Abstract:
An aircraft vent door system includes a vent door for a vent on an aircraft door. A cam, having a groove, is disposed on the vent door. The system also includes a movement assembly, which includes a roller disposed within the groove, and a lever coupled to the movement assembly. A portion of the lever extends beyond and proximate to the perimeter of the vent door. A second lever may also be attached to the aircraft door. The first lever pivots in response to the movement of the movement assembly, and urges the second lever to pivot. The second lever, in turn, urges the vent door open, thereby overcoming the sticking effect of, for example, built up ice or other obstructions.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application claims benefit from U.S. Provisional Patent Application No. 60/928,435, filed on May 9, 2007, the entire contents of which being incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates generally to vent door systems and, more particularly, to vent door systems that include lever mechanisms to open the vent door against the pressure caused by ice buildup. 
       BACKGROUND 
       [0003]    Vents are used countless applications to provide an entrance or exit for the flow of air. When it is necessary to control whether air flows through a vent, then a vent door is typically used. An example of where vent doors are used is on the passenger doors of commercial aircraft. Vents allow the pressure inside the aircraft to be equalized with the pressure on the outside of the aircraft after the aircraft lands. One problem with conventional vent doors is ice build-up. Ice build-up occurs particularly when the air temperature on one side of the vent door is much lower than the air temperature on the other side of the vent door. This causes ice to build up on the vent door. When the ice builds up around the edges of the door, it can cause the door to become stuck in a closed position. This frequently occurs in commercial aircraft, since the temperatures outside of the aircraft at cruising altitude are usually well below zero degrees Fahrenheit. Thus, it can be seen that there is a need for a vent door system that includes a way of overcoming the problem of ice buildup. 
       SUMMARY 
       [0004]    An embodiment of the present invention provides a vent door system. The vent door system includes a vent door. A cam is disposed on the vent door. The cam has a groove defined on it. The system also includes a movement assembly, which includes a roller, which is disposed within the groove, and a lever coupled to the movement assembly. A portion of the lever extends beyond and proximate to the perimeter of the vent door. 
         [0005]    The lever can be one of at least two levers. The second lever can be attached to a surface beyond the periphery of the vent door. 
         [0006]    A first portion of the cam can be attached to the vent door, and a second portion of the cam can pivotally attached to a surface outside of the vent door. The movement assembly can also include a first arm, a second arm, and a rod, with the first and second arms being connected to the rod such that, when the rod rotates about its longitudinal axis, the first and second arms move correspondingly, the first arm being coupled to the lever, the roller being attached to the second arm. Also, the cam can be a first cam, and the system can further include a second cam disposed on the vent door generally parallel to and facing the first cam, the second cam having defined thereon a groove. Also in this arrangement, the movement assembly can include a third arm having a roller that is disposed within the groove, with the third arm being connected to the rod. 
         [0007]    In addition, the lever can be pivotally attached to the vent door, and the movement assembly includes an arm that is coupled to the lever when the vent door is opened. During opening of the vent door, the arm urges the portion of the lever that extends beyond the vent door against a surface that is beyond the vent door. Also, when the vent door enters a partially open position, the arm can decouple from the lever. 
         [0008]    The vent door can include a generally planar panel, and a wall that surrounds and is generally perpendicular to the panel. In this arrangement, the panel and the wall define a cavity, and a generally planar member is disposed within the cavity and attached to the panel. Furthermore, the cam can be attached to the member. When used in an aircraft door having a vent opening defined therein, when the vent door is in a closed position, the vent door is seated within the opening. The vent door can have at least an open position, a movement assembly linked to the vent door, and a lever attached to the vent door. In this arrangement, the lever is coupled to the movement assembly when the vent door is in its closed position and uncoupled from the movement assembly when the vent door is in its open position. The lever can have a first end that protrudes beyond the periphery of the vent door, and a second end to which the movement assembly is coupled when the vent door is in its closed position. 
