WO2019001890A1

WO2019001890A1 - Method for uninstalling a suspension traction means, method for installing a suspension traction means and use of a driving mechanism of an elevator system

Info

Publication number: WO2019001890A1
Application number: PCT/EP2018/064398
Authority: WO
Inventors: Ahmed SATTAR
Original assignee: Inventio AG
Current assignee: Inventio AG
Priority date: 2017-06-27
Filing date: 2018-06-01
Publication date: 2019-01-03
Anticipated expiration: 2019-12-27

Abstract

A method for uninstalling a suspension traction means (60) for holding and moving an elevator car (20) from an elevator shaft (12) of an elevator system (10) is proposed, wherein the method comprises the following steps: - disposing the elevator car (20) such -- that the suspension traction means (60) hang loose for removing car-side end connections of the suspension traction means (60) and -- that the counter weight (30) rests on a surface; - blocking the elevator car (20) in the elevator shaft (12) such that no downward movement of the elevator car (20) is possible; - disconnecting the car-side end connections of the suspension traction means (60); - moving all suspension traction means (60) but a first suspension traction means (60) of the suspension traction means (60) out of a machine traction sheave (40) and/or a deflection sheave (45) of the elevator system (10); - disconnecting all suspension traction means (60) from the counter weight (30); - providing a spool (50) for winding up the first suspension traction means (60); - actuating a motor of the elevator system (10) for driving the machine traction sheave (40) in an elevator car (20) down direction for lifting up the first suspension traction means (60) from the elevator shaft (12) and winding up the first suspension traction means (60) on the spool (50).

Description

Method for uninstalling a suspension traction means, method for installing a suspension traction means and use of a driving mechanism of an elevator system

The present invention relates to a method for uninstalling a suspension traction means, a method for installing a suspension traction means and a use of a driving mechanism of an elevator system.

Suspension traction means, in particular ropes and/or belts, for holding and moving an elevator car of an elevator system have to be installed and/or uninstalled in an elevator shaft and/or have to be replaced from time to time.

One method of uninstalling the suspension traction means of an elevator system known in the start of the art is to cut the suspension traction means into pieces and to remove the suspension traction means piece by piece from the elevator shaft/ elevator system.

However, the suspension traction means cannot be reused then. Other methods known in the state of the art of uninstalling suspension traction means in an elevator system without damaging the suspension traction means and/or installing suspension traction means in an elevator system are technically laborious. This particularly applies to mid-rise and high- rise buildings due to the high weight of the suspension traction means.

There may be a need for a method for uninstalling a suspension traction means for holding and moving an elevator car from an elevator shaft of an elevator system, wherein the method is technically easy and prevents damaging the suspension traction means. Also, there may be a need for a method for installing a suspension traction means for holding and moving an elevator car in an elevator shaft of an elevator system, wherein the method is technically easy and prevents damaging the suspension traction means.

Furthermore, there may be a need for a way to install and/or uninstall suspension traction means in an elevator system wherein the way is technically simple and does not damage the suspension traction means.

Such needs may be met with the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims. According to an aspect of the present invention, a method for uninstalling a suspension traction means for holding and moving an elevator car from an elevator shaft of an elevator system is proposed, wherein the method comprises the following steps:

- disposing the elevator car such— that the suspension traction means hang loose for removing car-side end connections of the suspension traction means and

— that the counter weight rests on a surface; - blocking the elevator car in the elevator shaft such that no downward movement of the elevator car is possible; - disconnecting the car-side end connections of the suspension traction means; - moving all suspension traction means but a first suspension traction means of the suspension traction means out of a machine traction sheave and/or a deflection sheave of the elevator system; - disconnecting all suspension traction means from the counter weight; - providing a spool for winding up the first suspension traction means; - actuating a motor of the elevator system for driving the machine traction sheave in an elevator car down direction for lifting up the first suspension traction means from the elevator shaft and winding up the first suspension traction means on the spool.

