Note: Descriptions are shown in the official language in which they were submitted.
2 KWT ( ~KC ) - g 5 8 9 / PCT
.~ . 1 --
DESCRIPTION ~ :
Thick Belt and Device for Producing the Same
TECHNICAL FIELD
The pres~nt invention relates to a thick belt and a
device for producing the same, particularly to a thick
high-strenqth belt used, in place of a rope, as a safety
belt or for a sling for a flexible container.
BACKGROUND ART
A safety belt generally comprises a metal member
attached to one end of a rope and a hook attached to the
other end thereof. In a sling for a flexible container,
a rope is connected ~o a metal member attached to a
container body. Usually the connection of the rope with
the metal member is carried out manually by a process in
which a rope end is untwisted to a group of strands which
are then fixedly incorporated into the rope body. Since
this process requires skill as well as considerable
strength, it is difficult to obtain operators therefor
nowadays. If a narrow width woven fabric is used in
place of a rope, the connection may be easily carried out
through a sewing operation, but the handling thereof is
inferior to a rope due to its width.
In a woven fabric used for a sling requiring a high
strength, it is necessary to weave a number of warps into
a predetermined width of the fabric, whereby the fabric
must be three layerd, or two layered while adding a
plurality of reinforcing core yarns. An inspection of '~ ;~
eight slings available in the market showed that the
average thickness was 4.17 mm and the ~ thickness
was 5.2 mm (nyion). An estimate was obtained, from the
investigation of these weave structures, that the average
breakage strength is 7820 Kgf and the -~i is
10680 Kgf (polyester) if a strength utilization ratio is
assumed to be 80%. As there is a limit in the number of
warp which can be woven into a predetermined width, it is
necessary to weave fabrics with unwillingly widening its
~' 'J ~; ~ . ? ~
,.,,1"~
- 2 -
width, so that the strength requirement is fulfilled. Of
course, specially high-strength yarns, such as aramide
fiber yarns, may be used for this requirement, but these
are so expensive that they cannot be used for general
purposes.
The limitation of the warp numbers which can be
woven into a predetermined width of a narrow width
fabric, is mainly determined by the capacity of the loom
on which the fabric is produced. It is the above-
mentioned slings that are designed and produced withinsuch the strict limitation of the number of warps and
thus these fabrics were produced under an extremely
uppermost verge of the limitation of the conventional
art. The limitations of loom will be described below.
In a needle-type narrow loom, a weft is picked into --
- a warp shed from one side thereof, and received by a
latch needle positioned on the other side so that a
knitted selvage is formed. During the forma~ion of the
selvage, the weft is first caught by a hook of the latch
needle. There is no problem when the weft is received by
the hook from a back layer of a multilayered thick
fabric, but when it is received from a front layer, the
weft is liable to detach from the hook if the weft is
positioned above a tip end of the hook. Accordingly, a
fabric thickness under which a weaving operation is
~stably carried out is less than 5 mm in a gray fabric,
and less than 4.5 mm after the heat-set was carried out '~
thereto.
In a rack-and-pinion type narrow loom, the weaving ~ -
operation can be relatively smoothly continued even if a
number of warps are woven, because a shuttle passes -~
through a center of shedding while being gripped.
However, there is one drawback therein. That is, it is
necessary to increase the lengths of shuttle and shuttle '~
box relative to the dimensions of the weaving window so ~ ~;
that the shuttle is retained in the original shuttle box
until a rack of the shuttle engages with a pinion of an
3 _ 1 2 ~ 2
opposite shuttle box. This results in the lowering of
loom rotational speed, and since a wider space is
required, the loom is generally designed as narrow as
possible provided the shuttle can be safely passed.
Therefore, if a shedding motion is even slightly
disturbed when an extremely thick belt is woven, the
passage of shuttle is obstructed and this causes a
machine failure.
In a slide-hook motion-type narrow loom, a slide bar
movable both in the right direction and left direction
with reference to Fig. lOA, is provided in part of a
shuttle race. A vertical groove is provided in the slide
bar, in which a hook is movable upward and downward by a
cam provided inside a slay. Two holes are bored,
respectively in the right and left areas of the bottom
wall of the shuttle for receiving the hook therein when
the shuttle is in the shuttle box to move the shuttle
along by the displacement of the slide bar, while the
-~ hook is lowered when the shuttle passes through the
weaving window. After the shuttle has passed through the
weaving window, the hook returns to the hole in the
bottom wall of ihe shuttle to assist the movement of the
shuttle.