         [0009]    The movement assembly can include an arm with a hooked end. In this arrangement, the lever can have a first end that protrudes beyond the periphery of the vent door, and a second end. The hooked end of the arm is coupled to the second end of the lever when the vent door is in its closed position. Also, the lever can be pivotally attached to the door. In this arrangement, when the movement assembly pulls the door toward its open position, the hooked end of the arm pulls on the second end of the lever, causing the lever to pivot, and urging the first end of the lever against a surface that is beyond the periphery of the door. 
         [0010]    In another arrangement, the vent door system can include a cam attached to the door. The cam can have a groove defined on it, and the movement assembly includes an arm to which the roller is attached, such that when the arm pivots, the roller rolls along the groove and thereby urges the cam and the vent door away from a vent. The cam can have a first portion attached to the vent door, and a second portion pivotally attached to a surface outside of the vent door. Also, the cam can have defined thereon a groove, and the movement assembly can include a first arm, a second arm having a roller attached thereto, and a rod. The first and second arms can be connected to the rod such that, when the rod rotates about its longitudinal axis, the first and second arms move correspondingly. The first arm can be coupled to the lever, and the roller is disposed within the groove. 
         [0011]    Also, the lever can be pivotally attached to the vent door. In this arrangement, the movement assembly includes an arm that is coupled to the lever when the vent door is opened and, during opening of the vent door, urges the portion of the lever that extends beyond the vent door against a surface that is beyond the vent door. The vent door can have a generally planar panel, and a wall that surrounds and is generally perpendicular to the panel. The panel and the wall define a cavity, and a generally planar member can be disposed within the cavity and attached to the panel. Furthermore, the movement assembly can be attached to the generally planar member. Hence, in an arrangement where an aircraft door has a vent opening defined therein, when the vent door is in a closed position, the vent door is seated within the opening. 
         [0012]    Hence, in an aircraft door venting system according to an embodiment of the present invention, the aircraft door can have a vent and a vent door having an open position and a closed position. The vent door is seated within the vent when the vent door is in the closed position. The system also includes a rod disposed proximate to the vent door, and a first arm and a second arm attached to the rod. The first and second arms are generally perpendicular to the rod. The first arm has a hooked end and the second arm has a roller attached to it. The system also includes a cam having a first portion that is attached to the vent door and a second portion that is pivotally attached to a surface of the aircraft door. Defined on the cam is a groove, in which the roller is disposed. The system further includes a lever pivotally attached to the vent door, with one end of the lever being coupled to the hooked end of the first arm when the vent door is in the closed position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  illustrates an aircraft door that incorporates a vent system according to an embodiment of the present invention; 
           [0014]      FIG. 2  further illustrates the vent system as shown in  FIG. 1 ; 
           [0015]      FIGS. 3-6  illustrate an example of the operation of the lever in the vent system as shown in  FIGS. 1 and 2  according to an embodiment of the present invention; and 
           [0016]      FIGS. 7-8  illustrate modifications to the embodiment of the vent system as shown in  FIGS. 1 and 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    An embodiment of the present invention described herein is generally directed vent door system having a lever.  FIGS. 1-8  illustrate examples of the vent door system according to various embodiments of the present invention. The system, generally labeled  10 , is integrated with an aircraft door  8  in this example. The aircraft door  8  has a vent opening  9  (shown in  FIG. 6 ), around which a vent door frame  12  is disposed. The vent door frame  12  is attached to the aircraft door  8 . The system also includes a vent door  14 , which has an open position and a closed position. A flexible seal  13  is attached to the vent door  14 . When in its closed position, a peripheral lip  15  of the vent door  14  is seated against the seal  13  and within the opening around which the vent door frame  12  is disposed. The vent door  14  includes a front panel  18  and a wall  20 . The front panel  18  and the wall  20  define a cavity  22 . The vent door  14  further includes a first generally planar member  24  and a second generally planar member  26  that are integrally formed with the front panel  18  and run along the length of the vent door  14 . The vent door  14  further includes a first rib  27  and a second rib  28 , also integrally formed with the first panel  18 . Attached to the vent door  14  are two brackets  62  and  64 . The brackets  62  and  64  are fastened to the vent door  14  by bolts. 
