IMPROVED BLAST RESISTANT FOOTWEAR

CHAUSSURE PERFECTIONNEE RESISTANT AUX EXPLOSIONS

English Abstract

A boot (10) adapted to provide an improved level of protection against
explosive blasts is described. In one embodiment, the boot
has a sole (12), an upper (11) and a cocoon (13) portion which substantially
encloses the foot. The cocoon can be comprised of an aramid
weave (21), and/or, a further layer of carbon fibre (22) and/or woven ceramic
fibres or ceramic/glass-ceramic woven composite fibres. The
sole can incorporate layers of woven aramid and carbon fibres and a deflector
plate (23) to provide enhanced protection. In an alternative
embodiment, the cocoon can surround the boot and provide a quick and
relatively inexpensive means of improving the blast protection to
a wearer.

French Abstract

Botte (10) conçue pour offrir une meilleure protection contre les explosions. Dans un mode de réalisation, cette botte comporte une semelle (12), une tige (11) et un cocon (13) enveloppant sensiblement le pied. Ce cocon peut comprendre une armure en aramide (21) et/ou une couche supplémentaire en fibre de carbone (22) et/ou en fibres céramiques tissées ou en fibres composites céramiques/vitrocéramiques tissées. La semelle peut se composer de couches de fibres aramides et de carbone tissées, ainsi que d'une plaque déflectrice (23) afin d'offrir une meilleure protection. Dans une variante, le cocon peut entourer la botte, offrant ainsi un moyen rapide et relativement peu coûteux d'améliorer la protection de l'utilisateur contre les explosions.

Claims

7
CLAIMS:
1. An article of footwear comprising a cocoon (41) shaped to substantially
or entirely surround a boot (40), the cocoon (41) being in the form of a
bootee
having a sole (42) and an upper (43), the upper including a toe cap portion,
two side portions which extend from the front of the bootee to the rear of the
bootee and from the sole of the bootee to an edge distal the sole, and one or
more fastening means (49) extending from the upper edge and which, in use,
fasten the cocoon in place around the boot (40), the article of footwear being
characterised in that the cocoon further has at least one continuous layer of
blast-resistant material (44,45) embedded therein and extending throughout
the sole, toe cap portion and side portions of the bootee.
2. The article of footwear of claim 1 and further characterised in that said
at least one layer of blast-resistant material comprises at least one layer of
woven aramid fibres comprising at least 1-ply of at least 1000 dtex aramid
fibre.
3. The article of footwear of claim 1 and further characterised in that said
at least one layer of blast-resistant material comprises at least one layer of
woven ceramic fibres.
4. The article of footwear of claim 1 and further characterised in that said
at least one layer of blast-resistant material comprises at least one layer of
woven ceramic/glass-ceramic composite fibres.
5. The article of footwear of claim 2 and further characterised in that said
at least one layer of woven aramid fibres is incorporated within a sandwich
of layers of woven ceramic fibres.
6. The article of footwear of claim 2 and further characterised in that said
at least one layer of woven aramid fibres is incorporated within a sandwich
of layers of woven ceramic/glass-ceramic composite fibres.
7. The article of footwear of claim 2 and further characterised in that the
bootee sole (42) is comprised of rubber or polyurethane and has embedded
therein at least one further layer of woven aramid fibres.
8. The article of footwear of claim 7 and further characterised in that a
layer of carbon graphite fibres is sandwiched between the layer of woven
aramid fibres comprising said layer of blast resistant material and said one
further layer of woven aramid fibres.