One advantage hereof is that, generally, the suspension traction means is lifted technically easily out of the elevator shaft and wound on the spool, since the motor of the elevator system carries out the lifting of the suspension traction means. Hence, neither a large manual force nor many additional tools are needed for uninstalling the suspension traction means, typically. Furthermore, in general, the suspension traction means is handled with care, since the suspension traction means is guided over the machine traction sheave which is the normal way when the elevator car is moved up or down along the elevator shaft during normal operation of the elevator system. Normally, no external machine or force is necessary for lifting the suspension traction means out of the elevator shaft. Typically, this also saves costs. The spool can be turned manually. In particular, the counter weight rests on a surface also if the counter weight is blocked at its position in any way.

According to a second aspect of the present invention, a method for installing a suspension traction means for holding and moving an elevator car in an elevator shaft of an elevator system is proposed, wherein the method comprises the following steps: - providing a suspension traction means wound up on a spool; - disposing the suspension traction means onto a machine traction sheave and/or a deflection sheave of the elevator system; - actuating a motor of the elevator system for driving the machine traction sheave in an elevator car up direction for lowering the suspension traction means in the elevator shaft; and - connecting the suspension traction means to a counter weight of the elevator system.

One advantage hereof is that, generally, the suspension traction means is installed in the elevator shaft technically easily, since the motor of the elevator system carries out the lowering of the suspension traction means in the elevator shaft. Furthermore, typically, the suspension traction means is handled with care, since the suspension traction means is guided over the machine traction sheave which is the normal way when the elevator car moves up or down along the elevator shaft during normal operation of the elevator system. In general, no external machine or force is necessary for lowering the suspension traction means in the elevator shaft without damaging the suspension traction means. Normally, this also saves costs. The spool can be turned manually.

According to a third aspect of the present invention, a use of a motor driving mechanism of an elevator system is proposed , wherein the driving mechanism is adapted for moving an elevator car up and down along an elevator shaft of the elevator system, - for lowering a suspension traction means for holding and moving the elevator car in the elevator shaft from a spool in the elevator shaft, and/or - for lifting a suspension traction means for holding and moving the elevator car in the elevator shaft from the elevator shaft and winding up the suspension traction means on a spool.

One advantage hereof is that, generally, the suspension traction means can be installed and/or uninstalled in the elevator shaft technically easily. In general, no external machine or force is necessary for lifting the suspension traction means out of the elevator shaft and/or lowering the suspension traction means in the elevator shaft without damaging the suspension traction means.

Ideas underlying embodiments of the present invention may be interpreted as being based, inter alia, on the following observations and recognitions.

According to an embodiment of the method for uninstalling a suspension traction means, the suspension traction means are disconnected from the counter weight by removing all loops of the suspension traction means from a counter weight pulley, and wherein the method further comprises the following step: disconnecting the counter weight-side end connections of the first suspension traction means. One advantage hereof is that the method can also be used for an elevator system with a 2: 1 transmission, in general. Furthermore, typically, the suspension traction means are detached from the counter weight technically easily.

According to an embodiment of the method for uninstalling a suspension traction means, a rotational speed of the spool is adapted to a rotational speed of the machine traction sheave. By this, typically, the suspension traction means can be wound up on the spool technically easily. Furthermore, damage of the suspension traction means is prevented, typically. In particular, the two rotational speeds can be such that the same length of suspension traction means which is moved by the machine traction sheave or over the machine traction sheave in an amount of time is wound up on the spool in the same amount of time. Thus, typically, the creation of waves or bulges in the suspension traction means on the spool while winding up the suspension traction means is prevented.

According to an embodiment of the method for uninstalling a suspension traction means, the method further comprises the following step: guiding the car-side end connections of the suspension traction means through an elevator car pulley. One advantage hereof is that, normally, the method can also be used for an elevator system with a 2: 1 transmission.

According to an embodiment of the method for uninstalling a suspension traction means, the spool is driven by a spool motor and/or by the motor of the elevator system, in particular via a gearing mechanism. By this, normally, the spool does not have to be turned manually. Thus, typically, the winding up of the suspension traction means can be accelerated. Furthermore, in general, the safety of the method is increased since no manual interaction is necessary.

According to an embodiment of the method for uninstalling a suspension traction means, the motor of the elevator system is actuated for a set elevator car movement distance. Generally, this further simplifies the method, since the lifting of the suspension traction means does not have to be monitored and/or stopped manually. Furthermore, typically, the winding up of the suspension traction means can be accelerated.

