Abstract:
A goose neck style vent has a base that registers with a surface opening of a building, and upstanding walls which form a portion of a curved air flow pathway above the vent opening. A top portion of the vent registers with the base to complete the curved air flow pathway and define an air outlet opening. The top includes a screen that hinges to cover the air outlet opening. A flapper valve is positioned across the curved air flow pathway and is hinged to the base at one end. The opposite free end of the flapper valve is urged to a closed position by gravity and to an open position by air pressure from below. An upstanding air deflecting baffle extends above the free end of the flapper, and limits air gusts passing through the screen and under the free end of the flapper valve.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to the field of ventilation products and more particularly to exterior vents of the type that are used to vent the inside of buildings. Most particularly this invention relates to exterior vents which may be used to vent air from bathrooms, kitchens, dryers and the like or to allow air into the building in certain circumstances. 
       BACKGROUND OF THE INVENTION 
       [0002]    Modern buildings are being made ever more energy efficient which often translates into better insulation and less air infiltration through cracks, gaps or the like. As a consequence, the airflow into and out of the building envelope must be very carefully managed. 
         [0003]    Another consequence of a tighter building envelope however is the need to manage the exhaust air flow which may be required from other building systems. Three systems in particular have localized blowers to force vent air in certain circumstances, and they include bathroom exhaust fans, to vent moisture laden air from bathrooms, kitchen exhaust fans to vent the by products of cooking which may include steam, greasy vapours and smoke, and electric dryer exhausts, which again are for the purpose of venting moist air from the drying of laundry inside a dwelling or building envelope. 
         [0004]    Particular to these types of exhaust air is the back pressure created by the local appliance, such as the bathroom exhaust fan, the kitchen exhaust fan and the electric dryer exhaust blower. Also particular to these types of exhausts is the need to let the exhaust air out when there is a need to, but to prevent air from leaking out, or more precisely to prevent outside air from leaking in or infiltrating into the building envelope, when the appliance is not in use. Concomitant with this there is a need to make the air flow passageway impervious to pests, animals, rodents and the like, that might otherwise try to gain entry into the building. 
         [0005]    As a result, there is a need for vents which permit the air to be vented outside of the building, but which prevent unwanted air from infiltrating back into the building and which are protected from pests. Typically a flapper valve is used for this purpose which can open when the air is being exhausted and which closes when there is no air flow. A secondary need is to provide a screen or other structure which can be used to prevent animals or pests from getting into the building through the vent opening. 
         [0006]    Various designs have been proposed in the past including vents made from metal, but these tend to be expensive and easily damaged in transit. Further a metal flapper valve can make quite a bit of noise when it opens and closes. A problem with prior art designs is that wind or weather can change the air pressure around the exterior of the vent causing the flapper to flap up and down even when the inside appliance is not turned on and there is no need for the vent to be open. This constant chatter can become a serious issue to an occupant. 
       SUMMARY OF THE INVENTION 
       [0007]    What is desired is a simple to use, inexpensive, easy to install, and aesthetically pleasing vent that will allow air to escape when it is desired and yet will protect the vent from unwanted opening and closing of the flapper valve. Such a design would preferably be quiet and reliable and should also prevent unwanted pests and the like from intruding into the building through the vent. Such a vent would preferably respond to the need to vent air, but would otherwise be reliably closed to prevent the infiltration of weather and outside air. 
         [0008]    The present invention provides in a preferred embodiment a form of an inexpensive and yet durable vent. The vent may be formed from a flexible material such as sheet metal or molded plastic, such as polypropylene, which is durable and not easily damaged. Such a plastic vent will preferably have a flapper valve that opens and closes silently as compared to the prior art metal devices. The vent may include a built-in screen to limit weather and pests from impinging on the flapper valve or getting into the building through the vent. Most preferably the vent can be comprised of a number of separate elements that are easily molded and which can be easily assembled to form a complete vent structure having certain desirable features as explained below. 
