JPS61279284A - Feed controller of sewing machine - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sewing machine for forming decorative patterns, and more particularly to a device for controlling the feed at the end of one cycle of forming a decorative pattern.

[Conventional Technique W1] Zigzag sewing machines, in which the sewing machine motor automatically stops after the completion of one cycle of forming a decorative pattern, which is commonly used, perform vertical and reciprocating movements as the main shaft driven by the sewing machine motor rotates, and perform horizontal oscillating movements. A sewing needle that is attached to the sewing machine, a feeding device that applies a feeding movement with a variable feed amount to the workpiece cloth in synchronization with the up and down reciprocating movement of the sewing needle, and control of the swinging position of the sewing needle and the feeding movement of the feeding device. A pattern selection means for selecting a desired pattern from a plurality of decorative patterns to be formed, a detection means for detecting the end of the selected decorative pattern, and the above-mentioned in connection with the end detection by the detection means. and a stopping means for stopping the sewing machine motor. The feed device of this sewing machine has a feed dog that performs a well-known four-movement feed in each cycle of up and down reciprocation of the sewing needle. The settings are changed while the

[Problems to be Solved by the Invention] However, when the sewing machine automatically stops after completing one cycle of pattern formation and a new pattern is selected, the initial feed amount after selection is the same as the previously selected 1. Since the feed at the end of the cycle pattern was set before the sewing machine stopped, the feed amount appeared at the start of forming a new pattern, making it impossible to form a stitch at the desired position. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a feed control device for a sewing machine that prevents abnormal feed from appearing at the beginning of forming a new pattern after one cycle of pattern formation is completed.

[Means for Solving the Problems] In order to solve the above problems, the feed control device of the sewing machine of the present invention performs vertical reciprocating motion in accordance with the rotation of the main shaft driven by the sewing machine motor, and is capable of lateral oscillating motion. A sewing needle attached to the sewing machine, and a feeding device that imparts variable feeding motion to the work cloth in synchronization with the reciprocating movement of the sewing needle, and controlling the swinging position of the sewing needle and the feeding motion of the feeding device. A pattern selection means for selecting a desired pattern from a plurality of decorative patterns to be formed, a detection means for detecting the end of the selected decorative pattern, and the above-mentioned in connection with the end detection by the detection means. A zigzag sewing machine is provided with a stopping means for stopping a sewing machine motor, and the sewing machine motor automatically stops after the completion of forming one cycle of the decorative pattern, in which the feeding ink of the feeding device is zeroed in connection with end detection by the detecting means. , and maintains the setting state until a new pattern is selected by the pattern selection device.

[Operations and Effects of the Invention] The feed control device for a sewing machine of the present invention having the above configuration sets the feed amount of the feed device to zero after the detection means detects the end, and changes the setting state to a new one by the pattern selection means. By providing a zero feed setting means that maintains the sewing machine until the desired pattern is selected, the feed amount is set to zero before the sewing machine stops, so a new pattern can be selected and stitched after the sewing machine stops due to the formation of one cycle of decorative patterns. During formation, the first feed movement of the new pattern is not applied to the workpiece cloth, thus preventing the appearance of abnormal feeds. Therefore, when a new pattern is selected, the first stitch is formed directly below where the sewing needle is located, and the operator can reliably start stitch formation from the desired position.

[Embodiment] Next, a feed control device for a sewing machine according to the present invention will be explained based on an embodiment shown in the drawings.

The structure of the sewing machine 1 to which this embodiment is applied will be explained based on FIG. 2.

The sewing machine 1 includes a known stitch forming mechanism 100, a sewing machine frame 400, and an electric control device 500 that controls the sewing machine 1.
It is broadly divided into

The stitch forming mechanism 100 has a force that drives the sewing needle drive mechanism 110, the balance mechanism 120, and the hook 131. Drive mechanism 13
0 and a presser foot 141 that presses the work cloth downward by the biasing force of a spring (not shown). The stitch forming mechanism 100 further includes a cloth feeding mechanism 200 and a needle bar swinging mechanism 300.

