Abstract:
A connector assembly for accurately projecting fasteners for connecting two building members together while permitting limited relative motion between the members. The assembly includes a plate having one or more longitudinal slots. The plate is secured to or a part of one of the building members. The plate is connected to the other building member by fasteners projected through breakaway washers formed in the slots. The breakaway washers each have an opening for guiding the fastener and centering the fastener on the slot. Centering the fastener on the slot prevents inadvertent clamping of the plate and the other building member together so that limited relative motion is permitted.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a means of connecting building members together so the members can move relative to each other in response to dynamic building loads. 
     BACKGROUND 
     Movable or slidable construction member connections can be utilized in building design to prevent or limit damage due to varying or dynamic loads. Varying loads can arise from movement of equipment and personnel in the building as well as from environmental factors such as high winds and seismic activity. Flexing of construction members under varying load is expected and acceptable within code-specified limits. However, such flexing often means that some connections between members can cause damage if some relative movement between the connected members is not allowed. The building industry has recognized this problem. Movement between connected members has been accommodated by having sliding connections between the members to permit limited relative movement between the members while keeping the members otherwise securely connected together. 
     An approach commonly used is that of a slotted connection. In a typical configuration, a connector in the form of a plate or bracket is rigidly secured to or part of one of the members and slidably connected to the other member by means of one or more slots and fasteners. Typically the plate has slots, and shouldered or bushed screws, are projected through slots and into the other member. The screws are tightened to secure the members together but yet permit the members some range of relative sliding movement. The head of the fastener is prevented by the shoulder or bushing from clamping against the connector plate so that the plate can move along the length of the slot. For a more complete and detailed description of such connection devices, reference is made to U.S. Pat. Nos. 5,906,080; 6,612,087; 5,467,566; and, 7,503,150; the disclosures of these patents are expressly included herein by reference. 
     The degree to which such devices function as intended is dependent upon proper installation. For example, should a shouldered screw be inserted and tightened off center in the slot, the shoulder would overlap and clamp the plate to the member. This clamping would render the connection more or less rigid and not slidable. Avoiding this kind of improper installation requires time and installer dexterity to properly align the screw in the slot. 
     A need exists for a connection assembly that will provide for easy and accurate screw placement to prevent inadvertent clamping together of the building members being connected and to thus facilitate slidable connection between the members. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a connector for connecting two building members together such that the building members can move relative to each other. The connector includes a plate which is defined herein to mean a structure having sufficient surface area to enable the structure to connect two building members. Within the plate or structure is an elongated slot. Secured within the elongated slot is a breakaway washer that includes an opening for receiving a fastener. The fastener projects through the breakaway washer and connects to one of the building members. When a force is applied to the fastener, the force is transmitted to the breakaway washer, causing the breakaway washer to break away from its connection in the slot. This enables the breakaway washer and the fastener to move relative to the slot in the plate. This permits relative movement between the two building members. 
     Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a fragmentary perspective view of a portion of a building structure showing one embodiment of the connector assembly in a wall. 
         FIG. 2  is a fragmentary front elevation view of one embodiment of a connector assembly including a stud. 
         FIG. 3A  is a fragmentary side sectional view of one embodiment of connector assembly including a stud. 
         FIG. 3B  is a fragmentary side sectional view of one embodiment of connector assembly including a stud. 
         FIG. 4  is a bottom sectional view of one embodiment of connector assembly including a stud. 
         FIG. 5A  is a fragmentary side sectional view of one embodiment of the connector assembly including a stud web. 
         FIG. 5B  is a fragmentary front sectional view of one embodiment of the connector assembly including a stud web. 
         FIG. 6  is an exploded perspective view of one embodiment the connector assembly. 
         FIG. 7  is a fragmentary perspective view of a portion of a building structure showing one embodiment of the connector assembly in a wall. 
