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BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a device and method for providing improved joints in window and door casings. 
         [0003]    2. Description of the Related Art 
         [0004]    Windows and doors are typically enclosed with a framing casing structure as illustrated in  FIGS. 1A and 1B . The typical window casing will comprise a four-sided structure while a typical door casing requires a three-sided structure. A horizontal member  12  is illustrated with a vertical member  14 , joined by a 45 degree miter joint  20 , the vertical member miter cut illustrated as  16  and the horizontal member miter cut as  18 , the miter joint  20  being the connection between the vertical  16  and horizontal  18  member miter cuts. As is well known, a three-sided door casing will typically comprise a single overhead horizontal member  12  and two vertical members  14 , the vertical members  14  forming a miter joint  20  with the mitered ends of the horizontal member  12 . Similarly, a four-sided window casing will generally comprise an upper horizontal and a lower horizontal member with two vertical members therebetween, each of the four connection points being joined with a 45 degree miter joint  20 .  FIG. 1A  illustrates the miter joint  20  as being essentially gap-free. Thus, in this illustration, the vertical miter cut  16  and the horizontal miter cut  18  fit together virtually perfectly, providing the desired tight fit. Most typically, the degree of angles formed at all corners of the framing casing structure is approximately 90 degrees between adjacent members. 
         [0005]    Unfortunately, the miter joint  20  rarely provides a tight fitting joint on the first try. Even using a miter box set exactly on 45 degrees may not result in a tight fit on the first try for many reasons. The artisan must then either attempt to adjust the angle on the miter box slightly and recut or attempt to shave the previously cut but ill-fitting members in order to achieve a good tight fit. 
         [0006]    Moreover, once the desired tight fitting miter joint  20  is achieved, it is very common for the once-tight joint  20  to pull apart, with the once-joined members essentially retracting from each other, resulting in loss of aesthetics and function. This pulling apart of the joint  20  may be caused by one or more conditions. A primary cause involves the permeability of wood typically used in such casings to water. Since this wood absorbs and releases moisture relatively easily, the vertical and horizontal members of the casings will expand and contract accordingly depending on ambient humidity conditions. 
         [0007]    By way of example, if the conditions were relatively humid when the casing was installed, the vertical and horizontal members will be at, or near, a maximum expansion, as in the summer months in the upper Midwestern part of the United States. As the atmospheric humidity decreases post-installation during the fall and winter months, the vertical and horizontal members will naturally lose moisture and will contract in size. This contraction will, inter alia, result in a loss of tight fit of the vertical miter and horizontal miter cuts  16 ,  18 , resulting in a gap of the previously tight miter joint. 
         [0008]    One embodiment of this problem is illustrated in  FIG. 1B . The opened gap  22  in the previously tight fitting miter joint  20  of  FIG. 1A  forms as a result, e.g., of loss of moisture in the horizontal and vertical members  12 ,  14  after installation and formation of miter joint  20 . As the skilled artisan will readily understand, a loss of moisture in the wooden members  12 ,  14  will result in their contraction which, in turn, creates gap  22 . 
         [0009]    The formation of gap  22  is highly undesirable, both from an aesthetic as well as a functional and energy efficiency standpoint. As a result, artisans attempt to mitigate this problem by a variety of techniques, none of which completely solves the problem. Some of these mitigating techniques include gluing the miter cuts  16 ,  18  to prevent them from pulling apart. In addition, sealing any open, non-stained or non-painted surfaces to prevent moisture uptake and/or release is used. However, none of these techniques provide a satisfactory solution as they fail to prevent the gap  22  from forming, they simply attempt to reduce the size/width of gap  22 . 
         [0010]    Note here that gap  22  is illustrated in  FIG. 1B  as having a substantially equal width over its length. This may be interpreted as a case wherein the horizontal member  12  and vertical member  14  comprise wood of substantially similar moisture content when installed and/or having substantially the same moisture content capabilities, so that each member  12 ,  14  takes substantially the same moisture up and releases the same moisture amount. It may, however, be the case wherein one of the members  12 ,  14  comprises a different moisture content profile and, as a result, the gap  22  may not comprise an equal width over its length. In any case, gap  22  is undesirable and is not satisfactorily fixed or mitigated using any known techniques. 
         [0011]    The present invention overcomes these deficiencies. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    The invention provides a device and method for forming window and/or door casings that lock tight and do not gap. 
         [0013]    An object of the invention is to provide a method for forming window and door casings that comprise tight locking elements that do not gap. 
