Note: Descriptions are shown in the official language in which they were submitted.
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PROTECTIVE FOOTWEAR
RELATED APPLICATIONS
This is a continuation of United States Provisional Patent Application
No. 60/557,684 filed on March 31, 2004
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to protective footwear and, more
particularly, to protection against puncture injuries.
Description of the Prior Art
All materials used in the manufacture of protective footwear for
firefighters must satisfy minimum performance requirements for flame, heat,
tear cut
and puncture resistance as prescribed by The National Fire Protection Agency
(NFPA).
Traditionally, rubber or synthetic rubber has dominated firefighter
footwear boots in the style commonly referred to as "bunker style". More and
more
firefighters and other emergency responders are opting for leather (or
synthetic
fabric) boots. They offer enhanced comfort, breathability, flexibility and
protection.
Moreover, they can incorporate more features designed enhance the key
performance
factors described above.
Over the past five years, protective leather (or synthetic fabric)
footwear has become more and more popular for firefighters offering them many
benefits above traditional rubber footwear. Amongst the most important is
enhanced
comfort by fit and lightness. Leather (or synthetic fabric) allows for a
custom fit and
tougher mechanical protection. Additionally, leather (or combined leather and
synthetic fabric) allows firefighter (or other emergency responder) boot to be
lighter
than its rubber equivalent. Lighter weight footwear has important consequences
for
increasing work efficiency and duration, and reducing stress related injury. A
study
done by Study by R.G. Soule & R.F. Goldman, US Army Research Institute of
Environmental Medicine (Journal of Applied Physiology, Vol. 27, No.S, November
1969) reported that each additional kilogram of load carned on the feet
increased the
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expected energy costs to the human subject by a factor of 4 compared to the no
load
energy cost.
Firefighters and emergency responders wear boots to protect their feet
against heat, cold, cut water and puncture wounds and sprains. Their
activities are not
limited to walking, but running or crawling in all types of debris - often on
un-level
or unstable flooring. Puncture protection therefore offers real safety
benefits.
The human foot is a complex anatomical structure. It consists of 26
bones working synergistically to support and propel the human body. During
strenuous activity it can withstand forces of up to 250% of normal body
weight.
Firefighter and other emergency responders such as police, medical and USAR
personnel o$en perform at elevated activity levels, whether walking in burned
out
structural debris or extricating a human life from an entangle accident scene,
to more
recent rescues from otherwise complex situations.
The area most vulnerable to puncture is obviously the entire bottom
1 S sole area. This has long been recognized in general safety footwear.
Almost all
manufacturers have adopted the metallic puncture resistant plate that covers
the entire
sole area of the foot. This plate works in conjunction with the rubber sole of
the shoe.
If a wearer steps on a sharp protruding object, it will penetrate the
composite sole
material and be blocked by the metallic plate. Theoretically, there is no
danger of
redirection of the sharp object, as it remains embedded in the narrow channel
it
created as it pierced the rubber sole.
Other areas of vulnerability include the toes and the top of the foot.
These areas are most susceptible to crushing injury from heavy objects
falling. The
use of the steel (or composite) toecap has done much to address this danger.
An area not yet recognized by many manufacturers is the vulnerable
arch area, i.e. the inside portion of the instep. For the most part this area
remains
unprotected from vertical protrusions as well as multi-directional
protrusions.
Current patents with regards to arch inserts address athletic footwear.
All those investigated use composite materials for their flexibility and
lightness.
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U.S. Pat No. 5,918,338 teaches using a woven composite material in
sport footwear. It is designed to enhance the overall performance of athletic
shoes by
returning energy to the user's foot on being lifted after contact with the
ground.
U.S. Pat. No. 5,319,866 is directed to woven and non-woven arch
support materials) designed to improve the overall performance in athletic
shoes in
terms of weight, comfort and support.
U.S. Pat. No. 5.546,680 teaches providing protective inserts in
environments where sharp objects can puncture the footwear product. This
patent is
entirely specific to rubber footwear for firefighters. It recognizes the lack
of
protection to the inside portion of the human instep and claims a more
complete
protection by providing rubber footwear product with a rigid protective insert
that
protects the sole of the wearer's foot and also the inside or arched portion
of the
wearer's instep. The invention is specific to rigid steel and also mentions
other rigid
composite materials such as: rigid plastic fiberglass or graphite. It does
not, however,
address the problem of a penetrating object being deflected and causing injury
to
other areas of the foot.
The use of rigid inserts in the instep region poses possibility for
further risks to the wearer. When an object enters the vulnerable arch area
and is met
by a rigid material, such as steel, it is blocked and depending on the angle
of entry
and the force of the wearer the sharp object may actually be redirected to a
more
vulnerable unprotected area, as shown in Fig. 1. Rigid materials, such as
steel or
plastic are not designed to entrap the sharp protrusion, they are designed to
block and
prevent penetration.
SUMMARY OF THE INVENTION
It therefore an aim of the present invention to provide a protective
insert which is adapted to entrap sharp objects instead of blocking and
deflecting
them.
According to a general aspect of the present invention, the above
issues are addressed by providing complete arch protection in a manner that
does not
impede the flexibility of the boot. Additionally, the method of blocking the
protrusion
ensures that it is not redirected to a more vulnerable area.
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According to one embodiment of the present invention, there is
provided protective footwear comprising an arch protector having multiple
layers of
woven ballistic material, each layer including interlaced warp and weft yarns,
with
the warp and weft yarns of each of said layers having an orientation different
from
that of the neighboring layers. According to the present invention, there is
no need to
make use of any epoxies or resins as hardeners, which although tough, would
increase footwear rigidity and decrease comfort.
