JPH07178278A - Device for setting needle position in sewing machine - Google Patents

Abstract

PURPOSE:To provide the device tar setting needle position in the inexpensive sewing machine capable of setting the needle at the required position smoothly and accurate]y in the work of setting the needle position after stopping the sewing machine. CONSTITUTION:With the clutch mechanism, the interlocking between the sewing machine motor and an upper axis 1 is prevented and the upper axis of the sewing machine can be rotated. The device is provided with a rotating body 20 which is fixed to the upper axis and is rotated integrally with the upper axis, oscillating member 21 which moves with the rotation of the rotating body, and working member 25 which is abutted on either of the rotating body or to the oscillating member and makes reciprocating motion. When the interlocking between the sewing machine motor and the upper axis of the sewing machine is prevented, the operation member is moved and the upper axis of the sewing machine can be rotated to the set position through the rotating body or the oscillating member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle position setting device in a sewing machine, which moves a stop position of a sewing needle when a sewing operation is stopped to a predetermined position.

[0002]

2. Description of the Related Art The up and down movement of a sewing needle in a sewing machine is performed by the rotation of a sewing machine upper shaft which is interlocked with a sewing machine motor. Generally, between the sewing machine upper shaft and the sewing machine motor, as shown in FIGS. A transmission mechanism D and a clutch mechanism C as shown in the figure are interposed, and the driving force of the sewing machine motor 5 is transmitted to the sewing machine upper shaft 1 by these components. That is, the transmission mechanism D includes a pulley 2 fixed to one end of a sewing machine upper shaft 1 rotatably supported by the sewing machine arm M, and a pulley 4 provided on a rotation shaft of a clutch mechanism described later.
And a belt 3 connecting both pulleys,
The rotation of the pulley 4 is transmitted to the upper shaft 1 of the sewing machine via the belt 3 and the pulley 2.

The clutch mechanism C includes a clutch plate 6 fixed to a motor shaft 5a of a sewing machine motor 5, a rotating shaft 8 held by a motor bracket 7 coaxially with the motor shaft 5a, and a rotating shaft 8a. A rotary plate 9 fixed to one end of the brake plate 8, and a brake plate 10 fixed to the motor bracket 7 at a position facing the rotary plate 9.
A lever 11 for advancing and retracting the rotating shaft 8 is provided. By operating a foot pedal 12 connected to the lever 11, the state of the sewing machine upper shaft 1 can be switched among three states.

For example, when the foot pedal is released as shown in FIG. 5 (a), the lever return spring 13 causes the rotating plate 9 to press-contact the brake plate 10 and separate from the clutch plate 6, so that the rotating plate 9 rotates. The plate 9 is in a non-rotatable state, and the sewing machine upper shaft 1 is also in a stopped state. Also from this state
As shown in (c), when the foot pedal 12 is fully depressed, the lever 11 rotates counterclockwise around the fulcrum 11a, so that the rotating plate 9 is joined to the clutch plate 6 and the brake plate 10 is rotated. Away from. As a result, the rotating plate 9 rotates together with the clutch plate 6, and the upper shaft 1 of the sewing machine enters a rotating state. During the work, the sewing machine motor 5 is constantly driven and the clutch plate 6 is constantly rotating.

Further, when the foot pedal 12 is moved to an intermediate position between the release position and the connecting position as shown in FIG. 5 (b), the rotating plate 9 is moved to the clutch plate 6 as shown in FIG. And the brake plate 10 are not joined to each other, so that the rotating shaft and the upper shaft interlocked with the rotating shaft can freely rotate. Therefore, in this state, the operator can manually rotate the pulley 2 and the like, and the height of the sewing needle N can be set to an arbitrary position.

As described above, in the above-mentioned sewing machine, it is possible to instruct execution and stop of the sewing operation by the sewing machine by depressing and releasing the foot pedal 12, but when instructing to stop the sewing operation, the release timing of the foot pedal 12 It is impossible to always keep the sewing machine constant in one sewing cycle, and the degree of braking is slightly different for each sewing machine, so no matter how skillful an operator is, the stop position of the sewing needle is It usually changes every time the sewing operation is stopped.

However, after the sewing operation is stopped, the position of the sewing needle N includes a position where the subsequent work is easy to perform and a position where it is not easy to perform, and when the sewing needle N does not stop at the position where the work is easy to perform. , It is necessary to change its position manually. For example, when the sewing needle N stops at the cloth penetration position at the end of the sewing operation, the cloth cannot be taken out from the sewing machine table T in that state, and therefore the sewing needle needs to be lifted and pulled out from the cloth.

