Coated elevator rope clamp

Abstract

The present invention relates to a clamp or termination for coated elevator ropes in elevators. When coated elevator ropes are used, the insulating coating can cause static charges to build up on the ropes. These charges can create repulsive or attractive forces between parallel ropes, preventing the ropes from moving properly over pulleys and, in extreme cases, causing the coated elevator rope to derail. The wedge and socket clamp of the present invention is differentiated from prior art wedge and socket clamps in that piercing devices are provided in the low-tension zone of the clamp. These piercing devices can take the form of pins, fins, or other protrusions, and can establish an electrical connection between the wedge and a conductive tension member. Such an elevator clamp is capable of venting the accumulated static charge, enabling wear detection for each elevator rope.

Description

[Technical Field]

[0001] The present invention relates to a clamp for holding the end of an elevator rope, also known as a rope termination. [Background technology]

[0002] In the majority of elevators for the transportation of people or goods, the cabin or car is suspended on two or more tension members driven by a hoist. Shortly before the turn of the century, there was a trend to reduce the size of hoists to eliminate the need for a machine room at the top of the elevator shaft. To make this possible, conventional steel wire ropes with diameters of 8 mm or more, with steel wires having diameters greater than 1 / 2 mm and tensile strengths of less than 2000 MPa, - several steel cords arranged in a coated elevator belt, or - One steel cord in a coated elevator rope has been replaced by Steel cords include thin, high-tensile steel wires arranged in strands and further arranged in cords.

[0003] The use of these thin, high-tensile steel wires allows for the size of tension members to be reduced. For example, a 5mm diameter steel cord can now be replaced with an 8mm steel wire rope. As a result, the size of the drive pulleys of the hoist can be reduced, allowing for the use of direct drive motors without gearboxes, resulting in an overall reduction in the size and weight of the hoist. The hoist can be small enough to be mounted above or below the shaft, eliminating the need for a machine room on the roof.

[0004] However, when steel cords with thin, high-tensile steel filaments are used, the filaments are more susceptible to lateral forces and must be protected from direct contact with the pulleys, which is usually done by coating the wire with an abrasion-resistant polymer, mainly polyurethane.

[0005] While polymers provide very good protection for the steel filaments, they are generally poor conductors of electricity, and as a result, static charges can build up on the mantle of the tension member, which can result in a variety of problems. - Static charges can lead to electrostatic discharges, which is a risk in elevator shafts, which are generally kept dry and where dust accumulates over the years. Sparks can result in the initiation of dust fires. - Electrostatic charges can result in mutual repulsion of parallel elevator ropes. This force does not have to be large, but it does take a lot of force to deflect long elevator ropes hanging side by side. This can result in derailment of the elevator rope from the guide pulley and even the drive pulley. The problem of static charge buildup is further exacerbated when polymeric diverting pulleys are used in the path of the tension members. Of course, these problems do not occur with prior art steel wire ropes because static electricity does not build up in the highly conductive steel wires.

[0006] In particular, the latter problem can occur with coated elevator ropes because, in contrast to belts, circular elevator ropes do not have a preferential bending direction and are therefore more prone to flexing.

[0007] Various solutions may be proposed, such as using grounded conductive brushes to remove static charges, but the brushes wear out faster than desired. Also, the coating can be made conductive, but this increases the cost of the coating and also affects the properties of the coating.

[0008] A known coated elevator rope clamp for flat belts is described in WO 2006 / 029544 A1. It comprises a wedge and a wedge receiving section. The friction surface of the wedge receiving section, which is adjacent to the free end of the flat belt, has a higher surface roughness than the surface roughness of the remaining surface of the wedge receiving section, which is adjacent to the conveying end of the flat belt. The latter surface has a reduced surface roughness compared to the remaining surface of the wedge section. The clamp is specifically designed to prevent high point loads on the flat belt.