The sewing needle drive mechanism 110 causes the sewing needle 101 to reciprocate up and down. An upper shaft 112 (main shaft) is rotationally driven by a sewing machine motor 111 which is a main driving force generating device of the sewing machine 1 . The upper shaft 112 has a needle bar 113 that holds the sewing needle 101.
, balance crank 114 and button bar crank rod 1
15.

At an intermediate position of the upper shaft 112, there are provided a semi-disc-shaped needle up/down shutter 11281, a timing shutter 112b, and a disc-shaped rotary shutter 1120 with slits provided at circumferential positions. The needle up and down shutter 112a, the timing shutter 112b, and the rotary shutter 1120 are connected to the upper shaft 11 by a photocoupler or the like.
12 and outputs a timing signal to the electric control device 500.

The hook drive mechanism 130 drives a hook 131, which is a fully rotating front hook in this embodiment, and is operatively connected to a lower shaft 132 that is rotationally driven by a sewing machine motor 111. In addition to the full-rotation type front puller shown in this embodiment, other hooks such as a half-rotation or full-rotation type side puller, a side movable pulley, and a front movable pulley may be used.

The cloth feed mechanism 200 moves the workpiece cloth in the forward and rain direction in synchronization with the up and down reciprocating movement of the sewing needle 101. This cloth feed mechanism 200 includes a feed dog vertical feed mechanism 210 that moves a feed dog 201 that imparts a feed motion to the work cloth in the vertical direction.
and a feed dog horizontal feeding mechanism 220 that moves the feed dog 201 horizontally (back and forth).

The feed dog vertical feed mechanism 210 is driven by a vertical drive cam 211 provided on the left side of the lower shaft 132.

The vertical drive cam 211 is sandwiched between two prongs of a lever arm 213 that transmits the movement of the vertical drive cam 211 to the vertical feed shaft 212 and rotates and reciprocates the vertical feed shaft 212. A vertical arm 214 is attached to the left end of the vertical feed shaft 212 for vertically reciprocating the front end position of the feed base 202 to which the feed dog 201 is attached.

The feed table 202 and the upper and lower arms 2 are provided at the front left end of the feed table 202.
A tension coil spring 215 is attached to urge the feed base 202 downward so that the feed base 202 is always in contact with the feed base 14.

The feed dog horizontal feed mechanism 220 is configured such that the feed amount and feed direction of the work cloth are set by a feed adjustment actuator 221 using a swing-up motor whose rotation angle corresponds to the number of input pulses, an electromagnetic solenoid, or the like. It is provided. The feed adjustment actuator 221 drives and connects a feed adjuster 222 having a groove 222a on the left side. A horizontal feed cam 223 is provided on the right side of the lower shaft 132. At a position above the horizontal feed cam 223, a rear end portion of a horizontal feed lever 224, whose intermediate portion is rotatably supported and whose front end portion moves in an arc reciprocating motion in the vertical direction, comes into contact. The front end of the horizontal feed lever 224 has a feed angle separator 225 supported slidably in the groove direction in the groove 222a of the feed adjuster 222 on the right side of the upper end. A feed link 226 is rotatably attached to convert the circular reciprocating motion transmitted to the front end of the feed adjuster 222 into a reciprocating motion only in the horizontal direction of the groove 222a of the feed adjuster 222. Between the feed angle piece 225 and the upper end of the feed link 226, a front end of a horizontal feed link 227 that transmits horizontal reciprocating motion to the rear according to the amount of inclination of the groove 222a of the feed adjuster 222 is rotatably provided. connected. The rear end of the horizontal feed link 227 has a lever 228a at its right end that converts the horizontal reciprocating motion transmitted by the horizontal feed link 227 into an axially rotating reciprocating motion.
A lever 228a of a horizontal feed shaft 228 is rotatably connected to the horizontal feed shaft 228, which has a lever 228b on the left end side that converts the shaft rotational reciprocating motion converted by 8a again into a horizontal circular arc reciprocating motion. The upper end of the lever 228b of the horizontal feed shaft 228 is rotatably connected to the rear end of the feed base 202. As a result of the above, the feed dog is in the groove 222a of the feed adjuster 222.
horizontal reciprocation by an amount corresponding to the inclination angle of A tension coil spring 229 is attached to the front end of the horizontal feed lever 224 so that the horizontal feed cam 223 and the rear end of the horizontal feed lever 224 are always in contact with each other.

