JP6581810B2 - Looper threading device for chain stitch machine - Google Patents

Description

  The present invention relates to a looper threading device for a chain stitch sewing machine.

A conventional thread-sewing machine is equipped with a threading device that guides the looper thread to the looping-out port of the looper by air.
This threading device has a looper side thread guide path for guiding the looper thread to a thread feed hole at the tip of the looper, a pump for generating positive pressure air, and a thread guide for the apparatus side having a thread introduction port for inserting the looper thread. And a connecting pipe that connects the looper side yarn guide route and the device side yarn guide route by forward and backward movement (see, for example, Patent Document 1).
In this threading device, the positive pressure air from the pump is fed into the device-side yarn guide path through a route where the air flows from the middle of the device-side yarn guide route, so that the upstream side of the joining portion of the device-side yarn guide route. The side is in a low pressure state to obtain a suction force from the yarn introduction port.
When guiding the looper yarn, the connection pipe connects the looper-side yarn guide path and the device-side yarn guide route, and the positive pressure air from the pump is fed into the device-side yarn guide path to be inserted into the yarn introduction port. The looper thread was fed into the looper hole of the looper.

Japanese Patent No. 3355214

However, the conventional threading device has a large flow resistance on the looper side thread guide path side because the looper side thread guide path is connected to the thread feeding hole of the small diameter looper.
For this reason, when the looper side thread guide path and the apparatus side thread guide path are connected by the connecting pipe, the air that cannot enter the looper side thread guide path flows backward to the thread introduction port side, the looper thread is pushed out, and the looper In some cases, the thread could not be guided to the thread take-up hole.

  An object of the present invention is to satisfactorily guide the looper yarn to the looper.

The invention of claim 1 is a looper threading device for a chain stitch sewing machine.
A looper side thread guide path for guiding the looper thread to the thread feed hole at the tip of the looper;
An apparatus-side yarn guide path having a yarn introduction port for inserting a looper yarn;
A positive-pressure air supply unit that sends positive-pressure air in the middle of the device-side yarn guide path;
A connecting portion that connects the looper side yarn guide path and the device side yarn guide path;
Relief for allowing a part of the positive pressure air to escape to the outside of the looper side thread guide path at the boundary part of the looper side thread guide path and the apparatus side thread guide path or closer to the thread delivery hole side than the boundary part. It is characterized by having a mouth.

The invention described in claim 1 further includes
The escape port is formed at a connection end on the apparatus side thread guide path side in the looper side thread guide path or a connection end on the looper side thread guide path side in the apparatus side thread guide path. And

The invention described in claim 1 further includes
The connection end on the apparatus side thread guide path side in the looper side thread guide path or the connection end on the looper side thread guide path side in the apparatus side thread guide path is switched between a non-connected state and a connected state. It is possible, and when switching to the connected state, it is a structure that inserts the connection end of the other party's guide route and connects,
The escape port is a slit that is concave in the insertion direction.

  The present invention provides a relief port for allowing a part of positive air to escape to the outside of the looper side yarn guide path from the boundary part between the looper side yarn guide path and the apparatus side yarn guide path or to the yarn feed hole side from the boundary part. Therefore, even if excessive positive pressure air is supplied to the looper side yarn guide path, it can be discharged from the escape port to the outside, and air blowout from the yarn introduction port is suppressed. It is possible to perform good threading.

It is a perspective view of the looper threading device concerning this embodiment. It is a perspective view which shows the state which has the connecting pipe of an apparatus side thread | yarn guide path | route in a non-connecting position. It is a perspective view which shows the state which has the connecting pipe of an apparatus side thread | yarn guide path | route in a connection position. It is a perspective view of the connection pipe of the looper side thread guide path in which an escape port is formed. It is a side view of the connection pipe of the looper side yarn guide path in which an escape port is formed. It is a side view showing the state where the connecting pipe of the looper side yarn guide path and the connecting pipe of the device side yarn guide path are connected. It is sectional drawing which showed the arrangement | positioning location of the 1st and 2nd apparatus side thread | yarn guide path | route in a support block in the cross section along a XZ plane. It is a disassembled perspective view of a part structure of a support block and a 1st and 2nd apparatus side thread | yarn guide path | route. It is a perspective view of the lower end part of the introduction member of an apparatus side thread guide path. It is sectional drawing of the lower end part of the introduction member of an apparatus side thread | yarn guide path | route. It is sectional drawing of the connection part of the connection pipe of a looper side thread guide path, and the connection pipe of an apparatus side thread guide path. It is sectional drawing of the connection part of the connection pipe | tube of the looper side thread | yarn guide path | route and the connection pipe | tube of an apparatus side thread | yarn guide path | route which showed the case where the escape port was not formed virtually.

