Note: Descriptions are shown in the official language in which they were submitted.
CA 02518028 2005-08-30
Integrated Flexible Metatarsal Guard
With Extended Toe Cap
BACKGROUND OF THE INVENTION
[0001] Field of the Invention -- The present
invention relates generally to safety footwear, and
more particularly to safety boots and shoes that
integrally incorporate a flexible metatarsal guard
that covers the toe protector and protects the
metatarsal region (the instep region) of the wearer's
foot from injury caused by objects falling or rolling
onto the toe or metatarsal regions of the wearer's
foot.
[0002] The metatarsal region or instep of the human
foot extends forwardly from the front of the ankle to
the base of the toes and contains a number of
elongated bones extending side by side. The instep of
the foot is particularly vulnerable to impact and
crushing forces, especially those caused by falling or
dropped objects. This region of the foot may also be
injured if the metatarsal guard is allowed to move
from its intended position. Yearly, over 120,000
people are injured in such accidents. The American
National Standards Institute ("ANSI") has developed a
standard for footwear manufacturers to follow to
ensure proper foot protection. The current standard
is the ANSI Z41-1999 standard, which is approved by
the Occupational Safety and Health Administration
("OSHA"). A certification under this standard for
personal protective equipment including safety
footwear is necessary in order to obtain consumer
confidence.
[0003] Footwear manufacturers have manufactured
steel-toed boots and shoes with a variety of
metatarsal guards and cushions in an attempt to
prevent the injuries described above. The most common
method of protecting the metatarsal region is by
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placing a tough, rigid, synthetic plastic or metal
shield over the exterior of the shoe to cover the
metatarsal region of the foot. One example of such a
shield is illustrated in U.S. Patent No. 3,995,382, to
Smith. This method of protecting the metatarsal
region creates an unsightly and clumsy appearance of
the shoe. Furthermore, the rigid shield limits the
range of motion of the foot during walking or running.
The external metatarsal shield also pinches the instep
when bending or squatting. More importantly, this
type of metatarsal shield creates a snagging and
tripping hazard which could cause serious injury. The
disadvantages described above make the Smith safety
shoe an uncomfortable shoe that most people would not
wear.
[0004] Others have incorporated the rigid synthetic
plastic or metal metatarsal shield into a fabric or
leather cover usually matching the material the
footwear is made from. This covered shield is then
attached to the toe of the boot. In effect, the
metatarsal shield becomes a second tongue placed over
the exterior of the safety boot. This external shield
does not solve the problems mentioned above which are
associated with the uncovered, external metatarsal
protectors. The shoes remain bulky and clumsy in
appearance. Furthermore, the metatarsal protectors
continue to be rigid, which prevents a full range of
foot motion and results in fewer individuals wearing
such protective equipment. Lastly, these types of
metatarsal guards continue to present a tripping and
snagging hazard.
[0005] In an attempt to create a more aesthetically
pleasing and comfortable safety boot that minimizes
the tripping and snagging hazard presented by external
metatarsal shields, manufacturers have experimented
with integrating metatarsal protectors into a steel-
toed boot. U.S. Patent No. 4,102,062, to Adams,
.11M.1091176-1-2-
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discloses a metatarsal protector made from rigid
synthetic plastic material that is integrally
incorporated into the boot. This method of protecting
the metatarsal region continues to prevent the wearer
of the boot from walking freely, and limits the range
of motion of the foot because the rigid synthetic
plastic material cannot bend or flex with the contours
of the foot during walking or running. Because such
safety boots cannot bend or flex properly, and are
therefore uncomfortable, individuals are deterred from
wearing such footwear. Furthermore, the integrated
metatarsal protectors only cover the metatarsal region
and are attached or hinged side-by-side to the steel
toe cap.
