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BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a replacement window, and more particularly, to a double-hung replacement window resistant to hurricane-force winds.  
           [0003]    2. Description of the Prior Art  
           [0004]    Most replacement windows sold in the United States are subjected to air infiltration, water infiltration, and structural integrity tests before being made commercially available. These three tests remain widely accepted throughout North America and performed on just about every window or door currently sold in the United States.  
           [0005]    After Hurricane Andrew devastated Florida in August 1992, Dade and Broward counties enacted new window durability standards. As a result of the enacted standards, windows certified in Dade County are now subjected to a structural integrity test, a battery of missile impact tests, and a cyclical test.  
           [0006]    To test structural integrity, a double-hung replacement window specimen is mounted on a wall and exterior surfaces of the window specimen is exposed to elevated air pressure. As described herein, a double-hung replacement window generally includes a window frame, a first sash, a second sash, a first insulated glass unit positioned in the first sash, and a second insulated glass unit positioned in the second sash. Exterior surfaces are generally those surfaces which are exposed to nature, while interior surfaces are generally those surfaces exposed to an interior room of a structure.  
           [0007]    Water is then sprayed in and around the exterior window frame and sash surfaces of the double-hung replacement window specimen during the elevated air pressure exposure to simulate wind driven precipitation climate. The amount of air and water that penetrates through the double-hung replacement window specimen is then measured and recorded.  
           [0008]    Next, three specimens of a double-hung replacement window are placed on another wall in preparation for a missile impact test. The missile impact test simulates the ability of the double-hung replacement window to prevent large objects from penetrating through the window frame, sashes, and insulated glass units. The missile impact test is facilitated by a pneumatic cannon placed a few feet away from the double-hung replacement window, wherein the pneumatic cannon is loaded with a 2″×4″×7′ (approximate) piece of wood, or other object weighing nine pounds.  
           [0009]    In specimen one, a piece of wood fired at the double-hung replacement window at approximately fifty feet per second, and impacts the meeting rail of the sashes, wherein the meeting rails are defined as an overlap region of the first sash and the second sash. Another piece of wood is then shot directly into a center portion of one of the insulated glass units.  
           [0010]    In specimen two, a piece of wood impacts a center portion of one of the insulated glass units and another piece of wood impacts one of the insulated glass units approximately six inches away from one of the frame jamb. In specimen three, a piece of wood is fired at the meeting rail of the sashes and another piece of wood impacts one of the insulated glass units approximately six inches away from one of the frame jamb.  
           [0011]    During the missile impact test, the insulated glass units can develop holes no larger than approximately five inches by one-sixteenth of an inch, but the pieces of wood cannot penetrate through the insulated glass units and into a simulated living area. If holes are formed in the insulated glass units, the holes can be covered with plastic prior to cyclical testing.  
           [0012]    Finally, one or more of the battered and damaged double-hung replacement window specimens are then positioned in openings defined by one side of a hollow, box-shaped container. Each double-hung replacement window specimen is sealed in the opening to create an airtight seal. Air is then pumped into the hollow, box-shaped container, causing each specimen to bow or flex away from the container. The air is then evacuated, causing each specimen to bow inwardly toward the hollow portion of the box-shaped container. This cyclical test is repeated 9,000 times. If there is no failure, the double-hung replacement window passes certification.  
           [0013]    Because the durability tests are quite rigorous, a need exists for a replacement window which will pass the strict testing discussed above.  
         SUMMARY OF THE PRESENT INVENTION  
         [0014]    The present invention seeks to help provide a replacement window that will accommodate strict building codes. A replacement window according to the present invention generally includes a window frame having a window header, a window sill, a first frame jamb, and a second frame jamb, wherein the first frame jamb and the second frame jamb each connect the window header to the window frame, and the window header, the window sill, and the first frame jamb and the second frame jamb define a window frame opening.  
           [0015]    At least one sash may be positioned in the window frame opening. One type of sash, such as a first sash, generally includes a first sash header, a first sash sill spaced away from the first sash header and oriented substantially parallel to the first sash header, a first sash jamb connected to one end of the first sash header and one end of the first sash sill, and a second sash jamb spaced away from the first sash jamb and is oriented substantially parallel to the first sash jamb and is connected to another end of the first sash header and another end of the first sash sill, wherein the first sash header, the first sash sill, the first sash jamb, and the second sash jamb define a first opening.  
