WO2006127004A1

WO2006127004A1 - Elevator system having counterweights including channels to accommodate load bearing members and compensation members

Info

Publication number: WO2006127004A1
Application number: PCT/US2005/018417
Authority: WO
Inventors: Harold Terry; Boris Traktovenko; John J. Kriss; John M. Milton-Benoit
Original assignee: Otis Elevator Company
Priority date: 2005-05-24
Filing date: 2005-05-24
Publication date: 2006-11-30

Abstract

An elevator system (20) includes more than one elevator car (22, 32) within a hoistway (26) Counterweights (24) and (34) each include at least one channel (36, 40) to accommodate load bearing members (28) or compensation members (42) such that the elevator cars (22, 32) are able to move independent from each other. Disclosed arrangements allow for positioning compensation members (42, 50) and load bearing members (28, 38) within a single hoistway in a manner that does not interfere with movement of either elevator car and counterweight set.

Description

ELEVATOR SYSTEM HAVING COUNTERWEIGHTS

INCLUDING CHANNELS TO ACCOMMODATE LOAD BEARING MEMBERS AND COMPENSATION MEMBERS

1. Field of the Invention

This invention generally relates to elevator systems. More particularly, this invention relates to counterweight designs and compensation within elevator systems having more than one car in a hoistway.

2. Description of the Related Art

Elevator systems are well known. Various configurations are utilized depending on the needs of a particular situation. Some systems include load bearing roping, such as ropes or belts, that support the elevator car and a counterweight. In many high rise buildings, compensation is used to compensate for load imbalances that occur when an elevator car is in a highest possible position, for example. Typical compensation arrangements include a rope or chain suspended beneath an elevator car and a corresponding counterweight. Opposite ends of the rope or chain are secured to the car and counterweight, respectively. While known load bearing roping and compensation arrangements have proven useful for many elevator systems, there are difficulties presented when introducing more than one elevator car into a hoistway. When one elevator car is positioned above another in a hoistway, the typical load bearing roping and compensation arrangement for one elevator car would interfere with the operation or movement of the other car. Proposed arrangements are shown in U.S. Patent Nos. 1,896,776 and 5,584,364. The former does not address issues presented by a compensation arrangement. A drawback to the latter arrangement is that it includes special vibration dampers to accommodate the compensation ropes.

Another approach would be to run load bearing members and compensation members for one counterweight outside another. The drawbacks to this approach include requiring extra hoistway space, which reduces valuable rental space in a building. Additionally, special considerations are required to ensure adequate clearances between moving components. An alternative arrangement to accommodate load bearing roping and compensation roping is needed.

This invention addresses that need by providing unique counterweights and compensation for an elevator system having multiple cars in a hoistway.

SUMMARY QF THE INVENTION

An example elevator system includes a first elevator car and a second elevator car below the first elevator car in one hoistway. A first counterweight is in the hoistway and has a plurality of channels extending between ends of the first counterweight. A second counterweight in the hoistway is positioned above the first counterweight. The second counterweight has a centrally located channel extending between ends of the second counterweight. A first load bearing member passes through the centrally located channel on the second counterweight and supports the first elevator car and the first counterweight. A second load bearing member supports the second elevator car and the second counterweight. A plurality of first compensation members couple the first elevator car to the first counterweight. A plurality of second compensation members couple the second elevator car to the second counterweight. At least one of the second compensation members passes through one of the plurality of channels on the first counterweight. At least one other of the second compensation members passes through another of the plurality of channels on the first counterweight.

In one example, a portion of one of the first compensation members crosses a portion of at least one of the second compensation members. Another portion of another one of the first compensation members crosses a portion of at least one other of the second compensation members. The crossing of the compensation members does not necessarily include any physical contact between them.

In one example system, each first compensation member has a first end associated with an outside of the first elevator car and a second end associated with a central location on the first counterweight. In one example, each second compensation member has a first end associated with a central location on the second elevator car and a second end associated with a laterally outward location on the second counterweight. One example system, the counterweights, are on one side of the elevator cars and one of the first compensation members is shorter than another one of the first compensation members. The shorter first compensation member is associated with the side of the first elevator car that is closest to the counterweights. An example counterweight for use in an elevator system includes a frame having an end piece near each of a top and bottom of the frame. A plurality of vertical pieces extend between the end pieces. Each of the end pieces has at least one slot and at least one of the vertical pieces cooperates with the slots to establish at least one channel between the top and bottom of the frame and through the slot of each of the end pieces.

