WO2006011634A1

WO2006011634A1 - Elevator system

Info

Publication number: WO2006011634A1
Application number: PCT/JP2005/014140
Authority: WO
Inventors: Hiroyuki Kimura
Original assignee: Toshiba Elevator Kabushiki Kaisha
Priority date: 2004-07-28
Filing date: 2005-07-27
Publication date: 2006-02-02
Also published as: TW200613213A; CN100586830C; JP2006036487A; CN101018729A; TWI303237B; MY145728A

Abstract

An elevator system (100) has a first cage (31a) and a second cage (31b), which are placed in the vertical direction in one shaft (30). The first cage (31a) is connected to a first counter weight (32a) by a main rope (45a). The second cage (31b) is connected to a second counter weight (32b) by a main rope (45b). The first counter weight (32a) and second counter weight (32b) are placed in the vertical direction. The main ropes (45a, 45b) are wound around corresponding traction machines (41a, 41b), respectively. The traction machines (41a, 41b) are placed in the upper part of the shaft (30). By controlling the traction machines (41a, 41b) separately, the first cage (31a) and second cage (31b) are independently operated.

Description

D E S C R I P T I O N

ELEVATOR SYSTEM

Technical Field

The present invention relates to an elevator system which carries passengers and cargos to each floor in a building.

Background Art An elevator system generally has one cage in one shaft in a building. A cage moves in a shaft and carries passengers and cargos to a destination floor.

The numbers of passengers and cargos to move in a building increase as the number of floors of a building increases, and it becomes necessary to increase the number of elevator systems. However, if the ratio of elevator space to floor space of a building increases, the utility of total floor space decreases.

As a means of solving this problem, a double-deck elevator system has been proposed and put to practical use, in which two cages are stacked vertically in one body. However, in a double-deck elevator system, though only one cage must stop at a certain floor, the other cage must stop at the next floor. Thus, even if a double-deck elevator system has two cages, a carrying efficiency thereof is not much increased. Two cages must be operated to carry a few passengers or cargos even in a time zone when only a few passengers use an elevator. Hence it increases the power consumption required to carry one person.

Japanese Patent No. 3252575 and Jpn. Pat. Appln. KOKAI Publication No. 59-133188 disclosed an elevator system having two or more cages movable independently in one shaft. The elevator system described in the Japanese Patent No. 3252575 is configured as shown in FIG. 7. In this elevator system, a cage Ia for higher floors, a cage Ib for middle floors and a cage Ic for lower floors are placed vertically with space taken therebetween in a shaft 7. Traction machines 3a, 3b and 3c are provided for the cages Ia, Ib and Ic, respectively. The traction machines 3a, 3b and 3c have driving sheaves 4a, 4b and 4c, respectively. Main ropes 2a, 2b and 2c are wound around the driving sheaves 4a, 4b and 4c, respectively. One end side of each main rope 2a, 2b and 2c is connected to each cage Ia, Ib and Ic. The other end of each main rope 2a, 2b and 2c is guided to the rear of the cages Ia, Ib and Ic through deflector sheaves 5a, 5b and 5c, and connected to counter weights 6a, βb and 6c, respectively. The counter weights 6a, 6b and 6c are displaced by the deflector sheaves 5a, 5b and 5c not to interfere to one another.

In the elevator system described in the Japanese Patent No. 3252575, as shown in FIG. 7, the counter weights 6a, 6b and 6c are suspended from the deflector sheaves 5a, 5b and 5c at the position displaced to one another to prevent interference. Thus, a shaft 7 needs to be wide. The configuration of this elevator system is insufficient to increase the ratio of the space utility of a building.

Occupied space can be reduced by arranging the counter weights 6a, 6b and 6c longitudinally and moved along a pair of guide rails. However, if this configuration is applied to the elevator system shown in FIG. 7, the moving range of cages Ia, Ib and Ic is extremely limited. For example, when the cage Ia is moved up while the cages Ib and Ic are stopping at a lower floor, the counter weight βa interferes with the counter weight 6b on the way of ascending, and the cage Ia for higher floors may not reach the highest floor.

The elevator system described in the Jpn. Pat. Appln. KOKAI Publication No. 59-133188 is configured as shown in FIG. 8 and FIG. 9. The elevator system has a first cage 11a and a second cage lib in the same shaft 10. The first cage 11a is placed above the second cage lib. A first counter weight 12a and a second counter weight 12b are provided for the cages 11a and lib, respectively. A machine room 13 is provided above the shaft 10. Traction machines 14a and 14b corresponding to the first cage 11a and second cage lib are provided in the machine room 13. Main ropes 15a and 15b are wound around the traction machines 14a and 14b, respectively. The cages ; lla/llb and counter weights 12a/12b are suspended in the shaft 10 by the main ropes 15a and 15b. The cages 11a and lib are moved independently by driving the traction machines 14a and 14b separately.