According to an embodiment of the method for installing a suspension traction means, the method further comprises the following step: connecting a first end of the suspension traction means with a counter weight side fix point of the elevator system. One advantage hereof is that, normally, the method is technically easy and can also be used for an elevator system with a 2:1 transmission.

According to an embodiment of the method for installing a suspension traction means, the spool is driven by a spool motor and/or by the motor of the elevator system, in particular via a gearing mechanism. By this, normally, the spool does not have to be turned manually. Thus, typically, unwinding of the suspension traction means from the spool can be accelerated. Furthermore, in general, the safety of the method is increased since no manual interaction is necessary. Also, typically, damage of the suspension traction means and/or of the spool is prevented.

According to an embodiment of the method for installing a suspension traction means, the suspension traction means are connected to the counter weight of the elevator system by guiding the suspension traction means through a counter weight pulley. One advantage hereof is that, typically, the method can also be used for an elevator system with a 2: 1 transmission. Furthermore, in general, the suspension traction means can be installed in a short amount of time.

According to an embodiment of the method for installing a suspension traction means, a rotational speed of the spool is adapted to a rotational speed of the machine traction sheave. By this, typically, the suspension traction means can be unwound off the spool technically easily. Furthermore, damage of the suspension traction means is prevented, typically. In particular, the two rotational speeds can be such that the same length of suspension traction means which is moved by the machine traction sheave or over the machine traction sheave in an amount of time is wound up on the spool in the same amount of time. Thus, typically, the creation of waves or bulges in the suspension traction means while unwinding the suspension traction means is prevented. According to an embodiment of the method for installing a suspension traction means, the method further comprises the following step: guiding the suspension traction means through an elevator car pulley. One advantage hereof is that, in general, the method can also be used for an elevator system with a 2:1 transmission. Also, typically, the suspension traction means can be installed technically easy within a short amount of time.

It shall be noted that possible features and advantages of embodiments of the invention are described herein partly with respect to a method for installing a suspension traction means, partly with respect to a method for installing a suspension traction means and partly with respect to a use of a driving mechanism of an elevator system. One skilled in the art will recognize that the features may be suitably transferred from one embodiment to another and features may be modified, adapted, combined and/or replaced, etc. in order to come to further embodiments of the invention.

In the following, advantageous embodiments of the invention will be described with reference to the enclosed drawings. However, neither the drawings nor the description shall be construed as limiting the invention.

Fig. 1 shows a schematic side view of an elevator system with a 2: 1 ratio; Fig. 2 shows a schematic side view of the elevator system of Fig. 1 after

disconnecting the elevator car side end connection of the first suspension traction means;

Fig. 3 shows a schematic side view of the elevator system of Fig. 2 after

guiding the car-side end connections of the suspension traction means through an elevator car pulley;

Fig. 4 shows a schematic side view of the elevator system of Fig. 3 after

moving all suspension traction means but the first suspension traction means of the suspension traction means out of a machine traction sheave and a deflection sheave of the elevator system; Fig. 5 shows a schematic side view of the elevator system of Fig. 4 after removing all loops of the suspension traction means from a counter weight pulley,

Fig. 6 shows a schematic side view of the elevator system of Fig. 5 after winding up a part of the first suspension traction means on the spool;

Fig. 7 shows a schematic side view of the elevator system of Fig. 6 after further winding up the first suspension traction means on the spool and disconnecting the counter weight-side end connection of the first suspension traction means;

Fig. 8 shows a schematic side view of an elevator system with a 1 : 1 ratio; and

Fig. 9 shows a step of the installation method of a suspension traction means according to the present invention in an elevator system with a

2:1 ratio.

The figures are only schematic and not to scale. Same reference signs refer to same or similar features.

Fig. 1 shows a schematic side view of an elevator system 10 with a 2:1 ratio. The elevator system 10 is installed in an elevator shaft 12. The elevator system 10 comprises an elevator car 20 for moving people and/or goods. The elevator car 20 is connected to a suspension traction means 60 for holding and/or moving the elevator car 20. The suspension traction means 60 can comprise a rope and/or a belt. The suspension traction means 60 can also comprise several ropes and/or belts. The ropes and/or belts typically run parallel to each other.

