Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
  • F16G11/00—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes
  • F16G11/06—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes with laterally-arranged screws
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
  • F16G11/00—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes
  • F16G11/14—Devices or coupling-pieces designed for easy formation of adjustable loops, e.g. choker hooks; Hooks or eyes with integral parts designed to facilitate quick attachment to cables or ropes at any point, e.g. by forming loops
  • F16G11/146—Eyes

Definitions

• This invention relates to the field of load-carrying tensile members. More specifically, the invention comprises a synthetic tensile member assembly designed to permit easy inspection of defined regions in which high stress, high wear, or other significant conditions are expected to occur.
• Prior art tensile members are often made of steel wire.
• the diameter of each wire is significantly less than the diameter of the tensile member as a whole.
• the wires are formed into a cohesive unit by varying known processes, with helical wrapping being one good example.
• terminations shall mean an assembly on a portion of the tensile member that allows a load-transmitting device to be attached to the tensile member. Such terminations are most often attached to the ends of a tensile member but they may also be placed on an intermediate point in some cases,
• a termination is most often created by attaching a rigid loading fixture to the end of a tensile member in order to provide a consistent and reliable interface between the often- flexible components of the tensile member and external components.
• the loading fixture may be one solid piece or may be an assembly of two or more pieces.
• a simple prior art example is a closed Spelter socket.
• a Spelter socket is typically a metal casting or forging that includes a loading eye and an expanding cavity.
• the steel wires proximate the end of the tensile member are placed within the cavity and then splayed apart.
• the cavity is then filled with a potting compound.
• potting compound means any composition that transitions from a liquid to a solid over time. As one example, the potting compound may be lead.
• the potting compound may be a two-part epoxy. The two parts are mixed together and then placed in the cavity. The two parts then cross-link and solidify.
• the "termination" includes the Spelter socket (including the loading eye and cavity), the length of strands potted into the cavity, and the potting compound that has solidified in the cavity.
• the loading eye may be attached to some external object and the tensile member may then be used to transmit tension.
• Spelter sockets are made with many different types of loading features, including a tang or clevis with a transverse hole.
• the rigid loading fixture may be split into two pieces.
• the first piece contains the cavity used for potting. This piece is usually called an "anchor.”
• the second piece attaches to the anchor and includes a feature for transmitting a load - such as a loading eye.
• the anchor might include an external thread.
• the loading eye would then include an internal thread designed to engage the external thread on the anchor.
• a wire tensile member can be wrapped around a metal thimble and woven or clamped back on itself. The middle of the thimble then forms an "eye" through which a pin may be passed to secure the termination to an external object.
• the tensile member may be woven around a hollow transverse tube. The hollow tube then receives a transverse pin.
• the termination provides a rigid and consistent load-transference point for the tensile member. In other words, the point at which a load is to be transferred to the tensile member is clearly defined.
• Such a termination is defined as a "fixed termination.”
• tensile members such as slings that are made of a continuous loop of material.
• Such continuous-loop slings may be loaded at an infinite number of points (such as by passing a given point of the sling around a transverse pin).
• the present invention applies to fixed terminations.
• Tensile members are often used in "critical” applications where the failure of the tensile member could have catastrophic results.
• One good example would be a tensile member used as a "stay” in a crane.
• the portions of the tensile member lying outside the terminations are often subjected to abrasion forces, cutting forces, ultraviolet radiation, corrosion, debris infiltration, and other degrading phenomena.
• a tensile member will of course not remain in service forever. It must be inspected and periodically replaced.
• a long- established inspection regimen exists for steel wire tensile members used in critical applications. The outer wires of each tensile member bundle are visually accessible.
• One well-known criterion simply counts the number of broken wires that are visible on a tensile member's exterior and uses this as a pass/fail criterion. While somewhat cnide, this approach has been found to be effective for the prior art steel wire tensile members.
• Synthetic fibers have a very small diameter, on the order of a human hair, making it very difficult to inspect large sections. Synthetic fibers are also much softer than steel, making them more prone to snag and tear. They are also more susceptible to heat damage, debris infiltration, abrasion damage, ultraviolet degradation, and cutting damage. Thus, in many applications it is desirable to protect any exposed synthetic fibers in a tough external jacket.
• jacket should be understood to include any type of protective covering for a collection of synthetic fibers. It most commonly refers to a covering for a bundle of strands passing between two terminations, but it may also encompass some or al l of the terminations themselves.
