JPS5922554B2 - Main shaft drive device in electric sewing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a motor control circuit including a motor for driving a main shaft of a sewing machine, a controller that is suppressed to control the rotational speed of the motor, and a support that is inserted into the main shaft. a rotating body which is rotationally driven around the main shaft by the motor, and a space between the rotating body and the main shaft in order to always transmit the rotation of the rotating body to the main shaft and to interrupt the transmission as necessary. The present invention relates to a main shaft drive device in an electric sewing machine including a clutch means provided and a band wheel fixed to the main shaft.

In a conventional sewing machine that is capable of performing basting stitches by repeating the needle line, an engaging part of an engaging body that rots integrally with the main shaft of the sewing machine is provided with a stop lever when the main shaft rotates once. The stop lever is always located within the rotation locus of the engaging portion due to the action of the spring, and is once stopped in conjunction with the pressure of the controller to start the sewing machine. There is a type in which the engaging part returns to the original position immediately after moving out of the rotational locus, and a type in which the stop lever is always located outside the rotational locus of the engaging part due to the action of a spring and is due to suppression by the controller. There is a type in which the engaging portion moves within the rotation locus within one rotation of the main shaft based on the rotation of the main shaft.

Therefore, in either type, the engaging portion and the stop lever may come into contact when the main shaft is manually driven.

Therefore, in the former case, a device is required to move the stop lever against the action of the spring, and in the latter case, when the driving force of the main shaft is released, the stop lever returns to its original position by the action of the spring. A device is required to prevent the stop lever from immediately moving against the action of the spring during subsequent manual drive of the spindle.

The present invention has been made in view of the above circumstances, and an object thereof is to be able to perform basting stitches by repeating one stitch line by suppressing operation of a controller, and without providing a separate device. The object of the present invention is to provide a main shaft drive device that can freely manually drive the main shaft according to the sewing conditions, and furthermore, to provide a device that can easily switch between the basting stitch and the normal continuous line.

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

In the figure, 1 is the main shaft of the sewing machine supported on the sewing machine frame 2, and 3 is a pulley into which a shaft cylinder 4 is inserted, which is connected to a motor 6 via a belt 5, and rotates around the main shaft 1 together with the shaft cylinder 4. The pulley 3 and the shaft cylinder 4 constitute a rotating body.

Reference numeral 7 denotes a second shaft cylinder adjacent to one side of the shaft cylinder 4, which is fitted and fixed to the main shaft 1, and has an outer diameter equal to that of the shaft cylinder 4.

Reference numeral 8 denotes a cylindrical spiral spring tightly wound around both shaft cylinders 4 and 7, one end 8a located on the first shaft cylinder 4 side is erected outward in the radial direction, and the other end is pressed. Plate 9 and screw 1
0 to the 20th shaft cylinder 7.

Reference numeral 11 denotes an engaging body, ie, a sleeve, which has one engaging portion 11a and is fitted around the helical spring 8, and as shown in FIG. The upright end 8a of the helical spring 8 is fitted therein, and a cutout groove 11c for receiving the press plate 9 and screw 10 is also formed at the other end.

A tension spring 12 is tensioned between the sleeve 11 and the suppression plate 9 (see FIG. 1), and the sleeve 11 is placed in the center of the main shaft 1 with respect to the 20th shaft cylinder 7 and the main shaft 1. It is biased in the direction of rotation, and the end edge of the cutout groove 11b in the same direction is always kept in contact with the upright end 8a of the helical spring 8.

Therefore, the rotation of the pulley 3 is always caused by the rotation of the first shaft cylinder 4,
is transmitted to the main shaft 1 via the helical spring 8 and the second shaft cylinder 7,
In addition, when one end 8a of the helical spring 8 is locked by some means, the spring 8 is relaxed, the transmission of rotational force to the main shaft 1 is cut off, and the main shaft 1 is forcibly stopped. The helical spring 8 acts as a spring clutch.

Incidentally, reference numeral 13 denotes a handwheel which is fixed by a tightening screw 14 so as to rotate together with the main shaft 1, and is used to rotate the main shaft 1 manually.

A second cylindrical spiral spring 15 is tightly wound around the other side of the shaft tube 4, and has both ends 15a.

