[0001] The present invention relates to a footwear assembly for forming at least part of
an upper assembly of footwear, as well as to an upper assembly of footwear comprising
such footwear assembly. Moreover, the present invention relates to footwear comprising
such footwear assembly.
[0002] Protective clothing articles are used for wear in outdoor conditions like wet conditions
(such as rain, snow, wind, cold etc.), in outdoor activities (such as skiing, biking,
hiking, etc.) and should protect the wearer by preventing leakage of water or other
fluids into the article while keeping the wearer comfortable by allowing perspiration
to evaporate from the wearer to the outside of the article. In addition, such an article
should maintain the functional attributes of protection and comfort during ordinary
use.
[0003] Where flexibility of movement is essential, elastic or stretchable fabric laminates
with the above functional attributes are needed along with soft and drape able feeling..
A variety of attempts have been made to improve elastic, breathable laminated and
composite fabrics. Although, improvements have been made, many of these fabrics obtain
varying degrees of waterproofness, breathability, elasticity, elastic-recovery, and
comfort.
[0004] Thus, there remains a need for a composite that achieves a high degree of waterproofness,
breathability, elasticity, elastic-recovery, and comfort by in use within a variety
of applications, including footwear
[0005] In footwear, a particular requirement exists in that footwear should be easy to don
(to put on), as well as it should be as easy to doff (or to take off) the footwear.
Therefore, footwear should be designed such as to only loosely fit to the foot of
a person when donning or doffing the footwear. Nevertheless, it is required that footwear
fits the foot of a person after it has been donned and is subject to extended load
during use. Usually, this contradicting requirement is solved by use of dedicated
closing systems, particularly lacing systems. Velcro's and/or zippers are frequently
used as well, either in addition or alternative to laces. There is particularly a
problem with respect to children's footwear, since younger children typically are
not able to handle more complicated procedures required to don or doff footwear, like
putting on laces. Zippers or Velcro's are usually used in children's footwear as an
alternative to laces, since they are easier to handle. However, none of these systems
is really satisfying. While there exist footwear designs without any laces or zippers
(e.g. Chelsea boots), donning or doffing of such footwear usually demands great skills
and requires application of substantial forces. Thus, such footwear designs are far
from practical solutions to be handled by children.
[0006] Therefore, there exists a demand for footwear which is flexible enough so it can
be donned and/or doffed without the need to manipulate any laces or comparable systems,
but still is flexible enough to fit the foot of a wearer during use.
[0007] Embodiments disclosed herein provide for a footwear assembly configured to form at
least part of an upper assembly of footwear. The footwear assembly defines an instep
opening and comprises a water vapor permeable and waterproof functional layer having
a first elasticity, and a collar layer attached to the water vapor permeable and waterproof
functional layer such as to define at least part of the instep opening, the collar
layer having a second elasticity.
[0008] As used herein the instep opening is considered to be an opening of footwear configured
for insertion of a foot when putting on (or donning) the footwear and/or when taking
off (doffing) the footwear. The wearer's foot has to be inserted through the instep
opening when donning the footwear, and the wearer's foot has to be taken out again
through the same instep opening when doffing the footwear. This requires the portion
of the footwear assembly defining the instep opening to be able to adjust the instep
opening size. A loose fit where the instep opening does not hinder the movement of
the wearer's foot through the instep opening is required for donning or doffing the
footwear. A close fit around the ankle of the foot is desirable during use of the
footwear when the footwear is subject to extended load and thus should closely fit
the wearer's foot in the region around the ankle in order to guarantee stable support
of the foot, comfort, and particularly avoid blisters. While conventionally the size
of the instep opening is designed such as to be adjustable by use of lacing systems,
zippers, Velcros, or the like, the present invention suggests a different approach
based on providing elasticity or stretch ability of the footwear assembly in the portions
comprising the instep opening and the regions adjacent to these portions, particularly
the regions adjacent the ankle of the foot when the footwear is in use. As suggested
herein, the footwear assembly is provided with suitable elasticity or stretchability
in these portions, such as to allow the instep opening to adjust itself according
to the different requirements when donning and/or doffing the footwear, on the one
hand, and during use when the footwear assembly should fit to the wearer's foot in
the regions adjacent the ankle of the foot, on the other hand. The suggested configuration
particularly allows to achieve the desired flexibility of the footwear assembly without
having to apply large forces for donning and/or doffing, even though water vapor permeable
and waterproof functional layers are used, which are known to have only limited elasticity
properties or stretchability. Using the structure suggested herein it is possible
to achieve sufficiently good elasticity in the portions of the footwear assembly comprising
the instep opening and being adjacent to the ankle of the foot in use, even when functional
layer laminates with only limited elasticity properties or stretchability are used.
This allows to don or doff the footwear without the need to apply great skills and
large forces, and thus footwear designed according to the invention may be donned
and doffed even by children without any aid.
[0009] Throughout this disclosure the terms elasticity and stretchability are used equivalently
referring to the ability of a material to elongate in response to a tensile force
applied to it and to recover at least partly towards the original shape once the tensile
force is no longer applied.
[0010] Footwear designed as suggested herein may still be provided with laces and/or zippers.
However, it is no longer necessary to manipulate these for donning and/or doffing
the footwear. Rather, laces and/or zippers may have mere aesthetic function.
