Patent Publication Number: US-6336522-B1

Title: Deck elevator car with speed control

Description:
BACKGROUND TO THE INVENTION 
     1.Field of the Invention 
     The present invention relates to a double-deck elevator car whereby the raising and lowering of a cage frame comprising two vertically arranged cage chambers is controlled. 
     2. Description of the Related Art 
     Double-deck elevator cars are often used as a vertical means of transport within ultra-high-rise buildings and elsewhere in order to improve the efficient use of space. Capable of carrying large volumes of traffic, double-deck elevator cars comprise two vertically arranged cage chambers. With ordinary double-deck elevator cars, the distance between the two cage chambers is fixed, so that the height of all stories must be uniform if the upper and lower cage chambers are to land simultaneously. 
     Meanwhile, with the object of allowing the upper and lower cage chambers to land simultaneously where the height of the stories in a building is not uniform, double-deck elevator cars have been developed as disclosed in Japanese Laid-Open Patent Applications S48[1973]-76242 and H10[1998]-279231, wherein the distance between the upper and lower cage chambers is variable. 
     FIG. 1 is an explanatory diagram illustrating the double-deck elevator car disclosed in Japanese Laid-Open Patent Application S48[1973]-76242, wherein the distance between the cage chambers is variable. As FIG. 1 shows, two cage chambers (an upper cage chamber  2  and a lower cage chamber  4 ) are fitted within the cage chamber  1  of the double-deck elevator car, and a cage chamber drive device is fitted to one of them (the lower cage chamber  4  in the case of FIG.  1 ). The cage chamber drive device comprises a guide roller  5  fitted to the cage frame  3  of the lower cage, and an actuator  6  which drives the guide roller  5 . The lower cage chamber  4  is driven by the actuator  6  while being guided by the guide roller  4 . In this manner it is possible to alter the distance between the upper and lower cage chambers. 
     Similarly, FIG. 2 is an explanatory diagram illustrating the double-deck elevator car disclosed in Japanese Laid-Open Patent Application H10[1998]-279231, wherein the distance between the cage chambers is variable. As FIG. 2 shows, a crank  7 , motor  8  and ball screw  9  are employed as the cage chamber drive device, and the upper and lower cage chambers are made to move in opposite directions while keeping their weights balanced. This makes it possible to alter the distance between the upper and lower cage chambers without consuming too much power. In other words, the upper cage chamber  2  and lower cage chamber  4  are attached to the crank  7 , which is itself attached to the centre of the cage frame  1 , and two chambers are driven by the motor  8  and ball screw  9  in mutually opposite directions while retaining balance by virtue of their respective weights. 
     In this manner, a cage chamber drive device is attached to either the upper cage chamber  2  or the lower cage chamber  4 , which allows the height of the cage chambers to be altered, thus making it possible to vary the distance between them. 
     FIG. 3 illustrates a characteristic conventional speed pattern where the movable cage chamber is allowed to land by operating the cage chamber drive device after the double-deck elevator car stops. The characteristic curve S 1  represents the running speed pattern of the hoist which drives the cage frame  1  of the double-deck elevator car, while the characteristic curve S 3  represents the running speed pattern applied to the movable cage chamber by the cage chamber drive device. In this case the hoist drives the whole cage frame  1  and stops, after which it allows the movable cage chamber to land by driving it until the floor height of each story is matched. 
     FIG. 4 illustrates a characteristic conventional speed pattern where the cage chamber drive device is operated during the running of a double-deck elevator car in order to allow a movable cage chamber to land at a floor. The characteristic curve S 1  represents the running speed pattern of the hoist, while the characteristic curve S 3  represents the running speed pattern applied to the movable cage chamber by the cage chamber drive device. The characteristic curve S 2  represents the speed changes in the movable cage chamber. In this case the speed change S 2  of the movable cage chamber is the sum of the running speed pattern S 3  applied to the movable cage chamber by the cage chamber drive device and the running speed pattern S 1  of the hoist. Thus, the speed change pattern S 2  of the movable cage chamber changes in a less regular manner than the normal running speed pattern of an elevator car. 
