Patent Publication Number: US-10774469-B2

Title: Fid for rope splicing

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit under 35 U.S.C. § 119 of the earlier filing date of U.S. Provisional Application No. 62/414,447 filed 28 Oct. 2016 entitled “Fid for rope splicing,” which is hereby incorporated by reference in its entirety as if fully set forth herein. 
    
    
     TECHNICAL FIELD 
     The technology described herein relates to a fid for splicing rope and has particular application for splicing a thimble eye in high tensile strength ropes for towing, winching, and other high-tension applications. 
     BACKGROUND 
     A fid is a tool used to hold open knots and holes in canvas, and to separate the “lays” or strands of synthetic or natural rope for splicing. Many different designs for fids have been created throughout the centuries from sharpened bones or sticks to machined metal rods. In many modern configurations for rope splicing applications, fids are formed similar to knitting needles, with long, narrow, cylindrical shafts with a conically pointed tip end. One end of a rope is typically attached to an end of the fid opposite the pointed end. Most fids for synthetic rope splicing tend to be very long (e.g., up to 18 in. (45 cm) or longer) and have no structure for attaching an end of the rope to an end of the fid. Often the rope is merely taped to the end of the fid in order to attach the two together. This is not an elegant solution; it requires the availability of tape; and it often does not hold the rope sufficiently tight to resist the stress of the splicing activity. Other fid devices may define a threaded bore opposite the tip end into which the rope end may be twisted and held in place by the threading. This solution is also not desirable as the threads may also not provide an adequate retention force to hold the rope during splicing operations. 
     The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention as defined in the claims is to be bound. 
     SUMMARY 
     The technology disclosed herein relates to a fid that is made of separate components that can be easily assembled and disassembled by the user. In this manner the fid components can be easily stored or transported and then assembled when needed to create a fid of sufficient length to splice a synthetic rope or other types of rope. One component of the fid comprises an elongate shaft with a first that tapers to a point. The opposing end of the shaft may be machined to form a connection structure. In one embodiment, the connection structure may be a cylindrical end portion of the shaft. The end portion may be solid with threading as for a bolt formed in the outside surface thereof. Alternatively, the end portion may be hollow with threading on an interior cylindrical surface defining the hollow area. 
     An intermediate, interface component or coupler may have an elongate form with two opposing ends along a center axis. The coupler may have a first end that defines a cavity with threading on an interior cylindrical surface defining the cavity. Alternatively, the first end may be formed as a solid cylinder with threading as for a bolt formed in the outside surface thereof. The second end may also define a cavity for attaching the coupler to the third component of the fid that connects to an end of a length or rope. 
     The third component may take the form of a cylindrical, helically wound braid of thin wire cable or other similar flexible cable material forming a wire basket. A first end of the wire basket may be compressed and inserted into the cavity in the second end of the coupler and permanently affixed therein. In some embodiments second end of the coupler may be crimped to compress the sidewalls defining the cavity to crush against the first end of the wire braid and thereby retain the wire basket within the second end of the coupler. In other embodiments, the wire basket may be adhered within the cavity in the second end of the coupler or otherwise connected or retained therein. 
     The coupler with the attached wire basket may then be removably attached to the shaft by screwing the first end of the interface component onto (or within) the threaded end of the shaft to form the complete fid assembly. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. A more extensive presentation of features, details, utilities, and advantages of the present invention as defined in the claims is provided in the following written description of various embodiments of the invention and illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an assembled fid according to an exemplary implementation. 
         FIG. 2  is an isometric view of the fid of  FIG. 1  disassembled in three components. 
         FIG. 3  is an enlarged, isometric view of a portion of the disassembled fid components as indicated in  FIG. 2 . 
         FIG. 4  is a cross-section view of a portion of the assembled fid as indicated in  FIG. 1 . 
         FIG. 5  is an image of a storage pouch for the components of a disassembled fid. 
         FIG. 6  is an image of the fid components partially inserted into the pouch of  FIG. 5 . 
         FIG. 7  is an image of the separate fid components. 
         FIG. 8  is an image of a portion of the fid components readied for assembly by screwing the interface component and the shaft together. 
         FIG. 9  is an image of the helically braided cable of the fid compressed longitudinally to create a larger diameter for receipt of an end of rope. 
         FIG. 10  is an image of an end of a length of rope trapped within the helically braided cable. 
         FIG. 11  is an image of a needle tip of the fid inserted within a length of the rope at a first strand pass-through location. 