[0006] The evolution of metatarsal guards has been
advanced by others who have integrated hinged metal or
plastic metatarsal guards that abut end-to-end with
steel toe caps. Because separate metatarsal pieces
are overlapped or hinged and attached adjacent to the
steel toe, the wearer's foot is often pinched between
the movable parts. Additionally, these types of
guards have been found not to adequately distribute
the impact forces of falling objects, which may thus
result in point of contact injuries. Furthermore,
upon impact forces or over time, the metal, plastic
sections, rivets, and threaded, glued, or hinged
connections can break or come loose. This can cause
the safety footwear to become unwearable, or even
worse, can come loose and move out of the protective
area of the foot. As with other metatarsal
protectors, this type of metatarsal guard creates an
uncomfortable shoe that people do not want to wear.
[0007] Thus, there remains a need to provide a
metatarsal guard that protects the metatarsal region
of the foot from impacts or blows while at the same
time providing comfort, reliability, stability,
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flexibility and an aesthetically pleasing appearance
to the boot or shoe.
[00081 It is accordingly an aspect that the present
invention seeks to provide an integrated flexible
metatarsal guard that extends over the protective toe
cap. It is a related aspect that the present invention
protects the metatarsal region of the foot from
impacts or blows resulting from falling objects, as
well as keeping the metatarsal guard secure in its
intended position. This aspect must be accomplished
by meeting or exceeding the ANSI Z41-1999 standard.
It is a further related aspect of the present
invention that the guard be of a flexible nature to
allow a full range of motion of the foot, which will
provide the wearer with a boot or shoe that allows and
conforms to natural crouching, walking, or running
movements. Furthermore, the guard of the present
invention must be integrally positioned within the
footwear to create an aesthetically pleasing
appearance.
[0009] It is another aspect of the guard of the
present invention that it be light-weight and
comfortable. It must be light enough so as to not
fatigue the wearer. The guard of the present
invention must also be flexible, with non-moving parts
so as to prevent any pinching, cutting, or other
irritation of the wearer's foot. Optionally, the
guard of the present invention does not require the
use of coupling devices or materials, such as hinges,
tapes, or adhesives, to be integrally positioned
within the footwear and coupled to the protective toe
cap.
[00101 It is yet a further aspect of the present
invention that it fully and completely protect the
wearer's foot from impact to the metatarsal region and
extending over the toes. The guard of the present
invention, when used in conjunction with a protective
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toe cover, such as a steel toe, must extend over the
protective toe cover to protect the entire metatarsal
region of the foot and toe region. Additionally, the
guard of the present invention must act to transfer
and disperse impact forces from the region of impact
to a broader region, including the metatarsal and toe
regions, thereby distributing the force over a greater
surface area. This will prevent a direct, single
concentrated source of energy from the impact or blow,
and prevent point-of-impact injuries to the wearer's
foot. Furthermore, forces applied to the guard of the
present invention will be transferred to the
protective toe cover, thereby further reducing the
shock to the wearer's foot.
[0011] The guard of the present invention must also
be of construction which is both durable and long-
lasting, and it should require little or no
maintenance to be provided by the user throughout its
operating lifetime. In order to enhance the market
appeal of a boot or shoe incorporating the guard of
the present invention, it should also be of
inexpensive construction to thereby be affordable to
the broadest possible market. Finally, it is also an
objective that all of the aforesaid advantages and
objectives be achieved without incurring any
substantial relative disadvantage.
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SUMMARY OF THE INVENTION
[00121 The disadvantages and limitations of the
background art discussed above are overcome by the
present invention. With this invention, an improved
metatarsal guard that protects the metatarsal region
of the foot from impacts and provides improved support
and positioning of the metatarsal guard within a shoe
or boot by extending the metatarsal guard to
substantially surround and/or shadow a toe protector.
The present invention provides comfort, reliability,
stability, flexibility, and an aesthetically pleasing
appearance to the boot or shoe. The present invention
also meets the specified ANSI Z41-1991, Section 2
requirement for "Metatarsal Impact Resistance"
testing.
