KR20080069239A - Elevator load bearing member having a conversion coating on a tension member - Google Patents

Abstract

A load bearing member (22) useful in an elevator system (10) includes at least one elongated tension member (36), a conversion coating (46) on the elongated tension member (36), and a polymer jacket (34) at least partially surrounding the coated elongated tension member (36). In one example, the conversion coating (46) includes at least one of an oxide, a phosphate, or a chromate.

Description

ELEVATOR LOAD BEARING MEMBER HAVING A CONVERSION COATING ON A TENSION MEMBER}

In general, the present invention relates to a load bearing member for use in an elevator system. More specifically, the present invention relates to a load bearing member comprising at least one tension member and an outer polymer jacket.

Elevator systems are well known and used. Typical configurations include, for example, elevator caps that move between landings in a building to transfer passengers or cargo between different building floors. Motorized elevator machines move the rope or belt assembly, which typically supports the weight of the cap and moves the cap through the hoistway.

The elevator machine includes a machine shaft that is selectively rotatably driven by a motor. The machine shaft typically supports a sheave that rotates with the machine shaft. The elevator machine tracks the ropes or belts through the sheave to rotate the sheave in one direction to lower the cap and to rotate the sheave in the opposite direction to raise the cap.

Typically, the rope or belt includes one or more tension members to support the weight of the elevator cap. These tension members are encapsulated in the polymer jacket. One type of tension member includes steel strands with a polymer jacket. The jacket surrounds the tension members and provides traction between the rope or belt and the sheave.

Conventional jacket application processes leave portions of cords that are not covered with the jacket material. One known technique includes depositing a zinc coating on steel tension members to protect exposed portions from corrosion that may result from exposure to the environment in the hoistway.

One disadvantage of conventional jacket ropes and belts may be insufficient adhesion between the polymer jacket and the tension members. The adhesion provides a "pull-out" strength to maintain the desired alignment of the tension members and the jacket. The adhesive also serves to transfer the weight of the elevator cap from the jacket to the steel cords. If the weight is not effectively transferred from the weaker jacket material to the stronger steel material, the jacket may be subjected to excessive stress. The use of a zinc coating on steel as described above can further detract from the desired level of adhesion.

Another disadvantage of conventional ropes and belts can be frictional wear between steel strands. For example, when a rope or belt is bent over a sheave, the steel strands of the tension member slide against each other and rub together. Repeated sliding may cause steel strands to suffer undesirable wear over time. Conventional zinc coatings rarely reduce this agent.

There is a need for a rope or belt assembly with improved adhesion between tension members and a jacket. The present invention addresses this need and provides improved capabilities while avoiding the disadvantages and drawbacks of the prior art.

Exemplary load bearing members useful in elevator systems include one or more elongated tension members and a conversion coating on the elongated tension members. Some examples include polymer jackets that fully or partially surround the elongate tension member. In one example, the conversion coating comprises one or more of oxide, phosphate or chromate.

An exemplary method of making a load bearing member includes coating one or more elongate tension members with a conversion coating. One exemplary method includes surrounding the coated tension member in whole or in part with a polymer jacket. One example includes chemically bonding the conversion coating to the elongate tension member and mechanically bonding the conversion coating to the polymer jacket.

Various features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of the preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.

1 schematically illustrates selected portions of an exemplary elevator system;

2 schematically illustrates some selected portions of an exemplary load bearing member;

3 is a schematic cross-sectional view of an example strand of a tension member with a conversion coating;

4 is a schematic cross-sectional view of a second embodiment of a tension member exemplary strand having a conversion coating and a second coating;

5 is a schematic cross sectional view of selected portions of another exemplary load bearing member;

6 is a schematic cross-sectional view of an exemplary cord of a tension member.

1 schematically depicts selected portions of an example elevator system 10 that includes an elevator cap 12 that moves in a known manner between landings 16 in the hoistway 14. In the example shown, the platform 18 above the elevator cap 12 supports the elevator machine 20. The elevator machine 20 is a sheave 21 which moves a load bearing member 22, such as an elevator rope or belt, in the hoistway 14 to move the cap 12 and counterweight 24 up and down in a known manner. ). The load supporting member 22 supports the weight of the elevator cap 12 and the counterweight 24.

2 shows selected portions of an example load bearing member 22 that include a polymer jacket 34, such as polyurethane or another polymer, that surrounds the tension member 36 in whole or in part. Although the figure shows one tension member, the load bearing member 22 may include a plurality of tension members 36 as known (FIG. 3). One exemplary load bearing member 22 is a coated steel rope. Another exemplary load bearing member 22 is a flat coated steel belt.