     If the distance between the two cage chambers of a double-deck elevator car is adjusted by operating the cage chamber drive device after the cage frame has stopped, as in FIG. 3, running time is prolonged, which is inconvenient and uncomfortable for the passengers. It is also problematic because it leads to decreased transport capacity. 
     If on the other hand the cage chamber drive device is operated in such a manner that the distance between the two cage chambers is adjusted while the cage frame is running, as in FIG. 4, the problem is that it imparts a feeling of strangeness and anxiety to the passengers because the movement of the movable cage chamber is different from that of an ordinary cage frame  1 . 
     SUMMARY OF THE INVENTION 
     Accordingly, one object of the present invention is to provide a novel double-deck elevator car wherein it is possible to adjust the vertical distance between the cage chambers during operation in such a manner that the passengers do not sense any anxiety or discomfort. 
     With a view to attaining the above object, the present invention is a double-deck elevator car equipped with hoist for raising and lowering a cage frame on which are mounted two vertically arranged cage chambers, a hoist control device which controls the hoist and the speed of the cage frame, a cage chamber drive device which drives at least one of the vertically arranged cage chambers so as to alter the relative distance between the two cage chambers, and a cage chamber position control device which controls the cage chamber drive device, characterised in that the hoist control device controls the hoist in such a manner as to maintain a constant speed once the speed change of the cage frame has accelerated at a set rate of acceleration, then to decelerate at a set rate of deceleration and stop, and the cage chamber position control device controls the cage chamber drive device in such a manner as to allow the speed change of the cage chamber driven by the cage chamber drive device after the addition of the speed change of the cage frame to accelerate at a set rate of acceleration, to maintain a constant speed, then to decelerate at a set rate of deceleration and stop. 
     In the double-deck elevator car to which the present invention pertains, the hoist is controlled in such a manner as to maintain a constant speed once the speed change of the cage frame has accelerated at a set rate of acceleration, then to decelerate at a set rate of deceleration and stop. Meanwhile, the cage chamber drive device is controlled in such a manner as to allow the speed change of the cage chamber driven by the cage chamber position control device after the addition of the speed change of the cage frame to accelerate at a set rate of acceleration, to maintain a constant speed, then to decelerate at a set rate of deceleration and stop. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIG. 1 is a block diagram illustrating an example of a double-deck elevator car wherein the distance between the cage chambers is variable; 
     FIG. 2 is a block diagram illustrating another example of a double-deck elevator car wherein the distance between the cage chambers is variable; 
     FIG. 3 illustrates a conventional characteristic speed pattern where the movable cage chamber is allowed to land by operating the cage chamber drive device after the double-deck elevator car stops; 
     FIG. 4 illustrates a conventional characteristic speed pattern where the cage chamber drive device is operated during the running of a double-deck elevator car in order to allow a movable cage chamber to land at a floor; 
     FIG. 5 is a block diagram of the double-deck elevator car to which the present invention pertains; 
     FIG. 6 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the first embodiment of the present invention; 
     FIG. 7 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the second embodiment of the present invention; 
     FIG. 8 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the third embodiment of the present invention; 
     FIG. 9 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the fourth embodiment of the present invention; 
     FIG. 10 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the fifth embodiment of the present invention; 
     FIG. 11 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the sixth embodiment of the present invention; 
     FIG. 12 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the seventh embodiment of the present invention; 
     FIG. 13 illustrates characteristic modified speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the seventh embodiment of the present invention; 
     FIG. 14 illustrates another characteristic modified speed changes of the cage frame and movable cage chamber of a double-deck elevator car in a seventh embodiment of the present invention; and 
     FIG. 15 is a block diagram illustrating an example of a double-deck elevator car in the eighth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference now to the drawings, wherein like codes denote identical or corresponding parts throughout the several views, and more particularly to FIG. 5 thereof, one embodiment of the present invention will be described. 
     FIG. 5 is a block diagram of the double-deck elevator car to which the present invention pertains. In FIG. 5, an upper cage chamber  2  and a lower cage chamber  3  are mounted on a cage frame  1 , and a cage chamber drive device  10  is fitted to either the upper cage chamber  2  or the lower cage chamber  3 , or to both of them. In FIG. 5, a cage chamber drive device  4  is fitted to the lower cage chamber  3 , and this cage chamber drive device  10  comprises a guide roller  5  and an actuator  6 . 
