JPS5836389Y2 - Cloth presser metal fitting to prevent cloth from slipping - Google Patents

Description

[Detailed description of the invention] The present invention is an improvement of a presser foot fitting for a sewing machine, and in particular, a presser foot that has a means for preventing upper and lower cloth slippage and prevents the sewing from shrinking due to excessive tightening when pulling up the upper thread. It concerns metal fittings.

Various types of presser foot fittings having means for suppressing vertical fabric displacement are already known, but in such prior art, the presser foot part is usually separated from the inner and outer parts. When one of them loosens its pressure on the cloth surface as the needle rises, the other moves in conjunction with or follows the feed dog and moves forward by holding the cloth surface from above and below.

However, during this incremental cloth feed operation, the action of the presser foot is relaxed just above the needle hole in the throat plate, and the surface of the cloth pulled by the needle thread rises due to the needle thread tightening action of the thread take-up.
Particularly when sewing thin or soft fabrics, the sewing machine may become too tight, resulting in shrinkage.

The purpose of this invention is to solve this problem, and when the inner presser feeds the fabric step by step, the outer presser, which is floating above the fabric surface, feeds the fabric under the needle drop hole. This is characterized in that a spring with a needle hole is attached as a third presser means for pressing down the surface.

A cloth slip prevention presser device 1 is removably attached to the lower end of a presser bar 5 of a sewing machine with a screw 6.

This is widely known as, for example, an upper feed attachment of a sewing machine or a walking press foot, and if the right side in the figure is referred to as the front side as the side where the operator is located, there is a When the outer presser foot 2 of the inner and outer presser foot releases the pressure on the cloth surface, lever 1
Due to the action of an internal mechanism (not shown) linked to the needle bar 10 via the needle bar 1, the inner presser foot 3 is lowered, and at this time, the inner presser foot 3 is exposed on the throat plate 13 and works together with the feed dog 14, which enters the cloth feeding process, to feed the workpiece cloth. 12 from above and below, and when the outer presser foot 2 descends to press the workpiece cloth 12, the inner presser foot 3 rises, and at the same time, for example, by an elastic mechanism, , to return forward to the old position before the feed step, and a detailed explanation of its internal structure will be omitted.

The outer presser foot 2 is swingably supported by a pin 7 at the front end of a pair of arms 1a extending toward the front of the cloth slippage prevention presser device 1, slightly behind the needle drop position.

The outer presser foot 2 is barrel-shaped as usual, and the presser spring 4 is fixedly supported at its curved front end by a pair of caulking pins 9, as shown in FIG.

The presser spring 4 is made of an elastic wire bent into a shape resembling the cross section of a railway rail, and both expanded leg ends are supported on the tip of the outer presser foot 2, and the portion corresponding to the rail head is attached to the outer presser foot 2. The eye hole 4a is formed in the same shape as the needle hole 8, and that part is the lower side of the needle hole 8 and is used as a spring free end for the outer presser foot 2.
The pieces are arranged vertically so as to overlap each other with a smaller gap between them.

The support end to the outer presser foot 2 is attached so as to be above the outer presser foot 2 so that it does not interfere with the insertion of the work cloth 12.

To explain its action, the inner presser foot 3 stops advancing in the first half of the downward stroke of the needle bar 10, and at the same time, the pressure from the presser rod 5 increases, and when the outer presser foot 2 presses the work cloth 12. The presser spring 4 is pressed between the outer presser foot 2 and the work cloth 12, and the three are superposed in a layered manner on the throat plate 13 as shown in FIG.

After forming a stitch in this state, when the needle bar 10 rises and the thread take-up (not shown) pulls up the needle thread 15, the presser foot 2 is in a state floating above the work cloth 12 as shown in FIG. spring 4
The cloth surface is pushed down by the thread part to prevent the work cloth 12 from being lifted as the needle thread is pulled up.

This state is shown in an enlarged view in FIG. 4, and in the conventional system shown in FIG. Trapped,
The work cloth 12 is lifted at the seam that has just been formed, and the bobbin thread 16 is also let out accordingly.

Then, when proceeding to the next stitch, the bobbin thread 16 becomes too loose with respect to the binding of the needle thread 15, and as a result, the balance of the upper and lower threads is lost, and the needle thread side becomes slightly sagging, and the workpiece fabric 12 This results in an unsightly appearance at the sewing line, like a seam wrinkle.

In the case of the means having the presser spring 4 of the present invention, the fabric surface is not lifted even when the upper thread 15 is tightened, so the tightness of the upper and lower threads can be adjusted to maintain a good seam without disturbing the balance. is obtained.

In the case of the device according to the present invention, as in the case of the presser foot with means for preventing cloth slippage, a third presser means is provided for the inner and outer presser feet so that the cloth surface does not always rise just below the needle. By attaching a presser spring, it is possible to perform good sewing with less thread tangles and seam shrinkage, even when sewing thin or soft fabrics, and it is a means to prevent fabric slippage. This makes the effect of the presser foot metal fitting even better.

[Brief explanation of drawings]

FIGS. 1 and 2 are partial cross-sectional side views of a sewing machine equipped with the presser foot fitting of the present invention, each showing the operating state.
FIG. 3 is a partial plan view of the main part thereof, FIG. 4 is a partial cross-sectional view for explaining the function of the present invention, and FIG. 5 is a conventional technology for comparison with FIG. 2: External presser foot, 3: Inner presser foot, 4: Presser spring, 4a: Eye hole,
8: needle hole, 10: needle bar, 12: processed cloth, 14: feed dog.

Claims (1)

[Scope of utility model registration request] The material presser foot is divided into an inner presser foot and an outer presser foot, and when the outer presser foot is loosened from pressing the workpiece cloth in conjunction with the lifting and lowering of the needle bar of the sewing machine, the cloth is fed by the feed dog of the sewing machine. In the cloth presser metal fitting of the sewing machine, in which the inner presser clamps the work cloth between the feed dog and the feed dog during the action stroke to advance the feed, an elastic wire bent into the cross-sectional shape of a railway rail is used. Both leg ends of a presser spring are supported on the upper side of the warped front end of the outer presser foot, and the free end side portion of the presser spring is formed to have a shape substantially the same as the needle hole of the outer presser foot. The presser foot fitting prevents fabric slippage, wherein the guide portion is arranged to overlap with a small gap below the needle hole of the outer presser foot, and the presser spring is constantly pressed against the needle plate.