JP3189369B2 - Sewing machine threading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine having a needle bar to which a plurality of sewing needles are attached, and more particularly to a threading device for a sewing machine which passes a thread through an eye of a sewing needle.

[0002]

2. Description of the Related Art An example of a threading device for a sewing machine having a needle bar to which a plurality of sewing needles are attached, for example, a lock sewing machine is disclosed in JP-A-3-133483. In this configuration, as shown in FIG. 16, the shaft 1 is disposed along the left-right direction, and the shaft 1 is rotatably provided with its shaft center as a rotation fulcrum. The threading member 3 is attached via the. A threading needle 4 (corresponding to a threading hook) is provided at the tip of the threading member 3.

In this configuration, when a thread is passed through the right sewing needle 6, as shown by a solid line in FIG. 16, the fixing member 2 is adjusted so that the threading member 3 is set so as to be orthogonal to the shaft 1. The threading needle 4 is made to correspond to the eye hole of the sewing needle 5. Thereafter, by rotating the shaft 1, the threading member 3 is brought close to the sewing needle 6 from behind the sewing needle 6, and the threading needle 4 is advanced into the eye of the sewing needle 6. Then, after the thread is hooked on the threading needle 4, the thread is passed through the eye of the sewing needle 6 by rotating the shaft 1 in the reverse direction to retract the threading needle 4 from the eye of the sewing needle 6. Like that.

On the other hand, when a thread is passed through the left sewing needle 5, FIG.
As shown by the two-dot chain line in FIG. 6, the fixing member 2 is adjusted to set the threading member 3 at an angle to the shaft 1 so that the threading needle 4 corresponds to the eye of the sewing needle 5. Then, by rotating the shaft 1, the thread hooking needle 4 is advanced into the eye of the sewing needle 5 and retracted in a manner similar to the case of the sewing needle 6 described above, so that the thread is inserted into the eye of the sewing needle 5. Pass through the hole. Thereby, the threading operation is simplified as compared with the case where threading is performed using tweezers or the like.

[0005]

In the above construction, the threading needle 4 is formed of an elongated thin plate, and as shown in FIG. 17, the threading needle 4 is inserted into the eye 6a of the right sewing needle 6. In this case, there is a sufficient gap between the threading needle 4 and the inner surface of the eye 6a. However, when the threading needle 4 is caused to enter the eye 5a of the sewing needle 5 on the left, as shown in FIG. 17, the threading needle 4 is inclined, so that the gap between the threading needle 4 and the inner surface of the eye 5a is formed. The gap is much smaller. Therefore, the threading needle 4 is connected to the eye 5 of the left sewing needle 5.
When the threading needle 4 is moved into the area a, the threading needle 4 may collide with the sewing needle 5, and the threading needle 4, that is, the threading hook may be damaged.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a threading device for a sewing machine which can thread a plurality of sewing needles and can surely prevent breakage of a threading hook.

[0007]

SUMMARY OF THE INVENTION A threading device for a sewing machine according to the present invention includes a needle bar provided to be vertically movable and having a plurality of sewing needles mounted thereon, and a looper swinging in synchronization with the needle bar. In a threading device of a sewing machine, a substantially horizontal rotation is provided near the needle bar and provided near an upper portion of the needle bar.
A threading frame provided rotatably in the left-right direction with a fulcrum as an axis; a threading bar provided in the threading frame along the up-down direction; A threading hook that enters and retracts from the eye of the sewing needle in response to rotation about the axis of the rod as a rotation fulcrum; It is characterized in that there is provided a selecting means for selecting the threading hook to one of the plurality of sewing needles in accordance with a moving operation and making it correspond to the sewing needle.

[0008]

According to the above means, the selecting means rotates the threading frame in the left-right direction to select the threading hook to one of the plurality of sewing needles to correspond to the sewing needle. Then, the threading hook is rotated to enter the eye of the sewing needle and to retract from the eye to perform the threading. In this case, when making the threading hook correspond to one of the plurality of sewing needles, the entire threading frame is attached to the upper portion of the needle bar.
Left and right with a nearly horizontal rotation fulcrum provided nearby as the axis
In this configuration, the distance between the threading hook and the rotation fulcrum is increased. Therefore, when the threading hook rotates in response to the rotation of the threading frame, the threading hook hardly tilts.

