Abstract:
An air flow damper is formed of a multi-apertured flexible sheet sandwiched between two multi-apertured rigid plates, the sheet being slidable between the rigid plates and movable from an open configuration to a closed configuration in which latter the apertures of the rigid plates are sealably closed by the flexible sheet.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    Benefit of U.S. Provisional Application for Patent Ser. No. 61/282,130 filed on Dec. 22, 2009, which is incorporated herein by reference, is hereby claimed. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an air damper apparatus, and is more particularly concerned with an air flow damper. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is well known in the art to use air flow dampers in to regulate the flow of air through or into a space, for example through an air duct into a neighbouring space, e.g. a room or refrigerator. For example, U.S. Pat. No. 7,152,419, issued to Armour et al., and U.S. Pat. No. 4,879,878, issued to Polkinghorne, teach conventional air flow dampers which include at least one rigid fixed plate and a rigid movable plate, the fixed plate and movable plate both having perforations or apertures spaced apart one another by intermediate portions extending therebetween. The movable plate is typically movable relative to the fixed plate between closed and open configurations for the damper in which the respective intermediate portions thereof cover, respectively, more or less of the respective apertures of the fixed plate and vice-versa. Thus, in the open configuration, the amount of air which may circulate through the apertures, and the damper, is greater than in the closed configuration, in which the apertures are preferably completely covered. Unfortunately, for such conventional dampers, due to the rigid nature of the plates, a small amount of air is able to pass therebetween, even when the dampers are in a closed configuration in which the apertures are preferably completely covered. 
         [0004]    Accordingly, there is a need for an improved air flow damper. 
       SUMMARY OF THE INVENTION 
       [0005]    It is therefore a general object of the present invention to provide an improved an improved air flow damper. 
         [0006]    An advantage of the present invention is that the air flow damper provided thereby offers increased blockage or dampening of air flow. 
         [0007]    Another advantage of the present invention is that the air flow damper provides the increased dampening regardless of the direction of the flow of air. 
         [0008]    In one aspect, the present invention provides an air flow damper comprising:
       first and second rigid plates having a plurality of plate apertures and a plurality of plate spacer portions separating the plate apertures, the rigid plates being rigidly connected to one another with the plate apertures and plate spacer portions on each plate aligned with one another; and   a flexible sheet extending proximally adjacent and between the rigid plates and having a plurality of sheet apertures and a plurality of sheet spacer portions, the sheet being movable between an open configuration, in which sheet apertures and plate apertures are aligned to enable flow of air, and a closed configuration in which the sheet spacer portions close the plate apertures, the sheet spacer portions being in use movable by the flow of air into at least partially sealing abutment with the plate spacer portions and partially through the plate apertures to provide at least partial sealing of the plate apertures by the sheet spacer portions thereby to dampen the flow of air.       
 
         [0011]    Other objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein, with appropriate reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Further aspects and advantages of the present invention will become better understood with reference to the description in association with the following Figures, in which similar references used in different Figures denote similar components, wherein: 
           [0013]      FIG. 1  is a front perspective view of an embodiment of an air flow damper in accordance with the present invention; 
           [0014]      FIG. 1   a  is an exploded view of the air flow damper shown in  FIG. 1 ; 
           [0015]      FIG. 2  is a side sectional view of the air damper, taken along line  2 - 2  of  FIG. 1  in a closed configuration therefor; 
           [0016]      FIG. 2   a  is a side sectional view of the air damper, taken along line  2 - 2  of  FIG. 1  in an open configuration therefor; 
           [0017]      FIG. 3  is a side sectional view of the air damper, taken along line  3 - 3  of  FIG. 1  in a closed configuration therefor; 
           [0018]      FIG. 3   a  is a side sectional view of the air damper, taken along line  3 - 3  of  FIG. 1  in an open configuration therefor; 
           [0019]      FIG. 4  is a partial enlarged view of a top bracket of the air flow damper shown in  FIG. 1 ; and 
           [0020]      FIG. 5  is a top sectional view of the of the air flow damper, taken along line  5 - 5  of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    With reference to the annexed drawings the preferred embodiments of the present invention will be herein described for indicative purpose and by no means as of limitation. 