[00131 In one preferred aspect of the invention,
there is provided a safety shoe or boot having
improved protection for the metatarsal region of a
wearer's foot, comprising a sole, an upper having an
interior surface, the upper being affixed to the sole,
the upper and the sole defining a cavity for receiving
a wearer's foot. A rigid toe protector is affixed
between the upper an the side, and a flexible
metatarsal guard is integrally positioned inside the
upper, the metatarsal guard covering the instep region
of the wearer's foot- The metatarsal guard extends
forwardly from the front of the ankle to cover
substantially the entirety of the toe protector.
[00141 In an enhancement, the front portion of the
metatarsal guard of the present invention is
configured to shadow or overlap the toe protector. By
molding the metatarsal guard to shadow the shape of
the toe protector, the metatarsal guard of the present
invention can cover the toe protector without
requiring the use of adhesives. Essentially, the toe
protector acts as an anchor for the metatarsal guard
and prevents the metatarsal guard from shifting within
the shoe or boot. Alternatively, adhesives or tapes
can be used to more securely attach the metatarsal
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guard to the toe protector and/or to facilitate
assembly of the shoe or boot.
[0015] The configuration of the metatarsal guard of
the present invention improves the load distribution
of impacts resulting from falling or rolling objects.
Load forces are transferred to the toe protector
because the toe protector is located directly under
and supports the front portion of the metatarsal
guard. In addition, the metatarsal guard of the
present invention also includes a cushion for
absorbing impact forces.
[0016] The metatarsal guard preferably utilizes a
single flexible unitary plastic piece. The metatarsal
guard of the present invention preferably includes a
plurality of slits which are located on and extend
inwardly from the right and left lateral edge surfaces
of the metatarsal guard. These slits prevent the
metatarsal guard from impeding movement of the foot
when the wearer is crouching, walking, or running.
[0017] It may therefore be seen that the present
invention teaches a unitary flexible metatarsal guard
that extends to cover the toe protector. The
metatarsal guard allows a full range of motion of the
foot and conforms to natural crouching, walking, and
running movements. The metatarsal guard of the
present invention has no moving parts which could
pinch, cut, or other irritate the wearer's foot. The
metatarsal guard of the present invention does not
require the use of coupling devices such as hinges,
tapes or adhesives to retain the metatarsal guard in
place within the footwear and couple it to the toe
protector. Additionally, the metatarsal guard of the
present invention acts to transfer and disperse impact
forces from the region of impact to a broader region,
including the metatarsal and toe regions, thereby
distributing the force over a greater surface area.
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[0018] The metatarsal guard of the present invention is of a
construction which is both durable and long lasting, and which
will require little or no maintenance to be provided by the user
throughout its operating lifetime. The metatarsal guard of the
present invention is also of inexpensive construction to enhance
its market appeal and to thereby afford it the broadest possible
market. Finally, all of the aforesaid advantages and objectives of
the metatarsal guard of the present invention are achieved without
incurring any substantial relative disadvantage.
[0018A] A method of making a safety shoe or boot is also
disclosed, providing for improved protection for a wearer's foot
metatarsal region. The method includes attaching an inner lining
to an upper, the inner lining and the upper defining a void
therebetween; joining the upper to a sole, the sole and the upper
defining a cavity therebetween to accommodate the wearer's foot;
installing a rigid toe protector in the void, the toe protector
being located close adjacent to the upper at an end thereof which
will receive a wearer's toes when the wearer's foot is located in
the cavity. The method further includes producing a flexible
metatarsal guard adapted to flex and bend with the wearer's foot
such that the metatarsal guard will not inhibit the wearer's full
range of motion during natural walking and running movements, the
metatarsal guard also including a front portion designed to
overlay substantially the entirety of the toe protector and
inserting the flexible metatarsal guard into the void intermediate
the inner lining and the upper such that the front portion of the
metatarsal guard overlays the toe protector.
