JPH02109591A - Seam pattern overlap sewing feasible sewing machine - Google Patents

Abstract

PURPOSE:To efficiently execute overlap sewing by changing pattern data into other pattern data in which the sewing starting position of a seam pattern to be formed afterward becomes the neighborhood of the sewing ending position of another previously formed seam pattern in the title sewing machine to automatically form the seam pattern in which the sewing starting position and the sewing ending position are separated. CONSTITUTION:In addition to a pattern sewing means, an overlap sewing command means to overlap plural seam patterns at the same position and an overlap sewing control means to change the pattern data into other pattern data in which the sewing starting position of the seam pattern to be formed afterward becomes the neighborhood of the previously formed seam pattern and from the seam pattern to be formed afterward according to a command are provided. For the change of the pattern data, it is acceptable to inhibit the execution of some of the previously formed pattern data, namely, the pattern data from the sewing starting position to the position to be the sewing starting position of the seam pattern to be formed afterward, and it is also acceptable to create the pattern data for overlap sewing by removing unnecessary part for overlap sewing out of the pattern data of the previously formed sea pattern, to retain the removed data, and to return the pattern data for overlap sewing to the pattern data for the first sewing by adding the retained data after overlap sewing ends.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sewing machine, and more particularly to a sewing machine capable of overlapping stitches in which a plurality of the same stitch patterns are overlapped at the same position.

2. Description of the Related Art A sewing machine capable of automatically forming a seam pattern is equipped with a pattern sewing device that forms a seam pattern based on predetermined pattern data. When forming a stitch pattern using such a sewing machine, the sewing start position and the sewing end position may be separated from each other.

This will be explained using buttonhole sewing as an example. Buttonhole sewing is performed by combining several pattern stitches, but the number of stitches must be changed depending on the size of the button, and a special presser foot is used for this purpose. For example, there is a main body that is attached to the lower end of the presser bar, a presser frame that is held movably relative to the main body in a straight line and moves with the work cloth, and A presser foot is used that includes a first detected portion and a second detected portion that are separated by a distance.

The first detected part and the second detected part are detected by, for example, a position detector fixedly provided in the head of the sewing machine.

The presser frame is biased backward (on the opposite side from the operator) by a spring, and is always kept in its original position where it contacts the front end of the main body. A front end signal is emitted when the provided first detected part is detected by the position detector, and a rear end signal is emitted when the second detected part on the far side is detected. In a sewing machine equipped with such a presser foot and a position detector, buttonhole sewing is started from the front side of the workpiece cloth toward the rear side. When sewing is carried out from the front side to the back side of the workpiece cloth, the workpiece cloth and presser frame are fed forward, and as the sewing progresses, the seams become visible to the operator, making it possible to check the condition of the seams at the beginning of sewing. It is convenient.

When the buttonhole stitch shown in FIG. 10 is formed using the above-mentioned sewing machine, the sewing start position and the sewing end position are separated from each other. Sewing starts from position A and starts from position A.
Left seam part 200. After forming the second left ground seam portion 201, the left annular portion 202. A left edge overcast part 204 is formed, followed by a right ground seam part 206 and a rational part 208 . In addition to forming a right edge overlocking portion 210, a bar tacking portion 212 and a tacking portion 214 are formed and ending at position B. If sewing is performed in this order, there will be no deviation in the positions of the left and right annular portions 202 and 208 in the cloth feeding direction, and a beautiful stitch pattern without deformation will be obtained. The formation of the second left back seam part 200 ends at the first stitch after the rear end signal is issued from the position detector, and the second left back seam part 200 is formed.
Formation ends at the first stitch after the front edge signal is emitted from the position detector, but the position of the seam C at the end of the second lining sewn portion 201 is at most the same as the stitch of the second lining sewn portion 201. Variation in pitch is unavoidable, and the maximum positional deviation of stitch C is the sum of this stitch pitch and the mounting error of the second detected part. Therefore, there is a possibility that the position of the seam formed next to seam C will be shifted by approximately the same amount, but among the seams forming the left annular portion 202, the seam formed at the frontmost side The feed data for forming stitch E is such that even if stitch C is formed at the rearmost position, it is formed with the presser foot frame being pushed as far backward as possible by the work cloth; otherwise, is sized to allow some slippage between the work cloth and the feed dog. Therefore, no matter where the seam C is formed, the seam E is always formed at the same position, and the left annular part 202 is formed at a fixed position, and the seams forming the left annular part 202 is formed according to the data, resulting in beautiful seams as planned.

