U.S. patent application number 17/836819 was filed with the patent office on 2022-09-22 for lanyard.
The applicant listed for this patent is Milwaukee Electric Tool Corporation. Invention is credited to Trent T. Bauters, Andrew G. Wagner.
Application Number | 20220295971 17/836819 |
Document ID | / |
Family ID | 1000006391505 |
Filed Date | 2022-09-22 |
United States Patent
Application |
20220295971 |
Kind Code |
A1 |
Wagner; Andrew G. ; et
al. |
September 22, 2022 |
Lanyard
Abstract
A lanyard with attachment members such as a tool holding member,
tether key, or carabiner, is provided. The lanyard includes one or
more elastic cords within a sheath. The sheath has a much lower
elasticity than the elastic cord. The higher spring constant or
modulus of elasticity of the sheath limits the total extended
length of the lanyard in operation. The elastic cords stretch to
absorb the energy of falling equipment up to the length of the
outer sheath. The attachment members may be attached to the sheath
or may include components of the sheath and or the elastic cord.
The lanyard allows for an elastic response to absorb the energy of
a falling tool and a restraint to the total extended length of the
lanyard.
Inventors: |
Wagner; Andrew G.; (Lisbon,
WI) ; Bauters; Trent T.; (West Allis, WI) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Milwaukee Electric Tool Corporation |
Brookfield |
WI |
US |
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|
Family ID: |
1000006391505 |
Appl. No.: |
17/836819 |
Filed: |
June 9, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16931118 |
Jul 16, 2020 |
11382405 |
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17836819 |
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16240546 |
Jan 4, 2019 |
10716390 |
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16931118 |
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PCT/US2018/066873 |
Dec 20, 2018 |
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16240546 |
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62609078 |
Dec 21, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A45F 2005/006 20130101;
A45F 5/00 20130101; A45F 2200/0575 20130101 |
International
Class: |
A45F 5/00 20060101
A45F005/00 |
Claims
1. A lanyard comprising: a sheath comprising: a first end coupled
to a first attachment member, and a second end, wherein a linear
distance between the first end of the sheath and the second end of
the sheath defines a length of the sheath; and an elastic cord
coupled to the first attachment member, the elastic cord extending
the length of the sheath internal to the sheath and extending past
the second end of the sheath to define a loop external to the
sheath proximate to the second end of the sheath; wherein the
elastic cord includes a plurality of elastic strands.
2. The lanyard of claim 1, wherein the elastic cord is comprised of
elastic polymers.
3. The lanyard of claim 1, wherein the elastic cord is comprised of
natural rubber.
4. The lanyard of claim 1, wherein the elastic cord is comprised of
elastomers.
5. The lanyard of claim 1, wherein the elastic cord comprises a
plurality of elastic strands.
6. The lanyard of claim 5, wherein each of the plurality of elastic
strands is comprised of as elastomeric material.
7. The lanyard of claim 6, wherein the elastomeric material is
comprised of rubber.
8. The lanyard of claim 1, wherein the elastic cord is comprised of
thirty-six and fifty elastic strands.
9. A lanyard comprising: a first attachment member; a sheath
comprising: a sheath comprising: a first end coupled to the first
attachment member; and a second end, wherein a linear distance
between the first end of the sheath and the second end of the
sheath defines a length of the sheath; and a plurality of elastic
cords positioned internal to the sheath, each of the plurality of
elastic cords beginning at the first end of the sheath and
terminating at the second end of the sheath; wherein the sheath is
kinked about the plurality of elastic cords; and wherein each of
the plurality of elastic cords is free to extend within the length
of the sheath.
10. The lanyard of claim 9, further comprising a second attachment
member, wherein the second end of the sheath is coupled to the
second attachment member.
11. The lanyard of claim 10, wherein each of the plurality of
elastic cords is separately coupled to the sheath at a first end of
the sheath proximate to the first attachment member and at the
second end of the sheath proximate to the second attachment
member.
12. The lanyard of claim 9, wherein each of the plurality of
elastic cords has an elasticity that is greater than the elasticity
of the sheath.
13. The lanyard of claim 9, wherein each of the plurality of
elastic cords includes a plurality of elastic strands.
14. The lanyard of claim 13, wherein the plurality of elastic
strands comprises between thirty-six and fifty elastic strands.
15. The lanyard of claim 9, wherein the plurality of elastic cords
comprises four elastic cords.
16. The lanyard of claim 15, wherein between one hundred forty-four
and two hundred elastic strands extend the length of the sheath
internal to the sheath.
17. A lanyard comprising: an elastic cord; and a sheath surrounding
the elastic cord, the sheath comprising: a first end; and a second
end, wherein a linear distance between the first end of the sheath
and the second end of the sheath defines a length of the sheath;
wherein the elastic cord extends the length of the sheath from the
first end of the sheath to the second end of the sheath; and
wherein the elastic cord forms a first internal loop within the
sheath such that the elastic cord terminates at a location spaced
apart from both the first end of the sheath and the second end of
the sheath.
18. The lanyard of claim 17, wherein the elastic cord forms a
second internal loop within the sheath, such that the elastic cord
begins at a location spaced apart from both the first end of the
sheath and the second end of the sheath.
19. The lanyard of claim 18, wherein the elastic cord begins at a
location spaced apart from the location at which the elastic cord
terminates within the sheath.
20. The lanyard of claim 17, wherein the sheath is comprised of
nylon.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a continuation of U.S. patent Ser. No.