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[0018B] Another aspect of the invention provides a
safety shoe or boot having improved protection for the
metatarsal region of a wearer's foot, comprising a
sole, an upper having an interior surface, the upper
being affixed to the sole, the upper and the sole
defining a cavity for receiving a wearer's foot. A
rigid toe protector is affixed between the upper and
the sole, and a flexible metatarsal guard is
integrally positioned inside the upper, the metatarsal
guard having a first portion covering the instep
region of the wearer's foot and a second portion
extending forwardly from the first portion. The
second portion of the metatarsal guard covers
substantially the entirety of the toe protector, the
first portion of the metatarsal guard having right and
left lateral edges. A cushion absorbs impact forces,
the cushion being located under the first portion of
the metatarsal guard. A plurality of longitudinally
extending slits are located in each of the right and
left lateral edges of the metatarsal guard to allow
the first portion of the metatarsal guard to flex.
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DESCRIPTION OF THE DRAWINGS
[0019] These and other advantages of the present
invention are best understood with reference to the
drawings, in which:
[0020] Fig. 1 is a perspective, partially cross-
sectional view of a safety boot incorporating a
metatarsal guard which is manufactured in accordance
with the teachings of the present invention;
[0021] Fig. 2 is a side view of the metatarsal
guard from the safety boot illustrated in Fig. 1,
showing a cushion and a rigid toe protector;
[0022] Fig. 3 is a top view of the metatarsal guard
illustrated in Fig. 2;
[0023] Fig. 4 is a bottom view of the metatarsal
guard illustrated in Figs. 2 and 3, showing the
location of the rigid toe protector in phantom lines;
[0024] Fig. 5 is a first cross-sectional view of
the metatarsal guard illustrated in Figs. 1 through 4
along a longitudinal axis;
[0025] Fig. 6 is a second cross-sectional view of
the metatarsal guard illustrated in Figs. 1 through 5
along a lateral axis; and
[0026] Fig. 7 is a perspective view of the
metatarsal guard illustrated in Figs. 1 through 6..
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] The preferred embodiment provides a
metatarsal guard that protects the metatarsal region
of the foot from impacts or blows and provides for the
support and positioning of the metatarsal guard within
a shoe or boot by extending the metatarsal guard to
substantially surround or shadow a toe protector. The
metatarsal guard is in part adjacent to and interposed
between the interior surface of the footwear and the
toe protector. The front portion of the metatarsal
guard of present invention is configured to shadow and
overlap the toe protector. The toe protector thereby
acts as an anchor for the metatarsal guard and
prevents the metatarsal guard from shifting within the
footwear. The configuration of the metatarsal guard
improves the load distribution resulting from impacts
from falling or rolling objects. The metatarsal guard
also includes a plurality of slits located in the
right and left lateral edge surfaces thereof for
preventing the metatarsal guard from impeding movement
of the foot while the wearer is walking, running, or
crouching.
[0028] Referring first to Fig. 1, a safety boot 20
is shown with an integrally positioned flexible
metatarsal guard 34 which is made according to the
teachings of the present invention. Prior to a
discussion of the components of the present invention,
it may be helpful to first discuss the well-known
elements of a typical safety boot 20. The safety boot
20 has an upper member 22 which is attached to a sole
24.
[0029] Those skilled in the art will appreciate
that soles for safety footwear may also include other
structural elements such as a midsole, a steel plate
to prevent punctures, and cushions (none of which are
illustrated in Fig. 1). The upper member 22 includes
a tongue 26 and a vamp or an instep region 28, and may
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be made from leather or from any of a number of other
materials known to those skilled in the art, including
both natural and synthetic materials. A rigid toe
protector 32 is placed inside the toe region 30 of the
upper member 22 to protect the wearer's toes from
falling objects.
[0030] The toe protector 32 has a generally
U-shaped lateral cross-sectional configuration.
Typically, the toe protector 32 is placed between an
inner lining 23 and the interior of the upper member
22. The toe protector 32 lies adjacent to the
interior surface of the toe region 30 of the upper 22
and extends downwardly to the sole 24 on the sides and
front of the toe protector 32. This allows impact on
the safety boot 20 in the toe region to be transferred
from the toe protector 32 to the sole 24, and,
ultimately, to the ground.
