JPS623107Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shoulder seam tape cutting device for a sewing machine that cuts the protruding end of a reinforcing shoulder seam tape that is sewn together when sewing the shoulders of underwear or the like.

Normally, when sewing the shoulders of knitted underwear, etc., the front body 101 and the back body 102 of the fabric are overlapped with each other turned inside out, as shown in Fig. 1, and a reinforcing shoulder seam is attached to the overlapped shoulders. A tape 103 is attached, and an overedge stitch is performed integrally with this tape 103.

By the way, this reinforcing shoulder seam tape 103 is sewn with a slight protrusion from the edge of the fabric at the beginning and end of sewing, so the protruding portion of the tape 103 must be cut with scissors or the like after sewing, or it can be cut with a sewing machine. A cutter device installed behind the needle drop section automatically cuts the needle during sewing.

Especially the shoulder seam tape 103 that protrudes toward the sewing start side.
It is necessary to cut accurately along the neckline, and if this tape 103 remains protruding from the edge of the fabric, it will be removed when the wrapper removing tape is sewn along the neckline in the next process. The protruding part of the shoulder joint tape 103 remains inside the tape, deforming the collar shape and making the product look unsightly, and if such underwear is worn,
There is a problem that the collar part gets rough and the feel of the garment is impaired.

Therefore, if the shoulder seam tape 103 is cut by a worker using scissors after sewing, the cut can be made accurately along the neckline, and the above-mentioned problem will not occur, but it will require a large amount of sewing. Providing a separate process for cutting the shoulder joint tape in a mass production factory not only reduces productivity but also becomes a major hindrance to reducing the cost of sewn products.

Therefore, in the first part, as mentioned above, a cutter device is provided behind the needle drop, and when the edge of the fabric is detected by a fabric sensor installed in front of the cutter device, the cutter device is driven. Sewing machines that automatically cut the protruding ends of shoulder joint tapes have also been manufactured.

However, in conventional sewing machines equipped with this type of cutter device, the time from detecting the edge of the fabric to driving the cutter device is arbitrarily delayed using a delay circuit, etc., and the timing of cutting the shoulder seam tape can be freely adjusted. However, if you adjust the shoulder seam tape so that it is cut close to the edge of the fabric, the neckline is curved inward, so when the shoulder seam tape is cut, the fabric will be cut as well. There is a risk of cutting, and in order to avoid cutting the fabric, it is necessary to cut the shoulder seam tape at a position slightly away from the edge of the fabric, and this shoulder seam tape still remains protruding from the edge of the fabric. It was a result.

The present invention was developed in view of these circumstances, and its purpose is to create a shoulder seam that can accurately cut the shoulder seam tape along the neckline and that can be performed continuously at high speed. An object of the present invention is to provide a tape cutting device.

In order to achieve the above object, the shoulder seam tape cutting device of the present invention includes: a lower blade fixed to the sewing machine body near the rear of the presser foot; and an upper blade that cuts the tape in cooperation with the lower blade. , is placed between the tape cutting position and the presser foot above the fabric that advances as the sewing machine operates, and is lowered from above to come into contact with the front end of the fabric to temporarily stop the fabric from progressing. a shield that is movable between a shielding position that obstructs and a non-shielding position that is raised from the shielding position to allow the fabric to pass; and a shield that is moved from above to move the shielding body between the shielding position and the non-shielding position. a drive mechanism for moving the shield to a shielding position; a cloth sensor disposed above the front of the shield in the cloth traveling direction to detect the front edge of the cloth; and a cloth sensor for moving the shield to a shielding position by a signal from the cloth sensor. A control circuit that controls the drive mechanism and controls the upper blade and the lower blade to cut the tape protruding from the front end of the fabric while blocking the front edge of the advancing fabric with the shield brought to the shielding position. It is equipped with the following.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

Figure 2 is an enlarged view of the area around the needle drop of a single-needle overlock sewing machine, where 1 is the main body of the sewing machine, 2 is the needle bar with the sewing needle 3 attached to the tip, and 4 is the main body of the sewing machine 1.
A throat plate 6 fixed to the side via screws 5, 5 is a cloth presser that presses the cloth fed onto the throat plate 4 along the cloth traveling direction α.

This presser foot 6 is attached to the tip of a support arm 8 rotatably attached to the rear part of the sewing machine main body 1 via a pin 7.

Further, an auxiliary presser foot 9 is integrally provided at the rear end of the presser foot 6 to prevent the sewn fabric from curling.