• a jacket may be applied via an extrusion process, such as extruding a NYLON plastic jacket over a core of synthetic fibers.
• a jacket may also be added by dipping, spraying, wrapping, or braiding.
• a jacket may include any material or combination of materials.
• jacket is by no means limited to the particular method of application. Any material which protects the synthetic fibers could be considered a jacket. Because many tensile members are flexible, it may be desirable for the jacket material to be flexible. A flexible cable wrapped around a winch drum is one example.
• tensile members need not be flexible at all.
• a stay used in a crane often remains in one position at all times. It simply transmits a tensile load between two points.
• the jacket may be a piece of hollow steel tubing.
• a core of synthetic strands is passed through the hollow steel tubing and secured to a termination on each end.
• tension is removed from such an assembly, it does not go slack because of the relative stiffness of the jacket material.
• the primary 100 purpose of the assembly is still to carry tension, it is properly referred to as a "tensile member.”
• FIGs. 1 and 2 show the prior art approach of encasing the synthetic fibers in a surrounding jacket.
• termination 22 is created by attaching anchor 18 to tensile member 20.
• FIG. 2 shows a section view through the completed assembly. Fibers 26 are 105 placed in expanding passage 30 through anchor 18. They are then potted in place to create potted region 32. Attachment fixture 36 is connected to anchor 18 using threaded coupling 34.
• Jacket 24 is provided over the exterior of synthetic fibers 26. It preferably extends a short distance into anchor 18. In the embodiment shown, the jacket is received within jacket
• jacket 24 is preferably made of a tough material able to withstand normal use within the intended environment.
• a common example of a jacket is an extruded layer of NYLON or HDPE covering the exterior of the synthetic fiber core.
• the jacket and the rigid terminations in this example are able to withstand abrasive forces, cutting forces, and ultraviolet radiation.
• the jacket may include a woven metal reinforcement layer.
• the jacket may even be a solid metal tube.
• a primary objective of the jacket is to ameliorate most of the durability problems associated with using synthetic fillers.
• Such tensile members may break down gradually due to frictional wear, ultraviolet degradation, debris infiltration, chemical infiltration, etc. For example, when a tensile member made of synthetic fibers is dragged around the deck of a vessel, some fibers will be damaged. How r ever, this wear is not objectively quantifiable. The only way to
• the present invention solves this problem by provided an inspection region in a protected synthetic tensile member assembly having controlled anchor points.
• the inspection region selectively provides access to critical areas so that an inspector may view the fibers in these critical areas.
• the present invention comprises a protected synthetic tensile member assembly including one or more fixed terminations used to transmit a tensile load from the tensile member to an external component.
• the tensile member includes access for inspection of its 155 constituent fibers in at least one selected inspection region.
• the region is selected on the basis of the area of interest to the tensile member's use - such as the area of greatest stress concentration or the area of greatest abrasion.
• a removable cover is provided for the inspection region. A user may selectively remove this cover in order to gain access to the inspection region.
• FIG. 1 is a perspective view, showing a prior art tensile member.
• FIG . 2 is a sectional elevation view, showing the assembly of FIG . 1.
• FIG. 3 is an exploded perspective view, showing an embodiment of the present 165 invention.
• FIG. 4 is a sectional elevation view, showing the assembly of FIG. 3.
• FIG. 5 is an elevation view, showing some details of the assembly of FIG. 3,
• FIG. 6 is a sectional elevation view, showing an additional embodiment of the invention.
• FIG. 7 is a sectional elevation view, showing still another embodiment of the present invention.
• FIG . 8 is a perspective view, showing the embodiment of FIG. 7.
• FIG. 9 is a sectional elevation view, showing still another embodiment of the present invention.
• FIG. 10 is a perspective view, showing the use of a alignment marking on a tensile member jacket.
• FIG. 11 is a sectional detailed view, showing the use of a jacket having layers with differing colors.
• FIG. 12 is an elevation view, showing the application of the present invention to a 180 sling device.
• FIG. 13 is an exploded perspective view, showing an inspection region and cover for a sling device.
• FIG. 14 is an exploded perspective view, showing a alternate embodiment of the inspection region on a sling device.
• FIG. 1 is a sectional elevation view, showing a termination including two removable covers.
• Synthetic tensile member assemblies are used in a wide variety of applications, each of which imposes differing operating constraints.
• the operating constraints of a particular tensile member will often determine the areas of interest for inspection.
• a tensile member that is carrying a relatively static tensile load with potted terminations such as a crane boom pendant
• potted terminations such as a crane boom pendant
• the fibers will generally start to break in this location when the tensile member begins to fail.
• the removable cover When in place, the removable cover preferably provides suitable protection for the fibers it covers. It is also desirable for the removable cover to be removable and replaceable multiple times over the useful life of the tensile member (though an individual cover may need to be replaced by a new cover). These objectives may be achieved using a wide variety
• FIGs. 3-5 disclose the first embodiment of the present invention.
