Abstract:
An air conditioning apparatus has, a first domed door comprising a first pivot and a first sealing surface, and a second domed door comprising a second pivot and a second sealing surface, wherein, said second pivot is positioned different from said second pivot. With the above structure, the radial gap between the first sealing surface and the second sealing surface is varied when at least one of the two domed doors is moved. Accordingly, the air conditioning apparatus described above does not have to set the constant small radial gap or constant wide radial gap for the sake of reducing unintentional air leaking or preventing said friction.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of, U.S. Provisional Application No. (61/319,805) filed on (Mar. 31, 2010). The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to an air conditioning apparatus. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. In referring to the drawings,  FIG. 23  depicts a cross-sectional perspective view of a mode selecting device  110 . The mode selecting device  110  is a part of heating ventilating air conditioning unit (HVAC unit). The HVAC unit composes an air conditioning apparatus for a vehicle.  FIG. 24  depicts a cross-sectional perspective and exploded view of said mode selecting device  110  depicted in  FIG. 23 . 
         [0004]    The mode selecting device  110  has air conditioning case  111 , inner domed door  112  and outer domed door  113 . The air conditioning case  110  is provided with face opening  114 , def opening  115 , and foot opening (not shown). The air, having passed through the HVAC unit, will blow into the passenger compartment of the vehicle via said openings. The inner domed door  112  and the outer domed door  113  each have a pivot axis and a sealing surface. The position of the pivot axis of inner domed door  112  is the same position of the pivot axis of the outer domed door  113 . 
         [0005]    The inner domed door  112  and the outer domed door  113  can move separately to close the openings by means of an actuator (not shown). The mode selecting device  110  provides for a plurality of air distribution modes of the HVAC unit by adjusting the positions of the two domed doors  112 ,  113 . 
         [0006]    Although the above mode selecting device  110  has proven satisfactory for its intended purpose, there is still need for more improvement. For example, to reduce unintentional air leaking from the radial gap between the two sealing surfaces, it is preferable to set the radial gap as small as possible. However, setting the radial gap small may cause friction between the two domed doors  112 ,  113 . Such friction makes noise and vibration. 
       SUMMARY 
       [0007]    In order to overcome the deficiencies in the prior art, the present invention describes an air conditioning apparatus having a plurality of domed doors for controlling airflow comprising, a first domed door having a first pivot axis, a first sealing surface, and a first arm portion between the first pivot axis and the first sealing surface, a second domed door having a second pivot axis, a second seal surface, and a second arm portion between the second pivot axis and the sealing surface, and an air conditioning case accommodating the first domed door and the second domed door, wherein, said first pivot axis is positioned offset against the second pivot axis, said first domed door and said second domed door each can rotate relatively, and said second domed door is at least partially nested in the first domed door. With the above structure, the radial gap between the first sealing surface and the second sealing surface is varied when at least one of the two domed doors is moved. Accordingly, the air conditioning apparatus described above does not have to set the constant small radial gap or constant wide radial gap for the sake of reducing unintentional air leaking or preventing said friction. 
         [0008]    In another aspect of this disclosure, a rotation edge of the second sealing surface contacts the first domed door. With such a structure, the radial gap is eliminated. 
         [0009]    In another aspect of this disclosure, said second sealing surface has a seal member in the one of said rotation edges, and the seal member contacts the first domed door. With such a structure, the unintentional air leaking is further reduced. 
         [0010]    In another aspect of this disclosure, the air conditioning case defines an opening, the first sealing surface contacts the air conditioning case in one side of the opening, the second sealing surface contacts the air conditioning case in the other side of the opening, and the second domed door contacts the first domed door. With the above structure, the first sealing surface and the second sealing surface covers the opening defined by the air conditioning case together. 
         [0011]    In another aspect of this disclosure, an air conditioning apparatus further comprising, a controller for driving the first domed door and the second domed door, wherein, the said controller starts moving the first domed door and the second domed door in different timing. With such a structure, the controller can drive two domed doors smoothly. 
