Abstract:
An improved method of installing a storm window in a prime window includes application of locking clips at predetermined locations around the frame of the prime window. The storm window is positioned over the prime window and swung into place, whereupon the storm window frame snaps and is locked into place by the clips. Bulb seals around the storm window frame compress between the storm window frame and the frame of the prime window to insure a complete and reliable seal against the elements and maximize sound abatement.

Description:
REFERENCE TO RELATED APPLICATION 
     Priority is hereby claimed to the filing date of U.S. provisional application 61/238,408 filed Aug. 31, 2009. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to fenestration and more particularly to storm windows and their attachment to a prime window. 
     BACKGROUND 
     Storm windows are auxiliary windows that traditionally are attached over the outside of a main or prime window to provide additional insulation, resistance to storms and blowing rain, and increased sound abatement. A popular type of storm window is sometimes called the combination storm window. Combination storm windows commonly combine glass panels or glazing units and at least one insect screen. One or more of the glass panels can be raised and/or lowered or otherwise arranged to allow ventilation through the storm window and insect screen and can be closed to form a barrier or insulation against the outside environment. A combination storm window generally has a frame sized to be fitted within the frame or over the exterior trim of the prime window and this frame surrounds and supports the glass panels and insect screen of the storm window. Combination storm windows generally are attached to a prime window frame or its exterior trim using fasteners such as screws, and sealants such as silicone caulk. A typical combination storm window is disclosed in U.S. Pat. No. 4,274,468. 
     Combination storm windows are advantageous in that they are adaptable to changes in weather conditions simply by sliding their glass panels to different positions to provide ventilation or insulation as desired. The performance of traditional combination storm windows with single layer glass panes can be limited, however, particularly in situations where noise abatement is also desired. Noise abatement of a storm window can be significantly enhanced by using double glazed glass panels, which are becoming more common. However, this adds substantially to the weight of the glass panels, making them difficult to slide into different positions thus reducing the ease and convenience of the storm window. For this and other reasons, it has been found that in instances where noise abatement is a primary goal, it is useful to use one large single or double glazed glass panel sealed within a storm window frame and that covers the entire window opening. Storm windows with such panels, while effective, can be quite heavy and difficult or cumbersome to install. 
     For these and other reasons, a need exists for an improved method and associated apparatus for installing storm windows, and particularly heavy storm windows, over prime windows that addresses the above and other shortcomings of traditional installation techniques. It is to the provision of such a method and apparatus that the present invention is primarily directed. 
     SUMMARY 
     The entire contents of U.S. provisional patent application 61/238,408, to which priority is claimed above, is hereby incorporated by reference. 
     An improved method and apparatus for attaching a storm window to a prime window includes mounting clips at predetermined locations around the frame of the prime window. The storm window frame is configured to be snapped onto the clips in various alternative ways and the clips lock the storm window in place. Bulb seals or other flexible or resilient seals are provided between the interior frame surfaces of the storm window and exterior surfaces of the prime window to provide a complete and reliable seal between the storm window frame and the prime window frame or surrounding trim. The installation method includes moving one side of the storm window frame into the prime window frame and rotating the storm window into the prime window until the clips snap the storm window securely in place. The method is quick, attractive, more reliable, less subject to the skill of the installer, and provides a substantially complete seal that effectively blocks water, air, and provides significantly enhanced sound abatement. These and other features, aspects, and advantages will become apparent to those of skill in the art upon review of the detailed description set forth below, taken in conjunction with the accompanying drawing Figs., which are briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational cross section of a prime window and a storm window that embodies principles of the invention in one preferred form. 
         FIG. 2  illustrates a sequence of steps that can be applied to install a storm window according to an embodiment of the invention. 
         FIG. 3  is a cross sectional view of a prime window jamb to which an attachment clip according to an embodiment of the invention is mounted. 
         FIG. 4  is a perspective view of an attachment clip according to a second embodiment of the invention. 
         FIG. 5  is a cross sectional view of the clip of  FIG. 4  taken along line  5 - 5 . 
         FIG. 6  is a cross sectional view of a window jamb with the clip embodiment of  FIG. 4  attached thereto and with the frame of a storm window moving into engagement with the clip. 
