Abstract:
A multi-directional structural joint for interconnecting the ends of tubular structural pipes that includes rigid perpendicularly intersecting planar plates the peripheral edges of which include a plurality of radially projecting connecting stubs for securing the terminal ends of tubular structural members.

Description:
[0001]    This application is a continuation-in-part of co-pending application, Ser. No. 13/213,317, entitled Multi-Directional Structural Joint, filed Aug. 19, 2011 and claims the priority benefit of said application Ser. No. 13/213,317, pursuant to 35 U.S.C. §120. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a joint for interconnecting tubular structural members. 
       BACKGROUND OF THE INVENTION 
       [0003]    Tubular elements or pipes have advantages over other structural forms because of the load-transmitting qualities inherent in their circular cross section and their efficient strength to weight ratio. In the past the failure to employ them extensively in the construction of walls, trusses and truss-like structures was due to the lack of suitable connectors or coupling members for easily and efficiently joining their ends, especially when producing three dimensional frameworks. The object of the present invention is to provide a universal connection joint that enables quick, easy and efficient construction of tubular frameworks. 
       SUMMARY OF THE INVENTION 
       [0004]    The multi-directional universal structural joint of the present invention includes a base member that comprises intersecting perpendicular planar plates that support on their peripheral edges a plurality of radially disposed connector studs that are adapted for insertion into the hollow interior of tubular structural framing members (pipes) in either a planar or a three dimensional framework. The joint acts to interconnect a plurality of the tubular framing members in order to form a framework for any purpose, but is particularly suited for forming building walls and roof structures for emergency or temporary types of shelter. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a perspective view of an exemplary first embodiment form of the connection joint of the present invention having five stud connectors and where the connectors are cylindrical. 
           [0006]      FIG. 2  is a front view of the joint of  FIG. 1 . 
           [0007]      FIG. 3  is a rear view of the joint of  FIG. 1 . 
           [0008]      FIG. 4  is a side view of the joint of  FIG. 1 . 
           [0009]      FIG. 5  is a bottom view of a modified version of the connection joint where portions of the base plates have been removed to form a corner joint having appropriate points of connection for structural tubing. One of the studs is shown with a fragmentary end portion of the pipe to which the stud in connected. The pipe, and its connection to the stud, is typical of all pipe and stud interconnections in the cylindrical stud version of the joint of the present invention. The cross section is taken along lines  5 - 5  of  FIG. 5B . 
           [0010]      FIG. 5A  is an end view of the embodiment of  FIG. 5 . 
           [0011]      FIG. 5B  is a cross sectional view of the tubular element shown in  FIG. 5 . 
           [0012]      FIG. 6  is a front view of a fourth exemplary embodiment of the joint where a portion of each base plate has been removed where the connecting requirement is only for a reduced number of stud connection points. 
           [0013]      FIG. 6A  is an end view of the embodiment of  FIG. 6 . 
           [0014]      FIG. 7  is a detailed plan view of an exemplary framework utilizing the connection joint of the present invention to interconnect tubular structural elements in the horizontal and vertical planes. 
           [0015]      FIG. 8  is a perspective view of an exemplary structural framework utilizing tubular tension and compression members that are interconnected by the structural joint of the present invention. The dotted lines outline the portion of the structure that is shown in detail in  FIG. 7 . 
           [0016]      FIG. 9  is a perspective view of one base plate of a second embodiment of the structural joint where the connecting studs are planar instead of being cylindrical. 
           [0017]      FIG. 10  is a perspective view of the second embodiment where the two base plates are interconnected in the same fashion as the base plates of the first embodiment, as shown in  FIG. 1 . 
           [0018]      FIG. 11  is a front view of the assembled joint where a portion of one of the base plates of the joint has been removed to accommodate the requirements of the structure. The structural pipe members are shown fragmentarily and in cross section. 
           [0019]      FIG. 12  is a fragmentary plan view of a structure where the structural pipe members are interconnected with the second embodiment joint of the present invention. 
           [0020]      FIG. 13  is a cross sectional view taken along lines  13 - 13  in  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    One illustrative and exemplary version of the first embodiment of the multi-directional construction joint  2  of the present invention is shown in  FIG. 1 . All versions of the connecting joint have, as their base, two intersecting mutually perpendicular rigid plates, seen in  FIG. 1  and referred to with reference numerals  4  and  6 . The periphery of the plates may take any shape from a circle to a polygon but the preferred form is a regular octagon, as seen in  FIG. 1 , or some section of an octagon, as seen in  FIGS. 5 ,  6  and  7 . One or more cylindrical connecting studs  8  are fixedly mounted radially on the peripheral edge  7  of at least one of the plates  4  and  6 . The studs  8  in  FIGS. 1-4  are shown as tubular, however the studs may be in the form of solid dowels, as they are shown in the embodiments of  FIGS. 5-7 . For interconnecting the ends of a plurality of pipes  10 , each stud  8  is arranged for insertion into the interior of a pipe that is a component of a structural framework, such as the one illustrated in  FIGS. 7  and  8 . Preferably, in all versions of the joint, the longitudinal axes  9  of the studs (or radii) lie within the plane of the base plate on which the stud is mounted and all of the radial longitudinal axes intersect at a center point  11 . 
