AN ELEVATOR INSTALLATION AND A METHOD

Abstract

 The invention relates to an elevator installation comprising at least one elevator unit which is suspended by a rope (3), a safety gear moving with the elevator unit, one or more rotatable pulleys (4) over which the rope (3) runs, and a drive unit (5) engaging said rope via one of said pulleys for vertically moving the one or more elevator units via the rope (3). In order to obtain a simple solution for releasing an activated safety gear the elevator installation comprises a support member (10) supporting at least one of said one or more rotatable pulleys (4), and a lifting device (12) for vertically lifting the support member (10) with the at least one of said one or more pulleys (4) and for releasing the activated safety gear by moving the at least one elevator unit upwards.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

[0001] This invention relates to an elevator installation and a method, and more precisely to a solution for releasing an activated safety gear of an elevator unit.

DESCRIPTION OF PRIOR ART

[0002] For safety reasons an elevator unit, such as an elevator car or a counterweight has safety devices for stopping the movement of a falling elevator unit. One alternative is that these safety devices include an over speed governor which can be located in several alternative locations such as in the elevator hoistway or in a machine room. The over speed governor may utilize a safety rope which moves with the elevator unit and which is connected to a safety gear in order to provide an actuating force to the safety gear when needed.

[0003] In case the elevator unit moves downwards with a higher speed than allowed, the over speed governor prevents movement of the safety rope. As the safety rope is connected to the safety gear of the elevator unit that moves downwards while the safety rope is prevented from moving, an actuating force caused by the speed difference is provided to the safety gear. Due to this actuating force, the safety gear starts to brake the elevator car until it comes to a stop.

[0004] Previously there is known a solution where a guide rail is arranged in the elevator hoistway in a vertical position along the travel path of the elevator unit. Once the safety gear is activated, the safety gear grabs this guide rail by utilizing a movable force element which moves towards a narrower gap where it becomes jammed between the guide rail an an inclined surface of the safety gear. Due to this jamming the elevator unit is efficiently prevented from moving downwards until the activated safety gear is released.

[0005] In the above mentioned known solution one problem is that releasing of the activated safety gear is difficult. In praxis this releasing is done by pulling the rope which suspends the elevator unit by using clamps and a manual hoist, for instance. This is, however, a very cumbersome operation which requires time and patience.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to solve the above mentioned drawback and to provide a more practical and rapid way of releasing an activated safety gear. This object is achieved with an elevator installation and a method according to independent claims 1 and 13.

[0007] The use of a support that supports at least one rotatable pulley over which the rope suspending the elevator unit runs and of a lifting device for lifting the support member, makes it possible to release the activated safety gear in a simple and user friendly way. In that case the lifting device can move the elevator unit upwards together with the support member and the pulley.

BRIEF DESCRIPTION OF DRAWINGS

[0008] In the following the present invention will be described in closer detail by way of example and with reference to the attached drawings, in which

Figure 1 illustrates a safety gear of an elevator unit,

Figure 2 illustrates a first embodiment of an elevator installation, and

Figure 3 illustrates a second embodiment of an elevator installation.

DESCRIPTION OF AT LEAST ONE EMBODIMENT

[0009] Figure 1 illustrates a safety gear of an elevator unit. Figure 1 illustrates two elevator units 1 and 2 of which elevator unit 1 may be an elevator car and elevator unit 2 a counter weight. The elevator units 1 and 2 are suspended by a rope 3 in an elevator hoistway. The rope 3 runs over a rotatable pulley 4, which in this example is rotatably engaged with a drive unit 5 such that the drive unit 5 can vertically move the elevator units 1 and 2 in the hostway via the rope 3.

[0010] For security reasons elevator units are commonly provided with a safety gear which once activated brakes the elevator unit to prevent it from moving downwards. In the illustrated example elevator unit 1 is provided with such a safety gear 6. It should, however, be observed that in praxis only elevator unit 2 may be provided with a safety gear, or alternatively, both elevator units 1 and 2 may be provided with a respective safety gear.

[0011] In the illustrated example of Figure 1, the safety gear 6 is attached to the elevator unit 1 such that it moves with the elevator unit 1 in the hoistway. A safety rope 7 which is attached to the safety gear 6 connects the safety gear to an over speed governor 8. For simplicity pulleys and the other end of the safety rope 7 is not illustrated in Figure 1. The over speed governor 8 is, however, capable of determining the speed of the elevator unit 1 via the safety rope 7, which at the over speed governor moves downwards with the same speed as the elevator unit 1. Once a maximum allowed speed is exceeded, the over speed governor 8 activates the safety gear 6 to brake the elevator unit 1. This activation may be carried out such that the over speed governor 8 brakes the safety rope and thereby causes an actuating force to the safety gear 6.

[0012] In Figure 1 a guide rail 9 is arranged in the elevator hoistway in a vertical position along the travel path of the elevator unit 1. Once the safety gear is activated, the safety gear 6 grabs this guide rail by utilizing a movable force element which moves towards a narrower gap between the guide rail and an inclined surface in the safety gear, such that the force element becomes jammed between the guide rail 9 and the inclined surface. Due to this jamming the elevator unit 1 is efficiently prevented from moving downwards until the activated safety gear 6 is released. Such releasing may be done by moving the elevator unit 1 upwards, which causes the jammed force element to move out of the narrow gap.

