U.S. patent application number 17/497216 was filed with the patent office on 2022-01-27 for inspectable synthetic tensile member assembly.
The applicant listed for this patent is Richard V. Campbell. Invention is credited to Richard V. Campbell.
Application Number | 20220025958 17/497216 |
Document ID | / |
Family ID | |
Filed Date | 2022-01-27 |
United States Patent
Application |
20220025958 |
Kind Code |
A1 |
Campbell; Richard V. |
January 27, 2022 |
Inspectable Synthetic Tensile Member Assembly
Abstract
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 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.
Inventors: |
Campbell; Richard V.;
(Havana, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Campbell; Richard V. |
Havana |
FL |
US |
|
|
Appl. No.: |
17/497216 |
Filed: |
October 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16236945 |
Dec 31, 2018 |
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17497216 |
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13894463 |
May 15, 2013 |
10167928 |
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16236945 |
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International
Class: |
F16G 11/02 20060101
F16G011/02 |
Claims
1. A method for providing and inspecting a durable yet inspectable
tensile member assembly including synthetic fibers as a
tension-carrying element, comprising: (a) providing a tensile
member, including, (i) a core of synthetic fibers, said core having
an end, (ii) a termination on said end, said termination including
an anchor with an anchor exit where said fibers exit said anchor,
(iii) a jacket surrounding said core; (iv) an inspection region
located proximate said anchor exit; (b) providing a first cover
configured to cover a first portion of said inspection region; (c)
providing a second cover configured to cover a second portion of
said inspection region; (d) opening said first cover in order to
permit inspection of said first portion of said inspection region;
and (e) following said inspection of said first portion of said
inspection region, closing said first cover.
2. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 1 wherein
said inspection region encompasses a potting interface.
3. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 1, further
comprising providing a transparent sleeve covering said inspection
region underneath said first cover.
4. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 1, further
comprising providing interlocking features between said first cover
and said jacket.
5. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 1, further
comprising providing interlocking features between said first cover
and said anchor.
6. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 4, wherein
said interlocking features include a ring interlocking with an
annular recess.
7. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 1, further
comprising: (a) wherein said core of synthetic fibers has a second
end; (b) providing a second termination on said second end, said
second termination including a second anchor with a second anchor
exit where said fibers exit said second anchor; (c) providing a
second inspection region located proximate said second anchor exit;
(d) providing a third cover configured to cover a first portion of
said second inspection region; (e) providing a fourth cover
configured to cover a second portion of said second inspection
region; (f) opening said third cover in order to permit inspection
of said first portion of said second inspection region; and (g)
following said inspection of said first portion of said second
inspection region, closing said third cover.
8. A method for providing and inspecting a durable yet inspectable
tensile member assembly including synthetic fibers as a
tension-carrying element, comprising: (a) providing a tensile
member having a core of synthetic fibers, said tensile member
having an end; (b) providing a termination attached to said end of
said tensile member, said termination including an anchor with an
anchor exit where said core exits said anchor; (c) wherein said
anchor includes an internal passage and a length of said fibers lie
within said internal passage; with said fibers being locked into a
solidified potting compound, with said anchor completely
surrounding said length of said fibers; (d) providing a jacket
surrounding said core; (e) providing an inspection region proximate
said anchor exit; (f) providing a first cover configured to cover a
first portion of said inspection region; (g) providing a second
cover configured to cover a second portion of said inspection
region; (h) opening said first cover in order to permit inspection
of said first portion of said inspection region; and (i) following
said inspection of said first portion of said inspection region,
closing said first cover.
9. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 8 wherein
said inspection region encompasses a potting interface.
10. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 8, further
comprising providing a transparent sleeve covering said inspection
region underneath said first cover.
11. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 8, further
comprising providing interlocking features between said first cover
and said jacket.
12. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 8, further
comprising providing interlocking features between said first cover
and said anchor.
13. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 11, wherein
said interlocking features include a ring interlocking with an
annular recess.
14. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 8, further
comprising: (a) wherein said core of synthetic fibers has a second
end; (b) providing a second termination on said second end, said
second termination including a second anchor with a second anchor
exit where said fibers exit said second anchor; (c) providing a
second inspection region located proximate said second anchor exit;
(d) providing a third cover configured to cover a first portion of
said second inspection region; (e) providing a fourth cover
configured to cover a second portion of said second inspection
region; (f) opening said third cover in order to permit inspection
of said first portion of said second inspection region; and (g)
following said inspection of said first portion of said second
inspection region, closing said third cover.
