construction of the frame. It is an object of the invention to provide improved frames for panel structures, or at least to provide alternatives in the market place. Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common 10 general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. Summary of the invention In a first aspect the present invention provides a frame for a panel structure, the frame 15 including a first frame portion, a second frame portion, a first insulating member structurally connecting the first frame portion and the second frame portion, a second insulating member structurally supporting the first frame portion and the second frame portion such that the second insulating member is attachable to a building structural element for installation of the frame. 20 The second insulating member can project in a first direction beyond an edge of either the first frame portion or second frame portion to define a reveal. Preferably one of, the first frame portion and the second frame portion, defines a channel for receiving a portion of the second insulating member. The frame can include one or more fasteners projecting through at least one of the first 2:5 frame portion and the second frame portion and engaging with the second insulating 5 member to fasten at least one of the first frame portion and the second frame portion to the second insulating member. In one form of the invention one of the first frame portion and the second frame portion is not fastened to the second insulating member. 5 The second insulating member is preferably a board or board-like member. Preferably the second insulating member is timber or a timber-substitute. The first insulating member is preferably a synthetic insulating strip. Preferably, the first insulating member is a polyamide strip. One or both of the first frame portion and the second frame portion are preferably 10 formed of metal. Preferably the metal is aluminium. The first and second frame portions can include one or more extruded sections. The frame can be adapted for carrying a plurality of panels in a parallel arrangement, at least one of the panels including a peripheral frame portion on at least part of its periphery; the first insulating member defining an upstanding wall extending inwardly 15 within the frame and extending to or beyond an inside edge portion of the peripheral frame portion of a panel carried in the frame, so as to thermally shield the peripheral frame portion. In a second aspect the present invention provides a frame for carrying at least two spaced parallel panels, at least one of the panels including a panel frame at at least part 20 of its periphery; the frame including a first insulating member defining an upstanding wall extending inwardly within the frame, parallel to and intermediate the panels to thermally shield the panel frame. The first insulating member can extend to or beyond an innermost extent of the panel frames proximal to the first insulating member.
6 The frame can include a first frame portion and a second frame portion, wherein the first insulating member structurally connects the first frame portion and the second frame portion. In some embodiments one or both of the first frame portion and the second frame 5 portion with the first insulating member define respective channels in the frame in which a panel is receivable. Preferably the frame is adapted to carry at least one fixed panel and one sliding panel. The frame can be a frame made in accordance with an embodiment of the first aspect of the invention. 10 In a further aspect the present invention provides a method of installing a panel structure for closing an opening in a structure the panel structure including a frame and at least one panel carried within the frame, the method including fastening the frame of the panel structure to a structural member of the structure via an insulating member providing a thermal break in the frame. 15 The method can include passing one or more fasteners through the insulating member. Preferably the panel structure includes a frame made according to an aspect of the invention. In a further aspect the present invention provides a window including the frame a frame made according to an aspect of the invention. 21) In a further aspect the present invention provides a door including a frame made according to an aspect of the invention. To avoid confusion the following terminology regarding orientation and direction is used in this document. However, as will be appreciated, these directions and orientations are chosen to aid understanding not to limit the scope of the present invention.
7 Inward means towards the centre of an opening within a frame or panel mounted within the frame. Outward means toward the periphery of the frame - opposite to inward. The thickness of the frame is the dimension of the frame in the inward-outward direction e.g. parallel to the plane of the panel in an ordinary closed position. 5 Indoor and outdoor (and inside and outside, inner and outer) are used to describe directions oppositely facing sides of the frame and panel. The width of the frame is its dimension measured in the indoor-outdoor direction e.g. perpendicular to the plane of the panel in an ordinary closed position. Use of the terms indoor and outdoor (and inside and outside) should not be considered to imply that the frames described herein 10 are limited in framing openings in external walls or mounted in a particular orientation. A panel is used to refer to a member used to close an opening in the frame, e.g. such as the sash of a window frame or a door in a door frame. Typically a panel will be generally planar, but in some cases may be curved. A panel can be a single structural element (e.g. door of unitary construction) or comprised of a complex structure, e.g. a 15 pre-assembled double glazed window pane or window sash carrying one or more panes of glass. As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps. 20 Brief description of the figures Preferred embodiments of the present invention will now be described, by way of non limiting example only, with reference to the accompanying drawings. In the drawings: Figure 1 is a cross-sectional view of a section of a frame made in accordance with an embodiment of an aspect of the invention; and 25 Figure 2 is a cross-sectional view of a section of a frame, carrying a fixed panel and a sliding panel, and which is made in accordance with an embodiment of an aspect of the invention.
