JPS5923839B2 - Spindle fixed position stop device for sewing machines - Google Patents

Description

Detailed Description of the Invention The present invention provides a method for fixing the main shaft position in a sewing machine in which the main shaft is driven once at a constant low speed for several revolutions at the end of continuous sewing, and then the main shaft is mechanically stopped at a fixed position. This relates to a stopping device.

Conventionally, a sewing machine in which the main spindle was stopped at a fixed position at the end of continuous sewing work was disclosed in Japanese Patent Publication No. 1973 (1973) by the same applicant.
-1019, but the one described in the above publication does not include a stop lever for disengaging the drive connection between the main shaft and the sewing machine motor and stopping the main shaft of the sewing machine at a fixed position. A restraint means is provided for holding the controller in the operating position, and a constant low speed driving means is provided for driving the main shaft at a constant low speed for several rotations after the pressure of the controller is released, and the pressure of the controller is released. The sewing machine is configured to mechanically detect several revolutions of the main shaft, release the restraining means, move the stop lever to the operating position, and stop the main shaft of the sewing machine at a fixed position, and the mechanical structure is extremely complicated. Because of this, manufacturing and assembly are troublesome and expensive, it is difficult to maintain mechanical precision over a long period of time, and durability is poor.

The present invention has been made in view of the above circumstances, and by releasing the controller operation at the end of a continuous line,
The main shaft is then driven once at a fixed low speed for several rotations, and after that, the main shaft can be reliably stopped at a fixed position, and the main shaft is stopped at a fixed position in a sewing machine that has a simple configuration, can be manufactured at low cost, and is highly durable. The purpose is to provide equipment.

An embodiment of the present invention will be described below with reference to the drawings.

First, referring to Figures 1 and 2, 1 is the sewing machine frame 2.
A main shaft 3 is supported by a pulley into which a first cylinder 4 is inserted, which is connected to a sewing machine motor (described later) via a belt 5, and is driven to rotate once around the main shaft 1 together with the cylinder 4.

Reference numeral 6 denotes a 20th shaft cylinder adjacent to the shaft cylinder 4, which is inserted and fixed to the main shaft 1, and has an outer diameter substantially equal to that of the shaft cylinder 4.

Reference numeral 1 denotes a cylindrical helical spring tightly wound around both shaft cylinders 4 and 6, and one end γa located on the first shaft cylinder 4 side is erected radially outward so that the helical spring 7 The other end 7b is engaged with a groove 6a formed in the second shaft cylinder 6.

Therefore, the rotation of the pulley 3 is always caused by the rotation of the first shaft cylinder 4.
Spiral spring7. The rotation of the pulley 3 is transmitted to the main shaft 1 via the 20th shaft cylinder 6, but when one end of the helical spring 7 is locked by some means, the helical spring 7 is relaxed and the rotation of the pulley 3 is transmitted to the main shaft 1. It is not transmitted and main shaft 1 is stopped.
The spiral spring 7 serves as a spring clutch and also as a stop member connected to the main shaft 1.

Note that 9 is a band wheel fixed to the main shaft 1 by a fixing screw 10, and 11 is a retaining ring for regulating the axial movement of the pulley 3.

On the other hand, reference numeral 12 denotes a stop lever which is pivotally connected to a first support plate 13 fixed to the sewing machine frame 2 by a stepped screw 14, and one arm of the stop lever 12 has an engaging portion 8a formed in the sleeve 8.
A contact portion 12a positioned so as to be able to engage with the middle lever, and an engaging portion 12b bent so as to be able to engage with a claw portion of an intermediate lever (to be described later) are formed on the narrow arm. A guide portion 12b having a bent stepped portion 12c for guiding the movement of the lever is formed.

Reference numeral 15 denotes a tension spring as a spring means stretched between the stop lever 12 and the support plate 13, so that the contact portion 12a of the stop lever 12 is always located on the rotation trajectory of the engagement portion 8a. It has an effect on

When the abutting portion 12a of the stop lever 12 engages with the engaging portion 8a of the sleeve 8, one end 7a of the helical spring 7 is locked, and the main shaft 1 is stopped, the tip of the thread take-up of the sewing machine is The position of the retaining portion 8a is set to be approximately at the uppermost position, and therefore, the needle bar that supports the sewing machine needle at the lower end stops when it reaches a position slightly lower than the uppermost position.

