JP2650262B2 - Needle thread supply device of sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a needle thread supply device for a sewing machine.

(Prior Art) In a conventional upper thread supply device of a sewing machine, for example, as shown in FIG. The needle 106 is passed through a hook 105, a top bottle (not shown) or the like, and is passed through a needle hole of the needle 106, and is caught by a shuttle on the lower surface of the bead, as is well known, to perform sewing.

(Problems to be Solved by the Invention) In the above-mentioned conventional machine, the thread top is rotated and the thread is fed out with the consumption of the upper thread at the time of sewing. However, the thread fastening by the top bin is quite sharp. For this reason, the thread top easily overruns, and at that time, the thread may unwind itself from the thread top (particularly, such a phenomenon easily occurs in a smooth thread such as a piercing thread). For this reason, the upper thread tension has a disadvantage in that the mass of the thread top is added or not applied, and the tension fluctuates, and the harmony with the lower thread is disturbed, making it difficult to stitch. In addition, there is also a fear that the yarn which has come off from the yarn top often gets caught in the yarn stand and breaks the yarn.

As a means for preventing the above-mentioned inconveniences, a method of arranging a thread top as shown in FIG. 15 is also known. However, the drawback is that the thread is not fed smoothly unless the distance between the thread top and the thread hook is considerably long. is there. Therefore, there was a problem in the arrangement space.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to pay out a yarn without being affected by the mass of the yarn top.

[Configuration of the invention]

(Means for Solving the Problems) In order to solve the above-mentioned problems, in the present invention, the thread top is arranged horizontally, the entire thread is put in a cassette, and a mechanism for applying and adjusting the thread tension is provided in the cassette.

The upper surface of the cassette is mounted near the top bottle so that the upper surface of the cassette is the same as the frame surface of the sewing machine. Also,
A push button (hereinafter referred to as a release button) is provided near the cassette, and when the push button is pressed, the cassette is released, and the release button is indexed into a set side and a release side by an over-center spring. .

(Operation) When the release button is pressed down, the swingable cassette release lever, which is connected to one end of the release button and is biased by a spring, rotates clockwise, and releases a small amount of the thread cassette by its end.

Conversely, when the thread cassette is pushed downward, the release lever rotates counterclockwise against the spring, and pushes up the thread cassette release button to its original position.

(Embodiment) Hereinafter, an embodiment of the present invention applied to a small-sized piercing sewing machine will be described with reference to FIGS.

A crank 3 is fixed to one end of a main shaft 2 rotatably supported by a bead 1 with a bearing (not shown), and is connected to a needle bar arm 6 via a crank rod 4 and a crank pin 5. . The needle bar arm 6 has a pivot shaft 7 fixed at the center thereof supported by spherical bushings 8, 8, and a needle bar 9 fixed to one end. Set screw 1
The needle 13 is fixed by 2. The timing belt 22 is hung on the large timing gear 26a and the small timing gear 26b, and the ratio of the number of teeth between the large timing gear 26a and the small timing gear 26b is 2: 1. Thus, the shuttle 23 rotates twice during one rotation of the main shaft 2. A top bin crank pin is rotatably fitted to the crank 3, and a slide shaft 17 fixed to the top bin 19 via a bushing 15 and a bushing holder 16.
The top bottle 19 pivotally supported by the top bin shaft 18 swings while causing a quick return movement. One end of a top bin 19 is pivotally connected to one end of a top bin rod 21 by a pin 20. The other end of the top bin rod 21 is provided with a pair of grooves 21a, 21a and a hook 21b.

The machine frame 28 is screwed to the upper surface of the belt 1 and a guide plate 29 is fixed thereto. The guide plate 29 is substantially L-shaped, and its horizontal portion has grooves 21a, 21a of the top bin rod 21.
Has an elongated hole 29a which can be fitted and slid. In the vertical portion of the guide plate 29, there are provided long holes 29b, 29b into which pins with heads 33, 33 fixed to the slide plate are fitted and slidable. The top cover latch 34 has a T-shape. A hook portion 34a is formed on the first arm, a spring hook portion 34b is formed on the second arm, and a pressing operation portion 34c is formed on the third arm. A hole 34d is formed in the portion. Then, it is loosely fitted on a shaft 34 fixed to the guide plate 29 (see FIGS. 2 and 6). The spring 34 is hung on a spring hook portion 34b of the top cover latch 34 and a projection 32a provided below the slide plate 32 to urge the top cover latch 34 in a clockwise direction in FIG. The slide plate 32 is urged upward.