         [0018]    The vent door system  10  further includes a first cam  16  and a second cam  17 . Both the first and second cams  16  and  17  are shown in  FIG. 1 . In  FIGS. 2 ,  3 , and  7 , only the second cam  17  is shown. In  FIGS. 4 ,  5 ,  6 , and  8 , only the first cam  16  is shown. The first cam  16  is attached to the vent door  14  at points  16   a  and  16   b , while the second cam  17  is attached to the vent door  14  at points  17   a  &amp;  17   b . The vent door frame  12  also includes a hinge  19 . The first cam  16  is attached to the hinge  19  at point  16   c , which the second cam  17  is attached to the hinge  19  at point  17   c . The first cam  16  has defined thereon a groove  16   d . Similarly, the second cam  17  has defined thereon a groove  17   d . The vent door  14  moves from its open position to its closed position and vice versa via the movement of the first and second cams  16  and  17 . Specifically, the first and second cams  16  and  17  pivot about the hinge  19 , taking the attached vent door  14  with them. 
         [0019]    Also included in the vent door system  10  is a lever  50 . The lever  50  is an elongated member that has a first end  52 , a middle portion  54  and a second end  56 . The first end  52  has two generally planar members  52   a  and  52   b  that face one another and are generally parallel to each other. Between the two planar members  52   a  and  52   b  is a gap. A pin  58  connects the two planar members  52   a  and  52   b  across the gap. The middle portion  54  of the lever  50  is generally solid. Between the middle portion  54  and the second end  56  is a rounded portion  60 . The second end  56  of the lever  50  is generally solid and hooks at about a 90 degree angle. The lever  50  is attached to the vent door  14  by a bolt  58  that extends through a sleeve  51  that passes through a hole in the rounded portion  60  of the lever  50  and is anchored by the brackets  62  and  64 . The lever  50  pivots about the sleeve  51 . 
         [0020]    The vent door system  10  also includes a movement assembly, which imparts the force to the first and second cams  16  and  17  necessary to move the vent door  14  from its open to its closed position and vice versa. The movement assembly, generally labeled  30 , includes a rod  32  (shown in  FIG. 1 ) that is rotatable around its longitudinal axis, a first arm  34 , second arm  36  and third arm  38  that are attached to the rod  30 . The first arm  34  has a first end  35 , which is attached to the rod  32 , and a second end  37 , which is hooked. The second arm  36  has a first end and a second end. The first end of the second arm  36  is attached to the rod  32 . Disposed on the second end of the second arm is a roller  40 . Similarly, the third arm  38  has a first end and a second end. The first end of the third arm  38  is attached to the rod  32 . Disposed on the second end of the third arm  38  is a roller  42 . The roller  40  of the first arm  36  is disposed in the groove  16   d  of the first cam  16 , and the roller  42  of the second arm  38  is disposed within the groove  17   d  of the second cam  17 . 
