JPS5949832B2 - Spindle fixed position stop device for electric sewing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixed position stop device for a main shaft of an electric sewing machine, and more particularly to a manual operation unit provided with a sewing machine motor for driving the main shaft of the sewing machine.

In an electric sewing machine in which the operation and stopping of the sewing machine are controlled at least by the operation of It will be stopped mechanically on one side.

It is characterized by the fact that

A conventional mechanical spindle fixed position stopping device is a device for stopping the main spindle in two different angular positions when the sewing machine is stopped by a selection operation prior to the sewing machine operation, such as a needle up position where the needle is located above the workpiece cloth, and a needle up position where the needle is located above the workpiece cloth. There is a device disclosed in Japanese Patent Publication No. 48-4411 that is configured so that either of the needle lower positions located in the penetrating state stops at one end.

This device includes a rotary member that rotates integrally with the main shaft during operation of the sewing machine, and has one engaging portion for engaging with one stop lever 4 to stop the main shaft at a fixed position when the sewing machine is stopped. , the position of the engaging portion relative to the main shaft is set to one of two different predetermined angular positions by rotating it relative to the main shaft of the sewing machine by manual operation from outside the sewing machine frame prior to operation of the sewing machine. The angular position of the spindle is thereby changed.

” However, in order to rotate the rotary member relative to the main shaft in the above-mentioned conventional device and to connect it to the main shaft at the rotational position, not only does the specific configuration become complicated, but it also requires a lot of effort for the operator. This will force users to perform troublesome operations.
Even if it were to be commercialized, it would only increase the manufacturing cost of the sewing machine, and there is a concern that it would not be used in practice.

The present invention has been made in consideration of the above-mentioned circumstances, and its first purpose is to solve the drawbacks of the conventional device and to facilitate easy selection operations by the operator prior to operating the sewing machine. It is an object of the present invention to provide a mechanical main spindle fixed position stopping device that can accurately stop the main spindle at one of two different angular positions when the rimming machine is stopped, and furthermore, to A second object of the present invention is to provide a main shaft fixed position stopping device that can be temporarily driven and instantaneously and precisely stopped at the other angular position by a simple operation by an operator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an apparatus embodying the present invention will be described below in detail with reference to the drawings.

First, referring to FIGS. 2 to 5, a pulley 4 to which a shaft cylinder 3 is fixed is loosely fitted to a main shaft 2 which is rotatably supported on a sewing machine frame 1. sewing machine motor 6
The shaft cylinder 3 and the shaft cylinder 3 are rotated around the main shaft 2 by the rotation of the motor.

Adjacent to the shaft cylinder 3, a second shaft cylinder 7 is inserted and fixed to the main shaft 2, and has an outer diameter equal to that of the first shaft cylinder 3.

A cylindrical helical spring 8 is tightly wound around the two shaft tubes 3 and 7, and one end 8a located on the first shaft tube 3 side is erected outward in the radial direction and wrapped around the helical spring 8. The other end 8b is locked in a groove 7a formed in the second cylindrical cylinder 7.

Therefore, the rotation of the pulley 4 is always caused by the rotation of the first shaft cylinder 3,
The helical spring 8 is transmitted to the main shaft 2 via the second shaft cylinder 7, and when one end 8a of the helical spring 8 is locked by any means, the spring 8 is relaxed. The rotation of the pulley 4 is not transmitted to the main shaft 2, and the main shaft 2 is stopped, and the helical spring 8 acts as a clutch spring.

A flanged collar 10 is fitted onto the main shaft 2 on the right side of the second shaft cylinder 7, and three protrusions 10a protruding from the collar are bored in the end face of the second shaft cylinder 7. is fitted in the groove 7b,
A handwheel 11 fitted into the collar 10 is pressed against the flange by a mounting screw 12, so that it can normally rotate integrally with the main shaft 2.

Further, on the right side surface of the pulley 4, there is a protruding boss portion 4a located inwardly, a single spiral groove 4b having a starting end on the circumferential side of the base of the boss portion, and a spiral groove 4b that continues from the terminal end of the groove. A one step deeper annular groove 4C is formed.

Furthermore, on the outer periphery of the left end of the rotating body, that is, the sleeve 9,
An annular collar portion 9a having the same outer diameter as the boss portion 4a of the pulley 4 and an engaging portion 9b located to the right of the collar portion are formed.

On the other hand, the support plate 13 fixed to the sewing machine frame 1 has a
A pair of stop levers 14, 15 and a link lever 16 are pivotally connected by stepped screws 17 with spacers interposed therebetween.

One end of the stop lever 14 is provided with the sleeve 9.
a contact portion 14a positioned so as to be able to engage with the engaging portion 9b of the
is formed, and the other end side has an engaging portion 14 that plays a role to be described later.
b, and a bent portion 1 that can be engaged with the upper edge of the linking lever 16.
4C is formed, and a connecting portion 14d is formed in the intermediate portion.

The sleeve 9 is also attached to the tip of the other stop lever 15.
a contact portion 15a positioned so as to be able to engage with the engaging portion 9b of the
is formed, and a connecting portion 15b is formed at the base end.

Then, there is a pull lever between both stop levers 14 and 15. A spring 18 is tensioned and urges the stop levers 14, 15 so that the contact portions 14a, 15a thereof move onto the rotation locus of the engagement portion 9b of the sleeve 9.

Furthermore, a bent portion 1.degree. 6a is formed at one end of the linking lever 16 and can be relatively engaged with the upper edge of the support plate 13, and a linking portion 16b is formed at the other end.

Thus, when the abutting portion 14a of the one stop lever 14 engages with the engaging portion 9b and the sleeve 9 and one end 8a of the helical spring 8 are locked, the sewing machine stops.

The main shaft 2 of the sewing machine is stopped so that the tip of the thread take-up lever (not shown) is at the highest point, that is, the needle bar 19 supporting the sewing machine needle at the lower end is slightly lower than the top dead center.
The positional relationship between the engaging part 9b and the abutting part 14a of the stop lever 14 is set, and the abutting part 15a of the other stop lever 15 engages with the engaging part 9b, so that the sleeve 9 When one end 8a of the helical spring 8 is locked, the main shaft 2 of the sewing machine is moved with the needle 1 bar 19 located at approximately the lowest point.
The positional relationship of the abutting portion 15a of the stop lever 15 with respect to the engaging portion 9b is set such that the engaging portion 9b is stopped.

Furthermore, a switching arm 20 is attached to the support plate 13 with a stepped pin 2.
The shaft portion of the stepped screw 22 fixed to the support plate 13 is fitted into the throat (20a) formed at the lower end of the thrower (1) to limit the rotation range of the switching arm 20. It is regulated.

