U.S. patent application number 16/302672 was filed with the patent office on 2019-04-25 for long lived synthetic rope for powered blocks.
This patent application is currently assigned to Hampidjan hf. The applicant listed for this patent is HAMPIDJAN HF. Invention is credited to Hjortur Erlendsson.
Application Number | 20190119850 16/302672 |
Document ID | / |
Family ID | 60324949 |
Filed Date | 2019-04-25 |
United States Patent
Application |
20190119850 |
Kind Code |
A1 |
Erlendsson; Hjortur |
April 25, 2019 |
LONG LIVED SYNTHETIC ROPE FOR POWERED BLOCKS
Abstract
Disclosed is a method for producing a high strength synthetic
strength member containing rope and a resultant rope, comprising
multiple layers of twisted and braided yarns, wherein individual
sheaths enclosing individual strands are of a material such as
HMPE, PTFE or UHMWPE with a lower decomposition temperature than
the material of said strands being aramid, the method comprising
subjecting parts of the rope to heat and tension thereby
pre-stretching and creating a non-uniform or non-round shape of
said strands, further choosing a combination of braid and twist
angles as well as braid compressive forces to accommodate specific
strength and elongation relation between the individual rope
layers.
Inventors: |
Erlendsson; Hjortur;
(Kopavogur, IS) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HAMPIDJAN HF |
Reykjavik |
|
IS |
|
|
Assignee: |
Hampidjan hf
Reykjavik
IS
|
Family ID: |
60324949 |
Appl. No.: |
16/302672 |
Filed: |
May 17, 2017 |
PCT Filed: |
May 17, 2017 |
PCT NO: |
PCT/IS2017/050007 |
371 Date: |
November 19, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62337820 |
May 17, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D07B 2205/2071 20130101;
D07B 2201/2095 20130101; D07B 2205/2003 20130101; D07B 2207/4054
20130101; D07B 2201/1096 20130101; D07B 2201/209 20130101; D07B
2201/2089 20130101; D07B 2201/2052 20130101; D07B 2201/2055
20130101; D07B 2201/2041 20130101; D07B 2201/102 20130101; D07B
2201/2049 20130101; D07B 1/162 20130101; D07B 2401/205 20130101;
D07B 2205/205 20130101; D07B 5/00 20130101; D07B 5/12 20130101;
D07B 2205/2014 20130101; D07B 2201/2068 20130101; D07B 2207/4059
20130101; D07B 1/165 20130101; D07B 2501/2061 20130101; D07B 1/025
20130101; D07B 1/16 20130101; D07B 1/04 20130101; D07B 2201/2066
20130101; D07B 2201/2036 20130101; D07B 2501/2015 20130101; D07B
2501/2038 20130101; D07B 2401/206 20130101; D07B 2401/207 20130101;
D07B 2205/205 20130101; D07B 2801/10 20130101; D07B 2801/14
20130101; D07B 2207/4054 20130101; D07B 2801/60 20130101; D07B
2205/2003 20130101; D07B 2801/14 20130101; D07B 2201/2055 20130101;
D07B 2801/24 20130101; D07B 2201/2049 20130101; D07B 2801/24
20130101; D07B 2201/2066 20130101; D07B 2801/24 20130101; D07B
2201/2068 20130101; D07B 2801/24 20130101; D07B 2205/2014 20130101;
D07B 2801/10 20130101; D07B 2201/2089 20130101; D07B 2801/12
20130101; D07B 2205/2071 20130101; D07B 2801/20 20130101; D07B
2801/22 20130101; D07B 2201/209 20130101; D07B 2801/12 20130101;
D07B 2801/24 20130101; D07B 2401/205 20130101; D07B 2801/22
20130101; D07B 2205/2014 20130101; D07B 2801/10 20130101; D07B
2801/22 20130101; D07B 2207/4059 20130101; D07B 2801/14 20130101;
D07B 2801/60 20130101 |
International
Class: |
D07B 1/04 20060101
D07B001/04; D07B 1/16 20060101 D07B001/16 |
Claims
1. A method for forming a synthetic rope (1), the method having
steps of: a) providing a core (3) formed of at least a first
synthetic substance and selecting for the first synthetic substance
a thermoplastic substance; b) enclosing the core within at least a
flow shield capable of retaining within the flow shield at least
most and preferably all of the first synthetic substance when the
first synthetic substance is in a semi-liquid phase; c) providing
several individual primary strands (19) formed of fibers formed of
at least a second synthetic substance and selecting for the fibers
mainly and preferably exclusively fibers that are Aramid fibers;
the method characterized by steps of: d) forming from a third
synthetic substance at least several individual sheaths (21) where
at least a sheath (21) is formed about and enclosing at least one
of the several of the individual primary strands (19) formed of the
second synthetic substance, so that at least some and preferably
all of the individual primary strands (19) formed of the second
synthetic substance are each enclosed by at least one of the
individual sheaths (21) formed of the third synthetic substance,
where the third synthetic substance forming at least some of the
sheaths (21) has a lower decomposition temperature than does the
second synthetic substance; e) next, forming a hollow braided
strength member (7) about the core (3) from several of the
individual primary strands (19), where at least some and preferably
all of the individual primary strands (19) used in forming the
hollow braided strength member (7) have at least a sheath (21); f)
subjecting the strength member to tension and heat so as to cause
the core to experience a non-solid phase and so as to cause the
strength member and the core to become compacted and elongated;
followed by cooling both at least the strength member and the core
under tension so as to cause the strength member and the core to
become permanently compacted and permanently elongated; and g)
enclosing the strength member within an outer sheath (8), whereas a
rope having at least a strength member formed at least mainly of
synthetic fibers is produced.
2. The method of claim 1 further characterized by selecting for the
third synthetic substance a substance that is less brittle than is
the second synthetic substance.
3. The method of claim 2 further characterized by selecting to form
at least one and preferably all of the individual sheaths (21) with
a braided construction.
4. The method of claim 3 further characterized by selecting to form
at least one of the individual braided sheaths (21) comprising
fibers forming the braided construction forming the braided
sheath.
5. The method of claim 4 further characterized by selecting fibers
comprising HMPE.
6. The method of claim 4 further characterized by selecting fibers
comprising PTFE.
7. The method of claim 5 characterized by the further step of
selecting to also form the outer sheath (8) with a hollow braided
construction, and by selecting to adhere the hollow braided
strength member (7) to the hollow braided outer sheath (8) by steps
of: selecting to situate at least a fourth synthetic substance in a
flowable phase onto the exterior surface of several of the
individual sheaths (21) formed of the third synthetic substance
where such fourth synthetic substance is, when in a set and/or
solid state, an elastic and adhesive substance; followed by forming
a hollow braided outer sheath (8) about the hollow braided strength
member (7) and selecting to form the hollow braided outer sheath
(8) compressing against the exterior surfaces of at least portions
of several of the inner individual sheaths (21) formed of the third
synthetic substance.