           [0016]    Another type of sash, such as a second sash preferably used in combination with the first sash in double-hung replacement window applications, is also movably positioned in the window frame opening. The second sash generally includes a reinforced, second sash header, a second sash sill spaced away from the second sash header and oriented substantially parallel to the second sash header, a third sash jamb connected to one end of the second sash header and one end of the second sash sill, and a fourth sash jamb spaced away from the third sash jamb and is oriented substantially parallel to the third sash jamb and is connected to another end of the second sash header and another end of the second sash sill. The second sash header, the second sash sill, the third sash jamb, and the fourth sash jamb define a second opening. Unlike the first sash, the second sash header of the second sash is reinforced with a reinforcement member preferably connected to or encased in the second sash header. The reinforcement member preferably has a hollow, double I-beam shape and is made from vinyl, metal, wood, or other suitable material. The reinforcement member may extend along an entire length of the second sash header or may be sectioned into two pieces. A reinforcement pin may be positioned adjacent to the second sash header of the second sash.  
           [0017]    At least one jamb retainer clip may be positioned adjacent to the first frame jamb and another jamb retainer clip is preferably positioned adjacent to the second frame jamb. Each of the jamb retainer clips define a reinforcement pin orifice which receives a corresponding reinforcement pin, discussed above. The first frame jamb and the second frame jamb each also define a first balance track and a second balance track, and one jamb retainer clip may be positioned in the second balance track of the first frame jamb and another jamb retainer clip may be positioned in the second balance track of the second frame jamb.  
           [0018]    A plurality of shoe balances are also provided, wherein one of the plurality of shoe balances may be positioned in the first balance track defined by the first frame jamb, another one of the plurality of shoe balances may be positioned in the first balance track defined by the second frame jamb, another one of the plurality of shoe balances may be positioned in the second balance track defined by the first frame jamb, and another of the plurality of shoe balances may be positioned in the second balance track defined by the second frame jamb. The shoe balances slide in the balance tracks and are used to connect the sashes to the window frame.  
           [0019]    These and other advantages of the present invention will be clarified in the description of the preferred embodiment taken together with the attached drawings in which like reference numerals represent like elements throughout. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 is a plan view of an interior surface of a replacement window according to the present invention, with reinforcement elements shown in phantom;  
         [0021]    [0021]FIG. 2 is a perspective view of an exterior surface of the replacement window shown in FIG. 1;  
         [0022]    [0022]FIG. 3 is a perspective plan view of the interior surface of the replacement window shown in FIG. 2;  
         [0023]    [0023]FIG. 4A is a bottom view of a first sash;  
         [0024]    [0024]FIG. 4B is a bottom view of a second sash;  
         [0025]    [0025]FIG. 5 is a perspective view of the replacement window shown in FIGS. 1 and 3, with the first sash shown in FIG. 4A installed in the replacement window and pivoted away from a window frame of the replacement window and the second sash shown in FIG. 4B installed in the replacement window and pivoted away from the window frame of the replacement window;  
         [0026]    [0026]FIG. 6 is a perspective view of the second sash shown in FIG. 4B pivoted away from a window frame of the replacement window;  
         [0027]    [0027]FIG. 7 is a magnified perspective view of the window frame shown in FIG. 6;  
         [0028]    [0028]FIG. 8 is a cross-sectional end view of a second sash header according to the present invention;  
         [0029]    [0029]FIG. 9 is a top perspective view of the second sash header shown in FIG. 8; and  
         [0030]    [0030]FIG. 10 is a front elevation view of three windows showing impact locations.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]    The preferred embodiment of a replacement window  10  according to the present invention is generally shown in FIG. 1. The replacement window  10  includes a window frame  12 , a first sash  14 , a second sash  16 , a first insulated glass unit  18 , a second insulated glass unit  20 , a reinforcement member  22 , a reinforcement pin  24  preferably biased by a spring  26 , a pin lever  28  connected to the reinforcement pin  24 , and a jamb retainer clip  30  defining a reinforcement pin orifice  32 . The reinforcement pin  24  is received in the reinforcement pin orifice  32  defined by the jamb retainer clip  30 .  