Therefore, when the threading hook is inserted into the eye of the sewing needle, the gap between the threading hook and the inner surface of the eye does not become small. For this reason, when the threading hook is advanced into the eye of the sewing needle, the threading hook does not collide with the sewing needle, and damage to the threading hook can be reliably prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a two-needle type lock sewing machine will be described below with reference to FIGS.

First, referring to FIG. 1 and FIG.
Is provided on the supporting portions 12a and 12b of the sewing machine main body 12 via needle bar supports 12c and 12d so as to be vertically movable. The sewing machine main body 12 includes a sewing machine bed and a sewing machine arm (not shown). At the lower end of the needle bar 11, a plurality of, in this case, for example, two sewing needles 14 and 15 are attached side by side via a needle attachment portion 13. In this case, the needle tip of the left sewing needle 14 is
Is higher than the needle point. That is, the position of the eye hole 14a of the left sewing needle 14 is higher than the position of the eye hole 15a of the right sewing needle 15.

A needle bar holder 1 is provided at an intermediate portion of the needle bar 11.
6 is fixed, and the needle bar holder 16 has a link mechanism 1 attached thereto.
7 are connected. The needle bar 11 is reciprocally driven in the vertical direction by transmitting a driving force from a sewing machine motor (not shown) through an upper shaft, a crank mechanism (none is shown), and a link mechanism 17. . A positioning stopper 18 is fixed to a lower portion of the needle bar holder 16 of the needle bar 11. The left end of the positioning stopper 18 has a receiving portion 18a as shown in FIG.
Are protruding.

Further, a support portion 12 on an upper portion of the sewing machine main body 12 is provided.
The upper end 19a of the threading frame 19 is supported by a through a shaft 20. Thereby, the threading frame 1
Reference numeral 9 denotes a position in the vicinity of the needle bar 11, which is arranged on the front side in this case, and is provided to be rotatable in the left-right direction with the upper portion serving as a rotation fulcrum. A coil spring 21 is provided between the lower right end of the threading frame 19 and the sewing machine main body 12, and the threading frame 19 is urged to rotate rightward by the spring force of the coil spring 21.

As shown in FIG. 3, the threading frame 19 has a lower support piece 19b bent downward at the lower end and an intermediate support piece 19c on the left side of the intermediate portion. It is bent backward. A substantially U-shaped guide recess is formed on the right end side of the lower support piece 19b, and the needle bar 11 is arranged in the guide recess. Specifically, the lower end of the needle bar support 12d fixed to the support 12b is arranged in the guide recess.

A threading rod 22 is inserted and supported in a through hole formed on the left end side of the lower support piece 19b and a through hole formed in the intermediate support piece 19c so as to be vertically movable. ing. Thus, the threading rod 22 is provided on the threading frame 19 along the up-down direction, and is disposed substantially parallel to the needle bar 11.

A hook holding member 23 is attached to the lower end of the threading rod 22. This hook holding member 2
As shown also in FIG.
3a and the lower support piece 23b are projected, and the threading rod 22 is inserted into through holes formed in these support pieces 23a and 23b. The lower end of the hook holding member 23 has a knob 2 on the opposite side to the lower support piece 23b.
3c protrudes leftward in FIG.

On the upper side of the threading rod 22, a positioning member 24 is attached. This positioning member 24
The upper support piece 24a and the lower support piece 24
The threading rod 22 is inserted into through holes formed in the support pieces 24a and 24b.
A positioning protrusion 24c is provided at the upper right end of the positioning member 24.
Are formed. The positioning projection 24c comes into contact with the upper surface of the receiving portion 18a of the positioning stopper 18. Also, the lower support piece 24b of the positioning member 24
A shaft portion 24d protrudes from a front portion of the shaft portion 2.
4d is fitted in a guide groove 19d formed in the left end of the threading frame 19.

