Note: Descriptions are shown in the official language in which they were submitted.
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COMPRESSION KNITTED FABRIC AND COMPRESSION ARTICLE
PRODUCED THEREFROM
The invention relates to a knitted fabric according to the preamble of Claim
l, as
well as to a compression article produced from such a knitted fabric.
For producing compression articles, for example, compression socks or
compression
bandages, typically elastic knitted fabrics are used, which exhibit a certain
amount of
extensibility. Due to this extensibility of the elastic knitted fabric, the
compression article
applied to limbs, for example, an arm or a leg, exerts a compression pressure
on the
extremities. In this way, the compression effect exerted on the extremities is
inversely
proportional to the extensibility of the elastic knitted fabric, i.e., an
elastic knitted fabric
with low extensibility exerts a higher compression pressure than an elastic
knitted fabric
with high extensibility. Here, extensibility is understood to be the amount of
force that is
necessary to expand the knitted fabric by a certain amount.
From the state of the art, compression articles with compression effect
varying zone
by zone are already known. For example, CH 447 475-A describes a circular
knitted
compression sock with compression effect varying zone by zone, with the
differing
compression effect of each zone having the effect that the stitching of the
compression sock
contains elastic interlining threads, which have varying elasticity zone by
zone and which
are inserted into the stitching of the knitted fabric. In addition, DE 100 84
580 C2 describes
a knitted compression glove with at least one adapted region, wherein this
adapted region is
integrated seamlessly into the knitted fabric of the glove and features an
extensibility that
deviates from any adjacent parts of the compression glove. The differing
extensibility in the
individual regions is created either by the use of different types of knitted
fabrics or by the
use of threads that can be thermoset zone by zone through the use of heat.
The invention is based on the problem of providing a knitted fabric for
producing a
compression article, which has regions of different high compression, wherein
the
difference in the extensibility of the individual regions should be as high as
possible and
should be obtainable in a manner which is as simple and economical as
possible.
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This problem is solved with a knitted fabric with the features of Claim 1.
Advantageous configurations, as well as uses, of this knitted fabric follow
from the
subordinate claims. The invention is described in more detail below using
embodiments
with reference to the enclosed drawings. The drawings show:
Figure 1, schematic representation of the stitching of a knitted fabric
according to
the invention, which here is embodied as a circular knit fabric;
Figure 2, schematic representation of the stitching of a knitted fabric
according to
the invention, which here is embodied as a straight knit fabric;
Figure 3, schematic representation of a compression sock produced from a
knitted
fabric according to the invention.
Figure 1 shows the stitch pattern of a circular knit fabric according to the
invention.
The knitted fabric has a first region 1 with a certain amount of
extensibility. A second
region 2 with higher extensibility is seamlessly attached to the region 1. The
two regions 1
and 2 are stitched together. Both regions 1, 2 have a basic knit, which is
formed by a stitch
thread 3 and which is formed in the embodiment according to Figure 1 as a
right-left knitted
fabric with stitches 7 arranged in stitch rows m. Both regions 1 and [2] are
passed through
by weft threads 4. In the second region 2, in every second stitch row a weft
thread 4 is
drawn in. In the stitching cut out shown in Figure 1, these stitch rows are
the rows with the
numbering m-4, m-2, m, and m+2. In this way, every weft thread 4 is integrated
into the
basic knit formed by the stitch thread 3 in a non-stitch forming way.
Both the stitch thread 3 and also the weft threads 4 are formed from an
elastic
thread, for example, a core thread braided with polyamide, with the weft
thread 4 being
thicker than the stitch thread 3.
In the first region 1, in every second stitch row for the right-left knitted
fabric, thus
in the rows m, m+2, m-2 in the cut out shown in Figure 1, every second stitch
is left out, in
that the stitch thread 3 at the corresponding position is not formed into a
stitch but is instead
laid flat. The stitch lying under this missing position of the stitch row
underneath (in Figure
1, with regard to row m, this is the row m-1) is drawn up to the stitch row
lying above (thus
the row m+1) and there stitched into this stitch row m+1. The stitches
elongated in this way
are characterized in Figure 1 with reference symbol 8. Likewise, the weft
thread 4 also in
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the stitch row m in the first region 1 is pulled together with the stitch
thread 3 of the stitch
row m-1 lying underneath into the stitch row m+1 lying above and there
integrated into this
stitch row but not stitched.