         [0012]    In another aspect of this disclosure, said controller starts moving the second domed door while the first domed door is still moving. With such a structure, the controller can finish moving two doors quickly. 
         [0013]    In another aspect of this disclosure, an air conditioning apparatus comprising, an air conditioning case defining a face opening and a foot opening, a first domed door having a first pivot axis, a first sealing surface and a first arm portion between the first pivot axis and the first sealing surface, a second domed door having a second pivot axis, a second sealing surface, and second arm portion between the second pivot axis and the second sealing surface, wherein, said first pivot axis is positioned offset against the second pivot axis, said second domed door is at least partially nested in the first domed door, said face opening is surrounded by a first contact portion provided in the air conditioning case, the first sealing surface contacts the first contact portion, the foot opening is surrounded by a second contact portion provided in the air conditioning case, the second sealing surface contacts the second contact portion, the first contact portion is at least partially set along the first circle, a center of the first circle is the same as the first pivot axis, the second contact portion is at least partially set along the second circle, a center of the second circle is the same as the second pivot and said second domed door is at least partially nested in the first domed door. With the above structure, the radial gap between the first sealing surface and the second sealing surface is varied when at least one of the two domed doors is moved. Accordingly, the air conditioning apparatus described above does not have to set the constant small radial gap or constant wide radial gap for the sake of reducing unintentional air leaking or preventing said friction. Also, the face opening and the foot opening are closed by the contact of the respective sealing surface and contact portion. 
         [0014]    In another aspect of this disclosure, the air conditioning case further defines a defrost opening disposed between the face opening and the foot opening; the defrost opening is closed by both the first domed door and the second domed door. 
         [0015]    In another aspect of this disclosure, the first pivot axis is disposed near the foot opening relative to the second pivot axis, the second pivot axis is disposed near the face opening relative to the first pivot axis. With such a structure, the arm portions can be relatively longer. Such longer arm portions allow sealing surfaces to move faster than a shorter arm portion. 
         [0016]    In another aspect of this disclosure, the air conditioning case further defines second row passenger opening disposed on a side wall of the air conditioning case, and the second row passenger opening is closed by the first arm portion. 
         [0017]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0018]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0019]      FIG. 1  is a perspective view of an air conditioning unit in accordance with the present disclosure disposed in a front portion of a passenger compartment of a vehicle; 
           [0020]      FIG. 2  is a side sectional view of the air conditioning case constituting defroster mode; 
           [0021]      FIG. 3  is a side sectional view of the air conditioning case constituting foot-defroster mode; 
           [0022]      FIG. 4  is a side sectional view of the air conditioning case constituting foot mode; 
           [0023]      FIG. 5  is a side sectional view of the air conditioning case constituting Bi-level mode; 
           [0024]      FIG. 6  is a side sectional view of the air conditioning case illustrated in  FIG. 1 ; 
           [0025]      FIG. 7  is an example of domed door in accordance with the present disclosure; 
           [0026]      FIG. 8  is a sectional view of the air conditioning case in accordance with the first embodiment of the present disclosure, showing the contact portions provided in the air conditioning case; 
           [0027]      FIG. 9  is an example of domed door in accordance with another embodiment; 
           [0028]      FIG. 10  is a part of a sectional view of the domed door depicted in  FIG. 9  taken along dashed line E. 
