U.S. patent application number 09/814832 was filed with the patent office on 2001-11-15 for sewing machine.
This patent application is currently assigned to Pegasus Sewing Machine Mfg. Co., Ltd.. Invention is credited to Hayashi, Masanori.
Application Number | 20010039907 09/814832 |
Document ID | / |
Family ID | 18638125 |
Filed Date | 2001-11-15 |
United States Patent
Application |
20010039907 |
Kind Code |
A1 |
Hayashi, Masanori |
November 15, 2001 |
Sewing machine
Abstract
A sewing machine related to the present invention comprises a
needle plate and feed dogs. A second feed dog slot provided at the
cloth send-in side of a portal shaped needle hole of the needle
plate is shifted to the right side from the center of the portal
shaped needle hole. The left side first feed dog slot is extending
toward the second feed dog slot side in the cloth send-in side of
the portal shaped needle hole, so as to be formed a wide breadth
portion from side to side. A first cross-piece of the needle plate
is disposed between the wide breadth portion and a needle drop
portion of the portal shaped needle hole, and a second cross-piece
of the needle plate is disposed between the second feed dog slot
and said needle drop portion. The first cross-piece is formed wider
in the cloth feed direction than the second cross-piece. A
differential feed dog disposed in the cloth send-in side of the
needle drop portion is composed in a shape combining each feed dog
slots. Therefore the cloth can be fed so as not to deviate in the
lateral positions of the cloth end, and the spacing margin between
the outlet seam end and the seam is controlled at a specified
level, so that a sewn product of excellent appearance is
obtained.
Inventors: |
Hayashi, Masanori; (Osaka,
JP) |
Correspondence
Address: |
Felix J. D'Ambrosio
JONES, TULLAR & COOPER, P.C.
Eads Station
P.O. Box 2266
Arlington
VA
22202
US
|
Assignee: |
Pegasus Sewing Machine Mfg. Co.,
Ltd.
|
Family ID: |
18638125 |
Appl. No.: |
09/814832 |
Filed: |
March 23, 2001 |
Current U.S.
Class: |
112/312 |
Current CPC
Class: |
D05B 73/12 20130101;
D05B 27/08 20130101 |
Class at
Publication: |
112/312 |
International
Class: |
D05B 027/08; D05B
027/16 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 28, 2000 |
JP |
2000-128727 |
Claims
What is claimed is:
1. A sewing machine comprising a needle plate having a portal
shaped needle hole including a needle drop portion, a pair of first
feed dog slots disposed at right and left side across the portal
shaped needle hole extending back and forth in the cloth feed
direction of the portal shaped needle hole, a second feed dog slot
disposed ahead in the cloth feed direction of said portal shaped
needle hole and a third feed dog slot disposed behind in the cloth
feed direction of said portal shaped needle hole, a presser foot
disposed above this needle plate, and feed dogs moving in and out
from the feed dog slots of said needle plate so as to feed the
J-shaped folded cloth, wherein said second feed dog slot is
disposed ahead the nearer side of the portal shaped needle hole
being shifted to the right side first feed dog slot side from the
center of the portal shaped needle hole, and the left side first
feed dog slot of said pair of right and left first feed dog slots
is extending toward the second feed dog slot side ahead in the
cloth feed direction of the portal shaped needle hole, so as to be
formed a wide breadth portion from side to side, a first
cross-piece of the needle plate is disposed between the wide
breadth portion and the needle drop portion of the portal shaped
needle hole, said first cross-piece is formed wider in the cloth
feed direction than a second cross-piece of the needle plate
disposed between the second feed dog slot and the needle drop
portion of the portal shaped needle hole, said feed dog is composed
of a main feed dog disposed in each feed dog slot behind the cloth
feed direction from the needle drop portion of the portal shaped
needle hole, and a differential feed dog disposed in each feed dog
slot ahead in the cloth feed direction from the needle drop portion
of the portal shaped needle hole, and each differential feed dog is
composed in a shape combining the first feed dog slot and second
feed dog slot.
2. The sewing machine of claim 1, wherein said second feed dog slot
is a single one.
3. The sewing machine of claim 1, wherein three needles are
provided, and the portal shaped needle hole of said needle plate
has three needle drop portions corresponding to three needles, and
said second feed dog slot is disposed before the cloth feed
direction of the right side needle drop portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sewing machine used in
hemming of J-shaped folded cloth.
