Abstract:
An electric junction fixture is provided for preparing a wall or ceiling to accept an appliance such as an electric light fixture, inserted and mounted through a hole in the drywall or panel. Reduced stress levels in the drywall or panel are obtained by providing large areas of contact between the fixture and the drywall or panel.

Description:
BACKGROUND 
     1. Field of the Invention 
     This invention relates to a fixture for mounting electric lights and the like in walls and ceilings. During construction, fixtures are sometimes mounted on studs prior to installing paneling, plasterboard, or drywall. This does not always provide the optimum location with regard to locations of sinks, cabinets, desks and the like. Other fixtures can be installed after the paneling, plasterboard, or drywall is installed, and at a location to functionally suit the surroundings. This invention provides for such installations and is cost effective, easy to install, and structurally sound. 
     2. Description of Prior Art 
     Junction fixtures that mount to studs and beams are in common usage. This method restricts the location of the mounted fixture to stud or beam locations. 
     U.S. Pat. No. 7,117,591, Gertz, discloses a junction fixture that does not require mounting on a stud. The fixture is mounted through a hole in the panel or drywall. Screws are used to attach the fixture to the panel or drywall. 
     U.S. Pat. No. 6,241,368, Depino, discloses a junction fixture that does not require mounting on a stud. The fixture is mounted through a hole in the panel or drywall. A clamping mechanism, operated by screws and levers, clamps the fixture to the drywall. This clamping mechanism utilizes minimal area contact between the clamp and the drywall. 
     Electric lights and the like are attached to the junction fixture. Many are heavy and cantilevered at a significant distance from the panel or drywall. High stresses are therefore transferred from these arrangements to the panel or drywall. Screw attachments to the panel or drywall are often stressed beyond their yield strength. The act of changing light bulbs, for example, can produce added stress and can contribute to looseness or fracture. The small area used on the levers and clamps of some junction fixtures leads to high stress areas and to resulting looseness or fracture. 
     Hence, there is a need for a structurally sound junction fixture that produces low stress levels in the panel or drywall, is easy to install, and is inexpensive to manufacture. 
     PRESENT INVENTION—OBJECTS AND ADVANTAGES 
     Accordingly, the present invention overcomes these difficulties. Mounted through a hole in the panel or drywall, the units are easy to install. They are economical and provide a rigid and strong joint with the panel or drywall. Loads are distributed over large areas for minimum stress and distortion. 
     The unit of this invention has two main parts; a body and a cover. The body contains a central cylindrical cup with arms attached to the cylindrical cup that are diametrically opposed. The bottom of the cylindrical cup has at least one hole or “knock out” for passage of electrical wiring. A hole is provided in the panel or drywall that is slightly larger than the cylindrical cup of the body. The arms and the body are inserted through the hole in the panel. The cylindrical cup is then approximately centered in the hole. The cover is then applied to the body and attached with screws. The cover contains a skirt that takes up the space between the hole and the outside diameter of the cylinder, thus providing for a minimum space between the panel hole and the invention structure. Tightening the screws causes load distribution to the drywall by an appropriately large area flange around the cover on the exposed side of the panel, and the large area of the two arms attached to the cylinder on the opposite or back side of the panel. 
    
    
     
       DRAWING FIGURES 
         FIG. 1  shows an isometric view of the body. 
         FIG. 2  shows an isometric view of the cover. 
         FIG. 3  shows a cross-section of the invention installed in a panel or drywall. 
         FIG. 4  shows an exploded view of the invention. 
     
    
    
     DESCRIPTION 
       FIG. 1  shows a plan view of the body  10 . A cylindrical cup  12  has arm  14  and arm  16  attached and diametrically opposed. Arms  14  and  16  are integral with and rigidly attached to cup  12 . Cup  12  has a thin circumferential wall  18  and a bottom  20 . Bottom  20  has at least one hole  22  through which electrical wiring can pass. Internally threaded bosses  24  are attached to both circumferential wall  18  and bottom  20 . Arm  14  and aim  16  are shown as being of equal length but need not be so. In fact, for wall mounting, it may be desirable to have arm  14  (positioned above) be longer than arm  16  (positioned below) to absorb the higher moment loads associated with a hanging light fixture or the like (see  FIG. 4 ). Screws  26  are inserted in threaded bosses  24  and are ready to receive cover  30  as will be described. 
       FIG. 2  shows a plan view of cover  30 . Circular flat plate  32  contains a central hole  34  through which electrical wiring can pass. Circular slots  36  are strategically located to coincide with the spacing of bosses  24  of  FIG. 1 . Clearance holes  38  are located approximately at the mid point of circular slots  36  and provide clearance for entrance of the heads of screws  26  of  FIG. 1 . Single holes could be substituted for the clearance holes  38  and circular slots  36 . Threaded holes  40  and threaded studs  42  are provided for appliance attachment, such as lighting fixtures and the like. 
       FIG. 3  shows a circular panel hole  50  in panel  52 . Body  10 , in its entirety, is installed from the exposed side of panel  52  completely and entirely through hole  50  to the back side of panel  52 . Cylindrical cup  12  is then approximately centered in hole  50  from the back side of panel  52 . Then cover  30  is installed on the exposed side of panel  52 . In this view, cover  30  has been inserted onto body  10  over heads of screws  26 , and then cover  30  is rotated until screws  26  come to the stop provided in circular slots  36  (see  FIG. 2 ). Screws  26  are then tightened and the fixture is secure. Panel hole  50  is sufficiently large so that body  10 , complete with arms  14  and  16  and cup  12 , can integrally be easily inserted through panel hole  50  and then positioned as shown. Skirt  54  is of sufficient width to occupy the space between panel hole  50  and cylindrical cup  12 , in compliance with electrical code clearance requirements. Skirt  54  is of a length that allows compression of panel  52  between body  10  and cover  30 . Likewise, the offset from rim  56  of cup  12  to arm  14  and arm  16  allows compression of panel  52 . Arm  14  and arm  16  are shown in  FIG. 1  as rectangular in shape, but may be triangular or trapezoidal, etc, and may have projections  58  that penetrate panel  52  for added stability. The faying surface of arm  14  and arm  16  (with panel  52 ) may contain slight non-parallel bias to promote superior retention. Flange  60  of cover  30  is sufficiently large to provide ample area of engagement with panel  52 . 
       FIG. 4  is an exploded view of a wall mount incorporating the teaching of the invention. Arms  14  and  16  are shown as different in length. Body  10  is shown as having passed through hole  50  and now facing the back side of panel  52 . Cover  30  is facing the exposed side of panel  52 . 
     Body  10  and cover  30  may be made of metal or suitable nonmetallic material. 
     CONCLUSIONS 
     Accordingly, this invention is an inexpensive means of providing a junction fixture. The invention is easy to use and effectively distributes loading to the panel on which it is installed. 
     It will be appreciated that while particular embodiments of the invention have been shown and described, modifications may be made. It is intended in the claims to cover all modification that come within the true spirit and scope of the invention.