In the elevator system described in the Jpn. Pat. Appln. KOKAI Publication No. 59-133188, the cages 11a and lib and the counter weights 12a and 12b are placed vertically with space taken therebetween as shown in

FIG. 8 and FIG. 9. This reduces the width of the shaft 10 in a direction of the front and rear, and increases the ratio of the space utility in the floor of a building. However, since the machine room 13 for the traction machines 14a and 14b is provided above the shaft 10 in this elevator system, the ratio of the space utility in the height of a building is decreased.

Disclosure of Invention The present invention provides an elevator system, which has two or more cages in one shaft and increases the ratio of the space utility of a building in both horizontal and vertical directions.

An elevator system according to the present invention has cages, counter weights, ropes and traction machines in one shaft. The cages are placed in the vertical direction. The counter weights are provided for the cages one by one. The ropes connect the cages to the corresponding counter weights, and suspend them in the shaft. The ropes connected to the cages and counter weights are wound around the traction machines which move the pairs of cages and counter weights along the shaft. The traction machines are placed in the highest part of the shaft. Otherwise, the traction machine corresponding to the lowest cage is placed in the lowest part of the shaft, and the other traction machines are placed in the highest part of the shaft.

The traction machines include at least first and second traction machines. The highest cage corresponds to the highest counter weight. The first traction machine to drive the highest cage and counter weight is placed in the highest part of the shaft. The moving distance of the highest counter weight is 1/2 of the moving distance of the corresponding highest cage. The highest counter weight moves in a range higher than the middle part of the shaft. The second traction machines to drive one of remaining cages other than the highest cage and corresponding counter weight are provided in the middle part of the shaft. These cages and counter weights move in a range lower than the middle part of the shaft.

Otherwise, the highest cage corresponds to the highest counter weight. The first traction machine to drive the highest cage and counter weight is placed in the highest part of the shaft. The moving distance of the highest counter weight is 1/2 of the moving distance of the corresponding highest cage. The highest counter weight moves in a range higher than the middle part of the shaft. The second traction machines to drive one of remaining cages other than the highest cage and corresponding counter weight are provided in the lowest part of the shaft. These cages and counter weights moves in a range lower than the middle part of the shaft.

In this case, the traction machines are placed in the part corresponding to the space between the vertical wall of the shaft and the zone where the cage passes.

The highest cage stops the lowest floor of a building, when the other cages are shunted in the lower part of the shaft lower than the lowest floor.- The lowest cage stops the highest floor of a building, when the other cages are shunted in the upper part of the shaft higher than the highest floor.

The highest cage has a guide sheave in the upper part. The rope corresponding to the highest cage is wound around the guide sheave, and the highest cage is suspended in the shaft. The cages placed lower than the highest cage has a guide sheave in the lower part. The ropes corresponding to these cages are wound around the guide sheave, and the cages are suspended in the shaft.

The highest cage has a vibration stopper. The vibration stopper is used to pass the ropes wound around the cages placed lower than the highest cage along the side of the highest cage, and limits the swing width of the ropes.

The highest counter weight has a vibration stopper. The vibration stopper passes through the ropes, which suspend the counter weights placed lower than the highest counter weight, along the side of the highest counter weight, and limits the swing width of the ropes.

Brief Description of Drawings FIG. 1 is a side view showing the configuration of an elevator system according to a first embodiment of the present invention;

FIG. 2 is a horizontal sectional view of the elevator system taken along lines A-A in FIG. 1; FIG. 3 a perspective side view of the configura¬ tion of a modification of the elevator system shown in FIG. 1;

FIG. 4 is a side view showing the configuration of an elevator system according to a second embodiment of the present invention;

FIG. 5 is a side view showing the configuration of an elevator system according to a third embodiment of the present invention;

FIG. 6 is a side view showing the configuration of an elevator system according to a fourth embodiment of the present invention; FIG. 7 is a side view showing the configuration of an elevator system of a prior art;

FIG. 8 is a side view showing the configuration of another elevator system of a prior art; and

FIG. 9 is a front view of the configuration of the elevator system shown in FIG. 8.

Best Mode for Carrying Out the Invention An elevator system 100 according to a first embodiment of the present invention will be explained with reference to FIGS. 1 - 6. The elevator system 100 shown in FIG. 1 has a first cage 31a, a second cage 31b, a first counter weight 32a, a second counter weight 32b, a first main rope 45a, a second main rope 45b, a first traction machine 41a and a second traction machine 41b in one shaft 30 provided in a building. The first cage 31a is always placed above the second cage 31b. The first counter weight 32a is always placed below the second counter weight 32b.

The first cage 31a has a pair of rotatable guide sheaves 35 in the upper part. The second cage 31b has a pair of rotatable guide sheaves 36 in the lower part. The first counter weight 32a has a pair of rotatable guide sheaves 37 in the upper part. The second counter weight 32b has a pair of rotatable guide sheaves 38 in the upper part.

