JPS5827589A - Drive controller of cycle 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 Technical Field The present invention relates to a cycle sewing machine that completes a sewing operation such as sewing a button hole in a cycle corresponding to the required number of stitches, and particularly relates to a cycle sewing machine that completes a sewing operation such as sewing a button hole, etc. The present invention relates to a drive control device for a cycle sewing machine that can temporarily switch to a low-speed drive state immediately before the end of a sewing cycle and then automatically stop driving the sewing machine.

Conventional technology Conventionally, in this type of cycle sewing machine, the drive control device that controls one sewing operation has a mechanism that changes the rotation ratio of a rotary disk to the number of stitches to control cycle stitches such as button hole opening and sewing with respect to the main shaft of the sewing machine. The number of stitches required for one sewing operation of the button hole is set by changing the rotation ratio as appropriate using a rotation ratio changing means consisting of a gear, etc.
Further, a single cam piece having a deceleration cam portion and a stop cam portion integrally formed is fixed to the first turntable, and the sewing machine, which is in a high-speed driving state, is operated at high speed due to the action of the deceleration cam immediately before the end of one sewing cycle. The sewing machine is first switched to a low-speed drive state, and then the drive of the sewing machine is automatically stopped based on the action of the ray-stop cam section. There was a drive control device that was able to reduce the impact force.

However, in this drive control device, since the rotation angle ratio between the high-speed drive section and the low-speed drive section of the sewing machine in the rotary disk is constant, the rotation ratio changing means changes the rotation ratio of the rotary disk to the machine main shaft. When the number of stitches in the button hole Kaga9 is set to be small, the low speed Tt of the sewing machine that occupies one sewing cycle is inversely proportional to the rotation ratio. X1lE! The problem was that it took an hour longer, reducing work efficiency.

On the other hand, if the rotation ratio is increased and the number of buttonhole stitches is set to be small, the low-speed driving time will be shortened, making it impossible to reduce the impact caused by the sudden stoppage of the sewing machine. There was a risk of damage to various parts of the sewing machine.

Therefore, in order to solve the above problem, the applicant replaced the single cam piece consisting of the deceleration cam part and the stop cam part,
An independent deceleration cam piece and a stop cam piece are provided, the stop cam piece is fixed to the rotary disk, and the deceleration cam piece is attached to the rotary disk so that its position can be adjusted in accordance with the change in the number of stitches of cycle sewing. We have previously filed an application for a cycle sewing machine that can improve work efficiency by keeping the deceleration drive time almost constant just before the sewing machine stops.

However, in this cycle sewing machine, the installation position of the deceleration cam piece must be adjusted every time the number of stitches is changed, and this work is troublesome.

Purpose This invention has been made in order to solve the above-mentioned problems, and its purpose is to adjust the deceleration drive time of the sewing machine in response to changes in the number of stitches in cycle sewing without making any operation noise. This cycle sewing machine has excellent durability by being able to keep the deceleration drive time almost constant just before it stops, improving work efficiency, and reducing the impact force caused by sudden stopping operations of the sewing machine. to provide drive control devices for

EXAMPLE Hereinafter, an example in which the present invention is embodied in an industrial buttonhole sewing machine, which is a type of cycle sewing machine, will be described with reference to the drawings.

In FIG. 1, a sewing machine main body s2 is rotatably supported on a sewing machine frame 1, and a moving vehicle 3 and a shuttlecock 4 are provided at one end thereof. The belt 5 can be replaced with the moving vehicle 6 and the armature 4, respectively, and drives and connects the movable vehicle 6 or the armature 4 to a motor 6 whose speed can be changed. In this embodiment, the motor 6 is a pole-switching induction motor, and its polarity is switched and controlled by a control circuit to be described later, and the sewing machine main shaft 2 is rotated at a low speed of 90 Or, p, m and a high speed of 360 Or, plm. The rotation is controlled in two states of rotation.