[0003] 2. Description of the Related Art
[0004] Usually, a sewing machine used in hemming of J-shaped folded
cloth comprises, as shown in FIG. 4, a needle plate 102 having a
portal shaped needle hole 100 and the feed dog slots 104, 105, 106,
and the feed dogs (omitted in FIG. 4) projecting and retracting on
the top of the needle plate 102 from the first to third feed dog
slots 104, 105,106. The portal shaped needle hole 100 has two
needle drop portions 100b through which two needles 100a (see FIG.
5) pass. The first feed dog slots 104,104 of the needle plate 102
are disposed at the right and left side across the portal shaped
needle hole 100, each extending before and after the portal shaped
needle hole 100 in a state parallel to the cloth feed direction F.
The second feed dog slots 105,105 of the needle plate 102 are a
pair disposed at the right and left side ahead of the portal shaped
needle hole 100 in the cloth feed direction F. The third feed dog
slots 106,106 are a pair disposed at right and left side behind the
portal shaped needle hole 100 in the cloth feed direction F. The
J-shaped folded cloth set on the needle plate 102 is fed in the
cloth feed direction F by means of the feed dogs.
[0005] In the conventional sewing machine having the needle plate
102 and the feed dogs projecting and retracting from the feed dog
slots 104, 105, 106, when the feed dogs descend, a cloth end Wb of
the folded portion Wa of the J-shaped folded cloth W as shown in
FIG. 5 drops into the left side second feed dog slot of the pair of
right and left second feed dog slots 105,105 and the dropping state
continues until just before the portal shaped needle hole 100.
Accordingly, the cloth end Wb of the folded portion Wa is deviated
in lateral position with respect to the needle plate 102. In this
lateral position deviated state, if the folded portion Wa of the
J-shaped folded cloth W is sewn near the cloth end Wb, as shown in
FIG. 5, the spacing margin between the outlet seam end Wbb of the
folded portion Waa sewn to the cloth main body WW and the seam S is
not constant, and a corrugated state is formed, and the appearance
of the sewn product is impaired. Besides, the cloth end Wb dropping
into the left side second feed dog slot is sent by following up the
side end 105a of the left side second feed dog slot, and, as a
result, the spacing between the outlet seam end Wbb and the seam S
is not as specified.
SUMMARY OF THE INVENTION
[0006] The invention is devised in the light of the above problems,
and it is hence an object thereof to present a sewing machine
capable of feeding the cloth by stabilizing the lateral positions
of the cloth end of the folded portion when hemming the J-shaped
folded cloth, and controlling the spacing between the outlet seam
end of folded portion sewn to the cloth main body and the seam at a
specified level so as to obtain a sewn product of excellent
appearance.
[0007] To achieve the object, the sewing machine of the present
invention comprises a needle plate and feed dogs. The needle plate
includes a portal shaped needle hole having a needle drop portion,
a pair of first feed dog slots disposed at right and left side
across the portal shaped needle hole extending back and forth in
the cloth feed direction of the portal shaped needle hole, a second
feed dog slot disposed ahead in the cloth feed direction of the
portal shaped needle hole, and a third feed dog slot disposed
behind in the cloth feed direction of the portal shaped needle
hole. A presser foot is disposed above the needle plate, and feed
dogs move in and out from the feed dog slots of the needle plate so
as to feed the J-shaped folded cloth.
[0008] As the feature of the needle plate used in this sewing
machine, first, the second feed dog slot is disposed at the nearer
side of the portal shaped needle hole being shifted to the right
side first feed dog slot side from the center of the portal shaped
needle hole, and the left side first feed dog slot of the pair of
right and left first feed dog slots is extending toward the second
feed dog slot side ahead in the cloth feed direction of the portal
shaped needle hole, so as to be formed in a shape wide in the
lateral direction. A first cross-piece of the needle plate disposed
between the groove of the wide shape and the needle drop portion of
the portal shaped needle hole is formed wider in the cloth feed
direction than a second cross-piece of the needle plate disposed
between the second feed dog slot and the needle drop portion of the
portal shaped needle hole. The feed dog is composed of a main feed
dog disposed in each feed dog slot behind in the cloth feed
direction from the needle drop portion of the portal shaped needle
hole, and a differential feed dog disposed in each feed dog slot
ahead in the cloth feed direction from the needle drop portion of
the portal shaped needle hole, and each differential feed dog is
composed in a shape combining the first feed dog slot and second
feed dog slot.
