Abstract:
The claimed inventions relate generally to electrical boxes that may be installed to a ceiling, and more particularly to electrical boxes that incorporate a rigid member between the box top and side that provide resistance to a compressive force therebetween, providing structural support to the box when the rigid member is secured to a structural framing member. Disclosed herein are brackets and other devices for reinforcing ceiling electrical boxes to structural members, such as trusses and joists, against the load of fixtures including ceiling fans and lighting fixtures. Also disclosed herein are ceiling electrical boxes having built-in reinforcement. Additionally disclosed herein, explicitly or implicitly, methods of using and installing those brackets, devices and boxes. Detailed information on various example embodiments of the inventions are provided in the Detailed Description below, and the inventions are defined by the appended claims.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of U.S. patent application Ser. No. 10/722,955 filed Nov. 26, 2003, which claims the benefit of U.S. Provisional Application No. 60/484,912 filed Jul. 3, 2003, both of which are hereby incorporated by reference in the entirety. 
     
    
     BACKGROUND OF THE INVENTIONS  
       [0002]     Known in the art are electrical boxes intended to enclose wiring and connectors, those boxes also optionally including mountings for securing a lighting fixture. Certain of those boxes are suitable for mounting overhead just above a ceiling, attaching to a truss, joist or other structural support member. In a typical new installation metal or, more frequently, plastic light-duty boxes are installed, those being the most inexpensive type suitable for carrying a light-weight lighting fixture, for example a fixture housing a single medium-base bulb. It is often the case that a homeowner will wish to later install a heavier fixture, such as a ceiling fan or chandalier, to the originally installed electrical box. Many homeowners are not aware of the unsuitability of these light-weight boxes for those applications, and many install these heavier fixtures improperly and dangerously without upgrading the support structure.  
         [0003]     A ceiling fan, through normal operation, may create oscillatory stresses on the electrical box it is attached to. If attached to a light-duty box, these forces may carry through the fan support to the electrical box, which may cause the box to twist slightly on each oscillation. Over time this motion may cause the nails, or other fasteners, used to secure the electrical box to move and/or loosen, which may lead to failure of the electrical box supporting structure. Additionally, if the box structure is not sufficiently rigid, forces may be transferred to the drywall, or other material, of the ceiling. Now drywall, plaster, paneling and most other ceiling materials are not designed to carry loads. These materials may carry a load briefly, but over time cracks may develop leading to an unpredictable failure of the material. If both the electrical box supporting structure and the ceiling material fail, the result is a fixture falling at an unpredictable time, which can lead to property damage, personal injury and litigation against the makers of the ceiling fan, lighting fixture, electrical box manufacturer as well as other involved parties.  
         [0004]     In many areas earthquakes are a concern. A non-moving ceiling fixture mounted to a light-weight box may carry a load sufficiently well under static conditions for many years. Earthquakes are unpredictable events that may occur at any time, and in some locations with such severity as to cause large thrust and oscillatory motions on the lighting fixture and electrical box. A homeowner may be completely unaware of a dangerously supported fixture until a tremor causes it to fall. The dangers of inadequately supported lighting fixtures therefore encompasses more fixtures than ceiling fans.  
         [0005]     Now there are several electrical box types which will support a relatively heavy load, of which several are represented in U.S. patents. A usual type, represented by U.S. Pat. No. 6,242,696, utilizes wings attached to the side of the electrical box to attach to a structural member. This type requires installation prior to the installation of a finished ceiling to avoid damage thereto. Another type, represented by U.S. Pat. Nos. RE 38,120, 6,107,568, 6,191,362, 6,207,897 and 6,355,883, envisions a ceiling electrical box that attaches to an overhead structural support member from underneath through the use of screws or other fasteners generally driven upward through the top of the box and into the structural member. Those boxes either include a slot fitting the support member, or are designed to fit in a space between the support member and the surface of the finished ceiling. All of those designs have the disadvantage of reduced internal box volume, by which the number of electrical connections and wires is restricted over a common side-mounted nailed electrical box. Another type, represented by U.S. Pat. Nos. RE 33,147, 6,098,945, 6,465,736, and 6,595,479, utilizes an extendable rod or other structure fittable between the space between two joists or structural members. This type of electrical box, although avoiding impacts into the volume of the electrical box, carries a number of disadvantages. First, the use of the rod introduces a substantial lever arm; the rod must therefore be fairly heavy to avoid bowing under the fixture load. This type of box is typically constructed of steel or other metal, as the needed plastic supports would be very thick in comparison. These boxes tend are more complex and require more materials and building steps to fabricate. The cost of this type of box also tends to be much higher to the end user. A final type, represented in U.S. Pat. Nos. RE 34,603 and 6,100,469, utilizes fasteners through a metal electrical box sidewall into the adjacent structural member. This type relies on the strength of the sidewall to avoid the fastener head pulling through the sidewall material under load, and is therefore unsuitable for plastic materials. Furthermore, this type relies on the box structure to resist a downward force, which may place strain on welds and joints. Additonally, fasteners driven in a substantially horizontal direction limit the amount of driving force that can be applied to the fastener and may make installation difficult without specialized tools. And none of these box types provide a method of upgrading a ceiling electrical box to carry additional load.  