         [0014]    Another object of the invention is to provide a device for cutting the vertical and horizontal members comprising the window and/or door casings that comprise tight locking elements that do not gap. 
         [0015]    The figures and the detailed description which follow more particularly exemplify these and other embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0016]    The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, which are as follows. 
           [0017]      FIG. 1A  is a broken away front view of one embodiment of a known casing construction. 
           [0018]      FIG. 1B  is a broken away front view of one embodiment of a known casing construction. 
           [0019]      FIG. 2  is a perspective broken away view of one embodiment of a horizontal member of the present invention. 
           [0020]      FIG. 3  is a front view of one embodiment of an upper horizontal member of the present invention; 
           [0021]      FIG. 3A  is a front view of one embodiment of an upper horizontal member of the present invention; 
           [0022]      FIG. 4  is a front view of one embodiment of a lower horizontal member of the present invention; 
           [0023]      FIG. 5  is a perspective view of one embodiment of a right side vertical member of the present invention; 
           [0024]      FIG. 6  is a front broken away view of one embodiment of a right side vertical member of the present invention; 
           [0025]      FIG. 6A  is a front broken away view of one embodiment of a right side vertical member of the present invention; 
           [0026]      FIG. 7  is a front broken away view of one embodiment of a left side vertical member of the present invention; 
           [0027]      FIG. 7A  is a front broken away view of one embodiment of a left side vertical member of the present invention; 
           [0028]      FIG. 8  is a front view of the upper right corner of one embodiment of the present invention; 
           [0029]      FIG. 9  is a front view of the upper left corner of one embodiment of the present invention; 
           [0030]      FIG. 10  is a front view of the lower left corner of one embodiment of the present invention; and 
           [0031]      FIG. 11  is a front view of the lower right corner of one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]      FIGS. 2 ,  3  and  3 A illustrate one embodiment of the right side of a horizontal member, specifically an upper horizontal member  100 . The upper horizontal member  100  comprises a body  101  and an elongated horizontal surface  102  and a shortened horizontal surface  104  on opposing sides of the body  101 . The member  100  further comprises a male engager  106 U and a female engaging surface  108 U defined on the right side of the body  101 . 
         [0033]    The male engager  106 U comprises a head  110  and a neck  112 , each comprising a width, wherein the head  110  maximum width W 2 R is wider than the neck  112  minimum width W 1 R. 
         [0034]    Similarly, the female engaging surface  108 U comprises a head section  114  and a neck section  116 , each comprising a width, wherein the head section  114  maximum width W 3 R is wider than the neck section  116  minimum width W 4 R. 
         [0035]    As noted,  FIGS. 2 and 3  illustrate the right side of the upper horizontal member  100 . Turning now to  FIG. 3A , an embodiment of the left side of the upper horizontal member  100  is illustrated. The illustrated embodiment of the left side of the upper horizontal member  100  comprises the same structure and relative dimensions as that illustrated and described above in connection with  FIG. 3 , i.e., comprising a mirror image of the structure of the right side of the upper horizontal member  100 . 
         [0036]    Thus, male engager  106 U and female engaging surface  108 U are also defined on the left side of the body  101 . The male engager  106 U further comprises a head  110  and a neck  112 , each comprising a width, wherein the head  110  maximum width W 2 L is wider than the neck  112  minimum width W 1 L. 
         [0037]    The left side of body  101  also comprises female engaging surface  108 U, which further comprises a head section  114  and a neck section  116 , each comprising a width, wherein the head section  114  maximum width W 3 L is wider than the neck section  116  minimum width W 4 L. 
         [0038]    In a preferred embodiment, the dimensions of the male engager  106 U and the female engaging surface  108 U are the same on the right side and the left side of the body  101  of upper horizontal member  100 . Thus, W 1 R=W 1 L; W 2 R=W 2 L; W 3 R=W 3 L; and W 4 R=W 4 L is a preferred case. However, the present invention is not intended to be limited to this preferred embodiment. Further, the male engager  106 U and female engaging surface  108 U need not be circular or curvilinear as illustrated; instead geometric patterns or shapes, i.e., triangles or squares, etc. Therefore, the dimensions and geometric shape(s) of the right side male engager  106 U and female engaging surface  108 U may differ from those of the left side male engager  106 U and female engaging surface  108 U. What is required in all embodiments is that the male engager  106 U comprises a head  110  with a maximum width that is wider than the minimum width of the neck  112  and that the female engaging surface  108 U comprises a head section  114  with a maximum width that is wider than the minimum width of the neck section  116 . 