8
9. The article of footwear of claim 1 and further characterised in that the
fastening means (49) comprises straps extending from the side portions of the
bootee.
10. A boot (10) for a foot of a wearer, the boot having a sole (12) and an
upper (11), the sole (12) having at least one layer of woven aramid fibres
embedded throughout the sole, the boot being characterised in that a cocoon
(13) is incorporated integrally within the boot (10), the cocoon (13) being in
the form of a bootee having a sole and an upper, the upper including a toe
cap portion, and two side portions which extend from the front of the bootee
to the rear of the bootee and from the sole of the bootee to an edge distal
the
sole of the bootee, the boot (10) being characterised in that the cocoon
further has at least one continuous layer of blast-resistant material embedded
therein and extending throughout the sole, toe cap portion and side portions
of the bootee.
11. The boot of claim 10 and further characterised in that said at least one
layer of blast-resistant material comprises at least one layer of woven aramid
fibres comprising at least 1-ply of at least 1000 dtex aramid fibre.
12. The boot of claim 11 and further characterised in that said at least one
layer of woven aramid fibres is incorporated within a sandwich of layers of
woven ceramic fibres.
13. The boot of claim 11 and further characterised in that said at least one
layer of woven aramid fibres is incorporated within a sandwich of layers of
woven ceramic/glass-ceramic composite fibres.
14. The boot of claim 10 and further characterised in that the boot sole
(12) is comprised of an outer portion (14) and an intermediate portion (15).
15. The boot of claim 14 and further characterised in that the outer portion
(14) of the boot sole is comprised of rubber or polyurethane.
16. The boot of claim 14 and further characterised in that said at least one
continuous layer of blast-resistant material of the bootee is sandwiched
between the outer portion (14) of the boot sole and said at least one layer of
woven aramid fibres embedded in the boot sole.
17. The boot of claim 16 and further characterised in that a layer of carbon
graphite fibres is sandwiched between the layer of woven aramid fibres
comprising said layer of blast resistant material and said at least one layer
of
woven aramid fibres embedded in the boot sole.

9
18. The boot of claim 14 and further characterised in that the sole includes
a deflector plate (23).
19. The boot of claim 18 and further characterised in that the deflector
plate (23) is in the intermediate portion (15) of the sole.
20. The boot of claim 19 and further characterised in that the deflector
plate (23) has a first side directed towards the outer portion, the first side
having an angled surface to deflect the effect of an explosive blast away from
an interior of the boot.
21. The boot of claim 20 and further characterised in that the deflector
plate (23) is comprised of a composite of woven aramid and carbon fibres
embedded in an adhesive or polymeric matrix.
22. The boot of claim 21 and further characterised in that the ratio of
woven aramid fibres to carbon fibres is 50:50.
23. The boot of claim 14 and further characterised in that the boot upper
(11) is fabricated from an outer leather layer and an inner vamp layer of
leather or cotton, the upper of the bootee being positioned between the outer
layer and the inner vamp layer.
24. The boot of claim 23 and further characterised in that two further
layers of woven aramid fibres extend throughout the intermediate portion
(15) of the boot sole and extend at least partially into the upper (11) of the
boot (10).

Description

CA 022~64~4 1998-11-20
WO 97/43919 PCT/SG97/00010
IMPROVED BLAST RESISTANT FOOTWEAR
Field of the Invention
The present invention relates to the construction of footwear and, in
5 particular, to a boot which is constructed to protect the foot from serious
damage resulting from the impact of projectiles and explosions from anti-
personnel mines.
Background Art
Anti-personnel mines which are designed to explode as a person
10 steps on the mine represent a common and serious problem for any troops
deployed either on a conventional battle field or involved in guerilla warfare.
The amount of explosive present in a mine will dictate whether the
mine on exploding maims or kills the person triggering the mine. For those
devices designed simply to maim, protective footwear can play a role in
15 lessening the likelihood of serious injury. Such footwear can also have a role
in lessening the damage caused by the impact of projectiles such as bullets
and shrapnel.
The present inventor has developed boots, and in particular boot
soles, that can protect the foot of a person triggering an anti-personnel mine
20 containing reasonable quantities of explosive while still providing the wearer
with sufficient toe-to-heel flexion in the boot to allow activities such as
running, jumping and climbing (see Singapore Patent Application
nos 9500037-8 and 9501007-0). It would be desirable to have a further
improved boot that could protect the foot and lower leg of a wearer from
25 explosions produced by mines having larger quantities of explosive and from
- mines using high temperature explosives which can rip through boots of
earlier designs.
SummarY of the Invention
According to a first aspect, the present invention consists in footwear
30 comprising a cocoon of blast-resistant material shaped to substantially
surround a boot, the cocoon having a sole and an upper, the cocoon being
connected to the boot or the leg of the wearer of the boot.