Both ends 15b are erected outward in the radial direction, one end 15a of which protrudes outward through a notched groove 16a formed in the second sleeve 16 fitted around the helical spring 15, and the other end 15b also extends outward. It protrudes outward while being locked to the sleeve 16.

Therefore, when the pulley 3 and the barrel 4 are rotated, the helical spring 15 tends to rotate together with the barrel 4.

Further, reference numeral 17 denotes a mounting plate fixed to the sewing machine frame 2;
8 is a support arm rotatably attached to a shaft pin 19 fixed to the mounting plate 17, and is rotated counterclockwise in FIG. 4 by the action of a tension spring 20 stretched between it and the machine frame 2. A rotational force of 1 is applied to the mounting plate 17, and further rotation is restricted by one end abutting against a stopper 21 fixed to the mounting plate 17 so as to be adjustable in position.

Reference numeral 22 denotes a stop lever rotatably supported by the shaft pin 19, and the tip thereof is connected to the engaging portion 11a of the sleeve 11.
A contact portion 22a is formed which can come into contact with the pin 23 implanted in the support arm 18, and one side edge of the contact portion 22a comes into contact with the pin 23 by the action of a tension spring 24 stretched between the support arm 18 and the pin 23. , can rotate integrally with the support arm 18.

When the support arm 18 is in contact with the stopper 21, the stop lever 22 is held such that its contact portion 22a is located outside the rotation locus of the engagement portion 11a of the sleeve 11, and When the support arm 18 is moved against the action of the tension spring 20, the stop lever 22 moves so that its abutting portion 22a is positioned on the rotation trajectory of the engaging portion 11a. .

Further, reference numeral 25 denotes an abutment plate rotatably supported by the support arm 18 by a pivot 26, and a fourth
A clockwise rotational force is applied in the figure, and the abutting portion 25a formed at the distal end of the second sleeve 16
is in contact with the outer circumferential surface of the shaft, and further rotation is restricted.

In this state, the contact portion 25a is located on the rotation locus of the one end 15a of the second helical spring 15, and comes into contact with the one end from behind.

Furthermore, 28 is a stepped shaft 29 fixed to the mounting plate 17.
30 is a switching arm fixed to the connecting plate 28 so as to be able to adjust its position in the longitudinal direction, and is rotatable around the step shaft 29 together with the connecting plate 28. It is.

Reference numeral 31 denotes a spring tensioned between the mounting plate 1T and the connecting plate 28, which applies a clockwise rotational force to the switching arm 30 in the clockwise direction in FIG. acts so as to lightly contact the outer circumferential surface of the second sleeve 16, and in this state, the blocking portion 30a is located on the rotation locus of the other end of the second helical spring 15, and the other end and contact from the front.

Reference numeral 32 denotes a manual switching lever rotatably supported on the step shaft 29, and the tip of a locking pin 34, which is implanted in an elastic plate 33 fixed to the intermediate portion and passes through the lever 32, is attached to the mounting plate. Two holes 17a and 17b drilled in 17
By fitting into either of the two positions, it can be selectively moved to two positions.

A portion 32a of the switching lever 32 is bent backward through an opening 17c formed in the mounting plate 17 to prevent the switching lever 32 from wobbling forward in FIG. , another bent portion 32b is fitted into an opening 30b formed in the switching arm 30, and can be relatively engaged with a protrusion 30c formed on the edge of the opening.

Further, 35 is a chain ring whose one end is locked to the switching lever 32, and the other end is a slot bored in the abutting plate 25) 25b
has been incorporated into.

Further, referring to FIG. 1, numeral 36 indicates a switch mounting bracket fixed to the sewing machine frame 2, and numeral 37 indicates the mounting bracket 36.
The speed change switch is fixed to the operating section 37.
a projects outward from the shielding plate 38.

Reference numeral 39 is a connecting ring whose one end is locked to the operating portion 37a, and the other end is a slot bored in the manual switching lever 32).
It is inserted into e.

Next, the motor control circuit in this embodiment will be explained with reference to FIG.
2, the sewing machine motor 6, and a controller 43 for controlling power supply to the motor and rotation speed of the motor.
are connected in series.

The controller 43 is composed of a variable resistor 44 and a slider 44a thereof, and when the controller is subjected to a suppression operation, the slider 44a is connected to the variable resistance 44 and moves depending on the degree of suppression.