         FIG. 7  is a cross sectional view the clip of  FIG. 4  taken along line  7 - 7  thereof and with the clip attached to a prime window jamb securing the frame of a storm window to the prime window with a shim according to the invention being inserted. 
         FIG. 8  is the view from  FIG. 7  with the shim completely inserted securing the clip and storm window in place. 
         FIG. 9  is a cross sectional view illustrating a sub-frame attached to a prime window and a storm window attached to the sub-frame using an alternate embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made to the annexed drawing Figures, wherein like reference numerals refer, where appropriate, to like parts throughout the several views. Generally, the storm window attachment system of this disclosure uses installation clips for attaching a storm window or storm panel to a traditional prime window.  FIG. 1  shows, in cross section, a prime window  10 , along with a storm window  20 . Prime window  10  is made up top member or head jamb  11 , side members or side jambs  13 , and bottom member or sill  12 . Together the side jambs, head jamb, and sill form a rectangular frame that holds window panels or frames  3  and  4 . In a typical prime window, panels  3  and  4  are vertically slidable in jamb liner tracks to allow opening for ventilation. It will be recognized that this need not be the case, and that only one of the panels, typically lower panel  3 , may open for ventilation. It will further be recognized that in place of panels  3  and  4 , a single panel may be provided, as is the case with picture windows. Prime window  10  is further provided with interior jamb stops  14  and exterior jamb stops  15 , which hold sashes  3  and  4  in place, and also aids in sealing the window against air penetration. Exterior jamb stop  15 , in combination with similar projecting surfaces along head jamb  11 , side jambs  13 , and, in some windows, sill  12 , define a pocket that traditionally receives an insect screen but that also can receive a storm window. 
     Storm window  20  is configured with a rectangular frame  21  that surrounds and holds a glazing unit  24 , which may be a dual pane glazing unit or a single pane glazing unit, an openable glazing unit, or a sealed fixed glazing unit. In cases wherein storm window  20  is intended to reduce noise penetration, dual panes may be of different thicknesses, as this has been found to reduce sound transmission. In addition, one or both of the glass panes may comprise laminated glass, wherein two sheets of glass are laminated together with a sheet of polymeric material such as PVB between them, to provide enhanced sound damping. A seal between the frame of the storm window  20  and the prime window  10  may be provided by a resilient gasket  22 , which can be a traditional foam gasket, a bulb seal, flexible fins, or any other material and configuration that forms an adequate seal. The gasket  22  typically is attached to the frame of the storm window  20  and seals against exterior jamb stop  15  of the prime window. In other embodiments, however, gasket  22  may be attached to jamb stop  15  or to the prime window frame, to seal against storm window  20 , or gasket sections may be attached both to the storm window and the jamb. 
     Attachment clips  30 , one of which is illustrated in  FIG. 1 , are mounted to the prime window frame, in this case the side jamb  13 , and the clips are adapted to receive and secure the frame of the storm window  20  during installation, as described in detail below. Generally, in one embodiment the top of the storm window frame is moved into place against the head jamb of the prime window and the bottom of the storm window is pivoted inwardly as indicated by arrow  40  until the clips  30  engage and capture the storm window frame to secure the storm window in place with gasket  22  compressed between the storm window frame and the exterior stop of the prime window to form a seal. 
     As mentioned, additional or multi-layer glass panes when used for sound abatement and reduction of heat transmission can add significant weight to storm window  20 , thus adding to the difficulty and danger of handling the window during installation and removal. The storm window and installation system disclosed herein, illustrated simply in  FIG. 1  for clarity, permits easier installation of the storm window by allowing the installer to hold the storm window in a more stable position during installation. More specifically, and with reference to  FIG. 2 , storm window  20  can be installed by first placing the top edge  23  of the storm window frame against jamb stop  15  (and the opposite jamb stop) as indicated by the angled-most phantom outline in  FIG. 2 . The bottom of storm window  20  can then be pushed inwardly toward the prime window in direction  26  while at the same time pushing it generally upward in direction  27 . The upward pushing and inward tilting of storm window  20  toward the vertical is continued, as indicated by the next phantom outline in  FIG. 2 , until top rail  29  of the storm window frame  21  engages a channel  16  at the along the head jamb of prime window  10 . Channel  16  may be defined between the top portion  151  of the exterior jamb stop  15  and a downwardly depending lip  17  along the outer periphery of the prime window frame. The lip  17  may be part or an extension of a drip edge or exterior trim, or may simply be a strip of a suitable material such as aluminum or plastic that has been attached to prime window  10 . In any event, the channel  16  is sized to receive the top rail  29  of the storm window frame  21  when the storm window is slid upwardly as shown to capture the top rail  29 . 
