JPS5940477B2 - Sewing machine spindle fixed position stop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a main shaft fixed position stopping device for a sewing machine that can selectively perform continuous sewing with fixed position stopping and single stitch line for basting.

Conventionally, there is a sewing machine which is described in Japanese Patent Publication No. 1022-1987, filed by the same applicant, as a sewing machine that can selectively perform continuous sewing with stopping at a fixed position and single-stitch sewing for basting. The structure described in the publication is extremely complex and is expected to be difficult and expensive to manufacture.

In addition, a recent patent application No. 12941 of 1973 related to the same applicant
There are also sewing machines that selectively perform one-stitch line for basting stitches and normal continuous stitches that involve stopping in a fixed position as described in No. 5, but in the case of continuous stitching, the main shaft stops at the normal position. Therefore, there was a drawback that it was not possible to stop at a fixed position.

The present invention has been made in view of the above circumstances, and an object of the present invention is to selectively perform continuous stitching with stopping at a fixed position and single stitch line for basting with a simple configuration. To provide a fixed position stopping device for a main shaft of a sewing machine.

An embodiment of the present invention shown in the drawings will be described below.

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

Reference numeral 6 denotes a second 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 7 denotes a cylindrical helical spring tightly wound around both shaft tubes 4 and 6, and one end 7a located on the first shaft tube 4 side is erected radially outward. 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,
It is transmitted to the main shaft 1 via the helical spring 7 and the second shaft cylinder 6, but when one end of the helical spring 1 is locked by some means, the helical spring 7 is relaxed and the rotation of the pulley 3 is stopped. It is not transmitted to the main shaft 1, and the main shaft 1 is stopped.
The helical spring 7 serves as a spring clutch and also as a stop member connected to the main shaft 1.

Note that 9 is a handwheel fixed to the main shaft 1 with 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 shoulder screw 14, and one arm of the stop lever 12 has a retaining 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 12d having a bent stepped portion 12c for guiding movement of the lever is formed.

Reference numeral 15 denotes a spring means stretched between the stop lever 12 and the support plate 13, so that the abutting portion 12a of the stop lever 12 is always placed upright on the rotation trajectory of the retaining portion 8a. It acts like this.

When the contact portion 12a of the stop lever 12 engages with the retaining 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 engaging 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, 19 as an electromagnetic solenoid as an actuating member; 20 as an actuating arm that is pivotally connected to the plunger 18a of the electromagnetic solenoid 18 via a synthetic resin plate 21 (see FIG. 3); The resin plate 21 is fixed so as to move together with the intermediate lever 20 of the lever, 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.

Reference numeral 23 denotes a tension spring stretched between the intermediate lever 20 and the support plate 13. As is clear from FIG. It is located on the left side of the line connecting the locking point with the plunger 18a and the center point of the pivot shaft 22, and always urges the intermediate lever 20 upward and rotates around the pivot point with the plunger 18a. It provides rotational force in the 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.
A retaining 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 distal end of the operating lever is pivotally supported, 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 24 via the shaft pin 24b. is biased clockwise.

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 be able to come into contact with an operating pin, which will be described later. A rotational force is applied to the sewing machine (clockwise in FIG. 4), and one side edge abuts against a stocker hinge 40 implanted in the sewing machine frame 2 and remains stationary.

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 and holding the zigzag amplitude at zero and a cam surface 30b for setting and maintaining the zigzag amplitude at zero.
9 is drilled.

Reference numeral 41 denotes an operating pin implanted on the back side of the operating knob 31, and the operating knob 31 is rotated counterclockwise in FIG.
It is positioned so that it can come into contact with the operating lever 34 when it is rotated clockwise in FIG.

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 rotational force in the counterclockwise direction in FIG. 2 is applied by the action of a coiled spring 47 wound around.

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.

