Patent Application
20090139602
This invention relates generally to wire rope or cable and more particularly to a tool and method for splaying strands of a wire rope or cable outward from a core thereof at an end of the wire rope or cable.
It has long been known within the art to equip an end of a wire cable or rope with a frustoconical wedge fitted about a core of the wire rope between the core and the strands helically wrapped thereabout after having splayed the strands outward away from the core at the end of the rope, so that a similarly tapered bore of another body can be fitted over the wedge and the splayed ends spaced thereabout to effectively clamp the ends of the strands between the external walls of the wedge and the internal walls of the other body, thereby securing the bore-equipped body to the rope at the end thereof. Such securing of a bell sleeve, socket, stop, hook or other body is utilized in a variety of fields where cable or wire rope is used, including oil field applications, logging, mining, farming and transportation, such as in the use of a winch tractor.
For example, such a fastening means is disclosed in U.S. Pat. No. 4,055,365 of Kucherry for a chocker assembly of a dragline or winchline extended out from a landing or towing vehicle for dragging of cut logs to a landing area.
However, splaying of the strands of the wire rope outward from the core in order fit the wedge into the rope end may be difficult and time consuming, which, for example, may potentially lead to significant delay on the job in situations where on-site need for wire rope repair or replacement is necessary or desirable.
Although the detailed embodiments of the present invention are presented in the context of preparing a wire rope end to receive a wedge for cooperation with the tapered bore of a body to be secured to the rope, it should be appreciated that the tools and methods taught herein below for splaying the outer strands of a wire rope may be similarly applied for other purposes where such splaying is similarly desirable. For example, it is known within the art to apply molten material into the splayed end of a wire rope and allow it to harden to retain the tapered stop-defining shape at the end of the rope. The aforementioned use of a preformed wedge is an alternative to this approach, the wedge advantageously allowing formation of the tapered rope end in situations for molten material is not readily available or preparable, for example to form a connection on a new cable or form a new end connection on a broken cable at a remote job site.
According to a first aspect of the invention there is provided a tool for splaying strands of a wire rope at an end thereof outward away from a core of the rope about which the strands are disposed, the tool comprising:
a body defining a central opening and a plurality of outer openings extending into the body from a common side thereof, the central opening and the plurality of outer openings being sized and positioned for receipt of end portions of the central and strands at the end of the wire rope from the common side of the body, the outer openings each having an elongate shape extending outward away from the central opening along the common side of the body from an inner end to an outer end.
Preferably the elongate shapes of the outer openings along the common side of the body deviate from radial directions relative to the central opening to situate the outer end of each outer opening ahead of the inner end thereof in a common direction about the central opening.
Preferably the elongate shape of each outer opening extending between the inner and outer ends thereof is curved.
Preferably each outer opening is smoothly curved from the inner end of the outer opening to the inner end thereof.
Preferably sides of the elongate shape of each outer opening extending between the inner and outer ends thereof are concave to the common direction about the central opening.
Preferably the body is solid between the openings along the common side of the body.
Preferably at least one of the openings is defined by a respective recess extending only partially through the body from the common side thereof.
Preferably the outer openings are each defined by a respective recess extending only partially through the body from the common side thereof.
Preferably there is provided a handle projecting from the body along the common side thereof to define a lever by which the body can be rotated about the central opening.
Preferably the outer ends of the outer openings are equally spaced about the central opening.
Preferably the outer openings are each radially spaced from the central opening along the common side of the tool body by an equal amount.
The outer openings may consist of six openings equally spaced about the central opening.
According to a second aspect of the invention there is provided a tool for splaying strands of a wire rope at an end thereof outward away from a core of the rope about which the strands are disposed, the tool comprising:
a body defining a central opening and a plurality of outer openings extending into the body from a common side thereof, the central opening and the plurality of outer openings being sized and positioned for receipt of end portions of the central and strands at the end of the wire rope from the common side of the body;
the outer openings being arranged for splaying of the strands of the rope outward away from the core thereof at the end of the wire rope under rotation of the body in a first direction about the core at the end of the wire rope subsequent to receipt of the core and the strands in the central and outer openings respectively.
Preferably the outer openings are also arranged for directing the strands of the rope inward back toward the core thereof under rotation of the body in a second direction, opposite the first direction, about the core at the end of the wire rope subsequent to splaying of the strands.
According to a third aspect of the invention there is provided a method for splaying strands of a wire rope at an end thereof outward away from a core of the rope about which the strands are disposed, the method comprising simultaneously untwisting the strands from about the core in a first direction while forcing the strands outward away from the core at the end of the wire rope.
Preferably the method comprises sliding the strands along guide surfaces shaped and positioned to force each strand away from the core at the end of the wire rope under untwisting of the strands from about the core in the first direction.