The suspension traction means 60 is also connected to a counter weight 30. A first end of the suspension traction means 60 is or are fixed at an elevator car side fix point 27. From here the suspension traction means 60 runs or run through a car side pulley which is fixed at the top of the elevator car 20. Then the suspension traction means 60 is guided over a machine traction sheave 40. The machine traction sheave 40 is driven by a motor of the elevator system 10. By driving the machine traction sheave 40 the suspension traction means 60 is moved and, thus, the elevator car 20 is moved up and down in the elevator shaft 12.

The driving mechanism can comprise the motor, the machine traction sheave 40 and/or the deflection sheave 45.

From the machine traction sheave 40 the suspension traction means 60 runs over a deflection sheave 45. Normally, the deflection sheave 45 is a passive sheave, i.e., not actively driven. From here the suspension traction means 60 runs downward into the direction of the bottom 15 of the elevator shaft 12. Then, the suspension traction means 60 is guided through a counter weight pulley 35 which is fixed at the counter weight 30. Finally, from here, the suspension traction means 60 runs through a counter weight side fix point 37, where a second end of the suspension traction means 60 which is opposite to the first end of the suspension traction means 60 is fixed.

In the following the steps of a method for uninstalling a suspension traction means 60 according to the present invention is described in connection with the Fig. 2-7.

In a first step, the elevator car 20 is moved upward, i.e., closer to the machine traction sheave 40, such that the counter weight 30 rest on the bottom 15 of the elevator shaft 12 and the suspension traction means 60 is loose. In particular such that the suspension traction means 60 is loose enough (there is enough slack) that the first end of the suspension traction means 60 can be disconnected from the elevator car side fix point 27.

The elevator car 20 is blocked in the elevator shaft 12 such, that no downward movement, i.e., away from the machine traction sheave 40, is possible. The blocking can be done via one or two chain fails, in particular one chain fail on each side of the rails of the elevator car 20. Then, the suspension traction means 60 is or are disconnected from the elevator car side fix point 27. In particular, all suspension traction means 60 are disconnected from the elevator car side-fix point. The suspension traction means 60 are pulled out of the end connections at the elevator car side fix point 27.

Fig. 3 shows a schematic side view of the elevator system 10 of Fig. 2 after guiding the car-side end connections of the suspension traction means 60 through an elevator car pulley 25. The suspension traction means 60 is lowered onto the top of the elevator car 20 and removed from the elevator car pulley 25. In particular, all suspension traction means 60 are removed from the elevator car pulley 25.

All suspension traction means 60 but one first suspension traction means 60 are removed from the machine traction sheave 40 and the deflection sheave 45. The removed suspension traction means 60 are clamped to the counter weight side of the machine frame, e.g., with c-clamps. The suspension traction means 60 but the first suspension traction means 60 must not touch the deflection sheave 45.

Fig. 5 shows a schematic side view of the elevator system 10 of Fig. 4 after removing all loops of the suspension traction means 60 from a counter weight pulley 35. In the next step, all loops of the suspension traction means 60 which are wound around counter weight pulley 35 are removed. This can be done by opening the counter weight pulley 35. The loops of the suspension traction means 60 remain at essentially the same height in the elevator shaft 12.

If the counter weight pulley 35 is replaced there is no need to remove the suspension traction means 60 loops around the counter weight pulley 35. Instead, the counter weight pulley 35 is removed from the counter weight 30 or counter weight frame and stays connected to the suspension traction means 60.

Fig. 6 shows a schematic side view of the elevator system 10 of Fig. 5 after

winding up a part of the first suspension traction means 60 on the spool 50. A spool 50 is provided for winding up the first suspension traction means 60. The first end of the first suspension traction means 60 is wound onto the spool 50 manually. Then, the motor of the elevator system 10 drives the machine traction sheave 40 in the direction for downward movement of the elevator car 20 (lowering of the elevator car 20). I.e., the machine traction sheave 40 is turned in the counter clockwise direction in Fig. 6. This can be done in service mode of the elevator system 10.

By driving the machine traction sheave 40 in the elevator car 20 up direction, the suspension traction means 60 is lifted out of the elevator shaft 12. The spool 50 is either turned manually for winding up the suspension traction means 60. Alternatively, the spool 50 can be driven by the motor which drives the machine traction shave via a gear box. The needed turning speed or rational speed of the spool 50 depends on how much of the suspension traction means 60 is already wound up on the spool 50.

