Elevator

Abstract

An elevator has an elevator car and a counterweight suspended by hoisting ropes, which hoisting ropes are driven by a drive machine via a traction sheave, which elevator further includes a compensation rope in the lower shaft area between the car and the counterweight, which compensation rope runs around a compensation sheave arrangement in the shaft bottom, which elevator has a compensation device for the compensation of rope elongation. The compensation device includes a diverting pulley for the compensation rope connected to the counterweight, whereby the compensation rope is arranged to run over the diverting pulley, a tension weight connected with the free end of the compensation rope, a rope clamp arranged on the compensation rope and a clamp support for connecting the rope clamp to the counterweight. A compensation device is provided for the rope elongation which necessitates less vertical space in the elevator shaft.

Claims

1. An Elevator, comprising an elevator car; a counterweight suspended by hoisting ropes, the hoisting ropes being driven by a drive machine via a traction sheave; a compensation rope in a lower shaft area between the car and the counterweight, the compensation rope running around a compensation sheave arrangement in the shaft bottom; a compensation device for the compensation of rope elongation, the compensation device comprising: a diverting pulley for the compensation rope connected to the counterweight, whereby the compensation rope is arranged to run over the diverting pulley; a tension weight connected with a free end of the compensation rope; a rope clamp arranged on the compensation rope; and a clamp support for connecting the rope clamp to the counterweight, wherein the elevator is a high rise elevator provided with at least one of a shaft height of more than 50 m and a velocity of more than 3.5 m/s.

2. The elevator according to claim 1, further comprising an operating device configured to open and close the rope clamp on the compensation rope.

3. The elevator according to claim 2, wherein the operating device is configured to be operated only at a counterweight position below the lowest landing of the elevator.

4. The elevator according to claim 3, wherein the clamp support comprises an adjustment device configured to adjust the distance of the rope clamp from the diverting pulley.

5. The elevator according to claim 3, wherein a monitoring device is provided which monitors the rope tension of the compensation rope and outputs a tension signal to a control for operating at least one of the adjustment device and the operating device.

6. The elevator according to claim 2, wherein the clamp support comprises an adjustment device configured to adjust the distance of the rope clamp from the diverting pulley.

7. The elevator according to claim 2, wherein a monitoring device is provided which monitors the rope tension of the compensation rope and outputs a tension signal to a control for operating at least one of the adjustment device and the operating device.

8. The elevator according to claim 2, wherein the compensation sheave arrangement comprises a frame with a bearing for at least one compensation sheave.

9. The elevator according to claim 1, wherein the clamp support comprises an adjustment device configured to adjust the distance of the rope clamp from the diverting pulley.

10. The elevator according to claim 9, wherein a monitoring device is provided which monitors the rope tension of the compensation rope and outputs a tension signal to a control for operating at least one of the adjustment device and the operating device.

11. The elevator according to claim 1, wherein a monitoring device is provided which monitors the rope tension of the compensation rope and outputs a tension signal to a control for operating at least one of the adjustment device and the operating device.

12. The elevator according to claim 11, wherein the monitoring device is provided in connection with the compensation sheave arrangement.

13. The elevator according to claim 11, wherein the monitoring device is provided for monitoring the vertical play of the bearing.

14. The elevator according to claim 1, wherein the compensation sheave arrangement comprises a frame with a bearing for at least one compensation sheave.

15. The elevator according to claim 14, wherein the bearing is mounted in the frame with a dampening or spring mechanism allows a small vertical play of the bearing for the compensation of tension changes in the compensation rope.

16. The elevator according to claim 1, wherein the tension weight is a rope reel.

17. A method for maintaining the rope tension in a compensation rope of the elevator according to claim 1, said method comprising the steps of: monitoring the tension of the compensation rope; and in response to the tension signal, actuating an operating device in a lower part of the elevator shaft to open and close a rope clamp, which is provided in connection with a counterweight of the elevator, so that the compensation rope is able to be tensioned by a tension weight provided in connection with the counterweight.

18. The method according to claim 17, further comprising the step of measuring the tension of the compensation rope in connection with a compensation sheave arrangement at the shaft bottom.

19. The method according to claim 17, further comprising the steps of: issuing a low tension with a monitoring device when the tension of the compensation rope falls under a set threshold value; after receiving a low tension signal, taking the elevator out of operation with a control of the elevator and driving the counterweight to an operating position below the lowest landing, landing; activating the operating device to open the rope clamp; tightening the compensation rope with the tension weight; activating the operating device to close the rope clamp; and taking the elevator back into operation.

Description

(1) Hereinafter the invention is described schematically with the aid of the enclosed drawings.

(2) FIG. 1 is a traction sheave elevator with a compensation rope according to the background art,

(3) FIG. 2 shows a schematic drawing of a first embodiment of the invention with compensation device mounted to a counterweight,

(4) FIG. 3 an embodiment according to FIG. 2 where the tension weight of the compensation device is replaced by a rope reel,

(5) FIG. 4 an embodiment according to FIG. 2 where a compensation device with two diverting pulleys and two tension weights is used in connection with thin compensation ropes,

(6) FIG. 5 shows an embodiment with a counterweight having a compensation device with a diverting pulley, a tension weight, a rope clamp and an adjustment means for adjusting the distance between the rope clamp and the counterweight,

(7) FIG. 6 shows a second embodiment of a compensation sheave arrangement in the shaft bottom,

(8) FIG. 7 shows a schematic drawing of an elevator with a compensation device having an operating means for opening and tightening the rope clamp on the compensation rope, and

(9) FIG. 8 the arrangement of FIG. 7 with the during a tensioning step where the operating means opens and closes the rope clamp during the tensioning of the compensation rope.

