U.S. patent application number 14/118902 was filed with the patent office on 2015-05-21 for multi-thread chain stitch sewing machine with seam ravel preventing apparatus.
This patent application is currently assigned to Yamato Sewing Machine Mfg. Co., Ltd.. The applicant listed for this patent is Seiji Hashimoto. Invention is credited to Seiji Hashimoto.
Application Number | 20150136004 14/118902 |
Document ID | / |
Family ID | 47641059 |
Filed Date | 2015-05-21 |
United States Patent
Application |
20150136004 |
Kind Code |
A1 |
Hashimoto; Seiji |
May 21, 2015 |
MULTI-THREAD CHAIN STITCH SEWING MACHINE WITH SEAM RAVEL PREVENTING
APPARATUS
Abstract
A needle plate base in a multi-thread chain stitch sewing
machine with a seam ravel preventing apparatus is divided into a
left needle plate base for attaching a needle plate thereto and
supporting a swinging support shaft of a thread hanging hook; and a
right needle plate base for fixedly supporting a stopper member and
a thread handling air cylinder and a stopper air cylinder. The
right needle plate base is fastened to a sewing machine bed. The
left needle plate base is fastenably and unfastenably fastened to
an upper surface of the bed via screw members. Adjustment of stitch
performation, and maintenance, e.g., replacement of various kinds
of components stored inside the bed, can extremely easily and
simply be carried out without having much trouble and requiring
labor and time, and therefore, the stitch performation and
predetermined ravel preventing function can be constantly surely
reproduced.
Inventors: |
Hashimoto; Seiji; (Osaka,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hashimoto; Seiji |
Osaka |
|
JP |
|
|
Assignee: |
Yamato Sewing Machine Mfg. Co.,
Ltd.
Osaka
JP
|
Family ID: |
47641059 |
Appl. No.: |
14/118902 |
Filed: |
August 7, 2012 |
PCT Filed: |
August 7, 2012 |
PCT NO: |
PCT/JP2012/070714 |
371 Date: |
November 20, 2013 |
Current U.S.
Class: |
112/165 ;
112/260; 112/286 |
Current CPC
Class: |
D05B 1/10 20130101; D05B
65/06 20130101; D05B 73/12 20130101; D05B 65/02 20130101; D05B
3/025 20130101 |
Class at
Publication: |
112/165 ;
112/286; 112/260 |
International
Class: |
D05B 1/10 20060101
D05B001/10; D05B 65/06 20060101 D05B065/06; D05B 73/12 20060101
D05B073/12; D05B 65/02 20060101 D05B065/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 8, 2011 |
JP |
2011-183121 |
Claims
1. A multi-thread chain stitch sewing machine with a seam ravel
preventing apparatus wherein the multi-thread chain stitch sewing
machine comprises a needle having a drop position moving up and
down while holding a needle thread; a looper which is movable
forward and backward while holding a looper thread in a direction
substantially orthogonal to a vertical movement path of the needle,
and catches a needle thread loop formed below a needle plate by the
needle during a forward movement; and a needle plate base having
the needle plate attached thereto and being attached to an upper
surface of a sewing machine bed, and wherein the multi-thread chain
stitch sewing machine forms multi-thread chain stitch seams on a
fabric by allowing the looper to catch the needle thread loop
formed below the needle plate by the needle, and then by
interlooping the needle thread with the looper thread held by the
looper, the multi-thread chain stitch sewing machine with the seam
ravel preventing apparatus comprising: a needle thread holding
mechanism comprising (i) a thread hanging hook which is
approachable and departable with respect to the looper, and swings
around a vertically extending support shaft in a plane
substantially parallel to the needle plate between a standby
position away from the looper and a thread hooking position close
to the looper, and (ii) a hook actuator for drivingly swinging the
thread hanging hook to the standby position and the thread hooking
position; a stopper mechanism comprising (iii) a stopper member
disposed at a position farther away from the needle plate than the
thread hanging hook of the needle thread holding mechanism, and
permits temporary suspension and unsuspension of a swing of the
thread hanging hook from the thread hooking position to the standby
position so that the needle thread loop caught by the thread
hanging hook at the thread hooking position is held at a hold
position between the thread hooking position and the standby
position, and (iv) a stopper actuator for performing the suspension
and the unsuspension of the stopper member; a connecting member for
interlockingly connecting the thread hanging hook of the needle
thread holding mechanism and the stopper member of the stopper
mechanism; and a control section for controlling the needle thread
holding mechanism and the stopper mechanism in association with a
vertical movement of the needle, forward and backward movements of
the looper, and feed of the fabric, so that the looper is moved
forward after a normal sewing is terminated, the thread hanging
hook of the needle thread holding mechanism is brought near the
looper, the needle thread loop caught at the thread hooking
position is moved to the hold position, a resulting state is
maintained until the needle descends through the needle thread loop
caught by the looper, and thereafter, a sewing action for at least
one stitch is performed, wherein the needle plate base is divided
into two sections: a left needle plate base for attaching the
needle plate thereto and supporting a swinging support shaft of the
thread hanging hook; and a right needle plate base for fixedly
supporting the stopper member and the hook actuator and the stopper
actuator, and wherein the right needle plate base is fastened to
the sewing machine bed, and the left needle plate base is
fastenably and unfastenably fastened to an upper surface of the
sewing machine bed via screw members.
2. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 1, further comprising: a
feed reducing mechanism for feeding the fabric at a lower feed rate
than during a normal sewing under an operation command provided
from the control section, in the sewing action for the at least one
stitch.
3. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 1, further comprising: a
looper thread restraining mechanism for restraining feed of the
looper thread to the looper under an operation command provided
from the control section, after the looper thread is positioned
ahead of or behind the drop position of the needle.
4. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 1, wherein the stopper
mechanism comprises: the stopper member directly connected to the
hook actuator and moves linearly reciprocally; a swing lever
engageable with and disengageable from a part of the stopper
member; a spring for swingingly energizes the swing lever in a
direction in which the thread hanging hook is positioned at the
standby position; and the stopper actuator for disengaging the
swing lever from the part of the stopper member against an
energizing force of the spring.
5. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 4, wherein the swing lever
in the stopper mechanism is attached to a movable base attached
laterally position-adjustably to the right needle plate base.
6. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 4, wherein the hook
actuator of the needle thread holding mechanism and the stopper
actuator of the stopper mechanism are fixedly supported on a lower
surface of the right needle plate base in a vertical two-stage
fashion.
7. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 1, further comprising: a
looper thread holder which holds the looper thread extending from
the looper to the fabric at a more forward position than the drop
position of the needle by swinging together with the thread hanging
hook of the needle thread holding mechanism around the support
shaft in a plane substantially parallel to the needle plate,
between the thread hooking position, the hold position, and the
standby position; and an actuator for swinging the looper. thread
holder.
8. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 1, wherein the looper
thread holder is fastened together with the thread hanging hook of
the needle thread holding mechanism to swing integrally with the
thread hanging hook around the swinging support shaft in the plane
substantially parallel to the needle plate, between the thread
hooking position, the hold position, and the standby position.
9. The multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus according to claim 8, wherein the looper
thread holder is attached position adjustably to the thread hanging
hook.
10. The multi-thread chain stitch sewing machine with the seam
ravel preventing apparatus according to claim 1, wherein the hook
actuator of the needle thread holding mechanism and the stopper
actuator of the stopper mechanism are both air cylinders.
11. The multi-thread chain stitch sewing machine with the seam
ravel preventing apparatus according to claim 1, further comprising
a pin protruding upwardly from a connection end portion of the
connecting member, and a connection end portion of the thread
hanging hook is provided with a connecting hole that is insertable
into the pin from above the pin, and is drawable in an upward
direction.
12. The multi-thread chain stitch sewing machine with the seam
ravel preventing apparatus according to claim 1, wherein the left
needle plate base or the sewing machine bed comprise protruding
knock pins for positioning the left needle plate base to the sewing
machine bed at a plurality of positions away from a plurality of
fixedly connecting portions and connection release portions by the
screw members, and wherein the sewing machine bed or the left
needle plate base is provided with pin holes engageable with the
knock pins.
13. The multi-thread chain stitch sewing machine with the seam
ravel preventing apparatus according to claim 1, wherein a target
sewing machine is a horizontal tube type single needle multi-thread
chain stitch sewing machine.
14. The multi-thread chain stitch sewing machine with the seam
ravel preventing apparatus according to claim 1, wherein a target
sewing machine is a horizontal tube type multi-needle multi-thread
chain stitch sewing machine.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Stage application of
International Application No. PCT/JP2012/070714, filed on Aug. 7,
2012 and claims priority of Japanese application serial number
2011-183121 filed on Aug. 8, 2011, all of which are incorporated
herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a multi-thread chain stitch
sewing machine typically represented by a horizontal tube type
multi-thread chain stitch sewing machine, which forms multi-thread
chain stitch seams with a needle thread and a looper thread, and is
provided with a seam ravel preventing apparatus for preventing a
ravel from occurring in a certain portion at the end of sewing of
multi-thread chain stitch seams.
