JP2002321882A - Tensile member for elevator device and method of forming tensile member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method superior in efficiency and durability for driving an elevator device. SOLUTION: This tensile member 22 for the elevator device has the aspect ratio larger than 1. An increase in the aspect ratio reduces maximum rope pressure more than a conventional elevator rope, and enhances flexibility. Thus, a smaller sheave 24 can be used together with this tensile member. In a specific embodiment, the tensile member has plural independent load carrying cords 26 included in a common coating layer 28. The coating layer separates the individual cords, and determines a contact surface 30 for contacting with the driving sheave. The individual cords are composed of plural strands, and the respective strands are separated so as not to directly contact with the ether strand by a high polymer material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator system, and more particularly to a tension member for an elevator system.

[0002]

2. Description of the Related Art A general traction type elevator apparatus includes a car, a counterweight, a car and a counterweight.
It includes a book or more ropes, a drive sheave for driving the ropes, and a machine for rotating the drive sheave. These ropes are made of twisted or twisted steel wires, and the sheaves are made of cast iron. The machine can be used with or without gears. Geared machines allow the use of smaller, lower cost, high speed motors, but require additional maintenance and space.

[0003]

[0004] While common circular steel ropes and cast iron sheaves have been found to be very reliable and cost effective, they are not suitable for use. There is a limit. One limitation is the traction between the rope and the sheave. Such traction can be increased by increasing the contact angle of the rope or by cutting a groove in the sheave. However, when these techniques are used, the durability of the rope is reduced due to an increase in abrasion (contact angle) or rope pressure (cutting). Another way to increase traction is to provide a liner made of synthetic material in the sheave groove. Such a liner reduces the wear of the rope and the sheave while increasing the coefficient of friction between the rope and the sheave.

[0004] Another limitation in using circular steel ropes relates to the flexibility and fatigue properties of such circular steel ropes. The elevator safety code now states that the minimum diameter d of each steel rope (d _min = 8 for CEN)
mm, d _min = 9.5 mm (3/8 ") in ANSI
And the D / d ratio of the traction elevator is 40 or more (D / d ≧ 40). D
Is the diameter of the sheave. Thereby, the diameter D of the sheave is
It is defined as at least 320 mm (380 mm in ANSI). The greater the diameter D of the sheave, the greater the torque required of the machine to drive the elevator system.

[0005] Another disadvantage of common circular ropes is that the higher the rope pressure, the shorter the life of the rope. The rope pressure (P _rope ) is generated as the rope moves on the sheave and is directly proportional to the tension (F) on the rope and inversely proportional to the sheave diameter D and the rope diameter d (ie, P _rope is proportional to F / (Dd)). In addition, the maximum rope pressure received by the rope is further increased by the groove shape of the sheave to which the traction-enhancing technology such as making a cut in the sheave is applied.

[0006] Despite the techniques described above, scientists and technicians under the direction of the assignee of the present applicant provide efficient and durable methods and apparatus for driving an elevator system. Strives to develop.

[0007]

SUMMARY OF THE INVENTION In accordance with the present invention, a preferred tension member for an elevator has an aspect ratio greater than 1, where the aspect ratio is the width w of the tension member.
Defined as the ratio of thickness to thickness t (aspect ratio = w /
t). In another form of the invention, ropes other than flat ropes (such as circular ropes) benefit from one configuration of the invention.

One feature of the present invention is the flat shape of the tension member. The increased aspect ratio provides a contact surface defined by a width dimension that is optimized to distribute rope pressure. Thus, the maximum pressure on the tension member is minimized. Further, by increasing the aspect ratio compared to a circular rope having an aspect ratio equal to 1, the thickness of the tension member can be reduced while keeping the cross-sectional area of the tension member constant.

[0009] Further according to the present invention, the tension member has a plurality of independent load carrying cords contained within a common coating layer. This coating separates the individual cords and defines the contact surface with the drive sheave.

