JPH08155167A - Pressing device for material to be sewn - Google Patents

Abstract

PURPOSE: To provide a material pressing device which can suppress generation of puckering as much as practicable. CONSTITUTION: This pressing device for material to be sewn is composed of a throat plate and a cloth holder A having an aux. holder 3 energized in such a way as protruding slightly into a feed cog groove in the throat plate from the undersurface of a holder foot 1. For sewing a thicker material, a chamfer is formed on both sides of the upper part of the feed cog groove of throat plate confronting the aux. holder 3. A part of foot 1 at least farther than the needle drop position is warped upward so that the cloth feeding motions are made the most of.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for pressing a workpiece by cooperation of a needle plate and a cloth retainer.

[0002]

2. Description of the Related Art Conventionally, in order to prevent puckering (creases that occur in a sewn product due to shrinkage of the seam) from occurring, the sewn product is sewn while being pulled by hand, or the pre-pulling function of the hand is used. It was either sewn on a sewing machine equipped with a roller (puller).

[0003]

In the sewing in which the material to be sewn is pulled by hand, it takes skill to make the pulling force constant, and when the pulling force varies, puckering partially occurs. . Further, in sewing with a sewing machine equipped with a puller, pulling force does not act at all at the time of sewing a portion near the end of sewing that is not gripped by the puller, and puckering is remarkable.

Particularly, when the material to be sewn is a shape-stable material (for example, cotton cloth, it is dipped in low-temperature liquid ammonia for drying, treated with a resin, dried, and then sewn.
It is obtained by pressing and curing at high temperature for several minutes. )
In this case, puckering is memorized by heat treatment after sewing and cannot be erased after that, so it is necessary to take the utmost care not to cause puckering during sewing.

An object of the present invention is to provide a sewing-material pressing device capable of suppressing the occurrence of puckering.

[0006]

In order to achieve the above object, a sewing-material pressing device according to the present invention is provided with a needle plate and a lower surface of a presser foot so as to slightly project into a feed dog groove of the needle plate. And a cloth presser having a biased auxiliary presser. For sewing thick products, chamfers may be formed on both upper sides of the feed dog groove of the needle plate facing the auxiliary presser. Further, in order to make the most of the cloth feeding movement, it is preferable that at least the tip of the presser foot is bent upward.

[0007]

In the sewn product pressing device constructed as described above, the auxiliary presser is urged so as to project into the feed dog groove of the needle plate, and as a result, the work is sewn in cooperation with the feed dog. The range of gripping the object is expanded, and the material to be sewn is firmly gripped by the auxiliary presser and the feed dog, and is reliably fed. When chamfering is formed on both upper sides of the feed tooth groove of the needle plate facing the auxiliary presser, the work is pressed by the auxiliary presser and falls along the chamfer, so that the cloth feeding movement effectively works. When bending the presser foot upward from at least the needle drop position,
The material to be sewn is advanced to the needle drop position without any resistance, and the cloth feed movement is maximized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sewing-material pressing device according to the present invention will be described with reference to FIGS.

This sewn product pressing device comprises a presser foot A having a presser foot 1 having an auxiliary presser foot 3, and a needle plate 9.

The presser foot 1 itself, excluding the auxiliary presser foot 3, has a presser foot 1 and a presser foot support 2 as main members, which is not much different from the conventional one. However, as shown in FIG. 6, at least the tip of the presser foot 1 is bent upward from the needle drop position.

The presser foot support 2 is a presser bar 1 on the sewing machine head.
1, which is a member directly screwed to the presser foot 1, and the presser foot 1 is swingably attached to the presser foot support 2 by a presser foot support shaft 4.

As shown in FIG. 4, the presser foot support shaft 4 is inserted into a through hole 1b formed in the mounting portion 1a at the rear portion of the presser foot 1, and is located in front of the through hole 1b of the mounting portion 1a. Two concave portions 1c with which the pressing spring 7 is engaged are formed on the upper surface.

As shown in FIG. 2, the presser foot spring 7 is provided between the presser foot 1 in the set state and the presser foot support 2.
The front side of the presser foot 1 is urged to lower. The presser spring 7 causes the lower surface of the presser foot 1 to come into contact with the needle plate 9 or the material to be sewn with a uniform force when the presser bar 11 is lowered and lowered onto the needle plate 9.

The auxiliary presser foot 3 is housed in a slit 1d formed vertically from the mounting portion 1a of the presser foot 1 to the main body, and can be swung by the presser foot support shaft 4 inserted into the through hole 1b. It is attached. The rear portion of the auxiliary presser foot 3 is a spring receiving portion 3a extending upward to a position facing an auxiliary presser spring 6 described later. In addition, auxiliary foot 3
Is slightly smaller than the width of the feed dog groove 9a of the needle plate 9 described later. This is because the sewn product is more scratched as the auxiliary presser foot 3 is thinner.

The presser foot support 2 is formed with a female screw hole 2a penetrating obliquely in the front-rear direction. An auxiliary presser spring 6 is inserted in the female screw hole 2a to tighten the auxiliary pressurizing pressure adjusting screw 5. To be The auxiliary pressing spring 6 put in the female screw hole 2a engages with the upper end of the spring receiving portion 3a. 3 shown in FIG.
b is the engaging groove. By adjusting the tightening degree of the auxiliary presser foot pressure adjusting screw 5, the pressure of the auxiliary presser spring 6 against the auxiliary presser foot 3 can be adjusted, and the urging force of the auxiliary presser foot 3 can be adjusted according to the type and thickness of the material to be sewn. Can be adjusted.