     The cage frame  1  on which the upper cage chamber  2  and the lower cage chamber  3  are mounted is connected by way of a rope  11  to a counter-weight  12 , and is driven up and down by the sheave  14  of the hoist  13 . To this hoist is fitted, for instance, a pulse generator, proximity switch or similar cage position detector (not illustrated) for the purpose of detecting the position of the cage  1 . When the position of the cage is detected, a cage position signal P 1  is input to a hoist control device  15  and cage chamber position control device  16 . 
     The cage chamber position control device  16  has a memory device  17 , in which is stored data relating to the floor height dimensions of each story. Once the destination floors have been determined, the cage chamber position control device  16  calculates the distance between the two cage chambers in accordance with the floor height dimensions of the destination floors stored in advance in the memory device  17 , and controls the cage chamber drive device  10 . 
     Again, a cage position signal P 2  from the movable cage chamber driven by the cage chamber drive device  10  is apparatus is detected by, for instance, a proximity switch or similar movable cage position detector (not shown), and input to the hoist control device  15  and cage chamber position control device  16 . 
     The hoist control device  15  drives the hoist  13  and controls the speed of the cage frame  1  in accordance with the cage position signal P 1  from the cage frame  1  and the cage position signal P 2  from the movable cage chamber. Similarly, the cage chamber position control device  16  drives the cage chamber drive device  10  and controls the speed of the movable cage frame  1  in accordance with the cage position signal P 1  from the cage frame  1  and the cage position signal P 2  from the movable cage chamber. 
     In other words, in accordance with the cage position signal P 1  from the cage frame  1  and the cage position signal P 2  from the movable cage chamber, the hoist control device  15  controls the hoist in such a manner as to maintain a constant speed once the speed change of the cage frame  1  has accelerated at a set rate of acceleration, then to decelerate at a set rate of deceleration and stop. Meanwhile, the cage chamber position control device  16  controls the cage chamber drive device  10  in such a manner as to allow the speed change of the cage chamber driven by the cage chamber drive device after the addition of the speed change of the cage frame  1  to accelerate at a set rate of acceleration, to maintain a constant speed, then to decelerate at a set rate of deceleration and stop. 
     FIG. 6 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the first embodiment of the present invention. 
     The first embodiment is a double-deck elevator car wherein only one of the cage chambers moves, and this is the speed pattern where the movable cage chamber is driven by the cage chamber drive device  10  in the direction of travel of the elevator car. The horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2  of the movable cage chamber, and running speed pattern S 3  of the cage chamber drive device  10 . 
     As may be understood from the running speed pattern S 1  of the hoist  13  and the running speed pattern S 3  of the cage chamber drive device  10 , the cage frame  1  and movable cage chamber both accelerate at a uniform acceleration from time-point t 1  when they leave the departure floor to time-point t 2 , when they begin to run at constant speed. They then begin to decelerate simultaneously at time-point t 3 , doing so at a uniform deceleration to arrive and stop at the destination floor at time-point t 4 . The speed change S 2  of the movable cage chamber driven by the cage chamber drive device  10  is the total of the running speed pattern S 1  of the hoist  13  and the running speed pattern S 3  of the cage chamber drive device  10 . The speed which is generated in the movable cage chamber while running at constant speed is the rated speed of the double-deck elevator car. Consequently, the hoist  13  is driving the cage frame  1  at a speed which is less than the rated speed by the difference ΔS from the speed of the cage chamber drive device  10 . 
     Meanwhile, the acceleration (from t 1  to t 2 ) and deceleration (from t 3  to t 4 ) generated in the movable cage chamber are the rated acceleration of this double-deck elevator car. Consequently, the hoist  13  is driving the cage frame  1  at an acceleration and deceleration which are less than those of a conventional elevator car by the acceleration and deceleration of the cage chamber drive device  10 . 