[0009] The present inventors describe and propose herein means for solving the above problems. Summary of the Invention [Problem to be solved by the invention]

[0010] It is an object of the present invention to find a solution to the above-mentioned problems related to static charge buildup in coated elevator ropes. It is a further object of the present invention to provide coated elevator rope clamps or terminations that allow charge buildup on coated elevator ropes to be drawn off. Another object is to provide elevators having coated elevator ropes with these termination clamps. [Means for solving the problem]

[0011] Claim 1 describes a clamp according to a first aspect of the invention. The clamp or termination is for holding one of two ends of a coated elevator rope. Such elevator rope comprises one or more tension members surrounded by a coating. The tension members are electrically conductive, while the coating is electrically insulating. The clamp comprises a wedge and a socket body. The wedge fits within an internal tapered hollow formed by the socket body.

[0012] Such clamps are well known and are the subject of standardization, for example, EN 13411-6+A1:2008 "Terminations for steel wire ropes - Safety - Part 6: Asymmetric wedge socket." The socket is called "asymmetric" because the clamp's attachment point is directly aligned with the longitudinal axis of the elevator rope's most highly tensile section. The "most highly tensile section" of the elevator rope refers to the section of the elevator rope held between the wedge and the internal tapered hollow that is closest to the load tensioning the elevator rope. The part of the wedge that contacts the most highly tensile section of the elevator rope is called the wedge's "clamp track." The side of the internal tapered hollow where the most highly tensile section of the elevator rope is held is called the "alignment side" because this side must be aligned with the clamp's attachment point.

[0013] Outside the area under the most tension, the elevator rope folds back over the circular end of the wedge's wide side and is reinserted between the wedge and the internal tapered hollow. The tail end protrudes from the clamp on the side of the socket body opposite the side where the elevator rope entered. The track on the wedge from the end of the clamp track to the point where the elevator rope is no longer held by the socket body is called the "holding track." The portion of the internal tapered hollow that holds the rope against the wedge's holding track is angled relative to the alignment side due to the shape of the wedge and is therefore called the "sloped side" of the internal tapered hollow.

[0014] The clamp's mechanical retention principle is simple in that elevator rope tension draws the wedge into the internal tapered hollow, thereby firmly holding the elevator rope between the wedge and the socket body for at least the "clamping length." Moving beyond the clamping length, the force along the elevator rope's centerline decreases to zero, whereupon the elevator rope exits the retention length. The lateral force acting on the rope between the wedge and the internal tapered hollow of the socket body is approximately equal on the retention track inclined side and the clamp length-matching side.

[0015] According to a first aspect of the invention, the clamp of the invention is characterized in that the wedge comprises one or more puncture devices on the retaining track of the wedge.

[0016] According to a second aspect of the present invention, the clamp of the present invention is characterized in that the inclined side surface of the inner tapered hollow portion is provided with a puncture device.

[0017] The function of these "puncture devices" is to puncture through the sheath of the coated elevator rope. The puncture devices are conductive and establish electrical contact between the wedge and the conductive tension member of the coated elevator rope. Therefore, the puncture devices must be sharp enough and penetrate deep enough through the insulating sheath to reach the conductive tension member inside the coated elevator rope.

[0018] The presence of these "puncture devices" is counterintuitive in that standards require that the rope grooves in the wedge and socket bodies be free of marks and joints, while the present invention, through the presence of the puncture devices, requires just the opposite. In prior art bare steel elevator ropes, it is a requirement that the steel rope path be free of sharp marks or joints due to the risk of pinching the steel wire.

[0019] The inventors disagree with coated elevator ropes in that the steel wires are already cushioned by the polymer coating and there is less risk of extreme localized pressure on the steel wires. Additionally, the inventors believe that the puncture device adds additional holding force to the clamp.

[0020] In one embodiment of the present invention according to the first aspect, the wedge includes a contact member for electrically connecting the wedge to the socket body. While in most cases the wedge will contact the socket body, thereby potentially establishing electrical contact between the wedge and the socket, this is not always guaranteed, and in many cases the coated elevator rope prevents electrical contact between the socket body and the wedge. The contact member helps ensure this electrical contact.

