OA13037A - Sealing system for an energy efficient window. - Google Patents

Description

013037

Visioawall Corporation

5 SEALING SYSTEM FOR AN ENERGY EFFICIENT WINDOW

FIELD OF THE INVENTION 10 The présent invention relates to an energy efficient window and, in particular, to a sealing System for energy efficient Windows.

BACKGROUND OF THE INVENTION

Windows or glass areas are a significant weakness in heat insulation schemes for 15 buildings in hot or cold climates. A basic insulating window that is well-known isconstructed ftom two panes of glass within a rigid frame. The air space between the panesprovides heat insulation. It is also known to evacuate the air space or to SU the air space witha gas of lower thermal conductivity than air such as argon. One further method of enhancingthe insulating value of such a window is to increase the air space and provide transparent 20 partitions between the outer glass panes to reduce convective heat transfer within the unit.

Other technologies include providing selectively reflecting or low-emissivity coatingsto reduce radiant heat transfer through the window. As well, there hâve been significantimprovements in the window frame, both in the union of the glass panes and the design and 25 niaterial of the frame. The layers of glazing in an insulating unit must be held apart at theappropriais distance by spacers. Because of its excellent structural properties, windowmanufacturers hâve used aluminum spacers. Unfortunately, aluminum is an excellentconductor of heat and frie aluminum spacer used in most standard edge Systems represented asignificant thermal "short circuit" at the edge of the insulating glass unit, which reduces the 30 benefits of improved glazings. In addition to the increased heat loss, the colder edge is moreprone to condensation. A window comprising a compound glass element with an edge binding member isdescribed in U.S. Patent No. 5,260,112 (conesponding to Canadien Patent No. 2,029,148). 35 The edge binding member holds two glass planes apart in a parallel condition and seals friespace between the glass panes from the exterior. A suitable edge binding member must provide a stable mechanical bond between the glass panes to ensure the physical integrity ofthe window unit. The edge binding member must also be vapour tight to prevent thepénétration of vapour between the glass panes and conséquent condensation that will occurwithin the window unit. Lastly, the edge binding member must not provide a thermal bridgebetween the glass panes, or should at least minimize heat transfer from one pane to the other.With the edge binding member of this patent, a métal foil band wraps around a spacer andsubstantially bridges the glass panes. The spaeer is glued to the glass panes with an acrylateadhesive. At the outer edges of the métal band, close to the glass panes, the spacer isbevelled, creating a triangular void space. The void space is filled with a highly vapourrésistant hot-melt butyl adhesive.

While this System does provide a solution to the vapour block problem, a significantadditional problem arises. The spacer is typically made from a thermoplastic material with asignificantly higher thermal coefficient of expansion that the Steel band. The butyl adhesivetends to creep into the space between the plastic spacer and the métal band, thereby adhermgthe two together. When subject to thermal expansion or contraction, the different rates ofexpansion between the plastic and the métal may cause the spacer to fail, or it may disrupt theintegrity of the butyl seal.

Therefore, there is a need in the art for an energy efficient window unit whichincludes a spacer and seal System which mitigates the difficulties posed by the prior art

SUMMARY OF THE INVENTION

The présent invention is directed at energy efficient Windows having an edge spacerand sealing System. Therefore, in one aspect, the invention comprises a heat insulationwindow comprising: (a) a pair of outer panes defining an air space therebetween; (b) a spacing member disposed between the outer panes which maintain the panesin a spaced-apart relationship, the spacing member having a First and second 2 Π 13Q q 7 outer surfaces which are opposed and. parallel, and a third outer surfaceextending between the first and second outer surfaces; (c) wherein the spacing member defines a first sealing groove at the junctionbetween the first and third outer surfaces and a second sealing groove at thejunction between the second and third outer surfaces; (d) a gas-tight seal element contained within the first and second sealing grooves;and (e) a métal band parallel to and overlaying the third outer surface, wherein theband comprises edge flanges which fit into the first and second sealinggrooves, thereby isolating the third outer surface from the seal element

In a preferred embodiment, the window further comprises an interface layer between the thirdouter surface and the métal band. Further, the seal element comprises hot-melt butyladhesive and the métal band comprises a stainless steel foil. Also, the spacing membercomprises a central spacer and opposing latéral members, wherein the central spacerséparâtes the opposing latéral members and at least one latéral member comprises means forretaining an interior film.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of an exemplary embodiment withreference to the accompanying simplified, diagrammatic, not-to-scale drawings. In thedrawings:

Figure 1 is a cross-sectional view of edge spacer and sealing System of the présent invention.Figure 2 is a cross-sectional view of an alternative embodiment of the présent invention. 3 013037

DETAILED DESCRIPTION OF THE INVENTION

The présent invention provides for an energy efficient, heat insulating window design.When describing die présent invention, ail tenus not defined herein hâve their common art-recognized meanïngs.

Figure 1 shows a cross-sectionaî view of an edge spacer and sealing System of awindow unit (10). Those skilled in the art will realize that the members shown in cross-section in Figure 1 are provided continuously around the edge of the window unit (10) tocompletely seal the interior volume (12) from the exterior.