One example counterweight includes a plurality of fillers supported between vertical pieces so that the fillers do not interfere with the passage established by the channel. One example counterweight includes a plurality of such channels.

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

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 schematically shows selected portions of an elevator system designed according to an embodiment of this invention.

Figure 2 schematically shows an arrangement of compensation members as seen from one end of a hoistway.

Figure 3 schematically shows an alternative arrangement of compensation members as seen from one end of a hoistway.

Figure 4 is a partially exploded view of a selected portion of one example counterweight frame.

Figure 5 is a partially exploded view of another example counterweight frame. Figure 6 schematically shows another counterweight configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 schematically shows selected portions of an elevator system 20. A first elevator car 22 and a first counterweight 24 move within a hoistway 26 in a generally known manner. A load bearing member 28, such as a plurality of belts or ropes, supports the weight of the first elevator car 22 and the first counterweight 24. The load bearing member 28 couples them together to move in unison in a known manner.

A second elevator car 32 and a second counterweight 34 are also supported within the hoistway 26. As shown in the drawing, the second elevator car 32 is positioned below the first elevator car 22. The second counterweight 34 is positioned above the first counterweight 24.

The load bearing member 28 passes through a channel 36 in the second counterweight 34. Another load bearing member 38, such as a plurality of ropes or belts, supports the second elevator car 32 and the second counterweight 34 in a known manner.

The first counterweight 24 includes a plurality of channels 40 extending between ends (i.e., the top and bottom) of the first counterweight 24. A plurality of compensation members 42 extend through the channels 40 and couple the second elevator car 32 to the second counterweight 34. In the illustrated example, a first end 44 of each compensation member 42 is associated with the second elevator car 32. A second end 46 of each compensation member 42 is associated with the second counterweight 34. Known connections at the ends secure them in place. The compensation members 42 comprise known materials such as ropes or chains to provide compensation in a known manner. Because the hoistway 26 includes multiple cars and multiple counterweights, a traditional load bearing roping and compensation arrangement will not work. The first counterweight 24 includes the laterally outward channels 40 through which the compensation members 42 pass to allow the appropriate movement of the second elevator car 32 independent of and relative to the first elevator car 22. Another set of compensation members 50 couples the first elevator car 22 to the first counterweight 24 in a known manner. A first end 52 of each compensation member 50 is associated with an outside of the first elevator car 22. Second ends 54 of the compensation members 50 are associated with the first counterweight 24 in a known manner. The compensation members 50 comprise known materials for such purposes.

The illustrated arrangement of counterweight channels 36 and 40, load bearing roping and compensation members 42 and 50 allows for moving either car and counterweight set independent of and without interfering with the other.

One feature of the arrangement shown in Figure 1 can be appreciated from Figure 2, which is a schematic view from a bottom of the hoistway 26, for example. As can be appreciated from Figure 2, the compensation members 42 and 50 are arranged so that one of the compensation members 50 crosses one of the compensation members 42. The other compensation member 50 crosses the other compensation member 42. This crossing relationship does not include any intersection and does not require any contact between the different compensation members. Having an arrangement such as that shown in Figure 2 facilitates the necessary curvature at the bottom of the hoistway along which the compensation members must bend. In other words, a sufficient distance between the connection points on the elevator cars and the associated counterweights needs to be maintained to accommodate the natural bend or stiffness of the compensation members. Having an arrangement as shown in Figure 2 accommodates that aspect of the compensation members without requiring additional sheaves near the bottom of the hoistway.

Having a crossing relationship between the compensation members 50 and 42 allows for sufficient distance at the bottom of the hoistway 26 to accommodate the necessary bending of the compensation member 50B. Additionally, the distance across which the compensation members extend near the bottom of the hoistway 26 accommodates a compensation sheave for arrangements that require tie down compensation. As known, compensation sheaves may be one large sheave or a plurality of spaced sheaves. The arrangements shown in Figures 2 and 3 accommodate either type of compensation sheave depending on the needs of a particular situation.

