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[0001]    This patent application claims priority to U.S. Provisional Application Serial No. 60/303,669, which was filed on Jul. 7, 2001, and which is fully incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention encompasses a system and method for forming openings within and through a wall, particularly walls formed at least in part with concrete. The openings later serve as frames to install a door, a window, or the like.  
           [0004]    2. Background  
           [0005]    Concrete walls in building construction are often produced by first setting up two parallel form walls and placing fluid concrete into the space between the forms. After the concrete hardens, the builder then removes the forms, leaving the cured concrete wall.  
           [0006]    This prior art technique has drawbacks. Formation of the concrete walls is inefficient because of the time required to erect the forms, wait until the concrete substantially cures, and take down the forms. This prior art technique, accordingly, is an expensive, labor-intensive process.  
           [0007]    Techniques have developed for forming modular concrete walls that use a foam insulating material. The modular form walls are set up parallel to each other and connecting components hold the two form walls in place relative to each other while concrete is poured therebetween. The form walls, however, remain in place after the concrete cures. That is, the form walls, which are often constructed of foam insulating material, are a permanent part of the building after the concrete cures. The concrete walls made using this technique can be stacked on top of each other many stories high to form all of a building&#39;s walls. In addition to the efficiency gained by using the form walls in construction and also using them as part of the permanent structure, the materials of the form walls often provide adequate insulation for the building.  
           [0008]    When constructing such form walls, it is frequently desired to position windows, doors, garage doors, or other opening through the wall between the interior and exterior of the building. The typical prior art procedure for forming an opening involves constructing a frame from dimensional lumber and positioning the wood frame within and between the opposed pair of insulated concrete forms. The wood frame is sized to receive a structure of a desired dimension and then the frame is positioned within and through the pair of modular form walls, after which time the concrete is poured between the forms to circumscribe the exterior of the wood frame. When the concrete substantially cures, the wood forms are either removed so that the desired structure may be inserted into and through the opening formed within the wall structure or, more typically, remain in place and serve as the frame into which the structure, such as a window, is inserted.  
           [0009]    There are disadvantages with using dimensional lumber to form these openings however. The primary drawback is that even if the wood is initially straight, warping often occurs when the fluid concrete contacts the lumber during the construction of the wall. The result is that the opening left after the wood warps is not of the proper dimension to receive the desired structure, such as the window, resulting in the structure not fitting correctly within the opening. Such an improper fit mandates that the opening be re-dimensioned, which may include leveling some of the wood that extends too far into the opening or adding an appropriate filler if the opposite condition exists. Reworking the dimensions of the opening obviously is labor intensive—which increases costs—and also delays completion of the building.  
           [0010]    Even if the dimensional lumber does not warp during the construction phase (e.g., it is covered with a polyfilm before pouring the concrete), the wood is still subject to aging and the associated problems. For example, the wood may later warp, which may potentially cause buckling and cracking of the wall adjacent the wood. Other possible problems are rot, decay, and insect damage. These problems have resulted in some contractors having reservations about constructing concrete buildings using insulating concrete forms when openings are included in the design.  
           [0011]    One attempt to address the problems associated with using wood frames is disclosed in U.S. Pat. No. 6,070,375, which is incorporated herein in its entirety. This patent teaches a buck system for forming openings in concrete walls using a vinyl material to overcome the deficiencies with using dimensional lumber. However, the disclosed process currently has not been embraced by the industry.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention provides a plurality of assembly members formed of a non-wood material, such as polyvinyl chloride (“PVC”). Each assembly member, however, can be used similar to dimensional lumber so that builders are comfortable with its use. That is, the assembly members of the present invention may be used in the same manner as dimensional lumber to facilitate acceptance in the industry, but avoid the drawbacks of wood, such as warping, decay, rot, insect damage, or the like.  
           [0013]    In addition, the assembly members of the present invention may be used in conjunction with interlocking end caps and, collectively, be formed to an appropriate depth to match any standard dimension wall. In the preferred embodiment, the end caps have the same depth or thickness as the side panels and the assembly members are formed to be the same depth as the cavity into which the fluid concrete is poured during construction. The components are formed in select sizes so that they can be combined to form walls in almost any standard dimension. As such, the preferred embodiment of the present invention is “modular” by minimizing the number of different components, yet is still able to combine for any standard construction design.  