         [0021]    The functionality of the vent door system in an embodiment of the invention will now be described. To move the vent door  14  from its closed position to its open position, the following exemplary steps occur. First the rod  32  rotates (counterclockwise from the perspective of  FIGS. 4-6 ). This rotation causes the first arm  34 , the second arm  36  and the third arm  38  to rotate at or near 5 degrees (also counterclockwise from the perspective of  FIGS. 4-6 ). The rotation of the first arm  32  pushes the lever  50  against the frame  12 , thereby forcing the vent door  14  open approximately 2.5 millimeters, thereby breaking ice that may have been formed between the vent door  14  and the frame  12 . As the second arm  36  and third arm  38  rotate, the rollers  40  and  42  rotate against the profile of the respective grooves  16   d  and  17   d  of the first cam  16  and the second cam  17 , and the first and second arms  36  and  38  pull the first and second cams  16  and  17  in proportion to the profile of the grooves. This pulling force causes the cams  16  and  17 , along with the vent door  14 , to pivot counterclockwise (from the perspective of  FIGS. 4-6 ) about the hinge  19 . As the vent door  14  pivots, the first arm  34  decouples from the lever  50 . When the first, second and third arms  34 ,  36  and  38  have rotated at or about 75 degrees, the vent door  14  will have opened about 45 degrees. To close the vent door  14 , the rod  32  rotates clockwise (from the perspective of  FIGS. 4-6 ), thereby moving the first, second and third arms  34 ,  36  and  38  clockwise. The action of the second and third arms  36  and  38  along with the rollers  40  and  42  force the first and second cams  16  and  17  to rotate clockwise (from the perspective of  FIGS. 4-6 ) about the hinge  19 , which moves the vent door  14  into its closed position. As the vent door  14  closes, the first arm  34  reconnects with the lever  50 . 
         [0022]    Referring to  FIGS. 7 and 8 , another embodiment of the invention is shown. In this embodiment, the vent door system  10  includes a second lever  70  that is attached to the aircraft door  8  by a pivot  72 . The second lever  70  has a first section  74  and a second section  76 . The first section  74  is disposed between the second section  76  and the door  8  and has a hole through which the pivot  72  passes. The second section  76  is disposed on top of the first section  74  and is between the first section  74  and the second end  56  of the lever  50 . The first section  74  has a first portion  78  that slopes at an acute angle relative to the door  8 , and a second portion  80  that curves upward to a point that is substantially vertical relative to the door  8 . The second lever  70  is disposed within a depression  82  of the door  8 , so that it sits below the lever of the vent door  14 . When the vent door  14  is in the closed position, the tip of the second portion  80  is just below or touches the peripheral lip  15  of the vent door  14 . The remaining portions of the vent door system  10  have the same structures shown in  FIGS. 1-6  and previously described. 
         [0023]    To move the vent door  14  from its closed position to its open position, the following steps occur. First the rod  32  rotates (counterclockwise from the perspective of  FIGS. 7-8 ). This rotation causes the first arm  34 , the second arm  36  and the third arm  38  to rotate at or near 5 degrees (also counterclockwise from the perspective of  FIGS. 7-8 ). The rotation of the first arm  32  pushes the first lever  50  against the first portion  78  of the second section  74  second lever  70 . The second lever  70  rotates clockwise about the pivot  72 . The second portion  80  of the second section  74  of the second lever  70  pushes upward against the lip  15  of the vent door  14  thereby breaking ice that may have been formed between the vent door  14  and the frame  12 . As the second arm  36  and third arm  38  rotate, the rollers  40  and  42  rotate against the profile of the respective grooves  16   d  and  17   d  of the first cam  16  and the second cam  17 , and the first and second arms  36  and  38  pull the first and second cams  16  and  17  in proportion to the profile of the grooves. This pulling force causes the cams  16  and  17 , along with the vent door  14 , to pivot counterclockwise (from the perspective of  FIGS. 7-8 ) about the hinge  19  in the same fashion as shown in the description of the previous embodiment in  FIGS. 4-6 . As the vent door  14  pivots, the first arm  34  decouples from the lever  50 . When the first, second and third arms  34 ,  36  and  38  have rotated at or about 75 degrees, the vent door  14  will have opened about 45 degrees. To close the vent door  14 , the rod  32  rotates clockwise (from the perspective of  FIGS. 7-8 ), thereby moving the first, second and third arms  34 ,  36  and  38  clockwise. The action of the second and third arms  36  and  38  along with the rollers  40  and  42  force the first and second cams  16  and  17  to rotate clockwise (from the perspective of  FIGS. 7-8 ) about the hinge  19 , which moves the vent door  14  into its closed position. As the vent door  14  closes, the first arm  34  reconnects with the first lever  50 . 
         [0024]    It can be seen from the foregoing that a new and useful vent door system with a lever has been described. The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.