JP3314093B2 - Sewing machine thread tension adjusting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the ease of thread tension adjustment by a manufacturer, the reduction of the resistance value of the upper thread, and the ability of the user (sewing person) to change the thread tension when sewing the sewing machine. The present invention relates to a thread tension adjusting device for a sewing machine that can return to a standard thread tension set by a manufacturer and keep the standard thread tension set by a manufacturer forever.

[0002]

2. Description of the Related Art In a conventional sewing machine, as shown in FIG. 5, a thread tensioner 1 has a thread tension disc 1 and a spring receiving washer 4 and a spring 5 on a thread tension shaft 1b provided with a slit 1a at one end.
Is inserted and fixed with a screw 6, and a thread loosening pin 7 is inserted into the other end of the thread tension shaft 1b. The thread loosening pin 7 comes into contact with the spring receiving washer 4, and a press-up lever (not shown) of the sewing machine. ) Is raised, the surface of the cam provided on the presser lifting lever presses one end of the thread release pin 7, and the other end of the thread release pin 7 presses the spring receiving washer 4 to compress the thread tension spring 5 and the thread tension disc. The spring force applied to the upper and lower threads is cut off to facilitate pulling out the upper thread.

[0003] In a sewing machine in which a thread adjusting section is provided at an upper portion of an arm and a thread take-up spring is provided at a lower position, a thread guide is used to fold the upper thread at the thread take-up spring section.

[0004]

In such a thread tensioner, it is necessary to improve special sewing conditions, that is, to improve the feel, to perform sufficient thread tightening, or to change the balance between upper and lower threads. If the screw 6 is rotated and adjusted when it becomes necessary to sew the thread, the position of the standard thread tension set by the manufacturer cannot be known and cannot be returned. Folding using a guide gives a great resistance to the thread and adversely affects the sewing.

[0005]

According to the present invention, there is provided a thread tension plate fixed to a thread tension bar having a support arm bent at a right angle. A hole provided at one end of the disk portion, the thread tension plate holder, the first spring, and the adjusting arm is sequentially inserted, and the thread release lever is configured to protrude through an elongated hole of the support arm of the thread tension table. A thread tension portion and a boss protruding from the center of the adjustment dial were inserted into a long hole of the operation plate, and a projection provided on the operation plate was inserted into a fan-shaped cam groove of the adjustment dial, and provided at the center of the adjustment dial. The fixing screw passed through the through-hole is passed through the through-hole at the tip of the support arm, and is fixed with the fixing nut through the through-hole of the split spring having an engaging portion that engages with the notch provided on the end face of the adjustment dial. Dial adjustment part and the other end of the adjustment arm of the thread tension part A small screw that passes through the square hole of the operating plate and the through hole of the right-angle bent portion of the operating plate passes through a screw hole provided at the other end of the adjustment arm via a second spring. It is provided with a screw adjusting section in which the tip of the screw is fixed with a nut.

[0006]

According to the present invention, when the small screw of the operating plate is turned, the adjusting arm slides along the side because the slit of the adjusting arm is fitted with the side of the square hole of the operating plate, thereby causing the spring to move. Is compressed or loosened, the pressing force between the thread tension plate and the thread tension plate is adjusted, and the thread tension is set.

In this case, since the tip of the small screw is fixed with the self-locking nut at the end screwed into the adjusting arm, there is no need to remove the cover and retighten the lock nut after adjusting with the small screw.

Further, since the protrusion of the operation plate is inserted into the fan-shaped cam groove of the adjustment dial and the protruding boss of the adjustment dial is inserted into the elongated hole of the operation plate, when the adjustment dial is rotated, the length of the operation plate becomes longer. The hole slides along the central boss of the adjustment dial, and the adjustment arm incorporated in the actuation plate moves together to compress or loosen the first spring to adjust the thread tension.

Therefore, the manufacturer changes the first spring force by turning the small screw, adjusts the thread tension of the upper thread passing between the thread tension disc and the thread tension plate, and sets the standard thread tension.

