CA2120545C - Compensation and rope elongation arrangement - Google Patents
Compensation and rope elongation arrangementInfo
- Publication number
- CA2120545C CA2120545C CA 2120545 CA2120545A CA2120545C CA 2120545 C CA2120545 C CA 2120545C CA 2120545 CA2120545 CA 2120545 CA 2120545 A CA2120545 A CA 2120545A CA 2120545 C CA2120545 C CA 2120545C
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- CA
- Canada
- Prior art keywords
- counterweight
- suspension
- elevator
- compensation
- rope
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- Cage And Drive Apparatuses For Elevators (AREA)
Abstract
In an elevator system comprising an elevator car, a counterweight, a set of elevator suspension ropes on which the elevator car and the counterweight are suspended, a traction sheave whose motion is transmitted via the suspension ropes to the elevator car and to the counterweight, a compensating system includes a set of compensating ropes connected to the elevator car and the counterweight via at least one diverting pulley. A vertically adjustable buffer arrangement mounted in conjunction with the counterweight allows the system to compensate for changes in the length of the suspension and compensating ropes. The suspension ratio of the compensating ropes is an integer multiple (i.e. 1, 2, 3 etc) of the suspension ratio of the suspension ropes.
Finally, the rope suspension ratio on the side of the elevator car can be the same as that of the counterweight, or it may be different.
Finally, the rope suspension ratio on the side of the elevator car can be the same as that of the counterweight, or it may be different.
Description
2 120~45 The present invention relates to a compensation system in an elevator and to a system for compensating for the elongation of elevator ropes.
In elevators with a large hoisting height, compensating ropes are needed to balance the unstable moment imposed on the hoisting machinery as a result of the unequal weight of the hoisting ropes on either side of the hoisting machinery. This unstable moment changes continuously as the elevator car moves within the shaft. Without balancing, the motor has to be considerably larger, and, because of the great length of rope involved, the effect becomes worse with increased height of the elevator shaft. If the height of the shaft increases sufficiently without compensation, a situation ~:will arise where the friction of the hoist ropes on the }5 hoisting machinery is insufficient. Thus, high-rise elevators employ compensating ropes, which are typically tightened by 'means of a compensation tension weight.
~;In high-rise buildings, the elevators travel at a high velocity and in malfunction situations (such as gripping, .~20 hitting the buffers) both the car and the counterweight may ~- ~bounce through relatively long distances before their kinetic energy is exhausted. The result of such bouncing is a strong 'impact on the ropes, which may damage the elevator structures or injure people. For this reason, the compensation tension ,25 equipment in fast elevators in provided with a bounce ''eliminator. This bounce eliminator also reduces the space needed at the top of the shaft because less bouncing headroom ~-is required.
In high-rise buildings where the suspension ratio of the suspension ropes for the car and counterweight is 2:1, it is often necessary to use many compensating or balancing ~-ropes and a very heavy tension weight. Sometimes this need for compensation is so great that the moment caused by the ~'suspension ropes cannot be fully compensated, with the ;35 consequence that the motor size must be increased.
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For example, German patent publication 1251926 presents an elevator system in which the path of the ~ counterweight is halved (i.e. the suspension ratio of the - ropes associated with the counterweight is 2:1) and the counterweight is placed in the lower part of the shaft. In Finnish patent ~2823, the path of the counterweight is similarly halved and placed in the upper part of the shaft.
Unfortunately, there is currently no adequate compensation system for these systems, which is why it has been necessary to use large motors in them and also the height has been limited because of the friction.
Another problem in high-rise elevators is the ; elongation of the hoisting and compensating ropes. Usually the car and counterweight are suspended to a ratio of l:1 or 2:1. In both cases, buffers are placed below the car and '" counterweight. Buffers are used at the extreme ends of travel of the elevator car and/or counterweight for when, in cases of malfunction, the car travels beyond the topmost or v~ bottommost floor. When the car is at the bottommost floor, some distance usually remains between the car and the buffer, called car overtravel distance. Similarly, when the car is at the topmost floor, a counterweight overtravel distance r ~in~ between the counterweight and its buffer. Wh~n the ropes are elongated (which typically occurs during use of the '; 25 elevator) and the car still stops accurately at the extreme floors, the counterweight overtravel distance becomes reduced.
In the prior art, this counterweight overtravel distance has been corrected by removing extra pieces attached to the bottom ;~ of the counterweight. A disadvantage with such extra pieces - 30 is that they occupy a space and therefore increase the ;~' required safety distance at the upper and lower ends of the shaft.
- In high-rise elevators, there is also in the lower : part of the shaft a compensating device which tightens the compensating ropes between the car and the counterweight. As , the hoisting rope and the compensating rope are elongated, the .
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tension device moves gradually downwards. To prevent the compensating ropes from becoming loose, enough space has to be provided below the tension device to allow it to go as far down as required to accommodate elongation of the ropes. This necessitates rather deep pits in the shaft in cases of a large hoisting height. Even so, the ropes generally have to be shortened a few times during the early part of the service life of the elevator.