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a perspective view of a one embodiment of a wall formed using insulated concrete forms to provide context for the present invention.  
         [0015]    [0015]FIG. 2 is a perspective side view of a FIG. 1 taken along line  2 - 2 .  
         [0016]    [0016]FIG. 2A is an alternative view of FIG. 2 showing concrete disposed between the two opposed side panels.  
         [0017]    [0017]FIG. 3 is a perspective view of one side panel shown in FIG. 1.  
         [0018]    [0018]FIG. 4 is a perspective view of a connector shown in FIG. 3.  
         [0019]    [0019]FIG. 5 is an exploded perspective view of a web member showing an extender.  
         [0020]    [0020]FIG. 6 is a perspective view of one embodiment of the assembly member of the present invention.  
         [0021]    [0021]FIG. 7 is a cross-sectional end view of the assembly member shown in FIG. 6 interconnected to two end caps on its opposed sides.  
         [0022]    [0022]FIG. 8A is a perspective view of the assembly members and end caps, similar to those shown in FIG. 7, that are inserted into the insulated concrete forms shown in FIG. 1 to form a frame for a window.  
         [0023]    [0023]FIG. 8B is a vertically cut cross-sectional perspective view of FIG. 8A.  
         [0024]    [0024]FIG. 8C is a side end view of FIG. 8B.  
         [0025]    [0025]FIG. 8D is a horizontally cut cross-sectional perspective view of FIG. 8A.  
         [0026]    [0026]FIG. 8E is a top plan view of FIG. 8D.  
         [0027]    [0027]FIG. 9A is a perspective view of the assembly members and end caps, similar to those shown in FIG. 7, that are inserted into the insulated concrete forms shown in FIG. 1 to form a frame for a hinged door.  
         [0028]    [0028]FIG. 9B is a perspective view of FIG. 9A a vertically cut cross-sectionally without the bottom member shown in FIG. 9A.  
         [0029]    [0029]FIG. 9C is an end view of FIG. 9B.  
         [0030]    [0030]FIG. 9D is an end view of FIG. 9A.  
         [0031]    [0031]FIG. 10 is a cross-sectional side view showing the buck system of FIG. 7 and also showing two opposed side panels and the web members partially disposed therein, in which the buck system and side panels are interconnected in various combinations by flexible linking members traversing through extenders or slots. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]    The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, “a,” “an,” and “the” can mean one or more, depending upon the context in which it is used. The preferred embodiment is now described with reference to the figures, in which like numbers indicate like parts throughout the figures.  
         [0033]    As generally shown in FIGS.  1 - 10 , the preferred embodiment of the present invention comprises a buck system used in conjunction with a concrete form structure. Before describing the buck system, it is instructive to discuss one exemplary embodiment of an insulated concrete form system with which the buck system of the present invention may be used. As those skilled in the art will appreciate, the described insulated concrete form is exemplary to provide context in discussing the buck system of the present invention, and the buck system may be used with other insulated concrete forms within the scope of the present invention.  
         [0034]    Specifically, one concrete form system  10  is shown best in FIGS.  14  and includes at least two opposed longitudinally-extending side panels  20 , at least one web member  40  partially disposed within each of the side panels  20 , and a connector  50  disposed between the side panels  20  for connecting the web members  40  to each other. As shown in FIG. 2A, concrete C is poured between the side panels  20  so that it bonds with the side panels  20 , the web members  40 , and the connectors  50 . A more complete discussion of this and other designs are disclosed in U.S. Pat. No. 6,363,683 and pending U.S. patent application Ser. No. 09/848,595, filed on May 3, 2001, the disclosures of which are incorporated by reference in their entireties.  