         [0022]    Referring to  FIGS. 1 and 1   a , there is shown a front perspective view of an air flow damper, shown generally as  10 , in accordance with the present invention. As shown, the damper  10  includes first and second rigid plates, generally  12 , connected slightly spaced apart one from the other. An inner plate or sheet, shown generally as  14 , is movably, and preferably slidably, mounted between the plates  12 . The plates  12 , preferably identical, may be made of a rigid metal or plastic or the like. The sheet  14 , in contrast, is primarily constructed of a resilient and flexible material, such as a resilient and flexible plastic, but may have a plurality of at least partially rigid guide beams or ridges  50  extending from sheet retainer plate  132 , proximal sheet top  52 , to sheet bottom  54 . The guide ridges  50  are preferably parallel one another and protrude from both sheet faces  56  of the sheet  14 . 
         [0023]    The plates  12  are connected slightly spaced apart from one another by valve bracket, shown generally as  90 , and by spacing connectors, shown generally as  22 . The spacing connectors  22  are spaced apart and connect the plates  12  adjacent and along side walls  20  thereof. For example, the spacing connectors  22  may include spacing bolts  66  extending from inner plate face  58  of each plate  12  through bolt holes  60  of the other plate  12  and fixedly engaged in nuts or sockets  62  on the outer plate face  70  of the other plate  12  to connect the plates  12 . Each spacing bolt  66  has a spacing ring  64  against which the inner plate faces  58  of each plate  12  abut when connected to space the plates  12  apart from one another. 
         [0024]    Spacing apart of plates  12  is further ensured by upper plate wall  92  of each plate  12 , which extends across the top of plate  12  on both faces  58 ,  70  between plate side walls  20 . Specifically, the upper plate walls  92  are sized, shaped, and positioned to abut one another proximal side walls  20  over plate inner face  58  when the plates  12  are connected to one another by spacing connectors  22  and valve bracket  90 . An inner slot indentation  112  in each upper plate wall  92  forms a sheet slot  114  for sheet  14  between upper plate walls  92  when the plates  12  are connected. Similarly, first and second side brackets, shown generally as  116 , for receiving sheet mounting rods  120  are positioned on opposite ends  130  of the upper plate wall  92  proximal side wall  20 . Each side bracket  116  is formed from first and second side bracket halves  122 , one on each plate  12 , sized, shaped, and positioned such that when the plates  12  are connected to one another by spacing connectors  22  and valve bracket  90 , the side bracket halves  122  form side brackets  116 . The rod aperture indentations  126  of the halves  122  form a rod aperture  124  for each side bracket  116  through which rod  120  extends. 
         [0025]    Reference is now made to  FIGS. 1 ,  1   a , and  4 . The valve bracket  90  is fixedly connected to each plate  12  along upper plate wall  92 . Each plate  12  has a respective valve bracket half  94  connectable to the other bracket half  94 , by interlocking of outwardly protruding teeth  96  with inwardly recessed teeth  97  on top valve bracket plate  98  of each half  94 , to form the valve bracket  90 . Each top valve bracket plate  98  has a, preferably semicircular, mounting indentation  100 , which together form a, preferably circular, valve aperture  102  when the bracket halves  94  and plates  12  are connected and in which a solenoid valve  104  is mounted. 
         [0026]    The sheet  14  is connected at top sheet end  52  to plunger  106  of solenoid valve  104 , and is thereby movably mounted between plates  12 . Further, the sheet  14  is fixedly seated or held, proximal the top sheet end  52 , in a sheet retainer plate  132 . The sheet retainer plate  132  has sheet mounting rods  120  on opposing plate ends  134  thereof, each having an enlarged rod stopper  136  adjacent the retainer plate  132 . The sheet mounting rods  120  are positioned on the retainer plate  132 , and the side brackets  116  on the upper plate wall  92 , for slidable movable extension of the rods  120  in the rod mounting, or aperture,  124  of bracket  116  with sheet  14  extending through sheet slot  114  and the retainer plate  132  being disposed between the upper plate wall  92  and the upper side bracket wall  138  having rod apertures  124 . Accordingly, the retainer plate  132 , and notably sheet mounting rods  120  are movable back and forth in side brackets  116  through rod apertures  124  as sheet  14  is moved. The rod stopper  136 , however, is sized and shaped such that it may not pass through rod aperture  124  and thus limits movement of sheet  14 . Biasing means  140 , for example springs  140  through which rods  120  extend and which are connected to upper side bracket wall  138  and retainer plate  132  bias rods  120 , retainer plate  132  and sheet  14  upwardly away from upper plate wall  92 . 
