Patent Publication Number: US-9903107-B1

Title: Beam connector

Description:
TECHNICAL FIELD 
     The present invention relates to a structural apparatus for connecting beams. 
     BACKGROUND OF THE INVENTION 
     Domed structures provide certain advantages over other more traditionally shaped structures. Geodesic domes are one kind of domed structures. A geodesic dome is a portion of a geodesic sphere with a structural frame composed of a network of triangles wherein the vertices of the triangles are at points on the sphere and the sides of the triangles are along cords between the points. Geodesic domes may be simplified so that the vertices lie approximately on the sphere. The triangles create a self-bracing framework that gives structural strength while using a minimum of material. The design allows enclosure of large interior space, free from columns or other supports. 
     Geodesic sphere structures may comprise hubs and struts, wherein the struts are straight members that radiate from the hubs, and the hubs connect the struts together in a network of triangles. A single geodesic structure may comprise many different triangle patterns and varying triangle sizes. For example a three-frequency geodesic dome requires struts of three different lengths, 5-way hubs (connecting five struts) and 6-way hubs (connecting six struts). Unless otherwise indicated, the description herein will be based on a three-phase geodesic structure. 
     Five triangles share a vertex at a 5-way hub, and the triangle sides opposite the hub form a pentagon. Likewise, six triangles share a vertex at a 6-way hub, and the triangle sides opposite the hub form a hexagon. A three-phase geodesic sphere comprises a pattern of adjacent pentagons and hexagons having coincidental sides. 
     Struts are typically tubular construction and hubs are configured to receive the tubes, which results in a structure that has undesirable limitations with respect to supporting other components, such as exterior paneling, interior paneling, studs, insulation and utilities such as plumbing, wiring and HVAC. 
     Geodesic structures may also comprise wooden beams that have compound angles at their ends so that the ends of five or six beams mate together to form a snug hub joint, without a separate hub component. Such a joint is typically reinforced with additional construction materials such as metal straps and screws. This type of structure requires three different beam lengths with complex beam shapes. It also requires precision machining of complex, compound angles. Due to the various combinations of beam lengths and end shapes for different joints, construction can be very difficult and time consuming, requiring much care to provide the correct inventory of beams for a project, to select the right beams for each joint, to align the beams, and to assemble them into a joint. 
     There is a need for a beam connector that combines the benefits of a separate hub in a geodesic beam structure and simplifies the construction process, while providing a strong and easy to assemble joint. 
     The present invention is directed to an improved beam connector for connecting beams to form a geodesic structure. It provides a stronger joint and reduces material needs, manpower needs, and construction time. Due in part to the strength of the beam connector of the present invention, some of the beams in the geodesic pattern may be omitted from the structure. The remaining beams in the structure are disposed along the edges of adjacent hexagons and pentagons. Each beam connection comprises three beams instead of five or six. Therefore, the present invention provides even more material savings and even fewer beam joints to construct. 
     SUMMARY OF THE INVENTION 
     In a first aspect, the present invention provides a beam connector comprising a middle portion  41  ( FIG. 1 ) and three legs extending radially outward from the middle portion at a downward longitudinal pitch of 11.64° from a horizontal plane, wherein the second leg is disposed at a 124.31° angle counterclockwise from the first leg, the third leg is disposed at a 111.38° angle counterclockwise from the second leg, and the first leg is disposed at a 124.31° angle counterclockwise from the third leg. The first leg comprises an upper portion adapted for receiving at least one object forming a dihedral angle of 138.19° along the longitudinal pitch line of said leg. The second leg comprises an upper portion adapted for receiving at least one object forming a dihedral angle of 142.62° along the longitudinal pitch line of said leg. And the third leg comprises an upper portion adapted for receiving at least one object forming a dihedral angle of 142.62° along the longitudinal pitch line of said leg.) 
     In a second aspect, the present invention provides a beam connector comprising a middle portion and three legs extending radially outward from the middle portion at a downward longitudinal pitch of 11.64° from a horizontal plane, wherein the second leg is disposed at a 124.31° angle counterclockwise from the first leg, the third leg is disposed at a 111.38° angle counterclockwise from the second leg, and the first leg is disposed at a 124.31° angle counterclockwise from the third leg, and wherein at least one of the first, second and third legs is adapted for connection to a beam disposed longitudinally along the pitch of the leg. 