         [0006]     Thus, some of these boxes are relatively expensive to produce and install, while others may be installed only by creating new holes in a ceiling or otherwise causing new damage that must be repaired. In the market there is a general lack of products and methods that provide for upgrading of ceiling electrical boxes to support heavier loads. There is therefore a need for products which can create a box structure capable of supporting more than a light load which can be installed without causing damage to an existing ceiling.  
       BRIEF SUMMARY OF THE INVENTIONS  
       [0007]     The claimed inventions relate generally to electrical boxes that may be installed to a ceiling, and more particularly to electrical box ancillary devices, such as brackets and struts, that permit the carrying of heavy ceiling appliances such as ceiling fans and lighting fixtures. Disclosed herein are brackets and other devices for reinforcing ceiling electrical boxes to structural members, such as trusses and joists, against the load of fixtures including ceiling fans and lighting fixtures. Also disclosed herein are ceiling electrical boxes having built-in reinforcement. Additionally disclosed herein, explicitly or implicitly, methods of using and installing those brackets, devices and boxes. Detailed information on various example embodiments of the inventions are provided in the Detailed Description below, and the inventions are defined by the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIGS. 1A, 1B  and  1 C (herein after referred to as  FIG. 1 ) show an exemplary reinforcement bracket.  
         [0009]      FIGS. 2A, 2B  and  2 C show a four inch plastic electrical box with the bracket of  FIG. 1  installed.  
         [0010]      FIGS. 3A, 3B  and  3 C show a three inch plastic electrical box with the bracket of  FIG. 1  installed.  
         [0011]      FIGS. 4A, 4B  and  4 C show a three inch metallic electrical box with the bracket of  FIG. 1  installed.  
         [0012]      FIGS. 5A, 5B  and  5 C show an installation of two identical brackets into two types of electrical boxes.  
         [0013]      FIGS. 6A, 6B ,  6 C and  6 D show an exemplary electrical box with built-in reinforcement.  
         [0014]      FIG. 7  shows an alternate bracing electrical box with three flanges.  
         [0015]      FIGS. 8A, 8B ,  8 C and  8 D show an exemplary electrical box having flanges and an integrated bracket.  
         [0016]      FIGS. 9A and 9B  show an alternate electrical box having reinforcement.  
         [0017]      FIGS. 10A, 10B ,  10 C,  10 D and  10 E show another exemplary electrical box with flanges and an insert molded reinforcement.  
         [0018]      FIGS. 11A and 11B  show another exemplary reinforced electrical box.  
         [0019]      FIGS. 12A, 12B  and  12 C show an alternate reinforcing bracket.  
         [0020]      FIGS. 13A, 13B  and  13 C show an additional alternate reinforcing bracket. 
     
    
       [0021]     A discussion of several embodiments in accordance with the invention now follows.  