CA 022~64~4 1998-ll-20
WO 97/43919 PCT/SG97/00010
The sole of the cocoon may be comprised of rubber or polyurethane
and have embedded therein at least one further layer of woven aramid fibre.
The cocoon is preferably attached to the boot by straps extending from the
cocoon around the upper portion of the boot.
According to a further aspect, the present invention consists in a boot
for a foot of a wearer, the boot having a sole and an upper, the sole having at
least one woven aramid layer embedded through the sole, the boot being
characterised in that a cocoon of blast-resistant material is incorporated into
the boot such that it would substantially surround the entire foot of a wearer
of the boot.
In a preferred embodiment of both aspects the cocoon comprises at
least one sheet of blast-resistant material. The blast-resistant material can becomprised of an aramid weave comprising at least one-ply of at least 1000
dtex aramid (eg Twaron~ 2010). It can be composed of woven 1200 dtex
aramid such as Twaron~ 2040 having a 460 g/m2 tight plain weave. The
cocoon can comprise or include a layer of woven ceramic fibre or
ceramic/glass-ceramic woven composite fibre.
The cocoon in the second aspect is preferably shaped in the form of a
"bootee" that can be embedded in the sole and upper of the boot.
The aramid weaves comprising the protective layer in the cocoon can
be incorporated into a sandwich of layers including layers of woven ceramic
fibres or a separate ceramic/glass-ceramic composite woven fibre to further
increase the strength of the cocoon when exposed to high temperatures. A
layer of woven ceramic fibres can comprise the outermost layer of the
cocoon.
- The sole of the boot is preferably comprised of at least an outer
portion and an intermediate portion. The outer sole can be comprised of
rubber or polyurethane mo - ed to suit the requirements of the boot. The
portion of the cocoon extending through the sole preferably is positioned
between the outer portion and the at least one woven aramid layer embedded
in the sole.
The intermediate portion preferably has a plurality of layers of woven
aramid embedded within it. In one embodiment, the woven aramid layers can
- T

CA 022~64~4 1998-11-20
WO 97/43919 PCTISG97/00010
have carbon graphite fibres either interwoven with or between the aramid
layers to further strengthen the sole. In a preferred embodiment, there are 24
layers of aramid, carbon and ceramic woven fibres ~eg Toray,~/8HR,~
M60/M80 6K/12K TOW plain weave, the density of which ranges from
- 5 3009/m2 to 600g/m2).
The intermediate portion of the sole can also include a deflection
plate running along the sole from the toe to the heel. The deflector plate
preferably has a first side directed towards the outer portion, this side havingan angled surface designed to deflect the effect of an explosive blast away
from the foot. The deflector plate can be comprised of a composite aramid
fibres and carbon fibres embedded in an adhesive/polymer. The ratio of
aramid to carbon fibres in the composite is preferably 50:50 with the strands
of the fibres being approximately 85% unidirectional along the toe-to-heel
axis of the boot.
The sole can include an upper portion which comes into contact with
the foot of the wearer. The upper portion can be fabricated from chopped
aramid and nylon fibre board. In another embodiment, the upper portion can
comprise at least four layers of woven aramid adhered with adhesive/polymer
such as nylon.
The boot upper is preferably fabricated from leather and can have an
outer leather layer and an inner vamp layer of leather or cotton between
which the portion of the cocoon extending through the upper is positioned.
Stitching can be used to retain the layers constituting the cocoon in
place in the footwear. The stitching is preferably comprised of woven aramid
yarn. To ensure adequate strength is provided by the stitching, further layers
of woven aramid fibres (such as Twaron~2040) can be inserted in the
intermediate portion of the sole. Preferably, a layer of aramid fibres is
present above and below the at least one woven aramid layer in the
~ intermediate portion, with the additional layers extending at least partially into
the upper of the boot.
The boot is preferably shaped so as to enclose at least the ankle of a
wearer thus affording a level of protection for the ankle and the lower portion
of the leg.