           [0029]      FIG. 11  is a plain view of an air conditioning apparatus according to the second embodiment; 
           [0030]      FIG. 12  is a cross-sectional view taken along line D of the air conditioning apparatus illustrated in  FIG. 11 ; 
           [0031]      FIG. 13  is an enlarged view of  FIG. 12  depicting face air mode; 
           [0032]      FIG. 14  is a sectional view of the air conditioning apparatus depicting intermediate position between face air mode and Bi-level air mode; 
           [0033]      FIG. 15  is a sectional view of the air conditioning apparatus depicting intermediate position between face air mode and Bi-level air mode; 
           [0034]      FIG. 16  is a sectional view of the air conditioning apparatus depicting Bi-level air mode; 
           [0035]      FIG. 17  is a sectional view of the air conditioning apparatus depicting intermediate position between Bi-level air mode and foot mode; 
           [0036]      FIG. 18  is a sectional view of the air conditioning apparatus depicting intermediate position between Bi-level air mode and foot mode; 
           [0037]      FIG. 19  is a sectional view of the air conditioning apparatus depicting foot mode; 
           [0038]      FIG. 20  is a sectional view of the air conditioning apparatus depicting Foot-defroster mode; 
           [0039]      FIG. 21  is a sectional view of the air conditioning apparatus depicting defroster mode; 
           [0040]      FIG. 22  is a plain view of an air conditioning apparatus according to the third embodiment; 
           [0041]      FIG. 23  is a cross-sectional perspective view of a mode selecting device of prior art; and 
           [0042]      FIG. 24  is a cross-sectional perspective and exploded view of said mode selecting device depicted in  FIG. 23 . 
       
    
    
       [0043]    Corresponding reference numerals indicate corresponding elements throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0044]    The preferred and other embodiments will now be described more fully with reference to  FIGS. 1-22  of the accompanying drawings.  FIGS. 1-8  show the first embodiment. 
         [0045]      FIG. 1  is a partial perspective view depicting an interior of a vehicle  10  having a passenger compartment  12 , a dashboard  14  and an air conditioning unit  16 . Air conditioning unit  16  is disposed behind dashboard  14  at approximately the center of passenger compartment  12  in a side-to-side orientation. Air conditioning unit  16  may further include a blower assembly  18  and an air conditioning case  20 . Air conditioning case  20  houses an evaporator or cooling providing heat exchanger of a refrigeration system, a heater core or heat providing heat exchanger of a heating system, temperature adjusting mechanisms and air blowing mode selecting mechanisms. 
         [0046]    Air conditioning unit  16  is part of a more comprehensive air conditioning system which may further include a refrigerant compressor (not shown), a condenser (not shown), an expansion device (not shown) and an evaporator. Air conditioning unit  16  is also part of a vehicle heating system which includes the vehicle&#39;s engine (not shown), a water pump (not shown), a radiator (not shown) and a heating heat exchanger. Air conditioning unit  16  may further employ an air intake mechanism  22 , a defroster duct  24 , face duct  26 , foot duct  28 , and an air outlet mode selecting device  29 . Air intake mechanism  22  may be configured to select the ratio between inside air and outside air provided to blower assembly  18 . An inside/outside air switching door mechanism may adjust the ratio between inside air and outside air. 
         [0047]    Continuing with  FIG. 2 , the air conditioning case  20  has a face opening  38  corresponding to the face duct  26 , a defroster opening  46  corresponding to the defroster duct  24  and foot opening  50  corresponding to the foot duct  28 . The air blowing mode selecting device  29  has two domed doors. The first domed door  30  corresponds to the face opening  26  and defroster opening  24 . The second domed door  33  corresponds to the foot opening  28  and defroster opening  46 . First domed door  30  and second domed door  32  are mode doors.  FIG. 7  shows an example of domed door. The first domed door  30  and the second domed door  32  may pivot about or rotate about its pivot axis  34 ,  36 . The first domed door  30  and the second domed door  32  are further equipped with a sealing surface  31 ,  33 . In this embodiment, the sealing surfaces  31 ,  33  are curved surface. The curved surfaces  31 ,  33  have seal members  38 ,  40 ,  42 ,  44  such as rubber seals. The seal members  38 ,  40 ,  42 ,  44  are disposed along the rectangular edge of the sealing surfaces  31 ,  33 . More specifically, the seal members  38 ,  40 ,  42 ,  44  are at least disposed in the edges in the rotation orientation of the sealing surfaces  31 ,  33 . The edges in the rotation orientation are indicated by dashed line in  FIG. 7 . 