[Overall Configuration of Embodiment]
A looper threading device 100 mounted on an edge stitch sewing machine as a chain stitch sewing machine according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of the looper threading device 100. In FIG. 1, the Z-axis direction indicates a vertical vertical direction, the X-axis direction indicates a horizontal direction in which cloth feeding is performed, and the Y-axis direction indicates a horizontal direction orthogonal to the X-axis direction. Further, in the Y-axis direction, the standing body portion side of the sewing machine may be referred to as the rear side, and the surface side may be referred to as the front side.

The edge stitch sewing machine includes a lower looper 1 and an upper looper 2 which are provided on the lower side of the needle plate and reciprocate in synchronization with the vertical movement of the needle bar provided with the sewing needle.
The lower looper 1 has a thread feeding hole for feeding out the lower looper thread at a sharp distal end directed rearward, and captures the loop of the upper thread from the sewing needle by reciprocating the distal end part back and forth.
The upper looper 2 has a thread feeding hole for feeding the upper looper thread at a sharp tip directed obliquely upward to the front, and is moved from the lower looper 1 by reciprocating the tip to the front diagonally upward and the rear diagonally downward. Capture the loop of the lower looper thread. Further, when the upper looper 2 is moved obliquely upward in the front direction, the leading end of the upper looper 2 reaches the upper side from the edge of the cloth that is the sewing object, and at this time, the loop of the upper looper thread formed in the upper looper 2 The sewing needle enters and is captured.
In other words, the edge stitching machine performs edge stitching by the cooperation of the sewing needle, the lower looper 1 and the upper looper 2.

[Looper threading device]
The looper threading device 100 guides the looper yarn to the first looper side yarn guide path 10 that guides the looper yarn to the yarn feed hole at the tip of the lower looper 1 and to the yarn feed hole at the tip of the upper looper 2. Looper side yarn guide path 20, first device side yarn guide path 30 having a yarn introduction port 311 for inserting a lower looper yarn, and second device side yarn having a yarn introduction port 411 for inserting an upper looper yarn. A guide path 40, a positive pressure air supply unit 50 for feeding positive pressure air in the middle of the first and second apparatus side thread guide paths 30 and 40, a first looper side thread guide path 10 and a first apparatus. A side thread guide path 30 is connected, and a connection portion 60 is provided for connecting the second looper side thread guide path 20 and the second device side thread guide path 40.

[First looper side thread guide route]
2 is an enlarged perspective view of the first and second looper side yarn guide paths 10 and 20 and the first and second device side yarn guide paths 30 and 40 in a non-connected state, and FIG. 3 is an enlarged perspective view of the connected state. FIG.
As shown in FIGS. 1 to 3, the first looper side yarn guide path 10 is equipped so as to be embedded in a groove formed on one side in the X-axis direction of the lower looper 1, and a part thereof is curved. A pipe-shaped guide tube 11 and a straight cylindrical connecting tube 12 communicating with the guide tube 11 are provided.
One end of the guide tube 11 is connected to the yarn feeding port at the tip of the lower looper 1, and the other end is connected to the front end of the connection tube 12. The guide tube 11 and the connecting tube 12 are each formed with a threading hole that penetrates the center over the entire length, and the threading holes communicate with each other.

The connecting pipe 12 is fixedly supported in the vicinity of the base end portion of the lower looper 1, and the rear end portion thereof can be connected to the first device-side yarn guide path 30.
The first looper side thread guide path 10 reciprocates with the lower looper 1 during sewing. However, when the first looper side thread guide path 10 is connected to the first device side thread guide path 30 to pass the lower looper thread, The looper 1 is at a predetermined stop position, and the connection pipe 12 is maintained in the state along the Y-axis direction.

