US20150345133A1

US20150345133A1 - Structural reinforcement

Info

Publication number: US20150345133A1
Application number: US14/379,273
Authority: US
Inventors: Geoffrey Rajay Sidhu
Original assignee: Global Utility Patents Corp
Current assignee: Global Utility Patents Corp
Priority date: 2012-02-17
Filing date: 2012-02-17
Publication date: 2015-12-03
Also published as: WO2013120168A1; WO2013120165A1

Abstract

An apparatus for reinforcing adjacent parallel spaced apart wooden structural members. Each of the structural members extends between first and second edges. The apparatus comprises a rigid member having first and second ends and being sized to extend between adjacent first and second structural members. The apparatus further comprises a first socket connected to the first end of the rigid member sized to receive a first edge of the first structural member therein and a second socket connected to the second end of the rigid member. The second socket is sized to receive a first edge of the second structural member corresponding to the first edge of the first structural member therein.

Description

BACKGROUND OF THE INVENTION

1. Field of Invention
The present invention relates to structural reinforcement in general and in particular to reinforcing adjacent wood product structural members to each other.
2. Description of Related Art
In the field of construction, it is often desirable to make a structure as strong as possible. The strength of a building is desirable for the purposes of load bearing ability as well as resistance to outside loads such as earthquakes, wind and other environmental loading.
Building construction typically includes a plurality of elongate members connected each other to form walls, ceilings, floor and the like. In the case of walls, such elongate wall members are often referred to as studs while in ceilings and roofs, they may be referred to as joist.
One difficulty that exists is the tendency of relatively long structural members to lose strength and rigidity as their length increases. This is often required for floor and ceiling joists so as to provide larger rooms unobstructed by supporting walls and columns. Such long joists may commonly be subject to torsional buckling failure. Another difficulty that exists with floor joists is when they are exposed to dynamic environmental loads such as earthquakes, strong winds and the like. Under such loads, the floor joists may rotate axially along their length so as to lay flat instead of upright. The resulting horizontal and vertical deflection of the entire load above such a floor may contribute to an entire building failing or collapsing.
Conventional methods of reinforcing structural members has not been adequate to resolve the above difficulties. Previous attempts have tried to locate bridges or blocks between adjacent joists to distribute point loads located near a single joist to adjacent joists so as to distribute the load between more than one joist. Bridging involves locating a pair of crossed diagonal wooden members between adjacent joist whereas blocking typically includes locating a shortened length of the joist member transversely between the joists. Such attempts have not adequately solved the above difficulties. In particular, blocking or bridging is only able to act as a compressive member between the joists and will have a very limited ability to prevent the joists from moving away from each other.
When the joist members are subjected to torsional loading, the blocking members on one side of the joist are subjected to opposite loads. For example, when a torsional load is applied to the joist along the longitudinal axis of the structural member, the blocking member abutting one side of the top chord of the joist is subjected to a primarily compressive load, and the blocking member abutting opposite side of the top chord is subject to a tensile load. Similarly, for the same torsional load, the bottom chord on the same side of that joist will also be subjected to a tensile load. The compressive load may be conveyed efficiently to the blocking member abutting the top chord through the contacting surfaces of the blocking and the joist chord. However the tensile load on both blocking member on the opposite side of the top chord and on the bottom blocking member is born entirely by the fastening device used. Therefore unless such fasteners are specifically designed to bear tensile loads under repeated loading cycles, this is likely to cause premature failure of the structure when such fasteners, such as a nail or a screw pulls out. Due to the inability of bridging and blocking to effectively handle loads in tension, such reinforcing will not significantly assist in the reinforcing of a structure under cyclical environmental loads such as earthquakes, winds and the like.

