The subject matter disclosed herein relates to elevator systems. More specifically, the subject disclosure relates to tension members for elevator suspension and/or driving.
Elevator systems utilize ropes or belts operably connected to an elevator car, and routed over one or more sheaves, also known as pulleys, to propel the elevator car along a hoistway. Belts in particular typically include a plurality of wires at least partially within a jacket material. The plurality of wires is often arranged into one or more strands and the strands are then arranged into one or more cords. In an exemplary belt construction, a plurality of cords is typically arranged equally spaced within a jacket in a longitudinal direction. The cords are typically formed of a plurality of outer strands helically wound around a center strand and each strand is made up of a plurality of wires helically wound around a center wire. The belt is constructed by encapsulating one or more of the cords in the polymeric jacket, typically of a material such as polyurethane. One of two methods are most used, either direct extrusion of the jacket over the one or more cords, or application of the jacket to the one or more cords via a mold wheel process. In either process, volatile contaminants on the one or more cords can result in poor adhesion of the jacket to the steel cords and/or result in voids and bubbles in the jacket.
According to one aspect of the invention, a method of preparing one or more cords for a forming process of a belt for suspending and/or driving an elevator car includes arranging a plurality of wires into a one or more cords. The one or more cords are directed in a cord travel direction toward a jacket former. A high pressure airflow is directed at the one or more cords of to remove volatile contaminants from the one or more cords in a direction away from the jacket former.
Alternatively in this or other aspects of the invention, the high pressure airflow is at a pressure in the range of about 3-10 bar.
Alternatively in this or other aspects of the invention, the high pressure airflow is directed at the one or more cords via one or more nozzles.
Alternatively in this or other aspects of the invention, the one or more nozzles are one or more ribbon nozzles.
Alternatively in this or other aspects of the invention, the method includes utilizing a vacuum system located downstream of the high pressure airflow to remove contaminants dislodged by the high pressure airflow.
Alternatively in this or other aspects of the invention, the method includes heating the high pressure airflow and directing the heated high pressure airflow across the one or more cords to improve adhesion of the jacket material to the one or more cords.
According to another aspect of the invention, a belt for suspending and/or driving an elevator car includes a plurality of wires arranged into one or more cords. The one or more cords have volatile contaminants removed therefrom via a high pressure airflow applied thereto. A jacket substantially retains the one or more cords.
Alternatively in this or other aspects of the invention, the method includes applying the jacket material to the plurality of cords via extrusion.
Alternatively in this or other aspects of the invention, the jacket is formed from an elastomeric material.
According to yet another aspect of the invention, a cleaning apparatus for preparing one or more cords for forming of a belt for suspending and/or driving an elevator car includes a plurality of nozzles to direct a high pressure airflow at one or more cords to remove volatile contaminants from the one or more of cords.
The detailed description explains the invention, together with advantages and features, by way of examples with reference to the drawings.
Shown in
The sheaves 18 each have a diameter 20, which may be the same or different than the diameters of the other sheaves 18 in the elevator system 10. At least one of the sheaves 18 could be a traction sheave and driven by a machine 50. Movement of the traction sheave by the machine 50 drives (through traction) the one or more belts 16 that are routed around the drive sheave.
At least one of the sheaves 18 could be a diverter, deflector or idler sheave. Diverter, deflector or idler sheaves are not driven by a machine 50, but help guide the one or more belts 16 around the various components of the elevator system 10. The shape of the sheave 18 depends on the shape of the belt 16 that it engages. For example, one or more of the sheaves 18 may have a crown (i.e. a convex shape) along its axis of rotation to assist in keeping the one or more belts 16 centered, or in a desired position, along the sheaves 18. While such a shape may be used with the belt 16 shown in
In some embodiments, the elevator system 10 could use two or more belts 16 for suspending and/or driving the elevator car 12. In addition, the elevator system 10 could have various configurations such that either both sides of the one or more belts 16 engage the one or more sheaves 18 (such as shown in the exemplary elevator systems in
The belts 16 are constructed to have sufficient flexibility when passing over the one or more sheaves 18 to provide low bending stresses, meet belt life requirements and/or have smooth operation, while also being sufficiently strong to suspend and/or drive the elevator car 12.
The jacket 26 could be any suitable material, including a single material, multiple materials, two or more layers using the same or dissimilar materials, and/or a film. In one arrangement, the jacket 26 could be a polymer, such as an elastomer, applied to the cords 24 using, for example, an extrusion or a mold wheel process. In another arrangement, the jacket 26 could be a woven fabric that engages and/or integrates the cords 24. As an additional arrangement, the jacket 26 could be one or more of the previously mentioned alternatives in combination.
Referring now to
The jacket 26 can substantially retain the cords 24 therein. The phrase substantially retain means that the jacket 26 has sufficient engagement with the cords 24 such that the cords 24 do not pull out of, detach from, and/or cut through the jacket 26 during the application on the belt 16 of a load that can be encountered during use in an elevator system 10 with, potentially, an additional factor of safety. In other words, the cords 24 remain at their original positions relative to the jacket 26 during use in an elevator system 10. The jacket 26 could completely envelop the cords 24 (such as shown in
Referring to
Prior to entering the jacket former 32, the cords 24 are guided past a plurality of nozzles 34. The nozzles 34 direct a high pressure airflow 36 against the cords. 24. In some embodiments the pressure is in the range of about 3-10 bar at the cords 24.
The airflow 36 is urged over cords 24 at an injection angle 38 less than 90 degrees relative to a travel direction 40 of the cords 24 into the jacket former 32. Injecting the airflow at such an injection angle 38 ensures that volatile contaminants expelled from the cords 24 by the airflow 36 are blown upstream, away from the jacket former 32, as opposed to toward the jacket former 32. In some embodiments, after airflow 36 is injected over the cords 24 to dislodge the contaminants, the cords 24 pass through or past a vacuum system 40 to remove any remaining contaminants, preventing them from being redeposited on the cords 24.
In some embodiments, as shown in
In some embodiments, the airflow 36 is heated prior to entering former 32 to condition the cords 24 and promote better adhesion of the jacket 16 to the cords 24. The selected temperature depends on the material forming the cords 24 and jacket 26. For example, in some embodiments the airflow 36 is heated to between 200-500 degrees Celsius to increase a cord temperature to between about 100-200 degrees Celsius prior to the application of jacket 26 to the cords 24.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2012/060358 | 10/16/2012 | WO | 00 |