         [0035]    Each side panel  20  has a top end  24 , a bottom end  26 , a first end  28 , a second end  30 , an exterior surface  32 , and an interior surface  34 . The illustrated side panel  20  has a thickness (separation between the interior surface  34  and exterior surface  32 ) of approximately two (2) inches for commercial construction and two and a half (2 ½) inches for residential buildings, a height (separation between the bottom end  26  and the top end  24 ) of twenty-four (24) inches for commercial buildings and sixteen (16) inches for residential buildings, and a length (separation between the first end  28  and second end  30 ) of forty-eight (48) inches. Of course, these dimensions are exemplary and may be altered, if desired, or may be different in other form systems with which the present invention may be used.  
         [0036]    Referring still to FIGS. 1 and 2, the interior surface  34  of one side panel  20  faces the interior surface  34  of another side panel  20  and the opposed interior surfaces  34  are laterally spaced apart from each other a desired separation distance so that a cavity  38  is formed therebetween. Concrete—in its fluid state—is poured into the cavity  38  and allowed to substantially cure (i.e., harden) therein to form the wall  10 , as shown in FIG. 2A. Preferably the opposed interior surfaces  34  are parallel to each other. The side panels  20  are typically constructed of polystyrene, specifically expanded polystyrene (“EPS”), which provides thermal insulation, sound impedance, and sufficient strength to hold the poured concrete C until it substantially cures. As shown in FIGS.  1 - 3 , each side panel  20  shows six web members  40  formed into it. Portions of each web member  40  that extend through the interior surface  34  of the side panel  20  form one or more attachment points  44 . The attachment points  44  are disposed within the cavity  38  and are spaced apart from the interior surface  34  of the side panels  20  in the illustrated embodiment.  
         [0037]    Each attachment point  44  is sized to be complementarily and slidably received within one respective end  52  of the connector  50 , which is best shown in FIG. 4. The connectors  50  engage two attachment points  44  on opposed web members  40 , which position the interior surfaces  34  of the side panels  20  at a desired separation distance. That is, still referring to FIG. 4, the illustrated connector  50  has opposed ends  52  and a length extending therebetween. The ends  52  of the connectors  50  are each of a shape to engage one attachment point  44  of two respective web members  40  within opposed panels. Thus, the connectors  50  space the side panels apart from each other so that the web members  40  preferably do not directly contact each other; instead, each attachment point  44  independently engages the connector  50  that interconnects the web members  40  and, accordingly, the side panels  20 . The connection between the connectors  50  and the opposed web members  40  are sufficient to hold and support the side panels  20  as they are subject to hydrostatic and dynamic forces when the fluid concrete is poured into the cavity  38  during construction.  
         [0038]    As best shown in FIGS. 2 and 3, in one design each of the web members  40  has four spaced-apart attachment points  44 , in which the attachment points  44  for each web member  40  are vertically disposed within the cavity  38  in a substantially linear relationship. In an alternative design shown in FIGS. 5 and 10, the web member  40  includes five attachment points  44 . The groupings of the attachment points  44  allow the side panels  20  and web members  40  to be cut horizontally over a wide range of heights to satisfy architectural requirements, such as leaving an area for windows and doors, yet still have at least two or three attachment points  44  to maintain structural integrity of the wall.  
         [0039]    Such cuts into the side panels  20  or voids left in the walls relate to the present invention, which provides a buck system  70  for forming a frame  72  defining an opening within and through the wall as shown in FIGS.  6 - 9 D. A desired structure, such as a window, hinged door, or garage door (not shown), is mounted within the frame  72  after the concrete is poured and substantially cures.  
         [0040]    The buck system  70  forms a frame  72  using assembly members  80  and, in the preferred embodiment, also uses end caps  90  that are longitudinally aligned with and connected to the assembly members  80  forming the frame  72 . As best shown in FIGS. 6 and 7, each assembly member  80  has an interior surface  81 , an exterior surface  82 , opposed sides  84 , opposed ends  85 , and a length extending between the opposed ends  85 . In the preferred embodiment, at least three assembly members  80  are used in forming the frame  72 , in which at least one end of each assembly member  80  is adjacent or abuts one end of another assembly member  80  to form a non-linear angle therebetween. In the context of the exemplary insulated concrete form described above and as discussed in more detail below, the frame  72  typically uses three assembly members  80  for a door, as shown in FIGS.  9 B- 9 D, or includes four assembly members  80  for a window having its bottom ledge located above the subfloor on which the wall structure is disposed, as shown in FIGS.  8 A- 8 E.  