A worm 7 is attached to the other end of the main shaft 2 of the sewing machine, as shown in FIG. The worm foil 9, which is fixed to the worm wheel 9, is engaged with the worm wheel 9. The first needle number changing gear 10 is detachably attached to the other end of the first rotating shaft 8. The second rotating shaft 11 is arranged parallel to the first rotating shaft 8, and a second stitch number changing gear 12 that meshes with the first stitch number changing gear 10 is removably attached to one end of the second rotating shaft 11. At the same time, a rotary disk 16 is fixed to the other end.

The rotary disk 16 is connected to the sewing machine main shaft 2 via the worm wheel 7, the worm wheel 9, and the second and second stitch number changing gears 10.12, and as the sewing machine main shaft 2 rotates,
- It is designed to rotate once every sewing cycle. Further, the rotation ratio changing means is constituted by the first and second stitch number changing gears 10.12, etc., and by appropriately replacing both gears 10.12 with gears having different numbers of teeth, the sewing machine main shaft 2 The rotation ratio of the rotary disk 16 relative to the rotation speed can be changed.

A heart-shaped positive cam 14 is provided at the center of the surface of the rotary disk 16, and a cam follower 15 is engaged with the positive cam 14. And that cam follower 1
5 is reciprocated following the change in the cam surface based on the rotation of the rotary disk 16, and the reciprocating movement is transmitted to the double feed 9 through an appropriate transmission mechanism.
As a result, the feed force is applied to the work cloth according to the rotational speed of the rotary disk 16, and the rotation ratio of the rotary disk 16 to the main shaft 2 of the sewing machine is changed as described above. Based on the change, the feed speed of the work cloth is changed and the number of stitches for button holes is changed.

Further, a stop cam piece 16 for stopping the rotation of the sewing machine main shaft 2 is fixed to the surface of the creation rotary disk 16 with a screw 17, and the stop cam piece 16 is fixed at a predetermined angle counterclockwise with respect to the cam piece 16. A permanent magnet 18 is attached at a distance. The first and second sensors 19 and 20 as signal generating means are magnetic sensing elements such as Hall elements, and are connected to the rotary disk 16.
The second sensor 20 is located at a predetermined position on the sewing machine frame 1 so as to face the permanent magnet 180 and detect the rotational passage of the permanent magnet 180. The first sensor 19 is spaced from the second sensor 2 by a predetermined angle Tα in the clockwise direction with respect to the magnet 18.
0 in the clockwise direction by a predetermined angle Tβ. Therefore, when the rotary disk 16 is rotating counterclockwise, the first sensor 19 detects the rotational passage of the permanent magnet 18, and then the second sensor 20 detects the rotational passage of the permanent magnet 18 for a predetermined period of time (the rotary disk 1
6), the rotational passage of the surface magnet 18 is detected.

As shown in FIG. 1, a stop lever 21 serving as a drive stop means is rotatably supported by a support 22 on the sewing machine frame 1 via a pin 23, and is rotated by a tension spring 24 in the same figure. It is biased to rotate clockwise. A belt changing arm 25 is protruded from one side of the stop lever 21 so that one end of the belt 5 can be changed between the movable vehicle 6 and the free arm 4. A rotating arm 27 is rotatably supported at one end of the lever 21 via a pin 26. On one side of the rotating arm 27 is a projection 2 that can be engaged with a notch (not shown) formed on the outer surface of the moving vehicle 6.
8 is formed, and when engaged, the sewing machine main shaft 2 is stopped at a fixed position.

The pull rod 29 is disposed on one side of the stop lever 21 so as to pass through a guide body 60 rotatably supported with respect to the stop lever 21 and a part of the lever 21, and one end thereof is connected to the stop lever 21. It is supported by the other end of the rotating arm 27 so as to be relatively rotatable. In addition, a compression spring 61 is wound between the lower end of the thin wire drawing rod 29 and the guide body 60, so that the impact applied to the rotating arm 27 when the sewing machine main shaft 2 is stopped at a fixed position does not reach the stop L/bar 21. It has become.