The lower support piece 24b of the positioning member 24
An engagement recess 24e is formed at the left end of the hook holding member 23, while an engagement projection 23e is formed on the upper surface of the upper support piece 23a of the hook holding member 23.
d is protruded, and the engagement projection 23d is engaged with the engagement recess 24e. As a result, the hook holding member 23 and the positioning member 24 are connected and rotate integrally. A coil spring 25 is provided between the upper support piece 23a of the hook holding member 23 and the lower support piece 24b of the positioning member 24.

The lower support piece 2 of the positioning member 24
4b and the upper end 19a of the threading frame 19,
As shown in FIGS. 1 and 2, a coil spring 26 is provided. The positioning member 24, the hook holding member 23, and the threading rod 22 are urged to move upward by the spring force of the coil spring 26.

A positioning hole 24f is formed at the lower end of the positioning member 24, as shown in FIG.
At the lower opening edge of the positioning hole 24f, positioning portions 24g and 24h are formed on the left and right, and a pin 27 projecting at right angles to the threading rod 22 is selectively provided at the positioning portions 24g and 24h. To be fitted.
In this case, the height position of the positioning portion 24g on the left side in FIG. 5 is higher than the height position of the positioning portion 24h on the right side in FIG.

On the other hand, in the intermediate portion of the threading rod 22, for example, a lever member 28 as a selection means is rotatably provided. As shown in FIG. 6, the lever member 28 is substantially L-shaped, and includes a horizontally extending substrate portion 28a and a vertically extending piece portion 28b. Substrate 2
8a is formed with a through hole 28c.
A threading rod 22 is inserted into 8c.

A guide groove 28d extending in the vertical direction is formed in the standing piece 28b, and the pin 27 of the threading rod 22 is fitted in the guide groove 28d. An operation knob 28e is provided at the front end of the substrate 28a so as to project forward. The operation knob 28e projects forward through an opening 19e formed at the lower end of the threading frame 19.

Here, a positioning portion 2 for determining the rotational position of the threading frame 19 is provided at the right end of the substrate portion 28a.
8f and 28g are formed. These positioning parts 2
Reference numerals 8f and 28g selectively contact the lower end side surface of the needle bar support 12d of the support portion 12b of the sewing machine body 12.

In this case, when the operation lever 28 is rotated to the left, the positioning portion 28f comes into contact with the needle bar support 12d of the support portion 12b, and as shown in FIG. Is rotated to a position slightly inclined to the left with respect to the axis of. At this time, the positioning member 2
4 by fitting the pin 27 of the threading rod 22 into the positioning portion 24g on the left side in FIG. 5, the height position of the positioning member 24, that is, the positioning groove 24c is determined to be high, and the rotation of the operation lever 28 is performed. The moving position is maintained.

On the other hand, when the operation lever 28 is rotated to the right, the positioning portion 28g moves to the needle bar support 1 of the support portion 12b.
2d, and as shown in FIG.
9 rotates to a position slightly inclined rightward with respect to the axis of the needle bar 11. At this time, the positioning member 24
The pin 27 of the threading rod 22 is fitted to the positioning portion 24h on the right side in FIG. 5, so that the height position of the positioning member 24, that is, the positioning groove 24c is determined to be low, and the rotation of the operation lever 28 is performed. The position is maintained.

The lower support piece 2 of the hook holding member 23 will now be described.
A threading hook 29 is attached to the tip of 3b. The mounting structure of the threading hook 29 will be described with reference to FIG. The threading hook 29 includes a substantially L-shaped substrate portion 29a and a hook portion 29b protruding forward at a right angle from the front end of the substrate portion 29a. And
The threading hook 29 is held between two hook protection members 30 and 31.

The hook protection members 30, 31 are composed of substantially L-shaped substrate portions 30a, 31a and the substrate portions 30a, 3a.
Hook protection portions 30b and 31b are provided at right ends of the front portion 1a so as to protrude forward at right angles. The threading hook 29 and the hook protection members 30 and 31 are caulked by caulking studs 32 and are fastened and fixed to the distal end of the lower support piece 23b of the hook holding member 23 by screws 33. Then, it is attached to the hook holding member 23. A thread guide 30c is provided at the end of the hook protection member 30 on the screw mounting side.

