Patent Publication Number: US-6991534-B2

Title: Adjustable vent

Description:
TECHNICAL FIELD 
   The invention pertains to vents. Particular embodiments of the invention relate to adjustable vents which may be mounted on building surfaces. 
   BACKGROUND 
   Many buildings have vents which provide routes for exchange, ventilation, circulation and/or movement of air through the surfaces (eg. walls and ceilings) of the building. Buildings may have ventilation systems, which take in “fresh” air from outside of the building and expel “stale” air from inside the building. Fresh air may be taken into a building or stale air may be expelled from a building through one or more vents. Some buildings incorporate other systems and/or apparatus, such as air conditioning systems, heating systems and bathroom fans, which use vents to provide routes for the movement of air through building surfaces. 
   Typically, a vent is associated with a conduit which conveys air towards or away from the vent. A vent provides a vent passageway in fluid communication with its associated conduit to provide a means for air flow through a building surface. Vents may provide a number of additional functions. For example, vents may comprise features for preventing debris from entering their associated conduits or for providing a more aesthetically pleasing terminus for their associated conduits. 
   There are many vent designs known in the art. For example:
         U.S. Pat. No. 6,520,852 (McKee et al.) discloses a vent with a perimeter flange having a nailing means made of a material with a low coefficient of thermal expansion, such as aluminum. The vent further includes a grill structure and a cap. The cap, which is made from dent resistant plastic, is preferably molded to the nailing means;   U.S. Pat. No. 5,6435081 (Klein) describes a vent screen and vent, which include a vent duct, an exterior grill connected to one end of the vent duct, and a vent screen support assembly connected between the vent duct and the exterior grill; and   U.S. Pat. No. 6,682,415 (Vagedes) discloses a replacement dryer vent which includes a typical exterior vent portion and an interior tube portion. The tube portion extends into a building and has an internal diameter that increases toward its innermost edge (i.e. toward the interior of the building), such that the tube portion slips over the existing cylindrical duct already in the wall.       

   Vents typically comprise a flange or the like, which allows the vent to be mounted to a building surface using fasteners that project through the flange and into the building surface. Exposed fasteners used for this purpose may make the vent aesthetically unattractive. Exposed fasteners may also be susceptible to oxidation or similar consequences of being exposed to the environment. 
   Some vents comprise flow adjustment mechanisms. Such mechanisms allow the flow of air through the vent to be controlled. Because of frequent use and the associated wear, flow adjustment mechanisms used in vents often malfunction or break. Accordingly, there is a general desire to provide vents with flow adjustment mechanisms that are robust and relatively immune to breakage. Vents incorporating such robust flow adjustment mechanisms typically require that the flow adjustment mechanisms and their associated components are relatively large to provide the flow adjustment mechanisms with sufficient strength. 
   One drawback with such robust flow adjustment mechanisms is that the maximum rate of air flow through a vent and its conduit will typically be limited by the cross-sectional area of the conduit and/or the vent. Robust and correspondingly large flow adjustment mechanisms tend to occupy a larger portion of the vent and to impede the flow of air through the vent. 
   There is a need for vents which have relatively robust and strong flow adjustment mechanisms that do not unnecessarily impede the flow of air through the vent. There is also a need for vents which are attractive looking. 
   SUMMARY OF THE INVENTION 
   A first aspect of the invention provides a vent which comprises a body member and an adjustment member. The body member comprises a vent passageway that extends from an inward side to an outward side of the body member. The body member also comprises a collar having a collar passageway that extends from an inward side to an outward side of the collar. The collar passageway is in fluid communication with the vent passageway. The adjustment member comprises a head disposed to adjustably restrict a flow of air through the vent passageway and a stem. The stem, which may project inwardly from the head, has one or more stem portions. The one or more stem portions comprise one or more contact portions which engage an interior surface of the collar and which moveably couple the adjustment member to the body member. The one or more stem portions, alone or in combination with the interior surface of the collar, define one or more collar openings that extend through the collar passageway. 
   A position of the adjustment member may be adjustable relative to the body member to adjustably restrict the flow of air through the vent passageway. At least a portion of the flow of air through the vent passageway may flow through the one or more collar openings. One or more of the collar opening(s) may be defined between at least one stem portion and the interior surface of the collar. One or more of the collar opening(s) may be defined between a plurality of stem portions. 
   Inward movement of the adjustment member relative to the body member may decrease a size of an opening through which air may flow into and out of the vent passageway. Conversely, outward movement of the adjustment member relative to the body member may increase the size of the opening through which air may flow into and out of the vent passageway. 
   The one or more stem portions may have a wide variety of configurations. The one or more stem portions may comprise one or more blades and the one or more contact portions may comprise a plurality of contact portions that engage the interior surface of the collar at spaced-apart locations. The one or more blades may comprise a plurality of blades which extend radially in angularly spaced-apart directions. The angularly spaced-apart directions may be equally spaced from one another. The one or more blades may have different configurations. Each collar opening may be defined between two or more blades and/or between one or more blades and the interior surface of the collar. 
   The interior surface of the collar may be generally circular in cross-section and may comprise one or more helical threads. The one or more contact portions may comprise at least one contact portion that has one or more indents for engaging the one or more helical threads. Rotating the adjustment member relative to the body member in a first angular direction may cause corresponding inward movement of the adjustment member relative to the body member and a corresponding decrease in a size of an opening through which air may flow into and out of the vent passageway. Conversely, rotating the adjustment member relative to the body member in a second angular direction may cause corresponding outward movement of the adjustment member relative to the body member and a corresponding increase in the size of the opening through which air may flow into and out of the vent passageway. 