     Controlling in this manner allows both cage chambers to assume a running pattern of uniform acceleration from start, followed by constant speed, uniform deceleration and stop, so that despite the operation of the cage chamber drive device  10  the passengers sense the same acceleration change as in the running of an ordinary elevator car, and their comfort is not impaired. Moreover, the acceleration of the hoist  13  is suppressed in order to ensure that the acceleration of the movable cage chamber, which is being driven by the cage chamber drive device  10 , is equal to the rated acceleration of the double-deck elevator car. As a result, the acceleration generated even in the cage chamber driven by the cage chamber drive device  10  is no greater than normal, and the passengers do not sense the anxiety or fear which come from a high rate of acceleration. 
     FIG. 7 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in a second embodiment of the present invention. This second embodiment illustrates the speed changes in a double-deck elevator car which is configured in such a manner that the cage chamber drive device  10  drives the two cage chambers simultaneously in mutually opposite directions. 
     In FIG. 7, the horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2 ′ of the movable cage chamber which is driven in the opposite direction to the direction of travel, and running speed pattern S 3  of the cage chamber drive device  10 . 
     As in the first embodiment, the cage frame  1  and movable cage chamber are driven by the hoist  13  and cage chamber drive device  10 , both accelerating at a uniform acceleration from time-point t 1  when they leave the departure floor to time-point t 2 , when they begin to run at constant speed. They begin to decelerate simultaneously at time-point t 3 , doing so at a uniform deceleration to arrive and stop at the destination floor at time-point t 4 . 
     The speed change S 2  of the movable cage chamber driven by the cage chamber drive device  10  is the sum (total) of the running speed pattern S 1  of the hoist  13  and the running speed pattern S 3  of the cage chamber drive device  10 . Moreover, the speed change S 2 ′ of the movable cage chamber, which is being driven by the cage chamber drive device  10  in the opposite direction to the direction of travel, is the difference between the speed pattern S 1  of the hoist  13  and the running speed pattern S 3  of the cage chamber drive device  10 . 
     The acceleration and deceleration (from t 1  to t 2 , and from t 3  to t 4 ) generated in the movable cage chamber, which is being driven in the opposite direction to the direction of travel of the elevator car are additional to the acceleration and deceleration generated in the cage frame  1 , and are controlled in order to ensure that the total acceleration and deceleration are equal to the rated acceleration and deceleration of the elevator car, and that the constant speed (from t 2  to t 3 ) is also equal to the rated speed of the elevator car. Consequently, the hoist  13  drives the cage frame  1  at an acceleration (from t 1  to t 2 ), deceleration (from t 3  to t 4 ) and constant speed (from t 2  to t 3 ) which are less than the rated speed pattern of the elevator car by the acceleration and deceleration of the cage chamber drive device  10 . This is controlled by the hoist control device  15  and cage chamber control device  16 . 
     Controlling in this manner, as in the first embodiment, allows both cage chambers to assume a running pattern of uniform acceleration from start, followed by constant speed and uniform deceleration, so that despite the operation of the cage chamber drive device  10  the passengers sense the same acceleration change as in the running of an ordinary elevator car, and their comfort is not impaired. Moreover, the constant speed and acceleration generated in the movable cage chamber driven by the cage chamber drive device  10  in the direction of travel is controlled so as to be equal to the rated acceleration and constant speed of the elevator car, and thus the passengers do not sense the anxiety or fear which come from a high rate of acceleration. 
     FIG. 8 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the third embodiment of the present invention. This third embodiment illustrates the speed change pattern of a double-deck elevator car which is configured in such a manner that the cage chamber drive device  10  drives only one of the cage chambers, and does so in the direction of travel of the elevator car. 
     In FIG. 8, the horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2  of the movable cage chamber, and running speed pattern S 3  of the cage chamber drive device  10 . 
     The cage frame  1  is driven by the hoist  13 , and accelerates at the rated acceleration (from t 1  to t 2 ), when it begins to run at constant speed (from t 2  to t 3 ). The cage frame then begins to decelerate at a lower rate than the rated deceleration (from t 3  to t 4 ). At the same time, the cage chamber drive device  10  causes the movable cage chamber to begin accelerating (from t 3  to t 4 ) at a rate of the same magnitude as the one at which the hoist  13  causes the cage frame  1  to decelerate. Accordingly, the speed pattern S 2  of the movable cage chamber remains unchanged from t 3  to t 4 . In other words, it is maintained at the same magnitude as the rated speed of the elevator car. 