In this case, the knob 2 of the hook holding member 23
When the hook holding member 23 is rotated about the axis of the threading rod 22 by operating 3c, the threading hook 29 is rotated about the axis of the threading rod 22 as a rotation fulcrum. . Then, the threading hook 29 is moved in accordance with the rotation thereof so that the eye holes 14a, 1 of the sewing needles 14, 15 will be described later.
5a is entered and retracted from the eye holes 14a, 15a.

Next, the operation of the above configuration will be described with reference to FIGS.
This will be described with reference to FIG. First, the case where threading is performed on the left sewing needle 14 of the sewing needles 14 and 15 will be described. In this case, by rotating a pulley (not shown),
The position 1 is set in advance so as to be located within a range of about 3 mm before and after the top dead center. If the needle bar 11 is positioned at this position, the upper looper, the lower looper, the knife (not shown) for cutting the cloth end and the like do not obstruct the threading operation.

In this state, first, the knob 28c of the operation lever 28 is operated by a finger to rotate the operation lever 28 to the left, and the positioning portion 28f of the operation lever 28 is
The lower end of the needle bar support 12d of FIG. In this contact state, as shown in FIG. 1, the threading frame 19 has been rotated to a position slightly inclined leftward with respect to the axis of the needle bar 11, and the turning radius of the threading hook 29 is set to the left. It corresponds to the sewing needle 14 (see FIG. 10).

At this time, the positioning member 2
4 by fitting the pin 27 of the threading rod 22 into the positioning portion 24g on the left side in FIG. 5, the rotation position of the operation lever 28 is maintained, and the height position of the positioning member 24, ie, the positioning protrusion 24c. Is set to the high position. By setting the height position, the height position of the hook portion 29b of the threading hook 29 corresponds to the height position of the eye hole 14a of the left sewing needle 14.

Thereafter, the knob 23 of the hook holding member 23
c is manually operated to move the hook holding member 23 downward against the spring force of the coil spring 26.
2. The hook holding member 23 and the positioning member 24 move downward, and the positioning protrusion 24c of the positioning member 24 contacts the receiving portion 18a of the positioning stopper 18. This restricts the downward movement of the hook holding member 23, the threading rod 22, and the positioning member 24. In this state, the height position of the hook portion 29b of the threading hook 29 matches the height position of the eye hole 14a of the left sewing needle 14 (see FIG. 9).

Subsequently, the knob 23 of the hook holding member 23
By operating c with fingers, the hook holding member 23 is rotated to the front, and the threading hook 29 is rotated to the front as shown in FIG. As a result, the hook portion 29b of the threading hook 29 enters the eye 14a of the sewing needle 14.

In this state, as shown in FIG. 9, the thread 34 guided from the thread top (not shown) is guided by the thread guide portion 30c of the hook protecting member 30, and then the thread 34 is stretched to the front side of the eye hole 14a of the sewing needle 14. Hand over and hook on hook 29b. Thereafter, when the threading hook 29 is rotated backward, the hook portion 29b hooks the thread 34 while the eye 1
Retreat from inside 4a. When this retreat, hook part 2
9b passes the thread 34 into the eye 14a.

Here, the hook portion 2 of the threading hook 29 is used.
When the needle 9b enters the eye hole 14a of the sewing needle 14, the shaft portion 24d of the lower support piece 24b of the positioning member 24 is moved to the position shown in FIG.
As shown in the figure, the threading hook 2 is brought into contact with the lower left edge portion of the guide groove 19d of the threading frame 19 to thereby make the threading hook 2
9 is restricted from rotating further. This prevents the threading hook 29 from being broken by colliding with the sewing needle 14.

