Abstract:
A locating device for locating a body such as an electrical box behind a wall or ceiling. The device includes a first member positionable in the body and a second member that can be positioned on the outer surface of the wall or ceiling. A magnet positioned in the first member cooperates with a magnet positioned in the second member to maintain the second member in an aligned position with respect to the electrical box. Two magnets can be used to enhance the alignment of the second member with the electrical box. A circular first member can be used for locating circular boxes or lights. A second member having an arm can be used with a circular first member. The second member can include a plurality of apertures, each aperture sized to correspond to a specific size light or electrical box.

Description:
FIELD OF THE INVENTION 
     The invention relates to an apparatus and method for locating a device behind a wall or ceiling and, more specifically, the invention provides a device for defining the perimeter of a body rigidly mounted behind a wall or ceiling. 
     BACKGROUND OF THE INVENTION 
     During the construction of buildings and structures, object or bodies are fixedly associated or rigidly mounted with respect to structural frame members such as wood or metal studs. After the bodies are mounted to the structural frame members, sheet material such as drywall, paneling or plywood is placed over the structural members, concealing the bodies mounted to the structural members. Before the building or structure is complete, the sheet material must be cut or pierced to expose the bodies. Generally, the bodies are used for communicating electricity to predetermined positions in the building. 
     SUMMARY OF THE INVENTION 
     The invention provides a locating device for defining a perimeter of a body rigidly positioned behind a sheet of material, such as an electrical box mounted to a stud and positioned behind a sheet of drywall, paneling or plywood. The locating device includes a first member that can be positioned in the body and has at least one magnet. The locating device also includes a second member that can be positioned on an outer surface of the sheet of material adjacent to the body. The second member includes at least one magnet and means to define the perimeter of the body with respect to the outer surface of the sheet of material. The magnet of the first member cooperates with the magnet of the second member to substantially align the perimeter defining means of the second member with the perimeter of the body. 
     The means for defining the perimeter of the body can define the perimeter of the body with respect to the outer surface of the sheet material before the sheet material is pierced. The means for defining the perimeter of the body can be a perimeter of the second member. For example, the second member can be shaped to substantially correspond to the shape of the body. A marking instrument can trace the perimeter or outline of the second member and thereby define the perimeter of the body. Alternatively, the means for defining the perimeter of the body can be an aperture defined by the second member. For example, the second member can be shaped with an arm that can rotate about the magnet. The aperture can pierce the arm. As the arm is rotated around the magnet, the aperture can guide a marking instrument for tracing a circle and defining the perimeter of a circular body behind the sheet of material. The invention can be practiced with a plurality of first members, each of the plurality of first members configured to engage a differently configured body. The arm of the second member can include a plurality of apertures, each of the plurality of apertures spaced from the magnet a distance corresponding to a perimeter of one of a plurality of differently sized bodies. 
     The first and second member can each include more than one magnet. The magnets of the first and second members can cooperate with a predetermined magnetic force operable to maintain the second member adjacent to the first member on the outer surface of the sheet of material. For example, if the first and second member are aligned so that perimeter defining means is aligned with the perimeter of the body, the second member can remained positioned on the outer surface of the sheet material, maintained in position by the magnetic force between the magnets of the first and second members. Also, the second member can have a predetermined weight to maintain the second member adjacent to the first member on the outer surface of the sheet of material when a magnetic force between the magnets of the first and second members is fixed. The weight of the second member can be modified by forming the second member with a cavity for receiving a weight member. 
     In embodiments of the invention were the first and second members each include more than one magnet, the magnets of the first magnet can be oriented with opposite polarity. For example, a first magnet of the first member can include an outwardly facing surface having a North polarity and a second magnet of the first member can include an outwardly facing surface having a South polarity. The second member can include two magnets similarly oriented. In such an embodiment of the invention, the alignment of the perimeter defining means of the second member with the perimeter of the body can be enhanced. 
    
    
     Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
     FIG. 1 is an exploded isometric view of a first embodiment of the locating device according to the present invention; 
     FIG. 2 is an exploded isometric view of a second embodiment of a locating device according to the present invention; and 
     FIG. 3 is a partial cross-section isometric view of locating devices according to the present invention in operation in a structure. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Various embodiments of the invention are shown throughout the figures. The figures include common elements in different structural configurations. Common elements are designated with a common base numeral and differentiated with an alphabetic designation. 