[0021] The contact members may take the form of simple electrical connection wires between the socket body and the wedge, for example braided copper wire attached to the socket body and wedge, in this way the wedge and socket body are also held together in pairs.

[0022] The contact members may advantageously be in the form of conductive springs, such as leaf springs or spring washers, preferably made from a metal or metal alloy that conducts electricity well, such as copper, brass, bronze, copper beryllium, or similar material.

[0023] Because the wedge has an axis of symmetry along its longest length, care must be taken to properly insert the wedge into the socket body. If the puncture tool is oriented against the aligned side of the socket body, a combination of high tensile stresses and high lateral stresses can occur during loading. This combination of both, combined with a repetitive loading pattern, can certainly cause catastrophic fracture. To prevent this problem, the wedge is provided with a key that fits into a slot in the socket body to prevent incorrect insertion of the wedge. Advantageously, the key can be mated to the contact member.

[0024] In both the first and second aspects of the present invention, the puncture device can be a pin, fin, or other protrusion. A pin is a generally circular protrusion with a pointed tip. A fin is flat, long, and has a knife or ridge shape. Typically, they are oriented parallel to the axis of the coated elevator rope. Protrusions, bulges, and bulges can also function as puncture devices. They can end, for example, with an obtuse hemispherical top. In fact, when the coated elevator rope is pulled in the clamp, the lateral pressure between the inner tapered hollow and the wedge becomes so high that even these obtuse protrusions can penetrate the coating if they are high enough.

[0025] To this end, the height of the pins, fins, or other protrusions is greater than the thickness of the elevator rope's sheath. In one embodiment, this height is only slightly greater than the sheath's thickness, for example, by up to 20%. In another embodiment, the pins, fins, or protrusions can penetrate all the way to the center of the conductive tension member. For example, a simple screw can be introduced into the wedge's retaining track.

[0026] The materials from which the socket body and the wedge are made are not particularly different from those of known clamps. For example, malleable cast iron is recommended for the wedge. The socket body is made of spheroidal graphite cast iron, since it must withstand the extreme forces caused by the wedge's thrust. Both materials are good electrical conductors. Also, the piercing devices are preferably made from metal or metal alloys, since their function is to provide conduction. The metal pins, fins, or protrusions must be strong enough to be able to penetrate the coating. The same metal from which the wedge is made can be used (malleable iron), or brass or bronze pins, fins, or protrusions can be fixed in the wedge's retention path.

[0027] In the second aspect of the present invention, compromising the integrity of the socket body by drilling or notching it is less desirable. Because the socket body is made of ductile cast iron, any irregularities within the body that could cause stress buildup could result in catastrophic failure. Therefore, in the second aspect of the present invention, it is recommended that the puncture device be part of and integral with the cast socket body. Fins, pins, and other protrusions can be easily incorporated into the socket body casting mold. For example, fins can be easily incorporated into the slanted side of the socket body's symmetrical plane, allowing for easy removal even when the casting mold is made of two mirrored halves.

[0028] To prevent galvanic corrosion of the tension member, which is preferably made of steel filaments, the puncture device is optimally made of a metal or metal alloy having an electrochemical potential equal to or lower than that of the conductive tension member. For example, the use of a copper puncture device in contact with a steel cord as the tension member may result in premature corrosion of the steel filament, which is less desirable. If the steel filaments of the tension member are zinc-coated steel filaments, it may be advisable to coat the puncture device with zinc, for example, or to make them from zinc-containing pins.

[0029] In a further preferred embodiment of the invention, the wedge and socket are shaped to receive, conform to and fit the cross-sectional shape of the tension member. The following shapes come to mind: - The tension member has a circular cross section, as in the case of a circular coated elevator rope with one single steel cord in the center. The wedge surface and the aligned and / or inclined sides of the tapered hollow are provided with semicircular U-grooves. The tension member has a rectangular cross section with a thickness less than its width. The surfaces of the wedge and tapered hollow are flat and may have serrations to enhance grip. The serrations are not sufficient to pierce the polymer coating. - The tension member consists of a number of parallel circular steel cords encased in a polymer sheath, the cross section showing in-line (in-plane) circular sections connected to one another over their length. For example, Figure "XXXXXX".