Further, the speed change switch 37 is connected in parallel with the diode 42, and when the switch 37 is closed, the diode 42 is short-circuited and an alternating current voltage is applied to the motor 6. When the motor 6 is open, a half-wave rectified DC voltage is applied to the motor 6. Therefore, by the suppression operation of the controller 43, the rotational speed of the motor 6 is changed to two different maximum rotational speeds. Control can be performed in either one of the speed adjustment ranges.

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

1 to 6 show the state when the manual switching lever 32 is held at position A for performing the binding stitches, and the controller is released from being suppressed, and the switch 3T is in its operating section 37a. is switched to the position side and opened.

When the controller is suppressed, a half-wave rectified DC voltage is applied to the motor 6, the motor is activated, and the pulley 3 starts rotating together with the shaft cylinder 4.

As a result, the helical spring 8 is tightened on the one hand, rotates integrally with the shaft cylinder 4, and starts the main shaft 1.

Therefore, the sleeve 11 also maintains the relative positional relationship shown in FIG. 3 with the helical spring 8 and starts rotating integrally with the helical spring, that is, integrally with the main shaft 1.

On the other hand, the second helical spring 15 also tries to rotate together with the shaft cylinder 4, and its one end 15a touches the abutting portion 2 of the abutting plate 25.
5a to move the support arm 18 from the solid line position in FIG. 4 to the two-dot chain line position against the action of the tension spring 20.

The force resisting the action of the tension spring 20 is due to the fact that the abutment plate 25 abuts on one end 15a of the helical spring 15 from the direction of winding and tightening the spring, and that the abutment plate 25 abuts the one end 15a of the helical spring 15 at the abutting portion 25a.
Coupled with the fact that the contact with the outer circumferential surface of the sleeve 16 prevents it from rotating any further due to the action of the tension spring 27, this occurs reliably.

Accordingly, the stop lever 22 also moves from the solid line position to the two-dot chain line position in FIG. 3, and is located on the rotation trajectory of the engaging portion 11a of the sleeve 11.

When the support arm 18 and the stop lever 22 are moved to the above position, the other end 15b of the second helical spring 15 comes into contact with the blocking part 30a of the switching arm 30, and Rotation accompanying the shaft cylinder 4 is prevented, and slip occurs between the shaft cylinder 4 and the shaft cylinder 4.

Therefore, the force that causes the support arm to move beyond the two-dot chain line position against the action of the tension spring 20 is not transmitted to the support arm 18, and the frictional engagement between the helical spring 15 and the shaft cylinder 4 is prevented. The force generated thereby holds the support arm 18 in the position indicated by the two-dot chain line.

The movement position of this support arm can be adjusted by adjusting the longitudinal position of the switching arm 30 with respect to the connecting plate 28.

When the main shaft 1 rotates to sew one stitch and the needle reaches almost the uppermost position, the engaging part 11a of the sleeve 11 comes into contact with the abutting part 22a of the stop lever 22, and the sleeve 1
10 rotations are blocked.

However, the helical spring 8 is inserted into the notch groove 11 of the sleeve 11.
It further rotates together with the main shaft 1 by an angle corresponding to b, and one end 8a thereof comes into contact with the edge of the notch groove 11b on the rotational direction side.

As a result, the helical spring 8 expands and the transmission of the rotational force of the pulley 3 to the main shaft 1 is cut off, and the helical spring 8
The rotation of the main shaft 1 is forcibly stopped.

At this time, the balance is at the uppermost position, and the needle is at a position slightly lower than the uppermost position.

Further, the tension spring 12 stretched between the sleeve 11 and the suppression plate 9 is in an extended state.

And while the controller is pressed, the stop lever 22, the support arm 18, the sleeve 11 and the helical spring 8.1
5 etc. are held in that position, and the pulley 3 continues to rotate around the main shaft 1 together with the shaft cylinder 4.

When the operator releases the controller in this state, the power supply to the motor 6 is cut off, and the pulley 3 and shaft cylinder 4 stop at their normal positions.

As a result, the force due to the frictional engagement between the shaft cylinder 4 and the second helical spring 15 disappears, and the support arm 18 returns from the two-dot chain line position to the solid line position due to the action of the tension spring 20.

Accordingly, the helical spring 15 is rotated slightly clockwise in FIG. 4 together with the shaft cylinder 4 due to the return movement of the abutment plate 25, and returns to the solid line position.