' An object of the present invention is to provide an elevator system in which the required number of compensating ' ropes is always used so that the moment needed by the motor ;' is in; ized.
According to an aspect of the present invention, ~' there is provided an elevator system comprising: an elevator ;,r' 15 car; a counterweight; at least one elevator suspension rope for operatively supporting said elevator car and said counterweight within an elevator shaft; and a compensation system comprising at least one compensating rope operatively disposed in relation to said elevator car and said - 20 counterweight, a suspension ratio of said at least one compensating rope being an integer multiple (i.e. 1, 2, 3 etc.) of a suspension ratio of saidat least one suspension rope.
According to another aspect of the present invention, there is provided a compensation rope arrangement ~- in an elevator comprising an elevator car, a counterweight and ~' a set of elevator suspension ropes on which the elevator car and the counterweight are suspended, and a traction sheave ~' whose motion is transmitted via the suspension ropes to the ; 30 elevator car and counterweight, as well as a set of - compensating ropes and at least one diverting pulley belonging : to the set of suspension ropes and at least one buffer ' arrangement for the counterweight, wherein the suspension ratio of the compensating ropes is the same or multiplied by a constant as the suspension ratio of the suspension ropes, and the suspension ratio of the suspension ropes is the same . .
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According totheinvention, inadequatecompensation, i.e. a situation where the moment of the motor increases when the number of compensating ropes used is insufficient, is no longer unavoidable in high-rise buildings where the suspension ratio o~ the car and counterweight is 2:1. This is achieved by using, among other things, a 2:1 suspension for compensation on the side of the car and counterweight instead of the 1:1 compensation ratio used at present. As a result of this, the num~er of compensating ropes required is halved and also the weight of the compensation tension device is reduced. This suspension ratio can be further increased, in which case the number of compensating ropes and the weight of the compensation tension device are reduced.
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~'The present invention provides a compensation ~'solution for elevators in which the path of the counterweight has been halved. This is achieved by using a suspension ratio of 1:1 for the suspension and compensating ropes at the car-~side end and a corresponding ratio of 2:1 for both ropes at ;jthe counterweight-side end. The number of compensating ropes ,t'.'~'can be reduced so that the compensation suspension ratios on -~the car side and on the counterweight side are integer ~-25 multiples (i.e. 1, 2, 3, etc) of the respective ratios of the elevator suspension ropes. For example, if the suspension ~'~ratio of the suspension ropes on the car side is l:l, and 2:1 ~'on the counterweight side, then the corresponding suspension ~'ratio of the compensating ropes can be 2:1 on the car side and 4:1 on the counterweight side; or 3:1 on the car side and 6:1 on the counterweight side, and so on.
In all the cases mentioned above, the mutual suspension ratio of the suspension ropes and compensating ropes is the same or multiplied by an integer constant in relation to each other, so that the suspension ratio for the car may be different from that for the counterweight. As an :.:
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example, consider a case where the suspension ratio of the suspension ropes of the car is l:1 and the suspension ratio ~ of the suspension ropes of the counterweight is 2:1. The compensation can now be such that the compensation suspension ratio on the car side and on the counterweight side is obtained by multiplying the rope suspension ratios of the car and counterweight by an integer coefficient n. For example, if n=3, the compensation suspension ratio on the car side in the above-mentioned cases will be 3:1 and the compensation suspension ratio for the counterweight wi:Ll be 6:1.
Previously known cases are situations where the ratio of the suspension ropes of both the car and counterweight is l:l and the suspension ratio of the compensating ropes l:l. Another known case is one where the suspension ratio of both the car and counterweight is 2~1 and the suspension ratio of the compensating ropes 1:1. The present invention does not apply to these previously known cases.
The invention provides considerable advantages:
20 - In conventional high-rise freight elevators suspended to 2:1, a large number of compensating ropes and a heavy tension weight are needed. By using a double compensation suspension ratio (i.e.
n=2) according to the invention, the number of ropes can be halved and the size of the tension ~'' weight reduced.
- In very tall buildings, the invention allows the application of elevator designs according to Finnish patent 82823 and DE publication 1251926 . .
~ 30 ~which allow considerable savings in the guide rail - length and the number of attachments as the '~, counterweight only travels through half the travel ' of the car), while at the same time permitting full :,, -:, :' 2120~5 .
compensation for the weight of the suspension ropes.
- An existing design for a locking device preventing counterweight bounce can be utilised in a system according to the present invention.
- Rope elongation can be easily compensated for by using an adjustable buffer in accordance with the present invention.
~; - The adjustable buffer system is inexpensive and ; 10 easy to manufacture.
;~ - The buffer has a simple construction, for its ~: height can be reduced and increased by suitably ~; rotating the screw, and the adjustment can made to take place automatically.
