Patent Publication Number: US-6902040-B2

Title: Elevator car

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an exit structure included in an elevator cage provided with a pressure control system for controlling pressure in the cage or included in an airtight elevator cage sealed to secure a silent space therein. 
   2. Description of the Related Art 
   Recently, a rapid elevator is installed in a skyscraper to meet the requirement of nonstop and high-speed transportation to upper floors. An elevator cage of such rapid elevator is provided with a pressure control system to maintain a space in the cage at a predetermined pressure, thereby avoiding rapid pressure change in the cage for the passengers&#39; comfort. The walls of a conventional elevator cage are single-wall panels and hence it is difficult to maintain the space in the cage at a fixed pressure. When the pressure in the cage is controlled, the decorative inner surfaces of the walls of the cage are strained by pressure difference between the interior and the exterior of the cage. Some elevator cage have walls formed of double-wall panels assembled in airtight construction to maintain a set pressure in the cage and to isolate the space in the cage from external noise. 
   The elevator cage is provided with an exit normally closed by a door to enable passengers to escape from the cage in an emergency, such as failure in power supply. The exit must be opened when necessary. Therefore, gaps are formed between a structure defining the exit and the door, and hence it is impossible to prevent air flow between the interior and the exterior of the cage. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide an elevator cage provided with an exit normally closed by a door, and capable of preventing air flow between the interior and the exterior thereof through the exit, of efficiently controlling pressure therein, of satisfactorily isolating the space therein from external noise and of preventing the adverse effect of the variation of the pressure therein on the decorative inner surface of the walls thereof. 
   To achieve the objectives, the present invention provides an elevator car including: an elevator cage having a plurality of walls defining an interior space for passengers, the wall including an outer wall element and an inner wall element, the outer and the inner wall elements of one of the walls being provided respectively with openings forming an exit; an outer door that hermetically closes the opening of the outer wall element; and an inner door that covers the opening of the inner wall element but allows air to flow between the enclosed space and a space between the outer door and the inner door when the inner door is closed. 
   The inner door and the inner wall element may be configured so that a gap is formed between the inner door and the inner wall element when the inner door is closed, and the gap allows the air to flow between the interior space of the cage and a space between the inner and the outer door. 
   When the exit is provided in a side wall, the gap is preferably formed adjacent to a platform of the cage. 
   The inner and the outer doors may be connected with each other via a connecting member so that the inner and the outer doors move together. The connecting member is preferably made of vibration isolating member. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an elevator car provided with an exit structure according to the present invention; 
       FIG. 2  is a sectional plan view of the exit structure of the cage shown in  FIG. 1 ; 
       FIG. 3  is a front elevation of a handle shown in  FIG. 2 ; 
       FIG. 4  is a longitudinal sectional view of a cage shown in  FIG. 1 , which schematically shows internal structure of the cage and devices for controlling pressure in the cage; 
       FIG. 4A  is a longitudinal sectional view of the exit structure shown in  FIG. 2 ; 
       FIG. 5  is a sectional plan view of another embodiment of the exit structure; 
       FIGS. 5A  to  5 C are enlarged views of the area A of  FIG. 5 , which shows connecting members; 
       FIG. 6  is a sectional plan view of another embodiment of the exit structure; 
       FIG. 7  is a perspective view of an elevator car provided with a handle-turning-tool storage structure therein; 
       FIG. 8  is a sectional view of the handle-turning-tool storage structure of  FIG. 7 ; 
       FIG. 9  is a sectional view of assistance in explaining a method of manually opening doors included in an exit structure from inside the elevator car; 
       FIG. 10  is a side elevation of an automatic door opening mechanism for opening the doors of the exit structure; 
       FIG. 11  is a sectional plan view of the automatic door opening mechanism; 
     FIGS.  12 ( a ) and  12 ( b ) are a sectional view and a side elevation, respectively, of an inner door support mechanism; 
     FIGS.  12 ( c ) and  12 ( d ) are a sectional view and a side elevation, respectively, of an outer door support mechanism; 
       FIG. 13  is a sectional plan view of an exit structure incorporated into the ceiling of an elevator cage; and 
       FIG. 14  is a sectional plan view of an exit structure, in which an electromagnet is used as sealing means in place of packing. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will be described with reference to the accompanying drawings. 