8. The method of claim 6 characterized by the further step of
selecting to also form the outer sheath (8) with a hollow braided
construction, and by selecting to adhere the hollow braided
strength member (7) to the hollow braided outer sheath (8) by steps
of: selecting to situate at least a fourth synthetic substance in a
flowable phase onto the exterior surface of several of the
individual sheaths (21) formed of the third synthetic substance
where such fourth synthetic substance is, when in a set and/or
solid state, an elastic and adhesive substance; followed by forming
a hollow braided outer sheath (8) about the hollow braided strength
member (7) and selecting to form the hollow braided outer sheath
(8) compressing against the exterior surfaces of at least portions
of several of the inner individual sheaths (21) formed of the third
synthetic substance.
9. The method of claim 7 further comprising selecting to apply a
constrictive force by most and preferably by all sheaths (21) to at
least some and preferably any primary strand (19) that is a
constrictive force that is sufficiently low so that each of the
primary strands (19) is deformed during manufacturing of the rope
and adopts a non-circular cross section in the finished rope
product when viewed in a plane that is perpendicular to the long
dimension of the rope.
10. The method of claim 8 further comprising selecting to apply a
constrictive force by most and preferably by all sheaths (21) to at
least some and preferably any primary strand (19) that is a
constrictive force that is sufficiently low so that each of the
primary strands (19) is deformed during manufacturing of the rope
and adopts a non-circular cross section in the finished rope
product when viewed in a plane that is perpendicular to the long
dimension of the rope.
11. The method of claim 9 further comprising selecting to form at
least some of the individual braided sheaths (21) from flattened
fibers.
12. The method of claim 10 further comprising selecting to form at
least some of the individual braided sheaths (21) form flattened
fibers.
13. The method of claim 11 further comprising selecting to braid
the sheath from the flattened fibers in such fashion that at least
some of the flattened fibers are untwisted about their long
axis.
14. The method of claim 12 further comprising selecting to braid
the sheath from the flattened fibers in such fashion that at least
some of the flattened fibers are untwisted about their long
axis.
15. The method of claim 2 further characterized by selecting to
form at least one and preferably all of the individual sheaths (21)
comprising a wrapped tape.
16. The method of claim 15 further characterized by selecting a
tape comprising HMPE.
17. The method of claim 15 further characterized by selecting a
tape comprising PTFE.
18. The method of claim 15 further comprising selecting to apply a
constrictive force by most and preferably by all sheaths (21) to at
least some and preferably any primary strand (19) enclosed by any
sheath (21) that is a constrictive force that is sufficiently low
so that each of the primary strands (19) is deformed during
manufacturing of the rope and adopts a non-circular cross section
in the finished rope product when viewed in a plane that is
perpendicular to the long dimension of the rope.
19. The method of claim 16 further comprising selecting to apply a
constrictive force by most and preferably by all sheaths (21) to at
least some and preferably any primary strand (19) that is a
constrictive force that is sufficiently low so that each of the
primary strands (19) is deformed during manufacturing of the rope
and adopts a non-circular cross section in the finished rope
product when viewed in a plane that is perpendicular to the long
dimension of the rope.
20. The method of claim 17 further comprising selecting to apply a
constrictive force by most and preferably by all sheaths (21) to at
least some and preferably any primary strand (19) that is a
constrictive force that is sufficiently low so that each of the
primary strands (19) is deformed during manufacturing of the rope
and adopts a non-circular cross section in the finished rope
product when viewed in a plane that is perpendicular to the long
dimension of the rope.
21. The method of claim 18 characterized by the further step of
selecting to also form the outer sheath (8) with a hollow braided
construction, any by selecting to adhere the hollow braided
strength member (7) to the hollow braided outer sheath (8) by steps
of: selecting to situate at least a fourth synthetic substance in a
flowable phase onto the exterior surface of several of the
individual sheaths (21) formed of the third synthetic substance
where such fourth synthetic substance is, when in a set and/or
solid state, an elastic and adhesive substance; followed by forming
a hollow braided outer sheath (8) about the hollow braided strength
member (7) and selecting to form the hollow braided outer sheath
(8) compressing against the exterior surfaces of at least portions
of several of the inner individual sheaths (21) formed of the third
synthetic substance.
22. The method of claim 19 characterized by the further step of
selecting to also form the outer sheath (8) with a hollow braided
construction, and by selecting to adhere the hollow braided
strength member (7) to the hollow braided outer sheath (8) by steps
of: selecting to situate at least a fourth synthetic substance in a
flowable phase onto the exterior surface of several of the
individual sheaths (21) formed of the third synthetic substance
where such fourth synthetic substance is, when in a set and/or
solid state, an elastic and adhesive substance; followed by forming
a hollow braided outer sheath (8) about the hollow braided strength
member (7) and selecting to form the hollow braided outer sheath
(8) compressing against the exterior surfaces of at least portions
of several of the inner individual sheaths (21) formed of the third
synthetic substance.
23. The method of claim 20 characterized by the further step of
selecting to also form the outer sheath (8) with a hollow braided
construction, and by selecting to adhere the hollow braided
strength member (7) to the hollow braided outer sheath (8) by steps
of: selecting to situate at least a fourth synthetic substance in a
flowable phase onto the exterior surface of several of the
individual sheaths (21) formed of the third synthetic substance
where such fourth synthetic substance is, when in a set and/or
solid state, an elastic and adhesive substance; followed by forming
a hollow braided outer sheath (8) about the hollow braided strength
member (7) and selecting to form the hollow braided out sheath (8)
compressing against the exterior surfaces of at least portions of
several of the inner individual sheaths (21) formed of the third
synthetic substance.
24. The method of claim 1 characterized by the further step of
stranding the primary strands (19) directly from fibres and/or
filaments.
25. The method of claim 2 characterized by the further step of
stranding the primary strands (19) directly from fibres and/or
filaments.
26. The method of claim 18 characterized by the further step of
stranding the primary strands (19) directly from fibres and/or
filaments.
27. The method of claim 19 characterized by the further step of
stranding the primary strands (19) directly from fibres and/or
filaments.
28. The method of claim 20 characterized by the further step of
stranding the primary strands (19) directly from fibres and/or
filaments.
29. The method of claim 1 wherein the rope has a longer service
life when used with powered blocks and/or sheaves in comparison to
known synthetic strength membered ropes.
30. The method of claim 2 wherein the rope has a longer service
life when used with powered blocks and/or sheaves in comparison to
known synthetic strength membered ropes.
31. A rope having a solid core (3) formed of at a first synthetic
substance that mainly is a thermoplastic substance, and having a
strength member (7) formed of primary strands (19) formed of at
least a second synthetic substance and braided together with a
hollow braided construction about the solid core (3), the primary
strands (19) formed mainly of the second synthetic substance
comprising mainly Aramid filaments, the rope characterized in that:
a third synthetic substance forms several individual sheaths (21)
where at least one of the several individual sheaths (21) encloses
at least one the individual primary strands (19) formed of the
second synthetic substance, so that at least some and preferably
all of the individual primary strands (19) are each enclosed by at
least one of the individual sheaths (21); where the third synthetic
substance has a lower decomposition temperature than does the
second synthetic substance.