The first traction machine 41a and second traction machine 41b are provided in the upper part of the shaft 30 as shown in FIG. 1, and placed in the area formed between the vertical wall of the shaft 30 and the zone where the first cage 31a and second cage 31b run as shown in FIG. 2. The first main rope 45a is wound around the first traction machine 41a, and the second main rope 45b is wound around the second traction machine 41b.

One side of the first main rope 45a extending downward from the part wound around the traction machine 41a is sequentially wound around two guide sheaves 35 provided at the top of the first cage 31a and changed a direction upward thereby. The tail end of the first main rope 45a is connected to a fixing part 47 provided in the upper part of the shaft 30. The other side of the first main rope 45a is sequen- tially wound around two guide sheaves 37 provided at the top of the first counter weight 32a and changed a direction upward thereby. The tail end of the first main rope 45a is connected to a fixing part 48 provided in the upper part of the shaft 30. The first main rope 45a suspends the first cage 31a and first counter weight 32a movably in the vertical direction in the shaft 30. One side of the second main rope 45b extending downward from the part wound around the traction machine 41b is sequentially wound around two guide sheaves 36 provided at the bottom of the second cage 31b and changed a direction upward thereby, and the tail end of the second main rope 45b is connected to the fixing part 47 provided in the upper part of the shaft 30. The other side of the second main rope 45b is sequentially wound around two guide sheaves 38 provided at the top of the second counter weight 32b and changed a direction upward thereby, and the tail end of the second main rope 45b is connected to the fixing part 48 provided in the upper part of the shaft 30. The second main rope 45b suspends the second cage 31b and second counter weight 32b movably in the vertical direction in the shaft 30.

The first main rope 45a passes along the side of the second counter weight 32b to be drawn around. The second counter weight 32b has a circular vibration stopper 50 on both sides. The first main rope 45a is prevented from shaking by being passed through the vibration stopper 50.

The second main rope 45b passes along the side of the first cage 31a to be drawn around. The first cage 31a has a circular vibration stopper 51 on both sides. The second main rope 45b is prevented from shaking by being passed through the vibration stopper 51. As shown in FIG. 2, the cage guide rail 55 and weight guide rail 56 extend vertically in the shaft 30. The cage guide rail 55 is placed on both sides of the first cage 31a and second cage 31b. The first cage 31a and second cage 31b move vertically along the cage guide rail 55. The weight guide rail 56 is placed on both sides of the first counter weight 32a and second counter weight 32b. The first counter weight 32a and second counter weight 32b move vertically along the weight guide rail 56.

In FIG. 1, the floor of the lowest floor of a building is indicated by FL, and the floor of the highest floor is indicated by FH. The shaft 30 ensures sufficient retraction space 58 in the lower part for shunting the second cage 31b when the first cage 31a stops the floor FL of the lowest level. Likewise, the shaft 30 ensures sufficient retraction space 59 in the upper part for shunting the first cage 31a when the second cage 31b stops the floor FH of the highest level.

The elevator system 100 drives the traction machines 41a and 41b by an operation control unit to move the cages 31a and 31b independently. In this case, the operation control unit comprehends the operation states of the first cage 31a and second cage 31b, and drives the traction machines 41a and 41b not to cause collision of the cages within the shaft 30, thereby controlling the moving range of the first cage 31a and second cage 31b.

Especially, when the first cage 31a reaches the floor FL of the lowest floor, the second cage 31b has been moved to the retraction space 58 provided in the lowest part of the shaft 30. When the second cage 31b reaches the floor FH of the highest floor, the first cage 31a has been moved to the retraction space 59 provided in the highest part of the shaft 30. Thus, the first cage 31a and second cage 31b can reach every floor between the lowest floor FL and the highest floor FH.

The elevator system 100 can stop one of the cages, for example, the first cage 31a in the retraction space 59, and operate only the other second cage 31b to serve for each floor, in a time zone when a few passengers use an elevator. Compared with a double-deck elevator which must always operate two cages, the elevator system 100 can reduce the power consumption to almost the half, and is advantageous from the viewpoint of energy saving.

When a building is swayed by strong wind or shook by earthquake, the second main rope 45b passing along the side of the first cage 31a may shake toward the first cage 31a. But, as the second main rope 45b is limited its swing width by the vibration stopper 51 attached to the first cage 31a, the rope is prevented from contacting or colliding with the first cage 31a.

