Abstract:
An improved connection between supporting and supported structural members, particularly between the sheathing and framing members of curtain walls.

Description:
BACKGROUND OF THE INVENTION 
     The present invention belongs to a class of stud mounting clips that are useful in the construction of buildings, particularly light commercial buildings. 
     Many buildings are constructed with steel stud wall systems in order to achieve reduced environmental concerns, fire safety and reduced susceptibility to warpage, infestation, rust and rot. For a variety of reasons, it is often advantageous to construct these walls systems with connectors that permit a degree of relative movement between the framing members. Buildings often settle on their foundations once constructed, which can cause exterior walls to go out of plumb, in turn causing damage to the surrounding foundation and to interior structures such as floors. Exterior walls and frames, particularly of light commercial buildings, are often made from materials that have different coefficients of expansion than that of the structure&#39;s exterior sheathing. With exposure to extremes of temperature, gaps can be produced in the exterior sheathing panels if they expand or contract more than the framing, allowing cold air and moisture to intrude. Exterior walls of buildings are also subject to deflection from wind or seismic forces, and a degree of freedom of movement can reduce stress and prevent fracture of connected parts. And curtain walls (e.g., partition walls) are not designed to support vertical loads and must therefore by isolated from deflection of the primary load-bearing support structure of the building due to changes in live or dead loads carried by that structure. 
     A variety of slide, or slip, clips that permit relative movement between structural members have been made, but none have successfully optimized the use of material in the clips and the loads achieved by the clips. The slip clip connector of the present invention has been designed to achieve the maximum possible loads from the minimum amount of material, thereby realizing substantial savings, in cost as well as material, over the prior art. 
     The present invention also encompasses clips that include the same improvements to maximize load and minimize material use, but do not permit slip between members. 
     BRIEF SUMMARY OF THE INVENTION 
     A first aspect of the invention relates to an angled connector with rolled edge flanges that has a unique fastener geometry in one plate and reinforcing embossments in the other to more optimally distribute loads among fasteners and thereby achieve higher tension loads while using the smallest possible number of fasteners and the lightest possible material for the connector. 
     A second aspect of the invention relates to an angled connector with rolled edge flanges and slotted fastener openings that also have rolled edges, reinforcing the slotted fastener openings, stiffening the connector plate, and reducing unnecessary friction between the connector plate and the structural member to which it is attached. 
     The connectors of the present invention can be made from lighter-gauge materials than the prior art connectors of the same type, but the connectors of the present invention equal or exceed the same prior art connectors in performance. The preferred material for the connectors of the present invention is 16-gauge Grade 40 hot-dip galvanized G90 sheet steel. The ability to go down one or even two gauges results in substantial savings not only in the cost of sheet steel, but also in storage and transportation costs, both of which are reduced when the connectors are lighter and thinner than the prior art. The specific improvements of the present invention were only possible due to careful consideration and calculation using finite element analysis to ensure that loads are transferred inward from the roll-stiffened edges and distributed among the fasteners to maximize the strength of the connection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a wall stud-to-beam connection formed according to the present invention. 
         FIG. 1B  is a perspective view of a connector formed according to the present invention. 
         FIG. 2  is a cross-sectional cutaway view taken along view line  2 - 2  of the connection shown in  FIG. 1A . 
         FIG. 3A  is a front elevation view of a connector formed according to the present invention. 
         FIG. 3B  is a side elevation view of a connector formed according to the present invention. 
         FIG. 3C  is a top plan view of a connector formed according to the present invention. 
         FIG. 4A  is a front elevation view of a connector formed according to the present invention. 
         FIG. 4B  is a side elevation view of a connector formed according to the present invention. 
         FIG. 4C  is a bottom plan view of a connector formed according to the present invention. 
         FIG. 5A  is a perspective view of a wall stud-to-top plate connection formed according to the present invention. 
         FIG. 5B  is a perspective view of a connector formed according to the present invention. 
         FIG. 6  is a cross-sectional cutaway view taken along view line  6 - 6  of the connection shown in  FIG. 5A . 
         FIG. 7A  is a front elevation view of a connector formed according to the present invention. 
         FIG. 7B  is a side elevation view of a connector formed according to the present invention. 
