HK1139371B - Elevator system with multiple cars in hoistway - Google Patents

Description

Elevator system having multiple cars in hoistway

This application is a divisional application of PCT patent application (chinese national application No. 200480044881.1, international application No. PCT/US2004/042207, inventive name "elevator system having multiple cars in hoistway") filed on 16/12/2004, which has entered the chinese country stage.

Technical Field

This invention relates generally to elevator systems. More particularly, the present invention relates to an elevator system having more than one car within a hoistway.

Background

Many elevator systems include a car (car) and a counterweight (counterweight) connected together by ropes or other load bearing members. For example, a machine controls movement of a car to service guests between various floors within a building. As is well known, the counterweight and car typically move in opposite directions within the hoistway.

It has been proposed to include multiple elevator cars within a single hoistway. Such an arrangement provides advantages for enhancing or improving customer service, for example. Example patents related to elevator systems having multiple cars within a hoistway include U.S. patent nos. 1,837,643; no. 1,896,776; 5,419,414 No; nos. 5,584,364; and U.S. published application No. 2003/0075388. Each of these pieces discloses a different arrangement of elements in such an elevator system.

Various challenges arise when trying to provide multiple cars within a hoistway. For example, the movement of the system components must be controlled to avoid collisions between elevator cars. Also challenging is the placement of the counterweight and load bearing members between the counterweight and car in a manner that effectively uses hoistway space without requiring special modifications or undesirably large amounts of additional space.

The present invention provides several methods of arranging elevator system components to position multiple cars within a hoistway.

Disclosure of Invention

An example elevator system designed according to this invention includes a first elevator car and a first counterweight within a hoistway. A first load bearing member has a first length and connects the first elevator car to the first counterweight. A second elevator car within the hoistway is below the first elevator car. A second counterweight within the hoistway is above the first counterweight. A second load bearing member has a second length and connects the second elevator car to the second counterweight. The length of the load bearing member (i.e., the first length and the second length) allows contact between the first counterweight and the second counterweight but prevents contact between the first elevator car and the second elevator car.

By strategically selecting the length of the load bearing members and considering the counterweight buffer travel plus the expected dynamic jump of the elevator cars, it is possible to avoid contact between the elevator cars by maintaining a spacing between them at all times. In some examples, the size of the counterweight and the buffer associated with the counterweight are also selected to control the spacing between the elevator cars.

Another example elevator system includes a first elevator car, a first counterweight, a second elevator car, and a second counterweight. The second elevator car is below the first elevator car. The second counterweight is above the first counterweight. The load bearing members connecting the respective elevator cars and counterweights have different associated hoisting ratios (roping ratios).

In one example, a first load bearing member connecting the first elevator car and the first counterweight has an associated roping ratio of 1: 1. The second load bearing member has an associated draft ratio of 2: 1.

In another example elevator system designed according to this invention, the elevator car disposed above the other elevator cars has at least one passage in the housing of the cab (cab) portion through which at least a portion of the load bearing member associated with the lower elevator car passes.

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

Drawings

Fig. 1 schematically illustrates selected elements of an elevator system having more than one elevator car within a hoistway;

fig. 2A and 2B schematically illustrate an example elevator system configuration;

figures 3A and 3B schematically illustrate two roping scenario examples;

fig. 4A and 4B schematically illustrate another example elevator system configuration;

fig. 5A and 5B schematically illustrate another elevator system configuration;

fig. 6A and 6B schematically illustrate another example elevator system configuration;

7A-7C schematically illustrate another example elevator system configuration;

8A-8C schematically illustrate another example elevator system configuration;

9A-9C schematically illustrate another example elevator system configuration;

10A-10C schematically illustrate another example elevator system configuration;

figures 11A-11C schematically illustrate features of an elevator car for connecting an example roping arrangement.

Fig. 12 schematically illustrates an example arrangement in somewhat more detail consistent with the embodiment shown in fig. 11A-11C.

Detailed Description

Fig. 1 schematically illustrates selected portions of an elevator system 20. A first elevator car 22 connected with a first counterweight 24 is configured to move within a hoistway 26. Although not shown in fig. 1, the first elevator car 22 is connected to the first counterweight 24 by known ropes or belts. For the purposes of this description, "load bearing member" should be understood to mean one or more ropes or belts. A second elevator car 32 is disposed below the first elevator car 22 (according to the figure). The second elevator car 32 is coupled to a second counterweight 34 by a load bearing member (not shown) for movement within the hoistway 26 as is known.

In this example, the counterweights 24 and 34 travel along a common guide rail 36. In other words, the counterweights 24 and 34 share the same guide rails.

Another feature of the system 20 schematically illustrated in fig. 1 is that at least one buffer 38 is supported on at least one of the counterweights 24 and 34 to absorb the impact of the counterweights contacting each other. In one example, the bumper 38 is partially supported within the housing of the counterweight. A set of relatively small shock absorbers 39 is provided on at least one of the cars 22, 32.