15. A method for providing and inspecting a durable yet inspectable
tensile member assembly including synthetic fibers as a
tension-carrying element, wherein said tensile member assembly
includes a core of said synthetic fibers, a jacket surrounding said
core, an end, a termination attached to said end, said termination
including an anchor, an anchor exit where said core exits said
anchor, and an inspection region proximate said anchor exit,
comprising: (a) providing a first cover configured to cover a first
portion of said inspection region; (b) providing a second cover
configured to cover a second portion of said inspection region; (c)
opening said first cover in order to permit inspection of said
first portion of said inspection region; and (d) following said
inspection of said first portion of said inspection region, closing
said first cover.
16. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 15 wherein
said inspection region encompasses a potting interface.
17. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 15, further
comprising providing a transparent sleeve covering said inspection
region underneath said first cover.
18. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 15, further
comprising providing interlocking features between said first cover
and said jacket.
19. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 15, further
comprising providing interlocking features between said first cover
and said anchor.
20. The method for providing and inspecting a durable yet
inspectable tensile member assembly as recited in claim 15, wherein
said tensile member assembly includes a second end, a second
termination attached to said second end, said second termination
including a second anchor, a second anchor exit, and a second
inspection region proximate said second anchor exit, further
comprising: (a) providing a third cover configured to cover a first
portion of said second inspection region; (b) providing a fourth
cover configured to cover a second portion of said second
inspection region; (c) opening said third cover in order to permit
inspection of said first portion of said second inspection region;
and (d) following said inspection of said first portion of said
second inspection region, closing said third cover.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This non-provisional patent application is a divisional of
U.S. patent application Ser. No. 16/236,945. The parent application
listed the same inventor.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
MICROFICHE APPENDIX
[0003] Not Applicable member
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0004] 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.
2. Description of the Related Art
[0005] 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. In order for the tensile member to transmit a tensile
load, one or more terminations must be added. The word
"termination" 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.
[0006] 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. The term "potting compound" means any composition
that transitions from a liquid to a solid over time. As one
example, the potting compound may be lead. Molten lead is poured
into the cavity (with the splayed wires present) and the lead then
cools and solidifies. As a second example, 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.
[0007] Once the potting compound solidifies, the end of the steel
wire tensile member is locked to the Spelter socket and a
termination is thereby created. In this example, 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.
[0008] In some examples, 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. As an example, 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.
[0009] As those skilled in the art will know, many other types of
terminations exist. As another example, 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. In still another example, the tensile member may be woven
around a hollow transverse tube. The hollow tube then receives a
transverse pin. In all these examples, 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. Further, the
fibers that are actually connected to the load-transference point
are held in a consistently defined state (They are locked into the
termination in a consistent and repeatable way). Such a termination
is defined as a "fixed termination." This is to be contrasted with
some other prior art 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.
[0010] 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.
[0011] 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 crude, this approach has
been found to be effective for the prior art steel wire tensile
members.
[0012] It is now known to replace the steel wires in a prior art
tensile member with high-strength synthetic fibers. Examples
include KEVLAR, VECTRAN, DYNEEMA, TECHNORA, SPECTRA, POLYESTER,
NYLON, GLASS, CARBON, and ZYLON. The individual components of a
steel tensile member are most commonly referred to as "wires" while
the individual components of a tensile member made of synthetic
materials are most commonly referred to as "fibers" or "filaments."
For consistency in this disclosure, the term "fibers" will be used
for the synthetic components.
[0013] Pound-for-pound, synthetic tensile members have the
potential to be much stronger than steel tensile members. They
offer other advantages as well such as corrosion resistance and
easier handling. However, some characteristics of synthetic fibers
are less desirable. 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.
[0014] The term "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 all 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.
[0015] The term 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.
[0016] However, other tensile members need not be flexible at all.
For instance, a stay used in a crane often remains in one position
at all times. It simply transmits a tensile load between two
points. In that instance, 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. When tension
is removed from such an assembly, it does not go slack because of
the relative stiffness of the jacket material. However, as the
primary purpose of the assembly is still to carry tension, it is
properly referred to as a "tensile member."
[0017] FIGS. 1 and 2 show the prior art approach of encasing the
synthetic fibers in a surrounding jacket. In FIG. 1, termination 22
is created by attaching anchor 18 to tensile member 20. NG. 2 shows
a section view through the completed assembly. Fibers 26 are 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.
[0018] 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 receiver 28.
Thus, no portion of the synthetic fibers is exposed to the outside
world.