       DETAILED DESCRIPTION  
       [0022]     Disclosed herein are several brackets useful for reinforcing electrical boxes installed adjacent to a structural member, such as a truss or joist. Shown in  FIGS. 1A, 1B  and  1 C (herein after  FIG. 1 ) is an example of one particular reinforcment device in the form of a bracket designed for two specific electrical box types, although it might be installed in others. Bracket  11   a  includes two largely planar portions,  12   a  and  15   a , connected by bend  17   a . Planar portion  12   a , in this example, forms an interface providing a mating to the top of an electrical box at the inside. The ends of planar portions  12   a  and  15   a  are shaped to form an interface to the side of an electrical box at the inside, that interface being shown at  13   a  and  14   a . In this example, ends  13   a  and  14   a  provide two interfaces for two specific electrical box types, as will be discussed presently, one interface provided at  13   aa  and  14   aa  for a substantially flat electrical box sidewall and another interface at  13   ab  and  14   ab  for a screw boss, which are integral in many plastic electrical ceiling boxes. Planar portion  15   a  provides a strut-like portion providing resistance to a compressive force applied between the top and side interfaces. That strut-like portion functions to at least partially convert a downward force on the electrical box to a horizontal force in the direction of the structural member. In bracket  11   a , two fastener features, in this example recesses,  16   aa  and  16   ab  (shown  16   a  in  FIG. 1   b ) provide attachment points for screws. Recesses  16   aa  and  16   ab  are oriented so that fasteners inserted therein may fasten the bracket  11   a  through the electrical box sidewall and into an adjacent structural member. In this example, recesses  16   aa  and  16   ab  are configured to align fasteners at approximately 60 degrees from the vertical for an electrical box mounted to a vertical structural member surface. This permits the fasteners to be driven into the structural member with a single tool, such as an ordinary screwdriver or hammer, through many electrical box openings. It is preferred that this angle and the position of any fastener features be set so as to permit ease of access to the fasteners using ordinary tools, although other angles or positions may be chosen without departing from the larger scope of the invention. Preferably, the driving force may be directly applied by a tool external to the electrical box, for example a screwdriver or hammer. Recesses  16   aa  and  16   ab  may include a substantially cylindrical portion, not shown, for guiding the fastener at a desired angle relative to the bracket. In this example, recesses  16   aa  and  16   ab  provide seats for screws, which recesses are not threaded to provide free movement so that bracket  11   a  may be brought tightly into a supportive position. A bend  18   a  is provided near end  14   a  to orient that end perpendicular to the electrical box sidewall providing for transverse motion by which bracket  11   a  may be brought more snugly into a supportive position during installation of the bracket.  
         [0023]     The bracket  11   a  of  FIG. 1  may be fashioned utilizing ordinary sheet-metal die-processing procedures to make the various bends and and shapes of the bracket, as well as other reinforcing brackets. Preferred materials for reinforcing brackets, such as  11   a , include zinc-plated mild steel, due to that material&#39;s strength, durability, widespread availability and applicable manufacturing facilities. Other metals may be used, such as aluminum, brass or “pot” metals, keeping in mind that different thicknesses may be required to achieve necessary strength and bracing characteristics. Processes other than die processes may be used as desired, for example extrusion processes, particularly where a bracket is to be made from aluminum or its alloys.  
         [0024]     Shown in  FIGS. 2A, 2B  and  2 C (herein after  FIG. 2 ) is a four inch plastic electrical box  20   a  with bracket  11   a  installed;  FIG. 2A  showing a perspective view through the electrical box opening,  FIG. 2B  showing a bottom view, and  FIG. 2C  showing a sectional view through axis  1 . Electrical box  20   a  includes an aperture through which access is permitted to manipulate wires inserted into the electrical box and to make connections thereto. Electrical box  20   a  includes flanges  22   a  for holding nails  23  in a relative position whereby nails  23  may be driven into a support member to secure the box  20   a  into position. When bracket  11   a  is in installed position, top mating interface  12   a  (not shown) rests against the electrical box top inside surface  26   a , while side interface  14   aa  resting against a flat portion  21   a  of electrical box sidewall. Screws  24  are driven through bracket  11   a  and sidewall  21   a  into the structural member to secure the bracket  11   a  into installed position.  
