JPS63272394A - Empty ring sewing apparatus of overlock sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to overlocking the edges of a cloth using an overlock sewing machine to form a seam on the cloth, and then creating a hollow ring connected to the seam. This invention relates to an empty ring sewing device that is attached to the overlock sewing machine to cut the fabric by leaving a predetermined length from the sewing machine side, and to sew the continuous empty ring from the sewing machine side into the seam of the next fabric. .

[Prior art] A conventional hollow ring sewing device attached to an overlock sewing machine has a hollow ring sewing device that integrates a cutting blade and a clamping member made of an elastic material on the work surface in front of the needle drop. A ring holding/cutting device is provided, and when the sewing is completed, the worker brings the empty ring created along with the fabric to the front side, presses it against the cutting blade, and cuts the cut ring with the cutting edge. The free end is held between the clamping members, the empty ring left on the sewing machine side is held on the upper surface of the throat plate, and this empty ring is sewn into the seam of the next fabric to close the seam at the beginning of the sewing. This made it possible to prevent fraying without special bar-tacking work.

However, with such an empty chain sewing device, in order to cut the empty loop that is created by continuous threads on the fabric, the operator moves the fabric to the front side of the needle drop every time one piece of fabric is sewn. This had to be moved, which was a problem in improving work efficiency and making work more self-help.

For this reason, recently, as disclosed in Japanese Patent Application Laid-Open No. 53-128443, etc., an empty ring connected to a seam formed in the fabric is sucked into a suction tube at the rear side from the needle drop, and the suction tube is opened. The empty ring is cut from the sewing machine side with a cutter installed inside the sewing machine, leaving a predetermined length, and the free end of the empty ring extending from the sewing machine side is moved to the front side of the needle drop part by wind pressure. It has been proposed that after the free end of the empty ring is sucked in by the free end suction part of the empty ring, a hollow ring clamping part provided on the working surface of the cross plate is operated to clamp the free end of the empty ring. has been done.

[Problem that the invention seeks to solve]

However, in the conventional devices including the one disclosed in JP-A No. 53-128443, the empty ring holding part and the free end suction part of the empty ring are disposed on the work surface. The clamping part etc. got in the way of feeding the fabric, and the fabric could not be fed straight, resulting in poor appearance of the sewing, and in extreme cases, there was a risk of damaging the fabric.

In addition, with conventional devices, the length of the loop to be sewn into the seam of the fabric is determined by the cut point made by the cutter installed inside the opening of the suction tube, so it is necessary to change the length of the loop to be sewn depending on the product. In some cases, this was difficult to deal with.

The present invention has been made in view of the above-mentioned circumstances, and a first object is to provide an empty chain sewing device for an overlock sewing machine that does not cause any trouble in inserting cloth or feeding the cloth. The purpose is to

A second object of the present invention is to provide an empty ring sewing device for a vine overlock sewing machine that changes the length of the empty ring to be sewn into the seam of fabric.

[Means for solving problems]

In order to achieve the above-mentioned first object, the present invention is provided on the near side of the needle drop part, has an upper surface on the same plane as the working surface of the sewing machine, and has a free end of the empty ring that has been moved by wind pressure. a clamping plate movable in a direction intersecting the sewing axis to form an insertable insertion opening on the work surface; and a clamping plate provided above the working surface facing toward the insertion opening formed by the movement of the clamping plate. After inserting the free end of the empty ring into the insertion port using air blown from the air blowing port, the empty ring is inserted into the needle by moving the clamping plate and closing the insertion port. The gist is an empty chain sewing device for an overlock sewing machine, which is characterized by being clamped at the front side of the needle drop section. a first clamping plate that is located on the same plane as the working surface of the sewing machine and is movable in a direction intersecting the sewing axis to form an insertion opening on the working surface into which the free end of the empty ring that has been moved by wind pressure can be inserted; and, only when the first clamping plate is driven, can move together with the first clamping plate in a direction intersecting the sewing axis in close contact with the first clamping plate, and when only the first clamping plate moves, the first clamping plate and a second clamping plate forming the insertion opening between the two, and an air outlet provided above the work surface toward the insertion opening formed by the movement of the first clamping plate; After the free end of the empty ring is inserted into the insertion port by air blown from the air outlet, the first clamping plate is moved to close the insertion port, thereby clamping the empty ring on the near side of the needle drop. By moving the first clamping plate and the second clamping plate together in the empty ring clamping state, the empty ring is cut from the clamping part by a cutter installed on the movement trajectory of the empty ring due to this oscillation. The gist of the present invention is an empty chain sewing device for an overlock sewing machine, which is characterized by being able to perform the following functions.

[For production]

In the empty ring sewing device for an overlock sewing machine according to claim 1 of the present invention, the free end of the empty ring that has been moved by wind pressure enters the insertion opening formed by moving the clamping plate with air. The needle is inserted by air blown from the outlet, and then the clamping plate is moved to close the insertion opening, so that it is clamped at the front side of the needle drop. Moreover, the upper surface of the clamping plate is on the same plane as the work surface, so that the clamping plate does not interfere with the insertion of the next fabric from the front side.