         [0009]    Therefore, according to a first aspect the present invention provides an exterior vent for venting an interior space through a sloped surface opening in a building envelope, the exterior vent comprising: 
         [0010]    a base having a vent opening for registering with the surface opening in the building envelope and an attachment flange surrounding said vent opening for securing said vent to an outer surface of said building envelope around said surface opening; said base further having upstanding side and end walls to define said vent opening and to form a portion of a curved air flow pathway above said vent opening, 
         [0011]    a screen, 
         [0012]    a top which registers with said base to complete said curved air flow pathway and to define an air outlet opening which is facing generally in a different direction from said vent opening, said top including a screen secured to said top by means of a hinge, said top including attachment means to secure said top portion to said base and to trap said screen between said base and said top portion whereby said air outlet opening is covered by said screen, and 
         [0013]    a flapper valve positioned across said curved air flow pathway, said flapper valve being hinged to said base and having a free end; said flapper valve being urged to a closed position by gravity and to an open position by air pressure from below, said vent including a rest for said free end of said baffle, said rest having an upstanding weather deflecting baffle extending above said free end to limit air gusts from passing through said screen and under said free end of said flapper valve. 
         [0014]    In an alternate embodiment the present invention can be used as an air intake vent, with the flapper valve removed. The vent can also be used on a sloped roof surface. Another aspect of the invention includes an adaptor collar to interface with at least two and preferably three different duct sizes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Reference will now be made by way of example only to preferred embodiments of the invention by reference to the following drawings in which: 
           [0016]      FIG. 1  is a perspective view of an exterior vent according to the present invention; 
           [0017]      FIG. 2  is a cross sectional view along lines  2 - 2  of  FIG. 1 ; 
           [0018]      FIG. 3  is an exploded view of the adaptor collar, the flapper valve and the base portion of the vent of  FIGS. 1 and 2  with the top removed; 
           [0019]      FIG. 4  is a perspective view of a top portion of the vent of  FIG. 1 ; 
           [0020]      FIG. 5  is a perspective view the top portion of the vent with the first screen embodiment; 
           [0021]      FIG. 6  is a view of a duct collar of the present invention; 
           [0022]      FIG. 7  is a sectional view of the top and grill sections  FIG. 1  having a first screen embodiment; and 
           [0023]      FIG. 8  is a cross-sectional view of the components together as installed on a sloped roof surface. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    A gooseneck style vent, according to a preferred embodiment of the invention, is shown as  10  in  FIG. 1 . It includes a top  12  and a base  14 . A join line  16  exists between the base  14  and the top  12 . The base also includes a nailing flange  18  and a duct connector  20  ( FIG. 2 ) extending from said base  14  on an opposite side to said top 
         [0025]      FIG. 2  is a cross-sectional view through the duct connector  20 , the base  14  and the top  12 . As can be seen, the duct connector  20  includes at least two and in a preferred embodiment three different sized connectors for connecting to different sized ducts. These are shown as  22 ,  24  and  26  respectively. Most preferably, an installer would determine the duct size being connected to the duct and would remove with a knife or other sharp edge any connector sections which were too small. In this way a single connector can be made adaptable to at least two and preferably three standard duct sizes. 
         [0026]    The vent  10  of the present invention defines an air passageway having discreet sections. The first section  30  is the inside of the duct connector  20 . The next section  32  is inside of base  14  above the nailing flange  18 , but below a flapper valve shown as  34 . The next section  36  is between the flapper valve  34  and a screen  38  inside of top  12 . The next section is the flow through the screen  38 . The last portion is below the screen  38  and may be called an air flow outlet  40  described in more detail below. Each section of the airflow passageway through the vent is separately described below. 
         [0027]    The first section  30  of the air flow passageway is the duct connector portion  20 . As noted above, the present invention is intended to be easily field fastened to a duct leading from an air exhausting source (not shown). The source can be any conventional type of blower such as a bathroom fan, a kitchen fan, a dryer blower or the like. In most cases the blower will be designed to work with a standard sized round duct, which is piped from the blower location to the location where the vent is to be installed. This may be, for example, on a sloped roof surface of a building. The three different diameters presented by the duct connector  20  permit the installer to connect the duct to the vent in an air tight manner with a minimum of effort. All that is needed is to remove the duct diameter connectors which are too small. The connector  20  may be made from an easy to cut material, such as plastic, to facilitate the removal of the unwanted connector sections. While the cut can be made in a number of places it is preferred to cut through the horizontal platforms or steps between each duct section for each of access. As described in more detail below, a thin cut line or guide can be provided to assist in the trim step. 