16 is a mounting plate fixed to the sewing machine frame 2 with screws 17, 17, and 18 is a screw 1 attached to the bent portion 16a of the mounting plate 16.
9 and 19 are fixed electromagnetic solenoids; 20 is an intermediate lever that is pivotally connected to the plunger 18a of the electromagnetic solenoid 18 via a synthetic resin plate 21 (see FIG. 3); The intermediate lever 20
It is fixed so that it moves together with the magnetic field, and serves as a magnetic insulating plate.

Further, the intermediate portion of the intermediate lever 20 is provided with the stop lever 1.
A claw portion 20a that can be engaged with the engaging portion 12b of the intermediate lever 20 is formed, and the distal end portion of the intermediate lever 20 engages with the engaging portion 12b of the stop lever 12.
It extends so as to face the thin arm of.

23 is a tension spring stretched between the intermediate lever 20 and the support plate 13, and as is clear from FIG. 13 and the center point of the pivot shaft 22, and always urges the intermediate lever 20 upward and around the pivot point (pivot 22) with the plunger 18a. In the figure, a rotational force is applied in the clockwise direction.

Therefore, one side edge 20b of the intermediate lever 20 engages with the side edge of the bent step 12c of the stop lever 12, and the movement of the intermediate lever 20 is guided.

Further, the guide portion 12d of the stop lever 12 is connected to the intermediate lever 2.
It faces the front end 20c of the intermediate lever 20 from the front in FIG. 1, and restricts the forward movement of the front end of the intermediate lever 20.

Reference numeral 24 denotes a locking lever pivotally connected to the intermediate lever 20 by a pivot 25, and one end of which is connected to the engaging portion 12 of the stop lever 12.
An engaging portion 24a is formed to engage with the shaft pin 2 at the other end.
4b is provided protrudingly.

26 is a second support plate fixed to the sewing machine frame 2 by screws 27, 27; 28 is a second support plate fixed to the sewing machine frame 2 by screws 29;
The operating lever is pivotally supported at the tip thereof, and one arm thereof is formed with a fitting groove 28a into which the shaft pin 24b is slidably fitted.

30 is a changeover switch fixed to the mounting plate 16;
A contact portion 28b is formed on the thin arm of the operating lever 28 and faces the operating protrusion 30a of the changeover switch 30.

Reference numeral 31 denotes a tension spring stretched between the extending portion 28c of the operating lever 28 and the support plate 26, which normally biases the operating lever 28 in the counterclockwise direction and also closes the locking lever via the shaft pin 24b. 24 in the clockwise direction.

Next, referring to FIGS. 2 and 4, reference numeral 32 is a linking lever pivotally connected to the support plate 26 by a step screw 33, and one end of which engages with the extending portion 28c of the operating lever 28; and 34 is a step screw. An operating lever is pivotally connected to the sewing machine frame 2 by a screw 35, and has a pin 3 at one end that engages with the other end of the linking lever 32.
6 is implanted, and the other end is positioned so as to come into contact with an operating pin to be described later, and the operating lever 28 . A rotational force is applied in the counterclockwise direction in FIG. 2 (clockwise in FIG. 4) through the linkage lever 32, and one side edge comes into contact with a stopper pin 40 installed in the sewing machine frame 2, and the sewing machine comes to rest. are doing.

Reference numeral 37 denotes an operation knob as a manual means, which is located on the front side of the sewing machine frame 2 and is attached to the sewing machine frame 2 so as to be rotatable around the support shaft 38. A control knob 37 is provided on the back surface of the sewing machine frame 2 to adjust the zigzag amplitude. A cam groove 3 having a cam surface 39a for setting the zigzag amplitude to zero and a cam surface 39b for holding the zigzag amplitude at zero.
9 is drilled.

Reference numeral 41 denotes an operating pin implanted on the back side of the operating knob 37, and the operating knob 37 is shown in FIG.

It is positioned so that it can come into contact with the operating lever 34 when it is rotated counterclockwise (clockwise in FIG. 4).