The latch lever 32 as a holding means is attached to the sewing machine frame 1.
It is rotatably supported by an upper support 66 via a pin 64, and biased to rotate clockwise in FIG. 1 by a tension spring 65. A protrusion 66 is provided on one side edge of the latch lever 62 and engages with the stop cam piece 16 as the rotary disk 16 rotates counterclockwise. On the other hand, a hook portion 67 is formed on the other side of the lever 62, and an engaging protrusion 67 is formed on the locking lever 21.
8. And sewing machine master 1Il12
When the rotation is driven, the hook portion 67 is engaged with the engagement protrusion 68, and when the rotation is stopped, the hook portion 67 is disengaged from the engagement protrusion 68, as shown in Figure 1.

The construction 111 lever 69 is the support 40 on the sewing machine frame 1.
is rotatably supported via a pin 41, and a tension spring 42
It is urged to rotate clockwise, and is always engaged with a stopper 45 provided on the sewing machine frame 1 to be stopped at a predetermined rotational position. An operating pedal 45 is connected to one end of this operating lever 69 via a stopper 44, and the lower end protrusion 2 of the surface line stop lever 21 is connected to the other end.
A protrusion 46 is formed to engage with 1a. and,
The operating lever 69, the operating pedal 45, etc. constitute an operating means, and when the operating lever 69 is rotated counterclockwise based on the depression of the pedal 45, the protruding portion 46 of the lever 69 stops. Rotate the lever 21 clockwise. Then, as the stop lever 210 is rotated, the belt replacement arm 25Fi moves the belt 5 from the free arm 4 to the movable vehicle 6.
The hooks are now replaceable.

Micro switch 47 is the sHKeRWm lever! +
The actuator 47a of the switch 47 is pressed 1 by the lower edge of the lever 69 as the lever 69 rotates counterclockwise. In this embodiment, the timing at which the actuator 47a is pressed and the microswitch 47 is turned on is when the actuating lever 69 is rotated slightly when the belt 5 is completely switched from the armature 4 to the movable vehicle 6. It is now possible to do so.

Next, the electric control circuit of the industrial buttonhole/kari sewing machine constructed as described above will be explained.

In FIG. 4, a first flip-flop circuit (
(hereinafter referred to as the -OFF circuit) 51 is the initial set circuit 5
2, an on signal from the micro switch 47, and a detection signal from the second sensor 20 are input. The forward FF circuit 51 is initially set to the initialization signal of the initial setting circuit 52 so that the output signal S01, 011E, and C of its output terminal Q is at the L level), and in the initial setting state, the microswitch 47 is turned on. When a signal is input, the output signal 8G1 has a positive potential (hereinafter referred to as H level).
become. Further, the FF circuit 51 is connected to the microswitch 47.
When the detection signal from the second sensor 20 is input in the state where the ON signal is input, the sensor is turned on,
Output signal SG1 goes from ■ level to L level and null.

A second flip-flop circuit (hereinafter referred to as a second OFF circuit) 56 receives an initialization signal from the initial set circuit 54 and a detection signal from the first and second sensors 19 and 20. The FF circuit 53 receives the initialization signal from the initial set circuit 54, and the output of its output terminal Q goes high.
When the detection signal of the first sensor 19 is input in the initial set state, the output of the output terminal Q becomes L level. Further, when the detection signal from the second sensor 20 described in 1iiiI is input in the state where the detection signal from the first sensor 19 is input, the FF @ path 53 is reset, and the output from the output terminal Q is reset. changes from L level to H level.

The first photocoupler 55 is composed of a light emitting diode 55a and a phototransistor 55b, and the cathode terminal of the light emitting diode 55& is connected to the second F through a resistor 56.
It is connected to the output terminal Q of the F circuit 53. In the first photocoupler 55, when the output of the second FF circuit 53 is at L level, its light emitting diode 55 & emits light, the phototransistor 55b is turned on, and conversely, the output of the FF circuit 53 becomes H.
At the level, the light emitting diode 55a does not emit light and the phototransistor 55b is turned off.