The invention will be more readily understood from ~ the following description of a preferred embodiment thereof - given, by way of example, with reference to the accompanying ~;' drawings, in which:
20Figure 1 is a schematic illustration of a ~; compensating system according to a first embodiment of the ' invention;
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Figure 2 is a schematic illustration of a compensating system according to a second embodiment of the invention;
~'~ Figure 3 is a schematic illustration of a -~ compensating system according to a third embodiment of the invention; and Figure 4 shows a more detailed view of a buffer used in the various embodiments of the invention.
~:' '-~ Figure 1 schematically illustrates an elevator 1 comprising an elevator car 2, a counterweight 3 and elevator i~ suspension ropes 11 on which the elevator car 2 and the ~' 35 counterweight 3 are suspended, and a traction sheave 5 and a diverting pulley 15, whose motion is transmitted via the ;
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;~ suspension ropes 11 to the elevator car 2 and counterweight- 3. The elevator car 2 is suspended with a suspension ratio of 1:1 and the counterweight 3 with a suspension ratio of 2:1.
In this design, the compensating ropes 4 run from the car 2 to lower diverting pulleys 6 mounted on the floor of the shaft (for example) and further via an upper diverting pulley 7 ; mounted on the counterweight 3 to a tension device (for example a weight) 8 attached to the end of the rope. The ' tension device can move vertically as the ropes 4 and 11 are -~j 10 elongated. In this embodiment, the suspension ratio of the compensating ropes is the same as that of the suspension ropes, i.e. 1:1 on the car side and 2:1 on the counterweight side, so in this case their mutual coefficient is 1. In addition, a buffer structure 9 belonging to the buffer arrangement is provided below the counterweight.
Figure 2 presents a second embodiment, in which the suspension ratios of suspension ropes associated with the elevator car 2 and counterweight 3 are 1:1 and 2:1 respectively. The compensating rope 4 is attached to the bottom of the elevator car 2 and runs from there via the lower diverting pulleys 6, which in this case are mounted in the ' tension device 12 and over an upper diverting pulley 7 mounted below the counterweight 3 to a rope anchorage placed on the bottom 13 or wall of the elevator shaft. The tension device 12 can move in the vertical direction as the ropes 4 and 11 stretch. In this embodiment, the suspension ratio of the compensating ropes is the same as the suspension ratio of the suspension ropes, so the mutual coefficient of the suspension ratios is also 1. In this embodiment, too, a buffer structure 9 belonging to the buffer arrangement is placed below the counterweight 3.
In the embodiment illustrated in Figure 3, the car 2 and the counterweight 3 are suspended by means of suspension ropes 11, both with a suspension ratio of 1:1. Both ends of the compensating rope 4 are attached to the bottom 13 of the shaft. The compensating rope 4 is tightened over upper ''~
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diverting pulleys 7 and 14 by means of a tension device 12 suspended on the compensation rope 4, and which is provided with lower diverting pulleys 6. Thus the tension device 12 can move in the vertical direction. It is also possible to -~ 5 add to the design shown in Figure 3 a rope tensioning arrangement similar to that shown in Figure 1, by using a tension weight at one end of the compensation rope 4, as well as fixed lower diverting pulleys 6. In addition, there is a buffer structure 9b belonging to the buffer arrangement below ~'10 the counterweight 3 and a buffer structure 9a below the car 2. In this case, the suspension ratio of the suspension ropes is 1:1 for both suspension ropes associated the elevator car -~and the counterweight, while the corresponding suspension ratios of the compensating ropes is 2:1, so tbat the mutual coefficient of the suspension ratios is 2.
Figure 4 shows a schematic view of the counterweight 3 and buffer arrangement 9 located in the lower portion of the elevator shaft. The counterweight 3 is shown with a section 'removed. Above the counterweight 3 is a diverting pulley 10 for the suspension rope 11 and below it another diverting pulley 7 for the compensation rope 4. The compensating rope 4 comes up from a lower diverting pulley 18 to the diverting pulley 7 below the counterweight 3, passes around the diverting pulley 7 and is attached to a tension weight 8. The counterweight 3 moves vertically in the elevator shaft along guide rails 19. Similarly, the tension weight 8 moves along guide rails 20 and 19 in the bottom part of the elevator shaft. Due to rope elongation, the tension weight 8 moves gradually downwards, and the lower extent of travel of the counterweight 3 will also move gradually downwards. The rope elongation is the reason why the buffer structure 9 at the bottom of the elevator shaft should preferably be adjustable.
;The illustrated buffer structure 9 has a construction comprising a base part 24 with a screw 21 for height adjustment, mounted on the bottom of the elevator shaft below the counterweight 3. Mounted on the upper end of the screw ~ .
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: g 21 is a buffer part 23, whose top end receives a stop block 22 in the lower part of the counterweight 3 when the latter comes so far down that it is pressed against the buffer part 23. One 20 of the guide rails of the tension weight 8 is "~ 5 short as compared to the counterweight guide rail 19, and the - upper end of rail 20 remains below the upper surface of the buffer part 23 even when the latter is compressed and adjusted ' to its lowest position. When a new elevator is being installed, the height of the buffer part 23 is so adjusted that, when the counterweight 3 is in its low position, a suitable overtravel distance is left between the stop block 22 and the buffer part 23. In the course of time, the ; elongation of the tension ropes ll will reach a stage where the counterweight 3 goes down beyond its allowed low position.