16/931,118, filed Jul. 16, 2020, which is a continuation of U.S.
patent application Ser. No. 16/240,546, now U.S. Pat. No.
10,716,390, filed Jan. 4, 2019, which is a continuation of
International Application No. PCT/US2018/066873, filed Dec. 20,
2018, which claims the benefit and priority to U.S. Provisional
Application No. 62/609,078, filed on Dec. 21, 2017, which are
incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to the field of
tools. The present invention relates specifically to a lanyard for
connecting tools, or batteries, to an anchor point, for example,
while working at height. Lanyards are used to attach to/support
tools, batteries, components, and/or other equipment to provide
security when an operator inadvertently drops the equipment.
Lanyards also protect the tool or equipment from damage due to a
fall.
SUMMARY OF THE INVENTION
[0003] One embodiment of the invention relates to a lanyard. The
lanyard includes a first attachment member, a second attachment
member, a sheath, and an elastic cord. The sheath includes a first
end coupled to the first attachment member and a second end coupled
to the second attachment member. The sheath defines an extended
length between the first and second ends. The elastic cord has a
first elastic cord end and a second elastic cord end. The first
elastic cord end and the second elastic cord end are both attached
to the first attachment member. The elastic cord defines a loop
between the first attachment member and the second attachment
member wherein the elastic cord is stretchable between an
un-stretched length and stretched length. The un-stretched length
is less than the extended length, wherein the elasticity of the
sheath is less than the elasticity of the elastic cord.
[0004] Another embodiment of the invention relates to a lanyard.
The lanyard includes a first attachment member, a second attachment
member, a sheath, and four or more separate elastic cords. The
sheath includes a first end coupled to the first attachment member
and a second end coupled to the second attachment member. The
sheath defines an extended length between the first and second
ends. The four or more separate elastic cords are disposed within
the sheath. Each elastic cord is coupled between the first
attachment member and the second attachment member on opposite ends
of the sheath. The elastic cord is stretchable between an
un-stretched length and a stretched length. The un-stretched length
is less than the extended length, such that the elasticity of the
sheath is less than the elasticity of the elastic cords.
[0005] Another embodiment of the invention relates to a lanyard.
The lanyard includes a tool holding member, a carabiner, a sheath,
and one or more elastic cords. The sheath includes a first end
coupled to the tool holding member and a second end coupled to the
carabiner. The second end of the sheath is opposite the first end.
The fully extended sheath defines a limiting tensioned length of
the lanyard. One or more elastic cords are disposed within the
sheath and couple to the tool holding member on a first end of the
sheath and the carabiner at a second end of the sheath. The one or
more elastic cords have a pre-tensioned length and a tensioned
length. The tensioned length of the one or more elastic cords is
less than or equal to the limiting tensioned length of the sheath.
The limiting tensioned length of the sheath is between a 38% and
115% increase of the pre-tensioned length of the one or more
elastic cords.
[0006] Alternative exemplary embodiments relate to other features
and combinations of features as may be generally recited in the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] This application will become more fully understood from the
following detailed description, taken in conjunction with the
accompanying figures, wherein like reference numerals refer to like
elements in which:
[0008] FIG. 1 is a perspective view of a lanyard with a carabiner
and a loop, according to one embodiment.
[0009] FIG. 2 is a perspective view of a lanyard with two
carabiners, according to an exemplary embodiment.
[0010] FIG. 3 is a sectional view of a lanyard with a carabiner and
a loop formed from a single elastic cord that begins at a first end
and terminates at a second end of a sheath, according to an
exemplary embodiment.
[0011] FIG. 4 is a sectional view of a lanyard with two carabiners
and one elastic cord, according to an exemplary embodiment.
[0012] FIG. 5 is a sectional view of a lanyard with a carabiner and
a loop formed from a single elastic cord that begins at a first end
and terminates at the first end of a sheath, according to an
exemplary embodiment.
[0013] FIG. 6 is a sectional view of a lanyard comprising four
elastic cords extending from the first end to the second end of a
sheath, according to an exemplary embodiment.
[0014] FIG. 7 is a sectional view of one elastic cord of a lanyard,
according to an exemplary embodiment.
[0015] FIG. 8 is a plan view of a carabiner attachment member for a
lanyard, according to one embodiment.
[0016] FIG. 9 is a plan view of an open carabiner illustrating a
gate separation distance that is less than a wall separation
distance, according to an exemplary embodiment.
[0017] FIG. 10 is a plan view of a lanyard that illustrates
sections of the extended lanyard, according to an exemplary
embodiment.
[0018] FIG. 11 is a plan view of a drop test of the lanyard of FIG.
10.
[0019] FIG. 12 is a Table of data showing results from various drop
tests using the lanyard of FIG. 10.
[0020] FIG. 13 is a Table of data showing results from various drop
tests using the lanyard of FIG. 10, as related to the Table of FIG.
11.
[0021] FIG. 14 is a Table of data showing results from various drop
tests of the lanyard in FIG. 10, as related to the Table of FIG.
11.
[0022] FIG. 15 is a Table of data showing results from various drop
tests of the lanyard in FIG. 10, as related to the Table of FIG.
11.
[0023] FIG. 16 is a Table of data showing results from various drop
tests of the lanyard in FIG. 10, as related to the Table of FIG.
11.
[0024] FIG. 17 is a plan view of a lanyard coupled to a tether for
securing a tool, according to an exemplary embodiment.