Reference numeral 42 denotes a driven arm pivotally connected to the sewing machine frame 2 by a stepped screw 43. A driven pin 44 that fits into the cam groove 39 is implanted in the middle part of the driven arm, and a long hole 42a is bored in the tip part. has been done.

Reference numeral 45 denotes a rotating arm that is fitted and supported on the support shaft 38, and a linking pin 46 that fits into the elongated hole 42a of the driven arm 42 is implanted in the middle part of the rotating arm. A rotating force in the counterclockwise direction in FIG. 2 is applied by the action of the winding spring 47 wound around the shaft.

Therefore, the driven arm 42 is also urged in the same direction and the driven pin 4
4 engages with the cam surfaces 39a and 39b of the cam groove 39.

48 is a zigzag connecting rod whose lower end is connected to the rotating arm 45, and the tip thereof can change the position of a roller that engages with a zigzag swinging arm (not shown), as is well known. It is linked to the corresponding roller.

Further, in FIG. 4, reference numeral 49 denotes an elastic plate fixed to the sewing machine frame 2 by a fixing screw 50, and the bent end portion 49
a is a notch 3 formed on the outer peripheral surface of the operating knob 37;
7a to 37c to position the operating knob 31.

In addition, in Fig. 2, 51 is a cover.

Reference numerals 52 and 53 denote a power switch and a speed changeover switch that are fixed to the mounting plate 16 by screws 54 and 55, and the operation part 53 of this switch 53
The other end of the connecting rod 56, one end of which is connected to a, is slidably connected to an elongated hole 28e formed at the tip of the extending portion 28d of the operating lever 28.

When the operating portion 53a of the switch 53 is switched to the low speed side, the switch 53 is opened and the operating lever 28 is allowed to rotate clockwise and counterclockwise. When is switched to the high speed side, the operating lever 28 is restricted to a counterclockwise rotating position.

Then, when the operating lever 28 is rotated clockwise against the regulating force of the connecting rod 56, the operating portion 53a of the switch 53 is switched to the low speed side via the connecting rod 56 along with the rotation.

Next, the electric circuit in this embodiment will be explained with reference to FIG.

A is the armature winding LA and the field winding L1. This is a sewing machine motor consisting of an electric motor having an armature winding LA, and a noise prevention capacitor C1 is connected to both ends of an armature winding LA.

BR consists of four diodes DBI, DB2. DB3. DB
One of the AC input terminals a of the bridge rectifier circuit BR is connected to the field winding L1 of the sewing machine motor A.

57 and 58 are power terminals connected to an alternating current power supply AC,
One power terminal 57 is connected to the other AC input terminal of the bridge rectifier circuit BR via the power switch 52 and the power line X, and the other power terminal 58 is connected to the power line Y.
It is connected to the field winding L2 of the sewing machine motor A via.

Then, one side a of the feed current input terminal of the bridge rectifier circuit BR
and the positive side d of the DC output terminal, the diode DB3 is connected between
A sweets 53 is connected via.

MCT is the DC output terminal c of the bridge rectifier circuit BR,
d is a sewing machine controller connected through a fixed resistor Rm, and B is a luminaire circuit, for example, a variable speed drive circuit, comprising this controller MCT, the bridge rectifier circuit BR, and the switch 53.

T1 are AC input terminals a and b of the bridge rectifier circuit BR.
TD is a thyristor protection high IJ star connected in parallel to this thyristor T1, and R1 and C2 are thyristor protection resistors connected between the cathode and gate of the thyristor T1. and a waveform shaping capacitor, and GR is a full-wave rectifier circuit connected between the power lines X and Y.

C is a thyristor control circuit that controls the firing angle of the thyristor T1, and its configuration will be explained below.

Trl is an NPN type transistor, its collector is connected to the positive side of the DC output terminal of the full-wave rectifier circuit GR via a resistor Rcl, a variable resistor VRc1, and a bus P, and its emitter is connected to a diode DI of the polarity shown and a capacitor. It is connected to the negative side of the DC output terminal of the full-wave rectifier circuit GR via Cc and bus line N, and a protection resistor R2 is connected between the base and emitter of the transistor TRI.