When the threading hook 29 is rotated to enter and retract into the eye hole 14a, the threading hook 29 is positioned below the positioning projection 24c of the positioning member 24 which rotates integrally with the hook holding member 23. Engagement groove 24i formed in
Since the receiving portions 18a of the positioning stoppers 18 are fitted and arranged in the positioning members 24 (see FIGS. 1 and 9),
And the hook holding member 23 does not move up and down,
Therefore, the threading hook 29 does not move up and down.
Then, when the threading hook 29 is rotated backward and returned to the rotation start position, the positioning member 24, the hook holding member 23, and the threading rod 22 are moved upward by the spring force of the coil spring 26. And returns to the original state shown in FIG.

Next, the thread 34 is inserted into the eye 15a of the right sewing needle 15.
In order to pass the needle bar support 1b of the support portion 12b, the knob 28c of the operation lever 28 is manually operated to rotate the operation lever 28 to the right.
The lower end of 2d is brought into contact with the outer periphery. In this contact state, as shown in FIG.
The threading hook 29 is rotated to a position substantially parallel to the axis 1 and the turning radius of the threading hook 29 is set to the right.
(See FIG. 13).

At the same time, the positioning member 2
4 by fitting the pin 27 of the threading rod 22 into the positioning portion 24h on the right side in FIG. 5, the rotation position of the operation lever 28 is maintained, and the height position of the positioning member 24, ie, the positioning projection 24c. Is set to the low position. By setting this height position, the height position of the hook portion 29b of the threading hook 29 corresponds to the height position of the eye hole 15a of the right sewing needle 15.

Thereafter, similarly to the case of the sewing needle 14 described above, when the knob 23c of the hook holding member 23 is pressed down by a finger, the positioning projection 24 of the positioning member 24 is pressed.
c comes into contact with the receiving portion 18a of the positioning stopper 18, and the hook holding member 23, the positioning member 24 and the threading rod 22
Is restricted from moving downward (see FIG. 14). And
When the knob 23c of the hook holding member 23 is manually operated to rotate the hook holding member 23 toward the user, the hook portion 29b of the threading hook 29 is turned into the eye hole 15a of the sewing needle 15 as shown in FIG. To enter. Thereafter, the thread 34 is passed through the eye 15a of the sewing needle 15 in substantially the same manner as in the case of the sewing needle 14.

Here, the hook part 2 of the threading hook 29 is used.
When the needle 9b enters the eye hole 15a of the sewing needle 15, the shaft portion 24d of the lower support piece 24b of the positioning member 24 is moved to the position shown in FIG.
As shown in FIG. 4, the guide groove 19d of the threading frame 19
By contacting the lower left edge of the hook, further rotation of the threading hook 29 is restricted.
This prevents the threading hook 29 from being broken by colliding with the sewing needle 15.

According to the present embodiment having such a configuration, by rotating the operation lever 28, the threading frame 19 is rotated in the left-right direction, and the threading hook 29 is moved to the plurality of sewing needles 14, In this state, the threading hook 29 is rotated to enter the eye holes 14a, 15a of the sewing needles 14, 15, and into the eye holes 14a, 15a. And threading is performed.
In this case, the threading hook 29 is connected to the plurality of sewing needles 14 and 15.
In this case, the entire threading frame 19 is rotated with the upper portion thereof as a rotation fulcrum (shaft 20). Therefore, the threading hook 29 and the rotation fulcrum (shaft 20) The distance between becomes longer.

Therefore, when the threading hook 29 rotates in response to the rotation of the threading frame 19, the threading hook 29, that is, the hook portion 29b hardly tilts.
Therefore, the hook portion 29b of the threading hook 29 is
4 and 15, the hook portion 29b of the threading hook 29 and the eye holes 14a, 15a are inserted into the eye holes 14a, 15a.
The gap with the inner surface of a does not become small. Thus, unlike the conventional configuration (see FIGS. 16 and 17),
The hook portions 29b of the threading hooks 29 are
When entering the eye holes 14a and 15a, the hook 2
9b does not collide with the sewing needles 14 and 15,
The breakage of the threading hook 29 can be reliably prevented.

