The present invention relates to rope systems and methods and, more specifically to systems and methods for splicing ropes.
Rope splicing refers to the formation of a joint between two ropes or two parts of the same rope by partly untwisting and interweaving strands of the rope or ropes.
A splice can retain a very high percentage of the strength of the unspliced rope, but the splice tends to create a thickened portion of the rope. In some situations, this thickened portion of the rope does not adversely affect the use of the rope. In other situations, a thickened region of a rope can alter the operating characteristics of the rope and/or the manner in which the rope interacts with structures or mechanical assemblies for guiding and/or securing the rope.
The present invention relates to a particular form of rope splicing referred to as a short splice. A short splice minimizes the length of the thickened portion of the rope and thus minimizes some of the adverse effects of the splice on the operating characteristics of the rope.
The present invention is of particular significance in the context of forming an eye splice, and that application of the present invention will be described herein in detail. However, the principles of the present invention may have application to splices other than eye splices where short splices may be used.
The need thus exists for improved short splice systems and methods for ropes.
The present invention may be embodied as a rope system comprising a rope structure comprising an intact portion comprising intact strands and a disassembled portion comprising loose strands. The loose strands are passed into an interior of the rope structure. Each loose strand is passed from the interior of the rope structure to the exterior of the rope structure adjacent to an associated intact strand. Each loose strand is extended along and wrapped around its associated intact strand at at least one wrap location.
The present invention may also be embodied as a rope system comprising a braided rope structure defining an interior and an exterior and comprising an intact portion comprising a plurality of intact S-strands and a plurality of intact Z-strands and a disassembled portion comprising a plurality of loose strands. Each intact S-strand crosses a plurality of intact Z-strands. Each intact Z-strand crosses a plurality of intact S-strands. The plurality of loose strands is passed into the interior of the rope structure. Each loose strand is passed from the interior of the rope structure to the exterior of the rope structure adjacent to one of an associated intact S-strand and an associated intact Z-strand. Each loose strand associated with one of the intact S-strands is extended under at least one intact Z-strand crossing the associated intact S-strand and over at least one intact Z-strand crossing the associated intact S-strand and wrapped around its associated intact S-strand. Each loose strand associated with one of the intact Z-strands is extended under at least one intact S-strand crossing the associated intact Z-strand and over at least one intact S-strand crossing the associated intact Z-strand and wrapped around its associated intact Z-strand.
The present invention may also be embodied as a method of forming a rope system comprising the following steps. A braided rope structure defining an interior and an exterior is provided. The braided rope structure comprises an intact portion comprising a plurality of intact S-strands and a plurality of intact Z-strands and a disassembled portion comprising a plurality of loose strands. Each intact S-strand crosses a plurality of intact Z-strands. Each intact Z-strand crosses a plurality of intact S-strands. The plurality of loose strands is passed into the interior of the rope structure. Each loose strand is passed from the interior of the rope structure to the exterior of the rope structure. Each loose strand is associated with one of the intact S-strands or one of the intact Z-strands. Each loose strand associated with one of the intact S-strands is extended under at least one intact Z-strand crossing the associated intact S-strand and over at least one intact Z-strand crossing the associated intact S-strand. Each loose strand associated with one of the intact S-strands is wrapped around its associated intact S-strand. Each loose strand associated with one of the intact Z-strands extends under at least one intact S-strand crossing the associated intact Z-strand and over at least one intact S-strand crossing the associated intact Z-strand. Each loose strand associated with one of the intact Z-strands is wrapped around its associated intact Z-strand.
Referring initially to
Referring now to
Referring for a moment to
Based on the splice length L2, a loose strand length L4 is determined as shown in
Next, as perhaps best shown in
With the rope structure in the loop configuration as shown in
Next, as shown in
At this point, it should be noted that the individual braids of a braided rope structure are aligned with what is typically referred to as an S-axis or a Z-axis associated with the rope structure. The S- and Z-axes are both generally helical shapes that extend or are twisted in opposite directions. A given braided rope structure will define either an S-axis or a Z-axis for each strand of the rope. The S-axes are typically radially offset from each other, and the Z-axes are typically radially offset from each other. The S-axes are intertwined with the Z-axes for a particular rope structure. Typically, one half of the strands of any given rope structure will lie along the S-axis, and the other half will lie along the Z-axis. The “S” and “Z” in the terms “S-axis” identify the direction of the twist of the particular helical axis. In particular, the center portions of the letter “S” and the letter “Z” extend from bottom right to top left and bottom left to top right, respectively, and thus the use of these letters forms a mnemonic device for remembering and identifying the axes along which the strands of a braided rope structure extend. Accordingly, from either end of a length of rope, strands extending along the S-axis of the rope thus extend from lower left to upper right, while strands extending along the Z-axis of the rope extend from lower right to upper left. This S-axis/Z-axis reference system will be used in the remaining discussion of the example rope system 20.
The example rope structure 30, being a twelve strand braided rope, defines six S-axes and six Z-axes. As an additional shorthand, intact strands 60 extending along S-axes will be referred to as intact S-strands, while intact strands 60 extending along the Z-axes will be referred to as intact Z-strands. For consistency, the intact S-strands will be referred to using the reference character 60S and the intact Z-strands will be referred to using the reference character 60Z. When individual S-strands or Z-strands are identified, a numerical designator (e.g., 60Z1) will be appended to these reference characters. For clarity, lower case letters will be appended to the reference character “40” associated with individual loose strands 40 (e.g., 40a-l). Similarly, lower case letters will be appended to the reference character “52” associated with individual exit locations 54 (e.g., 52a-l)
Referring for a moment back to
Once these associations are defined, what will be referred to herein as a follow process will be performed for each associated pair of one loose strand 40 and its associated intact strand 60. The follow process involves extending the loose strand 40 along its associated intact strand 60 and either passing the loose strand 40 over or under any intact strands crossing the associated intact strand and making at least one rotation around the associated intact strand.