The same is true for the rational part 20, and the left and right annular parts 20
2, 208 are formed in a good-looking shape without shifting in position in the cloth feeding direction and without being crushed. Such a seam is obtained because the sewing order is determined so that the left and right annular portions 202 and 208 are formed from the frontmost position determined by the state in which the presser frame is pushed as far backward as possible. As a result, the sewing start position and the sewing end position are inevitably separated.

Note that the sewing start position A is a position where a seam is formed when the presser foot is lowered with the presser foot frame being urged backward by a spring, and this position A and the left and right annular portions 2
The deviation between the presser bar and the frontmost position E of 02 and 208 is caused by the clearance between the presser bar and the sewing machine frame that slidably holds the presser bar.

Problems to be Solved by the Invention When the sewing start position and the sewing end position are separated from each other as described above, it becomes troublesome to perform overlapping stitching in which a plurality of stitch patterns are overlapped at the same position.

This is because after the first stitch pattern has been formed, it is not possible to simply restart the sewing machine and perform sewing using the same pattern data as the first time.

To explain the buttonhole sewing shown in FIG. 10 as an example, if you simply restart the sewing machine after finishing sewing at position B, the stitching will start from the sewing start position as shown by the broken line in FIG. 10. - After the stitch pattern has been formed up to the position corresponding to the second stitch position of the left back sewing part 200, the process moves to forming the second lining sewing part 201 based on the trailing edge signal, and thereafter, the second lining sewing part 201 is formed. A stitch pattern is formed in the same way, but the rear ends of the left-hand stitching portions 200, 201 formed the second time protrude from the bartacking portion 212, resulting in an unsightly appearance.

Note that if the sewing is finished on the sewing start position side, this problem will not occur, and as shown by the - dotted chain line, the left base sewing part 216
After forming the left edge part 204 and the left annular part 20
2, and then the right side sewing part 206 and the bar tacking part 212.
After forming the right edge part 210 and the right annular part 20
8 and form a stop stitch portion, it is possible to finish sewing at the sewing start position side. However, in this case, the shape of the right annular portion 208 may be crushed, resulting in poor appearance. When an annular part is formed next to the hemline part of a zigzag weave, a shift occurs in the end position of the hemline part as in the case of the second left seam part 201. Among the seams that make up the annular part, the rear seams are formed according to the stitch data, while the front seams are positioned so that the presser foot frame is pushed as far backward as possible. Since it is regulated by position, the front seam will shift backwards relative to the rear seam, causing the annular part to lose its shape and look unsightly.

Therefore, the buttonhole stitch shown in FIG. 10 in which the sewing start position and the sewing end position are far apart is employed, and in the case of this buttonhole stitch, since the stitch data is special, overlapping stitching is possible. However, with the general stitch pattern, which is unsightly and cannot be used for practical purposes, the first and second stitches are misaligned, making it impossible to perform overlapping stitches.

Therefore, conventionally, when overlapping stitch patterns were required, 1
After the stitch pattern is formed for the first time, it is necessary to cut the sewing thread, return the workpiece cloth to the sewing starting position, and restart the sewing machine, making it troublesome to perform overlapping stitches.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide a sewing machine that can easily overlap stitch patterns in which the sewing start position and the sewing end position are separated from each other.

Means for Solving the Problems In order to solve the above problems, the present invention, as shown in FIG. 0)) In response to the commands of the overlap stitch command means, the sewing start position of the stitch pattern to be formed later is set to the stitch pattern formed previously. The invention is characterized in that it is provided with an overlapping stitch control means that changes the pattern data to be near the sewing end position and causes the pattern sewing means to form a subsequent stitch pattern.

