JPH07213772A - Shuttle body rotation preventing device for sewing machine horizontal shuttle - Google Patents

Abstract

PURPOSE:To prevent the rotation of a shuttle body and mitigate the impact and noise at the time of contact by reciprocatably supporting a hook member in the rotational path of a projection formed on the shuttle body or the like, elastically supporting the hook member, and bringing the projection into contact with the hook member. CONSTITUTION:A rotating hook 12 has a bayonet point 12a, and it is rotated centering on the vertical axis synchronously with the vertical movement of a sewing needle. A shuttle body 13 rotatably supports a bobbin thread bobbin 16, and it is rotatably supported by the rotating hook 12. A projection 17b is protruded in the horizontal direction on the periphery of the bobbin case 17 of a sewing machine horizontal shuttle 10. A hook member 22 is reciprocatably supported in the rotational path of the projection 17b. The hook member 22 is elastically supported by an elastic supporting means 27 so that the shuttle body 13 is located within the prescribed rotational phase range against the rotating force of the shuttle body 13 generated by the rotation of the rotating hook 12. The hook member 22 is brought into contact with the projection 17b, the rotation of the shuttle body 13 is prevented, and the impact at the time of contact is mitigated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner hook rotation preventing device for preventing the inner hook from rotating in accordance with the rotation of an outer hook in a horizontal horizontal hook of a sewing machine which rotates along a horizontal plane.

[0002]

2. Description of the Related Art FIGS. 7 to 9 are views showing a sewing machine horizontal hook which is generally used at present. The horizontal hook 1 is composed of an outer hook 2 and an inner hook 3 rotatably supported by the outer hook 2.
The outer hook 2 is horizontally rotatable together with a vertical hook shaft 4 fixed concentrically therewith. Further, the rotation of the inner hook 3 is restricted by the engagement with the needle plate 5.

That is, a projection 3a is formed on the peripheral portion of the inner hook 3, which is loosely fitted in a recess 5a formed on the lower surface of the needle plate 5, and the projections 3a are formed on both end surfaces 5a1 and 5a2.
The rotation of the inner hook is regulated by regulating the movement of the. The lower thread bobbin 6 is rotatably housed in the inner hook 3 directly or via a bobbin case. Here, a so-called latch hook in which the lower thread bobbin is directly inserted into the inner hook is shown.

In the horizontal hook 1 as described above, at the time of sewing operation, a force to rotate in the same direction is applied to the inner hook 3 due to friction with the outer hook 2. Therefore, the protrusion 3a and the one end face 5a1 are always in pressure contact with each other (see FIG. 9).
(See (a)) In order to pass the upper thread loop IL along the circumference of the inner hook 3, it is necessary to prevent the upper thread loop IL from being locked between the recess 5a and the protrusion 3a. Therefore, a sewing machine using the horizontal shuttle 1 is provided with a device called an opener, which allows the upper thread loop IL to pass between the recess 5a and the projection 3a.

In this opener, a movable member 7, which reciprocates by an actuator (not shown), abuts and separates from a projecting portion 3b formed on the peripheral portion of the inner hook 3, so that both end surfaces 5a are formed.
The gaps G1 and G2 are selectively provided between the protrusions 1 and 5a2 and the protrusion 3a.
To act to form. That is, at the beginning of the passage of the upper thread loop IL, the movable member 7 presses the projecting portion 3b of the inner hook 3 to force the protrusion 3a of the inner hook 3 and the one end surface 5a1 as shown in FIG. 9B. Gap between
1 to form the upper thread loop IL from the gap G1 to the inner hook 3
It is designed to guide you around. Also, the inner pot 3
After the upper thread loop IL is introduced into the inner hook 3, the movable member 7 releases the pressing force to the inner hook 3, so that the inner hook 3 rotates in the same direction as the outer hook 2 due to the friction with the outer hook 2. Protrusion 3a and recess 5
The one end surface 5a1 of a is in contact with the other end surface 5a2, and a gap G2 is formed between the other end surface 5a2 and the other end surface 5a2 (see FIG. 9 (a)). It is adapted to be pulled out from the inner pot 3 through this gap G2.

[0006]

As described above, in the conventional opener device, the movable member 7 operated by the actuator comes in contact with and separates from the protruding portion 3b of the inner hook 3. However, there is a problem that an impact sound is generated at the time of contact with the projecting portion 3b, and the working environment is deteriorated. In particular, in the current sewing machine in which the sewing operation is performed at a high speed, the movable member 7 is operated at a high speed in order to correspond to the sewing speed, so that the contact with the inner hook 3 is considerably violent. The generated impact noise is also loud.
Therefore, in a sewing factory or the like equipped with a large number of horizontal hook type sewing machines, the work environment is significantly deteriorated by this noise, which is a serious problem.

