Patent Publication Number: US-6981686-B2

Title: Modular support/enclosure wall assembly and kit

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to modular wall assemblies of the type used for earth excavations, concrete forms and temporary enclosures. More specifically, the invention relates to a unique set of parts and materials that facilitate the assembly and disassembly of such walls in the widest possible variety of shapes and layouts with a minimum number of different parts. 
     2. Description of the Invention 
     Construction forms for pouring concrete, and shoring forms for supporting the earthen sides of excavations and the like have been well known and widely used for many years. Similarly, the walls used to define such forms can also be employed when desired to construct temporary enclosures for storing and protecting construction equipment and supplies. However, the forms and elements available for these purposes in the prior art are generally limited in adaptability and restricted in the shapes and layouts that can be achieved without extensive inventories of different parts and materials. 
     The present invention overcomes these problems and other limitations of the prior art by providing a set of construction elements comprising a limited number of standard parts that can be interconnected easily in many ways to define a wide variety of configurations. The shape of each part reduces the required number of differently shaped parts to a minimum while permitting the parts to be interconnected with each other in a maximum number of different alignments and orientations. 
     That is, the parts of the wall system of this invention in general comprise a plurality of differently sized but otherwise substantially identical elongate rib elements that are interconnectable with each other to define a supporting framework or skeleton, and a plurality sheet-like skin elements of tough, stiffly flexible material that than can be fastened readily to the skeleton to define the desired wall structure. 
     The rib elements of the system of this invention each include a variety of specifically shaped and located bolt-receiving openings that allow the insertion of rib bolts to secure the rib elements to each other. Similarly, the skin elements are perforated in a regular pattern to receive threaded hanger bolts that serve to fasten the skin to the skeleton. The heads of the hanger bolts and the perforations in the skin are specifically shaped to permit the heads to pass through the skin in both directions under certain circumstances, to facilitate assembly and disassembly of a wall structure. 
     SUMMARY OF THE INVENTION 
     The present invention discloses a wall construction system incorporating uniquely shaped elongate rib elements of various predetermined lengths that are bolted together to form a skeleton or framework that supports and defines the shape of the wall. The wall structure is completed by securing a skin of sheet-like skin elements to the skeleton framework formed by the ribs. The threaded bolts that serve to hold the rib elements and skin elements in assembled relationship are specifically adapted to the nature and configuration of those elements. 
     The rib elements are beam-like in nature, having generally a trapezoidal transverse cross-section and a generally trapezoidal axial cross section; in this regard, each beam may be considered to be characterized by a central axis extending along the length of the beam, and the transverse cross-section accordingly lies in a plane that is normal to the central axis while the axial cross-section lies in a plane that passes through the central axis. Aside from variations in the length of the ribs and variations in the number of apertures in each rib depending upon its length, all of the ribs are substantially identical to each other in each structure. The number of different length ribs needed to construct usable walls in accordance with the invention depends primarily upon the construction application in which the system is being used and the corresponding size and nature of the walls that must be formed. For relatively small scale-construction projects requiring simple concrete-pouring forms and reinforcement of comparatively small excavated earth walls, three to six different lengths of ribs may be sufficient, while larger projects or projects requiring particularly complex wall shapes may require dozens of different rib lengths. 
     The trapezoidal cross-sectional shape of the rib elements provides convergingly related side and end walls on each rib. These sloping walls can be abutted against each other in various relationships to achieve desired straight or angular joints between adjacent ribs. And, as a result of the placement and configuration of the bolt-receiving openings in each rib, abutting ribs can be bolted together firmly, independently of the skin elements, to sustain desired framework shape. 
     The skin elements that are fastened to the rib-based framework comprise sheets of tough, stiffly flexible material, such as sheet steel or the newer composite materials of the type being used at this time in the fabrication of aircraft and automobile bodies. Each sheet of skin material may be of any suitable size, and for convenience one or more standard sizes may be made available. It is expected that size will be determined generally by weight and/or dimensions that can be handled conveniently by manual workers with or without machinery to assist them. In accordance with this invention, each sheet of skin is characterized by a regular pattern of through-holes distributed over the surface of the skin element, for accepting passage of hanger-bolt elements that allow the skin to be “hung”, that is anchored or fastened, to the skeletal framework of rib elements. 