4 is a perspective view of the connecting pipe 12, FIG. 5 is a side view, and FIG. 6 is a side view of the connecting pipe 12 with a connecting pipe 33 of a first device-side yarn guide path 30 described later inserted therein.
As shown in FIGS. 4 and 5, the outer diameter of the front end portion of the connecting pipe 12 is smaller than the outer diameter of the rear end portion, and the outer periphery of the small diameter front end portion is supported by the lower looper 1.
Further, the rear end portion of the connecting pipe 12 is wide open and gradually decreases in diameter toward the front. That is, a mortar-shaped conical surface 121 is formed at the rear end of the connection pipe 12, and the connection pipe 33 of the first device-side yarn guide path 30 inserted from the rear is guided to the center of the connection pipe 12. be able to.

Furthermore, a slit-like escape port 122 is formed at the rear end portion of the connection pipe 12 along the diameter direction of the connection pipe 12. As shown in FIG. 5, the escape port 122 is formed to be concave from the rear end surface of the connection pipe 12 toward the direction in which the connection pipe 33 of the first device-side yarn guide path 30 is inserted. . Then, as shown in FIG. 6, the bottom surface of the escape port 122 is somewhat forward from the front end portion of the connection tube 33 of the first device-side yarn guide path 30 inserted into the connection tube 12. The clearance is set so that a part of the positive pressure air that pumps the lower looper yarn between the connecting pipe 12 and the connecting pipe 33 of the first device-side yarn guide path 30 is discharged to the outside. S is formed.
The effect of the escape port 122 will be described later.

[Second looper side thread guide route]
The second looper side yarn guide path 20 is similar in structure and structure to the first looper side yarn guide path 10 described above, and the same structure as the first looper side thread guide path 10 is used. The description may be omitted.
As shown in FIGS. 1 to 3, the second looper side yarn guide path 20 is equipped so as to be embedded in a groove formed on one side in the X-axis direction of the upper looper 2, and a part thereof is curved. A pipe-shaped guide tube 21 and a straight cylindrical connection tube 22 communicating with the guide tube 21 are provided.
One end of the guide tube 21 is connected to the yarn feed port at the tip of the upper looper 2, and the other end is connected to the front end of the connection tube 22. The guide tube 21 and the connecting tube 22 are each formed with a threading hole penetrating the center of the guide tube 21 and the connecting tube 22, and the threading holes communicate with each other.

The connection pipe 22 is fixedly supported in the vicinity of the base end portion of the upper looper 2, and the rear end portion thereof can be connected to the second device-side yarn guide path 40.
The second looper side thread guide path 20 also reciprocates together with the upper looper 2 during sewing. However, when the upper looper thread is passed, the upper looper 2 is in a predetermined stop position, and the connecting tube 22 extends in the Y-axis direction. The state along is maintained.

The connecting pipe 22 is also supported by the upper looper 2 at the front end portion of the small diameter, the outer diameter of the front end portion being smaller than the outer diameter of the rear end portion. Moreover, it is the same as the connection pipe 12 in that a conical surface 221 having a mortar shape is provided at the rear end portion of the connection pipe 22 and a slit-shaped escape port 222 is formed.
Although not shown, the escape port 222 is also configured such that the bottom surface of the release port 222 is somewhat in front of the front end of the connection tube 43 of the second device-side yarn guide path 40 inserted into the connection tube 22. The depth S is set, and a gap S (see FIG. 6) is formed to discharge a part of the positive pressure air for pumping the upper looper yarn to the outside.

[Positive pressure air supply unit]
As shown in FIG. 1, the positive pressure air supply unit 50 includes a support block 51 fixedly mounted on the upper part of the bed portion of the edge stitching machine frame, a pump 52 built in the support block 51, and a drive source thereof. And a cover 54 attached to the upper part of the support block 51.

The motor 53 has an output shaft connected to the drive unit of the pump 52.
The pump 52 includes an intake port and an exhaust port, and the exhaust port is connected to a conduction path 516 formed in the support block 51. Then, positive pressure air generated by the operation of the pump 52 is supplied to the conduction path 516.
The pump 52 may be of any type as long as it is a small one that can be incorporated in the edge stitching machine.