To avoid this, the. base 24 of the buffer part 23 has been made adjustable so that by turning the screw 21 or lowering a hydraulic cylinder, the buffer part 23 is also lowered. In this way, the clearance between the buffer part 23 and the stop block 22 of the counterweight 3 can be adjusted to a suitable value whenever necessary. This adjustment can also be automated by adding limit switches 16 to the buffer base ....
and attaching a track 17 to the counterweight 3. These '~ determine a certain overtravel zone between the buffer part 23 and the stop block 22. The adjustment can be performed electrically by means of a motor at given intervals when the :' car is at the top floor and the counterweight in the low position. The motor transmits a vertical motion to the screw or opens a path for oil flow to a hydraulic cylinder through ' a valve system.
Such a buffer arrangement is also applicable to the embodiments of Figure 2 and 3, but a deep pit in the shaft is ; needed and possibly also the compensating ropes will have to be shortened, in which case some of the advantages of the ~" invention are ~; in;shed. The embodiments of Figure 2 and 3 '~ 35 can be more successfully used by employing a drum to the fixed r'~ end of one of the ropes and winding a portion of the :. ~ . , . : : ~. ' : . . .
,., ':, 10 '" compensating rope corresponding to the elongation onto the !'"'', drum.
' It is obvious to a person skilled in the art that different embodiments of the invention are not restricted to the examples described above, but that they may instead be varied within the scope of the following claims. In place of compensating ropes, it is possible to use belts, chains, etc.
' The tension weight in Figure 1 can be suspended via an - additional diverting pulley on the wall or bottom of the shaft. There may be one or more diverting pulleys in conjunction with the compensating rope or the suspension rope, and similarly there may be more than one diverting pulley in conjunction with the car. The places of the traction sheave and of the diverting pulley in conjunction with it can be interchanged. It is also obvious to the skilled person that ~; instead of the word "car" it is possible to use "car frame"
and instead of "counterweight", "counterweight frame" or "counterweight tank". In the buffer structure, the screw can be replaced by a hydraulic cylinder or other solutions ~ 20 permitting vertical adjustment, e.g. a telescopic structure !~i'' or a toothed rack or the like, by means of which the buffer -~ structure can be locked at a selected height. Instead of limit switches and a track, any other distance measuring , ' devices and structures can be used.
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In elevators with a large hoisting height, compensating ropes are needed to balance the unstable moment imposed on the hoisting machinery as a result of the unequal weight of the hoisting ropes on either side of the hoisting machinery. This unstable moment changes continuously as the elevator car moves within the shaft. Without balancing, the motor has to be considerably larger, and, because of the great length of rope involved, the effect becomes worse with increased height of the elevator shaft. If the height of the shaft increases sufficiently without compensation, a situation ~:will arise where the friction of the hoist ropes on the }5 hoisting machinery is insufficient. Thus, high-rise elevators employ compensating ropes, which are typically tightened by 'means of a compensation tension weight.
~;In high-rise buildings, the elevators travel at a high velocity and in malfunction situations (such as gripping, .~20 hitting the buffers) both the car and the counterweight may ~- ~bounce through relatively long distances before their kinetic energy is exhausted. The result of such bouncing is a strong 'impact on the ropes, which may damage the elevator structures or injure people. For this reason, the compensation tension ,25 equipment in fast elevators in provided with a bounce ''eliminator. This bounce eliminator also reduces the space needed at the top of the shaft because less bouncing headroom ~-is required.
In high-rise buildings where the suspension ratio of the suspension ropes for the car and counterweight is 2:1, it is often necessary to use many compensating or balancing ~-ropes and a very heavy tension weight. Sometimes this need for compensation is so great that the moment caused by the ~'suspension ropes cannot be fully compensated, with the ;35 consequence that the motor size must be increased.
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For example, German patent publication 1251926 presents an elevator system in which the path of the ~ counterweight is halved (i.e. the suspension ratio of the - ropes associated with the counterweight is 2:1) and the counterweight is placed in the lower part of the shaft. In Finnish patent ~2823, the path of the counterweight is similarly halved and placed in the upper part of the shaft.
Unfortunately, there is currently no adequate compensation system for these systems, which is why it has been necessary to use large motors in them and also the height has been limited because of the friction.
Another problem in high-rise elevators is the ; elongation of the hoisting and compensating ropes. Usually the car and counterweight are suspended to a ratio of l:1 or 2:1. In both cases, buffers are placed below the car and '" counterweight. Buffers are used at the extreme ends of travel of the elevator car and/or counterweight for when, in cases of malfunction, the car travels beyond the topmost or v~ bottommost floor. When the car is at the bottommost floor, some distance usually remains between the car and the buffer, called car overtravel distance. Similarly, when the car is at the topmost floor, a counterweight overtravel distance r ~in~ between the counterweight and its buffer. Wh~n the ropes are elongated (which typically occurs during use of the '; 25 elevator) and the car still stops accurately at the extreme floors, the counterweight overtravel distance becomes reduced.