In the slide-hook motion-type narrow loom, lower
side warps forming a shed are brought into contact with
the race and the shuttle runs thereon. When an extremely -
thicken belt is woven in which a warp volume exceeds a
certain level, the shuttle cannot clear the same, and
becomes liable to float, resulting in unstable running
and machine failure.
Further, while all parts in the loom frame, the
motor arrangement, the weft picking mechanism, the
shedding mechanism such as a dobby or the like, and the
take-up device must be constructed to be resistant to the
high warp tension, this requirement is not satisfactorily
fulfilled by the conventional loom.
An object of the present invention is, in a wider
_ 4 _ 2 1 2 t~
sense, to provide a narrow width fabric having a
thickness and a breakage strength per unit width
exceeding conventional knowledge and, in addition, to
provide a device for producing such a narrow fabric.
A first specific object is to produce a thick belt
having a cross-sectional shape as close as possible to
that of a rope.
A second specific object is to produce a narrow
fabric having a thickness more than 6 mm and a high
breakage strength, which has not been obtainable by a
conventional art. -
A third specific object is to obtain connection
means for the belt of the first object as with a rope, by
forming the fabric end wider, and with a suitable
thickness, to allow a sewing operation thereon.
A fourth specific object is to provide a device in a
loom which enables the execution of the first and second
inventions. ~-
DISCLOSURE OF THE INV~:N'l'lON ; ~
To achieve the above objects, a thick belt is ~-
provided, having a weave structure comprising more than
four layers, in which the outer two layers are woven in a
hollow weave while using a common weft and the inner
layers other than the outer two layers are woven in a
hollow weave while using another weft, characterized in
that a thickness in a widthwise central area of the belt
is more than one quarter of the belt width. Also a thick ~-
belt having a weave structure comprising more than two~ ~ -
layers characterized in that the thickness of the warp
bundle calculated by the formula (1) as shown in page 8,
based on a total denier of all the warps used is more - -~
than 2.5 mm and the thickness of the woven belt is more
than 6.0 mm except for the selvage area of the belt. i~
More specifically, the belt has a basic section
comprising the thick belt defined above and a flat
section extending lengthwise from the basic section which
is wider and thinner than the basic section; the flat
_ 5 _ ~12~62
section comprising a woven structure different from that
of the basic section and being wider and thinner relative
to the basic section.
Since the thick belt defined in the present
invention comprises the above technical constituents, a
high density, multilayered woven structure can be
effectively obtained by utilizing a loom, while, in the
conventional process, a plurality of yarns are knitted
into a rope in an ineffective manner. This novel thick
belt has a strength equal to that of the conventional
rope and can be used in place thereof. According to the
thick belt, a required rope-like structure can be
obtained through a usual sewing process instead of the
process used for a conventional rope.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. l is a cross-sectional view of a thick belt
according to the present invention, illustrating one
example of woven structure thereof;
Fig. 2 is a cross-sectional view of another thick
belt according to the present invention, illustrating
another example of woven structure thereof;
Fig. 3 is a plan view of a thick belt, illustrating
an arrangement of the basic section and the wider ~-
sections;
Fig. 4 is a cross-sectional view of a shuttle race -
used in the present invention, illustrating a shape of a
stepped recess formed therein;
Fig. 5 is a side view of a take-up motion used in
the present invention;
Figs. 6A through 6F illustrate a shape of
combination of take-up roller and pressing roller in a
take-up motion mechanism, respectively;
Fig. 7 is a weave structure used in a first
embodiment of the present invention;
Fig. 8 is a weave structure used in a second
embodiment of the present invention;
Figs. 9(A) and 9(B) are weave structures used in a
- 6 - 2~29~G2
third embodiment of the present invention; and
Fig. 10 illustrates a slide hook mechanism of a
shuttle loom used in the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
A thick belt according to the present invention will
be described below in more detail with reference to the
drawings. In the description, ~layer~ stands for a unit
of woven structure formed by the intersection of warp and ~ ~-
weft. A structure, such as reinforcing core yarn group
in which the warp and weft are not intersected with each
other is not referred to as ~'layer".
~ " : .:
Fig. 1 is a schematic illustration of cross-section
of a thick belt woven using double shuttles for one belt.
