Abstract:
There is provided a space-saving and compact swing type door structure of an aircraft restroom, in which a door is automatically closed and which is easy to use for a passenger using the restroom. The swing type door ( 40 ) is slidably hung at its upper end edge ( 44 ) from a rail disposed at an upper portion of a door frame by a guide structure including a slide pin ( 46 ) and is turnably connected in a predetermined position different from the hung position to the door frame by a linkage ( 60 ). Swinging operation in opening the door ( 40 ) deforms a spring provided in an automatic closing device ( 50 ). When a hand is released from the door ( 40 ), the door ( 40 ) is constantly biased in a closing direction by spring resilience through the linkage ( 60 ) and automatically returns to a closed position. Therefore, the restroom becomes easy to use, an aisle in front of the restroom can be used in an emergency, and it is possible to avoid contingencies caused by false recognition of an escape hatch.

Description:
The present application is based on and claims priority of Japanese patent application No. 2009-063886 filed on Mar. 17, 2009, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a door structure provided for coming into and going out of a restroom installed in an aircraft. 
     2. Description of the Related Art 
     Conventionally, doors of various opening/closing types have been used as restroom doors provided for coming into and going out of a restroom installed in an aircraft. At present, the types have become standardized as two types, i.e., a hinge panel type (opening outward) and a folding type (folding inward). 
     Because the hinge panel type door is basically an outward opening door that opens outward of the restroom, the door may block an aisle in front of the restroom when it opens. Such a door structure may obstruct passengers and crew escaping through the aisle in an emergency. Moreover, the open door is not designed to close automatically and needs to be closed manually. Because the folding type door is less common in houses and general buildings, passengers are likely to be confused about how to use it and the door is not really easy to use. Although the folding door folds inside the restroom and it does not block an aisle in opening and closing, the door in the folded state moves in a space in the restroom and a passenger needs to avoid the moving door. 
     If a passenger in a wheelchair uses the restroom, a locus of the folding type door interferes with the wheelchair. Therefore, the folding type door cannot be used as a door for a wheelchair restroom. Therefore, a restroom having the hinge panel type door is necessary for passengers using wheelchairs and two types of doors are often necessary in the same aircraft, which is disadvantageous to many users. Moreover, the folding door is opened by pulling a handle at a central hinge portion of the door and therefore it is difficult for a passenger with a hand disability to open the door from inside. 
     As described above, although there are doors moving in various manners, no restroom door satisfying requirements peculiar to aircraft such as functions, safety, maintainability, and light weight has been provided so far. 
     There is an example of a structure of a restroom unit for aircraft, which is formed compactly so that it can be installed in a small airplane, as disclosed in Japanese Patent Application Laid-Open No. 2008-6915. In this restroom unit for the aircraft, a door that can be opened and closed is provided on a side face of a restroom main body integrally formed in a box shape. This door is merely shown as left and right split doors and does not go much beyond conventional doors. 
     There is also an opening and closing device suitable for emergency or rescue activities with a door that can be opened or closed normally at normal times but can be opened or closed in an opposite direction (Japanese Patent Application Laid-Open No. 11-324473). This door opening and closing device is provided with a door frame, a door body (door panel) for opening and closing an opening portion of the door frame, door body supporting means supporting the door body in the opening portion so that the door body can be opened or closed, and door stops for holding the door body in a closed position. Door stops are located at a side wall of the opening portion made up of the door frame. The door body can be opened or closed by pulling toward a user or pushing in a door thickness direction at normal times but the door body can be forcibly opened in the opposite direction to the normal opening and closing direction. At normal times, the opening and closing direction of the door body is restricted by the door stops and the door body can be opened or closed toward the user or forward away from the user. On the other hand, the door body can be forcibly opened in the opposite direction to the normal opening and closing direction. Therefore, even if a person has fallen down on an indoor side where a door end side of the door body moves and the person who fell down obstructs the movement, the door body can be forcibly opened in the opposite direction. 
