JPH0354697Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a presser foot for a sewing machine.

(Prior art and its problems) In the feed mechanism of a swing lever type sewing machine, for example, as shown in FIG. In the case of the feed base 6 which is vertically swung by the vertical feed cam 5 fixed to the feed plate 6, the upper surface 7a of the feed dog 7 cannot always be kept parallel to the throat plate surface 8.

Therefore, in the normal design, the upper surface 7a of the feed dog 7 is
is set so that it is parallel to the throat plate surface 8. However, there are cases where the design target is not always achieved due to the accumulation of manufacturing errors in parts of the feed mechanism, and in this case, feed failure may occur in some stitches.

That is, when the feed dog 7 sinks to the throat plate surface 8, the fifth
If the upper surface 7a of the feed dog 7 is parallel to the throat plate surface 8 as shown in the figure, the entire bottom surface 9a of the presser foot 9 will always be in contact with the cloth between the upper surface 7a of the feed dog 7 or the throat plate surface 8. can be pressed effectively, so that during the subsequent penetration of the needle 10 into the fabric, the fabric is not thereby displaced relative to the presser foot 9.

However, as shown in FIG.
Due to the inclination (shown as an extreme inclination in the figure for ease of understanding) when the feed dog 7 sinks, even if the front end 7b of the feed dog 7 sinks below the throat plate surface 8, the rear end 7c protrudes from the throat plate surface 8. If this occurs, a gap will be formed between the presser foot 9 and the throat plate surface 8, making it impossible to press the cloth effectively and making the cloth unstable. As a result, the direction of the next feed by the feed dog 7 becomes unstable, and as a result, problems such as diagonal feed of the fabric are caused when zigzag is used in close stitching as shown in FIG. 7, for example.

Particularly when sewing a one-point pattern or the like with a sewing machine using automatic feed, there is a problem in that even slight fluctuations in feed cause the shape of the pattern to be distorted, resulting in an unsightly finished stitch.

(Means for Solving the Problems and Effects of the Invention) The present invention provides a presser foot for a sewing machine, in which a very small width is formed on the bottom of the presser foot, facing the ridges formed close to both sides of the needle hole in the needle plate. This is a presser foot for sewing machines that has a pair of rib-like protrusions parallel to the feed direction, and the feed dog sinks to the throat plate surface, especially in sewing machines equipped with a swing lever type feed mechanism. Even if the feed dog is tilted, the cloth is effectively pressed between the lower surface of the pair of rib-like protrusions and the throat plate lug.
As in the conventional example, a gap is formed between the presser foot and the throat plate surface, making it impossible to press the fabric effectively, making the fabric unstable, and causing the fabric to become unstable relative to the presser foot when the needle continues to penetrate the fabric. As a result, the direction of the next feed by the feed dog will no longer become unstable, and when the needle subsequently penetrates the fabric, the movement of the fabric relative to the presser foot is prevented, and obstacles such as diagonal feeding of the fabric can be avoided. It is possible to form stitches with good feed.

(Example) The present invention will be described below with reference to Examples, Figures 1a to 1c.
This will be explained with reference to the figures and FIG.

The bottom 12a of the presser foot 12 has the needle hole 1 of the throat plate 13.
A pair of legs 13b formed close to both sides of 3a
A pair of rib-shaped protrusions 12b are formed in parallel to the feeding direction, facing each other and close to both ends of the needle hole 12c of the presser foot 12. The width W and height H of the rib-like protrusion 12b are very small, and in this embodiment, the width W≒0.5 mm and the height H
= 0.10 to 0.15 mm, effective results were obtained in terms of cloth feeding.

(Operation Description) The operation of the embodiment of the present invention will be described below.
When sewing is performed using the presser foot 12 according to the embodiment of the present invention, as in the conventional example shown in FIG.
Even if the feed dog 7 is inclined when sinking from the throat plate surface 8, the rear end 7c of the feed dog 7, the throat plate surface 8, and the presser foot 9
In the embodiment of the present invention, the gap formed by the presser foot 1 is
A pair of rib-like protrusions 12b provided on the bottom surface 12a of 2
These rib-like protrusions 12b absorb the needle plate 13.
Since the cloth is effectively pressed between the hem 13b,
When the needle continues to penetrate the fabric, the movement of the fabric relative to the presser foot is prevented, and obstacles such as skew feeding of the fabric are prevented. For example, in zigzag close stitching as shown in FIG. Compared to the example, stitches with good feed can be obtained without problems such as diagonal feed of the cloth.

(Effects) As described above, according to the present invention, especially in sewing machines equipped with a swing lever type feed mechanism, when the feed dog sinks to the throat plate surface, even if the feed dog is tilted, the cloth is Since the lower surface of the rib-like protrusion is effectively pressed between the needle plate and the needle plate, a gap is formed between the presser foot and the throat plate surface, making it impossible to press the cloth effectively and causing the cloth to It becomes unstable and the fabric is moved relative to the presser foot during subsequent penetration of the fabric by the needle,
The direction of the next feed by the feed dog no longer becomes unstable, and when the needle continues to penetrate the fabric, the relative movement of the fabric to the presser foot is prevented, allowing good feeding without problems such as diagonal feeding of the fabric. The effect is that the seams can be formed.

[Brief explanation of the drawing]

1 to 3 relate to embodiments of the present invention,
Fig. 1a is a plan view of the presser foot, Fig. 1b is a back view of Fig. 1a, Fig. 1c is a sectional view taken along line A-A in Fig. 1a, and Fig. 2 is a sectional view of the throat plate taken along line B-B in Fig. 1a. FIG. 3 is a diagram showing an example of a contour for zigzag tight sewing formed on a cloth using the presser foot of the present invention. Figures 4 to 7 are diagrams for explaining the prior art, with Figure 4 showing a swing lever type feed mechanism, and Figures 5 and 6 showing a conventional presser foot. 4 is a diagram showing the feeding state by the feeding mechanism, FIG. 5 is a preferred state, FIG. 6 is a diagram showing an unfavorable state, and FIG. 7 is a zigzag close stitch formed on the cloth in the state shown in FIG. 6. It is a figure showing an example of the skeleton of the eye. 12 is a presser foot, 12a is a bottom surface, 12b is a rib-like projection, 13 is a needle plate, 13a is a needle hole, and 13b is a lever.

Claims (1)

[Scope of utility model registration request] In the presser foot of a sewing machine, a pair of rib-like protrusions with a slight width and height are formed parallel to the feed direction on the bottom surface of the presser foot, facing the ridges formed close to both sides of the needle hole in the throat plate, and A presser foot for a sewing machine, characterized in that the cloth is effectively pressed between the bottom surface of the pair of rib-like projections and the shank when the feed dog sinks from the throat plate surface.