Abstract:
A connector for connecting wall studs of two adjacent floors in a light frame building structure, the connector having a first attachment tab, a seat member, a diagonally slanted support leg, and a second attachment tab, all substantially planar. The connector is intended to be paired and the paired connectors joined by an elongated tie member that pierces the sill plates of the intervening floor structure.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the construction industry and, in particular, concerns a method of interconnecting building members with paired connectors and tie rods. 
     2. Description of the Related Art 
     In typical residential and light industrial and commercial building frame wall construction, load bearing frame walls comprise a series of studs and posts that are anchored to the foundation and covered with sheathing material installed over both sides of the frame. Typically, the frame is constructed from a number of vertically extending studs that are positioned between and connected to horizontally extending top and bottom plates. The bottom plate and the vertical studs are typically anchored to the foundation by some means. The sheathing material, which can be plywood, gypsum wallboard, siding, plaster, or the like, is then attached over the studs. 
     Natural forces commonly impose vertical and horizontal forces on the structural elements of the buildings. These forces can be the result of earth movements in an earthquake and from high-velocity winds, as in a hurricane or tornado. If these forces exceed the structural capacity of the building, they can cause structural failures leading to anything from minor damage to catastrophic destruction of the building, attendant economic loss, and injuries or fatalities. 
     The typical method of interconnecting the stories of a building is to use lengths of coil strap to tie the studs of an upper to story to the studs of the story below. The disadvantages of coil strap are manifold. Coil strap cannot be installed within a wall because of the intervening sill plates. Coil strap cannot accommodate any offset in the upper and lower studs. Wood shrinkage after strap installation across horizontal wood members can cause the strap to buckle outward. Coil strap is a general-purpose utility strap that is not tailored to the specific connection. Vertically-paired holdowns can eliminate some of the disadvantages of the coil strap, but holdowns are typically engineered for higher load values that are necessary in a floor-to-floor connection and therefore waste material and increase costs. 
     SUMMARY OF THE INVENTION 
     The present invention provides a single-piece connector that uses less material, and is therefore more economical to produce, than connectors in the prior art. In particular the diagonally-slanted support leg, preferably reinforced with shallow walls on either side, eliminates the need for an additional member to support or reinforce the seat member. 
     The present invention provides a connector that can be used, and a connection that can be made, inside the walls of the structure, thereby eliminating the exposure of coil strap, as in the prior art, which must be attached to the outer faces of the wall studs. 
     The present invention provides a connector with obround openings that permit limited adjustability and ease installation in narrow wall cavities. 
     The present invention provides a connection that is easy to install because it uses standard all thread rod, which is easily procured and can be easily run through a hole or holes drilled in the sill plates of the floor structure between the connected wall studs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the connector of the present invention. 
         FIG. 2  is a perspective view of the connection of the present invention. 
         FIG. 3  is a front elevation view of the connector of the present invention. 
         FIG. 4  is a side elevation view of the connector of the present invention. 
         FIG. 5  is a top plan view of the connector of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The connector  1  of the present invention is preferably formed out of galvanized sheet steel using automated machinery. The connector  1  is preferably formed by cutting, punching and bending the sheet steel. However, the connector  1  can be formed by any appropriate method and material, for instance by casting metals such as aluminum and molding plastics. 
     At its most basic, the connector  1  of the present invention comprises a first substantially planar attachment tab  2 , a first substantially planar seat member  3 , a first substantially planar support leg  6 , and a second substantially planar attachment tab  9 . 
     Preferably, the first attachment tab  2  has an attachment face  20  and an opposite outer face  21 . Preferably, the first attachment tab  2  is elongated, with two relatively long and parallel side edges  44  and a relatively short end edge  45  that connects the two side edges  44 . The end edge  45  preferably has two diagonal end portions  46  that cut off what would otherwise be sharp corners on the first attachment tab  2 . 