There may be provided the additional step of releasing the strands and inserting a wedge into the end of the rope over the core into space formed between the core and the strands during the twisting and forcing outward of the strands, in which case there may be provided yet a further step of simultaneously twisting the strands about the core in a second direction opposite the first direction while forcing the strands inward back toward the core at the end of the wire rope.
In the accompanying drawings, which are not to scale and which illustrate an exemplary embodiment of the present invention:
As shown in
As shown in
A plurality of slots S1-S6 are angularly spaced about the central recess 20, similarly recessed into the tool body 12 from the working face 18 thereof to extend only partially therethrough. The slots S1-S6 are also cylindrical, but are not circular in cross section. Instead, each slot has an elongate shape along the working face 18 and planes parallel thereto, perpendicular to the body's longitudinal axis 12A at positions therealong. The slots S1-S6 feature inner end portions S1i-S6i radially equidistant from the body's central axis 12A and the central recess 20 extending therealong and equally angularly spaced thereabout. The slots S1-S6 extend outward away from the central axis 12A and central recess 20 along the working face 18 to outer end portions S1o-S6o, but not in a radial fashion. Instead, each slot deviates from a radial direction, curving forward about central axis 12A and central recess 20 in the same common direction as the rest of the slots. Each slot thus has its outer end situated ahead of its inner end in this common direction about the central axis 12A and central recess 20, the common direction C being clockwise when facing the working face 18 in the illustrated embodiment. The elongate shape of each slot is rounded at both ends with a width of the slot remaining substantially constant along the slot between its opposite rounded ends. The width of the slots is chosen based on the diameter of the strands of the wire rope, such that the strands helically wrapped about the rope's core can have their ends fitted into the slots S1-S6 from the side of the tool to which the slots open at the working face 18.
Each slot is curved in the longitudinal direction of its cross sectional shape to define opposite curved sides 24, in generally concentric arcuate arrangement with one another, extending between the slot's opposite rounded ends. The curve of each slot is such that its sides 24 are concavely facing the common direction C about the central axis 12A and central recess 20 in which the outer end portions S1o-S6o of the slots S1-S6 are leading the inner end portions S1i-S6i. Like the inner end portions S1i-S6i of the slots S1-S6, the outer end portions S1o-S6o are all situated at the same radial distance from the central axis 12A and the central recess 20 along the working face 18, and are equally spaced from one another angularly about the central axis 12A and central recess 20 of the cylindrical body 12. Moving outward away from the central recess 20, each slot curves past the inner end of an adjacent slot, the outer end portion of each slot angularly aligning about the central axis 12A and the central recess 20 with the inner end portion of the next slot thereabout in the common direction. If each end portion of the slots is considered to be a cylindrical volume of circular cross section extending normally into the tool body 12 from the working face 18 with a diameter slightly exceeding that of the strands of a wire rope on which the tool is to be used, a radial plane projecting from the common central longitudinal axis 12A of the central recess 20 and the tool body 12 thus cuts diametrically through four slot end portions, one outer end portion and one inner end portion on each side of the central axis. This is illustrated in
In the illustrated embodiment of the tool, six slots S1-S6 are spaced apart around the central recess 20, corresponding to a six strand wire rope, commonly used in many applications and featuring six strands helically coiled around a central core. The aforementioned equal angularly spacing between inner ends and between outer ends around the central axis 12A is thus sixty degrees in the illustrated embodiment, as illustrated by equally spaced radial planes P1, P2 and P3 in
The tool 10 is used by inserting the end of a wire rope into the recesses of the tool body 12 from the side thereof faced by the working face 18, specifically to insert the end of the wire rope's core into the central recess 20 in the tool body 12 and the ends of the strands helically wrapped around the core into the inner end portions S1i-S6i of the slot-like recess S1-S6 from the open ends of the recesses 20, S1-S6 at the working face 18. Due to the size of radial spacing between the central recess 20 and the slot recess S1-S6 in the illustrated embodiment of the tool, the strands of the wire rope are first pried or unwound slightly from the core, for example after sliding an outer sleeve of a bell over the end of the wire rope during use of the tool in a bell installation, before placing the tool over the end of the rope so that the strands will fit into the slots. In alternative embodiments, if the radial spacing between the central recess and the surrounding slot-like recesses is formed of a sufficiently narrow portion of solid rigid material, it may be possible for this portion to wedge itself between the wire rope's core and strands simply by forcing the tool onto the end of the wire rope. With the end of the wire rope having been so inserted into the recesses of the tool body, for example by lowering the tool body onto the end of the rope with the working face directed theretoward, the handle 14 is then used to effect pivotal motion of the tool about the central recess 20 and the core of the wire rope disposed therein in a direction L opposite that of the common direction C in which the outer end of each slot-like recess S1-S6 leads the inner end thereof. This pivoting of the tool 10, in a counter-clockwise direction when viewing the working face 18 of the illustrated embodiment, exerts forces on the end portions of the rope strands tending to unwind, untwist or unwrap them from about the core.