   The one or more contact portions may slidably frictionally engage the interior surface of the collar. The one or more stem portions may comprise one or more contact portions that abut against the interior surface of the collar to form a slidable friction fit therewith. The interior surface of the collar may comprise one or more inwardly extending grooves and the one or more contact portions may comprise at least one contact portion that is slidably received in each of the grooves. The interior surface of the collar may comprise one or more projections and the one or more contact portions may comprise at least one inwardly extending groove which slidably receives the one or more projections. 
   The body member may comprise one or more brackets for supporting the collar in the vent passageway. 
   The vent may comprise one or more intermediate members that may be coupled between the body member and the adjustment member. Each intermediate member may comprise an intermediate vent passageway that extends from an inward side to an outward side of the intermediate member and an intermediate member collar having an intermediate collar passageway that extends from an inward side to an outward side of the intermediate member collar. Each intermediate collar passageway may be in fluid communication with the intermediate vent passageway. Preferably, at least a portion of each intermediate member collar is supported in its corresponding intermediate vent passageway. The one or more contact portions of the adjustment member may engage an interior surface of each intermediate member collar and may adjustably couple each intermediate member between the adjustment member and the body member. The one or more stem portions, alone or in combination with the interior surface of each intermediate member collar, may define one or more intermediate collar openings that extend through each intermediate collar passageway. 
   Air passing through the vent passageway may flow inwardly and/or outwardly through the intermediate collar openings. Each intermediate member may move inwardly and outwardly relative to the body member and/or the adjustment member to decrease or increase the size of the openings through which air may flow into and out of the vent passageway and each corresponding intermediate vent passageway. 
   One or more of the intermediate collar opening(s) may be defined between at least one stem portion and the interior surface of the intermediate member collar. One or more of the intermediate collar opening(s) may be defined between a plurality of stem portions. 
   The interior surface of each intermediate member collar may be generally circular in cross-section and may comprise one or more helical threads. The one or more contact portions may comprise at least one contact portion that has one or more indents for engaging the one or more helical threads. Rotating the adjustment member relative to an intermediate member in a first angular direction may cause corresponding inward movement of the adjustment member relative to the intermediate member and a corresponding decrease in a size of an opening through which air may flow into and out of the intermediate vent passageway and rotating the adjustment member relative to the intermediate member in a second angular direction may cause corresponding outward movement of the adjustment member relative to the intermediate member and a corresponding increase in the size of the opening through which air may flow into and out of the intermediate vent passageway. 
   Rotating the intermediate member relative to the body member in a first angular direction may cause corresponding inward movement of the intermediate member relative to the body member and a corresponding decrease in a size of an opening through which air may flow into and out of the vent passageway and rotating the intermediate member relative to the body member in a second angular direction may cause corresponding outward movement of the intermediate member relative to the body member and a corresponding increase in the size of the opening through which air may flow into and out of the vent passageway. 
   The body member may comprise a mounting flange for coupling the body member to a building surface. When the vent is mounted to the building surface, a plurality of fasteners may project through the mounting flange and into the building surface. The vent may comprise a trim member that is removably coupleable to the body member. When the trim member is coupled to the body member, the trim member may extend over an outward surface of the mounting flange at a distance spaced outwardly therefrom. The trim member may cover an outward side of any portions of the plurality of fasteners which extend outwardly past the outward surface of the mounting flange. The trim member may be shaped to define a channel and, when the trim member is coupled to the body member, the channel may open inwardly onto the outward surface of the mounting flange such that any portions of the plurality of fasteners which extend outwardly past the outward surface of the mounting flange are located in the channel. 
   The vent may comprise a trim member that is removably coupleable to the body member, wherein, when the trim member is coupled to the body member, the trim member covers outward ends of one or more fasteners used to mount the vent to the building surface. The trim member may comprise an interiorly projecting lip and the body member may comprise an exteriorly projecting lip. When the trim member is coupled to the body member, the interiorly projecting lip of the trim member may be received on an inward side of the exteriorly projecting lip of the body member. The trim member may comprise at least one groove and the body member may comprises at least one projection. When the trim member is coupled to the body member, the at least one projection may be received in the at least one groove. 
   Another aspect of the invention provides a vent that comprises a body member and an adjustment member. The body member has a vent passageway which extends from an inward side to an outward side of the body member and a surface that defines a bore in fluid communication with the vent passageway. The adjustment member comprises a head and a stem projecting inwardly from the head. The stem comprises a plurality of blades. The exterior edges of the blades are disposed to engage the bore defining surface. The blades, alone or in combination with the bore defining surface, define a plurality of passages through the bore. 
   The bore defining surface may comprise one or more helical threads and the exterior edge of at least one of the blades may comprise one or more indents for engaging the one or more threads. 
   Another aspect of the invention provides a vent comprising a body member and an adjustment member. The body member comprises a vent passageway that extends from an inward side to an outward side of the body member. The body member also comprises a collar. An interior surface of the collar defines a collar passageway which is in fluid communication with the vent passageway. The adjustment member comprises a head disposed to adjustably restrict a flow of air through the vent passageway and a stem that projects inwardly from the head. The stem has one or more stem portions. The one or more stem portions comprise one or more contact portions which engage an interior surface of the collar and which couple the adjustment member to the body member, such that the stem projects inwardly into the collar passageway and the adjustment member is inwardly and outwardly moveable relative to the body member. The one or more stem portions, alone or in combination with the interior surface of the collar, define one or more collar openings that extend through the collar passageway for permitting a flow of air through the collar passageway. 
   Another aspect of the invention provides a vent. The vent comprises a body member that defines a vent passageway. The vent also comprises a collar that defines a collar passageway. The collar is supported to provide fluid communication between the vent passageway and the collar passageway. The vent also comprises an adjustment member, coupling means for moveably coupling the adjustment member to the collar and passage means for permitting air flow through the collar passageway while the adjustment member is coupled to the collar by the coupling means. 