SUMMARY OF THE INVENTION

According to a first embodiment of the present invention there is disclosed an apparatus for reinforcing adjacent parallel spaced apart wooden structural members. Each of the structural members extends between first and second edges. The apparatus comprises a rigid member having first and second ends and being sized to extend between adjacent first and second structural members. The apparatus further comprises a first socket connected to the first end of the rigid member sized to receive a first edge of the first structural member therein and a second socket connected to the second end of the rigid member. The second socket is sized to receive a first edge of the second structural member corresponding to the first edge of the first structural member therein.
The first and second sockets may comprise c-shaped channels. The c-shaped channels may extend perpendicularly to a longitudinal axis of the rigid member. The c-shaped channel may be formed of first and second opposed flanges and a web portion therebetween.
At least one of the first and second opposed flanges may be selectably deformable so as to open the c-shaped channel. The c-shaped channels may include at least one fastener bore sized to pass a fastener therethrough so as to secure the c-shaped channel to the structural member. The first flange may include a perpendicular connecting tab extending from an edge thereof away from the c-shaped channels wherein the rigid member extends from the second flange.
The first and second sockets may be rigidly affixed to the rigid member. The first and second sockets may be integrally formed with the rigid member. The rigid member and the first and second caps may be formed of metal. The rigid member may comprise an elongate beam. The beam may be selected from the group consisting of a tube, a box section, an I-beam, a c-shaped channel, an L-shaped channel and a triangular cross section beam.
According to a further embodiment of the present invention there is disclosed a kit for reinforcing adjacent parallel spaced apart wooden structural members. The kit comprises a pair of rigid member having first and second ends and being sized to extend between adjacent first and second structural members.
Each rigid member further comprises a first socket connected to the first end of the rigid member sized to receive a first edge of the first structural member therein and a second socket connected to the second end of the rigid member. The second socket is sized to receive a first edge of the second structural member corresponding to the first edge of the first structural member therein.
The kit may further comprise a linking member extending between the first and second rigid members. The linking member may be substantially rigid.
According to a further embodiment of the present invention there is disclosed an apparatus for reinforcing adjacent parallel spaced apart wooden structural members. The apparatus comprises a first rigid member having first and second ends sized to extend between adjacent first and second structural members. The apparatus further comprises a first socket connected to the first end of the first rigid member sized to receive a first edge of the first structural member therein and a second socket connected to the second end of the first rigid member. The second socket is sized to receive a first edge of the second structural member corresponding to the first edge of the first structural member therein. The apparatus further comprise a second rigid member having first and second ends sized to extend between the first and second structural members. The apparatus further comprises a first socket connected to the first end of the second rigid member to receive a second edge of the first structural member therein and a second socket connected to the second end of the second rigid member. The second socket is sized to receive a second edge of the second structural member corresponding to the second edge of the first structural member therein. The apparatus further comprises a linking member extending between the first and second rigid members. The linking member may be substantially rigid.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view,

FIG. 1 is a perspective view of an apparatus according to a first embodiment of the present invention for reinforcing structural members as located between floor joists.

FIG. 2 is a front perspective view of the apparatus of FIG. 1.

FIG. 3 is a front perspective view of the apparatus of FIG. 1.

FIG. 4 is a cross-sectional view of a bottom bracket of the apparatus of FIG. 1 being applied to adjacent floor joists.

FIG. 5 is a cross sectional view of a connecting member being connected to the bottom bracket of the apparatus of FIG. 1.

FIG. 6 is a cross sectional view of a top bracket of the apparatus of FIG. 1 being applied to the adjacent floor joists.

FIG. 7 is a perspective view of an apparatus for reinforcing structural members according to a further embodiment of the present invention.

FIG. 8 is a plan view of a cut sheet useful for forming one of the rigid members of FIG. 1 having sockets on each end thereof.

FIG. 9 is a perspective view of an apparatus for reinforcing structural members according to a further embodiment of the present invention.

FIG. 10 is a perspective view of an apparatus for reinforcing structural members according to a further embodiment of the present invention.

FIG. 11 is a perspective view of an apparatus for reinforcing structural members according to a further embodiment of the present invention.

FIG. 12 is a perspective view of an apparatus for reinforcing structural members according to a further embodiment of the present invention.

FIG. 13 is a perspective view of an apparatus for reinforcing structural members according to a further embodiment of the present invention.

