Patent Application
20240076164
A variety of elevator systems are known. Some elevator systems use a hydraulic arrangement for moving the elevator car. Others are traction-based and include roping that suspends the elevator car and a counterweight. A machine causes movement of a traction sheave that, in turn, causes movement of the roping for moving the elevator car as desired.
Advancements have been made in monitoring systems for monitoring the health of the elevator system. Some of these health monitoring systems utilize the roping, which is more generally a load-bearing member of the elevator system. Even with the advancement, those skilled in the art have been striving to improve elevator load bearing member technology.
An elevator load bearing member according to an exemplary embodiment of this disclosure, among other possible things includes a plurality of load bearing wires, a polymer-based conductive adhesive coating on each of the plurality of the wires, and a jacket surrounding the wires. The jacket is adhered to the wires by the polymer-based conductive adhesive coating.
In a further example of the foregoing, the polymer-based conductive adhesive comprises an intrinsically conductive polymer.
In a further example of any of the foregoing, the intrinsically conductive polymer includes at least one of polyacetylene (PA), polyaniline (PAni), polypyrrole (PPy), polythiophere (PTh), poly(3,4-ethylene-dioxythiophene), PEDOT, and poly(phenylvinylene) (PPV).
In a further example of any of the foregoing, the intrinsically conductive polymer is functionalized to facilitate the adhesion of the jacket to the wires.
In a further example of any of the foregoing, the polymer-based conductive adhesive includes a non-conductive polymer adhesive and a conductive element.
In a further example of any of the foregoing, the conductive element includes at least one of carbon nanotubes, graphene, and metal powder.
In a further example of any of the foregoing, the nonconductive polymer adhesive includes at least one of an epoxy, a urethane, or an acrylate.
In a further example of any of the foregoing, the polymer-based conductive element comprises less than about 5% by weight of the conductive element.
In a further example of any of the foregoing, the conductive element comprises between about 0.5% and about 1% by weight of the polymer-based conductive adhesive.
In a further example of any of the foregoing, an electrical conductivity of the polymer-based conductive adhesive is at least about 10 siemens.
In a further example of any of the foregoing, the plurality of load bearing wires are steel wires.
A method of making a load bearing member for an elevator system according to an exemplary embodiment of this disclosure, among other possible things includes applying a polymer-based conductive adhesive coating onto a plurality of wires such that the polymer-based conductive adhesive facilitates electrical conduction between the wires, and surrounding the plurality of wires with a jacket, wherein the jacket is adhered to the wires by the polymer-based conductive adhesive.
In a further example of the foregoing, the polymer-based conductive adhesive comprises an intrinsically conductive polymer.
In a further example of any of the foregoing, the method also includes functionalizing the intrinsically conductive polymer to facilitate the adhesion of the jacket to the wires.
In a further example of any of the foregoing, the polymer-based conductive adhesive includes a non-conductive polymer adhesive and a conductive element.
In a further example of any of the foregoing, the conductive element includes at least one of carbon nanotubes, graphene, and metal powder.
In a further example of any of the foregoing, the polymer-based conductive element comprises less than about 5% by weight of the conductive element.
In a further example of any of the foregoing, the conductive element comprises between about 0.5% and about 1% by weight of the polymer-based conductive adhesive.
In a further example of any of the foregoing, an electrical conductivity of the polymer-based conductive adhesive is at least about 10 siemens.
In a further example of any of the foregoing, the plurality of wires are steel wires.
The jacket 34 includes an inner portion or layer 36 that is received against the cords 30. The inner portion 36 comprises a compressible material such as polyurethane, polyamide, polyester, or ethylene propylene diene monomer rubber (EPDM), or combinations thereof.
With continued reference to
Each of the wires 30 include a conductive adhesive coating 38. The conductive adhesive coating 38 adheres the wires 30 to one another and to the inner layer 36 of the jacket 34. Adequate adhesion is particularly important between the wires 30 and the jacket 34 to maintain the integrity of the load-bearing member 26 and prevent the wires 30 from debonding and/or pulling out from the jacket 34 and maintain the required tensile strength for the loadbearing member 26.
The conductive adhesive coating 38 also facilitates formation of the circuit discussed above for the health monitoring system 27. In other words, the conductive adhesive coating 38 facilitates electrical conduction between the individual wires 30. In general, the conductive adhesive coating 38 has an electrical conductivity of at least 10 siemens.
The conductive adhesive coating 38 may also provide corrosion protection to the wires 30, in some examples.
The conductive adhesive coating 38 is a polymer-based adhesive coating with a conductive element. In one example, the conductive adhesive coating 38 comprises a polymer that is intrinsically conductive, such as polyacetylene (PA), polyaniline (PAni), polypyrrole (PPy), polythiophere (PTh), poly(3,4-ethylene-dioxythiophene), PEDOT, or poly(phenylvinylene) (PPV). That is, the intrinsically conductive polymer is itself the conductive element in this example. The intrinsically conductive polymer can be applied to the wires 30 by any suitable method such as painting, spraying, dipping, etc.
In some examples, the intrinsically conductive polymer is functionalized according to any known method to improve its adhesive properties.
In another example the conductive adhesive coating 38 is polymeric composite material that includes a non-conductive polymeric adhesive and a conductive element. Polymer composites are well known in the art and the composite can be made by any suitable method of combining the non-conductive polymeric adhesive with the conductive element. Any known non-conductive polymeric adhesive such as epoxies, urethanes, or acrylates could be used. Likewise, any suitable conductive elements, such as carbon nanotubes, graphene, or metal powder could be used. In a particular example, the polymeric composite material comprises less than about 5% by weight of the conductive element. In a more particular example the polymeric composite material comprises between about 0.5% and about 1% by weight of the conductive element. In this way, the mechanical and adhesive properties of the conductive adhesive coating 38 are substantially the same as the properties of the non-conductive polymer adhesive. In other words, the addition of the conductive element does not substantially change the mechanical and adhesive properties of the non-conductive polymer adhesive.
As used herein, the term “about” has the typical meaning in the art, however in a particular example “about” can mean deviations of up to 10% of the values described herein.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
