JPS6022924Y2 - Step motor step-out prevention mechanism for sewing machines - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a step motor step-out prevention mechanism in a sewing machine.

A step motor in a sewing machine is mainly used as a pattern generator, and operates synchronously within a drive range formed by receiving drive pulses from a control circuit to operate a needle bar or cloth feed dog to generate a pattern.

In addition, since the needle bar operation and cloth feed dog operation have the same operation,
The following description will focus on the operation of the needle bar.

FIG. 1 shows a conventional sewing machine.

In the figure, 1 is the main body of the sewing machine, 2 is a needle bar, 3 is an oscillating body of the needle bar 2, 4 is a needle, and 5 is an oscillating width rod that gives movement to the oscillating body 3 during needle oscillation, one end of which is rotated by a pin 5a. It is freely supported by the rocking body 3.

6 is a step motor for driving during needle vibration, the other end of the vibration width rod 5 is pivotally supported by the step motor 6 via a crank 6a, and the rotation of the step motor 6 causes the rod 5 to perform a swinging motion. It is supposed to be done.

The step motor 6 rotates in response to drive pulses from a control circuit (not shown) provided inside the sewing machine body 1.

However, in such a conventional sewing machine, the swing rod 5 and the swinging body 3 are rotatably supported only by the pin 5a.

Therefore, the operator may accidentally remove the needle 4 when replacing the needle 4, etc.
, if the oscillator 3 is caused to oscillate by touching the needle bar 2, etc., the oscillation of the oscillator 3 will be directly transmitted to the oscillating width rod 5, shifting the rotational phase of the step motor 6, which will cause the start Since then, it has had the disadvantage of causing malfunctions and not being able to stitch the specified pattern.

Incidentally, this drawback also applies to the horizontal operation of the feed dog 15.

The purpose of this invention is to solve the above-mentioned drawbacks and to provide a step motor step-out prevention mechanism in a sewing machine that is simple in construction and inexpensive.

Hereinafter, embodiments of this invention will be described based on the drawings.

Incidentally, the same components as in the conventional column are designated by the same reference numerals, so detailed explanation thereof will be omitted.

Further, as described above, since the needle bar operation and the feed dog operation have the same operation, the needle bar operation will be mainly explained below.

FIG. 2 is an exploded perspective view showing an embodiment of the step-out prevention mechanism according to this invention.

In the figure, reference numeral 5 denotes a swinging rod that swings in relation to the rotational movement of a step motor 6 (see FIG. 1), and one end 5c of which has a bent portion 8a in the middle via a ball joint 7. A swing frame rod 8 is rotatably provided.

Reference numeral 9 denotes a swinging base plate having a small hole 9a at the tip, a vertical locking piece 9b at the base end, and a bending piece 9c in the middle. 9A, and the shaft tube portion 8A is inserted and rotatably supported on the shaft pin 10 provided upright on the swinging body 3 of the needle bar 2.

Reference numeral 11 denotes a rotation locking pin as a locking portion of the rocking base plate 9, which is installed upright near the shaft pin 10 of the rocking body 3, and is in contact with the tip of the rocking base plate 9 to lock the rocking base plate 9. This prevents rotation in one direction.

12 is a second shaft fitted onto the shaft tube portion 9A of the rocking table plate 9;
It is a wound spring as an elastic body, one end 12a of which engages with the bent piece 9c of the rocking base plate 9, and the other end 12b engages with the bent part 8a of the rocking frame rod to form the bent part 8a. is pressed against the vertical locking piece 9b of the swing base plate 9, and the swing base plate 9 and the swing frame rod 8 are normally integrally joined.

13 is a screw 3a provided on the upper part of the oscillating body 3 and a oscillating base plate 9.
A spring serving as a first elastic body is interposed between the small holes 9a, and due to the elastic force of this spring 13, the rocking table plate 9 is always in contact with the rotation locking pin 11.

Although the coiled spring 12 is used as the second elastic body, it is not limited to this, and any elastic body that can elastically connect the swinging base plate 9 and the swinging frame rod 8 may be used. The mounting position is also not limited to the above position.

Further, in the figure, 3A is a rotating shaft of a swinging body 3 provided in the sewing machine main body 1, 14 is a needle bar holder, and 12A is a plate that supports the coiled spring 12.

Next, the action will be explained.

Now, as shown in Figure 3, during normal operation, that is, the control circuit (
Step motor 6 receives drive pulses from (not shown)
(see FIG. 1) operate synchronously, and when the swing rod 5 moves in the direction of arrow X1 as shown in FIG. Since the swing frame rod 8 and the swing base plate 9 are both pressed together, they try to rotate on the shaft pin 10 in the direction of arrow Y1.

As a result, this rotational force is applied to the rotation locking pin 11 which is normally in contact with the rocking base plate 9 due to the tensile force of the spring 13, and the rocking body 3 moves in the direction of arrow P1 around the rotation axis 3A. oscillate.

Next, as shown in FIG. 4, when the swing rod 5 moves in the direction of the arrow X2 due to the synchronous operation of the step motor 6, the swing frame rod 8 and the swing base plate 9 are moved by the coiled spring 12 as described above. The rocking base plate 9 is integrally joined by the elastic force of
1, the swinging body 3 swings in the direction of arrow P2 about the rotation axis 3A, contrary to the above.