8 Detailed description of the embodiments Figure 1 illustrates a cross sectional view through a section of a window frame. For simplicity of description only one side of the frame is illustrated. As will be appreciated the other sides of the frame will be structurally substantially identical (although possibly 5 aesthetically different) to the side illustrated (but arranged in mirror image). The frame 10 shown in figure 1 includes an indoor frame portion 20, an outdoor frame portion 30, a first insulating member 40 and a second insulating member 50. The frame portions 20, 30 are aluminium extrusions and may be powder coated or otherwise suitably surface treated. 1C The frame 10 is adapted to receive a hinged panel within it. Thus the indoor frame portion 20 is shaped to include a stop projecting inwardly, and against which a panel installed in the frame abuts when closed. The outdoor frame portion 30 does not include a similar stop to allow a pivotally moveable panel (not shown) to be swung into position overlying the outdoor frame portion 40 and the insulating member 40 and abutting the 15 stop of the indoor frame portion 20. The insulating member 40 is a traditional "dog bone" and includes enlarged side portions 41. Each of the frame portions 20, 30 include a keyhole shaped channels 22, 32 dimensioned to receive the enlarged side portion 41 of the insulating strip 40. During manufacture, the enlarged side portions 41 of the strip 40 are inserted into the keyhole 20 shaped channels 22, 32 of each frame portion and the frame portions are roll-formed with a series of crimping rollers to tightly close the keyhole formations 22, 32 to thereby hold the insulating strip 40 in place. The insulating strip 40 thereby structurally connects the indoor frame portion 20 to the outdoor frame portion 30. The outdoor frame member 30 includes a channel 37 defined by two parallel spaced 25 wall portions 33 and 35 which each extend in an indoor-outdoor direction and a joining wall 34 extending transversely between the walls 33 and 35. This channel 37 is sized to receive the second insulating member 50.
9 The channel 37 defined by walls 33, 34, 35 is dimensioned to receive the insulating member 50. For this purpose the wall 35 includes a small recess 36 adjacent the intersection with the wall 34 which allows for some flexing in this region. The second insulating member 50 is fixed to the outdoor frame portion 30 using a series 5 of fasteners, in this case, screws 80 spaced along the length of the outdoor frame portion 30. The screws 80 extend through the wall 35 to engage in the insulating member 50 and thereby fasten the insulating member and the frame portion 30. The extrusions forming the indoor and outdoor frame portions 20 and 30 are formed to include surfaces 38 and 39 abutting the top surface of the second insulating member 10 50. In use the insulating member 50 supports the weight of the frame through these abutting portions 38 and 39 and hence the insulating member 50 structurally supports both portions of the frame and the weight of any panel mounted in the frame 10. In this embodiment the frame portion 20 is structurally connected to the insulating member 50 merely by abutment. It is possible that the indoor frame member could be fixed to the 15 second insulating member 50 using similar fasteners, although this has been found to be unnecessary - when a window frame is built up the frame defined by the frame portions 20 and the insulating members 50 become rigid, and in any case the outward forces on the frame (which would tend to hold the indoor frame portion 20 in abutment with the insulating member 50) are more severe than the inward forces likely to be 20 experienced. In this embodiment the insulting member 50 is a wooden board formed of grade A oak (timber). The insulating member 50 includes a portion 51 projecting in an indoor direction which forms a reveal. During installation, the reveal 51 allows the frame 10 to be easily installed by nailing or screwing through the reveal 51 and into a stud or other 25 structural element. Such a reveal is also aesthetically pleasing. In alternative forms the insulating member 50 can be formed from alternatives to timber (including but not limited to wooden products such as fibre board, ply etc.) having suitable thermal properties which can be used to both structurally support the frame portions and also be use for fixing the frame to a structure in use.