T2 is a thyristor whose anode is connected to the power line X
, its cathode is connected to the bus line N via a voltage dividing resistor Rd1 and a constant/low speed setting variable resistor VRd, and its gate is connected to the cathode of the diode D10 via a diode D2 with the polarity shown and a resistor Rc2. , and a protective resistor R3 is connected between the gate and cathode.

The variable terminal of the constant low speed setting variable resistor VRd is connected to the gate of the thyristor T1 via a diode D3 of the polarity shown.

C3 is a capacitor connected between the fixed terminals of the constant low speed setting variable resistor VRd, and D is a constant low speed drive circuit as a constant low speed drive means consisting of the thyristor control circuit C having the above configuration and the thyristor T1. It is.

E is an operating circuit for operating this constant low speed drive circuit, and its configuration will be explained below.

Tr2 is a PNP type transistor, its emitter is connected to the bus P, the base is connected to the signal input terminal ST via a resistor R4 and a transistor protection diode D4, and to the bus P via a resistor R5, The collector is connected to the changeover switch 30 having changeover terminals NP and BS via a transistor protection diode D5.

The changeover terminal NP of the changeover switch 30 is connected to the base of the transistor Trl via a resistor R6, and the signal input terminal ST is connected to the positive side d of the DC output terminal of the bridge rectifier circuit BR.

However, the changeover switch 30 changes over between the needle bar fixed position stopping function and the tightening function, and its changeover terminals NP and BS
is used as a terminal for stopping the needle bar in a fixed position and as a terminal for basting.

F is a variable speed drive scale B via the operating circuit E having the above configuration.
This is a solenoid actuating circuit as a circuit means connected to the solenoid actuating circuit, and its configuration will be explained below.

T3 is a thyristor whose anode is the electromagnetic solenoid 1
8 to the bus line P, and its cathode is connected to the bus line N.

DF is a flywheel diode connected to both ends of the electromagnetic solenoid 18.

cb is a capacitor, one of its terminals is resistor Rb1
is connected to the switching terminal BS via a resistor Rb.
2 and the gate of the thyristor T3 through a diode D6 of the polarity shown, and the external force is connected to the gate of the thyristor T3.
connected to the cathode of

Cn is a capacitor, one of its terminals is connected to the switching terminal NP via a diode DI of the illustrated polarity, a resistor Rn1, and a variable resistor VRn1 in series, and the resistor Rn
2 and the gate of said thyristor T3 via a diode DS of the polarity shown;
connected to the cathode of

R7 is a thyristor protection resistor connected between the cathode and gate of the thyristor T3.

The operation of this embodiment having the above configuration will be explained below.

1 to 6 show the positional relationship of each member when the sewing machine is set to the normal continuous edge state, and the operating lever 28 is moved counterclockwise in FIG. 1 by the action of the tension spring 31. The locking lever 24 is rotated to the maximum position, and the locking lever 24 is rotated clockwise in the figure and moved to the operating position.

Therefore, the abutting portion 28b of the operating lever 28 is separated from the operating protrusion 30a of the changeover switch 30, and as shown in FIG. 6, the changeover switch 30 closes the changeover terminal NP side.

In this state, when the power switch 52 is closed, the switch 53 is switched to the high speed side, and the sewing machine controller MCT is pressed to operate, the sewing machine motor A is supplied with power and started with AC power, and then The rotational speed of the sewing machine motor A is controlled by changing the resistance value of the variable resistor of the controller MCT (7) in accordance with the degree of suppression of the controller MCT (7).

On the other hand, when the power line Cn is charged to the illustrated polarity, and based on the conduction of the transistor T r 2 C', the transistor Tr1 is made conductive, and the capacitor Cc is charged to the illustrated polarity.

Simultaneously with the conduction of transistors Tr1 and Tr2, the gate potentials of thyristors T2 and T3 rise, and the thyristors T2 and T3 become conductive, exciting the electromagnetic solenoid 18 and charging the capacitor C3 to the illustrated polarity.