A sewing user (user) can perform sewing by changing the thread tension by rotating the adjustment dial. When the sewing is finished, the split spring is rotated back until it hits the notch of the adjustment dial, and the sewing machine is set to the manufacturer's setting. It can be returned to the standard thread tension.

[0010]

1 is an exploded perspective view of a thread tension adjusting device according to one embodiment of the present invention, FIG. 2 is a front view of the thread tension adjusting device of FIG. 1, and FIG. 3 is a side view of the thread tension adjusting device of FIG. 4 is a plan view of the thread tension adjusting device of FIG. 1. A projection 8a is projected from an upper portion of the thread tension table 8, and a support arm 8b bent at a right angle is formed slightly below the projection 8a. Bifurcated part 8 at the bottom of tone table 8
c (see FIG. 3).

A thread tension bar 9 is fixed to the thread tension table 8,
A thread tension plate 10, a thread tension plate 11, a washer 1
2. Disc portion 13a of thread release lever 13, thread tension disc presser 1
4. The first spring 15 is inserted, and the end of the thread tension bar 9 is further inserted into a through hole 16a provided at one end of the adjustment arm 16 to form a thread tension portion. Hole 1 at the end
6b, a slit 16c is provided substantially at the center of the lower part of the adjusting arm 16, and the thread release lever 13 projects through an elongated hole 8d provided in the support arm 8b.

The other end of the adjusting arm 16 is inserted into a square hole 18c of the operating plate 18, and a side of the square hole 18c of the operating plate 18 is slidably fitted into a slit 16c substantially at the center of the lower surface of the adjusting arm 16. Then, the small screw 22 having the end of the operating plate 18 inserted into the through hole 18e of the right-angle bent portion 18d is screwed into the screw hole 16b of the adjusting arm 16 via the second spring 23, and the end is Fix with self lock nut 24,
A screw adjusting unit (a thread tension adjusting device in a manufacturer) is configured.

The adjustment dial 17 has a sector cam groove 17a.
The boss 17b projecting to the center is inserted into the elongated hole 18a of the operation plate 18 and the operation plate 18
The adjustment screw 17 has a projection 18b inserted into the fan-shaped cam groove 17a of the adjustment dial 17, and a tip of a fixing screw 19 inserted into a through hole at the center of the adjustment dial 17 is attached to the support arm 8b of the thread tension table 8.
Is inserted into a through hole 8e provided at the end of the split spring 20, further inserted into a through hole 20a provided in the center portion of the split spring 20, and fixed with a fixing nut 21. An engagement portion 20b at one end of the split spring 20 is It is configured to engage with a notch 17c provided on one end surface of the adjustment dial 17, and constitutes a dial adjustment portion {an adjustment device performed by a sewing operator (user)}.

Further, a thread guide member 25 having a thread guide portion 25a parallel to a forked portion 8c at the lower portion of the thread tension stand 8 is fixed to the thread tension stand 8 with a fixing screw 26, and a thread guide roller is attached to the forked portion 8c. A thread guide roller 27 whose 27a is rotated by a rotation shaft 27b is fixed, and a thread take-up spring 28 is fixed near the forked portion 8c. An end of the thread take-up spring 28a protruding from the thread take-up spring 28 is It is inserted into the crescent-shaped guide groove 25b of the thread guide 25a.

In the thread tension adjusting device according to the embodiment of the present invention having the above-described structure, the thread drawn out from the thread wound through the thread pin of the sewing machine is hooked between the thread tension plate 10 and the thread tension plate 11. After being lowered therefrom, it is hooked on the thread guide roller 27a of the thread guide roller section 27, is hooked on the thread take-up spring 28a of the thread take-up spring section 28, is further passed through the balance of the sewing machine, and is then passed through the sewing needle.

Then, the sewing operator (user) operates the thread tension plate 1
When it is desired to change the pressing force between thread 0 and thread tension plate 11, that is, the thread tension, when the adjustment dial 17 is rotated, the operation plate 18 slides right and left along the central boss 17b of the adjustment dial 17, so that the operation is performed. Adjusting arm 16 incorporated in plate 18
Also move left and right to adjust the spring pressure of the first spring 15, and the position where the engaging portion 20 b of the split spring 20 engages with the notch 17 c of the adjustment dial 17 was adjusted by the manufacturer. Since the standard thread tension is set to the standard thread tension, the sewing operator (user) can easily return the original thread tension even if the adjustment dial 17 is arbitrarily rotated.