     There is also a slide-swing type door device in which a door panel is opened or closed by swinging the door panel in a front-rear direction while sliding the door panel in a width (lateral) direction. This door device has excellent partitioning properties (hermeticity, sound insulating properties), ease of opening and closing operations, space saving properties in opening and closing, and a compact entire device structure inherently required of doors. Moreover, door fitting works and maintenance are facilitated, the device is excellent in appearance, and is free of barriers, which is an improvement in usability (Japanese Patent Application Laid-Open No. 2000-248822). 
     There is also a slide-swing type door formed by providing a door panel in a frame body forming an opening portion so as to swing open or close in a front-rear direction while sliding in a width direction of the opening portion. The door includes a support fixed along one vertical frame of the frame body, a shaft body arranged along a longitudinal direction inside the support, support means for supporting the shaft body so that the shaft body can turn around its axis inside the support, and an upper rotation arm and a lower rotation arm having one ends secured respectively to upper and lower ends of the rotating shaft body and the other ends turnably supported at predetermined positions of an upper end face and a lower end face of the door panel (Japanese Patent Application Laid-Open No. 2002-242524). 
     Furthermore, there is also a swing-slide type door device in which a door panel slides while swinging along support bodies such as rails to thereby open or close a door opening and which can secure sealing properties of the door panel in a closed state of the door and enables a smooth opening operation of the door (Japanese Patent Application Laid-Open No. 2002-266548). 
     The space-saving and compact swing type door structure used for coming into and going out of the aircraft restroom has problems to be solved, i.e., to automatically close the door when a user of the restroom forgets to close it and to easily open the closed door and detach the door from a door frame by crew for security without using tools. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention, in a space-saving and compact swing type door structure, to provide a door structure of an aircraft restroom, which is useful as a door is automatically closed even if a user of the restroom forgets to close the door and which does not harm an environment in the aircraft by not blocking an aisle to interfere with other passengers and by clearing the aisle for passengers escaping in an emergency. Moreover, it is an object of the invention to provide a door structure of an aircraft restroom, in which crew can open the door that is closed from inside or easily detach the door from a door frame in case of emergency, e.g., when a user cannot move in the restroom. 
     In order to achieve the above-described object, the present invention provides a swing type door structure of an aircraft restroom including an door slidably hung at its upper end edge from a rail disposed at an upper portion of a door frame and a linkage that turnably connects the upper end edge of the door in a predetermined position different from the hung position to the door frame, wherein an automatic closing device is provided for applying resilience of a spring to the linkage to constantly bias the door in a closing direction. 
     According to the door structure of the aircraft restroom, when the door is opened, the spring of the automatic closing device is deformed by swinging operation in opening the door and resilience generated at this time acts on the linkage. In this way, the automatic closing device constantly biases the door in a closing direction. As a result, if a passenger using the restroom releases his/her hand from the door, the door always and automatically returns to a closed position and is useful. 
     In the door structure of the aircraft restroom, the spring of the automatic closing device may be a torsion spring for converting turning of the linkage into torsional deformation. The automatic closing device may have a damper for reducing a turning speed of the linkage turned in a returning direction by the resilience of the torsion spring. The door released from a hand automatically moves in the closing direction. Speed of the door is adjusted by the damper so as not to be excessively high, and as a result, a noise level of closing of the door is lowered as well giving consideration to a cabin environment. 
     In the door structure of the aircraft restroom, the door is slidably engaged in a position of its lower end edge corresponding to the hung position with a rail disposed at a lower portion of the door frame. Therefore, operation in opening and closing of the door is stabilized to suppress vibrations of the aircraft and prevent resonance of the door in the closing operation to achieve quietness. Guiding by the rails helps move the door smoothly. Because a pivot portion between the door and the linkage is provided with a release lever for detaching and attaching the pivot portion, it is possible to detach the entire door without using tools in an emergency, e.g., when a passenger falls down in the restroom. If a door trim on a hinge side of the door is made of soft rubber, the door does not injure fingers even if a user gets his/her fingers caught in the door. 