[0019] 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. In more extreme
examples, the jacket may include a woven metal reinforcement layer,
Of course, as explained previously, the jacket may even be a solid
metal tube. In any event, a primary objective of the jacket is to
ameliorate most of the durability problems associated with using
synthetic fibers.
[0020] However, the reader will also appreciate that the jacket
interferes with the vital inspection function. In the example of
FIGS. 1 and 2, there is no way for an inspector to look at the
fibers contained within the jacket. This lack of "inspectability"
has become a deterrent to the use of protected synthetic tensile
members in critical applications.
[0021] In fact, the prior art approach has often been to use the
synthetic fibers in an unprotected (unjacketed) state. The
relatively delicate fibers are left exposed to the elements so that
they can be inspected. This exposure introduces concerns regarding
predictability and overall reliability. 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. However,
this wear is not objectively quantifiable. The only way to
determine the strength reduction is to actually test the cable to
destruction.
[0022] One prior art approach has been to weave a continuous
"sling" of synthetic fibers. The sling is then surrounded by a
loose bag that provides some degree of protection. However, the
sling typically has no fixed and rigid loading points (It has no
fixed terminations). Such slings are intended to be passed around
particular objects (such as a pin having a minimum diameter) or
connected to general rigging hardware. However, a user encountering
such as sling has no idea whether it has been used incorrectly in
the past. The flexible bag encasing the core fibers may in fact be
concealing many broken or damaged fibers. Inconsistencies in the
hardware the sling is connected to create many potential unknowns.
The lack of environmental control creates issues with fiber
inspection due to the fact that there is no defined region of
interest.
[0023] While prior art tension members using synthetic fibers have
many known performance advantages, they do not tend to wear in a
controlled and predictable fashion when exposed to the environment
in which they are used. They ideally need to be protected from
environmental elements. However, they also need to be "inspectable"
to gain and retain the confidence of the community that uses
them.
[0024] 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.
BRIEF SUMMARY OF THE PRESENT INVENTION
[0025] 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 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.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0026] FIG. 1 is a perspective view, showing a prior art tensile
member.
[0027] FIG. 2 is a sectional elevation view, showing the assembly
of FIG. 1.
[0028] FIG. 3 is an exploded perspective view, showing an
embodiment of the present invention.
[0029] FIG. 4 is a sectional elevation view, showing the assembly
of FIG. 3.
[0030] FIG. 5 is an elevation view, showing some details of the
assembly of FIG. 3.
[0031] FIG. 6 is a sectional elevation view, showing an additional
embodiment of the invention.
[0032] FIG. 7 is a sectional elevation view, showing still another
embodiment of the present invention.
[0033] FIG. 8 is a perspective view, showing the embodiment of FIG.
7.
[0034] FIG. 9 is a sectional elevation view, showing still another
embodiment of the present invention.
[0035] FIG. 10 is a perspective view, showing the use of a
alignment marking on a tensile member jacket.
[0036] FIG. 11 is a sectional detailed view, showing the use of a
jacket having layers with differing colors.
[0037] FIG. 12 is an elevation view, showing the application of the
present invention to a sling device.
[0038] FIG. 13 is an exploded perspective view, showing an
inspection region and cover for a sling device.
[0039] FIG. 14 is an exploded perspective view, showing an
alternate embodiment of the inspection region on a sling
device.
[0040] FIG. 15 is a sectional elevation view, showing a termination
including two removable covers.
REFERENCE NUMERALS IN THE DRAWINGS
[0041] 18 anchor [0042] 20 tensile member [0043] 22 termination
[0044] 24 jacket [0045] 26 fibers [0046] 28 jacket receiver [0047]
30 expanding passage [0048] 32 potted region [0049] 34 threaded
coupling [0050] 36 attachment fixture [0051] 38 removable cover
half [0052] 40 removable cover half [0053] 42 cap screw [0054] 44
receiver [0055] 46 jacket ring [0056] 48 anchor ring [0057] 50
access hole [0058] 52 inspection region [0059] 54 anchor ring
receiver [0060] 56 jacket ring receiver [0061] 58 anchor opening
[0062] 60 tensile member opening [0063] 62 transparent sling [0064]
64 threaded cover [0065] 66 shoulder [0066] 68 threaded engagement
[0067] 70 cover [0068] 72 access port [0069] 74 alignment marking
[0070] 76 outer layer [0071] 78 inner layer [0072] 80 wound sling
[0073] 82 stirrup [0074] 84 tension member [0075] 86 casement
[0076] 88 cover [0077] 90 strap [0078] 92 snap [0079] 94 receiver
[0080] 96 pin receiver [0081] 98 first flange [0082] 100 second
flange [0083] 102 threaded boss [0084] 104 thimble [0085] 106 neck
anchor portion [0086] 108 distal anchor portion [0087] 110 threaded
engagement
DETAILED DESCRIPTION OF THE INVENTION
[0088] 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.