Reference numeral 48 denotes a zigzag connecting rod to which the lower end of the rotating arm 45I is connected, 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 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 fixed to the mounting plate 16 by screws 54, 54 and screws 55, 55;
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 the control lever 28 is switched to the high speed side, the operating lever 28 is restricted to a counterclockwise rotational 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 a sewing machine motor consisting of an armature winding LA and field windings Ll and L2, and a noise prevention capacitor C1 is connected to both ends of the armature winding LA.

BR is four diodes CBI. 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 Bk 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 of the AC input terminals a of the bridge rectifier circuit BR
and the positive side d of the DC output terminal, the diode DB3 is connected between
A switch 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 variable speed 7 drive circuit comprising this sewing machine 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.
A thyristor with the illustrated polarity is connected between the thyristors T1 and TD, a thyristor protection varistor connected in parallel to the thyristor T1, and R1 and C2 a thyristor protection resistor connected between the cathode and gate of the thyristor T1. It is a waveform shaping capacitor, and GR is a full-wave rectifier circuit connected between the power lines X and Y.

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

Tri is an NPN type transistor, its collector is connected to the positive side f of the DC output terminal of the full-wave rectifier circuit GR via a resistor Rcl, a variable resistor VRcl, and a bus line P, and its emitter is connected to a diode D1 with the polarity shown, It is connected to the negative side of the DC output terminal of the full-wave rectifier circuit GR via the capacitor 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 D1 via a diode D2 and a resistor Rc2 having the polarity shown. A protection 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 consisting of the thyristor control circuit C having the above configuration and the thyristor T1.

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 Tr1 via a resistor R6, and the signal input terminal ST is connected to the positive side df of the DC output terminal of the bridge rectifier circuit BR.

However, the changeover switch 30 changes over between the needle bar fixed position stop function and the basting 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 solenoid actuating circuit operated by the actuating circuit E having the above structure, and the structure thereof 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 connected to a resistor Rbl
is connected to the switching terminal BS via a resistor Rb.
2 and the gate of said thyristor T3 via a diode D6 of the polarity shown;
connected to the cathode of

Gn is a capacitor, one of its terminals is connected to the switching terminal NP through a diode DI of the polarity shown, a resistor Rnl, and a variable resistor VRnl in series, and a resistor KRn.
2 and the gate of said thyristor T3 via a diode D8 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 the resistance value of the variable resistor of the sewing machine controller MCT changes depending on the degree of pressing of the sewing machine controller MCT thereafter, thereby controlling the rotational speed of the sewing machine motor A.

On the other hand, when the fixed resistor Rm and the sewing machine controller MCT are connected in series, and the potential difference occurs between both ends of the circuit [based on this, when the power supply line As a result, the capacitor Cn is charged to the illustrated polarity, and the transistor Trl is charged based on the conduction of the transistor Tr2.
conducts, and the capacitor Cc is charged to the polarity shown.

Simultaneously with the conduction of the transistors Tri and Tr2, the gate potential of the thyristors T2 and T3 rises, causing the thyristors T2 and T3 to conduct, thereby exciting the electromagnetic solenoid 18 and charging the capacitor C3 to the illustrated polarity.

Since the thyristor T2 is conductive, the thyristor T1 reaches the potential set in the constant low speed setting resistor VRd.
Although the gate potential of sewing machine controller MCT increases,
During operation, the back electromotive force of the sewing machine motor A is applied to the cathode of the thyristor T1, and when the power line X is at a positive potential, the cathode potential of the thyristor T1 is higher than the gate potential, so the thyristor T1 continues to be cut off.

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. is controlled within the range of low speed.

Now, when the sewing machine motor A is started by pressure from the sewing machine controller MCT, the pulley 3 rotates together with the barrel 4 via the belt 5, and at approximately the same time, the electromagnetic solenoid 18 mentioned above is excited by the conduction of the thyristor T3. Therefore, the plunger 18a is shown in FIGS. 1, 3, and 6.
In the figure, the intermediate lever 20 is sucked downward, thereby causing the intermediate lever 20 to
is moved together with the plunger 18a against the action of the tension spring 23, whereby the locking lever 24 is moved along the pivot shaft 2 while its shaft pin 24b is guided by the fitting groove 28a.
It is moved downward with almost no rotation around 5.