Effects and Effects If the pattern data is changed in this way, when a later stitch pattern is formed, sewing is started near the sewing end position of the previously formed stitch pattern.

When changing the pattern data, among the pattern data of the previously formed stitch pattern, the pattern data between the sewing start position and the position that will become the sewing start position of the stitch pattern to be formed later is changed. It is also possible to prevent this from being executed, by creating pattern data for overlapping sewing by removing the portions of the previously formed stitch pattern data that are unnecessary for overlapping sewing, and saving the removed data. After sewing is completed, the saved data may be added to the pattern data used for overlapping sewing to restore the pattern data for the first sewing. In addition to the pattern data of the previously formed stitch pattern, pattern data is provided in which the sewing start position of the later formed stitch pattern is near the sewing end position of the previously formed stitch pattern. The pattern data can also be used when overlapping stitches are performed.

Further, depending on the stitch pattern, the pattern data can be changed by reversing the execution order of the pattern data. In the case of buttonhole stitching, if the execution order of the pattern data is reversed, the ground stitching will be done last, resulting in an unsightly look, so it is not possible to reverse the execution order, but even if it is reversed, There are also seam patterns that are acceptable. In this case, the subsequent stitch pattern is formed by tracing the previous stitch pattern backwards from its sewing end position to the sewing start position, so that overlapping stitching can be easily performed.

In this way, even if the sewing start position of a seam pattern to be formed later is set to a different position from the sewing start position of the seam pattern formed before by changing the pattern data, the sewing start position of the seam pattern to be formed later will be changed. The stitches after the start of sewing are formed according to the data for forming the stitch at the position corresponding to the stitch position among the pattern data of the previously formed stitch pattern. The stitches are formed without protruding from the formed stitch pattern, and overlapping stitches are beautifully performed. Furthermore, there is no need to cut the sewing thread once and return the workpiece cloth to the previous sewing start position, allowing efficient overlapping stitching.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

As shown in FIG. 2, the sewing machine of this embodiment has a bed 10 with a flat top surface, a pillar part 12 rising from the right end of the bed 10, and a cantilevered part from the upper end of the pillar part 12. The machine includes a sewing machine frame 18 consisting of an arm 14 extending substantially parallel to the bed 10 and a head 16 provided at the tip of the arm 14. The head 16 starts the sewing machine motor.

A motor start switch 20 for controlling the stop is provided, and the arm 14 has a display board 22 on which images representing a plurality of types of stitch patterns that can be formed by this sewing machine are displayed, and a display board 22 that is operated to select the stitch pattern. A pattern selection switch 24 is provided.

A needle bar 30 and a presser bar 32 (see FIG. 3) extend downward from the head 16. The needle bar 30 is attached to a needle bar stand (not shown) so as to be slidable in the vertical direction, and a sewing needle 34 is fixed to the lower end thereof. The needle bar 30 and sewing needle 34 are configured to be caused to reciprocate up and down by driving the sewing machine motor. Furthermore, the needle bar stand is oscillated by a needle oscillation actuator (not shown), so that the lateral position of the sewing needle 34 can be changed within a certain range. Further, an opening is formed in the upper surface of the bed 10, and this opening is closed by a needle plate 46. A needle hole 47 and a plurality of slots are formed in the throat plate 46, and a needle hole 47 that is long in the left-right direction and a plurality of slots are formed, from which a feed dog 48 as a cloth feed member can protrude upward.

The feed dog 48 is given a feed motion by a feed actuator (not shown), and works in conjunction with a presser foot 50 shown in FIG. 3 to feed the work cloth (not shown) in the front-rear direction.

The presser foot 50 is for buttonhole sewing, and includes a main body 52 attached to the lower end of the presser foot 32, and a fabric presser frame 54 held on the main body 52 so as to be relatively movable in the feed direction of the work cloth. It is equipped with The presser frame 54 is connected to the main body 52
It is always biased backward (to the side opposite to the operator) by a spring member (not shown) attached to the
The limit of rearward movement is defined by the contact with the front end of the main body part 50, and when the work cloth is not pressed, it is maintained at the original position shown in the figure. During sewing, the presser frame 54 is moved by the same amount in the same direction as the work cloth is fed forward (towards the operator) against the biasing force of the spring member. It should be noted that there is a slight clearance between the presser foot 32 and the sewing machine frame 18 that slidably supports it, and the cloth presser frame 54 is moved after the presser foot 32 is lowered to press the work cloth. , when pushed rearward through the work cloth by the feed dog 48, it moves backward a short distance, allowing the work cloth to move backward a short distance.