As shown in Figure 1, dual glass panes (14, 16) are spaced apart by a spacerassembly which comprises a central spacer (18) and a first latéral member (20) and a secondlatéral member (22). The first latéral member (20) has a first outer surface (21) which abutsup against the glass pane (14). Similarly, the second latéral member (22) has a second outersurface (23) which abuts up against the other glass pane (16). The first and second latéralmembers are attacbed to the glass panes by means of an adhesive (24) such as an acrylateadhesive or some other suitable adhesive as is well-known in the art. The latéral members(20, 22) may be preferably extruded from aluminum which is preferred for its light weight,rigidity and strength.

The central spacer (18) has a third outer surface (19) which is perpendicular to theplane of the glass panes (14, 16). In a preferred embodiment, the central spacer defines atleast one and preferably two dessicant chambers (26, 28) which are filled with a dessicatingmaterial. Vents (30) permit the passage of air to and from the dessicant chambers into theinterior air volume. The central spacer (18) interlocks with the two latéral members (20, 22)in order to maintain the two glass panes in a spaced and parallel relationship.

The central spacer (18) is preferably formed from a plastic material with a relativelylow heat conductivity to minimize any thermal bridging effect between one glass pane to the 4 013037 other. In a preferred embodiment, the central spacer if extruded from a thermoplasticmaterial such as polyvinylchloride or polyamide.

Each latéral member (20, 22) defines a sealing groove filled with a sealing material(32) immediately adjacent its junction with the central spacer. The sealing groove thereforeruns along the glass pane, outside of the central spacer, as shown in the Figures. The sealinggroove is filled with a vapour-proof gas tight seal (32) élément. Preferably, the seal elementcomprises hot-melt butyl adhesive, which is well known for its vapouT proof qualifies. Othersealing materials which are suitably vapour-proof are well known in the art. The sealinggroove (and therefore the seal 32) is shown as substantially square in cross-section, however,that is not an essenfial element of the invention. A capping band (34) is provided to cover the third outer surface (19). However,rather than extending to the glass panes, the band (34) is bent at either edge (34A, 34B) tofollow the contour of the sealing groove. The butyl seal (32) contacts the outer surface of theband (34). Therefore, the band (34) prevents the hot-melt butyl from creeping in between thethird outer surface (19) of the central spacer (18) and the interior surface of the band. Theband is preferably made from a strong, vapour-proof, oxidation-resistant and low heat-conductive material, such as a thin stainless Steel foil.

In both Figures 1 and 2, the window units shown include interior volume dividingfilms (40). Such films (40) enhance the insulating value of the window unit (10) however arenot essenfial éléments of the présent invention. In the embodiment shown in Figure 1, asingle film (40) is shown, whereas in Figure 2, a dual film (40) embodiment is shown. Ineach case, the film is suspended from a latéral member (20, 22) by means of a tensioningmember (42) which is preferably a helical spring. A plurality of springs (42) are providedaround the periphery of the window unit (10), thereby suspending the film (40) wdthin theinterior volume (21), substantially parallel to each glass pane. Each spring (42) is mounted ina channel formed in the latéral member. Each latéral member which includes means forsuspending the film includes a lip (44) which projects outward and contacts the film (40), inorder to seal the partitioned interior volume created by the film. 5 013037 5 As shown in Figure 1, the latéral members may be identical for ease of fabrication, even in an embodiment with a single interior film, where the latéral member (20) does notinclude means for suspending a film. In such an embodiment, however, the central portion(18) must hâve a slightly different profile to accommodate the asymmetric nature of thesingle film embodiment, as is shown in Figure 1. 10

As will be apparent to those skilled in the art, various modifications, adaptations andvariations of the foregoing spécifie disclosure can be made without departing from the scopeof the invention claimed herein. Ihe various features and éléments of the described inventionmay be combined in a manaer different from the combinations described or claimed herein, 15 without departing from the scope of the invention. 6

Claims (3)

1. 013037 WHAT IS CLAIMED IS:

   1. A heat insulation window comprising: (a) a pair of outer panes defining an air space therebetween; (b) a spacing member disposed between the outer panes which maintain the panesin a spaced-apart relaiionship, the spacing member having a first and secondouter surfaces which are opposed and parallel, and a third outer surfaceextending between the first and second outer surfaces; (c) wherein the spacing member defînes a first sealing groove at the junctionbetween the first and third outer surfaces and a second sealing groove at thejunction between the second and third outer surfaces; (d) a gas-tight seal element contained within the first and second sealing grooves;and (e) a métal band parallel to and overlaying the third outer surface, wherein theband comprises edge flanges which fit into the first and second sealinggrooves, thereby isolating the third outer surface from the seal element.
2. 2. The window of claim 1 wherein the seal element comprises a bulyl adhesive and themétal band comprises a stainless steel foil.
3. 3. The window of claim 1 wherein the spacing member comprises a central spacer andopposing latéral members, wherein the central spacer séparâtes the opposing latéral membersand at least one latéral member comprises means for retaining an interior film. 7