JPS5922555B2 - Electric sewing machine speed switching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed switching device for an electric sewing machine, and more particularly, the present invention relates to a speed switching device for an electric sewing machine. This invention relates to an electric sewing machine configured to be controlled in either one of the speed adjustment ranges.

In this type of electric sewing machine, in addition to normal continuous sewing in which the main shaft of the sewing machine is continuously driven during the suppressing operation of the controller, the main shaft of the sewing machine rotates once and then stops despite the continuation of the pressing operation of the controller. Sewing machines have already been provided that are configured to selectively perform lash stitches using a so-called needle line.

When performing the basting stitches with such a sewing machine, it is undesirable for the rotational speed of the motor to increase more than necessary from the viewpoint of its mechanism and work safety, and it is preferable that the controller be operated to suppress it to the maximum. However, it is necessary for the motor to rotate at a relatively low speed.

Therefore, the switch means for selecting the speed adjustment range of the motor is operable into three positions;
In the second position, normal continuous stitching is performed in different motor speed adjustment ranges, and in the third position, basting stitching with a single stitch line is performed at a relatively low speed.

However, in the above configuration, the switch means serves both to switch between continuous stitching and boxwood stitches and to switch the speed adjustment range of the motor, which not only complicates the structure but also makes it difficult for the operator to operate. There is a risk of incorrect usage.

The present invention has been made in view of the above circumstances, and the manual switching unit, which can be operated to select between normal continuous stitching and one-stitch line stitching, performs continuous stitching (when operated). , the speed adjustment range of the motor is freely selected by the switching operation of the switch means, and the manual switching body performs the binding stitch (when operated, the switch means sets the speed adjustment range of the motor to a relatively low range). The feature is that the motor rotation speed is restricted to a selectively operated state, and its purpose is to allow operators to use electric sewing machines that can selectively perform continuous stitching and basting stitches. It is an object of the present invention to provide a speed switching device that does not make mistakes in operation.

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 20th shaft cylinder adjacent to one side of the shaft cylinder 4, which is fitted and fixed onto 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 relaxes, cutting off the transmission of rotational force to the main shaft 1, and moreover, the main shaft 1 is forcibly stopped. The helical spring 8 acts as a spring clutch.

Incidentally, reference numeral 13 denotes a band wheel fixed to rotate together with the main shaft 1 by a tightening screw 14, 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 is the same (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 spring 200, the stop lever 22 moves so that its abutting portion 22a is located on the rotation locus of the engaging portion 11a.

Further, reference numeral 25 denotes an abutment plate rotatably supported by the support arm 18 by a pivot 26, which is activated by the action of a tension spring 27 having a weak spring force stretched between the support arm 18 and the support arm 18, as shown in FIG. A clockwise rotational force is applied to the second sleeve 16, and the abutment portion 25a formed at the tip abuts the outer circumferential surface of the second sleeve 16, thereby restricting further rotation.

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 tension spring stretched between the mounting plate 17 and the connecting plate 28, which applies a rotational force to the switching arm 30 in the clockwise direction in FIG. The blocking portion 30a acts so as to lightly contact the outer peripheral surface of the second sleeve 16, and in this state, the blocking portion 30a is located on the rotation trajectory of the other end of the second helical spring 15, and is in contact with the other end. Hit 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 set on an elastic plate 33 fixed to the intermediate part of the manual switching lever and passes through the lever 32, is attached to the mounting plate. By fitting into either of the two holes 17a, 17b drilled in the hole 17, 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 continuous punch whose one end is locked to the switching lever 32, and the other end is a slot 25b bored in the abutment plate 25.
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.

39 is a continuous punch whose one end is locked to the operating part 37a, and the other end is a slot bored in the manual switching lever 32).
It is inserted into c.

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 consists of a variable resistor 44 and a slider 44a thereof, and when the controller is pressed, the slider 44a is connected to the variable resistor 44 and moves depending on the degree of pressure.

Further, the speed switching switch 37 is connected in parallel with the diode 42, and when the switch 37 is patrolled, the diode 42 is short-circuited and an alternating current voltage is applied to the motor 6, and the switch 37 is activated. When it is open, a half-wave rectified DC voltage is applied to the motor 6. Therefore, by pressing the controller 43, the rotational speed of the motor 6 can be changed to two different maximum rotational speeds. It can be controlled in either one of the 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 basting stitches and the pressure on the controller is released, and the switch 37 has its operating portion 37a It 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 spring 27, this definitely occurs.

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 locus of the engaging portion 11a of the sleeve 11.