Due to this different integration of the weft threads 4 into the regions 1 or
2, these
regions exhibit different amounts of extensibility relative to each other. The
extensibility of
each region is namely determined essentially by the extensibility of the drawn-
in weft
thread 4. In the second range with higher extensibility, the weft thread has a
relatively small
free length, i.e., the weft thread 4 is integrated over a considerable region
of its length
between the stitches. In contrast, the free length of the weft thread 4 in the
first range 1 is
significantly larger, i.e., the weft thread 4 there has significantly larger
lengths, which are
not bound into a stitch. That is because the weft thread 4 in the first region
1 is drawn up by
a stitch in a stitch of the stitch row lying above, that is, into an elongated
stitch 8. In the
region between the stitch row m and the stitch row m+1 lying above, in which
the weft
thread 4 is drawn up, this lies free and is freely movable in this length
range. Therefore, the
knitted fabric in the first region 1 can be more easily extended than in the
second region 2.
The boundary line G, which separates the two regions 1 and 2 from each other,
here runs
essentially perpendicular to the weft thread 4.
As an alternative to the embodiment shown in Figure 1, instead of every second
stitch, every nth stitch in every stitch row m can be let out, with n > 3,
i.e., every third or
every fourth, etc., stitch in every stitch row m can be missing and the stitch
of the
underlying stitch row m-1 under this missing point can be pulled up to the
stitch row m+1
above.
In Figure 2, the stitch pattern of a flat knitted fabric is shown according to
the
invention. The flat knitted fabric is assembled according to the invention, in
turn, from a
first region 1 with low extensibility and a second region 2 with higher
extensibility
connected seamlessly to this first region. In both regions 1 and 2, a basic
knit with right
stitches r and left stitches 1 is formed by a first stitch thread 3. The
stitch thread 3 is hereby
assembled from a main thread 3a and a thin plaiting thread 3b. The main thread
3a consists
of a thin elastic thread, for example, a spandex thread, which is braided with
polyamide.
The plaiting thread 3b is formed by a polyamide thread.
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In the second region 2 (which, in Figure 2, lies on the left side of the
stitch pattern in
contrast to the representation of Figure 1 ), in each stitch row m, every
second stitch is
formed shorter than the stitch 7 of the basic knit. These shorter stitches k
are knitted with a
second stitch thread 5, as shown in Figure 2. The second stitch thread 5
creates the stitching
of the short stitches k of the stitch row m with the stitches k lying above or
below of the
stitch row m+1 or m-1 lying above or below. In this way, the stitch density in
the first
region 1 is higher than in the second region 2.
Both regions 1 and 2 are passed through, in turn, by weft threads 4 in a non-
stitch
forming way. The weft threads 4 are integrated between the right r and left 1
stitches of the
basic knit. As in the circular knit fabric according to Figure 1, the weft
threads 4 are
integrated to different degrees into the basic knit also for the flat knitted
fabric of Figure 2
in the two regions 1 and 2, whereby, in turn, a different extensibility is
produced in the two
regions 1 and 2, respectively. Hereby, in the first region 1, there is a
higher stitch density,
which leads to a stronger integration of the weft threads 4. Therefore, the
extensibility of
1 S the first region 1 is less than that of the second region 2 with lower
stitch density. As in the
embodiment of Figure 1, here the boundary line G between the first region 1
and the second
region 2 also extends approximately perpendicularly to the weft threads 4.
Relative to the knitted fabrics known from the state of the art with different
amounts
of extensibility zone by zone, the knitted fabric according to the invention
distinguishes
itself in that the difference in the extensibility of each zone can be
significantly larger.
Compared with the known knitted fabrics, in which the difference in the
extensibility is
achieved by the use of different types of yarn in the individual zones, the
knitted fabric
according to the invention can be created significantly more easily and also
inexpensively.
Figure 3 shows a compression sock 6 produced from a knitted fabric according
to
the invention. This sock is distinguished by a first region 1 with lower
extensibility and a
second region 2 with higher extensibility connected seamlessly to this first
region.
According to the different amounts of extensibility of the regions 1 and 2,
when the
compression sock is put on, different levels of compression are exerted on the
leg.
Corresponding to its low extensibility, the first region 1 with low
extensibility exerts a
higher compression on the leg than the second region 2 with higher
extensibility. The
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second region 2 with higher extensibility and consequently lower compression
effect is
arranged in the area of the calf for a compression sock. In this way, the sock
in the calf
region exerts lower compression on the leg than in the other area, whereby the
calf muscles
are protected while walking.