[0010] This configuration of the tension member allows for a more uniform distribution of the rope pressure across the tension member. This significantly reduces the maximum rope pressure as compared to elevators with conventional ropes having similar load carrying capabilities. Furthermore, at equivalent load capacity,
The effective rope diameter "d" (measured in the bending direction) is reduced. Therefore, the value of the sheave diameter “D” can be reduced without reducing the D / d ratio. Furthermore, by minimizing the diameter D of the sheave, a low-cost and small high-speed motor can be used as a driving machine without the need for a gearbox.

In a particular embodiment of the invention, the individual cords are constituted by strands of metallic material, organic fiber material, or a combination thereof. By incorporating a cord of material that is weight, strength, durable, and particularly flexible, and appropriately sized in the tensile member of the present invention, while maintaining maximum rope pressure within acceptable limits, The allowable drive sheave diameter can be further reduced. As described above, when the sheave diameter is small, the torque required for the machine that drives the sheave decreases, and the rotation speed increases. Therefore, it is possible to drive the elevator apparatus using a smaller and lower-cost machine.

To further extend the useful life of the tension member, the individual cords used in the present invention are treated to prevent fretting. This process is performed in two stages. First, a wire that is thinner than the center strand is used for the outer strand. This difference creates a gap between the outer strands. Thus, when subsequently forming a rope coating around the desired number of cords, the coating penetrates sufficiently into the gaps between the outer strands, preventing contact between the strands and preventing fretting. This is effective and results in a flexible tension member with a long service life. The present invention also teaches to provide a tensile member having a longer life or a higher rated load. In this regard, the present invention teaches providing a polymer coating around the central strand of each cord before winding the outer strand around the central strand. By doing so, in each cord, the contact between the outer strand and the central strand is reduced, and no fretting occurs between them. This increases the load carrying capacity of a tension member using this technique, or prolongs the useful life of such a tension member. In each case, the industry will benefit substantially. Coating the inner strands according to the present invention is applicable to all tension members, including but not limited to flat and circular tension members. The invention is described with reference to a flat tension member, since a flat tension member is preferred for other reasons.
One skilled in the art can use flat or circular (or other shapes) tension members for implementation.

Although primarily described herein with respect to a traction device used in an elevator application having a drive sheave, the tension member may be an indirect rope elevator device, a linear motor driven elevator device, and an automatic propulsion having a counterweight. It may also be useful and beneficial in elevator applications where a pulley is not used to drive the tensioning member, such as a lift. In such applications, the reduced size of the sheave may be useful to reduce the space required for the elevator installation. The above and other objects, features, and advantages of the present invention will become more apparent from the following embodiments and the accompanying drawings.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
2 is shown. The elevator device 12 includes a car 14,
It includes a counterweight 16, a traction drive 18, and a machine 20. The traction drive 18 includes a tension member 22 for interconnecting the car 14 and the counterweight 16, and a drive sheave 24. The pulling member 22 is in contact with the sheave 24 such that the rotation of the sheave 24 moves the pulling member 22, and thus the car 14 and the counterweight 16, respectively. The machine 20 engages and rotates the sheave 24. Although a machine 20 with gears is shown, this configuration is merely exemplary, and the invention can be used with either a machine with gears or a machine without gears.

The tension member 22 and the sheave 24 are shown in more detail in FIG. The tension member 22 is a single member including a plurality of cords 26 inside the common coating layer 28. Each cord 26 is composed of seven twisted strands, and each strand is preferably composed of seven twisted metal wires. In the preferred embodiment of the present invention, high carbon steel is used. The steel is preferably cold drawn and galvanized, and has the well-known strength and corrosion resistance obtained by such a treatment. The coating layer is preferably a polyurethane material and may include a fire protection component.

Referring to FIG. 3, in a preferred embodiment, each strand 27 of cord 26 has seven wires, with six wires 29 twisted about center wire 31. Has become. Each cord 26 is composed of one strand 27a arranged at the center and one strand 27 at the center.
and six outer strands 27b twisted around a. Preferably, the twist pattern of the individual wires 29 that make up the central strand 27a is
The wire 29 of the outer strand 27b is twisted in the opposite direction around the center wire 31 of the outer strand 27b, while being twisted in a single direction around the center wire 31 of 7a. In the same direction that the wire 29 is twisted around the center wire 31 in the strand 27a,
The outer strand 27b is twisted around the central strand 27a. For example, in one embodiment, each strand has a center wire 31; in the center strand 27a, six wires 29 are twisted clockwise around the center wire 31; in the outer strand 27b,
The wire 29 is twisted counterclockwise. Further, at the level of the cord 26, the outer strand 27b is twisted clockwise around the central strand 27a. The direction of twist improves the load distribution characteristics of all wires of the cord.

