Collecting Rope

1. Field of the Invention

The present invention relates to a collecting rope which is intended for use particularly for collecting of oil or other similar material from the surface of water.

2. Description of the Prior Art

There are numerous types of ropes intended for the collecting of oil or similar material, their most common structural form comprising a substantially unelastic core, which thus acts as the supporting structure of the rope, and over this core a varying number of layers, which usually consist of a material which makes the rope float, and a topmost layer, which has bristle-like thorns or spikes, which do the actual collecting. Sometimes the bristles are attached directly to a supporting cable or the like.

Development of technology has imposed new demands on collecting ropes, and known ropes have not been capable or responding to these demands. In addition, special demands have been set on ropes which operate under difficult conditions run a high risk of breakage. One development of new technology is the rotation of steel ropes about their longitudinal axis in order to improve their collecting efficiency. One such solution is introduced in Finnish Patent Specification No. 60424. Thus, if a steel rope is rotated about its longitudinal axis and the rope is caught on, for example, a rock, it is probable that some part of the apparatus, either the rope or the rotating device, is damaged. This has not been foreseen in prior known solutions.

The object of the present invention is to provide a collecting rope which can be rotated, if so desired, and in which, when the rope gets caught, the parts involved stop from rotating in order to prevent damage, and after possible damage, the rope can easily be brought into operating condition at low cost so that the entire rope need not be transported to the factory for repairs or be entirely replaced. In addition, the object is to provide a new, inexpensive, simple and effective structure for use under any conditions.

It should be noted that the terms "rope" and "bristle" used in this Application must not be interpreted narrowly. "Rope" is used in this connection to denote a long piece, without thereby limiting in any way its shape or thickness, and "bristle" denotes any known structure, from pile to spikes, capable of collecting oil or similar material.

The invention is described below in greater detail with reference to the accompanying drawings, in which

FIG. 1 is a longitudinal sectional representation of a rope according to the invention,

FIG. 2 is a similar sectional representation of a simplified embodiment of the rope according to the invention, and

FIG. 3 depicts cross section III--III of the rope according to FIG. 2.

The rope according to the invention as shown in FIG. 1 consists of the following parts: The core of the rope structure is a part which consists of an outer cylinder 1 and an inner cylinder 3, which are interconnected by means of a disc 2 to form a substantially rigid entity. The length of the double cylinder described is perhaps one-half the diameter of its outer cylinder. On the outer surface of the outer cylinder there are bristles 6, which are preferably of the same material as the cylinder itself, and in this case attached to the cylinder by means of, for example, fusion. On the other hand, the bristles or spikes can be attached to, for example, a separate "sock", which is pulled over the outer cylinder, in which case the spikes protrude substantially straight outwards. For example, polyethylene or polypropylene are suitable for use as the material of the cylinders and also the spikes. The space, indicated by 5, between the cylinders is filled with a material the purpose of which is to float the rope to the desired extent on the surface of water. Closed-cell foam plastics are suitable for this purpose. The foam plastic is installed in place in the form of pre-shaped dics, which substantially fill the intermediate space 5. To ensure attachment, barbs 4 can be used on the inner surface of the outer cylinder and on the outer surface of the inner cylinder. By means of the float layer 5 it is possible, when necessary, to attach the cylinders 1 and 3 to each other even without an intermediate disc 2.

Since the purpose is to rotate the chain in order to rotate the entire rope, the inside of the inner cylinder is provided with spike-like protrusions 11, the purpose of which is to produce a resilient joint in case the rope cannot rotate at that point because of, for example, being caught on a rock. In other words, only that cylinder unit which has been caught stops from rotating, while the other parts of the rope continue their rotation quite normally.

The placement of the above-described friction joint, which yields when necessary, inside the inner cylinder is by no means necessary. A similar effect can be produced by, for example, connecting to the stoppers 10, and to the intermediate pieces of material 5 adjacent to them, friction surfaces which keep the cylindrical parts moving together until the section is caught or something similar occurs. Undoubtedly, experts in the art will automatically come up with even other suitable solutions.