The second photocoupler 57 is also composed of a light emitting diode 57B and a phototransistor 57b, and the cathode terminal of the light emitting diode 57B is connected to the output terminal Q of the FF circuit 56 via a resistor 58 and a NOT circuit 59. has been done. The second photocoupler 57 performs the opposite operation to the first photocoupler 55, and when the output of the second OFF circuit 56 is at L level, its light emitting diode 57 & does not emit light, and the phototransistor 57b is turned off. Further, when the output of the circuit 56 is at H level, the light emitting diode 57B emits light and the phototransistor 57b is turned on. In addition, n ■ phototransistor 5
A resistor 60.61 is connected between 5b and 57b.

The differential amplifier circuit 62 has an inverting input terminal connected to the resistor 60.
61, and its non-inverting input terminal is grounded via a resistor 66. A charging/discharging capacitor 64 is connected between the inverting input terminal and the output terminal of the differential amplifier circuit 620, and is connected between the differential amplifier circuit 620 and the resistor 6.
0.61 etc. constitutes a kind of integration circuit. and,
When the phototransistor 55b is turned on and the phototransistor 57b is turned off, the phototransistor 55
The current flowing through the resistor 60 and the capacitor 64
is charged, the phototransistor 57b becomes operational, and the difference lIl! ] The output voltage Vout of the amplifying circuit 62 gradually decreases as shown in FIG. 5(a). Subsequently, when the phototransistor 55b is turned off from the charged state of the capacitor 64 and the phototransistor 57b is turned on, the capacitor 64 transfers the charged charge to the resistor 61 and the phototransistor 57.
b, the output voltage Vout of the differential amplifier circuit 62.

gradually increases as shown in FIG. 5(a).

The output voltage Vout of the differential amplifier circuit 62 is input to the comparator circuit 65 through a resistor 66 to its inverting input terminal.

A non-inverting input terminal of the comparator circuit 65 is connected to a variable resistor 68 for setting a reference voltage via a resistor 67, and is configured to input the reference voltage vth. The comparison circuit 65 is shown in FIG. 5(a).

As shown in (b), the output voltage Vout is the reference voltage vt
When the voltage is larger than h, the output voltage V% ratio is output at H level, and when it is smaller than h, the output voltage V% ratio is output at L level.

Both anode terminals of the first and second diodes 69 and 70 are connected to each other, and a positive power supply Vcc is applied through a resistor 71. The cathode terminal of the first diode 69 is connected to the output terminal of the comparison circuit 65, and the cathode terminal of the second diode 70 is connected to the output terminal of the transistor 76, which is connected to the power supply Vcc via the collector terminal return resistor 72. connected to the base terminal. As shown in FIGS. 5(b) and 5(C), when the output voltage of the comparator circuit 65 is at the V#fL level, the resistor 71
Since the current flowing through the comparator circuit 65 flows through the first diode 69, the transistor 76 is turned off and the output signal 8G2t-5 at H level is output through the resistor 71 when the output voltage Vo is at H level. Since the current flows through the second diode 70 to the base terminal of the transistor 760, the transistor 76 is turned on and outputs an L level output signal 5G2f:.

The NOR circuit 74 receives the output signal SG2 of the transistor 76.
and the output signal S01 of the -th OFF circuit 51,
An output signal outputted based on the Ryokawa power signal SG1, 802 is outputted to the base terminal of the transistor 77 via the resistor 76. Therefore, only when the L level output signal 8 (3i, 8G2) is input to the NOR circuit 74, the transistor 7
7 is turned on.

4. An electromagnetic relay 78 as a switch is connected to the collector terminal of the transistor 77, and when the transistor 77 is turned on, the relay 78 is energized and closes the normally open contact 78&, and the normally closed contact 78b. open the circuit. One end of each normally open contact 78B is connected to a three-phase AC power source via a power switch 79.1. The other ends are respectively connected to the low speed windings (8 poles) of the motor 6. Further, one end of the normally closed contact 78b is connected to a three-phase AC power source via a power switch 79, and the other end is connected to a high-speed stator winding (two poles) of the motor 6, respectively. Then, when the electromagnetic relay 78 is de-energized at the 4th point, three-phase AC! The motor 6 rotates at a high speed, and the sewing machine main shaft 2 is rotated at a speed of 360 Or, p, m since the sewing machine is supplied to the high-speed stator winding through the normally closed contact 78b. Further, when the electromagnetic relay 78 is energized,
Since the three-phase AC power is supplied to the low-speed stator winding through the normally open contact 78B, the motor 6 rotates at a low speed and rotates the sewing machine main shaft 2'f, 900r, pom. It has become.