[0011] Elasticity or stretchability of the functional layer as well as of the collar layer,
and any other layer mentioned herein, may be measured according to DIN EN 14704-1
(July 2005), method A. The test may carried out as set out therein, while using test
samples of the following configuration: Test sample width = 25 mm, test sample testing
length = 50 mm (testing length refers to the free length of the test sample in between
the clamps on its opposite side), whole length of test sample = 100 - 150 mm. The
test sample is subject to 5 consecutive test cycles. In each test cycle, the test
sample is subject to a constant tensioning force of 7.5 N, and the maximum elongation
E of the test sample is measured. Otherwise, test conditions are as set out in DIN
EN 14704-1 (July 2015), method A. A test sample is considered elastic in case it achieves
a maximum elongation E compared to its original length of at least 6 mm at the end
of the 5th test cycle. More preferably, a test sample may achieve a maximum elongation
E of at least 8 mm, at the end of the 5th test cycle. Even more preferably, a test
sample may achieve a maximum elongation E of at least 10 mm, at the end of the 5th
test cycle. In all cases, the test sample is required to have at least 80 % recovery,
measured 30 min after release of the tensioning force. Recovery refers to the remaining
elongation C according to DIN EN 14704-1 (July 2015). When relaxing the tensioning
force after the end of the 5th test cycle, the test sample recovers to a remaining
elongation C according DIN EN 14704-1 (July 2015). A test sample has at least 80 %
recovery in case the remaining elongation C is at most equal to 20 % of the maximum
elongation measured according to DIN EN 14704-1 (July 2015). For example, in case
the maximum elongation E of a test sample at 7.5 N is 6 mm, a remaining elongation
C ≤ 1.2 mm is required. In particular embodiments, a recovery of even 90% or more
after 30 min may be achieved.
[0012] The water vapor permeable and waterproof functional layer is required to have a first
elasticity in at least one direction, e.g. in machine direction. In such case, it
will be advisable to orient the functional layer such that the elasticity direction
is in the direction where most elongation is needed when donning or doffing the footwear.
In case the water vapor permeable and waterproof functional layer has a first elasticity
in more than one direction (e.g. in machine direction and in transverse direction),
it may be convenient to define the first elasticity with respect to the main direction
of elasticity, i.e. to the direction in which the elasticity of the water vapor permeable
and waterproof functional layer is largest, but this is not always required. In particular
embodiments, the water vapor permeable and waterproof functional layer may have the
configuration of a quarter section of an upper assembly. In further embodiments, the
water vapor permeable and waterproof functional layer may have the configuration of
a whole upper lining of an upper assembly or a bootie, except the portions around
the instep opening formed by the collar layer. In even further embodiments, the water
vapor permeable and water-proof functional layer may also include a shaft bottom layer,
or the whole bootie, except the portions around the instep opening formed by the collar
layer. In particular embodiments, the water vapor permeable and waterproof functional
layer may further have the configuration of a tongue portion.
[0013] Also, the collar layer is required to have a second elasticity in at least one direction,
e.g. in machine direction. Again, it will be advisable to orient the collar layer
such that its elasticity direction is in the direction where most elongation is needed
when donning or doffing the footwear. Frequently, the collar layer may have a second
elasticity in more than one direction (e.g. elasticity in machine direction and in
transverse direction, or elasticity in weft direction and in warp direction of the
knit or woven fabric from which the collar layer is made). In these cases it may be
convenient to define the second elasticity with respect to the main direction of elasticity,
i.e. to the direction in which the elasticity of the collar layer is largest.
[0014] It may also be convenient to define the first elasticity and the second elasticity
in the same direction. For example, it may be convenient to define the first elasticity
and the second elasticity both in the direction where the most elongation is needed
when donning or duffing a footwear.
[0015] The collar layer does not have to be waterproof. Neither does the collar layer have
to be water vapor permeable. In most cases, the collar layer may be water vapor permeable,
but not waterproof. This allows to make the collar layer from a highly elastic material,
and particularly from a material having elasticity in more than one direction, e.g.
in weft and warp direction. Combination of the water vapor permeable and waterproof
functional layer laminate with the collar layer allows to use a water vapor permeable
and waterproof functional layer laminate of only limited elasticity, while still allowing
sufficient donning/doffing capability, particularly donning/doffing without manipulating
any laces, zippers, or the like, and without requiring much forces and skills, due
to the elastic properties of the collar layer. Most elastic functional layer laminates
have elastic properties in only one direction. This limited elasticity of the waterproof
and water vapor permeable functional layer may be compensated for by selection of
a highly elastic collar layer material, particularly a material having elasticity
in at least two directions, and appropriate arrangement of the collar layer around
the instep opening where most stretchability is needed.
[0016] The donning and/or doffing characteristics of the footwear assembly will be determined
mostly by the collar layer and the second elasticity thereof. Therefore, usually the
second elasticity may be equal to, or larger, than a predetermined threshold. In embodiments,
the second elasticity may be required to fulfil at least one of the above mentioned
thresholds, when measured according to DIN EN 14704-1 (July 2015).
[0017] Except for cases where a highly elastic water vapor permeable and waterproof functional
layer is used, the collar layer may have a second elasticity equal to, or larger,
than the first elasticity. As mentioned before, when comparing the first elasticity
and the second elasticity, it may be convenient to measure the first elasticity and
the second elasticity in the same direction.