[0004] 2. Background Art
[0005] The horizontal tube type multi-thread chain stitch sewing
machine includes one or more needles moving up and down while
holding a needle thread, and a looper which moves forward and
backward while holding a looper thread in a direction substantially
orthogonal to a vertical movement path of the needle. In this
sewing machine, a needle thread loop formed below a needle plate by
the needle is caught by the forward movement of the looper, and the
needle thread is interloped by the looper thread held by the
looper, thereby forming the multi-thread chain stitch seams.
[0006] General multi-thread chain stitch seams formed by the
multi-thread chain stitch sewing machine have suffered from the
following problem. That is, as shown in FIG. 20, when an end
portion of a looper thread 10 cut at the end of sewing is pulled in
a direction indicated by the arrow in FIG. 20, the looper thread 10
slips out of the last needle thread loops 20a and 20b respectively
formed by needle threads 20 and 20. The slipping-out is likely to
propagate toward a sewing start point, thus causing ravel
throughout the entirety of the seams.
[0007] This ravel occurs similarly in multi-thread chain stitch
seams formed with a needle thread or two or more needle threads and
a looper thread.
[0008] For the purpose of preventing the ravel peculiar to the
seams formed by the multi-thread chain stitch sewing machine, the
present applicant has already developed and filed the patent
application related to the following multi-thread chain stich
sewing machine with a ravel preventing apparatus (hereinafter
referred to as the technique described in an already-filed patent
application of the present applicant).
[0009] The ravel preventing apparatus for the multi-thread chain
stitch sewing machine of the technique described in the
already-filed patent application (A two-needle sewing machine is
described here.) is configured by including (i) needles 2 and 2
(refer to FIGS. 11 to 17) moving up and down while holding the
needle threads 20 and 20, with respect to needle drop positions A
and A set with a distance laterally interposed therebetween at a
substantially middle portion of a needle plate P as shown in FIGS.
21 to 23; (ii) a looper 1 (refer to FIGS. 11 to 17) which can
perform forward and backward movements while holding a looper
thread 10 in an arrangement direction of the needle drop positions
A and A, and catches needle thread loops 20a and 20b formed below
the needle plate P during the forward movement; (iii) a thread
hanging hook 3 which can perform approach and departure movement
with respect to the looper 1, and swings around a vertically
extending support shaft 30 between a standby position away from the
looper 1 as shown in FIG. 21, and a thread hooking position
adjacent to the looper 1 as shown in FIG. 23, in a plane
substantially parallel to the needle plate P, and a thread handling
air cylinder (hereinafter including one called thread handling
cylinder) 32 as a hook actuator for drivingly swinging the thread
hanging hook 3 to the standby position and the thread hooking
position; (iv) a swing lever 9 which is disposed at a position
farther away from the needle plate P than the thread hanging hook
3, and swings around a vertically extending support shaft 90 in the
plane substantially parallel to the needle plate P so that the
needle thread loops 20a and 20b caught at the thread hooking
position by the thread hanging hook 3 are held at a hold position
between the thread hooking position and the standby position, and a
stopper lever 4; (v) a stopper air cylinder (hereinafter including
one referred to as a stopper cylinder) 42 as a stopper actuator for
drivingly swinging the stopper lever 4 from an engaging position at
which the stopper lever 4 engages with a part of the swing lever 9,
to a retracted position away from the engaging position; (vi) a
connecting rod 35 for interlockingly connecting the thread hanging
hook 3 and the swing lever 9; and (vii) a control section 8 (refer
to FIG. 8) which performs selective action control of the thread
handling cylinder 32 and the stopper cylinder 42 after terminating
the normal sewing, and allows the needle thread loop 20b, one of
those caught at the thread hooking position by the thread hanging
hook 3, to be held at the hold position so that a sewing action for
at least one stich is performed while maintaining the hold
state.
[0010] Structural members and structural portions in the ravel
preventing apparatus of the multi-thread chain stitch sewing
machine of the technique described in the already-filed patent
application by the present applicant, which are identical to or
corresponding to a ravel preventing apparatus as an embodiment of
the present invention described later, are identified by the same
reference numerals as in the embodiment of the present invention,
and their respective detailed descriptions are omitted here.
[0011] In the already-filed patent application by the present
applicant, after terminating the normal sewing, the foregoing
sewing action for a stitch is performed by controlling the actions
of the thread hanging hook 3, the stopper lever 4, and the swing
lever 9 via the control section. Thereby, as shown in FIG. 18, the
looper thread 10 passes through the final needle thread loop 20a on
the right side (the left side in FIG. 18) that is formed finally in
the multi-thread chain stitch seams M on a rear surface of a
fabric, and is turned back in front of the needle thread 20, which
slips out toward the rear surface of the fabric when sewing one
stitch for preventing ravel, and is then cut at a certain position
after passing through the right final needle thread loop 20a. On
the other hand, the needle thread 20 on the left side (the right
side in FIG. 18), which slips out toward the rear surface of a
fabric when sewing the one stitch, passes through a final needle
thread loop 20b finally formed at the end of the normal sewing on
the rear surface of the fabric, and allows the final needle thread
loop 20b to be selflooped, thereby forming chain stitch seams.
Consequently, the looper thread 10 enters into a state of being
pressed between the left needle thread 20 and the left final needle
thread loop 20b, as shown in FIG. 18.
[0012] Although FIG. 18 shows a state in which the left final
needle thread loop 20b and the needle thread 20 are loose in order
to clarify entanglement between the two, the actual left final
needle thread loop 20b is strongly tightened after the needle
thread 20 passes therethrough, thereby entering into a state
similar to that of the right final needle thread loop 20a, as shown
in FIG. 19. The looper thread 10 is strongly pressed between the
needle thread 20 and the left final needle thread loop 20b, and is
restricted in a state of being hung over the left final needle
thread loop 20 and the left needle thread loop 20c formed
immediately before. This restriction is maintained even when the
looper thread 10 is subject to a force exerted from any direction,
as shown in FIG. 19, thereby surely preventing occurrence of ravel
peculiar to the multi-thread chain stitch seams M.
[0013] Thus, the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the technique
described in the already-filed patent application by the present
applicant is capable of effectively preventing the occurrence of
ravel peculiar to the multi-thread chain stitch seams. However, the
following problem that needs improvement remains unsolved in the
multi-thread chain stitch sewing machine with the seam ravel
preventing apparatus.
[0014] That is, in the technique described in the already-filed
patent application by the present applicant, as shown in FIGS. 21
to 23, the thread hanging hook 3, the stopper lever 4, the swing
lever 9, the thread handling cylinder 32, the stopper cylinder 42,
which are the structural elements of the seam ravel preventing
apparatus, are supported to a laterally long and large needle plate
base 11 which has the needle plate P attached thereto, and is
fastened to an upper surface of a sewing machine bed. Specifically,
the support shaft 30 for the swing of the thread hanging hook 3 is
supported at a position in the vicinity of the rear side of the
needle plate P on the left side of the needle plate base 11. On the
other hand, the stopper lever 4, the swing lever 9, the thread
handling cylinder 32, and the stopper cylinder 42 are respectively
supported at positions away from the needle plate P on the right
side of the needle plate base 11. Also, the connecting rod 35 is
connected between a front end portion of the swing lever 9 and a
front end portion of an extended part 3c extended so as to be
folded forward from the support shaft 30 for swinging the thread
hanging hook 3. Reference numeral 6 in FIGS. 21 to 23 denotes a
looper thread holder fastened together with the thread hanging hook
3 via fixing screws 60 and 60.
[0015] Thus, in the multi-thread chain stitch sewing machine of the
technique described in the already-filed patent application by the
present applicant, all the structural elements of the seam ravel
preventing apparatus are supported by the laterally long and large
needle plate base 11. Therefore, if after the needle plate base 11
with the components of the ravel preventing apparatus installed and
supported thereon is attached to the upper surface of the sewing
machine bed, it becomes necessary to adjust, for example, stitch
performation by correcting the positions and the loci of actions of
members performing sewing action which are stored below the needle
plate base 11 and inside the sewing machine bed, such as the looper
and the members for actuating the looper, or it becomes necessary
to perform maintenance, such as replacement of various kinds of
components incorporated into the sewing machine bed, an operating
space that is wide enough to perform the adjustment and the
maintenance cannot be ensured only by removing the needle plate P.
Hence, to ensure the wide operating space, it becomes necessary to
perform an operation requiring labor in which predetermined
adjustment and maintenance are carried out after the entirety of
the long large needle plate base 11 is temporarily removed from the
sewing machine bed, and thereafter the entirety of the long and
large needle plate base 11 is reattached to the sewing machine
bed.
[0016] Particularly, air tubes 33 and 43 for supplying operating
air to the thread handling cylinder 32 and the stopper cylinder 42
are respectively connected to these two cylinders. Therefore, it
becomes necessary to perform extremely bothersome and
time-consuming operation in which when removing and attaching the
needle plate base 11, these two air tubes 33 and 43 are pulled out
from inside the sewing machine bed so that both do not obstruct the
removal and attachment operations, and after these operations, both
air tubes are pushingly returned to the inside of the sewing
machine bed. However, unless the bothersome and time-consuming
adjustment and maintenance operations are carried out, there is a
probability that the stitch performation is deteriorated, and a
predetermined ravel preventing function cannot be reproduced. This
necessitates the extremely bothersome and time and labor consuming
operations. This problem also still remains unsolved.