FIG. 7 is a cross-sectional view showing the arrangement locations of the first and second device-side yarn guide paths 30 and 40 in the support block 51 in a cross section along the XZ plane, and FIG. It is a disassembled perspective view of a part of structure of the 2nd apparatus side thread | yarn guide path | route 30,40.
As shown in FIGS. 7 and 8, the support block 51 includes two parts for holding a part of the configuration of the first and second device-side yarn guide paths 30 and 40 on the yarn introduction ports 311 and 411 side, respectively. The through holes 511 and 511 are formed so as to penetrate vertically.
Each through-hole 511 has a large-diameter portion 512 having the largest inner diameter, an equal-diameter portion 513 having a somewhat smaller inner diameter than the large-diameter portion 512, a conical tapered portion 514 that gradually decreases in diameter downward, and has the largest inner diameter. Small small diameter portions 515 are concentrically connected in order from the top.
The support block 51 is formed with a conduction path 516 that guides positive-pressure air generated from the pump 52 to the lower part of the large-diameter portion 512 of each through hole 511. With this conduction path 516, positive pressure air from the pump 52 can be supplied into the first and second apparatus-side yarn guide paths 30 and 40.

The cover 54 is a rectangular flat plate and is attached to the upper surface of the support block 51. The cover 54 is formed with openings 541 and 541 penetrating vertically at positions corresponding to the two through holes 511 and 511 of the support block 51. The openings 541 and 541 are somewhat smaller in diameter than the large diameter portions 512 and 512 of the through holes 511 and 511, and the yarn introduction ports 311 and 411 of the first and second device-side yarn guide paths 30 and 40 are provided. It is exposed upward.
Further, a threading start button 542 is provided in the vicinity of the rear end portion of the cover 54. When this threading start button 542 is pressed, the motor 53 starts to be driven and the pump 52 is activated to lower and upper looper yarns from the first and second device-side yarn guide paths 30 and 40 by air. Threading is possible.

[First and second device side thread guide paths]
As shown in FIGS. 1, 7, and 8, the first device-side yarn guide path 30 includes an introduction member 31 in which a yarn introduction port 311 for a lower looper yarn is formed, and an upper end portion connected to the introduction member 31. A pipe-shaped guide tube 32 and a pipe-shaped connection tube 33 connected to the lower end of the guide tube 32 so as to be movable back and forth.
The second apparatus-side yarn guide path 40 includes an introduction member 41 in which a yarn introduction port 411 for the upper looper yarn is formed, a pipe-shaped guide tube 42 whose upper end is connected to the introduction member 41, and a guide tube. And a pipe-like connecting pipe 43 movably connected to the lower end portion of 42.

The upper end portions of the introduction member 31 and the guide tube 32 of the first device-side yarn guide path 30 have the same structure as the upper ends of the second device-side yarn guide path 40 introduction member 41 and the guide tube 42. Are shown in common.
That is, each of the guide tubes 32 and 42 is disposed along the Z-axis direction with one end portion facing upward, the intermediate portion is curved, and the other end portion is directed frontward in the Y-axis direction. It is arrange | positioned in the state along.
And the outer diameter of the one end part of the guide pipes 32 and 42 corresponds substantially with the internal diameter of the small diameter part 515 of the through-hole 511, and the conical shape part diameter-expanded upwards at the one end part of the guide pipes 32 and 42. 321 and 421 are formed.
The inclination angles of the cone-shaped portions 321 and 421 coincide with the inclination angle of the tapered portion 514 of the through hole 511, and the guide tubes 32 and 42 inserted from above with respect to the through-hole 511 have the cone-shaped portion 321. , 421 are in close contact with the tapered portion 514 of the through hole 511 without any gap.

  The introduction members 31 and 41 are arranged inside the through hole 511 with their lower end portions inserted inside the conical portions 321 and 421 of the guide tubes 32 and 42.

In addition, circular flange portions 312 and 412 extending outward in the radial direction are formed on the outer peripheral surfaces of the introduction members 31 and 41. The flange portions 312 and 412 are positioned in the vicinity of the lower end portion of the large diameter portion 512 of the through hole 511 when the introduction members 31 and 41 are disposed inside the through hole 511.
In addition, O-rings 34 and 44 as sealing materials are arranged above the flange portions 312 and 412 of the introduction members 31 and 41.
The O-rings 34 and 44 are in close contact with the inner peripheral surface of the large-diameter portion 512 of the through hole 511 and the outer peripheral surface of the introduction members 31 and 41, and divide the internal space of the large-diameter portion 512 into two parts in an airtight state.
For this reason, the positive pressure air supplied from the conduction path 516 communicating with the lower portion of the large-diameter portion 512 is supplied only to the lower side of the O-rings 34 and 44, thereby preventing upward leakage.
The outer diameters of the O-rings 34 and 44 are larger than the inner diameter of the opening 541 of the cover 54 described above, and when the cover 54 is fixed to the upper surface of the support block 51, the O-rings 34 and 44 and the flange portions 312 and The introduction members 31 and 41 can be held from above via 412.