[0030] According to a third aspect of the present invention, an elevator is claimed. The elevator is conventional, comprising a cabin or car held, supported, and suspended from one or more elevator ropes. The elevator ropes comprise one or more electrically conductive tension members surrounded by an insulating sheath. At least one end of all of the elevator ropes is held by a clamp according to the first and / or second aspects of the present invention. At least one clamp is electrically connected to the electrically conductive tension member. For example, if there are three elevator ropes, there will be six ends. If one of the ends is held by the described clamp, the requirement is met.

[0031] In a further preferred embodiment, at least one end of each of said elevator ropes is held by a clamp according to the first or second aspect of the invention. In the example of three elevator ropes, this means that three, four, five or six ends are held in the clamp.

[0032] All ends of the elevator rope on the same side are preferably provided with one clamp according to the first or second aspect of the invention, for example all three ends of the elevator rope connecting to the cabin are provided with a clamp according to the invention, or all three ends connecting to the counterweight (1:1 rope routing) or to a fixed point on the elevator (2:1 rope routing) are provided with a clamp according to the invention.

[0033] If the clamps are electrically interconnected with one another, for example by being held to the same metal block, all conductive tension members will be at the same potential. Advantageously, all clamps can be grounded by grounding the metal block, thereby establishing static discharge.

[0034] The clamp of the present invention allows for monitoring the condition of the rope. For example, if both ends of a single elevator rope are equipped with a clamp of the present invention, it is conceivable to monitor the induction, capacitance, or resistance on the conductive tension member of that single elevator rope.

[0035] Alternatively, if only one end of a single elevator rope is electrically grounded, the condition of the coating can be monitored, for example, by capacitance measurement, or if the wire break punctures the coating, the wire break can be detected by mass contact (e.g., a copper pipe through which the coated elevator rope runs). [Brief explanation of the drawings]

[0036] [Figure 1] End terminations as known in the art are shown. [Figure 2] Clarify the various tracks on the wedge. [Figure 3] 1 shows a first embodiment of the first aspect of the present invention. [Figure 4] 2 shows a second embodiment according to the first aspect of the present invention. [Figure 5] 1 shows an embodiment of the second aspect of the present invention. [Figure 6] 1 shows an embodiment according to a third aspect of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] Similarities between different figures are marked with the same units and tens digits, while the hundreds digit refers to the figure number.

[0038] 1 shows an elevator rope termination or clamp 100 as is known in the art. Essentially, the clamp comprises a socket body 104 with a wedge 102 that fits into an internal tapered cavity 103. The coated elevator rope is looped around the wedge before fitting into the internal tapered cavity. Applying tension to the elevator rope causes the wedge to be drawn into the clamp, thereby holding the elevator rope.

[0039] 2 shows wedge 202 with coated elevator rope 206 looped around it. Clamping track 208 is a length along the side of the wedge that holds and presses the elevator rope against aligned side 516 of the inner tapered hollow. Holding track 210 begins just after the elevator rope passes through the tapered inner hollow for the first time and ends when the elevator rope passes through the inner tapered hollow for the second time.

[0040] 3 shows an embodiment of the invention according to a first aspect of the invention. The wedge is provided with four puncture devices 312 that reside in the retaining tracks of the wedge. In this embodiment, the puncture devices 312 have the form of pins. The pins have a height that is greater than the thickness of the coating. In this way, the pins 312 penetrate the coating to the tension member, ensuring electrical contact between the tension member and the wedge 302.

[0041] To ensure that the wedge 302 is also electrically connected to the socket body 104, the wedge 302 is provided with a contact member 314, in this case a conductive leaf spring that is fixed to the wedge 302, for example by screws or welding. When the wedge 302 is inserted into the internal cavity 103 of the socket body 104, the leaf spring presses against the inside of the internal cavity, thereby ensuring electrical contact between the wedge and the socket body. The socket body is further mechanically held and electrically connected to further wiring (not shown).