Another feature of the arrangement as schematically shown in Figure 2 is that the arrangement of the compensation members allows them to avoid interfering with movement of the other elevator car. For example, the compensation members 50 are positioned along outside of the second elevator car 32 so that they do not interfere with movement of the second elevator car 32 independent of the first elevator car 22.

Similarly, the first elevator car 22 and the compensation members 50 are able to move independent of the second elevator car 32. Having the second ends 54 of the compensation members 50 near a central location on the first counterweight 24 provides a sufficient connection surface between the counterweight 24 and the compensation members 50 to maintain a stable arrangement. The compensation members 42 are arranged to avoid interfering with the compensation members 50 and the load bearing member 28. The compensation members 42 in this arrangement have a centrally located first end 44 coupled with the second elevator car 32 and laterally outward positioned second ends 46 coupled to the second counterweight 34. The laterally outward spaced channels 40 accommodate the compensation members 42.

The example of Figure 2 shows an arrangement where the counterweights 24 and 34 are positioned behind the elevator cars 22 and 32. Figure 3 schematically shows an arrangement where the counterweights are on one side of the elevator cars. As can be appreciated from Figure 3, the second elevator car 32 has a front side 60 that includes doors to provide access to an interior of the car. A backside 62 is opposite the front side 60. Sidewalls 64 and 66 extend between the front side 60 and the back side 62 as known. The counterweights in this example are adjacent the side 64.

In the example of Figure 3, the compensation members 50 have slightly different arrangements and different lengths. A first compensation member 50A is associated with the side 66 of the elevator car 32. That compensation member 5OA must extend a longer distance than the other compensation member 50B, which is associated with the other side 64 of the car 32. The compensation member 50A must extend beneath the entire car 32 while the compensation member 50B does not.

The examples of Figures 2 and 3 provide a balanced weight distribution about the center of gravity of the cars and counterweights. Some symmetry in connections or terminations about the center of gravity ensures better operation. Balancing the weight avoids offset loading that might tend to cause undesirable loads and wear on the guidance components. Referring to Figure 4, selected portions of an example second counterweight 34 are shown in a partially exploded view. In this example, the second counterweight 34 has a frame that includes an end piece 70. A slot 72 in the end piece 70 provides an opening at one end of the channel 36. A plurality of vertical pieces 74, 76, 78 and 80 extend between the end piece 70 and a similar end piece (not illustrated) at an opposite end of the counterweight frame. The illustrated example includes face plates 82 and 84 that are received along a front and back side of the frame.

The vertical pieces 76 and 78 are positioned on opposite sides of the slot 72 to provide a channel along the central portion of the counterweight 34 to accommodate the load bearing member 28. The vertical pieces 74 and 76 cooperate to form a pocket for receiving a plurality of fillers 88, such as plates, to establish the desired mass of the counterweight in a known manner. The vertical pieces 78 and 80 cooperate to establish another pocket for receiving fillers. In this example, the fillers

88 are received on opposite sides of the channel 36, which includes the slots 72 at one end.

Figure 5 schematically shows selected portions of an example frame used for a first counterweight 24 like that used in the embodiment of Figure 1. In this example, an end piece 90 includes two slots 92 and 94 to provide openings at the ends of the laterally outward channels 40. In this example, the end pieces 74 and 76 cooperate to establish a channel through which the compensation members 42 can pass. Similarly, the vertical pieces 78 and 80 cooperate to establish a channel.

In this example, the vertical pieces 76 and 78 establish a pocket for receiving fillers 88 (see Figure 4), such as plates, to establish the desired mass of the counterweight 24. Although not illustrated in Figure 5, an opposite end of the frame includes an end piece like the end piece 90 in one example.

Another example counterweight arrangement 34' is schematically shown in

Figure 6. In this example, the channel 36' is open along one entire side of the counterweight. The channel 36' in this example does not have a slot with a closed periphery at the ends of the counterweight. Rather, the slots extend open to one side of the counterweight.

