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'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 5C 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 1b 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 4c (ceiling of the cage 1) and a bottom wall 4d (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) 4a and an exterior panel 4b (i. e., outer wall element). The top and the bottom walls 4c, 4d also may be of the double-wall panel structure. The interior and exterior panels 4a, 4b of one of the side walls 4 are provided with openings 5c, 5a, 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 4b 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 4a for inward turning about an axis aligned with the vertical axis of the hinge 9.

A frame 5b having an L-shaped cross section is arranged around the opening 5a (of the exit 5) of the exterior panel 4b, and is fixed to the exterior panel 4b. A door gasket 10 is attached to the inner periphery of the frame 5b. 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 4b and the outer door 7.

As shown in Fig. 3, a handle 11, provided with a locking arm lla, 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 lla engages with a stopping member 12 attached to the outer surface of the frame 5b. In this state, the frame 5b and the packing 10 placed thereon are held between the locking arm lla and the outer door 7, and thus the outer door 7 is held at a closed position in which the opening 5a 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 5b. 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 4b 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 4a and the exterior panel 4b. 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 4b, and thus flows into the space between the interior panel 4a and the exterior panel 4b.

Since the outer door 7 hermetically closes the opening 5a, air in the space between the interior panel 4a and the exterior panel 4b does not leak. In addition, the car doors lb 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 4a. 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 4d of the cage 1, passengers do not notice that the gap 17 exists. In Fig. 4A, the bottom part

of the interior panel 4a indicated by reference numeral 4a' is a part of the interior panel 4a providing a decorative surface of the interior panel 4a, however, the part 4a'may be a baseboard. Such baseboard should be interpreted as a part of the interior panel 4a of the side wall 4 in this specification.

As mentioned above, when the openings 5c and 5a 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 4b 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 4b 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 4b 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 <BR> <BR> made of rubber vibration isolator 18a, 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 18b, which has vibration isolating function and is also durable.

Alternatively, as shown in Fig. 5C, the connecting member 18 may be an oil damper 18c, which has a cylinder connected to one of the panels 4a, 4b (exterior panel 4b) and a rod connected to the other of the panels 4a, 4b (interior panel 4a). The oil damper 18c 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 4b 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 (4a) to store the handle turning tool 20 therein.

As shown in Fig. 8, a solenoid actuator 23 restrains a door 22a 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 22a.

Consequently, the door 22a 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 4b 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 4b 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 4a 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 28a on the interior

panel 4a. As shown in Figs. 12 (c) and 12 (d), outer door 7 is supported for turning by hinges 9 disposed between the bearings 28a on the interior panel 4a and coaxial with the bearings 28a; 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 4a. Since the sealing surfaces of the outer door 7 and the exterior panel 4b 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 4a. The outer door 7 and the exterior panel 4a 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 4a 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.