Abstract:
A universal hanging system for securing louver grilles over duct openings that allows existing louver grilles to be interchanged. The hanging system comprises a ferromagnetic support member that is fastened to the surface adjacent a duct opening. A magnet is employed to removably attach a louver grille to the support member.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates generally to hanging systems for louver grilles. In particular this invention relates to a universal hanging system that allows existing louver grilles to be interchanged.  
       BACKGROUND OF THE INVENTION  
       [0002]     Forced air heating and air conditioning systems are commonly used to control the temperature and humidity of an indoor environment in modern buildings. The systems generally operate by circulating the air within an enclosed space by drawing the air through intake louver grilles into intake ducts that lead to a furnace and/or air conditioner for controlling the temperature, the air optionally passed past a humidifier, before being circulated back through output ducts to exit through output louver grilles into the enclosed space.  
         [0003]     Access to the intake and output blocks is typically blocked by louvered grilles that are affixed to the wall, ceiling or floor through which the duct opening exits. Optionally, the grilles may be fixed directly to the duct itself. The most common method of fixing the grilles is by securing them with metal fasteners, and in particular screws, sunk into the wall surface adjacent to the duct opening. Plastic grilles may have integrated clips for retention over the duct opening. Generally the grilles are fixed in place at the time the building is constructed, or when new ducts are installed in the building.  
         [0004]     The air that is drawn through the intake grilles commonly carries dust, pollen and other suspended particles. These particles typically settle in the intake ducts and can create a potential health hazard.  
         [0005]     It is generally recommended to have the ducts cleaned, at least once a year on changing over from cooling to heating operations. The process of duct cleaning involves removing, at least, each of the intake grilles and vacuuming out particles or debris that have settled in the intake ducts. Removal of the output grilles and vacuuming the output ducts may also be desirable, although is required less frequently because the air is typically filtered at the furnace or air conditioner unit.  
         [0006]     Grilles are also used to cover ventilation or exhaust ducts. These grilles are similar in form to those used for heating and air conditioning ducts and often need to be regularly removed and replaced to facilitate cleaning or conducting repairs to any fan used to assist in exhausting air.  
         [0007]     The grille serves an aesthetic purpose, concealing the rough edges of wallboard around the duct opening, but also has a safety function in that it forms a physical barrier that prevents access to the duct. The grille is thus securely fastened to the wall or duct by at least two fasteners, in order to prevent inadvertent dislodgment. The problem that arises is that having to remove the fasteners for every grille is extremely time consuming. Often grilles may have different fasteners, requiring different styles or sizes of tools from other grilles in the same premises. Moreover, repeated loosening and retightening of the fasteners may lead to the fasteners no longer being able to retain the grille in place over the duct opening. Solutions for securing the grille include drilling new holes for fasteners, using oversized fasteners or using a replacement louver grille that has fastener holes in different locations. Oversized fasteners can cause difficulties in that they may be less aesthetic, or may require drilling out the existing holes in the grille.  
         [0008]     Plastic grilles often suffer from the integrated plastic clips breaking on removal, requiring a new replacement grille to be installed.  
         [0009]     The difficulty with using replacement grilles is that grilles are intended to last for decades, and when one breaks the original grilles may no longer be commercially available. This results in the replacement grille being of a different style from the rest of the existing grilles in the building. The only solution to this problem is to replace all of the grilles in the building.  
         [0010]     A need thus arises for a method of securing existing grilles in place without using conventional fasteners.  
       SUMMARY OF THE INVENTION  
       [0011]     According to an aspect of the invention there is provided a method and apparatus for securing a louver grille in place over a duct opening.  
         [0012]     According to another aspect of the invention there is provided a hanging system for securing a louver grille in place over a duct opening that allows existing louver grilles to be interchanged.  
         [0013]     According to another aspect of the invention there is provided a ferromagnetic support member and a magnet for removably securing a louver grille in place over a duct opening.  
         [0014]     According to another aspect of the invention there is provided a method of securing a louver grille over a duct opening by securing the grille with a magnet to a support member that is fastened onto a surface adjacent to the duct opening.  
         [0015]     Advantages of the invention include the ability to install a hanging system that is capable of accommodating and removably securing an existing louver grille in place over a duct opening without the use of fasteners.  
         [0016]     Further advantages of the invention include the ability to replace the existing fasteners that secure a louver grille without having to replace the existing louver grille. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     In drawings which illustrate by way of example only a preferred embodiment of the invention,  
         [0018]      FIG. 1  is a plan view of a support member.  