         FIG. 7C  is a bottom plan view of a connector formed according to the present invention. 
         FIG. 8A  is a perspective view of a connection formed according to the present invention. 
         FIG. 8B  is a perspective view of a connector formed according to the present invention. 
         FIG. 8C  is a top plan cross-sectional cutaway view taken along view line  8 C- 8 C of the connector shown in  FIG. 8B . 
         FIG. 9A  is a front elevation view of a connector formed according to the present invention. 
         FIG. 9B  is a side elevation view of a connector formed according to the present invention. 
         FIG. 9C  is a top plan view of a connector formed according to the present invention. 
         FIG. 9D  is a side elevation cross-sectional cutaway view taken along  9 D- 9 D of  FIG. 9A  of a connector formed according to the present invention. 
         FIG. 10A  is a front elevation view of a connector formed according to the present invention. 
         FIG. 10B  is a side elevation cross-sectional cutaway view of a connector formed according to the present invention. 
         FIG. 10C  is a top plan view of a connector formed according to the present invention. 
         FIG. 11A  is a perspective view of a wall stud-to-beam connection formed according to the present invention. 
         FIG. 11B  is a perspective view of a connector formed according to the present invention. 
         FIG. 12A  is a front elevation view of a connector formed according to the present invention. 
         FIG. 12B  is a bottom plan view of a connector formed according to the present invention. 
         FIG. 12C  is a side elevation view of a connector formed according to the present invention. 
         FIG. 12D  is a cross-sectional cutaway view taken along view line  12 D- 12 D of the connector shown in  FIG. 12A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is a building structural connection  1  between a first building structural member  2  and a second building structural member  3 . Preferably, the first building structural member  2  is a supporting member  2  and the second building structural member  3  is a supported structural member  3 . As shown in  FIGS. 1A and 8A , the first building structural member  2  is a horizontal beam with an attached ledger  2  and the second building structural member  3  is a vertically-oriented channel-shaped wall post  3 . As shown in  FIG. 5A , the first building structural member  2  is a horizontal beam with an attached vertically-oriented channel-shaped header  2 —the second building structural member  3  is a vertically-oriented channel-shaped wall post  3 . As shown in  FIG. 11A , the first building structural member  2  is a horizontal beam  2  and the second building structural member  3  is a vertically-oriented channel-shaped wall post  3 . 
     The connection  1  between the first building structural member  2  and the second building structural member  3  is made with a first connector  4 . The first connector  4  is preferably L-shaped, with a first plate  5  fastened to the first building structural member  2  and a second plate  6  fastened to the second building structural member  3 . Preferably, said first plate  5  and said second plate  6  are generally planar and joined at right angles to each other. In the most common embodiments, the connector  4  allows for relative vertical movement between the first and second building structural members  2  and  3 . A simple 90-degree change in orientation would allow the connector  4  to permit relative horizontal movement. The connector  4  is preferably made from 16-gauge cold formed sheet steel, bent, cut, embossed and punched on automated manufacturing machinery. Preferably, the connector  4  is used to connect cold formed steel structural members. 
     As shown in  FIG. 1B , the first plate  5  has first and second fastener openings  7  and  8  of a first plurality of fastener openings  9  that includes one or more additional fastener openings  10  in addition to said first and second fastener openings  7  and  8 . 
     The first plate  5  has a first inner edge  11 , a first outer edge  12 , a first side edge  13  and a second side edge  14 . 
     As shown in  FIG. 3C , the first fastener opening  7  is the closest of the first plurality of fastener openings  9  to the first side edge  13 . The second fastener opening  8  is the closest of the first plurality of fastener openings  9  to the second side edge  14 . The first and second fastener openings  7  and  8  are closer to the first outer edge  12  than the one or more additional fastener openings  10 . The one or more additional fastener openings  10  are closer to the first inner edge  11  than the first and second fastener openings  7  and  8 . 
     As shown in  FIG. 3A , the second plate  6  has a second plurality of fastener openings  15 , a first inner edge  16 , a first side edge  17  and a second side edge  18 . The first side edge  17  of the second plate  6  intersects the first inner edge  16  at a first corner juncture  24 . The second side edge  17  of the second plate  6  intersects the first inner edge  16  at a second corner juncture  25 . 