Then, as the intermediate lever 20 moves, the engaging part 12b engages with the claw part 20a and the engaging part 24a, and the stop lever 24
is rotated counterclockwise around the step screw 14 against the biasing force of the tension spring 15, and the abutting portion 12a is moved out of the rotation locus of the retaining 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 pusher 3 is transmitted to the main shaft 1, so that the main shaft 1 is activated.

Thereafter, the rotational speed of the main spindle 1 is arbitrarily adjusted according to the degree of suppression by the controller described above, and normal continuous sewing is performed.

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

Further, the zigzag amplitude during the continuous static state 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 from this state, if the operating knob 31 is turned clockwise (counterclockwise in FIG. 4), the cam The driven arm 42 rotates due to the engagement of the zigzag amplitude adjusting cam surface 39a of the groove 39 with the driven pin 44, and the rotating arm 45 is rotated clockwise in FIG. 2 against the action of the spring 41. A desired zigzag amplitude can be obtained by arbitrarily setting the position of the roller relative to the swing fulcrum of a known zigzag swing arm via the zigzag link rod 48.

Now, as described above, switch the changeover switch 30 to the changeover terminal N.
When the sewing machine controller MCT is released while switching to the P side and performing continuous sewing (however, the switch 53 can be closed or opened), no signal is supplied to the transistor Tr2 of the operating circuit E. At the same time, the transistor Trl to which the signal current is supplied from the transistor Tr2 is also cut off, and the capacitor Cn
The charges on and Cc begin to discharge.

On the other hand, when the sewing machine motor A is de-energized by releasing the pressure from the sewing machine controller MCT, the cathode potential of the thyristor T1 becomes lower than its gate potential, 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.

When the charges in the capacitors Cn and Cc are discharged and the gate potential of the thyristors T2 and T3 falls below the firing potential after a predetermined period of time has elapsed after the pressure of the sewing machine controller MCT is released, the thyristors T2 and T3 are cut off. I end up.

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 engaging portion 8a
It is returned to the position on the rotation trajectory of.

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 boot 93 and the main shaft 1. For example, the take-up lever is located at approximately the uppermost position, and therefore the needle bar is slightly lowered from the uppermost position (the main shaft 1 is stopped in this state).

Further, after the main shaft 1 is stopped, the thyristor T2 is cut off, and the cut-off of the thyristor T2 also cuts off the thyristor T1, so that no power is supplied to the sewing machine motor A, and the sewing machine motor A eventually stops.

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

Rotate the operating knob 3γ in the clockwise direction (in the counterclockwise direction in FIG. 2) in FIG.
If 9a is fitted into the notch 37c of the operation knob 37,
The operating pin 41 embedded in the operating knob 371 contacts the operating lever 34, and rotates the lever 34 from the solid line position to the two-dot chain line position in FIG.

Accordingly, the linkage lever 32 is rotated to the position shown in two-dot chain line in the figure, and the operating lever 28 is rotated clockwise from the position shown in FIG. 1 to the position shown in FIG. 1 against the tension spring 31. 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.
Switch 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.

1 and 8 show the vertical relationship of each member when the operating knob 37 is rotated to the basting position.

On the other hand, the driven pin 44 engages with the equal radius cam surface 39b of the cam groove 39 due to the counterclockwise rotation of the operating knob 3γ in FIG. Positioned in the state shown in the figure, the swinging fulcrum of the zigzag swinging arm is brought into alignment via the zigzag connecting 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
is closed and the sewing machine controller MCT is pressed to operate, the sewing machine motor A is driven at a low speed, Tr2 of the operating circuit E becomes conductive to charge the capacitor cb, and conducts the thyristor T3, so that the electromagnetic solenoid 18 is energized.

Therefore, the electromagnetic solenoid 18 is activated immediately and its plunger 18a is sucked downward in FIGS. 7 and 8, thereby causing the intermediate lever 20 to
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 it counterclockwise.