In the illustrated example, the thick belt 1 consists of
15 four layers; outer layers 2, 3 and inner layers 5, 6. -
For simplicity, the respective layer is shown in a weave
structure of 1/1, but other structures such as 2/1, 2/2,
3/1 or 3/3 may be preferably used because a number of
- warps can be woven into a predetermined width of the
20 belt. In the outer layers 2, 3, warps 61, 71 thereof are
woven in a hollow weave by a common weft 41. Also in the
inner layers 5, 6, warps 51, 52 thereof are woven in a
hollow weave by a common weft 42. It is possible to form
the inner layers as more than three layers. In the
25 latter case, although the inner layers are not tubular,
there is no problem at all. In the usual multilayered ~-
weave, connecting yarn is used for connecting the
respective layers with each other. However, the
connecting yarn is not used in this case, and the
30 warps 61, 71 are not restricted by the connecting yarn
and liable to be in a tubular form if the weft is picked
at a high tension. Thus, the belt has a substantially ~-
oval shape in cross-section as shown in Fig. 1. To ~-
obtain such the shape, it is indispensable to weave the
outer layers 2, 3 in a tubular form while using the
common weft 41 and to form the inner layer with at least
two layers 5, 6 while using another weft 42 to thicken
- 7 - ~2~G2
the central area of the belt. Although the warps 61, 71
of the outer layers are preferably of the same material
and thickness, this is not an indispensable condition. -
Since the inner warps are invisible from outside, they
are preferably arranged so that thicker yarns are closer
to a widthwise central area of the belt, whereby the ~-~
central area is further thickened. In this case, the
connecting yarn may preferably be used only in the inner
layers. The connecting yarn used is preferably one
having a good elasticity. Reinforcing core yarns may be
arranged between the adjacent layers, if necessary. A
group of reinforcing core yarns 7 are arranged between
the inner layers 5, 6 in the example shown in Fig. 1.
More warps are preferably distributed in a central area
of a front reed than in the remaining area. According to
these weaving conditions, it is possible to obtain a
thick belt with a cross-sectional shape closer to that of ~-
a rope. In addition, when a heat set is applied thereto,
the cross-section of the belt becomes circular, whexeby a
product far from the concept of the conventional belt and
having a cross-sectional shape similar to that of a rope -~
can result. It is necessary that, after the heat set,
the belt has a thickness of at least one quarter of the
belt width in a widthwise central area thereof, which is
the smallest thickness for easy manipulation. For
example, when the belt width is 32 mm, the thickness in
the central area should be more than 8 mm.
Fig. 2 shows a schematic cross-section of one
embodiment of a thick belt which is similar to a sling.
In the illustrated embodiment, the thick belt 1 consists
of two outer layers (front and back) 2, 3, a group of
reinforcing core yarns 7 interposed between both the
layers and a connecting yarn 8 connecting the front and
back layers. Even though three or four layers are
comprised, they may be woven by only one weft 41. The
use of single weft is not an indispensable condition but
two wefts may be used as shown in Fig. 1. Fig. 2
- 8 - ~2~.G2 ~
illustrates a very common structure of a thick belt,
having characteristics in that the total denier of the
warps used is larger than the conventional thick belt, -
resulting in a high breakage strength per unit width and -
a thickness, except for the selvage area, of more than
6 mm after heat setting operation was carried out. The
characteristics will be described below in more detail.
The following factors determine the breakage
strength and thickness of a narrow woven fabric. ;
1. Quality (breakage strength), denier and number
(total denier) of warps used in the fabric
2. Weave structure, weft denier and picks of weft
per unit length
When a woven fabric is designed, it is usual that
material, denier and number of warps to be used are first
decided while taking a required fabric strength into
account, then a weave structure, weft denier and picks of -~
weft per unit length are selected in a limited range
defined in accordance with a weaving technology. -
Regarding slings belonging to a field in which the
maximum strength is required as a narrow width fabric, an
analysis was made on the marketed products available from
various makers and listed on Table 1. According to this
table, a thickness of warp bundle used in the following -~ -
formula was 2.02 mm on average value and 2.42 mm
obtained by dividing a cross-sectional area of all warps
by a belt width; and a belt thickness was 4.17 mm on
average value and 5.20 mm maximum. It was assumed that -
nylon and polyester yarns have a breakage strength of
9 g/d and the strength utilization ratio is 80%.