     At time-point t 4  the cage chamber drive device  10  begins to decelerate at a uniform deceleration (from t 4  to t 5 ), at which time the combined deceleration of the cage frame  1  and the cage chamber are controlled in such a manner as to be of the same magnitude as the rated deceleration of the elevator car. That is to say, the deceleration of the movable cage chamber between time points t 4  and t 5  of the speed change S 2  is controlled in such a manner as to be of the same magnitude as the rated deceleration of the elevator car. 
     Controlling in this manner allows both cage chambers to assume a running pattern where, in spite of the difference in the timing of constant speed running, both accelerate uniformly, run at constant speed, decelerate uniformly and stop. As a result, the passengers do not sense anything unusual from the operation of the cage chamber drive device  10 . Moreover, the constant speed and acceleration generated in both the movable cage chambers do not exceed the rated acceleration and constant speed of the elevator car, and thus the passengers do not sense the anxiety or fear which come from a high rate of acceleration. 
     What is more, adjustment of the distance between the cage chambers by the cage chamber drive device  10  is implemented while the cage frame is moving at constant speed. Thus, it is possible to provide a smoother service than with the first and second embodiments with no impairment of comfort even if a call is received during running from an intermediate floor where the floor height is different, because the cage chamber drive device  10  can be controlled to match the dimensions between floors before landing at that floor. 
     FIG. 9 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in a fourth embodiment of the present invention. 
     This fourth embodiment illustrates the speed change pattern of a double-deck elevator car which is configured in such a manner that the cage chamber drive device  10  drives only one of the cage chambers, and does so in the opposite direction to the direction of travel of the elevator car. 
     In FIG. 9, the horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2  of the movable cage chamber, and running speed pattern S 3  of the cage chamber drive device  10 . 
     As the running speed pattern S 1  shows, the cage frame  1  is driven by the hoist  13 , and accelerates at the rated acceleration (from t 1  to t 2 ), when it begins to run at constant speed (from t 2  to t 4 ). At time-point t 3 , while the cage frame  1  is running at constant speed, the cage chamber drive device  10  causes the movable cage chamber to begin accelerating, as may be seen from running speed pattern S 3 . At time-point t 4 , when the cage frame  1  begins to decelerate, the cage chamber drive device  10  causes the movable cage chamber to switch from acceleration to deceleration (from t 4  to t 5 ). In this case, the change which the cage chamber drive device  10  causes to the acceleration of the movable cage chamber is controlled in such a manner as to be equal to that which the hoist  13  causes in the deceleration of the cage frame  1 , thus ensuring that no change occurs in the acceleration of the movable cage chamber at time-point t 4 . The deceleration of the cage frame  1  is the rated deceleration of travel of the elevator car. 
     Controlling in this manner allows both cage chambers to assume running patterns S 1  and S 2  where, in spite of the difference in the timing of constant speed running, both accelerate uniformly, run at constant speed, decelerate uniformly and stop. As a result, the passengers do not sense anything unusual from the operation of the cage chamber drive device  10 . Moreover, the constant speed and acceleration generated in both the movable cage chambers do not exceed the rated acceleration, rated deceleration and constant speed of the elevator car, and thus the passengers do not sense the anxiety or fear which come from a high rate of acceleration or deceleration. 
     What is more, as in the case of the third embodiment, adjustment of the distance between the cage chambers by the cage chamber drive device  10  is implemented while the cage frame is moving at constant speed. Thus, it is possible to provide a smoother service than with the first and second embodiments with no impairment of comfort even if a call is received during running from an intermediate floor where the floor height is different, because the cage chamber drive device  10  can be controlled to match the dimensions between floors before landing at that floor. 
     FIG. 10 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the fifth embodiment of the present invention. This fifth embodiment illustrates the speed change pattern of a double-deck elevator car which is configured in such a manner that the cage chamber drive device  10  drives both the cage chambers simultaneously in opposite directions. 
