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This is a continuation of application Ser. No. 900,161 filed on Aug. 25, 1986, now U.S. Pat. No. 4,712,336. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to portable wall structures and more particularly to a lightweight modular portable system for creation of display booths. 
     DISCUSSION OF THE PRIOR ART 
     The present invention is particularly adapted to the requirements of exhibitors at trade shows. A trade show exhibitor rents exhibition hall floor space at a particular location of a designated size. The exhibitor must make his own arrangements for means for designating the boundaries of the display area he has rented and separating his area from the area of adjacent exhibitors. Typically this is done by means of a display booth of some type. This can be done by placement of furniture pieces, by the use of open framework with cloth material or banners hanging from them, or by the means of complete wall structures particularly adapted for the uses of the exhibitor, including display of products and literature. 
     Relatively complete exhibit booths prepared especially for a particular exhibitor, or &#34;custom exhibiting,&#34; tend to be extremely expensive and, while to some degree they are portable, are not easily transported, handled, set up and taken down. Such a booth in its packing crate may weigh a total of several thousand pounds. Modular systems, which are either purchased by particular exhibitors or rented at the scene of a trade show, while being somewhat adaptable to various exhibit users, generally comprise relatively large wall elements which merely abut each other and are not normally interconnectable and interchangeable to create structures of various heights, widths or angles. Additionally, these structures tend to be bulky, difficult to handle and relatively heavy. Stated another way, they are not normally readily adaptable to a variety of use requirements Further, modular systems now available have either visible external structural framework or connective systems, which limit design capabilities and reduce appearance. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the present invention to provide a modular panel wall system from which a large variety of waIl or booth structures may be created at the site of ultimate use. The structure is also easily broken down and is lightweight and simple to pack and transport. The system of this invention, for equivalent wall area, is typically no more than one fourth the weight of the prior art systems described above. 
     The wall system of this invention is comprised primarily of a series of rectangular lightweight panels having a rigid frame and a foam or honeycomb core. The frame members are formed with elongated channel elements having a box-like cross section, each channel element being adapted to receive a flat bar which engages stop means in the channel, such as the shank of a screw or pin extending through the channel at a specific location. The flat bar has a plurality of configurations and alternatively is connected with a hinge element. The various configurations of flat bars and hinge elements enable the panel members to be stacked, interconnected in lateral adjacent relationship and formed at any desired angle one with respect to the other, as well as creating T-shaped wall element structures. 
     A kit comprising a multiplicity of similar wall panels and a multiplicity of connector elements of a plurality of configurations can be employed to create a structure of any shape or complexity. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The objects, advantages and features of this invention will be more readily appreciated from the following detailed description when read in conjunction with the accompanying drawing, in which: 
     FIG. 1 is a perspective view of a typical display assembly constructed with components of the present invention; 
     FIG. 2 is an enlarged view of one corner of a panel with the facing material cut away; 
     FIG. 3 is a sectional view taken on line 3--3 of FIG. 2; 
     FIG. 4 is a sectional view taken on line 4--of FIG. 2 with a connector element inserted; 
     FIG. 5 is a perspective view of an assembly of panels with a variety of types of joints; 
     FIG. 6 is an enlarged view of joint 6 of FIG. 5; 
     FIG. 7 is an enlarged view of joint 7 of FIG. 5; 
     FIG. 8 is an enlarged view of joint 8 of FIG. 5; 
     FIG. 9 is an enlarged view of joint 9 of FIG. 5; 
     FIG. 10 is an enlarged view of joint 10 of FIG. 5; 
     FIG. 11 is an enlarged view of joint 11 of FIG. 5; 
     FIG. 12 is a perspective view of the connector element used in joint 10; 
     FIG. 13 is a perspective view of an alternative connector similar to that of FIG. 12; 
     FIG. 14 a perspective view of the connector element used in joint 11; 
     FIG. 15 a perspective view of the connector element used in joint 6; 
     FIG. 16 is a perspective view of the connector element used in joint 9; 
     FIG. 17 is an enlarged fragmentary perspective view of a portion of channel element shown in FIG. 3; 
     FIG. 18 illustrates a connector element for joining two panels at angle; 
     FIG. 19 is a perspective view of an alternative connector element similar to that of FIG. 14 for straight wall connection 19; 
     FIG. 20 is a perspective view of an alternative connector element similar to that of FIG. 12 for straight wall connection 20; 
     FIG. 21 shows an alternative connector element similar to that of FIG. 4; and 
     FIG. 22 depicts yet another alternative connector element similar to that of FIG. 4. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference now to the drawing, and more particularly 1 thereof, there is shown a complex structure 21 employing panel and connector elements of the present invention. Note that the panels can be joined not only in vertical stacked (22) and horizontally connected (23) arrangements, but can create T-shaped intersections 24 of panels as well as combinations of different angles 25. 