In the prior art, this counterweight overtravel distance has been corrected by removing extra pieces attached to the bottom ;~ of the counterweight. A disadvantage with such extra pieces - 30 is that they occupy a space and therefore increase the ;~' required safety distance at the upper and lower ends of the shaft.
- In high-rise elevators, there is also in the lower : part of the shaft a compensating device which tightens the compensating ropes between the car and the counterweight. As , the hoisting rope and the compensating rope are elongated, the .
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tension device moves gradually downwards. To prevent the compensating ropes from becoming loose, enough space has to be provided below the tension device to allow it to go as far down as required to accommodate elongation of the ropes. This necessitates rather deep pits in the shaft in cases of a large hoisting height. Even so, the ropes generally have to be shortened a few times during the early part of the service life of the elevator.
' An object of the present invention is to provide an elevator system in which the required number of compensating ' ropes is always used so that the moment needed by the motor ;' is in; ized.
According to an aspect of the present invention, ~' there is provided an elevator system comprising: an elevator ;,r' 15 car; a counterweight; at least one elevator suspension rope for operatively supporting said elevator car and said counterweight within an elevator shaft; and a compensation system comprising at least one compensating rope operatively disposed in relation to said elevator car and said - 20 counterweight, a suspension ratio of said at least one compensating rope being an integer multiple (i.e. 1, 2, 3 etc.) of a suspension ratio of saidat least one suspension rope.
According to another aspect of the present invention, there is provided a compensation rope arrangement ~- in an elevator comprising an elevator car, a counterweight and ~' a set of elevator suspension ropes on which the elevator car and the counterweight are suspended, and a traction sheave ~' whose motion is transmitted via the suspension ropes to the ; 30 elevator car and counterweight, as well as a set of - compensating ropes and at least one diverting pulley belonging : to the set of suspension ropes and at least one buffer ' arrangement for the counterweight, wherein the suspension ratio of the compensating ropes is the same or multiplied by a constant as the suspension ratio of the suspension ropes, and the suspension ratio of the suspension ropes is the same . .
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According totheinvention, inadequatecompensation, i.e. a situation where the moment of the motor increases when the number of compensating ropes used is insufficient, is no longer unavoidable in high-rise buildings where the suspension ratio o~ the car and counterweight is 2:1. This is achieved by using, among other things, a 2:1 suspension for compensation on the side of the car and counterweight instead of the 1:1 compensation ratio used at present. As a result of this, the num~er of compensating ropes required is halved and also the weight of the compensation tension device is reduced. This suspension ratio can be further increased, in which case the number of compensating ropes and the weight of the compensation tension device are reduced.
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~'The present invention provides a compensation ~'solution for elevators in which the path of the counterweight has been halved. This is achieved by using a suspension ratio of 1:1 for the suspension and compensating ropes at the car-~side end and a corresponding ratio of 2:1 for both ropes at ;jthe counterweight-side end. The number of compensating ropes ,t'.'~'can be reduced so that the compensation suspension ratios on -~the car side and on the counterweight side are integer ~-25 multiples (i.e. 1, 2, 3, etc) of the respective ratios of the elevator suspension ropes. For example, if the suspension ~'~ratio of the suspension ropes on the car side is l:l, and 2:1 ~'on the counterweight side, then the corresponding suspension ~'ratio of the compensating ropes can be 2:1 on the car side and 4:1 on the counterweight side; or 3:1 on the car side and 6:1 on the counterweight side, and so on.
In all the cases mentioned above, the mutual suspension ratio of the suspension ropes and compensating ropes is the same or multiplied by an integer constant in relation to each other, so that the suspension ratio for the car may be different from that for the counterweight. As an :.:
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example, consider a case where the suspension ratio of the suspension ropes of the car is l:1 and the suspension ratio ~ of the suspension ropes of the counterweight is 2:1. The compensation can now be such that the compensation suspension ratio on the car side and on the counterweight side is obtained by multiplying the rope suspension ratios of the car and counterweight by an integer coefficient n. For example, if n=3, the compensation suspension ratio on the car side in the above-mentioned cases will be 3:1 and the compensation suspension ratio for the counterweight wi:Ll be 6:1.
Previously known cases are situations where the ratio of the suspension ropes of both the car and counterweight is l:l and the suspension ratio of the compensating ropes l:l. Another known case is one where the suspension ratio of both the car and counterweight is 2~1 and the suspension ratio of the compensating ropes 1:1. The present invention does not apply to these previously known cases.
The invention provides considerable advantages:
20 - In conventional high-rise freight elevators suspended to 2:1, a large number of compensating ropes and a heavy tension weight are needed. By using a double compensation suspension ratio (i.e.
n=2) according to the invention, the number of ropes can be halved and the size of the tension ~'' weight reduced.
