Patent Publication Number: US-6986230-B2

Title: Foldable support structure with hinged wall members

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This is a continuation-in-part of non-provisional application Ser. No. 10/186,285, filed Jun. 28, 2002 now U.S. Pat. No. 6,715,255. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to portable support structures for use in temporary fixtures such as trade shows and conventions, and particularly to a portable folding truss system having hinged side elements. 
   2. Description of Related Art 
   Commercial displays such as those used in trade show booths require strong structures that can be easily transported and configurable in a wide variety of forms. Such structures need to be lightweight, portable, and able to be quickly set up and broken down. 
   Prior art solutions have utilized truss members with folding elements that utilize rigid wall members coupled with rotatable wall members. The rotatable side members allow the truss to collapse. The trusses include internal diagonal pivoting members that serve to lock the truss into an open position. Although useful in some applications, this approach has deficiencies. 
   Using differently designed rigid and rotatable wall members as in prior art solutions increases the inventory of piece parts needed to build the truss, thereby making the truss more complicated and expensive to manufacture. Also, the non-symmetry of the assembled structure (due to the non-rigidity of the rotatable wall members) gives such a truss non-uniform load bearing characteristics when deployed horizontally. Therefore, if the user is not careful and/or cognizant of the requirement for a certain orientation, a structure according to the prior art design might be deployed in an unsafe manner with potentially catastrophic results. 
   It can be seen that there is a need for a collapsible/foldable truss member that is strong, easily fabricated and assembled into a temporary or permanent structure for a commercial display or other structural application. Further, a truss member that can be configured to provide horizontal support regardless of the truss member&#39;s orientation is also needed. The present invention fulfills these and other needs, and addresses other deficiencies of prior art implementations. 
   SUMMARY OF THE INVENTION 
   To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention discloses a portable support structure for use in a temporary or permanent display such as trade shows and conventions and stores, and particularly a portable folding truss system having locking wall members and locking hinge elements. 
   An apparatus in accordance with the principles of the present invention includes a foldable truss member including a plurality of adjacently connected side members together forming a peripheral boundary of the truss member. Each side member including an elongated support member having a side surface and a bridging member hingedly connected to the side surface of the support member at an attachment point of the support member. The bridging member having an extension at an edge of the bridging member opposite the attachment point. The side member also includes a plurality of hinge members pivotally joining the bridging member to the support member and an adjacent side member. Each hinge member allowing relative rotation of the side members. 
   Other embodiments of a system in accordance with the principles of the invention may include alternative or optional additional aspects. One such aspect of the present invention is that each bridging member also includes a sawtooth-shaped member having a first and second set of oppositely disposed peaks. The first set of peaks hingedly attached to the attachment point of the support member. The extensions of each bridging member including the second set of peaks. 
   Another aspect of the present invention is that the hinge members include surfaces frictionally engaging the bridging members. 
   Another apparatus in accordance with the principles of the present invention includes a foldable truss member including a plurality of adjacently connected side members together forming a peripheral boundary of the truss member. Each side member including an elongated support member having a side surface and a bridging member hingedly connected to the side surface of the support member at an attachment point of the support member. The bridging member having an extension at an edge of the bridging member opposite the attachment point. The side member also including a plurality of hinge members pivotally joining the extension of each side member to a support member of an adjacent side member. Each hinge member allowing relative rotation of adjacent side members. A plurality of edges between adjacent side members define a plurality of corners of the truss member. 
   Another aspect of the present invention is that each bridging member also includes a sawtooth-shaped member having a first and second set of oppositely disposed peaks. The first set of peaks hingedly attached to the attachment point of the support member and the extensions of each bridging member comprising the second set of peaks. 
   Another aspect of the present invention is that the hinge members include surfaces frictionally engaging the bridging members. Another apparatus in accordance with the principles of the present invention includes a foldable truss member including a plurality of side member means. Each side member means including a receiving means located at a lower edge of the side member means. The side member means adjacently arranged so that the lower edges of the adjacently arranged side member means form a closed shape having a plurality of corners. The side member means also including a plurality of hinging means connecting adjacently arranged side member means. The hinging means allowing relative rotation between adjacently arranged side member means so that the side member means are foldable into a substantially flat assembly. 
   Another aspect of the present invention is that the truss member also includes bridging means hingedly connecting at least two side member means. 
   Another aspect of the present invention is that the bridging means include a sawtooth-shaped member having a first and second set of oppositely disposed peaks. The first set of peaks hingedly attached to the attachment point of the side member means and the extensions of each bridging means hingedly connecting the second set of peaks to an adjacent side member means. 