Calculation formulas:
0.0119 ~(total denier of warps . fiber specific gravity)
= diameter of warp bundle assuming the same has a
circular cross~section (mm)
Cross-sectional area of warp bundle obtained by the
above formula (mm2) . woven width of belt (mm) =
thickness of warp bundle (mm) ... (1)
.~ ::::
;
~able I
i aker Weave Loom Material Thickness Width Total denier Assu ed strength Per 10 m width
(mm) (mm~ (Kgf) Denier Diameter Thickness Stren~ .,
' A 1/1 shuttle nylon 3.50 51.9 946620 6816 182393 4.76 1.78 1313
2 layers
B 1¦1 shuttle nylon 3.95 49.6 lOZ2280 7360 206105 5.0G 2.01 1484
; 2 layers
~ ' - C 1/1 shuttle nylon 4.00 52.6 1038240 747S 197384 4.95 1.92 1421
'r"'-"~" J'~'~'~'~''. ;' .~ ~ 3 layers
,.t~ ' D 1/1 shuttle nylon 5.20 51.2 1155840 8322 225750 5.30 2.20 1625
3 layers
E1¦1 shuttle nylon 4.10 52.2 1000440 7203 191655 4.88 1.87 1380
~ 3 layers
'"'-''-''' ' 5'~'-''''''- ' -' ' F 2/2 shuttle nylon 4.20 49.7 1051680 7572 211606 5.13 2.06 1524
2 layers
'- G 2/1 needlenylon 3.50 51.1 990360 7131 193808 4.91 1.89 1395
2 layers
" ~ r.~i H 1/1needle polyester 4.88 49.41483000 10678 300202 5.55 2.42 2161
2 layers
Average 4.1751.0 1086058 7820 213613 5.07 2.02 1538
Ref. nylon 6.00 50.01280000 9216 256000 5.64 2.50 1843
Ref. polyester 6.00 50.01550000 11160 310000 5.64 2.50 2232
* Calculations were made while assuming the specific gravity of nylon is 1.14 and that of polyester is 1.38.
* Assumed strength was calculated by [(total denier x 9 (g/d) x 0.8] . 1000. - ~~
W
,,
1 o ~ 1 2 ~ ~ 6 2
From the analysis of the conventional narrow fabrics
shown in Table 1, which are thought to be high-quality,
it is decided in the present invention that the thickness
of warp bundle should be at least 2.5 mm and the belt -
thickness should be at least 6.0 mm so as to exceed the
quality of the conventional products. Values cited as
reference in Table 1 are obtained by the reverse
calculation while defining the thickness of warp bundle
as 2.5 mm.
Fig. 3 illustrates a belt comprising a basic
section 10 having a rope-like shape shown in Fig. 1,
wider width sections 11 extending from the lengthwise -
opposite ends of the basic section 10 and joint
sections 12, 13 connecting both of the former two
sections with each other and having a gradually varying
width. The basic section 10 is a belt formed of a woven
structure consisting of more than four layers, in which
outer two layers are woven in a hollow weave by a common ~ ~
weft and the remaining layers other than the outer two ~ --
layers are woven as inner layers by another weft. The
thickness in the widthwise central area of the belt is
larger than a quarter of the belt width.
The wider section 11 is formed wider and thinner ~-
relative to the basic section 10 to be suitable for the
sewing operation. The width of the wider section is
preferably wider by at least 50% than that of the basic
section 10. Assuming that the belt is woven from the
left to the right as seen in Fig. 3, the joint section 12
lis formed so that the width thereof is gradually made
narrower and the thickness thereof is gradually thicker,
while the joint section 13 is formed so that the width
thereof is gradually wider and the thickness thereof is
gradually thinner. Lengths of the basic section 10 and ~ ~
the wider width section 11 are selected to be suitable -
for the expected use. The weaving process will be
described below in detail. .
Basically, the belt width is adjusted using a
11- 212~.G2
sector-shaped front reed which is movable upward and
downward. In this regard, since the basic section 10 is
thicker in the widthwise central area thereof, it is
necessary to widen the thick portion as much as possible
in the wider section 11. For this purpose, the reed
pitch is not uniform in the wider section, but coarser in
the central area and gradually finer toward the outside.
In the conventional belt with varying width, the
same weave structure is used in both the narrower and
wider sections. However, according to the present
invention, since the basic section 10 comprises more than
four layers in its weave structure and is difficult to
widen while maintaining this weave structure, the number
of layers in the basic section 10 is reduced in the joint
section 13 so that the width can be readily increased.
That is, if the basic section 10 has four layers, the
number of layers is reduced to two in the joint
section 13 and in the wider section. If the width
variation is greater, the number of layers in the joint
section may be further reduced from two to one for the
wider section. Beside the reduction of the number of
layers, it is possible to convert the weave structure of
the respective layer, for example, from 2/2 twill weave
to 1/1 plain weave~ However, it is better to vary the
number of yarns in a warp unit, while maintaining the
weave structure as it is, so that the number of layers
can be reduced without affecting the product appearance.
When the joint section 12 changes from the wider
section 11 to the basic section 10, the weaving process
is carried out in a reverse manner to the above.
The basic section 10 having the wider section 11 is
designed so that a reduction or increase of layers is
facilitated. For example, it is preferable not to use ~;
reinforcing core yarns in the basic section 10 because
the conversion of weave structure becomes difficult. In
this regard, it may be possible to build a proper number
of reinforcing core-like yarns into the basic section 10 ;;
: ~.