     In the door structure of the aircraft restroom, shapes of door handles are devised. The door handle provided outside the restroom of the door may be a paddle type handle and the door handle provided inside the restroom of the door may be a lever type handle. Provided outside the restroom is the paddle type handle that a user can operate without holding it and provided inside the restroom is the lever type handle and therefore even a passenger having a disability in his/her hand can easily open the door. 
     In the door structure of the aircraft restroom, as a main lock by operation of the door handles, the door is latch-engaged with or disengaged from the door frame by a main latch protruding and retracting at a side end edge of the door near the door handles and a sub-latch protruding and retracting via a rod at a side end edge of the door far from the door handle. Therefore, in this case, the latches are disposed on the left and right sides of the door and it is possible to firmly fix the door when the door is closed. Moreover, the left and right latches move synchronously through the rod and therefore need not be operated separately. A slide bolt for auxiliary locking is provided in an adjacent position to the lever type handle and a hidden lever for releasing the auxiliary lock by the slide bolt without using tools may be mounted on the paddle type handle. In the event of latch failure or when a passenger cannot release the auxiliary lock from inside, the crew can operate the hidden lever to thereby release the auxiliary lock of the door without using the tools, which provides a safety measure. Furthermore, the door panel may be made up of a honeycomb panel, in which case it is possible to reduce the door in weight while maintaining rigidity. 
     Because the door structure of the aircraft restroom according to the invention is formed as described above, an inner locus of the door moves along an inner wall of the restroom, although the door is a panel type door that is opened and closed in the same way as a general house door. Therefore, the locus becomes an obstruction in a smaller area in the restroom than a locus of a conventional folding type door and the door structure can be mounted on a wheelchair restroom and is extremely useful. The door does not greatly jut out when it opens and therefore does not severely block the aisle. Moreover, the door does not remain open but automatically closes if a user of the restroom forgets to close the door. As a result, the door does not interfere with other passengers and does not impair an environment in the aircraft. In this way, in an emergency, the aisle for escaping passengers and the like is secured near the restroom. If the aircraft is full of smoke, the passengers escape along evacuation lights disposed on a floor. If the door of the restroom is open, the passengers may mistake the door for an escape hatch, which may cause more confusion. However, the door is automatically closed and does not remain open and therefore it is possible to avoid such a situation. Moreover, it is possible to unify doors for all restrooms in the aircraft. By unifying how to handle and operate the doors, it is possible to improve convenience of the passengers and maintainability. 
     Because the locus on the outside of the restroom is also kept within a small area, even a wheelchair user can come closer to the door, which greatly improves operability as compared with a conventional panel type door. With regard to safety, to detach a door in an emergency, a conventional folding type door needs to be slightly folded inward because of its mechanism and is considerably heavy if a person has fallen over the door and a hinge panel type door cannot be detached without using tools. However, the door according to the invention can be detached from the restroom main body with a much smaller force by operating the tab from outside to detach a pin at the pivot portion of the linkage and sliding the door sideways. A general house door is not provided with such a mechanism in the first place. Although the opening and closing handles and the locking slide bolt are separate from each other in the operating portions of the latches in the conventional restroom door structure, they are compactly put together to thereby improve operability and economic efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an external perspective view of a door structure of an aircraft restroom according to the present invention; 
         FIG. 2  is a top view of the restroom showing a door locus at time intervals during opening and closing of the door structure of the aircraft restroom shown in  FIG. 1 ; 
         FIG. 3  is an enlarged plan view of the door locus corresponding to  FIG. 2 ; 
         FIG. 4  is a perspective view of a sliding guide structure at an upper edge portion of the door structure of the aircraft restroom shown in  FIG. 1 ; 