Likewise, when a building is swayed or shook, the first main rope 45a passing along the side of the second counter weight 32b may sway toward the second counter weight 32b. Even in this case, as the first main rope 45a is limited its swing width by the vibration stopper 50 attached to the second counter weight 32b, the rope prevented from contacting or colliding with the second counter weight 32b. The first cage 31a is suspended in the shaft 30 by the first main rope 45a wound around the guide sheave 35 provided at the top of the cage. The second cage 31b is suspended in the shaft 30 by the second main rope 45b wound around the guide sheave 36 provided at the bottom of the cage. Since there is no guide sheave between the first cage 31a and second cage 31b, the distance between the cages can be reduced. Namely, when the second cage 31b stops a certain floor N of a building, the first cage 31a can stop the adjacent floor (N + 1) . Therefore, the elevator system 100 can serve for two floors of N and (N + 1) at a time.

The first cage 31a and second cage 31b and the first counter weight 32a and second counter weight 32b are placed vertically each other in the shaft 30. In the upper part of the shaft 30, the traction machines

41a and 41b are provided in an area extended vertically in the space formed between the vertical wall of the shaft 30 and the zone where the first cage 31a and second cage 31b are running. The horizontal cross section of the shaft 30 can be reduced compared with the conventional system, and it is unnecessary to provide a machine room for traction machines in the upper part of the shaft 30. Therefore, the elevator system 100 increases the ratio of the space utility of a building in both horizontal and vertical directions. In the first embodiment, the first traction machine 41a and second traction machine 41b are provided in the upper part of the shaft 30 correspond¬ ing to the gap between the vertical wall of the shaft 30 and the zone where the first cage 31a and second cage 31b are moved. But, it is permitted to provide the first traction machine 41a and second traction machine 41b at a position out of the area corresponding to the space, as long as it is in the upper part of the shaft 30.

In the first embodiment, two counter weights 32a and 32b are suspended in the area in the rear side of the zone where the cages 31a and 31b are moved. But, when sufficient space is not ensured in the rear side of the cages 31a and 31b, it is permitted to suspend the first counter weight 32a on the right side and the second counter weight on the left side of the zone where the cages 31a and 31b are moved, as a modifica¬ tion shown in FIG. 3. In FIG. 3, same reference numerals are given to the same components having the same functions as those of the elevator system 100 of the first embodiment.

An elevator system 100a according to a second embodiment will be explained with reference to FIG. 4. Same reference numerals are given to the same components having the same functions as those in the elevator system 100 of the first embodiment, and detailed explanation will be omitted. The elevator system 100a of the second embodiment has a first traction machine 41a in the upper part of the shaft 30 and a second traction machine 41b in a pit 63 in the lower part of the shaft 30. The elevator system 100a has a deflector sheave 64 and a pair of turning sheaves 65 and 66 in proximity to the first traction machine 41a.

The first main rope 45a is wound around the first traction machine 41a. On the basis of the part wound around the first traction machine 41a, one side of the first main rope 45a is routed downward, sequentially wound around two guide sheaves 35 provided at the top of the first cage 31a on the way of routing, and changed a direction upward thereby. The tail end of the one side of the first main rope 45a is connected to the fixing part 47 provided in the upper part of the shaft 30.

The other side of the first main rope 45a is guided downward through the deflector sheave 64, wound around two guide sheaves 37 provided at the top of the first counter weight 32a, and changed a direction upward thereby. The tail end of the other side of the first main rope 45a is connected to the fixing part 48 provided in the upper part of the shaft 30. The first main rope 45a suspends the first cage 31a and first counter weight 32a movably in the vertical direction in the shaft 30. The second main rope 45b is wound around the second traction machine 41b provided in the pit 63. On the basis of the part wound around the second traction machine 41b, one side of the second main rope 45b routed upward is wound around the turning sheave 65, and changed a direction downward thereby. The turned second main rope 45b is sequentially wound around two guide sheaves 36 provided at the bottom of the second cage 31b, and changed a direction further upward thereby. The tail end of the one side of the second main rope 45b is connected to the fixing part 47 provided in the upper part of the shaft 30.

The other side of the second main rope 45b is extended upward from the second traction machine 41b, wound around the turning sheave 66, and changed a direction downward thereby. The turned second main rope 45b is extended downward, wound around one guide sheave 38 provided at the top of the second counter weight 32b, and changed a direction further upward thereby. The tail end of the other side of the second main rope 45b is connected to the fixing part 48 provided in the upper part of the shaft 30. The second main rope 45b suspends the second cage 31b and second counter weight 32b movably in the vertical direction in the shaft 30.

Like the elevator system 100 of the first embodiment, the elevator system 100a drives the traction machines 41a and 41b separately to move the cages 31a and 31b independently, thereby serving for every floor of a building.