Due to the helical wrapping of the strands about the core, forcing the ends of the strands in such a loosening direction L of a revolutionary path about the core tends to increases a length along the core which can be spanned by each strand. In other words, because the helical path of the strand extends both around and along the core, any selected length of the helical strand spans both axial and circumferential distances relative to the core, and so unwrapping the selected strand length from about the core frees up the portion of the selected length previously used to span circumferential distance, allowing this portion to now be stretched along the core instead. However, with the tool fitted over the end of the fixed-length core and the recesses being closed at the opposite face 22 of the tool body 12, the newfound increased length of each loosened strand obtained by circumferentially displacing the end of the strand in the loosening direction about the core end has no room to expand in a solely longitudinal manner along the portion of the core extending into the central recess of the tool body along the central axis 12A thereof, and thus is forced to instead expand outward away from the cores sliding the end of the strand along the respective one of the slots S1-S6 toward the outer end thereof.
In other words, the side walls 24 of the slots act as guiding surfaces, directing the ends of the strands outward away from the core of the wire rope under pivoting of the tool handle 14 to rotate the tool body 12 about the rope's core extending into the central recess 20 along the tool body's central axis 12A to effect untwisting of the strand ends from about the core.
As shown in
Compared to conventional methods of splaying cable ends, such as individually prying the ends of the strands outward from the core using a flathead screwdriver or other thin body as a lever, not only does use of the illustrated tool embodiment allow relatively quick and easy splaying of the wire rope strands due to the simultaneous splaying effect on all the strands under a single pivoting/rotating action, but it situates the strand ends in an evenly spaced fashion about the core due to the even spacing of the outer ends of the slots about the central recess, for example to fit the evenly spaced grooves of a conventional grooved wedge. The fitting of the tool over the cable end being splayed also improves on safety by reducing the likelihood of getting strands of steel wire embedded in one's hand. The positions of the outer end of each slot forward of the inner end thereof in the common direction C opposite the loosening direction L in which tool body is rotated to effect splaying of the strands reduces the circumferential distance about the central axis by which the strand ends are displaced during loosening relative to alternate embodiments in which both ends of each slot lie in the same radial plane relative to the central axis through the central recess. The shaping of each slots along a curved, arcuate or spiral path in the illustrated embodiment is chosen to better follow the twist of the cable compared to a straight or linear path between the ends of a slot, to encourage smooth outward motion of the wire rope strands in a more uniform manner.
Furthermore, it should be appreciated that after installing the wedge 200 into the splayed end of the wire rope, the tool may be used to tighten the splayed strands around the wedge. The strand and core ends are reinserted into the central recess and slot recesses respectively, but now with the strand ends fitting into the outer end portions S1o-S6o of the slots S1-S6, not the inner end portions. The tool body 12 is once again rotated about the rope core received in the central recess 20, but this time in an opposite direction T tending to tighten the strands about the core and the now surrounding wedge, direction T matching common direction C in which the outer ends of the slots lead the inner ends of the slots around the central recess 20. The movement of the strand ends along a revolutionary path in this tightening direction causing an effective shortening of the strands along the core due to re-wrapping of them circumferentially around the core that would occur in the absence of the wedge, the side walls 24 of the slots S1-S6 again acting as guide surfaces, but this time guiding the ends of the strands inward back toward the core under their effective shortening along the core.
Turning of the illustrated tool embodiment in one direction spreads the strands of a cable away from the center core to allow the wedge pieces to be set in place, with subsequent turning of the tool in the opposite direction tightening the strands onto the wedge in an equal and uniform manner, to allow the bell sleeve to relatively easily and quickly slid onto the wedges and cable.
It should be appreciated that the tool body need not necessarily be cylindrical or a solid body spanning fully between the working face and opposite side of the body to rigidly fill the space between the slots. For example, the slots may be formed by curved walls projecting from a flat disc-like carrying body defining the closed ends of the slots. However, the solid body construction improves the strength and durability of the tool. Furthermore, a lever like handle need not necessarily be provided, but such an arrangement improves the ease with which the tool body can be rotated to splay the wire rope ends. Furthermore, the central recess need not necessarily be located centrally on the tool body, although this provides a pleasant appearance and a well balanced feel during use.
The illustrated embodiment is for use with right hand lay wire rope. Alternate embodiments for left hand lay wire rope feature similar structure, but with the common direction C in which the outer ends of the slots lead the respective inner ends, the loosening or splaying direction L and the tightening direction T each being reversed from that shown and described in the illustrated right hand lay embodiment.
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