By the way, as shown in FIG. 3, the needle drop part P of the sewing needle 3 comes into contact with the front end _c1 of the fabric C, which is integrally sewn with a reinforcing shoulder seam tape 10, to temporarily stop the progress of the fabric C. A shielding body 11 is provided to prevent this. This shield 11 is integrally attached to the tip of an operating rod 13 of an air cylinder 12 constituting a drive mechanism, and controls the pneumatic pressure of compressed air that is pumped through an air tube 15 connected to the air cylinder 12. This allows the shield 11 to be driven up and down in the direction of the arrow β. That is, the shielding body 11 is lowered to a shielding position where the cloth C is prevented from advancing, and the shielding body 11 is raised to a non-shielding position where the cloth C is allowed to pass through.

The air tube 15 is connected to an air compressor (not shown), and the compressed air pumped from the air compressor is controlled by a solenoid valve (not shown) inserted in the middle of the air tube 15. That's what I do.

Incidentally, the above-mentioned solenoid valve is controlled by a control circuit which will be described later.

Further, the air cylinder 12 is attached to the distal end side of the support arm 8 via a bracket 16 and a screw 16'.

Immediately after the shield 11, there is provided a cutting mechanism 17 for cutting the shoulder joint tape 10 protruding from the front end of the fabric C whose progress is blocked by the shield 11.

This cutting mechanism 17 consists of an upper blade 18 and a lower blade 19 arranged in a direction perpendicular to the traveling direction α of the fabric C, and the upper blade 18 is a rotary solenoid (not shown) fixed to the sewing machine main body 1 side. The upper blade 18 is directly or indirectly connected to the drive shaft 20 of the rotary solenoid so that the upper blade 18 is driven to reciprocate within a certain angle by a rotary solenoid. Further, the lower blade 19 is located near the rear of the presser foot 6 and is fixed to the sewing machine main body 1 side via screws 21, 21.

Incidentally, the rotary solenoid also has the shielding body 1.
Like No. 1, it is driven by a control circuit that will be described later.

Further, a fabric sensor 22 is provided above the throat plate 4 in front of it in the fabric traveling direction.

This fabric sensor 22 has a light emitter and a light receiver integrated into the same housing, and reflects light emitted from a light emitter such as an LED on the needle plate 4 or the fabric feeding table 23, and The light is received by a light receiver such as a phototransistor, and when the light is blocked by the fabric traveling on the throat plate 4, a detection signal is output to the control circuit.

The projection position of the cloth sensor 22 is set at an appropriate position on the front side of the shielding body 11.

Further, this fabric sensor 22 is attached to a bracket 26 attached to the sewing machine main body 1 side via screws 25, 25.
It is attached to the tip of the holder via screws 27, 27.

Further, a tape guide 24 for guiding the shoulder seam tape 10 is provided above the presser foot 6, and this tape guide 24
The shoulder seaming tape 10 is fed out from the tip of the cloth C and attached to the shoulder portion of the cloth C so that it can be sewn integrally to the cloth C.

Further, 28 is provided just before the needle drop part P, and the edge of the fabric fed into the needle drop part P side is connected to the sewing machine main body part 28.
This upper knife is designed to trim just before sewing together with the lower knife fixed to the side.

Next, one embodiment of a control circuit for driving and controlling the shielding body 11 and the cutting mechanism 17 is shown in FIG.

The fabric sensor 22 is a detection element that switches its output signal from H level to L level at the same time fabric is detected, and maintains the output signal at H level when fabric is not detected.The output of this fabric sensor 22 is sent to the NOT circuit 3.
0 to the gate circuit _g1 of the sewing start counter 31, and also to the gate circuit g1 of the sewing end counter 32.
I am trying to input it directly into _g2 .

33 is a rotation detector that outputs a pulse signal synchronized with the needle movement of the sewing machine, and the pulse signal is sent to the sewing start counter 3 via a waveform shaping circuit 34.
1 and a sewing end counter 32, respectively.

The above-mentioned sewing start counter 31 and sewing end counter 3
2 is a timer element constructed from an IC circuit or the like, and when the signals input to the gate circuits _g1 and _g2 switch from L level to H level, the rotation detector 33 outputs a pulse signal. At the same time as starting counting, an H level signal is output to the output terminal, and when the pulse signal reaches a preset count number, the output signal changes from H level to L.
It is designed so that it can be switched depending on the level.

That is, the sewing start counter 31 outputs an H level signal at the same time as fabric detection, and switches to an L level signal at the same time as the count up.This output signal is amplified via the amplifier circuit 35, and the shielding member By supplying this to a solenoid valve inserted in the pneumatic circuit of the air cylinder 12 that drives the air cylinder 12 up and down, the shield 11 is lowered at the same time as the edge of the fabric is detected, and from this point on, a predetermined number of stitches has been counted. I am trying to raise it by

The output of the sewing start counter 31 is also supplied to the amplifier circuit 37 via the NOR circuit 36, and the rotary solenoid of the cutting mechanism 17 connected to the output side of the amplifier circuit 37 is connected to the rotary solenoid of the cutting mechanism 17 when the output signal of the sewing start counter 31 falls. In other words, the magnet is excited by the one shot output generated when the sewing start counter 31 counts up.

