JPH09294889A - Alarm device for replacing looper thread bobbin in sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alarm device for replacing a looper thread bobbin for enabling an operator securely to replace the looper thread bobbin by informing the operator of a need for a looper thread bobbin replacement when a product to be sewn is finished with sewing. SOLUTION: A pulse of stitch action signal 15 is issued at every stitch action from a sewing machine 1 to a stitch number subtraction circuit 12a where the number of stitches is decreased by one. When the number of stitches in the stitch number subtraction circuit 12a reaches zero or lower after repeated stitch actions, a signal 17 is sent to a buzzer actuation circuit 13. When a product is finished with sewing, a holder is shifted to an upper position to replace the product, a holder up signal 16 is issued to the buzzer actuation circuit 13. Here, if the signal 17 has been issued to the buzzer actuation circuit 13, the circuit 13 receiving both signals 16, 17 causes a buzzer 14 to sound, and a needlework operator is informed of a looper thread replacement timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bobbin thread bobbin replacement notification device for a sewing machine, which notifies a bobbin thread bobbin replacement time.

[0002]

2. Description of the Related Art A bobbin thread bobbin in which a bobbin thread of a sewing machine is wound is put in a bobbin case, and the bobbin case is used by being installed in a hook provided at the bottom of a bed. For this reason, the bobbin inside the bobbin cannot be observed from the outside, so it is not possible to know the remaining amount of the bobbin thread from the outside, and sewing is performed until the bobbin thread is completely exhausted, that is, the seam is not formed. I had no choice but to do it.

However, if the lower thread runs out during sewing,
Since the seams are cut off, it is not suitable for a part that requires continuous seams, and depending on the product, the sewing must be restarted from the beginning. Further, in order to replenish the bobbin thread, the bobbin thread bobbin needs to be replaced during the sewing, and there is a problem that the sewing operation must be interrupted.

Therefore, the number of stitches which is slightly smaller than the number of stitches that can be sewn by one bobbin bobbin in which the bobbin thread is fully wound is stored in advance, while the number of stitches is counted and counted. There has been invented a bobbin thread bobbin replacement notification device which sounds a buzzer to notify the bobbin thread bobbin replacement timing when the number of stitches sewn reaches the stored number of stitches.

According to this device, when the number of stitches for sewing reaches the stored number of stitches, the buzzer sounds even during sewing. Therefore, when the buzzer sounds during sewing, the sewing manufacturer stops the buzzer and replaces the lower thread bobbin after performing the remaining sewing. The remaining sewing can be performed after the buzzer sounds because the stored number of stitches is slightly smaller than the number of stitches that can be sewn by the bobbin thread bobbin.

[0006]

However, after the buzzer stops sounding and the remaining sewing is performed, the sewing manufacturer may forget to replace the bobbin thread bobbin and may start the next sewing. There was a problem. This is because the buzzer for notifying the replacement of the lower thread bobbin is stopped by the operator when the remaining sewing is finished. In such a case, the worker recognizes that the bobbin thread has been interrupted during the sewing operation and that the bobbin bobbin has not been replaced for the first time.

On the other hand, if the buzzer cannot be stopped until the bobbin bobbin is replaced, the operator will never forget to replace the bobbin bobbin and the above problem can be solved. However, on the other hand, the worker has to carry out the rest of the work while the buzzer continues to ring, resulting in a heavy mental burden. Further, since the sewing work is performed in the factory using a plurality of sewing machines, the buzzer continues to ring, which further increases the noise in the factory.
As a result, there is a problem that the efficiency of the sewing work is significantly reduced.

The present invention has been made to solve the above-mentioned problems, and an operator can reliably replace the lower thread bobbin by notifying the replacement of the lower thread bobbin at the end of the sewing of the sewn product. It is an object of the present invention to provide a bobbin bobbin replacement notification device for a sewing machine.

[0009]

In order to achieve this object, the bobbin thread bobbin replacement notification device for a sewing machine according to claim 1 has a smaller number of stitches than the sewable needle thread of the bobbin thread bobbin for accommodating the bobbin thread. The number of stitches for storing the number of stitches, the number of stitches for counting the number of stitches for sewing, and the notifying means for notifying the replacement of the bobbin thread bobbin, and further the end-of-sewing detecting means for detecting the end of sewing and its If the number of stitches counted by the stitch number counting means is equal to or more than the number of stitches stored in the stitch number storage means when the end of sewing is detected by the sewing end detection means, the notification means And an operating means for operating the.

According to the bobbin thread bobbin replacement notifying device of the sewing machine of the present invention, when the end of sewing of each sewn product is detected by the end of sewing detecting means, the number of stitches counted by the number of stitches counting means is detected. , The number of stitches stored in the stitch number storage means is compared. As a result of the comparison, if the counted number of stitches is equal to or more than the stored number of stitches, the notifying means is operated by the operating means to notify the replacement of the lower thread bobbin.