As shown in FIGS. 9 and 10, conical surfaces 314 and 414 having a diameter reduced downward are formed at the lower ends of the introduction members 31 and 41. The conical surfaces 314 and 414 have the same inclination angle as the conical portions 321 and 421 of the guide tubes 32 and 42 described above, and the conical surfaces 314 and 414 of the introduction members 31 and 41 and the conical portions 321 and 421 are formed. The inner surface can be in close contact with no gap.
A plurality of ventilation grooves 313 and 413 are formed in the conical surfaces 314 and 414 of the introduction members 31 and 41 in the vertical direction.
Accordingly, when positive pressure air is supplied from the conduction path 516 into the through hole 511, the positive pressure air passes through the plurality of ventilation grooves 313 and 413 and enters the guide pipes 32 and 42, and the guide pipe 32. , 42 and a plurality of ventilation grooves 313, 413, a downward airflow is generated below the junction point.
As a result, the insides of the yarn introduction ports 311 and 411 and the threading holes of the introduction members 31 and 41 located above the joining point of the guide tubes 32 and 42 and the plurality of ventilation grooves 313 and 413 are in accordance with Bernoulli's law. And a downward suction force from the yarn introduction ports 311 and 411 is generated.

As described above, each of the guide tubes 32 and 42 is supported by the support block 51 and has a shape along the Z-axis direction. The guide tubes 32 and 42 are curved at the intermediate portion and the other end is along the Y-axis direction. Looking forward in shape.
The other end portions of the guide tubes 32 and 42 are fixedly supported by a fixing bracket 72 attached to a main body plate 71 fixedly installed in the bed portion of the sewing machine.

Further, connecting pipes 33 and 43 made of straight cylinders are attached to the other ends of the guide pipes 32 and 42. The connecting pipes 33 and 43 have inner diameters substantially equal to the outer diameters of the other end portions of the guide pipes 32 and 42, and the other end portions of the guide pipes 32 and 42 are inserted into the guide pipes 32 and 42. It can slide against.
That is, the connecting pipes 33 and 43 can reciprocate along the Y-axis direction.

The connection pipes 33 and 43 of the first and second apparatus-side yarn guide paths 30 and 40 are respectively connected to the first and second loopers when the lower looper 1 and the upper looper 2 are in a predetermined stop position. They are arranged so as to be concentric with the connecting pipes 12 and 22 of the side thread guide paths 10 and 20.
When the connection pipes 33 and 43 are moved forward from the non-connection position (FIG. 2) to the connection position (FIG. 3), the front ends thereof are connected to the connection pipes 12 of the first and second looper side yarn guide paths 10 and 20. , 22 can be inserted into the conical surfaces 121, 221 and the insertion can be connected to each other.

[Connection]
As shown in FIG. 1, the connection portion 60 supports the connection pipes 33, 43 so as to be movable back and forth, and holds the connection pipes 33, 43 and is slidable back and forth with respect to the main body plate 71. A supported movable plate 62, a tension spring 63 that imparts forward movement to the movable plate 62, an operation lever 64 that inputs a forward / backward movement to the movable plate 62, and each looper 1 when moving from a non-connection position to a connection position. , 2 is provided with a stopper pin 65 for defining the position of 2.

  The support bracket 61 is plate-shaped, and has two support holes into which the connecting pipes 33 and 43 can be inserted into the wall surface portion along the XZ plane that is vertically raised from the main body plate 71 along the YZ plane. The connecting pipes 33 and 43 can be moved back and forth by sliding with respect to the support hole.