     The typical panel structure is shown in FIGS. 2-4. The frame of panel 29 is contemplated as being made of wood or other rigid material comprising elements 26 and 27 and a lightweight honeycomb core 28 with appropriate corner stiffener or fillet elements 31. The rigid end member 27 may be comprised of a single grooved element or it may be built up of separate elongated strips. An appropriate semi-stiff covering material 35 is coextensive with a broad side of the panel 29 and preferably a soft fabric covering 36 made in decorator colors provides the outer surface of the panel. Two opposite edges of the frame member of panel 29 are formed with a groove for receiving channel member 41. The channel member is formed of a rigid material, preferably extruded lightweight aluminum or equivalent. However, it is possible that the channel member could be made of a rigid plastic of suitable strength characteristics. Channel member 41 is anchored to frame member 27 by any appropriate means such as one or more screws 39, 42 having respective shanks 40, 43. Screw 42 adjacent either end of channel member 41 on panel 29 is located a distance A (FIG. 4) or B (FIG. 21) from the end of the channel and consequently from the abutting edge of the panel. Screw 39 spaced further into the channel is located a distance C from screw 42. 
     The connector elements and their function will be described with respect to FIGS. 4-20. The simple double-ended flat bar element 44 shown in FIG. 4 is employed for rigid edge-to-edge interconnection of two adjacent panels in p1anar configuration. End 45 of bar 44 is formed with a slot 46 having an enlarged tapered entryway 47, slot 46 having a blind inner end 51. The slot 46 in connector element 44 is dimensioned to closely engage the shanks of screws 39, 40, but normally the connector element will fit into channel 52 relatively loosely to facilitate panel interconnection. As shown in FIG. 4, connector element 44 is inserted into channel 52 (see FIGS. 3 and 17) until end 51 of slot 46 engages shank 43 of screw 42. At this point the shanks of both screws are engaged by the confronting edges of slot 46 so that connector element 44 remains positively oriented as shown in FIG. 4. It is contemplated that connector 44 will slide securely, but with minimum friction over the two screw shafts in such a manner as to assure alignment and rigidity of stacking components. Screw 39 may be termed guide means while screw 42 may be termed stop means. Another panel 29 having identical channel structure as the panel portion shown in FIG. 4 can be stacked on top of the panel with the lower end of this channel member engaging the upper end 53 of bar 44 with equivalent screw shanks engaging blind end 54 of slot 55. A similar structure exists at the other end of the panel so that when two panels are placed together with abutting edges, their opposite edge channel members are joined by two identical connector elements 44. Note with respect to FIG. 5 that such connector elements 44 would be used to join the distal ends of two stacked panels at their common ends 57, 58. 
     In order to create joint 6 as shown in FIG. 6, the connector element 60 of FIG. 15 is employed. This connector comprises two flat elements 61, 62 interconnected by means of a hinge structure 63 allowing one element to pivot with respect to the other. Fixed to one side of each flat element 61, 62 are slotted bars 64, 65 respectively, each formed in the manner of bar 44 but having one half the length of that bar. Respective element pairs 61, 64 and 62, 65 are interconnected by appropriate means such as welding. When it is desired to create a corner structure like that shown in FIG. 6, the connector element of FIG. 15 is inserted in two adjacent panels with slotted bar members 64, 65 projecting into the respective channel members and engaging the shanks of screws 42 mounted in the frames of the panels. This affords a smooth or closed outer corner structure. 
     To form the joint 7 as shown in FIG. 7, the connector device 71 is formed of hinged flat elements 72 and 73 substantially similar to elements 61 and 62 of FIG. 15, but with slots therethrough in the manner of the hinged elements of FIG. 14. This is an example of where it is desired to have the interconnection of two panels with the channel edge of one panel abutting the broad side of the other panel adjacent the channel end along the rigid frame area, forming a smooth outer corner. The total connecting device of the FIG. 7 configuration comprises hinged element 71 formed of slotted members 72 and 73 and two double-slotted bars 44. Joint 7 is formed by inserting one end of each bar 44 in the adjacent panels and then slipping the slotted hinged elements 72 and 73 over the projecting ends of slotted bars 44. Second panels 29 are then connected in the same manner above the panels shown in FIG. 7 to complete the outside corner shown in FIG. 5. 