         FIG. 12  is an image of a wire basket of the fid interlaced within a length of the rope at a second strand pass-through location. 
         FIG. 13  is an image of a needle tip of the fid inserted within a length of the rope at a bury opening position. 
         FIG. 14  is an image of the fid exiting the length of rope at a bury exit location. 
         FIG. 15  is an image of the fid separated from the rope end and the rope end extending from the bury exit location after being laced through a section of the rope in a bury sleeve. 
         FIG. 16  is an image of a fabricator smoothing an elongating the bury sleeve section of the rope to fully encapsulate the rope end therein. 
         FIG. 17  is an image of a first rope eye formed using the fid via the steps of  FIGS. 9-16 , an image of the fid in a disassembled state, and an image of a second rope eye formed as above and also around an through a metal thimble. 
     
    
    
     DETAILED DESCRIPTION 
     It is often desirable to splice lengths of rope together to make a longer length or rope or to splice a length of rope together with itself to form a structure for aid in connecting the rope to other devices or structures. For example, it may be desirable to form an eye in an end of a length of rope for easily connecting the rope to other devices, for example, a hook or a clevis, through which the rope may be easily attached to a load. Ropes with eyes so formed are often used in conjunction with a clevis, hook, caribiner, or other similar device for towing, winching, lifting, or lowering a load. 
     In recent years, high tensile strength, synthetic rope has been developed and used in towing and winching applications due to its lighter weight than steel cable and its higher strength under tension than steel cable of the same diameter. In fact, ropes woven of high-modulus polyethylene (HMPE) (e.g., Plasma, Spectra, Dyneema and Amsteel) are rated for many load applications including towing, winching, and mooring. Among other characteristics, HMPE rope has a high resistance to abrasion and ultraviolet degradation, low percentage of elongation, and it floats, which makes it favorable for marine applications. In addition, it is relatively easy to splice with a fid in accordance with the embodiments disclosed herein. In contrast, steel cables cannot generally be spliced and while loops or eyes can be formed, a ferrule must be crimped in place with a specialized crimping tool to hold two parallel wire cable sections together or a number of U-clamps may be bolted in place for the same purpose. In each case, the joint is rough and sharp and may not have achieve the same strength as a rope splice. 
     An exemplary implementation of a fid  100  constituted of separate components that can be easily assembled and disassembled by the user is shown in  FIG. 1 . In this configuration the fid  100  can be easily stored or transported and then assembled when needed to create a fid  100  of sufficient length to splice a synthetic rope or other types of rope. As detailed in the exploded view of  FIG. 2 , the fid  100  may be composed of three primary parts, a needle  102 , a coupler  104 , and a rope holder  106 . The needle  102  may be formed as an elongate, cylindrical shaft  110  with a conically-shaped tip  108  at a first end of the shaft  110 . In other embodiments, the cross section of the shaft  110  could take other forms than circular, for example, triangular, square, hexagonal, octagonal, elliptical, or other forms. The needle  102  may be made of steel, aluminum, or other metal or, in some embodiments, a high-strength plastic. A threaded connector  112  may be formed on a second end of the needle shaft  110  opposite the needle tip  108 . The threaded connector  112  may be formed on an outer surface of the cylindrical needle shaft  110  as shown. The outer diameter of the threads of the threaded connector  112  may be slightly less than a diameter of the needle shaft  110 . In alternate embodiments the threaded connector may be formed in a bore in the second end of the needle shaft with threading provided on an inside surface of a cylindrical wall refining the bore. 
     As depicted in greater detail in  FIGS. 3 and 4 , the coupler  104  provides an interface between the needle  103  and the rope holder  106 . The coupler  104  may be formed as a molded or machined metal or plastic tube composed of two sections. A needle receiver  114  forms a first section of the coupler  104  and is configured to mate and removably connect with the threaded connector  112  on the needle shaft  110 . The needle receiver  114  may define a threaded cylindrical sleeve  118  for mating with the threaded connector  112  of the needle  102 , i.e., the threaded connector  112  may be screwed into the threaded sleeve  118  to connect the needle  102  to the coupler  104 . As the diameter of the threaded connector  112  may be slightly less than a diameter of the needle shaft  110 , the outer surface of the needle shaft  110  may seamlessly abut the outer surface of the coupler  104 . Alternatively, in another embodiment, the threaded connector of the needle could be a female threaded socket and the coupler could instead define a shaft with threading on an outer surface thereof for mating with the threaded connector on the needle. In an exemplary embodiment, the second section of the coupler  104 , referred to herein as ferrule portion  116 , may be a formed as hollow shaft extending from the needle receiver  114  that defines a ferrule cavity  124  therein. 