The movable plate 62 has a support wall 621 raised by bending a front end portion of a long flat plate along the Y-axis direction.
The support wall 621 extends along the XZ plane and supports the connection pipes 33 and 43 so as to be slidable in the front-rear direction. Each connection pipe 33, 43 is equipped with a fastening ring 624, 624, and when moving from the connected position to the non-connected position, the support wall 621 moving backward is engaged with the fastening rings 624, 624. The connecting officers 33 and 43 can be moved backward. In addition, pressing springs 623 and 623 that are weaker than the tension spring 63 are in contact with the fastening rings 624 and 624 and urge the connection pipes 33 and 43 forward via the fastening rings 623 and 624. That is, the connecting pipes 33 and 43 can move as the movable plate 62 moves back and forth.

  The tension spring 63 has one end connected to the movable plate 62 and the other end connected to the support bracket 61. As a result, the movable plate 62 is always tensioned forward, and in a state where the movable plate 62 is not restrained, the connection pipes 33 and 43 are connected to the first and second looper side yarn guide paths 10 and 20. It will be in the state connected with the pipe | tubes 12 and 22. FIG.

  The operation lever 64 is supported so as to be rotatable about the X axis with respect to the main body plate 71, and the operation lever 64 is provided with a cam member 641 that rotates simultaneously. The cam member 641 is provided with a protrusion 642 that protrudes outward in the rotational radius direction. It is arranged to touch.

  When the operation lever 64 is rotated in the clockwise direction in FIG. 1, the projection 642 of the cam member 641 moves the movable plate 62 rearward through the convex portion 622, and the operation lever 64 is moved in the counterclockwise direction in FIG. 1. When rotated, the pressing by the cam member 641 is released and the movable plate 62 moves forward by the tension of the tension spring 63. That is, the connection pipes 33 and 43 are moved back and forth by the turning operation of the operation lever 64, so that the connection pipes 33 and 43 of the first and second device-side yarn guide paths 30 and 40 are moved in the first and second directions. The connection state and the non-connection state of the looper side yarn guide paths 10 and 20 with respect to the connection pipes 12 and 22 can be switched.

The stopper pin 65 is movable along the X-axis direction, and is biased by a spring (not shown) so that one end of the stopper pin 65 protrudes toward the cam member 641, and rotates the operation lever 64 counterclockwise. When moved, the cam member 641 is pressed against an inclined surface (not shown) so as to be pushed inward.
Further, a threading positioning collar (not shown) is fixed to the drive shaft that gives the reciprocating motion of the loopers 1 and 2, and the other end of the stopper pin 65 can be engaged with the outer peripheral surface of the threading positioning collar. It has become. A concave portion is provided on the outer peripheral surface of the threading positioning collar. When the stopper pin 65 is pushed into the concave portion by rotating the operation lever 64 counterclockwise, the drive shaft is fixed, Each looper 1, 2 can be stopped at a predetermined stop position.
That is, by rotating the operation lever 64 counterclockwise, the stopper pin 65 is pushed in, the upper looper 2 and the lower looper 1 are fixed at predetermined stop positions, and the connection pipes 12 and 22 at appropriate positions are fixed. Thus, the connecting pipes 33 and 43 can be connected.

[Operation of looper threading device]
As shown in FIG. 1, when the operation lever 64 is rotated counterclockwise, the cam member 641 pushes the stopper pin 65 inward, and fixes the lower looper 1 and the upper looper 2 at the predetermined stop positions described above. As a result, the connection pipe 12 of the first looper-side thread guide path 10 and the connection pipe 22 of the second looper-side thread guide path 20 are in a state along the Y-axis direction, and the first apparatus-side thread guide path. It is fixed at a position where it can be connected to the connection pipe 33 of the 30 and the connection pipe 43 of the second device-side yarn guide path 40.

Then, the movable plate 62 is moved forward by the rotation of the operation lever 64, and the connection pipe 33 and the second apparatus side thread guide of the first apparatus side thread guide path 30 urged by the pressing springs 623 and 623. The connection pipe 43 of the path 40 moves forward as the movable plate 62 moves.
Thereby, the connection pipes 33 and 43 of the first and second apparatus-side yarn guide paths 30 and 40 shift from the non-connection state of FIG. 2 to the connection state of FIG. 3, and the connection pipes 33 and 43 are respectively Inserted inside the conical surfaces 121 and 221 of the connection pipes 12 and 22 of the first and second looper side yarn guide paths 10 and 20, the connection pipe 33 and the connection pipe 12 are connected, and the connection pipe 43 and the connection pipe 22 is connected.