     The remaining key elements of the invention are rib-bolts that serve to secure the rib elements together to form a framework, and hanger-bolts that are used to secure the skin elements to the framework of ribs. The threaded rib bolts may be conventional in nature with a head portion at one end and a “free” end opposite the head portion for permitting a conventional threaded nut element to be threadedly engaged with the external threads of the bolt. However, as will be made evident herein, it is believed that it will be preferable to use rib bolts having a “free end” at each end thereof so that either end may be inserted conveniently into a bolt-receiving opening of closely matching diameter and either end may then engage a corresponding internally threaded nut element to tighten the bolt to the structure containing the bolt-receiving opening. Both the rib bolts and the hanger bolts are fastened to the rib elements using threaded nut elements having conventional internal threading to engage the external threading on the bolt elements. In addition, or alternatively, as will be explained herein, casement nut elements may be used together with or in lieu of conventional nut elements to both reinforce and accommodate the relatively long, thin configuration of the hanger bolts. In this regard, casement nuts will be seen to comprise an elongated sleeve-like structure having screw threads on the interior of the sleeve to engage the exterior threads of the hanger bolt. If desired, the casement nut sleeve may have a radially extending exterior flange at one end that can be abutted against an exterior surface of a rib element to draw the head of the hanger bolt toward the rib or, the sleeve may have threads extending to and accessible at each end thereof with threads formed on the exterior surface as well as on the interior surface so that a hanger nut element with a relatively large diameter central threaded opening can be threadedly engaged with the exterior of the casement nut and abutted against a rib element to draw the head of the hanger bolt toward the rib element. Although it is possible to use just one single type of bolt for both the rib-bolts and the hanger bolts, it is considered preferable to use a different bolt configuration for each application so as to best accommodate the different requirements and stress to which each is subject in the practical use of this invention, as outlined above and as will be further explained herein. 
     These and other and further features and advantages of this invention will be made more apparent to those having skill in this art, by reference to the following specification considered in conjunction with the accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a pictorial representation of a rib element that forms part of a wall system in accordance with this invention; 
         FIG. 2  is a transverse cross section of the rib element of  FIG. 1 , taken in the direction A—A; 
         FIG. 3  is an axial cross section of the rib element of  FIG. 1 , taken in the direction B—B; 
         FIG. 4  is a partial sectional detail view showing a joint coupling several rib elements to each other as they would appear in a framework in accordance with this invention; 
         FIG. 5  is a partial cross-sectional view of a supporting wall constructed in accordance with this invention; 
         FIG. 6A  is a plan view of a skin element sheet in accordance with this invention; 
         FIG. 6B  is a partial detail plan view of an opening in the skin element of  FIG. 6  with a hanger bolt in a given position relative thereto; 
         FIG. 7A  is a side view of a threaded hanger bolt for securing skin elements to rib elements in accordance with this invention; 
         FIG. 7B  is an end view of the hanger bolt of  FIG. 7A , showing the shape of the head portion of the bolt; 
         FIGS. 8A and 8B  are side and end views, respectively, of a threaded casement nut fastener for use with the bolt elements of this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENT 
     Referring now to  FIGS. 1 ,  2  and  3  of the drawings, the rib elements  20  of this invention can be seen to have an elongate beam-like shape comprising a plurality of wall members  22  including at least a pair of elongate, convergingly related side walls  24 ,  25 , and a pair of transverse convergingly related end walls,  28 ,  29  extending between side walls  24 ,  25  at the opposite ends of rib  20 . The structure of the disclosed rib element  20  is completed by a second pair of elongate sidewalls  32 ,  33  extending between sidewalls  24 ,  25  along the opposite elongate edges of each and between end walls  28 ,  29  on the opposite edges of the end walls that extend from one of converging sidewalls  24 ,  25  to the other. 
     Further in accordance with this invention, the second pair of side walls  32 ,  33  of rib element  20  comprises a base wall  32  and a crown wall  33  that are disposed in substantially parallel, spaced apart relationship at the top and bottom of beam-like rib  20 . As seen most clearly in  FIG. 2 , the transverse width of crown wall  33 , that is the dimension extending between the upper edges of side wall surfaces  24 ,  25 , is less than the corresponding transverse width dimension between the lower edges of the side wall surfaces at base wall  32 . This difference in width dimensions is illustrated most clearly in the trapezoidal cross-section of rib  20 , shown in  FIG. 2 . In turn, the trapezoidal cross section results from the sloping, i.e. converging, relationship of side wall surfaces  24 , 25 . 