         FIG. 5  is a perspective view showing a manner in which the sliding guide structure shown in  FIG. 4  is attached or detached through an attachment and detachment notch; 
         FIG. 6  is a perspective view of a sliding guide structure at a lower edge portion of the door structure of the aircraft restroom shown in  FIG. 1 ; 
         FIG. 7  is a sectional view of the sliding guide structure at the lower edge portion of the door structure of the aircraft restroom shown in  FIG. 6 ; 
         FIG. 8  is a partially enlarged perspective view of a structure for performing automatic closing of the door structure of the aircraft restroom shown in  FIG. 1 ; 
         FIG. 9  is a partial perspective view of a portion including an outer handle of an door shown in  FIG. 1  and seen from outside the door; 
         FIG. 10  is a partial perspective view corresponding to  FIG. 9  and showing a portion including an inner handle of the door and seen from inside the door; 
         FIG. 11  is a perspective view of an internal mechanism of a handle portion; 
         FIG. 12  is a perspective view showing states of sub-latches when both of a main lock and an auxiliary lock are in locked states in the handle portion; 
         FIG. 13  is a perspective view showing states of the sub-latches when the main lock is in the locked state while the auxiliary lock is in a lock released state in the handle portion; and 
         FIG. 14  is a perspective view showing states of the sub-latches when both the main lock and auxiliary lock are in the lock released states in the handle portion. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of a door structure of an aircraft restroom according to the present invention will be described below based on the accompanying drawings.  FIG. 1  is an external perspective view of a door structure of an aircraft restroom according to the present invention.  FIG. 2  is a (mirror-reversed) top view of the restroom showing a door locus at time intervals during opening and closing of the door structure of the aircraft restroom shown in  FIG. 1 .  FIG. 3  is an enlarged plan view of the door locus during opening and closing of the door structure shown in  FIG. 1 .  FIG. 4  is a perspective view of a sliding guide structure at an upper edge portion of the door structure of the aircraft restroom shown in  FIGS. 1 and 2 .  FIG. 5  is a perspective view showing details of the sliding guide structure shown in  FIG. 4 .  FIG. 6  is a perspective view of a sliding guide structure at a lower edge portion of the door structure of the aircraft restroom shown in  FIGS. 1 and 2 . 
     In  FIG. 1 , a restroom unit generally shown by a reference numeral  1  has a box-shaped restroom main body  5  formed by assembling panel materials and is installed at an appropriate position on a floor board of an aircraft. The restroom main body  5  is made up of a front panel  10 , a side wall panel  11 , a floor panel  12 , a ceiling panel  13 , and a back wall panel (not shown) into the box shape. An door (hereafter abbreviated as “door”)  40  is provided on a front face of the restroom main body  5  facing an aisle of the aircraft and a passenger or the like can open or close the door  40  to come into and go out of the restroom main body  5  passing by the open door  40 . 
     The door  40  is provided to be able to close a door opening portion formed by cutting out a part of the front panel  10  and has such a size as to occupy a part of an entire width of the front panel  10  in a lateral width direction and occupy the most of an entire height of the front panel  10  in a vertical direction except an area  15  at an upper portion where a door opening and closing mechanism is disposed. A honeycomb panel is used for the door  40  to reduce the door  40  in weight while maintaining rigidity. In association with the door  40 , a door handle portion  41  used for opening and closing operations and louver portions  43  for inflow of air from the aisle side are provided. A sloping doorsill  18  corresponding to height of the floor panel and for preventing stumbling is provided under the door  40 . A display portion for showing whether the restroom is occupied or unoccupied by colors, for example, can be provided near the door handle portion  41 . 
       FIG. 2  shows a unit with a different layout from the restroom unit shown in  FIG. 1 . As shown in  FIG. 2 , a toilet unit  20  at a far end in front of the door  40  and a vanity unit  30  positioned beside the toilet unit  20  and along the side wall panel  11  are disposed as lavatory equipment in the restroom main body  5 . The equipment may be known units and will not be described in detail. The swing type door  40  entirely made up of one door plate is provided on the front face of the restroom main body  5 . 