As the thyristor T2 becomes conductive, the gate potential of the thyristor T1 rises to the potential set in the constant low speed setting resistor VRd, but when the controller MCT is activated, the back electromotive force of the sewing machine motor A is applied to the cathode of the thyristor T1. In addition, when the power supply line X is at a positive potential, the cathode potential of this thyristor T1 is higher than the gate potential, so the thyristor T1 continues to be cut off.

Further, when the switch 53 is operated and opened, half-wave rectified power is supplied to the sewing machine motor A, and the sewing machine motor A is rotated at a low speed.
The rotation speed is controlled within a low speed range depending on the degree of suppression of the rotation speed.

Now, when the sewing machine motor A is started by the suppression of the controller MCT, the pulley 3 rotates together with the shaft cylinder 4 via the belt 5, and at the same time, the above-mentioned electromagnetic solenoid 1
8 is energized by the conduction of the thyristor T3, its plunger 18a is drawn downward in FIGS. The locking lever 24 is thereby moved by the locking lever 24 and its shaft pin 24.
b is guided by the fitting groove 28a and moved downward around the pivot shaft 25 with almost no rotation.

Then, as the intermediate shaft 20 moves, the engaging portion 12b
engages with the claw portion 20a and the engaging portion 24a, and the stop lever 1
2 is rotated counterclockwise around the step screw 14 against the biasing force of the tension spring 15, and the contact portion 12a, which is one end thereof, is moved out of the rotation locus of the engagement portion 8a of the sleeve 8.

When the abutting portion 12a of the stop lever 12 is disengaged from the engaging portion 8a of the sleeve 8, the helical spring 7 is tightened, and the rotation of the pulley 3 is transmitted to the main shaft 1, so that the main shaft 1 is activated.

Thereafter, the rotational speed of the main shaft 10 is arbitrarily adjusted depending on the degree of pressure from the controller MCT mentioned above, and normal continuous edge processing is performed.

At this time, the sleeve 8 fitted around the helical spring 7 also rotates together with the main shaft 1 together with the spring 7, but the abutment part 12a of the stop lever 12 Since it is located outside the trajectory, it does not pose any hindrance to the execution of continuous edges.

Further, the zigzag amplitude during continuous sewing can be arbitrarily set by rotating the operating knob 37.

That is, FIGS. 2 and 4 show a state in which the zigzag amplitude is set to zero, and before this state, if the operating knob 37 is turned clockwise (counterclockwise in FIG. 4), , cam surface 39a for zigzag amplitude adjustment of the cam groove 39
The driven arm 42 rotates due to the engagement with the driven pin 44, and the rotating arm 45 is rotated in the clockwise direction in FIG. 2 against the action of the coil spring 47. A desired zigzag amplitude can be obtained by arbitrarily setting the position of the roller with respect to the swing fulcrum of the zigzag swing arm.

Now, as described above, switch the changeover switch 30 to the changeover terminal N.
When switching to the P side and performing a continuous edge (however, the switch 53 can be closed or opened), if the pressure on the controller MCT is released, no signal is supplied to the transistor Tr2 of the operating circuit E, and the circuit is shut off. Along with being
The transistor Tr1, to which signal current is supplied from the transistor Tr2, is also cut off, and the capacitors Cn and C
The charge at c begins to discharge.

On the other hand, when the power to the sewing machine motor A is cut off by releasing the pressure of the controller MCT, the rotation of the sewing machine motor A gradually decreases, and the cathode potential of the thyristor T1 due to the back electromotive force of the sewing machine motor A decreases. The potential becomes lower than the gate potential applied to the thyristor T1, and the thyristor T1 becomes conductive.

When the thyristor T1 becomes conductive, the constant low speed drive circuit operates and drives the sewing machine motor A at a constant low speed.

After a predetermined period of time has passed since the suppression of the controller MCT is released, that is, after the main shaft 1 has rotated several times at a constant low speed, the charges in the capacitors Cn and Cc are discharged and the thyristor T
If the gate potential of thyristors T2 and T3 falls below the firing potential, the thyristors T2 and T3 will be cut off.

Then, the electromagnetic solenoid 18 is demagnetized by the interruption of the thyristor T3, the intermediate lever 20 is returned upward together with the plunger 18a by the biasing force of the tension spring 23, and the stop lever 12 is returned clockwise by the biasing force of the tension spring 15. The abutting portion 12a rotates and the retaining portion 8a
It is returned to the position on the rotation trajectory of.

