EP2020399A1

EP2020399A1 - Compact fixing element for elevator ropes

Info

Publication number: EP2020399A1
Application number: EP08380233A
Authority: EP
Inventors: Miguel Angel Madoz; Izaro Zulaika; Xabier Elizegi
Original assignee: Orona S Coop
Current assignee: Orona S Coop
Priority date: 2007-08-03
Filing date: 2008-07-30
Publication date: 2009-02-04
Also published as: ES2341930A1; ES2341930B1

Abstract

The invention relates to a compact fixing element for elevator ropes and elevator apparatus incorporating said fixing elements. This compact fixing element for elevator ropes comprises a first body for fixing the end of the rope to be fixed, a second body inserted between the first body and the rope to be secured and pressure means for applying pressure to the elevator rope through the second body.

Minimizing the plan projection of the fixing elements for the ropes, preventing the fleet angle or the angle which the rope forms with the vertical plane perpendicular to the rotating shaft of the sheave, is achieved with said fixing element.

Description

Object of the Invention

The object of the present invention relates to a compact fixing element for ropes, specifically steel ropes coated with a polymer material for the suspension and movement of the car of the elevator and of the counterweight.
The securing of the ropes at the terminal ends of elevators in a manner parallel to one another is achieved with these fixing elements for ropes, which prevents the ropes from forming a certain angle with the sheaves and therefore the premature degradation of the ropes and/or sheaves of the elevator.

Background of the Invention

Conventional elevators are made up of a car and a counterweight, supported by ropes which are pulled by friction by a sheave driven by an engine. Depending on the selected suspension configuration, the ends of the ropes are fixed to different elements of the installation. For example, in a suspension called 1:1, the car and the counterweight hang directly from the ends of the ropes, whereas in a suspension called 2:1, the car and the counterweight are supported by respective sheaves assembled on the car and counterweight on which the ropes pass, their ends being fixed in a framing arranged in the machine room of the elevator immediately above the shaft through which the car and the counterweight move.
In addition, the regulation in force regulating safety in elevators, EN81, requires that an automatic device for balancing the tension of the ropes at least at one of their ends be provided, which in the case of using springs must work under compression.
The conventional fixing element for fixing the ends of the ropes consists of a rope securing device which in its configuration is basically formed by three parts: the body, the wedge and the rod.
The end of the rope to be secured is bent, enveloping the wedge, and this assembly is introduced in the main rope securing device body. Thus, once the rope is subjected to tensile stress, the rope will be trapped between the body and the wedge by friction, preventing the possible escape due to the slipping of end of the rope. Furthermore, the free end of the rope is secured to the rest of the rope by means of several clips, normally 3.
A threaded rod is assembled and/or fixed on the rope securing device body, which rod will be useful for fixing the assembly of the rope securing device to the fixing point in the installation. The rope securing devices further have a spring in the rod which is useful for regulating the load supported by the rope in comparison with the rest of the ropes, seeking a uniform distribution of the load which they support.
A typical configuration of this solution is shown in Figure 1 attached to this description defining the state of the art and which is described in greater detail in the descriptive part of the technical solution of the present invention.
This same construction, but adapted to belts not to ropes, is described in European patent EP-1140689 and also in European patent EP-1254069 , in which the end of the belt to be secured encircles a wedge or double wedge which is secured to the rope securing device body and the latter has a rod which is fixed through elastic means to the structure of the elevator.
The latest developments in the field of elevators arise as a consequence of the disappearance of the machine room, such that all elements which were located therein are mostly located within the shaft of the elevator, the size of the elements forming the elevator taking on great importance. For this reason, the effort of the sector has been aimed at reducing the space occupied by the elements in order to be able to make optimal use of the space of the shaft. Among the elements limiting the space available in the shaft, there is the support on which the rope securing devices are fixed, which will be referred to throughout the description hereinafter as "rope landing".
Another problem which arises upon "opening" the ends of the ropes, is that it causes a certain angle between the rope and a vertical plane perpendicular to the rotating shaft of the sheave through which the rope passes, such that the rope comes in/out of the nearest groove with a certain angle which is known as a fleet angle, which is limited and attempted to be prevented, given that it is a source of premature degradation of the rope.
Recently, the rope landing is fixed directly to the counterweight and/or car guides, either through the support of the machine or on the side of the car directly to the guide. However, as mentioned in patent JP2001139259 , one of the problems which arises is that the assembly of the ends of the ropes must "open" sufficiently so as not to interfere in the contiguous rope securing devices, needing a considerable space for the rope landing. Patent JP2001139259 shows an intermediate part between the rope landing and the ends of all the ropes which is useful as a single common rope securing device. It thus solves the problem that the ends of the ropes open by optimizing the space occupied in the rope landing, i.e., it prevents the effect known as fleet angle which would lead to the premature degradation of the ropes. This rope securing device has as an advantage optimizing the space in the horizontal projection necessary for fixing the ends of the ropes, but on the other hand it has as a drawback the impossibility of independently regulating the tension of each rope since all of them are secured to the intermediate part, from which a threaded rod which is secured by intermediation of a spring regulating the tension for supporting the ropes starts.
Rope securing device solutions with a reduced projection as in Japanese patent JP11037224 , European patent EP-0619443 , etc...., have been adopted, which solutions are adapted to bare ropes without a polymer coating and which force the end of the rope against the rope securing device body and it is the plastic deformation between both which achieves removably securing these ends of the ropes to the rope securing device body.
However these technical solutions are not possible when dealing with ropes for elevators which are externally coated with a polymer, since the plastic deformation to which they would be subjected would make it so that they could only be used on a single occasion and upon being disassembled it would be necessary to change the rope, since the coating thereof would have been rendered unusable.
It would consequently be necessary to obtain a rope securing device for the rope landing, with minimal horizontal projection, which would prevent the fleet angle of the elevator ropes, which would be useful to secure metal ropes coated by a polymer and which would allow them to be disassembled on successive occasions without the rope and/or the rope securing device deteriorating.