     The swing type door  40  is connected at an upper portion to an automatic closing device  50  mounted on a box-shaped upper corner portion of the restroom unit with a linkage  60  interposed between the door  40  and the device  50 . The linkage  60  has one end portion turnably connected to the automatic closing device  50  and the other end portion turnably connected to an upper end edge  44  of an upper side of the door  40  at a pivot portion (joint pin)  45 . The linkage  60  is positioned above the upper end edge  44  of the door  40  and therefore does not directly interfere with the panel of the door  40 . The pivot portion  45  at the upper end edge  44  of the door  40  is disposed at a position deviated toward a door drive portion  50  from a central position of the upper end edge  44 .  FIG. 3  shows a locus L drawn by a side end edge  42  of the door  40  shown in  FIG. 1  when the door  40  is opened or closed. The other side end edge  42   a  of the door  40  moves along the side wall panel  11  when the door  40  is opened or closed. 
       FIG. 4  shows the sliding guide structure at the upper portion of the door  40  in the perspective view.  FIG. 5  is the perspective view showing details of the sliding guide structure shown in  FIG. 4 . A bracket  46   a  provided astride the upper end edge  44  is fixed to a position of the upper end edge  44  of the door  40  deviated toward the door handle portion  41  from the center and a slide pin  46  is provided on the bracket  46   a  to protrude upward. A rail  16  is disposed at a lower edge portion of the area  15  of the panel along a longitudinal direction of the lower edge portion and a groove  16   a  is formed in a central position in a width direction of the rail  16  to extend in a longitudinal direction of the rail  16 . On opposite sides of the groove  16   a , rail tracks  16   b ,  16   b  on which rollers (described later) can roll and inner wall faces  16   c ,  16   c  adjacent at right angle to the rail tracks  16   b ,  16   b  are formed. The slide pin  46  is fitted in the groove  16   a  and can slide in the groove  16   a  as the door  40  is opened or closed. 
     A roller unit  47  is mounted on a tip end of the slide pin  46 . The roller unit  47  has a sash hanger structure including two pairs of (four in total) rolling rollers  47   a  disposed to sandwich the slide pin  46 , having horizontal shafts, and capable of rolling on the rail tracks  16   b ,  16   b  of the rail  16  and a pair of guide rollers  47   b  disposed to sandwich the slide pin  46 , having vertical shafts, and capable of coming in contact with the inner wall faces  16   c ,  16   c  of the rail  16  to be guided by them. In other words, three rollers (two rolling rollers  47   a  and one guide roller  47   b ) are disposed on each side of the slide pin  46 . When the slide pin  46  slides in the groove  16   a  as the door  40  is opened or closed, the roller unit  47  is guided with the respective rolling rollers  47   a  rolling on the rail tracks  16   b ,  16   b  and the guide rollers  47   b  in contact with the inner wall faces  16   c ,  16   c . Therefore, the door  40  is hung in two different positions on opposite sides of the central position of the upper end edge  44 , i.e., by the linkage  60  and the rail  16  through the sliding guide structure. To detach the door  40  in an emergency, it is necessary to detach the slide pin  46  and the roller unit  47  from the rail  16 . Therefore, a detachment and attachment notch  17  larger in size than the roller unit  47  is formed in a position slightly deviated from a range of normal movement during opening and closing of the roller unit  47 . If the door  40  is moved along the rail  16  until the roller unit  47  is aligned with the position of the detachment and attachment notch  17 , the roller unit  47  can be detached through the detachment and attachment notch  17  and the door  40  can be detached from the area  15  at the upper portion of the front panel  10 . 
       FIG. 6  shows the sliding guide structure at a lower portion of the door  40  in the perspective view. The door  40  is provided with a slide pin  49  at a position of a lower end edge  48  corresponding to the position of the upper end edge  44  where the slide pin  46  is provided with a bracket  49   a  interposed between the lower end edge  48  and the slide pin  49 . The slide pin  49  is slidably engaged in a rail groove  19   a  formed in a rail  19  provided to the doorsill  18 . As a result, during opening and closing, the slide pins  46  and  49  are restricted and guided by the rails  16  and  19  with respect to the panel area  15  and the doorsill  18  at upper and lower edge portions of the door  40  and therefore stable and smooth opening and closing operation of the door  40  with suppressed vibrations can be obtained.  FIG. 7  is a cross-sectional view of the sliding guide structure at a lower portion of the door shown in  FIG. 6 . The slide pin  49  is mounted in an inside of the panel of the door  40  through a spring  49   b  and is engaged in the rail groove  19   a  by a biasing force of the spring  49   b . To detach the door  40 , the rail  19  is bent over a biasing distance of the spring  49   b  or a longer distance by stepping on the rail  19  or the like and the slide pin  49  can be detached from the rail groove  19   a.    