         [0032]    As shown generally in FIGS.  1 - 3 , the window frame  12  generally includes a frame header  34 , a frame sill  36  spaced away from the frame header  34  and oriented substantially parallel to the frame header  34 , a first frame jamb  38  connected to another end of the frame header  34  and one end of the frame sill  36 , and a second frame jamb  40  spaced away from the first frame jamb  38  and is oriented substantially parallel to the first frame jamb  38  and is connected to another end of the frame header  34  and the other end of the frame sill  36 . As shown in FIG. 2, the frame header  34 , frame sill  36 , first frame jamb  38 , and second frame jamb  40  may each further define a screen track  42  on an exterior portion of the window frame  12  for receiving a framed screen  44 . The window frame  12  may be made from vinyl, wood, metal, plastic, fiberglass, or any other suitable material.  
         [0033]    Referring again to FIGS.  1 - 3 , the first sash  14  defines a first opening  46  formed by a first sash header  48 , a first sash sill  50  spaced away from the first sash header  48  and oriented substantially parallel to the first sash header  48 , a first sash jamb  52  connected to one end of the first sash header  48  and one end of the first sash sill  50 , and a second sash jamb  54  spaced away from the first sash jamb  52  and is oriented substantially parallel to the first sash jamb  52 , and is connected to the other end of the first sash header  48  and the other end of the first sash sill  50 . The first insulated glass unit  18  is received in the first opening  46  defined by the first sash header  48 , the first sash sill  50 , the first sash jamb  52 , and the second sash jamb  54 . The first insulated glass unit&#39;s  18  construction is conventional, such as two panes of spaced-apart glass, two panes of spaced-apart safety glass, or two or three panes of spaced-apart coated glass, with any of the panes connected together by a peripheral seal to form an insulation air space between the panes of glass. Single panes of insulated glass may also be used. As shown in FIG. 2, weather stripping  56  may be positioned along peripheral edges of the first sash  14 . One half of a conventional window locking device  58 A may also be provided on the first sash sill  50 .  
         [0034]    Referring again to FIGS. 2 and 3, the second sash  16  is similar to the first sash  14 . The second sash  16  defines a second opening  60  formed by a second sash header  62 , a second sash sill  64  spaced away from the second sash header  62  and oriented substantially parallel to the second sash header  62 , a third sash jamb  66  connected to one end of the second sash header  62  and one end of the second sash sill  64 , and a fourth sash jamb  68  spaced away from the third sash jamb  66  and is oriented substantially parallel to the third sash jamb  66  and is connected to the other end of the second sash header  62  and the other end of the second sash sill  64 . The second insulated glass unit  20  is received in the second opening  60  defined by the second sash header  62 , the second sash sill  64 , the third sash jamb  66 , and the fourth sash jamb  66 . The second insulated glass unit  20  is also conventional. Weather stripping  56  may be positioned along peripheral edges of the second sash  16 . Another half of a conventional locking device  58 B may also be provided on the second sash header  62 .  
         [0035]    As shown in FIG. 4A, a first sash retaining arm  70  is positioned at an intersection of the first sash jamb  52  and the first sash sill  50 . A second sash retaining arm  72  is positioned at an intersection of the second sash jamb  54  and the second sash sill  64 . Likewise, as shown in FIG. 4B, a third sash retaining arm  74  is positioned at an intersection of the third sash jamb  68  and the second sash sill  64 . A fourth sash retaining arm  76  is positioned at an intersection of the fourth sash jamb  68  and the second sash sill  64 .  