In the above embodiment, if the needle bar 11 is positioned within a range of about 3 mm before and after the top dead center, the positioning projection 24c of the positioning member 24 will receive the positioning stopper 18 of the needle bar 11. The position of the threading hook 29 can be positioned with respect to the needle bar 11 by abutting on the needle bar 18a. Therefore, since it is not necessary to accurately position the needle bar 11 at one point, the positioning of the needle bar 11 can be easily performed. By the way, in order to move the needle bar 11 within a range of about 3 mm before and after the top dead center, the pulley should be rotated at an angle of about 3 mm.
It is necessary to turn it 0 degrees, which makes the alignment work much easier than in the case where it is exactly aligned to one point.

In the above embodiment, the present invention is applied to a two-needle type lock sewing machine. However, the present invention may be applied to a three-needle type lock sewing machine instead.

[0045]

As is apparent from the above description, the present invention is arranged near the needle bar and provided near the upper portion of the needle bar.
A threading frame is provided rotatably in the left-right direction around a substantially horizontal rotation fulcrum, and a threading bar is provided on the threading frame along a vertical direction. A threading hook which moves into and out of the eye of the sewing needle in accordance with the rotation about the axis of the threading rod as a rotation fulcrum, and rotates the threading frame in the left-right direction. And a selection means for selecting a threading hook corresponding to one of the plurality of sewing needles in accordance with the sewing machine, so that the threading can be performed through the plurality of sewing needles . Long distance between hook and pivot
Therefore, the threading hook is rotated according to the rotation of the threading frame.
When the thread rotates, the threading hook is almost
The threading hook enters the eye of the sewing needle
The gap between the threading hook and the inner surface of the eye hole is small.
And the threading hook is
Thus, there is an excellent effect that the threading hook can be reliably prevented from being broken.

[Brief description of the drawings]

FIG. 1 is a front view of the vicinity of a threading device according to an embodiment of the present invention.

FIG. 2 is a side view around the threading device.

FIG. 3 is a perspective view of a threading frame.

FIG. 4 is a perspective view of a threading rod, a hook holding member, a positioning member, and a lever member.

FIG. 5 is a partial rear view of the positioning member.

FIG. 6 is a perspective view of a lever member.

FIG. 7 is a perspective view of a positioning stopper.

FIG. 8 is an exploded perspective view of a threading hook.

FIG. 9 is a view corresponding to FIG. 1, showing a state where a hook holding member and the like are moved downward.

FIG. 10 is a cross-sectional view around the threading hook.

FIG. 11 is a view corresponding to FIG. 10, showing a state in which the threading hook has been rotated forward;

FIG. 12 is a diagram corresponding to FIG. 1;

FIG. 13 is a diagram corresponding to FIG. 10;

FIG. 14 is a diagram corresponding to FIG. 9;

FIG. 15 is a diagram corresponding to FIG. 11;

FIG. 16 is a front view showing a conventional threading device and its surroundings.

FIG. 17 is an enlarged front view of a sewing needle and a threading hook;

[Explanation of symbols]

11 is a needle bar, 12 is a sewing machine main body, 12a and 12b are support portions, 12c is a needle bar support, 14, 15 are sewing needles, 14a and 14a.
15a is an eye hole, 18 is a positioning stopper, 18a is a receiving portion, 19 is a threading frame, 20 is a shaft, 21 is a coil spring, 22 is a threading rod, 23 is a hook holding member, 24 is a positioning member, and 28 is a lever. Member (selection means), 28f,
28g is a positioning portion, 29 is a threading hook, 29b is a hook portion, and 34 is a thread.

Claims (1)

(57) [Claims] 1. A threading device for a sewing machine having a needle bar provided to be vertically movable and having a plurality of sewing needles attached thereto and a looper swinging in synchronization with the needle bar, the sewing machine being disposed near the needle bar. And provided near the upper part of the needle bar.
A threading frame provided to be rotatable in the left-right direction with the substantially horizontal rotation fulcrum as an axis; a threading bar provided in the threading frame along a vertical direction; A threading hook which is provided and which enters into the eye hole of the sewing needle and retreats from the eye hole in response to rotation about the axis of the threading rod as a rotation fulcrum; Selecting means for selecting the threading hook to one of the plurality of sewing needles in response to the turning operation of the sewing needle.