The present invention has been made by paying attention to the problems of the above-mentioned prior art, and the inner hook rotation preventing device for a horizontal hook sewing machine capable of preventing the rotation of the inner hook without generating a large noise when the sewing machine is driven. For the purpose of providing.

[0008]

SUMMARY OF THE INVENTION According to the present invention, an outer hook rotating in a positive direction about a vertical central axis in synchronism with the vertical movement of a sewing needle, and a lower thread bobbin directly or through a bobbin case. In a horizontal sewing machine that is rotatably supported and has an inner hook that is rotatably supported by the outer hook, the sewing machine is capable of reciprocating within a rotation path of a protrusion formed on the inner hook or bobbin case. The supported locking member and the locking member are elastically arranged so that the inner hook is positioned within a predetermined rotation phase range against the rotational force of the inner hook generated by the forward rotation of the outer hook. The elastic supporting means for supporting is provided.

In addition to the above structure, an adjusting means for adjusting the elastic force of the elastic supporting means is added, and a reverse rotation preventing stopper for preventing the inner hook from rotating when the outer hook rotates in the opposite direction is added. This is also effective, and it is also conceivable to provide a regulating means for regulating the moving range of the locking member.

[0010]

In the present invention, the rotation of the inner hook due to the contact with the outer hook is prevented by bringing the locking member into contact with the protruding portion of the inner hook of the sewing machine during the sewing operation. The engagement relationship between the needle plate and the inner hook is not particularly required. Therefore, unlike the conventional opener, it is not necessary to bring the movable member into contact with the inner hook to forcefully rotate it, and it is possible to suppress the generation of impact noise. Further, since the locking member is elastically supported by the elastic supporting means, a vibration in the rotating direction is generated in the inner hook due to a change in the rotational force applied to the inner hook from the outer hook, and the vibration is generated. Thus, the locking member and the protruding portion of the inner hook repeat the opening / closing operation. Therefore, the upper thread loop can smoothly pass between the locking member and the inner hook, and since there is no conventional engagement state between the needle plate and the inner hook, Introducing the upper thread loop into and removing it from the hook is extremely smooth. Therefore, even if the thread tension is set to a low tension, an appropriate stitch forming operation can be performed.

If the elastic force of the elastic support means can be adjusted, the locking member can always be held with an appropriate force in response to changes in the force applied from the inner hook to the locking member. it can. Furthermore, if a stopper for preventing reverse rotation is provided, the inner hook can be held in a substantially fixed position even when the bobbin thread bobbin is attached or detached, and the outer hook is rotated in reverse, so that the first stitch can be reliably performed. Appropriate sewing operation can be performed. Further, by restricting the moving range of the locking member, it is possible to stabilize the stitch forming operation without fear of excessive vibration in the contact state with the inner hook.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 1 and 2, 10 is a horizontal hook,
Reference numeral 15 is a needle plate, and 20 is an inner hook locking mechanism. Of these, the horizontal shuttle 10 in this embodiment is a so-called cap shuttle in which the bobbin thread bobbin 16 is supported by the inner shuttle 13 via the bobbin case 17, and has a configuration as shown in FIG.

In FIG. 3, reference numeral 12 denotes an outer hook having a sword tip 12a for catching the needle thread loop, which is fixed to the upper end of a vertical hook shaft 14 which rotates in synchronization with the lifting and lowering operation of the sewing needle. It rotates horizontally with 14. Reference numeral 12b is an arcuate race surface formed on the outer hook, and the center of the race surface is formed at a position coinciding with the center of the hook shaft. Reference numeral 13 denotes an inner hook. An arc-shaped race portion 13b slidably contacted by a race surface 12b of the outer hook 12 is provided on a peripheral surface portion of the inner hook so as to rotate about the hook shaft with respect to the inner hook. I'm supposed to get it. Further, a fitting convex portion 13a that fits into a bobbin case, which will be described later, is formed on the peripheral surface of the inner hook. In addition,
The inner hook 13 is not formed with a protrusion (FIG. 7, 3a) which is an engaging portion with the needle plate 15.