     In a third aspect, the present invention provides a beam and connector assembly comprising: a beam connector comprising a middle portion and three legs extending radially outward from the middle portion at a downward longitudinal pitch of 11.64° from a horizontal plane wherein the second leg is disposed at a 124.31° angle counterclockwise from the first leg, the third leg is disposed at a 111.38° angle counterclockwise from the second leg, and the first leg is disposed at a 124.31° angle counterclockwise from the third leg; and a beam connected at one end to and disposed longitudinally along the pitch of one of the first, second and third legs. 
     In a fourth aspect, the present invention provides a beam and connector assembly comprising: a plurality of beam connectors, each beam connector comprising a middle portion and three legs extending radially outward from the middle portion at a downward longitudinal pitch of 11.64° from a horizontal plane wherein the second leg is disposed at a 124.31° angle counterclockwise from the first leg, the third leg is disposed at a 111.38° angle counterclockwise from the second leg, and the first leg is disposed at a 124.31° angle counterclockwise from the third leg; and a plurality of beams, each connected at one end to a leg of a beam connector and at the other end to a leg of another beam connector, wherein the on-center spacing between adjacently connected beam connectors is the same. 
     In a fifth aspect, the present invention provides a beam connector kit for connecting beams in a hexagonal and pentagonal pattern, comprising: at least one beam connector that comprises a middle portion; three legs extending radially outward from the middle portion at a downward longitudinal pitch of 11.64° from a horizontal plane, wherein the second leg is disposed at a 124.31° angle counterclockwise from the first leg, the third leg is disposed at a 111.38° angle counterclockwise from the second leg, and the first leg is disposed at a 124.31° angle counterclockwise from the third leg; and a plurality of beams having the same length for connecting to said beam connectors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, may be best understood by reference to the following detailed description of various embodiments and the accompanying drawings in which: 
         FIG. 1  is a perspective view from above of one embodiment of a beam connector of the present invention; 
         FIG. 2  is another perspective of the beam connector of  FIG. 1  from another viewpoint from above the connector; 
         FIG. 3  is another perspective view of the beam connector of  FIG. 1  from yet another viewpoint from above the connector; 
         FIG. 4  is a perspective view of the beam connector of  FIG. 1  from beneath the connector; 
         FIG. 5  is a top plan view of the beam connector of  FIG. 1 ; 
         FIG. 6  is a bottom plan view of the beam connector of  FIG. 1 ; 
         FIG. 7A  is another top view of the beam connector of  FIG. 1  with cross section lines indicated; 
         FIG. 7B  is a cross section along cross section line  7 B- 7 B of  FIG. 7A ; 
         FIG. 7C  is a cross section along cross section line  7 C- 7 C of  FIG. 7A ; 
         FIG. 7D  is a cross section along cross section line  7 D- 7 D of  FIG. 7A ; 
         FIG. 8A  is a plan view of the beam connector of  FIG. 1  looking directly at the end of leg  10  along the direction of the pitch of the leg from view “V 8 ” of  FIG. 7B ; 
         FIG. 8B  is a close-up view of a feature  8 B of  FIG. 8A ; 
         FIG. 9A  is a plan view of the beam connector of  FIG. 1  looking directly at the end of leg  20  along the direction of the pitch of the leg from view “V 9 ” of  FIG. 7C ; 
         FIG. 9B  is a close-up view of a feature  9 B of  FIG. 9A ; 
         FIG. 10A  is a plan view of the beam connector of  FIG. 1  looking directly at the end of leg  30  along the direction of the pitch of the leg from view “V 10 ” of  FIG. 7C ; 
         FIG. 10B  is a close-up view of a feature of  10 B  FIG. 10A ; 
         FIG. 11  is a view of an entire geodesic sphere of the present invention without panels; 
         FIG. 12  is a Front view of entire geodesic sphere of the present invention with exterior panels; 
         FIG. 13  is a Right side view of  FIG. 12 ; 
         FIG. 14  is a Back view of  FIG. 12 ; 
         FIG. 15  is a Left side view of  FIG. 12 ; 
         FIG. 16  is a Top view of  FIG. 12 ; 
         FIG. 17  is a Bottom view of  FIG. 12 ; 
         FIG. 18  is an exploded partial view of 3-panel joint  18  of  FIG. 13 ; 
         FIG. 19  is a perspective view of a beam of the present invention; and 
         FIG. 20  is a perspective view of another beam of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-10  show a preferred embodiment of the beam connector of the present invention. The description herein describes the preferred embodiment of  FIGS. 1-10  unless otherwise indicated. 