CITED REFERENCES
[0017] Japanese Patent Application No. 2011-016821
[0018] Japanese Patent Application No. 2011-115174
SUMMARY OF THE INVENTION
Technical Problem
[0019] The present invention has been made in view of the foregoing
circumstances, and an object thereof is to provide a multi-thread
chain stitch sewing machine with a seam ravel preventing apparatus,
with which the occurrence of ravel peculiar to the multi-thread
chain stich seams can effectively be prevented, and the
maintenance, such as the adjustment of stitch performation by the
position correction of the members for performing sewing action,
and the replacement of various kinds of components stored inside
the sewing machine bed can extremely easily and simply be carried
out without having much trouble and requiring labor and time,
thereby allowing the stitch performation and predetermined ravel
preventing function to be constantly surely reproduced.
Solution to Problem
[0020] In order to achieve the above object, the multi-thread chain
stitch sewing machine with the seam ravel preventing apparatus
according to the present invention includes a needle moving up and
down while holding a needle thread; a looper which is movable
forward and backward while holding a looper thread in a direction
substantially orthogonal to a vertical movement path of the needle,
and catches a needle thread loop formed below a needle plate by the
needle during a forward movement; and a needle plate base having
the needle plate attached thereto and being attached to an upper
surface of a sewing machine bed. The multi-thread chain stitch
sewing machine forms multi-thread chain stitch seams on a fabric by
allowing the looper to catch the needle thread loop formed below
the needle plate by the needle, and then by interlooping the needle
thread with the looper thread held by the looper. The multi-thread
chain stitch sewing machine with the seam ravel preventing
apparatus includes (A) a needle thread holding mechanism having (i)
a thread hanging hook which is approachable and departable with
respect to the looper, and swings around a vertically extending
support shaft in a plane substantially parallel to the needle plate
between a standby position away from the looper and a thread
hooking position close to the looper, and (ii) a hook actuator for
drivingly swinging the thread hanging hook to the standby position
and the thread hooking position; (B) a stopper mechanism having
(iii) a stopper member which is disposed at a position farther away
from the needle plate than the thread hanging hook of the needle
thread holding mechanism, and permits temporary suspension and
unsuspension of a swing of the thread hanging hook from the hooking
position to the standby position so that the needle thread loop
caught by the thread hanging hook at the thread hooking position is
held at a hold position between the thread hooking position and the
standby position, and (iv) a stopper actuator for performing the
suspension and the unsuspension of the stopper member; (C) a
connecting member for interlockingly connecting the thread hanging
hook of the needle thread holding mechanism and the stopper member
of the stopper mechanism; and (D) a control section which controls
the needle thread holding mechanism and the stopper mechanism in
association with a vertical movement of the needle, forward and
backward movements of the looper, and feed of the fabric, so that
the looper is moved forward after a normal sewing is terminated,
the thread hanging hook of the needle thread holding mechanism is
brought near the looper, the needle thread loop caught at the
thread hooking position is moved to the hold position, a resulting
state is maintained until the needle descends through the needle
thread loop caught by the looper, and thereafter, a sewing action
for at least one stitch is performed.
[0021] The needle plate base is divided into two sections: a left
needle plate base for attaching a needle plate thereto and
supporting a swinging support shaft of a thread hanging hook; and a
right needle plate base for fixedly supporting the stopper member
and the hook actuator and the stopper actuator. The right needle
plate base is fastened to the sewing machine bed. The left needle
plate base is fastenably and unfastenably fastened to an upper
surface of the sewing machine bed via screw members.
Advantageous Effects of Invention
[0022] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus having the foregoing characteristic
features, after normal sewing is terminated, the looper is moved
forward, and the thread hanging hook of the needle thread holding
mechanism is brought near the looper, and the needle thread loop
caught by the looper is moved to the hold position and, in this
state, the sewing action for at least one stitch is performed.
Accordingly, the preceding needle thread loop is self-looped with
the needle thread held by the descending needle, and the looper
thread is held down by the self-looped portion, thereby preventing
slippage of the looper thread. That is, a seam ravel can surely be
prevented in its developmental stage.
[0023] Further in the present invention, the needle plate base
attached to the sewing machine bed is divided into the two
sections: the right needle plate base for attaching the needle
plate thereto and swingably supporting the thread hanging hook of
the needle thread holding mechanism; and the right needle plate
base for fixedly supporting the stopper member of the stopper
mechanism, the hook actuator, and the stopper actuator. Hence, as
compared with handling of the single long and large needle plate as
in the case of the technique described in the already-filed patent
application by the present applicant, the attachment (installation)
of the entirety of the ravel preventing apparatus with respect to
the sewing machine bed can be easily carried out with less effort
because the left and right needle plate bases can be individually
attached to the sewing machine bed, and the ravel preventing
apparatus can be incorporated into the sewing machine bed.
[0024] Furthermore, if after the seam ravel preventing apparatus is
incorporated into the sewing machine bed, it becomes necessary to
adjust stitch performation by correcting the position and motion
loci of components for carrying out the sewing action which are
stored below the needle plate base and inside the sewing machine
bed, such as the looper and the members for actuating the looper,
or it becomes necessary to perform maintenance, such as mending and
replacement, on various types of components stored below the needle
plate base and inside the sewing machine bed, it is unnecessary to
remove the right needle plate base for fixedly supporting the hook
actuator and the stopper actuator to which an air tube or an
electric power supply line is connected, and a sufficiently wide
operating space can be ensured by unfastening and removing only the
left needle plate base from the sewing machine bed.
[0025] Hence, the adjustment of sewing performation, and the
maintenance such as the mending and replacement on the various
types of components stored inside the sewing machine bed can be
performed extremely easily, simply, and efficiently only by
handling the small and lightweight left needle plate base to which
neither the air tube nor the electric power supply line clings.
This produces the effect that satisfactory sewing performation and
the predetermined ravel prevention function can constantly be
exhibited with superior reproducibility, thereby succeeding in
solving the problem remained unsolved in the already-filed patent
application by the present applicant.
[0026] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
the stopper mechanism is preferably made up of a stopper member
which is directly connected to the hook actuator and moves linearly
reciprocally; a swing lever engageable with and disengageable from
a part of the stopper member; a spring for swingingly energizes the
swing lever in a direction in which the thread hanging hook is
positioned at the standby position; and the stopper actuator for
disengaging the swing lever from the part of the stopper member
against an energizing force of the spring.
[0027] In this case, the action of the stopper member in a return
direction (the action in a direction in which the thread hanging
hook is positioned at the standby position) is performed by the
energizing force of the spring. Therefore, the stopper actuator for
actuating the swing lever that engages with or disengages from the
part of the stopper member may be one capable of pushingly driving
the stopper member. Hence, the use of an air cylinder as the
stopper actuator allows for employment of a single acting type air
cylinder, thereby achieving downsizing and cost reduction of the
stopper actuator.
[0028] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
the swing lever in the stopper mechanism is preferably attached to
a movable base attached laterally position-adjustably to the right
needle plate base.
[0029] In this case, by the lateral position adjustment of the
movable base with respect to the right needle plate base, the
timing that the looper comes out of the needle thread loop held by
the thread hanging hook can easily and appropriately be adjusted
attached to ensure self-looping for seam ravel prevention.
[0030] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
the hook actuator of the needle thread holding mechanism and the
stopper actuator of the stopper mechanism are preferably fixedly
supported on a lower surface of the right needle plate base in a
vertical two-stage fashion.
[0031] In this case, the two actuators are fixedly supported on the
right needle plate base in the vertical two-stage fashion, and
therefore the planar space occupied by these two actuators can be
reduced to permit compactness, thereby allowing them to be nicely
stored inside the sewing machine bed, compared with the case where
the two actuators are disposed at the positions separated from each
other (side-by-side arrangement) as in the case of the technique
described in the already-filed patent application by the present
applicant.
[0032] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
the thread hanging hook of the needle thread holding mechanism is
preferably provided with a looper thread holder which holds the
looper thread extending from the looper to the fabric at a more
forward position than the drop position of the needle by swinging
together with the thread hanging hook of the needle thread holding
mechanism around the support shaft in the plane substantially
parallel to the needle plate between the thread hooking position,
the hold position, and the standby position.
[0033] In this case, the looper thread is held at a position ahead
of the drop position of the needle by the looper thread holder that
cooperates with the thread hanging hook. This simple structure
allows the looper thread to be surely positioned together with the
needle thread. Accordingly, the self-looping can be surely
performed to more surely prevent the seam ravel.
[0034] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
the looper thread holder is preferably attached position adjustably
to the thread hanging hook.
[0035] In this case, a relative position between the needle thread
and the looper thread can be appropriately set, and the
self-looping can be performed more surely to further enhance the
seam ravel prevention effect.
[0036] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
the hook actuator of the needle thread holding mechanism and the
stopper actuator of the stopper mechanism are preferably both air
cylinders.
[0037] In this case, the thread hanging hook in the needle thread
holding mechanism and the swing lever in the stopper mechanism can
be operated with superior response on the basis of a control signal
from the control section, thereby achieving the reliable and
efficient seam ravel prevention effect after the normal sewing.
[0038] As these actuators, electromagnetic solenoids or the like
may be used.
[0039] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
a pin is preferably protruded upward from a connection end portion
of the connecting member, and a connection end portion of the
thread hanging hook is preferably provided with a connecting hole
that is insertable into the pin from above the pin, and is drawable
in an upward direction.