Various features of such an elevator system are described in various embodiments below. For example, load bearing members such as ropes or belts connect the elevator car and counterweight, respectively. One exemplary system feature designed according to this invention includes selecting the length of the load bearing member and considering the buffer travel of the counterweight buffer 38 and the desired dynamic jump of the elevator cars 22 and 32 to allow contact between the counterweights or associated buffers within the hoistway and prevent contact between the elevator cars. The difference is that the spacing between the car and the counterweight is greater than the counterweight buffer travel plus the desired dynamic jump in the elevator car. Given this description, those skilled in the art will understand how to combine car speed, buffer travel, component size, etc. to meet their particular needs. In some examples, the length of the load bearing member and its connection to the elevator system components ensure that the elevator cars do not contact each other under normal system operating conditions. Such an arrangement also provides, for example, sufficient overhead clearance above one car that is located below another car for maintenance or inspection procedures.

In the event that a counterweight jump or overspeed condition results in contact between the cars 22 and 32, the buffer 39 absorbs some of the energy associated with such an impact.

Another feature of an example elevator system designed according to this invention is that a first traction ratio of one elevator car and counterweight is different than a second traction ratio of the other elevator car and counterweight. Depending on the choice of hoisting ratio, different features can be incorporated into the elevator system designed according to the invention. This feature will be described in connection with corresponding examples which will be discussed below.

In some exemplary systems designed according to this invention, the roping placement strategy includes allowing some of the load bearing members to pass through a passage that is connected to at least the upper elevator car. For example, such a passageway allows for the use of various traction ratios while still maintaining space limitations within the hoistway.

Various combinations of such features may be used as desired for particular situations. Given this description, those skilled in the art will be able to determine how best to combine the disclosed features to meet the needs of their particular situation.

Fig. 2A and 2B schematically illustrate an example elevator system configuration. In this example, the first elevator car 22 is connected to the first counterweight 24 by a load bearing member 40. A drive sheave or traction sheave 42 causes movement of the load bearing member 40 to cause the desired movement of the elevator car 22 in a known manner. Guide sheaves 44 and 46 are included in the illustration to show how the load bearing member 40 travels within the hoistway to accommodate both elevator cars and to achieve the desired angle of wrap around the drive sheave 42.

The second elevator car 32 is connected to the second counterweight 34 by a load bearing member 50. A separate drive pulley 52 and guide wheel 54 are included for transporting the second load bearing member 50.

As can be appreciated from FIG. 2A, the load bearing members 40 and 50 each have an associated draft ratio of 1: 1. In this example, the first load bearing member 40 is selected based on the combined length of the second load bearing member 50 and the second counterweight 34 such that the counterweights 24 and 34 contact each other before the elevator cars 22 and 32 can contact each other. In other words, the length of the first load bearing member 40 is selected to prevent contact between the elevator cars 22 and 32. In one example, the length of the load bearing member 40 will be less than the combined length of the second load bearing member 50 and the distance between the bottom of the second counterweight 34 and the terminal end of the second load bearing member 50 connected to the counterweight 34. Where a buffer 38 is included between the counterweights, the size or stroke length of the buffer is also considered when selecting the length of the load bearing member 40.

Fig. 2A shows the arrangement of this example from the side, while fig. 2B shows the arrangement from the front (focusing only on the elevator cars 22 and 32). In this example, the counterweights 34 and 24 are behind the car 22.

The second load bearing member 50 is effectively "split" and some belts or ropes are provided on one side of the car 32 and other belts or ropes are provided on the other side of the car 32. In the example of fig. 2B, the load bearing member 50 is outside of the elevator car 22.

Figures 3A and 3B schematically illustrate two strategies for conveying load bearing members, some of which are on one side of the elevator car and others on the opposite side. In the example of fig. 3A, a single drive machine 60 is coupled to the drive sheave 52 to produce the desired movement of the load bearing member 50 and elevator car 32. In the example of fig. 3B, a separate drive machine (not shown) operates the drive sheave 52 to produce the desired car movement.

Figures 4A and 4B illustrate another example elevator system having load bearing members 40 and 50 each having an associated traction ratio of 1: 1. In this example, the counterweights 24 and 34 are disposed along the sides of the elevator cars 22 and 32. The view of figure 4A is a front view and the view of figure 4B is a side view (only the car and part of the load bearing member are shown). In this example, the guide wheels 54 and 56 are only used for some of the belts or ropes 50 of the second load bearing member (i.e., those extending from the right side of the car 32 in the figure). Which allows the load bearing member to be transported around the elevator car 22 to achieve side position counterweight placement.