     In FIG. 10, the horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2  of the movable cage chamber which is driven in the direction of travel of the elevator car, speed change S 2 ′ of the movable cage chamber which is driven in the opposite direction to the direction of travel of the elevator car, and running speed pattern S 3  of the cage chamber drive device  10 . 
     As the running speed pattern S 1  shows, the cage frame  1  is driven by the hoist  13 , and accelerates at the rated acceleration (from t 1  to t 2 ), when it begins to run at the rated constant speed (from t 2  to t 3 ). At time-point t 3 , while the cage frame  1  is running at the rated constant speed, the cage chamber drive device  10  causes the cage chambers to begin accelerating, as may be seen from running speed pattern S 3 . Accordingly, the speed change S 2 ′ of the movable cage chamber which is driven in the opposite direction to the direction of travel of the elevator car begins to decelerate, while the speed pattern S 2  of the movable cage chamber which is driven in the direction of travel of the elevator car maintains constant speed with the addition of the running speed of the movable cage chamber to that of the cage frame. 
     At time-point t 4  the running speed pattern S 3  of the cage chamber drive device  10  switches from acceleration to deceleration, and the running speed pattern S 1  of the hoist  13  increases the rate of deceleration. In this case, the change which the cage chamber drive device  10  causes to the acceleration of the movable cage chamber is controlled in such a manner as to be equal to that which the hoist  13  causes in the deceleration of the cage frame  1 , thus ensuring that no change occurs in the acceleration of the movable cage chamber which is being driven by the cage chamber drive device  10  in the opposite direction to the direction of travel of the elevator car. Moreover, the deceleration of the cage frame  1  is less than the rated deceleration of the elevator car by the amount of deceleration of the cage chamber drive device  10 . Consequently, the deceleration of the speed change S 2 ′ of the movable cage chamber which is being driven in the opposite direction to the direction of travel of the elevator car remains constant, while the speed change S 2  of the movable cage chamber which is being driven in the direction of travel of the elevator car decelerates with the addition of the deceleration due to the cage chamber drive device  10  to that due to the hoist  13 . The deceleration in this case is the rated deceleration of the elevator car. 
     Controlling in this manner allows both cage chambers to assume running patterns S 2  and S 2 ′ where both accelerate uniformly, run at constant speed, decelerate uniformly and stop. As a result, the passengers do not sense anything unusual from the operation of the cage chamber drive device  10 . Moreover, the constant speed, acceleration and deceleration generated in both the movable cage chambers do not exceed the rated acceleration, deceleration and constant speed of the elevator car, and thus the passengers do not sense the anxiety or fear which come from a high rate of acceleration or deceleration. 
     What is more, as in the case of the third and fourth embodiments, adjustment of the distance between the cage chambers by the cage chamber drive device  10  is implemented while the cage frame is moving at constant speed. Thus, it is possible to provide a smoother service than with the first and second embodiments with no impairment of comfort even if a call is received during running from an intermediate floor where the floor height is different, because the cage chamber drive device  10  can be controlled to match the dimensions between floors before landing at that floor. It should be added that in each of the above embodiments there is no impairment of comfort even if the time-points of the changes in the pattern of acceleration from start, constant speed, deceleration and stopping diverge slightly between the cage frame  1  and the movable cage chamber. 
     FIG. 12 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the sixth embodiment of the present invention. This sixth embodiment differs from the first embodiment as illustrated in FIG. 6 in that it adds a jerk where the acceleration of the cage frame  1  due to the hoist  13  and that of the movable cage chamber due to the cage chamber drive device  10  change. 
     In FIG. 11, the horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2  of the movable cage chamber which is driven in the direction of travel of the elevator car, and running speed pattern S 3  of the cage chamber drive device  10 . It goes without saying that this may also be applied to the second embodiment to the fifth embodiment as illustrated in FIGS. 7 to  10 . 
     This serves to eliminate momentary acceleration changes, rendering speed changes smoother and affording passengers a more comfortable ride. The addition of a jerk in this manner allows passengers within the cage chamber to remain almost completely unaware of any deterioration in comfort even if speed changes are not effected entirely in accordance with the control commands and are somewhat out of phase. 