     For the purposes of this description, references to the angle between two intersecting planes, or angle between two flat surfaces refers to the dihedral angle unless expressly indicated otherwise. Similarly, an angle of a plane or surface relative to vertical or horizontal refers to the dihedral angle to a reference vertical or horizontal plane. The dihedral angle is measured in a plane that is perpendicular to the line of intersection of the planes (also referred to herein as the “dihedral line”). As used herein, the term “dihedral angle” infers that there are two intersecting planes or two surfaces disposed at an angle to one another. A dihedral angle may be formed by surfaces of separate objects or by two surfaces of the same object. 
     With reference to  FIG. 1 , in a preferred embodiment, the improved beam connector comprises three legs  10 ,  20  and  30  extending radially outward from an axis through the center  40 . Although connectors of the present invention may be disposed in various orientations in a structure, for the purposes of describing a connector herein, the center axis is assumed to be vertical. With further reference to  FIGS. 7B-7D , each leg extends outward at a downward longitudinal pitch angle α of about 11.64°. Said pitch angle is measured from horizontal. 
     With further reference to  FIG. 5 , leg  20  is disposed at angle θH of about 124.31° counterclockwise from leg  10 , leg  30  is disposed at angle θP of about 111.38° counterclockwise from leg  20 , and leg  10  is disposed at angle θH of about 124.31° counterclockwise from leg  30 . 
     A line running in the same angular direction as a leg, through the center axis of the beam connector, and at the same pitch angle α of a leg may be referred to herein as the “pitch line” of the leg. 
     The legs divide space around the center into three “sectors.” In a completed structure such as a dome, the sectors will be covered by panels attached to the connector. Two hexagonal panels and one pentagonal panel may be assembled to each connector (see  FIGS. 11-19 ), and the corresponding sectors may be referred to as hexagonal sectors and pentagonal sectors. The sides of legs bounding a hexagonal sector and the sides bounding a pentagonal sector may be designated “H” and “P”, respectively. Leg surfaces may be provided with appropriate “H” and/or “P” markings. One leg has two hexagonal sides and two legs have a hexagonal side and pentagonal side as indicated in  FIG. 1 . 
     The two hexagonal panels and the pentagonal panel assembled to a connector are each oriented in a different plane from one another and their respective planes form a dihedral angle at their lines of intersection (also referred to herein as “dihedral lines”). In a preferred embodiment, the three panels form three dihedral angles on three dihedral lines that radiate outward from the center of the connector at the same pitch angle as the legs and same angular direction as the legs. 
     With reference to  FIG. 1 , in a preferred embodiment, the upper portion of leg  10  comprises top surface  11  and top surface  12 . Surfaces  11  and  12  are flat and are disposed in different planes from one another. Surfaces  11  and  12  form a ridge  13  along pitch angle α of the leg. Surface  11  is for providing support to a hexagonal panel, and surface  12  is for providing support to another hexagonal panel. 
     With reference to  FIG. 8B , surfaces  11  and  12  form dihedral angle βHH° of about 138.19° along the ridge. Angle φH° between surface  11  and surface  16  is about 69.09°. Likewise, angle φH° between surface  12  and surface  17  is about 69.09°. The edge formed by surfaces  11  and  16  and the edge formed by surfaces  12  and  17  are parallel to ridge  13 . 
     With reference to  FIG. 1 , in a preferred embodiment, the upper portion of leg  20  comprises top surface  21  and top surface  22 . Surfaces  21  and  22  are flat and are disposed in different planes from one another. Surfaces  21  and  22  form a ridge  23  along pitch angle α of the leg. Surface  21  is for providing support to a hexagonal panel, and surface  22  is for providing support to a pentagonal panel. With reference to  FIG. 9B , surfaces  21  and  22  form dihedral angle βHP° of about 142.62° along the ridge. Angle φH° between surface  21  and surface  26  is about 69.09°. Angle φP° between surface  22  and surface  27  is about 73.53°. The edge formed by surfaces  21  and  26  and the edge formed by surfaces  22  and  27  are parallel to ridge  23 . 