For instance, a tensile member that is carrying a relatively static
tensile load with potted terminations (such as a crane boom
pendant) often has the greatest stress concentration and bending
fatigue at the point where the freely flexing fibers in the tensile
member join the potted region in the anchor (the "potting
interface"). The fibers will generally start to break in this
location when the tensile member begins to fail. Thus, it is
advisable to define an "Inspection region" for such a tensile
member in the vicinity of the potting interface.
[0089] On the other hand, another tensile member might pass over a
pulley near its mid point. That point might then warrant inspection
and it would make sense to define an "inspection region" near the
tensile member's midpoint. In general, the present invention
operates by:
[0090] (1) Providing a synthetic tensile member that is protected
by a jacket;
[0091] (2) Providing the synthetic tensile member with at least one
pre-defined load-transference point (a fixed termination) that
defines a consistent and controlled point where a load is
transferred from the synthetic tensile member to some external
object;
[0092] (3) Defining one or more inspection regions where a user
wishes to be able to examine the fibers of the tensile member
(either visually or by other means); and
[0093] (4) providing a removable cover that selectively covers the
defined inspection region(s).
[0094] 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 of physical
components. In the following paragraphs, detailed descriptions are
provided for some of the invention's embodiments.
[0095] 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. In this embodiment the removable cover
is split into two halves 38, 40, These may be joined together by
any suitable means. In the example shown, 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.
[0096] It is important to protect the interior fibers from harmful
exposures during use. Therefore, in this embodiment, 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. One could also include one or
more sealing O-rings. One could also introduce an injected sealing
compound--such as a curable silicone--before clamping the two cover
halves together.
[0097] In the example of FIG. 3, anchor 18 is equipped with one or
more anchor rings 48. Likewise 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.
[0098] 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 the tensile member.
[0099] Another area where inspection may be desired is the point at
which the fibers exit the rigid anchor. Mild flexing will often
occur at this point, producing fatigue. Thus, when the tensile
member is overloaded or has experienced too much cyclic bending,
the fibers in one of these regions will tend to break down before
the balance of the fibers in the tensile member. Inspection region
52 allows visualization of the fibers proximate the potted region
interface.
[0100] 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:
[0101] (1) anchor opening 58 sized to admit anchor 18;
[0102] (2) anchor ring receivers 54 sized to receive and engage
anchor rings 48;
[0103] (3) jacket ring receiver 56 sized to receive and engage
jacket ring 46; and
[0104] (4) tensile member opening 60 sized to admit jacket 24.
[0105] Jacket ring 46 may be forms by depositing additional
material over jacket 24. It may also be formed by ultrasonically
deforming the end portion of the jacket to create a "bead." in
still other instances the jacket ring may be a separate piece that
is joined to the balance of the jacket by an adhesive or by simple
friction. In some instances, however, it may be preferable to omit
jacket ring 46 altogether. In that case, 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. Other gripping features may also be substituted
for the interface between the removable cover half and the anchor.
A connection between the cover and the jacket may also be created
using a separate adhesive.
[0106] For purposes of this invention, it is only important that
the jacket be held in place with a reasonable seal 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.
[0107] FIG. 6 shows a variation on the embodiment of FIG. 5. In
FIG. 6, inspection region 52 is covered by a transparent sleeve 62.
In this version, the transparent sleeve remains in position after
the cover halves have been removed. However, 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.
[0108] 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. When the user wishes to inspect the inspection region, he or
she grasps threaded cover 64 and unscrews it. Once the threaded
engagement is released the user is able to slide the threaded cover
down the jacket.
[0109] 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 true 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.
[0110] This action is shown in FIG. 8. 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.
[0111] Those skilled in the art will appreciate that many other
configurations for the inspection regions and covers are possible.
The design of these components is dependent on the tension member
construction, the location and size of the desired inspection
regions, and the level of durability required to manage the
unwanted elements.
[0112] FIGS. 9-14 serve to illustrate a few of these possible
additional embodiments. FIG. 9 shows an embodiment in which the
inspection regions are accessed through the anchor itself. 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.
[0113] 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.
[0114] As still more examples, the cover could span a large region
and be removed by pivoting or sliding. The cover would be "removed"
to permit access to the inspection region, yet would remain
attached to the balance of the tension member.
