JPH0523160B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a horizontal hook for a sewing machine having a hook shaft formed perpendicular to the rotating surface of the outer hook.

[Conventional technology]

3 to 6 are explanatory diagrams showing a horizontal hook and a horizontal hook device of a conventional sewing machine. Fig. 3 is a perspective view of the horizontal hook, Fig. 4 is an exploded perspective view showing the horizontal hook device, Fig. 5 is a perspective view showing the throat plate, and Fig. 6 is a plan view showing how the horizontal hook is installed on a two-needle sewing machine. It is a diagram. Here, the configuration of a conventional sewing machine horizontal hook and horizontal hook device will be explained with reference to these figures.

As shown in FIGS. 3 and 4, the horizontal hook is composed of an inner hook 1 and an outer hook 2. The inner hook 1 is provided with an inner hook stop 3, an opener stopper 4, a lower thread outlet 5, a bobbin support 6, and a lace 7. The inner hook stopper 3 is a protrusion provided horizontally outward from the upper line of the inner hook to prevent rotation of the inner hook 1, and is fitted into a groove 9 of a throat plate 8 shown in FIG. The grooves 9 are two stoppers 9 made on the back side of the throat plate 8.
The width of the groove 9 is larger than the width of the inner hook stopper 3. 4 per opener is a cam opposed by an opener to be described later. The bobbin thread outlet 5 is connected to a bobbin 10 (sixth
This is a slit through which the bobbin thread shown in the figure is taken out to the outside, and is formed in the inner hook 1 in an L-shape. A tension spring 11 is fixed to the outer surface of the inner pot in this portion with screws 12 and 13 so as to cover the feeding port 5. There are two types of tension springs 11, one with a forked tip and the other with a flat tip, and FIG. 4 shows one with a forked tip. Due to its forked shape, the tip fits into a hole 16 formed on the outer surface of the inner pot 1. The bobbin thread taken out to the outer periphery of the inner hook through the bobbin thread outlet 5 is
The bobbin thread is guided along the outer periphery of the inner hook and the inside of the tension spring 11 from the tip end to the needle hole, which will be described later, and the spring force of the tension spring 11 acts on the bobbin thread as tension. This tension is adjusted to a predetermined tension by tightening or loosening the screw 13. The bobbin support 6 is a support shaft for mounting a bobbin in the inner hook 1, and is provided integrally with the inner hook 1 at the center of the inner bottom surface of the inner hook. A bobbin presser 14 is provided at the upper end of the bobbin support 6, and this bobbin presser 14 is a presser for preventing the bobbin 10 (FIG. 6) installed in the inner pot 1 from coming off. A spring (not shown) in the bobbin support 6 moves the bobbin from the vertical position shown in FIG. 3 to the horizontal position shown in FIG. 4, resulting in the set state. A pobbin presser groove 15 into which the tip of the bobbin presser fits is provided on the upper edge of the inner pot 1.
4, the upper surface height of the bobbin holder 14 is approximately equal to the height of the inner hook 1. The race 7 is a protrusion on the circumference of the outer surface of the inner pot 1 and has a cut portion, and its function will be described later.

The outer hook 2 is provided with a tip 20, a race groove 21, and a hook shaft 22. Tip 20 is upper thread (needle thread)
This is a thread shaft catching claw for forming a stitch with the bobbin thread by capturing the loop formed in the inner hook 1 and going around the outer circumference of the inner hook 1. The race groove 21 is a groove into which the race 7 of the inner hook 1 fits, and is constructed by fixing the inner hook holder 23 to the upper surface of the outer hook 2 with screws 23a and 23b. A back plate 24 is fixed to the outer bottom surface of the outer hook 2 with screws 24a and 24b. The hook shaft 22 has the function of transmitting the rotation from the lower shaft (not shown) of the sewing machine to the outer hook 2 and at the same time operates an opener, which will be described later.For this purpose, an eccentric shaft 25 is integrated at the top of the hook shaft 22. is formed. Further, a through hole 26 is provided in the hook shaft 22, and has the function of supplying lubricating oil to the race portion through an oil string attached therein.

On the other hand, the horizontal pot device is constructed by adding an opener mechanism to the horizontal pot. The opener mechanism consists of an opener 30, an opener support 31, and a connecting rod 32, as shown in FIG. The connecting rod 32 is the hook shaft 22
It is an arm that interlocks the eccentric shaft 25 and the opener support 31, and one of the two rings is fitted to the eccentric shaft 25,
The other end is loosely fitted and fixed to the opener support 31 using a stepped screw 33 and a nut 34. The opener 30 is attached to the arm portion of the opener support 31 with a screw 35, and an opener support shaft 36 is fitted into a ring that serves as a fulcrum of the opener support 31. This shaft 36 is fixed with a screw to a hook stand (not shown) fixed to the sewing machine bed.