     The first seat member  3  preferably has an inner face  22  and an opposite outer face  23 . The first seat member  3  has a first tie member opening  4 , which is preferably obround to allow a degree of adjustability. The first seat member is integrally connected to the first attachment tab  2  at a first bend line  5 , which is preferably straight. 
     Preferably, the first support leg  6  has an inner face  24  and an opposite outer face  25 . The first support leg  6  has a second tie member opening  7 . The first support leg  6  is integrally attached to the first seat member  3  at a second bend line  8 , which is preferably straight. The first bend line  5  and the second bend line  8  are substantially parallel to each other and are separated from each other by the first seat member  3 . 
     The second substantially planar attachment tab  9  preferably has an attachment face  26  and an opposite outer face  27 . The second attachment tab  9  is integrally attached to the first support leg  6  at a third bend line  10 , which is preferably straight. The second bend line  8  and said third bend line  10  are substantially parallel to each other and separated from each other by said first support leg  6 . 
     Preferably, the first attachment tab  2  and the first seat member  3  are substantially orthogonal. The inner face  22  of the first seat member  3  and said inner face  24  of the first support leg  6  preferably define a first angle  28  that is acute. Preferably, the outer face  25  of the first support leg  6  and the outer face  27  of said second attachment tab  9  define a second angle  29  that is obtuse. 
     The first seat member  3  preferably has a first edge  30  and a second edge  31 . Preferably, the first edge  30  of the first seat member  3  is bent toward the outer face  23  of the first seat member  3  to form a first reinforcing side wall  32 . The second edge  31  of the first seat member  3  is preferably bent toward the outer face  23  of the first seat member  3  to form a second reinforcing side wall  33 . 
     Preferably, the first seat member  3  has a central portion  43  between the first reinforcing side wall  32  and the second reinforcing side wall  33  of the first seat member ( 3 ). The first reinforcing side wall  32  and the second reinforcing side wall  33  of the first seat member  3  preferably converge between the first bend line  5  and the second bend line  8  so that the central portion  43  of the first seat member  3  narrows between the first bend line  5  and the second bend line  8 . Preferably, the first reinforcing side wall  32  is bent up along a first bend  47  and the second reinforcing side wall  33  is bent up along a second bend  48 . The first bend  47  and the second bend  48  preferably form two shallow inward-facing arcs in the first seat member  3 . 
     The first support leg  6  preferably has a first edge  34  and a second edge  35 . Preferably, the first edge  34  of the first support leg  6  is bent toward the outer face  25  of said first support leg  6  to form a first reinforcing side wall  36 . The second edge  35  of the first support leg  6  is preferably bent toward the outer face  25  of the first support leg  6  to form a second reinforcing side wall  37 . 
     Preferably, the first support leg  6  has a central portion  41  between the first reinforcing side wall  36  and the second reinforcing side wall  37  of said first support leg  6 . The first reinforcing side wall  36  and the second reinforcing side wall  37  of the first support leg  6  preferably converge between the second bend line  8  and the third bend line  10  so that the central portion  41  of the first support leg  6  narrows between the second bend line  8  and the third bend line  10 . Preferably, the first reinforcing side wall  36  is bent up along a first bend  49  and the second reinforcing side wall  37  is bent up along a second bend  50 . The first bend  49  and the second bend  50  preferably form two shallow inward-facing arcs in the first support leg  6 . 
     Preferably, the first bend line  5  has a first reinforcing gusset  38  that bridges the first bend line  5  from the outer face  21  of the first attachment tab  2  to the outer face  23  of the first seat member  3 . 
     The first tie member opening  4  preferably has a reinforcing rim  39  that is bent toward the outer face  23  of the first seat member  3 . Preferably, the first tie member opening  4  is preferably obround to provide a degree of lateral adjustability. 
     The second tie member opening  7  is preferably obround. Because of the angle of the first support leg  6 , the second tie member opening must be elongated. 