         [0028]    The next section  32  of the airflow passageway is located in the base  14  of the vent  10  underneath the flapper valve  34 . In general the flapper valve  34  is hinged at one end  50  and has free end  52  which sits on a seat  54 . Gravity closes the flapper valve and urges the free end  52  onto the seat  54 . Air pressure below the flapper valve, created for example by an air exhausting source, will lift the flapper valve off the seat allowing the air to escape. 
         [0029]    The escaped air is now in the next section  36  between the flapper valve  34  and the screen  38 . The air can pass through the three dimensional screen  38  and then is found in the air outlet section  40 . This section  40  is defined by weather protecting side baffles  60  and an overhanging weather baffle  62 . These baffles help protect the screen  38  from inclement weather by restricting the ability of precipitation to impinge directly upon the screen  38 . It will be noted that the screen  38  is generally facing in a different direction in the air flow passageway from the duct connector  20 . In addition the screen  38  is designed to have generally rectangular corrugations  42  having outwardly facing surfaces  44  and secondary surfaces  46  perpendicular to the outwardly facing surfaces. In a preferred embodiment the outwardly facing surfaces can be made solid and the perpendicular surfaces can be made with grills  48  so that the air can flow out but weather, such as precipitation, which impinges on the screen from directly below is blocked. This style of screen may be called a three dimensional screen. 
         [0030]      FIG. 3  shows the base  14  separated from the other parts. The base  14  includes an angled throat section  70  which defines the second air flow passageway  32  below the flapper valve  34 . It can now be understood that the flapper valve  34  is easily snapped into place by means of opposed hinge pins  72  best seen in  FIGS. 2 and 8 ) built into flapper  34 . Opposed support flanges  71  and  73  are molded in to the base to provide a female snap feature for pivotally retaining each of the hinge pins  72 . Also shown are upwardly directed faces  74  and  76  which include attachment openings  78 . Four such openings  78  are shown, although more or fewer can also be used. The attachment openings  78  are to secure male attachment members  94  located in the top  12  as described below. 
         [0031]    Also shown is a ledge  80 , which goes up one side and then across the back and then down the other side. The base  14  has an angled top edge  82  and the ledge  80  may be generally parallel to or angled relative to the top edge  82  as it goes around the base  14 . The function of the ledge  80  is described in more detail below. 
         [0032]      FIG. 4  shows the top  12  with the preferred curved side baffles  60  and the overhanging baffle  62 , all of which may be used to shelter the screen  39  from inclement weather. The screen  39  is a second embodiment of the screen which may be preferred to use on a dryer vent. In this case, the screen is very open so that lint does not collect which could otherwise block the grill if the openings were smaller as shown in the first embodiment of  FIG. 1 . As shown the screen  39  is an outward position but is hinged to the top  12  along line  86 . Recesses  88  are formed so that when the screen  39  is hinged under, tabs on the screen register with the recesses  88  and can be secured therein. The recesses  88  are positioned so that the male members  94  register with attachment openings  78  in the base  14  when the recesses  88  are engaged. By means of the hinge line  86  which is the connection between the screen and the top the two parts can be molded together and then when it is time to assemble the top to the base, the hinge can be used to fold the screen under the front edge of the top in direction of arrow  90  until is covers the air outlet opening as shown in  FIG. 4 . Alternatively the screen could be a separate part, sandwiched between the top and the bottom. 
         [0033]      FIG. 5  shows an underside view of the screen  38  in the folded over position. Male attachment members  86  which are positioned to mate with the four attachment openings  78  formed in the base  14 . By means of the arrow headed ends  96  on the attachment members  94  they can be force fit through the openings and then locked in place against the underside of the ledge to secure the top  12  to the base  14 . While this provides good results it will be understood by those skilled in the art that various other locking configurations can be used without departing from the scope of the invention. Also, as shown in  FIG. 5 , are tabs  100  and  102  molded on the side edges of the screen  38  which snap into recesses  88  molded into top  12 . In the assembled configuration as shown in  FIG. 2 , the screen has been folded over and one edge  104  rests in the upwardly directed face  74 . Thus when the screen is trapped between the top  12  and the base  14 , one edge rests on the face  74  and the tabs  100  and  102  extending from the sides of the screen  38  engage with the recesses  88  in top  12  to support the sides of the screen so it is firmly held in place. 