• FIG. 3 shows how jacket 24 stops short of anchor 18 in this version, leaving a length of exposed synthetic fibers therebetween.
• the length of exposed fibers is the "inspection region" for this embodiment.
• the removable cover is split into two halves 38, 40. These may be joined together by any suitable means.
• six cap screws are fed through access holes 50 on one of the removable halves and then threaded into threaded receivers 44 on the other half.
• Each access hole includes a countersunk shoulder for the head of the cap screw to bear against and draw the two halves tightly together.
• a positive lock is provided between the cover and the jacket. This may be done using many different features, such as a long clamping surface, or a series of interlocking features.
• anchor 18 is equipped with one or more anchor rings 48.
• jacket 24 may include an integral or separate jacket ring 46.
• the two removable cover halves include annular recesses that are sized to receive and engage the anchor rings and jacket ring.
• FIG. 4 shows a sectional view through the assembly of FIG. 3 with one of the two removable cover halves still in place.
• Inspection region 52 in this embodiment is the annular region between the end of the jacket and the start of the anchor. For a tensile loading - especially with some flexure - the area of maximum stress concentration will often occur near the interface between potted region 32 and the freely flexing fibers within the balance of
• Inspection region 52 allows visualization of the fibers proximate the potted region interface.
• FIG. 5 is a non-sectional view showing one of the cover halves lying next to the tensile member assembly.
• Removable cover half 40 in this example includes:
• anchor opening 58 sized to admit anchor 18
• anchor ring receivers 54 sized to receive and engage anchor rings 48;
• jacket ring receiver 56 sized to receive and engage jacket ring 46
• Jacket ring 46 may be forms by depositing additional material over jacket 24. It may also be formed by uitrasonicaliy deforming the end portion of the jacket to create a "bead.”
• the jacket ring may be a separate piece that is joined to the balance of the jacket by an adhesive or by simple friction.
• the interior of the removable covers may simply incorporate gripping features - such as a knurled surface or annular ring recesses - configured to "bite" into the jacket.
• gripping features may also be substituted for the
• a connection between the removable cover half and the anchor may also be created using a separate adhesive.
• the jacket it is only important that the jacket be held in place with a reasonable sea! in order to prevent the ingress of unwanted factors based on the particular application, The unwanted factors could be UV light, chemicals, dirt, or other identified factors.
• the jacket, and its interface with the tension member, its interface with the termination(s), and its interface with any removable cover should be designed to provide an appropriate level of durability for the intended use.
• FIG. 6 shows a variation on the embodiment of FIG. 5,
• inspection region 52 is covered by a transparent sleeve 62.
• the transparent sleeve remains in position after the cover halves have been removed.
• the user is able to visually discern damaged or broken fibers through the transparent sleeve.
• the region of transparency may be a smaller window within a larger sleeve. The use of such a transparent region could be adopted to different portions of the anchor or jacket as well.
• FIGs. 7 and 8 disclose an additional embodiment that uses a different approach to attaching and removing the cover.
• Threaded cover 64 is a sleeve that selectively connects to anchor 18 via threaded engagement 68, The distal end of the threaded cover includes shoulder 66, which is sized to bear against jacket ring 46.
• shoulder 66 which is sized to bear against jacket ring 46.
• This type of cover provides good access to a useful inspection point
• Stress is generally concentrated in the neck region of the anchor. This is trae for a potted termination (such as shown) and also for spike-and-cone terminations, other compression devices, and nearly any other form of fixed termination. It is also useful to inspect such a transition region in the case of a spliced thimble where high stresses, abrasion, misalignment, or undesirable fiber-to-fiber slipping may occur,
• Threaded cover 64 is pulled down tensile member 20 in the direction indicated by the arrow. This motion reveals inspection region 52, When the inspection is complete, the user pushes the threaded cover back into engagement with the threads on anchor 18 and tightens it,
• FIG. 9 serves to illustrate a few of these possible additional embodiments.
• Anchor 18 is provided with one or more access ports 72. Each access port is threaded in order to receive a cover 70 (which is also threaded). When a cover 70 is removed, a user may visually inspect the synthetic fibers in inspection region 52. It is also possible to provide transparent windows in the anchor itself.
• the cover in this example could even be an injected volume of curable silicone.
• the silicone would be injected as a liquid and then cure to form a pliable solid.
• the resulting flexible plug could be pried out with a screwdriver when inspection is needed. It would then be "replaced” by injecting a new volume of silicone.
• the cover could span a large region and be removed by
• the cover would be "removed" to permit access to the inspection region, yet would remain attached to the balance of the tension member.
• FIG. 10 shows a termination 22 that incorporates a clevis joint configured to receive a pin
• overload holes 104 are provided in the region of the transverse hole. If a maximum specified tensile load is exceeded, overload holes 104 allow the transverse hole to elongate. This action tends to "clench" the pin that is passing through the hole. The metal will also be visibly deformed. These conditions will alert the user to the fact that the tensile member has been overloaded and should be removed from sendee,