(10) Identical or functional similar parts in the prior art drawing of FIG. 1 and the other figures are designated with the same reference numbers.

(11) FIG. 2 shows the inventive compensation device 30 having a diverting pulley 32 mounted at the bottom of the counterweight with a (not shown) support as well as with a rope clamp support 34 mounted also on the bottom of the counterweight 14. To the lower end of the rope clamp support 34 a rope clamp 36 is which is clamped on the compensation rope 22. The end of the compensation rope 22 exceeding the rope clamp 36 runs over the diverting pulley 32 and is connected to a tension weight 38.

(12) In the shaft bottom 40 the compensation sheave arrangement 20 is provided comprising a frame 44 on which two compensation sheaves 44, 46 are rotatable pivoted on bearings 48, 50. These bearings 48, 50 are mounted in horizontally fixed positions. Anyway they are movable with a play in direction to the shaft top via a dampening layer 52. This layer is made of an elastic material allowing a certain vertical play of the bearing 48, 50 in the upper direction dependent on the rope tension acting on the compensation sheaves. On the upper part of the frame a monitoring device 54 is provided in the form of a distance sensor which measures the distance of the bearing 50 to the monitoring device. Via this measurement the rope tension can be determined.

(13) FIG. 3 shows nearly the same arrangement of the compensation device as in FIG. 2 but in FIG. 3 instead of a tensioning weight a rope reel 39 is used. This has the effect that the compensation rope 22 which is set free in course of a tightening step because of the rearrangement of the rope clamp does not lead to a larger distance of the tension weight 38 to the counterweight 14 but is wound on the rope reel 39. Accordingly, this arrangement has a very low vertical space requirement.

(14) The same holds true for the embodiment of FIG. 4 where instead of one diverting pulley two diverting pulleys 32 a, 32 b are used as well as two tension weights 38 a, 38 b. The special advantage of this embodiment is the use of a compensation rope 40 with a very small diameter of less than 8 mm or even less than 6 mm. This allows the use of correspondingly small diverting pulleys 32 a, 32 b thus reducing the vertical dimension of the compensation device below the counterweight 14. In this embodiment also a rope termination 42 is used to limit the stroke along which the rope elongation can be compensated.

(15) FIG. 5 shows an embodiment which is nearly identical to FIG. 2 with the difference that in this embodiment an adjustment means 64 is used for supporting the rope clamp 36 with a variable distance on a clamp support base 56. In this embodiment a rotatable nut 58 holds a spindle 60 having on its lower free end 62 a support for the rope clamp 36. Via operation of the nut 58 the distance of the lower supporting end 62 of the spindle 60 from the rope clamp support base 56 can be adjusted. Via that adjustment means 64 a certain rope elongation can be compensated.

(16) The operation of the adjustment means 64 can be provided e.g. controlled by the signals of the monitoring device 54 in FIG. 2. The rotatable nut 58 can be provided with a rotation drive which allows automatic compensation of the rope tension. The drive may be provided with the counterweight or in the shaft bottom. In the latter case the operation of the adjustment means is only possible in an adjustment position of the counterweight at or near the shaft bottom

(17) FIG. 6 shows another embodiment of a compensation sheave arrangement 20. In contrast to the compensation sheave arrangement 20 of FIG. 2 this embodiment has also a second dampening layer 53 below the bearings 48, 50 of the compensation sheaves 44, 46. Accordingly, this arrangement allows a certain play of the bearings 52, 50 in both vertical directions up and down according to the current tension of the compensation rope 22.

(18) FIGS. 7 and 8 show the operation of the compensation device in an automated embodiment of the invention.

(19) In FIG. 7 the elevator is shown during operation. When the elevator control determinesbased on the signals of a monitoring device, e.g. the monitoring device 54 from FIG. 2that a lower threshold value for the compensation rope tension is exceeded the elevator is taken out of operation and the elevator control drives the counterweight 14 to an adjustment position in a lower part of the elevator shaft near the shaft bottom. In this position an operating means 70 is activated by the control to open the rope clamp 36. After the rope clamp 36 has been opened the tension weight 38 pulls the slackened compensation rope 22 over the diverting pulley so that the compensation rope is tightened again. Then the operating means 70 locks the rope clamp 36 on the compensation rope and the elevator is taken back into operation.

(20) As it may be seen particularly in FIGS. 2, 6, 7 and 8 the compensation sheave arrangement can be provided such that there is only a minor gap between the compensation sheaves 44 and 46 and the shaft bottom 40. This reduces the vertical height with respect to prior art solutions where the compensation device was provided in the compensation sheave arrangement and thus the complete play of the rope elongation had to be provided additionally between the compensation sheaves 44 and 46 and the shaft bottom 40.

(21) The different embodiments mentioned above can be combined arbitrarily as long as this is technically possible. The invention can be varied within the scope as defined by the enclosed claims.