Abstract:
A support frame is used to hold the position of a vertically-disposed air duct within a wall between wall studs. The support frame defines an opening that receives the air duct. The support frame has a flange extending around the opening that engages the air duct. The support frame may include notched ends that receive the opposed wall studs to position the support frame with respect to the duct opening formed in the floor boards.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field  
         [0002]     The present invention generally relates to heating, ventilation, and air conditioning installations and, more particularly, to the supports used to hold the air ducts in place. Specifically, the present invention relates to a support frame for a duct that is installed in a vertical wall between studs.  
         [0003]     2. Background Information  
         [0004]     Numerous air duct installations require a duct to be run in a vertical wall. One such installation is a cold air return duct that is run from the second floor of a house through the first floor wall into the basement. In this case, the duct passes through an opening formed in the second floor floor boards and an opening formed in the first floor floor boards. A metal duct is then positioned down or up through these openings between wall studs. This vertical section of duct must be securely held in place. In the past, the person installing the duct would have to fabricate custom holders on the job site from scrap material and use these holders to secure the vertical duct in place. Duct installers desire an improved support that obviates the need to custom form supports in the field.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     The invention provides a support frame configured to fit between wall studs. The support frame has a central opening adapted to receive a vertical air duct. The central opening may be rectangular or oval. Both openings are defined by upstanding flanges that are tilted inwardly toward each other to provide a frictional fit with the duct. The flanges are adjustable to accommodate ducts of different dimensions.  
         [0006]     The invention also provides a frame having formed notches adapted to receive standard studs to properly position the frame and opening with respect to the studs. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0007]      FIG. 1  is a perspective view of the support frame for a duct made in accordance with the concepts of the present invention.  
         [0008]      FIG. 2  is a top plan view of  FIG. 1 .  
         [0009]      FIG. 3  is a front elevation view of  FIG. 2 .  
         [0010]      FIG. 4  is a side elevation view of  FIG. 2 .  
         [0011]      FIG. 5  is a perspective view of a section of floorboard, floor joists, and wall studs with a duct opening formed in the floor boards between the wall studs.  
         [0012]      FIG. 6  is a view similar to  FIG. 5  showing a section of vertical duct being disposed in the duct opening with the support frame of the present invention being positioned between the wall studs.  
         [0013]      FIG. 7  is a view similar to  FIG. 6  showing the support frame of the present invention in an installed position.  
         [0014]      FIG. 8  is a top plan view of the assembly of  FIG. 7 .  
         [0015]      FIG. 9  is a section view taken along line  9 - 9  of  FIG. 8 .  
         [0016]      FIG. 10  is a front elevation view of the vertical duct extending between a floor and a ceiling and held in place with a pair of the support frames of the present invention.  
         [0017]      FIG. 11  is a perspective view of the support frame for an oval duct.  
         [0018]      FIG. 12  is a top plan view of  FIG. 11 .  
         [0019]      FIG. 13  is a front elevation view of  FIG. 12 .  
         [0020]      FIG. 14  is a side elevation view of  FIG. 12 . 
     
    
       [0021]     Similar numbers refer to similar parts throughout the specification.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     The support frame of the present invention is indicated generally by the numeral  10  in the accompanying drawings. Support frame  10  is used to hold the position of an air duct  12  in a wall  14  with respect to a floor board  16  as shown in  FIG. 7 . Support frame  10  is preferably fabricated from metal so that it will not burn or spread flames that may be disposed inside air duct  12 . Support frame  10  is configured to fit between the wall studs  18  of wall  14  and center air duct  12  with respect to the duct opening  20  defined by floor  16 . The person installing air duct  12  may thus easily position the upper and lower ends of air duct  12  as shown in  FIG. 10 . Support frame  10  is provided in at least two embodiments for rectangular and oval ducts as shown in  FIGS. 1 and 11 . Each embodiment is capable of supporting slightly different-sized ducts  12 . Each embodiment is also adapted to substantially seal duct opening  20  to prevent air from leaking through duct opening  20  after air duct  12  is installed.  
         [0023]     Support frame  10  includes a body  22  in the form of a thin plate. Body  22  defines a central opening  24  adapted to receive air duct  12 . As such, opening  24  has an outer perimeter that is larger than the outer perimeter of air duct  12  so that air duct  12  may readily slide through central opening  24 . Body  22  has a lengthwise direction and opposed ends at ends  26  at opposite ends of the lengthwise direction of body  22 . Each end  26  defines a notch  28  that is adapted to receive a portion of wall stud  18 . Central opening  24  is centered with respect to notches  28  allowing the user to properly locate central opening  24  with respect to wall studs  18  as depicted in  FIG. 6 . Body  22  thus extends beyond each wall stud  18  as depicted in  FIG. 7  so that duct opening  20  is sealed by body  22  when support frame  10  is installed. In an alternative embodiment of the invention, the overall length of body  22  may be reduced and notches  28  may be eliminated. In this embodiment, the person installing frame  10  determines the position of body  22  between studs  18 .  