         [0022]    The term “stud” is defined for purposes of this first embodiment of the inventive joint as a cylindrical dowel or tube having a length sufficient to establish a fixed connection with the base plate on which it is mounted and sufficient to establish purchase with the tubular member into which it is inserted or, in the case of a tube, as shown in  FIG. 1 , which is inserted in it. Although this form of the invention utilizes cylindrical dowels or tubes because the preferred form of structural members in the framework is cylindrical tubing or pipe it is to be understood that the structural members can be rectangular tubes or channels in which case the studs will have a corresponding shape in order to be snuggly mated with the structural member. 
         [0023]    One of the many benefits and advantages of the structural joint of the present invention is its universality. As seen in  FIG. 7 , the framework  12  comprises a plurality of tubular pipes  10  that are interconnected by several different modifications of the joint  2 , the particular form of the joint being dictated by the configuration of the pipes whose ends must be joined. The joint may connect pipes lying in the same, or first, plane that are either at 90° or 45° angles to each other or the joint may connect pipes lying in planes perpendicular to or at other angles to the first plane. 
         [0024]    Referring to  FIGS. 7 and 8 , the joint  2   a  interconnects planar pipes  10  that are at 90° and 45° angles to one another. As seen in more detail in Figures,  5 ,  5 A and  5 B, the plates  4   a  and  6   a  are modified octagons with plate  6   a  having a 90° outside curved surface  15  to accommodate one corner of the framework  12 . Connecting studs  8   a,    8   b  and  8   c  are mounted on the peripheral edges  18 ,  19  and  20  of the base plate  6   a.  Only the pipe  10  that is connected to stud  8   a  is shown in  FIG. 5  and that pipe is typical of all pipes in the structure that are interconnected by the joint of the present invention, including the vertical pipes  22 ,  23  and  28  shown in  FIG. 7 . Stud  8   a  is received within the hollow interior of the pipe  10 , the terminal end of which contains diametrically opposed slots  29  in the peripheral edge of the pipe. The slots are adapted to snugly receive the peripheral edge  18  of the base plate  6   a  which connection insures that the pipe will be plumb with the joint. As seen in  FIG. 5A , the perpendicular intersecting plate  4   a  is cut off beneath its intersection with the horizontal plate  6   a  because there is no requirement for a lower connecting stud in this particular configuration of pipes. The upper half of the plate  4   a  carries, on its peripheral edge, a connecting stud  8   d  which is for the purpose of connecting a vertical pipe component  22  of the framework  12 . 
         [0025]    Referring again to  FIG. 7 , the connecting joint  2   b  interconnects pipes  10  that are in longitudinal alignment with one another and also with pipes  10  that are disposed at 90° and 45° angles to the aligned pipes. The joint  2   b  also interconnects the planar pipes  10  with a vertical pipe component  23 . Although the joint  2   b  is not detailed in another figure of the drawings, it is apparent from the illustration in  FIG. 7  that the horizontally disposed plate  4   b  is slightly more than half an octagon with its cut-off edge  25  positioned to be in alignment with the outside surface of the aligned pipes  10  to provide a smooth base for a wall covering. Five of the octagonal sides of the plate  4   b  carry connecting studs  8   d  and  8   e  that interconnect the aligned pipes and studs  8   f,    8   g  and  8   h  that interconnect the 90° and 45° pipes  10  that are included in the structure. 
         [0026]      FIGS. 7 ,  6  and  6 A illustrate yet another version of the connecting joint. Utilizing a horizontal base plate  6   c  and a perpendicular plate  4   c,  the connecting joint  2   c  interconnects two sets of horizontally positioned aligned pipes, one set being at a 45° angle with the second set. The intersecting vertical plate  4   c  of the joint carries on its upper peripheral edge a connecting stud  8   n  that interconnects a vertical pipe  28  with the other tubular pipes that make connection with the joint  2   c.  If necessary, in the design of the truss or framework, another stud on an angled side of the vertical plate  4   c  could connect a pipe having a 45° angle orientation to the plane of the plate  6   c.    
         [0027]    Other configurations and forms of the connecting joint, as illustrated in  FIG. 7 , are, from the discussion of the generic version of  FIGS. 1-4  and the discussion of the joint variations depicted in  FIGS. 5 ,  6  and  7 , self-evident in their detailed construction and purpose. 
         [0028]    Fixation of the connection between the studs and the structural pipes may be by a press fit or the fix may be enhanced with glue or other type of fastening device. In any case the connection joint and its multiple variations, as described above, enables unskilled personnel to efficiently and quickly assemble a stable structure having interior and exterior walls and a roof that are ready for covering with any number of different types of construction material. The joint of the present invention enables economic and rapid construction of emergency housing units following natural disasters and provides means for economical housing in under privileged countries of the world. 
