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FIELD OF THE INVENTION 
       [0001]    The invention relates to windows and window frames, and more particularly relates to an impact-resistant window assembly for sheet metal garage doors that can be configured and adapted for use with both insulated and non-insulated doors. 
       BACKGROUND 
       [0002]    Modern residential garage doors can include a plurality of windows or “lights” that admit light and permit viewing through the doors. Overhead sectional garage doors can include such windows in an uppermost door panel that positions the windows at about eye level when the garage door is closed, for example. Such windows also can be arranged in another door section or in multiple door sections if desired. Such doors can typically include glass panes that are retained and supported within a window opening in a sheet metal door panel by a plastic frame or molding. 
         [0003]    Though such garage door windows can be both attractive and useful, such windows can be subjected to high wind pressure loads and flying objects during severe weather conditions, such as tornados and hurricanes. In some locales where such severe weather conditions are most likely, governments have enacted building codes that require such windows to be resistant to impacts by airborne missiles, such as wind-propelled debris, and to cyclic wind pressure loadings. For example, in Florida, testing application standard TAS 201-94 sets forth test procedures for demonstrating adequate resistance to large missile impact as required by Section 1626 of the  Florida Building Code, Building,  and TAS 203-94 sets forth test procedures for demonstrating adequate resistance to cyclic wind pressure loading as required by the  Florida Building Code  and TAS 201-94. 
         [0004]    Unfortunately, the plastic frames and glass panes of typical glazed garage doors fail under such severe impact and pressure conditions. Accordingly, there is a need for an impact-resistant window assembly for garage doors that meets the demanding criteria set forth in the most stringent modern building codes and standards. As used herein, the term “impact-resistant” means resistant to failure when subjected to impacts from airborne missiles which, under identical conditions, would cause a conventional plain glass window pane supported in a door by an all-plastic window frame to fail. 
         [0005]    Metal garage doors generally are produced in two general types: insulated doors and non-insulated doors. As used herein, the term “insulated” means including added thermal insulation having a resistance to heat transfer that is substantially greater than the resistance to heat transfer characteristic of steel or aluminum. Insulated metal garage doors typically include a plurality of sheet metal door panels backed by a panel of thermally insulating material. For example, each thin metal door section may be backed by polymeric foam panel having a thickness of about one-two inches. Because the sheet metal door panels are highly thermally conductive, the sheet metal skins of such doors do little to resist heat transfer through the door. The insulating panels act to block the transfer of heat through the door that otherwise would occur. Thus, such insulated garage doors are especially useful for installation in entryways to garages or other spaces that are actively heated or cooled. In contrast, non-insulated garage doors essentially include only the sheet metal door panels, and are best-suited for installation in entryways to garages or other spaces that are not actively heated or cooled. Apart from their insulating panels, insulated metal garage doors can be substantially identical to non-insulated metal garage doors. 
         [0006]    When an insulated metal garage door includes at least one glazed panel, the associated insulating panel that backs the sheet metal face skin necessarily includes one or more window openings that align with corresponding openings in the sheet metal face skin. Because the insulating panels typically are constructed of polymeric foam materials that are soft and brittle and can be easily damaged or broken, the portions of an insulating panel that surround a window opening are vulnerable to damage if left unprotected, and require support on the back of the door panel. Accordingly there is a need to support and shield the exposed edges of an insulating panel that surround a window opening in an insulated metal garage door panel. Of course, because non-insulated metal door panels don&#39;t include insulating panels, there is no need to support and shield the edges of an insulating panel that surround a window opening in such a door panel. 
         [0007]    Accordingly, there is a need for a universal impact-resistant window assembly for a metal garage door that can be adapted for use in door sections both with and without an insulation panel backing the section&#39;s sheet metal face skin. When used in an insulated door section, such a universal window assembly should be configured to support and shield the edges of an insulating panel that border an associated window opening in the door section. 
       SUMMARY 
       [0008]    In one embodiment, the invention includes a universal impact-resistant window assembly for a garage door of a type having a sheet-metal face skin. The window assembly is adaptable for installation in both insulated and non-insulated garage doors. The window assembly includes an impact-resistant window pane, and an interior metal frame configured to be installed within and around a window opening in the sheet-metal face skin. An exterior metal frame is configured to be installed within and around the window opening in the sheet-metal face skin, and is configured to cooperate with the interior metal frame to engage portions of the sheet-metal face skin that surround the window opening, and to retain the window pane therebetween. An exterior trim member is configured to substantially cover exterior portions of the exterior metal frame, and an optional interior trim member is configured to substantially cover interior portions of the interior metal frame. The interior trim member includes a rear flange configured to at least partially support an insulating panel proximate to the sheet-metal face skin when the window assembly is installed in an insulated door. 