[0042] 4 shows an alternative embodiment of the first aspect of the invention, in which the wedge 402 here comprises three acute-angled fins 412 in the retaining track. The height of the acute-angled fins is approximately half the diameter of the elevator rope, penetrating it more deeply. In this case, the electrical contact member 414, which also serves as a key for insertion into the internal hollow of the socket body, is also made in the form of a spring. The key slides into a recess in the internal hollow (not shown), thereby preventing the wedge from being inserted into the socket body with the fins 412 reaching the clamping track instead of the retaining track.

[0043] 5 shows a socket body 504 according to one embodiment of the second aspect of the present invention. In this embodiment, the socket body 504 is provided with a series of protrusions 512 located on the sloping sides of an internal tapered hollow 518. The aligned sides of the internal tapered hollow are designated 516 and are coincident with the center of the suspension bore 520. The series of protrusions 512 are, in this case, obtuse-angled hemispherical ridges perpendicular to the direction of the coated elevator rope formed in a casting mold for casting the socket body.

[0044] FIG. 6 illustrates an embodiment according to the third aspect of the present invention. An elevator 600 is shown with a cabin 630. The cabin 630 travels on a track (not shown) within an elevator shaft 601 and is carried by a coated elevator rope 606 that travels over diverting pulleys 632, 632' below the cabin 630, which are made of a non-conductive polymer. The cabin 630 is balanced by a counterweight 634 using a 2:1 rope routing with a diverting pulley 633. A drive and control mechanism 636 is mounted inside the elevator shaft 601 and has a series of parallel drive pulleys 638 for driving the coated elevator rope. The elevator rope is held in place by a prior art insulating clamp 640 on the side that lifts the counterweight 634 and a clamp 642 of the present invention to a fixed point at the top of the shaft.

[0045] The inventive clamp 642 is connected via an electrical control wire 644 that connects to the drive and control unit 636. A detector 646 is mounted adjacent to the drive and control unit 636. The detector 646 can be, for example, a conductive tube through which a length of elevator rope passes. If a broken filament of the tension member punctures the coating of the coated elevator rope, a short circuit occurs between the inventive clamp 642 and the detection circuit of the drive and control unit 636. The event can be monitored and recorded for timely replacement of the coated elevator rope.

[0046] By connecting the clamp of the present invention to ground, any static charge that builds up on the coated elevator rope is conducted to ground, preventing attraction or repulsion of the coated elevator rope. This specification includes the following disclosure. [Appendix 1] A clamp for holding an end of a coated elevator rope, the elevator rope having one or more tension members surrounded by a coating, the clamp comprising a wedge and a socket body having an internal tapered hollow, the wedge being receivable in the internal tapered hollow of the socket body, the wedge having a clamp track and a retaining track; the wedge comprises one or more puncture devices on the retaining track of the wedge, the puncture devices being for puncturing the sheath of the elevator rope, and the puncture devices being electrically conductive. Clamp. [Appendix 2] 2. The clamp of claim 1, wherein the wedge includes a contact member for electrically contacting the wedge with the socket body. [Appendix 3] 3. The clamp of claim 2, wherein the contact member is a conductive spring. [Appendix 4] 4. The clamp of any one of claims 1 to 3, wherein the wedge includes a key for insertion into the internal tapered hollow portion. [Appendix 5] A clamp for holding an end of a coated elevator rope, the elevator rope having one or more tension members surrounded by a coating, the clamp comprising a wedge and a socket body having an internal tapered hollow, the wedge being receivable in the internal tapered hollow of the socket body, the internal tapered hollow having aligned sides and angled sides; the inclined side of the inner tapered hollow portion is provided with a puncture device for puncturing the sheath of the elevator rope, and the puncture device is electrically conductive. Clamp. [Appendix 6] 6. The clamp of any one of claims 1 to 5, wherein the puncture device is a pin, fin, or protrusion having a height greater than the thickness of the coating of the elevator rope. [Appendix 7] 7. The clamp of any one of claims 1 to 6, wherein the material of the puncture device is a metal or metal alloy having an electrochemical potential that is equal to or lower than that of the conductive tension member. [Appendix 8] 7. The clamp of any one of claims 1 to 6, wherein the wedge and socket are shaped to receive a tension member having a circular cross-section. [Appendix 9] 7. The clamp of any one of claims 1 to 6, wherein the wedge and socket are shaped to receive a tension member having a rectangular cross-section. [Appendix 10] 7. The clamp of any one of claims 1 to 6, wherein the wedge and socket are shaped to receive a tension member having a cross-section comprising a line of circular portions connected to one another longitudinally. [Appendix 11] 1. An elevator comprising: a cabin supported by one or more elevator ropes, the elevator ropes comprising one or more electrically conductive tension members surrounded by an insulating sheath; At least one end of the elevator rope is held by a clamp according to any one of Supplementary Notes 1 to 10. Elevator. [Appendix 12] 12. The elevator of claim 11, wherein at least one end of each of the elevator ropes is held by a clamp of any one of claims 1 to 10. [Appendix 13] 13. The elevator of claim 11 or 12, wherein all of the conductive tension members are electrically connected to each other via the clamp. [Appendix 14] 14. The elevator of claim 13, wherein all of the conductive tension members are connected to ground at the same end of the elevator rope.