Comparison measurements on a sock produced from a knitted fabric according to
the invention have shown that the compression pressure exerted on the leg by
the sock in
the region 1 with lower extensibility can be set between 15 and 40 mm Hg,
while the
compression pressure in the second region 2, that is, in the embodiment of
Figure 3 in the
calf region, equals at most 20% to 50% of the compression pressure in the
bordering region
1 with lower extensibility.
From the knitted fabric according to the invention, other compression
articles, e.g., a
compression bandage for an arm or for the chest area (thorax), can be
produced. For a
compression bandage for an arm, the region with lower compression effect lies,
for
example, in the elbow area, in order to relieve stress on the elbow. The
arrangement of the
regions 1 and 2 with higher and lower compression effect, respectively,
depends on the
individual application of the compression article and is selected accordingly.
In Figure 4, a sock or stocking is shown, which is produced from a knitted
fabric
according to the invention. The shown sock 7 is suitable especially for use in
athletic
activities. The sock 7 consists of a leg 8 and a foot part 9. The foot part 9
comprises a tip
17, in which preferably an antibacterial silver thread is worked in, in order
to prevent, e.g.,
the formation of athlete's foot. The foot part 9 further contains an instep
area 16, which is
formed from a soft, honeycomb-pattern knitted fabric, in order to cushion the
instep area as
much as possible. The rear end of the foot part 9 is closed on the top side by
a stretching
zone 14 and on the bottom side by a heel 15. The stretching zone 14 is formed
from an
especially soft knitted fabric, for example, terry cloth or plush material, in
order to prevent
folds and pressure points on the skin. The heel 15 is formed from a knitted
fabric with
fibers that are as smooth as possible, in order to prevent the sock from
rubbing against the
heel area. The leg 8 is assembled from a bottom leg region 12, a calf region
10, and a shin
region 11. The leg 8 is produced from a knitted fabric described above with
different
amounts of extensibility. Here, the bottom calf [sic; leg] region 12 has an
average
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extensibility (and thus an average compression effect). Relative to the bottom
leg region 12,
the calf region 10 has a higher extensibility (and thus a lower compression
effect) and the
shin region 11 has a lower extensibility (and thus higher compression effect)
relative to the
bottom leg region 12. Preferably, the bottom leg region 12 has a compression
pressure
between 18-21 mm Hg and the compression pressure in the calf region 10 is less
by at least
10% than in the underlying region 12 of the leg 8. In contrast, the
compression pressure in
the region 11 of the calf is higher by more than 10% than in the underlying
region 12 of the
leg 8. An especially good wearing comfort is produced, for example, when the
compression
pressure in the calf region 10 is smaller by ca. 12% than in the underlying
region 12 of the
leg 8 and when simultaneously the compression pressure around the region 11 of
the shin is
higher by ca. 12% than in the underlying region 12 of the leg 8. Hereby, in
the region 11 of
the shin, an especially good stabilization of the foot, as well as good blood
circulation, is
promoted. Through the lower compression pressure in the calf region 10, the
calf muscles
are relieved from stress and therefore tend not to tire as quickly, which is
an advantage
especially when wearing these socks during athletic activities.
In an especially preferred embodiment, the compression pressure in the calf
region
10 decreases continuously or in steps from the bottom upwards. In Figure 4,
for example,
an embodiment is shown, in which the calf region 10 has a first, bottom region
1 Oa with a
compression pressure that is lower relative to the underlying leg region 12
and another
region 10b, which is adjacent to this first area at the top and in the back
and which has a
further reduced compression pressure relative to the first region 10a. Thus,
for example, the
compression pressure in the bottom calf region 10a equals approximately 55% of
the force
of the underlying leg region 12 and the compression pressure of the topmost
calf region 1 Oc
arranged at the back equals only 50% of this compression pressure.
At the top end, the leg 8 is closed by an elastic collar 18. The collar 18 is
formed
from a soft knitted fabric, which contacts the calf of the user as much as
possible without
folding .
The transition region 13 between the foot part 9 and the leg 8 likewise has a
lower
compression pressure than the adjacent regions of the foot part 9 and the leg
8, that is,
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especially the lower leg region 12 or the heel 15 and the stretching zone 14.
Through the
lower compression effect in the transition region 13, better movement is
guaranteed.
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