[0011]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of a sewing machine to which a bobbin thread bobbin replacement notification device of this embodiment is attached.

A pulley 5 is provided at the right end of the arm 7 of the sewing machine 1.
A belt 6 is stretched around the pulley 5. A drive pulley (not shown) is stretched on the other end of the belt 6, and the drive pulley is fixed to a rotary shaft of a drive motor (not shown). Therefore, when the drive motor is rotated, the rotation is transmitted to the pulley 5 via the drive pulley and the belt 6 to rotate the pulley 5.

The pulley 5 is fixed to one end of an upper shaft (not shown) provided in the arm 7, and the other end of the upper shaft is a drive for moving the needle 2 up and down as the upper shaft rotates. A mechanism is provided. With this drive mechanism, the needle 2 is configured to move up and down once each time the pulley 5 makes one rotation, that is, to move one needle.

On both sides of the needle 2, cloth is sewn to the bed 9 when sewing.
A presser foot 3 is provided for pressing down. Foot 3
Is at the lower position for pressing the sewn product on the bed 9 during sewing, and is moved to the upper position so as not to hinder the replacement of the sewn product at the end of sewing. Below the presser foot 3, a bobbin thread bobbin 4 for accommodating a bobbin thread is mounted in a hook under the bed 9. The table 8 is arranged flush with the bed 9,
At the right end of the table 8, a counter 12 for counting the number of sewing needles and the like, and a buzzer 14 for notifying the replacement time of the bobbin thread bobbin 4 are provided.

FIG. 2 shows the electrical construction of the lower thread bobbin replacement informing device. The bobbin thread bobbin replacement notification device 11 mainly includes a counter 12, a buzzer operation circuit 13, and a buzzer 1.
And 4.

The counter 12 includes a stitch number subtraction circuit 12a, a remaining stitch number display section 12b, a stitch number storage circuit 12c, a set value display section 12d, a reset button 12e, and four stitch number setting buttons 12f. This counter 1 is shown in FIG.
2 shows a top view of FIG.

The stitch number subtraction circuit 12a is a circuit for subtracting the number of stitches stored in the circuit 12a by one count each time the stitch operation signal 15 output from the sewing machine 1 is input. The needle operation signal 15 is a signal output from the sewing machine 1 one pulse for each needle operation. When the number of stitches becomes 0 or minus as a result of the subtraction, the stitch number subtraction circuit 12a outputs the signal 17 to the buzzer operation circuit 13 during that period.

The number-of-remaining-needle display column 12b is used for the stitch number subtraction circuit 12
The number of stitches stored in a is displayed in 4 digits. The stitch number storage circuit 12c is a circuit for storing the stitch number set by the stitch number setting button 12f, and the stitch number stored in this circuit 12c is retained even after the power is turned off. Further, the number of stitches stored in the stitch number storage circuit 12c is set in the set value display field 12
Displayed in 4 digits in d.

The reset button 12e is used for the stitch number storage circuit 1
It is a button for resetting the number of stitches stored in 2c to the stitch number subtracting circuit 12a. When the reset button 12e is pressed while the buzzer 14 is ringing, the value of the stitch number subtracting circuit 12a is reset, so that the output of the signal 17 ends, and as a result, the ringing of the buzzer 14 is stopped. This reset button 12e is pressed by the operator.

The stitch number setting button 12f is used for setting a stitch number in the stitch number memory circuit 12c which is slightly smaller than the number of stitches which can be sewn by the lower thread bobbin 4 in which the lower thread is fully wound. It is a button. The reason why the number of stitches that is slightly smaller than the number of stitches that can be sewn by the bobbin thread bobbin 4 is set in this way is that when the number of stitches subtracted by the stitch number subtraction circuit 12a becomes 0 or minus during sewing. This is because the bobbin thread bobbin 4 is exchanged after the sewn product during sewing is sewn up. Specifically, in the sewing machine 1 of this embodiment, the number of stitches that can be sewn by the lower thread bobbin 4 in which the lower thread is fully wound is about 5,500, and the number of stitches for finishing one sewn product is the sewn product. The number is about 100 to 200 needles, although it depends on the type. Therefore, 5000 is stored in the stitch number storage circuit 12c by the stitch number setting button 12f.
If the number of stitches is set, the number of stitches is stored with a margin of 500 stitches. Therefore, even if the value of the stitch number subtraction circuit 12a becomes 0 or minus in the middle of sewing, the sewn product in the middle of sewing is sufficiently sewn. be able to. Since there are four stitch number setting buttons 12f and the number of stitches that can be stored in the stitch number storage circuit 12c is four digits, each button 12f is an input button for each digit. Each stitch number setting button 12f is pressed by the operator, and each time the button is pressed, the digit value corresponding to the button is “0” → “1” → ... → “9” → “0”. And will be updated.