- 12 - 21~62
and use the same as connecting yarns when the number of
layers is reduced to two or three in the wider
section ll, so that the wider section is stable~
While it is necessary to vary a weft picking number
per unit length in accordance with the reduction or
increase of layers and the change of width, the detailed ~ ~ i
description thereof is eliminated in this specification ~-
because such the procedure is well-known from the prior
art.
Next, looms and other devices for producing the
thick belt described with reference to Figs. l and 2, and
having a thickness larger than that of the conventional
belt, will be explained.
As stated in the prior art, the m~xi~- number of
warps capable of being woven into a predetermined width
of narrow fabric is mainly decided by the limitations of
a loom, and it was found that the thick belt of the -~
present invention cannot be produced while using a
conventional loom. Accordingly, the present inventors
have studied how to develop a loom, and devices thereof,
capable of producing a thick belt according to the
present invention.
Two shuttles are necessary for the production of the
belt shown in Fig. 1. In the rack-and-pinion type loom,
a double shuttle mechanism becomes complicated because
one shuttle is exchanged with the other while moving
upward and downward, which results in the reduction of
the loom rotational speed. The slide hook motion type
loom is thus preferably used, because two shuttles are
positioned in a side-by-side manner in the same shed and ~-
either can be selected by a relatively simple means. In ~ ''
the conventional loom of this type, however, as expLained
with reference to Fig. 1, when a thick belt is woven
thereon, having a thickness in the widthwise central area
larger than one quarter of its width after heat setting,
the thickness of the warp bundle becomes more than 5 mm
in the widthwise central area during the weaving process,
'~
2~2~2
_ 13 -
if the warps are drawn into, for example, a 35 mm wide a
front reed. The shuttle cannot run over lower side warps
forming the shed when the warp bundle is extremely
voluminous.
To solve this problem, according to the present
invention, a stepped groove is provided in the shuttle
race so that the lower warp bundle is positioned below
the upper surface of the shuttle race when the shed is
formed. In addition, a plurality of exchangeable parts
are prepared, with varying groove depths and/or widths,
so that a suitable stepped groove is provided
corresponding to various belts of different widths and
thicknesses.
The detailed description will be made of the
exchangeable part for the stepped groove with reference
to Fig. 4. Fig. 4 illustrates one embodiment, in which
an exchanging part 24 having a stepped groove 22 is fixed
in a weaving window of a shuttle race 21 provided on the
upper surface of a slay 20. The cross-sectional shape of
the stepped groove 22 is preferably selected while taking
into account the maximum volume of the lower warp
bundle 26 forming a shed. It is variable in accordance
with the weave structure, with reference to the cross-
sectional shape of the thick belt to be woven, yarn
material, denier or number of the warps. In Fig. 6,
examples of the cross-sectional shape of the stepped
groove 22 are shown. A total length B, bottom length A,
r~xi depth C and end depth D of the stepped groove are -'~
listed in Table 2.
Table 2 ~ '
A B C D
1. 35 mm 65 mm 5 mm 2 mm
2. 20 mm 40 mm 8 mm 4 mm
3. S0 mm S0 mm 5 mm 5 mm
In this regard, the use of the exchangeable part 24
is not indispensable, but the stepped groove having, for
14 _ 2~ ~9 ~6'2
example, dimensions listed in item 3 of Table 2 may be
directly formed on the shuttle race. That is, the groove
having the maximum dimensions for the expected use may be
originally provided.
According to such the arrangement, it is possible
for the shuttle 23 to smoothly run through the shed 27 ~-
between the upper side warp bundle 25 and the lower side
warp bundle 26 even though the lower side warp bundle is
at the maximum volume when the warp bundle woven to be
the thick belt forms the shed, because the lower side
warp bundle can be accommodated in the groove 22.
An embodiment of a slide hook motion mechanism used
for the present invention will be explained with
reference to Figs. lO(A) through lO(C). In Figs. lO(B),
lO(C), a channel 94 opening to the shuttle race 21 is
provided in the slay 20, for guiding a slide bar 90, and
a cam 92 is provided in the inner side wall of the
channel 94 in the lengthwise direction thereof (in the
right or left directions in Fig. lO(A)). The cam 92 is
closer to the shuttle race 21 beneath a non-illustrated ~-
shuttle box so that a tip end of a hook 91 enters a bore
formed in the shuttle bottom, while the cam 92 is farther
from the shuttle race 21 beneath the stepped groove 22 so -
that the tip end of the hook 91 can pass under the
stepped groove 22. In short, in the present invention,
the upper ~urface of the slide bar 90 is at a level lower
than the bottom of the stepped groove 22 having the
-~i , depth, while in the conventional slide hook ~-~
motion mechanism, it is at substantially the same level
as the shuttle race 21.