[0025] FIG. 18 is a Table of data showing results from various drop
tests using the lanyard of FIG. 13.
[0026] FIG. 19 is a Table of data showing results from various drop
tests of the lanyard and tether shown in FIG. 13, as related to the
Table of FIG. 14.
DETAILED DESCRIPTION
[0027] Referring generally to the figures, various embodiments of a
lanyard are shown. Lanyards are used as a safety measure to secure
tools to an anchor point, for example, while working at height. To
enhance safety, a lanyard may couple to tools and tool batteries
and tether them when operating the tools at height. Various
regulations (e.g., OSHA regulations) may require a lanyard when an
operator uses tools height. When a tool is dropped at height, the
lanyard couples the tool to an anchor point and prevents the tool
from dropping. This prevents a safety hazard and also protects the
tool from the destructive influence of the fall.
[0028] Lanyards are designed to absorb and dissipate the energy of
a fall. Lanyards that are too stiff may break or snap at the
attachment points to either the tool or the anchor point or along
the lanyard itself. Stiff lanyards allow a predetermined falling
length, but often exhibit brittle material behavior and may break
unexpectedly along the lanyard or at the attachment members. This
brittle-like behavior is due to the stiff lanyards inability to
absorb the energy of the falling object. Elastic materials show a
far more ductile response to a falling object, but may not be
effective in preventing an object from falling a specified
distance. For example, a first object with a first weight will fall
a different distance than a second object with a second weight when
attached to the same elastic lanyard. Many factors, such as the
height of the fall, the weight of the supported object, the spring
constant of the elastic material, and others, determine the length
of the deflection needed to support a falling object with an
elastic lanyard. For a reliable lanyard, this unpredictability can
be problematic.
[0029] Applicant has found that the use of a sheath of a stiff or
inelastic material, such as nylon, surrounding an elastic material,
such as natural rubber, creates a combination lanyard with the
beneficial effects from both materials. The lanyard has a
predictable limit to the total deflection defined by the total
extended length of the inelastic sheath. In addition, the elastic
properties of the cords within the lanyard absorb and dissipate
most, if not all, the energy of the fall. This elastic energy
dissipation prevents brittle-like fractures at the attachment
points or along the sheath of the lanyard. The inelastic material
reliably limits the fall distance.
[0030] One common attachment member at the ends of a lanyard is a
carabiner. Carabiners can quickly attach to an anchor point, a
tool, or a tool tether (coupled to or attached to the tool).
Carabiners operate a gate in two positions, an open position and a
closed position. In the open position, the carabiner may receive a
loop or hook. Carabiners can be biased toward the closed position
so that when the loop is received, the carabiner closes around the
loop and prevents accidental release. However, often the loop is
bigger than the gap or opening created by the carabiner, either
between the gate and a first end of the carabiner or between the
gate and the internal walls of the carabiner. This can cause
binding of the loop within the carabiner and may prevent the
carabiner from closing around the loop. Applicant has found that
maintaining the distance between the gate and the internal walls of
the carabiner to be greater than the distance between the gate and
an end of the carabiner; lanyard binding is reduced. This is
because there is more room for the lanyard loop once it passes
through the gate (e.g., more room on the carabiner) than there is
between the gate and the end of the carabiner.
[0031] As shown in FIGS. 1-4, a lanyard 10 is provided. The lanyard
10 includes a sheath 14 with a first end 18 and an opposite second
end 22. The first end 18 of the sheath 14 is coupled to a first
attachment member 24 and the second end 22 is coupled to a second
attachment member 28. The extended sheath 14 defines an extended
length between the first and second ends 18 and 22 of the sheath
14. As illustrated in FIGS. 1-4, sheath 14 is bunched up or kinked
about an elastic cord 34. Thus the full extended sheath 14 is
greater than the distance shown. The elastic cord 34 is free to
extend within the length of the fully extended sheath 14. The full
length of the extended sheath 14 defines a reliable limit for the
distance the lanyard 10 will allow attached equipment to fall.
[0032] The sheath 14 can be made of nylon or other suitable
materials. For example, sheath 14 may be made from natural fibers
or wool, cashmere, cotton, silk, linen, hemp, and/or other natural
fibers. Sheath 14 may be made from synthetic fibers such as rayon,
polyester, acrylic, acetate, nylon, polyamides, and/or other
polymers. In this application, "nylon" will refer to any member of
the family of polyamides such as nylon 6,6; nylon 6; nylon 6,12;
nylon 5,10; and other polyamides. The sheath 14 can be formed from
a nylon sheet material or a composite material, e.g., nylon and
rubber. The sheath 14 may be formed from less than eighty strands
of nylon for every twenty strands of rubber. For example, the
sheath 14 may be formed of seventy-four strands of nylon for every
twenty-six strands of rubber. The sheath 14 may be formed from
seventy strands of nylon for every thirty strands of rubber. The
sheath 14 may be formed from sixty strands of nylon for every forty
strands of rubber.
[0033] In some embodiments, as shown in FIGS. 1, 3, 5 and 6, the
lanyard 10 includes a carabiner 26 as a first attachment member 24
and a loop 30 as a second attachment member 28. The loop 30 can be
secured to a power tool, and the carabiner 26 can be secured to a
fixed anchor point such as building, machine, a balcony rail/post,
or other mounting structure. In other embodiments, as shown in
FIGS. 2 and 4, the lanyard utilizes carabiners 26 as both the first
and second attachment members 24 and 28. In other embodiments,
instead of a carabiner 26 or loop 30, the first and second
attachment members 24 and 28 can be anything capable of securing
the lanyard 10 to a power tool and/or a fixed anchor point. As used
herein, a fixed anchor point will refer to any structure that the
lanyard is attached to that supports the equipment during a fall.