The empty chain sewing device for an overlock sewing machine according to claim 2 of the present invention is similar to the empty chain sewing device according to claim 1 by replacing the clamping plate with a first clamping plate. The empty ring is held between the first holding plate and the second holding plate, and the second holding plate is further driven to remove the empty ring held between the first holding plate and the first holding plate from the holding part using a cutter. disconnect.

〔Example〕

The present invention will be described below based on illustrated embodiments.

1 to 3F, reference numeral 1 denotes a cross plate of an overlock sewing machine, and a throat plate 2 is fitted into a working surface 1a of the cross plate 1 at a position corresponding to a sewing machine needle. This throat plate 2 is fixed to the cross plate 1 with bolts 3, and its upper surface is the work surface 1a.
constitutes part of. Further, the throat plate 2 is formed with a needle drop part 4 that vertically penetrates the working surface 1a, and moves rearward (in the direction of arrow B in the figure) from a portion adjacent to the needle drop part 4 as a starting point. An extending tongue 5 is integrally attached. Incidentally, the symbol X indicated by a dashed line in FIGS. 2A to 2C is the sewing axis of this overlock sewing machine, which coincides with the direction in which the cloth is fed through the needle drop portion 4.

A sewing axis
One side on the upper side and one side on the rear side of the sewing machine perpendicular to the sewing axis X are formed by the throat plate 2, and one side on the front side of the sewing machine perpendicular to the sewing axis X is formed by the cross plate 1, parallel to the sewing axis A recess 6 is formed in which one side is an open side. A holding plate 7 whose upper surface is flush with the working surface 1a is fitted into the recess 6 so as to be movable in a direction orthogonal to the sewing axis X.

The clamping plate 7 includes a first clamping plate 71 disposed on the open side of the recess 6 and a second clamping plate 72 disposed on the bottom side of the recess 6. The second holding plates 72 can be brought into close contact with each other at least on the needle drop portion 4 side. Also,
The mechanism described later allows the first clamping plate 71 to move independently in the direction perpendicular to the sewing axis X, thereby creating an empty ring insertion opening between it and the second clamping plate 72, as shown in FIG. H can be opened. On the other hand, the second
When the clamping plate 72 moves in the direction perpendicular to the sewing axis X, the first clamping plate 71 also moves along with it.

Reference numeral 8a denotes a presser foot that holds the fabric to be processed between it and the throat plate 2, and this presser foot 88 is attached to the tip of a presser foot 8b that is pivotably supported on the sewing machine main body M on the rear side. The presser foot 8b is oscillated by operating the air pump 8c to move the presser foot 88 up and down between the presser foot position and the presser release position.

Further, behind the tongue bar 5, a cloth guide 9 parallel to the sewing axis X and provided with a predetermined distance from the sewing axis X is provided on the work surface 1a.
It is set up from the ground.

An empty ring cut portion 10 is provided on the back side of the guide surface of this cloth guide 9.
is equipped with. This hollow ring cutting section 10 is connected to an air suction source (not shown), and is provided with a suction passage 11 in which the back surface of the cloth guide 9 is part of the inner wall, and a suction hole 11a of this suction passage 11 is connected to an air suction source (not shown). An opening is formed in the cloth guide 9 near the rear end of the plate 2, and a cutter 12 is provided in the suction hole 11a. This cutter 12 is connected to the suction hole 11
A fixed blade 12a whose cutting edge is fixed to the lower end of
The movable blade 1 is inserted into this suction passage 11 from the top surface of 1.
The movable blade 12b is driven by a member linked to the main shaft of the sewing machine so that its cutting edge intersects the cutting edge of the fixed blade 12a. By doing this, the empty ring generated when the sewing machine is driven is sucked in from the suction port 11a, and the fixed blade 12a and the movable blade 12b are used so that a constant length of the empty ring always remains on the throat plate side. disconnected. The drive of the movable blade 12b does not necessarily have to be linked to the drive of the sewing machine; for example, the number of stitches that move after the end of the fabric passes through the needle drop section 4 is counted, and this number of stitches reaches a set number. After stopping the sewing machine at this point, the sewing machine may be driven by a solenoid, or the operator may check that the required length of empty ring has been created and then drive the sewing machine by operating a pedal, etc. Good too.

On the back side of the cloth guide 9, an air pressure feed pipe 13 is arranged in parallel with the suction passage 11 and connected to an air supply source (not shown in FIGS. 1 to 3F). A nozzle 13a is provided at the tip of the air pressure pipe 3, the open end of which is connected to the cloth guide 9 in front of the suction hole 11a, and which blows out air in a direction perpendicular to the sewing axis X.

On the work surface la between the sewing axis X and the cloth guide 9 adjacent to the suction hole 11a of the suction passage 11, an air suction source for empty ring suction (not shown in FIGS. 1 to 3F) is connected. and a suction tube 1 disposed passing through the cross plate l.
No. 4 suction ports 14a are open. That is, this suction port 14a is arranged on an extension line parallel to the sewing axis X extending from the tip of the tongue 5.

The presser foot 8b supports a blow pipe 15 which is connected to an air supply source (not shown in FIGS. 1 to 3F) and has a nozzle 15a, which is an air outlet, at its tip. When the presser foot 8b raises the presser foot 8a to the presser release position, the nozzle 15a closes the first clamping plate 7.
1 is supported so as to blow air toward the insertion port 11 side formed by the drive.