As a result, the retaining portion 8a of the sleeve 8 rotating together with the main shaft 1 comes into contact with the contact portion 12a of the stop lever 12, relaxing the helical spring 7 and disengaging the driving connection between the pulley 3 and the main shaft 1. The main shaft 1 is stopped in a state in which the thread take-up lever is located, for example, at approximately the uppermost position, and the needle bar reaches a position slightly lower than the uppermost position.

Further, the capacitor Cc is set so that the thyristor T2 is cut off after a predetermined period of time has elapsed after the main shaft 1 is stopped, that is, after the thyristor T3 is cut off, and the thyristor T2 is cut off.
As a result of the cutoff of thyristor T1, the thyristor T1 is also cut off, and power is no longer supplied to the sewing machine motor A, and the sewing machine motor A eventually stops.

That is, after the main shaft 1 stops, the sewing machine motor A rotates the goo +73 at least once, and then stops.

Next, a case in which basting stitches are performed will be explained.

Rotate the operating knob 37 clockwise in FIG. 4 (counterclockwise in FIG. 2) to remove the bent end portion 4 of the elastic plate 49.
If 9a is fitted into the notch 37c of the operation knob 37,
An operating pin 41 implanted in the operating knob 37 contacts the operating lever 34 and rotates the lever 34 from the solid line position to the two-dot chain line position in FIG. 4.

Accordingly, the linking lever 32 is rotated to the position shown in two-dot chain line in the figure, and the operating lever 28 is rotated clockwise against the tension spring 31 from the position shown in FIG. 1 to the position shown in FIG. The contact portion 28b presses the operating protrusion 30a of the changeover switch 30, and the changeover terminal B of the changeover switch 30 is pressed.
The switch is made so that the S side is closed.

As a result of this rotation, the locking lever 24 is rotated counterclockwise, and its engaging portion 24a is moved to a non-operating position away from the engaging portion 12b of the stop lever 12.

At this time, even if the switch 53 is closed in the case of continuous sewing as described above, it is forcibly switched and opened via the connecting rod 56 by clockwise rotation of the operating lever 28. Ru.

7 and 8 show the positional relationship of each member when the operating knob 37 is rotated to the basting position in this manner.

On the other hand, when the operation knob 37 is rotated counterclockwise in FIG. 2, the driven pin 44 engages with the radial cam surface 39b of the cam groove 390, and the driven arm 42 and the rotating arm 45 are rotated as shown in FIG. In the state shown, the hole is aligned with the swing fulcrum of the zigzag swing arm via the zigzag link rod 48, and the zigzag amplitude is set and maintained at zero.

Therefore, even when the sewing machine is operated, the needle bar does not swing.

Therefore, as in the case of continuous sewing described above, the power switch 52 is
When the controller MCT is pressed and operated, the sewing machine motor A is driven at a low speed, and the T of the operating circuit E is activated.
r2 becomes conductive and charges the capacitor cb, and also makes the thyristor T3 conductive and energizes the electromagnetic solenoid 18.

Therefore, the electromagnetic solenoid 18 is activated immediately, and its plunger 18a is sucked downward in FIGS.
The lever 12 is moved around the step screw 14 against the action of the tension spring 15 by the engagement of the claw portion 20a with the engaging portion 12b of the stop lever 12. Rotate counterclockwise.

Due to this rotation, the contact portion 12a of the stop lever 12 moves out of the rotational trajectory of the retaining portion 8a of the sleeve 8.

As a result, the helical spring 7 is tightened and the main shaft 1 is driven in the same way as described above.

When the stop lever 12 rotates due to the downward movement of the intermediate lever 20, the bending step 12c presses one side edge 20b of the intermediate lever 20, and the intermediate lever 20 is rotated around the pivot 22. rotate it around.

