Abstract:
A truss bracket for mounting roof trusses and floor joists to wall systems absent traditional wood frame top plates utilizing in-plane end load bearing panels, resembling a chair, comprises a base plate with a vertical receiving plate extending upwards from the rear of the base plate for receiving a typical roof truss or floor joist and having downwardly extending mounting tabs along the left and right sides of the base plate suitable for being received by grooves in top track grooves of an in-plane end load bearing panel wall system or for attachment to the vertical sides of panels of a wall. The truss bracket provides high uplift load capacity by arranging all fasteners to the wall system and the truss or joint in shear when loaded.

Description:
RELATED APPLICATIONS 
     This non-provisional patent application, filed in the United States Patent and Trademark Office, is a Continuation-In-Part of U.S. patent application Ser. No. 12/147,444, filed Jun. 26, 2008, from which priority is claimed and whose disclosure is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to the construction industry and building materials; and, 
     more particularly to a truss bracket apparatus for mounting roof trusses, floor joists and similar construction components to wall systems. 
     BACKGROUND OF THE INVENTION 
     Traditional western construction practices for wood based home building are typically directed towards assembling a frame, formed from studs, upon which sheeting is installed in the form of plywood for outside surfaces and drywall for inside wall surfaces. The frame is first constructed by carpenters in a piecemeal fashion wherein the various members are cut and fastened into position. With the frame in place, sheeting is applied to form the wall surfaces. The frame provides the strength of the structure as the vertical stud members assume the load of the constructed walls. The top member of a wood frame, the top plate, is typically a horizontally disposed lumber section nailed to the vertical studs. Roof trusses rest on the top plate and are typically toe nailed to the top plate or an L-shaped clip is nailed into the top surface of the top plate and then nailed into a side surface of the roof truss. The attachment of the roof trusses to the top plate must have sufficient integrity to withstand uplift forces caused by wind load under the overhang of the roof. High uplift loads can pull the clip nails out of the top plate or dislodge the toe nailing. Also, the top plate is typically nailed to the studs, consequently uplift forces may also dislodge these fasteners by pulling the nails from the studs. 
     Wall systems comprising high in-plane end load bearing panels, such as disclosed by McDonald in U.S. Ser. No. 12/147,444, form hollow walls without studs or wood frame. These systems are often absent the wood frame top plate and therefore do not provide a nailing surface along the top of the wall for mounting clips or toe nailed roof trusses. These wall systems do not require a top plate as the panels forming the interior and exterior portions of the wall bear the load along the top end of the panel. The panels are secured in position by top and bottom sheet metal tracks to maintain the spacing between the panels and therefore no nailing surface is available along the top surface of a wall section. Similar challenges present themselves between stories when incorporating rim and floor joists. 
     There are a number of disadvantages exhibited when using toe nailing or L-shaped clips (L-clips) as indicated particularly when there is no top plate component suitable for receiving nails. In order to maximize the strength of a roof truss or floor joist mounting system, ideally the fasteners between the various elements should be in shear when load is applied. Toe nailing and L-clip arrangements all commonly include fasteners that are under tension under load thereby significantly reducing the strength of the connection that is critical under high wind uplift loads. In tension, nail type fasteners positioned vertically into the top surface of a top plate loose strength as the nails can be pulled out of the plate. Using an L-clip, fasteners fixing the clip to the truss are in shear under load, an ideal configuration; however, the fastening to the top plate is in tension. Toe nailing fasteners are primarily in tension under load. 
     Therefore, what is needed is an apparatus to secure roof trusses and floor joists to wall systems absent top plate nailing surfaces and to provide a means for connecting a roof truss or floor joist to a wall system wherein all fasteners are in shear. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to construction techniques utilizing in-plane end load bearing panels for studless hollow wall systems, and, more specifically, to a truss bracket apparatus facilitating attachment of roof truss and floor joists to wall systems absent top plate nailing surfaces providing high load capacity, speedy assembly, and low material and manufacturing costs, thereby substantially obviating one or more of the problems due to the limitations and disadvantages of the related art. 