     Referring now to FIG. 1, the invention provides a locating device  10  for defining at least a portion of a perimeter  14  of a body  12  with respect to an outer surface of a sheet of material wherein the body  12  is rigidly positioned behind the sheet of material. The locating device  10  includes a first member  18  positionable internal with respect to the body  12  and having at least one magnet  20 . The locating device  10  also includes a second member  22  positionable on an outer surface of a sheet of material adjacent to the body  12 . The second member includes at least one magnet  24  and includes means  26  for defining the perimeter  14  of the body  12  with respect to the outer surface of the sheet material. The magnet  20  of the first member  18  cooperates with the magnet  24  of the second member  22  to substantially align the perimeter defining means  26  with the perimeter  14  of the body  12 . 
     Referring now to FIG. 3, the body  12   b  is rigidly positioned or immovably associated with a structural member  28 . The body  12   b  is positioned behind a sheet  16  of material. The sheet  16  defines a wall and can be formed from drywall, paneling or plywood. 
     Referring now to FIG. 1, a first member  18   b  is shown positioned internal with respect to the body  12 . The first member  18  includes an outer surface  28  shaped to conform to at least a portion of an inner surface  30  of the body  12 . In FIG. 1, a plurality of first members can be positioned in a single body. As shown in FIG. 3, a single member  18   c  can be positioned in a body  12   b . As shown in FIG. 1, the outer surface  28  of the first member  18  can define at least one notch  32  to correspond to a boss  34  extending from the inner surface  30  of the body  12 . Notches can be defined at two opposite portions of the first member  18 , a second notch  32   a  is shown in phantom. 
     Referring now to FIG. 3, the second member  22   b  is positionable on an outer surface  36  of the sheet  16  adjacent the body  12   b  and the magnet  20   c  of the first member  18   c  can cooperate with a magnet of the second member  22   b , such as magnet  24  shown in FIG. 1, to substantially align perimeter defining means  26   b  with the perimeter  14   b  of the body  12   b . The magnets cooperate in that one of the magnets exposes toward the sheet  16   a  “north” pole, or a positive polarity, and one of the magnets exposes toward the sheet  16   a  “south” pole, or a negative polarity. The magnets can cooperate such that the second member  22   b  can be suspended on the sheet  16  by the magnetic attraction between the magnets. For example, if the magnet  20   c  of the first member  18   c  is not cooperating with the magnet of the second member  22   b , the member  22   b  will slide or fall to the ground. When the magnets of the first member  18   c  and the second member  22   b  are cooperating, the magnetic attraction between the magnets will substantially align perimeter defining means  26   b  with the body  12   b . The perimeter defining means  26   b  is aligned with the body  12   b  when the perimeter defining means  26   b  substantially corresponds to the perimeter  14   b.    
     In operation, the perimeter defining means  26   b  can define the perimeter  14   b  of the body  12   b  with respect to the outer surface  36  of the sheet  16  before the sheet  16  is pierced by a piercing or cutting tool. The first member  18   c  can be positioned internal of the body  12   b . The sheet  16  can be positioned and mounted with respect to structural members such as structural member  28  and conceal or hide the body  12   b . The second member  22   b  can be moved along the surface  36  of the sheet  16  until the magnetic attraction between the magnet  20   c  of the first member  18   c  and the magnet (not shown) of the second member  22   b  becomes apparent and the second member  22   b  can be left suspended with respect to the sheet  16 . A marking instrument can be used to trace the perimeter defining means  26   b , the tracing corresponding to the perimeter  14   b  of the body  12   b . In this embodiment of the invention perimeter defining means  26   b  is the perimeter  38   a  or outline or shape of the second member  22   b . The second member  22   b  can be removed from the sheet  16  and the sheet  16  can be cut or pierced to expose the body  12   b . A lid  42  can substantially close a cavity  40  of the second member  22 . 
     The first and second members can include textual information. For example, as shown in FIG. 1, the first member  18  and second member  22  can display the term “UP” to assist a user in aligning the first and second members  18 ,  22 . The textual information can be formed integral with the members  18 ,  22 , for example, stamped or molded with respect to the members  18 ,  22 . Alternatively, the textual information can be engaged with the members  18 ,  22 , such as with an adhesive label. 