         [0009]    In another embodiment, an impact-resistant window assembly is adapted for installation in a window opening in an insulated garage door or a non-insulated garage door, such door being of a type having a sheet metal face skin with a window opening therein. The window assembly includes a window pane, and an interior metal frame having a forward lip and a rear lip, the rear lip being inwardly offset from the forward lip. The window assembly also includes an exterior metal frame having an exterior lip, a rear land that is inwardly offset from the exterior lip, and a pane-retaining lip. The interior metal frame is disposed around the window opening on an interior side of the face skin, the forward lip of the exterior metal frame is disposed around the window opening on an exterior side of the face skin, and the interior metal frame is connected to the exterior metal frame. Portions of the sheet metal face skin are sandwiched between the forward lip and the exterior lip, and the window pane is retained within the window opening between the rear lip and the pane-retaining lip. 
         [0010]    Another embodiment of the invention includes a garage door having at least one impact-resistant window assembly for selective installation in either an insulated sheet metal door panel or a non-insulated sheet metal door panel. The window assembly includes an impact-resistant window pane, and a frame arranged and constructed to securely support the window pane within a window opening in the sheet metal door panel. An interior member is configured to be optionally removably connected to an interior portion of the frame, and includes a rearwardly extending flange arranged and constructed to at least partially support one or more insulation panels proximate to an interior side of sheet metal door panel of an insulated sheet metal door panel. The interior member can be excluded from the window assembly when the window assembly is installed in a non-insulated sheet metal door panel without one or more insulation panels. 
         [0011]    These and other aspects of the invention will be apparent from a reading of the following detailed description, together with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is an exterior elevation view of a metal sectional overhead door including a plurality of universal impact resistant window assemblies according to the invention. 
           [0013]      FIG. 2  is an interior elevation view of a non-insulated glazed door panel of the garage door shown in  FIG. 1 . 
           [0014]      FIG. 3  is an interior elevation view of an insulated glazed door panel of the garage door shown in  FIG. 1 . 
           [0015]      FIG. 4  is a cross-sectional view of the non-insulated glazed door panel shown in  FIG. 2  taken along section line  4 - 4 . 
           [0016]      FIG. 5  is a cross-sectional view of the insulated glazed door panel shown in  FIG. 3  taken along section line  5 - 5 . 
           [0017]      FIG. 6  is an interior elevation view of an impact-resistant window assembly installed in a non-insulated glazed door panel like that shown in  FIG. 2 . 
           [0018]      FIG. 7  is a cross-sectional view of the impact-resistant window assembly shown in  FIG. 6  taken along section line  7 - 7 . 
           [0019]      FIG. 8  is a cross-sectional view of the impact-resistant window assembly shown in  FIG. 6  taken along section line  8 - 8 . 
           [0020]      FIG. 9  is an interior elevation view of an impact-resistant window assembly installed in an insulated glazed door panel like that shown in  FIG. 3 . 
           [0021]      FIG. 10  is a cross-sectional view of the impact-resistant window assembly shown in  FIG. 9  taken along section line  10 - 10 . 
           [0022]      FIG. 11  is a cross-sectional view of the impact-resistant window assembly shown in  FIG. 9  taken along section line  11 - 11 . 
           [0023]      FIG. 12  is a perspective view of an interior metal frame portion of the window assemblies shown in  FIGS. 6-11 . 
           [0024]      FIG. 13  is a cross-sectional view of the interior metal frame shown in  FIG. 12  taken along section line  13 - 13 . 
           [0025]      FIG. 14  is a cross-sectional view of the interior metal frame shown in  FIG. 12  taken along section line  14 - 14 . 
           [0026]      FIG. 15  is a perspective view of an exterior metal frame portion of the window assemblies shown in  FIGS. 6-11 . 
           [0027]      FIG. 16  is a cross-sectional view of the exterior metal frame shown in  FIG. 15  taken along section line  16 - 16 . 