When forming a bending seam line S as shown in FIG. 6 (c), the sewing operation is temporarily stopped at the bending point P of the seam line S as shown in FIG. 6 (a). ,
After that, the cloth W is rotated by the bending angle of the seam and the sewing operation is started again.
If the cloth W is rotated with the sewing needle N penetrating as shown in (b), the cloth W can be accurately and easily rotated about the sewing needle N, and the stitch position and the stitch position at the time of restart of sewing and The pitch can be maintained properly. Therefore, when the sewing needle N is located above the cloth W when the sewing operation is once stopped, it is desirable to lower the sewing needle N to penetrate the cloth W.

Therefore, conventionally, when the sewing needle N stops at a position unsuitable for the subsequent work, first, the foot pedal is depressed to an intermediate position shown in FIG. 5 (b) to rotate the upper shaft 1 of the sewing machine. The sewing machine is set in a free state, and the pulley 2 and the flywheel are manually rotated while keeping the state to set the sewing needle N to a required position.

[0010]

However, when the position of the sewing needle N is set by rotating the pulley 4, it is necessary to visually check the position of the sewing needle N each time, which is troublesome. However, this has been a cause of lowering productivity. Further, since the sewing needle N and the pulley 4 are located at both ends of the sewing machine arm M, when the sewing machine arm M is long, the work is performed while one hand is extended, which imposes a heavy burden on the operator. There was also a problem.

Therefore, at present, there is also known one in which the rotational position of the upper shaft of the sewing machine is detected by a sensor and the stop position of the sewing machine motor is electrically controlled by the output from the sensor. However, in this case, a special motor such as an electromagnetic clutch motor or a servo motor, a control device therefor, and a sensor are required, which leads to a significant cost increase compared with the case of using a normal motor. There's a problem.

The present invention has been made by paying attention to the above-mentioned problems of the prior art. In the needle position setting work after the sewing machine is stopped, the sewing needle can be quickly and surely set to a desired position at a low cost. An object of the present invention is to provide a needle position setting device in a sewing machine having a structure.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a sewing machine having a sewing machine upper shaft and a sewing machine upper shaft capable of rotating by fixing the sewing machine motor and the sewing machine upper shaft by a clutch mechanism is fixed to the sewing machine upper shaft. The rotating body that rotates integrally with the upper shaft of the sewing machine, the swinging member that swings in conjunction with the rotary motion of the rotating body, and the reciprocating motion that can abut either one of the rotating body and the swinging member. An operating member provided in the sewing machine, the sewing machine motor and the upper shaft of the sewing machine are interlocked to move the operating member to a return position, thereby causing the sewing machine to move through the rotating body or the swinging member. The upper shaft is rotated to a preset position.

[0014]

According to the present invention, the position of the rotating body or the swing member with respect to the upper shaft of the sewing machine is set in advance, and thereafter the operating member is moved to the return position while the upper shaft of the sewing machine is in a rotatable state. By doing so, the sewing needle can always be set at a fixed position. That is, when the actuating lever is moved to the return position, the rotating body or the swinging member contacting the actuating lever rotates the upper shaft of the sewing machine to a predetermined position, and accordingly, the sewing needle moves in accordance with the rotating position. It is set to a predetermined position.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
It will be explained based on. In the drawings, the same or corresponding parts as those shown in the above-mentioned conventional technique are designated by the same reference numerals. In the figure, reference numeral 20 denotes an eccentric cam (rotating body) which is detachably fixed to an intermediate portion of the sewing machine upper shaft 1 by a screw or the like. The eccentric cam 20 has a disk shape, and its center is the center of the sewing machine upper shaft 1. It is fixed at a position that is offset from. Reference numeral 21 is a rocking rod as a rocking member that rocks along with the rotation of the eccentric cam 20, and an annular portion 21a is formed at one end of the rocking rod 21 to rotate on the outer peripheral surface of the eccentric cam 20. Fitting is possible. Reference numeral 22 denotes a rotary link whose one end is rotatably attached to the sewing machine arm M by a support shaft 23, and the other end of the swing rod 21 is rotated by an abutment pin 24. It is freely connected. The contact pin 24 projects to one side of the rotary link 22.

Reference numeral 25 is an operating lever (operating member) supported by the support shaft 23 so as to be rotatable and reciprocally movable. The operating lever 25 is urged upward by a return spring 27, and its upper surface is always in contact with a stopper 28 protruding from the sewing machine arm M. The lower surface of the actuating lever 25 faces the contact pin 24 and can be brought into contact with the contact pin 24 by rotating downward. Further, an operating portion 25a is formed at the other end of the operating lever 26, and the operating portion 25a projects from the front wall of the sewing machine arm M. Therefore, the operator pushes and releases the operating portion 25a to release the operating lever 26a.
Can be rotated.