  Further, when the start button 542 is pressed, the motor 53 and the pump 52 start driving, and the guide pipe 32 is passed from the ventilation grooves 313 and 413 at the lower ends of the introduction members 31 and 41 through the conduction path 516 as shown in FIG. , 42 flows into the positive pressure air. As a result, a suction force is generated at the yarn introduction ports 311 and 411 of the introduction members 31 and 41.

Then, positive pressure air is supplied to the yarn feeding hole of the lower looper 1 through the first device-side yarn guide path 30 and the first looper-side yarn guide route 10, and the second device-side yarn guide path 40 and the second device-side yarn guide path 40 The positive pressure air is supplied to the yarn feed hole of the upper looper 2 through the looper side yarn guide path 20.
At this time, the yarn feeding opening of each of the loopers 1 and 2 is small, and the guide pipes 11 and 21 of the looper side yarn guide paths 10 and 20 are provided along the loopers 1 and 2, so that the yarn catching is not hindered. As described above, the flow resistance of the looper side yarn guide paths 10 and 20 is larger than that of the device side thread guide paths 30 and 40 due to the use of a smaller diameter pipe.
Accordingly, there is a risk that air will not flow smoothly at the connection portion of the connection pipe 33 and the connection pipe 12 and the connection portion of the connection pipe 43 and the connection pipe 22 which are the boundaries.

As shown in FIG. 12, if there is no escape port formed in the connection portion between the connection pipes 33 and 43 and the connection pipes 12 and 22, there is no excessive air escape path, thereby the first apparatus side. There is a possibility that the internal pressure of the yarn guide paths 30 and 40 increases, and the air flows backward from the yarn introduction ports 311 and 411 of the introduction members 31 and 41 toward the outside.
However, as shown in FIG. 11, since the escape ports 122 and 222 are formed at the rear ends of the connection pipes 12 and 22, excess air is discharged from the escape ports 122 and 222 on the first and second looper sides. The yarn is discharged outside the yarn guide paths 10 and 20.

  Accordingly, the suction force is well maintained at the yarn introduction ports 311 and 411 of the introduction members 31 and 41. When the lower looper yarn is inserted from the yarn introduction port 311, the lower looper 1 is smoothly fed to the yarn feeding hole of the lower looper 1. Threading of the thread can be performed. Similarly, when the upper looper yarn is inserted from the yarn introduction port 411, the upper looper yarn can be smoothly fed to the yarn feeding hole of the upper looper 2 and the upper looper yarn can be threaded.

After the completion of threading, when the pressing of the start button 542 is stopped, the motor 53 and the pump 52 stop driving, and the supply of positive pressure air stops.
Then, when the operation lever 64 is rotated clockwise, the connecting pipes 33 and 43 are moved away from the connecting pipes 12 and 22.
Further, the stopper pin 65 is released from being pushed into the concave portion of the positioning collar by the cam member 641. As a result, the restriction state of the drive shaft is released, the loopers 1 and 2 can be operated, and the edge stitching machine can be sewn.

[Technical effects of the embodiment]
The edge thread sewing machine threading device 100 includes a rear end portion of the connection pipe 12 that is a boundary portion between the first looper side thread guide path 10 and the first apparatus side thread guide path 30, and a second looper. The first and second looper side yarn guide paths are used to pass a part of the positive pressure air to the rear end portion of the connecting pipe 22 which is a boundary portion between the side yarn guide path 20 and the second device side yarn guide path 40. Relief ports 122 and 222 are provided outside 10 and 20.
For this reason, even when excessive positive pressure air is supplied to the first and second looper side yarn guide paths 10 and 20, the air can be discharged to the outside from the relief ports 122 and 222, and the introduction member It is possible to suppress the backflow of air from the yarn introduction ports 311 and 411 of the 31 and 41 and to perform good threading.

  The relief ports 122 and 222 are connected to the boundary between the first looper side yarn guide path 10 and the first apparatus side thread guide path 30 and the second looper side thread guide path 20 and the second apparatus side thread guide path. Since it is provided at the boundary with 40, it matches the position where the flow resistance of air becomes high, excess air can be discharged effectively, the backflow of air from the yarn inlets 311 and 411 is sufficiently suppressed, and better Threading can be performed.