32. The rope of claim 31 where the third synthetic substance is
less brittle than the second synthetic substance.
33. The rope of claim 31 where the third synthetic substance is
more elastic than the second synthetic substance.
34. The rope of claim 31 where an elastic adhesive substance formed
from a fourth synthetic substance adheres interior surfaces of a
hollow braided outer sheath (8) to portions of exterior surfaces of
at least several of the inner sheaths (21) formed of the third
synthetic substance, where the third synthetic substance is more
elastic than the second synthetic substance and less elastic than
the fourth synthetic substance.
35. The rope of claim 32 where an elastic adhesive substance formed
from a fourth synthetic substance adheres interior surfaces of a
hollow braided outer sheath (8) to portions of exterior surfaces of
at least several of the inner sheaths (21) formed of the third
synthetic substance, where the third synthetic substance is more
elastic than the second synthetic substance and less elastic than
the fourth synthetic substance.
36. The rope of claim 35 where an elastic adhesive substance formed
from a fourth synthetic substance adheres interior surfaces of a
hollow braided outer sheath (8) to portions of exterior surfaces of
at least several of the inner sheaths (21) formed of the third
synthetic substance, where the third synthetic substance is more
elastic than the second synthetic substance and less elastic than
the fourth synthetic substance.
37. The rope of claim 31 where at least one and preferably all of
the individual sheaths (21) is formed with a braided
construction.
38. The rope of claim 37 where the braided construction comprises
fibers.
39. The rope of claim 38 wherein the fibers comprise PTFE.
40. The rope of claim 39 wherein the fibers comprise HMPE.
41. The rope of claim 40 wherein the HMPE fibers comprise a
flattened form.
42. The rope of claim 41 wherein the HMPE fibers comprising a
flattened form include at least some fibers that are untwisted
about their long axis.
43. The rope of claim 31 where at least some and preferably all of
the individual sheaths (21) comprise a wrapped tape.
44. The rope of claim 43 wherein the wrapped tape comprises
PTFE.
45. The rope of claim 43 wherein the wrapped tape comprises
HMPE.
46. The rope of claim 31 where at least the majority of strands
(19) comprise a non-circular cross section when viewed in a plane
that is perpendicular to the long dimension of the rope.
47. The rope of claim 37 where at least the majority of strands
(19) comprise a non-circular cross section when viewed in a plane
that is perpendicular to the long dimension of the rope.
48. The rope of claim 38 where at least the majority of strands
(19) comprise a non-circular cross section when viewed in a plane
that is perpendicular to the long dimension of the rope.
49. The rope of claim 46 wherein at least the majority of primary
strands (19) are stranded directly from fibers and/or
filaments.
50. The rope of claim 47 wherein at least the majority of primary
strands (19) are stranded directly from fibers and/or
filaments.
51. The rope of claim 48 wherein at least the majority of primary
strands (19) are stranded directly from fibers and/or
filaments.
52. The rope of claim 49 wherein longevity of the service life of
the rope when used with powered blocks and/or sheaves with loading
forces of at least two thousand kilograms and up to two thousand
tonnes is greater in comparison to prior known synthetic ropes.
53. The rope of claim 50 wherein longevity of the service life of
the rope when used with powered blocks and/or sheaves with loading
forces of at least two thousand kilograms and up to two thousand
tonnes is greater in comparison to prior known synthetic ropes.
54. The rope of claim 51 wherein longevity of the service life of
the rope when used with powered blocks and/or sheaves with loading
forces of at least two thousand kilograms and up to two thousand
tonnes is greater in comparison to prior known synthetic ropes.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to the technical
field of synthetic ropes and, more particularly, to a rope that
preferably is made from synthetic polymeric material, that has a
rather high breaking strength and that also has a rather light
weight compared to steel wire rope and that is capable of being
used with powered blocks, traction winches, powered winches,
powered drums, drum winches, powered capstans and in general any
powered turning element and/or rotating element capable of applying
force to a rope (hereinafter aggregately known as "powered
blocks"). Such synthetic ropes include but are not limited to crane
ropes, deep sea deployment and recovery ropes, tow ropes, towing
warps, trawl warps (also known as "trawlwarps"), deep sea lowering
and lifting ropes, powered block rigged mooring ropes, powered
block rigged oil derrick anchoring ropes used with blocks and also
with powered blocks, superwides and paravane lines used in seismic
surveillance including but not limited to being used with towed
arrays, yachting ropes, rigging ropes for pleasure craft including
but not limited to sail craft, running rigging, powered block
rigged anchor ropes, drag lines, and the like.
BACKGROUND ART
[0002] Due to the high costs of raw materials needed to produce
synthetic high strength ropes such as ropes made from state of the
art synthetic materials including UHMWPE and others, it is
important to increase the both the longevity as well as the
strength that can be obtained from synthetic high strength ropes
for a given amount of material. In the case of increased longevity,
the increase in longevity is important in order to reduce
replacement costs. Additionally, the increase in longevity can
permit use of lowered diameter and thus lighter and less expensive
to deploy ropes as in the present state of the art larger than
necessary initial diameters are selected in order to provide for a
minimum desired longevity of the rope due to anticipated rates of
decrease in rope strength and ultimate longevity. In the case of
increased strength, the increase in strength is important both to
decrease costs of raw materials and production process, costs of
rigging equipment needed to carry, lift, stabilize and stably float
and/or otherwise sustain and support the weight of the ropes, as
well to decrease drag in water and drag in air of such ropes. In
the environment of winches, drums and traction winches, i.e.
powered blocks, it is especially important to make such ropes more
readily usable on such powered blocks. Furthermore, it is important
to increase the life expectancy of such ropes in order to obtain
the greatest economic advantage from a given investment in any such
rope.
[0003] In the present state of the art, when forming high strength
synthetic strength members for use in forming a high strength rope,
the strongest synthetic fiber available at a certain price point
and suitable for a certain environment of intended deployment is
used. It is well known that synthetic high strength ropes have a
drawback of being very expensive. Furthermore, synthetic high
strength ropes are prone to a much more rapid rate of degradation
and experience failure sooner in comparison to steel wire ropes
when used on powered blocks, whether in protected environments or
in high temperature and abrasive environments, as opposed to when
such synthetic high strength ropes are used in static
applications.
[0004] Problematically, those high strength synthetic fibers that
are lightest and most desirable for many applications requiring
minimal weight due to the fact that they are relatively light in
weight both in air and in water, such as UHMWPE, also are prone to
creep. Conversely, high strength synthetic fibers that are the
least prone to creep or that are considered to not creep, such as
Aramids, are significantly heavier than UHMWPE. Numerous attempts
at reducing the weight of high strength synthetic ropes while also
eliminating the creep include combining Aramid fibers with UHMWPE
fibers, and combining lyotropic and/or thermotropic polymer
filaments with polyolefin filaments to form synthetic strength
members of a combination of such filaments. Many publications and
products with such filament combinations are known. The main idea
is that, since the ultimate tensile strengths of Aramid and UHMWPE
filaments are similar, and since UHMWPE filaments are significantly
lighter than Aramids, that by combining these fiber types into a
synthetic strength member that the weight of the strength member
can be reduced in comparison to forming the strength member solely
of Aramid filaments, while also eliminating the creep as when all
fibers are fully loaded the Aramid fibers prevent the strength
member from creeping.