[0013] Figure 2 illustrates a first embodiment of an elevator installation, which may be utilized to release an activated safety gear on the elevator unit 1 illustrated in Figure 1, for instance.

[0014] The embodiment of Figure 2 comprises a support member 10 which supports at least one of the rotatable pulleys 4 over which the rope 3 runs. In this example more than one pulley 4, and additionally, the drive unit 5 with an electric motor are supported by the support member 10, which may be implemented as a bed plate of the elevator installation.

[0015] In Figure 2 two elongated plinth beams 11 are fixedly mounted in the elevator hoistway. The beams 11 may be attached to a side wall of the hoistway, for instance, such that they remain stationary. The support member 10 is arranged on top of these beams 11 in such a way that a lifting device 12 for vertically lifting the support member 10, the pulleys 4 and the drive unit 10 is arranged between the support member 10 and the beams 11.

[0016] Once the safety gear 6 of an elevator unit 1 is activated to brake the elevator unit and braking is no longer needed, the lifting unit 12 can be activated to vertically lift the support member 10 such that the distance between the support member 10 and the beams 11 increases. As at least one pulley 4 over which the rope 3 runs is supported by the support member 10, also this pulley 4 will simultaneously be lifted together with the rope 3 and the elevator unit 1 which is supported by the rope 3. Due to the upward movement of the elevator unit 1, the safety gear 6 is released.

[0017] In the embodiment of Figure 2, the lifting device comprises a screw jacks 13. The number of screw jacks 13 may vary depending on the implementation. In the illustrated example it is, however, assumed that the support member is generally rectangular, and that there is one screw jack 13 in each corner, consequently four screw jacks 13. The lifting device 12 additionally comprises an electric motor 14 for rotating shafts 15 which are connected to each other and to the electric motor via gears 16. With such an arrangement it can be ensured that the screw jacks 13 lift the support member with a synchronized movement such that the horizontal orientation on the support member 10 does not change during lifting. A suitable lifting distance is about 400 mm which in most cases is sufficient to release the safety gear 6. The screw jacks 13 may be of spindle gear type with trapezoidal threads, for instance. One alternative is to dimension the screw jacks in such a way that each screw jack can lift about 15000 kg, for instance. Naturally the dimensioning varies depending on the implementation.

[0018] Figure 3 illustrates a second embodiment of an elevator installation. The embodiment of Figure 3 is very similar as the embodiment explained in connection with Figure 2. Therefore the embodiment of Figure 3 will be mainly explained by pointing out the differences between these embodiments.

[0019] In the embodiment of Figure 3 hydraulic jacks 13' are used in the lifting device 12' instead of screw jacks. Consequently, the lifting device 12' comprises a source 17' for a hydraulic fluid which may include a pump and an oil reservoir, a manifold 19' with control valves, and hoses 18' which provide the hydraulic jacks 13' with fluid from the fluid source 17'. Similarly as in the previous embodiment, the hydraulic jacks 13' lift the support member 10' with a synchronized movement during which the horizontal orientation of the support member does not change.

[0020] An advantage with using hydraulic jacks is that the same fluid source 17' may by utilized for more than one elevator installation. If there are several elevators arranged close to each other, it is sufficient to provide only one fluid source 17', in which case valves can be utilized to control the hydraulic fluid to hydraulic jacks of the correct elevator, in case the safety gear of one elevator unit has been activated. It is not necessary to integrate a hydraulic lifting system as a fixed part of a bed plate in an elevator installation, but instead the screw jacks may be attached in such a way that it can easily be removed and used elsewhere, if necessary.

[0021] The illustrated elevator installations of Figures 1 to 3 are very advantageous when used in high-rise or mega high-rise installations. In that case the vertical distance an elevator unit 1 needs to travel may be more than 50 m. It is also possible that the vertical distance is more than 300 m or even more than 500 m. Such installations can typically be found in very high buildings. If in that case a separate hoist needs to be connected to the rope 3 by means of a clamp, as in prior art solutions, the separate hoist must be located at a very high level above the ground. Additionally, in such installations the rope that needs to be lifted is very long and consequently very heavy, in particularly, if the rope is a traditional steel rope. The separate hoist must therefore be dimensioned to be able to lift a significant weight. Such problems can be avoided with the illustrated elevator installations.

[0022] In the illustrated embodiments of figures 1 to 3 the rope 3 may be a traditional rope made of steel. Alternatively, the rope 3 may also include a composite material, such as in combination with steel, for instance. Such composite material containing ropes 3 are advantageously used in high-rise or mega high-rise installations where the vertical travel distance of an elevator unit is significant, such as from 50 m to over 500 m in order to provide light weight ropes with excellent durability and bending properties. Such ropes 3 that include a composite material are difficult to grab with a clamp in order to lift an elevator unit with a separate hoist because the clamp easily damages the material of the rope 3. This problem can, however, be eliminated by using the elevator installation of figures 1 to 3.