In the example shown, the tension member 36 includes a plurality of strands 38, such as steel strands. Groups of strands 38 are bundled together to form cords 40. In the example shown, the tension member 36 includes one cord 40.

Circular cross sections of the strands 38 result in a space 41 between the strands 38. In the example shown, the material of the polymer jacket 34 penetrates in part or in part into the space 41 during, for example, an extrusion or other process used to form the polymer jacket 34. Fill in part of 41.

4 shows selected features of an example strand 38 made of steel and having an outer surface 44. In the example shown, the conversion coating 46 is chemically bonded to the outer surface 44. That is, the exemplary conversion coating 46 is formed on the outer surface 44 through chemical reactions rather than mechanical deposition, and chemically bonded to the strand 38. In one example, each strand 38 of cord 40 (FIG. 2) is individually coated with a conversion coating 46 prior to being wound on cord 40.

In one example, the conversion coating 46 includes a phosphate coating having a selected amount of chemical element manganese. In one example, manganese provides an advantageous crystallographic structure for mechanical interlocking with the polymer jacket 34 as described below. In another example, the conversion coating 46 includes a phosphate coating with one or more of zinc, nickel, chromium or iron to provide an advantageous crystallographic structure.

In another example, the conversion coating 46 includes one or more of chromium coating (hexavalent or trivalent) or black iron oxide to provide an advantageous crystallographic structure with additional corrosion inhibition.

In one example, the conversion coating 46 is sealed by known techniques to fill at least a portion of any pores of the conversion coating 46. In another example, the conversion coating 46 is left unsealed.

In one example, the conversion coating 46 inhibits the corrosion of the strands 38, promotes adhesion between the strands 38 and the polymer jacket 34, and wraps together the strands 38 that form the cord 40. To provide lubricity.

In another example, conversion coating 46 includes forming a phosphate coating using known conversion coating techniques such as chemical immersion, chemical spraying or another process. Exemplary phosphates include the chemical element phosphorus which binds to oxygen to form oxides. An active material, such as phosphoric acid, reacts with the outer surface 44 of the strand 38 to form a phosphorous oxide. The resulting phosphate coating is at least partially chemically bonded to the outer surface portion 44 and passivates the outer surface 44 to inhibit corrosion of the strand 38.

In the example shown, the phosphate coating provides abrasion and wear resistance between the strands 38 of the cord 40. When the load bearing member 24 is wrapped around the sheave 21 of the cord 40, the strands 38 can slide relative to one another in use. For example, phosphate is known to be a solid lubricant and allows the strands 38 to slide against each other with less friction as compared to the zinc-coated strands previously used. Chemically bonding the phosphate coating to the outer surface 44 of the strand 38 provides the advantage of preventing the phosphate coating from being easily delaminated, otherwise a coating that is not chemically bonded will result. Can be. If a portion of the coating is delaminated, the delaminated particles act as abrasive particles, for example to accelerate wear between the strands.

In the example shown, the phosphate conversion coating 46 has an irregularly-shaped outer surface 48. The irregularly-shaped surface 48 is produced from the crystallographic structure of the conversion coating 46. This surface mechanically promotes the locking of the polymer jacket 34 against the tension member 36 to form a strong bond. The chemical bonding between the conversion coating 46 and the strands 38 together with the mechanical locking between the conversion coating 46 and the polymer jacket 34 provides the advantage of strong adhesion between the polymer jacket 34 and the tension member 36. .

In one example, when the jacket 34 is under compression between the tension member 36 and the sheave 21, strong adhesion is achieved by the strands 38 and cords 40 of the tension member 36 from the polymer jacket 34. ) Facilitates efficient transfer of the weight of the elevator cap 12.

Strong adhesion also provides a latitude of type selection of the polymer for the polymer jacket 34. In one example, the polymer jacket 34 comprises a polyurethane variant or a type of polymer different from polyurethane. Without the conversion coating 46, the jacket material should have selected properties to achieve sufficient engagement between the jacket 34 and the tension member 36. According to the excellent adhesion provided by the conversion coating 46, there are a wide range of materials that are suitable candidates for forming the jacket. Another advantage associated with a more free choice of jacket material is that the choice can be made, in whole or in part, to promote better molding when forming the jacket. Given this description, those skilled in the art will be able to select appropriate coating components and jacket materials to meet the needs of their particular situation.