- In very tall buildings, the invention allows the application of elevator designs according to Finnish patent 82823 and DE publication 1251926 . .
~ 30 ~which allow considerable savings in the guide rail - length and the number of attachments as the '~, counterweight only travels through half the travel ' of the car), while at the same time permitting full :,, -:, :' 2120~5 .
compensation for the weight of the suspension ropes.
- An existing design for a locking device preventing counterweight bounce can be utilised in a system according to the present invention.
- Rope elongation can be easily compensated for by using an adjustable buffer in accordance with the present invention.
~; - The adjustable buffer system is inexpensive and ; 10 easy to manufacture.
;~ - The buffer has a simple construction, for its ~: height can be reduced and increased by suitably ~; rotating the screw, and the adjustment can made to take place automatically.
The invention will be more readily understood from ~ the following description of a preferred embodiment thereof - given, by way of example, with reference to the accompanying ~;' drawings, in which:
20Figure 1 is a schematic illustration of a ~; compensating system according to a first embodiment of the ' invention;
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Figure 2 is a schematic illustration of a compensating system according to a second embodiment of the invention;
~'~ Figure 3 is a schematic illustration of a -~ compensating system according to a third embodiment of the invention; and Figure 4 shows a more detailed view of a buffer used in the various embodiments of the invention.
~:' '-~ Figure 1 schematically illustrates an elevator 1 comprising an elevator car 2, a counterweight 3 and elevator i~ suspension ropes 11 on which the elevator car 2 and the ~' 35 counterweight 3 are suspended, and a traction sheave 5 and a diverting pulley 15, whose motion is transmitted via the ;
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;~ suspension ropes 11 to the elevator car 2 and counterweight- 3. The elevator car 2 is suspended with a suspension ratio of 1:1 and the counterweight 3 with a suspension ratio of 2:1.
In this design, the compensating ropes 4 run from the car 2 to lower diverting pulleys 6 mounted on the floor of the shaft (for example) and further via an upper diverting pulley 7 ; mounted on the counterweight 3 to a tension device (for example a weight) 8 attached to the end of the rope. The ' tension device can move vertically as the ropes 4 and 11 are -~j 10 elongated. In this embodiment, the suspension ratio of the compensating ropes is the same as that of the suspension ropes, i.e. 1:1 on the car side and 2:1 on the counterweight side, so in this case their mutual coefficient is 1. In addition, a buffer structure 9 belonging to the buffer arrangement is provided below the counterweight.
Figure 2 presents a second embodiment, in which the suspension ratios of suspension ropes associated with the elevator car 2 and counterweight 3 are 1:1 and 2:1 respectively. The compensating rope 4 is attached to the bottom of the elevator car 2 and runs from there via the lower diverting pulleys 6, which in this case are mounted in the ' tension device 12 and over an upper diverting pulley 7 mounted below the counterweight 3 to a rope anchorage placed on the bottom 13 or wall of the elevator shaft. The tension device 12 can move in the vertical direction as the ropes 4 and 11 stretch. In this embodiment, the suspension ratio of the compensating ropes is the same as the suspension ratio of the suspension ropes, so the mutual coefficient of the suspension ratios is also 1. In this embodiment, too, a buffer structure 9 belonging to the buffer arrangement is placed below the counterweight 3.
In the embodiment illustrated in Figure 3, the car 2 and the counterweight 3 are suspended by means of suspension ropes 11, both with a suspension ratio of 1:1. Both ends of the compensating rope 4 are attached to the bottom 13 of the shaft. The compensating rope 4 is tightened over upper ''~
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diverting pulleys 7 and 14 by means of a tension device 12 suspended on the compensation rope 4, and which is provided with lower diverting pulleys 6. Thus the tension device 12 can move in the vertical direction. It is also possible to -~ 5 add to the design shown in Figure 3 a rope tensioning arrangement similar to that shown in Figure 1, by using a tension weight at one end of the compensation rope 4, as well as fixed lower diverting pulleys 6. In addition, there is a buffer structure 9b belonging to the buffer arrangement below ~'10 the counterweight 3 and a buffer structure 9a below the car 2. In this case, the suspension ratio of the suspension ropes is 1:1 for both suspension ropes associated the elevator car -~and the counterweight, while the corresponding suspension ratios of the compensating ropes is 2:1, so tbat the mutual coefficient of the suspension ratios is 2.
Figure 4 shows a schematic view of the counterweight 3 and buffer arrangement 9 located in the lower portion of the elevator shaft. The counterweight 3 is shown with a section 'removed. Above the counterweight 3 is a diverting pulley 10 for the suspension rope 11 and below it another diverting pulley 7 for the compensation rope 4. The compensating rope 4 comes up from a lower diverting pulley 18 to the diverting pulley 7 below the counterweight 3, passes around the diverting pulley 7 and is attached to a tension weight 8. The counterweight 3 moves vertically in the elevator shaft along guide rails 19. Similarly, the tension weight 8 moves along guide rails 20 and 19 in the bottom part of the elevator shaft. Due to rope elongation, the tension weight 8 moves gradually downwards, and the lower extent of travel of the counterweight 3 will also move gradually downwards. The rope elongation is the reason why the buffer structure 9 at the bottom of the elevator shaft should preferably be adjustable.