Examples of a fixed anchor point include, but are not limited to, a
balcony, a rail or railing, a wall, a support, or other fixed
anchor locations for the lanyard.
[0034] In some embodiments, as shown in FIGS. 1 and 2, lanyard 10
may be coupled to a first linking member 32 and/or a second linking
member 36. Linking members 32 and 36 may have different
elastic/inelastic properties than lanyard 10. Linking members 32
and 36 may be another lanyard 10 coupled in series. Linking members
32 and 36 can be coupled in a semi-permanent fashion (e.g., through
one or more swivels 48) or in a releasable fashion (e.g., through
one or more carabiners 26). For example, first linking member 32
can link the first end 18 to the first attachment member 24, such
as the carabiner 26, and a second linking member 36 can link the
second end 22 to the second attachment member 28, such as the loop
30 in FIG. 1 or another carabiner 26 in FIG. 2. The first and
second linking members 32 and 36 can also be made of nylon, nylon
composite (e.g., nylon and rubber composite) or any other suitable
material.
[0035] As shown in FIGS. 1, 2, and 10, the first linking portion 32
is comprised of a loop section 40 and a stitched section 44 that
connects the loop section 40 to the first end 18 of the sheath 14.
As shown in FIGS. 1, 2, 3, 6, 8, 9 and 10 the carabiner 26 can
include a swivel 48 that permits the carabiner 26 to rotate with
respect to the sheath 14. In some embodiments, swivel 48 is fixed
and prevents rotation of the carabiner 26. In other embodiments,
swivel 48 resists rotation or allows rotation to discrete locations
about swivel 48. As shown in FIGS. 1, 2, and 10, the loop section
40 of the first linking member 32 loops around the swivel 48 to
couple the carabiner 26 to the first linking member 32.
[0036] As shown in FIGS. 3 and 4, lanyard 10 includes an elastic
cord 34 within sheath 14. Elastic cord 34 includes a group of
individual elastic strands 58 of a natural/synthetic rubber or
elastomeric material coiled together to form elastic cord 34. The
elastic cord 34 may be formed from rubber or other suitable elastic
materials. For example, the elastic cord 34 may be formed of
natural rubber, elastomers, elastic polymers, neoprene rubber,
unsaturated rubbers (e.g., polyisoprene or nitrile rubber buna-n),
saturated rubbers (e.g., ethylene propylene rubber), thermoplastic
elastomers (TPE), resilin, elastin, polysulfide rubber,
elastolefin, and/or other ductile elastic materials. In addition, a
composite sheath 14 or linking portion 32 or 36 may include these
materials in proportion to an inelastic material (e.g., nylon). For
example, sheath 14 or linking portion 32 or 36 may be formed from
less than eighty strands of inelastic material (synthetic or
natural, e.g., nylon 6,6) for every twenty strands of an elastic
material (synthetic or natural, e.g., polyisoprene or natural
rubber).
[0037] In some embodiments, as shown in FIG. 3, the elastic cord 34
is coupled to the first attachment member 24 (a carabiner 26) at
the first end 18 and defines the second attachment member 28 (a
loop 30) external to the second end 22. Sheath 14 surrounds the
elastic cord 34 and couples to the carabiner 26 at the first end
18. As shown in FIG. 4, elastic cord 34 can be coupled to carabiner
26 at the first end 18 and another carabiner 26 at the second end
22. For example, a loop 30 defined by the elastic cord 34 may be
internal to the sheath 14, such that loop 30 couples to attachment
member 28 (e.g., carabiner 26) or sheath 14 (e.g., at sheath end
22) and does not form an external loop 30. Sheath 14 may be coupled
to the second attachment member 28 (e.g., carabiner 26) to the
internal loop 30. Sheath 14 surrounds elastic cord 34 and couples
to the carabiners 26 at the first end 18 and second end 22. In some
embodiments, elastic cord 34 is coupled to the first and second
linking members 32 and 36 (e.g., as shown in FIGS. 1 and 2). In the
embodiments of FIGS. 3 and 4, the elastic cord 34 begins at the
first end 18 and terminates at the second end 22 of sheath 14.
[0038] Attachment members 24 and 28 may include a carabiner 26, a
loop 30, a latch, a tether key or tether end, a buckle, a fastener,
or another attachment to a tool or anchor point. Attachment members
24 and 28 may provide an anchor point to lanyard 10 or be a tool
holding member. In operation, the first attachment member 24, such
as the carabiner 26, can be secured to a fixed anchor point, and
the second attachment member 28, such as the loop 30, can be
secured to a tool (not shown) used by the operator. In this manner,
if and when the operator drops the tool, the tool is elastically
supported by the lanyard 10 up to the extended length of sheath 14,
which is secured to the anchor point. When the tool reaches the
extended length of sheath 14, the inelastic response of the sheath
14 dominates, providing a reliable limit to the distance the
falling object travels, regardless of the weight, the height
dropped, or other characteristics.