         [0036]    As shown in FIG. 5, the first sash header  48  has one or more conventional spring clips  78  which retract and protrude from intersections formed by the first sash header  48  and the first sash jamb  52  and the first sash header  48  and the second sash jamb  54 . The first and second frame jambs  38 ,  40  each define a first balance track  80  and a second balance track  82 . As shown in FIGS.  5 - 7 , included in the second balance track  82  of the first frame jamb  38  and in the second balance track  82  the second frame jamb  40  is the jamb retainer clip  30 , a shoe balance  84 , and a balance anchor  86 . The jamb retainer clip  30 , also shown in FIG. 1, is preferably made from polycarbonate, commercially available under the BAKELITE tradename, but may also be made from metal, wood, vinyl or any other suitable material.  
         [0037]    The shoe balance  84  is preferably a pretensioned balance known to those skilled in the art. In general, as shown in FIG. 7, the shoe balance  84  includes a balance housing  88 , a wheel  90  that is rotatable with respect to the balance housing  88  and defines a sash retaining arm orifice  92 , and a pretensioned, coiled strip  94  of metal or other suitable material that is encased in the balance housing  88 . One end of the coiled strip  94  is attached to the balance anchor  86  that is rigidly attached in the second balance track  82  defined by the first frame jamb  38 . The same is also true for a shoe balance  84  positioned in the second balance track  82  defined by the second frame jamb  40 , a shoe balance  84  positioned in the first balance track  80  of the first frame jamb  38 , and a shoe balance  84  positioned in the first balance track  80  of the second frame jamb  40 .  
         [0038]    As a shoe balance  84  slides in its corresponding balance track  80 ,  82 , indicated by arrow A 1 , the pretensioned, coiled strip  94  unrolls from the balance housing  88 . Accordingly, as the balance housing  88  is moved further away from its corresponding balance anchor  86 , the length of the pretensioned, coiled strip  94  that extends from the balance housing  88  increases. Conversely, if the balance housing  88  is moved toward its corresponding balance anchor  86 , indicated by arrow A 2 , the length of the pretensioned, coiled strip  94  that extends from the balance housing  88  decreases. The tension provided by the coiled strip  94  creates a restoring force that is calculated to approximately counterbalance the combined approximate weight of a sash and a double pane of glass.  
         [0039]    As shown in FIGS. 4A, 4B, and  7 , the sash retaining arms  70 ,  72 ,  74 ,  76  positioned on the first and second sashes  14 ,  16  are received in a corresponding sash retaining arm orifice  92  defined by wheel  90  of a corresponding shoe balance  84 . For example, FIG. 7 shows that the second sash  16  is installed in the window frame  12  by inserting the fourth sash retaining arm  76  in the sash retaining arm orifice  92  defined by the wheel  90  of the shoe balance  84  positioned in the second balance track  82  of the first frame jamb  38 . Similarly, but not shown in FIG. 7, the third sash retaining arm  74  is inserted into the sash retaining arm orifice  92  defined by the wheel  90  of the shoe balance  84  positioned in the second balance track  82  defined by the second frame jamb  40  of the window frame  12 . As shown in FIGS.  5 - 7 , when the first and second sashes  14 ,  16  are installed in the window frame  12  via the shoe balance  84 , the first and second sashes  14 ,  16  can be moved within the confines of the window frame  12 , indicated by arrows A 1  and A 2  or pivoted in a direction away from the window frame  12  and opposite to the framed screen  44 , if installed, as shown by arrows A 3 .  
         [0040]    Referring generally to FIG. 8, the reinforcement member  22  is preferably encased in the second sash header  62 . The reinforcement member  22  is preferably a hollow, double I-beam made from metal or other suitable material. The reinforcement member  22  preferably extends along an entire length of the second sash header  62 , but may also be segmented into two sections. A spring clip  78  is received in a cavity defined by the second sash header  62 , as is convention, and the pin lever  28  is connected to the spring clip  78  and to the reinforcement pin  28 . As shown in FIG. 9, the reinforcement pin  24  and the spring clip  78  are oriented coincident with an imaginary longitudinal axis L extending along the second sash header  62 , and positioned at an intersection of the second sash header  62  and the fourth sash jamb  68 . Both the reinforcement pin  24  and the spring clip  78  are biased by the spring  26  shown in phantom in FIG. 1. Another reinforcement pin  24  and another spring clip  78 , each also biased by a spring  26 , may also be oriented coincident with the imaginary longitudinal axis L extending along the second sash header  62  and positioned at an intersection of the second sash header  62  and the third sash jamb  66 .  