           [0028]      FIG. 17  is a cross-sectional view of the exterior metal frame shown in  FIG. 15  taken along section line  17 - 17 . 
           [0029]      FIG. 18  is a perspective view of a corner portion of the exterior metal frame shown in  FIGS. 15-17 . 
           [0030]      FIG. 19  is a perspective view of an exterior trim member portion of the window assemblies shown in  FIGS. 6-11 . 
           [0031]      FIG. 20  is a cross-sectional view of the exterior trim member shown in  FIG. 19  taken along section line  20 - 20 . 
           [0032]      FIG. 21  is a perspective view of an interior trim member portion of the window assembly shown in  FIGS. 9-11 . 
           [0033]      FIG. 22  is a cross-sectional view of the interior trim member portion shown in  FIG. 21  taken along section line  22 - 22 . 
       
    
    
     DETAILED DESCRIPTION 
       [0034]      FIG. 1  shows a metal sectional overhead garage door  10 ,  20  according to the invention. In one embodiment, the door is a non-insulated door  10  that includes at least one glazed door section  12 , and a plurality of non-glazed door sections,  14 ,  16  and  18 . The glazed door section  12  includes a sheet metal face skin  15  having a plurality of window openings or apertures in which impact-resistant window assemblies  100  are installed. In another embodiment also shown in  FIG. 1 , the door can be an insulated door  20  that includes at least one glazed door section  22 , and a plurality of non-glazed door sections,  24 ,  26  and  28 . The glazed door section  22  includes a sheet metal face skin  25  having a plurality of window openings or apertures in which impact-resistant window assemblies  200  are installed. As discussed in detail below, the window assemblies  100 ,  200  can have a substantial number of common components, such that in a first configuration  100 , the window assembly can be installed in a non-insulated door  10 , and in a second configuration  200 , the window assembly can be installed in an insulated door  20 . 
         [0035]      FIG. 2  shows a rear or interior view of a glazed non-insulated door panel  12 . As shown in  FIGS. 2 and 4 , the interior surface of the sheet metal face skin  15  is exposed, and the window assemblies  100  are supported within spaced apertures in the face skin  15 .  FIG. 3  shows a rear or interior view of a glazed insulated door panel  22 . As shown in  FIGS. 3 and 5 , the interior surface of the sheet metal face skin  25  is substantially covered by one or more insulation panels  30 , including portions of the face skin  25  around each of the window assemblies  200 . As shown in  FIG. 5 , a rear portion  170  of each window assembly  200  is configured to cover and protect inside edges of the insulation panel that surround the window assembly  200 , and to at least partially support and retain the insulation panel  30  behind the sheet metal face skin  25 . 
         [0036]    Details of one embodiment of an impact-resistant window assembly  100  for use in a non-insulated sheet metal door section  12  are shown in  FIGS. 6-8 , and are described below. As shown in  FIG. 7 , the window assembly  100  is configured to be assembled within an aperture  17  in a thin sheet metal face skin  15  of a door section  12 . The window assembly  100  includes an impact-resistant window pane  102 , an exterior metal frame  120 , an interior metal frame  106 , and an exterior trim member  130 . The impact-resistant window pane  102  can be laminated glass, polycarbonate, or any other substantially transparent impact-resistant material or combination of materials. 
         [0037]    One embodiment of an interior metal frame  106  for use in an impact-resistant window assembly  100  according to the invention is shown in  FIG. 7  and in  FIGS. 12-14 . In this embodiment, the interior metal frame  106  has a substantially rectangular shape, and includes a forward lip  110 , a rear lip  112 , and an outer wall  119  connecting the forward lip  110  to the rear lip  114 . As shown in  FIG. 12 , the interior metal frame  106  can be constructed from a single piece of sheet material. A plurality of spaced screw holes  114  can be located in the rear lip  112 . The interior metal frame  106  can be constructed of steel, such as galvanized low-carbon commercial steel, or any other suitable material. When constructed of steel, the frame  106  can have a nominal thickness of at least about 0.03 inch. 