[0039] In some embodiments, as shown in FIG. 5, elastic cord 34 has
a first end 38, a second elastic cord end 42, and a body 46 defined
between the first and second ends 38 and 42. Both the first end 38
and the second elastic cord end 42 are coupled to carabiner 26. The
body 46 is looped outside of the second end 22 of the sheath 14,
such that the body 46 defines loop 30. The elastic cord 34 extends
beyond the sheath 14 to form the external loop 30. As illustrated
in FIG. 5 loop 30 is external to sheath 14. In some embodiments,
loop 30 is internal to sheath 14 and couples to an attachment
member 24 or 28 (such as an inelastic loop 30 illustrated in FIG. 6
or a carabiner 26).
[0040] For example, in FIG. 5 loop 30, defined by elastic cord 34,
is external to the sheath 14 and defines the second attachment
member 28. Thus, in this embodiment, loop 30 is elastic, and there
are two elastic portions 50 and 54 defined by the body 46 of one
elastic cord 34. The elastic portions 50 and 54 of body 46 extend
within sheath 14 between the first and second ends 18 and 22 of the
sheath 14. For example, the first elastic cord end 38 and the
second elastic cord end 42 are both attached to the first
attachment member 24, and the elastic cord 34 defines a loop 30
between the first attachment member 24 and the second attachment
member 28. In other embodiments, loop 30, defined by elastic cord
34, is internal to the sheath 14. The loop 30 does not extend
beyond sheath 14 but includes elastic portions 50 and 54 such that
the first elastic cord end 38 and second elastic cord end 42 are
both attached to sheath 14 at a first end 18. The internal loop 30
may connect to an attachment member 28 at the second end 22 of
sheath 14.
[0041] The elastic cord 34 may stretch between an un-stretched
length and a stretched length. The un-stretched length is less than
the fully extended length of sheath 14. Thus, sheath 14 is bunched
up or kinked about the elastic cord 34. The elasticity of the
sheath 14 is less than the elasticity of the elastic cord 34. This
configuration enables the elastic cord 34 to stretch to absorb
energy when lanyard 10 is supporting a falling object. The
stretched length of the elastic cord 34 can vary between the
un-stretched length of elastic cord 34 and the fully extended
length of sheath 14. Between these limits, the stretched length of
the elastic cord 34 elastically absorbs the kinetic energy of the
falling object.
[0042] In some embodiments, as shown in FIG. 6, lanyard 10 includes
four or more separate elastic cords 34 within sheath 14. In some
embodiments, the four or more elastic cords 34 may form loops 30,
such that the first elastic cord end 38 and second elastic cord end
42 are both attached to the first attachment member 24, and the
elastic cords 34 define a loop 30 between the first attachment
member 24 and the second attachment member 28.
[0043] In the embodiment of FIG. 6, each elastic cord 34 is
separately coupled between attachment members 24 and 28 at either
end 18 or 22 of sheath 14. Each elastic cord 34 is coupled between
the first attachment member 24 and the second attachment member 28
on the opposite end of sheath 14. The elastic cords 34 are
stretchable between an un-stretched length and a stretched length.
The un-stretched length is less than the extended length of the
sheath 14, and the elasticity of sheath 14 is less than the
elasticity of elastic cords 34. As illustrated, attachment members
24 and 28 are a carabiner 26 and an inelastic loop 30 (e.g., nylon
and not defined by elastic cords 34), but may include any suitable
attachment member 24 or 28. In some embodiments, sheath 14 may
include 5, 6, 7, 8, 9, 10, or more separate elastic cords 34 within
the lanyard 10 separately coupled between attachment members 24 and
28 or forming loops 30.
[0044] In some embodiments, as shown in FIG. 7, elastic cord 34
includes between thirty-six and fifty elastic strands 58. Thus, in
embodiments such as the one shown in FIG. 5, because there are two
elastic portions 50 and 54 within the sheath 14, there are
effectively between seventy-two and one hundred elastic strands 58
of rubber between the first and second ends 18 and 22 of sheath 14,
but only thirty-six to fifty elastic strands 58 within elastic cord
34. Similarly, in embodiments such as the one shown in FIG. 6,
because there are four separate elastic cords 34 within the sheath
14, there are effectively between one hundred forty-four and two
hundred elastic strands 58 between the first and second ends 18 and
22 within sheath 14. Additional elastic cords 34 have between
N.times.36 and N.times.50 elastic strands 58, where N represents
the number of elastic cords 34 within sheath 14. For example, five
elastic cords 34 (N=5) have between 5.times.36=180 and
5.times.50=250 elastic strands 58. In some embodiments, two or more
elastic cords 34 may form a loop 30 within sheath 14 to create four
or more elastic portions 50 and 54. For example, two elastic cords
34 may form four elastic portions 50 and 54 and comprise between
seventy-two and one hundred elastic strands 58 of rubber.
[0045] Carabiner 26, as shown in FIGS. 8 and 9, has a body 62 with
a first end 66 and a second end 70 which functions as a latch or
gate 78. Gate 78 is pivotable over a range of motion 82 between a
first "closed" position and a second "open" position. For example,
when gate 78 moves from the closed position (illustrated in FIGS.
1-6) to the open position (illustrated in FIGS. 7-8), an opening 74
is formed between gate 78 and first end 66. Opening 74 is defined
when gate 78 is open between the first end 66 and second end 70 of
carabiner 26.
[0046] Carabiner 26 may be biased towards the closed position.