The thread take-up lever 39 has a substantially Y-shape. The first arm has a thread hook portion 39a, the second arm has a sensor operating portion 39b, and the third arm has a release lever portion 39c. A hole 39d is formed and loosely fits on a shaft 37 fixed to the mounting plate. One end 38a of the torsion spring 38 is hung on the thread take-up lever 39 and the other end 38b is hung on one of a plurality of holes 36a drilled around the 37 of the mounting plate 36 as shown in FIG. , The thread take-up lever 39 is always urged to rotate counterclockwise.
The photo interrupter 42 is attached to the mounting plate 36 via a spacer 41.
The thread portion 43a is engaged with the sensor operating portion 39b of the thread take-up lever 39. The mounting plate 36 is mounted on the guide plate 29 by screws 44. 46 is a lower casing, and 47 is an upper casing, which covers the mechanism. The upper casing 47 has a recess 47
a is provided and the thread cassette 100 (FIG. 9) is inserted.
The thread cassette 100 is composed of a thread 51 wound around a bobbin, a cassette 50,
It consists of leaf spring 52, pin 53, seal 54, cover 55,
The cassette 50 has a hole 50a at the center thereof, which is slightly larger than the outer diameter of the thread 51, and a T-shaped hole 50c through which the end 51a of the thread 51 is inserted, like the slit 50b through which the end 51a of the thread 51 is inserted. The thread 51 is received in the hole 50a, and the end 51a of the thread 51 passes through the slit 50b and the hole 50c and protrudes outside the cassette 100. The leaf spring 52 is substantially L-shaped, and has a protrusion at one end.
52a, which engages with one of a plurality of notches 50d provided on one side surface of the cassette body, and the other end of which clamps the end 51a of the thread 51 between the pin 53 and Has been granted.

If the type of thread or the thickness of the thread changes, the engagement between the notch 50d of the cassette body 50 and the projection 52a of the leaf spring 52 is changed, so that the pinching pressure between the pin 53 and the leaf spring 52 is changed. Can be adjusted to adjust the tension.

The cover 55 is formed of a transparent synthetic resin and is covered by the cassette body 50 to prevent the thread 51 from being released. One corner of the cover 55 is greatly chamfered,
The concave portion 47a of the upper casing 47 is also chamfered so that if the user mistakenly inserts the thread cassette 100 and tries to insert the thread cassette 100 in the opposite direction, the entirety does not enter, so that the user is immediately aware. Numeral 54 denotes a seal indicating the catalog number, yarn count, color tone, name and the like of the yarn, which is affixed to the side face of the cassette body 50 where the hole 50c is provided. At one end of the seal 54,
The slit 54a is cut and a seal 54 is attached so as to come near the hole 50c of the cassette body. Then
When the thread cassette 100 is not used, the holes 5 in the cassette body 50
By sandwiching the end 51a of the thread 51 coming out of 0c into the slit 54a, it is possible to prevent the end 51a of the thread 51 from being unintentionally fed out or conversely getting into the cassette 100 and getting stuck. I can do it. A thread cassette release button 56 is used to release the thread cassette 10 from the recess 47a of the upper casing 47. The tip of the thread cassette release button 56 is connected to one end of a thread cassette release lever 57.
The thread cassette release lever 57 has a pair of projections 57a, 57a at the center.
The thread cassette releasing lever 57 is engaged with a pair of notches 47b, 47b provided in a lower portion of the concave portion 47a of the upper casing 47, and swings about the projections 57a, 57a. It is possible. The thread cassette releasing lever is hooked so that one end of a spring 58 passes through the projections 57a, 57a, and the other end is engaged with a pair of notches 47c, 47c provided in a lower portion of the concave portion 47a of the upper casing 47. Hanged on a stopped pin. For this reason, when the thread cassette release button 56 is pressed downward, the thread cassette release lever 57 rotates clockwise in FIG. 6, and when the intermediate point is passed, the spring 58 attempts to further rotate clockwise. Although it receives a load, it is stopped by the thread cassette release button 56.

At this time, the thread cassette 100 is slightly released by the end portion 57b of the thread cassette releasing lever 57. On the contrary, when the thread cassette 100 is pushed downward, the thread cassette release lever 5
7 rotates counterclockwise against the spring 58 to push up the thread cassette release button. Then, after passing through the intermediate point, the spring 58 receives a load for further turning in the counterclockwise direction, but is stopped by the pin 59. Reference numeral 71 denotes a pilot lamp (not shown), which is turned on when a power switch is turned on, and is controlled by a microcomputer so as to flash when no pulse signal is output from the photointerrupter 42. 73
Is a lamp lens, and 72 is a substrate. Reference numeral 67 denotes a top cover that covers the upper casing 47, and is rotatable about a pair of hinge pins 63 fixed to the machine frame 28 by hinges 60. A spring 62 is hung on a spring hook 61 fixed to the hinge 60 and a spring hook 64 fixed to the machine frame 28, and constantly urges the top cover to open. Gears 60a, 60a are formed on the hinge 60, and mesh with the dampers 65, 65 attached to the machine frame 28 to soften the shock when the top cover 67 is opened. A hook 67a is formed at an end of the top cover 67, and when the top cover 67 is closed, the top cover latch is provided.
The top cover 67 is engaged with the hook portion 34a of the lock 34. Further, the tip of the hook 67a is
The slide plate 32 is pressed down by the top cover 67 against the spring 35.
69 is engaged with the hole 67b of the top cover 67 by the top cover button, and the arms 69a, 69a extending upward are provided with protrusions 69b, 6
9b is formed and fitted in the holes 67c, 67c of the top cover 67, and can swing. Further, the spring 70 is always biased outward. The top cover button 69 has a tongue-shaped projection 69c and is in contact with the pressing operation portion 34c of the top cover latch 34. The top bin cover 48 covers the hook 21h of the top bin rod 21, and a thread guide 49 is fixed to an upper surface thereof.