[0018] To provide sufficient extension of the instep opening when donning or doffing the
footwear, the collar layer may extend along at least 30% of circumference of the instep
opening, in particular at least 60% of circumference of the instep opening; in particular
at least 2/3 of the circumference of the instep opening. With any of these embodiments,
the collar layer does not necessarily have to extend around a contiguous section of
the circumference, but may extend around a number of circumference pieces, separated
by non-elastic portions comprising a water vapor permeable and waterproof functional
layer, or not. In a number of particular embodiments, the collar layer may extend
between 30 % and 60 % of the circumference of the instep opening. In a number of particular
embodiments, the collar layer may extend between 30 % and 2/3 of the circumference
of the instep opening (upper boundary not included), in particular between 60 % and
2/3 of the circumference of the instep opening (upper boundary not included). In a
number of particular embodiments, the collar layer may extend along 90% of the circumference
of the instep opening, in some embodiments even along the full circumference of the
instep opening.
[0019] In embodiments the collar layer may be attached to the water vapor permeable and
waterproof functional layer by means of a seam. In order not to compromise elasticity
of the collar layer and/or the water vapor permeable and waterproof functional layer,
the seam may have the configuration of an elastic seam. For example, the elastic seam
may be formed by a thread having a third elasticity. Elastic threads are widely used
in the art for providing elastic seams. For example, threads comprising, or even made
of, Lycra or Elasthan, are frequently used. As an alternative, or in addition using
an elastic thread the elastic seam may be formed by a stitch pattern providing elastic
characteristics, like a zig-zag stitch. A zig zag stich has elastic characteristics
by itself such that in this case a thread made of non-elastic material may be used.
In most embodiments, the elastic seam may extend along any portion where the water
vapor permeable and waterproof functional layer and the collar layer abut each other.
At least, the elastic seam may extend along at least 30% of the circumference of the
instep opening. In a number of particular embodiments, the elastic seam may extend
along 60%, along 2/3, or even along 90% of the circumference of the instep opening,
in some embodiments even along the full circumference of the instep opening.
[0020] As mentioned before, usually it will make sense if the elastic seam will extend at
least along any contact region where the water vapor permeable functional layer and
the collar layer are attached to each other around the instep opening. The elastic
seam may extend further than these contact regions, but this is not necessary. The
elastic seam may extend along only a part or parts of the contact region, in case
the collar layer extends along more than 2/3 of the circumference of the instep opening.
However, the elastic seam should extend along at least 2/3 of the circumference of
the instep opening in such embodiments. In case the collar layer extends along at
least 60 % of the circumference of the instep opening, it is possible that the elastic
seam may extend along only a part or parts of the contact region. However, the elastic
seam should extend along at least 30 % of the circumference of the instep opening
in such embodiments. Even in case the collar layer extends along at least 30 % of
the circumference of the instep opening, it is possible that the elastic seam may
extend along only a part or parts of the contact region. However, the elastic seam
should extend along at least 30 % of the circumference of the instep opening in such
embodiments.
[0021] As mentioned above, normally it will be convenient to measure the first elasticity
and the second elasticity in the same direction. Typically, the direction in which
the first elasticity and the second elasticity are measured will correspond to the
direction where most elongation is required when donning of doffing the footwear.
For most footwear designs, the direction where most elongation is required for donning
or doffing the footwear is roughly in the horizontal direction, between the heel and
the toe, and thus the first elasticity and the second elasticity may be measured in
a direction parallel to the horizontal direction. The horizontal direction usually
extends parallel to the plane of the tread of the shoe which contacts the ground in
use. Parallel as used herein may include an angular range of at most ± 25 degrees
with respect to the horizontal direction, particularly at most ± 15 degrees with respect
to the horizontal direction, particularly at most ± 10 degrees with respect to the
horizontal direction.
[0022] When the water vapor permeable and waterproof functional layer and the collar layer
are attached to each other via a seam, it may be conceivable that the first elasticity
and the second elasticity are measured in direction parallel the seam. Parallel as
used herein may include an angular range of at most ± 25 degrees with respect to the
seam, particularly at most ±15 degrees with respect to the seam, particularly at most
± 10 degrees with respect to the seam. The seam may be oriented parallel to the direction
in which most elongation is required during donning or doffing.
[0023] Particularly, a composite sample piece made of the water vapor permeable and waterproof
functional layer and the collar layer attached to each other by a seam may have a
fourth elasticity. The fourth elasticity may be equal to, or larger, than a predetermined
threshold. The fourth elasticity may be required to fulfil at least one of the above
mentioned thresholds, when measured according to DIN EN 14704-1 (July 2015). The fourth
elasticity may be equal to, or larger, than the first elasticity. The fourth elasticity
may even be equal to, or larger than, the second elasticity. In this way, the seam
connecting the water vapor permeable and waterproof functional layer and the collar
layer is sufficiently elastic to avoid compromising the elasticity of the water vapor
permeable and waterproof functional layer or the elasticity of the collar layer. As
mentioned such elasticity can be provided by using an elastic seam configuration,
e.g. a zig-zag stitch and/or using an elastic thread.
[0024] The fourth elasticity may measured in the same way as the first elasticity, i.e.
according to DIN EN 14704-1 (July 2015), method A. The test sample for measuring the
fourth elasticity has the same overall dimensions: width = 25 mm, test length = 50
mm, whole length of sample 100 - 150 mm. The first functional layer and the collar
layer cover half of the area of the test sample and are attached to each other along
a linear seam extending in the longitudinal direction of the test sample.