DETAILED DESCRIPTION

Referring to FIGS. 1 through 3, an apparatus for stabilizing adjacent structural members 6 according to a first embodiment of the invention is shown generally at 20. The apparatus 20 comprises a pair of parallel spaced apart first or top and second or bottom rigid members 22 and 24, respectively, each spanning between one of the top or bottom edge 8 of a pair of adjacent structural members 6. Each rigid member 22 and 24 includes a pair of sockets 26 and 28, respectively, sized to receive the top or bottom edge 8 or 10, respectively, of the structural member therein to form either a top or bottom bracket, respectively. The apparatus 20 also includes a connecting member 30 extending between the first and second rigid members 22 and 24. It will be appreciated that such a connecting member 30 will serve to retain the top and bottom sockets 26 and 28 in engagement on the structural member. Each set of top and bottom rigid members 22 and 24 and connecting member 30 may comprise a single structural reinforcing device. It will also be appreciated that in some embodiments, a single rigid member 22 or 24 with its connected sockets 26 or 28 may be utilized alone as a reinforcing device. In other embodiments, a pair of top and bottom rigid members 22 and 24 may be utilized without a connecting member 30 therebetween. As illustrated in FIG. 1, the top and bottom sockets 26 and 28 of an opposed pair of rigid members 22 and 24 cooperate together to retain the structural member therebetween.
Turning now to FIGS. 2 and 3, a front perspective view of the apparatus 20 is illustrated according to a first embodiment of the present invention. The top and bottom rigid members 24 may be formed of sheet metal bent into a c-shaped channel. With reference to the top rigid member 22, the channel may be formed of a web portion 32 having a pair of sides 34 and 36 at each side thereof. The sides 34 and 36 may be bent to the same side of the web portion 32 so as to extend from the same side of the web portion 32 as the top sockets 26. The bottom rigid member 24 may be formed in a like manner with a web portion 38 and sides 40 and 41. It will also be appreciated that although the rigid members 22 and 24 illustrated in FIGS. 1 through 3 may be formed of bent sheet metal, it may also be formed by other means such as an extruded, cast or welded structure. It will also be appreciated that one or both of the sides 34 or 36 and 40 or 41 may be omitted depending on the strength requirements of the application. As illustrated in FIGS. 4 through 6, the web portions 32 and 38 may include one or more bores 37 therethrough so as to permit a pair of rigid members 22 and 24 to be secured to a connecting member 30 as described below. As illustrated in FIG. 2, the sides of the rigid members may have notched portions 59 adjacent to the top and bottom sockets 26 and 28 so as to provide some flexibility during installation.
The top sockets 26 may comprise an open c-shaped channel formed of first and second top side flanges 42 and 44, extending from the top web portion 43 forming a channel opening 46. As illustrated, the web portion 32 of the top rigid member may extend from a side edge of the first side 42 of the top socket 26. As illustrated in FIGS. 2 and 3, the web portion 32, first side 42 and the rigid member 22 may be substantially orthogonal to each other although, it will be appreciated that the rigid member 22 may be optionally angularly offset from the top socket 26 so as to permit non-normal attachment to the structural members.
The bottom socket 28 may comprise an open c-shaped channel formed of first and second bottom side flanges 50 and 52, respectively extending from the web portion 45 of the bottom rigid member so as to form a channel opening 56. As illustrated, the web portion 38 of the bottom rigid member may extend from a side edge of the first side 50 of the bottom socket 28. As illustrated in FIGS. 2 and 3, the web portion 38, first side 50 and the rigid member 24 may be substantially orthogonal to each other although, it will be appreciated that the rigid member 24 may be optionally angularly offset from the bottom socket 28 so as to permit non-normal attachment to the structural members.
The top channel opening 46 is sized and shaped to correspond to the top edge 8 of the structural member. The bottom channel opening 56 is sized and shaped to correspond to the bottom edge 10 of the structural member. In many applications, the structural member 6 will comprise a floor or ceiling joist, such as by way of non-limiting example dimensioned lumber, space frame or I-joists formed of wood, metal or the like. Dimensioned lumber is commonly of a 1.5 inch width and therefore for such applications the top and bottom channel openings 46 and 56 will be sized to have a similar width opening. It will be appreciated that other thicknesses of structural members in general and joists in particular may also be utilized, such as, by way of non-limiting example, sized to accommodate a doubled up floor joist, a 2½ inch wide floor joist or other common wood or metal floor joist sizes. In some applications, the top and bottom channel openings 46 and 56 may be sized slightly larger than the width of the joist so as to facilitate installation. In particular, the top and bottom channel openings 46 and 56 may be up to 3.2 mm (⅛ of an inch) larger than the joist for which they are designed. The sizing of the top and bottom channel openings 46 and 56 for I-joists may be similarly selected to correspond to the I-joist to be used.