         [0025]     Bracket  11   a  is designed to reinforce two particular box types.  FIGS. 3A, 3B  and  3 C (herein after  FIG. 3 ) shows a three inch plastic electrical box  20   b  with bracket  11   a  intalled therein, with  FIG. 3A  showing a perspective view through the electrical box opening;  FIG. 3B  showing a view looking at the bottom, and  FIG. 3C  showing a sectional view through axis  3 . Electrical box  20   b  also includes flanges  22   b  for fastening the box  20   b  to a structural member by way of nails  23 . For this box, the installation position of bracket  11   a  also brings top mating surface  12   a  (not shown) against electrical box top inside surface  26   b . This electrical box  20   b  includes a boss  25   b  for insertion of a mounting screw, whereby a fixture may be attached to electrical box  20   b . Bracket  11   a  l rests against boss  20   b  at the side interfaces  14   ab  and optionally  1   3   ab  (not shown). Screws  24  are likewise driven through bracket  11   a  and sidewall  21   b  into the structural member to secure the bracket  11   a  into installed position.  
         [0026]     The design of bracket  11   a  permits use in metallic electrical boxes as well. In  FIGS. 4A, 4B  and  4 C a bracket  11   a  is shown installed into a 3 inch metal-type electrical box  20   c , with  FIG. 4A  showing a view from the box bottom,  FIG. 4B  showing a sectional view through axis  2 , and  FIG. 4C  showing a perspective view. This electrical box  20   c  includes alignment wings  22   c  with holes pre-formed to permit fastening to a structural member with nails, screws, or other fasteners. As in the plastic boxes, bracket  11   a  mates top mating surface  12   a  against the top of the electrical box  26   c , and also mates side interface  14   aa  against electrical box sidewall  21   c . To secure, screws  24  are driven through bracket  11   a  and sidewall  21   c  into the structural member, although pre-drilling of holes through sidewall  21   c  may be necessary if holes are not formed therein prior to installation.  
         [0027]      FIGS. 5A, 5B  and  5 C further illustrates the installation of two brackets of the type shown in  FIG. 1  using two electrical box types;  FIG. 5A  showing a view looking up through the bottom of the electrical boxes and at the ceiling,  FIG. 5B  showing a sectional view about the axis labeled  4 , and  FIG. 5C  showing an inverted perspective view (turned upside down for ease of viewing). Ordinary and modern construction utilizes wood structural members, of which one member  30  is shown. Member  30  might be the lower portion of a truss, a joist, or other structural member upon which a ceiling is to be fashioned. Ordinary construction utilizes drywall  31  fastened by nails or screws to structural members, one screw  32  being shown. Also shown are a four inch plastic electrical box  26   a  of the type of  FIG. 2  and one three inch plastic electrical box  26   b  of the type of  FIG. 3 . Both boxes  26   a  and  26   b  are normally installed prior to drywall application to structural member  30  through flanges, one  22   b  being shown, and nails  23 . Drywall  31  is applied afterward, and holes cut therein to provide access to the interior of the electrical boxes. After drywall  31  is installed, access to structural member  30  may be restricted, particularly if there is little or no access space surrounding structural member  30 . In other situations access may be inconvenient, for example where structural member  30  is the lower part of a truss accessible through an attic or other space. A bracket  11   a  may be installed without direct access to structural member  30  through the interior of the box. The bracket  11   a  is inserted into the box and placed in proper mounting position, next to the electrical box sidewall adjacent to the structural member. Screws  24 , or other fasteners, are then driven through the bracket  11   a , the electrical box sidewall  21   a  or  21   b  and into the structural member  30 .  FIG. 5B  includes a cutout  33  area to show screw  24  clearly.  