         [0038]    One embodiment of an exterior metal frame  120  for use in an impact-resistant window assembly  100  according to the invention is shown in  FIG. 7  and in  FIGS. 15-18 . In this embodiment, the exterior metal frame  120  has a substantially rectangular shape, and includes an exterior lip  126 , a rear land  122 , and a pane-retaining lip  124 . As shown in  FIGS. 16 and 17 , a plurality of screw holes  128  can be provided in the rear land  122 . As shown in  FIG. 18 , the exterior metal frame  120  can be constructed of a pair of opposed vertical members  123  and a pair of opposed horizontal members  126 . Each end of each vertical member  123  can be joined to an end of a horizontal member  126  by tabs  127   a,    127   b.  As shown in  FIG. 18 , the tabs  127   a,    127   b  can be arranged to overlap adjacent portions of an exterior lip  126  and a pane-retaining lip  124 , respectively, and connected thereto by one or more spot welds, for example. Alternatively, the exterior metal frame  120  can be formed from a single piece of material. Like the interior metal frame  106 , the exterior metal frame  120  can be constructed of steel, such as galvanized low-carbon commercial steel, or any other suitable material. When constructed of steel, the frame  120  can have a nominal thickness of at least about 0.03 inch. 
         [0039]    As shown in  FIG. 7 , the interior frame  106  can be positioned around a window opening  17  in the sheet metal face skin  15  of a door panel  12  such that the forward lip  110  abuts the interior surface of the face skin  15 . As also shown in  FIG. 7 , the exterior metal frame  120  can be positioned such that the rear land  122  and pane-retaining lip  124  are within the window opening  17 , and the exterior lip  126  abuts the exterior surface of the of the face skin  15  around the opening  17 . As shown in  FIG. 8 , a first plurality of screws  160  can be engaged through aligned screw holes  114  and  128  in the frames  106 ,  120 , thereby securely connecting the frames together. As shown in  FIGS. 7 and 8 , the forward lip  110  of the interior frame  106  and the exterior lip  126  of the exterior frame  120  cooperate to sandwich edges of the face skin  15  around the opening between the two frames  120 ,  106 , thereby securely supporting the connected frames  106 ,  120  in the opening  17 . 
         [0040]    As also shown in  FIGS. 7 and 8 , when the interior frame  106  and exterior frame  120  are assembled in the opening  17  as described above, the rear lip  112  of the interior frame  106  and the pane-retaining lip  124  of the exterior frame  120  cooperate to receive and support a window pane  102  therebetween. A first bead of an adhesive material  140  can be placed between the rear lip  112  and the window pane  102 , and a second bead of adhesive can be placed between the pane-retaining lip  124  and the window pane  102 . The beads of adhesive  140 ,  142  affix the window pane  102  to the assembled metal frames  106 ,  120 , and also form a substantially air-tight seal around the window pane  102 . The assembled metal frames  106 ,  120  are sized and configured to transmit substantial impact loads and substantial pressure loads on the window pane  102  to the surrounding sheet metal face skin  15 . 
         [0041]    As shown in  FIGS. 7 and 8 , the window assembly  100  can further include an exterior trim member  130 . Details of one embodiment of an exterior trim member  130  are shown in  FIGS. 19 and 20 . In the embodiment shown, the exterior trim member  130  has a substantially rectangular shape, and includes an inner edge portion  134  and an outer edge portion  136 . As shown in  FIGS. 7 and 20 , the exterior trim member  130  also can include a plurality of rearwardly extending bosses  132 . As shown in  FIG. 7 , the bosses  132  are configured to inwardly extend to the rear land  122  of the exterior metal frame  120 , and to be secured to the connected exterior and interior metal frames  120 ,  106  by a second plurality of screws  150  that are received in aligned screw holes  114 ,  128  and bosses  132 . As shown in  FIGS. 7 and 8 , when the exterior trim member  130  is connected to the metal frames  106 ,  120 , the outer edge portions  136  contact an exterior surface of the face skin  15  of the door panel  12 , and the inner edge portions contact an exterior surface of the window pane  102 . Accordingly, the exterior trim member covers the exterior metal frame  130 , hides the exterior metal frame from view from the outside of the door panel  12 , and provides a finished appearance to the exterior outer edges of the window  100 . In a preferred embodiment, the exterior trim panel  130  is constructed in a single piece from a molded polymeric material, such as high impact polystyrene, or the like. Preferably, exterior portions of the exterior trim member  130  include attractive architectural surface contours. 