As shown in FIG. 3, the small screw 22 of the screw adjustment section is mounted at a position where the screw can be turned by a screwdriver when the front cover of the sewing machine is opened.・ Because the lock nut 24 is used,
When adjusting the thread tension at the manufacturer, remove the body cover and tighten the self-lock nut 24,
Since there is no need for loosening, efficient work is possible, and also in the case of trouble repair at the customer, adjustment can be easily made similarly.

Further, by threading the thread on the thread guide roller 27a of the thread guide section 27 provided at a position distant from the thread tension section, the thread guide roller 27a is assembled to rotate lightly on the rotating shaft 27b. As a result, the yarn is rotated slightly by the passage of the yarn, and is not affected by the steep angle of the upper yarn, which has a favorable effect on the sewing.

[0019]

As described above, in the thread tension adjusting device of the present invention, (1) the self-lock nut is used in the case where the manufacturer adjusts the thread tension by turning the small screw. Therefore, the loosening of the small screw can be prevented while the front cover is opened and the small screw is kept rotating, and the work is easy and easy. (2) The sewing operator (user) rotates the adjustment dial to change the thread tension. In the case of sewing, the thread tension can be returned to the standard thread tension set by the manufacturer by returning the engaging portion of the split spring to the position where the notch portion of the adjusting dial is finally engaged.

(3) Further, since a thread take-up spring portion is provided at a lower position away from the thread tension portion, a rotary roller is provided at a steep angle turn-up portion of the upper thread, and the upper thread is hung. This reduces the resistance of the upper thread, and can have a favorable effect on sewing.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a thread tension adjusting device according to an embodiment of the present invention.

FIG. 2 is a front view of the thread tension adjusting device of FIG. 1;

FIG. 3 is a side view of the thread tension adjusting device of FIG. 1;

FIG. 4 is a plan view of the thread tension adjusting device of FIG. 1;

FIG. 5 is a side view of a conventional thread tension device.

[Explanation of symbols]

 8 Thread tension stand 9 Thread tension bar 10 Thread tension plate 11 Thread tension plate 12 Washer 13 Thread loosening lever 14 Thread tension plate holder 15 First spring 16 Adjustment arm 17 Adjustment dial 18 Operating plate 19 Fixing screw 20 Split spring 21 Fixing nut 22 Small Screw 23 Second Spring 24 Self Lock Nut

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) D05B 1/00-97/12

Claims (3)

(57) [Claims] A thread tension plate fixed to a projection provided on an upper portion of a thread tension table having a support arm bent at a right angle, a thread tension plate, a thread tension plate, a disk portion of a thread release lever, a thread tension plate presser,
The first spring and a hole provided at one end of the adjusting arm are sequentially inserted, and the thread loosening lever is configured to protrude through a long hole of the support arm of the thread tension table. Insert the boss protruding in the center into the long hole of the operation plate,
A protrusion provided on the operation plate is inserted into a fan-shaped cam groove of the adjustment dial, and a fixing screw passed through a through-hole provided at the center of the adjustment dial is passed through a through-hole at the tip of the support arm to perform the adjustment. A dial adjusting portion fixed with a fixing nut through a through hole of a split spring having an engaging portion engaged with a notch provided on an end surface of the dial; and a second end of the adjusting arm of the thread tension portion, a corner of the operating plate. A small screw passing through the hole and passing through the through hole of the right-angle bent portion of the operating plate is passed through a screw hole provided at the other end of the adjusting arm via a second spring, and a tip of the small screw is connected to a nut. A thread tension adjusting device for a sewing machine, comprising: 2. The thread tension adjusting device according to claim 1, wherein a self-locking nut is used for fixing the small screw. 3. The thread tension adjusting device according to claim 1, wherein a roller portion is provided at a steep angle turning point of the upper thread in a lower thread take-up spring portion of the thread tension table.