         [0028]     An electrical box may optionally have a reinforcing bracket built in. FIGS.  6 A-D (herein after  FIG. 6 ) show conceptually how this might be done in a metal-type box. Referring to  FIG. 6A , an electrical box  40   a  is made in an intermediate stage, the box having a top  45 , sides, and an unbent flap  41 . Electrical box  40   a  may be fashioned from usual processes for electrical box manufacture, including stamping, pressing, punching, spot welding and other techniques. In this example and prior to this stage, fastener features  42  have been stamped prior to the next step. Those fastener features might be, for example, screw guides, nail guides, or conical or countersunk structures for securing a screw head. In that step, flap  41  is bent as shown in  FIG. 6B , to form a brace  43  and a top interface portion  44  meeting with top  45 . Now it is to be understood that this step may actually include several successive steps in which bends are progressively made to flap  41 .  FIG. 6C  also shows the completed configuration as seen through the bottom of the box.  FIG. 6D  shows a sectional view through the axis labeled  5 . Now although it is not shown, sidewall  46  is preferably pre-punched or drilled with holes for fasteners to pass through when inserted in  42 , by which the installer may avoid drilling operations. This electrical box does not include wings or other extra-box support structures, but rather relies on the bracing structure formed by brace  43  and top interface portion  44  to stabilize the attachment of the electrical box  40   b  to a structural member. Preferably, at least three fastener features are included, as shown, in at least two axes to form a tri-point securement geometry. Electrical box  40   b  may be considered to be an “old work” or “rework” type box, as it may be conveniently installed to a finished ceiling. To do so, an installer would (1) find an attachable structural member, (2) cut a matching hole in the drywall, paneling, or other wall structure so the electrical box may be positioned next to the structural member, (3) insert the box and (4) fasten the box to the structural member through fastener features  42 .  
         [0029]      FIG. 7  shows an alternate bracing electrical box  50  having three flanges. Those flanges include two horizontal flanges  51 , which are included in conventional electrical boxes. An additional flange  52  is added substantially outside the plane formed by flanges  51 , in this example attached to and above the electrical box top  54 . Nails  53  are driven into a structural member during installation. Without the use of flange  52  and corresponding nail  53   a , a weighted box has a tendency to rotate about an axis passing through the points where the nails  53   b  enter the structural member, where the most stress occurs in the nail material. Flange  52  and nail  53   b , when used, prevent this rotation and keep the box in a more stable position. Now this box is more useful for new construction, as the task of driving the nails would be most difficult without tearing out a large section of wall necessary to swing a hammer or insert a power tool.  
         [0030]      FIGS. 8A, 8B ,  8 C and  8 D (herein after  FIG. 8 ) show another bracing electrical box  60   a  having conventional flanges  61  and an integrated bracket  62   a ,  FIG. 8A  showing a perspective view of the box internal space,  FIG. 8B  shows a view of the outside of the box looking at the sidewall in adjacency to the bracket,  FIG. 8C  shows a bottom view of the box and  FIG. 8D  shows a sectional view in the axis marked  6 . In this example, bracket  62   a  is molded out of plastic and integral to the structure of the electrical box. Ribbing  63  may be provided to resist the force applied by fasteners  64  when attached, while minimizing the amount of plastic material needed. This particular electrical box is useful for new installations where access to the structural member is not restricted.  
         [0031]     Shown in  FIGS. 9A and 9B  is an alternate electrical box  60   b  showing two different perspective views to the interior of the box. Electrical box  60   b  has the same integrated bracket  62   a  and ribbing  63  as box  60   a  of  FIG. 8 , but omits flanges  61 . This box may be installed in a similar manner to the box  40   a  of  FIG. 6 , and is considered to be an “old work” type box.  
         [0032]      FIGS. 10A, 10B ,  10 C,  10 D and  10 E (herein after  FIG. 10 ) show another bracing electrical box  60   c  having conventional flanges  61  and an insert molded bracket  62   b ,  FIG. 10A  showing a perspective view of the box internal space,  FIG. 10B  showing a view of the outside of the box looking at the sidewall in adjacency to the bracket, FIG,.  10 C shows a bottom view of the box,  FIG. 10D  showing a sectional view in the axis marked  7 , and  FIG. 10E  showing the detail in the area marked  8 . In this example, bracket  62   b  is molded in place during the molding process. Bracket  62   b  might be made of any stiff, strong and temperature insensitive material, for example steel, aluminum, brass, wood, carbon fiber, or other metal alloy or composite material, that withstands the temperatures of the plastic molding process and provides the desired reinforcement. Bracket  62   b  is placed in appropriate position inside the electrical box mold at the time the plastic part of the box is fabricated, the plastic generally encompassing or surrounding the bracket sufficiently to hold the bracket in place so that it does not become dislodged through ordinary use. Additional thicknesses of plastic material may be fashioned at the points of stress, for example  66  where bracket  62   b  meets the sidewall of the box and more particularly  65  where bracket meets the top of the box. Electrical box  60   c  is considered to be a “new work” type box.  