     With reference to  FIG. 1 , in a preferred embodiment, the upper portion of leg  30  comprises top surface  31  and top surface  32 . Surfaces  31  and  32  are flat and are disposed in different planes from one another. Surfaces  31  and  32  form a ridge  33  along pitch angle α of the leg. Surface  31  is for providing support to a pentagonal panel, and surface  32  is for providing support to a hexagonal panel. With reference to  FIG. 10B , surfaces  31  and  32  form dihedral angle βPH° of about 142.62° along the ridge. Angle φP° between surface  31  and surface  36  is about 73.53°. Angle φH° between surface  32  and surface  37  is about 69.09°. The edge formed by surfaces  31  and  36  and the edge formed by surfaces  32  and  37  are parallel to ridge  33 . 
     With reference to  FIGS. 4 and 6 , bottom surfaces  14  and  15  of leg  10 , bottom surfaces  24  and  25  of leg  20 , and bottom surfaces  34  and  35  of leg  30  are parallel to their corresponding top surfaces ( 11  and  12 ,  21  and  22 , and  31  and  32 , respectively) so that they form the same dihedral angle as their corresponding top surfaces and a dihedral line that is parallel to the corresponding ridge lines  13 ,  23  and  33 , respectively. 
     With reference to  FIGS. 1-3 , side surfaces  16  and  17  of leg  10  are vertical and parallel to one another and parallel to ridge  13 . Likewise, side surfaces  26  and  27  of leg  20  are vertical and parallel to one another and parallel to ridge  23 , and side surfaces  36  and  37  of leg  30  are vertical and parallel to one another and parallel to ridge  33 . 
     Although in the preferred embodiment shown in  FIGS. 1-10  the top and bottom surfaces of the legs are slanted and flat surfaces that conform to the dihedral shape formed by adjacent flat panels, alternate configurations may be provided as long as the beam connector is appropriately adapted to support the panels. For example, in alternate embodiments, panel edges may be provided with connecting features that are not coplanar with the panel surfaces and the legs may be provided with compatible connecting features. For example, the top surfaces of the legs may be at right angles to the sides of the legs and the panels may be provided with flanges or thick landings configured to conform to and to form a flush fit therewith. 
     In the preferred embodiment shown in  FIGS. 1-10 , the outer end surfaces  106 ,  206  and  306  of the legs are disposed in planes perpendicular to the respective leg&#39;s ridge line. 
     With reference to  FIG. 1 , leg extensions  18  and  19  of leg  10  form opening  101  for receiving the end of a beam. Likewise in legs  20  and  30 , leg extensions  28  and  29  form opening  201  for receiving the end of a beam, and extensions  38  and  39  form opening  301  for receiving the end of a beam. 
     With reference to  FIG. 7B , leg  10  may have a mortise cavity  102  for receiving a correspondingly sized and shaped tenon projection of a beam for forming a mortise and tenon joint. Although mortise and tenon joints commonly join perpendicularly aligned beams, in the preferred embodiment of this invention the beam is aligned longitudinally with the pitch of the leg. With reference to see  FIGS. 1, 4, 6 and 8 , leg  10  of the connector comprises top shoulder surface  104  and bottom shoulder surface  105  adjacent to the mortise cavity for mating with a corresponding shoulder surface of a beam adjacent to the beam tenon. Likewise, with further reference to  FIGS. 3, 4, 6, 9 and 10 , leg  20  may have mortise cavity  202  and top and bottom shoulders  204  and  205 , and leg  30  may have mortise cavity  302  and top and bottom shoulders  304  and  305 . 
     In an alternate embodiment, beams may be provided without tenons, in which case leg extensions  18 ,  19 ,  28 ,  29 ,  30  and  39  and openings  101 ,  201  and  301  provide for ease of assembly as beams may be slid into place between the leg extensions into the openings through the end of the openings or the top or bottom sides of the openings. A combination of beams with and without tenons may also be used. For example, tenons on the final beam of a geodesic sphere frame may interfere with assembly, and the beam may be provided without tenons so that each end of the beam may be slid sideways into connector openings. 