Fig. 5A and 5B schematically illustrate another elevator system configuration with load bearing members 40 and 50 each having an associated roping ratio of 2: 1. Fig. 5A is a side view and fig. 5B is a front view. In this example, the counterweights 24 and 34 are located behind the cars 22 and 32.

One feature of the first load bearing member 40 having a 2: 1 draft ratio setting is that it is possible to have the load bearing member 40 out of the opposite surface on the second counterweight 34. In this example, the guide wheels 62 travel with the second counterweight 34 through the hoistway. Another guide wheel 64 travels with the first counterweight 24. In this example, the diameter of the guide wheels 64 is selected to be larger than the outer diameter of the second counterweight 34 so that the load bearing member 40 is guided beyond the oppositely facing surfaces (i.e., right and left sides of the counterweight 34 in fig. 5A). Such an arrangement is possible so long as the first load bearing member 40 connecting the first elevator car 22 to the first counterweight 24 has an associated roping ratio of 2: 1. Such an arrangement is possible regardless of whether the second load bearing member 50 has an associated draft ratio of 2: 1.

Another feature of the example of fig. 5A and 5B is that the guide sheave 66 traveling with the second elevator car 32 is positioned relative to the car so that the load bearing member 50 is completely to one side of the car guide rails 68. In this example, the car guide rails 68 are aligned offset from the center of gravity of the elevator cars 22 and 32. In such an arrangement, centering the car guide rails 68 is not possible. In the illustration, the two sets of ropes or belts of the load bearing member 50 are behind the guide rails 68. By comparison, the example of fig. 2A may have one of the sides of the load bearing member 50 (i.e., the ropes or belts connected to one side of the car 32) secured to one side of the car guide rails and the other side (i.e., those connected to the opposite side of the car 32) secured to the opposite side of the car guide rails. Such a roping arrangement makes it easier to center the car guide rail with respect to the center of gravity of the elevator car.

Fig. 6A and 6B schematically illustrate another elevator system configuration with load bearing members 40 and 50 each having an associated 2: 1 roping ratio. In this example, the counterweights 34 and 24 are supported on the sides of the cars 22 and 32.

It is possible to arrange the drive sheave, the drive machine or both at the same vertical position or height in the shaft or machine room as long as at least one load bearing member has a 2: 1 hoisting ratio.

Fig. 7A-7C schematically illustrate another example elevator system configuration. In this example, the load bearing member 50 connecting the second elevator car 32 and the second counterweight 34 has an associated roping ratio of 1: 1. The first load bearing member 40 has a draft ratio of 2: 1. In this example, the traction ratio of the load bearing members is different. As can be appreciated from fig. 7A, for example, the use of a sufficiently large deflector sheave 64 in conjunction with the counterweight 24 allows the load bearing member 40 to be located outwardly of the oppositely facing outer surface of the second counterweight 34. In this example, some of the ropes or belts for the load bearing member 50 travel around the guide wheels 54 and 56 while others do not. This allows the belt or rope to travel around the outside of the first elevator car 22. The counterweights 34 and 24 are on the sides of the elevator cars 22 and 34.

Figures 8A-8C schematically illustrate another example elevator system configuration with a first load bearing member 40 having an associated roping ratio of 2: 1 and a second load bearing member 50 having an associated roping ratio of 1: 1. In the example of fig. 8A-8C, the counterweights 34 and 24 are located behind the elevator cars 22 and 32.

Fig. 9A-9C schematically illustrate another elevator system configuration. In this example, the first load bearing member 40 has an associated draft ratio of 1: 1. The second load bearing member 50 has an associated draft ratio of 2: 1.

Another feature of the present example structure is that the second counterweight 34 includes a passage 70, which in this example includes an opening through a central portion of the second counterweight 34. The passage 70 allows the first load bearing member 40 to pass through the second counterweight 34. Such an arrangement saves space, for example.

In the example of fig. 9A-9C, the counterweights 34 and 24 are located behind the elevator cars 22 and 32.

In another example arrangement shown in figures 10A-10C, the first load bearing member 40 has a draft ratio of 1: 1 and the second load bearing member 50 has a draft ratio of 2: 1. In this example, the second counterweight 34 and the first counterweight 24 are located on the sides of the elevator cars 22 and 32. The present example also includes a passage 70 through the second counterweight 34.

Configuring the elevator system as schematically shown in fig. 10A-10C may be considered an optimum solution for some situations because it requires a minimum number of sheaves near the top of the hoistway and it is possible to pass the first load bearing member 40 through the channel 70 in the second counterweight 34. Such an elevator system configuration is preferred, for example, for space saving considerations.