         [0048]    The domed doors  30 ,  32  each have two arm portions  11 . In this embodiment, the arm portions  11  are pie-shaped plate. The pie-shaped plate has two equal length sides, and the angle between the two equal length sides is acute angle F. The arm portions  11  are each disposed between the sealing surface  31 ,  33  and the pivot axis  34 ,  36  to support the sealing surface  31 ,  33 . 
         [0049]    In addition, in the sectional view, the first pivot axis  36  is disposed near the foot opening  50  relative to the second pivot axis  34 , the second pivot axis  34  is disposed near the face opening  48  relative to the first pivot axis  36 . With the above structure, the arm portions  11  can be relatively longer. Such longer arm portions  11  allow sealing surfaces  31 ,  33  to move faster than a shorter arm portion  11 . Moreover, domed doors  30 ,  32  may “nest” with each other; that is, the first domed door  30  may be pivotable to move within the second domed door  32 , or the second domed door  32  may be pivotable to nest within the first domed door  30 . 
         [0050]    When the domed doors  30 ,  32  are adjusted into specific positions, the seal members  38 ,  40 ,  42 ,  44  will contact respective contact portions  13   a ,  13   b ,  13   c  (depicted in  FIG. 8 ) of the air conditioning case  20  or the other domed door&#39;s sealing surface to prevent air from exiting specific air openings. In this embodiment, the seal members  38 ,  40 ,  42 ,  44  are made of rubber, but using other materials for seal members  38 ,  40 ,  42 ,  44  is possible. 
         [0051]    To permit airflow to flow to specific openings, as will be further explained below, domed doors  30 ,  32  have a “C” shape structure composed by the sealing surface  31 ,  33  and arm portions  11  in this embodiment. Of course in another embodiment, the domed doors may have holes or other mesh or frame structure to permit air to pass from one side of a door to another side of the same door. 
         [0052]      FIG. 9  and  FIG. 10  depict another embodiment.  FIG. 10  shows a cross-sectional view of the domed door depicted in  FIG. 9  taken along line E. The sealing surfaces  31 ,  33  have a frame structure  15  and a sail member  17 . The sail member  17  fixed to the frame structure  15  by means for fixing  19 , and covers the frame structure  15 . The means for fixing  19  allows relative movement between the frame structure  15  and the sail member  17 . Consequently, the sail member  17  can inflate towards the openings  46 ,  48 ,  50  by the airflow pressure, and contact the contact portions  13   a ,  13   b ,  13   c  to seal the openings  46 ,  48  and  50 . 
         [0053]      FIG. 8  shows contact portions  13   a ,  13   b ,  13   c  provided in the air conditioning case  20 . The first contact portion  13   a  surrounds about a perimeter of the face opening  48 . The second contact portion  13   b  surrounds about a perimeter of the foot opening  50 . The third contact portion  13   c  surrounds about a perimeter of the defroster outlet  46 . 
         [0054]    The first sealing surface  31  may contact both the first contact portion  13   a  and the third contact surface  13   c . The second sealing surface  33  contacts the second contact portion  13   b . The first contact portion  13   a  is at least partially set along with the first circle c 1 . The center of the first circle c 1  is the same as the first pivot axis  36 . The second contact portion  13   b  is at least partially set along with the second circle c 2 . The center of the second circle c 2  is the same as the second pivot  34 . 
         [0055]    In this embodiment, the seal members  38 ,  40 ,  42 ,  44  are disposed on the sealing surfaces  31 ,  33  side, but the seal members  38 ,  40 ,  42 ,  44  may be disposed in the contact portions  13   a ,  13   b ,  13   c  side. Turning back to the first embodiment; the  FIGS. 2-6  depict various arrangements of the domed doors  30 ,  32 . More specifically, various positions of a first domed door  30  and a second domed door  32  are depicted. In  FIG. 2 , air openings  46 ,  48 ,  50  may be connected to the defroster outlet duct  24 , a face outlet duct  26 , and a foot outlet duct  28  with each duct leading to a respective opening. 
