The invention relates to nautical mooring lines, and more particularly, to segments of mooring rodes that are stretchable.
A stretchable section is often included in a mooring cable or anchor rode for partly absorbing the stresses caused by wave actions on small boats, on buoys, or on similar floating structures. The elastic stretching of the rode helps to prevent damage to the craft or floating structure, as well as helping to prevent the loosening of its anchor. A stretchable segment is also sometimes included in a tow rope for dampening the shock of accelerating a floating object from rest, and for helping to even out the fluctuations in tension due to wave action during towing.
Generally, these stretchable segments include an elastomeric core surrounded by an extensible woven braid made from a synthetic polymer such as polyester or polyolefin.
A tension on the stretchable segment causes the braided outer layer of the rope to expand without resistance, while the inner elastic core stretches elastically and with increased resistance. Eventually, the braided outer layer reaches its maximum length, whereupon the tension load is transferred from the inner core to the outer braid, and the stretchable segment maintains its length until the tension is relieved.
An anchor rode is often partially wound on a capstan or around sheaves, and has shackles or knots at both ends thereof. Therefore, an anchor rode needs to be non-elastic along the segments thereof which are used for tying and along the segments susceptible to slippage and sharp bending. Hence, it is often desirable to make only a short segment of the anchor rode stretchable, as opposed to its full length. As a result, both ends of the stretchable segment are often submerged in a relatively harsh marine environment while in use, and are subject to both chemical and biological deterioration.
Various methods are used to attach the elastomeric core to the braid at the ends of the stretchable segment 16. Typically, the elastomeric core emerges from the outer braid at each end, and is clamped, taped, and/or interwoven with the outer braid. An example is shown in
As is illustrated in
Due to its smooth surface and other material properties, the tape or heat-shrinkable tubing 108 is typically resistant to water and salt, and is not susceptible to undue amounts of marine attachment and growth. The synthetic material of the outer woven braid 102 is also typically impervious to attack from fresh or salt water, and the regular extensions and contractions of the braid inhibit the attachment and growth of marine life.
However, the braid extensions are greatest at the center of the stretchable segment, and least near the ends. Therefore, a region often exists near each end of a stretchable segment of a rode where the covering braid is not protected by tape or heat-shrinkable tubing 108, and yet does not undergo sufficient extension and contraction to inhibit the attachment and growth of marine life. This can lead to an unappealing appearance, as well as maintenance issues when the mooring cable is raised and the attached marine life must be removed and disposed of. In the worst case, it can even lead to degradation and eventual mechanical failure of the rode.
What is needed, therefore, is a protective covering system for end portions of a stretchable segment of a mooring rode that inhibits access of surrounding marine life to the end portions but does not inhibit expansion and contraction of the end portions.
A fabric shield for protecting an elastic end portion of a stretchable segment of a mooring rode from abrasion and chafing, and also from surrounding water and marine life, includes a tube of shielding fabric arranged over the stretchable end portion in a rolling wall configuration that enables firm attachment of a distal end of the shield to the covering braid in the elastic end portion without inhibiting expansion and contraction of the elastic end portion. When the stretchable segment of the rode is stretched, the shield remains attached at both ends, and adapts to the change in length of the elastic end portion by partially unrolling the rolling wall.
The fabric shield of the present invention is attached to the non-elastic end of the stretchable segment of the rode at the shield's proximal end (the end nearest to the end of the rode) by any attachment means known the art, such as by sewing or clamping. The proximal end of the shield typically overlaps, or is overlapped by, the tape or heat-shrinkable tubing that covers the non-elastic end of the stretchable segment. The shield is attached at its distal end only to the braid of the elastic end portion by a means that does not inhibit stretching of the braid or movement of the elastomeric core within the braid. In some of these embodiments, the shield is attached to the braid at its distal end by sewing, and in other embodiments the shield is attached to the braid at its distal end by interweaving of a strap, such as a cable tie, through the shield and the braid.
In embodiments, the shield is made from nylon. In some embodiments the stretchable segment of the rode can be stretched to a length that is more than 50% longer than its unstretched length.