     The first inner edge  11  of the first plate  5  is joined to the first inner edge  16  of the second plate  6  to form an inner angular juncture  19 . Preferably the inner angular juncture  19  is 90 degrees. 
     As shown in  FIG. 1B , a first reinforcing flange  20  is attached to the first side edge  13  of the first plate  5  and to the first side edge  16  of the second plate  6 . A second reinforcing flange  21  is attached to the second side edge  14  of the first plate  5  and to the second side edge  18  of the second plate  6 . The first and second reinforcing flanges  20  and  21  are continuous, with no breaks at the juncture  19  between the first plate  5  and the second plate  6 . 
     As shown in  FIG. 3A , the connector  4  includes a first embossment  22  in the second plate  6 . The first embossment  22  is located between the second plurality of fastener openings  15  and the first inner edge  16  of the second plate  6 . The first embossment  22  reinforces the second plate  6  and is adjacent said first corner juncture  24 . 
     The connector  4  also includes a second embossment  23  in the second plate  6 . The second embossment  23  is located between the second plurality of fastener openings  15  and the first inner edge  16  of the second plate  6 . The second embossment  23  reinforces the second plate  6  and is adjacent the second corner juncture  25 . 
     The unique, staggered distribution of the first plurality of fastener openings  9  distributes load evenly among the fasteners  9 , while the first and second embossments  22  and  23  distribute loads in the second plate  6 , allowing the connector  4  of the present invention to be made from 16 gauge sheet metal while analogous connectors have to be made from 14 or even 12 gauge sheet metal, which is substantially more expensive to manufacture and transport, adding cost and waste at every stage. This distribution of fastener openings  9  is not found in any other slide, or slip, clip. 
     As shown in  FIGS. 1A-3A ,  3 C- 4 A,  4 C,  8 A- 9 A, and  9 C- 10 C, preferably the first connector  4  has one or more gusset darts  26  in the inner angular juncture  19  that reinforce the inner angular juncture  19 . 
     Preferably, a first plurality of fasteners  27  attaches the first plate  5  to the first building structural member  2 . A second plurality of fasteners  28  preferably attaches the second plate  6  to the second building structural member  3 . 
     Preferably, the fasteners  28  of the second plurality of fasteners  28  are screws  28 . The preferred fasteners  27  for attaching the connector  4  to first structural members  2  made from steel are #12 or #14 hex-head fasteners  27 , automated power-actuated gun-driven fasteners  27  or, alternatively, welds  27 . The preferred fasteners  27  for attaching the connector  4  to first structural members  2  made from concrete are concrete screws  27 . The preferred fasteners  28  for attaching the connector  4  through slots  15  are shouldered, or stepped-shank, screws  28 . 
     As shown in  FIGS. 1A-1B ,  3 A,  4 A,  5 A- 5 B,  7 A,  11 A- 11 B and  12 A, the second plurality of fastener openings  15  is preferably formed as a plurality of elongated slots  15  in the second plate  6  when movement between the structural member  2  or  3  and the connector  4  is desired. 
     Preferably, the first building structural member  2  is fastened to the first connector  4  so that the first building structural member  2  cannot move relative the first plate  5  of the first connector  4 . 
     The second building structural member  3  is preferably fastened to the first connector  4  so that the second building structural member  3  can move relative to the second plate  6  of the first connector  4 . 
     Preferably, the fasteners of the second plurality of fasteners  28  are shouldered, or stepped-shank screws  28 . Shouldered screws  28  have a head  29 , an unthreaded shank portion  30  immediately below the head  29 , a threaded shank portion  31  below the unthreaded shank portion  30 , and a tip  32 . The unthreaded shank portion  30  allows the second building structural member  3  and the fasteners  28  attached to it to move relative to the second plate  6  without interference between the second plurality of fastener  28  and the second plate  6  of the first connector  4 . 
     As shown in  FIGS. 1A-7C  and  11 A- 12 D, the elongated slots  15  preferably have rolled edges  33  that stiffen the elongated slots  15  and reinforce the second plate  6 . The rolled edges  33  also reduce friction between the second plate  6  and the second building structural member  3  by reducing the surface contact between the second plate  6  and the second building structural member  3 . 
