The invention relates to unit glazing of window panels, and more particularly to an improved structure for framing the glass panels used in window wall structures.
Window walls are widely used as the exterior sheathing of commercial buildings, and in particular, high rise buildings. Window walls typically consist of glass panels defining a major portion of the exterior surface of the building, with structural members separating the glass panels. A typical glass panel will be framed with structural members, i.e. with vertical members or mullions which connect to a lower horizontal member or sill and an upper horizontal member or header.
Modern window walls frequency make use of double pane window construction. In double frame construction, each window frame contains two parallel panes of glass separated by an air space. Double pane construction has two notable advantages over single pane construction, i.e., double pane windows substantially reduce exterior noise and have greater thermal efficiency than single pane windows.
One issue with either type of construction is how to seal the glass panes from the elements. Sealing of the window glass panes to the structural members is referred to as glazing. In general there are two types of glazing, i.e. traditional adhesive sealants such as RTV or elastomeric gaskets (i.e. rubber gaskets), or a combination of both. The modern trend has been to use elastomeric gaskets to seal the glass panes to the window framing structure. The window walls are then attached to a building's structural members via mechanical fasteners and seated around their perimeter with an adhesive sealant such as RTV.
One of the major costs associated with window walls is the labor required to make the walls at the jobsite. Making the walls requires cutting the framing members, i.e. mullions, sills and headers to size, cutting the rubber gaskets (glazing), and then building the window frame from the cut materials and installing the glass panes and elastomeric gaskets. The completed window wall frames are then installed in the building, typically using a combination of mechanical fasteners and adhesive sealants.
As may be seen, there remains a seed In the art for a system of framing window walls that reduces the labor cost associated with construction of window walls at the jobsite. Ideally, such a system would allow for the window walls to be constructed in a factory, leaving only the installation of the prefabricated walls to be done at the jobsite.
The invention comprises an apparatus and method for constructing prefabricated window walls in a factory. There are several advantages to prefabricating window walls in the controlled environment of a factory. In a factory setting, increased quality control and efficiency is possible through mass production of file window walls. All components needed to produce the walls can be readily stocked and labor savings may be achieved because the tasks necessary to fabricate the walls can be split up into a series of individual tasks that can be readily performed by lower skilled workers.
The system of the present invention comprises window wall framing members, i.e. vertical center mullions, intermediate horizontal framing members, vertical end mullions and horizontal headers and sills, of novel design which can be used to build either double or single pane window walls. In the exemplary embodiment, each center mullion and intermediate horizontal framing member comprises two aluminum extrusions which include provisions that allow the extrusions to snap together to create a composite, closed section, structure. When snapped together the mullions and intermediate horizontal framing members are generally in the shape of two hollow box sections interconnected by a web. Experimentation has shown that the composite box sections have similar structural properties to continuous box sections, i.e. comparable moments of inertia and cross-sectional area and thus have comparable ability to carry bending moment, transmit shear and resist buckling. The headers, sills and vertical end mullions of the present invention use a box type cross-section with a snap in close-out panel.
In fabricating either double or single pane window walls, the glass panes of the wall are captured between the framing members and are sealed at their outer surfaces by rubber gasketing. In the ease of double pane construction, the desired air gap between the panes is maintained by spacers. The spacers are positioned such that they are internal of the outer surface of the box sections of the mullions.
Each of the window frame assemblies with make up a window wall is square cut. Therefore, the sills, headers and end mullions of the window walls may be attached to the supporting building walls into which the window walls are set by means of mechanical fasteners such as screw races.
It is an object of the present invention to lower unit labor costs, improve quality control, and increase productivity by producing prefabricated window walls using standard parts on an assembly line. Other objects and advantages of the present invention will become apparent in the course of the following description.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The invention may, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
Referring to
The exemplary composite cross-sections of
Referring to
One advantage of the snap together construction of the present invention, is that mechanical fasteners, i.e. screws and the like, can be used to connect the vertical mullions 12 to the horizontal sills 14, headers 18 or intermediate horizontal framing members 16. The screw heads used to make these connections are hidden when the extrusions 20 and 22 which form the mullions 12 are snapped together.