[0009] According to the present invention, when the J-shaped folded
cloth is put onto the needle plate of the sewing machine, the
folded cloth is fed in the cloth feed direction by collaborative
action of the differential feed dog and the presser foot. At this
time, the second feed dog slot is disposed as being shifted to the
right side first feed dog slot side from the center of the portal
shaped needle hole, a wide slot extending from the left side first
feed dog slot is formed in the needle plate portion before the
portal shaped needle hole by this shifting, and the differential
feed dog is formed in the shape of combining the first feed dog
slot including this wide slot and second feed dog slot, and
therefore the cloth can be fed securely without causing deviation
in the lateral position due to drop of the cloth end of the folded
portion of the J-shaped folded cloth in the second feed dog slot
before the needle drop portion. Further, when the folded cloth is
fed forward to just before the needle drop portion of the portal
shaped needle hole, the cloth end of the folded portion is securely
supported by the first cross-piece formed widely in the cloth feed
direction, and the cloth can be fed up to the needle drop portion
while maintaining the specified lateral position without the cloth
end being fed along the side end of the second feed dog slot.
[0010] Thus, when hemming a J-shaped folded cloth, it is capable of
feeding the cloth by stabilizing the lateral positions of the cloth
end of the folded portion, and controlling the spacing between the
outlet seam end of folded portion sewn to the cloth main body and
the seam at a specified level, and therefore it is effective to
obtain a sewn product of excellent appearance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective appearance view of a double-chain
stitch sewing machine applied in the present invention.
[0012] FIG. 2 is a magnified plan view showing a needle plate of
said sewing machine.
[0013] FIG. 3 is a perspective view of a sewn product hemmed by
said sewing machine.
[0014] FIG. 4 is a magnified perspective view showing a needle
plate of a conventional sewing machine.
[0015] FIG. 5 is a perspective view of a sewn product hemmed by the
conventional sewing machine.
PREFERRED EMBODIMENT OF THE INVENTION
[0016] A preferred embodiment of the present invention is described
below while referring to the accompanying drawings.
[0017] FIG. 1 is a perspective appearance view of a sewing machine
applied in the present invention. This sewing machine 1 is a double
chain stitch sewing machine having three needles 2 and one looper
3. The sewing machine forms a seam S related to the stitch type 407
on the J-shaped folded cloth W (see FIG. 3) by means of three
needle threads 5 supplied into each needle 2 from a thread source
(not shown) through a thread tensioning device 4, and one looper
thread 6 supplied into the looper 3 through the same thread
tensioning device 4. Each needle 2 is fitted to a needle bar 7
which moves up and down in working with a sewing machine main shaft
D, and penetrates through three needle drop portions 9a, 9b, 9c of
the portal shaped needle hole 9 (see FIG. 2) of the needle plate 8
fixed to the bed portion la of the sewing machine 1. The looper 3
is mounted on the looper shaft (not shown) oscillating in working
with the sewing machine main shaft D, and moves reciprocally right
and left beneath the needle plate 8. Above the needle plate 8,
there is a presser foot 15 for pressing the folded cloth W onto the
needle plate 8.
[0018] The needle plate 8 includes, as shown in FIG. 2, a portal
shaped needle hole 9, a pair of first feed dog slots 10a, 10b, one
second feed dog slot 11 and a pair of third feed dog slots 12,12.
The portal shaped needle hole 9 has three needle drop portions 9a,
9b, 9c. The pair of first feed dog slots 10a, 10b is disposed at
right and left side across the portal shaped needle hole 9, and
extends before and after the cloth feed direction F of the portal
shaped needle hole 9. The second feed dog slot 11 is disposed ahead
in the cloth feed direction F of the portal shaped needle hole 9.
The third feed dog slots 12,12 are disposed behind in the cloth
feed direction F of the portal shaped needle hole 9.
