Bridging clip for truss joists

#This invention relates to truss joists of the type which are a composite of wooden top and bottom chords, usually 2 .times. 4's, held together by pinned metal diagonal struts assembled in a zig-zag configuration as disclosed in the Troutner, U.S. Pat. No. 3,137,899 for a Composite Truss.

#Composite truss joists of this type are utilized in the construction of roofs and ceilings spanning large distances between supporting walls and are considered to be a conventional method for construction of this type. When a plurality of lateral truss joists are placed in parallel alignment along two bearing walls, longitudinal bridging members are required between the truss joists to secure the lower chord members of said truss joists in vertical plumb alignment and for hanging ceilings panels or other loads therefrom. Various methods for installing and securing the longitudinal bridging members have been devised. One example of art of attaching bridging members to truss joists is the Troutner, U.S. Pat. No. 3,229,440, Bridging Clip for Trussjoist. This Troutner patent discloses a bridging clip comprised of a tubular metal shank with the respective ends flattened perpendicular to each other. One end has a hole for the cross pin which permits its assembly with the diagonal web members. The opposite end is nailed to the bridging member. Since this clip is preassembled with the cross web members in the main truss joist, a wider slot must be cut in the lower chord member, thus weakening the structure. No tolerance for misalignment of the longitudinal bridging members is provided. Securing the bridging member to the clip preassembled within truss joist is difficult since no means for supporting the bridging member during the attachment operation is provided. Another disadvantage is the minimal space within the truss joist construction for tool manipulation, since the longitudinal bridging members must be installed after the lateral truss joists are fixed to the bearing walls.

#In the prior art, the bridging clip attaches to only one side of the bridge thereby applying an eccentric load on the bridge tending to make the bridge unstable. This must be compensated for by special braces if a stable, maximum strength structure is to result.

#These and other advantages of the present invention are best understood through a reference to the drawings, in which:

#FIG. 1 is a fragmentary perspective view of a truss joist, partially broken away for clarity of illustration, showing the bridging clip attached to a longitudinal bridging member;

#FIG. 2 is a top elevation view with the ends of the bridging clip partially broken away;

#Referring initially to FIG. 1, a bridging clip 10 is shown attached to a longitudinal bridging member 11, which may be either a wooden 2 .times. 4 or a 2 .times. 6 as illustrated. The bridging member 11 is inserted between the metal struts 13 of the composite truss joist 15. The longitudinal bridging member 11 is raised by means of a slotted shim block 17 to clear the interference of the Vee formed by the adjoining metal web struts 13 which are anchored by pins 14 between the upper and lower chords 19 and 21 respectively of the truss joist 15. The shim block 17 is slotted at 18 to permit it to straddle the connected ends of web struts 13 in the routed slots 20 in the lower chord 21. The shim block 17 is of appropriate thickness to shim up the bridging member 11 to a horizontal level clearing the Vee of the adjoining struts 13. This type of simple shimming allows the longitudinal alignment of the bridging members 11 as they pass through the web struts 13 of a series of truss joists 15 in a roof construction. When properly positioned, the shim block 17 is secured to the lower chord 21 of truss joist 15 by nails 23. The method of attaching the bridging clip 10 to the truss joist 15 and bridging member 11 will be described heretofor.

#Referring now to FIGS. 2, 3 and 4, a bridging clip 10 is shown in detail. A bridging clip blank 25 prior to forming comprising a flat strap of 16 or 19 gauge metal, 28 inches in length and 11/2 inches in width is shown in FIG. 4. A plurality of nail holes 27 are drilled or punched in the ends 29 and 31 of the blank 25. Fold lines 35, 37 and 39 are shown as dotted lines on the blank 25. When the metal blank 25 is bent along fold lines 35, 37 and 39, it will assume the configuration as shown in FIGS. 2 and 3 to form the clip 20. Short spurs 41 and 43 are punched out inwardly from that portion of the blank 25 as bordered by fold lines 35 and 37. The spurs 41 and 43 clinch the shim block 17 in the assembly of the clip 10 to the bridging member 11. The ends 29 and 31 of the blank 25 when bent into its functional configuration as shown in FIG. 1, 2 and 3 straddle the bridging member 11 on opposite sides at a 60.degree. included angle as best shown in FIGS. 1 and 2. The central channel portion 45 of the formed clip 10 as best shown in FIG. 3 straddles the lower chord 21 of the truss joist 15 thereby securing the longitudinal bridging member 11 tightly against the lateral chord 21 through the shim 17. Short stud nails 47 are used to secure the ends 29 and 31 of the clip 10 to the side surfaces 49 and 51 of the bridging member 11. The combined angles of the fold lines 37 and 39 result in the offset parallel positioning of the inner surfaces 53 and 55 of the ends 29 and 31 of the blank 25 after it has been folded. The distance D between the parallel surfaces 53, 55 is equal to the thickness of the bridging member 11, thereby facilitating the attachment of the ends 29, 31 of the clip 10 to the opposite sides 49 and 51 respectively. The innermost set of nail holes 27 of the clip 10 are utilized when the bridging member is a 2 .times. 4. The outer set of holes 27a are used in conjunction with a 2 .times. 6 bridging member. The larger holes 33 are utilized when the clip is attached with bolts.

#Referring to FIG. 1, it will be apparent that the surfaces 53 and 55 will be symmetrically disposed on opposite sides of the bridge and when secured thereto will eliminate any eccentricity which would otherwise be present and which is inherent in the bridging clips of the prior art. This provides greater stability and structural strength to the inner connection between the truss joist and the bridge and to the overall structure.