Then, the arrow P1. of these rocking bodies 3. A zigzag pattern or the like is sewn onto a workpiece (not shown) by the swinging motion in the P2 direction.

Next, for example, while the sewing machine is running, the worker accidentally
If you move the needle bar 2 and cause the oscillating body 3 to oscillate, or if you accidentally move the needle bar 2 etc. when replacing the needle 4 etc. and cause the oscillating body 3 to oscillate, the following actions will occur as shown in Figures 5 and 6. As in the rocking body 3
Even with the swinging, the amplitude rod 5 does not swing, so the step motor 6 does not rotate, and the phase of the step motor 6 does not change.

That is, as shown in FIG.
When the shaft pin 10 is moved in the direction of the arrow P1, the shaft pin 10 also rotates in the P1 direction.As a result, the swinging frame rod 8 and the swinging base plate 9, which are integrally connected by the elastic force of the coiled spring 12, also move in the P1 direction. As a result, the swinging rod 5 is moved in the direction of the arrow X1, and the phase of the step motor is changed.

However, since the tip of the rocking base plate 9 is connected to the rocking body 3 by the spring 13, unless the spring 13 is stretched as shown in the figure, the rocking base plate 9 will also rotate in the direction of arrow Y2 and vibrate. Do not move the width rod 5 in the direction of the arrow X and force.

Therefore, the swinging rod 5 is connected to the crank 6b of the crank 6a (
(See Figure 1)
No force is applied to rotate the step motor 6, and the phase of the step motor 6 does not change at all.

Further, as shown in FIG. 6, when the operator accidentally moves the swinging body 3 in the direction of arrow P2, the shaft pin 10 also pivots in the direction of P2, thereby causing the swinging frame rod 8 and the swinging base plate 9 to move. Both of them try to rotate together with the oscillator 3, and as a result, the oscillating width rod 5
is moved in the direction of arrow X2 to change the phase of the step motor 6.

However, since the swing base plate 9 is brought into contact with the rotation locking pin 13 by the spring 13, and the swing base plate 9 and the swing frame rod 8 are joined by the coil spring 12, the coil spring 12 gradually The swing base plate 9 and the swing frame rod 8 are oppressed by
The relative joining relationship between the two ends offsets the force that moves the swinging width rod 5 in the direction of the arrow X2, and therefore the swinging width rod 5 does not move in the direction of the arrow X2.

Therefore, the phase of the step motor 6 does not change at all as described above.

Incidentally, in order to use the step-out prevention mechanism according to this invention as a step-out prevention mechanism for the step motor 16 for driving the cloth feed dog 5 shown in FIG.
The shaking width rod 19 provided through the oscillating width rod 19 and the swinging body 22 fitted into the feed link 21 connected to the cloth feed dog 15 via the feed adjuster 20 are connected via the step-out prevention mechanism according to this invention. This may cause the worker to accidentally touch the cloth feed dog 15 and cause it to move, or due to a feed jam or the like, an external force is applied to the feed dog compared to normal sewing, causing the feed dog to move. However, the phase of the step motor 16 for driving the cloth feed dog 15 does not change as described above.

As explained above, according to this invention, even if an operator touches the needle, needle bar, or feed dog and moves these oscillators during operation of the sewing machine, the step for driving the needle, needle bar, or feed dog will not be activated. There is no possibility that the rotational phase of the motor will change.

Therefore, it is possible to eliminate the disturbance of the stitch pattern and the deviation of the pattern due to the malfunction, and it is possible to perform beautiful pattern stitching.

Furthermore, since it has an extremely simple configuration, it is inexpensive and has good durability.

Furthermore, according to this invention, the torque of the step motor does not need to be so high that its rotational phase does not change, but a low torque sufficient to drive the driven side is sufficient, so a small and low cost step motor can be realized. A motor can be used.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts of a conventional sewing machine, Fig. 2 is an exploded perspective view of the tax control prevention mechanism according to this invention, and Figs. 3 to 6 are explanations of the operation of the step-out prevention mechanism shown in Fig. 2. It is a diagram. 3.22... Rocking body, 5, 20... Shaking width rod, 8... Rocking frame rod, 9... Rocking plate body, 10 ...Axis pin, 11... Rotation locking pin, 12... Wound spring as first elastic body, 13...... As second elastic body spring.

Claims (1)

[Claims for Utility Model Registration] A rocking body whose base end is swingably supported around a fixed axis and is equipped with a needle or a feed dog, a step motor, and a rocking body that swings in relation to the rotation of the step motor. A swinging width rod that moves, a swinging frame rod whose one end is supported by the swinging width rod, the other end of which is supported by a shaft pin provided on the swinging body, a swinging base plate rotatably supported by the shaft pin, and A vertical locking piece formed on the moving base plate, a locking part provided on the swinging body facing the swinging base plate, and interposed between the swinging body and the swinging base to always keep the swinging base plate in relation to the shaft pin. A first elastic body that urges the stop part to elastically lock, and is interposed between the swinging base plate and the swinging frame rod, and is always in the opposite direction with respect to the axis pin with respect to the direction of the urging force of the first elastic body. A step motor step-out prevention mechanism in a sewing machine comprising: a second elastic body acting on a second elastic body;