         [0039]    In the case of a door casing, which needs a three-sided casing, only an upper horizontal member  100  is typically required. However, for four-sided window casings, a lower horizontal member (not shown) is also needed. Thus, as will be readily understood by the skilled artisan, the lower horizontal member may be of the same shape and comprise the same design considerations as the upper horizontal member, with the only difference being that the elongated horizontal surface will be on the lower portion of the lower horizontal member. In practice, the upper horizontal member  100  would simply be rotated 180 degrees by the artisan. Thus, the lower horizontal member comprises a further embodiment of the present invention. 
         [0040]    One embodiment of the lower horizontal member  150  is illustrated in  FIG. 4 . As shown, member  150  is substantially duplicative in structure and geometry as the upper horizontal member  100 ; the two members  100 ,  150  are simply mirror images of each other. This is a preferred embodiment and is not intended to be limiting in any respect in terms of shape, size or geometry except as indicated herein. 
         [0041]    Thus, the lower horizontal member  150  also comprises right and left male engagers  106 L, each further comprising a head  110 L and a neck  112 L, wherein the head  110 L and neck  112 L comprise a width, wherein the right and left head  110 L comprise a maximum width W 2 RL, W 2 LL that is wider than the right and left neck  112 L minimum width W 1 RL, W 1 LL, respectively. 
         [0042]    Similarly, the right and left female engaging surfaces  108 L comprise a right and left head section  114 L and a right and left neck section  116 L, each further comprising a width, wherein the right and left head section  114 L each comprise a maximum width W 3 RL, W 3 LL is wider than the right and left neck section  116 L minimum width W 4 RL, W 4 LL, respectively. 
         [0043]    In a preferred embodiment, as with the upper horizontal member  100  discussed above, the dimensions of the male engager  106 L and the female engaging surface  108 L are the same on the right side and the left side of the lower horizontal member  150 . Thus, W 1 RL=W 1 LL; W 2 RL=W 2 LL; W 3 RL=W 3 LL; and W 4 RL=W 4 LL in the preferred case. However, as with the upper horizontal member  100 , the present invention is not intended to be limited to this preferred embodiment. Therefore, the dimensions and shape of the right side male engager  106 L and female engaging surface  108 L may differ from those of the left side male engager  106 L and female engaging surface  108 L. What is required in all embodiments is that the male engager  106 L comprises a head  110  with a maximum width that is wider than the minimum width of the neck  112  and that the female engaging surface  108 L comprises a head section  114 L with a maximum width that is wider than the minimum width of the neck section  116 L. 
         [0044]    Turning now to  FIGS. 5 and 6 , one embodiment of the upper portion of the right vertical member  200  is illustrated. The right vertical member  100  comprises a body  201  and an elongated vertical surface  202  and a shortened vertical surface  204  on opposing sides of the body  201 . The member  200  further comprises a male engager  206  and a female engaging surface  208  defined on the upper end of the body  201 . 
         [0045]    The male engager  206  comprises a head  210  and a neck  212 , each comprising a width, wherein the head  210  maximum width W 30 U is wider than the neck  212  minimum width W 40 U. 
         [0046]    Similarly, the female engaging surface  208  comprises a head section  214  and a neck section  216 , each comprising a width, wherein the head section  214  maximum width W 20 U is wider than the minimum width W 10 U of neck  216 . 
         [0047]      FIG. 6A  illustrates one embodiment of the lower right vertical member  200 , which is needed in the case of a window casing since a lower horizontal member will be required as illustrated in  FIG. 4  to complete the four-sided casing. As illustrated, the geometry and size of the male engager  206  and the female engaging surface  208  are mirror images of the upper portion of the right vertical member  200  illustrated in  FIGS. 5 and 6 . 
         [0048]    Thus, the lower right vertical member  200  as illustrated comprises a male engager  206  and a female engaging surface  208  defined on the upper end of the body  201 . 
         [0049]    The male engager  206  comprises a head  210  and a neck  212 , each comprising a width, wherein the head  210  maximum width W 30 L is wider than the neck  212  minimum width W 40 L. 
         [0050]    Similarly, the female engaging surface  208  comprises a head section  214  and a neck section  216 , each comprising a width, wherein the head section  214  maximum width W 20 L is wider than the minimum width W 10 L of neck  216 . 