For a successful such flat embodiment of the present invention, it is important to use wires 29 of very small dimensions. Each wire 29, 31 has a diameter of 0.
Less than 25 millimeters, preferably about 0.10
０．２0.20 mm. In certain embodiments, the diameter of the wire is 0.175 millimeter. The preference for the use of small sized wires has the advantage that smaller sheaves can be used.
Small diameter wires can withstand the bending radii of small diameter sheaves (about 100 millimeters in diameter) without overstressing the strands of the flat rope. In this particular embodiment of the invention, preferably the overall diameter is about 1.
By inserting a plurality of 6 millimeter, thin cords 26 into the elastomer of the flat rope, the pressure on each cord is significantly reduced over prior art ropes. n
Is the number of parallel cords inside the flat rope, for a given load and wire cross-section, the cord pressure is reduced to at least n- ^{1 / 2} .

Referring to FIG. 4, in another embodiment, the center wire 3 of the center strand 37a in each cord 26
5 is larger in diameter. For example, if the wire 29 (0.175 millimeters in diameter) of the embodiment described above is utilized, only the central wire 35 of the inner central strand of all cords will have a diameter of about 0.20 to 0.22 millimeters. The effect of changing the diameter of the center wire in this way is that not only the contact between the strands 37b twisted around the strand 37a is reduced, but also the contact between the wires 29 surrounding the wire 35 is reduced. Is to be done. In such an embodiment, the diameter of cord 26 is
It is slightly larger than 1.6 mm in the embodiment described above.

Referring to FIG. 5, in a third embodiment of the present invention, by expanding the concept of the second embodiment,
The contact between the wires and between the strands is further reduced. The cord of the present invention is constructed using three different sized wires. In this embodiment, the thickest wire is the center wire 202 of the center strand 200. A wire 204 having an intermediate diameter is disposed around the center wire 202 of the center strand 200 and the center strand 200
Has become part of. Wire 2 with this intermediate diameter
Reference numeral 04 further designates the center wire 206 of all the outer strands 210. The smallest diameter wire is
Each outer strand 210 is labeled 208.
At each wire 206. The diameter of all wires in this example is also less than 0.25 mm. In an exemplary embodiment, the wire 202 is 0.21 mm, the wire 204 is 0.19 mm, and the wire 206 is 0.19 m.
m, the wire 208 can be 0.175 mm. In this embodiment, wire 204 and wire 206
Are of equal diameter and are separately numbered simply to provide information about the location. The present invention relates to a wire 2
The diameters of the wire 04 and the wire 206 are not limited to those having the same diameter. All diameters of the wires used are exemplary only, reducing the contact between the outer wires of the central strand, reducing the contact between the outer wires of the outer strand, and reducing the contact between the outer strands. It is possible to reorganize according to the principle of joining as reduced.
In the described embodiment (for example only),
A gap of 0.14 mm is obtained between the outer wires of the outer strands. This gap is formed by the common coating layer 28.
Is sufficient to prevent contact between the outer strands.

This reduces fretting between the outer strands and greatly extends the life of the rope,
In the cords of the tension members, fretting still occurs between the contacting outer and central strands. Preventing fretting in this position allows for a further increase in service life or a higher rated load for both flat and non-flat tensile members. Referring to FIG.
The central strand 200 is surrounded by outer strands 210
Is pre-coated with a polymer coating 212 before winding. The polymer coating 212 can be formed as an extruded thermoplastic material or by impregnating a thermosetting material, such as a common rubber product, followed by curing. The use of a polyurethane or other material that is compatible with the common coating layer 28 allows the polymer coating 212 to melt and bond with the common coating layer 28. This is,
5 is one preferred embodiment of the present invention. In another embodiment of the present invention, the polymer coating 212 may be a modified polyamide or polyacetal low friction material. Such a low friction material ultimately results in a tensile member that imparts internal lubricity to the individual cords and that has significantly improved service life or rated load capacity. Although the coating 212 is used with cords having different wire and strand diameters in embodiments, the concept of coating 212 is fully applicable to any of the other cord embodiments described herein.