         [0027]    Each rigid plate  12  has a plurality of spaced apart respective plate apertures  18  and a plurality of spaced apart respective plate spacer portions  16 , both plates  12  preferably having an identical number of spacer portions  16  and an identical number of, preferably identically sized and shaped, apertures  18 . As shown, the plate apertures  18  and spacer portions  16  are preferably rectangular in shape. On each plate  12 , each plate aperture  18  is separated, i.e. spaced apart, from any adjacent plate aperture  18  by an adjacent plate spacer portion  16  of the plate  12 , the spacer portions  16  being preferably greater in height than height of the plate apertures  18 . Thus, the plate apertures  18  are longitudinally spaced apart from one another by spacer portions  16 , the alternating apertures  18  and plate spacer portions  16  extending longitudinally between the upper plate wall  92  and plate bottom wall  74 . As shown, the plate apertures  18  and spacer portions  16  are preferably rectangular in shape, although other shapes may be envisaged. 
         [0028]    Reference is now made to  FIGS. 1 ,  1   a , and  5 . Each rigid plate  12  also has, preferably, a plurality of plate columns or groups  26  of alternating plate apertures  18  and plate spacer portions  16 , again extending between upper plate wall  92  and plate bottom wall  74 , separated by a plurality of spaced apart guide slots  68  formed in the inner plate face  58 . Again, the rigid plates  12  preferably have an identical quantity of plate groups  26  and guide slots  68 , with each grouping  26  separated by an intermediate guide slot  68 , one guide slot  68  for each guide ridge  50 . Each guide slot  68  extends from the plate top  72  to a bottom slot end  76  proximal the plate bottom  74 . The guide slots  68  are spaced apart from one another at the same distance as the guide ridges  50  of sheet  14 , and are sized and shaped for receiving guide ridges  50  of sheet  14 , with the guide ridge  50  being slidably movable therein. Thus, the sheet  14  is movable back and forth in the sheet slot  114  by solenoid valve  104  and springs  140 , with guide ridges  50  in guide slots  68 , as best shown in  FIG. 5 . Optionally, but preferably, the guide slots  68 , indented into inner face  58 , form corresponding outer ridges  28  on the outer plate face  70 . 
         [0029]    Reference is now made to  FIGS. 1 ,  2 ,  2   a,    3  and  3   a . As shown, the rigid plates  12  are connected such that the plate groupings  26 , plate apertures  18 , and plate spacer portions  16  of each plate  12  are aligned with one another such that, but for the presence of sheet  14 , the plate apertures  18  provide generally unobstructed passage through damper  10 . In other words, the plate apertures  18  and spacer portions  16  are sized, shaped and positioned such that each plate aperture  18  and spacer portion  16  of one plate  12  are generally aligned with, respectively, a corresponding plate aperture  18  and spacer portion  16  on the other plate  12 . 
         [0030]    Similar to the rigid plates  12 , the sheet  14  has a plurality of spaced apart sheet apertures  30  separated by sheet spacer portions  32  and which are similar in shape to, respectively, plate apertures  18  and plate spacer portions  16 , and which extend in sheet groupings  80  between retainer plate  132  and sheet bottom  54 , separated by guide ridges  50 . While alternative shapes may be envisaged, sheet apertures  30  and sheet spacer portions  32  are also preferably rectangular in shape. Preferably, the number of sheet groupings  80  is identical to the number of plate groups  26 , with each sheet aperture  30  and sheet spacer portion  32  of each sheet group  80  corresponding to aligned pairs of plate apertures  18  and plate spacer portions  16 . The sheet apertures  30  are of similar size to plate apertures  18 , but perhaps slightly smaller in their respective height compared to sheet aperture height. However, the sheet spacer portions  32  are larger than plate apertures  18  and sheet apertures  30 , notably of greater height. 