Next, a driving mechanism for the holding plate 7 will be explained.

The first clamping plate 71 is driven by operating the first air cylinder 16 disposed inside the cross plate 1. To explain this in detail below, a mounting piece 71a is integrally formed on the lower surface of the first clamping plate 71, and a bracket 17 attached to the sewing machine body is attached to this mounting piece 71a.
The bracket 1 is inserted through the bracket 1 in a direction perpendicular to the sewing axis
One end of a rod 8 which is slidably supported by the rod 7 is fixed. A male thread 18a is screwed into the protruding portion of the rod 18 from the bracket 17.
A spring receiver 19 is screwed into the spring holder 19 . A compression spring 20 is stretched between the spring receiver 18 and the bracket 17, and the biasing force of the compression spring 20 causes the rod 18 to
The first clamping plate 71 attached to the first clamping plate 71 is urged in the direction of coming into close contact with the second clamping plate 72 (in the direction of arrow C in the figure). Piston rod 16a of the first air cylinder 16
A rod pressing member 21 is attached to the rod pressing member 21 which comes into contact with or comes close to the tip of the rod 18 in a state where the first clamping plate 71 is in close contact with the second clamping plate 72 when the piston rod 16a is retreating. has been done. still,
The piston rod 16a is provided with a male thread, and by adjusting a locking nut 22 screwed onto the male thread, the position of the rod pressing member 21 can be adjusted in the forward and backward direction of the piston rod 18a. It has become. The first air cylinder 16 is attached to a position where the rod pressing member 21 can suppress the rod 18 against the biasing force of the compression spring 20 by extending the piston rod 18a.

Next, driving of the second holding plate 72 will be explained.

The second holding plate 12 is driven by a second air cylinder 23 installed at the lower part of the cross plate 1 as a driving source. To explain this in detail, first, the second clamping plate 72 is integrally formed with an operating piece 72a that extends below the working surface 1a on the near side (on the arrow A side in the figure). This operation piece 7
When the second holding plate 72 comes into contact with the throat plate 2 on the sewing axis X, the second holding plate 2a also comes into contact with the contact member 24 formed integrally with the bracket 17. One end of a guide rod 25 is attached to this contact member 24, and the guide rod 25 extends in a direction perpendicular to the sewing axis X through the operation piece 72a.The other end of this guide rod 25 is attached to the cross plate l. It is connected to a fixed spring holder 26. The spring holder recess 26a formed in the spring holder 26 and the operation piece 72
A compression spring 27 is tensioned in the spring receiving recess 72aa formed at a, and the biasing force of the compression spring 27 biases the operation piece 72a toward the abutment member 24 side. On the other hand, the abutment member 24 and the bracket 17 integrated therewith have a notch 28 that opens on the abutment surface with the operation piece 72a.
is formed, and the tip of a swing arm 29 that transmits the operation of the second air cylinder 23 is inserted into this notch 28 . The swinging arm 29 is formed into an L-shape, and its corner portion 29a is pivotably supported, and the upper end of one side rising from the corner portion 29a is inserted into the notch 28 as described above. ing. Further, a rod receiver 29b that comes into contact with the piston rod 23a of the second air cylinder 23, which advances and retreats in the vertical direction, is formed at the tip of one side of the swing arm 29 extending laterally from the corner portion 29a. Therefore, when the piston rod 23a extends and pushes up the rod receiver 29b, the swinging arm 29 swings about the corner portion 29a, and the tip inserted into the notch 28 moves toward the contact member 29. It protrudes from the abutting surface of the operating piece 72a and presses the operating piece 72a toward the spring holder 26 against the biasing force of the compression spring 27. When the operating piece 72a is pressed in this manner, the second holding plate 72, which is formed integrally with the operating piece 72a, moves toward the first holding plate 71, taking the first holding plate 71 with it. . At this time, it goes without saying that the first holding plate 71 moves against the biasing force of the compression spring 20. Also, the second air cylinder 2
When the piston rod 23a of No. 3 is retreated, the tip of the swing arm 29 returns to the notch 28, so that the operation piece 72
'a is urged by the compression spring 27 to abut on the abutting member 24, and at the same time, the second holding plate 72 abuts on the needle plate 2 on the sewing axis X. In addition, in this way, the second holding plate 72
When the first clamping plate 71 moves to come into contact with the needle plate 2 on the sewing axis MX, the first clamping plate 71 also moves eight times toward the sewing axis x side together with the second clamping plate 72 due to the biasing force of the compression spring 20. Therefore, when the second air cylinder 23 is operated, the first clamping plate 71 and the second clamping plate 72 move together in close contact with each other.

A cutter 30 is disposed between the tongue 5 and the clamping plate 7, and includes a fixed blade 30a and a movable blade 30b, each having a cutting edge parallel to the sewing axis X.

As shown in FIG. 2C, this cutter 30 is used to cut an empty ring sandwiched between a first clamping plate 71 and a second clamping plate 72 when they move together toward the first clamping plate 71. ChL:I) Located on the u motion locus.