The cords 26 are of equal length, are substantially equally spaced in the width direction within the coating layer 28, and are arranged linearly along the width dimension. The coating layer 28 is formed from a polyurethane material, preferably a thermoplastic urethane, which material is passed over and through the plurality of cords 26 to restrain longitudinal movement of the individual cords 26 relative to other cords 26. Pushed out. Other embodiments include the use of transparent materials, which may be advantageous because they facilitate visual inspection of flat ropes. Of course, the color is independent of the structure. Other materials can be used as the coating layer 28 as long as the functions required for the coating layer such as traction, abrasion, transmission of the traction load to the cord 26, and resistance to environmental factors are sufficiently satisfied. Furthermore, if another material having less than the mechanical properties of the thermoplastic urethane is used, the further advantage of the present invention of drastically reducing the sheave diameter may not be obtained completely. When the mechanical properties of thermoplastic urethane are used, the sheave diameter is 1
It can be reduced to less than 00 mm. The coating layer 28 defines a contact surface 30 that contacts a corresponding surface of the drive sheave 24.

As shown more clearly in FIG. 7, the tension member 22 comprises a width w, measured transversely to the length of the tension member 22, and a tension member 2 about the sheave 24.
2 has a thickness t1 measured in the bending direction. Each code 2
6 have a diameter d and are separated by a distance s. Furthermore, the thickness t2 of the coating layer 28 between the cord 26 and the contact surface 30 and the thickness t3 between the cord 26 and the opposite surface are determined so that t1 = t2 + t3 + d.

The overall dimensions of the tension member 22 result in a cross-sectional area having an aspect ratio much greater than 1, where the aspect ratio is defined as the ratio of width w to thickness t1 (ie, aspect ratio = w / t1). Is done. When the aspect ratio is 1, it corresponds to a general circular cross section of a conventional circular rope. The higher the aspect ratio, the more the tension member 2
2 becomes flatter. When the tension member 22 is extended flat, the thickness t1 of the tension member 22 is minimized and the width w is maximized without sacrificing the cross-sectional area, that is, the load carrying capacity. This shape distributes the rope pressure over the width of the tension member 22 and reduces the maximum rope pressure as compared to a circular rope of equivalent cross-sectional area, ie, load carrying capacity. 2 in which five independent cords 26 are arranged in a coating layer 28.
In 2, the aspect ratio is larger than 5. The aspect ratio is illustrated as being greater than 5, but the aspect ratio is 1
It is believed that benefits are obtained with larger tensile members, especially with aspect ratios greater than 2.

The distance s between the adjacent cords 26 depends on the material and the manufacturing process of the tension member 22 and the tension member 22.
Determined by the stress distribution of the rope over the Considering the load, it is desirable to minimize the distance s between adjacent cords 26 and to reduce the amount of coating material between the cords 26. However, in view of the stress distribution of the rope, it may be limited to provide the cords 26 at close distances from each other so as to prevent excessive stress in the coating layer between adjacent cords 26. Based on these considerations, the separation distance can be optimized for specific load carrying requirements.

The thickness t2 of the coating layer 28 is determined by the stress distribution of the rope and the wear characteristics of the material of the coating layer 28. As described above, the coating layer 28
It is desirable to provide enough material to prevent excessive stress in the interior of the housing while maximizing the useful life of the tension member 22.

The thickness t3 of the coating layer 28 is determined by the use of the tension member 22. As shown in FIG. 1, the tension member 22 moves on a single sheave 24 so that the top surface 32 does not contact the sheave 24. In this application, the thickness t3 can be made extremely thin as long as the tension member 22 has a thickness enough to withstand the strain when moving on the sheave 24. It may also be desirable to cut grooves in the surface 32 of the tension member to reduce tension within the thickness t3. On the other hand, the tension member 22 is
For use in elevator systems that need to be bent in the opposite direction around the sheave, a thickness t3 equivalent to t2 may be required. In this application, both the top surface 32 and the lower surface 30 of the tension member 22 are contact surfaces, and the requirements for wear and stress on these surfaces are similar. In any application,
Preferably, a groove is cut in the lower surface 30 to obtain traction.