         [0056]    The first pivot axis  36  is positioned to offset against the second pivot axis  34 . The  FIG. 2  depicts defroster mode in the air blowing mode selecting device. The first domed door  30  secured over face outlet  48 . The seal member  38 ,  40  may contact the first contact portion  13   a  to prevent airflow from face outlet  48 . In addition, the second domed door  32  secured over foot outlet duct  50  such that seal member  42 ,  44  may contact the second contact portion  13   b  to prevent airflow from foot outlet  50 , airflow may almost only flow from defroster outlet duct  46 . Thus, with reference continuing with  FIG. 2 , airflow  52  is able to pass from a side  54  to a side  56  of domed door  30  and from a side  58  to a side  60  of domed door  32 . 
         [0057]      FIG. 2  also depicts a rear face outlet  62 . The air going into the rear face outlet  62  will be delivered to the second row passenger seat in the vehicle via a rear face duct (not shown). The rear face opening  62  may be covered or blocked by the arm portion  11  of the first domed door  30 . The rear face opening  62  may be located at a longitudinal end of one of domed doors  30 ,  32 . Depending upon design considerations, such as whether a vehicle is left or right hand drive, rear face opening  62  may be in a side wall of the air conditioning case  20 . 
         [0058]    Turning to  FIG. 3 , the  FIG. 3  depicts foot-defroster mode in the air blowing mode selecting device. The domed door  30  is depicted such that seal member  38  and seal member  40  are positioned to contact the contact portion  13  of air conditioning case  20  about face outlet  48  so that air is prevented from passing from face outlet  48 . The rear face opening  62  is covered by the first arm portion  11  to prevent airflow from flowing out of rear face outlet  62 . The second domed door  32 , on the other hand, will permit air flow  68  to be divided into air flow  72  which will flow through the second domed door  32  to foot outlet  50  and air flow  70  which will flow through first domed door  30  to defroster outlet  46 . The foot outlet  50  may be directed toward more than one foot duct  28 , as depicted in  FIG. 1 . The airflow  72 , for instance, that flows to foot outlet  50  when flowing to multiple foot outlets  28 ; however, configuring ducting taking into consideration other vehicle structures is within the scope of the present disclosure. 
         [0059]    Turning to  FIG. 4 ,  FIG. 4  depicts the foot mode. The first domed door  30  is depicted such that seal member  38  and seal member  40  contacts the contact portion  13  of the air conditioning case  20  about or near a perimeter of the face outlet  48 , to thereby block air flow from face outlet duct  48 . Simultaneously, the second domed door  32  is depicted such that seal member  44  contacts the contact portion  13  of air conditioning case  20  about or near a perimeter of defroster outlet duct  46 , seal member  44  contacts sealing surface  31  of the first domed door  30 , and thereby preventing air flow from exiting from defroster outlet duct  46 . 
         [0060]    Because of such arrangement of domed doors  30 ,  32 , air flow  74  is permitted to flow through domed doors  30 ,  32  and almost only into foot outlet duct  50 , thereby channeling air to one or more foot outlets  28 . Again, rear face outlet  62  may be covered to prevent airflow into rear face outlet  62 , which may be located in a wall  66  of air conditioning case  20 . 
         [0061]      FIG. 4  also depicts a partial nested arrangement of the first domed door  30  and the second domed door  32 . More specifically, the second domed door  32  may be partially nested within the first domed door  30 , or alternatively, the first domed door  30  may be partially nested within the second domed door  32 . Even with such nested arrangement, the first domed door  30  and the second domed door  32  may maintain separate pivot points  34 ,  36 . 