The horizontal hook device constructed as described above is mounted on a sewing machine bed (not shown) as shown in FIG. As can be seen from FIG. 6, the opener 30 corresponds to the opener 4 of the inner pot 1 in a positional relationship as shown in the figure. A feed dog 40 is positioned in the hole of the throat plate 8. This feed dog is fixed to a feed base (not shown) of the sewing machine feed mechanism, and forms an elliptical feed movement in synchronization with the needle movement. This movement acts on the sewing item mounted between the pressing mechanism and the sewing item, thereby feeding the sewing item. A needle hole 41 is formed in the center of the feed dog 40.

Next, the operation of the horizontal hook and opener mechanism will be explained. In FIG. 6, when the sewing machine is rotationally driven, the outer hook 2 rotates fully in the direction of arrow A (clockwise), and the opener 30 uses the opener support shaft 36 as a fulcrum to maintain the pitch between the screws 33, 35 and the opener support shaft 36. It swings in the directions of arrows B and C by an angle determined by the length and the amount of eccentricity of the eccentric shaft 25. opener 3
This oscillating motion of 0 allows the needle thread from the needle to easily pass through the inner hook stopper 3 and go around the outer periphery of the inner hook 1.

The situation in which the upper thread moves around the inner hook will be explained in detail with reference to FIGS. 7 to 9. FIG. 7 is a plan view for explaining how the upper thread is paid out by the horizontal hook device, FIG. 8 is a similar plan view of the lower thread, and FIG. 9 is a sectional view taken along the plane EE of FIG. 7. In FIG. 7, reference numeral 50 denotes an upper thread, and it shows how it goes around the inner hook 1. In other words, the tip 20 of the outer hook 2 that caught the loop of the upper thread.
(Fig. 4) rotates in the direction of arrow A, the loop of needle thread 50 traveling along the outer periphery of inner hook 1 moves to position 50.
It sequentially moves from a to position 50b.
Position 50a indicates the moment when the needle thread 50 that has passed through the needle hole 41 comes off the stopper 9a of the throat plate 8 and is about to enter the groove 9. At this point, the opener 30 is maximally displaced in the direction of arrow C. Therefore, the inner hook 3 of the inner hook 1 is forcibly moved to the position 3a shown by the broken line, creating a gap between the inner hook 3 and the stopper 9a, and as a result, as shown in FIG. The upper thread 50 moves from the solid line position 50c to the broken line position 50.
d, and passes through the gap between the inner pot stopper 3 and the stopper 9a.

Next, the operation of the opener 30 will be explained. FIG. 8 shows the path of the bobbin thread 51 that is paid out from the bobbin 10, and the position of the bobbin thread payout port 5 is clockwise in the outer hook 2 with respect to the line connecting the center of the bobbin support 6 and the inner hook stopper 3. The range is within two right angles in the counterclockwise rotation direction with respect to the rotation direction of .

Therefore, the tension for feeding out the bobbin thread 51 acts in a direction to rotate the inner hook 1 in the direction of arrow A, and the bobbin thread 51
30 to 100 gr when stopped by tension spring 11
A set tension is applied to the bobbin thread, and due to the high speed rotation of the outer hook 2, a high speed payout tension is applied to the bobbin thread. On the other hand, the inner hook 1 receives a rotational force in the direction of arrow A due to the frictional torque between the inner hook 1 and the outer hook 2, and the inner hook stopper 3 is pressed against the stopper 9a. Therefore, during sewing, the inner hook stopper 3 is pressed against the stopper 9a by the sum of these pressing forces. The opener 30 rotates the inner hook 1 in the opposite direction of the arrow A against this pressing force, relieves the pressing force between the inner hook stopper 3 and the stopper 9a, forms a gap, and prevents the needle thread 50 from passing. This is to make it easier.

After that, as the rotation progresses further and the needle thread 50 reaches the position 50b in FIG. , and the loop of needle thread 50 easily passes through the inner hook stopper. and upper thread 5
When the thread 0 completes its rotation around the inner hook 1, it intertwines with the bobbin thread to form a stitch.

[Problem that the invention seeks to solve]

As mentioned above, the opener mechanism is indispensable for the horizontal hook of conventional sewing machines, and as a result, the opener and the inner hook, as well as the inner hook stopper and the throat plate stopper collide with each other when the horizontal hook rotates at high speed, causing noise. Ta.
In particular, as the speed of sewing machines increases, the noise level becomes more noticeable, which significantly impedes the operability of sewing machines for sewing workers. Furthermore, there is a problem in that collision between the inner pot stopper and the stopper of the throat plate causes fatigue failure of the inner pot stopper.

The present invention has been made to solve these problems, and an object thereof is to obtain a horizontal hook for a sewing machine that can reduce noise by eliminating the opener mechanism by changing the structure of the horizontal hook.

[Means for solving problems]

The horizontal hook of the sewing machine according to the present invention is provided with a bobbin thread feed-out port in the inner hook within two right angles in the direction of rotation of the outer hook based on the line segment connecting the center of the bobbin support and the inner hook stopper. The shafts have the same diameter.