         [0051]      FIG. 7  illustrates one embodiment of the upper portion of the left vertical member  300 . The left vertical member  300  comprises a body  301  and an elongated vertical surface  302  and a shortened vertical surface  304  on opposing sides of the body  301 . The member  300  further comprises a male engager  306  and a female engaging surface  308  defined on the upper end of the body  301 . 
         [0052]    The male engager  306  comprises a head  310  and a neck  312 , each comprising a width, wherein the head  310  maximum width W 30 U is wider than the neck  312  minimum width W 40 U. 
         [0053]    Similarly, the female engaging surface  308  comprises a head section  314  and a neck section  316 , each comprising a width, wherein the head section  314  maximum width W 20 U is wider than the neck section  316  minimum width W 10 U. 
         [0054]    Turning now to  FIG. 7A , one embodiment of the lower left vertical member  300 , needed in the case of a four-sided casing, is provided. As illustrated, the geometry and size of the male engager  306  and the female engaging surface  308  are mirror images of the upper portion of the left vertical member  300  illustrated in  FIG. 7 . 
         [0055]    Thus, the lower left vertical member  300  as illustrated comprises a male engager  306  and a female engaging surface  308  defined on the upper end of the body  301 . 
         [0056]    The male engager  306  comprises a head  310  and a neck  312 , each comprising a width, wherein the head  310  maximum width W 30 L is wider than the neck  312  minimum width W 40 L. 
         [0057]    Similarly, the female engaging surface  308  comprises a head section  314  and a neck section  316 , each comprising a width, wherein the head section  314  maximum width W 20 L is wider than the minimum width W 10 L of neck  316 . 
         [0058]    The individual members having been described in detail, the assembly of the casing  400  will now be discussed.  FIGS. 8-11  show various embodiments of the lock joint of the present invention.  FIGS. 8 and 9  illustrate the upper right and upper left corners of the assembled casing, respectively.  FIGS. 10 and 11  illustrate the lower left and lower right corners of the assembled casing, respectively. 
         [0059]    Thus,  FIG. 8  illustrates upper horizontal member  100  in locked engagement with right vertical member  200 . Specifically male engager  106 U of upper horizontal member  100  fits within the female engaging surface  208  of vertical member  200  and male engager  206  of right vertical member  200  fits within the female engaging surface  108 U of upper horizontal member  100 . 
         [0060]    This locked engagement is created by sizing the respective engagement elements so that there is a complementary and tight fit. Accordingly, male engager  106 U&#39;s dimensions are complementary with those of the female engaging surface  208 , within which male engager  106 U is engaged. Similarly, male engager  206 &#39;s dimensions are complementary with those of the female engaging surface  108 U, within which male engager  206  is engaged. Because the male engager  106 U&#39;s maximum head  110  width W 2 R is larger than its minimum neck  112  width W 1 R, and because male engager  206 &#39;s maximum head  210  width W 30 U is larger than its minimum neck  212  width W 40 U, and because the respective female engaging surfaces  208  and  108 U are complementary with, respectively, the male engagers&#39;  106  and  206  when in locked engagement therewith as illustrated, any movement along the plane on which the casing  400  lies is severely limited. 
         [0061]      FIG. 9  provides a similar locked engagement between upper horizontal member  100  and left vertical member  300 . Specifically, male engager  106 U of upper horizontal  100  fits within the female engaging surface  308  of vertical member  300  and male engager  306  fits within the female engaging surface  108 U of upper horizontal member  100   
         [0062]    Again, the locked engagement is created by sizing the respective engagement elements so that there is a complementary and tight fit. Accordingly, male engager  106 U&#39;s dimensions are complementary with those of the female engaging surface  308 , within which male engager  106 U is engaged. Similarly, male engager  306 &#39;s dimensions are complementary with those of the female engaging surface  108 U, within which male engager  306  is engaged. Because the male engager  106 U&#39;s maximum head  110  width W 2 L is larger than its minimum neck  112  width W 1 L, and because male engager  306 &#39;s maximum head  310  width W 30 U is larger than its minimum neck  312  width W 40 U, and because the respective female engaging surfaces  308  and  108 U are complementary with, respectively, the male engagers&#39;  106  and  306  when in locked engagement therewith as illustrated, any movement along the plane on which the casing  400  lies is severely limited. 
         [0063]    In the case of a door casing, the embodiment provided by the combination of  FIGS. 8 and 9  provides the required three-sided casing  400 . 
