FI84803B - Device for equalizing the forces in adjoining lift cables - Google Patents

Abstract

The invention relates to a device for equalizing forces in lift ropes 1 by which the lift cage and the counterweight 3 have been induced to move with respect to each other. The invention has been realized such that the rope equalization is created by medium-acting equalizing members 5a, to which lift ropes 1 are fastened. In the equalizing members, in respect of each rope, there is a cylindrical chamber 6 present, within which there moves a piston 7. Each chamber has been connected by an equalization duct 8 to a corresponding space of the other rope and has been filled with a medium. <IMAGE>

Description

84803 5

EQUIPMENT FOR EQUALIZING THE FORCES OF PARALLEL ELEVATOR ROPES -ANORDNING FOR THE PURPOSE OF A BRACKET IN BREDVID VARANDRA LÖ-PANDE HISSLINOR

The present invention relates to a device for equalizing the forces of parallel elevator ropes, by means of which the elevator car and the counterweight are moved relative to each other, in which an elevator is arranged , and that the chamber spaces are connected to each other by equalization channels and filled with medium.

15 During the installation phase of an elevator, the load acting on the elevator ropes is equalized so that the stress acting on the different elevator ropes is the same. When an elevator is used, the ropes are stretched, which results in a higher load on some elevator ropes. These ropes, which are more heavily loaded than other elevator ropes, wear out more quickly. As a result of one rope becoming unusable, all elevator ropes must be replaced. Traction sheave elevators can have up to ten parallel ropes, which means that changing the ropes due to premature wear causes considerable costs.

In addition, the disadvantage is often that in normal use the diameters of the ropes differ slightly from each other and the rope grooves are slightly different in diameter. As a result of these differences, there is a creep in the elevator ropes, which consumes both the ropes and the traction sheaves.

Premature wear of elevator ropes can be prevented by an arrangement in which the loads of parallel ropes are equalized to a total of 35. In traction sheave elevators, leveling levers or leveling scales have been used to balance the rope forces with small amounts of rope. Attempts have been made to equalize the rope forces with large numbers of ropes 2 84803 by placing the springs at the end of the ropes and adjusting the compression of the springs to the same.

The publications SU-125 3929 A1, SU-125 7048 A1, DE-354 0266 C1 and 5 DE 372 0488 A1 disclose passive equalization of rope forces in which elevator ropes are attached to the piston rods of hydraulic cylinders and whose cylinder spaces are connected to each other.

These already known methods of compensating rope forces have been very limited in their 10 operating ranges. Their rope forces do not have sufficient compensating capacity or their adjustment range is not wide enough, which has led to premature wear of the ropes. In addition to this, they require manual adjustment, in which case the equalization of the rope forces has taken place in practice by 15 installers.

The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a reliable and automatic device for actively equalizing the elevator rope forces. The device according to the invention is characterized in that the compensating member has a sensing member moving with the rope and one or more switches monitoring the position of the rope, which are arranged to close and open by means of the sensing member, and that 25 are arranged in connection with the same compensating member; a pump, a fluid reservoir, a valve for each rope, and a fluid duct connecting the equalizer chamber chamber and the valve to each other and each valve further directly to the fluid reservoir and further to each other and through the pump of each valve to the fluid reservoir.

30;

A preferred embodiment of the device according to the invention is characterized in that the switch in the compensating member is connected to the pump so that when the elevator rope moves relative to the compensating member so that the sensing member hits and closes the switch, the pump starts and pumps medium from the tank through the valve. to the chamber space of the compensating member 3 84803, whereby the sensing member again disengages from the switch, the switch opens and the pump stops.

Another preferred embodiment of the device according to the invention is characterized in that a mechanical connection is provided between the piston and the valve, which adjusts the valve so that as the amount of medium in the chamber space of the compensating member becomes too large, the valve releases excess medium into the tank.

10

A further preferred embodiment of the device according to the invention is further characterized in that the valves are connected to each other in a fluid pattern so that when the pump is at rest and the mechanical connection is disconnected from the valve, i.e. in normal mode, the fluid can move freely from one chamber to another.

A further preferred embodiment of the device according to the invention is further characterized in that the mechanical connection is a spring between the piston and the valve.

Another preferred embodiment of the device according to the invention is characterized in that the medium-operated leveling member is arranged at both ends of the elevator ropes.

The invention provides many advantages over the prior art. With the device according to the invention, the maximum rope force is only slightly above the theoretical average. Kek-3Ö: with the rope suspension according to the invention, the service life of the ropes will be many times higher than the service life of the elevator ropes suspended in the current way. Likewise, the service life of the traction sheave ropes will increase compared to the current arrangement. Active rope force equalization also has a wider adjustment range. 35: All of the latter are also economically significant benefits.