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

As a result, the helical spring 7 becomes tightly wound and the main shaft 1 is driven by 1 as described above.

When the stop lever 12 rotates due to the movement of the intermediate lever 20 toward the lower blade, the bending film flow 12c presses one side edge 20b of the intermediate lever 20, and the intermediate lever 20
is rotated around the axis 22.

Therefore, the intermediate lever 20 is rotated while moving downward, and the movement locus of the tip of the claw portion 20a is on the right side of the curve shown in FIG. 8, while the engaging portion 12b of the stop lever 12 Since the movement locus at the left end is an arc 12 centered on the axis of the step screw 14, the claw portion 20a of the intermediate lever 20, which is moved by the action of the plunger 18a, moves downward from the intersection P of the two loci 11 and 12. When the intermediate lever 20 moves downward, the engagement with the engagement portion 12b is disengaged, and the stop lever 12 is not held by the subsequent downward movement of the intermediate lever 20, and the tension spring 1
5, the contact portion 12a returns to the rotational trajectory 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 in the uppermost position.

However, the boo 93 is idly rotating around the main shaft 1 until the pressure of the sewing machine control MCT is released, and the electromagnetic solenoid 18 is also in operation, and the intermediate lever 20 is held at the lowest position. The claw portion 20a of 20 is placed vertically below the engaging portion 12b of the stop lever 12.

When the sewing machine controller MCT is released from the pressure, the electromagnetic solenoid 18 is de-energized and the plunger 18a and the intermediate lever 20 are returned 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 sewing machine controller MCT is pressed, the stop lever 12 rotates against the action of the tension spring 15, and its abutting part 12a temporarily moves out of the rotational trajectory of the engaging part 8, and then During the movement, the main shaft 1 of the sewing machine is started, and then the stop lever 12 is rotated back due to the action of the pull spring 15, regardless of the continued pressing operation of the sewing machine controller MCT, and its contact portion 12a is brought into contact with the engagement part 12a. It is located on the rotation locus of the portion 8a.

From this f, when the main shaft 1 rotates approximately -, the engaging portion 8a
comes into contact with the abutting portion 12a of the stop lever 12 to stop the main shaft 1. At this time, the thread take-up lever is at approximately the uppermost position, and the sewing machine needle just reciprocates to form one stitch and press the top of the fabric. Stop at.

After that, release the pressure on the sewing machine controller MCT, move the workpiece cloth by hand, and press the sewing machine controller MC again.
When T is pressed, a new stitch is formed in the same manner as described above and the main spindle 1 is stopped.This stitch formation, in other words, by repeating so-called needle stitching, a new stitch is formed and the main shaft 1 is stopped. It is possible to perform basting stitches having a stitch interval.

Furthermore, when performing needle stitching, the helical spring 7 expands when the abutting portion 12a of the stop lever 12 abuts the engaging portion 8a of the sleeve 8, but the sleeve 8t causes the abnormal expansion. is prevented.

Then, the stop lever 12 rotates and its abutting portion 12
When a is separated from the retaining portion 8a, the expanded helical spring γ is immediately tightened, so that the sleeve 8 rotates slightly counterclockwise in FIG. 1.

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.

Furthermore, when the transistor Tr2 is turned on by the press of the sewing machine controller MCT, the capacitor cb is immediately charged, so even if the press of the sewing machine controller MCT is instantaneous, the charge in the capacitor cb is discharged and the thyristor T3 is The conduction continues until the potential drops below the ignition potential, and the electromagnetic solenoid 18 is reliably energized.