Reference numeral 16 is a bobbin thread bobbin which is rotatably inserted through a column 13c formed in the central portion of the inner hook 13.
A bobbin case 7 accommodates the lower thread bobbin 16. The inner surface of the bobbin case 17 is provided on the peripheral surface of the bobbin case 17.
Is formed with a fitting concave portion 17a into which the fitting convex portion 13a is fitted. After fitting both parts, the locking claw 13d protruding from the central portion of the inner hook 13 is bent to Pot 13
The bobbin case 17 can be integrally fixed. Further, the bobbin case 17 has an upper surface formed with a protruding portion 17b protruding outward. The protruding portion 17b corresponds to the protruding portion 3b of the latch hook shown in FIG. 7 and is generally formed on the cap hook. However, the protruding portion 17b shown here is an ordinary cap hook. It has a considerably large amount of protrusion as compared with that formed.

Since the inner hook 13 and the needle plate 15 are not engaged with each other in this embodiment as described above, the lower surface of the needle plate 15 shown here has a conventional concave portion. It is not formed and has a flat shape. In other words, the inner hook 13 and the needle plate 15 in this embodiment are simpler in shape than ordinary ones and can be manufactured at low cost.

On the other hand, the locking mechanism 20 of the inner hook 13 is shown in FIG.
And as shown in FIG. That is, 21
Is a mounting base bent in a crank shape, and is fixed to the machine frame of the sewing machine by screws 30. Reference numeral 22 is a locking member that is axially attached to the upper surface portion 21a of the mounting base by a shaft screw 23.
The locking member 22 has an L-shape, and an insertion hole 22a having a predetermined width H is formed in the rear portion thereof, and the locking member 22 serves as a regulation means formed by bending the upper surface 21a of the mounting base 21. The convex portion 21a1 is loosely inserted. This convex portion 21
The shape of a1 is such that a gap g can be formed with respect to the insertion hole 21a, and the rotation of the locking member 22 is restricted within the range of the gap g. Also, the locking member 2
The front end 22b of the protrusion 2 is located in the rotation path of the protrusion 17b of the bobbin case 17, and the one side surface 1 of the protrusion 17b.
It is possible to contact with 7b1.

Further, the above-mentioned convex portion 21a1 and shaft screw 2
3, the mounting base 21 may be provided with a hole and a shaft fitted in the hole may be provided. Reference numeral 24 is a screw shaft that is screwed into the rising portion 21b of the mounting base 21, and a cylindrical spacer 25 and a star-shaped spring receiver 26 are inserted through the shaft portion, and the screw shaft 24 is By tightening, both members can be firmly fixed to the rising portion 21b. A spiral spring (spring body) 27 as a coil-like elastic means is loosely inserted in the spacer 25, and one end of the spiral spring 27 is locked to the rear end of the locking member 22. The other end is locked to the spring receiver 26.
An adjusting means 29 for adjusting the elastic force of the spring 27 is constituted by the above 24, 25 and 26. Also 28
Is a stopper for preventing the reverse rotation of the inner hook 13, and is the protrusion 17b.
It is provided at a position facing the other side surface 17b2.

In this embodiment constructed as described above, a gap is formed between one side portion 22a1 of the insertion hole 22a of the locking member 22 and the convex portion 21a1 formed on the mounting base 21 prior to the start of the sewing operation. The position of the locking member 22 is set so that g is formed. The position of the locking member 22 can be set by rotating the spring receiver 26. That is, when the spring receiver 26 is rotated in the direction of the arrow a, one side portion 22a1 of the locking member 22 has a convex portion 21a.
If the spring receiver is moved in the direction away from a1 (arrow c direction) and the spring bearing is rotated in the arrow b direction, one side portion 22a1 moves in the direction approaching the convex portion 21a1 (arrow d direction). To do. When performing the sewing operation at a normal speed, not only between the one side portion 22a1 and the convex portion 21a1, but also the other side portion 2
It is desirable to set such that a gap is also formed between 2a2 and the convex portion 21a1 (see FIG. 4B).

When the sewing operation is started after the setting operation of the locking member 22 is performed in this way, a rotational force is applied to the inner hook 13 by friction with the outer hook 12, and the bobbin case 17
The projecting portion 17b comes into contact with the tip of the locking member 22 and rotates the locking member 22 in the arrow d direction against the elastic force of the spring 27. The strength of the rotational force applied to the inner hook 13 varies with one rotation of the outer hook 12 as one cycle. Then, at the time when the largest rotational force is applied to the inner hook 13 in each cycle, the locking member rotates most in the arrow d direction.