Further, the movable blade 30b performs reciprocating motion centering on the rear side of the fixed blade 30a in synchronization with the driving of the sewing machine, so that each blade edge intersects, thereby making the empty ring channel as shown in FIG. 2C. If it intersects with the cutter, it will be cut.

Note that 31 is a cloth edge detection sensor that detects the edge of the cloth.

Next, the operation of the ring sewing device constructed as described above will be explained with reference to the pneumatic circuit diagram shown in FIG. 4 and the schematic diagrams illustrating the operation process shown in FIGS. 3A to 3F.

First, the loop cutting section 10 is operated to cut the loop connected to the fabric from the fabric. That is, as will be described later, when the sewing machine is operated, the air suction source 10 connected to the suction passage 11
1 (shown only in FIG. 4) is in the operating state, the empty ring created by connecting to the seam of the fabric is automatically sucked into the suction hole 11a by feeding the fabric, and the movable blade 12b is driven. It is separated from the fabric by FIG. 3A shows a state in which the empty ring channel cut off from the fabric is sucked into the suction hole 11a. Incidentally, the base end side of this space-time ring Ch is wrapped around the tongue 5.

The following operation will be explained with reference to the timing chart shown in FIG.

When the driving of the sewing machine is stopped in the state shown in FIG. 3A, the suction by the air suction source 101 is also stopped.

Here, when the plunger 201a is pressed and the pilot air supply switching valve 201 is switched by depressing the footboard (not shown) of the sewing machine or the like, the pilot air is connected to the air supply path 301 from the pilot air supply source 102. Air is supplied. The pilot air sent to this air supply path 301 is sent to the pressure receiving part of the pneumatic switching valve 203 via the air supply path 302 and the switching valve 202C that constitutes the delay timer valve device 202 for setting the empty ring suction time. . As a result, the pneumatic switching valve 203 is switched to the side where the empty ring suction air suction source 103 and the above-mentioned suction tube 14 are connected, and the above-mentioned suction port 14a is connected.
The free end of the empty ring channel cut by the empty ring cutting section 10 is sucked as shown in FIG. 3B. At this time, the base end side of the empty ring ch is pulled out from the tongue 5 and the entire empty ring Ch is stretched.

Note that since the air sent into the air supply path 301 is also sent to the pressure receiving part of the pneumatic switching valve 205 via the shuttle valve 204, this pneumatic switching valve 205
is switched to the side that connects the pump operating air supply source 105 and the air pump 8c described above, and the air pump 8C raises the presser foot 88 as described above.

In this manner, when the plunger 201a of the pilot air supply switching valve 201 is pressed, suction from the suction port 14a and lifting of the presser foot 80 are simultaneously started, as is clear from FIG.

The delay timer valve device 202 includes a flow rate regulating valve 202.
a, an air tank 202b, and the switching valve 202c are connected in series. The air tank 202b is configured to release air to be sent to the pressure receiving part of the switching valve 202c when the amount of air inside reaches a predetermined amount. Therefore, by adjusting the amount of air sent to the air tank 202c per hour using the flow rate adjustment valve 202a and setting the time for the amount of air in the air tank 2Q2b to reach a predetermined amount, the air is supplied to the air supply path 301. After a predetermined time, the switching valve 202C is switched, and the supply of pilot air to the air supply path 302 is stopped. And air supply path 30
When the supply of pilot air to 2 is stopped, the pneumatic switching valve 203 switches to the side that disconnects the suction tube 14 from the empty ring suction air suction source 103, and the suction from the suction port 14a is stopped. will be stopped. That is, the suction time T1 of the suction port 14a shown in FIG. 5 is determined by adjusting the flow rate regulating valve 202a. As shown in FIG. 5, if the pressure on the plunger 201a of the pilot air supply switching valve 201 is released before the suction time T has elapsed, at that point the presser foot 8b is lowered and the suction port 14a is closed. The suction from is also stopped.

Reference numeral 206 designates a differential area double pilot valve, and among the pressure receiving portions of this differential area double pilot valve 206, a first pressure receiving portion 206a having a larger cylinder diameter is connected to the air supply path 302.
The air supply path 301 is connected to the second pressure receiving part 206b having a small cylinder diameter. This area difference double pilot valve 206 is connected to the air supply path 30.
1 and an air supply path 303 connected to a flow rate adjustment valve 207a, which will be described later.

That is, when the pilot air supplied to the air supply passage 301 is sent to the air supply passage 302 via the switching valve 202C, this area difference double pilot valve 206 is operated to control the air supply passage 301 and the air supply passage 303. Located on the side where the connection is cut off, the switching valve 202c switches the air supply path 30.
When pilot air is no longer sent to the second pressure receiving part 206b, the pilot air is supplied only to the second pressure receiving part 206b, thereby switching to the side where the air supply path 301 and the air supply path 303 are connected. Therefore, the area difference double pilot valve 206 supplies pilot air to the air supply path 303 at time 1+ (see FIG. 5) when the suction of the suction port 14a stops.

The delay timer valve device 207 for setting the clamping start time has the same configuration as the delay timer valve device 202 described above,
By adjusting the flow rate adjustment valve 207a, it is possible to set the time during which the air tank 207b sends air to the pressure receiving part of the switching valve 207c.