In addition to the feed dog horizontal feed mechanism 220 shown in this embodiment,
A triangular cam is provided on the upper shaft 112, etc., and the triangular cam is sandwiched between two-pronged rods, and the sliding movement range of the feed angle separator provided on the two-pronged rod is set by a feed adjuster, thereby controlling the workpiece cloth. Other thread horizontal feed mechanisms may be used, such as a mechanism in which the feed thread and feed direction are set.

The needle bar swing mechanism 300 is provided to determine the swing position of the sewing needle 101 by a needle bar swing actuator 301 using, for example, a stepping motor, an electromagnetic solenoid, etc. whose rotation angle corresponds to the number of input pulses. ing. The needle bar swing actuator 301 drives a vertical conversion gear 302 that converts the power of the needle bar swing actuator into vertical movement. The vertical direction conversion gear 302 is
It is connected to a transmission link 303 that transmits the vertical movement of the vertical direction conversion gear 302 upward. The upper end of the transmission link 303 has an L-shape, and a bent portion is rotatably supported.
It is rotatably connected to the right end of a connecting lever 304 that converts the vertical motion transmitted by the transmission link 303 into left and right circular arc motion. The needle bar stand 305, which supports the needle bar 113 in a vertically slidable manner, has an upper end rotatably supported by the sewing machine frame 400. The lower end of the connecting lever 304 and the lower end of the needle bar stand 305 are connected by a zigzag connecting rod 306, and the left and right circular arc movement of the lower end of the connecting lever 304 is transmitted to the lower end of the needle bar stand 305. As described above, the needle bar 113 is driven in the left-right direction by the operation of the needle bar swing actuator 301.

Although this embodiment shows a needle bar swinging mechanism with pre-swinging,
Other needle bar swing mechanisms such as an arc type may also be used.

The sewing machine frame 400 forms the outer shape of the sewing machine 1 (see FIG. 3). The sewing machine frame 400 includes a base portion 410 serving as a base, a pillar portion 420 standing upright on one end of the base portion 410, a bracket arm 430 supported in a cantilever manner by the pillar portion, and the bracket arm. It consists of a head 440 formed at the free end of 430.

Inside the base portion 410, a hook driving mechanism 130, a cloth feeding mechanism 200, and an electric control device 500 are housed. A sewing machine motor 111, a feed adjustment actuator 221, a needle bar swinging actuator 301, and the like are housed within the pillar portion 420. bracket arm 430
In the head 440, a sewing needle drive mechanism 110, a balance mechanism 1201, a needle bar swinging mechanism 300, a cloth presser mechanism, etc. are housed.

The sewing machine motor 11 is installed at the lower part of the front surface of the pillar section 420.
A speed adjustment knob 421 is provided to adjust the rotation speed of 1. A feed I setting knob 422 is provided above the speed adjustment knob 421 (on the upper side in the figure) for setting the feed amount of the work cloth by the cloth feed mechanism 200. The left side of the feed amount setting knob 422 (on the left side in the figure) should be influenced by the feed ffi setting knob 422 (this state is referred to as "manual") or not (
A manual/automatic feed changeover switch 423 is provided to select this state (referred to as "automatic"). Above the feed mountain setting knob 422, a sewing needle 1 is provided by the needle bar swinging mechanism 300.
A swing width setting knob 424 is provided for setting a swing width amount of 01. An amplitude manual/automatic changeover switch 425 is provided adjacent to the left side of the amplitude setting knob 424 for selecting whether or not to have an influence of the amplitude setting knob 424. . A plurality of operation keys 426 are provided above and to the right of the twisting width setting knob 424 for inputting pattern numbers corresponding to each pattern in order to select a sewing method or a stitch pattern. To the right of the operation key 426, the pattern selected by the operation key 426 is formed continuously, or one cycle is designated (one cycle of the same phase such as button ball, eyelet, letter, circle, pattern, etc. is completed). A continuous-one cycle designation changeover switch 427 is provided for selecting whether the sewing machine 1 is to be stopped or not. Above the operation switch 42G, a light emitting diode, which displays the pattern number input using the operation key 426, is provided.
A display device 428 that displays information using liquid crystal or the like is provided.