Thereafter, when the rotational force applied to the inner hook 13 is reduced, the locking member 22 is moved by the arrow c by the restoring force of the spring 27.
And the bobbin case 17 and the inner hook 13 are rotated in the reverse direction. At this time, the locking member 2
Although the rotation of 2 is restricted by the convex portion 21a1, the protruding portion 17b of the bobbin case 17 rotates in the opposite direction due to the inertial force even after the locking member 22 is locked, so that the protruding portion 17b is locked with the protruding portion 17b. A gap is instantaneously formed between the inner hook 13 and the member 22, and then the inner hook 13 rotates in the forward direction (X direction) due to friction with the outer hook 12 and comes into contact with the locking member 22 again.

Thus, the bobbin case 17 and the inner hook 1
3 vibrates in the rotation direction within a predetermined rotation phase range and repeats the opening / closing operation, so that the needle thread loop introduced into the inner hook 13 should be locked between the protrusion and the locking member. Therefore, it is possible to smoothly pass through the inner hook 13 and form proper seams. Also, the locking member 22 and the protrusion 1
Since the stroke of the opening / closing operation with 7b is smaller than the moving stroke of the movable member in the conventional opener, the relative speed at the time of contact between the two members 22 and 17b is considerably low, and the impact is not generated. Since it is absorbed and relaxed by the spring, a large noise is not generated when the locking member 22 and the protruding portion 17b are opened and closed unlike the conventional opener device. Therefore, in a sewing factory or the like that uses a large number of sewing machines, the noise level can be significantly reduced.

Further, in this embodiment, since the protruding amount of the protruding portion formed on the bobbin case 17 is set to be considerably larger than that of a normal cap hook, the rotation of the bobbin case 17 and the inner hook 13 is locked with a small force. It becomes possible to do. Therefore, a spring 27 having a small elastic coefficient can be used as the spring 27 that holds the locking member 22, and the cost of the device can be reduced.

By the way, in a normal cap pot,
The center of rotation P1 of the outer hook 12 (the center of rotation of the hook shaft 14) and the center P2 of rotation of the inner hook 13 with respect to the outer hook 12 are made to coincide with each other. This also applies to the first embodiment. However, as in the second embodiment of the present invention shown in FIGS. 5 and 6, the arc-shaped center of the race surface 12b formed on the outer hook 12 (the center of rotation of the inner hook 13 relative to the outer hook 12) P2 To
Even if the hook shaft 14 is biased with respect to the rotation center P1, the upper hook loop can be passed smoothly while locking the rotation of the inner hook 13 as in the first embodiment.

That is, in this case, when the outer hook 12 is rotated, the inner hook 13 and the bobbin case 1 are rotated along with the rotation.
7 makes a rotary motion about the center of rotation of the outer pot 12,
The protruding portion 17b and the locking portion 22 are brought into contact with each other. In this abutting state, the force applied from the protruding portion 17b to the locking member fluctuates with one rotation of the outer hook 12 as one cycle, and therefore the locking member 22 and the bobbin case 1 are caused by the interaction with the spring.
7 vibrates within a predetermined rotation phase range, and the vibration causes the locking member 22 and the protruding portion 17b to open and close. Therefore, also in this embodiment, the rotation of the inner hook 13 around the center of rotation can be prevented, and the upper thread loop can be smoothly moved along the circumference of the inner hook 13, which results in good sewn product quality. Can be obtained.

The center of rotation of the inner hook 13 is preferably set within the angle range indicated by Z in FIG. This angle range is based on a straight line passing through the tip of the sword tip 12a and the center of the shuttle shaft 14, and from this position, from the position rotated 30 degrees about the shuttle shaft 14 in the reverse direction of the outer shuttle 12 (Y direction), 210 Set between rotated positions, preferably,
Based on a straight line passing through the tip of the sword tip 12a and the center of the shuttle shaft 14, between the position rotated by 85 degrees about the shuttle shaft 14 and the position rotated by 145 degrees in the reverse direction of the outer shuttle 12 from here. Is set. The moving distance H of the center of rotation of the inner hook with respect to the center of rotation of the hook shaft is from 0, 02 to 0,
2 is preferred. Further, since the impact of the engagement between the locking member 22 and the protrusion 17b can be alleviated by the spring 27 as in the first embodiment, the generation of sound can be almost suppressed.

Although the spiral spring 27 is used as the elastic member for holding the locking member 22 in each of the above-described embodiments, the invention is not limited to this, and the elastic member may be used to support the locking member 22. It is also possible to For example, a coil spring or a leaf spring may be used as the elastic member, and the elastic member may be connected to the rear end of the locking member 22 and held. However, in this case, it is necessary to adjust the spring force by holding the other end of the spring by a position-adjustable spring receiver and moving the spring receiver forward and backward along the elastic force generating direction. For this reason, when a spring other than the spiral spring is used, a space corresponding to the moving stroke of the spring receiver must be secured, and consideration must be given to the installation position. In the example, since the elastic force is adjusted by rotating the spring receiver and enlarging and reducing the diameter of the spiral spring 27, it does not require a lot of space and can be configured compactly. There is an advantage that you can.