Description of the Invention

The compact fixing element for elevator ropes proposed by the present invention solves all the previously indicated problems shown by the state of the art since it provides individual fixing means for each elevator rope significantly reducing the plan projection with respect to traditional systems, thereby preventing the fleet angle of the ropes and therefore the premature wear thereof, at the same time being made up of an easy to assemble and disassemble element facilitating the maintenance operations of the ropes coated with polymer.
Another aspect of the invention consists of the approximately straight fixing of the terminal end of each rope without the necessary curvature as occurs in traditional wedge systems, thereby preventing permanent deformations of the ropes, the coatings or both, in addition to reducing the plan projection given that there is no free end of the rope and therefore it does not require assembling any clip for fixing this free end to the rest of the rope.
An object of the invention is that the ends of the ropes are secured by means of pressure, which will allow an easy assembly and disassembly of the ends of the rope from the rope securing device and the possible reuse of the ropes and/or rope securing devices on a number of occasions.
The rope used for these rope securing devices will be made of steel and preferably of high strength steel and with a polymer coating, more specifically an elastomer or thermoplastic material and preferably polyurethane.
Without considering the polymer coating, the rope used will have a diameter equal to or less than 6 mm, said rope being formed by steel wires with a diameter equal to or less than the 0.5 mm, high strength steel wires being used, such as wires with resistance to breaking equal to or greater than 2000 N/mm².
The compact fixing element proposed by the invention comprises:

a first body for fixing the end of the rope,
a second body, inserted between the first body and the rope to be secured.
pressure means applying pressure to the rope through the second clamping body located therein.