[0025] Otherwise, the test conditions apply as set out above with respect to the first elasticity:
The test sample is subject to 5 consecutive test cycles. In each test cycle, the test
sample is subject to a constant tensioning force of 7.5 N, and the maximum elongation
E of the test sample is measured. A test sample is considered elastic in case it achieves
a maximum elongation E of at least 6 mm at the end of the 5th test cycle. More preferably,
a test sample may achieve a maximum elongation E of at least 8 mm, at the end of the
5th test cycle. Even more preferably, a test sample may achieve a maximum elongation
E of at least 10 mm, at the end of the 5th test cycle. The test sample is required
to have at least 80 % recovery, measured 30 min after the tensioning force has been
released. Recovery refers to the remaining elongation C according DIN EN 14704-1 (July
2015). In particular embodiments, a recovery of even 90% or more after 30 min may
be achieved.
[0026] The water vapor permeable and waterproof functional layer may have the configuration
of a laminate made up with a water vapor permeable and waterproof membrane and at
least one textile layer attached to the water vapor permeable and waterproof membrane.
Such laminates are principally known in the art, e.g. from
US 5,804,011 which discloses a fabrics being stretchable in two dimensions. The textile layer
may have an elastic textile configuration, e.g may be made as a knit having an elastic
knit pattern (like a tricot, warp knit, or similar knit pattern). In such case the
textile need not necessarily include elastic threads to provide the desired elastic
characteristics. However, in a number of configurations, it may be helpful if the
textile layer comprises elastic filaments, e.g. made from elasthane, to further enhance
the elasticity of the textile layer.
[0027] The water vapor permeable and waterproof functional layer may include a water vapor
permeable and waterproof membrane. The membrane may be selected from polyurethane,
polyester, polyether, polyamide, polyacrylate, copolyether ester and copolyether amides,
as well as other suitable thermoplastic and elastomeric films. In an aspect of the
invention the waterproof, water vapor permeable membrane may be made of a fluoropolymer,
particularly made of microporous expanded polyterafluorethylene (ePTFE). The microporous
polytetrafluoroethylene membrane is a membrane of expanded polytetrafluoroethylene
as taught in
U.S. Pat. Nos. 3,953,566 and
4,187,390, to Gore. Such membranes of expanded polytetrafluoroethylene are present in commercially available
laminates from W. L. Gore and Associates, Inc., Elkton, Md., under the tradename GORE-TEX®
fabric. The water vapor permeable and waterproof functional layer may be composed
of a polyurethane coated microporous expanded polytetrafluoroethylene membrane made
substantially according to the teachings of
U.S. Pat. No. 4,194,041 and
U.S. Pat. No. 4,942,214 assigned to W.L. Gore and Associates, Inc, in Elkton, Md.
[0028] The collar layer may be a water vapor permeable and waterproof functional layer as
well, but this is not a requirement. Normally, the collar layer will not be a water
vapor permeable and waterproof functional layer. Rather, the collar layer may have
any desired configuration, given it provides for the required elasticity characteristics.
In some embodiments, the collar layer may be waterproof.
[0029] In some embodiments, the footwear assembly as described above may have the configuration
of an upper lining. As an upper lining, the footwear assembly is attached to the inner
side of an upper material from which an upper assembly of a footwear article is made.
In some embodiments, the upper lining may have the configuration of a water vapor
permeable and waterproof sock. Such a sock is also referred to in the art as a "bootie".
A bootie comprises an upper lining surrounding the upper side of a person's foot as
well as an upper bottom on which the sole of a person's foot rests. As such, the bootie
is an independent lining structurally separate from an upper material or an assembly
insole of the footwear article. In the course of manufacturing the footwear, the bootie
is inserted into the upper assembly such as to abut the inner side of the upper material
and the upper side of an assembly insole. The bootie may be fixed to the upper material
and/or to the assembly insole, but otherwise is independent of the upper material
and/or the assembly insole.
[0030] In some embodiments, the footwear assembly may have the configuration of a water
vapor permeable and waterproof upper lining to be attached to an upper bottom. Different
from a bootie, the upper lining according to such configuration does not include an
upper bottom, but only includes an upper lining surrounding the upper part of the
foot. In the course of manufacturing the footwear, the upper lining is to be closed
on its bottom side by an upper bottom. The upper bottom may be waterproof, if desired
water vapor permeable and waterproof. For example, the upper lining may attached to
upper bottom by lasting using a lasting glue. Alternatively, upper lining may be attached
to upper bottom by way of a strobel seam. Upper lining may attached to upper bottom
directly, or via an intermediate element, e.g. a sealing band or a netband. When a
netband is used, a waterproof seal may be obtained by injection molding of plastics
material, e.g. during assembly of a sole to the upper assembly.
[0031] In particular embodiments of the footwear assembly the water vapor permeable and
waterproof functional layer may extend up to a height of at least 20 % of the height
of the footwear assembly. In some embodiments, the water vapor permeable and waterproof
functional layer may extend up to a height between 20 % of the height of the footwear
assembly and 65 % of the height of the footwear assembly (upper boundary not included).
Particularly, the water vapor permeable and waterproof functional layer to a height
of at least 65 % of the footwear assembly, more in particular 90% or even up to a
height of at least 95 % of the footwear assembly. Such configuration is particularly
helpful in embodiments where the collar layer is not waterproof or where the collar
layer is waterproof, but not breathable. In case of a non-waterproof collar layer,
the higher the water vapor permeable and waterproof functional layer extends, the
better will be waterproofness of the footwear article. In case of a waterproof, but
non-breathable collar layer, the higher the water vapor permeable and waterproof functional
layer extends, the better will be the water vapor permeability of the footwear article.