Therefore, the switching valve 207c is switched after a predetermined time T2 after the pilot air is supplied to the air supply path 303, and the pilot air supply source 107 for the clamping operation is connected to the air supply path 304.

This air supply path 304 is connected to a delay timer valve device 208 for setting the air pressure feeding time for empty ring movement, a delay timer valve device 209 for setting the insertion opening time. Each flow rate adjustment valve 208a, 209a of the delay timer valve device 210 for setting the blow time
, 210a and the switching valves 208c, 209c, and 210c. Each delay timer valve device 20
8. 209 and 210 are flow rate adjustment valves 208a and 2, respectively.
09a.

210a, x attank 208b, 209b, 210b
, switching valve 208c.

By connecting 209c and 210c in series and adjusting the flow rate adjustment valves 208a, 209a, and 210a,
The time from when air is supplied to the air supply path 303 until the air is released from the air tanks 208b, 209b, and 210b is set. Each switching valve 208c, 209
c, 210c are air tanks 208b, 209b, 21
The air tanks 208b, 209b, and 0b are located on the side connecting the air supply path 304 to the air supply path 305, 308, and 307, respectively, until the air is released from the air tank 0b.
By releasing air from 210b, the connection between the air supply path 304 and the air supply paths 305, 306 and 307 is switched to the side that is disconnected. These air supply channels 305, 306,
307 are pneumatic switching valves 211° and 212.2, respectively.
It is connected to 13 pressure receiving parts. When air is supplied to the air supply path 305, the pneumatic switching valve 211 switches to the side that connects the driving air supply source 108 to the air pressure feed pipe 13 described above, and the pneumatic switching valve 212 switches the air By supplying air to the supply path 305,
The driving air supply source 109 is switched to the side where it is connected to the first air cylinder 16, and the pneumatic switching valve 213 is operated by supplying air to the air supply path 307.
The drive air supply source 110 is switched to the side where it is connected to the blow pipe 15.

By supplying air from the driving air supply sources 108, 109, and 110 in this manner, air is blown out from the nozzle 13a of the air pressure feed pipe 13, and the first air cylinder 16 is activated to extend the piston rod 16a. Air also blows out from the nozzle 15a of the blow vibe 15.
Therefore, the blowing of air from the nozzles 13a, 15a and the extension of the piston rod 16a are started simultaneously at time t2, as shown in FIG. time T3 when the piston rod 16a is being driven toward the extending side, time T4 when the piston rod 16a is being driven toward the extending side, and time T when air is being blown out from the nozzle 15a.

is set by adjusting the flow rate regulating valves 208a, 209a, and 210a. Incidentally, as shown in FIG. 5, these times T3. T4. T, is T s < T 4 (7s
is set to

When air is blown out from the nozzle 13a, the empty ring channel rotates around the tip of the tongue 5, as shown in FIG. 3C, and the free end CO of this empty ring channel is moved toward the front side of the sewing machine. . In this way, while the free end Go of the empty ring channel is moving, the piston rod 16 of the first air cylinder 16
When a is extended and the first clamping plate 71 is moved, an empty ring insertion opening H is formed on the front side of the sewing machine as shown in FIGS. An empty ring channel is blown into the insertion port H. As mentioned above, the reason why the air blowing time TS from the nozzle 15a is made longer than the driving time T4 of the first working cylinder 16 is because of the driving air supply source 109 and the first working cylinder 16.
This is because it takes some time after the air cylinder 16 is disconnected until the piston rod 16a retreats and the insertion port H is closed. As shown in the figure, the empty ring channel is held between the first holding plate 71 and the second holding plate 72 without loosening.

As described above, after the empty ring channel is clamped as shown in FIG. The air that was being sent to the pressure receiving part of the pneumatic switching valve 205 is cut off, and the pneumatic switching valve 205 is switched to the air supply source 1 for pump operation.
05 and the air pump 8C, and the presser foot 88 is lowered to the cloth presser position on the throat plate 2. Also,
By releasing the pressure on the plunger 201a, the switching valve 202c returns to its initial state, and the switching valve 202c returns to its initial state.
07C also returns to its original state and disconnects the pilot air supply source 107 for clamping operation from the air supply path 304.

Then, by cutting off the air supply to the factory supply path 304, the switching valves 208c, 209c, 210c
will also return to its original state.

Next, by operating the presser foot lifting footboard of the sewing machine, the plunger 214a of the pilot air supply switching valve 214 is pressed to connect the pilot air supply source 111 and the air supply path 301°. This air supply path 301°
The air supplied to the air is supplied to the pressure receiving part of the pneumatic switching valve 205 via the shuttle valve 204, and as a result, the pneumatic switching valve 205 is again connected to the pump operating air supply source 105 and the air pump 8C. Switching,
Presser foot 88 rises to the presser release position. After inserting the fabric into a predetermined position in this state, the operating section 214a
If the suppression is released, the pilot air supply source 11
1 and the air supply path 301° are cut off, the pneumatic switching valve 205 returns to its initial state, the air in the air pump 8C is removed, the presser foot 8a is lowered, and the fabric is sandwiched between it and the throat plate 2. It is.