         [0041]    Referring now to FIG. 7, there is preferably at least one end cap  90  for each assembly member  80 . Each end cap  90  has an engaging side  92  and an opposed exposed side  94 . The engaging side  92  is designed to complementarily and detachably connect to one respective side of the assembly member  80 . As shown in FIG. 7, there are two end caps  90  for each assembly member  80 , each end cap  90  connected to one respective side  84  of one assembly member  80 . It is further preferred that each end cap  90  has a length, in which the lengths of the end caps  90  are substantially the same as the assembly member  80  to which the end caps  90  are connected.  
         [0042]    Referring back to FIGS. 6 and 7, it is preferred that each of the assembly members  80  and end caps  90  include a respective plurality of hollow channels  86  extending lengthwise within their respective inner volumes, the inner volume for the assembly members  80  defined by the interior and exterior surfaces  81 ,  82  and the opposed sides  84  (and the end caps  90  having a similarly defined inner volume). The channels  86  are aligned side by side, are formed to extend substantially the length of each assembly member  80 , and may have a rectangular cross-section or other design, as show for example in FIG. 6. The channels  86  structurally strengthen the assembly members  80  without substantially increasing their cost or weight. If desired, the channels  86  may be selectively filled with insulating material that includes, for example, an expanded polyurethane foam, fiberglass materials, or any other similar material that increases thermal resistively through the frame  72 .  
         [0043]    Depending on the material used to form the components of the buck system  70 , it may also be desired to construct the channels  86  in a “double walled” design adjacent surfaces through which fasteners (not shown), such as screws, are inserted. Specifically, referring to FIG. 7, the channels  86  adjacent the exposed side  94  of the end cap  90  has a small cross-sectional area so that a fastener traverses through at least two structural walls to provide a more secure and stable connection between the end cap  90  and the fastener. Likewise, the channels  86  adjacent the exterior surface  82  of the assembly member  80  also may use a relatively small cross-sectional area for the same purpose. Again, the channels  86  through which the fasteners traverse may take different cross-sectional shapes and may have different cross-sectional sizes, as demonstrated by the exemplary embodiments shown in the drawings.  
         [0044]    Referring still to FIG. 7, to interconnect the engaging sides  92  of the end caps  90  to the sides  84  of the assembly members  80 , preferably a connecting means is integrally formed into both respective surfaces. Still referring to FIGS. 6 and 7, each side of the assembly member  80  includes both a longitudinally-extending groove  96  and protrusion  97  and the associated engaging side  92  of the end cap  90  has a mirror image groove  96  and protrusion  97 . Thus, as shown in FIG. 7, the protrusion  97  of each component is slidably received in the groove  96  of the adjacent component to interlock the end cap  90  to the assembly member  80 . As discussed below, this design allows different widths of end caps  90  to be used with different widths of assembly members  80 , contributing to the “modularity” of the present invention.  
         [0045]    The connecting means, however, can take different forms than that shown in FIGS. 6 and 7. For example, there may be only one groove on one component and one protrusion on the other, as opposed to having both a groove and protrusion on the sides of both components. As another example, one of the components may include a series of longitudinally-aligned orifices and the other component may include spaced-apart longitudinally-aligned stems that are complementarily received within the orifices to engage and lock the components together. Still other connecting means are contemplated, such as chemically bonding using glue, fusing, mechanically connecting with fasteners, and the like. It is also contemplated integrally forming the assembly members  80  and end caps  90  together, although this is currently less desirable since it reduces the modularity of the design for use in different situations with different types of buildings.  
         [0046]    As mentioned above, the preferred system of the present invention uses interchangeable components. Specifically, the width or depth between the opposed sides  84  of the assembly members  80  is preferably the same as that of the cavity  38  and the depth of the end caps  90  is correspondingly the same as that of the side panels  20 . Thus, for the exemplary embodiment of the concrete form system discussed above, the end caps  90  are manufactured in two widths: two inches for commercial blocks (i.e, twenty-four inches in height with a thickness of two inches) and two and a half inches for residential blocks (i.e., sixteen inches height with a thickness of two and a half inches). The assembly members  80  may be used with either size side panels  20  so that the components are interchangeable for residential and commercial structures.  