The diameter d of each cord 26 and the number of cords 26 will depend on the particular application. As described above, so that the flexibility of the cord 26 is maximum and the stress is minimum,
It is desirable to keep the thickness d as small as possible.

Although the present invention has been disclosed and described with reference to illustrative embodiments, those skilled in the art will recognize that various modifications, changes, and alterations may be made without departing from the spirit and scope of the invention.
Omissions and additions can be made.

[Brief description of the drawings]

FIG. 1 is a perspective view of an elevator apparatus.

FIG. 2 is a transverse cross-sectional view of the drive sheave showing the tension members and the sheave.

FIG. 3 is an enlarged sectional view of a single cord according to the present invention, with six strands twisted around a central strand.

FIG. 4 is an enlarged sectional view of another single cord according to the present invention.

FIG. 5 is an enlarged sectional view of another embodiment according to the present invention.

FIG. 6 is a cross-sectional view of a single cord having a polymer inner coating around a central strand.

FIG. 7 is a cross-sectional view of a flat rope exhibiting various dimensional characteristics.

[Explanation of symbols]

 Reference numeral 22: tension member 24: sheave 26: cord 28: common coating layer 30: contact surface

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Pedro S. Balanda United States, Connecticut, Farmington, Berkshore Drive 52 F Term (Reference) 3B153 AA14 AA24 AA34 AA45 AA47 BB20 CC20 CC22 CC27 CC52 DD22 FF04 GG03 GG40 3F305 BB02 BB14

Claims (16)

[Claims] 1. A plurality of wires configured to be a central strand, a polymer coating material surrounding the central strand, and a second plurality of wires configured to be a plurality of outer strands. And a tension member for an elevator apparatus, wherein the outer strand is disposed around the central strand so as to form a cord with the central strand. 2. The tension member of claim 1, wherein the tension member includes the plurality of cords extending parallel to one another and spaced apart from each other, and a polymeric coating surrounding the plurality of cords. A tension member for the elevator apparatus as described in the above. 3. The tension member according to claim 1, wherein the center strand includes a center wire and a plurality of outer wires. 4. The tension member according to claim 3, wherein the plurality of outer wires are wound around the center wire. 5. The outer strand of claim 3, wherein a diameter of a center wire of the outer strand is about 0.21 mm, and a diameter of the plurality of outer wires of the center strand is about 0.19 mm. Tension member of an elevator device. 6. The tension member according to claim 1, wherein each of the outer strands includes a center wire and a plurality of outer wires. 7. The tension member according to claim 6, wherein the plurality of outer wires of the outer strand are wound around the center wire of the outer strand. 8. The tension member according to claim 6, wherein the diameter of the center wire of the outer strand is about 0.19 mm. 9. The tension member according to claim 6, wherein the diameter of the outer wire of the outer strand is about 0.175 mm. 10. The tension member according to claim 1, wherein the polymer coating surrounding the central strand is polyurethane. 11. The tension member according to claim 1, wherein the polymer coating surrounding the central strand is polyamide. 12. The tension member according to claim 1, wherein the polymer coating surrounding the central strand is polyacetal. 13. The method of claim 1, wherein the polymer coating surrounding the central strand reduces contact between the outer strand and the central strand.
A tension member for the elevator apparatus according to any one of the preceding claims. 14. The tension member according to claim 1, wherein the polymer coating surrounding the plurality of cords is polyurethane. 15. Forming said central strand and said outer strand, extruding a polymer coating around said central strand, arranging said outer strand around said central strand to form a cord; The method according to claim 1, further comprising arranging a plurality of cords in a separated state, and covering the cords with a common coating. 16. forming the central strand and the outer strand, impregnating and curing the central strand with a thermosetting material, disposing the outer strand around the central strand to form a cord; The method of claim 1, further comprising: arranging a plurality of cords in parallel and spaced apart, and coating the cords with a common coating.