     The mounting mechanism provided is a truss bracket apparatus comprising a base plate, being a flat rectangular plate having a width, a length, and rear, left and right edges, a left mounting tab, being a flat rectangular plate having a top edge fixed to the left edge and along the length of the base plate and extending downwards from base plate, a right mounting tab, being a flat rectangular plate having a top edge fixed to the right edge and along the length of the base plate and extending downwards from the base plate and extending upwards; and a vertical receiving plate, being a flat plate having a bottom edge fixed to the rear edge of the base plate and extending upwards. The assembly resembles a chair form. A hollow wall system top track having at least two longitudinally arranged ribs fashioned in the track form longitudinal grooves in the top side of the top track for receiving the left and right mounting tabs of the truss bracket. The ribs protruding from the bottom of the top track are received by longitudinal grooves in the top edge of the in-plane end load bearing panels of the wall system. Fasteners are driven perpendicularly from the vertical side of the end load bearing panels, through the panel, into the groove in the top, into the rib of the top track, through the mounting tab of the truss bracket, through the opposing side of the rib of the top track, and into the opposing side of the groove and then into the opposing panel material. The fasteners fix the top track to the wall panels and also the truss bracket to the top track. A roof truss or floor joist is attached to the vertical receiving plate by fasteners positioned through bores in the vertical receiving plate and into the truss or joist; however, the vertical receiving plate may be used for attachment of other structural components as required. It will be appreciated that all fasteners are arranged such that uplift loads place the fasteners in shear, not tension, so as to substantially improve the strength of the connection as compared to prior art solutions. 
     It will further be appreciated that the truss bracket according to the present invention does not require the use of the top track of a wall system. For example, the truss bracket may be mounted on a convention wood frame top plate with the mounting tabs flush with the vertical sides of the top plate. Fasteners through the mounting tabs fixing the truss bracket to the vertical sides of the top plate will also be in tension in uplift load conditions thereby providing a substantial improvement in strength over L-clips and toe nailing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate embodiments of the invention and, together with the description, serve to explain the features, advantages, and principles of the invention. 
       In the drawings: 
         FIG. 1  is a perspective view of the truss bracket for studless hollow in-plane end load bearing panel walls according to the present invention. 
         FIG. 2  is a perspective view of a first alternate embodiment of the truss bracket according to the present invention illustrating the forward and rearward extending mounting tab extensions. 
         FIG. 3  is a perspective view of a second alternate embodiment of the truss bracket illustrating the vertically disposed receiving plate having a relief portion removed to facilitate attachment of a typical wood rim joist. 
         FIG. 4  is a perspective view of a third alternate embodiment of the truss bracket similar to  FIG. 3  illustrating the forward and rearward extensions of the mounting tab portions of the second embodiment of  FIG. 2 . 
         FIG. 5  is a perspective view of the truss bracket of  FIG. 1  mounted within the channels of a top track of a studless hollow in-plane end load bearing panel wall system and fastened to and receiving a typical wood roof truss assembly. 
         FIG. 6  is a cross section view of the truss bracket of  FIG. 1 , wall system and typical roof truss of  FIG. 5  taken along Line  6 - 6  of  FIG. 5  securing the typical roof truss received by the channels of the top track of a studless hollow in-plane end load bearing panel wall system showing details of the wall and track means for fastening to the wall system. 
         FIG. 7  is a cross section of the truss bracket, wall and truss of  FIG. 6  taken along Line  7 - 7  of  FIG. 6  wherein the roof truss means of fastening the truss bracket to a chords and gang plate of a typical roof truss. 
         FIG. 8  is a perspective view similar to  FIG. 5  illustrating the second embodiment of the truss bracket according to the present invention mounted in position in the top track of the wall system wherein the bracket extended mount tabs span two wall panels. 
         FIG. 9  is a perspective view showing the third embodiment of the truss bracket according to the present invention mounted in position in the top track of the wall system receiving a typical rim joist positioned within the joist relief of the truss bracket and a floor joist fixed to the vertical receiving plate. 
         FIG. 10  is a cross section of the third embodiment truss bracket, rim and floor joist of  FIG. 9  taken along Line  10 - 10  of  FIG. 9  wherein the means of fastening the truss bracket to a typical floor joist and a wall system is detailed. 