         [0019]      FIG. 2  is a side view of the same support member.  
         [0020]      FIG. 3  is a plan view of an alternative support member that includes multiple holes to accommodate fastening means.  
         [0021]      FIG. 4  represents an exemplar magnet.  
         [0022]      FIG. 5  is a plan view of an existing louver grille.  
         [0023]      FIG. 6  is a partially exploded view of an embodiment of the hanging system used in conjunction with an existing louver grille. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     The louver grille  50  in  FIG. 5  is typical of louver grilles commonly used to cover duct openings  60 . The grille openings  52  may be simple slots in the grille  50 , or more commonly include directional vanes that help to conceal the duct interior and, in the case of output ducts, to direct the flow of air out of the duct opening  60 .  
         [0025]     Louver grille  50  is usually constructed with an edge that extends back from the periphery of the face of the grille. The back of the edge generally rests in contact with the surface  70  that surrounds the duct opening  60  so that the face of the grille stands off from the surface  70  by a distance equal to the depth of the edge.  
         [0026]     Louver grille  50  typically includes pre-cut holes  54  to accommodate a screw fastener that is driven into an underlying surface  70  (either directly or into a plug or anchor lodged in the surface  70 ) in order to secure the louver grille  50  over a duct opening  60 . There is generally no provision in the prior art for alternate placement of the screw fastener if it strips out the hole in the underlying wall or ceiling surface  70 .  
         [0027]     The louver grille hanging system of the present invention makes use of ferromagnetic support members  10 . The support members  10  are fastened to the underlying surface  70  with at least one fastener, adjacent to a duct opening  60 . Optionally a support member  30  may include alternate holes for accommodating either multiple fasteners or to provide alternate locations for fasteners. The fasteners may be any one of those commonly used in the construction industry such as screws or nails, depending upon the composition of the underlying surface  70 . Permanent fasteners such as nails can be used, because the support member  10  or  30  is permanently mounted and does not need to be removed. Alternatively, if the underlying surface  70  is not amenable to accepting a fastener, such as concrete, steel or glass, then an adhesive material such as glue or double-sided tape may be used to secure the support member  10  or  30  to the underlying surface  70 .  
         [0028]     If the support member  10  or  30  is sized smaller than a side of the louver grille  50 , the fastening hole  12  in the support member  10  or  30  may be positioned over an intact portion of the underlying surface  70  and the support member  10  or  30  will still be covered by the louver grille  50 . This way, a fastener may be repositioned without having to reposition the louver grille  50 . An additional advantage to sizing the support member  10  or  30  smaller than a side of the louver grille  50  is that the support member  10  or  30  may be used with a variety of different grilles, so long as it is at least shorter than a side of a particular grille.  
         [0029]     The magnet  40  permits easy attachment and removal of the louver grille  50  to the support member  10  or  30 . If a ferromagnetic louver grille  50  is employed, then the magnet  40  may simply attach to both the louver grille  50  and the support member  10  or  30  by magnetic attraction. If louver grille  50  is made of a non-ferromagnetic material, such as aluminum, plastic or wood, then an adhesive material such as glue or double-sided tape may be used to attach the magnet  40  to the back face of the louver grille  50 . Once attached to the louver grille  50 , the magnet  40  may secure the louver grille  50  over the duct opening  60  by magnetic attraction to the support member.  
         [0030]     In order to maintain the magnet  40  in contact with both the support member  10  or  30  and the backside of the louver grille  50 , the thickness of the magnet  40  and support member  10  or  30  are chosen to approximately equal the depth of the edge that extends back from the periphery of the louver grille  50 . In this way, the back of the edge will be in contact with the surface  70  adjacent the duct opening  60  when the backside of the louver grille  50  is in contact with the magnet  40  that is in contact with the support member  10  or  30  secured to the surface  70 .  
         [0031]     Since not all louver grilles  50  have the same depth of edge, shims may be employed to increase the extent to which the support member  10  or  30  and magnet  40  project from the surface  70  until it equals the appropriate depth. In this way the system can accommodate a wide variety of louver grilles  50  without requiring prior knowledge of a particular grille&#39;s dimensions.  
         [0032]     Various embodiments of the present invention having been thus described in detail by way of example, it will be apparent to those skilled in the art that variations and modifications may be made without departing from the invention. The invention includes all such variations and modifications as fall within the scope of the appended claims.