In addition to supplying three-phase AC power to the motor 6, the power fjt large switch 79 also supplies the initial set time li! 5
Operating power is output at 2.54, and when the switch 79 is turned on, an initialize signal is output from the set circuits 52.54.

Next, the operation of the industrial buttonhole sewing machine constructed as described above will be explained.

Now, press the power switch 79 from the state shown in FIG.
Since the circuits 51 and 54 are initially set and the L level output signal 8G1°8G2 is input to the NOR circuit q4,
Transistor 77 is turned on and electromagnetic relay 78 is energized. Then, as the electromagnetic relay 78 is energized, the normally open contact 78B is closed and the normally closed contact 78b is opened, so the motor 6 starts rotating at a low speed and rotates the armature 4 via the belt 5.

Subsequently, when the operating pedal 45 is depressed, the stop lever 21 is rotated clockwise via the operating lever 69, and the belt 5 is switched from the free arm 4 to the movable vehicle 3. By changing the belt 5 on the moving wheel 6, the main shaft 2 of the sewing machine has a torque of 90 Or.

pom and the turntable 16 is rotated counterclockwise, and buttonhole overlocking is first started at a low speed. When the operating pedal 45 is further depressed, the operating lever 69 further rotates counterclockwise, and the rear end of the lever 69 turns on the microswitch 47f.

-OFF based on the ON operation of the micro switch 47
When the circuit 51 performs an inversion operation and the output signal 8Gi becomes H level, the transistor 77 is turned off. When the electromagnetic relay 78 is de-energized, the normally closed contact 78a is opened and the normally closed contact 78b is closed. Therefore,
Since AC power is supplied to the high-speed constant winding of the motor 6, the motor 6 rotates at both speeds, and the button hole stitching changes from a low speed to a high speed.

On the other hand, as the rotary disk 16 rotates counterclockwise, the projection 66 of the latch lever 32 and the stop cam piece 16 are disengaged, and the latch lever 62 is rotated clockwise by the tension spring 65. Therefore, the hook portion 67 of the lever 62 is brought into engagement with the engagement protrusion 68 of the line stop lever 21. Therefore,
Even if the operating pedal 45 is released in this state, the stop lever 45
1 is restricted from rotating in the counterclockwise direction, and the main shaft 12 of the sewing machine does not stop until the buttonhole stitching is completed.

When the rotary disk 16 further rotates in this state, the first sensor 19 eventually detects the passage of the permanent magnet 18 on the rotary disk 16 and outputs a detection signal to the second OFF circuit 53. The second OFF circuit 56 performs an inverting operation in response to this detection signal, turns on the first photocoupler 55, and turns off the second photocoupler 57, and the capacitor 64 starts charging. As the capacitor 64 is charged, the output voltage VouL of the differential amplifier circuit 62 gradually decreases as shown in FIG.
When the output voltage of the comparator circuit 65 is below V.

becomes L level, and the output signal S02 becomes H level. Therefore, at this point, the transistor 77 is not turned on, and the buttonhole stitching is performed at the read speed operation.

Then, the rotary disk 16 further rotates, and the permanent magnet 18
passes in front of the second sensor 20, the second sensor 20
detects the passage of the magnet 18 and outputs a detection signal to the first and second OFF circuits 51 and 55. -OFF circuit 5
1 performs an inversion operation in response to this detection signal, and outputs an L-level output signal SG1 to the NOR circuit 74 at the next stage. On the other hand, the second OFF circuit 53 also operates in reverse in response to this detection signal, turning off the first photocoupler 55 and turning on the second photocoupler 57, causing the capacitor 64 to stop discharging. Start. As the capacitor 64 starts discharging, the output voltage Vout of the differential amplifier circuit 62 gradually increases as shown in Figure 5). However, at this point, the output voltage Vout is smaller than the reference voltage vth, and the output of the comparator circuit 65 remains at the L level, so the output signal SG2 output to the NOR circuit 74 is currently held at the H level. Therefore, the transistor 77 cannot be turned on, and the button hole stitching continues to operate at high speed.