In addition, a vertical slot l-20b is provided in the middle part of the switching arm 20.
is bored, and the pair of stop levers 14, 15
A pair of links 23 and 24 each have one end pivotally connected to the connecting portions 14d and 15b of the connecting pin 25.
The shaft portion of the connecting pin 25 is fitted into the vertical slot 20b, and the movement of the connecting pin 25 is guided.

1, and another slot 2 is provided in the middle side of the switching arm 20.
0C is bored, and a bent portion of one end of the switching lever 26 pivotally attached to the support plate 13 fits therein.

At the other end of the switching lever 26, an operating section is attached to the sewing machine frame 1.
an operating knob 2 that protrudes outward through an opening formed in the
7 is fitted, and the switching arm 20 can be rotated by operating the switching lever 26 from outside the sewing machine frame.

And, between the switching arm 20 and the support plate 13, a second
As shown in the figure, a coil spring 28 is provided having a turn in the middle, each end of which is connected to the switching arm 2.
0 and the shaft pins 29 and 30 fixed to the support plate 13, respectively.

Therefore, when the switching lever 26 is operated to the position shown in FIG.
1 in the clockwise direction, and the right edge of the thrower 20a is moved and held in a state in contact with the stepped screw 22.

Furthermore, when the switching lever 26 is rotated counterclockwise from the position shown in FIG. It is moved to the right from the line segment connecting the axes of 30.

As a result, the coil spring 28 urges the switching arm 20 counterclockwise, contrary to the above, and the switching arm 20 pushes the switching arm 20 toward the slot 20.
The left edge of C is moved and held in contact with the stepped screw 22.

Furthermore, an operating lever 31 having a claw portion 31a formed at one end is attached to the support plate 13 so as to be rotatable and tiltable about the mounting shaft 32. Due to the action of the coiled spring 33 wound around the actuating lever 31, the claw portion 31a of the actuating lever 31 is urged inward in the radial direction of the pulley 4, and the claw portion 31a
is biased toward the pulley 4 side.

Further, the other end of the operating lever 31 is located near the engaging portion 14b of the stop lever 14, and as described later, the engaging portion 14b is engaged when the stop lever 14 is rotated counterclockwise. When the upright portion 31b that can face the portion 14b from below (see FIG. 4) and the linking lever 16 are rotated counterclockwise from the position shown in FIG. A hemispherical protrusion 31C is formed for tilting the lever 31 against the action of the coil spring 33.

Next, referring to FIGS. 1 and 2, a manual operating lever 34 is mounted above the jaw of the sewing machine so that it can be operated from the front side of the sewing machine. The sewing machine is rotatable between a position P1 for stopping the sewing machine and a position P2 for operating the sewing machine, and is configured to be selectively moved and held in either one of the plane positions.

A switching lever 35 is mounted within the sewing machine frame 1 so as to rotate in conjunction with the operation of the manual operation lever 34, and one end thereof is attached to the connecting portion 1 of the linking lever 16.
6b from above, and the linking lever 16 is always movable in conjunction with the switching lever 36 by the action of a tension spring 36.

Note that the connection mechanism for interlocking the manual operation lever 34 and the switching lever 35 mentioned above and the positioning mechanism for the manual operation lever 34 are disclosed in Japanese Patent Application No. 1983-1992 filed by the same applicant as the present invention. No. 19651 (Unexamined Japanese Patent Publication No. 1965)
2-.

The mechanism may be the same as that described in Japanese Patent Application No. 103254), and a detailed explanation thereof will be omitted as it is not necessary to understand the present invention, but if necessary, please refer to the above-mentioned application.

Thus, the intermediate lever 37 is perforated by the pivot 38.

It is rotatably mounted on the sewing machine frame 1 and connected to the switching lever 35 by a rod 39, and is connected to one end of a rotary lever 41 rotatably supported on the sewing machine frame 1 by another rod 40. connected.

The switch actuating cam body 42 is pivotally attached to the sewing machine frame 1 by a stepped screw 43, and is connected to the rotating lever 4 by a rod 44.
1.

The three switches 45 to 47 are arranged side by side on a switch box 48 fixed within the sewing machine frame.
Each actuator can engage with a cam surface 42a formed on the lower surface of the switch actuating cam body 42, and is selectively actuated.

The actuating arm 49 is attached to the stepped screw 43 so as to be able to rotate independently of the switch actuating cam body 42, and the lower part thereof is attached to the actuating arm 49 for actuating one switch 47 among the three switches. An actuating portion 49a that can be relatively engaged with the child is formed, and two pin-shaped protrusions 49b and 49C are integrally formed on the upper side.

Further, a linking plate 50 having a substantially inverted chevron-shaped cam slot 50a is rotatably attached to the lower end portion of the support plate 13 with a stepped screw 51, and a pin 52 fixed to the switching arm 20 is attached to the connecting plate 50. The cam slot 50a is fitted into the cam slot 50a.

The actuating arm 49 is moved to the second position by the action of a tension spring 53 stretched between the pin-shaped protrusion 49b and the sewing machine frame 1.
It is biased clockwise in the figure, and is held in that position by the other pin-shaped protrusion 49C relatively engaging with the horizontal extension 50b of the linking plate 50 from above.

Further, a one-arm operating lever 55 is rotatably attached to the bracket 54 fixed to the sewing machine frame 1, and the one arm is connected to an operating frame 56 (see FIG. 1) via a connection mechanism (not shown). , and is rotated by operating the operating frame 56.

The actuating arm 49 is operatively connected to the side arm of the actuating lever 55 via a rod 57 whose lower end fits into the pin-shaped projection 49b.

The support lever 58 is rotatably mounted on a pivot 59, and a pin 60 fixed to its lower end is fitted into an elongated hole formed in the one stop lever 14.

The engagement claw 61 is pivotally connected to the support lever 58, and the tension spring 6
2, the newly curved portion of one end is always held in a state in contact with one side edge of the support lever, and the claw portion 61a
are opposed to each other from above so that their distal ends can come into contact with engaging portions 55a formed on the side arms of the actuating levers 55.

3 push buttons for speed setting &3. 64. 65 and a power-on push button 66 are arranged side by side on the front side of the pillar portion of the sewing machine frame 1, and selectively operating these buttons closes a switch to be described later.

Further, the pattern selection knob 67 is disposed below the band wheel 11 and protrudes from the side cover 68, and by rotating the knob 67, a desired stitch pattern can be selected. is displayed by the cooperation of the pattern display board 69 and the movable pointer 70.

Furthermore, as is clear from FIG. 3, a base line 27a is carved on the front end surface of the operation knob 27 that protrudes outward through the opening 68a of the side cover 68. Indicates a stopped state.

In addition, 72 is a manual operation knob for amplitude adjustment, 73 is a manual operation knob for feed adjustment, 74 is an upper lid, and 75 is an intermediate pulley for connecting the motor 6 and pulley 4 via a belt.