   Further aspects of the invention, features of specific embodiments of the invention and applications of the invention are described below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In drawings which depict non-limiting embodiments of the invention: 
       FIG. 1  is an isometric view of an adjustable vent according to a particular embodiment of the invention in a closed configuration; 
       FIG. 1A  is an isometric view of the  FIG. 1  vent in an open configuration; 
       FIG. 2  is an isometric view of the  FIG. 1  vent from a different perspective; 
       FIG. 3  is an isometric view of a body member of the  FIG. 1  vent; 
       FIG. 4  is an isometric view of the body member of  FIG. 3  from a different perspective; 
       FIG. 5  is an isometric view of an adjustment member of the  FIG. 1  vent; 
       FIG. 6  is an isometric view of an intermediate member of the  FIG. 1  vent; 
       FIG. 7  is an isometric view of the intermediate member of  FIG. 6  from a different perspective; 
       FIG. 8  is an isometric view of a trim member of the  FIG. 1  vent; 
       FIG. 9  is an isometric view of the trim member of  FIG. 8  from a different perspective; 
       FIG. 10  is a sectioned isometric view of the  FIG. 1  vent; 
       FIGS. 11A and 11B  are respectively isometric views of a trim member and a body member of a vent according to another embodiment of the invention; 
       FIGS. 12A–12H  are schematic partial cross-sectional views of adjustment member stem portions and body member collars of vents according to alternative embodiments of the invention; and 
       FIG. 13  is a cross-sectional view showing one possible mechanism for coupling the trim member of  FIG. 8  to the body member of  FIG. 3 . 
   

   DETAILED DESCRIPTION 
   Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
   Aspects of this invention relate to adjustable vents that can be used to provide passages for air through building surfaces. For example, vents according to the invention may be used for bathroom or kitchen fans, air conditioning ducts, heating ducts or the like. 
   Vents according to some embodiments of the invention have a body member comprising a vent passageway that extends from an inward side to an outward side of the body member. Preferably, the body member is mountable to a building surface. The body member also comprises a collar having a collar passageway that extends from an inward side to an outward side of the collar. The collar passageway is in fluid communication with the vent passageway. Preferably, at least a portion of the collar is supported in the vent passageway. 
   An adjustment member, which comprises a head disposed to adjustably restrict a flow of air through the vent passageway and a stem. The stem, which may project inwardly from the head, comprises one or more stem portions. The stem portion(s) comprise one or more contact portions which engage an interior surface of the collar and which moveably couple the adjustment member to the body member. The stem portion(s), alone or in combination with the interior surface of the collar, define one or more collar openings that extend through the collar passageway. A position of the adjustment member may be adjustable relative to the body member to adjustably restrict the flow of air through the vent passageway. The collar opening(s) may be defined between two or more stem portions and/or between one or more stem portions and the interior surface of the collar. Air passing through the vent passageway may flow inwardly and/or outwardly through the collar opening(s). 
   The adjustable vent may also comprise one or more intermediate members that may be coupled between the body member and the adjustment member. Each intermediate member may comprise an intermediate vent passageway and an intermediate member collar having an intermediate collar passageway. The stem portion(s) of the adjustment member, alone or in combination with the interior surface of the intermediate member collar, also define one or more intermediate collar openings that extend through each intermediate collar passageway. A position of each intermediate member may be inwardly and outwardly adjustable relative to the adjustment member and the body member to increase or decrease the size of the openings through which air may flow into and out of the vent passageway. 
   The body member may comprise a mounting flange for coupling the body member to a building surface. The vent may also comprise a trim member, which is coupleable to the body member (or to some other component of the vent). The trim member may cover fasteners used to mount the vent to a building surface. In some embodiments, the trim member extends over at least a portion of an outward surface of the mounting flange at a distance spaced-apart therefrom and covers any portions of the fasteners that extend on the outward side of the mounting flange. 
     FIGS. 1–10  depict a vent  10  according to a particular embodiment of the invention. In most applications, vent  10  is mounted to a building surface  20  (shown in broken lines in  FIG. 1 ). Building surface  20  may generally be a ceiling, a wall, a floor or any other building surface and may be in the interior of the building or on the exterior of the building. In the illustrated embodiment, vent  10  comprises a body member  12 , an adjustment member  14 , an optional intermediate member  16  and an optional trim member  18 . Vent  10  is shown to be generally circular in shape. In alternative embodiments, vents according to the invention may have different shapes. By way of example only, vents according to the invention may be rectangular or partially rectangular and partially circular. 
   This description and the accompanying claims use a number of directional conventions to clarify their meaning:
         (i) “outward ”, “outwardly”, “outwardmost” and similar words are used to refer to a direction that is generally oriented to extend away from building surface  20  as shown by arrow  22  ( FIG. 1 );   (ii) “inward”, “inwardly”, “inwardmost” and similar words are used to refer to a direction that is generally oriented toward the inside of building surface  20  as shown by arrow  24  ( FIG. 1 );   (iii) “interior”, “interiorly”, “interiormost” and similar words are used to refer to directions that are generally oriented toward the symmetrical center of vent  10 , as shown, for example, by arrow  26  ( FIG. 1 ); and   (iv) “exterior”, “exteriorly”, “exteriormost” and similar words are used to refer to directions that are generally oriented away from the symmetrical center of vent  10 , as shown, for example, by arrow  28  ( FIG. 1 ).
 
Those skilled in the art will appreciate that directional terms used in this description and the accompanying claims depend on the specific orientation of vent  10  and building surface  20  to which vent  10  is mounted. Furthermore, as described above, vent  10  need not be circularly symmetric and may have other symmetrical or non-symmetrical shapes. Accordingly, these directional terms are not strictly defined and should not be interpreted literally or narrowly.