Fig. lO(B) is the illustration of a positional
relationship between shuttle race 21, slide bar 90,
hook 91, cam 92 and shuttle 23 beneath the shuttle box,
and Fig. lO(C) is that beneath the stepped groove 22.
According to a protrusion 93 of the hook entering the
cam 92, the hook is movable up and down according to the
height variation of the cam 92. In this regard, the
212~. (i2
- 15 -
slide bar 90 is reciprocated right and left by a non-
illustrated drive means. Through such the structure, the
tip end of the hook 91 is projected upward and engages
with the bottom bore of the shuttle 23 to displace the
same in the right/left directions, or the tip end of the
hook 91 disengages therefrom when the shuttle 23 passes
the weaving window so that the displacement of the
shuttle is stably carried out.
In the present invention, a slant section of the
cam 92 is elongated compared with the conventional one to
mitigate a shock caused by a longer up-down stroke of
hook 91 due to the lower arrangement of the slide bar 90
and length of the shuttle 23 is also elongated. However,
since such a modification can be designed when the length
of the weaving window and the maximum depth of the
stepped groove 22 are determined, a specific description
is not given.
Next, a mechanism for taking up a thick belt
according to the present invention during the weaving -
process will be explained.
A take-up motion mechanism is provided in a narrow
width loom, comprising at least two sets of roller unit,
each consisting of a take-up roller and a press roller ;
contacting the same, in whic~s at least one roller in the
respective roller unit has a circumferential groove 35 or
36 on the outer periphery thereof.
Fig. 5 illustrates one embodiment of the take-up
mechanism of the present invention. As shown in
Fig. 5(A), a woven belt 1 is taken up by a first take-up ~
roller 30 and press roller 31 set, and transferred to a ' ;
second take-up roller 32 and press roller 33 set via an
inte -~iate roller 37. The shape of groove 35, 36
provided on the outer periphery of at least one of take-
up roller and press roller in the respective roller unit
is designed to be conformable with the cross-sectional
shape of the thick belt to be woven, as shown in
Figs. 5(B) and 5(C). Examples of the groove shape are
- 16 - f~1 2
illustrated in Fig. 6.
In Figs. 6A and 6B, grooves of various shapes are
provided on both of the take-up rollers and press
rollers.
In Figs. 6C and 6D, grooves of various shapes are
provided only on the take-up rollers.
In Figs. 6E and 6F, grooves of various shapes are
provided only on the press rollers.
When the wider section is woven while varying the
cross-sectional shape thereof, two press rollers with
different grooves are preferably used while being
combined with one take-up roller.
In practice, a plurality of these take-up rollers or
press rollers, each having a groove different from the
other, are preliminarily prepared as exchangeable parts
so that replacement is easy.
The take-up roller shown in Fig. 5 has a relatively
large diameter of 150 mm for taking up a thick belt.
While the structures of the loom, such as a loom ~ ~
frame, motor arrangement, picking motion, shedding motion ~ ;
or take-up motion mechanism are designed to be durable ;~
against high power for weaving a thick belt according to
the present invention, compared with the conventional
loom, they are not special but can be designed or
selected on demand, whereby a detailed explanation is not ~-~
given. -
ExamPle 1
Yarn material: nylon
Weave structure: 2/2 twill weave, four layers
Fabric dimensions: ~ thickness 10 mm, width
26 mm
Front layer and back layer: warp 1680 d/4, 68 ends -
(warping on two beams) -
Inner layers: warp 1680 d/4, 60 ends (warping on -~
two beams)
weft 1680 d/l, 60 picks/3 cm
no connecting yarns or reinforcing
::
- 17 - h 1 2 ~ 3 ~J 2
core yarns are used.
A thick belt was woven under the weaving conditions
described above while using a narrow width loom of slide
hook motion type designed for the production of a thick
belt, with double shuttles, in the following manner.
a. Groups of warps of the 2/2 twill weave forming
the respective layers were separately warped on the
respective beams and drawn into four held. According to
this arrangement, one half of the warps in the respective
10- warp group were positioned on the upper or lower side of
the shed when this warp group was woven, and the
remaining warps were all positioned on the upper or lower
side of the shed, whereby the shedding motion could be ~ -
smoothly carried out even if the warp tension was small.
b. Fig. 7 illustrates a weave structure of the
above belt. Since the inter-warp rubbing during the
shedding motion is minimized, the shed is easily formed
even though the warp density is high. '
c. The weaving operation was carried out with the -
exchangeable part having a groove with a depth of 6 mm
and a width of 35 mm in the weaving window in the slay.
