Abstract:
A dryer vent designed to prevent bird and rodent ingress through the vent and further to prevent lint build-up includes a flap which has an edge portion recessed within the main body of the vent preventing birds and rodents from grasping the flap and opening it. Further, the dryer vent includes a rotating member such as a paddlewheel or a fan blade which rotates in response to air flowing through the vent thereby frightening birds and rodents.

Description:
BACKGROUND  
         [0001]    Household clothes dryers are typically vented through an exterior wall. The exterior opening is in turn generally covered by a hood or flaps. This prevents water from entering through the opening. Two problems that are typically encountered with dryer vents are lint build-up and bird and rodent ingress into the opening. Birds frequently will set up nests in the opening which in turn blocks the openings. Various guards and grills have been used to prevent this. Unfortunately these tend to accumulate lint which must be removed in order to ensure proper airflow. Both of these problems are even more significant when the vents are mounted above ground level and one does not have easy access to the dryer vent.  
         SUMMARY OF THE INVENTION  
         [0002]    The present invention is premised on the realization that a dryer vent which prevents rodents and birds from entering the opening and does not build up lint can be provided by incorporating a moving or rotating object in the air path which is caused to move or rotate by the exhaust air from the dryer.  
           [0003]    Further, the present invention utilizes a flap which is opened in response to this moving air. The flap has an outer edge which is recessed or protected to prevent a bird or rodent from grasping the edge of the flap, opening it and permitting access.  
           [0004]    The objects and advantages of the present invention will be further appreciated in light of the following detailed description and drawings in which: 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0005]    [0005]FIG. 1 is a perspective view of a first embodiment of the present invention.  
         [0006]    [0006]FIG. 2 is a cross-sectional view taken at lines  2 - 2  of FIG. 1.  
         [0007]    [0007]FIG. 3 is a perspective view of the vent shown in FIG. 1 partially in phantom and partially broken away.  
         [0008]    [0008]FIG. 4 is a cross-sectional view of an alternate embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0009]    The present invention is a dryer vent  10  having a front hood portion  12  and a rear circular edge  16  which defines a circular opening  18 . The hood is designed to face the exterior of a building and the edge  16  is extended through an opening (not shown) in the building. Between the hood portion  12  and the edge portion  16  is a plate portion  20  which defines opening  18 .  
         [0010]    Plate  20  includes an exterior flange  22  which provides a method to attach the vent  10  to the side  21  of a house. As shown, the edge  22  includes a plurality of nail holes  24 . Surrounding the opening on the outwardly facing side of plate  20  is a circular lip  26  which encircles at least the lower portion of the opening  18 . As shown, lip  26  extends from a left side  28  of hinge  34  to the right side  30 .  
         [0011]    The vent further includes a circular flap  32  which attaches to the main plate  20  at hinge structure  34 . This allows the flap  32  to rotate in the direction of arrow  36 .  
         [0012]    Flap  32  further includes a peripheral edge  48  which has a depth less than or equal to the depth of lip  26 . Thus when the flap is closed, its outboard edge is protected by lip  26 . In other words, lip  26  provides a portion of the plate that extends to the outer edge  48  of flap  32  or further preventing birds from grasping the edge  48  of the flap and opening it when the dryer is not in use.  
         [0013]    First and second tabs  38  and  40  extend from a lower extension portion  42  of plate  20  outwardly towards hood  12 . A shaft  44  runs between tabs  38  and  40 . As shown in FIG. 1, a paddlewheel fan blade  46  is rotably attached to shaft  44  permitting it to rotate freely. Alternatively, shaft  44  could be mounted to the side walls of the hood.  
         [0014]    To install the vent of the present invention, the rear edge  16  is attached to a conduit not shown which in turn is attached to the dryer exhaust. This tube can snap fit between edge  16  and lip  54  holding it in position. Nails or screws can be inserted through holes  24  holding the vent in position on the side  21  of the house.  
         [0015]    When the dryer is hooked up to this device, hot air will blow outwardly forcing the flap  32  to rotate in the direction of arrow  36  allowing the air to exhaust outwardly. This will also cause paddlewheel  46  to rotate which in turn will frighten rodents and birds, keeping them from attempting to enter the exhaust vent when the dryer is running.  
         [0016]    When the dryer is no longer operating, the flap  32  will fall back to the position shown in FIGS. 2 and 3 sealing the opening. Since the outer edge  48  of the lower portion of flap  32  is coterminous or even recessed within plate  20  (i.e., protected by lip  26 ), birds and rodents cannot easily grasp the edge  48  to open it and in fact would most likely attempt to pull on edge  26  to open the flap  32 . The upper portion of the flap  32  (although shown concealed) does not necessarily have to be protected as the rodents and birds cannot easily grasp the upper portion. However it is preferred to have this protective lip  26  extend substantially around the flap up to the hinge portion. The lip  26  can be removed and the flap  32  can simply be recessed in plate  20 .  
         [0017]    Since the fan wheel  46  can rotate easily, the flap  32  can open and engage the fan wheel  46 . Further, when the exhaust through the vent is discontinued, the fan wheel will allow the flap  32  to close.  
         [0018]    [0018]FIG. 4 shows an alternate embodiment of the present invention. Since the purpose of the invention is simply to maintain something in rotation in the open portion of the vent to deter rodents and birds from entering, this utilizes an alternate moving structure specifically this is a fan blade  60  rotably attached to a central shaft  62  which is in turn fixed to shaft  44  as shown in FIG. 3. Since both fan blades  46  and  60  rotate when the exhaust is blowing through the vent, lint does not tend to build up on the structures. Thus, even though they are directly in the air path, they do not accumulate lint.  
         [0019]    Although it is preferred to incorporate both a rotatable object and a protected flap edge in the vent, either of these features will independently deter rodents and birds from entering the exhaust opening  18 . Further, other movable structures other than the paddlewheel and fan blade shown in the Figures can be used to provide the same benefit as long as they are designed to move continuously in response to the air flow and preferably rotate in response to the air flow.  
         [0020]    This has been a description of the present invention along with the preferred method of practicing the invention, however, the invention itself should only be defined by the appended claims wherein