Therefore, the intermediate lever 20 is rotated while moving downward, and the movement locus of the tip of the claw portion 20a is a curve 11 shown in FIG. 8, while the stop lever 12
Since the movement locus of the left end of the engaging portion 12b is a circular arc 12 centered on the axis of the step screw 14, the claw portion 20a of the intermediate lever 20 that moves due to the attraction of the plunger 18a is moved downward by the intersection of the two loci 11t12. When the intermediate lever 20 moves downward, the engagement with the engagement portion 12b is disengaged, and the stop lever 12 is rotated back by the action of the tension spring 150 despite the subsequent downward movement of the intermediate lever 20, and the stop lever 12 returns to its contact position. The portion 12a returns to the position on the rotation locus of the engaging portion 8a.

As a result, the engaging portion 8a of the sleeve 8 rotating together with the main shaft 1 comes into contact with the abutting portion 12a of the stop lever 12, relaxing the helical spring 7 and disengaging the driving connection between the pulley 3 and the main shaft 1. , the main shaft 1 is stopped with the balance at the uppermost position.

However, the pulley 3 idles around the main shaft 1 until the pressure from the controller MCT is released, and the electromagnetic solenoid 18 is also in the operating state, and the intermediate lever 20 is held at the lowest position. The claw portion 20a is located below the engaging portion 12b of the stop lever 12.

When the controller MCT is released from the depression, the electromagnetic solenoid 18 is de-energized and the plunger 18a and the intermediate lever 20 return to the original position shown in FIG. 7 by the action of the tension spring 23.

At that time, the claw portion 20a is attached to the engaging portion 12 of the stop lever 12.
It is clear that b can be easily overcome.

In short, when the controller MCT is pressed, the stop lever 12 rotates against the action of the tension spring 15, and its abutting portion 12a temporarily moves out of the rotational trajectory of the engaging portion 8, and during this movement, the sewing machine The main shaft 1 starts, and then the stop lever 1
2 is rotated back due to the action of the tension spring 15 despite the continuation of the pressing operation of the controller MCT, and its abutting portion 12a is located on the rotation locus of the engaging portion 8a.

As a result, when the main spindle 1 rotates substantially, the retaining portion 8a comes into contact with the contact portion 12a of the stop lever 12 to stop the main spindle 1. At this time, the thread take-up lever is at the substantially uppermost position, and the sewing machine needle just goes back and forth to form one stitch and stops above the cloth.

After that, if the pressure of the controller MCT is released, the work cloth is moved by hand, and the controller MCT is pressed again, a new stitch is formed in the same operating state as described above, and the main spindle 1 is stopped. By repeating this stitch formation, or in other words, the so-called needle stitching, it is possible to perform basting stitches having a stitch interval of arbitrary length.

Furthermore, when performing needle stitching, the helical spring I expands when the abutting portion 12a of the stop lever 12 abuts the engaging portion 8a of the sleeve 8, but the sleeve 8 prevents this abnormal expansion. thwarted.

Then, the stop lever 12 rotates and its abutting portion 12
When a is separated from the engaging portion 8a, the expanded helical spring 7 is immediately tightened, so that the sleeve 8 rotates slightly counterclockwise in FIG. 7.

Therefore, even if the stop lever 12 immediately rotates back, it will not engage with the engaging portion 8a of the sleeve 8 before the main shaft 1 starts, and the main shaft 1 will always make one revolution.

Also, by pressing the controller MCT, the transistor T
When r2 becomes conductive, capacitor cb is immediately charged, so even if the suppression by controller MCT is instantaneous, thyristor T3 remains conductive until the charge in capacitor cb is discharged and becomes lower than the firing potential of thyristor T3. Continuing, the electromagnetic solenoid 18 is reliably energized.