[0031] The rigid toe protector 32 forms a space for
the wearer's toes and conforms to the general shape of
the toe region 30. Typically, the toe protector 32 is
made from steel, but it may also be manufactured from
synthetic polymers such as ABS plastic or other rigid
materials known by those skilled in the art to be
capable of withstanding impact forces from falling,
rolling, or static objects.
[0032] The components which have been discussed to
this point are presently known in safety boot
construction; however, the present invention includes
additional components which will now be discussed.
The flexible metatarsal guard 34 of the present
invention is integrally positioned inside the upper
member 22 and extends forwardly from the ankle to
cover the rigid toe protector 32, and will thus cover
the instep region 28 of a wearer's foot,. Preferably,
the metatarsal guard 34 closely shadows the outer size
and shape of the toe protector 32. The metatarsal
guard 34 is arched to follow the natural shape of the
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top of the foot's instep (the metatarsal region), and
extends forwardly to overlap at least the top and side
walls of the toe protector 32. In the preferred
embodiment, the metatarsal guard 34 overlaps the toe
protector 32 in its entirety so that the metatarsal
guard 34 is in part adjacent to and interposed between
the interior surface of the upper member 22 and the
toe protector 32 and the inner lining 23.
[0033] In the preferred embodiment, the metatarsal
guard 34 is retained in position over the toe
protector 32 without the use of adhesive.
Alternatively, the metatarsal guard 34 can be affixed
to the toe protector 32 by use of an adhesive. In
this embodiment, a wearer would not be able to feel
the edges of the forward portion of the metatarsal
guard 34 which overlaps the toe protector 32 while
wearing the safety boot 20. In addition, the close
fit of the metatarsal guard 34 over and around the toe
protector 32 provides further stability to the
metatarsal guard 34 and will prevent the metatarsal
guard 34 from shifting inside the safety boot 20.
[0034] A cushion 35 located underneath the
metatarsal guard 34 is included to increase the
comfort level and shock absorption capabilities of the
metatarsal guard 34. The cushion 35 may consist of a
single layer or multiple layers. Additional layers
will help further absorb impact forces from objects
impacting the toe of the safety boot 20.
[0035] Referring now also to Figs. 2 through 7, the
overall configuration of the metatarsal guard 34 shown
in the safety boot 20 in Fig. 1 is illustrated. As
best shown in Figs. 2 to 4, the metatarsal guard 34
includes a right lateral edge 50 and a left lateral
edge 52. In the preferred embodiment of the present
invention, the lateral edges 50 and 52 of the
metatarsal guard 34 do not fully reach the sole 24 on
either side of the safety boot 20. Alternately, the
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lateral edges 50 and 52 can be extended to rest on or
substantially abut the top surface of the sole 24 of
the safety boot 20.
[0036] A front portion 54 of the metatarsal guard
34 rests on top of the toe protector 32 as best shown
in Figs. 2 through 4 and 7. Accordingly, a
substantial portion of the load of an object falling
on the metatarsal guard 34 will be applied to the toe
protector 32 to which the front portion 54 of the
metatarsal guard 34 rests, thereby reducing the
portion of the load distributed on the instep of a
wearer's foot. The load of an impact is further
absorbed by and/or distributed to the cushion 35.
[0037] To facilitate flexion of the metatarsal
guard 34 and prevent the metatarsal guard 34 from
impeding flexion of the foot of a wearer in a walking,
running, or crouching posture, three side slits 36,
38, and 40 extend laterally into the right lateral
edge 50 of the metatarsal guard 34 and three side
slits 42, 44, and 46 extend laterally into the left
lateral edge 52 of the metatarsal guard 34 as best
shown in Figs. 3, 4, and 7. Those skilled in the art
will recognize that the slits 36, 38, 40, 42, 44, and
46 can be cut into the metatarsal guard 34, or,
alternately, the metatarsal guard 34 can be molded
with the slits 36, 38, 40, 42, 44, and 46 located
therein.