Although 111 ends most are collected on the lower side of
the shed consisting of 128 ends of warps of 1680 d/4,
they are accommodated within the margin of the stepped
groove, whereby no problems occur in the shuttle travel.
d. The shuttles were arranged in the same shed
such that one is on the near side and the other is on the
far side as seen from the front of loom. The nearer side
shuttle (1) was used for weaving the inner two layers and
the farther side shuttle (2) was used for the outer two
layers. The order of picking is the run-after-another
order; i.e., after (1) is picked, (2) follows in the same
direction, then (1) is picked in the opposite direction,
and next (2) follows thereto. Thereby the outer two
layers and inner two layers were respectively woven to a
tubular shape by one shuttle.
e. In this example, no connecting yarns were used
- 18 _ 212 n3G 2
so that the resultant product is as close as possible to
a rope-like shape. Since a connecting yarn was not used
at all and as the weave structure was a hollow weave, the
shape of the woven product was deformable whereby the
cross-section thereof easily becomes oval.
f. A take-up motion mechanism, similar to that
shown in Fig. 5, in which the take-up roller and press
roller had a qroove shown in Fig. 6(A) was used.
g. Since the warps are thick relative to the -
fabric width and the number thereof is relatively few,
the respective layer is woven in a non-compact manner.
Accordingly, the weft can shrink after heat setting so '~
that a tough and compact fabric is obtained. In
addition, the oval cross-section was more obvious in the
heat-set product than in the as-woven product.
h. The heat-set product had a width of 23.5 mm, a -~
thickness of 9.6 mm in the widthwise central area and a
breakage strength of 6100 Kgf, satisfying a JIS strength ~ ;~
standard of 5940 Kgf for 18 mm diameter nylon rope. -
While the above weave structure was selected in this
example so that the width can be partially widened as
stated later in Example 3, other structure may be adopted ~
such that the outer layer may be a 1/1 plain weave, the ~-
number of the inner layers may be more than three, -~;
reinforcing core yarns may be inserted between the
respective layers, or any of a structure is possible to --
be used with reference to the number of healds used.
Example 2
Yarn material: nylon ~ -
Weave structure: 1/1 plain weave, three layers
Fabric dimensions: thickness 7.2 mm, width 31.5 mm
Ground warp: 1680 d/4, 102 ends ~warping together
with selvage yarns on one beam per one of the three
layers)
Selvage warp: 1680 d/2, 16 ends
Connecting warp: 1680 d/l, 18 ends (warping on one ;~
beam) ~-
- 19 _ 212.~G2
Reinforcing core warp: 1680 d/6, 34 ends (warping
on one beam)
Weft: 1680 d/1, 30 pick/3 cm
A thick belt was woven under the weaving conditions
described above while using a narrow slide-hook motion
type loom, designed for the production of thick belt,
with double shuttles, in the following manner.
a. 34 ground warps were warped for each of the
three layers, while adding 8 ends of selvage yarns
respectively to the front and back layers. Each of the ~ ;
three layers was drawn into two healds. The connecting
warps were also drawn into two healds and the reinforcing
core warps were drawn into two healds (17 ends to one
heald). The reason for the division of the beams is to
lS reduce the warp tension during the shedding motion. ~
b. Fig. 8 illustrates a weave structure of the ~ ;
above belt. Since the inter-warp rubbing during the
shedding motion is minimized (only the connecting warps
rub each other at a third pick), the shed is easily
formed even though the warp density is high. The
reinforcing core warps were inserted between the three
layers while being divided into two groups.
c. In this example, it is not indispensable to use
double shuttles, and a single shuttle may be used.
Double shuttles may be used, taking weft supply
conditions into account. ~;~
d. The thickness of the warp bundle determined by
the formula described in the explanation of Fig. 2 was
3.44 mm because the total denier of warps is
1,112,160 denier and the fabric width is 31.5 mm. As
described before, with reference to Fig. 2, the thickness
of the warp bundle in the conventional product is at most
2.42 mm, and it is apparent that the warp volume is
increased in this example.
e. The weaving operation was carried out while
attaching an exchangeable part in the weaving window in
the slay, having a stepped groove 4 mm deep and 40 mm
'~:
- 20 - ~12~2
wide. The maximum number of lower side warps forming a
shed reached 577 ends, from a total of 662 ends, when a ~ '
single end has a thickness of 1680 denier. Even in this
case, the lower side warps were accommodated with a
margin in the groove whereby there were no problems in -
the travel of the shuttle.
f. While a take-up motion mechanism similar to
that shown in Fig. 5 was used, no circumferential groove
may be necessary in the take-up roller or press roller in
the case of the fabric having a flat surface except for ;
the selvage areas.
g. The product obtained after dyeing and heat-
setting the greige had a thickness of 6.5 mm and a width
of 30 mm and a breakage strength of 7,500 Kgf. This '~
strength value is only achievable by a conventional
product having a width of 50 mm.