[0005] However, while the issue of creep has largely been addressed
by the known art, known high strength synthetic strength member
ropes continue to experience a relatively high rate of degradation
in applications where the rope experiences high heats in comparison
to steel wire ropes, steel wire having a several fold greater
decomposition temperature in comparison to even Aramid fibers.
These applications can include high temperature applications, or
can include applications where constant bending and/or bend fatigue
results in high temperatures, especially in regions of the rope in
contact with or near powered blocks and or non-powered sheaves.
[0006] Nonetheless, due to their relatively light weights and also
due to their relative low diameters for a given strength, and also
due to their ability to not rust or oxidize in air and humid
environments at an appreciable rate compared to metal fibre ropes,
state of the art high strength synthetic ropes, such as ropes made
from Aramids (such as Technora.RTM.), UHMWPE and the like are
highly desirable in many applications where light weights and
minimal diameters are desired in order to minimize structural
loads, especially in crane ropes and deep water mooring
applications; in order to minimize the costs of structures to which
the ropes affix; and also where low drags are desired such as in
towed applications and mooring applications, the relatively low
diameters of such synthetic high strength ropes providing for
lowered drags compared to other synthetic ropes.
[0007] Due to the advantages of lightness of weight that high
strength synthetic strength member ropes offer, attempts continue
to be made to successfully deploy into industry on a wide scale
high strength synthetic strength member ropes for use with powered
blocks. However, the very high costs of such high strength
synthetic strength member containing ropes compared to ropes having
strength members formed of steel wire (i.e. "wire ropes), and the
fact that such high strength synthetic strength member containing
ropes when used with powered blocks experience rather fast
deterioration when experiencing high temperatures in comparison to
steel wire ropes, has resulted in the fact that today only limited
market acceptance has been gained for high strength synthetic
strength member containing ropes for use with powered blocks.
[0008] However, high strength synthetic strength member containing
ropes are also well known for being much safer for operators and
crew than are wire ropes, for the reason that high strength
synthetic strength member containing ropes do not store kinetic
energy at an appreciable level in comparison to wire ropes, and
thus during accidental severance do not generate the recoil that
steel wire ropes are well known for, such recoil being responsible
for many fatalities over the years.
[0009] WO 2004/020732 discloses a cable having a thermoplastic core
within a braided synthetic strength member. The cable is a heat
stretched cable exhibiting ultra-compactness and is useful for high
tension powered block applications. In one embodiment, disclosed is
a cable wherein the material of the thermoplastic core contacts
both the synthetic strength member and a braided synthetic sheath
formed about the outside of the strength member. However, this
embodiment has failed to be widely commercially accepted for the
reasons taught above, i.e. due to the fact that the strength of the
cable is reduced by such construction. In all embodiments of this
teaching, it is taught that the heat stretching and compacting of
the cable is accomplished either by simultaneously heating and
stretching with tension the combination of the strength member, the
thermoplastic core and a second sheath formed about the
thermoplastic core and also contained within the strength member,
the purpose of such second sheath being to prevent uncontrolled
flow of molten phase of the thermoplastic core during processing of
the rope, or by first applying the heat and subsequently applying
the tension.
[0010] WO 2011/027367, discloses a cable formed of three distinct
synthetic substances, where the strength member is adhered to a
braided sheath by a synthetic substance that differs from a
synthetic substance forming both the sheath and the strength
member, and also differs from another synthetic substance forming a
core contained within the synthetic strength member, and where the
elasticity of the synthetic substance adhering the synthetic
strength member to the synthetic sheath is greater than the
elasticity of any other of the synthetic substances forming the
cable. This cable has found more commercial acceptance for use with
high tension powered blocks in comparison to the cable taught in
above referenced WO 2004/020732 and is a viable synthetic rope in
the known art for use with high tension powered blocks such as
trawler winches for purposes such as trawl warps, and this cable
and its taught manufacturing processes represent both the state of
the art as well as the trend in the Industry. However, when used in
applications with powered blocks that require constant bending,
such as over sheaves, those portions of this cable in contact with
or proximal the powered block and/or a non-powered sheave, or those
portions of this cable that are experiencing the constant bending,
continue to experience failure at a faster rate in comparison to
failure experienced by steel wire ropes in the same application,
reducing the appeal of this rope and causing it to not be widely
accepted into industry.
[0011] Due to the extremely high cost of high strength synthetic
strength member containing ropes in comparison to steel wire ropes,
and also due to their premature failure and short life spans when
used with powered blocks in comparison to steel wire ropes, the
adoption of high strength synthetic strength member ropes for use
with powered blocks has been limited. For example, the majority of
the world's trawlers even in highly developed regions continue to
use steel wire rope as trawl warps, despite the great weight and
safety concerns caused by such weight when the steel wire rope is
stored on a trawl winch--i.e. vessel instability, it being well
known that the weight of such stored wire trawling warps has often
been implicated in vessel capsize.
[0012] Thus, it can be appreciated that a long felt need continues
to exist in the industry for a high strength synthetic strength
member containing rope that has a much longer life span in
comparison to known high strength synthetic strength member
containing ropes when used with powered blocks and/or sheaves so as
to promote adoption into industry of these safer ropes for the
benefit of operators and crew.
DEFINITIONS
Synonyms
[0013] The terms "fiber"; "fibre"; and "filament", in singular or
in plural, are synonymous for purposes of the present
disclosure.
Disclosure
[0014] It is an object of the present disclosure to provide for a
high strength synthetic strength member containing rope for use
with powered blocks that addresses the above stated long felt need
in the industry.
[0015] It is an object of the present disclosure to provide for a
high strength synthetic strength member containing rope capable of
being used with powered blocks that has improved tolerance to
constant bending over powered blocks and sheaves in comparison to
known synthetic strength member containing ropes and thus exhibits
improved strength retention over time in comparison to known
synthetic strength member containing ropes.
[0016] It is another object of the present disclosure to provide
for a high strength synthetic strength member containing rope
capable of being used with powered blocks that exhibits improved
strength.
[0017] It is yet another object of the present disclosure to
provide for a high strength synthetic strength member containing
rope capable of being used with powered blocks that exhibits both
improved strength retention over time, and especially that has
improved tolerance to constant bending over powered blocks and
sheaves in comparison to known synthetic strength member containing
ropes.