Like the elevator system 100 of the first embodiment, the elevator system 100a has retraction spaces 58 and 59. When the first cage 31a reaches the floor FL of the lowest floor, the second cage 31b has been shunted to the retraction space 58 provided in the lowest part of the shaft 30. When the second cage 31b reaches the floor FH of the highest floor, the first cage 31a has been shunted to the retraction space 59 provided in the highest part of the shaft 30. Thus, the first cage 31a and second cage 31b can stop every floor between the lowest floor FL and highest floor FH. The elevator system 100a can stop one of the cages, for example, the first cage 31a in the retrac¬ tion space 59 and operate only the other second cage 31b to serve for each floor, in a time zone when a few passengers use an elevator. Compared with a double- deck elevator which must always operate two cages, the elevator system 100a can reduce the power consumption to almost the half and is advantageous from the viewpoint of energy saving.

When a building is swayed by strong wind or shook by earthquake, the second main rope 45b is controlled its swing width by the vibration stopper 51 attached to the first cage 31a, the rope is prevented from contacting or colliding with the first cage 31a.

Likewise, the first main rope 45a is controlled its swing width by the vibration stopper 50 attached to the second counter weight 32b, the rope is prevented from contacting or colliding with the second counter weight 32b.

The first cage 31a is suspended in the shaft 30 by the first main rope 45a wound around two guide sheaves 35 provided at the top. The second cage 31b is suspended in the shaft 30 by the second main rope 45b wound around two guide sheaves 36 provided at the bottom. Since there is no guide sheave between the first cage 31a and second cage 31b, the distance between the cages can be reduced. Namely, while the second cage 31b stays a certain floor N of a building, the first cage 31a can stop the next floor (N + 1) .

Therefore, the elevator system 100a can serve for two floors of N and (N + 1) at the same time. The first cage 31a and second cage 31b and the first counter weight 32a and second counter weight 32b are placed vertically each other in the shaft 30. The traction machines 41a and 41b are provided in the upper and lower parts of the shaft 30. The horizontal cross section of the shaft 30 can be reduced compared with the conventional system, and it is unnecessary to provide a machine room for traction machines in the upper part of the shaft. Therefore, the elevator system 100a increases the ratio of the space utility of a building in both horizontal and vertical directions.

An elevator system 100b according to a third embodiment will be described with reference to FIG. 5. Same reference numerals are given to the same components having the same functions as those in the elevator systems 100 and 100a of the first and second embodiments, and detailed explanation will be omitted. In the elevator system 100b of the third embodiment, the first counter weight 32a is placed higher than the second counter weight 32b. The first traction machine 41a is provided in the upper part of the shaft 30, and the second traction machine 41b is provided in the middle part of the shaft 30 in the vertical direction. The deflector sheave 64 is placed in proximity to the first traction machine 41a.

In the main rope 45a wound around the first traction machine 41a, on the basis of the part wound around the traction machine, one side is extended downward and connected directly to the top of the first cage 31a. The other side of the first main rope 45a is routed downward through the deflector sheave 64, wound around two guide sheaves 37 attached to the top of the first counter weight 32a, and changed a direction upward thereby. The tail end of the other side of the first main rope 45a is connected to the fixing part 48 provided in the upper part of the shaft 30. The first main rope 45a suspends the first cage 31a and first counter weight 32a movably in the vertical direction in the shaft 30.

The second traction machine 41b is placed in the middle part of the shaft 30 in the vertical direction, in the part corresponding to the space formed in the horizontal direction between the vertical wall of the shaft 30 and the zone where the cages 31a and 31b are run. The second main rope 45b is wound around the second traction machine 41b. In the second main rope 45b, on the basis of the part wound around the traction machine 41b, one side is extended downward, sequentially wound around two guide sheaves 36 provided at the bottom of the second cage 31b, and changed a direction upward thereby. The tail end of the one side of the second main rope .45b is connected to a fixing part 70 provided in the middle part of the shaft 30. The other side of the second main rope 45b is extended downward from the second traction machine 41b, sequentially wound around two guide sheaves 38 provided at the top of the second counter weight 32b, and changed a direction upward thereby. The second main rope 45b turned is extended upward, and the tail end of the other side of the second main rope 45b is connected to a fixing part 71 provided in the middle part of the shaft 30. The second main rope 45b suspends the second cage 31b and second counter weight 32b movably in the vertical direction in the shaft 30.

The elevator system 100b ensures the retraction space 58 which is same as those in the first and second embodiments, below the floor FL of the lowest level. In the elevator system 100b, when the first cage 31a reaches the floor FL of the lowest floor, the second cage 31b has been shunted to the retraction space 58. In the elevator system 100b, the moving distance of the first counter weight 32a is 1/2 of the moving distance of the first cage 31a. The moving distance of the second counter weight 32b is the same as the moving distance of the second cage 31b. In the elevator system 100b, even when the first cage 31a moves in the shaft 30 to stop all floors, the first counter weight 32a moves only in the upper side range higher than the middle part of the shaft 30. As the second counter weight 32b is suspended between the fixing part 71 and the second traction machine 41b provided in the middle part of the shaft 30, it does not interfere with the first counter weight 32a.