     As shown in  FIGS. 2 and 3 , the door  40  during opening or closing is shown in a plurality of positions and attitudes at some midpoints of opening and closing at time intervals. When the fully closed door  40  is opened by operating the door handle portion  41  in an opening direction shown by an arrow, an opening degree gradually increases while the door  40  is restrained at two points, i.e., the pivot portion  45  connected by the linkage  60  turning about the door drive portion  50  and the slide pin  46  sliding along the rail  16 . The opening degree reaches a maximum when the door  40  is in a position substantially along the side wall panel  11  of the restroom main body  5 . 
       FIG. 8  is a partially enlarged perspective view of a structure for performing automatic closing of the door structure of the aircraft restroom shown in  FIG. 1 . As shown in  FIG. 8 , the upper end edge  44  of the door  40  is connected to the restroom main body  5  with the automatic closing device  50  and the linkage  60  interposed therebetween. The automatic closing device  50  includes, inside itself, a torsion spring  52  having one end portion  52   a  fixed to a case  51  and the other end portion  52   b  engaged with a pin  61  standing on the linkage  60 . When the door  40  is opened, the torsion spring  52  is twisted in a winding direction by turning operation of the linkage  60  through the pin  61  and energy is stored by torsional deformation of the spring. If a hand is released from the door  40 , a force of the torsion spring  52  for winding again applies a force in a closing direction shown in the drawing on the linkage  60  via the pin  61  and therefore the door  40  is automatically closed. In this manner, the door  40  automatically moves in the closing direction when it is released from the hand, closing speed of the door  40  is adjusted by a damper so as not to be excessively high, and a noise level of closing of the door  40  is lowered as well in consideration of a cabin environment. 
     The damper may be a rotary damper  53  provided between the linkage  60  and a frame of the door  40  below the torsion spring  52 . Because the damper  53  is disposed parallel to the torsion spring  52  between the linkage  60  and the door frame, rotation of the linkage  60  is input to the rotary damper  53  and the rotary damper  53  performs functions of slowing down the rotation and dampening momentum of the closing door  40  when the door  40  tries to close due to the force of the torsion spring  52  for winding again. 
     A release lever  62  is connected to a lower portion of the pivot portion (joint pin)  45  turnably connecting the upper end edge  44  of the door  40  and the linkage  60 . A notch  63  is formed in the upper end edge  44  of the door  40  to allow access to the release lever  62  from outside the door  40 , i.e., from a side of the aircraft aisle, and the release lever  62  is provided in an exposed state in the notch  63 . By pushing down the release lever  62 , it is possible to disengage the pivot portion  45  from the linkage  60 . Therefore, in an emergency when a passenger has fallen down in the restroom or at a time of cleaning the restroom, it is possible to disengage the door  40  and the linkage  60  from each other without using special tools. By sliding the sliding guide structure to the position of the detachment and attachment notch  17  beyond the normal movement range and detaching the sliding guide structure from the rail  16  through the detachment and attachment notch  17  in this position, it is possible to detach the door  40  that has been disengaged from the linkage  60  from the front panel  10 . Because a soft rubber trim  56  is attached along the side end edge  42   a  opposite to the handle  41  side of the door  40  as shown in  FIG. 8 , the door  40  does not damage fingers even if a user gets his/her fingers caught in the door  40  in closing the door  40 . 