     With reference to the structure of ribs  20  thus far described and illustrated, it should be noted that although a relatively short rib having a length of say, 12 or 16 inches, is shown, ribs of any desired and suitable length up to several feet, may be created and employed, if desired. For ribs having a substantial length, additional access openings  72 , and bolt-receiving openings  38 , as well as hanger bolt openings  94 , may be provided as the length of side walls  24 ,  25  and  32 ,  33  increase. Desirably, the spacing between spaced-apart openings along the length of these sidewalls will be made consistent and uniform for all lengths of ribs  20  so as to provide the modularity of spacing and assembly that is an underlying feature of this invention now made apparent by this disclosure. 
     It will be understood readily by those of ordinary skill in the art that the angle formed by sloping side walls  24 ,  25  and base wall  32 , as shown in  FIG. 2 , can be of any desired value. It will be understood further that the angle defined at the intersection of end wall surfaces  28  and  29  with base wall surface  32  similarly may be of any desired value. However, an angle of 67.5 degrees is considered preferable for the intersection of the sidewall surfaces  24 ,  25  as well as end wall surfaces  28 ,  29  with base wall surface  32  for the purposes of this invention. It can be seen that two trapezoidal shapes having equal base angles of 67.5 degrees can be abutted in side-by-side relationship, with the base angles adjacent each other, to dispose the adjacent base surfaces at an angle of 135 degrees relative to each other, and accordingly, the base surface of a third trapezoidal shape abutted against the remaining outside surface of either one of the first two, again with base angles in adjacent relationship, will result in the two outermost base surfaces being disposed at an angle of 90 degrees relative to each other. Still further, it will be understood that a “regular” trapezoid, i.e. one with equal base angles of 67.5 degrees will have equal “crown” angles of 112.5 degrees. For the purposes of this invention, the “crown” angle is considered to be the angle defined by the intersection of crown wall  33  with any one of end walls  28 ,  29  or side walls  24 ,  25 . 
     In accordance with basic geometrical analysis it is evident that the trapezoidal shapes incorporated into the rib elements of this invention make it possible to abut the rib element walls in combinations that create both angular and straight, or “linear”, joints. That is, the base angle and the crown angle in a trapezoid are complementary in that their sum is 180 degrees, i.e. a straight line. And, the sum of two base angles is 135 degrees, which is the complement of 45 degrees. Accordingly, when two ribs are abutted together with the base angle of one adjoining the crown angle of the other, the adjacent exterior sides of the ribs will define a straight line; and correspondingly, if three ribs are abutted together in series, with their base angles in adjacent relationship, the base surfaces of the two outermost ribs will define a right angle relative to each other. 
     To achieve the desired connections between abutting rib elements, each element includes various bolt-receiving openings in combination with access openings that permit insertion of fastener bolts  50  as well as assembly of threaded fastener nuts  60  onto the ends of the bolts. As shown most clearly in  FIG. 1  of the drawings, each end wall  28 ,  29  includes a central, bolt-receiving through-hole  36 . And, as illustrated in the cross-section of  FIG. 3 , bolt-receiving openings  36  have the shape of truncated conical sections, flaring outwardly from a given diameter in wall surface  28 ,  29  toward a wider diameter at the interior of the rib. 
     In accordance with this invention and with the unique disclosed function of coupling rib elements  20  to each other with their corresponding axial and/or transverse axes disposed either in line or at an angle to each other, the tapered shape of bolt receiving openings  36  permits threaded fastener bolt members  50  to be inserted into openings  36  at an angle relative to the axis of the opening as well as relative to the longitudinal axis of the rib element. In this regard, threaded fastener nut elements  60  (see  FIGS. 8A and 8B ) are also tapered in shape from one end to the other to facilitate wedging of the nut  60  within the bore  36  as the nut enters through the wider open end of the bore within ribs  20 , when two adjacent ribs are fastened together by means of the bolt  50  and a nut  60  at each end of the bolt. To simplify xx 
     For the purposes of this invention, it will be understood that bolts of more conventional design (not shown) having a head portion, preferably tapered, at one end and a threaded body portion at the other end, may be used in certain applications of the invention. However, when it is desired to fasten two rib elements  20  together as shown, for example, in  FIG. 4 , it will be preferable to employ headless bolts  50  which may be engaged by nut elements  60  at opposite ends thereof to facilitate insertion of the bolts into the restricted but accessible interior spaces  70  provided by the illustrated access openings  72  in and/or between sidewalls  24 ,  25 . 