Therefore, in the elevator system 100b, the first traction machine 41a and second traction machine 41b are controlled so that the second cage 31b does not interfere with the first cage 31a in the area lower than the fixing parts 70 and 71. When the first cage 31a is positioned higher than the middle part of the shaft 30, the first cage 31a and second cage 31b move just like two independent elevators, and can serve for all floors of a building.

A building usually has an entrance at a certain lower floor. People visiting a building use an elevator 100b to move from the entrance floor to a destination floor. In other words, the number of passengers in a cage decreases as the cage rises to higher floors causing the passengers getting off. In the elevator system 100b, the first cage 31a and second cage 31b are operated for the floors lower than the middle of the shaft, and only the first cage 31a is operated for the floors higher than the middle of the shaft. Namely, the elevator system 100b is configured to operate two cages for the lower floors with a high utility, and one cage for the higher floors with a low utility. This increases the operating efficiency compared with a conventional double-deck elevator system.

Further, in the elevator system 100b, while the first cage 31a stops the floor FL of the lowest floor, the second cage 31b is shunted to the retraction space 58. Therefore, the first cage 31a can serve for all floors. The second cage 31b serves for the floors lower than the middle of the shaft 30 where the second traction machine 41b is provided.

When a building has an entrance leading to a station, for example, at any floor between a middle floor and a lowest floor, two large flows of people, they are going up and down from the entrance, may occur. In such a case, the elevator system 100b can increase the operation efficiency by using the first cage 31a for the people going upstairs and the second cage 31b for the people going downstairs.

Further, in the elevator system 100b, only the first cage 31a is operated for each floor while the second cage 31b stands by in the retraction space 58 in a time zone with a few passengers. In this way of operation, the elevator system 100b can reduce the power consumption to almost the half of a double-deck elevator which always operates two cages at a time. This is advantageous from the energy-saving viewpoint. In the elevator system 100b, the first cage 31a and second cage 31b and the first counter weight 32a and second counter weight 32b are placed vertically each other, the first traction machine 41a is provided in the upper part of the shaft 30, and the second traction machine 41b is provided in the middle part of the shaft 30. In the elevator system 100b, the horizontal cross section of the shaft 30 can be reduced compared with a conventional elevator, and it is unnecessary to provide a machine room for traction machines in the upper part of the shaft 30. Therefore, the elevator system 100b can increase both the ratio of the floorage utility and the ratio of the vertical space utility of a building.

An elevator system 100c according to a' fourth embodiment will be explained with reference to FIG. 6. In the elevator 100c of the fourth embodiment, the first cage 31a and second cage 31b, the first counter weight 32a and second counter weight 32b, the first traction machine 41a, the deflector sheave 64, and the fixing parts 48, 70 and 71 are placed at the same positions as those in the elevator system 100b of the third embodiment. A difference point from the elevator system 100b of the third embodiment is that the second traction machine 41b is provided at a different position and turning sheaves 78 and 79 are newly provided. In the elevator system 100c of the fourth embodiment, as in the elevator system 100b of the third embodiment, the first counter weight 32a is placed above the second counter weight 32b. The first traction machine 41a is placed in the upper part of the shaft 30. The second traction machine 41b is placed in the pit 63 lower than the floor FL of the lowest floor in the shaft 30 as same as the case of the second embodiment. The deflector sheave 64 is placed in proximity to the first traction machine 41a, the turning sheaves 78 and 79 are placed at a vertical level similar to the fixing parts 70 and 71 prepared at the middle of the shaft 30.

In the first main rope 45a wound around the first traction machine 41a, on the basis of the part wound around the traction machine, one side is extended downward, and the distal end is connected directly to the top of the first cage 31a. The other side of the first main rope 45a is extended downward through the deflector sheave 64, wound around two guide sheaves 37 attached to the first counter weight 32a, and changed a direction upward thereby. The tail end of the other side of the first main rope 45a is connected to the fixing part 48 prepared in the upper part of the shaft 30. The first main rope 45a suspends the first cage 31a and first counter weight 32a movably in the vertical direction in the shaft 30. In the second main rope 45b wound around the second traction machine 41b, on the basis of the part wound around the traction machine, one side is extend upward, wound around the turning sheave 78, changed a direction downward thereby, wound around two guide sheaves 36 attached to the bottom of the second cage 31b, and extended again upward thereby. The tail end of one side of the second main rope 45b is connected to the fixing part 70 provided at the middle of the shaft 30.

The other end side of the second main rope 45b is extended upward from the second traction machine 41b, wound around the turning sheave 79, bent downward thereby, wound around the guide sheave 38 attached to the top of the second counter weight 32b, and extended again upward thereby. The tail end of the other side of the second main rope 45b is connected to the fixing part 71 prepared at the middle of the shaft 30. The second main rope 45b suspends the second cage 31b and second counter weight 32b movably in the vertical direction in the shaft 30.