   Referring to  FIG. 1  showing an elevator car according to the present invention, the elevator cage  1  is held on a frame la provided with a guide device  2  at each of its four corners. The guide devices  2  are engaged with guide rails (not shown) installed in an elevator shaft to guide the elevator car for vertical movement along the not-shown guide rails. An exit structure  3  is incorporated into one of the side walls  4  of the cage  1  to enable persons to escape from the cage  1  when the elevator comes to an accidental standstill due to power failure or the like. The cage  1  is provided with car doors  1   b  that hermetically closes the entrance of the cage  1 . 
   The cage  1  is formed by assembling a plurality of walls. The plurality of walls include side walls  4  (vertical walls), a top wall  4   c  (ceiling of the cage  1 ) and a bottom wall  4   d  (platform of the cage  1 ). Referring to  FIG. 2  showing the exit structure  3  in a sectional plan view, each of the side walls  4  has a double-wall panel structure, namely, is composed of an interior panel (i.e., inner wall element)  4   a  and an exterior panel  4   b  (i.e., outer wall element). The top and the bottom walls  4   c,    4   d  also may be of the double-wall panel structure. The interior and exterior panels  4   a,    4   b  of one of the side walls  4  are provided with openings  5   c,    5   a,  respectively, to form an exit  5 . The exit  5  is closed by doors  8  including an inner door  6  and an outer door  7 . The outer door  7  is pivotally attached to the exterior panel  4   b  via hinges  9 , which are disposed in a space between the inner door  6  and the outer door  7 . The outer door  7  can be turned on the vertical axis of the hinge  9  to open inward. The inner door  6  is pivotally supported on the interior panel  4   a  for inward turning about an axis aligned with the vertical axis of the hinge  9 . 
   A frame  5   b  having an L-shaped cross section is arranged around the opening  5   a  (of the exit  5 ) of the exterior panel  4   b,  and is fixed to the exterior panel  4   b.  A door gasket  10  is attached to the inner periphery of the frame  5   b.  When closed, the outer periphery of the outer door  7  comes into close contact with the door packing  10  to seal hermetically a gap between the exterior panel  4   b  and the outer door  7 . 
   As shown in  FIG. 3 , a handle  11 , provided with a locking arm  11   a,  is fixed on the outer surface the outer door  7 . When the handle  11  is placed at a locking position indicate by continuous lines, the locking arm  11   a  engages with a stopping member  12  attached to the outer surface of the frame  5   b.  In this state, the frame  5   b  and the packing  10  placed thereon are held between the locking arm  11   a  and the outer door  7 , and thus the outer door  7  is held at a closed position in which the opening  5   a  of the exit  5  is hermetically closed by the outer door  7 . A door switch  13  for detecting the position of the outer door  7  and an actuating rod  14  for operating the door switch  13  are attached to the outer surface of the frame  5   b.  When the handle  11  is placed at the locking position indicate by continuous lines, the rod  14  operates the door switch  13  to produce a door-closed signal indicating that the outer door  7  is closed. 
   As shown in  FIG. 2 , a door switch  15  is attached to the inner surface of the exterior panel  4   b  so as to be operated by the inner door  6 . When the inner door  6  is closed, the door switch  15  is operated by the inner door  6  to generate a door-closed signal indicating that the inner door  6  is closed. A tool inserting hole  16  is formed in the inner door  6  to manually operate the handle  11 . 