Display panels 432 and 433 are provided on the front side of the bracket arm 430, and display panels 432 and 433 displaying a plurality of shapes 431 of sewing methods and stitch patterns that can be formed by the sewing machine 1. The display panel 433 on the right side is provided so that the contents of the sewing method and stitch pattern displayed on the display panel 433 can be switched by operating a display panel switching lever 434 provided at the bottom of the display panel 433. .

A start/stop switch 441 is provided at the lower right side of the front surface of the head 440 to instruct the sewing machine motor to start and stop. Above the start/stop switch 441,
A return switch 442 is provided for changing the feed direction of the workpiece cloth and instructing back stitching such as tacking stitches and reverse stitching. A needle position changeover switch 443 is provided above the return switch 442 for setting whether to stop the sewing needle 101 at the upper position or the lower position when the sewing machine motor 111 is stopped. A needle stop position indicator lamp 444 is provided above the needle position changeover switch 443 to indicate the setting state of the needle position changeover switch 443 by lighting a light emitting diode or the like.

Next, the electric control unit N500 that controls the sewing machine 1 configured as described above will be explained based on FIG.

Electricity charge 'm@W 500 is timing signal generator 50
1. Needle position detector 502, pattern selection device 503, data reading device 504, stitch data memory 505, latch 50
6, a feed drive circuit 507, a needle swing drive circuit 508, an end detection circuit 509, a one cycle designation device [510], a start/stop designation device 511, a motor control circuit 512, and a motor drive circuit 513.

The timing signal generator 501 generates a feed change permission signal FT and a needle swing permission signal BT (see FIG. 4) in accordance with the locus of the sewing needle 101 (see FIG. 4). The feed change permission signal FT is generated by detecting the rotational position of the needle up and down shutter 112a provided on the upper shaft 112 using a photocoupler, etc., and outputting the "old" output at the position where changes in the feed amount and feed direction of the work cloth are permitted. Similar to the feed change permission signal FT, the needle swing permission signal BT detects the rotational position of the needle up/down shutter 112a using a photocoupler or the like, and is output as "old" at the change permission position of the swing position of the sewing needle 101. Ru.

The needle position detector 502 is connected to the needle position changeover switch 44 described above.
It operates in conjunction with 3. When the needle position changeover switch 443 is set so that the sewing needle 101 stops at the upper position, the position of the slit for stopping counting provided in the above-mentioned rotary shutter 112C provided on the upper shaft 112 is detected with a photocabra or the like, and the sewing needle “Old” when 101 is in a predetermined upper position
Generates a needle up stop signal. Needle position changeover switch 443
When the sewing needle 101 is set to stop at a lower position, the position of the slit for stopping the needle down provided on the outer periphery or the inner periphery of the slit for stopping the counting of the rotary shutter 1120 is detected by a photocoupler, etc., and the sewing needle 101 is stopped at a predetermined position. When the needle is in the lower position, the old needle down stop signal is generated.

The pattern selection device 503 is a pattern selection device for selecting a desired pattern from among a plurality of decorative patterns formed by controlling the swinging position of the sewing needle 101 and the feeding motion of the feed dog 201. Panel 432.4
When the pattern number corresponding to the pattern of the figure 431 displayed at 33 is set using the operation key 426 provided on the pillar section 420, a leading address signal corresponding to the set pattern number is output. It is also equipped with a one-shot multivibrator that generates an "old" reset signal P1 in synchronization with the setting of the pattern number by the operator.
It is connected to the input side of an OR circuit 504a connected to the R terminal.

The data reading device [504] adds the number of needle swing permission signals 8T from the timing signal generator 501 connected to the CK terminal to the start address output from the pattern selection device 503, and sequentially adds the addition result to the stitch data memory 505. Output towards.

Further, the OR circuit 504a connected to the PR terminal inputs the reset signal P1 of the pattern selection device 503 described above and the final stitch signal P2 output from the termination detection circuit 509 described above, and the operator inputs the pattern number. A signal is supplied to the PR terminal of the data reading device i1504 at the time of setting or every time the pattern selected by the pattern selection device 503 is formed for one cycle. The data reading device @ 504 loads the start address from the pattern selection device 503 in response to the signal supplied to the PR terminal.