When the support arm 18 and the stop lever 22 are moved to the above positions, the other end 15b of the second helical spring 15 comes into contact with the blocking part 30a of the switching arm 30, and the further end of the helical spring 15 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 due to the frictional engagement between the helical spring 15 and the shaft cylinder 4, The resulting force holds the support arm 18 in the two-dot chain position.

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 is stopped, and 10 rotations of the main shaft are 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 pressing plate 9 is in an extended state.

Then, while the controller is pressed, the stop lever 22, the support arm 18, the sleeve 11 and the helical springs 8, 1
5 and the like 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 L 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 L.
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. By repeating this process, the stitch interval of any length can be sewn. It is possible to perform lash stitches with

By the way, when performing this basting stitch, the switch 37 is restrained in the open state by the continuous punch 32, and as long as the manual changeover 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 10th shaft cylinder 4 is rotated with the main shaft 1.
The helical spring 8 slips around the shaft cylinder 4 and can rotate in the forward direction of rotation.

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 helical spring 8 is tightened, so that 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 is engaged with the abutting portion 25a of the abutting plate 25 so as to expand, and slips between the helical spring 15 and the shaft cylinder 4, and the stop lever (-22 resists the action of the tension spring 20). and will not be moved.

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 200.

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 32a of the switching lever 32.

When the operating portion 37a is switched to the position H side, the switch 37 is closed, the diode 42 is 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 pressing operation of the controller. The maximum number of rotations is considerably higher than that for the above-mentioned lash stitching.

Therefore, after performing the above-mentioned continuous sewing, the binding stitch should be performed again (
When switching the manual switching lever 32 from position B to position A, the switch 37 is closed and its operating portion 3γ
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 while you are in it.

As is clear from the detailed embodiments of the present invention,
When the manual switching unit is selectively operated to perform normal continuous stitching, the rotational speed of the motor is controlled in one of two speed adjustment ranges having different maximum rotational speeds by pressing the controller. The maximum rotational speed of the motor can be selected arbitrarily by a switch means that can be operated manually from outside the sewing machine frame, and when the manual switching body is operated to perform the binding stitch, the maximum rotational speed of the motor can be selected as desired. The switch means is restrained so that the rotational speed of the motor is controlled by the suppressing operation of the controller in the lower speed adjustment range, and when the continuous sewing is performed, the switch means controls the rotational speed of the motor to the maximum rotational speed. If control is selected in the higher speed adjustment range, when the manual switching unit is operated to select to perform binding stitches, the switching means is forced to operate in conjunction with the operation. The change operation is performed.

Therefore, an excellent speed switching device is provided in which the operator does not operate the switch means incorrectly, can safely and easily perform binding stitches, and does not increase the rotational speed of the motor more than necessary. This is what we provide.

[Brief explanation of drawings]

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 an explanatory diagram of the band wheel shown in Fig. 1.
■An enlarged cross-sectional view of the line, Figure 3 is a cross-sectional view of the ■--■ line of Figure 2, Figure 4 is a cross-sectional view of the IV-IVV line of Figure 2, and Figure 5 is a cross-sectional view of the line V-V of Figure 3. 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 helical spring, 11 is a sleeve having an engaging portion 11a, 13 is a band wheel, 15 is a second helical spring,
18 is a support arm, 20 is a tension 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. Includes a motor for driving the main shaft of the sewing machine and a controller that is pressed to control the rotational speed of the motor, and that the rotational speed of the motor is set to the maximum speed by pressing the controller. A speed control circuit capable of controlling one of two speed adjustment ranges having different speeds, and a switch means disposed in the speed control circuit and manually operable from outside the sewing machine frame to select the speed adjustment range. and a drive mechanism configured to start a main shaft of the sewing machine by a suppressing operation of the controller, to continuously drive the main shaft during the pressing operation, and to stop driving the main shaft by releasing the suppressing operation of the controller. and a stop means disposed in connection with the drive mechanism for basting stitches, which stops the main shaft of the sewing machine when the main shaft of the sewing machine rotates once despite continued suppression by the controller, and actuating the stop means. a manual switching unit that can be operated from outside the sewing machine frame in order to selectively set it in a state in which it is possible to operate or in a state in which it cannot operate, and to perform normal continuous stitching and basting stitches as desired; and the manual switching unit. When the body is selectively operated to perform continuous stitching, the switch means can be manually operated freely, and when the manual switching body is selectively operated to perform basting stitches, the maximum rotational speed of the motor of the switch means can be freely operated. A speed switching device for an electric sewing machine, characterized in that the speed switching device for an electric sewing machine is provided with a connecting means for connecting the manual switching member and the switching means in order to restrict the speed adjustment range to the one in which the speed is lowered to be selected.