         [0024]     Support frame  10  further includes a flange  30  that extends up from body  22  adjacent opening  24 . Flange  30  is angled inwardly with respect to opening  24  as shown in  FIGS. 2-4  and  12 - 14 . In the rectangular embodiment of the invention depicted in  FIGS. 1-4 , flange  30  is provided in the form of four flange sections  32  that are disposed on opposed sides of rectangular opening  24 . As depicted in  FIGS. 2-4 , opposed flange sections  32  are angled toward each other. Flange sections  32  may thus pivot with respect to body  22  to accommodate differently-sized air ducts  12 . The pivoting nature of flange sections  32  also provide a biasing force against air duct  12  to dampen vibrations and to help hold air duct  12  before connectors  34  are used to connect flange sections  32  to air duct  12 . In the oval embodiment of support frame  10  depicted in  FIGS. 11-14 , flange  30  is continuous about opening  24 . Flange  30  is angled inwardly to define a frustum as shown in  FIGS. 13 and 14 . The angled nature of flange  30  allows flange  30  in the oval embodiment of support frame  10  to accommodate air ducts  12  of slightly differing sizes. The angled nature also creates a biasing force against air duct  12  from flange  30  to dampen vibrations and to help hold air duct  12  in place before connectors  34  are installed. In either embodiment, flange  30  may include tabs  36  that extend from the upper end of flange  30 . Tabs  36  are also angled inwardly as depicted in  FIG. 14  and provide additional biasing force and adjustment capabilities to support frame  10 . Each flange  36  defines at least one connector opening  38  adapted to receive connector  32 . In the preferred embodiment, each connector opening  38  is adapted to receive a sheet metal screw  34  in a manner that allows the threads of the sheet metal screw to bite into tab  36 . Flange  30  and tabs  36  may also be trimmed with appropriate cutters by the person installing air duct  12  if the outer dimension of air duct  12  is too large to be received by flange  30 . The user may also cut slits into flange  30  to increase its flexibility if needed.  
         [0025]     Body  22  defines a plurality of connector openings  38  with a series of openings disposed in opposed lengthwise directions along the opposed lengthwise edges of body  22 . Body  22  also defines one opening adjacent notch  28 . Openings  38  may be adapted to receive sheet metal screws as described above or nails.  
         [0026]     Support frame  10  is used with a duct installation assembly as shown in  FIGS. 5-10 .  FIG. 5  depicts the rough opening having opposed wall studs  18  extending up from floor board  16  on either side of a duct opening  20 . The installer may position duct  12  up through opening  20  and then slide support frame  10  down over the end air duct  12 . The user may also first install support frame  10  by positioning notches  28  about studs  18  and securing body  22  to floor  16  with appropriate connectors in a nature of screws or nails. In some cases, body  22  may also be secured with an appropriate adhesive. Once support frame  10  is secured, the user may push duct  12  up through central opening  24  until air duct  12  is properly positioned with respect to floor  16  and studs  18 . The user may then connect flange  30  to air duct  12  with connectors  34  as depicted in  FIG. 7 .  FIGS. 7 and 8  show how support frame  10  seals opening  20  to prevent undesired airflow between different floors of the building.  FIG. 10  shows how air duct  12  is securely held by support frame  10  on different floors of the building.  
         [0027]     Although the installation drawings show support frame  10  used with a rectangular duct, the same steps may be used to install an oval duct. The oval embodiment of support frame  10  is also intended to be used with round ducts by changing the shape of central opening  24  and flange  30 . In this application, the term oval includes shapes having straight sidewalls and curved ends as shown in  FIG. 12 , circular shaped, and egg or elliptical shapes.  
         [0028]     Body  22  may be fabricated in standard  16  inch lengths to fit between standard wall studs  18 . The  16  inch length allows support frames  10  to be used with adjacent studs without overlapping the ends of body  22 . The dimensions of central opening  24  may be varied so that support frame  10  will work with different sized ducts  12 . Central opening  24  should remain centered between the ends and sides of body  22  regardless of the dimensions of central opening  24 .  
         [0029]     In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.  
         [0030]     Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.