       

   As shown best in  FIGS. 1 ,  3  and  4 , body member  12  comprises a first flange  30  which extends inwardly into building surface  20  ( FIG. 1 ). In the illustrated embodiment, an interior surface of first flange  30  defines a vent passageway  32 . Vent passageway  32  is an aperture which extends from an inward side to an outward side of body member  12  to facilitate the passage of air through vent  10 . 
   Body member  12  also comprises a collar  44  which defines a collar passageway  47 . Collar passageway  47  extends from an inward side to an outward side of collar  44  and is in fluid communication with vent passageway  32 . In the illustrated embodiment, collar  44  is supported by plurality of angularly spaced-apart brackets  42 , which extend interiorly from an interior surface of first flange  30  into vent passageway  32 . Preferably, at least a portion of collar  44  is located in vent passageway  32 . Brackets  42  are preferably spaced-apart from one another to provide passages  43  ( FIG. 3 ), which permit air flow through vent passageway  32 . In the illustrated embodiment, collar  44  is supported by four brackets  42 ; however, body member  12  may comprise an alternative number of brackets  42  or any alternative means for supporting collar  44  such that collar passageway  47  is in fluid communication with vent passageway  32 . 
   Vent  10  also comprises an adjustment member  14  (shown best in  FIG. 5 ), which may be coupled to body member  12  and disposed to adjustably restrict the flow of air through vent passageway  32 . Adjustment member  14  comprises an inwardly extending stem  52  and a generally exteriorly extending head  58 . 
   Stem  52  of adjustment member  14  comprises one or more stem portions  53 . Stem portion(s)  53  comprise one or more contact portions  55  which engage the interior surface of collar  44  to adjustably couple adjustment member  14  to body member  12  in a manner that facilitates inward and outward movement of adjustment member  14  relative to body member  12 . Stem portion(s)  53  define one or more collar openings  51  ( FIG. 2 ) that extend through collar passageway  47 . Collar opening(s)  51  may be defined between two or more stem portions  53  and/or between one or more stem portions  53  and the interior surface of collar  44 . Air passing through vent  10  may flow inwardly and/or outwardly through collar opening(s)  51 . 
   Head  58  of adjustment member  14  extends generally exteriorly from stem  52 . The exterior extension of head  58  tends to restrict the flow of air through the outward end of vent passageway  32 . Inward movement of adjustment member  14  relative to body member  12  causes head  58  to move closer to body member  12 , thereby decreasing the size of the opening through which air may flow into and out of vent passageway  32 . Conversely, outward movement of adjustment member  14  relative to body member  12  causes head  58  to move further from body member  12 , thereby increasing the size of the opening through which air may flow into and out of vent passageway  32 . 
   Stem portion(s)  53  of adjustment member  14  may have a wide variety of configurations. The illustrated embodiment of adjustment member  14  comprises a plurality of stem portions  53 A,  53 B,  53 C,  53 D (collectively, stem portions  53 ) which, in turn, comprise a plurality of contact portions  55 A,  55 B,  55 C,  55 D (collectively  55 ). Contact portions  55  engage the interior surface of collar  44  at spaced-apart locations. Collar openings  51  are defined between pairs of stem portions  53  and the interior surface of collar  44 . Collar openings  51  extend through collar passageway  47 . 
   In the illustrated embodiment, stem portions  53  comprise blades  50 A,  50 B,  50 C,  50 D (collectively  50 ), which extend radially at angularly spaced-apart locations. In the embodiment of  FIGS. 1–10 , adjustment member  14  comprises four blades  50 , which are symmetrically angularly spaced-apart from one another about axis  60  of stem  52 . Each blade  50  comprises a contact portion  55  at its exterior end. Adjustment member  14  may comprise a different number of blades  50 , which may be angularly spaced-apart from one another by different angular separations that may or may not be symmetric. In some embodiments, one or more of blades  50  do not comprise contact portions  55  (i.e. one or more of blades  50  do not contact the interior surface of collar  44 ). In still other embodiments, blades  50  have other configurations. 
   Advantageously, stem portions  53 , collar  44  and head  58  provide a robust air flow adjustment mechanism, the components of which may be made sufficiently large and correspondingly strong to be relatively immune from breakage. In addition, the collar openings  51  that extend through collar passageway  47  minimize the blockage of vent passageway  32  by the components of the flow adjustment mechanism, thereby permitting a wide range of air flow through vent passageway  32  and vent  10 . In particular, the presence of collar openings  51  permits the flow of air through collar passageway  47 , such that collar passageway  47  (i.e. the interior of collar  44 ) may be an effective part of vent passageway  32 . In some embodiments of the invention, a combined cross-sectional area of collar openings  51  is at least 50% of the cross-sectional area of collar passageway  47 . In other embodiments, a combined cross-sectional area of collar openings  51  is at least 75% of the cross-sectional area of collar passageway  47 . 
   In some embodiments of the invention, the interior surface of collar  44  is generally circular in cross-section and comprises one or more helical threads  48 , thereby defining a threaded bore  46 . In such embodiments, one or more contact portions  55  of stem portion(s)  53  comprise one or more indents  56  for engaging helical thread(s)  48 . In the illustrated embodiment, the contact portion  55  on the exterior end of each blade  50  comprises a plurality of indents  56  for engaging helical thread(s)  48 . In these embodiments, rotating adjustment member  14  relative to body member  12  causes corresponding inward or outward movement of adjustment member  14  relative to body member  12  and a corresponding decrease or increase in the size of the opening through which air may flow through vent passageway  32 . 