Further, in the above embodiment, the case where the present invention is applied to the cap hook has been described as an example, but it is also possible to apply to the latch hook shown in FIG. Is not particularly limited to the above embodiment. In addition, it is effective to provide a regulation means for regulating the rotation range of the locking member in the direction in which the protrusion is rotated in the reverse direction.

[0028]

As described above, in the inner hook rotation preventing device of the sewing machine horizontal hook according to the present invention, the locking member is reciprocally supported within the rotation path of the protrusion formed on the inner hook. At the same time, an elastic support member that elastically supports the locking member is provided, and the protrusion of the inner hook is brought into contact with the locking member to prevent rotation of the inner hook, and elastically supports the impact at the time of contact. Since the elastic force of the member absorbs and relaxes the noise, a large impact sound unlike the conventional one is not generated, and the noise at the work site can be significantly reduced. Further, the locking member and the projecting portion are opened and closed by the elastic force of the elastic support member and the like, and there is no engagement between the needle plate and the inner hook. The loop can pass through the inner hook very smoothly, and an appropriate stitch forming operation can be stably performed. When the adjusting means according to the second aspect is provided, the elastic force can be changed according to the sewing conditions, so that the optimum stitch can be provided corresponding to the type of thread and the sewing machine driving speed. When the stopper for preventing reverse rotation according to claim 3 is provided, even if the inner shuttle rotates in the reverse direction due to an external force or the like, the inner hook is locked by the reverse rotation preventing stopper, so damage to the shuttle is prevented. Further, when a hook in which the center of rotation of the hook is biased with respect to the center of rotation of the hook shaft is used, when the upper thread passes, the protrusion of the hook and the locking member are separated more accurately. A beautiful seam is formed.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a configuration of a peripheral portion of the locking member shown in FIG.

FIG. 3 is an exploded perspective view showing a configuration of a horizontal sewing machine for sewing machines and the like in the above embodiment.

4A and 4B are diagrams showing a setting state of a locking member in the above embodiment, FIG. 4A shows a state where one side portion of the locking member and a convex portion are joined, and FIG. 4B shows one side of the locking member. It shows a state in which the portion and the convex portion are joined.

FIG. 5 is an explanatory side view showing a horizontal sewing machine for a sewing machine according to a second embodiment of the present invention.

6 is an explanatory plan view of what is shown in FIG. 4. FIG.

FIG. 7 is an exploded perspective view showing a configuration of a latch hook that has been generally used conventionally.

FIG. 8 is an explanatory perspective view showing a conventional opener device.

FIG. 9 is a front view showing an operating state of a conventional opener device, FIG. 9 (a) shows a state in which a movable member presses a protruding portion,
Each of (b) shows a state in which the movable member is separated from the protruding portion.

[Explanation of symbols]

 12 Outer hook 12a Sword tip 16 Lower thread bobbin 13 Inner hook 17b Projection 21a1 Projection 22a Insertion hole 21 Mounting base 22 Locking member 26 Spring receiver 24 Fixing member 27 Vortex spring (elastic support means) 28 Reverse rotation prevention stopper 29 Adjustment means

Claims (3)

[Claims] 1. An outer hook having a sword tip, which rotates in a positive direction around a vertical central axis in synchronization with a vertical movement of a sewing needle, and a lower thread bobbin which is rotatably supported and at the same time. A sewing machine horizontal hook provided with an inner hook rotatably supported by the hook, and a protrusion protruding horizontally toward the peripheral surface of the inner hook or the bobbin case, and a rotation path of the protrusion. And a locking member that is reciprocally supported by the locking mechanism so that the inner hook is positioned within a predetermined rotation phase range against the rotational force of the inner hook caused by the outer hook rotating in the forward direction. An inner hook rotation preventing device for a horizontal hook of a sewing machine, comprising elastic supporting means for elastically supporting a member. 2. The inner hook rotation preventing device of the sewing machine horizontal hook according to claim 1, further comprising adjusting means for adjusting the elastic force of the elastic supporting means. 3. The inner hook rotation preventing device for a horizontal sewing machine according to claim 1, further comprising a reverse rotation preventing stopper for preventing rotation of the inner hook due to reverse rotation of the outer hook. Inner hook rotation prevention device for the horizontal hook of the sewing machine.