[0032] In particular embodiments of the footwear assembly the collar layer may comprise
elastic extensions on its side opposite the water vapor permeable functional layer.
These extensions may be configured to be folded over and attached to an upper material
layer, such as to form an elastic backing layer covering openable portions, tongue
portions and/or gusset portions of the upper material layer. In such configurations,
the collar layer may be folded over at the periphery of the instep opening such that
the extensions extend from the instep opening downwards. The downwards extending portions
might be attached to the inner side of the upper material layer and thereby allow
to cover any openable portions in the upper material layer by an elastic layer on
the inner side. This is a particularly elegant design to cover openings or slits in
the upper material, which would otherwise have to be covered by some flexible material.
In one example gusset portions required laterally from a tongue in conventional footwear
designs might be replaced completely by such folded over extensions of the elastic
collar layer. The same applies to any portions in the upper material layer where zippers
are provided. The slits in the upper material being created when the zipper is opened
might be easily backed by the elastic material of the folded over extensions of the
collar layer.
[0033] Any of the embodiments of a footwear assembly described above may be used in the
manufacturing of an upper assembly of footwear. The upper assembly may comprise an
upper material layer surrounding at least an upper portion of a foot, and the footwear
assembly according to any of the previous embodiments. The footwear assembly as described
above may form an upper lining arranged on an inner side of the upper material layer,
the upper lining being independent of the upper material to such extent that the upper
lining at least in the region of the water vapor permeable and waterproof functional
layer and the elastic collar is able to adapt its shape independently of the upper
material layer. Hence, the upper material can be designed such as to only loosely
fit to the foot, particularly in the regions adjacent to the instep opening and the
regions around the ankle of the foot, without compromising comfort or stability of
the foot in use. This allows a simple donning or doffing of the footwear, even in
case upper materials with poor elasticity are used, without compromising stability
and comfort to the person wearing the footwear.
[0034] The upper material layer and/or the upper lining layer may be configured to be attached
to an upper bottom layer in such a way as to form a waterproof and water vapor permeable
upper assembly.
[0035] In embodiments, the upper material layer may comprise at least one openable portion,
tongue portion and/or gusset portion, and the collar layer of the upper lining layer
may comprises elastic extensions on its side opposite the water vapor permeable functional
layer. The extensions may be folded over and may be attached to the upper material
layer on an inner side thereof. Thereby, the extensions of the collar layer may form
an elastic backing layer covering the at least one openable portion, tongue portions
and/or gusset portions of the upper material layer, as described in detail above.
[0036] The invention will be described in more detail in the following by way of exemplary
embodiments which are sown in the figures. These show:
Fig. 1 shows a highly simplified and schematic view of a footwear assembly having
the configuration of a water vapor permeable and waterproof functional layer bootie
for a low cut shoe;
Fig. 2 shows a highly simplified and schematic view of a footwear assembly having
the configuration of a water vapor permeable and waterproof functional layer bootie
for a mid cut shoe;
Fig 3 shows a highly simplified and schematic view of a footwear assembly having the
configuration of a water vapor permeable and waterproof functional layer bootie for
a high cut shoe;
Fig. 4 shows a highly simplified and schematic view of a footwear assembly having
the configuration of a water vapor permeable and waterproof functional layer bootie
for a mid cut shoe with an upper material layer attached to the footwear assembly;
Fig. 5 shows a highly simplified and schematic view of the footwear assembly of Fig.
4 in a view from the from tip of the footwear; and
Fig. 6 shows a highly simplified and schematic view of a mid cut footwear comprising
the footwear assembly of Figs. 4 and 5, in a completed state.
[0037] Figs. 1 to 3 show highly simplified and schematic views of a footwear assembly 10
having the configuration of a water vapor permeable and waterproof functional layer
bootie. Fig. 1 shows a bootie for a low cut shoe. Fig. 2 shows a bootie for a mid
cut shoe, and Fig. 3 shows a bootie for a high cut shoe. The following considerations
relate to all embodiments shown in Figs. 1 to 3, unless explicit reference is taken
to only one of the Figs.
[0038] The footwear assembly 10 (bootie) comprises a water vapor permeable and waterproof
functional layer laminate 12, as described above, and a collar layer 14. The collar
layer 14 is attached to the functional layer laminate 12 such as to form an upper
portion of the footwear assembly 10 and surrounding an instep opening 8. The collar
layer 14 is attached to the water vapor permeable and waterproof functional layer
laminate 12 by an elastic seam 18. The collar layer 14 is made from an elastic fabric
having elasticity in two dimensions, namely the warp and weft directions of the fabric.
The collar layer 14 is made from a fabric having required elastic characteristics
to allow easy donning and doffing, particularly applying only moderate forces and
not requiring to open any laces or zippers. However, the collar layer 14 is not waterproof.
[0039] The water vapor permeable and waterproof functional layer 12 is a laminate formed
by a water vapor permeable and waterproof membrane and a textile layer attached to
the water vapor permeable and waterproof membrane. The water vapor permeable and waterproof
functional membrane may be made from expanded PTFE which is attached to a supporting
textile layer according to the teaching of
US 5,804,011. The microporous polytetrafluoroethylene membrane is a membrane of expanded polytetrafluoroethylene
as taught in
U.S. Pat. Nos. 3,953,566 and
4,187,390, to Gore. The water vapor permeable and waterproof functional layer may be composed of a polyurethane
coated microporous expanded polytetrafluoroethylene membrane made substantially according
to the teachings of
U.S. Pat. No. 4,194,041 and
U.S. Pat. No. 4,942,214 assigned to W.L. Gore and Associates, Inc, in Elkton, Md..The membrane may also be
made of polyurethane (PU), polyether ester (PES), polyethylene or combinations of
these materials.