[0040] In this case, when the left needle plate base is removed
from the sewing machine bed in an upward direction by unfastening
it from the upper surface of the sewing machine bed in order to
perform the maintenance, such as mending and replacement, on the
various types of components stored inside the sewing machine bed,
the connection between the thread hanging hook and the connecting
member can be released only by raising the left needle plate base,
without requiring any troublesome operation, such as unfastening
and removing a screw that connects the connecting member and the
thread hanging hook, or pulling-out of a connecting pin.
Additionally, after the adjustment and maintenance, the thread
hanging hook and the connecting member can be returned to the
predetermined connected state only by fixedly fastening the left
needle plate base to the sewing machine bed from above. This
further saves time and trouble during the adjustment and
maintenance.
[0041] In the multi-thread chain stitch sewing machine with the
seam ravel preventing apparatus according to the present invention,
the left needle plate base or the sewing machine bed are preferably
provided with protruding knock pins which are capable of
positioning the left needle plate base to the sewing machine bed at
a plurality of positions away from a plurality of fixedly
connecting portions and connection release portions by means of the
screw members, and the sewing machine bed or the left needle plate
base is preferably provided with pin holes engageable with the
knock pins.
[0042] In this case, when the left needle plate base is attached to
and detached from the sewing machine bed, the left needle plate
base can be surely positioned at a predetermined position in the
sewing machine bed by the engagement between the plurality of knock
pins and pin holes. Therefore, even when the left needle plate base
is repetitively attached to and detached from the sewing machine
bed every time the adjustment and maintenance are carried out, the
left needle plate base can be attached to the sewing machine bed by
constantly ensuring predetermined position and posture.
Consequently, besides the normal sewing, the seam ravel prevention
function can also be constantly performed appropriately surely.
[0043] The seam ravel preventing apparatus of the present invention
is suitably applicable to a horizontal tube type multi-thread chain
stitch sewing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a perspective view showing a general appearance of
a horizontal tube type multi-thread chain stitch sewing machine
with a seam ravel preventing apparatus according to an embodiment
of the present invention;
[0045] FIG. 2 is a perspective view showing the structure of the
main parts of the seam ravel preventing apparatus in the horizontal
tube type multi-thread chain stitch sewing machine;
[0046] FIG. 3 is a perspective view showing a state in which a part
of the structure of the main parts of the seam ravel preventing
apparatus is removed;
[0047] FIG. 4 is a plan view showing the structure of the main
parts of the seam ravel preventing apparatus;
[0048] FIG. 5 is a bottom plan view of the main parts for
explaining the structure of a stopper mechanism and a first action
thereof in the seam ravel preventing apparatus;
[0049] FIG. 6 is a bottom plan view for explaining the structure of
the stopper mechanism and a second action thereof;
[0050] FIG. 7 is a bottom plan view for explaining the structure of
the stopper mechanism and a third action thereof;
[0051] FIG. 8 is a bottom plan view for explaining the structure of
the stopper mechanism and a fourth action thereof;
[0052] FIG. 9 is a block diagram showing the configuration of a
control system of the horizontal tube type multi-thread chain
stitch sewing machine including the seam ravel preventing
apparatus;
[0053] FIG. 10 is a time chart for explaining operation contents of
a control section in the seam ravel preventing apparatus;
[0054] FIG. 11 is an explanatory drawing of a first ravel
prevention action by the seam ravel preventing apparatus;
[0055] FIG. 12 is an explanatory drawing of a second ravel
prevention action by the seam ravel preventing apparatus;
[0056] FIG. 13 is an explanatory drawing of a third ravel
prevention action by the seam ravel preventing apparatus;
[0057] FIG. 14 is an explanatory drawing of a fourth ravel
prevention action by the seam ravel preventing apparatus;
[0058] FIG. 15 is an explanatory drawing of a fifth ravel
prevention action by the seam ravel preventing apparatus;
[0059] FIG. 16 is an explanatory drawing of a sixth ravel
prevention action by the seam ravel preventing apparatus;
[0060] FIG. 17 is an explanatory drawing of a seventh ravel
prevention action by the seam ravel preventing apparatus;
[0061] FIG. 18 is a view of a seam structure of twin-needle
multi-thread chain stitch obtained by the present invention, viewed
from the rear surface of a fabric;
[0062] FIG. 19 is an explanatory drawing of ravel prevention effect
of the seam structure shown in FIG. 18;
[0063] FIG. 20 is a view of a general seam structure in a portion
at the end of sewing, viewed from the rear surface of the
fabric;
[0064] FIG. 21 is a plan view roughly showing the structure of the
main parts of the seam ravel preventing apparatus of the technique
described in the already-filed patent application by the present
applicant;
[0065] FIG. 22 is a bottom plan view roughly showing the structure
of the main parts of the seam ravel preventing apparatus of the
technique described in the already-filed patent application by the
present applicant; and
[0066] FIG. 23 is a plan view for explaining action states of the
main parts of the seam ravel preventing apparatus of the technique
described in the already-filed patent application by the present
applicant.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0067] An embodiment of the present invention is described below
with reference to the accompanying drawings.
[0068] FIG. 1 is the perspective view showing the general
appearance of the horizontal tube type multi-thread chain stitch
sewing machine according to the embodiment of the present
invention. FIGS. 2 and 3 are the perspective views showing the
structure of the main parts of the seam ravel preventing apparatus
included in the horizontal tube type multi-thread chain stitch
sewing machine according to the present invention. FIG. 4 is the
plan view showing the structure of the main parts of the seam ravel
preventing apparatus. The following description is made using terms
"left," "right," "forward," and "backward" indicated by arrows in
FIGS. 2 to 4. That is, the term "forward" denotes the side near a
sewing operator. The term "backward" denotes the side away from the
sewing operator. The terms "left" and "right" denote the left and
right, viewed from the front near the sewing operator.
[0069] In the present embodiment, structural members and structural
portions, which are identical to or corresponding to the technique
of the already-filed patent application by the present applicant
described with reference to FIGS. 21 to 23, are described using the
same reference numerals.
[0070] As shown in FIG. 1, in the horizontal tube type multi-thread
chain stitch sewing machine according to the present embodiment of
the present invention, a sewing machine arm C and a sewing machine
bed B are extended substantially horizontally toward the left from
an upper position and a lower position of a body section D,
respectively. As shown in FIG. 4, the horizontal tube type
multi-thread chain stitch sewing machine includes a looper 1, two
needles 2 and 2 (refer to FIGS. 11 to 17), a needle plate base 11
secured to an upper surface of the sewing machine bed B, a seam
ravel preventing apparatus H incorporated into the needle plate
base 11, and a needle plate P secured onto the needle plate base
11. The needles 2 and 2 move up and down via actions of a needle
bar driving mechanism. Alphabetic characters A and A in FIGS. 2 and
4 denote needle drop positions (descent positions) of the needles 2
and 2, respectively. The needle drop positions A and A are set with
a distance laterally interposed therebetween at a substantially
middle portion of the needle plate P.
[0071] The looper 1 moves forward and backward (left forward motion
and right backward motion) via the actions of the looper driving
mechanism. A solid line in FIG. 4 indicates a state in which the
looper 1 has moved to a left forward position, and a broken line in
FIG. 4 indicates a state in which the looper 1 has moved to a right
backward position. As shown by the solid line in FIG. 4, a front
end portion of the looper 1 at the left forward position extends
leftward across the needle drop positions A and A. As shown by the
broken line in FIG. 4, the front end portion of the looper 1 at the
right backward position is located rightward away from the needle
drop positions A and A.
[0072] The horizontal multi-thread chain stitch sewing machine sews
a fabric (not shown) set on the needle plate P by the up and down
movements of the needles 2 and 2, and the left forward and right
backward movements of the looper 1. The fabric is pressed against
the needle plate P by a presser foot (not shown), and is fed in a
direction of arrow Y in FIG. 4 by the action of a feed mechanism
installed inside a sewing machine bed B. The feed mechanism
includes a feed dog that repeats the following movements in which
the feed dog moves in a backward direction while protruding from
the needle plate P, and moves in a forward direction while sinking
under the needle plate P. The fabric is intermittently fed in a
direction of arrow Y by the feed dog.
[0073] The foregoing needle bar driving mechanism, looper driving
mechanism, and feed mechanism are well known mechanisms which
operate mutually synchronously by power transmission from a sewing
machine spindle (not shown). The needles 2 and 2 respectively hold
needle threads 20 and 20 (refer to FIGS. 11 to 17), and pass
through the fabric and reach below the needle plate P during
discontinuation of the fabric feeding, and thereafter, these
needles move up and pass through the fabric in an upward direction.
The looper 1 holds a looper thread 10 (refer to FIGS. 11 to 17),
and moves toward the left at the same moment that the needles 2 and
2 start moving up, thereby catching loops 20a and 20b of the needle
threads 20 and 20 which are formed below the needle plate P. The
fabric is fed when the needles 2 and 2 move up. The needle 2 and 2
move down while passing through the fed fabric, and catch the
looper thread 10 held by the looper 1 retracted toward the right.
The multi-thread chain stitch sewing machine forms multi-thread
chain stitch seams on the fabric by repeating the forgoing
actions.