   Another aspect of the present invention is that the hinge means include surfaces frictionally engaging the bridging means and the hinge means are fixedly connected to the side member means. 
   Another apparatus in accordance with the principles of the present invention includes a foldable truss member including a plurality of side member means each including a lower edge and two side edges. The side member means adjacently arranged so that the lower edges of the adjacently arranged side member means form a closed shape. The side member means also include a plurality of hinging means connected between the side edges of the adjacently arranged side member means. The hinging means allowing relative rotation between adjacently arranged side member means so that the side member means are foldable into a substantially flat assembly. The side edges of the side member means defining a plurality of corners of the truss member. 
   Another aspect of the present invention is that the truss member also includes bridging means hingedly connecting at least two side member means. 
   Another aspect of the present invention is that the bridging means include a sawtooth-shaped member having a first and second set of oppositely disposed peaks. The first set of peaks hingedly attached to the attachment point of the side member means and the extensions of each bridging means hingedly connecting the second set of peaks to an adjacent side member means. 
   Another aspect of the present invention is that the hinge means include surfaces frictionally engaging the bridging means and the hinge means are fixedly connected to the side member means. 
   A method in accordance with the principles of the present invention includes a method of assembling a truss member including adjacently coupling a plurality of side members to form a peripheral boundary for each of the truss members. Each of the side members including an elongated edge hingedly attached to a bridging member. The bridging members hingedly attached to adjacent side members. The method also includes relatively rotating side members and the bridging members to place the side members of the truss member in a deployed configuration. 
   Another aspect of the present invention is that the method also includes relatively rotating the adjacent side members about the elongated edges with a folding force sufficient to overcome the holding force of a plurality of hinge members and rotating the side members to put the truss member in a folded configuration. 
   Another aspect of the present invention is that the method also includes at least two adjacent side members are hingedly connected together via a plurality of hinge members connecting the side members to a bridging member. 
   A method in accordance with the principles of the present invention includes a method of assembling a truss member including adjacently coupling a plurality of side members to form a peripheral boundary for each of the truss members. Each of the side members including an elongated edge hingedly attached to an adjacent side member. The elongated edges of the side members defining a plurality of corners of the truss member. The method also including rotating the adjacent side members about the elongated edges to put the side members of the truss member in a deployed configuration and rotating the side members to overcome a holding force in the deployed configuration of the truss member to prevent further relative rotation of the side members. 
   Another aspect of the present invention is that the method also includes relatively rotating the side members to overcome a folding force sufficient to overcome the holding force of a plurality of hinge members and rotating the adjacent side members to place the truss member in a folded configuration. 
   Another aspect of the present invention is that the method also includes adjacent side members are connected via a plurality of hinge members which connect a plurality of bridging members between adjacent side members. 
   The foregoing objects, advantages and distinctions of the invention, among others, are obtained in a presently preferred construction that provides a portable foldable truss system having locking wall members and locking hinge elements. 
   These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and form a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to accompanying descriptive matter, in which there are illustrated and described specific examples of an apparatus in accordance with the invention. 
   BRIEF DESCRIPTION OF THE DRAWINGS 
   Referring now to the drawings in which like reference numbers represent corresponding parts throughout: 
     FIG. 1  illustrates a perspective view of a foldable truss according to an embodiment of the present invention; 
     FIG. 2  illustrates a side view of a side member according to an embodiment of the present invention; 
     FIG. 3A  illustrates a perspective view of a hinge member according to an embodiment of the present invention; 
     FIG. 3B  illustrates a perspective view of the hinge member interacting with a bridging member extension according to an embodiment of the present invention; 
     FIG. 3C  illustrates a perspective view of an alternate hinge member illustrating locking features according to an embodiment of the present invention; 
     FIG. 4  illustrates an end view of the foldable truss member showing a partially folded configuration according to an embodiment of the present invention; 
     FIG. 5  illustrates a perspective view of a locking frame according to an embodiment of the present invention; and 
     FIG. 6  illustrates a partial side view of a display structure according to an embodiment of the present invention. 

   While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail herein. It is to be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. 
   DETAILED DESCRIPTION OF THE INVENTION 
   In the following description of the illustrated embodiments, references is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration, various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized, and structural and functional changes may be made without departing from the scope of the present invention. 
   The present invention discloses a portable support structure for use in a temporary or permanent display such as trade shows and conventions and stores, and particularly a portable folding truss system having locking wall members and locking hinge elements. 