   In the illustrated embodiment, vent  10  also comprises an optional intermediate member  16 , which is shown best in  FIGS. 6 and 7 . Intermediate member  16  may be coupled between adjustment member  14  and body member  12 . Intermediate member  16  comprises a first intermediate flange  70  that defines an intermediate vent passageway  74 . Intermediate vent passageway  74  extends from an inward side to an outward side of intermediate member  16  to facilitate the passage of air therethrough. In the illustrated embodiment, intermediate vent passageway  74  is circular in cross-section. In other embodiments, intermediate vent passageway  74  may have other cross-sectional shapes. 
   Intermediate member  16  is preferably positioned such that intermediate vent passageway  74  is in fluid communication with vent passageway  32  of body member  12  (see  FIG. 2 ). The cross-sectional areas of first intermediate flange  70  and intermediate vent passageway  74  of intermediate member  16  may be less than the cross-sectional areas of first flange  30  and vent passageway  32  of body member  12 , such that intermediate member  16  can be used to restrict the flow of air through vent  10  as explained further below. 
   Intermediate member  16  comprises an intermediate member collar  78  which defines an intermediate collar passageway  81 . Intermediate collar passageway  81  extends from an inward side to an outward side of intermediate member collar  78 . Intermediate collar passageway  81  is in fluid communication with intermediate vent passageway  74 . In the illustrated embodiment, intermediate member collar  78  is supported by a plurality of angularly spaced-apart brackets  76 , which extend interiorly from an interior surface of first intermediate flange  70  into intermediate vent passageway  74 . Preferably, at least a portion of intermediate member collar  78  is located in intermediate vent passageway  74 . Brackets  76  are preferably spaced-apart from one another to provide passages  79  ( FIG. 6 ), which permit air flow through intermediate vent passageway  74 . In the illustrated embodiment, intermediate member collar  78  is supported by four brackets  76 ; however, intermediate member  16  may comprise an alternative number of brackets  76  or any alternative means for supporting intermediate member collar  78  such that intermediate collar passageway  81  is in fluid communication with intermediate vent passageway  74 . 
   Preferably, as shown in the illustrated embodiment, intermediate member  16  is aligned with body member  12 , such that intermediate member collar  78  is aligned with body member collar  44 . Stem  52  of adjustment member  14  may extend inwardly through the interior of both intermediate member collar  78  and body member collar  44 . Contact portion(s)  55  of stem portion(s)  53  of adjustment member  14  may engage the interior surfaces of both intermediate member collar  78  and body member collar  44  to couple intermediate member  16  between body member  12  and adjustment member  14  in a manner which facilitates independent inward and outward movement of intermediate member  16  and adjustment member  14  with respect to body member  12 . 
   The one or more stem portions  53  of adjustment member  14  also define one or more intermediate collar openings (not shown in the illustrated views) that extend through intermediate collar passageway  81 . The one or more intermediate collar openings may be defined between two or more stem portions  53  and/or between one or more stem portions  53  and the interior surface of intermediate member collar  78 . Air passing through vent  10  may flow inwardly and/or outwardly through these intermediate collar openings (i.e. through intermediate collar passageway  81 ). 
   In the illustrated embodiment, both intermediate member  16  and adjustment member  14  may be moved inwardly and outwardly relative to body member  12 . This relative movement between adjustment member  14 , intermediate member  16  and body member  12  determines the size of opening  84  ( FIG. 1A ) between adjustment member  14  and intermediate member  16  and the size of opening  86  ( FIG. 1A ) between intermediate member  16  and body member  12 . Opening  84  permits the flow of air into and out of the outward ends of vent passageway  32  and intermediate vent passageway  74 . Opening  86  bypasses intermediate vent passageway  74  and permits the flow of air into and out of the outward end of vent passageway  32 . 
   Referring to  FIG. 1A , adjustment member  14  may be independently moved outwardly (or inwardly) relative to both intermediate member  16  and body member  12  to cause a corresponding increase (or decrease) in the size of opening  84 . Similarly, intermediate member  16  may be independently moved relative to both body member  12  and adjustment member  14 . Intermediate member  16  may be moved outwardly (i.e away from body member  12  and toward adjustment member  14 ) to cause a corresponding increase in the size of opening  86  and a corresponding decrease in the size of opening  84 . Intermediate member  16  may also be moved inwardly (i.e toward body member  12  and away from adjustment member  14 ) to cause a corresponding decrease in the size of opening  86  and a corresponding increase in the size of opening  84 . Intermediate member  16  and adjustment member  14  may also be moved together in an outward (or inward) direction relative to body member  12  to cause a corresponding increase (or decrease) in the size of opening  86 . 
   In the illustrated embodiment, the interior surface of intermediate member collar  78  is generally circular in cross-section and comprises one or more helical threads  82 , thereby defining a threaded bore  80 . Preferably, at least the interior surface of intermediate member collar  78  is substantially similar in size to the interior surface of body member collar  44 . In addition, the pattern of thread(s)  82  on the interior surface of intermediate member collar  78  is preferably similar to that of thread(s)  48  on the interior surface of body member collar  44 . 
   As discussed above, one or more contact portions  55  of stem portion(s)  53  of adjustment member  14  may comprise one or more indents  56 . Indent(s)  56  may engage helical thread(s)  82  on intermediate member collar  78  and helical thread(s)  48  on body member collar  44 . With this configuration, adjustment member  14  may be independently rotated relative to body member  12  and intermediate member  16  to cause corresponding inward or outward movement of adjustment member  14  relative to body member  12  and intermediate member  16  and a corresponding decrease or increase in the size of opening  84 . Similarly, intermediate member  16  may be independently rotated relative to body member  12  and adjustment member  14  to cause corresponding inward movement of intermediate member  16  relative to body member  12  and adjustment member  14 , a corresponding increase in the size of opening  84  and a corresponding decrease in the size of opening  86 . Intermediate member  16  may also be rotated in the opposite angular direction relative to body member  12  and adjustment member  14  to cause corresponding outward movement of intermediate member  16  relative to body member  12  and adjustment member  14 , a corresponding decrease in the size of opening  84  and a corresponding increase in the size of opening  86 . Intermediate member  16  and adjustment member  14  may also be rotated together relative to body member  12  to cause corresponding inward or outward movement of intermediate member  16  and adjustment member  14  relative to body member  12  and a corresponding decrease or increase in the size of opening  86 . 