The buzzer operating circuit 13 is a circuit for receiving the presser foot position signal 16 output from the sewing machine 1 and the signal 17 output from the stitch number subtracting circuit 12a, and causing the buzzer 14 to ring. The presser foot upper position signal 16 is a signal output from the sewing machine 1 when the presser foot 3 is at the upper position. Foot 3
Is at the lower position at the time of sewing and is moved to the upper position at the end of sewing. Therefore, by detecting the presser upper position signal 16, it is possible to recognize the end of sewing of each sewn product.

Next, the operation of the bobbin thread bobbin replacement notifying device 11 thus constructed will be described. First, the sewing manufacturer installs the bobbin thread bobbin 4 which is wound around the bobbin thread inside the hook under the bed 9. Next, the number of stitches setting button 12f
Is operated to set a slightly smaller number of stitches than the number of stitches that can be sewn by one bobbin thread bobbin 4. As described above, the number of stitches that can be sewn on the bobbin thread bobbin 4 of this embodiment is about 5,500, so 5000 stitches are set by the stitch number setting button 12f with an allowance of 500 stitches. The set number of 5000 stitches is stored in the stitch number storage circuit 12c and displayed in four digits in the set value display field 12d of the counter 12. When the reset button 12e is pressed by the sewing manufacturer,
The number of 5000 stitches stored in the stitch number storage circuit 12c is loaded (set) to the stitch number subtraction circuit 12a, and the value is displayed in four digits in the remaining stitch number display field 12b of the counter 12.

The sewing manufacturer who has carried out the above initial setting places the sewn product on the table 8 and the bed 9 of the sewing machine 1,
The work clamp 3 is moved to the lower position and sewing is started. This sewing is performed by rotating a drive motor (not shown). Specifically, the rotation of the drive motor is transmitted to the drive pulley (not shown) and the pulley 5 via the belt 6 to rotate the upper shaft (not shown) fixed to the pulley 5. The rotation of the upper shaft is converted into a vertical movement by a drive mechanism (not shown) to cause the needle 2 to perform a sewing operation. The needle 2 is operated by one rotation by one rotation of the pulley 5, and a needle operation signal 15 is output from the sewing machine 1 to the needle number subtraction circuit 12a of the bobbin thread bobbin replacement informing device 11 for each pulse of the needle operation.

The stitch number subtraction circuit 12a subtracts the stitch number stored in the circuit 12a by one count each time one pulse of the stitch operation signal 15 is input. The subtracted number of stitches is displayed in the remaining stitch number display field 12b of the counter 12. When the sewing operation is repeated and the number of stitches in the stitch number subtraction circuit 12a is subtracted to 0 or minus, a signal 17 is output from the stitch number subtraction circuit 12a to the buzzer operation circuit 13. Since the presser foot 3 of the sewing machine 1 is at the lower position during sewing, the presser foot upper position signal 16 is not output from the sewing machine 1 during that time. Therefore, during sewing, even if the signal 17 is output from the stitch number subtracting circuit 12a, the buzzer operating circuit 13 is not operated and the buzzer 14 is not sounded.

When the sewing of one sewn product is completed, the presser foot 3 is moved to the upper position in order to replace the sewn product. Then, the presser foot upper position signal 16 is output from the sewing machine 1 to the buzzer operation circuit 13 of the bobbin thread bobbin replacement notification device 11. At this time, if the value of the stitch number subtracting circuit 12a is 0 or negative, the signal 17 is also output to the buzzer operating circuit 13, so the buzzer operating circuit 13 sounds the buzzer 14 in response to both signals 16 and 17. The sewing manufacturer is notified of the replacement time of the lower thread bobbin 4.

When the buzzer 14 is sounded, the sewing manufacturer presses the reset button 12e of the counter 12,
The ringing of the buzzer 14 is stopped and the bobbin thread bobbin 4 of the sewing machine 1 is replaced. In the bobbin thread bobbin replacement notification device 11, when the reset button 12e is pressed, the value of the stitch number storage circuit 12c is reset in the stitch number subtraction circuit 12a, so that the value of the stitch number subtraction circuit 12a turns positive. Therefore, the output of the signal 17 from the stitch number subtracting circuit 12a is stopped, and in response to this, the buzzer operating circuit 13 causes the buzzer 14 to operate.
Stops ringing. Further, when the reset button 12e is pressed, the initial number of 5000 stitches loaded from the stitch number storage circuit 12c to the stitch number subtraction circuit 12a is displayed in the remaining stitch number display field 12b of the counter 12. By replacing the bobbin thread bobbin 4 and pressing the reset button 12e in this way, the sewing machine 1 and the bobbin thread bobbin replacement notification device 11 are returned to the initial state. After that, the above-described operation is repeated according to the sewing work.