In this way, after the fabric is sandwiched between the presser foot 88 and the throat plate 2, the sewing machine is driven to form a seam at the edge of the fabric. A pilot air supply switching valve 215 is provided so that a plunger 215a is pressed when the footboard is pushed forward to drive the sewing machine, and when the plunger 215a is pressed, the pilot air supply source 112 and the air supply are switched off. switch to the side where the line 308 is connected. The air supply path 308 is connected to a pressure receiving portion of the pneumatic switching valve 216 and one of the shuttle valves 217 .

The pneumatic switching valve 218 switches to the side connecting the air suction source 101 and the suction passage 11 when air is sent to the switching operation section. In this manner, at the same time as the sewing machine is driven, the air suction source 101 and the suction passage 11 are connected, and air is suctioned from the suction hole 11a.

For this reason, an empty ring created to a length that reaches the suction hole 11a is always sucked into the suction hole 11a and cut by the cutter 12.

On the other hand, the air sent from the air supply path 308 to the shuttle valve 217 is sent to the pressure receiving part of the pneumatic switching valve 218 via the shuttle valve 217, and the air switching valve 218 is connected to the pilot air supply source 113 and the air supply Switch the line 309 to the connecting side.

The air supply path 309 is connected to a flow rate adjustment valve 219a and a switching valve 219c of a delay timer valve device 219 for setting a cutting start time.
pneumatic switching valve 221
It is also attached to a boat.

The air supply path 307 is connected to the pressure receiving part of this pneumatic switching valve 221, and when air is not being sent to this air supply path 307, that is, at all times,
A pneumatic switching valve 221 connects the air supply path 309 to an air passage 310 connected to the other end of the shuttle valve 217 . Therefore, when the -star pneumatic switching valve 218 switches and the pilot air supply source 113 and the air supply path 309 are connected, even if the sewing machine is stopped and the air supply path 30B receives the pressure from the pneumatic switching valve 218. Even if air is no longer sent to the air supply source 11
3 is sent to the pressure receiving part of the pneumatic switching valve 218 via the pneumatic switching valve 221, shuttle valve 217, etc. Air continues to be supplied from the pilot air supply source 213 to the air supply path 309 unless the connection is severed.

When air is sent into the air supply path 309 as described above, the delay timer valve device 219
9a to set the time for the air tank 219b to release air, the switching valve 219C is connected between the air supply path 309 and the air supply path 311 after a predetermined time T6 after air is sent into the air supply path 309. switch to the side that does. This air supply path 311 is connected to the pneumatic switching valve 220c via the switching valve 220c which is not receiving pressure in the pressure receiving part.
It is connected to an air supply path 312 connected to the pressure receiving section 22. The switching valve 220C constitutes a part of a delay timer valve device 220 for setting a cutting end time, and this delay timer valve device 220 includes a flow rate regulating valve 220a.
, an air tank 220b, and the switching valve 220C, and the air supply path 311 is connected to the flow rate adjustment valve 220a. Therefore, by adjusting the flow rate adjustment valve 220a, the switching valve 220C can be adjusted to the air supply path 311.
After a predetermined time T7 after air is supplied to the air tank 2
Pressed by the air released from 20 b 7), the connection between the air supply path 311 and the air supply path 312 is switched to the side that is disconnected.

The pneumatic switching valve 222 is configured such that when air is being fed into the air supply path 312, that is, after the switching valve 219c is switched by air released from the air tank 219b, the switching valve 220C is switched by the air released from the air tank 220b. During a predetermined time period T7 until the air is switched by air, the air is switched to the side that connects the driving air supply source 114 and the second air cylinder 23. As a result, during the predetermined time T7, the piston rod 23a of the second air cylinder 23 presses the rod receiver 29b of the swinging arm 29 upward, and due to this pressure, the swinging arm 29 is centered around the corner portion 29a. to sway. Due to this swinging, the upper tip of the swinging arm 29 is moved from the operating piece 7 integrally formed on the second holding plate 72.
2a, the compression spring 27 stretched between the operating piece 72a and the spring holder 26, and the first clamping plate 71
The first clamping plate 71 and the second clamping plate 72 clamp the empty ring channel by pressing against the biasing force of the compression spring 20 biasing toward the clamping plate, as shown in FIG. 3F. Move this empty ring channel to the side where it approaches the cutter 30. As a result of this movement, when the empty ring channel intersects with the cutter 30 and is inserted between the fixed blade 30a and the movable blade 30b, the movable blade 30b is driven in synchronization with the driving of the sewing machine. The empty ring channel sewn into the seam of the fabric is separated from the portion held by the first holding plate 71 and the second holding plate 72.

As is clear from the above description of the operation, the length of the empty ring to be sewn into the fabric can be changed by changing the timing at which the first clamping plate 71 and the second clamping plate 72 are moved together. That is, to put it conversely, by adjusting the flow rate adjustment p 219 a of the delay timer valve device 219,
By changing the predetermined time T6 from when the sewing machine is driven until the second air cylinder 23 is activated, the length of the empty ring to be sewn into the fabric can be selected.