5 shows selected features of a second embodiment of an example strand 38 that includes an underlayer coating 58 under the conversion coating 46. In one example, underlayer coating 58 includes a zinc coating for additional corrosion protection of strand 38. Exemplary underlayer coating 58 is deposited by spray, dip, or other process, and provides a sacrificial corrosion coating, while conversion coating 46 provides a passivated coating.

In the example shown in FIG. 6, the cord 40 is coated with a conversion coating 46 after the cord is formed rather than each individual strand 38 is coated. In the example shown, the spaces 41 between the strands 38 convert so that the conversion coating 46 coats the strands 38 entirely or partially towards the center of the cord 40 rather than just the periphery 50. Large enough to allow at least partial penetration of the coating 46. In another example, the amount by which strands 38 are directed towards the center of cord 40 is coated by the type of conversion coating process used, the type and viscosity of the chemicals of the conversion coating, and between the strands 38. Depends on the size of the spaces 41. Given this description, those skilled in the art will be able to select appropriate parameters to meet the needs of their particular situation.

7 shows selected portions of another embodiment of an example load bearing member 22 having a tension member 36 that includes a plurality of cords 40 wound together. Although only one tension member 36 is shown in the drawing, as is known, the load bearing member 22 may include a plurality of tension members 36. In the example shown, each individual strand 38 and each individual cord 40 are wound together so that each individual strand 38 and each individual cord 40 is coated prior to forming the tension member 36. Rather, the entire tension member 36 is coated with a conversion coating 46. Exemplary conversion coating 46 is formed on the periphery of tension member 36 through chemical reactions rather than by mechanical deposition as described above. Depending on the needs of a particular situation, those skilled in the art having the benefit of this description may choose to coat the individual strands 38, the individual cords 40, or the entire tension member 36. .

While preferred embodiments of the invention have been disclosed, those skilled in the art will understand that specific modifications may be made within the scope of the invention. To this end, the following claims should be understood to determine the scope and composition of the invention.

Claims (20)

In a load supporting member for use in an elevator system, At least one elongated tension member; And And a conversion coating on said elongate tension member. The method of claim 1, And said conversion coating comprises at least one of oxide, phosphate or chromate. The method of claim 2, The conversion coating is load supporting member, characterized in that it comprises at least one of manganese phosphate, nickel phosphate, chromium phosphate, zinc phosphate or iron phosphate. The method of claim 1, And a polymer jacket surrounding the elongated tension member in whole or in part. The method of claim 4, wherein The polymer jacket is a load supporting member, characterized in that it comprises polyurethane. The method of claim 4, wherein And the conversion coating is chemically bonded to the elongate tension member and mechanically coupled to the polymer jacket in whole or in part. The method of claim 4, wherein And the elongate tension member comprises a strand having an outer surface, wherein the conversion coating is chemically bonded to the outer surface and mechanically or wholly or partially mechanically bonded to the polymer jacket. The method of claim 7, wherein And a plurality of steel strands, said conversion coating being in whole or in part between said steel strands. The method of claim 4, wherein The elongate tension member includes a cord having a plurality of wound strands each having an outer surface, wherein the conversion coating is chemically bonded to at least a portion of the outer surfaces and mechanically or wholly or partially bonded to the polymer jacket. Load supporting member, characterized in that the. The method of claim 4, wherein And wherein the conversion coating comprises an irregularly shaped surface that is mechanically coupled in whole or in part to the polymer jacket. The method of claim 1, And a zinc coating under the conversion coating. In the method of manufacturing a load supporting member for an elevator system, A method of manufacturing a load bearing member comprising coating an elongate tension member with a conversion coating. The method of claim 12, A method of manufacturing a load bearing member, comprising the step of forming at least one of an oxide, phosphate, hexavalent or trivalent chromium conversion coating. The method of claim 13, A method of manufacturing a load bearing member comprising the step of forming at least one of manganese phosphate, nickel phosphate, chromium phosphate, zinc phosphate or iron phosphate conversion coating. The method of claim 12, And enclosing the coated elongate tension member in whole or in part with a polymer jacket. The method of claim 15, And mechanically coupling the conversion coating to the polymer jacket. The method of claim 12, A method of manufacturing a load bearing member, comprising depositing a zinc underlayer coating prior to conversion coating. The method of claim 12, Chemically bonding the conversion coating to the elongated tension member. The method of claim 12, Forming the elongate tension member from a plurality of strands and forming the conversion coating in whole or in part between the plurality of strands. The method of claim 12, Forming the elongate tension member from at least one cord comprising a plurality of strands and forming the conversion coating on the at least one cord.

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