   In some embodiments of the invention, as shown best in  FIGS. 1–4 , the exterior surface of first flange  30  of body member  12  comprises one or more exteriorly extending protrusions  34  and/or interiorly extending indents (not shown), which may be used to couple first flange  30  to the interior wall(s) of a conduit  36  (shown in dotted outline in  FIG. 1 ) located within building surface  20  and/or to retain conduit  36  in fluid communication with vent passageway  32 . In other embodiments, first flange  30  has similar coupling features on its interior surface. In still other embodiments, first flange  30  and vent passageway  32  are located in a position proximate to conduit  36  to facilitate fluid communication therebetween. 
   In the illustrated embodiment, the interior surface of first flange  30  and vent passageway  32  are generally circular in cross-section. Those skilled in the art will appreciate that this circular shape merely represents one among many possible shapes of first flange  30 . A particular size and/or shape of first flange  30  may be selected to conform with the size and/or shape of conduit  36 . For example, first flange  30  may be square or rectangular in cross-section. 
   In some embodiments of the invention, as shown best in  FIGS. 1 ,  2  and  3 , body member  12  also comprises an exteriorly extending mounting flange  38  which may be used to mount vent  10  to building surface  20 . Preferably, at least a portion of the inward surface of mounting flange  38  extends generally parallel with the plane of building surface  20 . In this manner, first flange  30  may extend inwardly into building surface  20  and mounting flange  38  may abut against building surface  20  for mounting thereto. In the illustrated embodiment, mounting flange  38  comprises a plurality of spaced-apart apertures  40 . Fasteners (not shown) may be inserted through apertures  40 , so as to project through mounting flange  38  and into building surface  20  for mounting vent  10  to building surface  20 . Typical fasteners may include screws, nails, rivets, staples or the like. In some embodiments, apertures  40  are not required and fasteners may be driven directly through mounting flange  38  and into building surface  20 . In other embodiments, adhesive may be used to couple mounting flange  38  to building surface  20 . In still other embodiments, first flange  30  is used to mount vent  10  to building surface  20  using a friction fit. Such friction fitted embodiments may or may not have a mounting flange  38 . 
   In the illustrated embodiment, as shown best in  FIG. 10 , body member  12  comprises a generally “U-shaped” bent portion  88 , which is located around an exterior perimeter of first flange  30  at an outward end thereof. Bent portion  88  connects first flange  30  to exteriorly extending mounting flange  38 . First flange  30  may have different shapes and/or sizes and mounting flange  38  may have different shapes and/or sizes. Accordingly, those skilled in the art will appreciate that bent portion  88  may also have different configurations, depending on the shapes and sizes of first flange  30  and mounting flange  38 . For example, first flange  30  may be circular in cross-section and mounting flange  38  may be rectangular in cross-section. In such an embodiment, bent portion  88  has a different shape to form a transition between first flange  30  and mounting flange  38 . In other embodiments, bent portion  88  is not provided and mounting flange  38  extends directly from an exterior surface of first flange  30 . 
   Vent  10  may also comprise an optional trim member  18  (shown best in  FIGS. 8 ,  9  and  10 ), which is coupleable to body member  12  (or to some other component of vent  10 ). Trim member  18  extends over at least a portion of an outward surface of mounting flange  38  at a distance spaced-apart therefrom. Trim member  18  may be used to cover portions of fasteners that extend on the outward side of mounting flange  38 . 
   In the embodiment illustrated in  FIGS. 8 ,  9  and  10 , trim member  18  is generally annular in shape and comprises an inwardly extending portion  92  and a flange portion  96 . Inwardly extending portion  92  of trim member  18  is shaped to conform with an exterior surface of bent portion  88 . Flange portion  96  of trim member  18  extends generally exteriorly and inwardly from an outward end of inwardly extending portion  92  to form a trim member channel  98 . Trim member channel  98  is located between an interior surface of flange portion  96  and an exterior surface of inwardly extending portion  92 . 
   In accordance with one particular embodiment shown best in  FIG. 13 , body member  12  comprises an outwardly projecting rim  21  which may be used to help couple trim member  18  to body member  12 . In the illustrated embodiment, rim  21  extends outwardly from an outer surface of mounting flange  38  and is located at an exterior perimeter of mounting flange  38 . Rim  21  comprises an exteriorly projecting lip  19 . Preferably, exterior projecting lip  19  is shaped to conform with the interior surface of flange portion  96  of trim member  18 . In alternative embodiments, lip  19  may comprise a plurality of spaced apart protrusions rather than a lip extending all of the way around rim  21 . The interior surface of flange portion  96  of trim member  18  comprises a corresponding interiorly projecting lip  17  at an inward end thereof. Preferably, interiorly projecting lip  17  is shaped to conform with an exterior surface of rim  21 . 
   With this configuration, trim member  18  may be coupled to body member  12  by pushing trim member  18  inwardly over body member  12 , such that the interiorly projecting lip  17  of trim member  18  is received on an inward side of the exteriorly projecting lip  19  of body member  12 . Interiorly projecting lip  17  then abuts against the exterior surface of rim  21  and exteriorly projecting lip  19  abuts against the interior surface of flange portion  96 . Interiorly projecting lip  17  (and trim member  18 ) are secured in place (i.e. prevented from moving outwardly) by exteriorly projecting lip  19 . Coupling trim member  18  and body member  12  may involve resiliently deforming trim member  18  and/or body member  12  to form a “snap together” fit, wherein trim member  18  is securely but removably coupled to body member  12 . 