Those skilled in the art who have the benefit of this description will be able to select an appropriate arrangement to meet their particular needs. 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

CLAIMSWe claim:

1. An elevator system, comprising: a first elevator car in a hoistway; a second elevator car in the hoistway below the first elevator car; a first counterweight in the hoistway that has a plurality of channels extending between ends of the first counterweight; a second counterweight in the hoistway above the first counterweight, the second counterweight having a centrally located channel extending between ends of the second counterweight; a first load bearing member passing through the centrally located channel and supporting the first elevator car and the first counterweight; a second load bearing member supporting the second elevator car and the second counterweight; a plurality of first compensation members coupling the first elevator car to the first counterweight; and a plurality of second compensation members coupling the second elevator car to the second counterweight, at least one of the second compensation members passing through one of the plurality of channels on the first counterweight and at least one other of the second compensation members passing through another of the plurality of channels.

2. The elevator system of claim 1, wherein a portion of one of the first compensation members crosses a portion of at least one of the second compensation members and a portion of another one of the first compensation members crosses a portion of at least another one of the second compensation members.

3. The elevator system of claim 1, wherein each first compensation member has a first end associated with an outside of the first elevator car and a second end associated with a central location on the first counterweight.

4. The elevator system of claim 3, wherein the central location is vertically aligned with the centrally located channel on the second counterweight.

5. The elevator system of claim 3, wherein each second compensation member has a first end associated with a central location on the second elevator car and a second end associated with a laterally outward location on the second counterweight.

6. The elevator system of claim 3, wherein one of the first compensation members is shorter than another one of the first compensation members.

7. The elevator system of claim 6, wherein the elevator cars each have a front, a back and two sides and wherein the counterweights are positioned along one of the sides and wherein the first end of the one first compensation member is associated with the one side of the first elevator car.

8. The elevator system of claim 1, wherein the first counterweight includes a frame having end pieces near a top and bottom, respectively, of the first counterweight and wherein each of the laterally outward channels comprises a slot through each of the end pieces.

9. The elevator system of claim 8, wherein the frame includes vertical pieces extending between the end pieces on opposite sides of each of the slots.

10. The elevator system of claim 9, wherein the first counterweight includes at least one filler supported between two of the vertical pieces that are positioned between the slots.

11. The elevator system of claim 1, wherein the second counterweight includes a frame having end pieces near a top and bottom, respectively, of the second counterweight and wherein the centrally located channel comprises a slot through each of the end pieces.

12. The elevator system of claim 11, wherein the frame includes inner vertical pieces extending between the end pieces on opposite sides of the slots and outer vertical pieces extending along lateral edges of the second counterweight.

13. The elevator system of claim 12, wherein the second counterweight includes at least one filler supported between a first inner vertical piece and a first outer vertical piece and at least one filler supported between a second inner vertical piece and a second outer vertical piece.

14. A counterweight for use in an elevator system, comprising: a frame having an end piece near each of a top and bottom of the frame and a plurality of vertical pieces extending between the end pieces, each of the end pieces having at least one slot, at least one of the vertical pieces cooperating with the slots to establish at least one channel between the top and bottom of the frame and through the slot of each of the end pieces.

15. The counterweight of claim 14, wherein there is at least one of the vertical pieces on each side of the slots.

16. The counterweight of claim 14, including a plurality of slots in each of the end pieces and a corresponding plurality of channels.

17. The counterweight of claim 16, including at least one filler positioned between the channels.

18. The counterweight of claim 16, including a first one of the vertical pieces laterally inward of one of the channels and a second one of the vertical pieces laterally inward of another of the channels and including at least one filler positioned between the first and second vertical pieces.

19. The counterweight of claim 14, wherein the frame includes inner vertical pieces extending between the end pieces on opposite sides of the slots and outer vertical pieces extending along lateral edges of the frame.

20. The counterweight of claim 19, including at least one filler supported between a first one of the inner vertical pieces and a first one of the outer vertical pieces and at least one filler supported between a second one of the inner vertical pieces and a second one of the outer vertical pieces.