     As shown in  FIGS. 1A-3C , in a preferred embodiment, the connector  4  of the present invention has four fastener openings  9  in the first plate  5 , which is fixedly attached to the first building structural member  2 . The two outer corners  34  of the first plate  5  are chamfered to save material and make the connector  4  easier and safer to handle. A first fastener opening  7  is near the first outer corner  34  and a second fastener opening  8  is near the second outer corner  34 . The two additional fastener openings  10  are between the first fastener opening  7  and the second fastener opening  8  and are closer to the inner angular juncture  19  between the first plate  5  and the second plate  6 . The connector  4  also has first and second embossments  22  and  23  in the second plate  6 . The embossments are trapezoidal. The first embossment  22  is near the first corner juncture  24  of the second plate  6  and the second embossment  23  is near the second corner juncture  25  of the second plate  6 . The second plate  6  has two elongated slot openings  15  that extend across the second plate  6  generally parallel to the inner angular juncture  19  between the first plate  5  and the second plate  6 . The slots  15  have rolled edges  33  that reinforce the slots  15  and stiffen the second plate  6 . The rolled edges  33  are rolled down to project slightly from the attachment side  40  of the second plate  6 , which has an open side  41  facing in the opposite direction. The attachment side  40  of the second plate  6  faces the second building structural member  3 . Similarly, the first plate  5  has an attachment side  38  and an open side  39  facing in the opposite direction. The attachment side  38  of the first plate  5  faces the first building structural member  2 . There is a single round pilot hole  35  halfway between the slots  15  and midway between the first and second side edges  17  and  18  of the second plate  6 . As with the first plate  5 , the outer corners  36  of the second plate  6  are chamfered. A first outer edge  37  of the second plate  6  runs from corner  36  to corner  36 . The first end  42  of the first reinforcing flange  20 , and the first end  43  of the second reinforcing flange  21 , both projecting from the first plate  5 , are angled to match the chamfered outer corners  34  of the first plate  5 . Similarly, the second end  44  of the first reinforcing flange  20 , and the second end  45  of the second reinforcing flange  21 , both projecting from the second plate  6 , are angled to match the chamfered outer corners  36  of the second plate  6 . 
     As shown in  FIGS. 4A-4C , in another preferred embodiment the connector  4  is basically the same as shown in  FIGS. 1A-3C , except that the second plate  6  is much longer from first inner edge  16  to first outer edge  37 . The second plate  6  therefore has a third elongated slot opening  15  and a pair of elongated embossments  46  that run parallel to, and between, the first and second side edges  17  and  18 , from the first and second trapezoidal embossments  22  and  23  almost to the nearest of the elongated slots openings  15 . The elongated embossments  46  help to stiffen the longer second plate  6 . 
     As shown in  FIGS. 5A-7C , in a third preferred embodiment the orientation of the connector  4  is different and the second plate  6  projects down instead of to the side. In this case, the connector  4  is narrower, in order to fit within a first building structural member  2  that is a channel-shaped header  2 . In this embodiment, there is only one additional fastener opening  10  between the first and second fastener openings  7  and  8  of the first plurality of fastener openings  9  in the first plate  5 . This embodiment also demonstrates the reinforcing capacity of the rolled edges  33  of the elongated slot openings  15  in the second plate  6 , since there are no first and second embossments  22  and  23  in the second plate  6 . Because the elongated slot openings  15  are oriented longitudinally, parallel to the first and second side edges  17  and  18  of the second plate, the rolled edges  33  stiffen most of the second plate  6  between the first and second reinforcing flanges  20  and  21 . 
     As shown in  FIGS. 8A-10B , in fourth and fifth preferred embodiments the connector  4  is made with a second plurality of fastener openings  15  in the second plate  6  that are conventional round and triangular fastener openings  15 , rather than elongated slot openings  15 . Conventionally, round openings  15  denote those that must be filled to achieve normal load values; triangular openings  15  denote those that can be filled to achieve a maximum load value in excess of the normal load values. These embodiments are intended for applications where a slip, or slide, connection is not required. 