         [0047]    It is also contemplated in the preferred embodiment using, for example, both four (4) and six (6) inch wide assembly members  80 . These assembly members  80  may be joined together using the connecting means to fit, for example, a twelve (12) or fourteen (14) inch thick concrete wall. In fact, with this design, the present invention may fit any thickness concrete wall in two-inch increments starting with a four-inch wide wall. Such a design and the interchangeable end caps  90  contribute to the modular concept that reduces manufacturing costs of the components of the present invention and allow the manufactured components to be used in numerous combinations of building designs. As one skilled in the art will appreciate, the contractor may select components of the desired dimensions for that wall design from a collection of materials and assemble those components at the construction site.  
         [0048]    Referring again to FIGS. 6 and 7, another feature of the preferred embodiment of the present invention is the inclusion of at least one flange  98  for each assembly member  80 . Each flange  98  extends from a portion of either the assembly member  80  or the adjacent connected end cap  90 . As best shown in FIG. 7, there are two flanges  98  that are each integrally formed to one assembly member  80 . The flanges  98  each have a contacting surface  99  that is serrated and is adapted to engage the interior surface  34  of the assembled side panels  20 . As will also be discussed below, the spacing between the contacting surfaces  99  of the flanges  98 —or the contacting surfaces  99  of the outermost flanges  98  if multiple assembly members  80  are laterally together to be a width wider than the described embodiment (i.e., eight inches)—are spaced apart the same width as the cavity  38 . Thus, the contacting surfaces  99  of the flanges  98 , which preferably include some lateral flexibility, are slid into the cavity  38  formed between the opposed side panels  20  to position stationarily the assembly member(s)  80  relative to the side panels  20 . Stated differently, the flanges  98  frictionally engage the interior surface  34  of the side panels  20  to hold the assembly members  80  of the frame  72  in position.  
         [0049]    One means to ensure that the flange  98  does not move relative to the side panel  20  during the pouring of the concrete is to use a fastener (not shown) to interconnect a portion of the flange  98  to a portion of the side panel  20 . For example, the fastener may be a screw disposed through a portion of the flange  98  and the side panel  20 , in which the screw is preferably a wood screw with wide threading. The fastener can also take the form of a chemical bonding substance, such as glue, or the like. As one skilled in the art will appreciate, use of a fastener is most prevalent when forming a structure having one side panel, such as a tilt-up wall disclosed in U.S. patent application Ser. No. 09/848,595.  
         [0050]    Another option to position stationarily the assembly members  80  relative to the side panels  20  is using an extender attached to the slot formed in the assembly member  80 . Still referring to FIGS. 6 and 7, the interior surface  81  of the assembly member  80  includes a longitudinally-extending slot  88  disposed intermediate its opposed sides  84  and the slot  88  is of a size to complementarily receive the tip end  62  of an extender  60 , which is shown in FIGS. 5 and 10. The tip end  62  is preferably rectangular in plan view—as is the attachment point  44 —and the base end  64  is similar in design to the end  52  of the connector  50 . The tip end  62  is slid into the slot  88  of the assembly member  80 .  
         [0051]    The body  66  of the extender  60  defines a passage  68  therethrough. As will be noted by FIG. 5, the passage  68  is of a dimension to allow a portion of at least one flexible linking member  100 , such as a zip-tie as shown in FIG. 10, plastic tie strap, tie wire, or other similar component, to be received therethrough. Since the assembly member  80  is oriented at a non-parallel angle to the interior and exterior surfaces  32 ,  34  of the side panels  20 —specifically being disposed at right angle—the normally linear connectors  50  shown in FIG. 4 cannot feasibly be used. One skilled in the art will appreciate by referring to FIG. 10 that the extender  60  connected to the assembly member  80  within its slot  88  may be used with a flexible linking member  100  to provide a connection to the adjacent side panels  20 . That is, the linking member  100  passing through the passage  68  of the extender  60  connected to the slot  88  of the assembly member  80  also connects either to another extender  60  attached to an attachment point  44  of one web member  40 ; to a slot  41  extending through the web member  40 ; and/or wrapped around a connector  50  interconnecting two opposed side panels  20  (not shown). Such a connection supports the frame  72  mounted against the side panels  20  as shown in FIGS.  8 A- 9 D and buttresses the frictional hold of the flanges  98  and/or the external bracing (which is discussed in more detail below). Of course, other designs for the extender and the slot may be used within the scope of the present invention.  