     With the top edge of the storm window in place in the channel at the top of the prime window, the bottom edge of storm window  20  can be pivoted inwardly in direction  40  until storm window  20  moves toward a substantially vertical orientation. Just before becoming fully received in the frame of the prime window, the storm window frame engages installation clip  30  according to the disclosure. Installation clip  30  has previously been mounted to the jamb stop  15  (and a like clip has been attached to the opposite jamb stop). The clip  30  includes a springable leg that projects into the pocket of the prime window frame and a projection in the form of a tang  31  that snaps into a receiving portion of storm window frame to hold the storm window in its installed position. 
     With storm window  20  secured by clips  30  in its installed position, resilient gasket  22  becomes compressed against jamb stop  15  to form a reliable seal between the storm window frame and the prime window. The compressed gasket  22  also urges the frame of the storm window  20  outward against lip  17  at the head jamb and against the tangs  31  of installation clips  30  located adjacent the sill. Accordingly, the storm window frame becomes wedged between the jamb stop  15 , the top lip  17 , and the clips  30  on the side jambs of the prime window. It will be appreciated that while  FIGS. 1 and 2  show only one installation clip  30 , a preferred embodiment includes at least two such clips, one on each side jamb of the prime window opposite one another. More than two clips  30  also can be used depending on the size and weight of the window and other application specific factors. In any event, the storm window  20  becomes securely and sealingly locked in place within the prime window by simply rotating it into position and pressing it into the pocket of the prime window against the resiliency of the gasket  22 . 
       FIG. 3  illustrates more clearly one possible configuration of the clip  30 , and the interaction of its tang  31  with the receiving portion  36  of a storm window frame  21  as the storm window  20  is pressed into its final installed position, which is illustrated in phantom lines in  FIG. 3 . The clip  30  has U-shaped mounting portion  37  that is sized to fit onto the exterior jamb stop  15  of the prime window frame to mount the clip to the frame. A leg  38  projects outwardly from the mounting portion  37  adjacent the interior wall of the side jamb  13  and, because of the resiliency of the material from which the clip is made, the inner portion of the leg  38  is spring biased slightly away from the wall. A projection, in the form of a tang  31  in this embodiment, projects at an angle from the leg  38  of the clip generally toward the interior of the window. 
     As the storm window  20  moves toward the exterior jamb stop  15  during installation, the outer edge of the storm window frame engages and begins to slide along the tang  31 , which begins to depress or spring the leg  38  toward the interior wall of the side jamb  13 . Subsequently, the gasket  22 , which in  FIG. 3  is a bulb seal, engages the jamb stop  15  of the prime window frame. Further inward pressure on the storm window compresses the gasket  22  until the tang  31  snaps into the receiving portion  36 , in this case a slot, formed along the edge of the storm window frame. The outward pressure imparted by the compressed gasket  22  causes the inside wall of the receiving portion  36  to be pressed slightly outwardly and tightly against the end of the tang  31 , thus holding the tang securely in place within the receiving portion and maintaining the compression of the gasket  22 . A groove or other feature may be formed along the inside wall of the receiving portion  36  for engaging affirmatively with the end of the tang and preventing it from moving out of the receiving portion  36  absent inward pressure being applied to the storm window. 
     In the event that it becomes necessary to remove storm window  20  from the prime window, clips  30  can be released by progressively inserting a putty knife or similar thin tool into the space between the frame of the storm window  20  and the clip  30 . Inward pressure can be applied to the storm window at the same time against the force of the compressed gasket  22  to disengage the end of the tang from the inner wall of the receiving portion  36  of the storm window frame. The inwardly moving tool engages the tang  31  of the clip  30  and progressively moves it out of the receiving portion  36  of the storm window frame. The resiliency of gasket  22 , when the window is released, urges the storm window outward a slight distance beyond the tang  31 . This prevents reengagement of the tang  31  with the receiving portion  36  when the tool is extracted. The same procedure can be performed at the locations of other clips until all clips are all released. The storm window can then simply be pivoted out of the prime window and lowered away in a simple and easily manageable process. 