     In the exemplary implementations disclosed herein, the rope holder  106  may take the form of a cylindrical, helically-wound, wire basket  122 . The due to the nature of the weave, the wire basket  122  may be compressed or elongated along the center longitudinal axis of the cylindrical form. As the wire basket  122  is elongated, e.g., by pulling on the longitudinal ends, the diameter of the wire basket  122  decreases. As the wire basket  102  longitudinally shortens, e.g., by pushing each longitudinal end toward the other, the diameter of the wire basket  122  increases. In an elongated state creating a narrow diameter, one end of the wire basket  122 , referred to herein as the crimped portion  120 , may be inserted within the ferrule cavity  124  of the ferrule portion  116  of the coupler  104 . The ferrule portion  116  may then be crimped about the crimped portion  120  of the wire basket  122  to permanently retain the crimped portion  120  within the ferrule portion  116  and thus connect the rope holder  106  to the coupler  104 . In other embodiments, the crimped portion  120  may be retained within the ferrule portion  116  by other methods or structures, for example, by adhesive, welding, or a mechanical fastener. 
     Exemplary methods for storage, assembly, and use of the fid  100  depicted in and described with respect to  FIGS. 1-4 , are presented in conjunction with  FIGS. 5-17 .  FIGS. 5 and 6  depict an exemplary storage pouch for holding the components of the disassembled fid  100 . The pouch  130  may be formed with two pockets  132   a/b  in which the needle  102  and the combined coupler  104  and rope holder  106  may be inserted and stored. A flap  134  with a closure structure  136  (e.g., half of a hook and loop fastener material) may be provided to retain the components of the fid  100  within the pouch  130  by covering the open ends of the pockets and fastening to a closure structure  138  on an outer surface of the pouch  130  (e.g., and opposing half of a hook and loop fastener material). Other closure structures may include buttons, snaps, ties, etc. 
     The needle  102  and the combined coupler  104  and rope holder  106  may be removed from the pouch  130  and assembled by screwing the coupler  104  onto the threaded connector  112  on the end of the needle shaft  110  as shown in  FIGS. 7 and 8 . The needle shaft  110  may also be provided with additional features to aid in the splicing process. As shown in  FIG. 7 , the needle shaft  110  may have a number of markings printed thereon. One set of markings may be bury length markings  126  provided to aid the user in measuring the length of the splice to be made in the rope or the size of opening for an eye to be spliced. The bury length markings  126  may be in the form of a common measurement scale, for example, inches or centimeters. In the example of  FIG. 7 , the bury length markings  126  are shown in inches and 7 inches are marked on the needle shaft  110 . The entire length of the needle  102  from the tip  108  to the end of the threaded connector  112  may be 8.25 inches as in the exemplary embodiment shown or it may be any other shorter or longer length as desired. The needle shaft  110  may further be provided with bury depth guide markings  128 , which indicate to the user the recommended bury depth of the end of the rope within the splice in order to ensure that the splice will hold under tension. For example, with respect to typical HMPE rope, a bury length of 20-27 inches may be recommended to form a structurally sound splice in ⅜ in. diameter rope. Similarly, a bury length of 22-32 in. may be recommended to form a structurally sound splice in 7/16 in. diameter rope and a bury length of 25-36 in. may be recommended to form a structurally sound splice in ½ in. diameter rope. 
     In order to attach an end of a rope to the fid  100 , the wire basket  122  needs to be prepared to receive it. As shown in  FIG. 9 , the open end of the wire basket  122  may be pushed toward the coupler  104  in order to increase the diameter of the wire basket  122 . A free end of a length of rope  140 , referred to herein as a bury end  142  of the rope  140 , may be inserted into the wire basket  122  and then the wire basket  122  may be elongated by pulling on the open end of the wire basket  122  along the bury end  142  of the rope  140  until the wire basket  122  tightly grips the bury end  142  as shown in  FIG. 10 . The tightening is simply a normal behavior of a cylindrical, helically wound braid, usually the common biaxial braid. Pulling the entire braid of the wire basket  122  lengthens and narrows it. The length is gained by reducing the angle between the warp and weft threads of the biaxial braid at their crossing points, which reduces the radial distance between opposing sides and hence the overall circumference. The more one pulls, the more the circumference shrinks and the braid tightens. Thus, the wire basket  122  functions to retain the bury end  142  when in longitudinal tension with respect to each other like a “Chinese finger trap” toy. 