A dog 56 is fixed to the presser frame 54, and a positioning portion 58 is provided at a distance from the dog 56 in the feeding direction. A moving member 60 is also attached to the presser frame 54 so as to be relatively movable in the feeding direction. Moving member 6
A dog 62 and a positioning part 64 are provided at both ends of the
is provided.

The distance between the positioning parts 58 and 64 can be adjusted by moving the moving member 60, and the button can be moved between the positioning parts 58 and 64.
If you set it so that it is sandwiched in the diametrical direction by
The distance between the dogs 56 and 62 in the feeding direction is set to be equal to the outer diameter of the button.

A position detection switch 68 is attached to the sewing machine head 16 to detect the position of the work cloth. This switch 68
is equipped with a lever 70 that is rotatable about a horizontal axis perpendicular to the cloth feeding direction. The lower end of the lever 70 has a dog 56,
62, and a common contact 72 is attached to the upper end thereof, and fixed contacts 74, 76 are provided on both sides of the common contact 72 of the head 16 in the feeding direction, respectively.
is installed. The lever 70 is rotated by the dog 56 when the work cloth is sent backward, and the common contact 72
By closing the fixed contact 74, the switch 68 generates a front end signal indicating that the front end of the buttonhole seam is being formed. is rotated by the dog 62, the common contact 72 and the fixed contact 76 are closed, and a rear end signal is generated indicating that the rear end of the buttonhole seam is being formed. ing.

Figure 4 shows the control device of this sewing machine. This control device is
CPU80. Pattern ROM82. Program ROM8
4. RAM86. It is mainly a computer equipped with a bus 88 that connects them. An input interface 90 is connected to the bus 88, and the motor start switch 2
0. Pattern selection switch 241 position detection switch 68. A needle down position sensor 92 that issues a needle down signal when the sewing needle 34 is at the needle down position below the bed 10. Sewing needle 34 is at bed 1
A counting position sensor 94, etc., which generates a needle up signal when the needle is at a counting position above 0, is connected.

An output interface 98 is also connected to the bus 8th,
Sewing machine motors 110 . Feed amount adjustment pulse motor 11
2. A needle swing pulse motor 114 and a display panel 22 are connected.

As shown in FIG. 5, the RAM 86 is provided with a data pointer for storing addresses of stitch data used for sewing, a working memory for storing data necessary when executing a program, etc., and a pattern ROMB2 for buttonhole sewing. Pattern data for each of the other pattern stitches is stored. The pattern data is formed for each stitch, and each of the plurality of stitch data making up the pattern data includes feed data that instructs the feed amount and feed direction of the work cloth, and the swing amount and swing of the sewing needle 34. and rocking data indicating the direction. The feed amount is the feed amount from the previous stitch position, and the swing amount is the swing amount from the center position of the swing range of the sewing needle 34. Further, the stitch data includes data that is executed repeatedly and data that is executed only once, and the pattern data of buttonhole stitches formed in this embodiment is configured as shown in the following table.

In the above table, F is feed data, Z is swing data, LO
OP is repeated data. In the feed data, the number on the left represents the feed direction, l is backward (the stitch is formed from the front side to the back side), 0 is forward (the stitch is formed from the back side to the front side) represents. Also, the number on the right side represents the feed amount. Note that the feed amount and swing amount are expressed in hexadecimal notation, and A is 10 in decimal notation. B is 11. C corresponds to 12. In the rocking data, the number on the left side represents the rocking direction, where 1 represents rocking to the left and 0 represents rocking to the right. Moreover, the number on the right side represents the amount of rocking. Among the repeated data, FSW is
This indicates that the formation of the stitch pattern should be completed at the first stitch after the trailing edge signal is issued, and the BSW starts forming the stitch pattern at the first stitch after the leading edge signal is issued. Indicates that formation of the eye pattern should be completed.