In accordance with a preferred embodiment of the invention, multiple
layers of woven ballistic fabric, with the warp and weft yarns of each layer
having an
orientation different from that of its neighboring layer provides contoured
protection
that is flexible and moves with the foot of the wearer. This constitutes an
important
consideration in leather (or synthetic fabric) boots worn by firefighter and
other
emergency responders. These boots are designed for maximum comfort and
mobility.
In accordance with a further general aspect of the present invention,
1 S there is provided a protective footwear comprising a sole and an upper for
receiving a
wearer's foot, and a flexible protector of woven ballistic yarns integrated to
said
upper to entangle and trap penetrating obj ects.
In accordance with a further general aspect of the invention, there is
provided a footwear comprising a body for receiving a wearer's foot, and a
flexible
puncture protective arch insert integrated to said body at an instep portion
thereof,
said flexible puncture protective arch insert comprising multiple overlying
layers of
woven ballistic fabric, each layer having interlaced warp and weft yarns, the
warp and
weft yarns of at least a plurality of said layers having an orientation
different from
that of neighboring layers, said multiple overlying layers providing
protection by
entrapping encountered puncturing objects, thereby preventing redirection to
unprotected areas of the wearer's foot.
In accordance with a still fixrther general aspect of the invention, there
is provided a protective footwear comprising a body for receiving a wearer's
foot,
said body having inner and outer flexible layers, and a lateral puncturing
protector
mounted between said inner and outer flexible layers in the arch area of the
wearer's
foot, the lateral puncturing protector including a fiber material woven in
multi-
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directional layers, the fiber material defining a plurality of catching
interstices in
which a sharp edge of a sharp object is captively received when pushed under
pressure against said lateral puncturing protector.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the accompanying drawings, showing
by way of illustration a preferred embodiment thereof, and in which:
Fig. 1 is an enlarged cross-sectional view illustrating how a
conventional rigid puncture resistant plate can block and redirect a sharp
object to
another unprotected area of a wearer's foot;
Fig. 2 is a perspective view of a protective footwear incorporating an
arch protector made of multiple layers of woven ballistic fabric in accordance
with
one embodiment of the present invention;
Fig. 3 is a perspective view of the protective footwear illustrating the
flexibility of the arch protector;
Fig. 4 is an enlarged cross-sectional view of the protective footwear
illustrating how a nail is entangled and trapped into the arch protector, and
Fig. 5 is a cross-sectional view illustrating the mufti-layer construction
of the protective layer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As will be seen hereinafter, the present invention is generally directed
to a footwear protective insert adapted to trap the sharp objects, such as
nails, to
prevent them from being redirected to more vulnerable area of the wearer's
foot. The
present invention is particularly applicable to all styles of leather (or
synthetic fabric)
safety boots worn by firefighters and other emergency responders. The
protective
insert can advantageously be used as an arch protector to protect the wearer
from
mufti-directional punctures to the arch area of the foot. However, it is
understood that
the present invention could have other applications.
More specifically, one embodiment of the present invention generally
relates to the adaptation of a special ballistic grade pliable protector,
designed to
protect the vulnerable arch area of the foot from mufti-directional punctures,
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incorporated into leather (or synthetic fabric) boots worn by firefighters and
other
emergency responders. Because of its unique material application, it offers
protection
based on the principles of ballistic protection, where the piercing object is
entangled
and never redirected.
Now refernng to Figs. 2 to 4, there is shown a protective footwear 10
(a leather or synthetic fabric firefighter boot in the illustrated example)
comprising a
flexible arch protector 12. The arch protector 12 covers the entire arch area
of the
wearer's foot. The arch protector 12 is preferably provided in the form of an
insert
placed between inner and outer flexible layers 14 and 16 forming part of the
upper of
the leather boot. The protector 12 extends upwardly from the sole 18 of the
footwear
10.
The arch protector 12 is made of multiple flexible overlying layers of
woven ballistic material. The protector 12 preferably incorporates ballistic
grade
nylon, Kevlar~ or other puncture resistant fiber materials. As shown in Fig.
5, each
layer 20a, 20b, 20c . . . includes a matrix of interlaced warp and weft yarns
22 and 24.
The warp and weft yarns 22 and 24 of adjacent or neighboring layers 20a, 20b
and
20c extend in different directions. This arrangement provides a flexible
puncture
resistant insert which is adapted to trap the sharp object in its webbing
instead of
redirecting it, as the prior art inserts do.
The arch protector 12 provides puncturing protection without affecting
flexibility of the boot (see Fig. 3). The arch protector 12 is flexible by
itself and is
installed between two flexible layers 14 and 16 of material. This composite
construction provides contoured protection that is flexible in that the
flexibility of the
inner and the outer layers 14 and 16 is preserved when assembled to protector
12.
The protector 12 is allowed to move and flex with foot of the wearer (see Fig.
3),
thereby providing maximum comfort and mobility.
When a sharp object (for instance the nail N shown in Fig. 4) is
encountered, the arch protector 12 will deform under the pressure applied by
the
object to trap the sharp edge thereof within its webbing, thereby preventing
redirection of the sharp object to another unprotected area. The flexibility
of the
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backing, i.e. the inner layer 14, of the arch protector 12 permits the
deformation
thereof.
In view of the foregoing, it can be readily appreciated that the present
invention provides an additional, more complete and comfortable protective
insert to
the entire bottom of a footwear and prevents lateral multi-directional
protrusions
from coming into the vulnerable arch area, i.e. the inside portion of the foot
that
extends laterally from the composite heal four inches towards the front of the
foot in
an arch form.