10 This construction advantageously allows for a slimline appearance by minimising the thickness of the frame. In this form the thickness of the frame at the point of the first insulating strip is little more than the thickness of the insulating members 40, 50. This is not only aesthetically pleasing but has the substantial commercial benefit of minimising 5 the amount of material used in the product. It should also be noted that the outdoor frame portion 30 includes a recess 60 in which a further stop or other extruded section may be inserted to enable it to receive a sliding or a fixed panel. This advantageously allows for a common extrusion (ie the extrusion forming the outdoor frame portion 30) to be used to form a variety of frame 10 configurations. The outdoor frame portion 30 also includes an extension 70 extending in the outdoor direction to shield the insulating member 50 from weathering and present an aesthetically pleasing exterior. Figure 2 illustrates an embodiment of the present invention that is adapted to carry two panels 100, 110 in spaced parallel planes, e.g. a fixed panel 100 and sliding panel 110 15 mounted in the manner typically found in sliding doors, or two moving panels as found in double hung windows. In this embodiment the frame 200 is of similar overall construction to that of figure 1, in so far as it includes an indoor frame portion 20' an outdoor frame portion 30' which are coupled by a first insulating member 40' and separated and supported by a second 20 insulating member 50'. The first insulating member 40' is generally shaped like an inverted "T" and includes an upstanding, inwardly extending central portion 42 and laterally extending enlarged side portions 41' similar to the portions 41 of the insulator 40 of figure 1. The first insulating member 40' is engaged in channels 22', 32' in the frame portions 20' and 30' during 25 manufacture to structurally connect the indoor frame portion 20' to the outdoor frame portion 30' in a manner similar to that described above. The frame members 20', 30' and the upstanding portion 42 of the first insulating member 40' combine to define an inner channel 20A and an outer channel 30A in which 11 panel frames 120 and 130 of panels 100 and 110 are mounted. More particularly the indoor frame portion 20' and the insulating member 40' each define an upstanding inwardly extending wall portion and together define a channel 20A in which a sash 130 is received. Similarly the outdoor frame portion 30' also defines an upstanding inwardly 5 extending wall portion, which together with the insulating member 40' defines an outer channel 30A in which the fixed panel 100 is received. The fixed panel 100 is double glazed and includes two spaced panes of glass 101, 102 separated by spacer 103. The panes 101, 102 are supported on panel frame 120 in the form of a block (or glazing rebate) and held in place in the outer channel 30A by a 10 suitable glazing bead or wedge. The moving panel 110 includes double thickness of glass 111 spaced from another sheet of glass 112 by the spacer 113. The panes 111, 112 and space 113 are carried by the peripheral panel frame 130. As explained below, in the preferred form of this aspect of the present invention the panel frame 130 is formed of a single extrusion and need not be thermally broken. Although other 15 embodiments could use a thermally broken panel frame on the moving panel 110, or the panel frame would simply be formed of a material having a low thermal conductivity. The panels 100, 110 are illustrated as being side by side, of course the person skilled in the art will appreciate that this represents the open position. The panel frame 130 includes a downwardly extending channel in its underside for 20 holding the rolling element 132 to facilitate movement along a track 150 mounted to the floor of the inside channel on frame portion 20'. It should be noted that in this embodiment the innermost extent 43 of the upstanding wall portion 42 defined by the insulating member 40' extends inwardly to a point in line with the innermost extent 131 of the portion of panel frame 130 proximal the insulating 25 member 401. The first insulating member 401 extends inwardly beyond the panel frame 120 (which is the preferred arrangement). The insulating member 40' thereby shields the outside of the panel frame 130 from direct exposure to the outside atmosphere and radiant energy. This arrangement can result in a significant reduction of thermal contact between the outside environment and the inside environment via the panel frames 120, 12 130. In an ideal construction this thermal shielding effect can obviate the need for the panel frames to be individually thermally broken and thereby leads to simplified construction of the panel frames 120, 130. In a preferred form, a frame of the type illustrated in Figure 2 will also include an 5 insulating mullion mounted between the fixed and movable panels. This mullion preferably shields the central portion of the peripheral frame of the movable panel 110 in the same manner that the upstanding inwardly extending portion 42 of the first insulating member 40' shields the portion of the peripheral panel frame 130 shown in the figure. 10 Each of the indoor frame portion 20' and the insulating member 40' include an elongate channel for carrying a brush seal 140. Brush seals 140 seal between the indoor frame portion 20' and the sash 130 and between the insulating member 40' and the sash 130. Similarly the insulating member 40' and the outdoor frame portion 30' each include channels for carrying seals to seal against the sheet of glass 102, 101 respectively. 15 As described in connection with the first embodiment, the second insulating member is attached to the inside and outside frame portions 20' 30' and structurally supports the frame portions and enables the frame 110 to be installed by nailing or screwing through the member 50' and into a stud or other structural element. Even if this second structurally supporting insulating member 50' is replaced by a traditional "dog bone" 20 type insulating strip, an arrangement with a thermally shielding insulating member may still provide significant improvements over the traditional construction of frames with one or more channels. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features 2:5 mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.