   Advantageously, trim member  18  may be coupled to body member  12  after body member  12  is already mounted to building surface  20 . As discussed above, fasteners may project through apertures  40  and/or other portions of mounting flange  38  and into building surface  20 . When trim member  18  is coupled to body member  12 , trim member channel  98  provides room for the heads (or the other parts) of the fasteners, which may extend outwardly from mounting flange  38 . In this manner, trim member  18  covers the fasteners used to mount vent  10 , providing vent  10  with a more aesthetically pleasing appearance and providing some protection for the fasteners. 
   Those skilled in the art will appreciate that interiorly projecting lip  17  and exteriorly projecting lip  19  represent only one of many possible ways in which trim member  18  may be coupled to body member  12 . One possible alternative embodiment is shown in  FIGS. 11A and 11B , which respectively depict an alternative trim member  18  and an alternative body member  12 . In the embodiment of  FIGS. 11A and 11B , the exterior surface of bent portion  88  comprises a plurality of projections  90  at spaced-apart locations around its perimeter. Inwardly extending portion  92  of trim member  18  comprises a corresponding groove  94  on its interior surface. Trim member  18  is preferably resiliently deformable such that it may be pushed inwardly over body portion  12  and projections  90  may be received in groove  94  to form a “snap together” fit. 
   In still other embodiments, trim member  18  is coupled to body member  12  by other means, such as by threadable coupling(s) and/or other types of deformable grooves, projections, indents and/or surfaces, for example. Inwardly extending portion  92  and/or flange portion  96  of trim member  18  may be coupled to an outward end of first flange  30 , to bent portion  88  and/or to mounting flange  38  of body member  12 . As discussed above, first flange  30 , bent portion  88  and mounting flange  38  may have different shapes and/or sizes. Similarly, trim member  18  may have different shapes and/or sizes to facilitate coupling to various components of vent  10 . 
   In the embodiment illustrated in  FIGS. 1–10 , exteriorly extending head  58  of adjustment member  14  has a contoured shape comprising an outwardly projecting central portion  64 , an intermediate portion  62  and an exterior portion  68  (see  FIG. 5 ). Outwardly projecting central portion  64  (or other portions of head  58 ) may optionally comprise grooves  66 , which may help users to rotate adjustment member  14  by providing a place where users may engage a tool, their hands and/or their fingers to rotate adjustment member  14 . In other embodiments, grooves  66  may be replaced and/or augmented with outwardly projecting tabs and/or indents having different shapes. In the illustrated embodiment, intermediate portion  62  extends sharply inwardly from central portion  64  in region  62 A and then extends gradually outwardly and exteriorly in region  62 B until it reaches exterior portion  68 . Exterior portion  68  extends even more gradually outwardly as it extends exteriorly from intermediate portion  62 . 
   In the embodiment illustrated in  FIGS. 1–10 , intermediate member  16  also comprises a second intermediate flange  72  which extends generally exteriorly from inwardly extending first intermediate flange  70 . Preferably, second intermediate flange  72  extends exteriorly at least as far as an interior edge of first flange  30  of body member  12 . As shown best in  FIG. 10 , when intermediate member  16  is adjusted to an inward position, an exterior portion of second intermediate flange  72  contacts an outward surface of bent portion  88  of body member  12 . When second intermediate flange  72  contacts the outward surface of bent portion  88 , opening  86  ( FIG. 1A ) is substantially closed and only a minimal amount of air flow is permitted between second intermediate flange  72  and bent portion  88 . In other embodiments, second intermediate flange  72  may be sized and/or shaped such that when intermediate member  16  is adjusted to an inward position, an exterior portion of second intermediate flange  72  contacts one or more of: first flange  30  of body member  12 , bent portion  88  of body member  12 , mounting flange  38  of body member  12  and/or flange portion  96  of trim member  18 . 
   In embodiments comprising optional intermediate member  16 , head  58  of adjustment member  14  is preferably sized such that it extends in the exterior direction at least as far as an interior edge of second intermediate flange  72 . When adjustment member  14  is adjusted to an inward position relative to intermediate member  16 , the exterior portion  68  and/or the intermediate portion  62 B of head  58  contacts an outward surface of second intermediate flange  72 , such that opening  84  ( FIG. 1A ) is substantially closed and only a minimal amount of air flow is permitted between head  58  of adjustment member  14  and second intermediate flange  72  of intermediate member  16 . 
   Accordingly, in the embodiment illustrated in  FIGS. 1–10 , vent  10  can be adjusted from a minimum air flow configuration by rotating adjustment member  14  to an inward position, where head  58  of adjustment member  14  abuts against second intermediate flange  72  of intermediate member  16 , and by rotating intermediate member  16  to an inward position, where second intermediate flange  72  abuts against bent portion  88  of body member  12 . If air flow is desired, then adjustment member  14  may be rotated, such that head  58  of adjustment member  14  moves outwardly relative to second intermediate flange  72  to permit air flow into and out of intermediate vent passageway  74  and vent passageway  32  through opening  84 . Adjustment member  14  may be rotated to move inwardly or outwardly to control the size of opening  84 . If more air flow is desired, then adjustment member  14  and intermediate member  16  may be rotated together relative to body member  12 , such that second intermediate flange  72  moves outwardly relative to bent portion  88  to permit air flow into and out of vent passageway  32  through opening  86 . Thereafter, the air flow may be controlled by rotating adjustment member  14 , intermediate member  16  and/or body member  12  relative to one another as discussed above to control the size of openings  84 ,  86 . 