Further, the stop lever 22 also moves together with the support arm 18 due to the action of the tension spring 24, and the engagement portion 1 of the sleeve 11 moves.
1a and returns to the original position (solid line position in FIG. 3) outside the rotation locus of the engaging portion.

Therefore, the helical spring 8, which had been expanded until then, is tightened by the spring force, so that one end 8a of the helical spring 8 becomes the third one.
While rotating counterclockwise in the figure, the sleeve 1
1 rotates in the same direction by the action of the tension spring 12 and returns to the solid line position in FIG.

At this time, the main shaft 1 does not rotate at all.

After that, by manually transporting the workpiece cloth to the desired position and pressing the controller again, a new stitch can be sewn by the same operation as described above. Basting stitches with intervals can be performed.

By the way, when performing this basting stitch, the switch 37 is restrained in the open state by the chain link 32, and as long as the manual switching lever 32 is held at position A, its operating section 3
7a to the position H side to close the switch 37, and even if the controller is pressed to the maximum, its maximum rotation speed will be compared to when the switch 37 is closed. As a result, the impact between the stop lever 30 and the engaging portion 11a of the sleeve 11 is relatively reduced.

Further, when the band wheel 13 is manually rotated in the forward rotation direction of the main shaft 1 in order to rotate the main shaft 1 during the basting, the second shaft cylinder 7 is rotated with the helical spring 8 to rotate the main shaft 1. However, since the contact plate 25 is in contact with one end 15a of the second helical spring 15 so as to tighten the spring 15, the first shaft cylinder 4 is rotated together with the main shaft 1.
The helical spring 8 can be rotated in the forward direction of rotation, and the helical spring 8 slips around the barrel 4.

Therefore, the stop lever 22 does not move within the rotation locus of the engaging portion 11a of the sleeve 11 against the action of the tension spring 20, and the main shaft 1 can be freely manually rotated in the forward rotation direction. obtain.

Furthermore, when the main shaft 1 is manually rotated in the reverse direction by the band wheel 13, the first degree centigrade helical spring 8 is tightened, so the shaft cylinder 4 and the pulley 3 rotate in the same direction.
At this time, one end 15a of the second helical spring 15 is connected to the spring 1.
5, engages with the abutting portion 25a of the abutting plate 25 so as to expand the abutment plate 25, and slips between the helical spring 15 and the shaft cylinder 4,
The stop lever 22 is not moved against the action of the tension spring 20.

Therefore, the main shaft 1 can be manually rotated freely in both forward and reverse directions.

Next, when the manual switching lever 32 is switched from position A to position B to perform normal continuous sewing, the switching lever 32 is operated to switch from position A to position B.
The bent portion 32b of No. 2 engages with the protrusion 30c of the switching arm 30,
The lever 30 is rotated against the action of the tension spring 31, and the abutting plate 25 is rotated through the connecting punch 35 against the action of the tension spring 27.

Therefore, the contact portion 25a of the contact plate 25 and the blocking portion 30a of the switching arm 30 are connected to both ends 1 of the second helical spring 15.
5a and 15b, and are held in the state shown in FIG. 7.

When the controller is pressed in this state, the pulley 3 rotates together with the shaft cylinder 4, and the main shaft 1 is rotationally driven via the helical spring 8, as described above.

At this time, the second helical spring 15 also rotates together with the shaft cylinder 4, but since its one end 15a does not engage with the contact portion 25a of the contact plate 25, the stop lever 22
At the same time, the main shaft 1 is continuously rotated without being moved against the action of the tension spring 20.

Further, in the case of continuous stitching, the switch 37 can be opened and closed as desired by manual operation of the operating portion 37a, and the continuous punch 39 moves within the slot l□ 32a of the switching lever 32.

Then, the operation section 37. When a is switched to position H, the switch 37 is closed and the diode 42
are short-circuited, and an alternating current voltage is applied to the motor 6.

Therefore, compared to when the switch 37 is open, the electric power supplied to the motor 6 increases, and the motor 6 can be driven at a relatively high speed despite the same suppression operation of the controller. The maximum rotational speed is considerably higher than that for basting.

When the manual switching lever 32 is switched from position B to position A in order to perform basting stitches again after performing the continuous sewing, the switch 37 is closed and the operation section 37 is closed.
When the switch a is switched to the position H side, the operating portion 37a is forcibly switched to the position side via the connecting punch 39, the switch 37 is opened, and the switching lever 32 is held at the position A. You are bound to that state for as long as you are.