On the other hand, the sewing end counter 32 starts counting when the sewing end of the fabric passes the projection position of the fabric sensor 22 and the output of the fabric sensor 22 switches from the L level to the H level. Therefore, the output signal is switched from the H level to the L level.The output signal of the sewing end counter 32 is supplied to the rotary solenoid of the cutting mechanism 17 via the NOR circuit 36 and the amplifier circuit 37, and this rotary solenoid is used to switch the output signal from the sewing end counter 32 to the sewing end counter 32. The magnet is excited by a one-shot output generated when the counter 32 counts up.

The rotation detector 33 is connected to a magnet embedded in the outer periphery of a pulley (not shown) directly connected to the main shaft in the sewing machine main body 1, and is disposed close to the outer periphery of this pulley to prevent the passage of the magnet. It is constructed of a Hall element or the like that detects the movement of the needle without contact, and outputs a pulse signal that is synchronized with the rotational speed of the main shaft, that is, synchronized with the movement of the hands.

Further, variable resistors 38 and 39 are inserted into the input circuits of the sewing start counter 31 and the sewing end counter 32, respectively, for setting the count numbers of the counters 31 and 32, respectively.

Next, the operation of this device will be explained with reference to the time chart shown in FIG.

When the shoulder part of the undergarment or the like is inserted between the needle plate 4 and the cloth presser foot 6 and the sewing machine is started, the tape guide 24
The shoulder seam tape 10 is attached to the shoulder of the fabric C, sewn integrally with the fabric C, and is sent to the rear of the needle landing point P together with the fabric C. When sewing is continued in this state, the front end _c1 of the fabric C reaches the projection position of the fabric sensor 22, and the fabric sensor 22
Since the output of switches from H level to L level,
At the same time that the sewing start counter 31 starts counting, the shielding body 11 descends and switches to a shielding state that prevents the advancement of the fabric C (the state shown in FIG. ₂ ).
If the number of pulse signals output from the rotation detector 33 during the period from when the front end c1 of the fabric C abuts against the shield 11 until a certain minute time has elapsed is set, then as shown in FIG. 3, when the front end _c1 of the fabric C abuts against the shield 11, its progress is temporarily impeded, and the shield 11
In contrast, the shoulder seam tape 10 sewn to the shoulder portion _c2 of the fabric C passes through the position where the shield 11 is provided, so that only the end 10a of the shoulder seam tape 10 protrudes from the front end portion _c1 of the fabric C.
At the same time as the sewing start counter 31 counts up, the upper blade 18 of the cutting mechanism 17 is driven to cut off the protruding shoulder seam tape 10. At the same time as the upper blade 18 is driven, the shield 11 rises as shown in Fig. 4, releasing the shielding state of the fabric C, and the fabric C from which the protruding end of the shoulder seam tape 10 has been cut off continues to be fed to the rear of the sewing machine main body 1.

As the sewing progresses and the sewing end of the fabric C passes through the projection position of the fabric sensor 22, the fabric sensor 22
Since the output of is switched from L level to H level,
The sewing end counter 32 starts counting, and when the sewing end counter 32 counts up, the upper blade 18 of the cutting mechanism 17 is driven again, and the shoulder seaming tape 10 connected to the sewing end of the fabric C is cut. It turns out. By the way, at the sewing end side of the fabric C, the shoulder joint tape 10 does not necessarily have to be cut exactly along the edge of the fabric, but is usually cut in a state where it protrudes a little from the edge of the fabric. The shoulder seam tape 10 protruding from the edge of the fabric is cut off when the edge of the fabric is trimmed by an upper knife and a lower knife provided just in front of the needle drop part during the sleeve attaching process.

Therefore, in the present invention, when cutting the shoulder seam tape 10 protruding from the sewing start end side of the fabric C, the fabric C is
Since the shoulder seam tape 10 is cut with the front end c ₁ of the fabric C temporarily obstructed and the front end c 1 of the fabric C blocked, the front edge c ₁ of the fabric C is not cut. In addition, only the protruding end portion of the shoulder joint tape 10 can be accurately cut along the front end _c1 of the fabric C.