The left extrusion 22 of the composite cross-section 19 is complex multi-channel shape which includes a window pane channel 36 for receipt of two spaced apart panes of window glass 42 and 44. The window panes 42 and 44 are separated by a spacer 48. An air gap is maintained between the glass panes by means of the spacer 48. The window pane channel 36 of the extrusion 22 is of sufficient size to hold a setting block 40. The left extrusion 22 also includes upper and lower gasketing channels 45 and 46, for the receipt of window pane gasketing 38.
The right extrusion 20 of the composite cross-section 19 is also generally in the form of a complex multi-channel shape. The right extrusion 20 also includes a window pane channel 34 for receipt of two spaced apart panes of window glass 42 and 44. The window panes 42 and 44 are separated by a spacer 48. The spacer 48 maintaining an air gap between the glass panes 42 and 44. The right extrusion 22 also includes upper and lower gasketing channels 45 and 46, for the receipt of window pane gasketing 38.
The window panes 42 and 44 are sealed or glazed to the framing members by means of the elastomeric gasketing 38. (Glaring is a term of art used in the window installation industry. Although the term originally referred to the use of putty-like glazing compounds, the term now includes gasketing with elastomeric materials.) The glazing or gasketing prevents air and water intrusion past the window panes.
With reference to
The composite cross-section 19 is in the overall form of a box section. Experimentation has shown that composite box sections can have similar structural properties to continuous box sections, i.e. the composite box may have comparable moments of inertia and cross-sectional area to a continuous box section of the same dimensions and wall thickness and thus have comparable ability to carry bending moment, transmit shear and resist buckling. Analysis verified by experimental results has shown that by increasing the wall thickness 42 of the upper and lower cap members 24A, 24B, 30A and 30C, the wall thickness of the remaining walls of the extrusions 20 and 22 can be reduced without sacrificing the load carrying capacity of the framing-members which use the composite cross-section 19, and like composite cross-sections. Generally, the wall thickness 42 of the upper and lower cap members should be about 1.5 times, or greater, than that of the wall thickness 43 of the web portions of the composite cross section.
With reference to
Referring now to
Referring now to
The left extrusion 52 includes a window pane channel 66 for receipt of a single pane of window glass 98. The left extrusion also includes upper and lower gasketing channels 73 and 75 for the receipt of window pane gasketing 77. The right extrusion 54 likewise includes a window pane channel 68 for receipt of a single pane of window glass 98. The window pane channel 68 of the right extrusion 54 is sized to be sufficiently large to receive a setting block 72. The right extrusion 54 also includes gasketing channels 45 for the receipt of window gasketing 46.
Referring now to
Suitable materials for the extrusions which comprise the exemplary composite cross-sections of the several types of framing members described above include various aluminum alloys, other metallic materials such as stainless steel, as well as many types of plastics. Suitable materials and methods of producing extrusions are known to those of skill in the art. Any material that can be extruded or formed into the disclosed shapes is potentially suitable. The window pane gasketing can be made from several types of elastomeric materials, which are known to those of skill in the art.
The foregoing detailed description and appended drawings are intended as a description of the presently preferred embodiments of the invention and are not intended to represent the only forms in which the present invention may be constructed and/or utilized. Those skilled in the art will understand that modifications and alternative embodiments of the present invention which do not depart from the spirit and scope of the foregoing specification, drawings, and appendix of the claims Mow are possible and practical. It is intended that the claimed invention covers all such modifications and alternative embodiments.
This application claims priority, from U.S. Provisional Application Ser. No. 61/642,263, filed in May 3, 2012, entitled IMPROVED UNIT GLAZING CONSTRUCTION FOR WINDOW PANELS.
Number | Date | Country | |
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61642263 | May 2012 | US |