       FIG. 9  is a partial perspective view of a portion including the handle portion  41  of the door shown in  FIG. 1  and seen from outside the door.  FIG. 10  is a partial perspective view corresponding to  FIG. 9  and seen from inside the door. Both the drawings show internal structures with surface panels of the door  40  detached. As shown in  FIGS. 9 and 10 , the handle portion  41  of the door  40  has the door handles of different shapes on the inside and the outside. In other words, provided on the outside is a paddle type handle  70  on which a user can hook his/her fingertips without holding it to operate and provided on the inside of the restroom is a lever type handle  80  that is easy to operate. By employing different types of handles on the inside and outside, even a passenger having a disability in his/her hand can open or close the door. 
     When the user hooks his/her fingers on the paddle type handle  70  from outside the door  40  to pull and raise the handle  70  or when the user rotates the lever type handle  80  in any direction from inside the door  40 , the operation is converted into a protruding or retracting operation of a main latch  71  provided to protrude from the side end edge  42  near the handles  70  and  80  of the door  40  via an internal mechanism (described later in detail) and a protruding or retracting operation of a sub-latch  73  provided to protrude from the side end edge  42   a  on the far side from the handles  70  and  80  through a rod  72  traversing the door  40 . The main latch  71  and the sub-latch  73  are respectively made up of latch bolts. When the main latch  71  and the sub-latch  73  protrude, they are simultaneously engaged in a main latch engagement hole portion and a sub-latch engagement hole portion disposed in the frame of the restroom main body  5  to thereby main-lock the door  40  on opposite sides to reliably close the door. When both the latches  71  and  73  retract and become disengaged from both the engagement hole portions, the door  40  can be pulled and opened as it is. In this manner, with the latch structure of the door  40 , the main latch  71  and the sub-latch  73  respectively provided on the left and right sides of the door are actuated synchronously by operating any of the paddle type and lever type handles  70  and  80  and by operating the lever type handle  80  in any direction of clockwise and counterclockwise directions. Therefore, it is unnecessary to separately operate the respective latches  71  and  73  and the door  40  can be fixed firmly when the latches  71  and  73  are closed. 
     Even if a passenger or the like enters the restroom and operates the handle  80  to main-lock the door  40 , it is still possible to operate the handle  70  from outside to release the main lock of the door  40 . Therefore, as another lock mechanism to be operated by the passenger or the like in the restroom from inside the restroom to lock the door  40 , an auxiliary lock is provided. In other words, in the vicinity of the handle  80 , a slide lever  81  can slide laterally in a slot  84 . The slide lever  81  is connected to a slide bolt  82  inside the handle portion  41 . When the slide lever  81  is slid rightward as shown in FIG.  10 , the slide bolt  82  protrudes from the side end edge  42  and is engaged in an engagement hole portion on an opposite side to auxiliary-lock the door  40 . Moreover this movement of the slide bolt  82  is converted into a protruding operation of a sub-latch  86  from the side end edge  42   a  through a rod  83  traversing the door  40  to auxiliary-lock the door  40  at the sub-latch  86  as well. The auxiliary lock with the slide bolt  82  cannot be cancelled by operating the paddle type handle  70  from outside the door  40 . When the slide lever  81  is slid in an opposite direction, the slide bolt  82  and the sub-latch  86  engaged in the engagement holes are disengaged and the auxiliary lock can be released. 
     As a safety measure in case the slide lever  81  is operated from inside the restroom to engage the slide bolt  82  and the sub-latch  86  and it is impossible to release the auxiliary lock of the door  40 , a hidden lever  85  is disposed in the paddle type handle  70  so that the crew can release the door lock without using tools. The hidden lever  85  is connected to the slide bolt  82  and it is possible to release the auxiliary lock by the slide bolt  82  and the sub-latch  86  by operating the hidden lever  85 . Moreover, the slide bolt  82  may be made up of a magnet body to supply electric power to the restroom in synchronization with the locking. 