   In preferred embodiments of the invention, the components of vent  10  (including body member  12 , adjustment member  14 , optional intermediate member  16  and optional trim member  18 ) are fabricated from plastic. These plastic components of vent  10  may be injection molded using one or more molds. In alternative embodiments, one or more of the components of vent  10  or parts of the components of vent  10  are fabricated from other suitable materials, such as aluminum, steel or other metals, for example. In addition, the components of vent  10  may be fabricated using techniques other than injection molding, such as blow molding, rotational molding, spin casting and/or conventional machining techniques, for example. 
   As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:
         In the embodiments illustrated in  FIGS. 1–11B , collar passageway  47  (i.e. the interior surface of collar  44 ) is circular in cross-section and comprises threads  48  to define a threaded bore  46 . With this configuration, adjustment member  14  may be threadably coupled to body member  12 . In general, only the interior surfaces of collar  44  is required to be circular in cross-section. In alternative embodiments, threaded bore  46  may be provided by a component of any shape, which is penetrated by a bore having a generally circular cross-section.   In some embodiments, the interior surface of collar  44  is not threaded and contact portion(s)  55  of stem portions  53  engage the interior surface of collar  44  using other techniques, such as slidable frictional engagement. In such embodiments, the interior surface of collar  44  may be, but need not be, circular in cross-section.     FIG. 12A  is a partial schematic cross-sectional view of a collar  44  of body member  12  and stem portions  53 A,  53 B (collectively  53 ) of adjustment member  14  according to an alternative vent embodiment. In the embodiment of  FIG. 12A , the interior surface of collar  44  is rectangular in cross-section. Stem portions  53  comprise contact portions  55 A,  55 B,  55 C,  55 D (collectively  55 ) that slidably frictionally engage the interior surface of collar  44  at the corners thereof. The engagement between contact portions  55  and the interior surface of collar  44  permits adjustment member  14  to be slidably moved inwardly and outwardly relative to body member  12 .  FIG. 12B  schematically depicts a partial cross-sectional view of a collar  44  of body member  12  and stem portion  53  of adjustment member  14  according to another alternative vent embodiment. In the embodiment of  FIG. 12B , the interior surface of collar  44  is rectangular in cross-section and comprises a pair of inwardly extending grooves  83 A,  83 B. Contact portions  55 A,  55 B of stem portion  53  are received in grooves  83 A,  83 B for slidable frictional engagement therewith to permit inward and outward movement of adjustment member  14  relative to body member  14 . The embodiments of  FIGS. 12A and 12B  are merely representative examples of slidable frictional engagement between adjustment member  14  and body member  12 . Those skilled in the art will appreciate that slidable frictional engagement between adjustment member  14  and body member  12  may be provided by a variety of alternative configurations of stem portions  53  and collars  44 . For example, collar  44  may be circular in cross-section and still facilitate slidable friction engagement. In another example, contact portions  55  of stem portions  53  may comprise inwardly extending grooves which receive corresponding projections from the interior surface of collar  44  and still facilitate slidable frictional engagement.   In the embodiment illustrated in  FIGS. 1–10 , collar  44  is located in vent passageway  32 . In general, brackets  42  may extend inwardly or outwardly such that collar  44  is not located in vent passageway  32 .   In the embodiment illustrated in  FIGS. 1–10 , stem portions  53  comprise blades  50  which extend radially outwardly and which comprise contact portions  55  at their exterior ends for engaging the interior surface of collar  44  at angularly spaced-apart locations. This configuration is not generally necessary.  FIGS. 12C–12H  show non-limiting examples of partial cross-sectional views of stem portion(s)  53  of adjustment member  14  and collar  44  of body member  12  according to other possible embodiments. In each case, stem portion(s)  53  define one or more collar openings  51  on the interior surface of collar  44  (i.e. in collar passageway  47 ). Stem portion(s)  53  may define collar opening(s)  51  between two or more stem portions  53  and/or between one or more stem portions  53  and the interior surface of collar  44 . In each case, stem portion(s)  53  comprise one or more contact portions  55  which adjustably engage the interior surface of collar  44 . However, it is not necessary that there be a one to one correspondence between stem portions  53  and contact portions  55 . In some embodiments, one or more stem portions  53  do not have a contact portion  55 . In some embodiments, a single stem portion  53  may have a plurality of contact portions  55 . The engagement between contact portions  55  and the interior surface of collar  44  may comprise threadable engagement, slidable frictional engagement or other forms of adjustable engagement. Those skilled in the art will appreciate that the embodiments shown in  FIGS. 12C–12H  are merely representative examples and that many other different configurations of stem portions  53  and collars  44  are possible.   Some alternative embodiments lack a separate collar  44 . In such embodiments, stem portions  53  of adjustment member  14  may engage the interior surface of first flange  30 .   All of the alternative embodiments and variations of collar  44  and stem portions  53  described above may also be applied to intermediate member collar  78 .   In some embodiments, vent  10  comprises more than one intermediate member  16 . Each intermediate member  16  is coupled between adjustment member  14  and body member  12  in substantially the same manner as in the above-described embodiment having one intermediate member.   In some embodiments, there is no need for trim member  18 . For example, fasteners used to mount vent  10  to building surface  20  may be left uncovered. In an alternative example, body member  12  may be designed to receive fastener covering plugs in specific locations, such that fasteners may project through mounting flange  38  and then subsequently be covered by such plugs.   The embodiments described above describe the flow of air through vent  10 . Those skilled in the art will appreciate that other fluids may flow through vent  10  and that solid and/or liquid matter may be suspended in air (or other fluids) that flow through vent  10 .       

   Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.