     FIG. 1  illustrates a perspective view of a foldable truss according to an embodiment of the present invention. In  FIG. 1 , a truss member  100  includes a plurality of side members  102 . The side members  102  are adjacently connected to form a peripheral boundary of the truss member  100  such that the lower edges  101  of the side members  102  form a closed shape such as a rectangle or a square. The side members  102  include a support member  104  and a bridging member  106  connected by hinge members  108 . The bridging members  106  are formed of a continuous length of tubular material formed into a generally planar sawtooth or V-shape. The bridging members  106  include one or more extensions  107  located at an edge opposite where the bridging members  106  join the support members  104 . The extensions  107  are located at distal angular corners of the sawtooth shape. The truss member  100  is formed by joining multiple side members  102  and bridging members  106  using a plurality of hinge members  108 . 
   The hinge members  108 , shown in  FIG. 1 , are fixed to each support member  104  and pivotally join the bridging members  106  to adjacent support members  104 . The hinge members  108  allow relative rotation of adjacent side members  102  while preventing the adjacent side members  102  from separating. As illustrated in  FIG. 1 , the truss member  100  contains four, pivotable, side members  102 , thereby allowing the truss member  100  to be folded substantially flat for storage and shipment. 
   The hinge members  108  can be configured to hold the truss member  100  in a deployed configuration. In a deployed configuration, the side members  102  are rotated to an orientation so that the truss member  100  takes on the shape desired for the intended installation. Typically, this shape is a rectangle or square (as exemplified in  FIG. 1 ) although it may be desired to make the deployed shape a parallelogram, triangle, or other polygon. The hinge member  108  may include locking or frictional features that retain the side members  102  in position once the side members  102  are oriented in the deployed configuration. Details of the locking and/or frictional features of the hinge members  108  will be described at a later point herein below. 
   The foldable truss member  100  may also be made to form a rigid support structure through use of a locking frame  110  or by other means such as cross member braces detailed elsewhere herein. The locking frame  110  is a rigid assembly with locking members  112  that interface with two or more support members  104  of the truss member  100  in a deployed configuration. The example shown in  FIG. 1  shows a square or rectangular locking frame  110  with a locking member  112  at each corner. 
   The locking members  112  interface with receiving ends  114  of the support members  104 . The locking members  112  are inserted into the receiving ends  114  to retain the truss member  100  in the deployed orientation. The receiving ends  114  may be formed as recesses or open ends of the support members  104 . The locking members  112  typically extend from a top and bottom side of the locking frame  110 , enabling multiple truss members  100  to be assembled end-to-end into a rigid support structure. 
   It is appreciated that alternate forms of a locking frame  110  can be used with a truss member  100  according to the present invention. Alternate structural elements known in the art can used to couple two or more side members  102  to make the truss member  100  rigid. For example, the locking frame  110  can be fabricated of a plate material having protruding locking members  112 , or as a bar with two locking members  112  at each end. The locking members  112  can be made to encompass the receiving ends  114  and thereby allow the use of solid support members  104 . 
   Turning now to  FIG. 2 , a side view of an embodiment of a side member  102  is shown. The truss member  100  is formed by adjacently connecting a plurality of side members  102  to form the outer walls of the truss member. Note that the side members  102  may be made substantially identical. Not only does this reduce the number of fabricated parts required to manufacture the truss member  100 , it is also appreciated that a truss member  100  utilizing substantially identical side members will have symmetric transverse load characteristics (i.e. loads that are perpendicular to the longitudinal axis of the truss member). This makes such a truss member  100  ideal for horizontal installations, as there is no need for a preferred orientation of the side members  102 . 
   The side member  102  is formed by attaching a bridging member  106  to a support member  104  with hinge members  108 . The support member  104  is preferably formed from a tubular material, although it need not be hollow. Any cross-sectional shape of the support member  104  is appropriate, although a rectangular, square, or round cross sectional shape is typically the most useful. The illustrated support member  104  is formed from a square tube material. 
   The bridging member  106  is fixed to one side of the support member  104  at attachment points  204  with hinge members  108 . The bridging member  106  can be tubular or a bar member bent into a sawtooth shape and attached with hinge members  108  to the support member  104 . It is appreciated that the bridging member  106  can alternatively be formed from various elements, including a pattern cut from a sheet material or any elongated member (e.g. bar) formed into the desired shape. Further, although the bridging members  106  and other truss member components are typically made from metals (e.g. steel, aluminum, copper, brass, zinc, etc), the components can also be made alternate materials such as woods, plastics, carbon fiber, corrugated cardboard and composite materials. 