Stitch data memory 505 stores images 431 displayed on display panels 432 and 433 of bracket arm 430.
Stitch data for forming a stitch pattern corresponding to the stitch pattern is stored in advance. This stitch data memory 505 receives the output signal from the data reading device 504, and receives the output signal from the operation key 426.
Stitch data for forming a stitch pattern corresponding to the pattern number set by is output. That is, the feed data DF regarding the feed amount and feed direction of the work cloth, and the sewing needle 10
Stitch data consisting of the swing data DB regarding the swing position 1 is output. The final data in the feeding data OF for each pattern and the data one stitch before that data are zero feeding data so that the amount of feed of the work cloth by the fabric feeding mechanism 200 is zero. Further, the final data for each pattern is a final needle code indicating the end of the pattern, and a low speed command code for commanding the rotational speed of the sewing machine motor 111 to be low is stored two stitches before the final needle code ( (See Figure 5).

The launch 506 inputs the feed change permission signal FT output from the timing signal generator 501 and the feed data DF output from the stitch data memory 505, and outputs the feed change permission signal Q.
Every time a rising signal of FT is generated, the sending data DF is held and the held data is output.

The feed drive circuit 507 drives the feed adjustment actuator 221 of the feed pile horizontal feed mechanism 220 based on the feed data DF output from the latch 506, and as a result, the feed amount and feed direction of the work cloth by the cloth feed mechanism 200 are adjusted. teeth,
The feed l and feed direction are determined according to the feed data OF.

The needle swing drive circuit 508 drives the needle bar drive actuator 301 based on the swing data DB output from the stitch data memory 505, and as a result, the needle bar drive! llv! 1
The sewing needle 101c is set at a position in the left-right direction according to the swing data DB from the mechanism 300d.

The end detection circuit 509 is a detection means for detecting the end of the decorative pattern selected by the pattern selection device 503, and when the last needle code in the stitch data in the stitch data memory 505 is "old", It outputs the "old" final stitch signal P2 (see Figure 4), and outputs the "old" low speed command signal P3 (see Figure 4) when the low speed command code in the stitch data is set to "old". do.

This final needle signal P2 and low speed command signal P3 are input to a timing signal generator 501 which is input to an end detection circuit 509.
The needle swing permission signal BTkm generated by BTkm is synchronized and output.

The one cycle designation device 510 generates the old 1 cycle designation signal P4 when the continuous-1 cycle designation switch 427 is switched to 1 cycle designation, and its output is connected to the motor drive circuit 513. It is connected to the input side of the AND circuit 512a.

The start/stop designation bag @511 operates in conjunction with the start/stop switch 441 provided on the head 440, and when a start is instructed, the ``L'' is activated, and when a stop is instructed, the ``L'' is activated.

A starting/stopping position MP5 of W'' is generated.

The motor control circuit 512 inputs the low speed command signal P3 of the end detection circuit 509, the output of an AND circuit 512a which inputs the output of the one-cycle designated bag WI510, and the start/stop designated bag N.
511 and the output of the needle position detector 502 are input. In this motor control circuit 512, the continuous-1 cycle designation switch 427 is switched to 1 cycle designation,
In addition, when the end detection circuit 509 generates the low speed command signal P2, the start/stop designation device 511 is reset in response to the counting stop signal or the needle down stop signal at the third stitch of the low speed command signal P2, and the sewing machine motor 111 is stopped. It is provided.

Motor drive circuit 513 controls the speed and starts and stops sewing machine motor 111 based on the output signal of motor control circuit 512.

Next, the operation of the above embodiment will be explained.

When the power (not shown) is turned on and the operator operates the operation key 426, the pattern number of the stitch pattern desired by the operator is set in the pattern selection device 503. When the start/stop switch 441 is turned on, the stitch forming mechanism 100, cloth feeding mechanism 200, needle bar swinging mechanism 300, and electric control device 500 operate to sew a desired stitch pattern onto the work cloth.

