| 1. | Safety ropes used for fastening of vessels and other mobile objects, primarily made of elastic, bending, natural or synthetic fibres, and layed of strands, wherein one rope consists of several main strands and one or more auxiliary strands of larger stretching coefficient than the main strands; or the main rope of more strands being made in the form of a double loop with a longer and thinner auxiliary rope. |
| 2. | Safety ropes as claimed in Claim 1, w h e r e i n the rope (1) includes one or more auxiliary middle strands (2) of larger stretching coefficient, around which there are twisted four normally righthand twisted main strands (3) of lesser stretching coefficient. |
| 3. | Safety ropes as claimed in Claim 1, wherein the rope (4) includes one main middle strand (5) around which there are twisted three main righthand layed strands (6) and one auxiliary strand (7) of larger stretching coefficient then the main strands. |
| 4. | Safety ropes as claimed in Claim 1, wherein the rope (8) includes four pairs of strands, out of which two are twisted righthand and two lefthand ; where the seven main strands (9), (10), (11), (12), and one auxiliary strand (13) are of larger stretching coefficient than the main strands. |
| 5. | Safety rope as claimed in Claim 1, wh e re i n the double loop (14) includes main rope (15), loops (16) and (17), auxiliary rope (18), which is thinner and longer than the main rope between the points (19) and that it is interlaced with the main rope in the points (19). |
| 6. | Safety ropes as claimed in Claims 1 to 5, w h e r e i n they are bound at the end of a mooring line as an addition (supplement) for mooring of ships or other mobile objects. |
According to the International Patents Classification, the invention is classified as B 63 B 21/20: Performing operations; transporting-Ships or other waterborne vessels; related equipment-Tying-up ; Shifting, towing, or pushing equipment; Anchoring-Adaptations of chains, ropes, hawsers, or the like, or of parts thereof.
2. TEHNICAL PROBLEM While mooring ships to the shore, the strong jerk that occurs when the overloaded ropes break, throws the broken ends of the rope away. The ropes are mainly made of flexible and pliable materials (natural and synthetic fibres). Because of the relatively great mass of those ropes and because of the great speed that the broken ends of the rope are thrown away with, large force impuls occurs at the breaking point. At mooring the ships, this problem often ends with accidences, even fatalities. This invention deals with solution to this problem.
3. STATE OF ART As far as the author is aware, there are no technical solutions by means of which the consequences of sudden breaking of overloaded ropes could be prevented or at least soothed.
4. DISCLOSURE OF THE INVENTION The force impuls that occurs because of the instant rope breaking can be soothed if its ends are kept together at the point of breaking, after the rope breaks. The solution to this tehnical problem is, according to this invention, described in two embodiments.
According to the first embodiment, with ropes with more strands, at least one auxiliary strand of rope is made of a material of a higher stretching coefficient, that would break subsequently, after the rope main strands would break. After breaking, auxiliary strand would keep the split ends of other strands together. After further pulling (distension), the auxiliary strand would break as well (the more elastic part), but because of the small breaking force (the auxiliary strand has a signifficantly smaller diameter) there would't be such a strong jerk in this case.
The force impuls does not suffice to throw the rope off strongly.
According to the other embodiment, the effect of sequential breaking of rope is achived by the design of a rope with two paralel connections named"double loop".
Both connections are made of the same material with several strands, where one connection-rope is considerably thicker and it carries the load (main), while the other connection-rope is thinner and serves for stopping the jerk (auxiliary). The breaking of the auxiliary connection, after the main connection had already broken, is in this case accomplished because of a difference in length ; that is-the auxiliary connection is somewhat longer than the main connection, so that it remains unloaded, untill the main connection breaks.
5. ILLUSTRATION DESCRIPTIONS The figures added to the description, and making a part of the description of invention, illustrate the best solution for embodiment of the invention, and help explaning the main principles of the invention.
Figure 1. shows four strands, twisted together right-hand, over a core of considerably larger streching coefficient.
Figure 2. shows four strands, twisted together right-hand, with one outer core of considerably larger streching coefficient.
Figure 3. shows eight strands twisted together, with four left-and four right-hand construction, twisted in pairs; one strand having considerably larger streching coefficient.
Figure 4. shows a double loop.
Figure 5. shows a diagram of binding a double loop with a mooring line.
6. DETAILED DESCRIPTION OF INVENTION EMBODIMENTS First embodiment The construction of a rope made of two materials of different streching coefficients is shown in Figures 1,2 and 3.
Figure 1. shows a rope 1 made of one auxiliary central strand 2, of significantly larger streching coefficient, around wich there are four strands twisted together 3, normally right-hand construction, made of a material of lower stretching coefficient.
Figure 2. shows a rope 4 made of one main central strand 5, around which there are twisted four strands, right-hand construction, of which strand 5 and three main strands 6 are of lesser, and the auxiliary strand 7 is of larger stretching coefficient.
Figure 3. shows a rope 8 made of eight strands, two pairs having right-hand construction and two left-hand construction. The pairs of the main strands 9,10, 11 and 12 are made of a material of smaller stretching coefficient, and the auxiliary strand 13 of larger stretching coefficient.
According to this invention, breaking of the rope caused by a strong jerk would not be simultaneous, because the main strands would break first (since they are of lesser stretching coefficient), and then the auxiliary strand (made of a more elastic material).
Second embodiment The other solution to the problem mentioned above is shown in Figure 4., and makes a"double loop"that is attached to the main mooring line, so that the main line does not break when it is overloaded, but the double loop breaks first instead.
According to the Figure 4., on the double loop 14 with two parallel connections there are the main rope 15, loops 16 and 17, and the auxiliary rope 18, that is interlaced with the main rope in knots 19. The auxiliary rope 18 is thinner and longer than the part of the main rope between the knots 19 on loops 16 and 17.
The double loop 14 is attached to the main mooring line, as shown in Figure 5.
Because the auxiliary rope 18 is longer, it is not overloaded by normal overload of the main rope 15. The auxiliary rope is activated only after the main rope breaks, in such a way that it keeps the broken ends of the main rope together. After further pulling of the rope, the auxiliary rope also breaks, but because of the smaller breaking force (the diameter is smaller) the jerk will not be as strong as with the broken ends of the main rope. The force impact is not strong enough to throw the broken main rope off, and therefore the danger of accidence is reduced.
This solution to the problem of breaking of the main rope offers an additional advantage of easy replacement of the broken double loop with another double loop, so that the vessel or other mobile object main mooring line can be used again.
A double loop of exactly determined maximum stretching force would be made for every vessel mooring line, according to its breaking force and how old and/or worn the rope is. In this way double loops for each rope would be prepared, regardless of the purpose for which it will be used.
7. INVENTION APPLICATION All ropes that are now used for mooring of vessels or other mobile objects could be replaced with ropes made according to the first embodiment of this invention.
One of the strands of larger stretching coefficient, by means of which breaking of that particular strand would be postponed, would prevent the jerk of previously broken ends of strands of smaller stretching coefficient.
In the same way, for every determined thickness, material and breaking strength of the main rope, double loops can be provided. That would make a standard piece of equipment for every mooring line. In that way the possible breaking of vessel mooring lines will be pointed exactly to the double loop, which prevents the jerk and strike of the broken ends. In a simple way, by attaching a new double loop, the main rope can be put completely back in function right away, once again secured to break at the point of double loop in case of overloading, with no dangerous consequences of the strike.
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