     A splice within the rope  140  to form an eye may be initiated as shown in  FIG. 11 . The tip  108  of the needle  102  may be passed between the braids of the rope  140  at a first strand pass-through location  144  at a distance along the length of the rope  140  away from the bury end  142  to form a loop for a rope eye  150 . This distance for the first strand pass-through location  144  from the free end of the bury end  142  of the rope  140  may be calculated to be the combination of the desired bury length to form a strong splice and the desired circumference of the rope eye  150 . The entire fid  100  may be pulled through the rope  140  at the first strand pass-through location  144  until a desired size of a rope eye  150  is created. The tip  108  of the needle  102  may then be passed between the braids of the rope  140  at a second strand pass-through location  146  closely adjacent to the first strand pass-through location  144  opposite the rope eye  150  and in an opposite lateral direction from the direction the bury end  142  passed through the rope  140  at the first strand pass-through location  144 . The bury end  142  may be pulled fully through the second strand pass-through location  146  as shown in  FIGS. 12 and 13 . 
     The needle tip  108  may then be inserted in to the rope  140  at a bury opening location  146  closely adjacent to the second strand pass-through location  146  further away from the rope eye  150 . The needle  102  may be directed down the longitudinal core of the rope  104  within a core channel surrounded by the braided strands forming the rope  140 . The entire fid  100  is advanced within and along the length of the rope  140  for the entire length of the bury end of the rope  140  within a bury sleeve portion  152 . The needle tip  108  may be pushed out of the core of the rope  140  at a bury exit location  154 . The needle  102 , the core  104 , and the rope holder  106  may all be expressed through the bury exit location  154  by bunching the rope  140  in the bury sleeve portion  152  toward the eye  150  to shorten the length and increase the diameter as shown in  FIG. 14 . The bury end  142  of the rope  140  may then be removed from the rope holder  106  by bunching the braid of the wire basket  122  longitudinally to increase the diameter and release the bury end  142  as shown in  FIG. 15 . The user may then sleeve the bunched bury sleeve portion  152  of the rope  140  beneath the rope eye  150  toward the bury exit location  154  to pull it over and re-encapsulate the bury end  142  within the bury sleeve portion  152  of the rope  104  extending from the rope eye  150 . Any excess length of the bury end  142  extending beyond the bury exit location  154  may be trimmed with a cutting tool. 
     A completed form of a spliced rope  140  forming a rope eye  150  at a terminal end of the rope  140  is shown in  FIG. 17 . The splice  156  thereby formed within the rope  140  results in a smooth surface of the rope  140  through the bury sleeve portion  152  and around the rope eye  150  at the terminal end of the rope  140 . When under tension, the rope  140  elongates and the circumference of the rope wave reduces to compress the bury end  142  within the bury sleeve  152 . This radially inward compression force holds the bury end  142  within the bury sleeve  152  to maintain the strength of the splice  156 . The weaving of the bury end  152  of the rope  140  through the first and second strand pass-through locations  144 ,  146  also helps prevent the splice  156  from failing when the rope  140  is placed under tension. Additionally, stitching with a strong, small-diameter cord through the splice  156  may be used to prevent slippage of the bury end  142  within the bury sleeve  152  and thereby maintain the integrity of the splice. Once the splice  156  is complete, the fid  100  may be disassembled and stored in the pouch  130 . 
     An alternate implementation of a rope eye  150 ′ is also presented in  FIG. 17 . In this embodiment, the rope  140 ′ is threaded through and around a steel thimble  160 , which provides form and reinforcement to the rope eye  150 ′, particularly against crushing and friction forces that could damage the rope  140  when the rope eye  150 ′ is under tension. The rope  140 ′ may first be fed through the thimble  160  before attachment of the fid  100  to the bury end of the rope  140 ′ to begin the splicing operation and a first strand pass-through location immediately adjacent a point at which the bury end of the rope  140  exits a channel of the thimble  160 . 
     All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader&#39;s understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto may vary. 
     The above specification, examples, and data provide a complete description of the structure and use of exemplary embodiments of the invention as defined in the claims. Although various embodiments of the claimed invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of the claimed invention. Other embodiments are therefore contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments and not limiting. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.