         FIG. 8  is a fragmentary perspective view of a header showing one embodiment of the connector assembly. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     With reference to the drawings, the connector assembly of the present invention is indicated generally by the numeral  10 . Table 1 contains a listing of the 
                                   TABLE 1               Reference Numerals and       Illustrative Parts                                     1   Overhead building structure            2   Track            2A   Track web            2B   Track flange            3   Stud            3A   Stud web            3B   Stud flange           10   Connector assembly           12   Plate           12A   Clip web           12B   Clip flange           12C   Clip bend line           14   Elongated slot           14A   Slot edge           16   Fastener           16A   Fastener head           16B   Flange of fastener head           16C   Fastener shoulder           16D   Fastener shoulder face           16E   Fastener shaft           20   Breakaway washer           22   Centering opening           24   Breakaway tab                        
illustrative part names and their respective reference numerals as used throughout the description. Connector assembly  10  is provided to slidably connect together two building members. Included in connector assembly  10  is a plate with one or more elongated slots  14  formed in the plate. See  FIG. 6 . Each slot  14  formed in the plate has an integral breakaway washer  20  formed therein. Breakaway washer  20  is configured or designed to break away from the slot  14  and once the breakaway washer breaks away from slot  14 , it can move back and forth within the slot.
 
     Connector assembly  10  further includes a fastener  16  to secure the plate to one of the two building members, cooperating with one of the slots  14  and the breakaway washer  20  formed in the slot to provide a slidable connection between the two building members.  FIGS. 1 and 7  show wall structures that include connector assembly  10  connecting a series of studs  3  to a header track  2  that is secured to an overlying floor or roof structure  1 . 
     In the embodiment of  FIGS. 1-6 , connector  10  includes a plate  12  bent in the form of a clip having a clip web  12 A and a clip flange  12 B disposed at approximately a right angle to the clip web, the bend being about clip bend line  12 C. Breakaway washer  20  disposed within slot  14  is connected to an edge  14 A by breakaway tabs or connectors  24 . Breakaway washer  20  includes a centering opening  22 , and the washer is positioned in slot  14  such that the centering opening is generally centered transversely in the slot as shown in  FIG. 6 . Washer  20  is generally annular, but may be of any peripheral shape such that the width of the washer measured transversely across slot  14  is less than the transverse width of elongated slot  14 . Slots  14  with breakaway washers  20 , centering openings  22 , and breakaway tabs  24  may typically be formed by a conventional stamping operation. Stamping operations producing variously shaped cutouts are well known to those of ordinary skill in the manufacture of metal fabrication components. 
     Each fastener  16  includes a head  16 A having a flange  16 B, a shoulder  16 C having a face  16 D, and a shaft  16 E projecting away from the face as shown in  FIG. 6 . Flange  16 B defines a periphery enclosing an area that is advantageously wider than the transverse width of elongated slot  14 . Shoulder  16 C has a height D (see  FIGS. 5A and 5B ) that provides for a clearance between plate  12 , and head flange  16 B, when connector assembly  10  is assembled as illustrated in  FIGS. 4 ,  5 A, and  5 B. Face  16 D defines a periphery enclosing an area having a width or diameter S (see  FIG. 4 ) that is advantageously narrower than the transverse width of elongated slot  14 . Shaft  16 E is generally of a self-drilling, self-tapping design common to conventional sheet metal screws. Fasteners  16  may be formed by well known methods of sheet metal screw fabrication. 
     When shaft  16 E of fastener  16  is guided into centering opening  22  and projected therethrough, face  16 D contacts breakaway washer  20  without contacting clip web  12 A outside slot  14 . With fastener  16  so disposed, head flange  16 B extends over clip web  12 A outside the slot and is generally spaced away from the web as shown in  FIGS. 3B ,  4 ,  5 A, and  5 B. 