     The attachment system of this disclosure can also be configured for use with prime windows of configurations other than those shown in  FIGS. 1 through 3 . For example, a popular method of producing window frames is to extrude a metal or thermoplastic material into lineal stock having a suitable cross sectional profile for a window frame. The stock is then cut into suitable lengths and assembled into window frames in known ways. Frames made in this manner typically include, as part of the extrusion profile, an inward extending tab or stop that, together with the adjacent wall of the lineal, defines a pocket within which an insect screen can reside if installed. By removing the insect screen, this pocket may receive the frame of a storm window panel that can be installed generally as described above and fastened with a clip according to an alternate embodiment of the invention. 
     An installation clip adapted for use with prime windows of this sort is illustrated in  FIG. 4 . Clip  40  comprises base portion  400  from which a narrow U-shaped tab engaging section extends. The tab engaging section is formed with a first tab engagement wall  402  and a second tab engagement wall  404  connected together by a bight portion  415 . Tab engagement walls  402  and  404  define between them a tab engagement channel  403 . The tab engagement channel  403  is sized to fit or be clipped onto the tab of the aforementioned extruded window lineals to secure the clip  430  onto the lineals for installing a storm window panel generally as described above. More specifically,  FIG. 5  shows a cross sectional profile of a section of clip  40  being mounted onto tab  602  of an extruded lineal  60 . The channel  403  is sized to be pressed onto tab  602  to mount and secure the clip to the tab. When the clip is fully moved onto the tab  602 , the base  420  of the clip projects outwardly from the tab and is fabricated to form a latch  429  having a lead-in ramp  410  and a hook  408 . Due to the resiliency of the material, preferably metal, from which the clip is made, the leg  400  yieldably spring biases the latch  429  toward the inside of the window. A shim tang  430  projects in the opposite direction from the latch toward the lineal  60  for engaging with a shim to lock the latch  429  to a storm window frame as described in more detail below. 
       FIG. 6  shows clip  40  installed on screen stop tab  602  of an extruded lineal of window frame  60 . A portion  62  of a storm window frame is shown being moved toward into the pocket of the prime window frame toward the clip  40 . It will be understood that  FIG. 6  depicts the bottom portion of a side rail of the storm window frame and that the storm window has been raised up into engagement with the head jamb of the prime window as described above and its bottom portion is being pushed inwardly into the pocket for attachment in direction  63 . 
     The storm window frame  62  is formed with an attachment slot  79  at the end of a flat ramp  78  as shown. It will be seen from  FIG. 6  that as the storm window frame moves toward the prime window, the lead-in ramp  410  of the latch is engaged by the flat ramp  78 . Further movement of the storm window frame progressively depresses the latch against the bias of the resilient leg toward the prime window frame as the flat ramp  78  moves past the latch of the clip. When the trailing end of the flat ramp  78  reaches the hook  408  of the latch, the latch snaps into the attachment slot  79  with the hook portion  408  of the latch resting against the trailing edge of the flat ramp  78 . In this way, the storm window snaps into place within the prime window in the position generally shown in  FIG. 7 . A bulb seal or other gasket (not shown) is generally disposed in the gasket slot  77  and is compressed against the tab  602  thereby forming a seal. As with the prior embodiment, the outward force generated by the compressed gasket bears against the hook  408  of the latch tending to hold the latch more firmly in place. 
     While making clip  40  from a material having a relatively high elastic modulus may, in many cases, hold the frame  62  of the storm window in engagement with window frame  60 , there may be cases wherein it is useful to lock hook portion  408  in more secure engagement with engagement portion  79 . This can be achieved according to one embodiment of the invention by use of a shim  70  as illustrated in  FIGS. 7 and 8 . For this purpose a notch  420  ( FIG. 4 ) is formed in the base  400  of the clip  40  and the notch has a width predetermined to accommodate passage of a shim  70 . As shown in  FIG. 7 , a locking shim  70  can be inserted as indicated by the arrow through the slot  420  in the clip  40 . As the shim  70  progresses, it eventually engages the shim tang  430  of the clip, as illustrated in phantom lines in  FIG. 7 . Further pressing in of the shim  70  wedges the shim between the window lineal  60  and the shim tang  430  as illustrated in  FIG. 8 . The latch of the clip is this locked to the frame of the storm window preventing it from removal. 