Claims

1. A clamp for holding an end of a coated elevator rope, the elevator rope having one or more conductive tension members surrounded by an insulating coating, the clamp comprising a wedge and a socket body having an internal tapered hollow portion, the wedge being receivable in the internal tapered hollow portion of the socket body, the wedge having a clamping track and a retaining track; the wedge is provided with one or more puncture devices on the retaining track of the wedge for puncturing the insulation coating of the elevator rope, the puncture devices being electrically conductive and being pins, fins, or protrusions having a height greater than a thickness of the insulation coating of the elevator rope. Clamp.

2. The clamp of claim 1 , wherein the wedge includes a contact member for placing the wedge in electrical contact with the socket body.

3. The clamp of claim 2 wherein the contact member is a conductive spring.

4. A clamp according to any one of claims 1 to 3, wherein the wedge is provided with a key for insertion into the internal tapered hollow.

5. A clamp for holding an end of a coated elevator rope, the elevator rope having one or more conductive tension members surrounded by an insulating coating, the clamp comprising a wedge and a socket body having an internal tapered hollow, the wedge being receivable in the internal tapered hollow of the socket body, the internal tapered hollow having aligned sides and angled sides; the inclined side surface of the internal tapered hollow portion is provided with a puncture device for puncturing the insulating coating of the elevator rope, the puncture device being a pin, fin, or protrusion that is conductive and has a height greater than a thickness of the insulating coating of the elevator rope. Clamp.

6. The clamp of any one of claims 1 to 5, wherein the material of the puncture device is a metal or metal alloy having an electrochemical potential that is equal to or lower than that of the conductive tension member.

7. A clamp according to any preceding claim, wherein the wedge and socket are shaped to receive a tension member having a circular cross section.

8. A clamp according to any preceding claim, wherein the wedge and socket are shaped to receive a tension member having a rectangular cross section.

9. A clamp according to any one of claims 1 to 5, wherein the wedge and socket are shaped to receive a tension member having a cross section comprising a series of circular portions connected together longitudinally.

10. 1. An elevator comprising: a cabin supported by one or more elevator ropes, the elevator ropes comprising one or more electrically conductive tension members surrounded by an insulating sheath; At least one end of the elevator rope is held by a clamp according to any one of claims 1 to 9. Elevator.

11. 11. An elevator according to claim 10, wherein at least one end of each of the elevator ropes is held by a clamp according to any one of claims 1 to 9.

12. 12. The elevator of claim 10 or 11, wherein all conductive tension members are electrically connected to each other via the clamps.

13. 13. The elevator of claim 12, wherein all conductive tension members are connected to ground at the same end of the elevator rope.

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