         [0052]    One skilled in the art will further appreciate that the extender  60  and the flexible linking member  100  additionally act as an “anchor” for the concrete. That is, the extender  60  and the flexible linking member  100  have surfaces that the fluid concrete surrounds as it is poured into the cavity  38  so that the cured concrete better holds the frame  72  in position after curing. Also, the slot  88  further or independently assists in anchoring the frame  72  to the cured concrete.  
         [0053]    The assembly members  80 , end caps  90 , and flanges  98  are each preferably formed of a vinyl material that is extruded, most preferably polyvinyl chloride (“PVC”), which inherently has fire retardant characteristics. Vinyl materials are strong but not brittle, may be cleaned, and do not require painting or other preserving after installation when covered, which usually occurs for window and door bucks. However, the components may be formed from alternative materials including, for example, other vinyl-type materials, fiberglass, aluminum and its alloys, and other similar materials. Regardless of the material chosen, it is preferred to use a low cost material that is resistant to corrosion and decay, can accept nails or screws, yet have sufficient structural strength to support the forces applied by the fluid concrete when the wall is being formed.  
         [0054]    One aspect of the present invention is that it functions almost the same as dimensional lumber with which construction workers are familiar. That is, the preferred material—similar to wood—may be made readily cut using a hand saw or hand held power saw and also may be nailed, screwed, or glued. PVC satisfies these requirements. In addition, in the preferred embodiment, the assembly members  80  and end caps  90  are provided in lengths of eight (8) feet, which is similar to the dimension that lumber is sold and used by construction workers.  
         [0055]    As one skilled in the art will further appreciate, the components of the present invention may be easily stored before use because they are in a disassembled condition, reducing the amount of space necessary for shipment and storage at the construction site. Shipping dissembled components also minimizes potential damage that may occur during transportation to the construction site prior to installation.  
         [0056]    During construction, the components are cut, if necessary, at the construction site to a desired length for the frame  72  to be formed. However, it is preferred that the assembly members  80  and end caps  90  be assembled prior to sawing, in which the components are longitudinally staggered, i.e., the ends  85  of the assembly members  80  are positioned so that they are approximately the midpoint of the length of end caps  90  and vice versa. Thus, a rigid, interlocking joint is formed as a result of this staggered positioning of the assembly members  80  and end caps  90 . It is further preferred that the components further be chemically bonded together, such as with a PVC glue if the end caps and assembly members are formed of PVC. This design makes a strong assembled component and minimizes waste. For example, an entire construction may be completed with only a few unused remnants, a minimization of waste that other systems and dimensional lumber do not provide.  
         [0057]    To install a window buck such as that shown in FIGS.  8 A- 8 E, the side panels  20  are first positioned. Referring specifically FIG. 8A, each end of all four assembly members  80  and end caps  90  is adjacent or abuts a respective end of an adjacent corresponding component to form a ninety (90) degree angle to define a rectangular window frame  72 . The window frame, accordingly, has a top, a bottom, and two opposed sides and, as illustrated, includes two end caps  90  attached to each of the respective four assembly members  80 .  