When a predetermined period of time has elapsed after the start of discharge of the capacitor 64, that is, when the turntable 16 reaches just before one revolution, the output voltage VouL of the differential amplifier 62 reaches the reference voltage vth as shown in FIG. 5(a). Comparison circuit 6
The output voltage Vo of No. 5 becomes H level. Then, the transistor 73 at the next stage is turned on, and the output signal 8()2 output to the NOR circuit 74 changes from the H level to the L level. When the output signal 8G2 of the KL level is input to the NOR circuit 74, the next stage transistor 77 is turned on and the electromagnetic relay 78 is excited. Therefore, the normally open contact 78& is closed and the normally closed contact 78b is opened, so that the motor 6 is rotated from a high speed to a low speed, and the button hole stitching is operated at a low speed just before the end of sewing.

Then, when the rotation 613 further rotates from this state and the stop cam piece 16 on the facing plate 13 engages with the protrusion 66 of the latch lever 62, the lever 62 is rotated counterclockwise. When the hook portion 67 of the lever 62 and the engagement protrusion 68 of the stop lever 21 are disengaged, the stop lever 21 is rotated counterclockwise. Therefore, belt 5
The belt is switched from the movable wheel 3 to the free arm 4 by the belt switching arm 25, and the transmission of the driving force to the main shaft 2 of the sewing machine is cut off.
The latch lever 32 (7) is stopped in a state where it is engaged with the protrusion 36, and the sewing of the button hole is completed. When it is time to sew the next button hole, the user depresses the operating pedal 45 again, and the button hole sew is completed in exactly the same manner as described above.

As described above, in this embodiment, the timing at which the sewing machine shifts from high-speed drive to low-speed drive immediately before the end of button hole stitching is as follows:
It is determined by the charging time and discharging time of the capacitor 64, and the start of charging and the start of discharging are performed based on the detection of the passage of the permanent magnet 18 on the rotary disk 13 by the first and second sensors 19 and 20. Therefore, when changing the gear ratio of the first and second stitch number changing gears 10.1''2 to increase the rotational speed of the rotary disk 16, the number of stitches in the button hole or the hook can be reduced. In this case, the time for the permanent magnet 18 to rotate from the first sensor 19 to the second sensor 20 is not short, and the charging time is shortened.In other words, by reducing the number of stitches, the rotation of the rotary disk 13 is As the speed increases, the discharge starts earlier.As a result, the time for the output voltage Vout of the differential amplifier 62 to reach the reference voltage 'vth or more also becomes earlier, so the sewing machine The low-speed driving time immediately before the main @2 stops is approximately the same as in the above embodiment.On the other hand, when the rotational speed of the rotary disk 13 is slowed down and the number of stitches in the button hole stitching is increased, teeth,
The start of discharge is delayed. Therefore, the time for the output voltage Vout of the differential amplifier circuit 62 to reach the reference voltage vth or higher is delayed, so that the low-speed driving time immediately before the main shaft 2 of the sewing machine stops is approximately the same as in the embodiment described above, even though the number of stitches is increased. becomes.

Therefore, unlike conventional methods, there is no need to adjust the deceleration drive time of the sewing machine in response to changes in the number of stitches for tightening the buttonholes, and the sewing machine can be stopped immediately. The deceleration drive time in ff can be kept almost constant regardless of the change in the number of stitches, improving work efficiency and reducing the impact force caused by sudden stopping operations of the sewing machine. .

