JP2000308780A - Vertical shuttle for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent needle thread from being dragged effectively, when the needle thread passes through a shuttle support part comprising a shuttle support and an inner shuttle, and to make it very easy to maintain the shuttle. SOLUTION: This vertical shuttle comprises an outer shuttle 5 which is rotated by being connected to a shuttle driving shaft 3 mounted on a shuttle support 2 horizontally and an inner shuttle 6 which is fitted to the inside of the outer shuttle 5 so as to be able to rotate relatively. In this case, the inner shuttle 6 can stop rotating, by forming a protrusion part 16 in the front surface of the inner shuttle 6 and pressing the protrusion part 16 against a shuttle support 14 which is fixed to a shuttle support 2 and extended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement in a vertical hook of a sewing machine.

[0002]

2. Description of the Related Art A shuttle of a sewing machine has a function of tangling a bobbin thread with an upper thread. Horizontal pots are known. For example, FIGS. 7 and 8 show a vertical shuttle 30 according to the prior art, in which an outer shuttle 31 attached to an end of a horizontally disposed shuttle shaft 33 and an inner hook fitted inside the outer shuttle 31 are shown. It is basically composed of the shuttle 32. The outer shuttle 31 is rotatably driven in one direction with the rotation of the shuttle shaft 33, and the inner shuttle 32 is fitted inside the outer shuttle 31 so as to be relatively rotatable. A concave portion 34 functioning as a supported portion is formed in the outer peripheral portion of the front surface of the inner shuttle 32, and the concave portion 34 is fitted to a support portion 35a of the shuttle support 35 fixed to the frame side of the sewing machine while maintaining a required space. The inner pot 3
2 is prevented from rotating together with the outer hook 31. When the sewing needle (not shown) descends, the upper thread that arrives at a position behind the concave portion 34 in the inner shuttle 32 is captured by a point 36 provided on the outer shuttle 31 at a predetermined timing. Then, the upper thread is transferred to the inner hook 3 with the rotation of the outer hook 31.
After orbiting around 2, it is pulled up by a balance (not shown) at a predetermined timing, passes through the support portion 35 a of the shuttle support 35 and the concave portion 34 of the inner shuttle 32, and is removed from the shuttle 30. Thus, the upper thread and the lower thread are entangled to form a series of stitches.

[0003] Incidentally, the inner hook 32 is provided with the hook support 3 as described above.
5 supports the outer shuttle 31 so as not to rotate therewith. However, since a rotational force that tends to rotate together with the rotation of the outer shuttle 31 inevitably acts on the inner shuttle 32, a gap is provided between the support portion 35a of the shuttle support 35 and the concave portion 34 of the inner shuttle 32. In spite of this, due to the rotational force of the outer shuttle 31, as shown by a two-dot chain line in FIG.
Is constantly in contact with the supporting portion 35a. As a result, the upper thread is supported by the support portion 35a of the hook support 35.
The upper thread is subjected to resistance when it comes out of the space between the inner thread 32 and the concave portion 34 of the inner shuttle 32, thereby adversely affecting the thread tightening, and in the worst case, causing thread breakage. Has been pointed out.

[0004] For this reason, as a prior art, the upper thread is
5 at the timing when it comes out between the supporting portion 35a of the hook 5 and the concave portion 34 of the inner hook 32, the inner hook 32 is rotated in the direction opposite to the rotation direction of the outer hook 31 so that the supporting portion 35a of the hook 35
A device called a "hook opener" has been proposed in which a contact portion between the upper thread and the rear portion 34a of the concave portion 34 is separated so that no resistance is applied to the upper thread when the thread comes out.

[0005]

The shuttle opener according to the prior art described above mainly has a mechanical structure such as a link mechanism using a rotation of a shuttle drive shaft connected to the outer shuttle 31 as a drive source. However, in the space in which the shuttle is mounted, lint and the like easily accumulate with use over time, and since the lubricating oil is scattered during rotation of the shuttle, the shuttle opener mounted in the space easily breaks down. Has disadvantages. In addition, due to the small mounting space of the pot, maintenance such as repair and repair is inevitably difficult, requiring much labor and time, and also the pot opener requires a complicated mechanism, increasing the manufacturing cost etc. Had various disadvantages.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has been proposed in order to solve the problem in a favorable manner. It is another object of the present invention to provide a vertical hook of a sewing machine which effectively prevents a resistance from being applied to the upper thread and makes maintenance extremely easy.