     Connector assembly  10  may accordingly be configured to connect one of the studs  3  to header or track  2  by the utilization of one of the clips  12  and two of fasteners  16  using the following steps. Each clip flange  12 B is secured conventionally to a header web  2 A. See  FIG. 1 . The upper end portion of stud  3  is positioned such that stud web  3 A abuts clip web  12 A. The upper end of stud  3  is spaced downward from clip flange  12 B by a distance H to provide clearance for movement between the stud and header web  2 A as shown in  FIGS. 2 ,  3 A, and  3 B. One of the fasteners  16  is projected through each of the vertical elongated slots  14  in clip web  12 A and into stud web  3 A. Upon tightening, shoulder face  16 D of each fastener  16  will abut one of the corresponding breakaway washers  20  such that the breakaway washer is clamped between the face and stud web  3 A as shown in  FIGS. 3A ,  3 B,  5 A, and  5 B. Flange  16 B will overlie but be spaced away from clip web  12 A by clearance D due to fastener shoulder  16 C, as shown for example in  FIG. 4 . After washer  20  breaks away from edges  14 A of elongated slot  14 , header  2  and stud  3  are generally free to move relatively up and down along the length of the slot as indicated by the doubled-arrowed movement lines shown  FIG. 5A . However, stud  3  and header  2  are constrained by slot edges  14 A against significant horizontal movement transverse to the slot. Likewise significant horizontal movement normal to clip web  12 A is constrained by flange  16 B. 
     In the embodiment of  FIGS. 7 and 8 , stud  3  is connected directly to header  2  without the use of a clip. Header flanges  2 B form plates, each plate or flange having a series of vertical elongated slots  14  disposed therein. Each slot  14  has a breakaway washer  20  with opening  22 , configured as described above albeit that the slots are formed in header flanges  2 B rather than in clips or connectors. To connect one of the studs  3  to header  2 , the upper end portion of the stud is positioned between header flanges  2 B with the upper end of the stud spaced downwardly from header web  2 A. One of the fasteners  16  is aligned with centering opening  22  of one of the breakaway washers  20 . Fastener shaft  16 E is guided through centering opening  22  and projected into stud flange  3 B. Fastener  16  is generally tightened against breakaway washer  20  such that fastener flange  16 B remains spaced apart from header flange  2 B in the same manner as was described above. After washer  20  breaks away from edges  14 A of elongated slots  14 , header  2  and stud  3  are generally free to move relatively to each other up or down. However, relative horizontal movement transverse to slot  14  is constrained by slot sides  14 A. Relative horizontal movement normal to header flanges  2 B is constrained both by the header flanges and flanges  16 B of fasteners  16 . 
     It is appreciated that breakaway tabs or connectors  24  provide only minimal connection between each breakaway washer  20  and the plate in which slot  14  is formed. Breakaway tabs  24  are generally designed so as to keep the breakaway washer  20  integral with the plate during pre-construction handling and initial assembly of connector assembly  10 . Indeed, breakaway tabs  24  may fail, detaching breakaway washer  20  from its plate under the action of a very small force. Such a force could occur during or after construction. For example, small loads imposed during construction or small dynamic loads due personnel or equipment in the building after construction may give rise to enough force to fracture or break tabs  24 . In any event, when washer  20  is broken away, the connection provided by connector assembly  10  becomes a slidable connection. Even if washer  20  is not broken away inadvertently as just described, large externally applied loads such as from wind or earthquake or large dynamic loads due to personnel and equipment in the building cause washer  20  to break away. Once washer  20  of a particular breakaway assembly  10  is broken away, the connection provided to the connected structural members becomes slidable. 
     Connector assembly  10  may be implemented in various connecting configurations found, in particular, in light metal framed buildings. The embodiments of  FIGS. 1-6  and  FIGS. 7-8  are but two examples. The appropriate sizing of elements of connector assembly  10  may be accomplished by experiment and/or structural analysis. 
     The terms “underside,” “downward,” “upward,” “top,” “bottom,” “upperside,” “upper,” “horizontal,” “vertical”, and similar terms or variations of the terms may be used throughout this disclosure. The terms are used merely for illustrative purposes and are not intended to limit the scope of the invention in any way. 
     The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.