     As shown in  FIGS. 11A-12D , in a sixth preferred embodiment the connector  4  is substantially wider and attaches to the top or bottom of the first building structural member  2  rather than to a side. This embodiment is used in particular where a wall post or stud  3  bypasses the supporting beam  2 . In this embodiment there is a third reinforcing flange  47  attached to the first outer edge  37  of the second plate  6 , running from the first outer chamfered corner  36  to the second outer chamfered corner  36 . Instead of a staggered first plurality of fastener openings  9 , the first plurality of fastener openings  9  is a line of fastener openings  9  running from the first side edge  13  of the first plate  5  to the second side edge  14  of the first plate  5 . The second plate  6  is stiffened by two pairs of elongated embossments  46  that are centrally located. There are three parallel elongated slot openings  15  with rolled edges  33  at each end of the second plate  6 , near the first side edge  16  and the second side edge  17  of the second plate  6 , respectively. 
     As shown in  FIGS. 1A-4C  and  8 A- 10 C, the first embossment  22  in the second plate  6  is preferably six material thicknesses from the first side edge  17  of the second second plate  6 ; the second embossment  23  in the second plate  6  is preferably six material thicknesses from the second side edge  18  of the second plate  6 . 
     Preferably, the first embossment  22  in the second plate  6  is generally trapezoidal, with a first diagonal edge  48  that generally leads toward the gusset dart  26  closest to the first side edge  17  of the second plate  6 ; preferably, the second embossment  23  in the second plate  6  is generally trapezoidal, with a first diagonal edge  48  that generally leads toward the gusset dart  26  closest to the second side edge  18  of the second plate  6 . The diagonal edges  42  and  43  funnel load toward the gusset darts  26  and the inner additional fastener openings  10  in the first plate  5 . Load is funneled inward and away from the first and second reinforcing flanges  20  and  21  in order to distribute load to the inner additional fastener openings  10  of the first plurality of fastener openings  9 . In general, load is predominantly resisted where the connector  4  is stiffest, and the first and second embossments  22  and  23 , in combination with the gusset darts  26 , stiffen the connector  4  so that load is more evenly distributed among the first plurality of fastener openings in the first plate  5 . 
     The first and second embossments  22  and  23  in the first plate  6  are preferably embossed to a depth of one material thickness, most preferably 0.057 inches. A greater embossment depth than two material thicknesses would exceed the sheet metal&#39;s ability to stretch without fracturing. 
     Most preferably, the first and second embossments  22  and  23  in the first plate  6  minor each other. Each has a first vertical edge  49  parallel to the first and second side edges  17  and  18  of the second plate  6 . In the preferred embodiments shown in  FIGS. 1A-4C , in which the first and second plates  5  and  6  are four inches wide, the first vertical edge  49  of the first embossment  22  faces, and is 0.25 inches away from, the first side edge  17  of the second plate. The first vertical edge  49  of the second embossment  23  faces, and is 0.25 inches away from, the second side edge  18  of the second plate. The first and second embossments  22  and  23  extend an additional 0.938 inches away from the first and second side edges  17  and  18 , respectively. Each of the first and second embossments  22  and  23  has a first horizontal edge  50  that is orthogonal to the first vertical edge  49  and parallel to the first inner edge  16  of the first plate  6 . The first horizontal edges  44  of the first and second embossments  22  and  23  face, and are 0.375 inches away from, the first inner edge  16  of the first plate  6 . Each of the first and second embossments  22  and  23  has a second horizontal edge  51  further away from the first inner edge  16  of the first plate  6 , parallel to the first horizontal edge  50 , and 0.5 inches away from the first horizontal edge  50 . The second horizontal edges  45  are shorter than the first horizontal edges  44 . First diagonal edges  42  join the first horizontal edges  44  to the second horizontal edges  45 ; the angle between the first diagonal edges  42  and the first horizontal edges is 35 degrees. The edges  42 - 45  of the first and second embossments  22  and  23  meet at rounded corners  52  with 0.125-inch radii. 