[0115] It is preferable to combine other stress-indicating features
with the provision of the covered and protected inspection region.
FIGS. 10 and 11 illustrate some of these features. NG. 10 shows a
termination 22 that incorporates a clevis joint configured to
receive a pin through a transverse hole. Several 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
service.
[0116] Also, since the protection tensile member is covered, it may
be important to control certain movements that could go unnoticed
and that might adversely affect strength. In many synthetic fiber
constructions, it is important to ensure that the tension member is
not significantly twisted. 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--such as a yellow
alignment marking on a black background. It may also be desirable
to rotationally interlock the jacket and the core of synthetic
fibers it contains. 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. Of course, there are many
possible alignment markers that could be used continuously or at
certain intervals along the tensile member. Even printed text could
be used for this purpose.
[0117] It is also preferable for the jacket to visually indicate a
significant form of wear such as burns, cuts, scrapes, scuffs, or a
full breach. FIG. 11 shows one approach to providing such a
feature. Jacket 24 includes two layers--outer layer 76 and inner
layer 78. The two layers may be provided in contrasting colors
(possibly using different materials). For example, 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 certain type of protection (cut resistance) while the inner
layer might be designed for a different type of protection
(moisture resistance).
[0118] 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.
[0119] The preceding embodiments have included terminations where a
length of fibers is potted into an anchor. In the field of
synthetic tension member, there are of course other types of
terminations and the invention is by no means limited to ropes or
cables with anchor-based terminations. FIGS. 12-14 provide
illustrations of the invention applied to other types of tension
members and terminations.
[0120] 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 or
sheave to convey a load. In some cases this may be configured with
one tensile leg, and in other cases the synthetic fibers may wrap
back around to form a "grommet" (circular configurations with two
or more tensile legs and a fixed termination at each end. In the
case where grommets or round slings are used, 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 a
defined point during the use of the tensile member.
[0121] FIG. 12 shows still another type of tensile member and
termination. In this version a very long fiber or a series of
twisted yarns 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 placed in a
mold). The result is tension member 84 passing between the two
stirrups 86. Such an assembly is thereby entirely sealed, with the
end terminations sealed to the center region and a protective
jacket covering all the fibers.
[0122] FIG. 13 shows the 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 in an area
where stresses are concentrated. 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.
[0123] Still another approach is shown in an exploded state in FIG.
14. In this embodiment, fibers are wound around or ropes are
spliced to two-sheave-type termination bodies. In this example, 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-hearing element that
passes through the casement and covers inspection region 52. Cover
88 includes first flange 98 that bears against a first side of the
casement. Second flange 100 bears against the opposite side of the
casement when threaded boss 102 is threaded into a threaded
receiver in cover 88. Pin receiver 96 is a smooth cylindrical hole
configured to receive a linking pin that attached the stirrup to
something else. Of course, many other designs could be used to
provide a cover for this type of inspection region.
[0124] It is preferable in this example to cover the inspection
region with a transparent sleeve (configured to be a close sliding
fit for cover 88). The presence of such a transparent sleeve allows
the desired visual inspection without allowing the fibers within
the inspection region to become disorganized and protrude into the
cylindrical cavity needed to receive the cover.
[0125] For a spliced rope, terminated round sling, grommet, or
fiber-wound sling design, inspection of these inner bearing and
sliding elements would be useful. This area, like the entry point
into an anchoring or termination body, is a leading stress and wear
point.
[0126] FIG. 15 shows an embodiment in which an enlarged inspection
region is provided. In addition, 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 this version, 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.
[0127] 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 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). In the case of a mechanical termination (such
as a spike-and-cone) the extended inspection region allows the user
to visualize an additional length of fibers. These transitional
regions tend to carry high stress concentrations are subject to
wear over use. The extended inspection region may only be used some
of the time (such as to help ensure the proper initial setup of
this region when it is first loaded).
[0128] Additional features and variations for the present invention
include the following:
[0129] 1. A version where a substantial portion of the termination
or the cable jacket is transparent;
[0130] 2. A version where the removable cover is a piece of tape, a
helical wrapping, a wire wrapping, or a painted layer; and
[0131] 3. A version where each individual termination on each
individual tensile member is gathered into a larger collector of
terminations (in order to build a much larger tensile member, for
example).
[0132] Although the preceding description contains significant
detail, it should not be construed as limiting the scope of the
invention but rather as providing illustrations of the preferred
embodiments of the invention. As an example, the removable covers
could assume many different forms and could attach in different
ways. Thus, the scope of the present invention should be fixed by
the claims rather than the specific examples given.
* * * * *