These features are completed by the fundamental fact that the plan projection of the fixing element is such that the distance between the centers of the section of the ropes corresponding to every two adjacent fixing elements is less than or equal to three times the distance between contiguous grooves of the traction and/or deviation sheaves, preferably approximately equal to the distance between contiguous grooves, thereby achieving a passing of the ropes with a very small angle with respect to the grooves of the sheaves or even the ropes being parallel at the height of the fixing element and preventing the fleet angle in any of the cases and thereby a premature wear of the ropes since such ropes do not fall on the grooves of the sheaves with a pronounced angle.
The purpose of the first end body for fixing the rope is to be secured to the fixing point of the shaft of the elevator chosen for it, either directly or through a spring regulating the tension of the rope, the rope assembly and the securing parts forming which has been called a "rope landing". This fixing point can consist of a metal part directly secured to the walls of the shaft of the elevator or a support which is fixed to the counterweight guides and/or elevator guides, or it can also be secured directly to the car and/or counterweight in the 1:1 suspension configuration. This first body is further useful as a support for the rest of the components of the fixing element.
The second body is inserted or joined to the first of the bodies described and the end section of rope to be secured by this rope securing device enters therein, adopting an approximately straight position. This second element is capable of trapping the end of the rope, for which it can be constructed in the form of several sections adjustable in relation to one another between which there are adjustment stops limiting the constriction of the rope inserted between these sections. This construction causes the approximation of these elements forming the second body and therefore achieves the clamping of the rope on the rope securing device preventing the separation thereof.
The friction force between the polymer coating of the rope and the second fixing body is at least 80% of the breaking load of the rope, such that the contact length between the end of the rope with polymer coating and the second body clamping the rope must be such that it achieves fixing the rope on the rope securing device and the friction force between both is maintained within the previously indicated values.
In order to achieve a perfect securing of the end of the rope on the second rope securing device body, it is attempted that the contact surface between the second body and the polymer coating of the rope have a high friction, which can be achieved in several ways, such as for example by knurling the inner body of the second part, or providing a surface treatment increasing the friction force, or making the contact surface of the second body rough, or including protrusions such as teeth, or including a chip coating, etc...., i.e., means increasing the friction between the second rope securing device body and the end of the rope preventing the slipping between both and thereby the rope securing device being separated from the rope.
The fixing element comprises pressure means for achieving the necessary friction force, which means apply pressure on the second body and therefore on the rope clamped therein. In a simple conception, these pressure means can be screws which are screwed on the first of the bodies and tightened against the rope to the second of the bodies. A locking element is arranged to prevent pressure from being involuntarily lost, for example by means of the loosening thereof.
The second rope securing device body can be formed by a wedge-shaped arrangement and a threaded element which tightens second body on the rope, aided by the wedge shape, in which case the threaded element for tightening the wedge can have a lock nut element preventing the pressure loss of the rope on the rope securing device, or it can have a screw-shaped retention element preventing the involuntary pressure loss thereof.
The first body for fixing the rope is generally carried out in a single part, although it could be formed in two or more parts, which allow rotation in relation to one another and therefore the auto-orientation of the ropes, thereby preventing stress or turning torques in the ropes themselves or in the coupling, which are not exclusively the actual tensile stress exerted by the ropes when supporting the elevator.
The elevator apparatus incorporating at least one fixing element for ropes as previously defined is also an object of the invention.

Brief Description of the Drawings

To complement the description being made and for the purpose of aiding to better understand the features of the invention according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description, in which the following has been shown with an illustrative and non-limiting character:

Figure 1 depicts a typical state of the art configuration of a rope securing device for elevators.
Figure 2 equally depicts a typical configuration of a traditional rope landing of an elevator and the space problems which it represents.
Figure 3 depicts the effect of the fleet angle which occurs when a certain angle between the rope and the groove of the sheave occurs.
Figure 4 depicts respective transparent and sectional perspective views of a first technical solution alternative of the rope securing device of the invention.
Figures 5 to 9 depict different technical solution alternatives of the rope securing device of the invention.