Next, the electric circuit configuration will be explained with reference to FIG. 7. Reference numeral 81 is an AC power supply, 82 and 83 are thyristors for controlling the power supply to the sewing machine motor 6, and the anode of one thyristor 82 is connected to the pushbutton. It is connected to one of the AC power sources 81 through a power switch 84 that is opened and closed by the operation of 66, and is also connected to one AC input terminal of a full-wave rectifier circuit 85, and the anode of the other thyristor 83 is directly connected to the While connected to the other side of the AC power supply,
It is connected to the other AC input terminal of the full-wave rectifier circuit 85.

Further, the cathodes of the thyristors 82 and 83 are connected to the DC bus A through a diode 86 in common.

The positive DC output terminal of the full-wave rectifier circuit 85 is connected to the conductor B, and the negative DC output terminal is connected to the common bus C.

87 is a firing circuit for supplying firing pulses to the thyristors 82 and 83 in order to control their conduction angles;
The collector is connected to the common bus C via a phase control capacitor 91, and a series circuit of a switch 92 and a capacitor 93 and a diode 94 are connected in parallel to the capacitor 91. are connected to each other.

The switch 92 is closed when the AC power source 81 is 50 hertz.

Further, the conducting wire B is connected to a common bus C through a resistor 95 and two Zener diodes 96 and 97, and the auxiliary bus is connected to the anode side of one of the Zener diodes 96.

Reference numeral 98 denotes a reference signal generation circuit for generating a reference signal corresponding to a predetermined rotational speed of the sewing machine motor 6, and includes a DC circuit including resistors 99, 100 and a Zener diode 101.

102 is a firing pulse generating circuit for controlling the conduction of the thyristors 82 and 83, which includes a PNP transistor 10;
3. NPN transistor 104, pulse transformer 10
5 primary winding 105a and a resistor 106.

The base of the transistor 103 is connected to the connection point p1 between the resistors 99 and 100, and the emitter is connected to the connection point p2 between the collector of the transistor 88 and the capacitor 91 via a diode 107.

108 is a capacitor for absorbing high frequency radiation.

Further, one end side of the secondary winding 105b of the pulse transformer 105 is connected to a resistor 109 and a diode 110 or 111.
It is connected to each gate of the thyristors 82 and 83 through the thyristors 82 and 83, and the other end side is connected to the cathodes of both thyristors.

112 and 113 are the thyristors 82 and 83, respectively.
is a resistor connected between the gate and cathode of

Further, 114 is a detection circuit for generating a speed signal proportional to the rotational speed of the sewing machine motor 6, and a first branch 116 consisting of a resistor 115 connected between the DC i-current bus A and the connection point p1. and a resistor 117 connected in parallel with the branch circuit.
and a second branch 1 consisting of a series circuit of a diode 118
19, and the counter electromotive force of the sewing machine motor as the speed signal is selectively supplied to both branch paths 116 and 119.

120 is a flywheel diode connected in parallel with the sewing machine motor 6.

Furthermore, 121 is the phase control capacitor 91 and 93.
This is a residual charge removal circuit for completely discharging the full-wave rectified voltage near the zero value of the full-wave rectified voltage applied to the conductor B.

In this circuit, a resistor 122, a Zener diode 1
23, a series circuit of resistor 124 connects the conductor B and common bus C
The anode of the Zener diode 123 is connected to the base of the transistor 125.

The collector of that transistor is connected to another transistor 126
The base is connected via a resistor 128 to an auxiliary bus line E led out from the cathode of the Zener diode 96 via a diode 127.

The emitters of both transistors 125 and 126 are connected to a common bus C, and furthermore! -Ran resistor 126
The collectors of are connected to the connection points p1 and p2 via diodes 129 and 130, respectively.

Next, a circuit configuration for controlling the above-mentioned ignition circuit 87 will be explained.

131 is a voltage generation circuit for generating a speed setting voltage corresponding to a desired speed of the sewing machine motor 6;
It consists of resistors 134 to 137 connected in series between the emitter of C.3 and the common bus C.

And each connection point of the resistor I)3. p4. l)
5 is the push button 6 for selectively setting the rotational speed of the sewing machine motor 6 to one of high speed, medium speed, and low speed.
5. It is connected to one contact of each of the selection switches 138 to 140, which are closed in conjunction with the pressing operations of 64 and 63, respectively, and the other contact of each of the three selection switches is connected to the above-mentioned changeover switch. They are commonly connected to the contact a of the switch 45.

The emitter of the transistor 133 is connected to the base of a transistor 141 for supplying base current to the transistors 1 to 88 described above, the collector of the transistor is connected to the auxiliary bus E, and the emitter is connected to the resistor 142. It is connected to the common bus line C via.

Further, the contact point of the changeover switch 45 is the connection point p5.
The common contact C is connected to the common bus line C via a capacitor 143 and to the base of a transistor 145 via a diode 144.

A resistor 14 is connected between the auxiliary bus line E and the common bus line C.
The collector of the transistor 147 connected through the transistor 1 is connected to the transistor 1 through the Zener diode 148.
45, and the cathode of the Zener diode 148 is connected to the auxiliary bus E through a resistor 149 to provide a constant emitter voltage to the transistor 145.
is also connected.

Further, the collector of the transistor 145 is connected to a resistor 15.
0 to the auxiliary bus line E, and is also directly connected to the base of a transistor 133, whose collector is connected to a resistor 17 with a small resistance value.
1 to the auxiliary bus E.

Furthermore, a circuit configuration for controlling starting and stopping of the sewing machine will be explained.

A capacitor 151 is connected between the auxiliary bus line E and the common bus line C through a changeover switch 47, and another capacitor 152 is connected in parallel through the changeover switch 47.

A contact a of the changeover switch 47 is connected to the base of a transistor 153 whose collector is connected to the auxiliary bus E, and whose emitter is connected to the common bus C via a diode 154 and a resistor 155.

156, 15; 7 are transistors forming a Schmitt circuit 158, each emitter of which is connected to the auxiliary bus E via a resistor 159.

The base of one transistor 1560 is connected to the cathode of the diode 154 via a diode 160, and the collector is connected to the common bus line C via a resistor 161.

The base of the other transistor 157 is connected to the connection point between the resistor 161 and resistors 162 and 163 forming a series circuit, and the collector
7 via a resistor 164, and to the common bus line C via a resistor 165.

Furthermore, another transistor 16 is connected between the collector of the transistor 133 and the positive side of the capacitor 151.
6 is connected, and the base of the transistor is connected to the anode of the Zener diode 148 via a resistor 167.

In addition, 168 is a resistor, 169 is a smoothing capacitor, 170
is a transistor protection diode.