         [0034]    It can now be appreciated that two transverse weather baffles can be formed in association with the screen. One, close to the hinge, rotates downwardly as the screen is rotated under and ends up becoming the overhanging baffle  62 . A second which extends in an opposite direction and is located towards a free end of said screen is rotated into place as an internal weather deflecting baffle  106  (best seen in  FIG. 2 ). Once the screen is locked in place between the top and the base, the baffle  106  is positioned above the valve seat of the flapper valve to protect the flapper valve from inclement weather or gusts of wind that might pass through the screen. Such an internal weather deflecting baffle helps to prevent the flapper valve from being constantly displaced by stray air currents. In this way the clattering noise associated with some of the prior art designs, which noise is caused by the constant banging of the flapper valve up and down, may be mitigated. 
         [0035]      FIG. 6  shows the duct connector  20  which may be used as part of the present invention. As can be seen, in this form it is a separate element that can be installed beneath the nailing flange  18  of the base  14  and which extends backwardly through the opening in the building envelope to connect with a duct carrying the air to be exhausted. It can be secured to the base  14  by gluing or the like, or it can be simply fit onto the duct as appropriate and then the base  14  can be nailed in place over top of the duct connector with nails or other fasteners that at the same time fasten the duct connector in place. The duct connection can be provided with cut guides  106 ,  105  as shown between the steps  26 ,  29  and  22 . 
         [0036]      FIG. 7  shows the screen  38  and top portion  12  as molded. In this configuration, the screen  38  is in an extended position, which best demonstrates the relationship of the two weather baffles to the screen  38 . As noted above, overhanging baffle  62  is located at the end closest to the hinge  92 , and will extend downwardly as the screen is rotated into its folded over position. At the opposing end of screen  38  is an extension that is angled such that, when the screen is rotated into its folded position, it rests flat against upwardly directed face  74  on the base  14  (see  FIG. 2 ) and will become seat  54  on which flapper valve  34  rests in its closed position. The internal weather deflecting baffle  106  also extends from the opposing end of screen  38 , from a point adjacent to but inwardly from seat  54 . Preferably, the baffle  106  and seat  54  extend from substantially the same point on screen  38 , as shown in  FIG. 8 , and form a substantially V-shaped structure. Thus, when the screen is rotated into its folded over position, the internal baffle  106  will extend upwardly above the free end of flapper valve  34 , and limit the influence of infiltrating air gusts to pass under the free end of the flapper valve. 
         [0037]      FIG. 8  shows the wall  120  of the house supporting rafters  122  and a roof deck  124 . The duct  126  is attached to the adaptor  20  as shown, in this case on the step  26 . Shingles would also be installed in a known manner on the roof deck as will be understood by those skilled in the art. The adapter collar  20  can also be installed under the roof sheating  124 . 
         [0038]      FIG. 8  also shows all of the components together in an installed position on a roof  108 . As can be seen there is a line  110  that extends up from the nailing flange on a diagonal and a second line  112  that is above the first line  110 . The base  14  is a male part and the top  12  is a female part that fits over and onto the male part. The bottom edge of the top fits over the side walls of the base and at the point that the attachment members of the top are secured within the attachment openings of the base, the lower edge of the sides of the top  12  rest on a ledge along line  110  formed on the base  14 . The base can extend up a fair ways from the ledge  110 , inside of the ledge, so that there is a large amount of internal overlap between the base  14  and the top  12 . This provides for structural stiffness as well as forming a connection between the base and the top that will prevent water from flowing through the joint. Quite simply the inner base wall overlap is too large for any water to find its way through the overlap, even if it could get into it in the first place. 
         [0039]    In another embodiment the invention may be used as an intake vent, in which case there would be no collar nor any flapper valve as part of the vent. As well, in some cases a form of dryer vent may be used, as noted above with a lint compatible or lint passing grill. The foregoing description describes various embodiments of the invention but the scope of the invention is limited only by the appended claims. Various modifications and alterations to the invention are possible without departing from the scope of the claims attached. Some of these have been discussed above and other will be apparent to those skilled in the art.