     Referring to FIG. 1, where the locating device  10  is applied to define the perimeter  14  of the body  12 , a plurality of first members similar to first members  18  and  18   b  can be positioned internal of the body  12  after the body has been rigidly mounted to a structural member and a sheet of material has been positioned over the body  12 . The second member  22  can be moved along a surface of the sheet until the magnetic attraction between the magnet, such as a magnet  20  of one of the first members positioned internal of the body  12  and the magnet  24  of the second member  22  becomes apparent and the second member  22  can be left suspended with respect to the sheet. A marking instrument can be used to trace the perimeter defining means  26 , the tracing corresponding to the perimeter  14  of the body  12 . These steps can be repeated for each of the first members positioned internal of the body  12 . The perimeter  14  of the body  12  can be defined by the outline or outermost markings of the several tracings. 
     Referring now to FIGS. 1 and 3, the at least one magnet of the first member can include first and second magnets and the at least one magnet of the second member can include third and fourth magnets. For example, the first member  18  can include magnets  20  and  20   b . The second member  22  can include magnets  24  and  24   b . The magnets  20  and  20   b  can be mountable with respect to the first member  18  spaced apart relative to one another a first, or predetermined distance. The first distance can selected based on the configuration of the first member. For example, a larger first member can include two magnets spaced apart a greater distance than two magnets associated with a smaller first member. The magnets  24  and  24   b  can be mountable with respect to the second member  22  spaced apart relative to one another the first distance. It has been found that increasing the number of magnets mounted with respect to the first member  18  and the second member  22  can enhance the alignment of the perimeter defining means  26  with the body  12 . The magnets mounted with respect to the first member  18  and the second member  22  can be oriented such that magnet  20  exposes a magnetic field toward the sheet  16  having a positive polarity or “north” pole and the magnet  20   b  can expose a magnetic field toward the sheet  16  having a negative polarity or a “south” pole. Similarly, the magnet  24  can expose toward the sheet  16  a negative polarity and the magnet  24   b  can expose toward the sheet  16  a positive polarity. Such an embodiment of the invention can be advantageous if the body  12  is asymmetrical about a particular axis. 
     Referring now to FIG. 2, in a second embodiment of the locating device  10   a , a first member  18   a  positionable internal with respect to a body  12   a . The first member  18   a  includes at least one magnet  20   a . The locating device  10   a  also includes a second member  22   a  having at least one magnet  24   a . The magnets  20   a  and  24   a  cooperate to substantially align perimeter defining means  26   a  with the body  12   a.    
     Referring now to FIG. 3, the second member  22   c  is positionable on an outer surface  44  of a sheet  16   a , such as a ceiling, adjacent the body  12   b . The second member  22   c  includes perimeter defining means  26   c . The body  12   b  is rigidly positioned behind the sheet  16   a  to structural members  28   a  and  28   b.    
     Referring now to FIG. 2, the second member  22   a  can include an arm  46  rotatably engagable with respect to the magnet  24   a . Perimeter defining means  26   a  can include at least one aperture  48  defined by the second member  22   a.    
     Referring now to FIG. 3, the body  12   b  is rigidly positioned with respect to the structural members  28   a  and  28   b . The first member  18   d , similar to the first member  18   a  shown in FIG. 2, is positioned internal with respect to the body  12   b . The sheet  16   a , defining a ceiling, is positioned with respect to the structural members  28   a  and  28   b , covering or concealing the body  12   b  and first member  18   d . The second member  22   c  is moved about the outer surface  44  of the sheet  16   a  until the cooperation between the magnet  20   d  of the first member  18   d  and the magnet of the second member  22   c  is perceived and the second member  22   c  is suspended by the cooperation between the magnets. A marking instrument can be inserted with respect to the aperture  48   a  of the second member  22   c  and the arm  46   a  can be rotated about the magnet of the second member  22   c . The tracing or marking formed by the marking instrument during the rotation of the arm  46   a  about the magnet defines or corresponds to the perimeter  14   c  of the body  12   b.    
     The second member  22   a  can include a plurality of apertures similar to aperture  48 , as shown in FIG.  2 . The locating device  10   a  can also include a plurality of differently sized first members. Each of the plurality of first members can be sized to be positionable internal with respect to a plurality of differently sized bodies. Each of the apertures defined by the second member  22   a  can correspond to a differently sized body. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.