The suspension traction means 60 is guided over the deflection sheave 45 which also turns while the suspension traction means 60 is lifted.

The spool 50 has a projection in the middle of a circular disk. The suspension traction means 60 is wound around the projection of the spool 50, layer for layer.

Also, it is possible that several or all suspension traction means 60 are lifted at the same time. For this, all suspension traction means 60 to be lifted are guided over the deflection sheave 45 and the machine traction sheave 40. Each suspension traction means 60 is wound up on a separate spool 50.

The movement of the machine traction sheave 40 can be controlled by a controller of the elevator system 10, wherein the controller controls the movement of the elevator car 20 during normal operations. The controller can be set in automatic mode to move the elevator car 20 a set distance. This drives the machine traction sheave 40 over such a distance that the corresponding or equal length of the suspension traction means 60 is lifted out of the elevator shaft 12 and wound on the spool 50.

Fig. 7 shows a schematic side view of the elevator system 10 of Fig. 6 after further winding up the first suspension traction means 60 on the spool 50 and disconnecting the counter weight-side end connection of the first suspension traction means 60. When almost all of the suspension traction means 60 is wound up on the spool 50, i.e., there is (almost) no slack in the suspension traction means 60, the second end of the suspension traction means 60 is disconnected from the counter weight side fix point 37. Then the rest of the suspension traction means 60 can be wound onto the spool 50.

Now, the first suspension traction means 60 is completely wound on the spool 50. The spool 50 with the suspension traction means 60 can be taken away.

Next, the steps from Fig. 4 to Fig. 7 can be repeated for the next suspension traction means 60.

Thus, one or several suspension traction means 60 can be removed technically easily and without damaging the suspension traction means 60.

For removing a suspension traction means 60 from a 4:1 elevator system 10, the steps shown in Fig. 2 to Fig. 7 are essentially same; as additional steps the suspension traction means 60 has to be removed from the additional pulleys.

Fig. 8 shows a schematic side view of an elevator system 10 with a 1 : 1 ratio. Here, the elevator car side fix point 27 is at the elevator car 20 itself. Also, the counter weight side fix point 37 is at the counter weight 30 itself. The suspension traction means 60 is disconnected from the elevator car 20. Then, all but one suspension traction means 60 are disposed such that only a first suspension traction means 60 of the suspension traction means 60 touches the machine traction sheave 40 and the deflection sheave 45. The second end of the suspension traction means 60, either only of the first suspension traction means 60 or of all suspension traction means 60, are disconnected from the counter weight 30. Then the first end of the suspension traction means 60 is wound up on a spool 50. The machine traction sheave 40 is driven in the elevator car 20 down direction and the first suspension traction means 60 is wound up on the spool 50.

Fig. 9 shows a step of the installation method of a suspension traction means 60 according to the present invention in an elevator system 10 with a 2: 1 ratio. The machine traction sheave 40 or motor of the elevator system 10 can also be used for installing one or several suspension traction means 60 in an elevator system 10. The counter weight 30 rests on the bottom 15 of the elevator shaft 12 and the elevator car 20 is blocked in a high position in the elevator shaft 12 such that no downward movement of the elevator car 20 is possible.

Firstly, the spool 50 with the suspension traction means 60 being wound on the spool 50 is disposed. The second end of the suspension traction means 60 is guided over the machine traction sheave 40 and the deflection sheave 45 and fixed to the counter weight side fix point 37. Then, the machine traction sheave 40 is driven in the elevator car 20 up direction, i.e., the machine traction sheave 40 is turned in the clockwise direction in Fig. 9. This way, the suspension traction means 60 is lowered into the elevator shaft 12.

Next, the suspension traction means 60 is lowered such that the loop of the suspension traction means 60 can be connected to the counter weight pulley 35 of the counter weight 30. Then, the suspension traction means 60 is connected to the counter weight side pulley. Then, the first end of the suspension traction means 60 is guided through the elevator car pulley 25 of the elevator car 20 and, then, fixed to the elevator car side fix point 27. The length of the suspension traction means 60 can be adjusted and/or cut to a length needed before fixing the suspension traction means 60 to the elevator car side fix point 27.

Now, the suspension traction means 60 is installed in the elevator system 10. Next, additional suspension traction means can be installed in the same way.

Alternatively, all suspension traction means 60 can be installed at the same time.