FSW+1 indicates that the formation of the stitch pattern should be completed at the second stitch after the trailing edge signal is issued.

Furthermore, the program ROM 84 stores various programs necessary for sewing in addition to the buttonhole sewing control programs shown in the flowcharts of FIGS. 6 to 8. The buttonhole sewing will be explained below.

When sewing buttonholes using the sewing machine configured as described above, the operator first inserts the workpiece cloth into the feed dog 48.
and the presser frame 54. Then, buttonhole sewing is selected by operating the pattern selection switch 24 the same number of times. As a result, the pattern data for buttonhole sewing is transferred from the pattern ROM 82 to the working memory of the RAM 86, and also
The data for forming a stitch is read out, and the feed amount adjusting pulse motor 112. Needle swing pulse motor 11
4 is driven, the feed amount is set to O, and the sewing needle 34 is positioned at the center position of the swing range. Buttonhole sewing is started by turning on the motor start switch 20 or by manual operation by the operator. First, a case where buttonhole sewing is performed for the first time and sewing is started by turning on the motor start switch 20 will be described. The CPU 80 sequentially executes the control programs shown in FIGS. 6 to 8 together with other control programs.
In step Sl (hereinafter abbreviated as Sl. The same applies to other steps), it is determined whether or not the motor start switch 20 has been operated, and if it has not been operated, the determination result is NO and the program is programmed. The execution returns to the main routine, and if it has been operated, it is determined in S2 whether or not the selected pattern is buttonhole sewing, and if another pattern is selected, the determination result is No. The program execution then returns to the main routine. Since buttonhole stitching is selected here, the judgment result is Y.
ES, and it is determined in S3 whether or not a rear end signal is being generated. At the start of sewing, the presser frame 54 is at its original position and the front end signal is being emitted, so the determination result is NO and the program execution returns to the main routine.

Note that in step 5101 of the program in FIG. 7, it is determined whether or not it is time to read stitch data. The feed amount of the work cloth is adjusted by driving the feed il adjustment pulse motor 112 when the sewing needle 34 is not in the needle down position, that is, when the sewing needle 34 is in the needle down position. The 5IOI is executed only when the lower position is reached. The working memory is provided with an area for storing the position of the sewing needle 34 detected by the needle down position sensor 92 and the counting position sensor 94, so that the position of the sewing needle 34 when the 5 lot determination is made is stored. It has become.

In 3101, the needle position stored in the working memory (the position of the sewing needle 34 when 5101 was executed last time)
is compared with the current position of the sewing needle 34, and if the sewing needle 34 is currently in the needle down position but was in the counted position last time, YES
The data is then read out. In other cases,
That is, when the sewing needle 34 is at the counting position, or when it is currently and previously at the needle down position, the determination result is No.

One stitch data is read out during one reciprocation of the needle bar 32.

If the determination result for 5 lots is YES, it means that it is time to read out the stitch data, and the feed amount is adjusted. If the determination result of 5IOI is NO, the program execution returns to the main routine.

When sewing is started by turning on the motor start switch 20, the operation turns on the sewing machine motor 110.
is activated, the sewing needle 34 forms a stitch at the No. 1 position, and when the needle down position signal is issued, the determination result of 3101 becomes YES, and the next determination result of 3102 also becomes YES. Then, in step 3103, it is determined whether or not a rear end signal is being generated. Since the trailing edge signal is not emitted at the time when the No. l stitch is formed, the determination result is NO, the data pointer is updated in 5105, and the stitch data for forming the 2nd stitch is read in 5106. After being fed, the feed amount adjusting pulse motor 112 is driven at 3111, and the feed amount becomes Nα.
The size is set to form two stitches.

After the buttonhole sewing feed control routine is executed, the needle swing control routine shown in FIG. It is oscillated by the amount specified by the stitch data, and stitches No. 2 are formed in conjunction with the feeding of the work cloth.