   Referring to  FIG. 4  schematically showing the cage  1  in a longitudinal sectional view, connected to the top of the cage  1  is an upper duct  31 , which opens into the interior space of the cage  1  at a position between a ceiling-lighting fixture  32  and the side wall  4 . An upper fan  33 , for introducing air into the interior space of the cage  1 , is attached to the duct  31 . A check valve  34 , which exclusively allows air to flow from the exterior space to the interior space of the cage  1 . 
   Connected to the bottom of the cage  1  is a lower duct  35 , which opens into the space between the interior panel  4   a  and the exterior panel  4   b.  A bottom fan  36  for discharging air in the cage  1  and a rapture disk  37  is attached to the duct  35 . The duct  35  is provided with a solenoid valve  38  to open and close the duct  35 . 
   When pressurizing the interior space of the cage  1 , the upper fan  33  operates to introduce air into the interior space of the cage  1 . Thereupon, air in the interior space of the cage  1  flows into the space between the inner door  6  and the outer door  7  through a gap  17  or an air passage formed between the lower edge of the inner door  6  and the interior panel  4   b,  and thus flows into the space between the interior panel  4   a  and the exterior panel  4   b.    
   Since the outer door  7  hermetically closes the opening  5   a,  air in the space between the interior panel  4   a  and the exterior panel  4   b  does not leak. In addition, the car doors  1   b  hermetically closes the entrance of the cage  1 , air in the interior space of the cage  1  does not leak. Accordingly, pressure in the space between the inner door  6  and the outer door  7  substantially the same as that in the interior space of the cage  1 , but is higher than that in the exterior space of the cage  1 . 
   When depressurizing the interior space of the cage  1 , the bottom fan  36  operates to discharge air from the interior space of the cage  1  through the gap  17 . 
   In case of an accident, such as power failure of the elevator system or emergency stop of the elevator car, the solenoid valve  38  is opened to equalize pressures in the interior and the external spaces of the cage  1 . The rupture disk  37  avoids rapid change in pressure in the interior space of the cage  1 . 
   Referring to  FIG. 4A  showing the exit structure in a longitudinal sectional view in detail, a gap  17  or an air passage is formed between the lower edge of the inner door  6  and the interior panel  4   a.  The gap  17  permits air to flow from the interior space of cage  1  into the space between the inner door  6  and the outer door  7 . Since the gap  17  is formed adjacent to a platform  4   d  of the cage  1 , passengers do not notice that the gap  17  exists. In  FIG. 4A , the bottom part of the interior panel  4   a  indicated by reference numeral  4   a ′ is a part of the interior panel  4   a  providing a decorative surface of the interior panel  4   a,  however, the part  4   a ′ may be a baseboard. Such baseboard should be interpreted as a part of the interior panel  4   a  of the side wall  4  in this specification. 
   As mentioned above, when the openings  5   c  and  5   a  are closed by the doors  6 ,  7 , respectively, the interior space in the elevator cage  1  and the space between the inner door  6  and the outer door  7  are maintained at the same pressure because those spaces communicate with each other by means of the gap  17 , and the gap between the periphery of the outer door  7  and the exterior panel  4   b  is sealed with the door packing  10 . Thus, the elevator cage  1  is sealed hermetically and the pressure in the elevator cage  1  is controllable, and the interior of the elevator cage  1  is isolated from noise generated by the moving elevator cage  1 . Sealing engagement between the outer door  7  and exterior panel  4   b  using the packing  10  achieves noise reduction of −2 to −3 dB in the elevator cage  1 . 
   Since the space in the elevator cage  1  and the space between the inner door  6  and the outer door  7  are maintained at the same pressure, only the outer door  7  is affected by the pressure difference between the interior and the exterior of the elevator cage  1 , and hence the decorative inner surface of the inner door  6  will not be strained by the pressure difference. 
   Since the positions of the inner door  6  and the outer door  7  are detected by the door switches  13  and  15 , respectively, the vertical movement of the elevator cage  1  with either of the inner door  6  or the outer door  7  in an open state is inhibited to ensure the safety of passengers in the elevator cage  1 . 