         [0042]    As shown in  FIGS. 9-11 , an interior metal frame  106 , an exterior metal frame  120 , a window pane  102 , and an exterior trim member  130  as described above can also be used in an impact-resistant window assembly  200  installed in an insulated sheet metal door panel  22  having a face skin  25  and one or more thick insulation panels  30 . In this embodiment, the window assembly  200  additionally includes an interior trim member  170 . Details of one embodiment of the interior trim member  170  are shown in  FIGS. 21 and 22 . In this embodiment, the interior trim member  170  includes a forward flange  174  and a rear flange  172 . The forward flange  174  can include a plurality of spaced screw holes  176  extending therethrough. In a preferred embodiment, the interior trim member  170  is constructed in a single piece from a molded polymeric material, such as high impact polystyrene, or the like. 
         [0043]    As can be seen by comparing  FIGS. 10 and 11  to  FIGS. 7 and 8 , the interior metal frame  106 , the exterior metal frame  120 , and the window pane  102  can be assembled together in a window opening  19  in a sheet metal face skin  25  of an insulated door panel  22  in a manner that is identical to the assembly described above for installation in an opening  17  in a face skin  15  of a non-insulated door panel  12  (as shown in  FIGS. 7 and 8 ). In particular, the metal frames  106 ,  120  are connected together in the opening  19  by a first plurality of screws  160 . When so connected, the forward lip  110  of the interior frame  106  and the exterior lip  126  of the exterior frame  120  again cooperate to sandwich edges of the face skin  25  around the opening  19  between the two frames  120 ,  106 , thereby securely supporting the connected frames  106 ,  120  in the opening  19 . In addition, the rear lip  112  of the interior frame  106  and the pane-retaining lip  124  of the exterior frame  120  again cooperate to receive and support a window pane  102  therebetween. As described above, a first bead of an adhesive material  140  can be placed between the rear lip  112  and the window pane  102 , and a second bead of adhesive can be placed between the pane-retaining lip  124  and the window pane  102 . 
         [0044]    In this window assembly  200 , both the exterior trim member  130  and the additional interior trim member  170  are connected to the adjoined metal frames  106 ,  120  by a third plurality of screws  180 . The screws  180  are received in holes  176  in the interior trim member  170 , aligned holes  114  and  128  in the connected metal frames  106 ,  120 , and bosses  132  of the exterior trim member. As shown in  FIGS. 10 and 11 , when thus assembled in the opening  19 , the outer edge portions of the exterior trim member contact the face skin  25 , and the rear flange  172  of the interior trim member  170  contacts back surfaces of the insulation panel(s)  30 . Accordingly, the interior trim member  170  and the exterior trim member  130  cooperate to sandwich the face skin  25  and the insulating panel  30  therebetween, and to at least partially secure the insulation panel  30  against a rear surface of the face skin  25 . In addition, the rear flange  172  covers and protects the fragile edges of the insulation panel  30  that surround the window opening  19 . The forward flange  174  of the interior trim member  170  substantially covers interior portions of the interior metal frame  106 , thus shielding the interior frame  106  from view. The exterior trim member  130  and interior trim member  170  combine to provide a finished appearance to the outer edges of the window  200  on both the inside and outside of the glazed door panel  22 . 
         [0045]    The above description of various embodiments of the invention is provided to illustrate particular aspects and features of the invention, and not to limit the invention thereto. Persons of ordinary skill in the art will recognize that certain changes and modifications can be made to the described embodiments without departing from the invention. For example, though the impact-resistant window assemblies have been shown and described as being rectangular in shape, the windows can have substantially any polygonal or other outer shape. All such changes and modifications are intended to be within the scope of one or more of the appended claims.

Summary:
A universal impact-resistant window assembly for a garage door of a type having a sheet-metal face skin includes a window assembly adaptable for installation in both insulated and non-insulated garage doors. The assembly includes an impact-resistant window pane, and an interior metal frame installed within and around a window opening in the sheet-metal face skin. An exterior metal frame is installed within and around the window opening in the sheet-metal face skin. The exterior metal frame cooperates with the interior metal frame to engage portions of the sheet-metal face skin that surround the window opening, and to retain the window pane. An exterior trim member substantially covers exterior portions of the exterior metal frame, and an optional interior trim member substantially covers interior portions of the interior metal frame. A rear flange of the optional interior trim member at least partially supports an insulating panel proximate to the sheet-metal face skin when the window assembly is installed in an insulated door.