[0018] It is yet another object of the present disclosure to
provide for a high strength synthetic strength member containing
rope capable of being used with powered blocks and satisfying the
above stated objects of the present disclosure where such rope is
capable of being used in substitution of steel wire strength member
containing ropes for applications including but not limited to
trawl warps, anchoring lines, seismic lines, oil derrick anchoring
and mooring lines, tow ropes, towing warps, deep sea deployment and
recovery ropes, deep sea lowering and lifting ropes, powered block
rigged mooring ropes, powered block rigged oil derrick anchoring
ropes used with blocks and also with powered blocks, superwides and
paravane lines used in seismic surveillance including but not
limited to being used with towed arrays, yachting ropes, rigging
ropes for pleasure craft including but not limited to sail craft,
running rigging, powered block rigged anchor ropes, drag lines,
climbing ropes, pulling lines and the like.
[0019] Disclosed is a method for producing a high strength
synthetic strength member containing rope capable of being used
with powered blocks, and the product resultant of such method,
where such rope has lighter weight and similar or greater strength
than steel wire strength member containing ropes used with powered
blocks, and where also such rope has, in comparison to known
synthetic strength member containing ropes, a longer service life
and especially improved strength retention over time when used with
powered blocks and and/or sheaves.
Description
[0020] Most broadly, the present disclosure is based upon the
surprising and unexpected discovery that the tolerance to bend
fatigue induced heat of a rope having a high strength synthetic
strength member formed of fibers considered to be highly heat
tolerant and especially Aramid fibers, can be increased by
combining, in a certain fashion and construction not previously
known, fibers that are lesser heat tolerant than are the Aramid
fibers.
[0021] Broadly, the long lived synthetic rope for powered blocks of
the present disclosure is based upon the surprising discovery that
by forming a rope from multiple primary strands each formed of a
combination of (i) Aramid fibers and (ii) other, significantly less
heat tolerant fibers, where the Aramid fibers mainly form the body
of the strand and the less heat tolerant fibers are concentrated at
the outer regions of each strand, forming the strength member about
a thermoplastic core and subjecting the strength member to
heat-stretching and subsequent cooling under tension so as to
permanently compact and permanently elongate the strength member,
followed by enclosing the strength member within an outer sheath,
that a high strength synthetic strength membered rope having a long
service life and improved tolerance to bend fatigue induced high
heats when used with powered blocks and/or sheaves is achieved.
[0022] Preferably, the rope thus formed has a longer service life
when used with powered blocks and/or sheaves in comparison to known
synthetic strength membered ropes
[0023] The long-lived synthetic rope for powered blocks of the
present disclosure includes: a first synthetic substance, that
preferably forms a core that is located internal the rope's
strength member; a synthetic strength member formed with a hollow
braided construction about the core and formed of a plurality of
individual primary strands (that themselves can be formed of yarns
other substrands) where each of the individual primary strands is
formed of a second synthetic substance; a third synthetic substance
forming a plurality of individual primary strand sheaths where at
least some and preferably all of the individual primary strands are
each enclosed by preferably one of the individual primary strand
sheaths formed of the third synthetic substance; and, a final outer
sheath enclosing the strength member formed of the primary strands
that are preferably each enclosed within an primary strand sheath,
where the second synthetic substance has a higher decomposition
temperature than does the third synthetic substance, preferably at
least one point seven to one point nine times more/greater; and has
a higher rigidity than does the second synthetic substance, and
where constrictive force applied by most and preferably by any
primary strand sheath to the primary strand it encloses is lesser
in comparison to constrictive force applied by the final outer
sheath to the strength member.
[0024] Preferably, the constrictive force applied by most and
preferably by any primary strand sheath to the primary strand it
encloses is sufficiently low so that each of the primary strands is
readily deformed during manufacturing of the rope and adopts a
non-circular cross section in the finished rope product whereas the
finished rope product itself adopts a cross section that is either
circular or oval, or that appears to a casual observer with an
unaided human eye to be either circular or oval, without regard to
surface irregularities resultant of forming a braided sheath (e.g.
without regard to the pits and valleys formed between braid weaves
of braided sheath, though such are preferably filled by a fourth
synthetic substance discussed below).
[0025] Preferably, but optionally, a fourth synthetic substance
contacts the primary strand sheaths formed of the third synthetic
substance and adheres the primary strand sheaths formed of the
third synthetic substance to the final outer sheath enclosing the
strength member that preferably is a braided sheath enclosing the
hollow braided strength member, where the fourth synthetic
substance is more elastic in comparison to all of the first,
second, and third synthetic substances.
[0026] Preferably, the third synthetic substance is less brittle
than is at least the second synthetic substance.
[0027] Preferably, a fifth synthetic substance forms a braided
sheath about the thermoplastic core and such sheath is hollow
braided about a thermoplastic rod prior to the strength member
being hollow braided about the thermoplastic rod.
[0028] Most preferably, and vitally, the second synthetic substance
has a higher decomposition temperature than does the third
synthetic substance, and especially a decomposition temperature
that is at least one hundred degrees C. greater than the
decomposition temperature of the third synthetic substance and more
preferably that is at least one hundred thirty degrees C. greater
than the decomposition temperature of the third synthetic substance
and yet more preferably that is about one hundred forty degrees C.
greater or even more than is the decomposition temperature of the
third synthetic substance. In some embodiments, it is preferred
that the decomposition temperature of the second synthetic
substance is at least three hundred degrees C. greater than is the
decomposition temperature of the third synthetic substance, such as
from three hundred fifty to three hundred seventy degrees C.
greater.
[0029] Preferably, the third synthetic substance is used in forming
a sheath enclosing each of the primary strands that are formed of
the second synthetic substance and that form the hollow braided
strength member. In one embodiment of the present disclosure, the
third synthetic substance is extruded and/or pultruded over a
primary strand to form the primary strand sheath. In another
embodiment of the present disclosure, the third synthetic substance
is formed as a tape. Then, each of the individual primary strands
formed of the second synthetic substance and that are intended to
be the main strands forming the rope's strength member are wrapped
with this tape. Preferably the tape formed of the third synthetic
substance is wrapped about individual primary strands in such as
fashion as to have the tape's edges overlap one another, such as
with a fifty percent overlap. The extent of the overlapping is such
that after stretching steps taught herein the tape continues to
cover all of the exterior of any distinct primary strand about
which the tape is used to form a distinct primary strand sheath.
The wrapped strands are then used to form the hollow braided
strength member in such a fashion that individual primary strand
sheaths formed of the third synthetic substance contact one another
after the primary strands are braided together to form the hollow
braided strength member. In other terms, the wrapped primary
strands are then used to form the hollow braided strength member in
such a fashion that the construction of the hollow braided strength
member has several braided primary strands formed of the second
synthetic substance, where several and preferably all of the
primary strands formed of the second synthetic substance are each
individually enclosed within a sheath formed of the third synthetic
substance, where in the finished hollow braided strength member
various of the individual primary strand sheaths formed of the
third synthetic substance contact one another. In another
embodiment that is a presently most preferred embodiment, the third
synthetic substance is used to form other strands, or fibers or
filaments, that are used to form braided sheaths about the primary
strands formed of the second synthetic substance so as to form
braided primary strand sheaths rather than extruded and/or
pultruded, or tape wrapped primary strand sheaths. In one
embodiment, the third synthetic substance is use to form flattened
and/or tape like strands, and these flattened and/or tape like
strands formed of the third synthetic substance are not twisted
about their long axis and/or mainly are not twisted about their
long axis when forming the braided primary strand sheaths about the
individual strands formed of the second synthetic substance, or can
be twisted about their long axis as they are used to form the
braided primary strand sheaths, though being not twisted about
their long axis when used to form the braided primary strand
sheaths presently is preferred.