[0038] The slits 36, 38, and 40 extend from near
the right lateral edge 50 toward a top surface 48 of
the metatarsal guard, as best shown in Fig. 5.
Similarly, the slits 42, 44, and 46 extend from the
left lateral edge 52 toward the top surface 48 of the
metatarsal guard 34. The side slits 36, 38, 40, 42,
44, and 46 allow the metatarsal guard 34 to flex and
thereby prevent the metatarsal guard 34 from impeding
movement of the foot when the wearer is crouching,
walking, or running. Optionally, the cushion 35 can
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also include corresponding slits (not shown herein) to
help the cushion 35 conform to the shape and movement
of the metatarsal guard 34.
[0039] Although the preferred embodiment shows six
slits 36, 38, 40, 42, 44, and 46, one skilled in the
art can modify the metatarsal guard 34 of the present
invention to include fewer or more slits, as well as
varying the length or configuration of the slits. In
addition, multiple apertures can be incorporated into
the metatarsal guard 34 to further facilitate and
increase the flexion of the foot. The apertures,
which are shown only in Fig. 1, can be combined with
the slits as shown in Fig. 1, or used separately (not
shown in the figures), to enhance the flexion of the
metatarsal guard 34.
[0040] The metatarsal guard 34 is positioned within
the safety boot 20 as shown in Fig. 1. The metatarsal
guard 34 may be held in place between the inner lining
23 and the toe protector 32 on the bottom side thereof
and the interior surface of the upper member 22 of the
safety boot 20 on the top side thereof. Alternately,
the metatarsal guard 34 can be attached to one or both
of the inner lining 23 and the toe protector 32 or the
interior surface of the upper member 22 using a
double-sided adhesive tape material. As mentioned
previously, the metatarsal guard 34 can also be held
in place using adhesives if desired.
[0041] The metatarsal guard 34 may be made from a
sheet of robust, flexible plastic material. Although
other plastic materials could be used, the metatarsal
guard 34 is preferably made of high density
polyethylene or high density polypropylene. The
metatarsal guard 34 may be manufactured using molding
techniques such as injection molding techniques which
are well known to those skilled in the art.
Alternatively, the metatarsal guard 34 can be die cut,
laser cut, or water cut from flat plastic sheet
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CA 02518028 2005-08-30
material, and then thermoformed on a template to
obtain a shape that can be integrally positioned
within the safety boot 20.
[0042] The cushion 35 can be attached to the
underside (bottom) of the metatarsal guard 34 by any
of a variety of techniques which are well known in the
art. For example, the cushion 35 can be attached,
glued to, or even sewn onto the metatarsal guard 34.
The cushion 35 could instead be attached to the
metatarsal guard 34 using a double-sided adhesive tape
material.
[0043] The cushion 35 can be a single flexible
layer of impact-absorbent material or a flexible
sandwich of several materials which can bend to
accommodate the natural movement of a foot. For
example, the cushion 35 could have one or more layers
of a cross-linked polyethylene foam material that
absorbs impact forces of falling or rolling objects
and retains the shape of the instep region 28 of the
upper member 22. Although a polyethylene foam layer
is described herein, it would be apparent to those
skilled in the art to substitute other materials that
provide the requisite cushioning and other
characteristics in safety boots.
[0044] An example of a material which may be used
for the cushion 35 is a cellular urethane foam
material manufactured by Rogers Corporation under the
trademark PORON. Although such a material is utilized
in the preferred embodiment, other types of materials
such as neoprene sponge, vinyl sponge, sponge rubber,
latex foam, and solid viscoelastic material may be
used instead.
[0045] Optionally, the cushion 35 can also include
a material having a mechanical design which allows the
material to absorb force, such as the rubber material
manufactured by Esjot Goldenberg of Ense, Germany
under the trademark META-TEC. Other types of
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mechanical force absorption materials known to those
skilled in the art could also be used. Furthermore,
either a single force absorption layer and/or several
force absorption layers could be used to make the
cushion 35.