         [0062]    Turning now to Bi-level air mode depicted with  FIG. 5 , the first domed door  30  and the second domed door  32  are depicted to permit Bi-level flow of air into passenger compartment  12  ( FIG. 1 ). More specifically, the first domed door  30  is positioned such that only part of face opening  48  is covered and such that only part of defroster opening  46  is covered; however, the second domed door  32  covers the part of defroster opening  46  that the first domed door  30  does not cover. At the same time, the second domed door  32  also permits part of foot opening  50  to accept airflow. Thus, airflow  76  may be divided into airflow  78  that flows from face opening  48  and into airflow  80  that flows into foot opening duct  50 . 
         [0063]    In this Bi-level air mode, arm portion of the first domed door  30  covers a part of the rear face opening  62  to permit airflow from only part of rear face opening  62 . Moreover, in Bi-level air mode, sealing between domed doors  30 ,  32  may be necessary to prevent air from passing between small spaces between domed doors  30 ,  32 . 
         [0064]    Turning now to face air mode depicted with  FIG. 6 , an arrangement and positioning of domed doors  30 ,  32  may be such that seal members  38 ,  40  of the first domed door  30  contact the contact portion  13   c  on HVAC case  20  about a periphery of defroster outlet duct  46  to prevent air flow into defroster outlet duct  46 . At the same time, the second domed door  32  may be positioned such that seal members  42 ,  44  contact the contact portion  13   b  on a periphery of foot outlet duct  50  to prevent airflow into foot outlet duct  50 . Thus, with such an arrangement, airflow  86  through air conditioning case  20  is almost only permitted to flow into face opening  48  and rear face opening  62 , which are left uncovered. 
         [0065]    Again, with the positioning of the first domed door  30  and the second domed door  32 , as depicted in  FIG. 6 , partial nesting of domed doors  30 ,  32  may occur. Thus, the first domed door  30  may be nested within the second domed door  32  or the first domed door  32  may be nested within the second domed door  30 . With domed doors  30 ,  32 , positioned as depicted in  FIG. 6 , airflow  86  is almost only permitted to flow from face opening  48  and rear face opening  62 . 
         [0066]      FIGS. 11 to 21  show the second embodiment of the present invention, having similar elements as the first embodiment, referred by the same reference numerals. In the first embodiment, the air conditioning case have rear face opening  62 , but in this second embodiment, the air conditioning case  20  does not have rear face opening  62  or the rear face opening  62  is covered by a lid. 
         [0067]      FIG. 11  shows plain view of an air conditioning apparatus  16  according to the second embodiment. The air conditioning apparatus  16  has an air conditioning case  20 , a blower assembly  18 , and a controller  200 . The air conditioning case  20  defines an airflow passage. The air conditioning case  20  is a duct member. The airflow passage has a plurality of airflow outlets  26 ,  28 . The airflow openings are face outlet  26 , foot outlet  28 , and def outlet  46  (depicted in  FIG. 12 ) in this embodiment. The upstream end of the airflow passage is connected to the blower assembly  18 . Actuators  201 ,  202  are attached to the side wall of the air conditioning case  20 . The actuators control air-mixing door axis  203 , a first domed door pivot axis  36 , and the second domed door pivot axis  34 . 
         [0068]    The blower assembly  18  has an air intake unit  22  and a blower fan  204 . The air intake unit  22  introduces either recirculation airflows from vehicle passenger compartment or outside fresh air from outside of the passenger compartment. The blower fan  204  creates airflow blown into said air conditioning case  20 . The controller  200  controls the air intake unit  22 , the blower fan  204 , air mixing door  205  (depicted in  FIG. 12 ) and domed doors  30 ,  32  (depicted in  FIG. 12 ) based on the various information input from the plurality of vehicle sensors  206  or switches  207  in this embodiment. The controller  200  drives said two domed doors  30 ,  32  respectively, and the controller  200  disposes the two domed doors  30 ,  32  in several particular rotational angles. The several particular rotational angles each form the one of the predetermined air distribution mode. 