CA 022~64~4 1998-11-20
WO 97/43919 PCT/SG97/00010
Brief Descriotion of the Drawinqs
Hereinafter given by way of example only, preferred embodiments of
the invention are described with reference to the accompanying drawings, in
which:
Figure 1 is a vertical cross-sectionat view of the boot according to the
present invention;
Figure 1A is a vertical cross-sectional view of the cocoon present in
the boot depicted in Figure 1;
Figure 2 is an enlarged and simplified cross-sectional view of the mid-
boot region along line ll-ll of the boot depicted in Figure 1; and
Figure 3 is a vertical cross-sectional view of an alternative
embodiment of a cocoon that surrounds a boot.
Descriotion of the Preferred Embodiment
A boot having the features of a preferred embodiment of the present
invention is generally depicted as 10 in Figures 1 and 2. The boot 10 has a
standard shaped upper 11 adapted to enclose at least the foot and ankle of a
wearer, a composite sole 12 and a cocoon of blast-resistant material 13 in
the shape of a bootee (see Fig. 1A).
As is depicted in Figures 1 and 2, the blast-resistant layers 18 and 19
can extend throughout the entire upper 1 1 by including layers 18 and 19
between the outer leather layer 25 and the inner vamp leather layer 26 in the
upper quarter of the upper 11. These layers can be connected to the layers
in the bootee portion 13 by appropriate stitching 30.
The composite sole comprises an outer polyurethane sole 14 having a
tread 17, an intermediate sole portion 15 and an upper sole portion 16.
The cocoon 13 consists of at least one layer of ceramic or
ceramiclglass-ceramic woven composite fibre making up the outer cocoon 19
and at least one layer of aramid weave 18. The aramid weave 18, in this
embodiment, comprises at least one-ply of at least 1000 dtex aramid having
a satin or plain weave ~eg Twaron~ 2010). The layers 18 and 19 surround
the foot of a wearer of the boot 10 and once placed in the boot 10 are
embedded in the upper boot portion 11 and between the outer sole 14 and
the intermediate sole 1 5 .
' '' - T ---

CA 022~64~4 1998-11-20
WO 97/43919 PCT/S~97/00010
To improve the blast resistance of the sole 12, the intermediate sole
15 has a plurality of layers of woven aramid fibre 21 and carbon fibre 22
embedded in the polyurethane. A deflector plate 23 also extends from the
toe to the heel of the sole 12 and further serves to strengthen the sole 12.
5 The deflector plate 23 has an angled lower surface 24, the angle of the
surface 24 being adapted to deflect the effect of an explosive blast away
from the foot of a wearer of the boot 10. The deflector plate 23 is
comprised of a composite 50:50 woven aramid fibre and carbon fibre
embedded in adhesive/polymer.
The boot upper 11 is fabricated from an outer leather layer 25 and an
inner vamp leather layer 26. The cocoon 13 is supported between the layers
25 and 26.
To hold the various layers together, stitching 27 through the side of
the boot can be employed as depicted in the drawings. The stitching 27 can
be comprised of woven aramid fibres (eg. 420 dtex aramid) and/or polyester.
To improve the strength of the stitching, two further layers 28 and 29 of
aramid fibres are inserted in the intermediate portion 15 of the sole and
extend into the upper 11 as depicted in Figure 2.
A boot having the features described above will be effective in
providing protection from explosions of anti-personnel mines containing at
least 60 grams and possibly 80 grams of pressed compound B explosive.
An alternative embodiment of the invention is depicted in Figure 3. In
this embodiment, the standard army boot 40, having a sole 46, is surrounded
by an outer cocoon 41 into which the boot 40 has been placed. The cocoon
has the features of the cocoon 13 described above except rather than fitting
- within the boot, the cocoon 41 surrounds the boot and provides a quick and
relatively inexpensive means of improving the blast-resistance of standard
army boots. In the embodiment of the cocoon depicted in Figure 3, the
- cocoon 41 has a sole 42 and an upper 43, the upper having an inner surface
47 and an outer surface 48. Embedded within the sole 42 and upper 43 is at
least one layer of ceramic or glass-ceramic fibre 45 and a layer of woven
aramid weave 44. If desired, the sole 42 can have a plurality of layers of
woven aramid fibre, preferably 4 layers, together with polymers, such as

CA 022~64~4 l998-ll-20
WO 97/43919 PCT/SG97/00010
nylon and/or carbon fibre embedded therein. A deflector plate, as described
above, could also be incorporated into the sole 42.
The cocoon 41 could be strapped to the boot 40 by straps 49 as
depicted in Figure 3. Alternative means of attachment could be employed as
5 desired.
It will be appreciated by persons skilled in the art that numerous
variations and/or modifications may be made to the invention as shown in the
specific embodiments without departing from the spirit or scope of the
invention as broadly described. The present embodiments are, therefore, to
10 be considered in all respects as illustrative and not restrictive.

Representative Drawing