[0030] A presently preferred substance and structure for forming
the second synthetic substance is a lyotropic polymer filament
and/or a thermotropic polymer filament. Aramids are useful, such as
Technora.RTM.. A newly developed fibre termed T200WD is presently
preferred. Preferably, these fiber and/or filaments, formed of the
second synthetic substance, are then further used to form yarns;
the yarns are then further used to form strands; then these strands
are further enclosed in sheaths formed of the third synthetic
substance; and next these strands enclosed in such sheaths are then
used in forming the hollow braided strength member.
[0031] A presently preferred substance for forming the third
synthetic substance is Polytetrafluoroethylene (PTFE). UHMWPE also
is considered useful, as is HMPE.
[0032] Most preferably, the method includes the additional step of,
prior to enclosing the strands formed of the second synthetic
substance within sheaths formed of the third synthetic substance,
including about and between fibres forming the strength member a
fourth synthetic substance where such fourth synthetic substance is
capable of adhering one to another various fibres forming the
strength member, such fourth synthetic substance having an
elasticity that is lesser than the elasticity of the second
synthetic substance.
[0033] An advantage of the disclosed synthetic rope for powered
blocks is that it has greater tolerance to heat fatigue, that is
caused by bending fatigue, than known synthetic ropes for powered
blocks, thus reducing the long term costs to use the rope, thus
promoting use of such ropes in environments where such ropes are
known as being more safe for operators and crew, as discussed
above.
[0034] Possessing the preceding advantages, the disclosed synthetic
rope for powered blocks answers needs long felt in the
industry.
[0035] It can readily be appreciated that these and other features,
objects and advantages are able to be understood or apparent to
those of ordinary skill in the art from the following detailed
description of the preferred embodiment as illustrated in the
various drawing FIGS.
BRIEF DESCRIPTION OF DRAWINGS
[0036] FIG. 1 is a plan view of a portion of a rope of the present
disclosure.
[0037] FIG. 2 is a view of a cross section of the Rope of the
present disclosure taken along line A-A of FIG. 1.
[0038] FIG. 3 is an expanded detail view of a portion of the cross
section of the rope of the present disclosure shown in FIG. 2 that
is indicated by reference character B. The expanded detailed view
includes a braided outer sheath of the rope of the present
disclosure, a portion of the strength member of the rope of the
present disclosure where such portion of the strength member is
proximal the braided outer sheath, as well as associated
structures.
BEST MODE FOR CARRYING OUT THE DISCLOSURE
[0039] FIG. 2 and FIG. 3 illustrate essential constructional
components of one of the most preferred embodiments for use with
high tension powered blocks of the long lived synthetic rope for
powered blocks of the present disclosure that is identified by the
general reference character 1. FIG. 2 depicts a preferably
thermoplastic shaped supportive core 3 enclosing an optional core 2
that can be an elongatable conductive structure capable of
transmitting information and/or data, or that can be a lead core,
or other, the shaped supportive core 3 being enveloped within a
flow shield sheath 5. Strength member 7 encloses the combination of
the shaped supportive core 3, its enveloping flow shield sheath 5
and its optional core 2. The strength member is formed of several
individual primary strands 19. The various individual primary
strands 19 preferably are of uniform construction, or of similar
construction. Each of the individual primary strands 19 is enclosed
within a distinct primary strand sheath 21. The individual primary
strands 19 are each formed of fibres and/or filaments that are
formed of the second synthetic substance, that preferably is an
Aramid. Each of the distinct primary strand sheaths 21 are formed
of the third synthetic substance, and preferably formed of either a
wrapped tape of PTFE or a braided sheath formed of PTFE, HMPE or
UHMWPE.
[0040] Exterior sheath 8 preferably is of a braided construction
and is adhered to strength member 7 by elastic adhesive substance
layer 9, that preferably is formed of a settable adhesive substance
such as an adhesive polyurethane having a high elasticity and a
high shear strength, such as a two or more component PUR.
Preferably braided exterior sheath 8 is formed of multiple
coverbraid strands 10 by use of a braiding machine, the coverbraid
strands 10 preferably are of a laid construction. Preferably, there
are thirty-two individual strands 10 forming the coverbraided
exterior sheath 8, each strand 10 having between twenty-four to
thirty-six UHMWPE or HMPE fibers in each strand, preferably of a
abrasion resilient construction. However, any quantity of strands
10 forming the coverbraided exterior sheath 8 that provide
sufficient wear resistance and strength transfer to the strength
transfer to the strength member are useful, including but not
limited to twenty-four, twenty-eight, thirty-six, forty-two,
forty-eight, up to sixty-four and even much more. The braid tension
on each strand 10 forming the coverbraided exterior sheath 8 during
braiding operations is preferably about sixty-three kilogram, and
can be from forty to one hundred sixty kilograms. Importantly, the
braid tension on each strand forming a braided primary strand
sheath 21 during braiding operations of any such braided primary
strand sheath 21 when a braided sheath variant is selected for the
primary strand sheaths 21 is lesser per strand forming a braided
sheath 21 in comparison to the braid tension used per strand 10
during braiding operations when forming the coverbraided exterior
sheath 8. The braid tension on each strand forming a braided
primary strand sheath 21 during braiding operations of any such
braided primary strand sheath 21 is preferably about seven
kilograms, and can be from ten grams to thirty kilograms, though
optionally it is nine times less than the braid tension used per
strand 10 during braiding operations when forming the coverbraided
exterior sheath 8, and is at least forty percent less.
[0041] Optionally, and preferably, as shown in more easily visible
detail in FIG. 3, elastic adhesive substance gap filling surface
layer 13 fills in depressions on the surface of rope 1 formed in
between adjacent coverbraid strands 10. The core 2 is optional, and
is preferred for deep sea deployment and retrieval applications,
trawl warp applications and in the case of certain other
applications, but not necessarily in the case of anchor lines and
deep water oil derrick mooring and/or anchoring lines or yachting
lines, although in some cases it may be used in such
applications.
[0042] Shaped supportive core 3 also defines the first synthetic
portion of the rope of the present disclosure mentioned above, and
elastic adhesive substance layer 9 also defines the second
synthetic portion of the rope of the present disclosure as
mentioned above.
[0043] In order to form the rope of the present disclosure:
Preferred Fabrication Methods
[0044] There are two preferred embodiments of the present
disclosure: one is a rope of the present disclosure for use in
applications where the rope of the present disclosure is subject to
storage under high compressive pressure, such as when used with
high tension winches and drums, such as when used as a trawler's
warp; another is where the rope of the present disclosure is not
subject to storage under high compressive pressure, such as is
common in many yachting applications.