[0040] Water Vapor Permeability (WVP) as used herein concerning the functional layer may
be tested as defined in EN ISO 15496 (2004), also known as the "Cup Test". A 20 x
20cm or Ø 100mm sample of functional layer or functional layer laminate is placed
onto a container containing water and covered with a membrane. Then a cup containing
potassium acetate and being covered by the same membrane is placed on the sample.
Water vapor passes through the functional layer into the cup, whose weight increase
is then determined. The functional layer is considered water vapor permeable or breathable
if the WVP is greater than or equal to 0,01 g/ (Pa*m
2*h). If the required size of the sample cannot be obtained, a smaller sample may be
used for the measurement using a smaller cup containing half the amount of potassium
acetate specified in the Norm, i.e. 50g instead of 100g and mixed with 15,6g of water.
In case a smaller cup is used, the applied area in the calculation needs to be adjusted,
accordingly.
[0041] A functional layer may be considered waterproof in case a 100 cm
2 sample of the material under investigation is able to withstand a water ingress pressure
of at least 0.05 bar. Particularly, the material may even withstand a water pressure
of at least 1 bar. The method for carrying out this test is described in the ISO Standard
No. 811 (1981) (EN 20811 (1992)). The measurement is carried out by exposing a 100
cm
2 sample of the material under investigation to a rising water pressure. For this purpose,
distilled water having a temperature of 20±2°C is used. The rise in the water pressure
is 60±3 cm H
2O/min. The water ingress pressure of the sample under investigation is that pressure
at which water passes through the opposite side of the sample under investigation.
If a 100 cm
2 sample cannot be obtained, a smaller sample may be used for the measurement. There
is a linear correlation between sample size and water ingress pressure, so that the
water ingress pressure may be calculated for a 100 cm
2 sample.
[0042] The water vapor permeable and waterproof membrane is attached to a textile layer
in such a way that the water vapor permeable and waterproof functional layer 12 has
the configuration of an elastic laminate having at least one direction of elasticity,
usually in the machine direction. In some configurations, the water vapor permeable
and waterproof functional layer may have elasticity in two directions, as shown in
US 5,804,011, for example. To impose elastic characteristics to the laminate, the textile layer
may have an elastic textile configuration, e.g may be made as a knit having an elastic
knit pattern (like a tricot, warp knit, or similar knit pattern). In such case the
textile need not necessarily include elastic threads to provide the desired elastic
characteristics. However, in a number of configurations, it may be helpful if the
textile layer comprises elastic filaments, e.g. made from elasthane to further enhance
the elasticity of the textile layer. In Figs. 1 to 3, the main direction of elasticity
of the water vapor permeable and waterproof functional layer 12 is indicated by the
arrow A. The main direction of elasticity of the water vapor permeable and waterproof
functional layer 12 is directed in the direction where the most elongation and flexibility
is required when donning or doffing a footwear article with the footwear assembly
12 having the configuration of a bootie. Tests have shown that such direction of most
elongation and flexibility is the direction from the heel to the toe of the bootie
for all bootie configurations shown in Figs. 1 to 3.
[0043] In all embodiments shown in Figs. 1 to 3, the main direction of elasticity of the
functional layer laminate 12 and the main direction of elasticity of the collar layer
14 are directed parallel to the direction A in which most flexibility and elongation
is required for donning and doffing. Also the elastic seam 18 connecting the functional
layer laminate 12 with the collar layer 14 is directed parallel to such direction
A in which most flexibility and elongation is required for donning and doffing. The
elastic seam 18 has the configuration of a zig zag stitch which provided for elasticity
irrespective of whether an elastic thread is used to carry out the stitches.
[0044] There is a difference between the low cut bootie 10 shown in Fig. 1, the mid cut
bootie 10 shown in Fig 2, and the high cut bootie 10 shown in Fig. 3 with respect
to the height where the most elongation and flexibility is required when donning or
doffing. In the low cut bootie 10 (see Fig. 1), the most flexibility is required at
a height substantially equal to the height of the instep opening 8, as the bootie
only extends up to a height slightly below the ankle of the foot and roughly up to
the height of the instep of the foot. Also for the mid cut bootie 10 shown in Fig.
2, the most flexibility for donning and doffing is required at a height roughly equal
to the height of the instep of the foot. However, in this configuration, the bootie
extends up to a height slightly above the ankle of the foot, and hence the height
of maximum elongation and flexibility is at some distance below the height of the
instep opening 8. For the high cut bootie 10 shown in Fig. 3, the bootie extends up
to a height well above the ankle of the foot. In this configuration, it has turned
out that the height of maximum elongation for donning and doffing is only slightly
above the ankle of the foot, and thus is substantially lower than the height of the
instep opening 8. In all embodiments as shown in Figs. 1 to 3, the functional layer
laminate 12 extends up to such a height that the elastic seam 18 connecting the functional
layer laminate 12 and the collar layer 14 is roughly in the same height as the height
of maximum elongation when donning or doffing a footwear including the respective
bootie 10. Such configuration allows to optimally use the elasticity provided by the
collar layer 14 to provide flexibility for donning and doffing, and fit the foot in
the region around the ankle, when the footwear is used. It is however important in
such configuration that the seam 18 provides sufficient elasticity to avoid losing
the additional elasticity provided by the collar layer 14.