It is possible to use another, even simpler embodiment of the rope in question. It differs from that described above in that it has no inner cylinder. Such a rope is depicted in FIGS. 2 and 3, and owing to its simplicity it is to be considered the preferred embodiment. In the float layer material a hole is made, through which a chain 9 is passed, whereby a naturally suitable friction joint is created between the chain and the float material, without any extra protrusions. This sets considerable demands on the material, also regarding its resistance to wear, since the material must endure also the strains caused by the chain. Several such polymer types, highly resistant to wear, are known among ordinary commercial brands.

The collecting rope of FIG. 2 is thus composed of a cylindrical part 1, to which the bristles 6 which collect oil or the like are attached. Inside the cylinder there is a float layer 5, which substantially fits inside the cylinder and in the center of which there is a bore into which a chain or some other suitable supporting and drive member 9 has been fitted. Over the chain or the like there is preferably, as shown in FIG. 3, vulcanized, or fitted in some other suitable manner, a layer 14 of, for example, plastic or rubber. Such a layer has been found to be advantageous for several reasons. First, the said layer 14 protects the float layer because the edges of the chain are thus rounded and, furthermore, two materials of almost the same type come against each other and thus their adherence to each other for rotation, as well as their durability, is good. If a chain is involved, the surface layer 14 improves its properties in that the shortening of the chain, which is due to a new position of the links in relation to each other, is very slight during the rotating.

The chain 9 is made up of links of the desired type, in which case an ordinary closed-link chain is entirely suitable for the purpose, but its variants such as a chain the links of which are pressed almost together in the middle so that the adjoining links cannot move in the longitudinal direction are also equally suitable for the purpose. The chain is also made up of rather short sections in such a manner that it can be divided, whereupon the replacement of broken links is rapid and easy. In such a case the joint is opened and as many links are removed as necessary for access to the broken link, and the unbroken links, together with the link replacing the broken link, are replaced, whereafter the joint is closed. The rope is again fully usable. The chain joint can be made by means of any coupling known in the art, such as a shackle, which is appropriate in its simplicity. The possibility of dividing the chain can be arranged, when necessary, even in each joint between the links of the rope, although about every tenth or twentieth joint, or an even greater interval, is a more common alternative owing to the low frequency of divisions.

To illustrate the size of the rope, it can be noted by way of example that the diameter of each section is typically about 100 mm and the length of the section about 50 mm. Of course, deviations in either direction are possible, according to the purpose of use. It is, however, highly improbable that the diameter of the sections would exceed 500 mm. A rope of a rather small diameter adapts evenly and precisely to the waves, in which case its usability, for example, on open sea, is excellent compared with ropes previously known in the art. Inability to operate under open-sea conditions has been one of the greatest disadvantages of known structures.

The collecting rope is assembled in such a way that a sufficient number of individual cylinders with their contents are threaded onto a chain 9, at suitable intervals there are placed stoppers 10, which ensure that, when the rope is reeled, not only the chain 9 moves but also the rope material moves along with it. A chain which consists of separate units which can turn in relation to each other has been found to be good, since in that case the rope will press evenly on the water surface and the chain will not produce extra strains in the rope. It has been found in practical experiments that it is advantageous to use occasional clearly longer bristles or spikes. Long bristles are useful for the reason that lumps present in the oil being collected do not easily remain on an even bristle surface, but long bristles will catch them well. In accordance with the invention, this requirement is fulfilled by fitting, between the cylinder units, at suitable intervals, discs 8, which consist of bristles bound together, their outermost ends 7 being free and of such a length that they rise substantially higher from the rope surface than do the bristles 6. On the other hand, a corresponding structure can also be produced by a suitable shaping of the bristles attached to the cylinder 1.

The float material discs 5 come preferably somewhat outside the ends of the cylinders. As a result, the rope is flexible, since the disc material yields and compresses when two adjacent cylinder units turn in relation to each other, as happens when the rope forms a shape deviating from straight. The fact that a relatively soft foam plastic or similar material is against the corresponding part of another unit also protects the long bristles 7 protruding from between the units.

The rope according to the invention is not easily damaged, since it yields when the risk of damage is greatest. The most common reason for damage is the rope being caught on rocks or other obstacles present in shallow water when the operation is carried out near the coast. If, however, there is damage, it very rarely involves very many cylinder units.