[0074] The seam ravel preventing apparatus H included in the
foregoing horizontal tube type multi-thread chain stitch sewing
machine includes a needle thread holding mechanism, a stopper
mechanism, a connecting rod 35 as a connecting member for
interlockingly connecting a thread hanging hook 3 (described later)
of the needle thread holding mechanism and a stopper member 4
(described later) of the stopper mechanism, and a control section 8
(described later).
[0075] The needle thread holding mechanism includes the thread
hanging hook 3, and a reciprocating type thread handling cylinder
32 as a hook actuator for drivingly swinging the thread hanging
hook 3 around a vertical extending support shaft 30 between a
standby position away from the looper 1 and a thread hooking
position adjacent to the looper 1. The supporting shaft 30 as the
swing center of the thread hanging hook 3 is disposed in the
vicinity of a right back side corner of the needle plate P, and is
supported on the needle plate base 11.
[0076] The thread hanging hook 3 has an arcuately curved shape, and
is continuously formed so as to be folded forward at a front end
portion of a support arm 3e extending leftward from the support
shaft 30. A front end portion of the thread hanging hook 3 is faced
onto the needle drop positions A and A from the left back on a
lower side of the needle plate P. An outward protruding hook
portion 3b is formed at the front end portion of the thread hanging
hook 3. The support arm 3e has an extended portion 3c extending
forward from the support shaft 30, and one end of the connecting
rod 35 is connected to a front end portion of the extended portion
3c.
[0077] As shown in FIG. 4, a looper thread holder 6 having an
arcuately curved shape is fastened together with a base part of the
thread hanging hook 3 via two fixing screws 60 and 60. A front end
portion of the looper thread holder 6 extends forward substantially
along the left side of the thread hanging hook 3, and is faced onto
the needle drop positions A and A at a front position of the front
end portion of the thread hanging hook 3. A looper thread receiving
portion 6a branched into two is formed at the front end portion of
the looper thread holder 6. The looper thread holder 6 permits
position adjustment with respect to the thread hanging hook 3 by
unfastening the fixing screws 60 and 60. The position adjustment
ensures holding of the looper thread 10 by the looper thread
receiving portion 6a located at the front end.
[0078] As shown in FIGS. 5 to 8, the stopper mechanism is comprised
of a stopper member 4 which is fastened to a front end portion
(left end portion) of an output rod 31 of the thread handling
cylinder 32 via a fixing screw 36, and is linearly reciprocally
drivingly moved in a lateral direction due to expansion and
contraction of the thread handling cylinder 32 by operating air
supplied via an air tube 33; a swing lever 9 engageable with and
disengageable from a part of the stopper member 4; a spring 91
which allows the swing lever 9 to be engaged with the part of the
stopper member 4, and swingingly energizes in a direction in which
the thread hanging hook 3 is located at the standby position; and a
stopper cylinder 42 of single acting type (drivingly push-out type
in the left direction) as a stopper actuator which forcibly
disengages the swing lever 9 from the part of the stopper member 4
against the swing energizing force of the spring 91.
[0079] The output rod 41 of the stopper cylinder 42 is configured
to swing the swing lever 9 counterclockwise against the swing
energizing force of the spring 91 as the stopper cylinder 42 is
drivingly pushed out toward the left by the operating air supplied
via the air tube 43.
[0080] The swing lever 9 is supported on the upper surface of a
swing lever mount (movable mount) 92 so as to be swingable around
the center of the vertically extending support shaft 90. The swing
lever 9 has at a front end portion thereof an engaging claw 9a
engageable with the part of the stopper member 4. As shown in FIG.
5, the swing lever 9 is contacted with a side part of the stopper
member 4 by the energizing force of the spring 91 during the time
the stopper member 4 is drivingly moved toward the left by the
expansion stroke of the thread handling cylinder 32, that is,
during the time the thread hanging hook 3 is moved to the standby
position. As shown in FIG. 6, the swing lever 9 swings clockwise
around the support shaft 90 by the energizing force of the spring
91, and the engaging claw 9a at the front end thereof enters a
state of being engageable with the part of the stopper member 4
while the stopper member 4 is drivingly moved toward the right by
the contraction stroke of the thread handling cylinder 32.
[0081] As shown in FIG. 7, by allowing the contracted thread
handling cylinder 32 to resume somewhat the contraction stroke, the
engaging claw 9a at the front end of the swing lever 9 engages with
the part of the stopper member 4, thereby temporarily suspending
the leftward driving movement of the stopper member 4. In the state
in which the stopper member 4 is thus temporarily suspended, the
thread hanging hook 3 moves to the hold position between the
standby position and the thread hooking position, and remains there
via the connecting rod 35. At this time, the hook portion 3b at the
front end of the thread hanging hook 3 moves from the thread
hooking position shown in FIG. 4 (between the right and left needle
drop positions A and A) to left back of the left needle drop
position A, and hooks the left needle thread 20 and holds it at the
hold position. The looper thread holder 6 moves forward to the
front of the looper 1, and the looper thread receiving portion 6a
at the front end thereof holds the looper thread 10 at a more
forward position than the left needle drop position A.
[0082] Further, as shown in FIG. 8, the swing lever 9 is swung
counterclockwise against the swing energizing force of the spring
91 by allowing the output rod 41 to be drivingly pushed out toward
the left as the stopper cylinder 42 expands. This swing allows the
engaging claw 9a at the front end of the swing lever 9 to be
disengaged from the part of the stopper member 4, thereby releasing
the temporary suspension of the stopper member 4. Consequently, the
thread handling cylinder 32 is subjected to a maximum expansion
stroke, and the thread hanging hook 3 and the looper thread holder
6 are swingingly returned to the standby position via the
connecting rod 35.
[0083] As described above, in the present embodiment, the thread
hanging hook 3 and the looper thread holder 6 of the needle thread
holding mechanism swing into the standby position, the thread
hooking position, and the hold position by the expansion and
contraction strokes of the thread handling cylinder 32 and the
stopper cylinder 42.
[0084] The horizontal tube type multi-thread chain stitch sewing
machine in the present embodiment further includes a thread cutting
mechanism 5 for cutting the needle threads 20 and the looper thread
10 after a sewing action is terminated. As shown in FIGS. 16 and
17, the thread cutting mechanism 5 includes a thread cutting hook
50, a thread cutting knife 51, a leaf spring 59 for pressing the
thread cutting hook 50 against a sliding contact part between
itself and the thread cutting knife 51, and a thread cutting
actuator 58 (refer to FIG. 9). The thread cutting hook 50 has at a
front end portion thereof a first hook part 51 and a second hook
part 53 which are protruding backward. The thread cutting mechanism
5 is well known, and therefore, description and illustration of
other detailed structures are omitted here.
[0085] FIG. 9 is the block diagram showing the configuration of the
control system of the horizontal tube type multi-thread chain
stitch sewing machine including the seam ravel preventing apparatus
H as described above. A pedal depresson signal 21a and a pedal back
signal 21b generated by a pedal switch 21, a needle position signal
22 generated when the needles 2 and 2 are in the vicinity of a top
dead center, a thread cut signal 23, and a needle thread wipe
signal 24 are respectively inputted to the control section 8 of the
multi-thread chain stitch sewing machine.
[0086] On the other hand, the control section 8 outputs action
control signals to the thread handling cylinder 32, the stopper
cylinder 42, and the thread cutting actuator 58, respectively. The
thread hanging hook 3 and the looper thread holder 6 act as
previously described according to the action control signals
outputted from the control section 8 to the thread handling
cylinder 32 and the stopper cylinder 42, and the thread cutting
actuator 58 of the thread cutting mechanism (not shown) expands and
contracts according to the thread cut signal 23 outputted from the
control section 8.
[0087] The control section 8 also outputs action control signals
respectively to a sewing machine motor 80 as a driving source of
the sewing machine spindle, a presser foot cylinder 81 for moving
up and down a presser foot for pressing the fabric, an air wiper 82
for wiping up the needle threads 20 and 20 to be cut as described
later, a feed reducing mechanism 83 for adjusting a fabric feeding
rate, and a looper thread restraining mechanism 84 for restraining
the feed of the looper thread 10 to the looper 1.
[0088] The feed reducing mechanism 83 reduces the fabric feed rate
by changing a mode of operation of the feed dog in the feed
mechanism. For example, time period during which the feed dog acts
on the fabric on the needle plate P is reduced by inclining an
action passage of the feed dog with respect to the needle plate P
so as to reduce time period during which it protrudes upward from
the needle plate P, or a unit feed pitch by the feed dog is reduced
by changing a length of a lever for cyclically operating the feed
dog. The feed reducing mechanism 83 of this type is well known, and
therefore detailed illustration and description thereof are omitted
here.
[0089] The looper thread restraining mechanism 84 includes a thread
tension disc for squeezing a mid-portion of the looper thread 10 to
be fed to the looper 1, and an actuator that operates to increase
or decrease strength to squeeze the looper thread by the thread
tension disc. The strength to squeeze the looper thread by the
thread tension disc is enhanced to increase resistance applied to
the looper thread 10, thereby restraining the feed of the looper
thread 10. The looper thread restraining mechanism 84 of this type
is well known, and therefore detailed illustration and description
thereof are omitted here.