[0007]

In order to overcome the above-mentioned problems and achieve the intended object, a vertical shuttle of the sewing machine according to the present invention is connected to a shuttle drive shaft horizontally disposed on a shuttle support. In a vertical hook of a sewing machine comprising a rotating outer hook and an inner hook rotatably fitted inside the outer hook, a convex portion is formed on a front surface of the inner hook, and the convex portion is connected to the hook. The inner hook is prevented from rotating by being brought into contact with a hook support that is fixed to the support and extends.

[0008]

The convex portion of the inner hook constantly contacts the forward side of the outer hook in the rotating direction of the outer hook in the concave portion of the hook support as the outer hook is driven to rotate. At the time of withdrawal from the shuttle, a gap for removing the upper thread is secured between the concave portion of the hook support and the convex portion of the inner shuttle.
Therefore, no resistance is applied to the upper thread when it comes out of the shuttle.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of a vertical hook of a sewing machine according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view, partially broken away, showing a hook support supporting a vertical hook. A shuttle drive shaft 3 is rotatably supported horizontally on the shuttle support 2, and an outer shuttle 5 constituting a part of the vertical shuttle 1 is fixed to the end of the shuttle drive shaft 3. A driven gear 7 is fixed to the other end of the shuttle drive shaft 3, and the driven gear 7 meshes with a drive gear 10 fixed to a drive shaft 8 that is supported through the shuttle support 2. Therefore, by rotating the drive shaft 8 in one direction by a drive source (not shown),
The outer shuttle 5 is driven to rotate counterclockwise in FIG. 2 via the two gears 7, 10 and the shuttle drive shaft 3. As shown in FIG. 2, the upper surface of the shuttle support 2 is covered with a needle plate 12 provided with a needle hole 11 for allowing a sewing needle (not shown) to pass therethrough.

An inner hook 6 that is rotatable relative to the outer hook 5 is fitted inside the outer hook 5. But inner pot 6
Is fixed to the shuttle support 2 with screws 13 and is non-rotatably held by a shuttle support 14 that extends toward the near side of the vertical shuttle 1. The hook support 14 can be finely adjusted in the mounting position. That is, the needle drop hole 15 in the inner pot 6
A convex portion 16 is formed on the front surface located in front of the hook, and a concave portion 17 is formed in the shuttle support 14 to hold a space allowing the loose fit of the convex portion 16. With the operation of the sewing machine, the outer shuttle 5 is rotated in the counterclockwise direction in FIG. 2 as described above, but the inner shuttle 5 is kept in a substantially stopped state without being driven to rotate.

As shown in the enlarged view of FIG. 5, the convex portion 16 of the inner hook 6 is formed so as to be loosely curved in a tapered shape on its plane and to be left-right asymmetric. That is, the left end surface 16a of the convex portion 16 is
6b has a gentler gentle slope as a whole.
In other words, in the protruding portion 16 of the inner hook 6, the portion where the upper thread a captured by the outer hook 5 comes into contact with is a flat-section tapered flat curved surface inclined at an obtuse angle with respect to the front surface of the inner hook 6. It is formed as a side end surface 16a having a shape. In addition, convex part 1
The formation position of 6 is as follows. For example, in FIG. 2, when the outer hook 5 rotates counterclockwise,
Similarly, a counterclockwise rotation force acts on the inner pot 6. For this reason, the gentle slope 16a of the convex part 16 in the inner pot 6 (left end face)
Is constantly in contact with the left side wall surface 17a of the concave portion 17 in the shuttle support 14. In this state, the protrusion 16
Is formed so as to protrude to a position displaced leftward from the center of the inner hook 6, as shown in FIGS. 3 (c) and 4 (c).

[0013]

Next, the operation of the vertical shuttle of the sewing machine according to this embodiment will be described. The sewing needle (not shown) descends,
After the lower end portion of the sewing needle has passed through the needle hole 11 of the needle plate 12 and reached the bottom dead center, it turned to ascending and rose by a predetermined amount (a so-called “needle hook timing”). Outer pot 5
Is captured by the sword tip 5a provided in the sword. 3 (a) and 4 (a) when the point 5a slightly passes the bottom dead center position.
The upper thread a that has moved along the front surface of the inner hook 6 as shown in FIG. 5A comes into contact with the left end face 16 a of the projection 16.