The retraction space 58 is provided in the lower part of the shaft 30 to keep the second cage 31b when the first cage 31a stops the floor FL of the lowest floor of a building.

In the elevator system 100c configured as described above, the first cage 31a and second cage 31b and the first counter weight 32a and second counter weight 32b are operated in the same way as in the third embodiment. When the first cage 31a and first counter weight 32a are moved, the moving distance of the first counter weight 32a is 1/2 of the moving distance of the first cage 31a. When the second cage 31b and second counter weight 32b are moved, the moving distance of the second counter weight 32b is the same as the moving distance of the second cage 31b.

Operation of the first traction machine 41a and second traction machine 41b is controlled, so that the first cage 31a does not interfere with the second cage 31b in the range lower than the position where the fixing parts 70 and 71 are provided. Since the first cage 31a and second cage 31b can be operated as independent elevators in the elevator system 100c the operation efficiency for each floor in a building is increased.

While the first cage 31a stops the floor FL of the lowest floor, the second cage 31b stands by in the retraction space 58. Only the first cage 31a can serve for all floors. The second cage 31b serves for the range lower than the middle of the shaft 30 where the fixing parts 70 and 71 are provided. When a building has an entrance leading to a station, for example, at a certain floor between a middle floor and a lowest floor, there may be generated two large flows of people, which are separated upward and downward from entrance floor. In such a case, the elevator system 100c can increase the operation efficiency by using the first cage 31a for the people going upstairs and the second cage 31b for the people going downstairs. Further, in the elevator system 100c, only the first cage 31a is operated for each floor while the second cage 31b stands by in the retraction space 58 in a time zone with a few passengers. Therefore, the elevator system 100c can reduce the power consumption to almost the half of a double-deck elevator which always operates two cages at a time. This is advantageous from the energy-saving viewpoint.

Since the first cage 31a and second cage 31b and the first counter weight 32a and second counter weight 32b are placed in the vertical direction in the elevator system 100c, the horizontal cross section of the shaft 30 can be reduced compared with a conventional elevator. Further, in the elevator system 100c, the first traction machine 41a is placed in the upper part of the shaft, and the second traction machine 41b is placed in the lower part of the shaft 30. Therefore, it is unnecessary to provide a machine room for traction machines in the upper part of the shaft 30. The elevator system 100c can increase the ratio of the floorage utility and the ratio of the vertical space utility of a building. In the embodiments described hereinbefore, the elevator system has two cages and two counter weights in one shaft. In the elevator system according to the present invention, it is also possible to provide three or more cages and counter weights of the corresponding number in the vertical direction in a shaft.

Industrial Applicability

An elevator system according to the present invention is effective when applied to a high-rise building where a time zone and floors to use an elevator are uneven.

Claims

C L A I M S

1. An elevator system (100) comprising: a plurality of cages (31a, 31b) which are placed in the vertical direction in a shaft (30) and moved independently in the shaft (30); a plurality of counter weights (32a, 32b) which are provided for the cages (31a, 31b) one by one; ropes (45a, 45b) which connect the cages (31a, 31b) to the corresponding counter weights (32a, 32b) as pairs, and suspend them in the shaft (30) ; and a plurality of traction machines (41a, 41b) which are placed in the highest part of the shaft (30) and around which one of the ropes (45a, 45b) is wound to move a pair of the cages (31a, 31b) and the correspond- ing counter weights (32a, 32b) along the shaft (30) .

2. An elevator system (100a) comprising: a plurality of cages (31a, 31b) which are placed in the vertical direction in a shaft (30) and moved independently in the shaft (30); a plurality of counter weights (32a, 32b) which are provided for the cages (31a, 31b) one by one; ropes (45a, 45b) which connect the cages (31a, 31b) to the corresponding counter weights (32a, 32b) as pairs, and suspend them in the shaft (30); and a plurality of traction machines (41a, 41b) around which one of the ropes (45a, 45b) is wound to move a pair of the cages (31a, 31b) and corresponding counter weights (32a, 32b) along the shaft (30), wherein the traction machine (41b) corresponding to the cage (31b) placed lowest in the cages (31a, 31b) is placed in the lowest part of the shaft (30), and the traction machine (41a) corresponding to the other cage (31a) is placed in the highest part of the shaft (30) .