     The shape of the shim tang  430  prevents the shim from being pulled back out, and thus locks the storm window securely in place within the prime window and also serves as a security measure against would-be thieves who might otherwise attempt to remove the storm window for access. The material from which the shim  70  is made can be any material with sufficient strength and longevity to perform the functions of the shim. For example, wood or aluminum might be used to fabricate the shim  70 , although polymeric materials such as PVC or ABS plastics have been found useful as well. 
     The material from which the clip  40  is fabricated likewise may be any material that provides the strength and resiliency required for holding the storm window in place. A useful material for the clip  70  (and the clip  30  of the prior embodiment) is AISI 301 half hard stainless steel having a thickness of about 0.014 inches. While other metals may also be used, stainless steel is especially suitable in that it resists corrosion and is less likely to produce rust stains on the exterior of the window frame. Stainless steel also has an inherent spring constant that has been shown to be appropriate for the present invention. 
     Some window styles, such as casement windows, may not incorporate screen stops or other features for defining a pocket for receiving a storm window. In such cases, adaptor frames, or sub-frames, may be used.  FIG. 9  shows one such solution in the form of a partial view of a sub-frame  92  attached to a frame  90  of a casement window, also shown in partial view. Stop portion  931  and wall portion  932  of the sub-frame define a panel receiving pocket  930 . Partially shown storm window frame  94  is installed in panel receiving pocket  930  of sub-frame  92  and held in place with one or more clips  93  according to the invention. Clips  93  are anchored to sub-frame  92  by a frictional fit within slot  920 . Clips  93  may further be adapted to receive a shim, in the manner portrayed in the embodiment of  FIG. 4   
     It is contemplated that sub-frame  92  may incorporate an edge receiving channel at the top of the window frame to receive the top edge of a storm window panel, prior to bringing the panel into engagement with clips  93 . In alternative embodiments, it may be useful to locate a channel for initially receiving the bottom edge of a storm window panel at the bottom of the sub-frame, so as to support the storm window panel as it is being tilted upwardly into place and into engagement with clips near the top of the sub-frame. While such an installation is the opposite of that discussed with respect to prior embodiments, the principles are the same except that the weight of the storm window panel is supported by the sill of the prime window during installation. This embodiment may be particularly useful for noise abatement applications, in which the storm window panels can be significantly heavier than simple storm windows. 
     An alternate embodiment of the method and apparatus of this invention uses clips on the top or head jamb of the prime window instead of along the side jambs as described above. In this embodiment, the top rail of the storm window frame itself has a groove to receive projections of the clips to hold the top of the storm window in place as the storm window is rotated into the prime window. For this alternate embodiment the top rail of the storm window frame is attached to the prime window in a similar manner as the sides of the storm window in prior embodiments, i.e. by being positioned onto the clips. A similar approach can also be used for first attaching the storm window along the bottom or frame of the window and then moving the top of the storm window into engagement with the clips at upper portions of the prime window. 
     The method and apparatus of this disclosure have been described above within the context of preferred embodiments and methodologies considered by the inventors to represent the best modes of carrying out the invention. It will be apparent to those of skill in the art, however, that a wide variety of modifications, additions, and deletions might well be made to the illustrated embodiments within the scope of the invention. For example, the flexible seal has been described primarily as a bulb seal attached to the storm window frame or to the prime window frame. This seal can, however, take on a variety of other configurations and need not be pre-attached to either the storm window or the prime window. Further, the particular configurations of the clips shown and described is not limiting and any clip configuration that effectively mounts to a prime window frame and receives and locks the storm window in place might be substituted to obtain the same result in substantially the same way. The materials from which the various components are fabricated might include aluminum, spring steal, plastic, PVC, or any other material suitable to the goals of the disclosure. The storm window is illustrated and described herein as being mounted on the exterior side of the prime window. This is not a limitation of the invention, however, and the storm window or another type of panel might just as well be mounted on the interior side of the prime window according to the methodology of the disclosure. These and other revisions and additions might be made by skilled artisans without departing from the spirit and scope of the invention, which is delineated only by the claims.