Applying pressure to gate 78 pivots the gate 78 between the closed
position in which the gate 78 engages the second end 70 and the
open position, in which the gate 78 has pivoted the maximum
possible distance over the range of motion 82, thus maximizing the
expanded opening 74. Once pressure is released, gate 78 engages the
second end 70 in the closed position. Gate 78 can latch and/or lock
to the second end 70 of carabiner 26 to securely close carabiner 26
and keep it closed. In some embodiments, gate 78 is biased by a
biasing member, such as a spring (not shown), towards the closed
position. Gate 78 may include a lock or cover (not shown) that
rotates or slides to cover second end 70 and secure gate 78 in the
closed position to prevent accidental opening or release of
carabiner 26.
[0047] The body 62 of the carabiner 26 may optionally be attached
to swivel 48 and includes a first end 66, a first wall portion 86,
a second wall portion 90, and a second end 70. The shape of
carabiner 26 is defined by body 62 at the first wall portion 86 and
the second wall portion 90. The first wall portion 86 is
approximately parallel to the gate 78 when the gate 78 is in the
closed position and the second wall portion 90 is linked to the
first wall portion 86. For example, second wall portion 90 may make
an acute, obtuse, or right angle with first wall portion 86. As
illustrated, the second wall portion 90 makes an acute angle with
the first wall portion 86, which is approximately parallel to gate
78 in the closed position. Other configurations and embodiments of
carabiner 26, including non-parallel and/or alternate angles are
envisioned.
[0048] As shown in FIGS. 8-9, a gate separation distance 94 is
defined as the distance between the gate 78 and the second end 70
in the open position where gate 78 has pivoted the maximum possible
distance over the range of motion 82 and maximized opening 74. A
wall separation distance 98 is defined as the minimum distance
between the gate 78 and the first wall portion 86 or the second
wall portion 90 over the pivotal range of motion 82. As illustrated
in FIG. 8 the horizontal wall separation distance 98 is less than
the vertical wall separation distance 98. Thus the wall separation
distance 98 is the horizontal wall separation distance 98.
[0049] By inspection of FIGS. 8-9 we see two different
relationships of the gate separation distance 94 and wall
separation distance 98, as defined above. In FIG. 8 the minimum
wall separation distance 98 (e.g., horizontal wall separation
distance 98) is less than the gate separation distance 94. In FIG.
9 the vertical wall separation distance 98 in the open position is
less than the horizontal wall separation distance 98. Therefore the
vertical wall separation distance 98 defines the wall separation
distance 98. In FIG. 9, the gate separation distance 94 is less
than the minimum ("vertical") wall separation distance 98.
[0050] Carabiner 26 includes gate 78 pivotably coupled to a first
end 66 of carabiner 26. Gate 78 is configured to clasp a second end
70 of the carabiner 26 in a closed position. Rotation of the gate
78 to an open position defines the minimum wall separation distance
98 between gate 78 in the open position and walls 86 and 90 of the
carabiner 26. The open position also defines a gate separation
distance 94 between the second end 70 of the carabiner 26 and gate
78. In some embodiments, the minimum wall separation distance 98
between the gate 78 and walls 86 and 90 is greater than the gate
separation distance 94 between the gate 78 and the second end 70 of
carabiner 26.
[0051] In the configuration of FIG. 9, the first wall portion 86
and second wall portion 90 are arranged with respect to the gate 78
such that the wall separation distance 98 is greater than the gate
separation distance 94. Thus, in the second position of the gate
78, any square or round article, loop, or hook that is large enough
to enter the carabiner 26 through the opening 74 can move past gate
78 and allow gate 78 to move back to the closed position. This
allows carabiner 26 to lock the article or hook securely. In other
words, the first wall portion 86 and second wall portion 90 are
arranged with respect to the gate 78 such that the article or hook
does not force gate 78 to stay open. Ensuring that the gate
separation distance 94 is less than the minimum wall separation
distance 98 reduces binding and ensures that gate 78 can return to
the closed position. In this manner, the carabiner 26 of FIG. 9
provides greater ease of use for an operator than the carabiner 26
of FIG. 8.
[0052] FIGS. 10-19 illustrate the lengths of various lanyards 10
measured in the test. FIGS. 10 and 17 define two tested
configurations of lanyard 10. FIG. 11 illustrates the test
methodology. FIGS. 12-16 illustrate the measured results of the
test applied to lanyard 10 of FIG. 10. FIGS. 18-19 illustrate the
measured results of the test applied to lanyard 10 of FIG. 17.
[0053] As shown in FIG. 10, a total length 102 of the lanyard 10
can be broken down into six separate sub-lengths: (1) a length 106
of the carabiner 26; (2) a length 110 of the loop section 40; (3) a
length 114 of the stitched section 44; (4) a length 118 of the
elastic cord(s) 34 (not shown in FIG. 10) between the first and
second ends 18 and 22 and within the sheath 14; (5) a length 122 of
the second linking member 36; and (6) a length 130 of the loop 30.
The purpose of the test is to see how the elasticity of these
lengths varies while supporting various weights dropped from the
height of the un-stretched elastic cord(s) 34 above a fixed anchor
point (or 2.times.'s the unsupported distance of the un-stretched
elastic cord(s) 34).