A) Continuous - When the 1 cycle designation changeover switch 427 is set to continuous, for example, suppose that one cycle of the stitch forming pattern selected by the pattern selection device 503 consists of n stitches (the (See Figure 5).

The stitch data memory 505 generates a low speed command code from two stitches before the final needle code (nth stitch data) [(n-2)th stitch data] and detects the end.

The circuit 509 generates the "old" low speed command signal P3 from two stitches before the final needle code. At this time, since the one-cycle designation device 510 is generating an output of "tow", the AND circuit 512a remains "LOW". Therefore, the sewing machine motor 111 is continuously driven without decelerating or stopping.

The stitch data memory 505 generates a final stitch code in response to successive outputs of the n-th stitch data (final data), and the end detection circuit 509 generates an "old" final stitch signal P2. Data reading device 5 by output of “Old”
04 loads the start address, and the stitch pattern is repeated.

The feed data DF in the stitch data memory 505 generates a zero feed code from the (n-1)th stitch data 1 one stitch before the final data. As a result, the feed amount of the cloth feed mechanism 200 is set to zero from one stitch before the end of one cycle of the stitch pattern, so the last feed amount of the stitch pattern and the first feed amount of the next stitch pattern is set to zero, and the final needle position of one cycle of a stitch pattern and the first needle position of the next pattern are at the same position with respect to the feeding direction. When stopping the sewing machine 1, turn off the start/stop switch 441.
The sewing machine 1 stops at a predetermined counting stop position or needle down stop position depending on the selection state of the needle position changeover switch 443 and the needle position detector 502.

B) When the continuous - 1 cycle designation switch 427 is set to 1 cycle designation, for example, suppose that 1 cycle of the stitch pattern selected by the pattern selection device 503 consists of n stitches ( (See Figure 5).

The stitch data memory 505 generates a low-speed command code from two stitches before the final needle code, which is the nth stitch data, and the end detection circuit 509 generates a low-speed command code from two stitches before the final needle code, which is the nth stitch data.
A low speed command signal P3 is generated.

At this time, since the one-cycle designation device 7510 is generating the "old" output, the AND circuit 512a outputs the output of "H Bi" to the motor control circuit 512. 'It i'
As a result, the motor drive circuit 513 is instructed to decelerate the sewing machine motor 111, and the AND circuit 51
The sewing machine motor 111 is stopped at a predetermined needle up stop position or needle down stop position according to the selected state of the needle position changeover switch 443 and the needle position detector 502 at the third stitch after 2a is set to "old". It is output to the motor drive circuit 513 (FIG. 4 shows the case where accounting is stopped).

The stitch data memory 505 generates a final stitch code by reading the final data, and the end detection circuit 509 outputs "Hi".
The final needle signal @P2 is generated. This final needle message @P1 “
The data reading device 504 loads the start address by outputting 'lli'.

The feed data DF in the stitch data memory 505 generates a zero feed code from one stitch before the final stitch code. As a result, the feed amount of the cloth feed mechanism 200 is set to zero from two stitches before the end of one cycle of the stitch pattern, so the last feed of the stitch pattern is set to zero, and the feed amount of the cloth feed mechanism 200 is set to zero. Sewing machine 1 stops with the feed amount set to zero. Therefore, when restarting after selecting a new pattern, etc., the feed amount of the fabric feed mechanism 200 is set to zero until the first feed change permission signal FT is generated. The work cloth is not transferred from the stop position of the sewing machine 1, the sewing start position is prevented from shifting, and the stitch can be reliably formed from the position desired by the operator.

□ Next, another embodiment of the present invention will be described based on FIG. 6.

In this embodiment, a zero feed switching device @520 is provided between the latch 506 and the feed drive circuit 507 of the previous embodiment. This zero feed switching device 520 includes a zero feed data generating device 521, a multiplexer 522, and a multiplexer switching circuit 523.

The zero feed data generation device 521 outputs zero feed data DZ in which the feed amount of the work cloth by the cloth feed mechanism 200 is set to zero.

The multiplexer 522 has boats PA and PB, inputs the zero feed data DZ output from the zero feed data generator 521 to the boat PA, inputs the feed data OF output from the latch 506 to the boat PB, One of the ports PA and PB is selected by the output of the multiplexer switching circuit 523 to output the input data.