;The illustrated buffer structure 9 has a construction comprising a base part 24 with a screw 21 for height adjustment, mounted on the bottom of the elevator shaft below the counterweight 3. Mounted on the upper end of the screw ~ .
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: g 21 is a buffer part 23, whose top end receives a stop block 22 in the lower part of the counterweight 3 when the latter comes so far down that it is pressed against the buffer part 23. One 20 of the guide rails of the tension weight 8 is "~ 5 short as compared to the counterweight guide rail 19, and the - upper end of rail 20 remains below the upper surface of the buffer part 23 even when the latter is compressed and adjusted ' to its lowest position. When a new elevator is being installed, the height of the buffer part 23 is so adjusted that, when the counterweight 3 is in its low position, a suitable overtravel distance is left between the stop block 22 and the buffer part 23. In the course of time, the ; elongation of the tension ropes ll will reach a stage where the counterweight 3 goes down beyond its allowed low position.
To avoid this, the. base 24 of the buffer part 23 has been made adjustable so that by turning the screw 21 or lowering a hydraulic cylinder, the buffer part 23 is also lowered. In this way, the clearance between the buffer part 23 and the stop block 22 of the counterweight 3 can be adjusted to a suitable value whenever necessary. This adjustment can also be automated by adding limit switches 16 to the buffer base ....
and attaching a track 17 to the counterweight 3. These '~ determine a certain overtravel zone between the buffer part 23 and the stop block 22. The adjustment can be performed electrically by means of a motor at given intervals when the :' car is at the top floor and the counterweight in the low position. The motor transmits a vertical motion to the screw or opens a path for oil flow to a hydraulic cylinder through ' a valve system.
Such a buffer arrangement is also applicable to the embodiments of Figure 2 and 3, but a deep pit in the shaft is ; needed and possibly also the compensating ropes will have to be shortened, in which case some of the advantages of the ~" invention are ~; in;shed. The embodiments of Figure 2 and 3 '~ 35 can be more successfully used by employing a drum to the fixed r'~ end of one of the ropes and winding a portion of the :. ~ . , . : : ~. ' : . . .
,., ':, 10 '" compensating rope corresponding to the elongation onto the !'"'', drum.
' It is obvious to a person skilled in the art that different embodiments of the invention are not restricted to the examples described above, but that they may instead be varied within the scope of the following claims. In place of compensating ropes, it is possible to use belts, chains, etc.
' The tension weight in Figure 1 can be suspended via an - additional diverting pulley on the wall or bottom of the shaft. There may be one or more diverting pulleys in conjunction with the compensating rope or the suspension rope, and similarly there may be more than one diverting pulley in conjunction with the car. The places of the traction sheave and of the diverting pulley in conjunction with it can be interchanged. It is also obvious to the skilled person that ~; instead of the word "car" it is possible to use "car frame"
and instead of "counterweight", "counterweight frame" or "counterweight tank". In the buffer structure, the screw can be replaced by a hydraulic cylinder or other solutions ~ 20 permitting vertical adjustment, e.g. a telescopic structure !~i'' or a toothed rack or the like, by means of which the buffer -~ structure can be locked at a selected height. Instead of limit switches and a track, any other distance measuring , ' devices and structures can be used.
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Claims (16)
1. An elevator system comprising:
an elevator car;
a counterweight;
at least one elevator suspension rope for operatively supporting said elevator car and said counterweight within an elevator shaft; and a compensation system comprising at least one compensating rope operatively disposed in relation to said elevator car and said counterweight, a suspension ratio of said at least one compensating rope being an integer multiple of a suspension ratio of said at least one suspension rope.
an elevator car;
a counterweight;
at least one elevator suspension rope for operatively supporting said elevator car and said counterweight within an elevator shaft; and a compensation system comprising at least one compensating rope operatively disposed in relation to said elevator car and said counterweight, a suspension ratio of said at least one compensating rope being an integer multiple of a suspension ratio of said at least one suspension rope.
2. An elevator system as claimed in claim 1, wherein the suspension ratio of that portion of said at least one suspension rope supporting the elevator car is an integer multiple of the suspension ratio of that portion of said at least one suspension rope supporting the counterweight.
3. An elevator system as claimed in claim 1, wherein the suspension ratio of that portion of said at least one suspension rope supporting the counterweight is an integer multiple of the suspension ratio of that portion of said at least one suspension rope supporting the elevator car.
4. An elevator system as claimed in claim 1, 2 or 3, wherein one end of said at least one compensation rope is fixedly attached to the elevator car, and the other end of said at least one compensation rope is fixedly attached to a tension device, said at least one compensation rope extending from said elevator car to said tension device via at least one lower diverting pulley fixedly mounted near a base portion of the elevator shaft, and an upper diverting pulley mounted on said counterweight, whereby a suspension ratio of that portion of said at least one compensation rope associated with said elevator car is 1:1, and a suspension ratio of that portion of said at least one compensation rope associated with said counterweight is 2:1.