Furthermore, according to the present invention, the drive mechanism operates the shield from above to prevent the front end of the fabric from advancing, so even if the front part of the fabric accumulates in folds on the side of the shield. Even if an attempt is made to climb over the shield, the shield and the actuating rod of the drive mechanism that operates the shield stand vertically apart, thereby reliably preventing the front end of the fabric from climbing over. Therefore, even when the fabric is advanced at high speed, the position of the tape cut point does not shift due to the front edge of the fabric crossing over, and the tape protruding from the front edge of the fabric is accurately cut while the fabric is advancing at high speed. Can be cut.

Moreover, in the case of the present invention, the lower blade is disposed near the rear of the presser foot, and the lower blade and the upper blade immediately cut the sewn tape, so that the fabric progresses faster. Even at high speeds, there is almost no unevenness in the tape's advancing speed, and for this reason, the tape can be reliably cut at the desired position by controlling the control circuit based on the detection of the front edge of the fabric by the fabric sensor. , it is possible to effectively eliminate inaccurate tape cutting caused by high-speed advancement of fabric and tape.

As described above, the shoulder seam tape cutting device for the sewing machine of the present invention not only can accurately cut the shoulder seam tape at the position where it should be cut, but also can cut it continuously at high speed and reliably. The effect is huge.

The front end c ₁ of the fabric C corresponds to the neckline of underwear, and the shoulder seam tape 1 is attached along this neckline.
0 can be cut accurately, so when the lapel removal tape is sewn to the neckline in the next process, the protruding end of the shoulder seam tape will not remain in the lapel removal tape, and the collar shape will be maintained. There is no risk of spoiling the feeling when wearing clothes neatly.

In addition, in this embodiment, the fabric sensor 22 and the rotation detector 33 which outputs pulse signals synchronized with the needle movement of the sewing machine, and the sewing start and rotation detector 33 which is energized by the detection signal of the fabric sensor 22 and counts the pulse signals of the rotation detector 33, Sewing end counters 31 and 32 are provided so that the drive of the shield 11 and the cutting mechanism 17 can be controlled in accordance with the movement of the needle of the sewing machine, so that it is not affected by the operating speed of the sewing machine, temporary stops during sewing, speed changes, etc. Therefore, accurate timing control can be performed.

Note that this example describes the cutting of shoulder seam tape that is sewn integrally to the shoulders of underwear, but it is not limited to such shoulder seam tape, and can also be applied to cloth tape that is sewn integrally with the fabric. , and can be widely applied when it is necessary to accurately cut the cloth tape along the edge of the cloth.

Further, in this embodiment, the shielding body 11 is constructed of a plate-like object, and this plate-like object is driven up and down by a drive mechanism such as an air cylinder 12. However, for example, an electromagnetic solenoid or the like may be used as the drive mechanism. The advance of the dough C may be temporarily obstructed by placing a plunger of this electromagnetic solenoid or a rod-shaped shield attached to the plunger facing the path through which the dough C passes. Further, the timing for switching the shielding body 11 to the shielding state may be when the sewing machine starts operating.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a state in which a shoulder seam tape is sewn to the shoulder of an underwear, Fig. 2 is a perspective view showing an embodiment of the present invention, and Fig. 3 is a shield and cutting mechanism of the same embodiment. FIG. 4 is a perspective view showing the non-shielding state of the shield in the same embodiment, FIG. 5 is a block diagram showing the control circuit of the same embodiment, and FIG. 6 is a time chart of the same embodiment. be. 6... Presser foot, 10... Shoulder joint tape, 11...
... Shielding body, 12 ... Drive mechanism (air cylinder), 18 ... Upper blade, 19 ... Lower blade, 22 ... Cloth sensor, C ... Cloth, C ₁ ... Front end of cloth.

Claims (1)

[Scope of Claim for Utility Model Registration] A sewing machine that sews shoulder seam tape onto fabric, a lower blade fixed to the sewing machine body near the rear of the presser foot, and an upper blade that cuts the tape in cooperation with the lower blade. and a part between the tape cutting position and the presser foot, which is disposed above the fabric that advances as the sewing machine operates, and is lowered from above and brought into contact with the front end of the fabric to temporarily slow the progress of the fabric. a shielding body that is movable between a shielding position that prevents the fabric from passing through and a non-shielding position that is raised from the shielding position and passes through the fabric; a drive mechanism for moving the shield to the front end of the shield; a cloth sensor disposed above the front of the shield in the fabric traveling direction to detect the front edge of the cloth; and a cloth sensor configured to bring the shield to a shielding position by a signal from the cloth sensor. The driving mechanism is controlled, and the tape protruding from the front end of the fabric is cut by the upper blade and the lower blade while the front edge of the advancing fabric is blocked by the shield brought to the shielding position. A shoulder seam tape cutting device for a sewing machine, characterized in that it is equipped with a control circuit.