As described above, air will continue to be supplied to the air supply path 309 from the pilot air supply source 113 unless the pneumatic switching valve 221 is switched to disconnect the air supply path 309 from the air passage 310. The pneumatic switching valve 221 connects the blow pipe 15 and the driving air supply source 110 by a series of operations started by pressing the plunger 201a of the pilot air supply switching valve 201 described above. Switching occurs only when air is fed into the air supply path 307. Therefore, in a state where no air is sent into the air supply path 307, the second air cylinder 23 will not be driven even if the sewing machine is once stopped and then driven again. In this way, by providing a circuit constituted by the shuttle valve 217, the pneumatic switching valve 218, the pilot air supply source 113, the pneumatic switching valve 221, and the air passage 310 between the air supply paths 308 and 309, the fabric Even if the driving of the -H sewing machine is stopped at a corner or the like, the second clamping plate 72 will not operate unnecessarily thereafter.

In this manner, the empty loop created by connecting the sheet to the end of the previous fabric can be cut off from this fabric and sewn into a seam formed on the next fabric for a predetermined length.

In order to function the empty ring sewing device of the overlock sewing machine according to the present invention, the area difference double pilot valve 206 is removed from the pneumatic circuit shown in FIG. The air supply path 301a, which replaces the air supply path 301 in the fourth country connected to the switching valve 201, is directly connected to the flow rate adjustment valve 207a of the delay timer valve device 207 for setting the clamping start time, and the air supply path 301a is connected to the switching valve 202C. The air supply path 302a may be connected only to the pressure receiving part of the pneumatic switching valve 203. However, in FIG. 6, the same parts as in FIG. 4 are given the same reference numerals. In the case of this FIG. 6, each flow rate regulating valve 207a, 202 of the delay timer valve device 207 and the delay timer valve device 202 for setting the empty ring suction time.
An air supply path 301a is connected to both a and a. For this reason, as shown in FIG. 5, the suction time T from the suction port 14a has elapsed, and after a predetermined time T elapses, the nozzle 13a is opened.

Air blowing from 15a and first air cylinder 16
In order to operate the delay timer valve device 2,
It is necessary to adjust the flow rate adjustment valve 207a of No. 07 so that the switching valve 207C switches to the side that connects the air supply paths 301a and 304 after TI+72 after air is fed into the flow rate adjustment valve 207a. Therefore, in the pneumatic circuit shown in FIG. 6, when the suction time T1 is changed by adjusting the flow rate adjustment valve 202a of the delay timer valve device 202,
If a is left as is, the predetermined time T2 will also change, so even if the suction time T1 is changed, the predetermined time T2 will not change.
If it is desired to keep the flow rate constant, it is necessary to adjust the flow rate adjustment valve 207a as well as the flow rate adjustment valve 202a.

Next, FIG. 7 shows that the shuttle valve 217, pneumatic switching valves 218, 221, pilot air supply source 113, and air supply path 310 are removed from the pneumatic circuit shown in FIG. 4 and connected to the pilot air supply switching valve 215. An air supply path 308a, which replaces the air supply path 308 in FIG. 219c is also shown, and other parts in this air circuit diagram are given the same symbols as in FIG. 4. In this air circuit diagram in Figure 7,
After pressing the plunger 215a of the pilot air supply switching valve 215 by driving the sewing machine, when the driving of the sewing machine is stopped and the pressure on the plunger 215a is released, the air supply path 308a is air will no longer be fed. Therefore, the second air cylinder 23 is driven every time the sewing machine is driven, and when forming seams on multiple edges of one piece of fabric in succession, when forming seams on the second and subsequent edges, the second air cylinder 23 is driven. The second air cylinder 23 will operate unnecessarily. However, the pneumatic circuit shown in FIG. 7 is still capable of achieving the effects of the present invention.

As is clear from the above description of FIGS. 6 and 7, in order to achieve the effect of the present invention, the differential area double pilot valve 206 as shown in FIG. 6 is removed from the pneumatic circuit of FIG. 4, and Furthermore, as shown in FIG. 7, it is also possible to use a pneumatic circuit excluding the shuttle valve 217, pneumatic switching valves 218, 221, pilot air supply source 221, and air passage 310.

Next, FIG. 8 shows another embodiment of the empty chain sewing device for an overlock sewing machine according to the present invention. In this embodiment, instead of the suction tube 14 disposed inside the cross plate l in FIG. 1, a suction tube 14° is disposed on the work surface la, and the suction port 1 of this suction tube 14°
4'a can be placed near the suction hole 11a of the hollow ring cutting part 10 and on an extension line along the sewing axis X extending from the top of the tongue 5. In this way, there is no need to make a hole for the suction port in the cross plate 1 as shown in Fig. 1, but when sewing the cloth, it is necessary to make it so that it does not get in the way of the passage of the cloth. It is necessary to move the suction tube 14' from above the work surface la. The means for moving this suction tube 14° from above the work surface la to a place where it does not interfere with the passage of the fabric may be one in which this suction tube 14° is moved back from the work surface by a sliding method, or The suction tube 14° may be rotated about a predetermined position so that ``a'' draws an arc. In this way, the inlet 14°a
When disposing the suction tube 14' on the work surface la, it is necessary to move the suction tube 14' onto the work surface la only during suction. To do this automatically, for example, in the pneumatic circuit diagram shown in FIG. At the same time as connecting the suction tube 14°, move the suction tube 14° to a predetermined position on the work surface la, and disconnect the suction tube 14° from the empty ring suction air supply source 103.
It is sufficient to add a circuit configuration for moving the 4° g from the work surface la to a location where it does not interfere with the passage of the fabric.