In the buttonhole sewing start control routine, during the first sewing, if the workpiece cloth is fed forward and the trailing edge signal is issued, S
The determination result in step 3 is YES, and in S4 it is determined whether the data pointer is at the beginning, but the determination result is NO.
, and only steps 31 to S3 or 31 to 34 are performed. Therefore, the buttonhole sewing feed control routine will be mainly described below. If the determination result in step 5101 is YES when stitch Na2 is to be formed, the data pointer is updated in step 3105, and the address of the stitch data for forming stitch Na3 is indicated. According to this data, 3 stitches are formed, but N1
The data forming the 1L3 stitch and the next Nα4 stitch are paired, and when the data instructing repeat execution and the rear end signal are issued, the data next to the paired data is executed. Data FSW that instructs to
is attached. Therefore, when 5105 is executed due to the formation of stitch No. 4, the data pointer is
The state is updated to indicate the address where the data for forming the stitch α3 is stored, and the stitch N053 is formed again. In this way, until the rear end signal is issued, Nα3.
A plurality of Nα4 stitches are formed, and the -th left ground stitching portion 120 is formed.

If the rear end signal is issued, the determination in 5103 becomes YES and 5104 is executed, but during sewing, the determination result in 5104 always becomes NO. The data pointer is updated in step 5105 regardless of whether the trailing edge signal is issued or not. Then, if the rear end signal is issued, No.
, 5 is read out, but this stitch is formed only once, and after it is formed, N
086 stitches are formed. This stitch Nα6 and the next stitch Nα7 are stitches that are repeatedly formed until a front end signal is issued, and by forming a plurality of these stitches, the second human-sewn portion 122 is formed. Then, when the front end signal is issued, the data for forming the stitch Nα8 is read out, and the left annular portion 124 is subsequently formed by forming the stitch Nα17. The formation of the second human-seamed portion 122 ends at the first stitch after the front end signal is issued from the position detection switch 68, but the position of the terminal stitch of the second human-sewn portion 122 is at most It is inevitable that the stitch pitch of the second stitched portion 122 varies, and the maximum positional deviation of the terminal stitch is the sum of this stitch pitch and the installation error of the position detection switch 68.

Therefore, there is a possibility that almost the same amount of deviation will occur in the position of the next seam 8 formed, but Nα of the seams forming the left annular portion 124 is
The feed data for stitch No. 9 indicates that even if the terminal stitch is formed at the rearmost position, the feed data for stitch No. 9 is in front of the original position where the stitch No. The feed data is set so that it is formed at the frontmost position determined by being pushed as far backward as possible. Therefore, 1. As explained in the prior art, the left annular portion 12
4 is always formed at a constant position in the feeding direction of the work cloth according to the scheduled stitch data.

After the stitch No. 17 is formed, the stitch No. 18 is formed, but the data for forming this stitch and the next stitch No. 19 is repetitive data and a trailing edge signal is generated. After that, data FSW+1 indicating that the formation of the stitch pattern should be finished with the second stitch is attached, and a plurality of stitches Nα1B and Nα19 are formed to form the left edge overcast portion 126. be done. If the trailing edge signal is issued just before the No. 18 stitch is formed, Na1B, t4a1
After the stitch No. 9 is formed, the data for forming the stitch No. 20 is read out, and if the trailing edge signal is issued just before the stitch No. 19 is formed, then Nα19. After the stitch N1118 is formed, the data for forming the stitch k20 is read out. Then, after the seam of floor 20 is formed, Nα
Stitches No. 21, No. 22, and No. 22 are formed, but these are also stitches that are repeatedly formed until the front end signal is supplied.
A plurality of them are formed to form the right side seam portion 128.

Subsequently, stitches 23 to 32 are formed to form the right annular portion 130.

No. 2 formed at the frontmost side of the right annular portion 130
The data is created so that the stitch number 4 is formed at the frontmost position in the same way as the stitch number Nα9, so that the left and right annular portions 124 and 130 do not shift in position in the cloth feeding direction, and , formed into a beautiful shape without deformation.