   In case of an accident, such as power failure, occurs, the handle  11  is operated from outside the cage  1  to turn the inner door  6  and the outer door inward to positions indicated by two-dot chain lines in  FIG. 2  to open the exit  5 . The doors  6  and  7  can be unlocked and opened by inserting a handle turning tool in the tool inserting hole  16  from inside the cage  1  and turning the handle  11  with the handle turning tool. 
   In view of reducing wind noise that is generated by the moving elevator cage  1 , it is preferable to reduce unnecessary projections projecting outward from the cage  1  as much as possible and to form the elevator cage  1  in a structure having flat surfaces. To this end, the hinge  9  suspending the outer door  7  on the exterior panel  4   b  is disposed in the space between the inner door  6  and the outer door  7  so that the hinge  9  does not project outside and the transmission of unpleasant noise to the interior of the elevator cage  1  is reduced. 
   Referring to  FIG. 5  showing another embodiment of the exit structure, the inner door  6  and the outer door  7  are united by connecting members  18 . Thus, the inner door  6  and the outer door  7  can be simultaneously opened and closed in a body, and hence only one door switch for providing a signal to inhibit the vertical movement of the elevator car with the inner door  6  and the outer door  7  in an open state may be provided in connection with either the inner door  6  or the outer door  7 , which is effective in reducing the cost of the exit structure. 
   Preferably, the connecting members  18  are made of vibration isolating members. The vibration isolating members prevent the outer door  7  from being strained when the pressure in the elevator cage  1  is controlled and the transmission of vibrations of the outer door  7  to the inner door  6  when the elevator cage  1  moves. 
   As shown in  FIG. 5A , the connecting member  18  may be made of rubber vibration isolator  18   a,  such as neoprene rubber. Silicon rubber, which is very flexible, may be used instead of neoprene rubber. 
   Alternatively, as shown in  FIG. 5B , the connecting member  18  may be made of a spring  18   b,  which has vibration isolating function and is also durable. 
   Alternatively, as shown in  FIG. 5C , the connecting member  18  may be an oil damper  18   c,  which has a cylinder connected to one of the panels  4   a,    4   b  (exterior panel  4   b ) and a rod connected to the other of the panels  4   a,    4   b  (interior panel  4   a ). The oil damper  18   c  shows a good vibration isolating performance even if the amplitude of the vibration is large. 
   In the embodiments shown in  FIGS. 2 and 5 , the inner door  6  and the outer door  7  open inward, and the area of the outer door  7  may be smaller than that of the inner door  6 . Since the outer door  7  having a smaller area has a higher rigidity, the outer door  7  having a small area can be easily brought into close contact with the exterior panel  4   b  and hence the number of necessary sealing members can be reduced. The small outer door  7  will not interfere with parts attached to the outer surface of the elevator cage  1 . 
   Alternatively, as shown in  FIG. 6 , the inner door  6  and the outer door may be supported for outward opening on an elevator cage  1 . In this exit structure, the inner door  6  may be formed in an area smaller than that of the outer door  7 . The inner door  6  having a small area improves design for the interior of the elevator cage  1  and increases the degree of freedom of determining the position of an exit  5 . 
   Fresh air cannot be supplied into the airtight elevator cage  1  when the elevator is brought accidentally to a standstill by power failure or the like. In such a case, instructions to be followed by passengers in the elevator cage  1  are announced by a loudspeaker placed in the elevator cage  1 . Then, the passenger in the elevator cage  1  turns the handle  11  with a handle turning tool  20  inserted in the tool inserting hole  16  to open the doors  6 ,  7  inward. As shown in  FIG. 7 , a tool storage structure  22  is formed in an inner wall  21  ( 4   a ) to store the handle turning tool  20  therein. As shown in  FIG. 8 , a solenoid actuator  23  restrains a door  22   a  included in the tool storage structure  22  from opening while the elevator is in normal operation and hence the handle turning tool  20  cannot be taken out of the tool storage structure  22 . When power failure occurs, the solenoid actuator  23  becomes inoperative to release the door  22   a.  Consequently, the door  22   a  can be opened and the handle turning tool  20  can be taken out of the tool storage structure  22 . The handle turning tool  20  is used for unlocking the door  7 . Then, the doors  6 ,  7  can be opened by hand. 