Description of a Preferred Embodiment

Figures 1 to 3 depict the state of the art and the problems which the rope securing device currently used in elevators have. Figure 1 thus shows a rope securing device of the type normally used, formed by a main body or rope securing device body (1) in which a wedge body (2) is inserted, between which wedge the rope (3) is trapped and retained. The rod (5) is joined to this rope securing device body through the rotating pin (4), which rod is secured at the fixed joining point to the shaft of the elevator through a spring (6) regulating the tension of the rope, its compression run being limited by means of respective nuts and lock nuts. This joining point can be the walls or the ceiling of the elevator shaft, or the guides, either counterweight guides and/or guides of the elevator itself, or directly the actual car and/or counterweight.
As can be seen in this figure, the width of the body (1) is influenced by the curvature that the rope (3) may have, but what is unquestionable is the large width occupied by this rope securing device above all when it is combined with other rope securing devices of a traction system of the elevator with multiple ropes, as shown in Figure 2.
Figure 2 shows a "rope landing" of a conventional elevator. This figure depicts the support (7) of the rope landing to which all the rods (5) are secured through the corresponding springs (6) regulating the tension of the ropes. These rods are secured to the bodies (1) of the different rope securing devices and these will secure the ropes (3). This figure is very relevant, since it can be observed how the rope securing devices are placed in a staggered arrangement in two rows for the purpose of occupying less space, but despite that fact, the gap between the ropes at their ends is rather pronounced, such that the ropes reaching the first deviation sheave do so at a certain angle, as shown in Figure 3, and it shows how this causes the fleet angle effect in which the rope is degraded by the stresses which are generated in the rope by the contact with the side walls of the grooves of the sheaves (8), the greater the effect the greater the angle formed by the ropes with the grooves of the sheaves.
Figure 4 depicts a first embodiment of the object of the rope securing device of the invention, said rope securing device formed by means of:

a first body (9) for fixing the end of the rope (3),
a second body (10), inserted between the first body and the rope (3) to be secured.
pressure means (11), applying pressure to the rope (3) through the second clamping body located therein.

With the rope securing device of the invention, the fundamental purpose sought, in addition to its being a safe element for securing the ropes, is that the plan projection of the fixing element is such that the distance between the centers of the section of the ropes corresponding to every two adjacent fixing elements is less than or equal to three times the distance between contiguous grooves of the traction and/or deviation sheaves, whereby preventing a fleet angle between ropes and sheaves prematurely deteriorating the ropes.
The first body (9) forms what is the rope securing device body and from it the rod (5) projects at the upper part, on which the spring regulating the tension of the rope will be fixed. This first body (9) has a central orifice (12) in which the second body (10) is inserted and within such second body, the rope (3). This second body (10) can be divided into two halves or be in a single part with an open groove, for the purpose of allowing the constriction of the central orifice through which the rope (3) of the elevator is introduced. The groove or grooves will define the contact between the parts of the second body and will be the maximum tightening stop of the second body.
This same figure depicts the pressure means (11) which in this case are formed by screws which are screwed on the first body (9) and tighten the second body (10) against the rope (3) inserted therein. In order to prevent the pressure means (11) from loosening during the operating locking elements (13) preventing this loosening are arranged.
As a supplement of this embodiment a retention nut (14) is arranged which prevents the fall during the assembly or disassembly of the second body (10) and which will be joined by means of screwing to the first body.
Figure 5 depicts an embodiment variant of the rope securing device of the invention formed in this by means of:

a first body (9) for fixing the end of the rope (3),
a second body (10), inserted between the first body and the rope (3) to be secured.
pressure means (11), applying pressure to the second body applying pressure to the rope (3) through this same second body.