ExamPle 3
According to this embodiment, a flat wider ~
section 11 consisting of one layer of 2/2 twill weave and ~-
having a width of 45 mm and a thickness of 2.8 mm was
added in the lengthwise direction to the basic section 10
consisting of four layers of 2/2 twill weave and having a
width of 23.5 mm. Particulars are as follows.
a. The width was varied by using a conventional
sector-shaped front reed movable upward and downward. In
this regard, since the basic section 10 in this example
is thicker in the widthwise central area, it is necessary
to widen the belt portion as much as possible in the
wider section 11. Accordingly, the reed for the wider
width section does not have a uniform pitch but has a ;~
coarse pitch in the central portion which becomes finer
toward the extremities thereof. The basic section 10 of
this example was woven in accordance with the weave -~
structure shown in Fig. 7.
b. At the beginning of the widening process, the
first and second layers of 2/2 twill weave in the basic -
section are grouped into a single layer of 2/2 twiil ~ ~-
21,~352
~ 21 -
,
weave and the third and fourth layers are grouped into
another single layer of 2/2 twill weave so that the
original four layers are converted to two layers. Then
thus-obtained two layers of 2/2 twill weave are converted
to a single layer of 2/2 twill weave at the final stage
of the widening process. Such a conversion of weave
structure has an advantage in that as the number of
layers is reduced, the width can be smoothly increased.
In Fig. 9, weave structures in the two layer section and
the one layer section are illustrated.
That is, Fig. 9(A) shows a weave structure used
for forming a transition section in which the four layers
have been converted to the two layers; i.e., that
corresponding to the section 13 in Fig. 3, while
Fig. 9(B) shows a weave structure used for forming
another transition section in which the two layers have
been converted to one layer; i.e., that corresponding to
the section 11 in Fig. 3.
c. When a wider section is narrowed to become a
basic section, the process reverse to the above is
carried out.
d. Although it is indispensable that two kinds of
wefts are picked while using double shuttles when the
basic section is woven as described in Example l, it is
possible to operate only one shuttle and rest another
shuttle when the wider section is woven. In this
example, one shuttle was used for weaving the two layered
portion of the joint section but two shuttles were used
for weaving the single layered portion thereof.
e. The number of picks is also varied in -
accordance with the reduction/increase of layers. As
this is done in the conventional manner, the detailed ; ;~
description will be omitted in this text. The number of
picks in the wider section in this example was
18 picks/3 cm.
f. The width of the wider section was 46 mm in
greige and became to 45.5 mm after heat-setting while the
9.52
22 -
thickness thereof was 2.8 mm.
Since the present invention comprises the above-
mentioned technical features, it is possible to provide a
narrow woven fabric having a large thickness and a
superior breakage strength per unit width exceeding a
level of the strength thereof which could be
conventionally obtained. Further, it is possible to
provide mechanisms for a loom capable of producing such a
thick belt. The effects of the present invention are as
follows~
a. In the first invention, a narrow fabric is
obtained, capable of being easily manipulated and having
a cross-sectional shape closer to that of rope. This
narrow width fabric can be used in a field in which a
rope has been conventionally used.
b. In the second invention, it is possible to
produce a thick belt having a width of more than 6 mm
which is the upper limit of the prior art product. As a
result, a thick belt is obtainable which has a greater
breakage strength relative to the conventional thick belt
of the same material and width. Thereby it is possible
to reduce the fabric width to maintain the breakage
strength at the same level relative to the conventional
product made of the same material.
c. In the third invention, since a wider section
is provided while extending a basic section corresponding -~
to the thick belt of the first invention, it is possible
to connect the fabric by the sewing the wider width
section when the same is used in place of a rope. Thus,
the popular and conventional rope connecting method
called as "satsuma" (splice) in Japanese, is no more
required to use for connecting at least two ropes
therefore, the operability for connecting ropes is
greatly improved. Particularly, such the product is
suitable as a safety belt or a sling for a flexible
~ container. ~ -
d. In the fourth and fifth inventions, the present
~, ~
23 2129~2
thick belt can be effectively woven. The production of
the present thick belt might be impossible if these
inventions were not made.
:- ......