The multiplexer switching circuit 523 is connected to the pattern selection device 503.
, termination detection circuit 509, one cycle designation device M510
, and is provided to input the output signal from the start/stop designation device 511 and to switch between the input ports PA and PB of the multiplexer 522. The one-shot multivibrator 523a receives the low-speed command signal P3 of the termination detection circuit 509.
The one-shot multivibrator 52 generates a pulse signal of a predetermined width by being triggered by the rising edge signal of
3b is triggered by the "old" rising signal of the startup stop signal P5 of the startup stop designation device 511 and generates a pulse (number n) of a predetermined width. , the output of the one-shot multivibrator 523b is inputted.The J-type flip-flop 523d is a well-known type, and the output of the one-shot multivibrator 523a is inputted to the J terminal, and the output of the OR circuit 523C is inputted to the However, once the "old" output is input to the J terminal, the "old" output state is maintained, and once the "old" output is input to the K terminal, it is reset and the output state is 'tow'. Hold.AND circuit 52
30 inputs the 1 cycle designation signal P4 of the one cycle designation device 510 and the output of the type flip-flop 523d to J-, and the 1 cycle designation signal @P5 and the type flip-flop 523d to J- are both "old". When generating an output signal, it generates an 'old' output. The multiplexer 522 selects the boat PA by causing the AND circuit 523e to generate an 'old' output. That is, the continuous -1+j cycle designation switch 427 is set to 1 cycle,
In addition, two stitches before the end of one cycle of the stitch pattern (n-2), the sewing machine motor 111 decelerates in response to the low speed command signal P3.
At the third stitch, the sewing machine motor 111 stops at a predetermined needle stop position or needle down stop position according to the needle position changeover switch 443 and the needle position detector 502.

The next feed change permission signal F when the low speed signal P3 is set to “old”
When T occurs, two stitches before the end of one cycle),
The AND circuit 523e becomes "Ili", the multiplexer 522 selects the boat PA, and the feed amount of the cloth feed mechanism 200 is set to zero. Therefore, the final addition of the seam pattern:
The sewing machine 1 stops with the feed amount of r cloth being set to zero and the feed port of the cloth feed mechanism 200 being set to zero. When the sewing machine 1 is restarted or a new stitch pattern is selected, the type flip-flop 523d is reset to J-, and the multiplexer 522 selects the boat PB, until the first feed change permission signal @FT is generated when the sewing machine 1 is stopped. During this period, the feed amount of the cloth feed mechanism 200 is set to zero, so when the sewing machine 1 is restarted, the workpiece cloth is not transferred from the stop position of the sewing machine 1 and the sewing start position is This prevents the stitch from shifting and allows the worker to reliably form the seam from the desired position.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electric control device showing an embodiment of the feed control device of a sewing machine according to the present invention, FIG. 2 is a schematic diagram of a stitch forming mechanism, FIG. 3 is a front external view of the sewing machine, and FIG. A time chart, FIG. 5 is a table showing an outline of data for forming a stitch pattern stored in the stitch data memory, and FIG. 6 is a block diagram of an electric control device showing another embodiment of the present invention. It is.

Claims (1)

[Scope of Claims] 1) A sewing needle that performs vertical reciprocating motion as the main shaft driven by the sewing machine motor rotates and is attached so as to be able to swing in the horizontal direction, and processing that is synchronized with the vertical reciprocating motion of the sewing needle. A feeding device that applies a feeding movement with a variable feed amount to the cloth, and a pattern selection device that selects a desired pattern from among a plurality of decorative patterns formed by controlling the swinging position of the sewing needle and the feeding movement of the feeding device. , a detection means for detecting the end of the selected decorative pattern, and a stop means for stopping the sewing machine motor in connection with the end detection by the detection means, and completion of one cycle of formation of the decorative pattern. In a zigzag sewing machine in which the sewing machine motor automatically stops later, the feed amount of the feed device is set to zero in connection with the end detection by the detection means, and the set state is maintained until a new pattern is selected by the pattern selection means. A feed control device for a sewing machine, characterized in that a zero feed setting means is provided.