The connecting member 30 may be formed of a rigid or resilient flexible members such as, metal straps, bars, chain and the like, by way of non-limiting example. As illustrated in FIG. 2, the connecting member 30 may be formed of a web portion 48 having sides 54 extending therefrom so as to form a c-shaped channel. As illustrated in FIG. 2, the connecting member may be connected to the same sides of the top and bottom rigid members 22 and 24 together in substantial vertical alignment with each other. In other embodiments, such as illustrated in FIG. 1, the connecting member may be secured to opposed sides 34 or 36 of the rigid members such that the top and bottom rigid members 22 and 24 are vertically offset from each other. The web portion 48 of the connecting member 30 may also have bores 53 (as illustrated in Figure adapted to
The top and bottom sockets 26 and 28 may include one or more fastener bores 58 located in any one or more of the flanges or webs forming the socket. The fastener bores 58 are sized to permit nails, screws or other suitable fasteners to be passed therethrough so as to secure the top or bottom socket 26 or 28 to the structural member 6. The top and bottom sockets may also include apertures 55 through the side flanges 42 and 44 and 50 and 52 to permit nails, screws or other suitable fasteners to be passed therethrough so as to secure the sockets to the structural members 6 therein. As illustrated in FIG. 11, the apertures 55 may comprise circular bores, a plurality of bores, slots or any other suitable opening. Optionally, the top and bottom sockets 26 and 28 may include barbs, spikes or other suitable projections from an interior surface thereof so as to engage the joist when the apparatus 20 is secured thereto. Adhesives may also be applied between the top and bottom edges 8 and 10 of the structural member and the top and bottom sockets 26 and 28. The top and bottom sockets 26 and 28 may also include an optional connecting tab 60 extending therefrom for fastening adjacent top and bottom sockets to each other with fasteners and the like. As illustrated, the connecting tabs 60 may extend to one side of the top and bottom sockets although it will be appreciated that they may also extend to any combination of, opposed sides, same sides, or both sides thereof.
As illustrated in FIG. 2, the height of the connecting member 30 will correspond generally to the height of the structural members 6. As discussed above, the top rigid member 22 is sized to extend between a top edge 8 of one structural member 6 and a top edge 8 of an adjacent structural member. In practice, the length of the rigid member 22 will depend upon both the spacing distance between them. Similarly, the bottom rigid member 24 is sized to extend between a bottom edge 10 of one structural member 6 and a bottom edge 10 of an adjacent structural member. Generally, the distance between the structural members, which is commonly expressed in centre to centre distance will correspond to the distance to the centres of the two top or bottom c-shaped channel openings 46 or 56. By way of example, for a floor constructed of 302 mm (11⅞ inches) high joists spaced 406 mm (16 inches) apart, length of the rigid members 22 and 24 from the center of the c-shaped channel openings 46 or 56 of the apparatus 20 would similarly be 406 mm (16 inches) It will be appreciated that other lengths will apply for joists of differing spacing.
As illustrated in FIG. 8, the rigid members 22 and 24 may be cut from a single sheet of metal, such as, by way of non-limiting example, steel, stainless steel, aluminium or galvanized steel. The sheet metal may be cut into a blank 90 as illustrated in FIG. 8 according to known methods and thereafter bend into the desired shape as illustrated and described above. By way of non-limiting example, the blank 90 may be formed with the rigid member having the web portion 32 and side 34 and 36 adjacent thereto. The first and second sides 42 and 44 of the top sockets may be also formed to either sides of the socket web portions 43. Thereafter, the blank may be bent along bend lines 94 to form the top bracket as set out above. As illustrated in FIGS. 2 and 3, the two top sockets 26 may be bent to a common side of the web portions 32 although it will be appreciated that the two top sockets 26 may optionally be bent to opposed sides thereof as illustrated in FIG. 11. Furthermore, the two bottom sockets 28 may also be bent to opposite sides such that each set of top and bottom sockets 26 and 28 on a common structural member 6. In such a manner, it will be observed that an apparatus 20 formed from such offset sockets will have each of the top sockets offset from each other and each of the sockets along each structural member offset from each other with the sockets located diagonally from each other being located to the same side to facilitate interconnection with adjacent reinforcing devices as illustrated in FIG. 1.
Any thickness of metal as required to provide the necessary strength may be utilized such as between 12 and 22 gauge. In particular, it has been found that sheet metal of between 16 and 20 gauge has been useful. It will also be appreciated that the apparatus 20 may also be formed of non-metal materials, such as, by way of non-limiting example, carbon fibre, fibreglass, plastics, ceramics and composite materials. It will also be appreciated that although c-shaped channels are illustrated and described above for the rigid members 22 and 24 and the connecting member, other cross-section shapes may be utilized as well, such as, by way of non-limiting example, bar, tube, box section, I-beam, c-shaped channel, L-shaped channel, a triangular cross section beam, or any other suitable member. It will also be appreciated that although elongate, substantially straight members are shown, non-straight members may also be utilized, such as, by way of non-limiting example, arcuate, space frame, plates or any other shape as long as the top and bottom sockets 26 and 28 are rigidly translationally fixed relative to each other so as to securely locate top and bottom edges 8 of adjacent structural member relative to each other.