One general aspect of the present invention is a stretchable segment of a mooring rode having a shield for protecting a proximal elastic portion of the stretchable segment. The stretchable segment includes a stretchable section having an extendable outer braid surrounding an elastomeric inner core, the stretchable section being attached at one end to an inelastic end of the stretchable segment; a tube of shielding fabric, the tube being folded back onto itself, such that an inner portion of the tube extends from a distal end of the tube to a fold, and an outer portion of the tube extends back from the fold to a proximal end of the tube, the inner portion of the tube being thereby covered by the outer portion of the tube, and the distal end of the tube being thereby located between the proximal end of the tube and the fold; a first attachment mechanism fixing the proximal end of the tube to the inelastic end of the stretchable segment; and a second attachment mechanism fixing the distal end of the tube to the outer braid at a location distal to a proximal elastic portion of the stretchable section, so that the proximal elastic portion is covered by the tube, said second attachment mechanism being configured to allow substantially unhindered movement of the elastic inner core through the outer braid, so that expansion and contraction of the proximal elastic portion is substantially unhindered by attachment thereto of the tube.
In some embodiments, the second attachment mechanism includes stitches attaching the distal end of the tube to the outer braid. In other embodiments the second attachment mechanism includes a strap that is interwoven through the shielding fabric of the tube and the outer braid. And in some of these embodiments the strap is a cable tie.
In various embodiments the first attachment mechanism includes a clamp that compresses the proximal end of the tube against the inelastic end of the stretchable segment.
In certain embodiments, the stretchable segment is more than 50% longer in a maximally stretched configuration than it is in an unstretched configuration. In some embodiments the shielding fabric includes nylon.
And in embodiments, the inelastic end of the stretchable segment is covered by tape or by heat-shrinkable tubing.
Another general aspect of the present invention is a method for protecting a proximal elastic portion of a stretchable segment of a mooring rode, the stretchable segment including an extendable outer braid surrounding an elastomeric inner core, the proximal elastic portion being an elastic portion of the stretchable segment that is adjacent to an inelastic end of the stretchable segment. The method includes sliding a tube of shielding fabric over the stretchable segment and past the proximal elastic portion, so that a distal end of the tube is closest to the proximal elastic portion, but the tube does not surround any part of the proximal elastic portion; attaching the distal end of the tube to the outer braid of the stretchable segment using a first attachment mechanism that does not hinder extension of the extendable outer braid or of the elastomeric inner core; folding a proximal end of the tube back over the distal end, thereby creating a fold in the tube, such that the distal end of the tube is located between the proximal end and the fold; and attaching the proximal end of the tube to the inelastic end of the stretchable segment, so that the proximal elastic portion is fully covered by the tube.
In some embodiments, attaching the distal end of the tube to the outer braid of the stretchable segment includes sewing of the distal end of the tube to the outer braid. In other embodiments attaching the distal end of the tube to the outer braid of the stretchable segment includes interweaving of a strap through the shielding material and the outer braid. And in some of these embodiments the strap is a cable tie.
In various embodiments, attaching the proximal end of the tube to the inelastic end of the stretchable segment includes using a clamp to compresses the proximal end of the tube against the inelastic end.
In certain embodiments, the stretchable segment can be stretched to a length that is more than 50% longer than an unstretched length of the stretchable segment.
In some embodiments, the shielding fabric includes nylon. And in other embodiments, the inelastic end of the stretchable segment is covered by tape or by heat-shrinkable tubing.
The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.
With reference to
As is illustrated in
In the embodiment of
In various embodiments, the shield 200 is attached to the stretchable segment 16 of the rode 10 at the shield's proximal end 202 by any suitable attachment means known the art, such as by sewing or clamping. The shield 200 is attached at its distal end 204 only to the braid 102 by a means that does not inhibit extension of the braid 102 or movement of the elastomeric core 100 within the braid 102. In some of these embodiments, the shield 200 is attached to the braid 102 at its distal end 204 by sewing. In other of these embodiments, the shield 200 is attached to the braid 102 at its distal end 204 by interweaving of a strap, such as a cable tie, through the shield and the braid. An example of a cable tie 300 being interwoven through a shield 200 and through the underlying braid 102 is shown in
A side view of an embodiment 200 of the present invention installed at one end of a stretchable segment 16 is presented in
In embodiments, the stretchable segment 16 of the rode 10 can be stretched to a length that is more than 50% longer than its rest length.
The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.
This application claims the benefit of U.S. Provisional Application No. 61/664,185, filed Jun. 26, 2012, which is herein incorporated by reference in its entirety for all purposes.
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Number | Date | Country | |
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20130340665 A1 | Dec 2013 | US |
Number | Date | Country | |
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61664185 | Jun 2012 | US |