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[0001]    This application is a Utility Application claiming the benefit of the earlier filing date of Provisional Application Ser. No. 60/209,689, filed Jun. 6, 2000. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The invention pertains to multi-track storm doors having movable panes. More particularly, the invention pertains to such doors which incorporate two tracks for pane movement.  
         BACKGROUND OF THE INVENTION  
         [0003]    Storm doors with movable/storable panes of glass are known. Many such doors provide a fixed screen and a pane movable to open or close the screen.  
           [0004]    Storm doors with removable, interchangeable panes and screens are also known. Full length and half-length panes and screens can be interchanged to provide a full glass door in cold weather and half or full screen doors in warm weather.  
           [0005]    Triple track storm windows are also known. Such windows combine the advantages of double hung, independently movable panes with a movable screen.  
           [0006]    Triple track storm windows while effective in fixed installations are heavy and present mounting problems in doors. While known doors can be opened or converted to screens, their flexibility and ease of use could be improved.  
           [0007]    There continues to be a need for more versatile storm doors. Preferably such improvements could be made without substantially increasing door cost or weight. In addition, it would be preferable if ease of use and convenience could also be enhanced.  
         SUMMARY OF THE INVENTION  
         [0008]    A storm door incorporates first and second independently movable glass panes. The door has an elongated rectangular frame which bounds an interior region. A screen carried by the door covers the internal region.  
           [0009]    The frame carries pairs of first and second tracks. One pair of tracks extends along each elongated side of the frame.  
           [0010]    One glass pane is slidable along one track. A second is slidable, independently of the position of the first pane, along the second track. One of the panes is sandwiched between the screen and the other pane.  
           [0011]    In one embodiment, the elongated sides of the frame are oriented so as to be substantially perpendicular to a horizontal plane. The panes can be moved vertically between upper and lower positions.  
           [0012]    In one state, the panes completely close the interior region substantially blocking any flow therethrough. In a second state, one pane can be moved down to permit air to flow through an upper section of the screen. In a third state, one pane can be moved up to permit air to flow through a lower section of the screen. Finally, both panes can be moved down and up, respectively to permit simultaneous upper and lower air flow through the screen while only needing two inserts.  
           [0013]    Latches can be used to lock the panes at selected locations. Minimal overlaps exist between the panes in one state, where the panes cover the interior region. As the interior region is uncovered, or opened to permit air to flow through, the panes relatively move toward one another and the overlap increases.  
           [0014]    Advantages of the present door configuration include:  
           [0015]    1. readily manufacturable and cost effective due to incorporating features, such as the screen, into the door frame; and  
           [0016]    2. reduction in needed material due to incorporating necessary features into the frame.  
           [0017]    Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a front elevational view of a door in accordance with the present invention;  
         [0019]    [0019]FIG. 2 is a sectional view of the door of FIG. 1 taken along plane  2 - 2  of FIG. 1;  
         [0020]    [0020]FIG. 2A is a sectional view of the door of FIG. 1 taken along plane  2 A- 2 A of FIG. 1;  
         [0021]    FIGS.  3 A-D taken together illustrate rear elevational views of the door of FIG. 1 in different ventilating conditions;  
         [0022]    [0022]FIG. 4 is a sectional view of the door of FIG. 1 taken along plane  4 - 4  of FIG. 1;  
         [0023]    [0023]FIG. 5 is an enlarged fragmentary view of a portion of FIG. 4;  
         [0024]    [0024]FIG. 6 is an isometric view of a lower right corner with the lower pane positioned for ventilation; and  
         [0025]    [0025]FIG. 7 is an isometric view of a lower right corner with the lower pane closed. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    While this invention is susceptible of embodiment in many different forms, there are shown in the drawing and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.  
         [0027]    The figures illustrate the various aspects of a storm door  10  in accordance with the present invention. The door  10  includes a frame  14  having elongated, generally vertical sides  14   a, b  with top and bottom sections  14   c,d.    
         [0028]    The frame  14  bounds an interior region  16 . The region  16  is covered, in part, by upper pane assembly  20   a , and lower pane assembly  20   b . The region  16  is completely covered by screen  20   c.    
         [0029]    Each frame side  14   a,b  carries a respective track pair  22   a,b  and  24   a,b . The tracks enable independent, vertical movement of each of the pane assemblies  20   a,b . The tracks  22   a ,  24   a  are spaced further apart, as discussed in more detail subsequently, than are the tracks  22   b ,  24   b.    
         [0030]    Each pane assembly  20   a,b  includes bounding elements such as extruded aluminum elements  26   a,b,c,d  and  28   a,b,c,d . In each instance, a window  26   e  and  28   e  is carried by respective bounding elements. The bounding elements carry respective whether strip retaining recesses such as recesses  30   a,b  and  32   a,b.    
         [0031]    Screen  20   c  is locked to frame  14  by spline  36 . The spline  36  retains the screen  20   c  in the frame by slidably clamping the screen  20   c  into spline receipt regions, such as  38   a,b  in respective frame elements  14   a,b . Exterior surfaces  36   a,b  of the spline  36  each provide a slider pad for the adjacent pane assembly  20   a . This interaction also protects the screen  20   c  from a moving pane assembly or sash.  
         [0032]    Door  10  can be rotatably installed in frame  40  which can in-turn be installed in door opening D. The door  10  can include an internally located mortise lock  42 . Alternately, an exterior, surface mount lock could be used.  
         [0033]    The pane assemblies can be positioned with minimal overlap, see FIG. 3A. In this configuration, region  14  is closed and breezes can not flow through screen  16 . Alternate configurations illustrated in FIGS.  3 B,C,D provide for top, bottom or duel ventilation. This variety of configurations is achieved using only two sets of tracks and two inserts, pane assemblies  20   a,b . The door  10  thus provides three track-like features with only two tracks.  
         [0034]    It will be understood that the pane assemblies  20   a,b  can be retained in the respective set of tracks in a variety of ways as would be known to those of skill in the art. One way is to use spring loaded latches, such as latch  44 , which engage openings, such as  44   a , in the respective frame members  14   a,b . Other retaining mechanisms can be used without departing from the spirit and scope of the present invention.  
         [0035]    In the closed configuration, FIG. 3A, the pane  20   a, b  assemblies overlap slightly near the center  16 - 1  of the screen  20   c . This overlap prositions a generally horizontally extending weather strip between the pane assemblies to contribute to sealing the door from exterior weather conditions.  
         [0036]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.

Summary:
A two track storm door exhibits three track-like features. A rectangular frame defines an open bounded region. A screen fills the open region. Two glass panes, one for each track, are movable independently of one another to close or open the region.