After that, Na33. A plurality of 34 stitches are formed until a rear end signal is issued, and a right edge overcast portion 132 is formed.
Furthermore, after stitches Nα35 to Nα40 are formed to form the bar tacking portion 134, stitches No. 41 to 43 are formed at the same position to form the bar tacking portion 136, and the first buttonhole sewing is performed. ends. Note that when the seam 43 is formed, the data pointer is updated to specify the address where the data for forming the seam Nal is stored.
After forming the stitch No. 43, the sewing needle 34 is moved to a position directly beside the stitch No. 43 and directly above the center of the needle swing range indicated by 0 in FIG. 9.

When buttonhole sewing is started by the operator's manual operation, the sewing needle 34 is inserted into the workpiece cloth and a NAL stitch is formed by that operation, and the rest is the same as when the buttonhole sewing is started by turning on the motor start switch 20. When the stitch data is read out, the work cloth is fed and the sewing needle 34 is swung according to the contents of the data to form the stitches. After an appropriate number of stitches have been formed, even if the motor start switch 20 is operated, the buttonhole sewing start control routine does not have any effect. Sewing continues.

Next, the case of performing overlapping stitching will be explained. Overlap stitching may also be started by turning on the motor start switch 20, or by manual operation by the operator. Hereinafter, a case where overlapping stitching is started by turning on the motor start switch 20 will be described. In this case, the determination result of Sl becomes YES, and 32. The determination results in S3 and S34 are also YES, and when the number is 35 or less, the overlap stitching start process is performed. Overlapping stitching is performed after the formation of the buttonhole stitch is once completed, and at that time, the data pointer is at the beginning, but the presser frame 54 is moved to the front side and a rear end signal is issued. ing. 33°34 (same as 3103 and 3104) are provided to determine this state, and if both of these determination results are YES, overlapping stitching is performed. In S5, the data pointer is updated to specify the data for forming the seam 2, then in S6 the data is read out, and in S7 the feed data included in the data moves the work cloth backward. A determination is made as to whether or not the data is data to be sent to, that is, data for forming stitches from the back side to the front side. N [The feed data for forming the L2 stitch is the data that sends the work cloth forward, so the judgment result is N.
0, and from now on, until the judgment result of S7 becomes YES, S
5 to S7 are repeatedly executed.

When the stitch data forming the stitch 6 is read out,
Since the feed data included in that data is data for sending the work cloth backward, the determination result in S7 is YES, and S8
At , it is determined whether or not the sewing needle 34 is at the counting position. When the first buttonhole sewing is automatically completed, the sewing needle 34 is moved to a position above the workpiece cloth, and if the sewing needle 34 is at the counting position, the determination result in S8 becomes YES, and the sewing needle 34 is moved to a position above the workpiece cloth. Needle swing pulse motor 1
14 is driven. As a result, the sewing needle 34 is moved to the position determined by the swing data for forming the stitch Nα6, that is, Nα
43 and is moved to a position S on the extension line of the second human-seamed portion 122, thereby forming a seam. If the determination result in 5101 becomes YES due to this formation, the data pointer is updated in 3105 to specify data for forming the No. 7 stitch, and hereafter, NQ
, 6 and subsequent stitches are formed in the same manner as the first buttonhole sewing, and the stitches are formed from the second human-seamed part 122 to the stop-stitched part 136, exactly overlapping them. In this embodiment, the execution of the pattern data for forming the stitches Nal to 5 from the sewing start position of the first buttonhole sewing to the vicinity of the sewing end position, which is the start position of the second buttonhole sewing, is skipped. Therefore, the buttonhole sewing data itself stored in the pattern ROM 82 can be used for overlapping sewing without making any changes.

Note that when buttonhole sewing is completed, the sewing machine may be stopped by the operator with the sewing needle 34 still stuck in the workpiece cloth at the position where the Na43 stitch is to be formed, and in this case, the determination result in S8 is No. becomes. At this time, 31
At 0, the feed amount is set to 0, and at Sll, the feed amount adjustment pulse motor 112 is driven to bring the feed amount to 0. Next, step 3101 is executed, but since the sewing needle 34 remains stuck in the positive stitch position 43, the determination result is No and no data is read until the next stitch is formed. Therefore, when step 5202 is executed, the sewing needle 34 is oscillated based on the oscillation data for forming the stitch Nα6, but since the feed amount is set to O, the stitch is formed at the position S. S1
0. By performing S11, the feed data of the stitch data of Nα6 read out in S6 is prevented from being executed.
A seam is formed at a position directly beside the seam and on the extension line of the second human-seamed portion 122.