         [0033]      FIGS. 11A and 11B  show an alternate electrical box  60 d similar to the box  60   c  of  FIG. 10 , with  FIGS. 11A and 11B  showing two different perspective views to the interior of the box. Electrical box  60   d  has the same insert molded bracket  62   b  as box  60   a  of  FIG. 10 , but omits flanges  61 . This box may also be installed in a similar manner to the box  40   a  of  FIG. 6 , and is considered to be an “old work” type box. Now the above described boxes may include alignment features, such as tabs, to align the electrical box into proper position with respect to the ceiling surface, particularly if the boxes are intended for old-work installations.  
         [0034]      FIGS. 12A, 12B , and  12 C show an alternate configuration of a reinforcing bracket  11   b , including  FIGS. 12A and 12C  showing perspective views and  FIG. 12B  showing a side view. This bracket  11   b  includes a substantially flat surface  12   b  for mating with the top of an electrical box. Mating surfaces  13   b  and  14   b  are provided to rest against an electrical box sidewall, that sidewall preferably being flat. Two legs  15   b  extend between mating surfaces  13   b  and  14   b  connecting the bracket portion including mating surface  12   b  with the bracket portions containing fastener features  16   b . A separation  19  is provided between the two legs  15   b  to permit mounting around an obstruction in the electrical box, for example a screw boss. The compressive portion of this bracket  11   b  is small, and is mainly around the bend at  13   b . Because of this, this bracket is preferably constructed of stiffer and/or stronger materials than that of  11   a  to maintain a similar bracing capacity.  
         [0035]      FIGS. 13A, 13B  and  13 C show another alternate configuration of a reinforcing bracket of the type of  11   a ,  FIGS. 13A and 13C  showing perspective views and  13 B a side view. Bracket  11   c  includes a top mating interface  12   c , fastener features  16   c , and a strut portion  15   c . This bracket is intended to fit an electrical box having a substantial cylindrical sidewall, for example the 3 inch ceiling electrical box shown in FIGS.  3 A-C, and thus curved regions  13   ca  and  14   ca  are provided to mate thereto. Side interface areas  13   cb  and  14   cb  may be used to mate to a fastener boss, as in the bracket of  11   a . Bends  17   c  and  18   c  are included to orient strut portion  15   c , top mating surface  12   c , and side interface areas  13   ca ,  13   cb ,  14   ca  and  14   cb  in positions that will mate well with the intended electrical boxes, provide reinforcement and orient fastener features in a direction that assists the insertion of fasteners therein into a structural member. Bracket  11   c  may be made using similar methods and materials as to that of bracket  11   a.    
         [0036]     Now it is preferred that reinforcement brackets, devices or features be designed to consume a minimal amount of the interior volume, so as to maximize the number of wires and electrical connections that can be made within the electrical box.  
         [0037]     A kit containing a reinforcement device and necessary fasteners may be advantageously assembled for the convenience of the installer. Such a kit might be included, for example, in the product packaging of an electrical applicance, for example a ceiling fan or lighting fixture, providing added convenience to the installer of the product in situations where the use of the bracket is desirable. A fastener bit suitable for insertion into a drill may also add to the convenience of the installer at a reasonable expense.  
         [0038]     A preferred fastener type for use with reinforcement devices and brackets is the pilotless screw, as commonly used in decking, fencing and drywall applications. That type of screw can be driven into woods used for construction as well as many plastics with minimal splitting and/or stretching of the material. The use of that type of screw simplifies the installation of the bracket by reducing the need for drilling pilot holes, which under many circumstances will be awkward given the overhead working position and the restrictions of available access to the interior of the particular electrical box, and further require the use of long drill bits or adapters which may not be in the equipment inventory of typical installers. The use of screws is also preferred to mitigate the effects of thermal and humidity cycles, which is a known problem with nails.  
         [0039]     While reinforcing brackets, devices, and electrical boxes containing reinforcement and the use of those have been described and illustrated in conjunction with a number of specific configurations and methods, those skilled in the art will appreciate that variations and modifications may be made without departing from the principles herein illustrated, described, and claimed. The present invention, as defined by the appended claims, may be embodied in other specific forms without departing from its spirit or essential characteristics. The configurations described herein are to be considered in all respects as only illustrative, and not restrictive. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.