   The bridging member  106  includes extensions  107  that interface with hinge members  108  of an adjacent side member  102 . The hinge members  108  are attached to the support member  104  at a location on the support member  104  generally in alignment with the bridging member extensions  107 . The hinge members  108  are typically removably, as opposed to being permanently attached, thereby making assembly easier and allowing for assembly, disassembly, and re-assembly of the truss member  100  as desired. 
     FIG. 3A  shows an embodiment of an attachable hinge member  108 . The hinge member  108  includes a mounting surface  302  with mounting holes  305 . The mounting holes  305  align with holes on the support member  104  (not shown). The mounting holes  305  are adapted to receive fasteners, such as bolts, screws, rivets, locking pins, etc. The hinge member  108  includes a hinge channel  306  for receiving the extension  107  of a bridging member  106  therethrough. The hinge channel  306  is disposed through a portion of the mounting surface  302  and includes flared ends  308  that allow a generally curved extension  107  to freely rotate through 180 degrees within the hinge channel  306 . 
   The hinge member  108  may include features that allow the truss member  100  to maintain its deployed configuration during installation. These features are detailed in  FIGS. 3B and 3C . In  FIG. 3B , a portion of a bridging member  106  is shown in solid line with the extension  107  located within the hinge channel  306  oriented in a typical deployed configuration of the truss member  100 . The orientations of the bridging member  106  corresponding to the folded configurations of the truss member  100  are shown using broken lines. Between the orientations illustrated are intermediate configurations, where the bridging member  106  is located when truss member  100  is being folded or deployed. In one embodiment, the hinge member  108  includes features that hold the extension  107  in a deployed configuration by using either friction and/or elastic deformation of the extension  107  to resist rotation of the bridging member  106 . 
   An example of hinge features that resist rotation of the bridging member  106  are shown in  FIG. 3C . In  FIG. 3C , the flared end  308  of the hinge channel  306  includes three portions of differing geometry. These portions include one or more terminal portions  310 , a center portion  312  and one or more intermediate portions  314 . These portions  310 ,  312 ,  314  correspond to the orientation of the extension  107  within the hinge member  106  when the truss member  100  is in the folded, deployed, and intermediate configurations, respectively. The terminal portions  310  are designed to offer little or no interference with the extension  107 , thereby allowing easy rotation of side members  102  in the folded configuration. The intermediate portions  314  offer varying resistance where the intermediate portions  314  are adjacent the center portion  312 . The center portion  312  typically offers some resistance to rotation of the extension  107 , although preferably less resistance than the intermediate portions  314 . Having less resistance at the center portion  312  gives the user feedback that the truss member  100  has attained the deployed configuration, because the extensions  107  will “snap” into the center portion  312 . 
   The portions  310 ,  312 ,  314  of the hinge member  108  can offer changing resistance to rotation of the extension by various means. In the example of  FIG. 3C , the portions  310 ,  312 , and  314  are formed by fillets or small grooves that form the hinge channel  308 . It is appreciated that forming a fillet radius different than the inner bend radius of the extension  107  will cause the fillets to ride or rub (frictionally interfere) at contact points against portions of the extension  107 . Also, the portions  310 ,  312 ,  314  of the hinge member  108  are arrayed generally radially about a rounded portion  318  of the hinge channel  306 . The rounded portion  318  has a substantially constant semicircular profile throughout the hinge channel  306  in order to effectively restrain the side members  102  during deployment of the truss member  100 . The portions  310 ,  312 ,  314  of the hinge member  108  may have varying shapes and be located at varying radial distances from the rounded portion  318  in order to increase or decrease interference with the extension  107 . For example, as shown in  FIG. 3C , the intermediate portions  314  are located radially closer to the rounded portion  318  than the other portions  310 ,  312  and are somewhat flattened, thereby giving the flared end  308  a peaked appearance. In this way, the intermediate portion  314  causes an increase in friction and/or elastic deformation of the extension  107 , thereby resisting rotation of the extension  107 . 
   Truss members  100  may be constructed that have a large number of extensions  107  along the side members  102 . In this case, it may be desirable to include a mixture of hinge members  108  alternately configured according to both the configurations shown in  FIG. 3A  and  FIG. 3C . This allows the folding action of the truss assembly  100  to be “tuned”, so that holding forces are not excessive. 
