Patent Publication Number: US-2010124876-A1

Title: Air duct outlet

Description:
BACKGROUND OF THE INVENTION 
     This invention relates in general to an outlet for an air duct and more particularly to an outlet configured to apply the Coanda effect. U.S. Pat. No. 6,902,474, discloses an air duct outlet with single vane air stream direction control. With the reference to the drawings and reference numerals of the &#39;474 patent, an air duct outlet ( 10 ) includes a housing ( 12 ) comprising a first wall ( 18 ) and a convexly-curved second wall ( 20  or  22 ) that are in adjacent, spaced-apart relationship. The first wall ( 18 ) and the second wall ( 20  or  22 ) define an air passageway ( 24  or  26 ) having an inlet ( 24   a  or  26   a ) and a flared outlet ( 24   b  or  26   b ). The air duct outlet ( 10 ) also includes a vane ( 30  or  32 ) pivotally attached within the air passageway ( 24  or  26 ). The vane ( 30  or  32 ) is movable between a first position wherein the vane ( 30  or  32 ) is disposed in face-to-face adjacent relationship with the first wall ( 18 ) and a range of positions that are increasingly transverse to the first wall ( 18 ). An air stream flowing through the air passageway ( 24  or  26 ) is deflected by an amount that increases with each position of the vane ( 30  or  32 ) in the range such that the air stream adheres to a portion of the second wall ( 20  or  22 ) by an amount that increases with each position of the vane ( 30  or  32 ) in the range. Also, the air stream exits from the outlet ( 24   b  or  26   b ) in a direction that is increasingly transverse to a direction normal to the outlet ( 24   b  or  26   b ). 
     SUMMARY OF THE INVENTION 
     In summary, the invention is an air duct outlet. The air duct outlet includes a housing comprising a first wall being substantially planar and a second wall being at least partially convex to the first wall. The first wall and the second wall are disposed in adjacent, spaced-apart relation and defining at least two sides of an air passageway. The air passageway extends along a flow path between an inlet and a flared outlet. The air duct outlet also includes a vane pivotally disposed within the air passageway along the flow path. The vane is movable between a first position wherein the vane substantially blocks the air passageway and a range of other positions that are increasingly substantially parallel to the first wall. An air stream flowing through the air passageway is deflected by the vane an amount that decreases with each position more remote of the first position over the range such that the air stream adheres to the second wall by an amount that increases with each position more remote of the first position over the range. Also, the air stream exits from the air duct outlet in a direction that is increasingly transverse to the first wall as the vane moves away from the first position. 
     Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exemplary embodiment of the invention in an exemplary operating environment; 
         FIG. 2  is an exploded view of the exemplary embodiment of the invention shown in  FIG. 1 ; 
         FIG. 3  is a simplified cross-sectional view taken along section lines  3 - 3  in  FIG. 1 ; and 
         FIG. 4  is an illustration of the performance of the exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT 
       FIG. 1  shows an interior  10  of a vehicle in which the exemplary embodiment of the invention is incorporated. An air duct outlet  14  according to an exemplary embodiment of the invention is shown positioned adjacent to a dashboard  16  in the vehicle. The dashboard  16  is exposed in the interior  10  of the vehicle and defines a first aperture  18 . The air duct outlet  14  can direct air to flow through the aperture  18 . A register  20  can be engaged with respect to the aperture  18  to enhance the aesthetic appearance of the intersection of the air duct outlet  14  and the aperture  18 . The register  20  can also support structures for closing the air duct outlet  14 , such as a knob  22 . The operation of the knob  22  in closing the air duct outlet  14  will be discussed below. The register  20  can include a frame  24  supporting the knob  22  for pivoting movement and can also define a second aperture  26 . Air passing out of the air duct outlet  14  can pass into the interior  10  of the vehicle through the aperture  26 . 
     Referring now to  FIG. 3 , the air duct outlet  14  includes a housing  28 . The exemplary housing  28  is formed from first and second housing members  30 ,  32  connected together. In alternative embodiments of the invention, the housing  28  may be formed as single, integral structure or may be formed from more than two housing members. 
     The housing  28  includes a first wall  34  that is substantially planar. The first wall  34  need not be perfectly planar in all embodiments of the invention. As shown by the Figures, the exemplary first wall  34  includes a first and second portions  36 ,  38  that are at a slight angle to one another. The first and second portions  36 ,  38  are integral with one another, defined by the second housing member  32 . The first wall  34  also includes a third portion  40  defined by the first housing member  30 . The first and third portions  36 ,  40  of the first wall  34  are substantially coplanar. 