3. An elevator system (100b) comprising: a plurality of cages (31a, 31b) which are placed in the vertical direction in a shaft (30) and moved independently in the shaft (30); a plurality of counter weights (32a, 32b) which are provided for the cages (31a, 31b) one by one; ropes (45a, 45b) which connect the cages (31a, 31b) to the corresponding counter weights (32a, 32b) as pairs, and suspend them in the shaft (30) ; and a plurality of traction machines (41a, 41b) around which one of the ropes (45a, 45b) is wound to move a pair of the cages (31a, 31b) and the corresponding counter weights (32a, 32b) along the shaft (30), wherein the cage (31a) placed highest in the cages (31a, 31b) corresponds to the counter weight (32a) placed highest in the counter weights (32a, 32b) ; the traction machine (41a) which drives the highest cage (31a) and highest counter weight (32a), is placed in the highest part of the shaft (30) ; the highest cage (31a) moves from a highest floor to a lowest floor; the highest counter weight (32a) moves in a range higher than the middle part of the shaft (30) by 1/2 of the moving distance of the highest cage (31a) ; the traction machine (41b) which drives one cage (31b) other than the highest cage (31a) and the corresponding counter weight (32b) , is provided in the middle part of the shaft (30); and the cage (31b) other than the highest cage (31a) and the corresponding counter weight (32b) move in a range lower than the middle part of the shaft (30) .

4. An elevator system (100c) comprising: a plurality of cages (31a, 31b) which are placed in the vertical direction in a shaft (30) and moved independently in the shaft (30) ; a plurality of counter weights (32a, 32b) which are provided for the cages (31a, 31b) one by one; ropes (45a, 45b) which connect the cages (31a, 31b) to the corresponding counter weights (32a, 32b) as pairs, and suspend them in the shaft (30); and a plurality of traction machines (41a, 41b) around which one of the ropes (45a, 45b) is wound to move a pair of the cages (31a, 31b) and the corresponding counter weights (32a, 32b) along the shaft (30) , the traction machines include at least first and second traction machines, wherein the cage (31a) placed highest in the cages (31a, 31b) corresponds to the counter weight (32a) placed highest in the counter weights (32a, 32b) ; the first traction machine (41a) which drives the highest cage (31a) and highest counter weight (32a) , is placed in the highest part of the shaft (30); the highest cage (31a) moves from a highest floor to a lowest floor; the highest counter weight (32a) moves in a range higher than the middle part of the shaft (30) by 1/2 of the moving distance of the highest cage (31a) ; the second traction machine (41b) which drives one cage (31b) other than the highest cage (31a) and the corresponding counter weight (32b), is provided in the middle part of the shaft (30) ; and the remaining cage (31b) other than the highest cage (31a) and the corresponding counter weight (32b) move in a range lower than the middle part of the shaft (30) .

5. The elevator system (100, 100a) according to claim 1 or 2, wherein the traction machines (41a, 41b) are placed in a part corresponding to the space between the vertical wall of the shaft (30) and the zone where the cages (31a, 31b) pass.

6. The elevator system (100b, 100c) according to claim 3 or 4, wherein the traction machines (41a, 41b) are placed in a part corresponding to the space between the vertical wall of the shaft (30) and the zone where the cages (31a, 31b) pass.

7. The elevator system (100, 100a, 100b, 100c) according to any one of claims 1, 2, 3, and 4, wherein the cage (31a) placed highest in the cages (31a, 31b) stops at the lowest floor (FL) , when the other cage (31b) is shunted in the shaft (30) lower than the lowest floor.

8. The elevator system (100, 100a) according to any one of claims 1, 2 and 5, wherein the cage (31b) placed lowest in the cages (31ba, 31b) stops at the highest floor (FH) , when the other cage (31a) is shunted in the shaft (30) higher than the highest floor.

9. The elevator system (100, 100a) according to any one of claims 1, 2 and 5, wherein the cage (31a) placed highest has an upper guide sheave (35) at the top; the rope (45a) corresponding to the highest cage (31a) is wound around the upper guide sheave (35) ; the remaining cage (31b) other than the highest cage (31a) has a lower guide sheave (36) at the bottom; and the rope (45b) corresponding to the cage (31b) other than the highest cage (31a) is wound around the lower guide sheave (36) .

10. The elevator system (100b, 100c) according to claim 3 or 4, wherein the cage (31b) other than the highest cage (31a) has a lower guide sheave (36) at the bottom; and the rope (45b) corresponding to the cage (31b) other than the highest cage (31a) is wound around the lower guide sheave (36) .

11. The elevator system (100, 100a, 100b, 100c) according to any one of claims 1, 2, 3, and 4, wherein the cage (31a) placed highest has a vibration stopper (51) ; said vibration stopper (51) passes the rope (45b), which suspends the cage (31b) other than the highest cage (31a), along the side of the highest cage (31a) , and limits the vibration of the rope (45b) .

12. The elevator system according to any one of claims 1, 2 and 5, wherein the counter weight (32a) placed highest has a vibration stopper (50); said vibration stopper passes the rope (45b), which suspends the counter weight (32b) other than the highest counter weight (32a) , along the side of the highest counter weight (32a) , and said vibration stopper (50) limits the swing width of the rope (45b) .