5. An elevator system as claimed in claim 1, 2 or 3, wherein one end of said at least one compensation rope is fixedly attached to the elevator car, and the other end of said at least one compensation rope is substantially fixedly attached to a portion of the elevator shaft, said at least one compensation rope extending from said elevator car to the fixed end via a tension device supported on said at least one compensation rope near a base portion of the elevator shaft by means of at least one lower diverting pulley mounted on said tension device, and an upper diverting pulley mounted on said counterweight, whereby a suspension ratio of that portion of said at least one compensation rope associated with said elevator car is 1:1, and a suspension ratio of that portion of said at least one compensation rope associated with said counterweight is 2:1.
6. An elevator system as claimed in claim 1, 2 or 3, wherein both ends of said at least one compensation rope are substantially fixedly attached to respective portions of the elevator shaft, said at least one compensation rope extending from one substantially fixed end to the other substantially fixed end via an upper diverting pulley mounted on said counterweight, a tension device supported on said at least one compensation rope near a base portion of the elevator shaft by means of at least one lower diverting pulley mounted on said tension device, and another upper diverting pulley mounted on said counterweight, whereby a suspension ratio of that portion of said at least one compensation rope associated with said elevator car is 2:1, and a suspension ratio of that portion of said at least one compensation rope associated with said counterweight is also 2:1.
7. An elevator system as claimed in claim 1, 2 or 3, further comprising buffer means operatively disposed at a lower extent of travel of said counterweight, said buffer means including vertically adjustment means for compensating for changes in the extent of travel of said counterweight as a result of changes in the length of said suspension and/or said compensation ropes.
8. An elevator system as claimed in claim 7, wherein said vertical adjustment means includes a screw operatively mounted in a base portion of said buffer means, said buffer means being vertically adjustable by rotation of said screw.
9. An elevator system as claimed in claim 7, further comprising detector means for detecting a lower extent of travel of said counterweight, and control means for automatically adjusting said buffer means in response to said detected lower extent.
10. A compensation rope arrangement in an elevator comprising an elevator car, a counterweight and a set of elevator suspension ropes on which the elevator car and the counterweight are suspended, and a traction sheave whose motion is transmitted via the suspension ropes to the elevator car and counterweight, as well as a set of compensating ropes and at least one diverting pulley belonging to the set of suspension ropes and at least one buffer arrangement for the counterweight, wherein the suspension ratio of the compensating ropes is the same or multiplied by a constant as the suspension ratio of the suspension ropes, and the suspension ratio of the suspension ropes is the same or different on the side of the car and on the side of the counterweight.
11. A compensation arrangement in an elevator according to claim 10, wherein the suspension rope and compensation suspension ratio on the side of the elevator car is 1:1 and the corresponding ratio on the side of the counterweight is 2:1.
12. A compensation arrangement in an elevator according to claim 11, wherein the lowest compensation diverting pulleys are fixedly mounted in place so that they cannot move in the vertical direction, and the compensating ropes are tensioned by means of a separate tension weight which is placed at one end of the compensating rope and is able to move in the vertical direction as the ropes are elongated.
13. A compensation arrangement in an elevator according to claim 12, wherein the compensating rope passing via a diverting pulley attached to the counterweight is attached to the bottom or wall of the elevator shaft and the compensation diverting pulleys are mounted on a tension device which is able to move in the vertical direction.
14. An arrangement for compensating the elongation of the suspension and compensation ropes of an elevator, wherein a buffer structure placed below the counterweight is provided with means for adjustment in the vertical direction.
15. An arrangement according to claim 14, wherein the buffer structure comprises a buffer part whose vertical adjustment is implemented by using a base in which the adjusting element is a screw.
16. An arrangement according to claim 14 or 15 characterized in that the screw is adjusted automatically in the vertical direction.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI931523A FI94854C (en) | 1993-04-05 | 1993-04-05 | Kompensationslinarrangemang |
| FIFI931523 | 1993-04-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2120545A1 CA2120545A1 (en) | 1994-10-06 |
| CA2120545C true CA2120545C (en) | 1997-12-02 |
Family
ID=8537682
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2120545 Expired - Lifetime CA2120545C (en) | 1993-04-05 | 1994-04-05 | Compensation and rope elongation arrangement |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2120545C (en) |
| FI (1) | FI94854C (en) |
-
1993
- 1993-04-05 FI FI931523A patent/FI94854C/en active
-
1994
- 1994-04-05 CA CA 2120545 patent/CA2120545C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2120545A1 (en) | 1994-10-06 |
| FI94854C (en) | 1995-11-10 |
| FI931523A (en) | 1994-10-06 |
| FI94854B (en) | 1995-07-31 |
| FI931523A0 (en) | 1993-04-05 |
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| EEER | Examination request | ||
| MKEX | Expiry |
Effective date: 20140407 |