As is clear from the detailed embodiments of the present invention,
The stop lever is located outside the rotation locus of one of the engaging parts of the engaging body, which normally rotates integrally with the main shaft due to the action of the spring.
By moving the engaging portion onto the rotation locus against the action of the spring by the action of an actuating piece that rotates within a certain angle range through frictional engagement with a rotating body that is rotationally driven around a main shaft by a motor. , the main shaft is stopped after one revolution to form one stitch, and basting stitches with arbitrary stitch spacing can be performed by repeatedly pressing and releasing the pressure from the controller, and can also be done manually. When driving the main shaft, the stop lever is always located outside the rotation locus of the engaging portion, so it can be rotated completely freely without the need for any special device.

In addition, when performing normal continuous sewing, it is only necessary to operate the manual switching unit, and during continuous sewing, the actuating piece rotates integrally with the rotating body, so the durability of the actuating piece is reduced. The object of the present invention is to provide a main shaft drive device that has excellent practical effects, such as being able to maintain high performance and prevent deterioration in performance.

[Brief explanation of the drawing]

The drawing shows an embodiment of the device embodying the present invention.
Fig. 1 is an explanatory diagram of the band wheel and the device cover removed, as seen from the band wheel side, and Fig. 2 is the same as Fig. 1.
■ An enlarged cross-sectional view along the line, Figure 3 is a cross-sectional view along the ■-■ line in Figure 2, Figure 4 is a cross-sectional view along the IV-IVV line in Figure 2, and Figure 5 is a cross-sectional view along the line V-V in Figure 3. , FIG. 6 is a motor control circuit diagram, and FIG. 7 is a diagram corresponding to FIG. 4 for explaining the case of normal continuous stitching. In the figure, 1 is the main shaft of the sewing machine, 3 is a pulley, 4 is a shaft cylinder, 6 is a motor, 8 is a spiral spring, 11 is a sleeve as an engaging body having an engaging part 11a, 13 is a band wheel, and 15 is an operating piece. 18 is a support arm, 20 is a spring, 22 is a stop lever, 25 is a contact plate, 30 is a switching arm, 32 is a manual switching lever, 37 is a switch, and 43 is a controller.

Claims (1)

[Scope of Claims] 1. A motor for driving the main shaft of the sewing machine, a motor control circuit including a controller that is pressed to control the rotational speed of the motor, and a motor control circuit that is inserted and supported by the main shaft and that is supported by the main shaft. A rotary body that is rotationally driven around a main shaft by a motor, and a rotary body that is provided between the rotary body and the main shaft in order to always transmit the rotation of the rotary body to the main shaft and to interrupt the transmission as necessary. An electric sewing machine is equipped with a clutch means fixed to the main shaft, and a band wheel fixed to the main shaft. a rotating engaging body; a stop lever that can move between on and outside the rotation trajectory of the engaging portion of the engaging body; and the stop lever is always positioned outside the rotation trajectory of the engaging portion. an actuating piece that can rotate within a predetermined angular range with the rotating body through frictional engagement; and rotation of the actuating piece based on the rotation of the rotating body to move the stop lever against the action of the spring. The actuating piece and the actuating piece are moved onto the rotation locus of the engaging part so that the actuating piece and the actuating piece can be returned to their original positions by the action of the spring when the rotation of the rotating body is stopped. and an actuating connection means provided between the stop lever and the engaging portion of the engaging body, the clutch means interrupts transmission of the rotational force of the rotary body to the main shaft, and the main shaft is rotated. When the rotational driving force of the rotating body is released and the stop lever is disengaged from the engaging portion of the engaging body by the action of a spring, the engagement is stopped at a fixed position. 1. A main shaft drive device comprising: means for rotating the combination at a fixed angle relative to the main shaft in a positive rotation direction thereof. 2. In the apparatus according to claim 1, a manual control device operable from outside the sewing machine frame acts on the operation coupling means to interrupt the operation connection between the stop lever and the actuation piece, and causes the actuation piece to rotate together with the rotating body. 1. A main shaft drive device, characterized in that a switching unit is provided so that normal continuous stitching and basting stitching, in which the main shaft is continuously driven, can be appropriately selected.