Further, the switch 46 shown in FIG. 3 is not included in the electric circuit shown in FIG. 7 because it is not related to the present invention.

The operating mode of the apparatus of this embodiment configured as described above will be explained.

1 to 3 and 7 show the state when the manual operation lever 34 is located at the first position P1 and the operation of the sewing machine is stopped, and both the changeover switches 45 and 47 are Connected to the contact side.

Then, the switching arm 20 is moved and held by the operation knob 27 via the switching lever 26 to a position for stopping the sewing machine at the needle-up position, and when the high-speed setting push button 65 is pressed, the selection switch 138 is turned on. It is closed, and the other selection switches 139 and 140 are open.

When the push button 66 is pressed, the power switch 84 is closed and the capacitor 151 is instantly charged.

In this state, transistor 153 is off, which causes transistor 1 in Schmitt circuit 158 to
56 is on and another transistor 157 is off.

Therefore, when the transistor 147 is turned off, the transistor 145 is turned off, but the transistor 133 is supplied with the base current through the resistor 150 and is turned on.

In this state, the emitter potential of the transistor 133, that is, the voltage at the point p6, is a voltage determined by the voltage division ratio between the speed setting resistor group 132 and the resistor 171, and the transistor 133
41 is in the on state, and based on this, the transistor 8
8 is in the off state.

Therefore, the ignition circuit 87 does not operate, no ignition pulse is generated from the ignition pulse generation circuit 102, and the thyristor 82,
83 is kept in an off state to keep the sewing machine motor 6 in a stopped state.

Now, in order to operate the sewing machine, if the manual operation lever 34 is rotated from position P1 to position P2 in FIG.
The switching lever 35 in the figure is moved upward, and on the other hand, the linking lever 16 is rotated counterclockwise due to the action of the bow 1 spring 36, and the stop lever 14 is rotated at its bent portion 14C.
is rotated in the same direction through engagement with the linking lever 16, and on the other hand, the switch actuating cam body 42 is rotated via the rod 39, the intermediate lever 37, the rod 4□0, the rotating lever 41, and the rod 44. Rotated.

As the stop lever 14 rotates, its abutting portion 14a moves out of the rotation locus of the rotating body, that is, the engaging portion 9a of the sleeve 9, and the connecting pin 25 moves vertically of the switching arm 20 via the link 23. 20b, and via the link 24 the other stop lever 15 is rotated clockwise from the position in FIG. 2 against the action of the tension spring 18.

Further, due to the rotation of the linking lever 16, its side surface comes into contact with the hemispherical protrusion 31C of the operating lever 31.1, and presses the protrusion, causing the operating lever 31 to tilt against the action of the coil spring 32.

Therefore, the claw portion 31a of the actuating lever 31 separates from the annular groove 4C of the pulley 4, rotates under the action of the coil spring 32, and comes into contact with the boss portion 94a of the sleeve 9 (see FIG. 6).
.

In FIG. 4, the moving positions of each member when the manual operating lever 34 is moved and held at the second position P2 are shown by solid lines, and the linked lever 16 has its bent portion 16a aligned with the support plate 1.
3, it is held in the illustrated position.

The rotation of the switch actuating cam body 42 causes the changeover switches 45 and 47 to switch to the contact a side.

As a result, the charge on the capacitor 151 is transferred to the transistor 15.
3 and turns on that transistor.

Therefore, one transistor 1 of the Schmitt circuit 158
56 is turned off and the other transistor 157 is turned on, turning on transistor 1247.

As the transistor 147 turns on, the I transistor 166 is turned on, and the transistor 15 is transferred to the contact a side via the changeover switch 47.
Since the base voltage is applied to transistor 1,
531 is kept in the on state.

While the changeover switch 47 is connected to the contact a side, the capacitors 151 and 152 are constantly charged to a voltage determined by the resistors 171 and 168.

On the other hand, due to the transition of the transistor 147 to the on state and the switching of the changeover switch 45 to the contact a side, the bases of the transistors 1 to 145 are connected to the point p8.
, that is, a voltage that is approximately equal to the voltage at the connection point p3 in the speed setting resistor group 132 is applied.

Thereby, the collector voltage of the transistor 145 has a value corresponding to the potential difference between the points p3 and p8.

On the other hand, when the selection switch 139 for medium speed setting is closed, the collector voltage of the transistor 145 has a value corresponding to the potential difference between points p4 and p8, and the selection switch 149 for low speed setting The collector voltage of the transistor 145 when the transistor 145 is closed is the point p5 and the point p8.
The value depends on the potential difference between and.

Then, point I)3 in the speed setting resistor group 132.
p4. Since the voltage at p5 is in a step-wise decreasing relationship, the collector voltage of the l transistor 145 is lowest when the selection switch 138 is closed and highest when the selection switch 140 is closed.

The collector voltage of the transistor 145 is applied to the base of the transistor 133, and a speed setting voltage is generated at its emitter, point p6, which decreases as the speed setting selected by the selection switches 138 to 140 increases.

The emitter voltage is determined by applying the speed setting voltage to the base of the transistor 14, and the emitter voltage is applied to the base of the transistor 88.

Therefore, the collector current of the transistor 88 also becomes a constant value depending on the speed setting voltage, and the charging of the phase control capacitor 91 every half cycle is extremely fast when the selection switch 138 for high speed setting is closed. It will be done.

Then, at the point in time when the voltage at the connection point p2 exceeds the voltage at the connection point p1, the transistors 103 and 104 are turned on almost simultaneously, and as a result, the secondary winding 1 of the pulse transformer 105
A trigger pulse is generated at 05b and the thyristors 82 and 83
are simultaneously triggered, and the one to which a forward voltage is applied between the anode and cathode becomes conductive, and power is supplied to the sewing machine motor 6, causing it to rotate.

In this way, if the collector current of the transistor 88 is set to a certain value by selectively closing the selection switches 138 to 140, the conduction angles of the thyristors 82 and 83 are substantially determined in accordance with the set value of the collector current. , the sewing machine motor 6 is maintained at a substantially constant rotational speed according to the set value.

Sho this mi. While the thin motor 6 is rotating, the rotational speed of the motor 6 fluctuates in accordance with variations in the load. In the circuit of this embodiment, a speed detection circuit 114 is provided, and the voltage at the connection point p1 is controlled by the operation of the detection circuit. As a result, the rotational speed of the motor 6 is stably maintained without significant fluctuations in the set rotational speed despite variations in the load.

Since such a mode of operation is not necessary for understanding the present invention, it will be omitted, but its details are disclosed in Japanese Patent Application No. 122,876/1987, filed by the same applicant as the present invention.

When the motor 6 is started, the pulley 4 rotates together with the shaft cylinder 3, and the main shaft 2 is started by the tightening of the helical spring 8. During the subsequent steady operation, the height set by the push button 65 is maintained. The sewing machine is operated at the same speed.