[0045] Moreover, the configuration of the height of the elastic seam 18 as shown in Figs.
1 to 3 allows the waterproof functional layer laminate 12 to extend up to a height
as far as possible, thereby ensuring maximum waterproofness of the footwear. This
even applies for the low cut bootie of Fig. 1, since in this configuration the functional
layer laminate may extend almost up the maximum height of the bootie (e.g. the functional
layer laminate may extend up to 90 %, or even up to 95 %, of the height of the bootie
below the instep opening 8). For the mid cut bootie of Fig. 2, the functional layer
laminate may extend up to about 70 % to 90 %, in most cases up to about 75 to 85 %,
of the height of the bootie 10 at the instep opening 8. However, in absolute height
this is still the same height, or even higher, than with the low cut bootie 10, in
any case the functional layer laminate 12 always may extend up to a height roughly
comparable to the instep of the foot. With respect to the high cut bootie 10 shown
in Fig. 3, in order to allow easy donning and doffing it is advisable to allow the
collar layer 14 to extend at a substantial vertical portion below the instep opening
8, down to a height slightly above the ankle of the foot where the maximum elongation
during donning and doffing will be required (see the constriction in the bootie cross
section visible in Fig. 3). Therefore, the functional layer laminate will extend into
much less height when expressed in relative terms with respect to the height of the
instep opening, roughly up to a height of 60 % to 80 %, particularly up to a height
of 65 % to 75 % of the height of the instep opening. However, such height is still
well above the ankle and thus provides for sufficient waterproofness.
[0046] In the embodiments shown in the Figs. 1 to 3 the footwear assembly 10 forms an upper
lining bootie to be attached to the inner side of an upper material 30 (see Figs 4
- 6) of an upper assembly. The upper lining bootie 10 has a sock shape configuration
formed by two of the water vapor permeable and waterproof functional layers 12 and
an upper bottom functional layer 22. As more clearly visible in Fig. 5 the water vapor
permeable and waterproof functional layer 12 forms one of two upper side parts 12
of the bootie 10. Both upper side parts 12, 12 are connected with each other by a
longitudinally extending seam 13 which is sealed by a seam tape (not shown). The upper
bottom layer functional layer 22 is connected to each of the two water vapor permeable
and waterproof functional layers 12, 12 also by way of seams which are sealed by respective
seam tapes (not shown).
[0047] Also visible in Figs. 1 and 2 is a tongue portion 16 formed by the collar layer 14.
The tongue portion 16 is also connected to the water vapor permeable and waterproof
functional layer laminate 12 by way of an elastic seam 20. As more clearly shown in
Figs. 4 to 6, the tongue portion 16 comprises an extension portion 26 which is folded
over at the instep opening 8 such that the folded over section 26 may be connected
to the inner side of an upper material 30, and thus forms a water gusset portion (see
particularly Figs. 4 and 5). As the material of the collar layer 14 is highly elastic,
such water gusset portions 26 allow a foldfree fit of the tongue portion 26 to the
foot at each time, including donning and doffing. Conventional water gussets, which
would lead to folds, are completely superfluous. This increases comfort.
[0048] Fig. 4 shows a highly simplified and schematic view of a mid cut footwear assembly
having the configuration of a water vapor permeable and waterproof functional layer
bootie 10 for a mid cut shoe with an upper material layer 30 attached to the footwear
assembly. Fig. 5 shows a highly simplified and schematic view of the footwear assembly
of Fig. 4 in a view from the toe portion of the footwear. Fig. 6 shows a highly simplified
and schematic view of the mid cut footwear comprising the footwear assembly of Figs.
4 and 5, in a completed state.
[0049] As can be seen in Figs. 4 to 6, the upper material layer 30 is attached to the footwear
assembly 10 in the region of the instep opening 8. Thus, it is particularly helpful
in case the collar layer 14 comprises elastic extensions 24, 26, 28 on its side opposite
the water proof and water vapor permeable functional layer 12. These extensions 24,
26, 28 are be configured to be folded over and attached to the upper material layer
30 on an inner side thereof. Thereby, the extensions 24, 26, 28 form a backing layer
covering openable portions (like the zipper portion 32 of the upper material 30 visible
in Fig. 6), tongue portions and/or water gusset portions of the upper material layer
30. In such configurations, the collar layer 14 may be folded over at the periphery
of the instep opening 8 such that the extensions 24, 26, 28 extend from the instep
opening 8 downwards. The extensions may be arranged between the upper material and
the footwear assembly. The downwards extending portions 24, 26, 28 are attached to
the inner side of the upper material layer 30 and thereby allow to cover any openable
portions in the upper material layer 30 by an elastic layer on the inner side. This
is a particularly elegant design to cover openings or slits in the upper material
30, which would otherwise have to be covered by some flexible material. E.g.water
gusset portions required laterally from a tongue in conventional footwear designs
might be replaced completely by such folded over extensions 24, 26 of the elastic
collar layer. The same applies to any portions in the upper material layer where zippers
32 are provided. The slits in the upper material being created when the zipper 32
is opened might be easily backed by the elastic material of the folded over extensions
28 of the collar layer 14.