[0090] At the end of the sewing for forming the multi-thread chain
stitch seams, the control section 8 executes a seam ravel
prevention operation in the multi-thread chain stitch seams by
allowing the thread hanging hook 3 and the looper thread holder 6
to act in association with the sewing machine motor 80, the presser
foot cylinder 81, the air wiper 82, the feed reducing mechanism 83,
and the looper thread restraining mechanism 84.
[0091] FIG. 10 is the time chart showing time series operation
contents of the control section 8 for the purpose of ravel
prevention. The control section 8 is a computer including a CPU, a
ROM, and a RAM. The ravel prevention operation according to the
time chart shown in FIG. 10 is executed by a series of operations
of the CPU according to a control program stored in the ROM.
[0092] FIGS. 11 to 17 are the explanatory drawings of the ravel
prevention operation by the ravel preventing apparatus H in the
horizontal tube type multi-thread chain stitch sewing machine of
the present invention, and show operation statuses of the thread
hanging hook 3 and the looper thread holder 6, and the thread
cutting hook generated by the operation of the control section 8
according to the time chart of FIG. 10.
[0093] When the sewing operator using the sewing machine terminates
normal sewing, the operator suspends a depressing operation of a
pedal for driving the sewing machine, and then performs the ravel
prevention operation. In this case, the operator performs a pedal
back operation of the pedal. The pedal switch 21, attached to the
pedal, outputs the pedal depression signal 21a during the pedal
depression operation, and outputs the pedal back signal 21b in
response to the pedal back operation.
[0094] When the normal sewing is terminated, and the pedal for
driving the sewing machine is returned from a depressed state to a
neutral state at time S1 in FIG. 10, namely, when neither the pedal
depression signal 21a nor the pedal back signal 21b is outputted
from the pedal switch 21, the control section 8 outputs a
suspension command to the sewing machine motor 80 by referring to
the needle position signal given to the input side. Consequently,
the sewing machine is temporarily suspended in a state in which the
needles 2 and 2 are positioned in the vicinity of the top dead
points and the looper 1 has moved toward the left.
[0095] Thereafter, the control section 8 stands by until the pedal
is subjected to the pedal back operation. When the pedal back
operation is performed, and the pedal back signal 21b is inputted
to the input side at time S2 in FIG. 10, the control section 8
starts the ravel prevention operation as described below. When the
pedal depression signal 21a is inputted again from the pedal switch
21, the control section 8 returns to the normal sewing action.
Therefore, the sewing operator can continue the normal sewing by
performing the pedal depressing operation again.
[0096] In FIG. 10, though the neutral state is maintained during a
period of time between S1 and S2, maintaining the neutral state is
not necessarily required. The pedal operation at the end of the
normal sewing may be continuously shifted from the pedal depression
state to the pedal back state. In this case, when passing through
the neutral position in the shift progress, it enters a non-signal
state in which neither the pedal depression signal 21a nor the
pedal back signal 21b is outputted. Using the non-signal state as a
trigger, the control section 8 starts the ravel prevention
operation after achieving the state in which the needles 2 and 2
are raised to near the top dead points and the looper 1 is moved
toward the left, as described above.
[0097] Also in the time chart of FIG. 10, though the pedal back
operation at time S2 is continued during execution of the ravel
prevention operation described later, it is unnecessary to continue
the pedal back operation until the ravel prevention operation is
terminated, and the ravel prevention operation is continuously
executed by the operation of the control section 8 even after the
input of the pedal back signal 21b is suspended.
[0098] FIG. 11 shows the states of the needles 2 and 2 and the
looper 1 at the start of the ravel prevention operation. The
needles 2 and 2 have passed through and are now located above the
fabric on which multi-thread chain stitch seams M are formed by the
two needle threads 20 and 20 and the looper thread 10. The looper 1
has moved toward the left below the fabric, and is in a state of
catching the needle thread loops 20a and 20a respectively formed by
the needles 2 and 2. When the needle threads 20 and 20 and the
looper thread 10 are cut in this state, the portion at the end of
sewing as shown in FIG. 20 is formed.
[0099] After starting the ravel prevention operation, the control
section 8 firstly provides an operation command to the thread
handling cylinder 32 on the output side. In response to this
command, the thread handling cylinder 32 moves from a state of
expansion shown in FIG. 5 to a state of contraction shown in FIG.
6, and the stopper member 4 is drivingly moved toward the right.
Accordingly, the thread hanging hook 3 and the looper thread holder
6 move from the standby position to the thread hooking position by
swinging around the support shaft 30 via the stopper member 4 and
the connecting rod 35. At this time, the hook portion 3b at the
front end of the thread hanging hook 3 hooks the needle thread loop
20a on one side (left side), and the swing lever 9 in the stopper
mechanism swings clockwise around the support shaft 90 by the
energizing force of the spring 91, and the engaging claw 9a at the
front end thereof enters the state of being engageable with the
part of the stopper member 4.
[0100] Immediately thereafter, the control section 8 provides an
operation command to the thread handling cylinder 32. Under the
operation command, the thread handling cylinder 32 expands somewhat
from the state shown in FIG. 6 to the state shown in FIG. 7, and
the stopper member 4 is linearly drivingly moved toward the left.
During the slight expansion of the thread handling cylinder 32, the
engaging claw 9a at the front end of the swing lever 9 engages with
the part of the stopper member 4, thereby temporarily suspending a
leftward driving movement of the stopper member 4. In the state in
which the leftward driving movement of the stopper member 4 is
temporarily suspended, as shown in FIG. 12, the thread hanging hook
3 moves via the connecting rod 35 to the hold position between the
standby position and thread hooking position, and remains there and
holds the left needle thread loop 20a at the hold position. The
looper thread holder 6 moves toward the front of the looper 1, and
the looper thread receiving part 6a at the front end thereof holds
the looper thread 10 at a more forward position than the left
needle drop position A.
[0101] After the thread hanging hook 3 and the looper thread holder
6 are thus moved to and remain at the hold position, the control
section 8 provides operation commands respectively to the sewing
machine motor 80, the feed-reducing mechanism 83, and the looper
thread restraining mechanism 84 at time S3 in FIG. 10. These
operation commands are provided by referring to the needle position
signal 22 in a period of time during which the needles 2 and 2 move
down and move up again to the positions near the top dead points.
Accordingly, the sewing action for one stich on the fabric is
carried out. The sewing for the one stitch is carried out at a
lower feed rate than during the normal sewing by the action of the
feed-reducing mechanism 83. The sewing for the one stitch is also
carried out by the action of the looper thread restricting
mechanism 84 in a state in which the feed of the looper thread 10
to the looper 1 is restrained. This improves tightness of the
looper thread 10 at the end of the sewing, thereby enhancing the
ravel prevention effect described later.
[0102] As shown in FIG. 12, the thread hanging hook 3 and the
looper thread holder 6 continue the holding of the needle thread 20
and the looper thread 10 until the fabric feed is completed, and
the needles 2 and 2 pass through the fabric and move down, and the
left needle 2 passes through the needle thread loop 20a held by the
thread hanging hook 3 and catches the needle thread loop 20a. At
this time, the looper thread 10 held by the looper thread holder 6
is located across the front of the left needle 2, as shown in FIG.
12. Hence, the left needle 2 does not catch the looper thread 10,
and the looper thread 10 is merely caught behind the looper 2 by
the right needle 2.
[0103] At the time the left needle 2 catches the needle thread loop
20a, namely, at time S4 in FIG. 10, the control section 8 allows
the stopper cylinder 42 of the stopper mechanism to expand by
providing an operation command to the stopper cylinder 42.
Accordingly, the output rod 41 is drivingly pushed out toward the
left. Consequently, as shown in FIG. 8, the swing lever 9 is swung
counterclockwise against the swing energizing force of the spring
91, and the engaging claw 9a at the front end of the swing lever 9
is disengaged from the part of the stopper member 4, thus allowing
for a release of the temporary suspension of the stopper member 4.
Upon the release of the temporary suspension of the stopper member
4, the thread handling cylinder 32 is expanded to its maximum at
time S4. Consequently, as shown in FIG. 13, the thread hanging hook
3 and the looper thread holder 6 performs a return movement from
the hold position to the standby position by swinging around the
support shaft 30 via the stopper member 4 and the connecting rod
35, and then releases the holding of the needle thread loop 20a and
the looper thread 10.
[0104] The looper 1 then performs a right retraction action as the
needles 2 and 2 move down, and slips out of the caught needle
thread loop 20a. Upon the slipping-out of the looper 1, as shown in
FIG. 14, the right needle 2 enters a state of catching the looper
thread 10 similarly during the normal sewing, whereas the left
needle 2 enters a state of catching the left needle thread loop
20a.
[0105] In this state, the looper 1 converts to a left forward
movement, and the needles 2 and 2 convert to an upward movement. As
shown in FIG. 15, the looper 1 that performs the left forward
movement catches the left and right needle thread loops 20a and
20b, and the needles 2 and 2 that move up pass through the fabric
in the upward direction. Accordingly, the needle thread 20 caught
by the looper 1 interloops the looper thread at the position of the
right needle 2, whereas the needle thread 20 performs so-called
selflooping, that is, looping the previously formed needle thread
loop 20a with the needle thread 20 at the position of the left
needle 2.