     In addition to axial bolt-receiving openings  36 , each rib element  20  may be seen to incorporate other openings  38 ,  40  and  42  in the side walls  24 ,  25 , base walls  32  and crown walls  33  thereof. Openings  38 , in side walls  24 ,  25 , illustrated most clearly in  FIGS. 1 ,  2  and  3  of the drawings, can be seen to have substantially the same shape and serve the same function as bolt-receiving openings  36  in end walls  28 ,  29 . That is openings  38  taper outwardly from a narrower opening at the outer surface of the side walls to a wider opening in the interior of the rib. The tapered shape of openings  38  serves the same function as the tapered shape of openings  36 , namely permitting skewing of the axis of an inserted bolt  50  to accommodate angular displacement of the axes of adjoining openings coupled by a common bolt. The tapered shape of openings  38  further accommodates “nesting” and wedging of tapered nut elements  60  within the holes. 
     By contrast with the bolt-receiving openings, substantially enlarged access openings  72  in side walls  24 ,  25  are provided for the purpose of allowing access to the interior spaces  70  of rib elements  20  so that nuts  60  may be manipulated and tightened, manually or otherwise, onto the ends of bolts  50 . It will be understood readily by those having skill in the art, that the shape of openings  72  need not be rectangular or any specific shape whatsoever, provided only that the openings are sufficient in size to permit insertion and tightening of nut elements  60  on the ends of fastener bolts  50  within the interior of the rib structure. 
     Still further and finally with reference to openings in the walls of ribs  20 , crown walls  33  and base walls  32  may be seen to include axially elongate slot-shaped bolt-receiving openings  40 ,  42 . In accordance with the disclosed use and functions of this invention, openings  40  in crown wall  33  are aligned with openings  42  in base walls  32  so that hanger bolts  80 , shown in  FIG. 7 , may extend completely through a rib element  20  from the crown wall side  33  to the base wall side  32  (and vice versa). 
     Where the free end  83  of hanger bolt  80  extends beyond rib  20 , a nut element  60  or any other suitable form of threaded nut device may be threaded onto the free end to tighten the bolt against the rib. For the purpose of conveniently tightening a hanger bolt  80  relative to a rib element  20 , it should be noted that any threaded nut element may serve this purpose, but for the purposes of this invention, a casement nut member  82  with a flange or in combination with a fastener nut is deemed preferable. In this regard, a casement nut  82  has an elongated tubular shape that is, a sleeve-like shape, that is threaded internally to engage the threaded body of hanger bolt  80  in conventional threaded relationship, while the exterior surface of nut  82  is threaded also to receive an assembly nut member  86  in similarly conventional threaded relationship. For convenience in actual use, assembly nut member  86  may have a conventional, e.g. hexagonal nut shape or may be interchangeable with assembly nut member  60  so as to reduce the number of different parts required for use and assembly of walls in accordance with the invention. In the alternative, casement nut  82  may be provided with a radially extending flange, not shown, at one end thereof to serve as an abutment that directly engages an outer surface of a rib member and eliminates the need for an assembly nut  86  to serve this purpose. 
     To facilitate manipulation and rotation of casement nut  82  as it is threaded onto hanger bolt  80 , an axial driver portion  85  may be provided with a non-threaded exterior surface that can be engaged easily either manually or with any suitable conventional tool; axial portion  85  is shown extending axially from one end of nut  82 , but it should be understood readily that such driver portions may be provided alternatively at both ends of the nut or at any portion of the length of the nut intermediate its ends, if desired. 