   An auxiliary power supply  24  may be held above the elevator cage  1  as shown in  FIG. 7  to open the doors  6 ,  7  automatically by using power supplied by the auxiliary power supply  24 . As shown in  FIG. 10 , a solenoid actuator  25  is supported on the exterior panel  4   b  opposite to the handle  11 . The solenoid actuator  25  is energized by power supplied by the auxiliary power supply  24 . As shown in  FIG. 11 , an inner door operating solenoid actuator  26  is supported on the inner surface of the exterior panel  4   b  opposite to the inner door  6 . 
   When power supply to the power system of the elevator is interrupted due to power failure or the like, the auxiliary power supply  24  supplies power to the solenoid actuator  25 , and then the solenoid actuator  25  turns the handle  11  in an unlocking direction. Power is supplied to the solenoid actuator  26  immediately after the supply of power to the solenoid actuator  25 , and then the solenoid actuator  26  pushes the inner door  6  into the elevator cage  1  to pen the inner door  6  and the outer door  7  automatically. Consequently, fresh air can be supplied through the elevator shaft into the elevator cage  1 . The inner door  6  is connected to the interior panel  4   a  by a door stopper  27 . The door stopper limits the opening angle of the inner door  6  to a predetermined angle to ensure that persons are prevented from falling off the elevator cage  1  when the inner door  6  and the outer door  7  are opened. The door stopper  27  can be removed when the passengers escape through the exit from the elevator cage  1 . 
   FIGS.  12 ( a ) to  12 ( d ) show comparatively door support structures respectively suspending the inner door  6  and the outer door  7 . As shown in FIGS.  12 ( a ) and  12 ( b ), the inner door is supported for turning by bearings  28   a  on the interior panel  4   a.  As shown in FIGS.  12 ( c ) and  12 ( d ), outer door  7  is supported for turning by hinges  9  disposed between the bearings  28   a  on the interior panel  4   a  and coaxial with the bearings  28   a;  that is, the inner door  6  and the outer door  7  have a common axis of turning. The common axis of turning of the inner door  6  and the outer door  7  extends near the decorative surface (inner surface) of the inner door  6  and apart from the outer door  7 . Thus, it is easy to install the inner door  6  with its inner surface extended substantially flush with the inner surface of the interior panel  4   a.  Since the sealing surfaces of the outer door  7  and the exterior panel  4   b  are spaced from the axis of turning of the outer door  7 , parts of the sealing surfaces near the hinges  9  can firmly compress the door gasket and hence the elevator cage  1  can be sealed in a sufficiently airtight state. 
     FIG. 14  shows another structure for establishing sealing engagement between the outer door  7  and the exterior panel  4   a.  The outer door  7  and the exterior panel  4   a  are configured so that the contacting surfaces thereof are disposed in plane-parallel face-to-face relationship with each other when the outer door  7  is closed. An electromagnet  40  attracts outer door  7  so that the outer door  7  engages with the exterior panel  4   a  hermetically. 
   The construction of the foregoing exit structures according to the present invention can be applied to an exit structure  29  formed in the ceiling of the elevator cage  1  as shown in  FIGS. 1 and 13 . The exit structures may also be applied to cages of double-deck elevators. Preferably, an upper cage of a double-deck elevator is provided with the foregoing exit structure in its platform (floor of the cage). 
   The exit structures are also applicable to elevators located outdoor, preventing penetration of rainwater, snow and wind into the interior space of the cage. It is possible that the exterior panel rusts doe to the raindrops, however, the decorative surface of the interior panel will never be adversely affected.