[0054] FIG. 11 shows the positions of the lanyard 10 both before
and after a 2.times. drop test. The drop test height column of the
Table in FIG. 12 uses the reference "2.times." when referring to
the lanyard 10 being dropped, as indicated by arrow 170, from a
height 174 that is two times the un-tensioned length 142 of the
elastic cords 34 within lanyard 10. The un-tensioned length 142 of
the lanyard 10 shown in FIG. 11 corresponds to "Pre-drop total
length 102" column or the un-tensioned length of the lanyard 10 for
the 2.times. drop test trials. A dotted line 178 indicates when the
elastic cords 34 within lanyard 10 become tensioned and stretch.
The test is designed to not extend to the fully extended length of
sheath 14 to test the elastic response of the lanyard 10 system.
For the lanyard 10 tests of FIG. 10, tool 150 is secured to loop 30
and dropped from an initial position 182 (2.times. the un-stretched
length of the elastic cord(s) 34) to a final position 186 in which
the elastic cord(s) 34 is fully stretched within sheath 14.
Carabiner 26 of lanyard 10 is secured at the point 162. A fully
stretched length 190 of elastic cord(s) 34 and other components of
lanyard 10, shown in FIG. 11, corresponds to the "Stretched Total
Length 102" column in the Table for the 2.times. drop test height
trials.
[0055] For each category of weight-rated lanyard 10, there are
three types of drop tests, as explained below. First, the lanyard
10 was subjected to a first 2.times. drop test while supporting the
rated weight of the lanyard 10 and a peak force on the lanyard 10
was measured for this first drop. Second, the lanyard 10 was
subjected to nine more individual 2.times. drop tests while
supporting the rated weight of lanyard 10. For each of these nine
additional drops, the peak force on lanyard 10 was measured. The
value listed in the Table in FIG. 12 represents the maximum
individual peak force measured among the ten total drops, which
includes the first drop and the nine subsequent drops supporting
the rated weight of lanyard 10. Third, lanyard 10 was subjected to
three 2.times. drop tests while supporting two times the rated
weight of lanyard 10, and the peak force was measured for each of
those three drops. The maximum individual peak force measured among
those three drops is listed in the table of FIG. 12. For example,
for the ten-pound weight-rated lanyard 10 with a total pre-drop
length of 921 mm, the peak force of the first drop while supporting
ten pounds was 82 lbf., the maximum peak force over ten drops while
supporting ten pounds was 123 lbf., and the maximum peak force over
three drops while supporting twenty pounds was 268 lbf.
[0056] During a drop, the length 118 of the elastic cord(s) 34 can
change between four separate stages: (1) an initial un-tensioned
stage; (2) a tensioned stage when the length of the elastic cord(s)
34 is less than the length of the unkinked sheath 14; (3) a
tensioned stage where the length of the elastic cord(s) 34 is equal
to the fully extended length of sheath 14; and (4) a fully
stretched stage in which the elastic cord(s) 34 and/or the sheath
14 become entirely stretched. In the Table above, the initial
un-tensioned stage values are represented in the "Un-tensioned
length 118 of elastic cord(s) 34" column, and the fully stretched
stage values are represented in the "Fully stretched length 118 of
elastic cord(s) 34" column.
[0057] When the elastic cord(s) 34 becomes the same length as the
unkinked sheath 14, it is between 38% and 115% longer than its
un-tensioned length. When the elastic cord(s) 34 becomes the same
length as the unkinked sheath 14, the sheath 14 becomes tensioned,
and the elastic cord(s) 34 and the sheath 14 begin stretching
together as a system. As demonstrated in the Table above, the
respective lengths of the sheath 14 and elastic cord(s) 34 are
selected to provide a lower peak force when a weight (e.g., of a
tool) is near the lanyards' rated weight and when the weight on the
tool 150 is dropped from a height greater than the un-tensioned
length 142 of lanyard 10.
[0058] Because the sheath 14 is inelastic, the fully extended
length of sheath 14 roughly defines a limiting tension length of
lanyard 10. When the one or more elastic cords 34 within sheath 14
are stretched between a pre-tensioned length and a tensioned
length, they are unrestrained up to the fully extended length of
the sheath 14. When the tensioned length reaches the length of the
fully extended sheath 14, the elastic cords 34 reach the limiting
tension length of lanyard 10. Thus, the tensioned length of the
elastic cord(s) 34 is less than or equal to the limiting tensioned
length of sheath 14. In some embodiments, the limiting tension
length of sheath 14 is between 30% and 125% greater than the
pre-tensioned length of the elastic cord(s) 34. In some
embodiments, the limiting tension length of sheath 14 is between
38% and 115% greater than the pre-tensioned length of elastic
cord(s) 34. The limiting tension length of sheath 14 may be between
45% and 110% of the pre-tensioned length of elastic cord(s) 34. The
limiting tension length of sheath 14 may be between 50% and 105% of
the pre-tensioned length of elastic cord(s) 34. The limiting
tension length of sheath 14 may be between 55% and 100% of the
pre-tensioned length of elastic cord(s) 34.
[0059] In the tests described below, the length of the sheath 14
was selected to study the elastic properties of the elastic cord(s)
34. As such, the length of sheath 14 was selected to be greater
than the elastic response of the lanyard 10 system to prevent the
limiting tensioning length of the sheath 14 from interfering with
the test results.
[0060] As shown in the Table in FIG. 12, test data of different
weight-rated lanyards 10 demonstrate the respective stretching
lengths of the above six sub-lengths when the lanyards 10 are
subjected to different drop tests. In all of the drop tests listed
in the Table of FIG. 12, the length 106 of the carabiner 26 remains
constant at 86 mm and does not change as the lanyard 10 stretches.