     With reference to  FIGS. 2 and 4 , in a preferred embodiment, the legs may be provided with holes  1 ,  2  and  3  for receiving fasteners for fastening beams and panels to the beam connector. The fasteners may comprise threaded fasteners, dowels, nails, pins, or any other suitable type of fastener. Holes  1  are for fastening exterior panels to the top of the leg, holes  3  are for fastening interior panels to the bottom of the leg, and holes  2  are for fastening beams to the leg. Holes  1  and  3  may be aligned so that a single fastener may run through the connector from top to bottom, and holes  2  on either side of the leg may likewise be aligned so that a single fastener may run through the connector from side to side. 
     With reference to  FIG. 11 , the improved beam connector of the present invention provides for the construction of an entire geodesic sphere frame  99 , or a portion thereof such as a dome, using a plurality of beam connectors  100  having the same size and shape and a plurality of beams  50  having the same size and shape. 
     With reference to  FIGS. 19 and 20 , beam  50  may comprise a span portion  51  having a top surface  52 , bottom surface  53 , side surfaces  54  and fastener holes  55 . Beam  50  may further comprise tenon  56 . The beam may have fastener holes  57 . Beam top and bottom surfaces  52  and  53  may be adapted to directly support and connect with panels, for example, they may have a dihedral shape conforming to the shape of the beam connector legs, or they may be provided with other connecting structure compatible with corresponding connecting structure of the panels. 
     Beam length of  FIG. 11  is chosen for illustration purposes and does not necessarily represent the beam length of a dwelling or other inhabitable geodesic structure. Beam length may be chosen according to the desired size of the geodesic structure. While adhering to angular specifications, linear dimensions of beam connectors may be chosen according to design preferences, such as to be compatible with chosen beam thickness and width, or to provide desired strength or assembly characteristics. 
     The spacing between beam connectors may be defined herein as the distance from the center of one connector to the center of the adjacent connector along the beam connecting them (referred to herein as the “on-center” spacing). It is understood that the center axes of adjacent beam connectors are not parallel to one another and that on-center distance is dependent upon the location along the center axes at which the distance is measured. Comparison of on-center distances assumes a consistent standard. 
     With reference to  FIGS. 12-18 , the geodesic structure of the present invention may comprise exterior hexagonal panels  60  and exterior pentagonal panels  70 . The hexagonal and pentagonal features of the geodesic structure may be referred to herein as “sides” of the structure. The structure may further comprise interior hexagonal panels  80  ( FIG. 18 ) and interior pentagonal panels  90  (not shown). In a preferred embodiment, the panels comprise beveled edges so that the edges of adjacent panels may form a flush joint when assembled in a geodesic structure. The dihedral angle formed by the top surface and edge of the hexagonal panel may be about 69.09° and the dihedral angle formed by the top surface and edge of the pentagonal panel may be about 73.53°. 
     Panels  60 ,  70 ,  80  and  90  may comprise fastener holes for accepting fasteners for fastening the panels to beam connectors and/or beams. 
     The space between interior and exterior panels in geodesic structures of the present invention may accept studs, insulation, plumbing, wiring, HVAC and other things. 
     The legs of the beam connector may be widened as necessary to provide a broader seating surfaces  11 ,  12 ,  21 ,  22 ,  31  and  33  for the panels to accommodate location of panel fasteners further away from the panel edges. Additionally or in the alternative, in order to provide broader seating surface and accommodate more widely spaced panel fastener locations, beam connectors may be provided with flanges extending laterally outward from each leg along the slope of the respective top surfaces  11 ,  12 ,  21 ,  22 ,  31  and  33 . 
     Geodesic structures of the present invention may further comprise parallel studs spanning the hexagonal and pentagonal spaces between beams. Structures may further comprise horizontal floors and vertical walls of tradition construction in the interior of the sphere. 
     The expression of linear and angular dimensions herein to the second decimal place or otherwise do not imply or impose greater precision or tighter tolerances than are generally accepted with conventional manufacturing methods for structural frame components or generally accepted for framing in the construction trade. Clearances in the joints allowing for finite adjustment before tightening may be desirable for ease of assembly and may be required to accommodate typical dimensional variances in individual parts. 
     While the invention has been particularly shown and described with reference to certain embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the invention without departing from the spirit and scope of the invention as described in the following claims.