   A truss member  100  may be assembled by locating the extensions  107  of a first side member  102  within the channels  306  of associated hinge members  108 . The associated hinge members  108  are then attached to the support member  104  of a second side member  102 , trapping the extensions  107  of the first side member  102  between the associated hinge members  108  and the support member  104  of the second side member  102 . This process is repeated for all side members  102  so the side members  102  form a closed periphery. 
   After assembly, the truss member  100  can be expanded for use or folded into a substantially flat folded configuration for storage or transport.  FIG. 4  illustrates an end view of a partially folded truss member  100 . The truss member  100  is folded by moving the side members  102  in the directions indicated by the curved arrows in  FIG. 4 . While being folded, the adjacent side members  102  rotate relative to each other at the edges of the side members  102  joined by the hinge members  108 . Expanding the truss member  100  to the deployed configuration involves moving the side members  102  in directions opposite those indicated by the curved arrows and installing a locking frame  110  to retain the truss member in the deployed orientation. 
     FIG. 5  shows details of the locking frame  110  used to achieve rigidity of the assembled truss member  100 . The locking frame  110  in  FIG. 5  is a rigid frame having four sides  504  and four corners  506 . Cross bracing  508  may be included for added strength. The locking members  112  in this embodiment are formed as posts that protrude generally perpendicular to a plane defined by the four sides  504 . The locking frame  100  is attached by inserting the locking members  112  of the locking frame  110  into the receiving ends  114  of the truss member  100 . Locking holes  502  are included in the locking members  112 . The locking holes  502  align with locking holes  503  on the support members  104  (best seen in  FIGS. 1 and 2 ). An interference member (not shown) can be passed through holes  502 ,  503  to lock the truss member  100  to the locking frame  110 . 
     FIG. 6  is a partial view of a display structure  400  created by connecting two truss members  100  to a locking frame  110 . The first and second truss members  100  are expanded to the deployed configuration. The locking frame  110  is inserted into the receiving ends  114  on the lower edges  101  of the first truss members  100 . The second truss member  100  is similarly attached to the locking frame  110  and thereby rigidly coupled to the first truss member  100 . 
   A fastening member (e.g. interference member)  602  can be used to create a positive locking engagement between the locking frame  110  and the truss members  100 . The mounting holes  502 ,  503  are aligned such that fastening members  602  can be placed through the holes  502 ,  503 . In this example, exemplary fastening members  602  include a quick release pin  604 , a welded locknut/screw assembly  606  and a nut/bolt assembly  608 . Other fastening members  602  such as clips, rivets, wire ties, snaps, latches, clamps, and etc., may also be used to fasten the truss members  100  and the locking frames  110 . 
   In some display structures  400 , the truss members  100  have sufficient strength to preclude the need for a locking member  110  at every junction. At those junctions, the display structure  400  may be connected by placing independent (i.e. not interconnected) locking members  112  between the receiving ends  114 . Independent locking members  112  may also be fixed with fastening members  602 , as described herein above. 
   The truss member  100  and display structure  400  according to the present invention can be beneficially be adapted for all manner of structural uses, particularly those of a temporary or seasonal nature. In particular, one such configuration desirable for uses such as displays or point of sale fixtures is described herein in detail. A truss member  100  having approximately 12″×12″ cross sectional dimensions is preferable in these applications. The individual truss member lengths can vary from about 6″ to about 80″. The support members  102  are formed from ¾″ to 1″ square steel tubing welded to 3/16″ wire lacing forming the bridging members  106 . The hinge members  108  are investment cast from steel and finished with a smooth finish along the hinge channel surfaces  306 . Fabricating the truss assembly  100  from steel offers advantages of low cost, high strength, and magnetic properties for easy attachment of magnetic graphics. The steel is typically powder coated for appearance and corrosion resistance. The support members can be of different sizes and of different materials than stated above, such as round tubes and plastics, aluminum or other materials with sufficient strength. In general, the strength of coupled truss members  100  in this specific application should be able to be safely used over a 40 foot span with no load. Loads up to a few hundred pounds can be supported either applied centrally or distributed. Such load bearing capability would enable the truss to safely support item such as computer or TV monitors, lights and signage, typically used in an exhibit/display. The weight of the truss member  100  so configured will range from ½ pound to 10 lbs for truss lengths between 6″ and 80″. 
   The foregoing objects, advantages and distinctions of the invention, among others, are obtained in a presently preferred construction that provides a portable support structures for use in temporary fixtures such as trade shows and conventions, and particularly to a portable folding truss system having hinging side elements. 
   The foregoing description of the exemplary embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not with this detailed description, but rather by the claims appended hereto.