[0046] Testing has been used to verify the safety
of footwear incorporating the metatarsal guard 34 of
the present invention. ANSI has developed standards
for footwear manufacturers to follow to ensure proper
foot protection. The current standard is the ANSI
Z41-1999 standard, which is approved by OSHA.
Footwear bearing the ANSI Z41 label must meet or
exceed the ANSI Z41 standard requirement for that
product category.
[0047] The metatarsal guard 34 of the present
invention was tested for "Metatarsal Impact
Resistance" testing in' accordance with ANSI standard
Z41-1999, Section 2 as Class 75 footwear. The
metatarsal guard was tested using an impact test
apparatus with a 50-pound steel metatarsal impactor
dropped from a height that provides the required
impact velocity (as outlined in ANSI Z41-1999, Section
2, which is 96 1.9 inches per second). The minimum
impact clearance, which is the distance from the
insole to the metatarsal guard, is one inch for men's
footwear and 15/16 inches for women's footwear.
[0048] Table 1 below shows the recorded results of
the testing for men's footwear.
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CA 02518028 2005-08-30
Table 1: ANSI Z41, Class 75 Test Results
Trial Number Impact Clearance (inches)
1 1 4/16 inches
2 1 3/16 inches
3 1 4/16 inches
4 1 3/16 inches
1 4/16 inches
6 1 4/16 inches
[0049] As can be seen, the metatarsal guard 34 of
the present invention not only met but exceeded the
5 specified ANSI Z41-1999, Section 2 requirement for
"Metatarsal Impact Resistance" testing. Table 1
clearly shows that the metatarsal guard 34 of the
present invention exceeded the minimum impact
clearance requirement by at least 3/16 of an inch.
[0050] It may therefore be appreciated from the
above detailed description of the preferred embodiment
of the present invention that it provides a unitary
flexible metatarsal guard that extends to cover the
toe protector. The metatarsal guard allows a full
range of motion of the foot and conforms to natural
crouching, walking, and running movements. The
metatarsal guard has non-moving parts so as to prevent
any pinching, cutting, or other irritation of the
wearer's foot.
[0051] The metatarsal guard does not require (but
may optionally utilize) the use of coupling devices or
materials, such as hinges or adhesives, to maintain it
in position within the footwear and coupled to the toe
protector. Additionally, the metatarsal guard acts to
transfer and disperse impact forces from the region of
impact to a broader region, including the metatarsal
and toe regions, thereby distributing the force over a
greater surface area.
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CA 02518028 2005-08-30
[0052] Finally, it should be noted that the
metatarsal guard 34 of the present invention maximizes
protection of the instep of a wearer's foot, maintains
a high level of comfort even when the wearer is in a
crouching posture, and is robust and stable when used
in the safety footwear. Furthermore, the metatarsal
guard of the present invention exceeded the specified
ANSI Z41-1991, Section 2 requirements for "Metatarsal
Impact Resistance."
[0053] Although the foregoing description of the
metatarsal guard of the present invention has been
shown and described with reference to particular
embodiments and applications thereof, it has been
presented for purposes of illustration and description
and is not intended to be exhaustive or to limit the
invention to the particular embodiments and
applications disclosed. It will be apparent to those
having ordinary skill in the art that a number of
changes, modifications, variations, or alterations to
the invention as described herein may be made, none of
which depart from the spirit or scope of the present
invention. The particular embodiments and
applications were chosen and described to provide the
best illustration of the principles of the invention
and its practical application to thereby enable one of
ordinary skill in the art to utilize the invention in
various embodiments and with various modifications as
are suited to the particular use contemplated. All
such changes, modifications, variations, and
alterations should therefore be seen as being within
the scope of the present invention as determined by
the appended claims when interpreted in accordance
with the breadth to which they are fairly, legally,
and equitably entitled.
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