         FIG. 11  is a cross section view taken on Line  11 - 11  of  FIG. 10  showing the vertical receiving plate of the third embodiment of the truss bracket fastened to a typical floor joist. 
         FIG. 12  is a perspective view similar to  FIG. 9  illustrating the third embodiment of the truss bracket according to the present invention mounted in position in the top track of the wall system wherein the bracket extended mount tabs span two wall panels and fixed to a typical floor joist with a typical rim joist positioned with the recess of the vertical receiving plate. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. Where examples are presented to illustrate aspects of the invention, these should not be taken as limiting the invention in any respect. 
     Now referring in greater detail to the various figures of the drawings wherein like reference characters refer to like parts, there is shown in  FIG. 1 , is a first embodiment of the present invention, a truss bracket, shown at  8 , suitable for fixing a typical roof truss to the top of a wall section. The truss bracket  8  comprises a rectangular base plate  12  having a width and rear, left and right edges, a left mounting tab  14  being a plate having a top edge fixed to the left edge of the base plate  12  and extending downwards, a right mounting tab  16  being a plate having a top edge fixed to the right edge of the base plate  12  and extending downwards, and a vertical receiving plate  18  having a bottom edge fixed to the rear edge of base plate  12  and extending upwards. A side surface of a typical roof truss is disposed adjacent to the vertical receiving plate  18  and fixed to the bracket  8  by means for fastening the bracket to the truss. The vertical receiving  18  plate has a width the same as the base plate  12  facilitating the attachment of roof trusses. Vertical receiving plate bores  20  for fasteners are provided to insure that a sufficient number of fasteners are installed so as to achieve a structurally sound assembly. 
     Referring to  FIG. 2  wherein a second embodiment  22  of the truss bracket is illustrated, the downward extending left  26  and right  28  mounting tabs, similarly attached at the top edges to the base plate  24 , each have extensions to the front and rear of the bracket  22  thereby providing additional surface contact with a wall structure. The vertical receiving plate  30  fixed to the rear of the base plate  24  has a width the same as the base plate  24  also making the second embodiment  22  best suited for roof truss attachment applications wherein the roof truss is fixed with a means for fastening the bracket through vertical receiving plate bores  32 . 
     A third embodiment  34  of the truss bracket according to the present invention is illustrated in  FIG. 3  having the same base plate  36  and left  38  and right  40  mounting tabs, and having vertical receiving plate  42  similarly fixed to the rear edge of the base plate  36  wherein the width of the vertical receiving plate  42  is reduced to accommodate a wood frame rim joist. The rim joist relief  46  provides clearance for a rim joist mounted longitudinally along the left side of the base plate  36  and flush with the top surface of the base plate  36 . A floor joist may then be fixed to the vertical receiving plate  42  with a means for fastening the bracket through vertical receiving plate bores  44 . 
     Referring now to  FIG. 4 , a fourth embodiment  48  of the truss bracket is illustrate being similar to the third embodiment  34  having forward and rear extensions to the left  52  and right  54  mounting tabs downwardly disposed from the left and right edges of base plate  50 . A similar rim joist relief  60  provides access for a rim joist and narrowing the width of the vertical receiving plate  56  comprising vertical receiving plate bores  58  for a means of fastening a floor joist to the plate. 
     A typical roof truss mount assembly utilizing the truss bracket according to the present invention is shown in  FIGS. 5 ,  6  and  7 . A top track  62  of a in-plane end load bearing panel studless hollow wall system is shown in position longitudinally mounted along the top of a wall section and, being an elongate plate, having left  64  and right  66  grooves forming downward facing ribs in the track  62  positioned within longitudinal grooves with the top end of the panels  68 . The truss bracket  8  is positioned in the top track  62  with the left and right mounting tabs respectively in grooves  64  and  66 . A typical roof truss is illustrated having a bottom chord  74  positioned perpendicularly across the top of the wall section and flush with truss bracket  8  vertical receiving plate  18 . The top chord  72  of the roof truss is typically fixed to the bottom chord  74  by a gang plate  76  whose position is not critical with respect to the truss bracket  8 . The vertical receiving plate  18  is fixed by fasteners  80  to the roof truss. 
