Sewing – Special machines – Traveling sewing machine
Reexamination Certificate
1999-09-17
2001-07-24
Nerbun, Peter (Department: 3741)
Sewing
Special machines
Traveling sewing machine
C112S475020
Reexamination Certificate
active
06263815
ABSTRACT:
TECHNICAL FIELD
This invention relates to a sewing system and a sewing method, and more particularly to a sewing system and a sewing method which are suitable for sewing a knitted fabric (knitted goods) having stitches and a high expansibility and a stitchless woven fabric having a low expansibility together, and knitted fabrics together.
BACKGROUND OF THE INVENTION
A knitted fabric is manufactured by knitting yarn by a knitting needle or a knitting stick, and it therefore has a texture in which a plurality of stitches are continuously intertwined with each other, and a high expansibility. In order to manufacture a knitted product, for example, a sweater etc. by sewing such knitted fabrics, a single-purpose sewing machine (which will hereinafter be referred to as “linking sewing machine”) is used. As shown in
FIG. 36
, this linking sewing machine
80
is provided with a throat plate
82
on which a plurality of locking needles
81
are arranged at predetermined intervals similarly to the teeth of a comb.
Each of the locking needles
81
has a shape of the letter “L”, and is provided with a locking portion
81
a
and a fixed portion
81
b
as shown in
FIG. 37
, the fixed portion
81
b
being fastened to a lower surface of the throat plate
82
by welding etc. The locking portion
81
a
is sharp edged at a free end section thereof, and provided with a guide groove
81
c
in a front surface thereof.
As shown in
FIG. 38
, loops (stitches)
83
a
of one knitted fabric
83
are fitted forcibly in order around the locking needles
81
on the throat plate
82
with loops
84
a
of the other knitted fabric
84
fitted forcibly in order therearound from the opposite side, a sewing needle
85
being then moved up and down to sew up the loops
83
a,
84
a
of the two knitted fabrics together.
When the sewing needle
85
moves down from an upper dead center toward a lower dead center, a tip of the needle advances along the guide groove
81
c
of the locking needle
81
to pass between the loops
83
a,
84
a
of the two knitted fabrics. The sewing needle
85
then enters a space under a sewing machine bed
86
through a hole
86
a
formed therein, and a sewing thread inserted through a thread hole of a tip portion of the sewing needle is guided to a position close to a tip portion
87
a
of a wedge-shaped looper
87
. The looper
87
, which is rotated in a predetermined direction, captures the sewing thread at its tip portion
87
a
when the sewing needle
85
enters into an upward return stroke, to form a loop, which is retained until the sewing needle
85
has thereafter moved down to the same position, the sewing thread being then passed through this loop to form a chain-like seam, whereby the sewing of the two knitted fabrics
83
,
84
is attained.
The throat plate
82
is engaged with a table
88
of a comparatively large length disposed on the front side of the sewing machine bed
86
and extending so as to cross a sewing machine body at right angles thereto. A guide rail
89
is fixed (
FIG. 37
) to a lower surface of the throat plate
82
, and fitted in a guide groove
88
a
formed in the table
88
, so that the throat plate
82
is rendered laterally slidable on the table
88
.
A feed gear
90
is provided below the throat plate
82
, and meshed with the fixed portions
81
b,
which are arranged in the form of a rack on the lower surface of the throat plate
82
, of the locking needles
81
. This feed gear
90
is connected to a driving power source for the sewing needle
85
via transmission means, such as another gear
91
and a belt (not shown), and adapted to be rotated synchronously with the vertical movements of the sewing needle
85
. Namely, each time the sewing needle
85
makes one upward and downward travel, the throat plate
82
slides by a distance corresponding to a distance between two adjacent fixed portions
81
b,
and a subsequent locking needle
81
moves to a position just under the sewing needle
85
. The looper
87
is also connected to the above-mentioned driving power source via a transmission mechanism (not shown), and adapted to make one full turn synchronously with one upward and downward travel of the sewing needle
85
.
Thus, the two knitted fabrics
83
,
84
can be sewed together by forming a chain-like seam, so that a predetermined expansibility can be secured in the sewn portions of the knitted fabrics. Accordingly, the linking sewing machine can be adapted excellently to the property of knitted products having an expansibility. Since the sewing operation is carried out by carefully thrusting the locking needles
81
on the throat plate
82
into the loops
83
a,
84
a
of the knitted fabrics, the loops are arranged beautifully on the sewn portion. This can not only improve the design effect but also effectively prevent the knitted fabrics from coming loose at terminal end portions thereof.
However, in order to beautifully arrange the stitch loops on the sewn portion as mentioned above, it is necessary that the locking needles
81
on the throat plate
82
be thrust into all the loops
83
a,
84
a
in order without skipping any one of them, and this work is necessarily performed by manual operations of a skilled worker at present. Under the circumstances, even when the reduction of the sewing time is attempted by electrifying a driving means for the linking sewing machine
80
, it takes time to set objects to be sewn on the throat plate
82
, so that the improvement of an overall productivity by the sewing machine is greatly limited.
In a conventional linking sewing machine
80
, it is necessary that a sewing machine body be replaced in accordance with the coarseness or density of the stitches of the knitted fabrics
83
,
84
, objects to be sewn. The coarseness or density of the knitted fabrics
83
,
84
is determined by a gauge of the knitting machine, and the intervals of the locking needles
81
on the throat plate
82
are also regulated so as to match the same with the gauge. The timing of the upward and downward movements made by the sewing machine body of the sewing needle
85
and the intermittent feeding of the throat plate
82
is done fixedly in practice by selecting the kind and its combination of inside-provided gears. Therefore, in order to use a throat plate
82
matching the gauge of changed knitted fabrics
83
,
84
, the sewing machine body has to be replaced by a sewing machine body provided with a single-purpose gear structure specially adapted to this gauge, and this constitutes a large load on the improving of a labor effectiveness and a desire to make plant and equipment investment.
In order to obtain an article of clothing of certain function and design, the necessity of sewing a knitted fabric having a high expansibility and a woven fabric having a low expansibility together may arise. When the linking sewing machine
80
is used in such a case, stitches can be captured by the locking needles
81
. This enables loops to be arranged on a sewn portion, and the characteristics of the knitted fabrics to be effectively utilized. However, when a woven fabric having a low expansibility is sewn so as to form a chain-sewn fabric having an expansibility, a lot of fine wrinkles occur on the woven fabric, so that using for this purpose a linking sewing machine made solely for knitted fabrics is not suitable.
Therefore, the sewing of a knitted fabric and a woven fabric together has heretofore been done by a lock stitch sewing machine which is used to sew woven fabrics together. Unlike a linking sewing machine in which fabrics are sewn together with one yarn to form a chain-sewn fabric, the lock stitch sewing machine is adapted to combine upper and lower yarn with each other, so that a rigid and non-expansible seam is formed.
When a lock stitch sewing machine is thus used, a dense and strong seam is certainly formed owing to the intertwined upper and lower yarn, and fine wrinkles do not therefore occur on the woven fabric. However, the lock stitch sewing machine does not, of course, have locking needles, and cannot sew knitted fabr
Hashimoto Yoshiko
Knoble & Yoshida LLC
Nerbun Peter
LandOfFree
Sewing system and sewing method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sewing system and sewing method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sewing system and sewing method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2515061