As explained above, in this embodiment, when continuous stitching is selected,
When the controller MCT is operated to energize the sewing machine motor A, at the same time, the electromagnetic solenoid 18 is energized by the lunoid action circuit F via the actuating circuit E, thereby moving the plunger 18a downward and causing the stop lever 12 to engage the tension spring 15. The contact portion 12a of the sleeve 8 is rotated so that it is positioned outside the rotation locus of the retaining portion 8a of the sleeve 8, and the main shaft 1
is continuously driven, and when the controller MCT is released, the electromagnetic lenoid 18 is continuously energized for a predetermined time by the thyristor T3, which is maintained in a conductive state for a predetermined time corresponding to the discharging time of the capacitor Cn. , the thyristor T1 for driving the sewing machine motor A at a constant low speed is made conductive by the thyristor T2 which is maintained in a conductive state corresponding to the discharge time of the capacitor Cc, and the main shaft after the controller McT is released. The main shaft 1 is driven at a constant low speed with the electromagnetic solenoid 18 energized for several rotations, and then the energization of the electromagnetic solenoid 18 is released based on the interruption of the thyristor T3, and the stop lever 12 The return rotation of spindle 1
is stopped in place, after which thyristors T1 and T2
Since the sewing machine motor A is configured so that the power is cut off based on the interruption of It provides stable operation over a long period of time without applying force, and has excellent durability.

In the above embodiment, the sewing machine motor A is configured to move and start in response to the operation of the controller MCT, but it is not necessarily necessary to operate in conjunction with the operation (for example, the sewing machine motor A may be configured to start in conjunction with the opening and closing of the power switch 52). You can also use it as

Further, in the above embodiment, the power of the sewing machine motor A is transmitted to the main shaft 1 via the spiral spring 7, but the power of the sewing machine motor A is directly transmitted to the main shaft 1, so that the main shaft 1 stops. At times, the rotation of the sewing machine motor A may be locked.

In this way, the present invention releases the operation of the controller at the end of a continuous edge, so that the spindle is then driven at a constant low speed for several revolutions, and then the spindle can be reliably stopped at a fixed position. Compared to the conventional structure described in Japanese Patent Publication No. 48-1019, it is possible to provide a main shaft fixed position stopping device for a sewing machine that has a simpler structure, can be manufactured at a lower cost, and is highly durable.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view of the main part with the cover and band wheel removed, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. The figure is in Figure 1.
- Figure 4 is a cross-sectional view partially cut away along line ■.
FIG. 5 is a partial enlarged view of FIG. 1, FIG. 6 is an electric circuit diagram, FIG. 7 is a diagram equivalent to FIG. 1 in different operating states, and FIG. 7 is a partially enlarged view of FIG. 7; FIG. In the drawing, 1 is a main shaft, 2 is a sewing machine frame, 8 is a sleeve (an engaging part body), 8a is an engaging part, 12 is a stop lever, 12a is a contact part (one end), 12b is an engaging part, 15 is a tension spring (spring means), 18 is an electromagnetic solenoid, 20 is an intermediate lever, 2
4 is a locking lever, 28 is an operating lever, 30 is a changeover switch, 37 is an operating knob, 52 is a power switch, 53 is a switch, 57 and 58 are power terminals, X and Y are power lines, P and N are bus bars, MCT is the controller, A is the sewing machine motor (electric motor), B is the variable speed drive circuit (electric circuit), D is the constant low speed 1 drive circuit (constant low speed drive means), F
is the solenoid actuating circuit (circuit means).

Claims (1)

[Claims] 1. A main shaft of the sewing machine rotatably supported on the sewing machine frame, an electric motor for driving the main shaft, and controlling the supply of electric power to the electric motor to control the speed of the electric motor. an electric circuit including a controller operated by an operator to adjust the sewing machine; an engaging body having one engaging part and rotating integrally with the main shaft; and an engaging part body rotatably pivoted to the sewing machine frame. and a stop lever, one end of which is positioned on the rotation locus of the engaging portion under the action of a spring means; an electromagnetic solenoid for rotation against the action of spring means, the electromagnetic solenoid being energized during operation of said controller and in its energized state for several rotations of the spindle after release of said controller operation; circuit means for connecting said electromagnetic solenoid to said electrical circuit such that said electromagnetic solenoid is retained; and a constant low speed driving means for driving at a constant low speed until after the bias is released, and the main shaft of the sewing machine is continuously driven while the controller is operated, and the main shaft of the sewing machine after the controller is released. The main shaft is driven at a constant low speed with the electromagnetic solenoid energized for several rotations, and then the electromagnetic solenoid is deenergized and the stop lever returns to its original position under the action of the spring means, with one end 1. A main shaft fixed position stopping device for a sewing machine, characterized in that the main shaft is stopped at a fixed position by engaging with an engaging part of an engaging part body.