As shown in FIG. 4, the attachment portion 1 of the presser foot 1 is attached.
A through hole 1e for inserting the rocking | fluctuation control pin 8 into a non-moving state is formed in the rear of the through hole 1b of a.
Further, as shown in FIG. 2, the presser foot support shaft 4 of the auxiliary presser foot 3 is
A hole 3b slightly larger than the outer diameter of the rocking restriction pin 8 is formed behind the hole through which is inserted. When the auxiliary presser foot 3 is swingably set in the slit 1d of the presser foot 1, first, the swing restriction pin 8 is inserted into the through hole 1e and the hole 3b so as to communicate with each other. The presser foot 1 is fitted into the lower part of the presser foot support 2 and the presser foot support shaft 4 is inserted.

Therefore, the lower surface of the auxiliary presser 3 on which the auxiliary presser spring 6 and the auxiliary presser pressure adjusting screw 5 are also set slightly protrudes from the lower surface of the presser foot 1 into the feed dog groove 9a of the needle plate 9. Then, when pushed up by the feed dog 10, since the inner diameter of the hole 3b is larger than the outer diameter of the rocking regulation pin 8 and there is play, it can rotate counterclockwise about the presser foot support shaft 4. . The degree of protrusion from the lower surface of the presser foot is such that it does not interfere with the feed dog 10 when the feed dog 10 returns in the cloth feed movement.

On the needle plate 9, as shown in FIG.
A feed tooth groove 9a corresponding to 0 is formed, and chamfers 9b are formed on both upper sides of the center feed tooth groove 9a facing the auxiliary presser foot 3 (dots in the figure, shaded by dots). There is.

By the way, the locus 14 of the cloth feed movement of the feed dog
Has a substantially elliptical shape, as shown in FIG. In sewing with a sewing machine that employs the workpiece pressing device of the present invention, the auxiliary presser foot 3 is attached to the feed dog that makes such a movement.
7, the lower surface thereof slightly protrudes into the feed dog groove 9a of the needle plate 9 and is urged downward by the auxiliary pressing spring 6. Therefore, the material to be sewn for sewing is securely gripped by the auxiliary presser foot 3 and the feed dog as compared with the conventional one without the auxiliary presser foot 3, and is reliably fed. Moreover, the grip range L2 of the sewing-material pressing device of the present invention having the auxiliary presser 3 is obviously larger than the conventional gripping range L1 that does not include the auxiliary presser 3, and the grip time of the workpiece is 5 to 6%. Because of the longer length, the sewn product can get the highest rating with the least puckering.

In particular, when a chamfer 9b is present in the center feed tooth groove 9a, as shown in FIG. 8, the sewing work F sandwiched between the cloth presser A and the needle plate 9 is attached to the auxiliary presser foot 3. When pressed, it falls along the chamfer 9b, and the feed dog 1
The cloth feed motion due to 0 can be effectively received. This is effective when the thickness of the material to be sewn is large.

Further, since the presser foot 1 in the sewn product pressing device of the present invention is warped upward at least beyond the needle drop position, the sewn product can be advanced to the needle drop position without resistance, and the cloth is sewn. The feeding movement can be used to the maximum.

[0022]

Since the present invention is configured as described above, it has the following effects.

That is, the auxiliary presser is urged so as to slightly project from the lower surface of the presser foot into the feed dog groove of the needle plate, and the range in which the work is gripped is increased in cooperation with the feed dog. The sewn product is firmly gripped between the auxiliary presser foot and the feed dog, is reliably fed, and puckering hardly occurs. When chamfering is formed on both upper sides of the feed dog groove of the needle plate facing the auxiliary presser, a thick material can be sewn without puckering. Further, when at least the tip of the presser foot is warped upward beyond the needle drop position, the occurrence of puckering can be further reduced.

[Brief description of drawings]

FIG. 1 is a perspective view seen from below a cloth presser constituting a sewing-material pressing device of the present invention.

FIG. 2 is a partially cutaway side view of a presser foot which constitutes the sewing device pressing device of the present invention.

FIG. 3 is a perspective view of a presser foot support member of a cloth presser.

FIG. 4 is a perspective view showing how the auxiliary presser is attached to the presser foot according to the present invention.

FIG. 5 is a plan view of a needle plate and feed dogs that constitute the sewing-material pressing device according to the present invention.

FIG. 6 is a side view illustrating a warped state of the presser foot according to the present invention.

FIG. 7 is a side view for explaining a protruding state of the auxiliary presser into the tooth groove according to the present invention.

FIG. 8 is a rear view illustrating the effectiveness of chamfering formed on both upper sides of the feed dog groove.

[Explanation of symbols]

 A Presser foot 1 Presser foot 2 Presser foot support 3 Auxiliary presser foot 4 Presser foot support shaft 5 Auxiliary presser foot pressure adjusting screw 6 Auxiliary presser spring 8 Swing regulating pin 9 Needle plate 9b Chamfer 10 Feed tooth 12 Needle bar 13 Needle

Claims (3)

[Claims] 1. A sewing machine pressing device comprising a needle plate and a cloth presser having an auxiliary presser biased so as to slightly project from a lower surface of the presser foot into a feed dog groove of the needle plate. 2. The sewn product pressing device according to claim 1, wherein chamfers are formed on both upper sides of the feed dog groove of the needle plate facing the auxiliary presser. 3. The sewn product pressing device according to claim 1, wherein at least a portion of the presser foot beyond the needle drop position is warped upward.