Further, since the relief ports 122 and 222 are formed from slits, the formation is easy, and it becomes possible to reduce the production cost of the apparatus and improve the productivity.
Further, the connection pipes 33 and 43 of the device side thread guide paths 30 and 40 are inserted into the connection pipes 12 and 22 of the looper side thread guide paths 10 and 20, respectively, and the connection is made. Reference numeral 222 denotes a slit that is concave in the insertion direction. Therefore, the opening amount of the relief ports 122 and 222 can be easily adjusted according to the depth of insertion of the connection tubes 33 and 43 with respect to the connection tubes 12 and 22, and by optimizing the air discharge amount, It is possible to further suppress the occurrence of air blowing from the yarn introduction ports 311 and 411 and perform better threading.

[Others]
Note that the escape ports 122 and 222 need not be slits as long as excess air can be discharged to the outside. For example, a through hole penetrating from the inside of the connecting pipes 12 and 22 to the outside and a plurality of small holes may be used, and the peripheral wall on the rear end side of the connecting pipes 12 and 22 may be a mesh.

The relief ports 122 and 222 may be formed on the front end side of the connection pipes 33 and 43 of the device-side yarn guide paths 30 and 40.
Further, the connecting pipes 33 and 43 are made larger in outer diameter than the connecting pipes 12 and 22, a conical surface is formed at the front ends of the connecting pipes 33 and 43, and the connecting pipes 12 and 33 are formed on the conical surfaces of the connecting pipes 33 and 43. The rear end portion of 22 may be inserted.

  Further, the relief ports 122 and 222 are not limited to the boundary positions between the looper side yarn guide paths 10 and 20 and the device side yarn guide paths 30 and 40, and may be provided closer to the yarn delivery port side of the loopers 1 and 2. . That is, you may provide in the middle of each looper side thread | yarn guide path | route 10,20. In this case as well, excess positive pressure air can be discharged to the outside of the looper side thread guide paths 10 and 20, and good threading can be performed.

  Further, the threading device 100 has been illustrated as being mounted on an edge stitch sewing machine. However, the looper thread may be threaded through another loop stitching machine, for example, a loop feeding hole of a looper of a double chain stitch machine. good. In that case, since the upper looper is not mounted on the double chain stitch sewing machine, only the lower looper is threaded.

DESCRIPTION OF SYMBOLS 1 Lower looper 2 Upper looper 10 1st looper side thread guide path 11 Guide pipe 12 Connection pipe (connection end part)
121 Conical surface 122 Relief port 20 Second looper side thread guide path 21 Guide pipe 22 Connection pipe (connection end)
221 Conical surface 222 Relief port 30 First device side yarn guide path 31 Introduction member 311 Yarn introduction port 32 Guide tube 321 Conical portion 33 Connection tube 40 Second device side yarn guide route 41 Introduction member 411 Thread introduction port 42 Guide Pipe 421 Conical part 43 Connecting pipe 50 Positive pressure air supply part 60 Connecting part 61 Support bracket 100 Threading device

Claims (1)

A looper side thread guide path for guiding the looper thread to the thread feed hole at the tip of the looper;
An apparatus-side yarn guide path having a yarn introduction port for inserting a looper yarn;
A positive-pressure air supply unit that sends positive-pressure air in the middle of the device-side yarn guide path;
A connecting portion that connects the looper side yarn guide path and the device side yarn guide path;
Relief for allowing a part of the positive pressure air to escape to the outside of the looper side thread guide path at the boundary part of the looper side thread guide path and the apparatus side thread guide path or closer to the thread delivery hole side than the boundary part. Make a mouth ,
The escape port is formed at a connection end portion on the apparatus side yarn guide path side in the looper side yarn guide path or a connection end portion on the looper side thread guide path side in the device side yarn guide path,
The connection end on the apparatus side thread guide path side in the looper side thread guide path or the connection end on the looper side thread guide path side in the apparatus side thread guide path is switched between a non-connected state and a connected state. It is possible, and when switching to the connected state, it is a structure that inserts the connection end of the other party's guide route and connects,
A looper threading device for a chain stitch sewing machine, wherein the relief port is a slit that is concave in the insertion direction .

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