         [0069]      FIG. 12  shows a cross-sectional view of the air conditioning apparatus  16  depicted in  FIG. 11  taken along line D. The air conditioning case  20  accommodates an evaporator  208 , an air mixing door  205 , heater core  209 , auxiliary heat exchanger  210 , and domed doors  30 ,  32 . The evaporator  208  is a cooling heat exchanger used for cooling air passing through. The air mixing door  205  is an airflow direction switching device. The air mixing door  205  divides airflow passed through the evaporator  208  into two airflows. The one of the two airflows is directed to pass through the heater core  209  and auxiliary heat exchanger  210 . The other airflow is directed to the bypass passage  211  to bypass the heater core  209  and the auxiliary heat exchanger  210 . 
         [0070]    The air mixing door  205  is controlled by the controller  200  based on the target temperature of air outlet (TAO). The TAO is calculated by the controller  200  based on the thermal loads. The heater core  209  and the auxiliary heat exchanger  210  are heat providing heat exchangers. The auxiliary heat exchanger  210  may be an electrical heater, gas heater or heat radiating device for other heating equipment in the vehicle. 
         [0071]    The domed doors  30 ,  32  composes outlet mode selecting device  29 . The domed doors further comprise pivots  34 ,  36  and sealing surfaces  31 ,  33 . The sealing surfaces  31 ,  33  are connected to the respective pivots  34 ,  36  by the arm portion  11 . The pivots  34 ,  36  are positioned different form each other. In this embodiment, the arm portions  11  are pie shaped in cross-sectional view. Also, the arm portions  11  may be symmetrical or asymmetrical in cross-sectional view. The two domed doors  30 ,  32  are controlled and disposed in the specific positions by the controller  200  to compose one of predetermined air distribution modes. One of the two domed doors may be nested in the other domed door. In this embodiment, the nested domed door is called inner domed door  32 , and the other domed door is called outer domed door  30 . 
         [0072]    The air conditioning case  20  defines contact portions  13   a ,  13   b , and  13   c . The contact portions  13   a ,  13   b , and  13   c  each surround respective airflow opening  46 ,  48 ,  50 . The contact portions  13   a ,  13   b , and  13   c  are along the sealing surfaces  31 ,  33 . In other words, the contact portions  13   a ,  13   b , and  13   c  are aligned along trails (dashed line A and B depicted in  FIG. 13 ) of the sealing surfaces  31 ,  33 . The trails correspond to the circle c 1  and c 2  depicted in  FIG. 8 . 
         [0073]      FIG. 13  shows enlarged view of  FIG. 12 .  FIG. 13  depicts the positions of domed doors  30 ,  32  composing face air mode. In the face air mode, the Def opening  46  and Foot opening  50  are closed by the two domed doors  30 ,  33 . The Def opening  46  are closed by the outer domed door  30 . The air conditioned airflow mainly blown into the Face outlet  48 . The seal members  40 ,  38  of the outer domed door  30  are contacting the contact portion  13   c  on the inner surface of the air conditioning case  20 . The Foot opening is closed by the inner domed door  32 . The seal members  42 ,  44  of the inner domed door  32  are contacting the contact portion  13   b  on the inner surface of the air conditioning case  20 . In this face air mode domed door layout, there is a radial gap between the outer domed door&#39;s sealing surface  31  and inner domed door&#39;s sealing surface  33 . The radial gap is sealed by the protrusion  213  of the air conditioning case  20 . In other words, the duct member  20  provides a protrusion  213  for filling said radial gap. 