[Effect]

In the present invention, in order to reduce the noise caused by the opener and the inner hook hitting the opener due to the high-speed rotation of the horizontal hook, and the noise from the inner hook stopper and throat plate stopper due to the lower thread feeding tension of the horizontal hook, the bobbin thread is The feeding tension is applied in the opposite direction to the pressing force generated in the rotational direction of the outer hook, so that the upper thread passes through the inner hook stopper portion without operating the opener mechanism, and the above-mentioned noise is suppressed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the inner hook, and FIG. 2 is a plan view for explaining how the bobbin thread is paid out.

In FIGS. 1 and 2, the symbols in the figures are the same as those in the prior art described above.

As shown in FIG. 1, the feature of the inner hook 1 of the present invention is that the opener 4 shown in the prior art is abolished and the position of the bobbin thread outlet 5 is changed. The bobbin thread outlet 5 is located between the center of the bobbin support 6 and the inner hook stopper 3.
This figure shows that the inner hook 1 is provided with a bobbin thread outlet 5 within two right angles when the outer hook 2 is rotated clockwise with respect to the line segment connecting them. An L-shaped slit is formed in the bobbin thread outlet 5 from the bottom of the bobbin holding groove 15 into which the tip of the bobbin holding 14 fits, and extends from the bottom of the bobbin hook 1 to the inner hook 1. A tension spring 11 is fixed to the outer surface of the inner hook 1 in the vicinity of the lower thread outlet 5 by screws 12 and 13 so as to cover the lower thread outlet 5. In this embodiment, the tension spring 1 has a forked tip.
1 is shown, the tip end is fitted into the hole 16 formed on the outer surface of the inner hook 1, and the bobbin thread 51 is held by the tension spring 11.

According to the present invention, the outer pot has a structure including an opener 30, an opener support 31, a connecting rod 32, and an opener support shaft 3.
6 and other opener mechanisms are no longer required, and therefore the eccentric shaft 25 integrally formed with the hook shaft 22 shown in the outer hook 2 of the conventional horizontal hook can be removed, and the rotation from the lower shaft of the sewing machine can be transferred to the outer hook 2. The hook shaft 22 to be operated can be configured to have the same diameter.

Next, the effect will be explained. In FIG. 2, 51 is a lower thread, 10 is a bobbin, and 2 is an outer hook.

In the figure, when the sewing machine is rotated, the outer hook 2 is rotated in the direction of arrow A. On the other hand, the bobbin thread 51 from the bobbin 10 that has passed through the bobbin thread outlet 5 is transferred to the inner hook 1.
is fed out in a direction that rotates it in the opposite direction of arrow A. This feeding tension is generated in the direction opposite to the rotation of the outer hook 2 in the direction of arrow A, and as a result, the inner hook 1 and the outer hook 2
The rotational force acting on the inner hook stopper 3 is limited to almost zero by canceling out the frictional torque in the direction of arrow A generated between the inner hook and the inner hook. Therefore, the pressing force of the inner hook stopper 3 on the stopper 9a or 9b hardly acts, so that even if there is no opener mechanism, the upper thread 50 passes through the inner hook stopper 3 in the same way as in the case shown in the prior art. This can be done on the principle of operation.

Furthermore, although the above embodiment has been described with reference to the case where the outer hook 2 rotates clockwise, even in a horizontal hook where the outer hook 2 rotates counterclockwise, the position of the bobbin thread outlet 5 is at the center of the bobbin support 6. 2 by rotating the outer hook 2 counterclockwise with reference to the line connecting the inner hook stopper 3.
A tension spring 11 is fixed to the outer surface of the inner hook 1 in the vicinity of the lower thread outlet 5 by screws 12 and 13 so as to cover the lower thread outlet 5.

〔Effect of the invention〕

As explained above, the present invention has a structure in which the rotational force applied to the inner hook by the bobbin thread is applied in the opposite direction to the rotational force due to friction of the outer hook, thereby eliminating the need for an opener mechanism that requires complicated machining. A simple and inexpensive horizontal pot device can be obtained.
Further, noise caused by the collision between the opener, the inner hook stopper, and the throat plate can be eliminated, and fatigue damage caused by the collision between the inner hook stopper and the throat plate can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is an explanatory diagram explaining the operation of the present invention, and Figures 3 to 6 are configuration diagrams of a conventional horizontal hook and horizontal hook device.
FIGS. 7 to 9 are explanatory diagrams for explaining the operations in FIGS. 3 to 6. FIG. In the figure, 1 is an inner hook, 2 is an outer hook, 3 is an inner hook stop, 5 is a bobbin thread outlet, 6 is a bobbin support, 11 is a tension spring, and 22 is a hook shaft. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An inner hook having a bobbin support, an inner hook stopper, and a bobbin thread outlet; a tension spring fixed to the outer surface of the inner hook so as to cover the bobbin thread outlet; In a horizontal hook of a sewing machine, which is composed of a fitted outer hook and a hook axis formed perpendicular to the rotating surface of the outer hook, the bobbin thread outlet of the inner hook is connected to the center of the bobbin support and the inner hook stop is connected to the hook. A horizontal hook for a sewing machine, characterized in that it is provided in a range within two right angles in the rotational direction of the outer hook with reference to a connecting line segment.