         [0029]    A second and preferred form of the structural joint is shown in  FIGS. 9-13 . Similar to the first embodiment, the preferred form has a base comprising two intersecting mutually perpendicular rigid plates  34  and  36 , as seen in  FIG. 10 . The generic form of each plate is shown in  FIG. 9 , however it is understood that each of the plates  34  and  36  may be cut and shaped to fit the requirements of the structure, just as the base plates  4  and  6  of the first embodiment are shaped to conform to the structure, as shown in  FIGS. 5 ,  6  and  7 . 
         [0030]    The difference between the joints of the first and second embodiments is the configuration of the connecting studs. In the first embodiment the studs are shown to be cylindrical, that is, either tubular or solid, in the form of a dowel. In the preferred form, the connecting studs  40 ,  41 ,  42  and  43  are formed as a planar column radially projecting from the peripheral edge  44  of the plate and being co-planar with the plate and having a distal end portion and first and second lateral sides. The lateral aspect of the distal end  45  at the top of the stud forming column is sized and dimensioned to be equal to the inside diameter of the structural pipe  10  to which it is to be connected. 
         [0031]    Among the eight connecting studs on each plate there are four different stud configurations. As will be explained in more detail subsequently, six of the studs contain transverse stabilizing wings  62  and  64 . Two of the diametrically disposed studs  40  and  43  do not contain the transverse wings, however when the first plate  34  is interconnected to the second plate  36 , by means of mating their respective radial slots  37 , the complimentary studs  40  and  43  on the second plate form the equivalent of stabilizing wings for the studs  40  and  43  on the first plate, thus forming a cross that contacts four points on the inside surface of the pipe, as shown in  FIG. 13 . 
         [0032]    In order to provide for  45  degree connections, four of the studs  41  project a greater distance from the center of the plate than do the studs  40 ,  42  and  43  and thus have a slightly different base configuration where the stud intersects the periphery of the plate. 
         [0033]    As seen in  FIG. 11 , the terminal ends of the pipes that are connected to studs  40 ,  42  and  43  are seated on the peripheral edge  44  of the base plate  34 . The terminal ends of the pipes that are connected to studs  41  are seated on ledges  49  on the lateral sides of the studs  41 . Formed into the opposing lateral sides of each of the studs is a pair of locking latches, each one of which comprises a pivotal arm  51  and a hook  53 . The arm  51  is integral with the plate and the stud and the thin dimension of the proximal end of the arm permits the arm to pivot about its proximal end, considering that the base plate is constructed of a plastic material that possesses elastic properties. 
         [0034]    The structural pipe  10  that engages a connecting stud is provided with diametrically opposed holes  54  and  55  that are positioned in the pipe so as to respectively receive the hooks  53  of the locking latches. The pipes that engage the complimentary studs  40  and  43  are provided with four diametrically disposed holes  54  and  55  in order to receive the four hooks  53  of the combined complimentary studs  40  and  43 . As the pipe  10  is being forced over the stud to make the connection, the terminal end of the pipe contacts the sloping upper surface  56  of the hook  53  and cams the hook into the cut-out  57 . When the holes  54  and  55  in the pipe appear at the level of the depressed hooks  53  the spring biased hooks spring into the respective holes in the pipe, thus locking the pipe in position on the stud. The pipe  10  may be removed from the stud by depressing each of the latching hooks out of their respective holes  54  and  55  and pulling the pipe off of the connecting stud. 
         [0035]    As mentioned earlier, in order to improve on the stability of the pipe connection, each of the studs may be provided with a pair of transverse wings  62  and  64  that are disposed perpendicular to and disposed on each side of the connecting studs  41  and  42 . In cross section at the distal end of the stud, the stud and the wings form a Greek cross, that is, a cross where the upright and the transverse beams are of equal length, as shown in  FIG. 11 . The wings are laterally dimensioned to fit tightly into the inside of the pipe, creating a four point contact between the connecting stud and the pipe. A lip  65  is formed at the lower end of each wing so as to act as an additional support for the terminal end of the pipe connected to that stud. 
         [0036]    Further stabilization of the joint structure is provided by a pair of spaced apart ribs  67  that project from the surface of plate  34 . The spacing between the ribs is equal to the thickness of plate  36 . When the two plates are interconnected, as shown in  FIG. 10  the ribs  67  make close contact with the surface of plate  36  so that the plate will not tend to rotate about its central axis. 
         [0037]      FIG. 12  is a plan view showing an example of the structure that can be created using the structural joint of the second and preferred embodiment. The obvious advantage of the second embodiment is that it requires no glue to secure the structural tubular members to the connecting joint and the structure may be disassembled without damaging or destroying the joints or the structural pipes.