[0106] After the sewing action for the one stitch, it is finished
in a state in which the needles 2 and 2 move up to the vicinity of
the top dead points, and the looper 1 reaches the vicinity of the
end of the leftward movement. Thereafter, the control section 8
stands by until a thread cut signal 23 is applied thereto. Upon
receipt of the thread cut signal 23 at time S5 in FIG. 10, the
control section 8 allows the thread cutting actuator 58 of the
thread cutting mechanism to perform a predetermined operation by
providing an operation command to the thread cutting actuator 58.
Accordingly, the thread hanging hook 50 reaches a forward movement
end along the upper part of the looper 1, as shown in FIG. 16. At
this time, the first hook part 52 at the front end of the thread
cutting hook 50 passes through the needle thread loops 20a and 20b
held by the looper 1 to the left side of the looper thread 10
extending from the front end of the looper 1 to the fabric, and the
second hook part 53 is opposed to the left needle thread 20 from
the left side thereof.
[0107] Subsequently, the thread cutting hook 50 located at the
forward movement end performs a right backward movement. At this
time, the first hook part 52 catches the looper thread 10, and the
second hook part 53 successively catches the two needle threads 20
and 20. The looper thread 10 and the needle threads 20 and 20
caught in this manner are then pulled to a retraction end of the
thread cutting hook 50, and are cut by being brought into sliding
contact with an edge portion at the front end of the thread cutting
knife 51, as shown in FIG. 17. An end portion of the cut looper
thread 10 is held in sandwich fashion between the thread cutting
hook 50 and the leaf spring 59 at a position closer to the looper 1
than a cutting position.
[0108] The looper thread restraining mechanism 84 continues to
operate and applies a predetermined tensile force to the looper
thread 10 extending from the front end of the looper 1 to the
fabric, until the foregoing thread cutting operation is terminated.
This ensures that the first hook part 52 at the front end of the
thread cutting hook 50 catches and cuts the non-loose looper thread
10.
[0109] After the foregoing cutting operation, the control section 8
stands by until a needle thread wipe signal 24 is inputted thereto.
When the needle thread wipe signal 24 is inputted thereto at time
S6 in FIG. 10, the control section 8 allows the air wiper 82 to
operate by outputting an operation command to the air wiper 82. The
air wiper 82 blows out air and blows up cut end portions of the
needle threads 20 and 20 that are continuous with the needles 2 and
2. Thereafter, the control section 8 allows the presser foot
cylinder 81 to act to raise the presser foot for pressing the
fabric by outputting an operation command to the presser foot
cylinder 81 at time S7 in FIG. 10, thereby terminating the sequence
of the ravel prevention operation.
[0110] The foregoing sequence of the ravel prevention operation
produces the multi-thread chain stitch seams M by the horizontal
tube type multi-thread chain stitch sewing machine, as shown in
FIG. 18. Referring to FIG. 18, the looper thread 10 is passed
through the inside of the right needle thread loop 20a (the left in
FIG. 18 in which the seams M are viewed from the rear surface of
the fabric) which is finally formed in the multi-thread chain
stitch seams M on the rear surface of the fabric, and is turned
back in front of the right needle thread 20 that goes through the
rear surface of the fabric during the sewing action for one stitch
for the purpose of the ravel prevention, and is then cut at a
certain position after being passed through again the inside of the
right final needle thread loop 20a.
[0111] On the other hand, the left (the right in FIG. 18) needle
thread 20 that goes through the rear surface of the fabric during
the sewing action for the one stitch for the ravel prevention
passes through the left needle thread loop 20b finally formed on
the rear surface of the fabric during the normal sewing, and forms
a chain stitch seam by selflooping the left final needle thread
loop 20b, as previously described. Therefore, as shown in FIG. 18,
the looper thread 10 enters a state of being pressed between the
left needle thread 20 and the left final needle thread loop
20b.
[0112] In FIG. 18, the left final needle thread loop 20b is
illustrated in a loose state in order to clarify entanglement with
the needle thread 20. However, as shown in FIG. 19, the actual left
final needle thread loop 20b is strongly tightened after the needle
thread 20 passes therethrough, and enters the same state as the
right final needle thread loop 20a. Then, when the cut end portion
of the looper thread 10 is pulled in the arrowed direction as shown
in FIG. 19, the loop of the looper thread 10 passing through in
front of the right needle thread 20 is contracted and pulled into
the right final needle thread loop 20a. As a result, the needle
thread 20 enters a state of being held between the looper thread 10
and the right final needle thread loop 20a, and the needle thread
20 and the looper thread 10 make a knot as shown in FIG. 19. This
knot also applies resistance to the looper thread 10, and performs
the function of preventing slipping-out of the looper thread 10.
Accordingly, in the state as shown in FIG. 19, the left selflooping
portion and the right knot cooperate to surely prevent the ravel of
the multi-thread chain stitch seams M.
[0113] The characteristic features of the multi-thread chain stitch
sewing machine with the seam ravel preventing apparatus having the
foregoing structure and ravel prevention operation as described in
detail above, namely, the improved structure employed in the
present invention in order to solve the problem remained unsolved
in the already-filed patent application of the present applicant is
described below by focusing on FIGS. 2 to 4.
[0114] As shown in FIGS. 2 to 4, the needle plate base 11 attached
to the upper surface of the sewing machine bed B is divided into a
left needle plate base 11L and a right needle plate base 11R. The
left needle plate base 11L has the needle plate P detachably
attached to the upper surface thereof via a set screw 100, and
supports the support shaft 30 as the center of swing of the thread
hanging hook 3 of the needle thread holding mechanism.
[0115] Screw holes 101 are formed at a plurality of front and rear
portions (two portions) in the vicinity of the left end part in the
left needle plate base 11L, specifically, at portions away from the
attachment position of the needle plate P in the vicinity of the
front end (left end) of a sewing machine arm C indicated by a
virtual line in FIG. 4. The left needle plate base 11L is attached
to the upper surface of the sewing machine bed B so as to permit
fastening and unfastening (attachment and detachment).
[0116] Further, as shown in FIG. 3, the upper surface of the sewing
machine bed B and the left needle plate base 11L are provided with
knock pins 103 and pin holes 104 into which the knock pins 103 fit,
at positions away from two fastening positions via set screw
members 102. The pin holes 104 are inserted into and engaged with
the knock pins 103 from above, thereby positioning the left needle
plate base 11L at predetermined position and posture with respect
to the sewing machine bed B. In this state, the set screw members
102 are screwed into the screw holes 102, thereby allowing the left
needle plate base 11L to be fastened against the upper surface of
the sewing machine bed B.
[0117] Although the present embodiment describes and illustrates
one in which the knock pins 103 protrude upward from the upper
surface of the sewing machine bed B, and the pin holes 104 are
formed in the left needle plate base 11L or, alternatively, the
knock pins 103 may protrude downward from the lower surface of the
left needle plate base 11L, and the pin holes 104 may be formed in
the upper surface of the sewing machine bed B.
[0118] On the other hand, the right needle plate base 11R
constitutes a cylinder attachment base for supporting the thread
handling cylinder 32 and the stopper cylinder 42 (hereinafter the
right needle plate base 11R is referred to as the cylinder
attachment base). The foregoing stopper mechanism is disposed at a
lower part of the cylinder attachment base 11R. To be specific, as
shown in FIGS. 5 to 8, the thread handling cylinder 32 is fixedly
supported on the lower surface of the cylinder attachment base 11R
via an attachment screw 105. The stopper cylinder 42 is disposed
below the thread handling cylinder 32 in a two-stage fashion, and
the stopper cylinder 42 is fixedly supported on the cylinder
attachment base 11R via an attachment screw 106.
[0119] The cylinder attachment base 11R is installed in a fixed
state to a side surface of the sewing machine bed B via a set screw
107. The phrase "fixed state" denotes the state in which the ravel
preventing apparatus H is fixed to a predetermined position by
fastening the set screw member 107 when installing it into the
sewing machine bed B, and is fixed at a predetermined installation
position after the installation without performing any positional
adjustment or the like.
[0120] One end (right end) portion of the connecting rod 35 is
rotatably connected to the stopper member 4 in the stopper
mechanism by a pin screw 108. In a certain part of the cylinder
attachment base 11 R which corresponds to a connecting part between
the one end of the connecting rod 35 and the stopper member 4 by
the pin screw 108, a long groove 109 that is long in a lateral
direction is formed so as to allow for a linear reciprocating
movement of the stopper member 4 that linearly reciprocates in the
lateral direction in response to the expansion and contraction of
the thread handling cylinder 32.
[0121] A connection end portion 35a of the other end of the
connecting rod 35, which is connected to an extended part 3c
connected to the thread hanging hook 3, is bent downward in a depth
corresponding to a substantial thickness of the extended part 3c. A
pin 110 is protruded upward from the connection end portion 35a of
the downward bent connecting rod 35. On the other hand, the
extended part 3c is provided with a connecting hole 111 that is
insertable into the pin 110 from above the pin 110 and is drawable
in an upward direction. This eliminates the need to perform an
operation for fixedly connecting the connecting rod 35 and the
extended part 3c, for example, releasing an interlocking state
between the two by unfastening a set screw or the like, when the
left needle plate base 11L is removed from the sewing machine bed B
by unfastening it from the sewing machine bed B. That is, the
connecting hole 111 of the extended part 3c can be drawn upward
from the pin 110, and the interlocking state between the connecting
rod 35 and the extended part 3c (the thread hanging hook 3) can be
released only by raising the left needle plate base 11L. Also, when
attaching the left needle plate base 11L to the sewing machine bed
B, only by an operation of shifting the left needle plate base 11L
from above toward the sewing machine bed B, the connecting hole 111
is inserted into the pin 110 from above, thereby allowing the
connecting rod 35 and the extended part 3c (thread hanging hook 3)
to return to the interlocking state. The connection end portion 35a
of the connecting rod 35 needs not necessarily be bent downward.