[0045] In forming a preferred embodiment of the present disclosure
for use in applications where the rope of the present disclosure is
subject to storage under high compressive pressure:
[0046] First is provided a plurality of fibres and/or filaments
formed of the second synthetic substance, that preferably is an
Aramid, and preferably a new fibre known as T200WD. The fibres
and/or filaments are used in forming several distinct primary
strands 19. Preferably, twelve distinct primary strands 19 are
formed. The primary strands 19 may be stranded directly from the
fibres and/or filaments, or, first yarns may be formed and the
yarns used to form the primary strands 19. The primary strands 19
may be braided, including loosely braided so as to provide
noticeable constructional elongation, but twisted, and especially
lightly twisted, as suitable for Aramids, and using known methods
for forming strands formed of Aramids for use in forming a braided
rope, is preferred.
[0047] Second, each of the distinct (the term "distinct" herein
including "individual") primary strands 19 is enclosed within a
distinct sheath 21, known also herein as a "primary strand sheath".
Each distinct primary strand sheath 21 preferably is formed of a
third synthetic substance having properties taught supra, and
especially is formed of PTFE, but less preferably of HMPE or
UHMWPE. The individual primary strand sheaths 21 may be formed by
wrapping a tape formed of PTFE about each strand in such a fashion
that edges of the tape overlap one another. The extent of the
overlapping is such that after stretching steps taught herein the
tape continues to cover all of the exterior of any distinct primary
strand 19 about which the tape is used to form a distinct primary
strand sheath 21. A fifty percent overlap is considered useful.
However, it is presently preferred to form each of the distinct
primary strand sheaths 21 as a braided sheath, where strands formed
of PTFE may be used as strands to form each such braided primary
strand sheath 21. Alternatively to PTFE, UHMWPE is also a suitable
substance for the third synthetic substance, or tape like filaments
of HMPE. When a braided sheath is selected for the individual
primary sheaths 21, it is preferred to select to form the braided
individual primary sheaths 21 with a braid angle that differs from
the braid angle of any exterior sheath 8 that may be formed in
subsequent steps as described herein and below. Most preferably,
the braid angle selected for forming the braided individual primary
sheaths 21 is a braid angle that is lesser than a braid angle
selected for forming the exterior sheath 8, i.e. that is a "longer
braid angle" or a "more acute" braid angle in comparison to a braid
angle selected for forming the exterior sheath 8, the terms "longer
braid angle" and "more acute braid angle" having the same meaning
and being readily understood by those skilled in the art. The braid
angle selected for the individual sheaths 21 may be similar
(including "same") as the twist angle selected for forming primary
strands 19 from fibers. That is, the same angle defined by fibers
and/or filaments, or by yarns, forming primary strands 19, relative
to the long axis of a straight (not bent) primary strand 19, can be
selected as the braid angle for forming the individual sheaths 21
when it is selected to form the individual sheaths 21 with a
braided construction, and preferably with a hollow braided
construction, as described in more detail below
[0048] Third, several, and preferably twelve of distinct primary
strands 19 each enclosed within a distinct prima strand sheath
21.
[0049] Fourth, the primary strands 19 now enclosed within primary
strand sheaths 21 are used to form a braided strength member having
a hollow braided construction that is achieved by using a braiding
machine to form the twelve (or other quantity) of primary strands
19 each enclosed within a distinct sheath 21 about a thermoplastic
rod that forms the core 3, where the primary strands 19 are formed
in a hollow braided construction about the thermoplastic rod
forming the core 3. While twelve strands 19 are preferably
preferred, it is possible to use from eight to forty-eight.
Alternative to hollow braided, the strength member may be parallel
laid, laid (including twisted) or plaited, but a hollow braided
construction is preferred. It is highly preferably and important
for a preferred embodiment of the instant disclosure that a hollow
braided strength member is selected that has a thermoplastic core
shaped so as to support the natural interior shape of the hollow
braided strength member under tension approaching breaking strength
of the strength member. Preferably, for a strength member is
provided a braided strength member where the primary strands 19
forming the strength member have been stretched so as to remove
constructional elongation and so as to cause compaction of the rope
body, e.g. of the strength member and all contained within it,
after the primary strands 19 have been braided into the strength
member, so that the resultant strength member is unable to elongate
greater than 5% before reaching break point when measured at an
original tension of 1000 Kg, and preferably so that the resultant
strength member is unable to elongate greater than 4% before
reaching break point when measured at an original tension of 1000
Kg.
[0050] In forming a strength member for the preferred form of the
instant disclosure the following further steps are employed:
[0051] First; a thermoplastic elongate object and especially a core
formed of Polyethylene is provided, e.g. a PE rod, that ultimately
forms core 3.
[0052] Second; a tightly woven braided flow-shield sheath 5 is
braided around the thermoplastic rod. Filaments are selected to
form the flow-shield sheath that are not made either liquid or
semi-liquid at a temperature selected to change the phase of the
thermoplastic rod, but rather that have a much higher softening
point, and that are made of a synthetic substance unlike the
synthetic substances of either the first, second, third or fourth
synthetic substances, thus defining a fifth synthetic substance.
Polyester is suitable.
[0053] Third; the primary strands 19 where each strand 19 is
enclosed by a distinct primary strand sheath 21 are loaded onto
bobbins that are loaded onto cars of a braided machine capable of
forming hollow braids and are braided around the thermoplastic rod
surrounded by a flow-shield sheath, so as to form a hollow braided
strength member including a thermoplastic core surrounded by a
flow-shield sheath.
[0054] Fourth; the braided strength member having the thermoplastic
rod surrounded by the flow-shield sheath as its core is then
subject to tension and to heat, preferably by being subject first
to tension and secondly to heat, while maintaining the tension, in
such a fashion and under such conditions that the thermoplastic
selected to form the thermoplastic core becomes semi-liquid, i.e.
molten, at a temperature that is used to permanently elongate the
braided strength member by applying about thirteen percent of the
cool strength member's breaking force to the heated strength
member. The flow shield-sheath mainly or entirely stops the phase
changed thermoplastic core from exiting the flow-shield sheath.
That is, the majority of the thermoplastic core is unable to exit
the flow-shield sheath even when the thermoplastic core is either
liquid or semi-liquid, i.e. molten, despite enormous constrictive
and compressive forces applied to the phase changed thermoplastic
core as a result of the high tensions applied to the strength
member, such high tensions able to permanently elongate the
strength member under the conditions taught supra and herein.
[0055] A preferred tension to be used in the disclosed processes
for forming the disclosed rope is about thirteen to fifteen percent
(13-15%) of the break strength of the strength member when such
break strength is measured at room temperature, with up to
twenty-two percent being useful, and in some cases even more.