     FIG. 12 illustrates characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the seventh embodiment of the present invention. This seventh embodiment illustrates the speed change pattern of a double-deck elevator car which is configured in such a manner that the cage chamber drive device  10  drives one of the two cage chambers in the direction of travel of the elevator car. 
     The horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2  of the movable cage chamber, and running speed pattern S 3  of the cage chamber drive device  10 . 
     As may be understood from the running speed pattern S 3 , the cage chamber drive device  10  finishes accelerating between time-point t 3  when the hoist  13  starts to decelerate, and time-point t 4  when it attains uniform deceleration. The movable cage chamber is driven at a constant speed until time-point t 5  when the hoist  13  begins to reduce its deceleration. Moreover, it finishes decelerating by time-point t 4  when the hoist  13  stops. The distance between the two cage chambers is adjusted and they stop slightly before or substantially at the same time as the hoist  13  stops. 
     In other words, the cage chamber position control device  16  controls the cage chamber drive device  10  in such a manner that it begins to operate at substantially the same time as the hoist switches from constant speed to deceleration, and alters the distance between the two cage chambers at uniform speed while the hoist  13  is driving the cage frame  1  at a uniform deceleration prior to stopping (from t 4  to t 5 ). 
     In this case, the hoist control device  15  and cage chamber position control device  16  control both the cage chambers so as to decelerate in the manner represented by the speed changes S 1  and S 2 . The cage chamber drive device  10  is made to cease operating at substantially the same time as the hoist stops. 
     Moreover, the hoist control device  15  calculates the deceleration times from t 3  to t 4 , from t 4  to t 5  and from t 5  to t 6  required to stop at each floor, and transmits this data to the cage chamber position control device  16 . The cage chamber position control device  16  calculates the acceleration, deceleration and other information required to move the cage chamber drive device  10  on the basis of time data from the hoist control device  15  and data on the distance between floors at the destination floor which is stored in the memory device  17 . In this manner the cage chamber drive device is controlled so that the movable cage chambers finish moving when the hoist stops. 
     No precise description of the working of the memory device  17  has been given with respect to the first embodiment to the sixth embodiment, but it is the same as in this embodiment. 
     Controlling in this manner allows the fixed cage chamber to assume the same running pattern as an ordinary elevator car. 
     As a result it goes without saying that the passengers do not sense anything unusual about the adjustment of the distance between the cage chambers. Even in the movable cage the passengers scarcely sense anything unusual and there is no impairment of comfort because all they feel is constant speed followed by acceleration (from t 3  to t 4 ), then deceleration at a constant rate (from t 4  to t 5 ) and stop (from t 5  to t 6 ), which is the same running speed pattern as with an ordinary elevator car. 
     What is more, because the cage chamber drive device  10  starts to operate as soon as a stopping floor is nominated and the hoist begins to decelerate, there is no need to alter the speed of the cage chamber drive device  10  in response to intermediate calls. 
     FIG. 13 illustrates modified characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in the seventh embodiment of the present invention. In this modification, acceleration time (from t 3  to t 4 ′, and from t 5 ′ to t 6 ′) is prolonged in comparison with the example illustrated in FIG.  12 . This is achieved by allowing the hoist control device  15  to exert less control than normal on the rate of acceleration when the hoist switches from constant speed to deceleration. This means that the rate of acceleration of the moving cage chamber is lower than in the example illustrated in FIG. 12, so that the passengers sense even less unusual in the action of adjusting the distance between the cage chambers. 
     FIG. 14 illustrates other modified characteristic speed changes of the cage frame and movable cage chamber of a double-deck elevator car in a seventh embodiment of the present invention. This example shows speed changes in a double-deck elevator car which is configured in such a manner that the cage chamber drive device  10  drives the two cage chambers simultaneously in mutually opposite directions. 