         [0064]      FIG. 10  provides a similar locked engagement between lower horizontal member  150  and left vertical member  300 . Specifically, male engager  106 L of lower horizontal member  150  fits within the female engaging surface  308  of vertical member  300  and male engager  306  fits within the female engaging surface  108 L of lower horizontal member  150 . 
         [0065]    Again, the locked engagement is created by sizing the respective engagement elements so that there is a complementary and tight fit. Accordingly, male engager  106 L&#39;s dimensions are complementary with those of the female engaging surface  308 , within which male engager  106 L is engaged. Similarly, male engager  306 &#39;s dimensions are complementary with those of the female engaging surface  108 L, within which male engager  306  is engaged. Because the male engager  106 L&#39;s maximum head  110 L width W 2 LL is larger than its minimum neck  112 L width W 1 LL, and because male engager  306 &#39;s maximum head  310  width W 30 L is larger than its minimum neck  312  width W 40 L, and because the respective female engaging surfaces  308  and  108 L are complementary with, respectively, the male engagers&#39;  106 L and  306  when in locked engagement therewith as indicated in the Figure, any movement along the plane on which the casing  400  lies is severely limited. 
         [0066]    Finally, to complete a four-sided casing  400 ,  FIG. 11  provides a locked engagement between lower horizontal member and right vertical member  200 . Specifically male engager  106 L of lower horizontal member  150  fits within the female engaging surface  208  of vertical member  200  and male engager  206  of right vertical member  200  fits within the female engaging surface  108 L of upper horizontal member  100 . 
         [0067]    This locked engagement is created by sizing the respective engagement elements so that there is a complementary and tight fit. Accordingly, male engager  106 L&#39;s dimensions are complementary with those of the female engaging surface  208 , within which male engager  106 L is engaged. Similarly, male engager  206 &#39;s dimensions are complementary with those of the female engaging surface  108 L, within which male engager  206  is engaged. Because the male engager  106 L&#39;s maximum head  110 L width W 2 RL is larger than its minimum neck  112 L width W 1 RL, and because male engager  206 &#39;s maximum head  210  width W 30 L is larger than its minimum neck  212  width W 40 L, and because the respective female engaging surfaces  208  and  108 L are complementary, respectively, to the male engagers&#39;  106 L and  206 , when in locked engagement therewith, any movement along the plane on which the casing  400  lies is severely limited. 
         [0068]    The embodiments illustrated comprise members having a single male engager and a single female engaging surface, each being complementary in geometry, i.e, shape and size, with a single female engaging surface and a single male engager, respectively, on an adjacent member. This is a preferred embodiment, though the skilled artisan will readily recognize that the present invention is not limited to just one male engager and/or female engaging surface. The present invention may comprise more than one male engager and/or more than one female engaging surface per member in the casing structure. For example, the horizontal member(s) may comprise two male engagers on both the right and left side in addition to one female engaging surface. In this embodiment, both the right and left vertical members will require two complementary female engaging surfaces at both the upper and lower portions of each member to lockingly engage the two male engagers, as well as one male engager to engage the female engaging surface of the horizontal members. What is required is that each member of the casing structure comprise at least one male engager and at least one female engager, with complementary geometry on the adjacent member(s). Many alternative embodiments present themselves, each of which are well within the scope of the present invention. 
         [0069]    The members of the present invention may be constructed using a jig which is shaped to provide the necessary complementary geometry, i.e., the at least one male engager and the at least one female engager for each member and each adjacent member pair. As is well understood, the jig is fashioned to provide essentially a negative image of the desired member shaping. Each member of the casing structure will require its own jig. The jig may be formed of any material which will hold its shape, i.e., wood, metal, plastic and the like. Once formed, the jig may be placed over the wood to be used for a member, the outline of the at least one male engager and at least one female engager traced or otherwise marked. The jig may be removed, or may be left in place, and the tracings or markings are then used to cut the at least one male engager and at least one female engager shapes. 
         [0070]    Further, each member of the casing structure discussed herein may be formed, as will be recognized by the skilled artisan, by machining the geometry and structures discussed. 
         [0071]    The present invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the present specification.

Summary:
The invention provides a method for providing improved and locking joints in window and door casings. Complementary geometric shapes are provided on each adjacent joint member to provide locking engagement thereof. This locking engagement helps prevent the gaps that typically result in known 45 degree miter joints as a result of expansion and contraction due to water uptake and release.