[0056] Importantly, the tension applied to the strength member, and
thus necessarily also applied to the filaments forming the strength
member, preferably is a static tension and/or a generally static
tension and/or a very slowly fluctuating tension. After applying a
predetermined tension (including approximately a predetermined
tension), and while under such predetermined tension simultaneously
the strength member, its filaments, and its thermoplastic core are
heated to a predetermined temperature and/or to approximately a
predetermined temperature as taught above and herein, with a
minimum temperature of eighty (80) degrees C. being most preferred.
The use of a long oven having many capstans able to accommodate a
very long length of the strength member and turning at varying
speeds and/or rates of rotation so as to maintain the tension on
differing portions of the strength member located between different
capstans, and thus by extension on the filaments forming the
strength member as well as on the thermoplastic core also forming
the strength member is highly useful, especially for permitting an
endless flow production process.
[0057] Fifth; when the braided strength member and its
thermoplastic core and the thermoplastic core's flow shield have
been elongated to a predetermined amount so as to create an
ultra-compact rope, and to experience a reduction in overall
exterior diameter of the rope of thirty and up to forty-five
percent in comparison to the rope's overall exterior diameter prior
to the stretching and heat processing steps, the now elongated
strength member and its elongated thermoplastic core are cooled
while sufficient tension is maintained and applied to the strength
member and thus by extension to its primary strands 19 and to its
thermoplastic core 3 during the cooling process so that all such
components are cooled to their respective solid states while under
a tension that results in the cooled primary strands 19 as well as
the cooled distinct primary strand sheaths 21 enclosing the primary
strands 19, as well as the strength member and its thermoplastic
core 3, having been permanently elongated so as to cause the
strength member:
[0058] a) to acquire a lower elongation than it had prior to its
having been permanently elongated;
[0059] b) to acquire a substantially lesser diameter and a greater
compactness than it had prior to its having been permanently
elongated;
[0060] c) to acquire to its thermoplastic content core a permanent
solid shape, having at its surface the flow shield sheath also
taking the same shape as the exterior of the core, that supports
the interior cavity of the permanently elongated hollow braided
strength member in such a fashion that the filaments and braid
strands forming the strength member are sufficiently less able to
move relative to one another in a direction perpendicular to the
long dimension of the permanently elongated strength member in
comparison to prior to the strength member having been permanently
elongated so as to reduce filament to filament abrasive wear, and
also so as to preclude crushing of the rope, especially under high
compressive forces such as occurs during winding and storage on a
high tension drum, the necessary tension to achieve such result for
any particular filament type able to be experimentally determined
by one of ordinary skill in the art after having read the present
disclosure.
[0061] This cooling also is best accomplished and undertaken using
capstans turning at varying speeds so as to maintain a tension on
the elongated strength member and its components during the entire
cooling process and period that precludes their shortening, so that
the final cooled strength member has the values of elongation to
break point as taught above and herein for a most preferred
embodiment of the instant disclosure, and also the other properties
taught as above and herein, as also is accomplishable in an endless
flow production method.
[0062] Sixth; optionally, and preferably, an elastic adhesive
substance, that is a fourth synthetic substance, is used to adhere
the formed strength member to an exterior braided sheath 8. The
fourth synthetic substance is chosen as a flowable settable
adhesive substance. While it is in a liquid and/or semi-liquid
(including "flowable") phase it is situated upon the outside
surface of the preferably permanently elongated strength member, in
contact with surfaces of multiple of the distinct primary strand
sheaths 21 formed of the third synthetic substance. Then a
preferably braided exterior sheath 8 is formed about the
combination of the permanently elongated strength member and the
flowable settable adhesive substance. The settable adhesive
substance is situated upon the strength member at temperature that
is lower than a phase change temperature of third synthetic
substance. When a braided sheath is selected for the individual
primary strand sheaths 21, it is preferred to select to form the
braided individual primary strand sheaths 21 with a braid angle
that differs from the braid angle of the exterior sheath 8. Most
preferably, a braid angle selected for forming braided individual
primary strand sheaths 21 is a braid angle that is lesser than a
braid angle selected for forming the exterior sheath 8. The braid
angle of the inner sheath 21 is an angle defined between (i) an
imaginary line lying coaxial and parallel to the long axis of the
primary strand 19 enclosed by the braided primary strand sheath 21
when the primary strand 19 is not curved or bent, but is straight;
and (ii) a long dimension visible for any individual braid strand
forming the braided construction of a primary strand sheath 21 when
viewed in plan photographic view and when the primary strand 19
enclosed by the primary strand sheath 21 is straight (not bent).
Similarly, the braid angle of the exterior sheath 8 is an angle
defined between: (a) an imaginary line lying coaxial and parallel
to the long axis of the rope when the rope is straight; and (b) a
long dimension visible for any individual braid strand forming the
braided construction of exterior sheath 8, when viewed in plan
photographic view when the rope is straight.
[0063] Contrary to the state of the art, knowledge in the field and
trend in the industry for forming braided sheaths, the braid angle
selected for the individual sheaths 21 may, preferably, be similar
(including "same") as the twist angle selected for forming primary
strands 19 from fibers. That is, the same angle defined by fibers
and/or filaments, or by yarns, forming primary strands 19, relative
to the long axis of an straight primary strand 19, can be selected
as the braid angle for forming the individual sheaths 21 when it is
selected to form the individual sheaths 21 with a braided
construction, and preferably with a hollow braided
construction.
[0064] When selecting to form at least one and preferably all of
the individual primary strand sheaths 21 with a braided
construction; this process step is further, and most preferably,
modified by additionally selecting a braid tension for forming at
least one, and preferably all, of the braided individual sheaths 21
that is a braid tension that is lesser than a braid tension
selected for forming the exterior sheath 8 about the final formed
and final processed strength member that preferably has had the
elastic adhesive substance situated exterior the itself, i.e.
situated exterior the final processed form of the strength member,
prior to the exterior sheath 8 being braided about the strength
member.
INDUSTRIAL APPLICABILITY
[0065] Ropes formed by teachings of the present disclosure may be
used as crane ropes, deep sea deployment and recovery ropes, tow
ropes, towing warps, trawl warps (also known as "trawlwarps"), deep
sea lowering and lifting ropes, powered block rigged mooring ropes,
powered block rigged oil derrick anchoring ropes used with blocks
and also with powered blocks, deep sea mooring ropes, deep sea
winch lines, superwides and paravane lines used in seismic
surveillance including but not limited to being used with towed
arrays, yachting ropes, rigging ropes for pleasure craft including
but not limited to sail craft, running rigging, powered block
rigged anchor ropes, drag lines, and other.
[0066] Although the present disclosure has been described in terms
of the presently preferred embodiment, it is to be understood that
such disclosure is purely illustrative and is not to be interpreted
as limiting. Consequently, without departing from the spirit and
scope of the disclosure, various alterations, modifications and/or
alternative applications of the disclosure are, no doubt, able to
be understood by those ordinarily skilled in the art upon having
read the preceding disclosure. Accordingly, it is intended that the
following claims be interpreted as encompassing all alterations,
modifications or alternative applications as fall within the true
spirit and scope of the disclosure.
* * * * *