In operation, and with reference to FIGS. 4 through 6, a bottom rigid member 24 may be located on the bottom edges 10 of a pair of opposed adjacent structural members 6 by moving the bottom rigid member 24 in an upward direction as indicated generally at 80 in FIG. 3 such that the bottom edges 10 of the structural members 6 are retained within the bottom sockets 28 thereof. A connecting member may then be engaged with bottom rigid member 24 by aligning, in a direction generally indicated at 82 in FIG. 5, the bores 53 of the connecting member with the bores 37 of the bottom rigid member 24 and passing bolts 39, screws or other fasteners therethrough. Although the bores 37 are illustrated as being located at positions substantially in the middle of the top and bottom rigid members, in the accompanying figures, it will be appreciated that these bores may also be located at other locations therealong as well, such as proximate to one of the sockets 26 or 28 so as to provide a substantially unobstructed region between the elongate structural members 6 for locating pipes, plumbing, wiring and the like. The top rigid member 22 may then be located such over the top edges 8 of the structural members 6 such that the top edges 8 are retained within the top socket 26 thereof by moving the top rigid member 22 in a downward direction generally indicated at 84. Thereafter, bolts or fasteners 39 may be passed through the bores 37 and 53 in the top rigid member 22 and connecting member 30. Fasteners may also be passed through the fastener bores 58 so as to secure the rigid members to the structural members or through bores 62 in the tabs 60 to secure the apparatus 20 to adjacent devices.
With reference to FIG. 7, a bracket 100 for use in forming either the top or bottom of the apparatus 20 is illustrated according to a further embodiment of the present invention. The bracket 100 comprises a planar portion 102 extending between first and second ends, 104 and 106, respectively. The bracket 100 may further include first and second end walls, 108 and 110, extending perpendicularly from the first and second ends 104 and 106. The first and second end walls 108 and 110 define first and second structural member receiving locations 112 and 114, respectively. The bracket 100 may also optionally include first and second strengthening ribs 116 and 118 extending along the planar portion 102. The bracket 100 may also include connecting tabs 120 extending from the first and second end walls 108 and 110. As illustrated in FIG. 12, the planar portion 102 may be angularly oriented between the first and second end walls 108 and 110 so as to permit the first and second end walls 108 and 110 to be offset from each other along the structural member 6.
With reference to FIG. 9, a bracket 140 for use in forming either the top or bottom of the apparatus 20 is illustrated according to a further embodiment of the present invention. The bracket 140 comprises a planar portion 142 extending between first and second ends, 144 and 146, respectively. The bracket 140 further includes first and second sockets, 150 and 152, respectively, located at the first and second ends 144 and 146 oriented to receive the structural member therein in a direction generally perpendicular to the planar portion 142 as illustrated. The planar portion 142 may also optionally include strengthening ribs 148 extending along the planar portion 102. As illustrated the strengthening ribs 148 may extend away from the planar portion 142 in an opposite direction from the orientation of the sockets 152 although it will be appreciated that they may also extend in the same direction. The sockets 150 and 152 are each formed of interior and exterior walls, 154 and 156, respectively with a bridging portion 158 therebetween. As illustrated, the planar portion 142 extends from the top most edge of the interior walls 154 so as to form a space 170 thereunder. When the bracket 140 is installed on a pair of parallel floor joists, the space will be maintained between the planar portion 142 and a flooring material so as to provide a location to contain plumbing wiring and the like. The height of the space 170 may be adjusted by providing an interior wall 154 if different heights. As illustrated, the interior wall 154 may have a height less than the height of the exterior wall, although it will be appreciated that the height of the interior wall may also be the same or greater than the height of the exterior wall as well. The bracket 140 may also include connecting tabs 160 extending from the exterior walls 156 for securing to adjacent brackets, as set out above. As illustrated in FIG. 13, the planar portion 142 may be angularly oriented between the first and second sockets 150 and 152 so as to permit the first and second first and second sockets to be offset from each other along the structural member 6.
Although as illustrated above, the ridged members are illustrated as being substantially straight, it will be appreciated that other shapes between pairs of sockets 26 or 28 may also be utilized having other shapes or profiles as well. In particular, the rigid members may be curved, or arcuate or formed of a plurality of rigidly or pivotally connected member segments. With reference to FIG. 10 an apparatus for stabilizing adjacent structural members according to a further embodiment of the invention is shown generally at 180. The apparatus 180 comprises central plate 182 extending between first and second sides 184 and 186, respectively and top and bottom edges 188 and 190, respectively. The plate supports the top sockets 26 and bottom sockets 28 therefrom and may optionally include an opening 192 or aperture therethrough as desired by a user for passing pipes, wires, plumbing or the like. Although the opening 192 is illustrated as being substantially circular in FIG. 10, it will be appreciated that other shapes may also be useful as well, such as, by way of non-limiting example, square, rectangular, oval, triangular, octagonal or irregular.
While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.