     For the purposes of this invention, the diameter of the threaded body portion of hanger bolt  80  may be substantially less than the diameter of fastener bolts  50 , and accordingly the outer threaded diameter of casement nut  82  may be made equal to the diameter of fastener bolts  50 , so that tapered nut elements  60  may be used to engage both fastener bolts  50  and casement nut members  82 . Although this arrangement is considered preferable, it should be appreciated that various other and different dimensions may be adapted without departing from the spirit and scope of this invention. A significant advantage of the elongate casement nut configuration is that it is expected that hanger bolts  80  frequently will require substantial lengths, on the order of 12 inches or more, and the casement nut, which can be provided with a significant, but lesser length, on the order of 3 or 4 inches for example, will serve to enhance the tensile strength and rigidity of the hanger bolt especially in the localized area where such enhancement is most needed; namely, at the point where an anchor nut  60  is used to apply force to tighten the hanger bolt relative to a rib  20 . 
     As illustrated in one form in  FIG. 5 , the structural outer skin elements  90  of this invention (shown in detail in  FIG. 6 ) are “hung” on a framework of ribs by hanger bolts  80  which are positioned to extend through a hanger bolt opening  94  in each of one or more skin members  90  and through hanger bolt slots  40 ,  42  in ribs  20 . As described above, hanger bolts  80  may be tightened relative to ribs  20  by applying a suitable fastener nut  86  directly to the threaded exterior of bolt  80  or by positioning a casement nut  82  on the exterior of bolt  80  and then applying a fastener nut  86  to the threaded exterior of casement nut  82 . 
     A feature of this invention is the unique way in which hanger bolts  80  are engaged to skin elements  90 . As shown generally in  FIG. 6 , each skin member  90  incorporates a plurality of slot-shaped hanger bolt openings  94  arranged in a substantially uniform array that preferably has the form of a coordinate grid. The openings  94  are located over substantially the entire surface of each sheet  90  so that hanger bolts  80  may be engaged with the surface of the skin at or very close to any desired position on the skin. A further unique aspect of the engagement of bolts  80  with skin elements  90  is the relative shapes of the heads  87  of bolts  80  and the hanger bolt openings  94  in sheets  90 .  FIGS. 6A and 7B  illustrate that the shapes are substantially identical, subject to the understanding that openings  94  are dimensioned to be sufficiently larger than the dimension of bolt heads  87 , so that the bolt heads  87  may pass through openings  94  in either direction when the two have been properly aligned with each other.  FIG. 6B  illustrates how the head  87  of a hanger bolt  80  may be positioned transversely to the axial length of slot-shaped opening  94  so that head  87  engages the surface of sheet  90  circumjacent opening  94  and prevents the head from passing through the sheet. It will now be understood that hanger bolt  80  may be rotated about the central axis of the bolt, when desired, to position bolt head portion  80  in axial alignment with the axial length of opening  94 ; as a feature of this invention, bolt head portions  87  are dimensioned to pass freely through openings  94  when the head and the opening are aligned in this first position, and to preclude passage of the head portion through the opening when the two are positioned in the second position, illustrated in  FIG. 6B . Accordingly, assembly of a wall in accordance with this invention can be achieved by first positioning hanger bolts  80  in desired positions on a framework constructed of ribs  20 , with the threaded portions of the hanger bolts extending through selected hanger bolt-receiving openings  40 ,  42  in the ribs of the framework and with the head portions  87  of the hanger bolts  80  positioned on the outer side of the frame where the skin will be mounted. When skin elements  90  are placed in position on the outside of the frame of ribs  20 , the heads  87  of hanger bolts  80  are first aligned to pass through the openings  94  and then rotated to the position shown in  FIG. 6B  to prevent the heads from being withdrawn from engagement with the skin  90  when bolts  80  are later tightened (i.e. bolted) to ribs  20 . It should be readily understandable, now, that the head portion  87  of a single bolt  80  can be extended in this manner through more than one sheet element  90 , so that two or more overlying sheet elements can be fastened to each other and to a common rib element by a single hanger bolt  80 , as illustrated in  FIG. 5 . 
     Although a preferred embodiment of the invention has been illustrated and described, it will be obvious to those having skill in this art that various other forms and embodiments of the invention now may be visualized, readily, by those having skill in this art, without departing substantially from the spirit and scope of the invention set forth in the accompanying claims.