         [0031]    The sheet  14  is movable in sheet slot  114 , with guide ridges  50  sliding in guide slots  68 , towards plate bottom walls  74  from a default closed configuration, shown as  160 , into an open position or configuration, generally  162 , by extension of plunger  106  through actuation of valve  104 . As will be appreciated by one skilled in the art, the solenoid valve  104  is typically actuated by application of electrical current. When the solenoid valve  104  is deactuated, by cutting flow of electrical current thereto, the sheet  14 , plunger  106 , and retaining plate  132  are biased by springs  140  away from plate bottom walls  74  back into closed position or configuration  160 . 
         [0032]    In the open configuration, the plunger  106  is extended, thus extending or expanding springs  140 , and the sheet apertures  30  are aligned with, i.e. extend across, the plate apertures  18 , thus enabling flow of air A through apertures  14 , and damper  10 . In open configuration  162 , the sheet spacer portions  32  are aligned with plate spacer portions  16 , possible extending slightly into plate apertures  18 . Further, in open configuration  162 , the guide ridges  50  are preferably seated abutting bottom slot end  76  and the sheet retainer plate  132  abuts the upper plate wall  92  across sheet slot  114 . 
         [0033]    When the solenoid valve  104  is deactuated, the springs  140  resiliently contract upwardly away from upper plate wall  92 , thus pulling the retaining plate  132  and sheet upwardly away from plate bottom wall  74  into the closed configuration  160 , where the sheet spacer portions  32  are aligned with and overlay respective corresponding pairs of plate apertures  18  therefor. As the sheet spacer portions  32  are larger than the plate apertures  18 , the sheet spacer portions  32  extend completely to cover the plate apertures  18  and partially over adjacent plate spacer portions  16  in closed configuration  160 , thus dampening the air flow. Advantageously, due to flexible nature of sheet spacer portions  32 , the air flow pushes the sheet spacer portions  32  in a direction A of air flow into at least partially sealing abutment with the adjacent plate spacer portions  16  of the plate  12   a  positioned furthermost in direction A, thus providing at least partial sealing of plate apertures  18  of the plate  12   a  positioned furthermost in direction A. This partial sealing provides additional air flow dampening. Obviously, should the direction A of air flow be reversed, the air flow would push the sheet spacer portions  32  into at least partially sealing abutment with the adjacent plate spacer portions  16  of the other plate  12   b . As shown in  FIG. 3 , rod stopper  136  is sized, shaped, and positioned such that, when sheet  14  is in closed configuration, rod stopper  136  abuts against upper side bracket wall  138 , thus preventing further movement of sheet  14  by springs  140 . 
         [0034]    It should be noted that that the positioning of sheet  14  and orientation of the spacer portions  16 ,  32 , apertures  18 ,  30 , springs  140 , and solenoid valve  104  could be rearranged such that the open configuration  162  would be the default, maintained by springs  140 , and that the closed configuration would require extension of plunger  106 . Further, one skilled in the art will appreciate that the structure of the damper affords a rather simple assembly and construction. In brief, the plates  12  and sheets are manufactured separately. The plates  12  are then fastened to one another, with connectors  22  and bracket teeth  96  as described above, with sheet  14  engaged in sheet slot  114  and springs  140  placed in side brackets  116 . Conventional air flow damper fasteners  200  are used to attach damper  10  to a duct, conduit or the liked, and wire  202  provides connection to a source of electrical current to operate solenoid valve. Alternatively, a damper slot could be formed in a side of the duct and through which the damper  10  could be slidably inserted and removed, possibly with a clipping or snapping mechanism to hold the damper  10  in place, thus allowing easy removal and reattachment of the damper  10  for washing of the damper  10 . Such clipping mechanism could include a damper plate connected to the side of the duct, for example with screws, and having a plate slot aligned with the duct slot, the damper being snappably or clippingly retained and releasable on damper plate when slidably inserted and removed through damper and plate slots. 
         [0035]    Although the present damper has been described with a certain degree of particularity, it is to be understood that the disclosure has been made by way of example only and that the present invention is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope and spirit of the invention as hereinafter claimed.