In this case, it is clear from the above-described configuration that the rotating five-part body or sleeve 9 together with the helical spring 8 rotates integrally with the main shaft 2.

When the sewing machine is operated in this manner, the desired four sewing operations are performed with the amplitude and feed amount arbitrarily set by the first and second manual operation knobs 72 and 73. When the bottom push button 63 or 64 is pressed, the push button 65 is released and the selection switch 13 is pressed.
8 is opened, the other selection switch 139 or 140 is closed, the conduction angle of the thyristor 82, 83 is narrower than in the above case, and the sewing machine motor 6 is rotated at a corresponding rotational speed (low speed or medium speed). ).

After performing the desired sewing in this way, in order to stop the operation of the sewing machine, the manual operating lever 34 is returned from the second position p2 to the first position p1, and the switching lever 35
The switch actuating cam body 42 is also moved back.

By moving the switching lever 35 back and forth, the linking lever 16
also rotates clockwise in FIG. 4, and the stop lever 1
4 also rotates slightly to follow the link lever 16 due to the action of the tension spring 18, and thereby the other stop lever 15 also rotates slightly via the links 23 and 24.

However, since the engaging portion 14b of the stop lever 14 comes into contact with the upright portion 31b of the operating lever 31, subsequent rotation of the stop levers 14 and 15 is prevented.

Further, due to the return of the linking lever 16, the operating lever 31
The pressing of the protrusion 31C is released, and the claw 31a of the operating lever moves along the annular flange 9a of the sleeve 9 and the boss 4a of the pulley 4, and then fits into the starting end of the spiral groove 4b.

On the other hand, the return rotation of the switch operating cam body 42 causes the changeover switches 45 and 47 to return to the contact side.

By switching the changeover switch 45, the capacitor 152 that had been charged starts discharging at a certain time constant determined by the resistors 168 and 155, etc., and the base voltage of the transistor 153 becomes almost equal to the emitter voltage. The transistor 153 is held in the on state until the voltage is reached.

Therefore, the transistor 157 in the Schmitt circuit 158 remains on for a while even after the changeover switch 47 returns to the contact side, and as a result, the transistor 157 remains on for a while.
47 is also kept in the on state.

Then, due to the return of the changeover switch 45 to the contact side, a voltage equal to that at the point p5 is generated at the point p9, which is the same as when the selection switch 140 is closed despite the closing of the selection switch 138, and for the reason described above. The collector current of the transistor 88 is thereby reduced, the thyristors 82, 83 continue to conduct alternately every half cycle with a narrow conduction angle, and the sewing machine motor 6 continues to rotate at a low speed.

Thus, the claw portion 31a of the operating lever 31 is connected to the pulley 4.
As the lever 31 continues to rotate, it moves while being guided by the spiral groove 4b, and the actuating lever 31 gradually moves 4 against the action of the coil spring 33.
Rotated clockwise in the figure.

Before the claw portion 31a comes off the end of the spiral groove 4b and fits into the annular groove 4C, the upright portion 31b of the operating lever 31 disengages from the engagement portion 14b of the stop lever 14. The stop lever 14 is rotated back by the action of the tension spring 18, and its abutting portion 14a abuts against the circumferential surface of the rotating body, that is, the sleeve 9, and is positioned within the rotation locus of its engaging portion 9b (Fig. 4). ).

At this time, the other stop lever 15 is also rotated via the links 23 and 24 to the position indicated by the two-dot chain line in the figure by the action of the tension spring 18, but its abutting portion 15a is connected to the engaging portion 9b.
It is located outside the rotation locus of.

Therefore, within one rotation of the main shaft 2 after the stop lever 14 returns, the engaging portion 9b comes into contact with the abutting portion 14a, and the main shaft 2 is stopped with the balance reaching the uppermost position.

At this time, one end 8a of the helical spring 8 is locked, the spring 8 expands, the pulley 4 idles, and the claw portion 31a of the operating lever 31 is inserted into the annular groove 4C of the pulley 4 after a while. insert.

Thereafter, as the discharge of the capacitor 152 progresses, the emitter voltage of the transistor 156 becomes higher than the base voltage, and that transistor 156 is turned on and the other transistor 157 is turned off.

As a result, the transistor 147 is turned off and the transistor 145 is turned off, so that the transistor 88 in the ignition circuit 87 is turned off for the reason described above, and the thyristor 82,
The ignition pulse is no longer supplied to the sewing machine motor 6.

The power supply is cut off and the motor 6 is stopped.

If the manual operation lever 34 is again moved to the second position p2 in order to start sewing the material after the sewing machine has stopped in this way, the sewing machine operates in the same manner as described above.

When the sewing machine is operated at the speed selected by the push buttons 63 to 65 and the manual operation lever 34 is operated to return to the first position p1, the sewing machine starts operating at a low speed regardless of the speed set by the push buttons. The operation continues for several revolutions of the main shaft, and then the sewing machine is stopped when the thread take-up lever reaches its highest position.

As is clear from the above description, the actuating lever 31, the spiral groove 4b, etc. constitute a mechanical delay means that temporarily prevents the stop levers 14 and 15 from returning due to the action of the tension spring 18. Moreover, the condenser 152 and the Schmidt circuit 158 cause the first stop levers 14 and 15 to return with a delay and the main shaft 2 of the sewing machine to the predetermined position, despite the return of the manual operation lever 34 to the sewing machine stop position p1. This serves to supply power to the sewing machine motor 6 until the sewing machine motor 6 is reliably stopped.

Further, in the residual charge removal circuit 121, the transistor 125 is turned off until a full-wave rectified voltage exceeding the voltage set by the Zener diode 123 appears on the conductor B, and during this time the transistor 126 is turned on. Therefore, the residual charge in the phase control capacitor 91 after the triggering of the thyristors 82 and 83 is
The voltage is completely discharged through the transistor 126 during a certain period when the voltage is approximately zero for each cycle, and fluctuations in the conduction angles of the thyristors 82 and 83 due to accumulation of residual charges are prevented.

By the way, it is often desired to stop the operation of the sewing machine in a state where the needle has penetrated the workpiece cloth 1 in the middle of desired sewing.

In such a case, the apparatus of this embodiment may be operated as follows.

That is, in FIGS. 2 and 3, if the operating knob 27 is operated so that the pointer 27a matches "needle down" in the display 71, the switching lever 26 is rotated and the switching arm 20 is moved to the stepped pin. 21 in a counterclockwise direction.

As the switching arm 20 rotates, the connecting pin 25 fitted in the vertical slot 20b is moved, so the pair of links 23 and 24 are moved, and the stop levers 14 and 15 are rotated as follows. be done.

