Abstract:
The present invention is an improved duct end filtering device which increases the efficiency of a duct-end filter and which increases the ease with which filters can be removed and replaced.

Description:
This application claims benefit of a provisional application No. 60/367,669 filed on Mar. 26, 2002. 

   TECHNICAL FIELD 
   This invention relates to improvements in a duct end filter apparatus, and more particularly to novel means for increasing the efficiency of and removing of the filter components of the same. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a Filter Apparatus and more particularly pertains to an Improved Duct End Filter Apparatus which permits a user to readily change filter inserts by novel means and which also contains novel means designed to maximize the filter&#39;s efficiency by increasing the filter&#39;s contact with the grill. 
   2. Description of the Prior Art 
   The use of Filter Apparatus is known in the prior art. More specifically, Filter Apparatus heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the wide variety of designs encompassed by the crowded prior art which have been developed for the fulfillment of myriad objectives and requirements. 
   Known prior art Filter Apparatus include U.S. Pat. Nos. 4,334,899, 5,114,448, 5,176,570, 5,462,569, 5,525,145, 5,689,969, and 5,863,310. Known prior art devices which specifically increase a filter&#39;s contact with a frame include U.S. Pat. No. 4,601,737. 
   While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose an Improved Duct End Filter Apparatus. The inventive device includes a filter insert, a grill, a housing with sub-elements that increase the surface contact between the filter insert and the grill, and a filter support frame, or bezel, which facilitates the easy removal of the filter insert. 
   In these respects, the Improved Duct End Filter Apparatus according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus which significantly improves the efficiency and ease of maintenance of conventional duct end filter apparatus. 
   SUMMARY OF THE INVENTION 
   It is among the objectives of the invention to provide a duct end filtering apparatus which improves the efficiency of the filter by increasing the degree to which the filter contacts the grill and housing. 
   Another objective of the invention is to facilitate easy removal of the filter by means of a grill that friction-fits into the housing and a filter that is in slideable engagement with the grill and bezel. 
   A further objective of the invention is to provide a vent or cold air return device which installs in such a way that no screws are apparent from the device&#39;s exterior. 
   Still another objective of the invention is to provide the aforementioned increased filtering efficiency at a lower cost by virtue of the invention&#39;s lack of a need for gaskets or seals aside from those produced by its novel friction fit design. 
   Another objective of the invention is to provide a duct end filtering system that is made of plastic that is colored, thereby eliminating the need to paint the components of the system that normally would require painting. 
   In accordance with the invention there is provided a housing of the sort designed for forced air heating and cooling vents or for cold air return vents. The housing may contain pre-drilled holes for mounting which are preferably positioned such that they will be covered by the grill when that element is in place. The housing contains sub-elements which are designed to facilitate the filter&#39;s contact with the grill. In the case of one embodiment of vents, these sub-elements are one or more, preferably two, extensions from the housing apparatus. In the case of a second embodiment of vents, this sub-element extends at least partially along the back of the housing element, preferably across the housing element, and the sub-element contacts the filter by means of extensions from the sub-element. The housing further contains one or more slots designed to accept hinge flanges attached to the grill and a lip area or areas along the inside of its opening for accepting the friction-fit flange or flanges attached to the grill element. 
   In further accordance with the invention there is provided a grill that connects to the housing by means of one or more, hinge flange sub-elements preferably located at the bottom of the grill and a friction fit by means of one or more, flange sub-elements preferably located at the top of the grill. The grill may contain fixed or adjustable louvers for the direction of air flow. There is also provided a filter which may or may not be disposable and which may be of a 2-ply construction. The filter preferably contacts the grill and the sub-elements of the housing element and rests inside of the bezel element. The bezel is attached, preferably in a non-removable fashion, to the grill and permits the filter to be slid in and out easily. The grill attaches to the housing, or is held in place by, snap fit means such as tabs or flanges. The outer dimensions of the bezel attached to the grill are preferably less than or equal to the outer dimensions of the bottom and sides of the housing and the inner dimensions of the bezel are preferably greater than or equal to the dimensions of the area of the grill element through which air flows. In any event, the bezel should preferably not significantly impede the flow of air through the filter element or the grill element. 
   Any or all of the components of the apparatus, including the housing, bezel, and grill, may be made of plastic, preferably ABS. Elements made of plastic may be pigmented in any desired color. 
   These and other objects and advantages will become apparent from the following description of two particular forms of the invention as illustrated in the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded front view of the invention as the invention is embodied as a hot or cold air vent; 
       FIG. 2  is an exploded front view of the invention as the invention is embodied as a cold air return vent; and 
       FIG. 3  is an exploded front view of the invention as the invention is embodied as a multi-direction diffuser. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings in which like reference numerals index like parts, there are shown the preferred embodiments of the present invention both as a cold or hot air vent and as a cold air return vent. 