         [0041]    When the first and second sashes  14 ,  16  are in a closed position, as shown in FIGS.  1 - 3 , forces acting on the window panes  18 ,  20  and the sashes  14 ,  16  are transferred along the reinforced second sash  16  via the reinforcement member  22 , through the reinforcement pins  24 , through the jamb retainer clips  30 , and into the first and second frame jambs  38 ,  40  of the window frame  12 . It has been found that this arrangement provides strength to the replacement window  10 .  
         [0042]    To clean the first and second insulated glass units  18 ,  20 , as shown generally in FIG. 9, the second sash  16  is pivoted by retracting the spring clip  78  and reinforcement pin  28  combinations into the second sash header  62 , as indicated by opposing arrows A 4 . The retraction moves the opposed reinforcement pins  24  from their corresponding reinforcement pin orifices  32 , while simultaneously allowing the spring clips  78  to clear the second balance track  82 . The second sash  16  may then be pivoted in the direction indicated by arrows A 3 . The first sash  14  can then be moved in the direction indicated by arrow A 1  and then pivoted in the direction of arrow A 3  after the spring clips  78  are retracted into the first sash header  48 .  
         [0043]    Three double-hung windows, made as described above with dimensions of 44 inches wide by 60 inches high with a 4 inch deep frame (upper vent 39{fraction (3/16)} inches wide by 28¾ inches high and lower vent 40{fraction (3/16)} inches wide by 29¾ inches high) were tested according to Dade County (Florida) Protocols PA 201 (the Missile Impact Test) and PA 203 (Cyclic Wind Pressure Test).  
         [0044]    In the Missile Impact Test, a 9 lb., 2 inch×4 inch×96 inch #2 Southern Yellow Pine stud was propelled at the three test windows at a velocity of 50 ft./sec. (34 mph). The location of the test impact points for each window is shown in FIG. 10 as A and B for window Example 1, shown C and D for window Example 2, and shown as E and F for window Example 3. In each instance, no penetration of the stud was observed.  
         [0045]    Next, each of the windows was subjected to the cyclic wind pressure test. This test is conducted after the Missile Impact Test has been completed. By simulating the forces applied to a window by repeated severe wind gusts, this test exposes possible weaknesses in the window assembly created by the missile impacts. In this test, the window assembly is installed in a chamber, and pressures are applied for only a few seconds and repeated several hundred times. The deflection of the components and the anchorage system are examined. The three window examples were exposed to the following conditions:  
                                           Pressure   Duration       Number of Pressure Cycles   (fps)   (seconds)                   Positive Pressure Cycles               3500    +29   1       300   +35   1       600   +47   1       100   +58   1       Negative Pressure Cycles        50   −67   2       1050   −54   1        50   −41   2       3350   −34   1                  
 
         [0046]    The three sample windows were structurally intact, operable, and all parts were securely in place at the conclusion of the tests. These results indicate that the replacement window of the present invention meets the strict building code requirements of Dade County (Florida) PA 201 and PA 203, and other such building codes requiring rigorous performance standards in hurricane prone areas.  
         [0047]    As is described above, the present invention transmits forces applied to the windows and sashes of a replacement window, such as a double-hung replacement window, through a reinforced sash, reinforcement pins, and jamb retainer clips. The force is then more evenly distributed through the frame jambs. This allows a replacement window according to the present invention to withstand violent replacements.  
         [0048]    The invention has been described with reference to the preferred embodiment. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Summary:
A replacement window having a window frame, the window frame having a window header, a window sill, a first frame jamb, and a second frame jamb, wherein the first frame jamb and the second frame jamb each connect the window header to the window frame and the window header, the window sill, and the first frame jamb and the second frame jamb define a window frame opening. A sash having a reinforced sash header may be movably positioned in the window frame opening. A reinforcement pin may be positioned adjacent to the reinforced first sash header of the sash, and a jamb retainer clip may be positioned adjacent to the first frame jamb, the jamb retainer clip defining a reinforcement pin orifice, wherein the reinforcement pin orifice receives the reinforcement pin.