That is, in the first half of the rotation of the switching arm 20, one of the stop levers 14 is biased clockwise by the action of the tension spring 18, so that the connecting pin 25 is pressed against the stop lever 14 in a stationary state. Link 23 in connecting portion 14d
is rotated together with its link 23 in the counterclockwise direction in FIG. 2 around the pivot point.

Therefore, only the other stop lever 15 is rotated counterclockwise in the figure via the link 24, and comes into contact with the circumferential surface of the sleeve 9 to prevent further rotation.

Therefore, in the latter half of the rotation of the switching arm 20, the connecting pin 25 is connected to the connecting portion 15b of the other stationary stop lever 15.
It will be rotated together with the link 24 around the pivot point of the link 24 at.

As a result, the stop lever 14 is rotated counterclockwise in FIG.
It is moved and placed outside the rotation locus of b.

Further, when the switching arm 20 rotates, the pin 52 fixed to the lower end of the switching arm 20 fits into the cam slot 50a of the linking plate 50, so that the linking plate 50 is rotated one reciprocating movement.

Due to the forward movement of the linking plate 50, the actuating arm 49 weakens and is rotated counterclockwise in FIG. Press to activate the selector switch,
Thereafter, the return rotation of the actuating arm 49 due to the backward movement of the linking plate 50 releases the pressure on the actuator of the changeover switch 47.

According to the above embodiment, the changeover switch 47 is temporarily switched to the contact a side in FIG. 7, and the electric charge of the capacitor 151 is applied to the base of the corresponding resistor 153, and another capacitor 152 starts charging instantly. .

Therefore, the transistor 153 is turned on, and the transistor 147 is turned on in the same manner as in the previous case.

Part 1 - transistor 1 is turned on by turning on transistor 147.
66 is turned on, and the capacitor 152 is instantly and sufficiently charged via the changeover switch 47 which is temporarily switched to the contact a side.

Despite the return to the contact side, the transistor 153 is kept on for a certain period of time by the action of the capacitor 152, and the transistor 147 also remains on for a certain period of time.

Moreover, the transition to the on state of the transistor 147 and the contact point are located on the side.

Due to the action of the changeover switch 45 that remains closed, the selection switch 140 for low speed setting is set at the point p6 in the voltage generation circuit 131, regardless of the closed state of the selection switches 138 to 140, as is clear from the above explanation. As with the closed case, a high speed setting and voltage are generated, and the thyristor 8 is activated by the action of the ignition circuit 87 and the ignition pulse generation circuit 102.
2 and 83 are alternately conductive for a certain period of time at a narrow conduction angle, and the sewing machine motor 6 is temporarily driven to rotate at a low speed.

In this way, the switching lever 26 is controlled by the operating knob 27.
By the needle down selection operation, the engaging portion 9 of the sleeve 9 has been
The stop lever 14 that was in contact with the stop lever 14 disengages from the engaging portion 9b and moves out of its rotational trajectory, and prior to this, the contacting portion 15a of the other stop lever 15 moves out of the rotational trajectory of the engaging portion 9b. The sewing machine motor 6 is started in parallel with the movement of the stop levers 14 and 15.

Therefore, when the main shaft 2 starts and rotates at a low speed together with the sleeve 9, that is, the rotating body, and the engaging part 9b comes into contact with the abutting part 15a of the stop lever 15, as shown in FIG. , that is, when the needle penetrates the work cloth and reaches approximately the lowest point, does the rotation of the main shaft 2 stop? After that, the power supply to the sewing machine motor 6 is cut off.

In this so-called needle-down stopped state, preparations for subsequent sewing operations such as rotation of the workpiece cloth after the presser foot is lifted can be carried out without positional deviation, which is convenient.

By operating the operating knob 27, the switching arm 20 is stably held by the action of the coil spring 28 with the stepped screw 22 in contact with the left edge of the thrower 20a.

Then, when the manual operation lever 34 is moved from the first position p1 to the second position p2 while the switching lever 26 is set to "needle down", the sewing machine is operated and a new sewing is performed. When the manual operation lever 34 is returned to the first position p1 after the desired sewing is completed, the sewing machine stops with the needle reaching approximately the lowest point.

To explain this operating mode, the operating mode of the electric circuit is exactly the same as the above-mentioned "needle up" selection, so please refer to the above explanation, and other parts will be briefly explained with reference to Fig. 8. do.

That is, by operating the manual operation lever 34 from the first position p1 to the second position p2, the switching lever 35 moves from the solid line position to the two-dot chain line position, and the linkage lever 16
6, the bent portion 16a follows and rotates until it comes into contact with the support plate 13.

By the rotation of the linking lever 16, the stop lever 14 is rotated from the solid line position to the two-dot chain line position via the bent portion 14C, and the pair of links 23, 24 and the vertical slot of the connecting pin 25) 20b are rotated. Through the movement along the line, the other stop lever 15 is also rotated to the two-dot chain line position, and its abutting portion 15
a moves out of the rotation locus of the engaging portion 9b of the sleeve 9.

On the other hand, when the linking lever 16 rotates, one edge of the linking lever 16 presses the hemispherical protrusion 31C of the actuating lever 31, so it moves in the same manner as in the previous case, as shown in FIGS. 4 and 6. take a position.

The sewing machine is operated in such a state, and after performing the desired sewing work, the manual operation lever 34 is moved to the sewing machine stop position p.
1, the switching lever 35 and the linking lever 1
6 immediately returns to the position shown in FIG.
The main shaft 2 of the sewing machine is driven to rotate at a low speed for a while, which can be immediately restored by the action of mechanical delay means such as the following.

When the bent portion 31b of the operating lever 31 is disengaged from the engaging portion 14b of the stop lever 14, both stop levers 14.
15 is relatively rotated back by the action of the tension spring 18, and the abutting portion 15a of the stop lever 15 enters into the rotation locus of the engaging portion 9b of the sleeve 9, and the abutting portion 15a of the sleeve 9 By coming into contact with the outer circumferential surface, subsequent rotation is prevented.

Therefore, the stop lever 14 is also prevented from rotating clockwise from the solid line position shown in FIG.
is located outside the rotation locus of the engaging portion 9b.

Therefore, after the abutting portion 15a of the stop lever 15 enters into the rotation locus of the engaging portion 9b of the sleeve 9,
Within the rotation, the engaging portion 9b comes into contact with the abutting portion 15a, the main shaft 2 is stopped and the pulley 4 idles, and then the power supply to the sewing machine motor 6 is cut off and the pulley 4 also stops. .

When the main shaft 2 is stopped, the needle is located at approximately the lowest point.

It's obvious.

After the sewing machine has stopped in this way, if the manual operation lever 34 is moved to the second position p2 again to start sewing, the above-mentioned operation is repeated and the sewing machine is operated by pressing the push buttons 63 to 65. .