         [0058]    The window frame  72  formed from four assembly members  80  and eight end caps  90  as shown in FIG. 8A are positioned within and through the wall structure at a desired location and secured by a compression fit between the flanges  98  and the interior surface  34  of the side panels  20 . That is, as noted above, the flanges  98  connected to the assembly member  80  or end caps  90  are spaced apart at substantially the same width as the depth or thickness of the cavity  38 . Accordingly, the flanges  98  that are slightly flexible in the preferred embodiment bend inwardly when inserted into the cavity  38  so that the flanges  98  frictionally hold the frame  72  in position. The non-smooth, serrated contacting surfaces  99  of the flanges  98  assist in positioning the frame  72 . If the web members  40  and their attachment points  44  interfere with the flanges  98  when inserted into the cavity  38 , notches and other areas of the flange  98  can be trimmed away to accommodate the frame  72 . As also discussed above, additional means may be used internally to position the frame  72  stationarily relative to the side panels  20 , such as using the extenders  60  and flexible linking members  100  (which are not shown in FIGS. 8C and 8E) and/or fasteners between the side panels  20  and the flanges  98 .  
         [0059]    The bottom of the window frame  72 , however, may optionally include only end caps  90  so that the cavity  38  adjacent the bottom is in free communication with the outside. That is, instead of having an assembly member  80  disposed between the cavity  38  and the outside environment, that assembly member is missing but the two bottom end caps  90  are used. These two bottom end caps  90 , called stand-alone end caps, are disposed substantially horizontally and elevationally below the three assembly members  80 . The length edges or engaging sides of the two stand-alone end caps are spaced apart from each other to provide a gap in the bottom of the window frame  72  that allows the cavity  38  to vent during placement of the concrete. This gap may be monitored to ensure that the concrete reaches the bottom of the window frame  72  and also may be used as a port through which concrete is poured into the cavity  38  during construction.  
         [0060]    Referring now to FIGS.  9 A- 9 D, the illustrated frame  72  is designed to receive a hinged door instead of a window as discussed above. Besides the changed dimensions, the primary difference is the use of the bottom portion of the frame  72 . As shown in FIG. 9A, a bottom member is included in the frame  72 . However, this bottom member may be either be temporary to function as bracing or be permanent. FIG. 9B shows the bottom member removed from the frame  72  after the concrete has substantially cured or set.  
         [0061]    For a garage doorframe (not shown) that has an upper portion extending more than eight feet—the length of the assembly members  80  and the end caps  90  in the preferred embodiment—the components are preferably assembled staggered relative to each other and glued, as discussed above. This design using staggered joints forms a unitary solid plank and has desirable physical and structural strength characteristics. Alternatively, the assembly members  80  and end caps may be aligned to abut linearly end to end (i.e., in eight foot segments) and angle braces or other horizontal bracing devices interconnect each of the linearly abutting components to support their connection and prevent separation during placement of the concrete. These temporary supports are then removed after the concrete cures.  
         [0062]    As illustrated, external bracing may also be used to support the frame  72  during installation. As shown in FIGS.  8 A- 8 E, corner angle braces  74  may be included at each corner of the frame  72  and secured with drywall screws (not shown). Usually four corner angle braces  74  are sufficient for supporting a window or a hinged doorframe. However, if necessary (due to the weight of the concrete above), the frame  72  can be braced either horizontally or vertically across the opening with additional bracing if warranted. For example, bracing may be provided using in a conventional manner with one metal or wooden brace (not shown) used for approximately every three feet of opening.  
         [0063]    After the side panels  20  and frames  72  are assembled, positioned, and braced, concrete is poured into the cavity  38  formed between the interior surfaces  34  of the side panels  20  and the interior surfaces  81  of the assembly members  80  to create the concrete wall. Once the concrete substantially cures or dries, any external bracing holding the frame  72  in position may be removed and then the window or door may be inserted into the frame  72 .  
         [0064]    Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention. For example, the buck system  70  of the present invention is discussed in context of the insulated form system described above; however, one skilled in the art will appreciate that the present invention can be used with other building systems and designs, e.g., the forms may be standard concrete wall forms or insulated concrete forms using designs different from the embodiment discussed herein.

Summary:
A buck system for forming a frame to insert a window, door, or the like into a wall. The buck system includes assembly members that have a width that corresponds to the dimension of the cavity, if any, and optionally includes end caps. The assembly members and end caps are preferably formed of materials that avoid the drawbacks of dimensional lumber. It is noted that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims pursuant to 37 C.F.R. §1.72(b).