The spool 50 is either turned manually for unwinding the suspension traction means 60. Alternatively, the spool 50 can be driven by the motor which drives the machine traction shave via a gear box. The needed turning speed or rotational speed of the spool 50 depends on how much of the suspension traction means 60 is still wound up on the spool 50. I.e., the turning speed or rotational speed of the spool 50 is synchronized with or adapted to the turning speed or rotational speed of the machine traction sheave 40. In particular, the two rotational speeds can be such that the same length of suspension traction means 60 which is moved by the machine traction sheave 40 or over the machine traction sheave 40 in an amount of time is unwound off the spool 50 in the same amount of time.

Finally, it should be noted that the term "comprising" does not exclude other elements or steps and the "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

List of reference signs

10 elevator system

12 elevator shaft

15 bottom of the elevator shaft

20 elevator car

25 elevator car pulley

27 elevator car side fix point

30 counter weight

35 counter weight pulley

37 counter weight side fix point

40 machine traction sheave

45 deflection sheave

50 spool

60 suspension traction means

Claims

1. Method for uninstalling a suspension traction means (60) for holding and moving an elevator car (20) from an elevator shaft (12) of an elevator system (10), wherein the method comprises the following steps:

- disposing the elevator car (20) such

- that the suspension traction means (60) hang loose for removing car-side end connections of the suspension traction means (60) and

- that the counter weight (30) rests on a surface;

- blocking the elevator car (20) in the elevator shaft (12) such that no downward movement of the elevator car (20) is possible;

- disconnecting the car-side end connections of the suspension traction means (60);

- moving all suspension traction means (60) but a first suspension traction means (60) of the suspension traction means (60) out of a machine traction sheave (40) and/ or a deflection sheave (45) of the elevator system (10);

- disconnecting all suspension traction means (60) from the counter weight (30);

- providing a spool (50) for winding up the first suspension traction means (60);

- actuating a motor of the elevator system (10) for driving the machine traction sheave (40) in an elevator car (20) down direction for lifting up the first suspension traction means (60) from the elevator shaft (12) and winding up the first suspension traction means (60) on the spool (50).

2. Method according to claim 1 , wherein

the suspension traction means (60) are disconnected from the counter weight (30) by removing all loops of the suspension traction means (60) from a counter weight pulley (35), and wherein the method further comprises the following step:

disconnecting the counter weight-side end connections of the first suspension traction means (60).

3. Method according to claim 1 or 2, wherein

the spool (50) is driven by a spool motor and/or by the motor of the elevator system (10), in particular via a gearing mechanism.

4. Method according to one of the preceding claims, wherein

a rotational speed of the spool (50) is adapted to a rotational speed of the machine traction sheave (40).

5. Method according to one of the preceding claims, wherein

the motor of the elevator system (10) is actuated for a set elevator car (20) movement distance.

6. Method for installing a suspension traction means (60) for holding and moving an elevator car (20) in an elevator shaft (12) of an elevator system (10), wherein the method comprises the following steps:

- providing a suspension traction means (60) wound up on a spool (50);

- disposing the suspension traction means (60) onto a machine traction sheave (40) and/or a deflection sheave (45) of the elevator system (10);

- actuating a motor of the elevator system (10) for driving the machine traction sheave (40) in an elevator car (20) up direction for lowering the suspension traction means (60) in the elevator shaft (12); and

- connecting the suspension traction means (60) to a counter weight (30) of the elevator system (10).

7. Method according to claim 6, further comprising the following step:

8. Method according to claim 6 or 7, wherein

the suspension traction means (60) are connected to the counter weight (30) of the elevator system (10) by guiding the suspension traction means (60) through a counter weight pulley (35).

9. Method according to one of the claims 6-8, wherein

10. Use of a motor driving mechanism of an elevator system (10), wherein the driving mechanism is adapted for moving an elevator car (20) up and down along an elevator shaft (12) of the elevator system (10),

- for lowering a suspension traction means (60) for holding and moving the elevator car (20) in the elevator shaft (12) from a spool (50) in the elevator shaft (12),

and/or

- for lifting a suspension traction means (60) for holding and moving the elevator car (20) in the elevator shaft (12) from the elevator shaft (12) and winding up the suspension traction means (60) on a spool (50).