When overlapping stitching is started by the operator's manual operation, the determination result of Sl is NO, and when the sewing needle 34 is lowered and a stitch is formed at position 0, the determination result of 5IOI is YES, and 3102.3103 The determination result of .5104 is also YES, and the overlap sewing start processing of S l , 07 to 5109 is performed in the same manner as 35 to S7. Na
810 when the data forming the stitch No. 6 is read out.
After the determination result in step 9 is YES and the feed amount is set to 0 in 5110, the feed amount adjustment pulse motor 112 is driven in 5111. As in the case where overlapping stitching is started by turning on the motor starting switch 20, the feed data of the data forming the stitches of the sewage 6 is not executed. Then, when 5202 is executed, the sewing needle 34 is
It is oscillated based on the oscillation data for forming stitches 6 and 6, and a stitch is formed at position S. below,
Overlapping stitching is performed in the same way as when starting when the motor start switch 20 is turned on, and after an appropriate number of stitches have been formed, when the motor start switch 20 is operated, buttonhole sewing is continued by the sewing machine motor drive. Ru.

As is clear from the above explanation, in this example,
Sewing needle 34. Feed dog 48. Sewing machine motor 110, feed amount adjustment pulse motor 112. Needle swing pulse motor 114. Pattern ROMB 2. Program ROM84 Sl, 3
2,3101,3102.5105,3106,5il
1, 5201 and 5202, a part of the CPU 80 that executes these steps, etc. constitute a pattern sewing means, and a program ROM 80 S3. S 4. S10
3°3104 and a part of the CPU 80 that executes the steps constitute overlap stitching command means,
S5~Sll and 5107~ of program ROM80
The part that stores the steps 5110 and the part of the CPU 80 that executes these steps constitute the overlap stitch control means.

In the above embodiment, the data pointer is updated without vertical movement of the sewing needle at the start of overlap stitching, and the stitch data is read and its content is determined.
Execution of data forming stitches α1 to Nα5 was skipped, but at the start of overlap stitching, the data pointer changed to a value indicating the data for stitch Nα6, which is the sewing start stitch of overlap stitching. It may also be set directly.

The embodiments described in detail above are literally illustrative, and the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing the configuration of the present invention. FIG. 2 is a perspective view schematically showing the appearance of a sewing machine that is an embodiment of the present invention. FIG. 3 is a perspective view showing the head of the sewing machine. FIG. 4 is a block diagram showing the configuration of the control device of the sewing machine. FIG. 5 is a diagram showing the configuration of a RAM of a computer that constitutes the main body of the control device. Figure 6. FIG. 7 and FIG. 8 show the program R of the computer mentioned above.
3 is a flowchart showing each control program stored in OM. FIG. 9 is a plan view showing buttonhole stitches formed by the sewing machine. FIG. 10 is a diagram illustrating buttonhole sewing using a conventional sewing machine. 10: Bed 34: Sewing needle 50: Presser foot 52X main body 54: Presser frame 56, 62: Dog 68: Position detection switch 120: First production area sewing section 122: Second left sewing section 124: Left annular section 126: Left Overedge part 12
8: Fabric sewing part 130: Right annular part 132: Right edge edge part 134: Bar tacking part 136: Stacking part Fig. 1 Fig. 3 Rising direction

Claims (1)

[Scope of Claims] A sewing machine equipped with a pattern sewing device that automatically forms a stitch pattern in which a sewing start position and a sewing end position are separated based on pattern data, further comprising: Overlapping stitching commanding means for instructing that stitches should be formed in an overlapping manner; and in response to instructions from the overlapping stitching commanding means, the sewing start position of the stitch pattern to be formed later is set to Overlap stitching control means for changing the pattern data to be in the vicinity of the sewing end position of the stitch pattern and causing the pattern sewing means to form a subsequent stitch pattern. A sewing machine that can sew.