     The housing  28  also includes a second wall  42  that is at least partially convex to the first wall  34 . The exemplary second wall  42  includes a first and second portions  44 ,  46  that are at a slight angle to one another. The first and second portions  44 ,  46  of the second wall  42  are integral with one another, defined by the second housing member  32 . The second wall  42  also includes a third portion  48  defined by the first housing member  30 . The exemplary third portion  48  of the second wall  42  can diverge away steeply from the plane of the first portion  44  of the second wall  42 . 
     The first wall  34  and the second wall  42  are disposed in adjacent, spaced-apart relation and define at least two sides of an air passageway  50  that extends along a generalized flow path represented by an axis  52 . In the exemplary embodiment of the invention, the first wall  34  and the second wall  42  define top and bottom guide surfaces of the air passageway  50 . However, in alternative embodiments of the invention, the structures could be inverted such that the first wall  34  and the second wall  42  define lateral sides of the air passageway  50 . It is noted that the illustrated axis  52  is positioned directly between the first wall  34  and the second wall  42  along its length and does not necessarily represent the movement of air. 
     The air passageway  50  extends between an inlet  54  and a flared outlet  56 . Along the axis  52  between the second portion  38  of the first wall  34  and the second portion  46  of the second wall  42 , the air passageway  50  converges slightly. This aspect of the air passageway  50  can be desirable to increase the likelihood that air stream flowing through the air passageway  50  will be fully laminar prior to traveling further downstream. Along the axis  52  between the first portion  36  of the first wall  34  and the first portion  44  of the second wall  42 , the air passageway  50  maintains a substantially constant cross-sectional area. This aspect of the air passageway  50  can be desirable to maintain laminar flow of the air stream passing through the air passageway  50 . Along the axis  52  between the third portion  40  of the first wall  34  and the third portion  48  of the second wall  42 , the cross-sectional area of air passageway  50  increases. The exemplary second wall  42  extends a greater distance than the exemplary first wall  34  between the inlet  54  and the outlet than the first wall  34 . Also, the exemplary second wall  42  extends a greater distance from a downstream end of the first portion  44  to the outlet  56  than the distance that the first wall  34  extends from a downstream end of the first portion  36  to the outlet  56 . 
     Based on the structure described above, in the exemplary embodiment of the invention, the first wall  34  and the second wall  42  are closer to parallel at the inlet  54  than at the outlet  56 . In the exemplary embodiment of the invention, the first wall  34  and the second wall  42  are transverse at the outlet  56 , fully perpendicular or less than perpendicular.  FIG. 3  also shows that a downstream end of the first wall  34 , the end of the first wall  34  at the outlet  56  is recessed relative to a downstream end of the second wall  42  such that the downstream end of the first wall  34  is spaced from a line extending tangent to the downstream end of the second wall  42 . This aspect of the exemplary structure can be desirable if the dashboard of the vehicle is especially laid-back. 
     The air duct outlet  14  also includes a vane  58  pivotally disposed within the air passageway  50  along the flow path. The vane  58  is movable between a first position (shown in phantom) wherein the vane  58  substantially blocks the air passageway  50 . The first position of the vane  58  (shown in phantom) can be an end limit of movement. It is noted that the “first position” of the vane  58  need not be an end limit of travel of the vane  58  in alternative embodiments of the invention. 
     The vane  58  can be moved through a range of other positions away from the first position that are increasingly substantially parallel to the planar first wall  34 . In the exemplary embodiment of the invention, the vane  58  is rotatable about a pivot axis  60  and wherein the first position and the other positions are further defined as angular positions about the pivot axis  60 . 
       FIG. 3  shows an exemplary position of the vane  58  is solid line that can be a second end limit of movement. As the vane  58  moves further from the first position toward an opposite end limit of movement, the air stream flowing through the air passageway  50  is deflected by the vane  58  an amount that decreases with each position more remote of the first position over the range. For example, when the vane  58  is in the position shown by phantom line in  FIG. 3 , the vane  58  is deflecting the air stream a maximum amount. In such a position, the vane  58  is deflecting to the point of blocking the air stream. 
     On the other hand, when the vane  58  is in the position shown by solid line in  FIG. 3 , the vane  58  is deflecting the air stream a minimum amount. The vane  58  is disposed in the air stream, so as theoretical matter some deflecting will occur. However, when the vane  58  is in the position shown by solid line in  FIG. 3 , the vane  58  is essentially drawing at least part of the air stream in a desired direction through the Coanda effect rather than deflecting the air steam. An arrow  59  represents the drawing of air over the vane  58  in manner consistent with the Coanda effect. 