4 84803

The invention will now be described in detail by means of preferred embodiments with reference to the accompanying drawings, in which Fig. 1 shows a simplified and oblique front elevational view of a suspended elevator according to the invention, Fig. 2 .

15

Fig. 1 shows a simplified elevator rope suspension, in which the elevator ropes 1 passing through the traction sheave 2 of the elevator machine are attached to the leveling members 5a and 5 according to the invention both on the counterweight 3 side and at the 20 car end of the elevator car 4.

The leveling member 5a on the counterweight 3 side, which is according to the prior art, is fastened to the counterweight 3 in a suitable manner, for example by means of fastening screws 20. The leveling member 25a comprises a body part in which cylindrical bores are made for each elevator rope. Each cylindrical bore is open across its width toward the bottom of the leveling member 5a. Instead, on the side of the leveling member 5a from which the elevator ropes enter the leveling member, the bore narrows to a smaller diameter bore central to the aforementioned wider bore and extending from the former wider bore through the leveling member 5a as viewed in the direction of the elevator. Tightly fitted to the smaller bore is a tubular piston rod 9a which reciprocates in the direction of the elevator rope '35. A portion of the piston rod 9a is permanently within the aforementioned wider bore. The piston rod 9a is further attached to the piston 7, which moves 5 84803 in the former wider bore with the piston rod and closes the wider bore tightly in a cylindrical space, forming the bottom of the cylindrical space. The enclosed space thus created is hereinafter referred to as chamber 6.

Adjacent chambers are connected to each other by compensating channels 8 located in a compensating member mounted according to Fig. 3 at the top of the chambers 6. The chambers 6 contain a liquid medium, preferably hydraulic oil. The elevator ropes 1 are attached to the lower end of the piston rods 9a, whereby the elevator ropes 10 pass through the piston rods 9a to the other side of the pistons 7. Between the lower end of the piston rod 9a and the end of the elevator ropes there is a spring 18, within the limits of which the elevator rope can move slightly with respect to the piston rod in the longitudinal direction of the piston rod. The open end of the bore has a locking ring 15 which prevents the piston 7 from escaping from the bore.

As a result of the elongation in the rope 1, the piston 7 located in the chamber 6 moves downwards in the compensating member mounted according to Fig. 3, whereby the medium 20 moves into the chamber 6 from the adjacent chambers through the compensating channels 8. The rope 1 can then move towards the counterweight and the other ropes away from the counterweight, respectively. The transition of the ropes ends in a state of equilibrium in which the ropes act. . the forces are equal.

25;

The compensating member 5 at the elevator car side end is normally attached to the elevator car 4. Due to the suspension of the elevator car, the leveling member 5 may also be fixed to a fixed location in the elevator shaft or in the elevator machine room. The compensating member 5 comprises a body part, in which there are corresponding bores as in the compensating member 5a on the counterweight side. Correspondingly, each bore has a piston 7, which further has a piston rod 9. An elevator rope 1 and a sensing member 11 extending laterally 35, which can be, for example, a lever-like or plate-like body, are attached to the free end of the piston rod. In the vicinity of each sensing element there is a switch 10 which is mounted relative to the sensing element so that the sensing element reaches to close and open the switch. The piston 7 on one side and the piston rod 9 on the other close the bore into a chamber 6 in the same way as in the counterweight 5a on the counterweight side. Likewise, the chamber 6 contains a medium such as hydraulic oil. In addition, in connection with the compensating member 5, there is a so-called 3/2-way valve 14 for each chamber 6. From the chamber 6 a compensating channel 21 leads to the valve 14. The valves 14 are further connected to each other from the same openings in the intermediate channel 10 21a so that in the normal state all the chambers 6 are connected to each other by a chain equalizing channel 21 - valve 14 - low passage 21a - equalizing channel 21 through.

In connection with the compensating member 5 there is still a medium tank 13, a pump 12 and a pump drive motor 16. The pump is connected 15 to one tank 13 and to another intermediate duct 21a via duct 22. In addition, a drain channel 23 leads from each valve 14 to a medium tank 13. The motor 16 is controlled by switches 10 / from the control unit 17. Between the piston 7 and the valve 14 there is a spring 15 which guides the valve 14.

In the leveling member 5 attached to the elevator car 4, the position of the elevator rope 1 is monitored by a sensing member 11 which, as the rope drifts away from the elevator car 4, drifts with the rope onto the switch 25 and closes the switch. The switch, in turn, is connected to the circuit of the pump 16 so that when the switch closes, the engine 15 starts and the pump 12 starts pumping oil from the medium tank 13 through the valve 14 to the cylindrical chamber 6. The pump runs until the volume of the chamber 6 is large enough to move off switch 10, and the switch opens. Depending on the control, the pump may still run for some time after the switch has been opened, so that there is no immediate situation in which the switch closes.