 The operation will be described below according to the sewing procedure.

When the top cover button 69 is pressed, the tongue-shaped projection 69c presses the pressing operation portion 34c of the top cover latch 34, the top cover latch 34 rotates counterclockwise against the spring 35, and the hook portion 34a is moved to the top cover 67. Off the hook 67a. Since the top cover 67 is urged by the spring 62 to be always opened, it opens as shown in FIG. Meanwhile, slide plate
32 is the spring 35 because the pressing force of the top cover 67 is lost.
And the protrusion 32c of the slide plate 32
Twists the release lever portion 39c of the thread take-up lever 39 with a torsion spring 38.
Push up against the power of. For this reason, the thread take-up lever 39
Is rotated clockwise, and the sensor operating portion 39b relieves the slit portion 42a of the photointerrupter 42. At this time, the signal output from the photointerrupter 42 is always Hi, and the microcomputer determines that the top cover 67 is open.
Next, when the thread cassette 100 is inserted into the concave portion 47a of the upper casing 47, the thread cassette releasing lever 57 swings against the spring 58, and the thread cassette releasing button 56 is raised. End 51 of thread 51
Pull out a hook 39a of thread take-up lever 39, top bin rod 2
The hook 13 is passed through the needle 13 via a hook thread guide 49 which is pulled on the hook 21b.

〔The invention's effect〕

It is also conceivable to adjust the thread tension using a computer with one object of the present invention. However, it is difficult to automatically determine the type of the yarn, and since the change in the yarn tension greatly changes depending on the material and thickness of the yarn, this idea is still poorly feasible.

In the present invention, since the yarn is stored in a cassette, a tension appropriate for the type and thickness of the yarn is set for improvement. You can start sewing simply by passing a thread through a needle with a beak.

In addition, by inserting a slit into the sealing member attached to one side of the cassette from which the yarn is fed, when the cassette is not used, the yarn end is sandwiched between the cassette and careless yarn feeding and winding. Can be prevented.

The thread cassette can be easily pushed up and taken out by operating the release button, and can be quickly and surely mounted by simply pushing the thread cassette, which contributes to an improvement in working efficiency.

[Brief description of the drawings]

FIG. 1 is an external view of a sewing machine provided with the apparatus of the present invention, FIG. 2 is an exploded view of essential components, FIG. 3 is a plan view of the sewing machine with a top cover removed, and FIGS. AA, BB in FIG. 3,
FIG. 7 is a view showing the top cover opened, FIGS. 8 and 9 are longitudinal and transverse sectional views of the thread cassette, respectively, and FIGS. 10 to 13 are a spindle sensor and a thread break sensor. 14 and 15 are diagrams illustrating the prior art. 19 ... Top bottle, 39 ... Thread take-up lever, 47 ... Sewing casing, 47a ... Recess, 50 ... Cassette body, 51 ... Thread, 52 ... Leaf spring, 54 ... Seal, 54a ... Slit, 55 ... cover, 56 ... thread cassette release button, 57 ... thread cassette release lever, 58 ... spring (indexing), 100 ... thread cassette

Claims (2)

(57) [Claims] 1. A yarn wound around a bobbin, horizontally disposed, and steered from its outer periphery, a hole sufficient to store the yarn,
A cassette body having, on one side thereof, a hole through which the end of the yarn extends outwardly, and a plurality of notches on the other side; a substantially L-shape; The thread cassette comprises a main body of the cassette, a leaf spring, and a cover enclosing both of them, and the upper surface thereof is flush with the machine frame surface of the sewing machine, and is provided in a recess provided near the top bin of the sewing machine casing. An upper thread supply device for a sewing machine which is detachably mounted and provided with a release button for the thread cassette in the vicinity of the thread cassette. 2. A yarn wound around a bobbin, horizontally disposed, and steered from its outer periphery, a hole sufficient to store the yarn, and a hole on one side of which an end of the yarn is outwardly exposed. A cassette body having a plurality of notches on another side surface, a leaf spring having a substantially L shape, holding the thread at one end and having a projection at the other end, and a thread cassette comprising the cassette body and the leaf spring. The upper surface is made flush with the machine frame surface of the sewing machine, and is removably mounted in a recess provided near the top bin of the sewing machine casing. A thread cassette release lever extending in the horizontal direction and swingably supported at a central portion thereof, and a spring for splitting the release lever in both directions with the swing center as a boundary, wherein one end of the thread cassette release lever is provided. To the vertical direction guided by the hole in the casing. It supported the upper thread supply device of a sewing machine having a thread cassette release button.