Claims

What is claimed is:

1. An apparatus for reinforcing adjacent parallel spaced apart wooden structural members, each of said structural members extends between first and second edges, the apparatus comprising:

a rigid member having first and second ends and being sized to extend between adjacent first and second structural members;

a first socket connected to the first end of said rigid member, said first socket being sized to receive a first edge of said first structural member therein; and

a second socket connected to said second end of said rigid member, said second socket being sized to receive a first edge of said second structural member corresponding to said first edge of said first structural member therein.

2. The apparatus of claim 1 wherein said first and second sockets comprise c-shaped channels.

3. The apparatus of claim 2 wherein said c-shaped channels extend perpendicularly to a longitudinal axis of said rigid member.

4. The apparatus of claim 3 wherein said c-shaped channel is formed of first and second opposed flanges and a web portion therebetween.

5. The apparatus of claim 4 wherein at least one of said first and second opposed flanges is selectably deformable so as to open said c-shaped channel.

6. The apparatus of claim 4 wherein said c-shaped channels include at least one fastener bore, sized to pass a fastener therethrough so as to secure said c-shaped channel to said structural member.

7. The apparatus of claim 4 wherein said first flange includes a perpendicular connecting tab extending from an edge thereof away from said c-shaped channels wherein said rigid member extends from said second flange.

8. The apparatus of claim 1 wherein said first and second sockets are rigidly affixed to said rigid member.

9. The apparatus of claim 1 wherein said first and second sockets are integrally formed with said rigid member.

10. The apparatus of claim 1 wherein said rigid member and said first and second caps are formed of metal.

11. The apparatus of claim 1 wherein said rigid member comprises an elongate beam.

12. The apparatus of claim 11 wherein said beam is selected from the group consisting of a tube, a box section, an I-beam, a c-shaped channel, an L-shaped channel and a triangular cross section beam.

13. A kit for reinforcing adjacent parallel spaced apart wooden structural members comprising a first apparatus of claim 1 for engaging top edges of adjacent first and second structural members and a second apparatus of claim 1 for adjacent bottom edges of said first and second adjacent structural members.

14. The kit of claim 13 further comprising a linking member extending between said first and second rigid members.

15. The kit of claim 14 wherein said linking member is substantially rigid.

16. An apparatus for reinforcing adjacent parallel spaced apart wooden structural members comprising:

a first rigid member having first and second ends and being sized to extend between adjacent first and second structural members;

a first socket connected to said first end of said first rigid member, said first socket being sized to receive a first edge of said first structural member therein;

a second socket connected to said second end of said first rigid member, said second socket being sized to receive a first edge of said second structural member corresponding to said first edge of said first structural member therein;

a second rigid member having first and second ends and being sized to extend between said first and second structural members;

a first socket connected to said first end of said second rigid member, said first socket being sized to receive a second edge of said first structural member therein; and

a second socket connected to said second end of said second rigid member, said second socket being sized to receive a second edge of said second structural member corresponding to said second edge of said first structural member therein; and

a linking member extending between said first and second rigid members.

17. The apparatus of claim 16 wherein said linking member is substantially rigid.