• Alignment marking 74 may be added to the tensile member jacket to show any significant twist. The alignment marking is preferably of a contrasting color -
• An extruded jacket may include a protrusion that extends inward into the core.
• the protrusion in the extruded profile creates a longitudinal rib that inhibits any rotation of the jacket with respect to the core.
• alignment markers there are many possible alignment markers that could be used 350 continuously or at certain intervals along the tensile member. Even printed text could be used for this purpose.
• Jacket 24 includes two layers - outer layer 76 and inner layer 78. The two
• 355 layers may be provided in contrasting colors (possibly using different materials).
• the outer layer may be black while the inner layer is yellow. A scuff that is deep enough to penetrate the outer layer will thereby appear as a yellow streak on the black jacket.
• the outer layer may also be designed for a certam type of protection (cut resistance) while the inner layer might be designed for a different type of protection (moisture resistance).
• Such a multi-layer jacket construction provides a visual "go/no-go" indication for the tensile member assembly. Separate retirement or repair criteria could then be applied to each layer of the jacket.
• FIGs. 12-14 provide illustrations of the invention applied to other types of tension members and terminations.
• One way to create a termination is to pass a braided rope around a stiff thimble or sheave and then weave it back into itself. A transverse pin is then passed through the thimble
• this may be configured with one tensile leg, and in other cases the synthetic fibers may wrap back around to form a "grommet" (circular configuration) with two or more tensile legs and a fixed termination at each end.
• grommets or round slings it is important for purposes of this invention that some form of fixed termination be used. This allows the stress to be controlled and located at
• FIG. 12 shows still another type of tensile member and termination.
• a very long fiber or a series of twisted yams or ropes is passed repeatedly around the two stirrups 82 until a thick bundle is produced.
• the entire assembly is then sealed into casement 86 (which may be a urethane or a two-part epoxy that is hardened in situ after the assembly is
• FIG. 13 shows die inclusion of an inspection region 52 on the outside portion of a stirrup 82.
• the inspection region is an opening in the casement that reveals the fibers inside
• Cover 88 is selectively placed over the inspection region when no inspection is desired. Cover 88 is secured using strap 90. One or more snaps 92 on strap 90 snap into receiver 94, Of course, many other designs could be used to adequately cover such an arrangement,
• 390 fibers are wound around or ropes are spliced to two-sheave-type termination bodies.
• a transverse hole is provided through casement 86 (The casement is the protective jacket in this case).
• Inspection region 52 is simply the interior of this transverse hole, where stresses are concentrated.
• Cover 88 is a cylindrical load-bearing element that passes through the casement and covers inspection region 52.
• Cover 88 includes first flange 98 that bears
• Pin receiver 96 is a smooth cylindrical hole configured to receive a linking pin that attached the stirrup to something else.
• many other designs could be used to provide a cover for this type of inspection region.
• This area like the entry point into an anchoring or termination body, is a leading stress and wear point.
• FIG. 15 shows an embodiment in which an enlarged inspection region is provided.
• this embodiment includes two separate cover pieces that provide a progressive level of access. Threaded cover 64 is similar to the configuration shown in FIG. 7. However, in
• the anchor has been split into two pieces - neck anchor portion 106 and distal anchor portion 108.
• the two anchor portions are selectively engaged via threaded engagement 110.
• the user may choose to unscrew threaded cover 64 and thereby gain access to the inspection region it covers.
• the user may then go further by unscrewing neck anchor portion 415 106 from distal anchor portion 108.
• This allows the user to extend the inspection region well into the potted region of the termination (for the case of a potted termination).
• a mechanical termination such as a spike-and-cone
• the extended inspection region may 420 only be used some of the time (such as to help ensure the proper initial setup of this region when it is first loaded).
• Additional features and variations for the present invention include the following: 1 . A version where a substantial portion of the termination or the cable jacket is transparent;
• removable cover is a piece of tape, a helical wrapping, a wire wrapping, or a painted layer

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Piles And Underground Anchors (AREA)
• Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
• Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
• Information Retrieval, Db Structures And Fs Structures Therefor (AREA)
• Helmets And Other Head Coverings (AREA)

Priority Applications (4)

Applications Claiming Priority (4)

Publications (1)

Family

ID=49584231

Family Applications (1)

Country Status (4)

Cited By (5)

Citations (7)

Family Cites Families (1)

• 2013
  • 2013-05-15 SG SG10201609589UA patent/SG10201609589UA/en unknown
  • 2013-05-15 AU AU2013262883A patent/AU2013262883B2/en active Active
  • 2013-05-15 CA CA2873464A patent/CA2873464C/fr active Active
  • 2013-05-15 WO PCT/US2013/041055 patent/WO2013173405A1/fr not_active Ceased
  • 2013-05-15 SG SG11201407658WA patent/SG11201407658WA/en unknown

Patent Citations (7)

Also Published As

Similar Documents

Legal Events