Note that the present invention is not limited to the thin wire embodiment, and the micro switch 47 may be mounted in a position such that, for example, the motor 6 immediately rotates at high speed as soon as the operation pedal 45 is depressed, and the sewing machine main shaft 2 is driven at high speed. The relative mounting of the first and second sensors 19, 20 and the permanent magnet 18 may be changed as appropriate without departing from the spirit of the present invention, such as by changing the positions as appropriate.

Effects As detailed above, according to the present invention, the deceleration drive time of the sewing machine can be adjusted in response to changes in the number of cycle sewing stitches.
There is no need to perform adjustment work, and the deceleration drive time immediately before the sewing machine stops can be kept constant, improving work efficiency and reducing the impact force caused by sudden stopping of the sewing machine. This makes it possible to create a cycle sewing machine with excellent durability.

[Brief explanation of the drawing]

Fig. 4 is a front view of the main parts of an industrial button hole sewing machine embodying the present invention, Fig. 2 is a perspective view showing the state of connection between the main shaft of the sewing machine and the rotary disk, and Fig. 3 is a front view of the rotary disk. , Figure 4 is an electrical circuit diagram, M5 diagrams (a) and (b). (0) is a waveform diagram of the output voltage, and FIG. 6 is a rotation speed curve diagram of the main shaft of the sewing machine. Sewing machine frame 1, sewing machine main fI12, moving vehicle 3, army 4
, a motor 6 as an electric motor, first and second needle number changing gears IO, 12 as rotation ratio changing means, rotary disk 16, stop cam piece 16, permanent magnet 18, first and second as signal generating means. sensor 19°20, a stop lever 21 as a drive stop means, a latch lever 62 as a holding means,
An actuation lever 69 as an actuation means, as well as an operation pedal 4
5. A microswitch 47 as a first control means, a first flip-flop circuit 51, a second flip-flop circuit 56, and second and second photocouplers 55,5.
7. Differential amplifier circuit 62, capacitor 64, comparison circuit 6
5. Transistor 73.77, NOR circuit 74, electromagnetic relay 78° as a switch Patent applicant Brother Industries, Ltd. Representative Patent attorney Hironobu Onda Figure 3

Claims (1)

[Claims] 1. A sewing machine main shaft (2), an electric motor (6) with a speed switching gradient for driving the sewing machine main shaft (2) at high and low speeds, and a motor (6) connected to the electric motor (6). , a switch (78) for switching the electric motor (6) between a high-speed drive state and a low-speed drive state, and a switch (78) provided between the electric motor (6) and the sewing machine main shaft (2), the electric motor (6) The rotation of the sewing machine main shaft (2)
and a stop position for stopping the sewing machine main shaft (2) in the normal position tK at the same time as the transmission is cut off. drive stop means (21), and actuation means (39, 4) for switching the drive stop means (21) to the drive position at the start of a sewing cycle;
5), a holding means (52) for holding the drive stop means (21) switched in accordance with the operation of the actuating means (39, 45) at the nJ marking drive position, and the actuating means (39, 45); 4
first control means (47, 51) for switching the switch (78) to the high speed drive state in response to the operation of
), a rotary disk (16) that rotates in conjunction with the sewing machine main shaft (2) to control cycle sewing, and the rotary disk (1
6) and the sewing machine main shaft (2), for changing the rotation ratio of the rotary disk (16) to the sewing machine main shaft (2) to change the number of stitches in one sewing cycle. a changing means (10, 12), which is provided on the rotary disk (16) and releases the holding action of the holding means (62) at the end of the -M! cycle and stops the drive stopping means (21) at the normal position; a stop cam piece (16) for
) from high speed to low speed, the rotary disk (16
) signal generating means (19) for generating a signal responsive to the speed of the
, 20), and the signals from the signal generating means (19, 20) are input, and the sewing machine main shaft (2) is driven at low speed before stopping, regardless of the change in the number of stitches by the rotation ratio changing means (10, 12). The switching means (78) so as to keep the time substantially constant.
1. A drive control device for a cycle sewing machine, comprising second control means (55, 57, 62, 64, 65, etc.) for setting the timing of switching to a low-speed drive state.