On the other hand, 30 is a well-known needle bar elevating mechanism for converting the rotational movement of the upper shaft 1 of the sewing machine into the elevating movement of the needle bar NL provided on the sewing machine arm M so as to be able to ascend and descend. The needle bar elevating mechanism 30 includes a needle bar link 31 fixed to one end of the sewing machine upper shaft 1, a needle bar rod 32 axially attached to one end of the needle bar link 31, and a needle bar rod 32. A connecting shaft 33 for rotatably connecting the end portion to the needle bar, and a needle bar roller 3
4 and the needle bar link 3 together with the upper shaft 1 of the sewing machine.
When 1 is rotated, the needle bar rod 32 moves the needle bar NR.
It is designed to be converted into a vertical movement. The sewing machine upper shaft 1 is connected to the sewing machine motor 5 by a transmission means D and a clutch means C having the same structure as the conventional sewing machine shown in FIG.

Next, the operation will be described based on the above configuration. When the operating portion 25a is in the released state, the operating lever 25
Is held by the return spring 27 at the contact position (raised position) with the stopper 28. Here, as shown in FIG. 5C, the foot pedal 12 is fully depressed, and the sewing machine motor 5
When the sewing machine is started by connecting the sewing machine upper shaft 1 to the sewing machine, the eccentric cam 20 rotates with the rotation of the sewing machine upper shaft 1, and the swing rod 21 fitted to the outer periphery of the eccentric cam 20 swings. As a result of the movement, the rotary link 22 moves around the support shaft 23 as a fulcrum,
The rocking motion is performed in the angle range θ from the position to the position b. The swinging movement of the rotary link 22 causes the contact pin 24 to move up and down with respect to the actuating lever 25. At this time, however, the actuating lever 25 is held in the raised position, so that the contact pin 2 is held.
4 does not interfere with the operating lever 25, and the rotation operation of the sewing machine upper shaft 1 is not hindered.

When the foot pedal 12 is released and the sewing operation is stopped by disconnecting the interlock between the sewing machine upper shaft 1 and the sewing machine motor 5, the sewing needle N releases the foot pedal 12 and determines how the brake is applied. Stop at various positions depending on the situation. If the stop position is not suitable for the next work, the foot pedal 12 is depressed to the intermediate position shown in FIG.
Is made rotatable, and the operating lever 25 is pushed down to the lowest position (returning position) while maintaining this state, whereby the sewing needle N can be held at an appropriate preset position.

That is, when the operator pushes down the actuating lever 25 against the return spring 27, the lower surface thereof abuts against the abutment pin 24 and presses the abutment pin 24.
4 moves along with the rotation link 22 along a rotation path centered on the support shaft 23. By this movement, the rocking rod 21 moves downward while rotating the eccentric cam 20, and the contact pin 24 and the center of the upper shaft 1 of the sewing machine and the contact pin 2 move.
At the time of being located on the straight line connecting the center of 4 with each other, the rotation link 22 and the contact pin 24 reach the lowest point b, and the downward movement is blocked (see FIG. 3). This means that the operating lever 25 has reached the lowest position (forward position).

During this time, the sewing machine upper shaft 1 also rotates integrally with the eccentric cam 20, and the sewing needle N is set at a height position corresponding to the rotation. The height position of the sewing needle N set here can be set to an arbitrary position by previously adjusting the fixed position of the eccentric cam 20 with respect to the sewing machine upper shaft 1 in the rotation direction. For example, when the sewing needle N is moved to the top dead center by pushing down the operating lever 25, first, the fixing state of the eccentric cam 20 to the sewing machine upper shaft 1 is released, and then the operating lever 25 is moved. This can be performed by rotating the sewing machine upper shaft 1 while moving it to the lowest position to move the sewing needle N to the top dead center, and then fixing the eccentric cam 20 to the sewing machine upper shaft 1 again. The foot pedal 12 must be held at an intermediate position even when the sewing machine upper shaft 1 is rotated in this setting work.

As described above, when the sewing needle N is positioned at the top dead center by lowering the operating lever 25, the work of taking out the cloth after the sewing operation is completed can be performed quickly and easily. it can. That is, when the sewing needle N stops in a state of penetrating the cloth after the sewing operation is finished, after the foot pedal 12 is depressed to an intermediate position,
By lowering the operating lever 25 to the lowest position, the sewing needle N can be reliably moved to the top dead center,
It is not necessary to visually check the position of the sewing needle N each time as in the conventional case. For this reason, the time required from the end of the sewing operation until the cloth is taken out is greatly reduced, and the burden on the operator is also significantly reduced.

When the operating lever 25 is lowered, the sewing needle N
If the eccentric cam 20 is fixed to the upper shaft 1 of the sewing machine so that is located at the bottom dead center, the bent seam S as shown in FIG.
It is effective when forming That is, FIG. 6B
When the sewing operation is temporarily stopped at the bending point P of the seam S as shown in, when the sewing needle N stops in the state of being pulled out from the cloth W, the operating lever 25 is pushed down to ensure that the sewing needle N is The bottom dead center is reached and the cloth penetrates. Therefore, after the sewing operation is stopped, the cloth can be rotated accurately and quickly around the sewing needle N, and the productivity is significantly improved.