     Preferably, the first attachment tab  2  has a plurality of fastener openings  40 , and the second attachment tab  9  also has a plurality of fastener openings  40 . Most preferably, the first attachment tab  2  has twelve fastener openings and the second attachment tab  9  has three fastener openings  40 . The fastener openings  40  in the first attachment tab  2  and said second attachment tab  9  preferably are obround, providing a degree of lateral adjustability. 
     The connector  1  of the present invention is preferably formed first by cutting the connector  1  from sheet metal, preferably 12 gauge galvanized sheet steel. Preferably, the first seat member  3  is bent up from the first attachment tab  2  at the first bend line  5 . The first support leg  6  is preferably bent down from the first seat member  3  at the second bend line  8 . Preferably, the second attachment tab  9  is bent up from the first support leg  6  at the third bend line  10 . 
     At its most basic, the connection  11  of the present invention comprises a first structural member  12 , a second structural member  15 , a third structural member  18  between the first structural member  12  and the second structural member  15 , a first connector  1  attached to the first structural member  12 , a second connector  1  attached to the second structural member  15 , and a first tie member  19  interconnecting the first connector  1  and the second connector  1 . 
     Preferably, the first structural member  12  has a first side face  13  and a first end  14 . The second structural member  15  preferably has a first side face  16  and a first end  17 . Preferably, the third structural member  18  is sandwiched between the first end  14  of the first structural member  12  and the first end  17  of the second structural member  15 . 
     The first connector  1  is preferably attached to the first side face  13  of the first structural member  12 . Preferably, the second connector  1  is attached to the first side face  16  of the second structural member  15 . 
     Preferably, the first tie member  19  is restrained against the first seat member  3  of the first connector  1  and restrained against the first seat member  3  of the second connector  1 . Preferably, the first tie member  19  is all thread rod (ATR), preferably ⅜″ (0.9525 centimeter) in diameter. The first tie member  19  is preferably 4 to 5 feet (1.2192 to 1.524 meters) long and grade A307 or better. Preferably, the first tie member  19  is restrained with matching nuts  51 , preferably augmented with cut washers. The first tie member  19  preferably passes through the first tie member opening  4  and the second tie member opening  7  in the first connector ( 1 ), and the first tie member  19  passes through the first tie member opening  4  and the second tie member opening  7  in the second connector  1 . 
     Preferably, the first structural member  12  and the second structural member  15  are vertically oriented, the third structural member  18  is horizontally oriented, and the first tie member  19  is vertically oriented. In the preferred embodiment, the connection  11  of the present invention is a vertical floor-to-floor connection  11 . However, the connector  1  of the present invention could be used in a horizontal purlin-to-purlin connection  11  or the like. The connector  1  of the present invention could also be used singly, rather than paired, for example as a holdown. 
     The first structural member  12  is preferably an upper-storey wall stud  12 . The second structural member  15  is preferably a lower-storey wall stud  15 . The third structural member  18  is preferably an intervening floor  18 . 
     Preferably, the floor  18  comprises a horizontal bottom plate  20 , a floor diaphragm  21  and a floor beam  22 . The bottom plate  20  supports the first structural member  12 , the first end  14  of the first structural member  12  resting on the bottom plate  20 . The floor diaphragm  21  supports the bottom plate  20 . The floor beam  22  supports the floor diaphragm and preferably rests on a top plate  23 . The top plate  23  rests on the first end  17  of said second structural member  15  and the top plate  23  is supported by the second structural member  15 . In this embodiment, the first end  14  of the first structural member  12  is the lower end  14  of the first structural member  12  and the first end  17  of the second structural member  14  is the upper end  17  of the second structural member  14 . 