When the sewing machine is operated at the selected speed and the manual operation lever 34 is operated to return to the first position p1, the operation of the sewing machine is temporarily continued at a low speed regardless of the speed set by the push button. After that, the sewing machine is stopped when the needle reaches the lowest point.

So. Then, when it is desired to move the needle upward for attaching and detaching the work cloth, etc., the switching lever 26 is rotated upward by operating the operating knob 27, and the switching arm 20 moves clockwise, contrary to the case described above. The pair of stop levers 14 and 15 are rotated, and the pair of stop levers 14 and 15 are moved from the solid line position shown in FIG. 8 to the position shown in FIG. Move relationally to a position.

That is, in the first half of the rotation of the switching arm 20, the connecting pin 25
is rotated clockwise in FIG. 8 together with the link 24 around the pivot point of the link 24 at the connecting portion 15b of the stationary stop lever 15, and only the stop lever 14 is rotated through the link 23 in the clockwise direction in FIG. The contact portion 14a contacts the outer circumferential surface of the sleeve 9 to prevent further rotation.

Therefore, in the second half of the rotation of the switching arm 20, the connecting pin 25 is attached to the link 23 at two points around the pivot point of the link 23 at the connecting portion 14d of the stationary stop lever 14.
At the same time, the stop lever 15 is rotated clockwise via the link 24 against the action of the tension spring 18, whereby the abutting portion 15a is moved to a position outside the rotational trajectory of the engaging portion 9b. do.

Also, due to the rotation of the switching arm 20, the connecting plate 5
0 is rotated back and forth once, and the changeover switch 4 is moved by the operating arm 49.
7 is temporarily activated and the sewing machine motor 6 is activated as described above.
is temporarily driven to rotate at low speed.

Therefore, the main shaft 2 rotates at low speed together with the sleeve 9,
As shown in FIG. 2, when the engaging portion 9b comes into contact with the abutting portion 14a of the stop lever 14, that is, when the balance reaches approximately the uppermost position, the rotation of the main shaft 2 is stopped. .

As described above, in the present embodiment, a pair of engaging parts 9b formed on the sleeve 9, which is a rotating body that rotates integrally with the main shaft 2 of the sewing machine, can be engaged at different angular positions of the main shaft 2. Stop levers 14 and 15 are provided, and both stop levers are normally biased by the action of a tension spring 18 so as to move onto the rotation locus of the engaging portion 9b, and a switching lever 26, a switching arm 20, and a pair of stop levers 14 and 15 are provided. A switching means consisting of links 23, 24, etc. is provided, and by selective operation of the switching means, only one of the pair of stop levers 14 and 15 can enter into the rotation locus of the engaging portion 9b, and the sewing machine During operation, both stop levers 14 and 15 are switched to the switching lever 35.
The engaging portion 9b is moved out of the rotation locus by the action of the linking means such as the linking lever 16, and the one stop lever selected by the switching means based on the operation of the manual operation lever 34 to stop the sewing machine is moved. Due to the action of the tension spring 18, the engaging portion 9b returns to the rotation trajectory, and the main shaft 2 is stopped at one of two different angular positions.

Further, the main shaft 2, which is stopped at one angular position, is temporarily driven by the selection operation of the switching means to the other, and is stopped at the other angular position.

Furthermore, the device of this embodiment is capable of single-stitch stitching, and the operating mode of the needle stitching will be briefly explained.

In the state shown in FIGS. 1 and 2, when the operating portion 56 is pressed downward, the operating lever 55 is rotated, and its engaging portion 55a abuts and supports the claw portion 61a of the engaging claw 61. At the same time as the lever 58 is rotated, the actuating arm 49 is rotated via the rod 57 against the tension spring 53.

Due to the rotation of the support lever 58, the stop lever 14 is rotated against the action of the tension spring 18, and its contact portion 14a moves out of the rotational trajectory of the engagement portion 9b of the sleeve 9, and the other stop lever 14 is rotated against the action of the tension spring 18. The lever 15 is also rotated against the action of the tension spring 18.

Further, the changeover switch 47 is operated by the rotation of the operating arm 49, and as is clear from the above-described embodiment, the sewing machine motor 6 is driven and the main shaft 2 is started together with the sleeve 9.

During the rotation of the operating lever 55, the engaging portion 55a of the operating lever 55 deviates from the rotation locus of the claw portion 61a of the engaging claw 61, so that the support lever 58 and the pair of stop levers 14
．． 15 returns to its original position by the action of a tension spring 18.

Therefore, when the main shaft 2 rotates exactly one rotation, the engaging portion 9b of the sleeve 9 comes into contact with the abutting portion of the stop lever 14 to stop the main shaft 2 and expand the helical spring 8. The driven pulley 4 becomes idle.

Thereafter, when the pressure on the operating portion 56 is released, the operating lever 55 returns, thereby the operating arm 49 also returns, the pressure on the actuator of the changeover switch 47 is released, and after a while, the sewing machine motor 6 stops.

As a result, one seam is formed in the processed cloth,
Basting stitches can be performed by repeating this needle stitching operation.

Furthermore, in the circuit configuration shown in FIG. 7, the manual operation lever 34 is operated to the sewing machine operating position P2 prior to turning on the power by pressing the push button 66, and after the changeover switch 47 is switched to the contact side. Even if the switch 84 is closed and the power is turned on, the Schmitt circuit 158 will not operate because the capacitor 151 is not charged.
The sewing machine motor 6 does not start.

When the manual operation lever 34 is once returned to the sewing machine stop position P1 and then moved to the position P2 again, the sewing machine motor 6 is started and the sewing machine is operated normally.

This phenomenon is extremely effective in terms of safety measures.

That is, when the sewing machine is running, the power switch 84 is opened by releasing the push button 66 to stop the sewing machine, and after temporarily interrupting the sewing operation, the power switch 84 is closed by casually operating the push button 66. Even if this were done, the sewing machine would not start unexpectedly and there would be no risk of putting the operator in danger.

In the device of this embodiment, one engaging part 9b is provided in the sleeve 9 of 'θ as a rotating member, and a pair of stop levers 14 and 15 are selectively engaged with the one engaging part 9b. The main shaft 2 of the sewing machine can be stopped at two different angular positions.Instead, the sleeve 9 is provided with two engaging portions corresponding to the pair of stop levers, respectively. Even if it is provided separately, it is possible to achieve exactly the same operation as the device of this embodiment.

In addition, in the present embodiment, the drive control circuit for the sewing machine motor 6 is entirely installed in the sewing machine main body, and its drive is controlled by moving the operating lever 34 as a manual operating unit θ disposed on the front side of the sewing machine. When the circuit is activated, its manual operating lever 34 and the pair of stop levers 14
, 15 are operatively connected by linking means such as a switching lever 35 and a linking lever 16, but instead of this, a foot-operated controller is used as the manual operation unit,
In addition, as the linking means, the above-mentioned Japanese Patent Publication No. 48-441
It is also possible to use an electromagnetic solenoid as disclosed in Publication No. 1.