Fig. 11A-11C schematically illustrate another elevator system configuration. In this example, the first load bearing member 40 has an associated draft ratio of 1: 1. The second load bearing member 50 has an associated draft ratio of 2: 1. Portions of the second load bearing member 50 belt or rope extending between the second elevator car 32 and the top of the hoistway 26 pass through a passage 80 in the elevator car 22. In the example shown, the channel 80 has a size designation at 82 that is large enough for a belt or rope of the second load bearing member 50 to be provided through the channel 80. In this example, the load bearing member 50 has an associated draft ratio of 2: 1. Thus, as long as the first elevator car 22 is stationary, there is no relative movement between the load bearing member 50 and the first elevator car 22 within the channel 80 even as the second elevator car 32 moves.

Locating the passage 80 on the elevator car 22 saves space within the hoistway because the ropes or belts of the load bearing member 50 do not need to travel outside of the elevator car 22.

As can be appreciated from fig. 11C, the passage 80 fits within the housing of the passenger compartment portion of the example first elevator car 22. Although not shown, the elevator car includes a frame and a car portion supported on the frame in a known manner. The car portion has an exterior housing and defines a space for carrying passengers by the elevator system. In this example, the channel 80 preferably fits within the housing of the elevator car portion.

Figure 12 schematically illustrates an arrangement in which a channel 80 is connected to a portion of a car that typically houses an elevator car operating panel 90. In this example, at least one interior side wall 92 of the elevator car supports the car operating panel 90, which includes a touch screen or buttons that are easily accessible to passengers on the side of the side wall 92. The opposite side of the sidewall 92 (i.e., the outwardly facing side relative to the interior of the car) faces the interior of the channel 80. By accommodating the belt or rope of the load bearing member 50 in a space adjacent to or connected to the space for accommodating the car operating panel 90, space savings in the hoistway can be achieved without sacrificing a significant amount of additional capacity inside the elevator car body portion.

The various examples described above illustrate elevator system configurations having strategically sized load bearing members, traction ratios, and various combinations of features for achieving better space usage, reducing the number of components required, or both. Given this description, those skilled in the art can select a combination of features that works best for their particular situation.

The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.

Claims (12)

1. An elevator system comprising:

a first elevator car within a hoistway;

a first counterweight within the hoistway;

a first load bearing member having an associated first roping ratio and coupling the first elevator car to the first counterweight;

a second elevator car in a hoistway below the first elevator car;

a second counterweight within the hoistway above the first counterweight; and

mating the second elevator car to a second load bearing member of the second counterweight independently of the first elevator car, the second load bearing member having an associated second roping ratio that is different from the first roping ratio.

2. The elevator system of claim 1, wherein the first traction ratio is 1: 1 and the second traction ratio is 2: 1.

3. The elevator system of claim 1, wherein the first load bearing member has a first length and the second load bearing member has a second length, and wherein at least the first length and the second length allow contact between the first counterweight and the second counterweight and prevent contact between the first elevator car and the second elevator car.

4. The elevator system of claim 3, wherein the first and second lengths are such that a distance between a contact surface proximate a bottom of the second counterweight and a contact surface proximate a top of the first counterweight is less than a distance between possible contact surfaces of the first and second elevator cars.

5. The elevator system of claim 3, comprising at least one buffer supported for movement with a selected one of the counterweights, the buffer disposed at least partially between the counterweights, and wherein the first length is selected based at least in part on a characteristic of the buffer.

6. The elevator system of claim 1, wherein the first roping ratio is 2: 1, the elevator car has a front, a back, and sides, and wherein the counterweight is disposed along one of the sides.

7. The elevator system of claim 1, wherein the elevator system includes a first machine for moving the first elevator car and a second machine for moving the second elevator car, and wherein at least one of the first and second roping ratios is 2: 1 and the first and second machines are located in the same generally vertical position relative to the hoistway.

8. The elevator system of claim 1, wherein the elevator system includes a guide rail for guiding movement of the first counterweight and second counterweight, wherein the second counterweight has oppositely facing sides facing the guide rail and oppositely facing outer surfaces generally perpendicular to the sides, wherein the first traction ratio is 2: 1, and a portion of the first load bearing member is disposed outwardly of each outer surface.

9. The elevator system of claim 8, wherein the elevator system includes a sheave connected with the first counterweight about which the first load bearing member travels, and wherein the sheave provides a spacing between portions of the first load bearing member that is greater than a distance between the outer surfaces.

10. The elevator system of claim 1, wherein the first elevator car has a passenger compartment portion including at least one passage through which at least a portion of the second load bearing member passes.

11. The elevator system of claim 1, wherein the first elevator car has a passenger compartment portion and at least one passage in the compartment portion through which at least a portion of the second load bearing member passes, the passage between an inner side wall of the compartment portion and an outer housing.

12. The elevator system of claim 11, wherein the car portion inner side wall has an inner surface for receiving at least a portion of a car operating panel, and the channel is positioned along an opposite side of the side wall.