         [0074]      FIG. 14  and  FIG. 15  show intermediate state between Bi-level air mode and face air mode. The controller  200  at first drives the outer domed door  30  to inter mediate portion of the Face outlet  48  and the Def outlet  46 . Then the controller  200  drives inner domed door  32  to open the Foot outlets ( FIG. 15 ). The seal member  42  of the inner domed door  32  contact the inside surface of the outer domed door&#39;s sealing surface  31 . In other words, when the controller  200  drives both the two domed doors  30 ,  31  to change the air distribution modes, the controller  200  starts moving one of the two domed door  30  alone, and then, the controller  200  allows the other one of the domed door  32  to start. Therefore, the controller  200  starts moving the first domed door  30  and the second domed door  32  in different timing. Furthermore, the controller  200  starts moving the second domed door  32 , while the first domed door  30  is still moving. With the above structure, the controller  200  can drive two domed doors smoothly and quickly. 
         [0075]    The gap between outer domed door&#39;s sealing surface  31  and inner domed door&#39;s sealing surface  33  varies when the relative position of the outer domed door  30  and the inner domed door  32  differs. The double headed arrows in  FIG. 15  indicate the gap. Because of the different positions of the two domed doors respective pivots  36 ,  34 , the gap becomes smaller when the inner domed door  32  moves to towards the outer domed door  30 . A pair of rotational angles, which provides the least gap or contact, would compose the face air mode in this embodiment. 
         [0076]      FIG. 16  shows Bi-level air mode position. The Face opening  46  and the Foot opening  48  opened half way. The temperature conditioned airflow divided in two airflows, and go into Face opening  48  and Foot opening  50 . 
         [0077]      FIG. 17  and  FIG. 18  show the intermediate state between the Bi-level air mode and the foot mode. The controller  200  drives outer domed door  30  in clock-wise direction to close the Face outlet  48 . The dashed line depicted in  FIG. 16  shows the position of the outer domed door  30  in Bi-level air mode. Then the controller  200  closes the Def outlet  46  by moving the inner domed door  32  in clock-wise direction ( FIG. 18 ). The seal member  40  disposed in the rotation edge of the inner domed door&#39;s sealing surface  33  contacts to the inner surface of the outer domed door&#39;s sealing surface  31 . The dashed line depicted in  FIG. 18  shows the position of the inner domed door  32  in the Bi-level air mode. 
         [0078]      FIG. 19  shows a foot mode. The temperature controlled airflow goes into the foot opening  50 . The seal members  40 ,  38  of the outer domed door  30  are contacting the contact portion  13   a  on the inner surface of the air conditioning case  20 . The seal member  44  of the inner domed door  32  is contacting the contact portion  13   b  on the top of the protrusion  213 . The seal member  42  of the inner domed door  32  is contacting the inner surface of the outer sealing surface  31 . 
         [0079]      FIG. 20  shows Foot-Def mode. The temperature controlled airflow is divided into two airflows. The airflow is blown into the Foot opening  50  and Def opening  46 . The seal members  40 ,  38  of the outer domed door  30  are contacting the contact portion  13   a  on the inner surface of the air conditioning case  20 . The contact portion  13   b  provided on the top of the triangle shape protrusion  213  may briefly contacts the inner sealing surface  33 . 
         [0080]      FIG. 21  shows defroster mode. The Face opening  48  is closed by the outer domed door  30 . The Foot opening  50  is closed by the inner domed door  32 . The seal members  40 ,  38  of the outer domed door  30  are contacting the contact portion  13   a  on the inner surface of the air conditioning case  20 . The seal member  42  of the inner domed door  32  is contacting the contact portion  13   b  on the top of the triangle shape protrusion  213 . The seal member  44  of the inner domed door  32  is contacting the contact portion  13   b  of the air conditioning case  20 . 
         [0081]      FIG. 22  shows the third embodiment. In the above second embodiment, two domed doors  30 ,  32  are driven by two respective actuators  202 . But in this third embodiment, one actuator  202  drives both outer domed door  30  and inner domed door  32  via the link mechanism  214 . 
         [0082]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention. 
         [0083]    Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
         [0084]    The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0085]    When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0086]    Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
         [0087]    Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.