     Details of the attachment to the wall section are illustrated in the cross section view provided in  FIG. 6 . The top track  62  secures the right panel  68  to the left panel  78  providing a predetermined wall cavity spacing. The grooves left  64  and right  66  of the top track  62  form ribs and are shown in position within grooves in the top end of the panels  78 ,  68 . The base plate  12  is mounted flush with the top track  62  and with the left  14  and right  16  mounting tabs positioned within the top track grooves  64  and  66 . Fasteners  82  are disposed through the panels  78  and  68 , the top track grooves  64  and  66  and the mounting tabs  14  and  16 . Uplift forces on the truss bracket necessarily load fasteners  82  in shear thereby providing outstanding load capacity and secure attachment to the wall panels  78  and  68 . Fasteners  82  are preferably screws having a drill point as fasteners bores are not present in the mounting tabs  14  and  16 ; however, any suitable means for fastening may be used including self-tapping screws, screws, brads, nails and bolts. 
     A further cross section view of the truss bracket assembly taken longitudinally along a wall section, as in  FIG. 7 , shows details of the attachment of a typical roof truss to the vertical receiving plate  18  wherein fasteners penetrate the gang plate  76  securing the bottom chord  74  to the bracket. A portion of the top chord  72  may also be engaged by fasteners  80  depending upon the positioning of the roof truss on the wall section. 
     In  FIG. 8 , the second embodiment  22  of the truss bracket having extended left  26  and right  28  mounting tabs is illustrated in position within the top track  62  grooves  64  and  66  wherein the mounting tabs bridging the gap  84  between adjacent abutting panels  68  and  86  so as to provide additional structural integrity to the wall system. Fasteners  82  secure the top of the wall panels  68  and  86  to the top track  62  and the truss bracket  22 . Similarly fasteners  80  secure the vertical receiving plate  30  to the roof truss bottom chord  74 , gang plate  76  and top chord  72 . 
     Referring next to  FIGS. 9 ,  10  and  11  illustrating a floor joist application utilizing the third embodiment of the truss bracket  34 , a floor joist  90  is mounted perpendicular to a wall section and flush with the vertical receiving plate  42  by fasteners  80  penetrating the bores of the receiving plate  42  and into the floor joist  90 . A typical rim joist  88  is illustrated in position mounted longitudinally along the wall section and in the joist relief of the truss bracket  34 . The wall section utilizes the same top track  62  with longitudinal grooves  64  and  66  receiving the mounting tabs of the bracket  34  and secured by fasteners  82  to the wall panels  78  and  68 . 
     In  FIG. 10 , the mounting of the truss bracket mounting tabs  52  and  54  to the top track  62  grooves  64  and  66  is the same as other embodiments. The placement of the rim joist  88  in the relief in the vertical receiving plate  42  provides clearance for the joist  88  on top of the wall section and positioning over load bearing panel  78 . 
     As shown in  FIG. 11 , the means for fastening the floor joist  90  to the vertical receiving plate  42  in perpendicular disposition relative to rim joist  88 . The base plate  36  flush with the top track  62  and mounting tab  52  within top track groove  62  in the left panel  78 . 
       FIG. 12  illustrates the fourth embodiment of the truss bracket  48  being similar to the third embodiment wherein the left  52  and right  54  mounting tabs are extended to the front and rear so as to accommodate bridging the gap  84  between adjacent panels  68  and  86  in rim joist  88  and floor joist  90  mounting applications. In a similar fashion, vertical receiving plate  56  is secured to the floor joist  80  and the truss bracket mounting tabs  52  and  54  are secured in the top track  62  left  64  and right  66  grooves by fasteners  82 . 
     The truss bracket may be constructed of any suitable material; however, the truss bracket may be readily constructed of flat sheet metal cut appropriately so as to form the vertical receiving tab and mounting tabs by folding or bending the sheet metal along the left, rear and right edges of the base plate. This low cost manufacturing method avoids having to weld components while maintaining the integrity of plated surfaces and maximizing the strength of the edge connections.