1. Footwear assembly (10) for forming at least part of an upper assembly of footwear,
the footwear assembly (10) defining an instep opening (8) and comprising:
- a water vapor permeable and waterproof functional layer (12) having a first elasticity,
and
- a collar layer (14) attached to the water vapor permeable and waterproof functional
layer (12) such as to define at least part of the instep opening (8), the collar layer
(14) having a second elasticity.
2. The footwear assembly (10) according to claim 1, wherein the collar layer (14) has
elastic properties in more than one direction.
3. The footwear assembly (10) according to claim 1 or 2, wherein the second elasticity
is equal to, or larger, than a predetermined threshold.
4. The footwear assembly (10) according to any of claims 1 to 3, wherein the second elasticity
is equal to, or larger, than the first elasticity.
5. The footwear assembly (10) according to any of claims 1 to 4, wherein the collar layer
(14) extends along at least 30% of the instep opening (8), particularly along at least
60 % of the instep opening (8), particularly along at least 2/3 of the instep opening
(8).
6. The footwear assembly (10) according to any of claims 1 to 5, wherein the collar layer
(14) is attached to the water vapor permeable and waterproof functional layer (12)
by means of an elastic seam (18).
7. The footwear assembly (10) according to claim 6, wherein the elastic seam (18) is
formed by a thread having a third elasticity.
8. The footwear assembly (10) according to claim 6 or 7, wherein the elastic seam (18)
is formed by a stitch pattern providing elastic characteristics.
9. The footwear assembly (10) according to any of claims 6 to 8, wherein the elastic
seam (18) extends along at least 30% of the circumference of the instep opening (8),
particularly along at least 60% of the circumference of the instep opening (8), particularly
along at least 2/3 of the circumference of the instep opening (8).
10. The footwear assembly (10) according to any of claims 1 to 9, wherein the first elasticity
and the second elasticity are measured in the same direction.
11. The footwear assembly (10) according to any of claims 1 to 10, wherein the first elasticity
and the second elasticity are measured in a direction parallel to the horizontal direction.
12. The footwear assembly (10) according to claim 10 or 11, wherein the water vapor permeable
and waterproof functional layer (12) and the collar layer (14) are attached to each
other via a seam (18) and the first elasticity and the second elasticity are measured
in direction parallel the seam (18).
13. The footwear assembly (10) according to any of claims 1 to 12, wherein a composite
sample piece made of the water vapor permeable and waterproof functional layer (12)
and the collar layer (14) attached to each other by a seam (18) has a fourth elasticity,
the fourth elasticity being equal to, or larger, than a predetermined threshold.
14. The footwear assembly (10) according to any of claims 1 to 13, wherein the water vapor
permeable and waterproof functional layer (12) has the configuration of a laminate
made up with a water vapor permeable and waterproof membrane and a textile layer attached
to the water vapor permeable and waterproof membrane.
15. The footwear assembly (10) according to claim 14, wherein the textile layer has an
elastic textile configuration.
16. The footwear assembly (10) according to claim 13 or 14, wherein the textile layer
comprises elastic filaments.
17. The footwear assembly (10) according to any of claims 1 to 16, wherein the water vapor
permeable and waterproof functional layer includes a water vapor permeable and waterproof
film made of a fluoropolymer, particularly ePTFE.
18. The footwear assembly (10) according to any of claims 1 to 17, wherein the collar
layer (14) is water vapor permeable, but not waterproof.
19. The footwear assembly (10) according to any of claims 1 to 18, having the configuration
of an upper lining.
20. The footwear assembly (10) according to claim 19, having the configuration of a water
vapor permeable and waterproof sock.
21. The footwear assembly (10) according to claim 18, having the configuration of a water
vapor permeable and waterproof upper lining to be attached to a waterproof upper bottom.
22. The footwear assembly (10) according to any of claims 1 to 21, wherein the water vapor
permeable and waterproof functional layer (12) extends to a height of at least 20
% of the height of the footwear assembly (10), particularly to a height of at least
65 % of the footwear assembly (10), particularly to a height of at least 95 % of the
footwear assembly (10).
23. The footwear assembly (10) according to any of claims 1 to 22, wherein the collar
layer (14) comprises elastic extensions (24, 26, 28) on its side opposite the water
vapor permeable functional layer (12), the extensions (24, 26, 28) being configured
to be folded over and attached to an upper material layer (30), such as to form a
backing layer covering openable portions (32), tongue portions and/or gusset portions
of the upper material layer (30).
24. Upper assembly of footwear, the upper assembly comprising
- an upper material layer (30) surrounding at least an upper portion of a foot, and
- the footwear assembly (10) according to any of the previous claims, wherein the
footwear assembly (10) according any of the previous claims forms an upper lining
arranged on an inner side of the upper material layer (30), the upper lining being
independent of the upper material (30) to such extent that the upper lining at least
in the region of the first functional layer (12) and the elastic collar (14) is able
to adapt its shape independent of the upper material layer (30).
25. The upper assembly according to claim 24, wherein the upper material layer (30) and/or
the upper lining layer is configured to be attached to an upper bottom layer in such
a way as to form a waterproof and water vapor permeable upper assembly.
26. The upper assembly according claim 24 or 25, wherein the upper material layer (30)
comprises at least one openable portion (32), tongue portion and/or gusset portion,
and the collar layer (14) of the upper lining layer comprises elastic extensions (24,
26, 28) on its side opposite the water vapor permeable and waterproof functional layer
(12), the extensions (24, 26, 28) being folded over and attached to the upper material
layer (30), such as to form a backing layer covering the at least one openable portion
(32), tongue portions and/or gusset portions of the upper material layer (30).