[0023] One alternative is that the rope 3 utilized in the illustrated embodiments of Figures 1 to 3 is composite containing rope 3. In that case a rope 3 in the form of a belt may be used, which has width substantially larger than the thickness thereof. This makes it well suitable for elevator use as bending of the rope is easy, which is necessary in most elevators. Such a rope may contain a number of load bearing members that are arranged in a row after each other in parallel with the longitudinal direction of the rope 3 throughout the entire length of the rope 3, in which case they provide excellent longitudinal stiffness for the rope 3. Such a rope 3 may have an elastic coating of an elastomer such as polyurethane, for instance, which forms an outer surface for the rope 3. In that case the elastic coating may provide the rope with good wear resistance, protection, and isolate the load bearing members contained in the elastic coating from each other. The elastic coating may also provide the rope with high friction.

[0024] Each of said load bearing members may be made of composite material comprising reinforcing fibers embedded in a polymer matrix. The reinforcing fibers may be carbon fibers, which are most advantageous in terms of longitudinal stiffness as well as weight. To reduce buckling of fibers and to facilitate a small bending radius of the rope, the polymer matrix may be hard, and in particular non-elastomeric. Preferred materials include epoxy resin, polyester, phenolic plastic and vinyl ester. The composite material may be arranged such that the individual reinforcing fibers are parallel with the length direction of the rope. Thus, they provide excellent longitudinal stiffness for the rope. The individual reinforcing fibers may be distributed in the matrix substantially evenly, such that substantially all the individual reinforcing fibers of the load bearing member are bound to each other by the matrix.

[0025] It is to be understood that the above description and the accompanying figures are only intended to illustrate the present invention. It will be obvious to a person skilled in the art that the invention can be varied and modified without departing from the scope of the invention.

Claims

1. An elevator installation comprising:

at least one elevator unit (1, 2) which is suspended by a rope (3)

a safety gear (6) moving with the elevator unit (1, 2) and which is arranged to be activated to brake the elevator unit (1, 2) under predetermined conditions,

one or more rotatable pulleys (4) over which the rope (3) runs, and

a drive unit (5) engaging said rope via one of said pulleys for vertically moving the one or more elevator units (1, 2) via the rope (3), characterized in that the elevator installation comprises:

a support member (10, 10') supporting at least one of said one or more rotatable pulleys (4), and

a lifting device (12, 12') for vertically lifting the support member (10, 10') with the at least one of said one or more rotatable pulleys (4) and for releasing the activated safety gear (6) by moving the at least one elevator unit (1, 2) upwards.

2. The elevator installation of claim 1, wherein the drive unit (5) is supported by the support member (10, 10').

3. The elevator installation of claim 1, wherein the lifting device (12) comprises a screw jack (13).

4. The elevator installation of claim 3, wherein the lifting device (12) comprises at least two screw jacks (13) rotationally connected to each other for driving the at least two screw jacks (13) to lift the support member (10) with a synchronized movement.

5. The elevator installation of claim 1 or 2, wherein the lifting device (12') comprises a hydraulic jack (13').

6. The elevator installation of claim 5, wherein the lifting device (12') comprises at least two hydraulic jacks (13') which are connected to a common fluid source (17') for lifting the support member (10') with a synchronized movement.

7. The elevator installation according to claim 1 or 2, wherein
the elevator installation comprises a first and a second elongated beam (11, 11') fixedly mounted in an elevator hoistway,
the support member (10, 10') is a bedplate supporting at least one of said one or more rotatable pulleys (4) and the drive unit (5), and
the lifting device (12, 12') comprises four screw jacks (13) or hydraulic jacks (13') synchronized to move the support member in relation to the first and second beam (11, 11').

8. The elevator installation according to one of claims 1 to 7, wherein the elevator installation is a high-rise installation where the drive unit (5) vertically moves the elevator unit (1, 2) more than 50 m.

9. The elevator installation according to one of claims 1 to 8, wherein the elevator installation is a high-rise installation where the drive unit (5) vertically moves the elevator unit (1, 2) more than 500 m.

10. The elevator installation according to one of claims 1 to 9, wherein the rope (3) is a composite material containing rope.

11. The elevator installation according to one of claims 1 to 10 wherein the rope (3) comprises an elastic coating.

12. The elevator installation according to one of claims 1 to 10 wherein the rope (3) comprises a coating of polyurethane.

13. A method for releasing an activated safety gear (6) of an elevator unit (1) which is suspended by a rope (3) running over a rotatable pulley (4) which is supported by a support member (10, 10'), characterized in that the method comprises:

activation of a lifting device (12, 12') to lift the support member (10, 10') and the rotatable pulley (4) for releasing the activated safety gear (6) by moving the elevator unit (1) upwards.

14. The method according to claim 13, wherein said activation comprises rotation of an inlet axis (15) of at least one screw jack (13).

15. The method according to claim 13, wherein said activation comprises feeding of a fluid to at least one hydraulic jack (13').

Drawing