As is clear from the above explanation, this example is
- When continuous stitching is selected for the sewing machine that performs one-stitch line for basting stitches and normal continuous stitches with fixed position stop described in No. 129415, the operation knob 37 is rotated clockwise. The structure includes a locking lever 24 that allows the plunger 18 of the electromagnetic lens 18 to be used during continuous sewing.
When a is moved downward E, the engaging portion 2 of the locking lever 24
4a engages with the engaging portion 12b of the stop lever 12, and while the plunger 18a is moved downward, the abutting portion 12a holds the stop lever 12 out of the rotation locus of the retaining portion 8a of the sleeve 8. so that when the electromagnetic solenoid 18 is de-energized, the stop lever 12 moves to the plunger 18a.
The abutting portion 12 is rotated back with the return movement of the
Since a is made to fall within the rotation locus of the retaining part 8a of the sleeve 8, the main spindle 1 is stopped at a fixed position in the case of continuous sewing as well as in the case of a single stitch line, and the thread take-up is stopped at approximately the highest position. , the sewing machine needle will always be located above the fabric when stopped.

In the above embodiment, the sewing machine motor A is configured to start in conjunction with the operation of the sewing machine controller MCT.
The sewing machine motor A does not necessarily have to be operated in conjunction with each other; for example, the sewing machine motor A may be started in conjunction with the opening and closing of the power switch 52.

Further, in the above embodiment, the electromagnetic solenoid 18 is used as an operating member for rotating the stop lever 12 against the tension spring 15 as a spring means. However, instead of the electromagnetic solenoid 18, for example, The intermediate lever 18 may be configured to be moved directly by the operator.

As described above, the present invention has a much simpler structure than that described in Japanese Patent Publication No. 48-1022, and selectively performs continuous sewing with stopping at a fixed position and single stitch line for basting. It is possible to provide a fixed position stop device for the main shaft of a sewing machine.

[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 1 in Figure 1.
Figure 4 is a cross-sectional view partially cut away along line -1.
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. 0 is a partially enlarged view of FIG. 1 In the drawing, 1 is a main shaft, 2 is a sewing machine frame, 8 is a sleeve (retaining part body), 8a is an engaging part, 12 is a stop lever, 12b is an engaging part, 15 is a tension spring (spring means), 18 is an electromagnetic solenoid (actuating member), 20 is an intermediate lever (actuating arm), 24 is a locking lever, 28 is an operating lever, 30 is a changeover switch, 37 is an operating knob (manual means) ), 52 is a power switch, 53 is a switch, 51 and 58 are power terminals, X and Y
is a power line, P and N are busbars, A is a sewing machine motor, and F is a solenoid operating circuit.

Claims (1)

[Scope of Claims] 1. An engaging part body having one engaging part and rotating integrally with the main shaft of the sewing machine, and an engaging part body rotatably pivoted to the sewing machine frame and always held at one end by the action of a spring means. a stop lever placed vertically on the rotation locus of the engaging portion; an actuating member body actuated by an operator's operation to cause the stop lever to rotate against the action of the spring means; and the actuating portion. An actuating part provided between the body and the stop lever engages the stop lever when the body is actuated, moves the stop lever once out of the rotation locus of the retaining part, and then immediately engages the stop lever. an actuating arm for a single needle line that disengages the engagement and allows the stop lever to return to its original position by the action of the springing means and stops the main shaft at a fixed position every revolution; and an actuating arm adjacent to the actuating arm. is provided between the stop lever and the actuating part body, and engages with the stop lever while the actuating part body is in operation to hold the stop lever out of the rotation locus of the retaining part, and the actuating part A locking lever for continuous sewing that allows the stop lever to return to its original position by the action of the springing means when the operation of the body is released and stops the main shaft at the fixed position after its continuous rotation, and its locking lever. The locking lever is connected to a lever and is selective to either an active position in which the locking lever operates for the continuous sewing or a non-working position in which the locking lever cannot always be engaged with the stop lever regardless of the operation of the operating member body. A manual means operable from outside the sewing machine frame is provided to move and stand the sewing machine vertically, and by selective operation of the manual means, continuous sewing with stopping at a fixed position and single stitch line for basting can be selectively performed. A device for stopping a main shaft of a sewing machine at a fixed position. 2. Claim 1, wherein the actuating member is constituted by an electromagnetic solenoid, the actuating arm is attached to the plunger of the electromagnetic solenoid, and the locking lever is pivotally connected to the actuating arm. The main shaft fixed position stop device for the sewing machine described in 2.