In this embodiment it must be pointed out how the second body (10) is a longitudinally open body with a groove (15), in one of which sections it has a threaded area in which the pressure means consisting of a third body (11), in this case carried out as a nut, are inserted. The fact that the second body (10) is cone-shaped and the more the third body (11), i.e., the nut, is introduced, the more the groove (15) closes and therefore the more the second body (10) tightens against the rope, is a relevant feature. In order to prevent the loosening of the third body (11) with respect to the second body (10) a second nut is introduced acting as a lock nut and by means of tightening the nut and lock nut the loosening of the retention system of the ropes is prevented.
Figure 6 depicts an alternative solution for the rope securing device which shows the first body (9) for fixing the rope securing device, the second body (10) of the rope securing device formed by a cylindrical body open on the side and projecting in respective side flanges (17), such that when such flanges are tightened in relation to one another by means of the third body (11) or third bodies, the cylindrical area tightens the rope (3) against itself.
Figure 7 depicts another alternative solution of the rope securing device of the invention. This solution shows the first body (9) for fixing the rope securing device having a cone-shaped extension and inside which the end of the rope (3) for supporting the elevator is introduced. As the second body (10), there is arranged an inner cone-shaped body which, together with the cone shape of the first body (9), causes a relative movement between both bodies reducing the diameter of the central orifice in which the end of the rope (3) is inserted. This second body (10) has a longitudinal grooving which, when said grooving is closed, presses the rope located therein and secures the rope, preventing the rope from coming out of said rope securing device. In order to compress the second body (10) against the rope (3) the third body (11) is used, which body literally pushes said second body (10) against the first body (9) and the cone shape of both of them compresses the rope, fixing it with respect to the rope securing device. In this case the means preventing the loosening of the third body (11) against the second body (10) can be made using the configuration of the first body (9) as observed in the attached figure.
Figure 8 depicts another solution of the rope securing device of the invention. This solution shows the first body (9) for fixing the rope securing device and on this device the second body (10) is joined, which body has a cylindrical shape inside which the rope (3) is placed, that body (10) having a hollow cone-shaped protrusion arranged on one side, inside which the third wedge-shaped body (11) is arranged, which the more it penetrates, the more secure the rope (3) is against the walls of the second body (10). A threaded ring (19), which could be a nut, is arranged to prevent this third body (11) from coming out, preventing the backwards movement of the wedge-shaped third body (11) in charge of retaining the rope.
Figure 9 depicts a version of the rope securing device of the invention similar to that of Figure 4, in which the first body (9) is divided into two sections, one which blocks the rope securing device and the second hollow one in which the elevator rope is introduced therein. The second body (10) is cylindrical and clamps the elevator rope and can be divided into two halves or be a single part with an open groove for the purpose of allowing the constriction of the central orifice through which the rope (3) of the elevator is introduced. This body (10) traps the rope (3) as a result of the action of the third body (11), formed in this case by three screws compressing the second body (10) against the rope (3) of the elevator.

Claims

Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material for the suspension and movement of the car of the elevator and of the counterweight comprising
- a first body for fixing the end of the rope,

- a second body, inserted between the first body and the rope to be secured,

- pressure means applying pressure to the rope through the second clamping body located therein.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that the section of rope which is enveloped by the second body adopts an approximately straight position.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 2, characterized in that the plan projection of the fixing element is such that the distance between the centers of the section of the ropes corresponding to every two adjacent fixing elements is less than or equal to three times the distance between contiguous grooves of the traction and/or deviation sheaves.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that the rope has a circular section.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that both the first and second bodies, as well as the pressure means, forming same are dismantleable and separable from the end of the rope, rendering the rope and/or the fixing element reusable.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that the rope which is fixed thereby has a diameter without a polymer coating equal to or less than 6 mm.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claims 1 and 6, characterized in that the rope which is secured therein is formed by steel wires with a diameter equal to or less than 0.5 mm, and in that the resistance of the wires to breaking is equal to or greater than 2000 N/mm².
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that the polymer element for coating the rope is an elastomer or thermoplastic material.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claims 1 and 8, characterized in that the friction force between the polymer coating of the rope and the second fixing body is at least 80% of the breaking load of the rope.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that it comprises stop means for applying pressure on the mentioned rope.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that the contact length between the end of the rope with a polymer coating and the second body clamping the rope, must be such that it maintains a friction force between the polymer coating of the rope and the second fixing body of at least 80% of the breaking load of the rope, wherein the second body has in the contact surface with the coating of the rope a surface for increasing the friction force.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 11, characterized in that the contact surface of the second body with the coating of the rope is rough.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 1, characterized in that the pressure means for applying pressure on the end of the rope have at least one locking element preventing the involuntary pressure loss of the mechanism.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claims 1, 2, 3, 4 or 5, characterized in that the first body can be divided into at least two parts between which means are located for allowing the rotation between both parts.
Compact fixing element for elevator ropes, specifically steel ropes coated with a polymer material according to claim 14, characterized in that the rotation means for rotating the parts in relation to one another forming the first body consist of an axial bearing.
Elevator apparatus incorporating at least one fixing element for ropes, as defined in any of claims 1 to 15 at the end of the traction ropes of the elevator.