In the above embodiment, the sewing needle is moved to the predetermined single set position by the single operating lever 25, but by providing two operating levers as the operating members. It is also possible to set the sewing needle at two positions. For example, in the above embodiment, if an operating lever facing the lower side of the contact pin 24 is rotatably attached by the support shaft 23 in addition to the operating lever 25, the sewing needle N has a phase difference of 180 degrees. Can be set to a position.

That is, when the sewing needle N can be moved to the bottom dead center by pushing down one operating lever 25 as in the above embodiment, the sewing needle N is pushed up by pushing the other operating lever. Can be moved to top dead center. Therefore, in this case, the sewing needle can be set to an appropriate position by operating the lever in both the rotating work and the removing work of the cloth.
More excellent operability can be obtained.

The actuating lever can also be actuated by the driving force of an actuator or the like, and if the actuator is actuated in response to the depression operation of the foot pedal to an intermediate position, the needle can be operated only by pedal operation. It becomes possible to set the position.

In the above embodiment, the sewing machine upper shaft 1 is rotated from the operating lever 25 via the contact pin 24, the swing rod 21 and the eccentric cam 20, and as a result, the position of the sewing needle N is set. However, an operating lever that can reciprocate up and down within a range larger than the lifting range of the sewing needle is provided, and an abutment pin that can abut this operating lever is provided on the needle bar so as to raise or lower the operating lever. By doing so, the needle bar may be moved to the top dead center or the bottom dead center, and the present invention is not particularly limited to the configuration shown in the above embodiment. In this case, the needle bar link 31
Corresponds to the rotating member, and the needle bar NL corresponds to the swinging member.

[0028]

As described above, according to the present invention, in the sewing machine in which the clutch mechanism can switch between the interlocking and disconnection of the sewing machine motor and the upper shaft of the sewing machine, and the upper shaft of the sewing machine can be turned in the disconnected state. , The sewing machine upper shaft is rotated to a predetermined position by moving the reciprocally movable actuating member to the return position, so that the operator first needs the sewing needle for the sewing machine upper shaft. After setting the height position of the sewing needle, the sewing needle can be quickly and surely set to the preset height position by an extremely simple operation of only moving the operating member forward. Therefore, if the present invention is applied, the sewing needle can be quickly and surely set to an appropriate position in, for example, taking out the cloth after the sewing operation is completed or rotating the cloth when forming a bent seam. It becomes possible and productivity can be improved significantly.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is an enlarged side view of a main part of what is shown in FIG.

FIG. 3 is a side view showing a state in which the operating lever is lowered in the apparatus shown in FIG.

FIG. 4 is a side view showing an interlocking relationship between a sewing machine motor and a sewing machine upper shaft in the sewing machine.

5 is a partially longitudinal side view showing the clutch mechanism in the one shown in FIG. 4, (a) showing a state in which the foot pedal is released, and (b) depressing the foot pedal to an intermediate position. The state (c) shows the state where the foot pedal is fully depressed.

FIG. 6 is an explanatory perspective view showing a sewing procedure when forming a bent seam line.

[Explanation of symbols]

 M sewing machine arm 1 sewing machine upper shaft NL needle bar N sewing needle 30 needle bar lifting mechanism 5 sewing machine motor C clutch mechanism 20 eccentric cam (rotating body) 21 swinging rod (rocking member) 25 actuating lever (actuating member)

Claims (1)

[Claims] 1. A sewing machine upper shaft rotatably instructed by a sewing machine frame, a needle bar elevating mechanism for converting rotation of the sewing machine upper shaft into an elevating motion of a needle bar holding a sewing needle, and the sewing machine upper shaft. A sewing machine motor that acts as a drive source for the shaft, and a clutch mechanism that connects and disconnects the sewing machine motor and the sewing machine upper shaft are provided, and by cutting the interlocking between the sewing machine motor and the sewing machine upper shaft by the clutch mechanism, In a sewing machine in which the upper shaft of the sewing machine is rotatable, a rotating body that is fixed to the upper shaft of the sewing machine and rotates integrally with the upper shaft of the sewing machine, and a swinging member that swings in conjunction with the rotational movement of the rotating body. An operating member that is reciprocally movable so as to come into contact with either one of the rotating body and the swinging member, and when the interlocking between the sewing machine motor and the sewing machine upper shaft is in a cutoff state, the operating member The return position Hand position setting apparatus in a sewing machine, characterized in that by moving and so as to rotate to a position to set the axial perforation in advance through the rotary body or the swing member and the.