[0019] The second feed dog slot 11 is shifted in one of the lateral
direction from the center of the portal shaped needle hole 9, and
is disposed specifically ahead in the cloth feed direction of the
right side needle drop portion 9c of the three needle drop portions
9a 9b, 9c. Of the first feed dog slots 10a, 10b, the left side
first feed dog slot 10a is extended toward the second feed dog slot
11 side ahead in the cloth feed direction of the portal shaped
needle hole 9 so as to form a wide breadth portion 10aa from side
to side. A first cross-piece 13a of the needle plate 8 is disposed
between the wide breadth portion 10aa and the left side needle drop
position 9a of the portal shaped needle hole 9. The first
cross-piece 13a is formed more widely in the cloth feed direction F
than a second cross-piece 13b of the needle plate 8 disposed
between the second feed dog slot 11 and the right side needle drop
position 9c of the portal shaped needle hole 9.
[0020] This double-chain stitch sewing machine 1 further comprises
a feed dog 14 which moves in and out from the feed dog slots 10a ,
10b, 11, 12, said feed dog 14 feeds the folded cloth W in the cloth
feed direction F. This feed dog 14 is composed of main feed dogs
14a disposed behind the cloth feed direction F from the needle drop
portions 9a, 9b, 9c of the portal shaped needle hole 9, and
differential feed dogs 14b disposed ahead in the cloth feed
direction F from the needle drop portions 9a, 9b, 9c of the portal
shaped needle hole 9. The differential feed dogs 14b are formed in
each shape conforming to the shape of the first feed dog slots 10a,
10b and second feed dog slot 11. That is, in the wide breadth
portion 10aa of the first feed dog slot 10a, a wide breadth feed
dog portion 14bb integrally extending from one of the differential
feed dog is positioned.
[0021] In the double chain stitch sewing machine 1 having such
configuration, the hemming operation is explained below.
[0022] When the J-shaped folded cloth W is put onto the needle
plate 8 of the sewing machine 1, the folded cloth W is fed to above
the portal shaped needle hole 9 in the cloth feed direction F by
cooperation of the presser foot 15 and differential feed dogs 14b.
At this time, the second feed dog slot 11 is disposed as being
shifted to the right side first feed dog slot 10b side from the
center of the portal shaped needle hole 9, and the wide breadth
portion 10aa extended from the left side first feed dog slot 10a is
formed in the portion of the needle plate 8 before the portal
shaped needle hole 9 produced by this shifting, and the
differential feed dogs 14b in a shape including the wide breadth
feed dog portion 14bb are disposed in the shape of the first feed
dog slot 10a including the wide breadth portion 10aa and second
feed dog slot 11, and the right side first feed dog slot 10b
extends before and after the cloth feed direction F of the portal
shaped needle hole 9, so that the folded portion Wa of the J-shaped
folded cloth W is securely fed to both cross-pieces 13a, 13b
without being shifted in the lateral position.
[0023] When the cloth end Wb of the folded portion Wa of the
J-shaped folded cloth W is fed to just before the portal shaped
needle hole 9, the cloth end Wb of the folded portion Wa is
securely held from beneath by the first cross-piece 13a formed
widely in the cloth feed direction F, and hence the cloth end Wb of
the folded portion Wa is not sent along the side of the second feed
dog slot 11, and is sent onto the needle drop portions 9a, 9b, 9c
while maintaining the specified lateral positions. It means that
the folded portion Wa is straightly sent in the cloth feed
direction F by the differential feed dog 14b. In particular, when
the cloth end Wb of the folded portion Wa is sewn by the sewing
machine 1 so as to protrude by a specified amount from the seam S,
as shown in FIG. 3, the spacing margin t between the outlet seam
end Wbb of the folded portion Waa sewn to the cloth main body WW
and the seam S is constant, and the appearance of the sewn product
is very excellent.
[0024] In the embodiment, the present invention is applied to the
double-chain stitch sewing machine having three needles, but not
limited to this, the present invention may be also applied to a
double-chain stitch sewing machine having two needles, or a
multi-needle flat seamer sewing machine, and the hemmed sewn
products of excellent appearance as described herein are
obtained.
[0025] The entire disclosure of Japanese Patent Application No.
2000-128727 filed on Apr. 28, 2000 including specification, claims,
drawings and summary are incorporated herein by reference in its
entirety.
* * * * *