ES2203293B1 - Elevator cable based on braided aramid consists of a braided aramid core coated with polyurethane, surrounded by steel cables - Google Patents

Abstract

The elevator cable based on braided aramid comprises a central core of braided aramid (1) coated with polyurethane (2) and surrounded by sets of cables (3). The steel cables (3) of each set surround a central core made as a string of steel filaments (4).

Description

Cable for lifting devices.

The present invention, as its own title indicates refers to a cable for elevators and forklifts, which they join the cabin on the one hand and on the other end a counterweight, going through a top drive pulley.

Elevator or forklift cables usually they consist of an inner soul of steel or of natural organic fibers, around which they are arranged a series of cable packages, usually also of steel. A mixed solution, with a central soul separated from packages envelopes by an insulating layer is represented in the document EPO444245.

EP0633350 describes a formed cable by a central soul with a series of steel cable packages, which is surrounded by a series of cable packages of which the outer filaments are metallic and surround a central soul of larger diameter formed by a synthetic material, such as polyethylene, polypropylene, polyamide or other substances analogous

EP2141851 describes a cable that It comprises a central cable package, surrounded by a jacket envelope, around which a second group of cables are located, likewise protected externally by another synthetic envelope. The cables are in both cases, both in the inner layer and exterior, aramid and the inner cable sheath is polyester, plastic or silicone, while the envelope External is polyurethane.

Since a fault in the cables that hangs the elevator car could have dire consequences for people who use it, the safety coefficients that are They require lifts and forklift cables are very high. In Spain, the elevator cables are required to be steel and that the relationship between the diameter of the pulleys and the cable diameter is at least 40. The reason for these generous pulleys is to minimize fatigue and wear of Steel cables, in their continuous swing on the pulleys.

Now, if what you want is a machinery of elevator that occupies a smaller volume, particularly in height, it is required to reduce the diameter of the pulleys and consequently the diameter of the cable that supports the cabin, for this purpose the use of new synthetic fibers that have resistance mechanical comparable to steel and even higher if Consider the density of steel and aramid. These fibers they have a very small diameter which makes them extraordinarily flexible Similarly, the strands of perlithic steel, which used in the reinforcement of automobile tire covers, they have a very small diameter and are particularly flexible and resistant to fatigue with alternating loads.

The solution proposed here consists of use a central soul formed by a single aramid rope braided, while the outer shell is formed by Steel cables and / or steel filament ropes. Thus the part of the cable that is in contact with the pulleys, which is visible subject to considerable wear, the steel cables that effectively resist wear. The cable packages that envelop the central soul are formed by a nucleus constituted by a string of very thin and therefore flexible filaments of Perlithic steel of high mechanical resistance, surrounded by successive Steel cables that resist wear mentioned above.

The core core of the cable is formed by a single strand of braided aramid, instead of parallel aramids, to prevent the upper fibers from lengthening more than lower fibers, thus ensuring that all aramid fibers work together and are under more effort homogeneous. Since aramids degrade if they are put to the light is coated this rope or aramid cape with polyurethane or polyamide, preferably the first since it resists in greater Measure abrasive wear and withstand more temperatures high.

This central soul formed with a rope or cape of braided aramid presents a starry section of vertices finished off, whose openings allow the provision of packages external cables to provide the cable assembly with a more uniform section near the circular. Cable section it is a function of that of the inner aramid soul and the rope of perlithic steel that constitutes the core of the packages of peripheral cables; keeping the section of the steel cables regardless of the resulting cable.

The object of the invention will be better understood with the help of the following description based on a practical example of embodiment; This description is made in based on the drawings in the annexed plan, in which:

Figures 1 and 2 show in each section transversal two cable structures for lifting devices made in accordance with the present invention.

In both figures a cable (A) is observed that it has a central soul (1) and an envelope formed by packages of cables (B) of less diameter.

The central bore (1) has a single body of star section, topped vertices, made in aramid braided, provided with an outer covering (2) of polyurethane or polyamide. The resulting cable section (A) determines the number of points or arms of this star (1), as you can appreciate when comparing the figures in the annexed plan, so that the dimensions of the openings and arms are equivalent regardless of the cable section.

For its part, the envelope structure of said central structure (1) consists of various cable packages (B), of which one of them constitutes a central nucleus (4) in around which other cables (3) of less than or equal are distributed size.

According to the present invention the cables (3) located around the central core (4) are made of steel, while said central core (4) is formed by a rope made with Perlithic steel filaments.

The section of the peripheral strings (4) depends of which you have the cable (A), however the section remains of the steel cables (3), as shown in figures 1 and 2.

It is not considered necessary to extend this description so that any subject matter expert understands the scope of the invention and the advantages thereof drift

The materials, form and arrangement of elements will be subject to variation as long as it does not suppose an alteration of the essential characteristics of the invention, which are claimed below:

Claims (4)

1. Cable for lifting devices composed of a central core, surrounded by a plurality of cables, characterized in that: a) the central core is formed by a single strand (1) of braided aramid, provided with an outer sheath (2) of polyurethane or polyamide; b) the outer cables (3) - (4) are made of steel and / or strands of perlitic steel filaments and are arranged in packages (B). 2. Cable, according to the preceding claim, characterized in that the central core (1), of braided aramid, has a starry section of rounded vertices, in whose openings the external cable packages (B) are arranged. Cable according to the preceding claims, characterized in that each of the external packages (B) has a central cord (4) of perlitic steel filaments, surrounded by a plurality of steel cables (3). 4. Cable, according to the preceding claims, characterized in that the section of the inner rope (4) has a diameter equal to or greater than the steel cables (3); and because the diameter of said rope is a function of that of the central core (4) and both of the cable (A).