That is, the connecting rod 35 may have a flat plate shape.
[0122] A swing lever attachment base (movable base) 92, which
supports the swing lever 9 in the stopper mechanism so as to be
swingable around the vertically extending support shaft 90, is
attached to the cylinder attachment base 11R so as to permit
lateral position adjustment via a long hole 93 being long in a
lateral direction and a set screw 94. Accordingly, even after the
cylinder attachment base 11R is installed in the fixed state into
the sewing machine bed B via the screw member 107, timing the
looper 1 slips out of the needle thread loop 20a held by the thread
hanging hook 3 can be optionally adjusted by performing the lateral
position adjustment of the swing lever attachment base 92 with
respect to the cylinder attachment base 11R. This ensures the
selflooping for the seam ravel prevention.
[0123] In the horizontal tube type multi-thread chain stitch sewing
machine with the seam ravel preventing apparatus H employing the
structure having the foregoing characteristic features, when the
seam ravel preventing apparatus H is installed into the sewing
machine bed B, the left needle plate base 11L and the right
cylinder attachment base 11R, which are obtained by dividing the
needle plate base 11 into right and left sections, can be
individually attached to the sewing machine bed B. Hence, as
compared with handling of the single long and large needle plate as
in the case of the technique described in the already-filed patent
application by the present applicant, the attachment (installation)
operation of the entirety of the ravel preventing apparatus H with
respect to the sewing machine bed B can be easily carried out with
less effort.
[0124] Additionally, if after the needle plate base 11 (the left
needle plate base 11L and the right cylinder attachment base 11R)
is installed into the sewing machine bed B, it becomes necessary to
adjust stitch performation by correcting the position and motion
loci of the components for performing sewing action which are
located below the needle plate base 11 and are stored inside the
sewing machine bed B, such as the looper 1 and actuating members
therefor, or it becomes necessary to perform maintenance, such as
mending and replacement, on various types of components stored
below the needle plate base 11 and inside the sewing machine bed B,
it is unnecessary to remove the cylinder attachment base 11R by
which the thread handling cylinder 32 and the stopper cylinder 43
respectively having the air tubes 33 and 43 attached thereto are
strongly supported during the installation thereof. A sufficiently
wide operating space can be ensured only by unfastening and
removing the left needle plate base 11L from the sewing machine bed
B.
[0125] Hence, the adjustment of sewing performation, and the
maintenance such as the mending and replacement on the various
types of components stored inside the sewing machine bed B can be
performed extremely easily, simply, and efficiently only by
handling the small and lightweight left needle plate base 11L to
which the air tubes 33 and 34 do not cling. Consequently,
satisfactory sewing performation and the predetermined ravel
prevention function can constantly be exhibited with superior
reproducibility, thereby solving the problem remained unsolved in
the already-filed patent application by the present applicant.
[0126] The present embodiment employs the structure in which the
swing lever 9 in the stopper mechanism is swingingly energized by
the spring 91 in the direction in which the thread hanging hook 3
in the needle thread holding mechanism is positioned at the standby
position. Therefore, the action of the stopper member 4 in the
return direction (the action in the direction in which the thread
hanging hook is positioned at the standby position) is performed by
the energizing force of the spring 9. This allows for employment of
a single-acting type air cylinder as the stopper cylinder 42 for
actuating the swing lever 9 that engages with or disengages from
the part of the stopper member 4, thereby achieving downsizing and
cost reduction of the stopper cylinder 42.
[0127] The present embodiment also employs the structure in which
the thread handling cylinder 32 in the needle thread holding
mechanism and the stopper cylinder 42 in the stopper mechanism are
fixedly supported on the lower surface of the cylinder attachment
base 11R in the vertical two-stage fashion. Therefore, the planar
space occupied by the two air cylinders 32 and 42 can be reduced to
permit compactness of the entirety of the ravel preventing
apparatus H, thereby allowing the ravel preventing apparatus H to
be nicely stored inside the sewing machine bed B, compared with the
case where the two air cylinders 32 and 42 are disposed at the
positions separated from each other (side-by-side arrangement) as
in the case of the technique described in the already-filed patent
application by the present applicant.
[0128] The present embodiment further employs the structure for
attaching the looper thread holder 6 to the thread hanging hook 3
in the needle thread holding mechanism. The looper thread holder 6
holds the looper thread extending from the looper 1 to the fabric
at a more forward position than the drop position of the needle 2
by swinging together with the thread hanging hook 3 in the plane
substantially parallel to the needle plate P around the vertically
extending support shaft 30 between the thread hooking position, the
hold position, and the standby position. This simple structure can
surely position the looper thread 10 together with the needle
thread 20. Thereby, the selflooping can be surely performed to
further ensure the seam ravel prevention effect.
[0129] Particularly, by position-adjustably attaching the looper
thread holder 6 with respect to the thread hanging hook 3, the
relative positions of the needle thread 20 and the looper thread 10
can appropriately be set, and the selflopping can be more surely
performed to further enhance the seam ravel prevention effect.
[0130] The present embodiment further employs the structure in
which the pin 110 is protruded upward from the connecting end
portion 35a of the connecting rod 35, and the connecting hole 111,
which is insertable into the pin 110 from above the pin 110 and is
upward drawable, is formed at the connecting end portion (extended
part 3c) closer to the thread hanging hook 3. Therefore, when the
left needle plate base 11L is unfastened from the upper surface of
the sewing machine bed B and is removed in an upward direction from
the sewing machine bed B in order to perform the adjustment of
stitch performation and the maintenance, such as the mending and
replacement, on the various types of components stored inside the
sewing machine bed B, the thread hanging hook 3 and the connecting
rod 35 can be disengaged from each other only by raising the left
needle plate base 11L, without requiring any troublesome operation,
such as unfastening and removing the screw connecting the
connecting rod 35 and the extended part 3c closer to the thread
hanging hook 3, or pulling-out of the connecting pin. Additionally,
after the adjustment and maintenance, the thread hanging hook 3 and
the connecting rod 35 can be returned to the predetermined
connected state only by fastening the left needle plate base 11L to
the sewing machine bed B from above. This further saves the labor
in the adjustment and maintenance.
[0131] Although the foregoing embodiment has described the case of
using the air cylinders as the hook actuator and the stopper
actuator, electromagnetic solenoids may be used as these
actuators.
[0132] Although the foregoing embodiment has also described the
case of forming the multi-thread chain stitch seams by the two
needles 20 and 20 and the single looper thread 10, it is applicable
to one which forms multi-needle double chain stitch seams by using
three or more needle threads, or one which forms one-needle chain
stitch seams by using one needle thread, or a top-cover
multi-thread chain stitch sewing machine which performs top cover
sewing on multi-thread chain stitch seams.
[0133] The foregoing embodiment has also described the case of
performing the ravel prevention in which one of the needle thread
loops formed by the two needle threads 20 and 20 is caught and held
at the hold position, and in this state, the sewing action for one
stitch is performed for selflooping. Alternatively, a plurality of
needle thread loops may be caught and held at the hold position,
and the sewing action in the hold state may be for two switches or
more without being limited to one stitch.
[0134] The foregoing embodiment has also described the case where
the looper thread holder 6 the thread hanging hook of the needle
thread holding mechanism is preferably provided with a looper
thread holder which holds the looper thread extending from the
looper to a fabric at a more forward position than the drop
position of the needle by swinging together with the thread hanging
hook around the support shaft in the plane substantially parallel
to the needle plate between the thread hooking position, the hold
position, and the standby position. Alternatively, the looper
thread holder 6 and the thread hanging hook 3 may be disposed
separately and be individually operated by a dedicated actuator
different from the thread handling cylinder 32 for actuating the
thread hanging hook 3. Further alternatively, it is not essential
to install the looper thread holder 6.
INDUSTRIAL APPLICABILITY
[0135] The needle plate base is divided into the left and right
sections, which are configured to be individually handled as the
left needle plate base and the right cylinder attachment base.
Hence, the attachment (installation) of the entirety of the ravel
preventing apparatus to the sewing machine bed, and the adjustment
of sewing performation, and the maintenance such as the mending and
replacement on the various types of components stored inside the
sewing machine bed can be performed easily with less labor, thus
permitting a suitable application to the multi-thread chain stitch
sewing machine.
[0136] What has been described above are preferred aspects of the
present invention. It is of course not possible to describe every
conceivable combination of components or methodologies for purposes
of describing the present invention, but one of ordinary skill in
the art will recognize that many further combinations and
permutations of the present invention are possible. Accordingly,
the present invention is intended to embrace all such alterations,
combinations, modifications, and variations that fall within the
spirit and scope of the appended claims.
* * * * *