     Preferably, the fastener openings  9  of the first plurality of fastener openings  9  in the first plate  5  are round and match the size of the first plurality of fasteners  27 . Exact positioning of the first plurality of fasteners  27  is necessary in order to correctly calculate the loads distributed among the first plurality of fasteners  27 . Furthermore, if the fastener openings  9  of the first plurality of fastener openings  9  were oversized or slotted, the material of the first plate  5  would be more likely to tear around the fasteners  27  of the first plurality of fasteners  27 , reducing maximum achievable loads. Furthermore, the removing additional material from the first plate  5  would reduce the first plate  5  and weaken the connection  1 . 
     As shown in  FIGS. 1A-10C , in the preferred embodiments in which the first plate is four inches wide, the first fastener opening  7  of the first plurality of fastener openings  9  is preferably 0.5 inches on center from the first side edge  13  of the first plate  5 . The second fastener opening  8  of the first plurality of fastener openings  9  is preferably 0.5 inches on center from the second side edge  14  of the first plate  5 . If there is only one additional fastener opening  10  in the first plate  5 , as shown in  FIGS. 5A-7C , it is preferably spaced 1.625 inches on center from both the first side edge  13  and the second side edge  14 . If there are multiple additional fastener openings  10 , one is 1.25 inches on center from the first side edge  13  and one is 1.25 inches on center from the second side edge  14 . If there are two additional fastener openings  10 , as shown in  FIGS. 1A-4C  and  8 A- 10 C, they are 1.5 inches on center from each other. The first and second fastener openings  7  and  8  preferably are 0.625 inches on center from the first outer edge  12  of the first plate  6 . The additional fastener openings  10  preferably are 0.75 inches from the first outer edge  12  of the first plate  6 . The round fastener openings  9  of the first plurality of fastener openings are preferably 0.216 inches in diameter. The round fastener openings  15  of the second plurality of fastener openings are preferably 0.190 inches in diameter. 
     As shown in  FIGS. 1A-4C  and  8 A- 10 C, the gusset darts  26  are preferably embossed to a maximum height of 0.125 inches, each with two sides  53  defining an inner angle of 80 degrees, as shown in  FIG. 8C . Preferably, there are two gusset darts  26 , one spaced 1 inch on center from the first corner juncture  24  in the second plate  6 , and one spaced 1 inch on center from the second corner juncture  25  in the second plate  6 . 
     As shown in  FIGS. 1A-1B ,  3 C,  4 C,  8 A- 8 B,  9 C,  10 A and  10 C, the first embossment  22  preferably extends further from the first side edge  17  of the second plate  6  than the first fastener opening  7  is spaced from the first side edge  13  of the first plate  5 . The second embossment  23  extends further from the second side edge  18  of the second plate  6  than the second fastener opening  8  is spaced from the second side edge  14  of the first plate  5 . A first of the gusset darts  26  extends further from the first corner juncture  24  in the second plate  6  than the first fastener opening  7  is spaced from the first side edge  13  of the first plate  5 . And a second of the gusset darts  26  extends further from the second corner juncture  25  in the second plate  6  than the second fastener opening  8  is spaced from the second side edge  14  of the first plate  5 . 
     Preferably, as shown in  FIGS. 1A-7C  and  11 - 12 D, the fastener openings  15  of the second plurality of fastener openings  15  in the second plate  6  are slots  15  that are 0.25 inches wide and 2.375 inches long. Preferably, the rolled edges  33  of the second plurality of fastener openings  15  are 0.083 inches tall. The fastener openings  15  of the second plurality of fastener openings  15  are mutually spaced 1.25 inches on center. 
     Preferably, as shown in  FIGS. 1A-10C , the first and second reinforcing flanges  20  and  21  are 0.25 inches tall from the first and second side edges  17  and  18 , respectively, of the second plate  6 , and from the first and second side edges  13  and  14 , respectively, of the first plate  5 . 
     As shown in  FIGS. 1A-4C  and  8 A- 10 C, the connector  4  is preferably 4 inches wide from the first reinforcing flange  20  to the second reinforcing flange  21 , inclusive. As shown in  FIGS. 5A-7C , the connector  4  is preferably 3.25 inches wide from the first reinforcing flange  20  to the second reinforcing flange  21 , inclusive. As shown in  FIGS. 1A-10C , the first plate  5  measures 1.5 inches from the first inner edge  11  to the first outer edge  12 . The length of the second plate  6  varies according to the distance between, and the size of, the first and second building structural member  2  and  3 .