It should be noted that the empty chain sewing device of the overlock sewing machine according to the present invention is of course not limited to the above-mentioned embodiment. For example, although the above-mentioned embodiment uses a pneumatic circuit, it may be replaced with an air cylinder or the like. The device may be operated by an electric circuit using a solenoid or the like, or a hydraulic circuit or a combination of the above circuits may be used.

〔Effect of the invention〕

As is clear from the above description, according to the empty ring sewing device for an overlock sewing machine according to claim 1 of the present invention, the upper surface of the plate that clamps the empty ring is on the same plane as the work surface. This prevents the clamping plate from interfering with the fabric being inserted onto the throat plate from the front side of the sewing machine, which could impede the fabric from feeding straight or damage the fabric, which would impair the quality of the product. It has the effect of not having any.

Further, according to the empty ring sewing device for an overlock sewing machine according to claim 2 of the present invention, in addition to the effect provided by the device described in claim 1, the clamped empty ring can be sewn into a second Since cutting can be performed from the clamping portion by driving the clamping plate, it is possible to appropriately change the length of the empty ring to be sewn into the seam of the next fabric.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the empty chain sewing device of an overlock sewing machine according to the present invention, and FIGS. 2A to 2C are cross plates illustrating the operation of the clamping plate. Cutaway plan view, Figures 3A to 3
Fig. F is a perspective explanatory view showing the empty ring processing process by the embodiment device, and Fig. 4 is a diagram showing an example of the pneumatic circuit of the embodiment device.
Fig. 5 is a timing chart diagram showing the operation of the ring sewing device based on the pneumatic circuit diagram of Fig. 4, Fig. 6 is a diagram showing a modification of the pneumatic circuit, and Fig. 7 is a diagram showing another modification of the pneumatic circuit. FIG. 8 is a partially cutaway perspective view showing another embodiment of the present invention. la... Working surface 4... Needle drop portion 7... Clamping plate 71... First clamping plate 72... Second clamping plate 11a... Suction hole 12... Cutting device 15a...・Nozzle (air outlet) H...Insertion port X...Sewing shaft patent applicant Pegasus Sewing Machine Manufacturing Co., Ltd. Agent
People Patent Attorney Takashi Suzue - Figure 2B Figure 2C

Claims (2)

[Claims] (1) Attached to an overlock sewing machine that forms a seam by overlocking on the edge of the fabric and creates an empty ring connected to the seam at the end of the fabric, the empty ring is provided on the rear side from the needle drop part. It is sucked into the suction hole and cut by a cutter at the suction hole, and the free end of the empty ring separated from the fabric is moved by wind pressure toward the front side of the needle drop, and the moved empty ring is cut into the needle. In the empty ring sewing device of an overlock sewing machine, which is designed to clamp the empty ring on the front side of the needle drop part and sew this clamped empty ring into the seam to be formed on the next fabric, it is provided on the front side of the needle drop part. , a clamp whose upper surface is on the same plane as the working surface of the sewing machine and which is movable in a direction intersecting the sewing axis to form an insertion opening on the working surface into which the free end of the empty ring that has been moved by wind pressure can be inserted; the plate, and an air outlet provided above the work surface toward the insertion port formed by the movement of the clamping plate, and the free end of the empty ring is heated by the air blown from the air outlet. An empty ring sewing device for an overlock sewing machine, characterized in that, after the empty ring is inserted into the insertion opening, the empty ring is held in front of the needle drop by moving a clamping plate to close the insertion opening. (2) Attached to an overlock sewing machine that forms a seam by overlocking at the edge of the fabric and creates an empty ring connected to the seam at the end of the fabric, the empty ring is provided on the rear side from the needle drop part. It is sucked into the suction hole and cut by a cutter at the suction hole, and the free end of the empty ring separated from the fabric is moved by wind pressure toward the front side of the needle drop, and the moved empty ring is cut into the needle. In the empty ring sewing device of an overlock sewing machine, which is designed to clamp the empty ring on the front side of the needle drop part and sew this clamped empty ring into the seam to be formed on the next fabric, it is provided on the front side of the needle drop part. , the upper surface of which is on the same plane as the working surface of the sewing machine, and which is movable in a direction intersecting the sewing axis to form an insertion opening on the working surface into which the free end of the empty ring that has been moved by wind pressure can be inserted; The first clamping plate is movable in a direction intersecting the sewing axis together with the first clamping plate in close contact with the first clamping plate only when the first clamping plate itself is driven, and when only the first clamping plate moves. A second clamping plate that forms the insertion opening between the clamping plate and the first clamping plate, and an air outlet provided above the work surface toward the insertion opening formed by the movement of the first clamping plate. After inserting the free end of the empty ring into the insertion port using air blown from the air outlet, move the first clamping plate and close the insertion port to insert the empty ring on the front side of the needle drop. At the same time, by moving the first clamping plate and the second clamping plate together in the empty ring clamping state, the empty ring is removed from the clamping part by a cutter installed on the trajectory of the empty ring as it moves. An empty chain sewing device for an overlock sewing machine, characterized in that it is capable of cutting.