     The air stream can adhere to the second wall  42  by an amount that increases with each position more remote of the first position over the range and such that the air stream exits from the air duct outlet  14  in a direction that is increasingly transverse to the planar first wall  34  as the vane  58  moves away from the first position. Thus, when the vane  58  is in the position shown in solid line in  FIG. 3 , the air flow will adhere to the second wall  42  a maximum amount. When the vane  58  is in the position shown in phantom line in  FIG. 3 , the air flow will adhere to the second wall  42  a minimum amount. 
     The vane  58  can include a cross-sectional profile in a plane perpendicular to the flow path that includes at least one arcuate surface. The cross-sectional profile of the exemplary vane  58  includes a first arcuate surface  62  confronting and convex to the first wall  34 . The cross-sectional profile of the exemplary vane  58  also includes a second arcuate surface  64  confronting and concave to the second wall  42 . 
     The air duct outlet  14  can also include a plurality of louvers pivotally disposed in the air passageway  50  downstream of the vane  58 . One or more or all of the louvers can have the same cross-sectional profile as the vane  58  or can have different cross-sectional profiles. The exemplary air duct outlet  14  includes a first set of louvers  66  arranged side-by-side across the air passageway  50 . Each of the first set of louvers  66  can be pivotal about a respective axis  68  extending perpendicular to the flow path. 
     The exemplary air duct outlet also includes a second set of louvers  70  downstream of the first set of louvers  66  and arranged side-by-side across the air passageway  50 . Each of the second set of louvers  70  can be pivotal about a respective axis  72  extending perpendicular to the flow path. The axes  68  of the first set of louvers  66  are transverse to the axes  72  of the second set of louvers  70 . The exemplary louvers  66  can be arranged vertically and the exemplary louvers  70  can be arranged horizontally. 
     Each of the second set of louvers  70  can include a cross-sectional profile perpendicular to the flow path with first arcuate surface  74  confronting and convex to the first wall  34  and a second arcuate surface  76  confronting and concave to the second wall  42 . Each of the first set of louvers  66  can include a cross-sectional profile that is substantially planar. 
     Referring now to  FIG. 2 , the air duct outlet  14  can control a flow of air into the interior  10  (shown in  FIG. 1 ) of the vehicle. When it is desired to change flow characteristics, the knob  22  can be engaged. If the flow is occurring, the knob  22  can be pivoted to stop the air flow. As shown in  FIG. 2 , the knob  22  is coupled to the vane  58  though a linkage  78 . The vane  58  can move through the range of positions in response to movement of the knob  22 . The louvers  66  and  70  can be moved between end limits of travel to define a range positions from relatively more open to relatively more closed. Movement of both sets of louvers  66 ,  70  can be accomplished through a knob  80 . The knob  80  can be directly mounted on one of the louvers  70  and can be grasped by a vehicle occupant to pivot the louver  70  about its axis of rotation. A linkage  84  can couple all of the louvers  70  together such that pivoting movement of the louver  70  engaged with the knob  80  results in pivoting movement of all the louvers  70 . 
     The knob  80  can be directly mounted on one of the louvers  70  for sliding movement in a transverse direction. The knob can also be coupled to the louvers  66  a fork attachment  86  and a fork  88 . Lateral sliding movement of the knob  80  can cause one of the louvers  66  to pivot about its axis of rotation through the fork attachment  86  and the fork  88 . A linkage  90  can couple all of the louvers  66  together such that pivoting movement of the louver  66  engaged with the knob  80  results in pivoting movement of all the louvers  66 . 
       FIG. 4  shows the operation of the exemplary air duct outlet  14  and also shows the air stream moving in pattern referred to as the Coanda effect. A cubic form  82  represents the desired target for the air flow. The air duct outlet  14 , by the cooperative action of the vane  58 , the louvers  66 , the louvers  70 , and inner surfaces of the housing  28 , cause the air stream to bend and flow towards the cubic form  82 . As shown in  FIG. 4 , the second wall  42  is tangent to the dashboard  16  at the outlet  56 . Also, the first wall  34  is substantially horizontal in the vehicle. As set forth above, alternative embodiments of the invention could be rotated ninety degrees or any other angle. The rotation can result in horizontal or vertical positioning and either set of louvers can be disposed in horizontal or vertical positions when closed or opened. 
     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.