As described above, according to the bobbin thread bobbin replacement informing device 11 of this embodiment, since the notification of the replacement of the bobbin thread bobbin 4 is made at the end of the sewing of the sewn product, the bobbin thread bobbin 4 is replaced. You can surely exchange it without forgetting. Further, since the buzzer 14 for notifying the replacement of the bobbin thread bobbin 4 is sounded only at the end of sewing and is not sounded during sewing, the notification sound of the buzzer 14 lowers the working efficiency of sewing. There is no.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Is easily guessed.

For example, in the above embodiment, the number of stitches for sewing is counted using the needle operation signal 15 output from the sewing machine 1, and the end of sewing is detected using the work clamp upper position signal 16. However, instead of these signals 15 and 16, the pulley 5 of the sewing machine 1 is provided with a reflector and a sensor for detecting the reflector, and the rotation number and the stop position of the pulley 5 are detected to detect the number of sewing needles. Alternatively, it may be configured to detect the end of sewing and the end of sewing. Specifically, when the pulley 5 is rotated once, the needle 2 is moved by one needle, so that the number of rotations of the pulley 5 detected by the reflecting plate and the sensor is counted as the number of sewing needles. On the other hand, at the end of sewing, the needle 2 is moved to the upper position to replace the sewn product and is temporarily stopped at that position. Therefore, the reflecting plate and the sensor are installed so that the needle 2 can be detected in the upper position. By arranging it on the pulley 5, the end of sewing is detected by the stop position of the pulley 5. In the sewing machine 1 in which the needle operation signal 15 and the presser foot upper position signal 16 are not output, the lower thread bobbin replacement notification device 11 of this embodiment is configured by providing the pulley 5 with the reflector and the sensor as described above. It becomes possible to install.

Although the buzzer 14 which has been sounded is stopped by pressing the reset button 12e, the sounding of the buzzer 14 may be stopped when the bobbin bobbin 4 is replaced. . Specifically, a sensor is provided in the hook for accommodating the lower thread bobbin 4, and a signal indicating whether or not the lower thread bobbin 4 is mounted in the head is output from the sensor to the lower thread bobbin exchange notification device 11. To configure. The bobbin bobbin 4 is driven by the signal output from the sensor.
If it is detected that the
When it is judged that the bobbin thread bobbin 4 has been replaced, the buzzer 14 stops ringing. The operation at this time is similar to the operation when the reset button 12e of the embodiment is pressed, the number of stitches stored in the stitch number storage circuit 12c is loaded into the stitch number subtraction circuit 12a, and the stitch number remains. Number of stitches display column 1
2b is displayed and the output of the signal 17 is stopped.

Further, in the present embodiment, the notification of the replacement of the lower thread bobbin 4 is performed by ringing the buzzer 14, but it is also possible to notify the operator of the replacement of the lower thread bobbin 4. Instead of ringing the buzzer, another one can be used. Further, the counting of the number of stitches is performed by counting down by one count, but it may be incremented by one count.

[0032]

According to the bobbin thread bobbin replacement notification device of the sewing machine of the first aspect, since the notification of the bobbin thread bobbin replacement is performed at the end of the sewing of the sewn product, forgetting to replace the bobbin thread bobbin. There is no effect, and there is an effect that it can be replaced reliably.

[Brief description of drawings]

FIG. 1 is a perspective view of a sewing machine equipped with a bobbin thread bobbin replacement notification device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of a bobbin thread bobbin replacement notification device.

FIG. 3 is a top view of a counter.

[Explanation of symbols]

1 sewing machine 2 needles 3 presser foot 4 bobbin thread bobbin 11 bobbin thread bobbin replacement notification device 12 counter 12a stitch number subtraction circuit (stitch number counting means) 12c stitch number storage circuit (stitch number storage means) 13 buzzer operating circuit (sew end detection means) , Operating means) 14 buzzer (informing means) 15 needle operation signal 16 work clamp upper position signal

Claims (1)

[Claims] 1. A needle number storage means for storing a smaller number of stitches than a sewable stitch number of a lower thread bobbin for accommodating a lower thread, a needle number counting means for counting the number of sewing needles, and a lower thread bobbin In a bobbin thread bobbin replacement notifying device for a sewing machine, which is provided with notifying means for notifying replacement, sewing end detecting means for detecting the end of sewing, and the stitch number counting means when the end of sewing is detected by the sewing end detecting means. A lower thread of a sewing machine, comprising: an actuating means for actuating the informing means when the number of stitches counted by is equal to or more than the number of stitches stored in the stitch number storage means. Bobbin replacement notification device.