As examples of loose strands following Z-strands,
As examples of loose strands following S-strands,
In any event, the follow process illustrated in
Referring now to
The loose strands 40 are slightly oversized to facilitate the follow process described above, and the extra portions of the loose strands remaining as shown in
The process of associating loose strands with either S-strands or Z-strands and the follow process are determined based on the characteristics of the particular rope structure 30 and particular resulting rope systems 20. With different rope structures and rope systems, different associations between loose strands and intact strands may be made, both for twelve strand rope structures and certainly for rope structures having fewer or more than twelve strands. And the operational use of the rope system 20 may dictate a longer or shorter spacing between wrap locations and different over and under passes of intact strands crossing the followed intact strand. The example rope system 20 is thus but one example of many rope systems that may be made using the principles of the present invention.
Turning now to
Referring initially to
As discussed above, braided ropes are formed of strands that extend along an S-axis and a Z-axis. The coordinate system or method of the present invention makes use of these axes to define locations along the rope. Further, a braided rope structure defines what will be referred to as rope openings between each pair of adjacent S-strands and each pair of adjacent Z-strands. These rope openings allow access to the interior space defined by a particular braided rope structure. One or more loose strands may be inserted from the exterior of the rope structure into the interior spaced defined by the rope structure or from the interior of the rope structure to the exterior of the rope structure through anyone of these rope openings.
The coordinate system or method of the present invention identifies a particular rope opening of a particular rope structure as an origin opening and uses a first or absolute numerical coordinate system that identifies every other rope opening in the particular rope structure with respect to the defined origin opening and the S- and Z-axes defined with respect to that particular rope structure. Every other rope opening is identified by a positive or negative integer for each of the S- and Z-axes. Spaces towards the bitter end of the rope structure from the origin opening are assigned negative integers, while spaces towards the standing end of the rope structure from the origin opening are assigned positive integers. The notation for the first or absolute numerical coordinate system takes the form of integers within a set of parenthesis (e.g., (s,z)).
The coordinate system or method of the present invention may further use an alternate relative numerical coordinate system to identify the relative position of one rope opening with respect to another opening. This alternate relative numerical coordinate system is of particular significance when identifying or implementing a splice pattern remote from the origin opening. The notation for the second or relative numerical coordinate system takes the form of integers within a set of brackets (e.g., <s,z>).
Given a system for identifying every rope opening defined by a particular rope structure, the particular pattern of tucks and wraps that a given loose strand must follow to obtain a predefined splice system may be defined. In particular, specifying a succession of rope openings using the numerical reference system described above identifies the rope openings that the loose strand alternately enters (in) and exits (out) or exits (out) and enters (in) as the predefined splice system is formed.
In addition, the loose strands may further be uniquely identified to facilitate the use of the coordinate system or method of the present invention. For example, the loose strands formed at the bitter end of a twelve strand rope comprise six S-strands identified using the upper case letters A, B, C, D, E, and F and six Z-strands using the lower case letters a, b, c, d, e, and f. When two or more strands are handled together and follow identical routs may be represented by grouping or concatenating their indices (e.g., As or AB).
Additionally, a particular splice system may require that a particular loose strand be split as the splice system is formed. For example, a strand may be split to facilitate the formation of a tapered splice. If a strand is split, an apostrophe (′) may be added to the letter associated with the strand before the split (e.g., strand A is split to form a strand identified as A′).
Referring now back to
Referring for a moment to
The coordinate system or method described above is applied to an example splice system of the present invention. In particular, the following Tables B, C, and D describe the formation of an example splice system of the present invention.
Table B specifies that all of the loose strands are inserted into the rope through the origin opening and the removed from the rope at various initial exit locations such as the exit locations 54 depicted and described above.
With loose strands extending through the corresponding initial exit locations as described above, the relative coordinate system is used to define the follow process defining the interaction of each loose strand with the rope structure. The following Table C indicates that the follow pattern performed by the individual S-strands:
The following Table D indicates that the follow pattern performed by the individual Z-strands:
In addition to the coordinate systems and methods and reference systems described above, the rope structure itself may be altered with indicia that facilitate the implementation of a splice system using the coordinate systems and methods of the present invention. For example, the loose ends may be color coded, cross-hatched, and/or labeled with the information that facilitates the identification of the individual strands when performing the follow process required to form a particular splice system. Further, portions of the intact portion of the rope structure may be identified using indicia to indicate reference points or structures such as the origin opening and/or the origin S-strand and origin Z-strand. Such reference points or structures may also facilitate the identification of particular rope openings when performing the follow process required to form a particular splice system.
The present invention may be implemented using forms other than those specifically described above.
This application (Attorney's Ref. No. P216924) claims benefit of U.S. Provisional Application Ser. No. 61/468,985 filed Mar. 29, 2011, the contents of which are incorporated herein by reference.
Number | Date | Country | |
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61468985 | Mar 2011 | US |