1. Field of Invention
The present invention relates generally to structural reinforcement and in particular to an apparatus and system for modularly supporting a plurality of joists.
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 loose 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 edges of 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 lead 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.
According to a first embodiment of the present invention there is disclosed an apparatus for supporting brace members between a plurality of adjacent parallel spaced apart joists wherein each of the joists extends between top and bottom edges. The apparatus comprises a joist engaging member adapted to engage the joist proximate to a top or bottom edge thereof and a brace supporting platform angularly extending from each side of the cup in a direction towards the other of the top or bottom edge of the joist.
The joist engaging member may comprise a cup adapted to receive one of the top or bottom edge of the joist therein. The cup may comprise a base plate and at least one joist engaging side plate extending from the base plate, wherein the base plate and the at least one side plates are positioned to receive one of the top or bottom edge of the joist therein. The side plates may include fastener bores extending therethrough. The base plate includes fastener bores extending therethrough. The base plate may extend substantially a length corresponding substantially to the length of the joist.
The brace supporting platform may comprise a substantially planar member extending from the cup. The brace supporting platform may include fastener bores extending therethrough. The brace supporting platform may have a width between first and second side edges corresponding substantially to a width of the brace member.
The brace supporting platform may further include side walls extending from the first and second side edges. The side walls may include fastener bores extending therethrough. The base cup and the brace supporting platform may be formed of a unitary sheet of material.
The apparatus may further comprise at least one hanger member extending from the joist engaging cup, the hanger member having fastener bore therethrough for passing fasteners so as to suspend the apparatus from a beam.
According to a further embodiment of the present invention there is disclosed a system for supporting a plurality of adjacent parallel spaced apart joists, each of the joists extending between top and bottom edges. The system comprises a plurality of brackets comprising a joist engaging cup adapted to receive one of the top or bottom edge of the joist therein and a brace supporting platform angularly extending from each side of the cup in a direction towards the other of the top or bottom edge of the joist. The system further comprises a plurality of brace members sized to be received on the brace supporting platforms and extend diagonally between a top and bottom edges of adjacent joists.
The cup may comprises a base plate and at least one joist engaging side plate extending from the base plate, wherein the base plate and the at least side plate are positioned to receive one of the top or bottom edge of the joist therein.
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.
In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view,
Referring to
As illustrated in
With reference to
The side plates 34 are spaced apart by a distance to correspond to the top or bottom edge 16 or 18 of the joist 10. 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 side plates 34 will be spaced apart by a similar distance. 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 side plates 34 and 56 may be spaced apart by a distance slightly larger than the width of the joist so as to facilitate installation. In particular, the side plates 34 may be spaced apart by a distance of up to 3.2 mm (⅛ of an inch) larger than the joist for which they are designed.
The brace supporting platforms 40 comprise substantially planar angled plates 42 extending from the base at an angle 48 as illustrated in
The angled plate 42 includes side plates 44 extending therefrom in the same direction from the base plate as the angled plate 42 as illustrated. The side plates 44 are substantially parallel to each other and are spaced apart by a distance corresponding to the width of the brace member 60. As illustrated, each of the angled plate 42 and the side plates 44 may include fastener apertures 46 extending therethrough which may comprise slots, circular bores or a plurality of bores as set out above. In such a manner, it will be observed that the brace supporting platform 40 is sized and shaped to receive and retain a brace member 60 therein. By way of non-limiting example, the side plates 44 may be substantially rectangular as illustrated in
The braces members 60 may be formed of any suitable elongate rigid material, such as, by way of non-limiting example, wood, metal, plastic or composite materials. In particular, it has been found useful to form the brace members 60 of dimension lumber such as, by way of non-limiting example, 2×2, 2×3s or the like. In such a manner, the brace members 60 may be cut to the desired length to extend between the top and bottom edges 16 and 18 of adjacent joists 10 as will be more fully described below. As illustrated, each brace member 60 may be separate although connected to the brace brackets 22 in matching crossed pairs. Alternatively, the pairs of brace members 60 may be secured to each other in a cross before installation.
Turning now to
The brace brackets 22 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 70 as illustrated in
Although the above system is described as having a single pair of brace support platforms 40 extending from each brace bracket 22, each brace bracket 22 may also include more than one set of brace support platforms as illustrated in
Turning now to
With reference to
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.