   The embodiment illustrated in  FIG. 1  is intended for use as a duct end filtering apparatus for attachment most commonly to a heating or air conditioning vent. In the embodiment illustrated in  FIG. 1 , the housing element  26  mounts to a surface by means of screws  22 . The housing has predrilled holes to accept the screws  24 , which predrilled holes are located such that they will not preferably be visible from the exterior of the apparatus when it is fully assembled. The louvered grill  12  attaches to the housing  26  first by means of the hinge flanges  10  which are accepted by the corresponding hinge notches  18 . The filter  14  is placed behind the grill element  12  by sliding it behind the grill  12  into the bezel  16  attached to the grill  12 . The grill is then affixed to the housing element  26  by means of the snap-fit flanges  20 . When the entire apparatus is assembled, the extensions  28  protruding from the housing  26  will be in contact with the filter  14  and will hold the filter  14  in close proximity to the grill  12 . In this embodiment the grill  12 , housing  26 , bezel  16 , and extensions protruding from the housing  26  are made of ABS plastic. 
   In use, a user would first affix the housing  26  to a wall at a duct end of an air conditioning or heating system by means of screws  22 , which screws would be accepted by the predrilled holes  24 . The user would then affix the lower portion of the combined grill  12  and bezel  16  to the housing  26  by means of inserting the hinge flanges  10  into the corresponding hinge notches  18 . The user would then slide the filter  14  behind the grill  12  and into the bezel  16 . Finally, the user would close the system by attaching the top of the grill  12  to the housing  26  by pressing the snap-fit flanges  20  into the housing  26 , where they engage in a snap-fit. Once the system is assembled, it would filter air passing through it, which filtering would be improved by means of the extensions  28  holding the filter  14  close to the grill  12 . The user would be able to readily change the filter  14  by first opening the snap-fit of the top of the grill  12  to the housing  26  and then pivoting the grill  12  along the hinge formed by the hinge flanges  10  and the corresponding hinge notches  18 , sliding the filter  14  out from behind the grill  12  and inserting either the same filter after it has been cleaned or else an entirely new filter. 
   The embodiment illustrated in  FIG. 2  is intended for use as a duct end filtering apparatus most commonly for attachment to a cold air return vent. In the embodiment illustrated in  FIG. 2 , the housing element  26  mounts to a surface by means of screws  22 . The housing has predrilled holes to accept the screws  24 , which predrilled holes are located such that they will not be visible from the exterior of the apparatus when it is fully assembled. The louvered grill  12  attaches to the housing  26  first by means of the hinge flanges  10  which are accepted by the corresponding hinge notches  18 . The filter  14  is placed behind the grill  12  by sliding it behind the grill  12  into the bezel  16  attached to the grill  12 . The grill  12  is then affixed to the housing  26  by means of the snap-fit flanges  20 . When the entire apparatus is assembled, the cross-member sub-element  30  will hold the filter element  14  in close proximity with the grill element  12  by virtue of the raised portions&#39;  32  of the cross-member sub-element  30  contact with the filter element  14 . In this embodiment the grill  12 , housing  26 , bezel  16 , cross-member sub-element  30  and the raised portions of the cross-member sub-element  32  are made of ABS plastic. Alternatively, the housing of each embodiment may not require predrilled holes and it is contemplated that the bezel may be attached to the housing while still accomplishing the purposes of the invention. 
   In use, a user would first affix the housing  26  to a wall at a duct end of an air conditioning or heating system by means of screws  22 , which screws would be accepted by the predrilled holes  24 . The user would then affix the lower portion of the combined grill  12  and bezel  16  to the housing  26  by means of inserting the hinge flanges  10  into the corresponding hinge notches  18 . The user would then slide the filter  14  behind the grill  12  and into the bezel  16 . Finally, the user would close the system by attaching the top of the grill  12  to the housing  26  by pressing the snap-fit flanges  20  into the housing  26 , where they engage in a snap-fit. Once the system is assembled, it would filter air passing through it, which filtering would be improved by means of the raised portions  32  of the cross-member holding the filter  14  close to the grill  12 . The user would be able to readily change the filter  14  by first opening the snap-fit of the top of the grill  12  to the housing  26  and then pivoting the grill  12  along the hinge formed by the hinge flanges  10  and the corresponding hinge notches  18 , sliding the filter  14  out from behind the grill  12  and inserting either the same filter after it has been cleaned or else an entirely new filter. Yet a further embodiment is shown in  FIG. 3  as a multi-direction diffuser commonly used in industrial or commercial heating or air conditioning systems. Such a diffuser is available commonly available as a one, two, three or four way deflector and located at the open end of a duct, either mounted vertically in a wall or horizontally as suspended from a ceiling, This diffuser unit also contains a removable filter, a grill with an attached bezel  46  for slideably engaging the filter  44 . When suspended from the ceiling the housing  56  may actually lay between the overhead ceiling tiles attached to the heat or cold end cap by an adapter which engages the grill in a hinged snap-fit or locking mechanism ( 40 ,  48 ) in order that the filter is held in close proximity to the grill  42 . 
   A preferred filter for all embodiments in a 2 ply construction with a first layer polysorb pad and a second layer of laminated polysorb and electret, one such source being Columbus Industries, Inc, of Ashville, Ohio. However, it should be recognized that any number of filter materials intended to trap or collect airborne particles is contemplated. It is expected that the choice of filter material may vary based on the types and sizes of airborne particles to be collected.