If the rope 1 drifts in the other direction, i.e. towards the elevator car, so much that the spring 15 arranged between the piston 7 and the valve 14 opens the valve 14, the medium oil can pass from said chamber 6 to the medium tank 13 via the drain channel 23. At this point, the rope 1 begins to slide back to its original position. The valve 14 closes 5 back to its normal position when the rope 1 has returned to the center of its range of motion and the compressive force of the spring 15 has weakened sufficiently.

In the cases shown in the figures, all the pistons 7 and the valve 14 are within the limits of the normal range. As already mentioned, the pay gap at the rope location is due to both the elongation of the ropes and the overall displacement of the ropes. The total transition is caused by e.g. the fact that the ropes are always slightly different in thickness from each other, so that the thicker rope passes faster over the traction and folding wheels than the thinner rope. In addition, the displacement is caused by the fact that the diameters of the different grooves of the traction wheel are not exactly equal. The combined effect of the above factors causes differences in the relative displacement of the ends of the ropes, but since the movement of the elevator is reciprocating, these differences alone are not yet decisive. Instead, the decisive factor is the slip of the rope on the traction sheave. The slip due to friction differences causes the ropes to drift slowly in different directions. This drift is also affected by the permanent stretching of the rope. By now calculating the permanent rope end differences due to slips and elongations of the joint with the previously mentioned differences in diameters and thicknesses, the interaction momentarily accelerates the rope end drift to such an extent that pump 12 has to pump more oil into chamber 6 or valve 14 has to drain oil from chamber 6. .

It will be clear to a person skilled in the art that the invention is not limited exclusively to the exemplary embodiments presented above, but can be varied within the scope of the appended claims 35. Thus, for example, the position of the compensating members is not tied exclusively to the elevator car and the counterweight, but may vary depending on the suspension. In addition, the active balance member 84 843 may be a counterweight counterbalance member instead of the one now shown. Likewise, the medium can be a pressure medium other than hydraulic oil, for example brake fluid. The control of the directional valves 14 in the compensating member 5 also does not have to be mechanical, spring-operated, but can be, for example, electrical control by means of a sensing member.

Claims (7)

9 84803 An apparatus for equalizing the forces of parallel elevator ropes (1), by means of which the elevator car (4) and the counterweight (3) 5 are moved relative to each other, in which the elevator is provided with an intermediate compensating member (5, 5a) to which the parallel elevator ropes (1) are attached. and which compensating member consists at each rope of a chamber space (6) and a piston (7) moving inside the chamber space, and that the chamber-10 spaces are connected to each other by equalization channels (8, 21 and 21a) and filled with medium, characterized in that the compensating member (5) is a sensing member (11) moving with the rope and one or more switches (10) for monitoring the position of the rope, arranged to close and open by means of the sensing member 15, and a pump (12), a medium tank (13) ), a valve (14) for each rope and a medium duct (21, 23, 21a, 22) connecting the chamber space (6) of the compensating member and the valve to each other and to each vessel. the valve further directly to the 20 medium tanks and further to each other between each valve and through the pump of each valve to the medium tank. Device according to claim 1, characterized in that the switch (10) in the compensating member (5) is connected to the pump (12) such that after the elevator rope has moved so far relative to the compensating member that the sensing member (li) has hit and closed the switch, the pump starts and pumps the medium from the tank (13) through the valve (14) into the chamber space (6) of the compensating member, whereby the sensing member again disengages the switch-30; the switch opens and the pump stops. Device according to Claim 1 or 2, characterized in that a mechanical connection (15) is provided between the piston (7) and the valve (14), which adjusts the valve 35 so that the medium in the chamber space (6) of the compensating member (5) when the amount becomes too large, the valve releases excess medium into the tank (13). 10 84803 Device according to one of Claims 1 to 3, characterized in that the valves (14) are connected to one another by a fluid pattern (21, 21a) such that the pump (12) is at rest and the mechanical connection (15) is disconnected from the valve, i.e. in the normal state, the medium can move freely through the valves (14) from one chamber state to another. Device according to one of Claims 1 to 4, characterized in that the mechanical connection (15) is a spring between the piston (7) and the valve (14). Device according to one of Claims 1 to 5, characterized in that the medium-operated compensating element (5, 5a) is arranged at both ends of the elevator ropes (1). Device according to one of Claims 1 to 6, characterized in that each elevator rope (1) is fastened to the leveling element (5a) by means of a spring (18). 11 84 8 03