     The top plate  23  is preferably a double top plate  23 . Preferably, the first structural member  12 , the second structural member  15 , the bottom plate  20 , and the top plate  23  are all formed from nominal 2×4″ lumber. The connector  1  of the present invention is preferably used on at least a single 2× stud. The lumber is preferably Douglas Fir, Larch or Southern Pine. Alternatively, Spuce, Pine, Fir or Hem Fir may be used. The allowable tension load (the maximum load that the connection  11  is designed to provide) for the connection  11  of the present invention 1830 pounds (830.074 kilograms) with Douglas Fir, Larch or Southern Pine and 1570 pounds (712.140 kilograms) with Spuce, Pine, Fir or Hem Fir. Load values are based on a minimum lumber thickness of 1½″ (3.81 centimeters). 
     Preferably, a first plurality of fasteners  24  attaches the first attachment tab  2  of the first connector  1  to the first side face  13  of the first structural member  12 . A second plurality of fasteners  24  preferably attaches the second attachment tab  9  of the first connector  1  to the first side face  13  of the first structural member  12 . Preferably, a third plurality of fasteners  24  attaches the first attachment tab  2  of the second connector  1  to the first side face  16  of the second structural member  15 . A fourth plurality of fasteners  24  preferably attaches the second attachment tab  9  of the second connector  1  to the first side face  16  of the second structural member  15 . Although separate mechanical fasteners  24  are preferred, integral mechanical fasteners  24  such as nail prongs could be employed, for instance if the connectors  1  were factory preinstalled on the structural members. Similarly, fasteners  24  could be eliminated if the connectors  1  were attached with a sufficiently strong adhesive or if they were welded or otherwise bonded to structural members made of materials other than wood, such as metals or plastics, particularly if the connectors  2  were likewise. Most preferably, the fasteners  24  are nails  24 , specifically fifteen 10 d×1½″ (0.148 inch [0.375 92 centimeter] diameter by 1.5 inches [3.81 centimeters] long) nails. Preferably, the nails  24  are driven straight into the first structural member  12  and the second structural member  15 , but the connection  11  of the present invention preferably allows for the nails  24  to be driven in at up to a 30 degree angle with no reduction in load capacity. 
     The first connector  1  is preferably attached to the first side face  13  of the first structural member  12  proximate the first end  14  of the first structural member  12 , preferably no more than 18″ (45.72 centimeters) from the third structural member  18 . Preferably, the second connector  1  is attached to the first side face  16  of the second structural member  15  proximate the first end  17  of the second structural member  15 , preferably no more than 18″ (45.72 centimeters) from the third structural member  18 . 
     The preferred method of making the connection  11  of the present invention consists first of selecting the first structural member  12 , the second structural member ( 15 ), and the third structural member ( 18 ). The preferred method then consists of placing the third structural member  18  between the first end  14  of the first structural member  12  and the first end  17  of the second structural member ( 15 ). As most preferably practiced, this is done as part of erecting a multistory structure, with a plurality of wall studs in each story wall and a floor between each pair of stories. The preferred method then consists of attaching the first connector  1  to the first side face  13  of the first structural member  12 , and attaching the second connector  1  to the first side face  16  of the second structural member  15 . 
     Then a hole  42  is preferably drilled in, and though, the third structural member  18 . Preferably, the hole  42  is ½″ to ¾″ (1.27 to 1.905 centimeters) in diameter and approximately 1½″ (3.81 centimeters) away from the first side face  13  of the first structural member  12  and the first side face  16  of the second structural member  15 . The preferred method then consists of passing the first tie member  19  through the hole  42  in the third structural member  18 , passing the first tie member  19  through the first tie member opening  4 ) and the second tie member opening  7  in the first connector  1 , and passing the first tie member  19  through the first tie member opening  4  and the second tie member opening  7  in the second connector  1 . 
     Finally, the method of making the connection  11  of the present invention consists of restraining the first tie member  19  against the first seat member  3  of the first connector  1  and against the first seat member  3  of the second connector  1 . The first tie member  19 , which is preferably ⅜″ (0.9525 centimeter) all thread rod (ATR), is preferably restrained with matching nuts  51  and standard cut washers. Preferably, the connectors  1  are offset no more than 3″ (7.62 centimeters) from each other.