     In FIG. 14, the horizontal axis represents the speed, while the vertical axis represents time, and the drawing illustrates the running speed pattern S 1  of the hoist  13  (speed change of the cage frame  1 ), speed change S 2  of the movable cage chamber which is driven in the direction of travel of the elevator car, speed change S 2 ′ of the movable cage chamber which is driven in the opposite direction to the direction of travel of the elevator car, and running speed pattern S 3  of the cage chamber drive device  10 . 
     As in the example illustrated in FIG. 12, the hoist  13  causes the cage frame  1  to accelerate at a fixed acceleration after leaving the departure floor, then to switch to constant speed, and decelerate at time-point t 3 . It is controlled in such a manner that it decelerates thereafter at a fixed deceleration from time-point t 4  when it attains the rated deceleration to time-point t 5  when the deceleration begins to decrease, continuing to do so from time-point t 5  until it stops at time-point t 6 . 
     The speed change S 2  of the movable cage chamber driven by the cage chamber drive device  10  in the direction of travel is the sum of the running speed pattern S 1  of the hoist  13  and the running speed pattern S 3  of the cage chamber drive device  10 . Meanwhile, the speed change S 2 ′ of the movable cage chamber driven by the cage chamber drive device  10  in the opposite direction to the direction of travel is the difference between the running speed pattern S 1  of the hoist  13  and the running speed pattern S 3  of the cage chamber drive device  10 . 
     As may be understood from the running speed pattern S 3 , the cage chamber drive device  10  finishes accelerating between time-point t 3  when the hoist  13  starts to decelerate, and time-point t 4  when it attains uniform deceleration. The movable cage chamber is driven at a constant speed until time-point t 5  when the hoist  13  begins to reduce its deceleration. Moreover, the cage chamber drive device  10  finishes decelerating by time-point t 6  when the hoist  13  stops. The distance between the two cage chambers is adjusted and they stop slightly before or substantially at the same time as the hoist  13  stops. 
     Controlling in this manner, as in the case of the example illustrated in FIG. 12, allows the fixed cage chamber to assume the same running pattern as an ordinary elevator car, which is to say in both cage chambers constant speed followed by acceleration (from t 3  to t 4 ), then deceleration at a constant rate (from t 4  to t 5 ) and stop (from t 5  to t 6 ). As a result, the passengers scarcely sense anything unusual and there is no impairment of comfort. 
     What is more, because the cage chamber drive device  10  starts to operate as soon as a stopping floor is nominated and the hoist  13  begins to decelerate, there is no need to alter the speed of the cage chamber drive device  10  in response to intermediate calls. 
     There follows a description of the eighth embodiment of the present invention. FIG. 15 is a block diagram of a double-deck elevator car in the eighth embodiment of the present invention. This eighth embodiment differs from the first embodiment illustrated in FIG. 5 in that the cage chamber position control device  16  and memory device  17  are housed within the hoist control device  15 . 
     The hoist control device  15  houses the cage chamber position control device  16  and memory device  17 , and the configuration is such that control commands for the hoist  13  and for the cage chamber drive device  10  are issued simultaneously from the hoist control device  15 . 
     In this configuration, the fact that the control commands are issued to the cage chamber drive device  10  by means of a tail cord (not illustrated) from a hoist control device  15  housed in the elevator car machine room means that a large number of cables are required, but concentrating them in one control device makes for simplicity in the transmission of data between control devices and allows cost savings to be made. 
     As has been explained above, the present invention controls a double-deck elevator car by adjusting the distance between the two cage chambers so that irrespective of status of action to implement distance correction and stop status between cage chambers and it is able to run according to a speed pattern whereby it accelerates at a fixed acceleration, maintains a constant speed, and then decelerates at a fixed deceleration. This allows passengers to feel as if they were riding in an ordinary elevator car. 
     With the present invention, the running speed patterns of both the upper and lower cage chambers are such that they accelerate at a fixed acceleration, maintain a constant speed, and then decelerate at a fixed deceleration irrespective of the action of the cage chamber drive device and stop. Moreover, even if intermediate calls mean that the elevator car stops at destination floors with different floor heights, passengers do not sense anything strange about the running of the cage chamber drive device, and are able to feel as if they were riding in an ordinary elevator car. 
     Obviously, numerous additional modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the present invention may be practiced otherwise than as specifically described herein.