In this case, as with conventional sewing machines, the operation, stopping, and operating speed of the sewing machine are controlled by the pressure, release, and degree of pressure of the foot-type controller as a manual operation unit.

As is clear from the above description, the present invention relates to an electric sewing machine that is equipped with a sewing machine motor for driving the main shaft of the sewing machine, and in which at least the start and stop of the sewing machine is controlled by operation of a manual operation unit. A pair of stop levers are provided so as to be able to engage at different angular positions of the main shaft with an engaging portion formed on a rotating body that rotates integrally with the main shaft,
The pair of stop levers are always urged to move on the rotation locus of the engaging portion of the rotary member by the action of the spring means, and either one of the pair of stop levers is moved by the selection operation of the switching means. The engaging part of the rotary part body can enter onto the rotation locus of the engaging part, while the other stop lever cannot enter, and when the sewing machine is operating, both stop levers stop the rotation of the engaging part of the rotary part body by the action of the linking means. One stop lever that has been moved out of the trajectory and selected by the switching means based on the operation of the manual operation member body to stop the sewing machine is returned to the rotation trajectory of the engaging portion by the action of the spring means. This system allows the main spindle to accurately stop at one of two different angular positions when the sewing machine stops, and the operation for selecting the stopping position is extremely simple, and it does not require the conventional mechanical method of setting the main spindle. This is extremely practical as it does not require the complicated operation of selecting a stop position in a position stop device.

Furthermore, if the switching means is operated in a state in which the main shaft is stopped at one angular position due to contact between one of the pair of stop levers and the engaging portion, the engaging portion of the rotating body is The other stop lever, which was located outside the rotational trajectory, enters the rotational trajectory of its engaging portion, and the one stop lever withdraws against the action of the spring means, and the switch means is actuated to stop the sewing machine. Since the motor is configured to be driven temporarily, the main shaft can be temporarily rotated from one stopping angular position and stopped at the other angular position quickly and accurately, and the stopping position can be changed very easily. It exhibits excellent practical effects.

[Brief explanation of the drawing]

The drawings show one embodiment embodying the present invention.
The figure is a perspective view showing the external appearance of the sewing machine, Figure 2 is a front view of the main parts with the side cover and band wheel removed, Figure 3 is a partial sectional view taken along line III-III in Figure 2, and Figure 4 is a partial sectional view taken along line III-III in Figure 2. The figure is an enlarged front view of the part corresponding to Figure 2 to explain the operation mode,
Fig. 5 is a cross-sectional view taken along the line V-V in Fig. 4, Fig. 6 is a right side view taken from the line VI-VI in Fig. 4, which shows a partial cross-section, and Fig. 7 explains the drive control of the sewing machine motor. FIG. 8 is an enlarged front view corresponding to FIG. 4 for explaining different operating modes. In the figure, 1 is the sewing machine frame, 2 is the main shaft, 6 is the sewing machine motor, and 9
14 is a sleeve as a rotating body having an engaging portion 9b;
and 15 a pair of stop levers, 16 a linking lever, 18
20 is a switching arm, 23 and 24 are a pair of links, 26 is a switching lever, 34 is a manual operating lever as a manual operating unit, 35 is a switching lever, 42 is a switch operating cam unit, 45 and 47 is a changeover switch, 49 is an operating arm,
50 is a linking plate.

Claims (1)

[Claims] 1. An electric sewing machine that is equipped with a sewing machine motor for driving a main shaft of the sewing machine and whose operation and stop of the sewing machine is controlled by operation of a manual operation member, which has at least one engaging part. The rotating part rotates integrally with the main shaft of the sewing machine, and the engaging part of the rotating part can be selectively moved on the rotation locus, and the engaging part of the rotating part can be moved at different angular positions of the main shaft. a pair of stop levers that can be engaged with the engaging portion; a spring means that urges the pair of stop levers to move onto a rotation locus of the engaging portion of the rotating body; and any one of the pair of stop levers. a manually operable switching means operatively connected to the pair of stop levers for selectively moving one of the engaging portions of the rotating member onto a rotational locus of the engaging portion of the rotary member body under the action of the spring means; A pair of stop levers and a manual operation part body are operatively linked, and one of the stop levers is located on the rotation locus of the engaging part of the rotary part body in connection with the operation of the manual operation part body for operating the sewing machine. a linking means for moving the stop lever out of the rotational trajectory against the action of the spring means; and a linking means for moving the stop lever out of the rotational trajectory against the action of the spring means; A device for stopping a main shaft of a sewing machine at a fixed position, characterized in that the main shaft of a sewing machine is stopped at one of two different angular positions. 2. The switching means connects a switching lever that can be operated from outside the sewing machine frame, a switching arm that rotates when the switching lever is operated, and the pair of stop levers, and switches the pair of stop levers to the r switching mode. A main shaft fixed position stopping device according to claim 1, comprising a pair of links for operatively connecting to the arms. 3. An electric sewing machine that is equipped with a sewing machine motor for driving the main shaft of the sewing machine, and whose operation and stop of the sewing machine is controlled by operating a manual operation part, which has at least one engaging part, A rotating part that rotates integrally with the main shaft, and a rotating part that can be selectively moved on the rotation locus of the engaging part of the rotating part and engages with the engaging part of the rotating part at different angular positions of the main shaft. a pair of stop levers that can be combined; a spring means for biasing the pair of stop levers to move onto a rotation trajectory of the engaging portion of the rotary member; and selecting one of the pair of stop levers. a manually operable switching means operatively connected to the pair of stop levers for moving the engagement portion of the rotary member onto a rotational locus by the action of the spring means; and and a manual operation part body, and one stop lever located on the rotation locus of the engaging part of the rotary part body in connection with the operation of the manual operation part body for sewing machine operation. a linking means for moving the sewing machine out of the rotation locus against the action of a spring means; and a switch means disposed in relation to the switching means, the sewing machine It consists of an electric circuit means for temporarily exciting the motor, and the main shaft can be temporarily rotated from one angular position and stopped at the other angular position by selecting the switching means when the sewing machine is stopped. A spindle fixed position stopping device characterized by: 4. The switching means includes a switching arm that is rotated by an operation from outside the sewing machine frame, and a pair of switching arms that connect the pair of stop levers to each other and operatively connect the pair of stop levers to the switching arm. 4. The main shaft fixed position stopping device according to claim 3, comprising a link and a linking plate that rotates once in conjunction with the rotation of the switching arm to temporarily operate the switch means.