When the outer hook 5 further rotates from the above state,
As shown in FIG. 3 (b), FIG. 4 (b) and FIG.
The convex portion 16 is pushed rightward in the figure against the counterclockwise rotating force acting on the inner hook 6 by the upper thread a moving along the front surface of the inner hook 6, and as a result, the inner hook 6 is moved. It turns clockwise. The clockwise rotation of the inner hook 6 secures a gap between the gentle slope 16a (the left end face) of the projection 16 and the left wall face 17a of the recess 17, and the upper thread a passes through the gap. As a result, a state in which the convex portion 16 can pass through forward can be achieved.

Next, when the outer hook 5 further rotates, FIG.
As shown in FIGS. 4 (c), 4 (c) and 5 (c), the upper thread a moving along the front surface of the inner hook 6 has a gentle slope 16
a (the left end surface), while passing through the gap between the front surface of the convex portion 16 and the concave portion 17 while sliding on the right end surface 16b side of the convex portion 16. When the upper thread a completely moves to the right side, the pressing force of the upper thread a against the convex portion 16 is released, so that the inner shuttle 6 is rotated counterclockwise by the rotational force constantly acting. Then, the gently inclined surface 16a (left end surface) of the convex portion 16 returns to a state in which it comes into contact with the left wall surface 17a of the concave portion 17 again.

Thereafter, the upper thread a is pulled up by the thread pulling action of a balance (not shown) accompanying the rotation of the inner hook 6,
When the sword tip 5a of the outer hook 5 substantially reaches the top dead center, the upper thread a
Comes out from between the convex portion 16 of the inner hook 6 and the concave portion 17 of the hook support 14. However, at this time, as shown in FIG.
Since a gap is secured between the hook support 14 and the right side wall surface 17b of the concave portion 17, the upper thread a comes out of these gaps without resistance.

In the vertical hook according to the present embodiment, a rotating force acts on the inner hook 6 together with the rotation of the outer hook 5, and as shown in FIG. 16a (left end surface) abuts against the left wall surface 17a of the concave portion 17 of the shuttle support 14 to cross over the convex portion 16 of the upper thread a (from the state shown in FIG. 3B to the state shown in FIG. 3C). ) Is blocked. However, the upper thread a engages with the convex portion 16 in the process of being moved along the front surface of the inner hook 6 with the rotation of the outer hook 5 after being captured by the sword tip 5a of the outer hook 5, and Is turned in the opposite direction once at a required timing to release the blocking state. Accordingly, the upper thread a itself functions as a shuttle opener, and can smoothly pass over the convex portion 16. Therefore, even without a complicated mechanism such as a hook opener, the upper thread a can be smoothly pulled out of the hook 1 by the lifting action of the balance, thereby adversely affecting the thread tightness, causing thread breakage, etc. Is eliminated.

[0018]

As described above, according to the vertical hook of the sewing machine according to the present invention, the upper thread can be smoothly pulled out from the hook without using the hook opener of a complicated mechanism, which has an adverse effect on the thread tightening. Good sewing can be performed without causing breakage or thread breakage. In addition, since a kettle opener is not required, it is possible to reduce the manufacturing cost and to obtain beneficial advantages such as easy maintenance.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view showing a shuttle and a shuttle support.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a front view of the shuttle showing the process of pulling out the upper thread from the shuttle over time.

FIG. 4 is an enlarged front view of a main part showing a state of a convex portion of the inner hook, a concave portion of the hook support, and an upper thread in FIG. 3 from the front.

FIG. 5 is an enlarged plan view of a main part, showing from a top the respective states of a convex portion of the inner hook, a concave portion of the hook support, and an upper thread in FIG.

FIG. 6 is a sectional view taken along line BB of FIG. 5 (c).

FIG. 7 is a plan view showing a conventional hook supporting structure.

FIG. 8 is an enlarged explanatory view showing a convex portion of the inner hook and a concave portion of the hook support in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hook 2 Hook support 3 Hook drive shaft 5 Outer hook 6 Inner hook 14 Hook support 16 Convex part 16a Slope (left end face) 16b Side end face (right end face) 17 Concave a Upper thread

Claims (1)

[Claims] 1. A vertical sewing machine comprising an outer hook which is connected to a hook drive shaft horizontally disposed on a hook support and is rotated, and an inner hook which is rotatably fitted inside the outer hook. In the hook, a convex portion is formed on the front surface of the inner hook, and the convex portion is fixed to the hook support and is brought into contact with a hook support that extends, thereby preventing the inner hook from rotating. A vertical hook of a sewing machine.