       FIG. 11  shows the internal mechanism of the handle portion  41  in a perspective view. In the paddle type handle  70 , a base attachment  75  is supported on a frame  90  of the handle portion  41  to be turnable about a vertical shaft  91 . A latch main body  92  integrally connected to the main latch  71  is slidably supported on the frame  90  in the lateral direction and is constantly biased by a spring  93  in such a direction that the main latch  71  protrudes from the side end edge  42  (i.e., in a locking direction of the door  40 ). Therefore, in the closed state of the door  40 , the main latch  71  protrudes from the side end edge  42  due to a biasing force of the spring  93  applied to the latch main body  92 , the sub-latch  73  protrudes from the side end edge  42   a  through the rod  72 , and the door  40  is locked by both the latches  71  and  73 . If the paddle type handle  70  is pulled and raised, the base attachment  75  turns about the vertical shaft  91  to slide the latch main body  92  against the biasing force of the spring  93 , retract the main latch  71  into the side end edge  42 , and simultaneously retract the sub-latch  73  into the side end edge  42   a  through the rod  72  to thereby release the lock (main lock) by both the latches  71  and  73 . 
     The lever type handle  80  is connected to a turning lever  94  housed in the latch main body  92  by a central shaft  95 . The central shaft  95  is in an elongated hole  96  in the latch main body  92  and is prevented from interfering with sliding movement of the latch main body  92  due to operation of the paddle type handle  70 . When the lever type handle  80  is turned in any of the clockwise and counterclockwise directions, the turning lever  94  turns about the central shaft  95  and any of two tip end portions  97 ,  97  of the turning lever  94  comes in contact with the latch main body  92  according to the turning direction to slide the latch main body  92  against the biasing force of the spring  93 . Operations after that are similar to those for operating the paddle type handle  70  and therefore will not be described again. 
     At an upper portion in the frame  90 , the slide bolt  82  connected to the hidden lever  85  is slidably disposed. A color display portion  98  is provided to the slide bolt  82  and can indicate the occupied or unoccupied state (e.g., red indicates the occupied state while green indicates the unoccupied state) of the restroom by selectively showing the color display portion  98  to the outside through a window  99  formed in the surface of the door  40 . 
       FIGS. 12 to 14  show engaged and disengaged states of the sub-latches of the door structure of the aircraft restroom.  FIG. 12  is a perspective view showing states of the sub-latches  73  and  86  when both the main latch  71  and slide bolt  82  are engaged on the handle portion  41  side. When the door  40  is closed, the rod  72  is retracted in the door panel and a plate  100  is turned at a horizontal shaft  101  at a central portion to protrude the sub-latch  73 . Similarly, because the slide bolt  82  is engaged, the rod  83  is retracted in the door panel and a plate  102  is turned at the horizontal shaft  101  at a central portion to protrude the sub-latch  86  corresponding to the slide bolt  82 . Therefore, both the main lock and the auxiliary lock of the door  40  are in the locked states due to both the sub-latches  73  and  86 . 
       FIG. 13  shows a state in which the auxiliary lock due to the slide bolt  82  is released from the state shown in  FIG. 12 . Because a tip end portion of the rod  83  protrudes from the door panel, the plate  102  turns about the horizontal shaft  101  and the sub-latch  86  retracts. As a result, the auxiliary lock is released. At this time, however, the sub-latch  73  (i.e., the main lock) is still in the engaged state.  FIG. 14  shows a state in which the main lock is released as well from the state shown in  FIG. 12 . Because a tip end portion of the rod  72  forming the main lock protrudes from the door panel as well, the plate  100  turns about the horizontal shaft  101  and the sub-latch  73  retracts. As a result, both the sub-latches  73  and  86  are disengaged and all the locks of the door  40  are released. 
     Although the opening and closing handles and the locking slide bolt are separate from each other in the operating portions of the latches  71  and  73  in the conventional restroom door structure, they are compactly put together in the invention as described above to thereby improve operability and economic efficiency. 
     Although the embodiment of the door structure of the aircraft restroom has been described above, it is apparent that the invention can be applied to a door structure of a restroom for other vehicles where light weight is pursued.