     Another corner structure slightly different from that of FIGS. 6 and 7 is shown in FIGS. 10 and 11 employing the connector devices of FIGS. 12 and 14. FIG. 12 shows a hinged element 74 much like that of FIG. 15 except that it results in a corner appearing finished from the inside rather than the outside as seen in FIGS. 6 and 7. Otherwise the element of FIG. 12 operates in a manner identical with that of FIG. 15. Similarly, connector 75 of FIG. 14 functions together with two bars 44 to form the joint shown in FIG. 11 in a manner similar to that shown in FIG. 7. 
     A T-shaped junction is depicted in FIGS. 8 and 9 and employs the triple-hinged element 80 of FIG. 16 together with a triple-hinged element 87 configured as a combination of FIG. 16 and FIG. 12. By means of the device of FIG. 16, together with three double-slotted bars 44, two panel members 81, 82 are interconnected in end-to-end abutment and these panels are further interconnected in side-to-end abutment with panel 83. Hinged element 80 is formed of three mutually hinged flat slotted members 84, 85 and 86 with the resulting relationship forming the joint of FIG. 9. Similarly, the joint of FIG. 8 is formed of a connector 87 having three flat elements 91, 92 and 93, each attached to three half length slotted bars extending downwardly from the flat hinged members and projecting into the channels at the adjacent edges of panels 94, 95 and 96. 
     To make a stepped corner junction, that is, by placing a panel 29 on top of panel 97 of FIG. 5, the connecting element 98 of FIG. 13 would be used. This would provide a finished structure for the top right hand corner of panel 95 and would provide, in conjunction with a double-slotted bar 44, means for connecting a panel vertically on top of panel 97. Of course, a double-slotted bar 44 would be used to interconnect the right hand end of such a panel with panel 97, as was done at joint 58. 
     It should be noted that the flat rigid connector bar may be formed at any desired angle as shown in FIG. 18 where bar 102 has a relatively small angle which may be used to create the canopy structure 25 of FIG. 1. 
     A modified structure is shown in FIG. 21 where a plain flat bar 103 is inserted into slots in the channel members. The stop means, abutting pins 104, are placed somewhat further from the open end of the channel but stability is maintained because the channel is configured to closely confine bar 103. 
     Another modification is shown in FIG. 22 where the slotted connecting member 108 is not a flat bar but is a cylindrical rod. It could as well have a square, rectangular or any other cross section, but in any case it should preferably have a slot functioning together with the two screw shanks as in FIG. 4. 
     Where one does not desire a hinged connection of two adjacent panels, elements 105 and 106 shown in FIGS. 19 and 20 respectively, may be used. Joint 19 in FIG. 5 employs connector element 105 together with two flat bars 44. Connector element 106, a flat plate with two fixed parallel half length bars 107, provides the top connector of joint 20. 
     It should be appreciated that elements such as hinged member 80 of FIG. 16 can be turned over to provide a joint such as that shown in FIG. 9 but with panel 83 abuting the surface of panel 81 instead of panel 82. Similarly, various combinations of hinged and fixed horizontal elements together with full and attached half length flat elongated bar elements may be created to satisfy different requirements for different structures. Other reversals of the various connector elements provide complete versatility to enable one to construct a booth or similar structure with all of the complexity of that shown in FIG. 1 or even structures of greater extent and complexity. 
     An opaque, light weight, honeycomb structure is shown for the panels of this invention. The area inside the rigid frame could also be transparent, completely open or have partial sliding panels to provide openings as desired. For possibly ultimate modularity, all of the panels would be relatively small and of the same size. However, if the panels have modular dimensions, such as being whole integer multiples of a certain length, significant modularity is available. Taking human factors into consideration, a 19-inch module is desirable. The primary requirements of this invention are substantially rigid modular frames with channel members along their edges, and connecting elements adapted to fit into the channels to interconnect adjacent panels. 
     In view of the above description, it is likely that modifications and improvements will occur to those skilled in the art which are within the scope of the appended claims.

Summary:
A portable modular wall assembly system with interchangeable interconnecting elements for creating display booths and room dividers. The system comprises a series of modular panels of different shape, construction and function, together with a series of connector elements adapted to interconnect with each of said panels to form a variety of structures.