Similarly, in all of the tests, the length 114 of the stitched
section 44 of sheath 14 remains constant at 36 mm and the length
122 of the second linking member 36 (e.g., nylon) remains constant
at 36 mm. In other words, none of the lengths 106, 114, 122 change
as the lanyard 10 is stretched while dropped. Because the sheath 14
has a large modulus of elasticity (spring constant) and a lower
elasticity than the elastic cord(s) 34, the sheath 14 limits the
length the lanyard 10 can stretch.
[0061] FIGS. 13-16 illustrate data from the drop tests correlating
respectively to the 10 lb. weight-rated lanyard 10 with a pre-drop
total length 102 of 921 mm, the 10 lb. weight-rated lanyard 10 with
a pre-drop total length 102 of 1381 mm, the 15 lb. weight-rated
lanyard 10, and the 50 lb. weight-rated lanyard 10, as related to
the results shown in FIG. 12.
[0062] In another embodiment of a lanyard 192 shown in FIG. 17, the
lanyard 192 includes, in series, a first carabiner 194, a swivel
member 196, a first linking member 198 including a loop section 202
and a stitched section 206, a sheath 210, a second linking member
214 including a stitched section 218 and a loop section 222, a
second carabiner 226, a tether 230, and a tether attachment member
236. As in previous embodiments, elastic cord(s) 34 (not shown in
FIG. 17) is arranged within sheath 210 and is coupled between the
stitched section 206 of the first linking member 198 and the
stitched section 218 of the second linking member 214.
[0063] As shown in FIG. 17, a total length 240 of the lanyard 192
can be broken down into nine separate sub-lengths: (1) a length 244
of first carabiner 194; (2) a length 248 of loop section 202; (3) a
length 252 of stitched section 206; (4) an unstretched length 256
of elastic cord(s) 34 (not shown in FIG. 17) between the stitched
section 206 of the first linking member 198 and the stitched
section 218 of the second linking member 214 and within the sheath
210; (5) a length 260 of the stitched section 218; (6) a length 264
of the loop section 222; (7) a length 268 of the second carabiner
226; (8) a length 272 of the tether 230; and (9) a length 276 of
the tether attachment member 236. Additionally, total length 240
can be subdivided into first sub-length 280, from first carabiner
194 to second carabiner 226, and a tether 230 sub-length 284, from
tether 230 to tether attachment member 236.
[0064] The same drop tests illustrated in FIG. 11 were performed
with lanyard 192 in the same manner as described above, and the
results are listed in a Table shown in FIG. 18. In all of the drop
tests listed in the Table of FIG. 18, the lengths 244, 268 of the
first and second carabiners 194 and 226 both remain constant at 86
mm and 96 mm, respectively, and do not change as the lanyard 192
stretches. Similarly, in all of the tests, the length 252 of the
stitched section 206 of sheath 14 and the length 260 of the
stitched section 218 of sheath 14 both remain constant at 36 mm. In
other words, none of the lengths 244, 252, 260 and 268 change as
the lanyard 192 is stretched while dropped. This suggests that the
sheath 14 has a large modulus of elasticity or spring constant and
a lower elasticity than the elastic cord(s) 34. Thus the length of
sheath 14 defines a practical limit to the total extension of the
lanyard 10. The elastic cord(s) 34 is free to stretch and absorb
the energy of a fall up to the extended length of sheath 14.
[0065] FIG. 19 illustrates data from the drop tests correlating
respectively to the lanyard 192, as related to the results shown in
FIG. 18. Specifically it shows the percentage elongation of the
elastic cord(s) 34 for 2.times. tests on (1) the first drop at the
rated weight, (2) the maximum elongation after 10 drops at the
rated weight, and (3) the maximum elongation after 3 drops at twice
the rated weight for lanyard 192.
[0066] For purposes of this disclosure, the term "coupled" means
the joining of two components directly or indirectly to one
another. Such joining may be stationary in nature or movable in
nature. Such joining may be achieved with the two members and any
additional intermediate members being integrally formed as a single
unitary body with one another or with the two members or the two
members and any additional member being attached to one another.
Such joining may be permanent in nature or alternatively may be
removable or releasable in nature.
[0067] It should be understood that the figures illustrate the
exemplary embodiments in detail, and it should be understood that
the present application is not limited to the details or
methodology set forth in the description or illustrated in the
figures. It should also be understood that the terminology is for
the purpose of description only and should not be regarded as
limiting.
[0068] Further modifications and alternative embodiments of various
aspects of the invention will be apparent to those skilled in the
art in view of this description. Accordingly, this description is
to be construed as illustrative only. The construction and
arrangements, shown in the various exemplary embodiments, are
illustrative only. Although only a few embodiments have been
described in detail in this disclosure, many modifications are
possible (e.g., variations in sizes, dimensions, structures, shapes
and proportions of the various elements, values of parameters,
mounting arrangements, use of materials, colors, orientations,
etc.) without materially departing from the novel teachings and
advantages of the subject matter described herein. Some elements
shown as integrally formed may be constructed of multiple parts or
elements, the position of elements may be reversed or otherwise
varied, and the nature or number of discrete elements or positions
may be altered or varied. The order or sequence of any process,
logical algorithm, or method steps may be varied or re-sequenced
according to alternative embodiments. Other substitutions,
modifications, changes and omissions may also be made in the
design, operating conditions and arrangement of the various
exemplary embodiments without departing from the scope of the
present invention.
* * * * *