JPS6138535Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an empty chain stitch presser mechanism for a sewing machine.

Conventionally, an empty ring presser that works together with a feed dog to send out an empty ring formed by a chain seam forming mechanism in the cloth feeding direction, the empty ring presser 1 has its vertical axis 2 as shown in Fig. 3. Supports the presser foot 3 so as to be movable up and down,
The structure was such that a downward pressing force was applied by a spring 4.

For this reason, in the conventional loop presser 1, when the front end of the fabric enters below the tip of the loop presser 1, the shaft 2 becomes "kinked" and the loop presser 1 does not rise upwards smoothly, causing the loop presser 1 to move upward. If a fabric jam occurs at the tip of the presser foot 1, or if a thick layer of fabric enters below the tip of the presser foot 3, the tip of the presser foot 3 will rise upwards and tilt, and as a result, the empty ring presser foot 1 However, since the tip is tilted upward and cannot press the empty ring, the formation of the empty ring becomes unstable, resulting in skipped stitches.

This invention aims to eliminate the above-mentioned conventional drawbacks.

An embodiment of this invention will be described below with reference to FIGS. 1 and 2.

Reference numeral 5 denotes a sewing machine presser foot that forms overlock seams and double chain seams parallel to the edge of the fabric, and forms a tongue piece 7 for the oversewing stitches in front of the center notch 6. Then, a needle hole 8 for a needle forming a double chain stitch is formed inside the needle hole. Reference numeral 9 denotes front rollers, and four of them are arranged in parallel so as to be rotatable about shafts 10 perpendicular to the cloth feeding direction with respect to the presser foot 5, and their outer peripheries are provided so as to protrude slightly below the lower surface of the presser foot 5. ing.

Reference numeral 11 denotes rear rollers, and three of them are rotatably arranged in parallel on shafts 13 perpendicular to the cloth feeding direction with respect to the rear support parts 12a and 12b of the presser foot 5, and their outer peripheries are slightly below the lower surface of the presser foot. It is provided so as to protrude downward.

Reference numeral 14 denotes a presser arm 14, whose central portion is rotatably supported between the rear rollers with respect to the shaft 13, and whose rear end is bent at a right angle to form a spring hook 15.

Reference numeral 16 designates a ring presser foot, which is disposed in the notch 6 of the presser foot 5 and located behind the needle hole 8 of the double chain stitch of the presser foot 5 in the cloth feeding direction, and its base is connected to the presser foot arm 14. It is rotatably supported at the tip by a pin 17. 18 is a spring, whose base is supported on the outer periphery of the protruding end of the shaft 13, and whose one end is locked to the upper surface of the presser foot 5;
It is locked to the lower end of the spring hook 15 of the presser arm 14 at the other end, and applies a rotational force in the counterclockwise direction about the shaft 13 to the presser arm 14, thereby always pressing the empty ring presser 16 downward. .

Further, this pressing force is received when one end of the pin 17 comes into contact with a receiving portion 19 formed on the presser foot 5, and when this pin 17 is in contact with the receiving portion 19, the lower surface of the ring presser 16 It is provided so as to be slightly below the outer peripheral lower surface of the front and rear rollers.

Reference numeral 20 denotes a support arm of the presser foot 5, which receives downward pressing force and whose lower end is rotatably connected to the presser foot 5 by a pin 21.

This invention has the above structure, and when the support arm 20 is lowered to press the lower outer periphery of the front and rear rollers 9, 11 of the presser foot 5 against the upper surface of the throat plate (not shown),
The empty ring presser 16 resists the elastic force of the spring 18 and presses the shaft 13.
The pin 17 is slightly rotated clockwise around the center, and the pin 17 rises slightly from the receiving part 19 of the presser foot 5, and the lower surface of the ring presser 16 is pressed against the upper surface of the throat plate by the elastic force of the spring 18.

When the sewing machine is operated from this state, an overlock stitch is formed at the tongue piece 7, and an empty ring of a double chain stitch is formed at the needle hole 8 of the presser foot 5. Then, the empty loop of the double chain stitch is sent out in the cloth feeding direction together with the empty ring presser 16 by the feed dog provided oppositely below the empty ring presser 16.

Further, when the cloth is fed to the front lower surface of the presser foot 5 and the front end of the cloth enters the front end of the ring presser 16, the ring presser 16 rotates slightly around the pin 17, and the presser arm 14 moves to the shaft 13. The front end of the cloth smoothly enters below the ring presser 16 by rotating against the spring 18.

Furthermore, if a thick stepped part of the cloth or the like enters below the tip of the presser foot 5, causing the tip of the presser foot 5 to rise upwards and cause the presser foot 5 to tilt, the presser foot arm 14 will be moved by the spring 1.
The ring presser 16 rotates counterclockwise around the shaft 13 due to the acting force of the ring presser 8, and has a degree of freedom around the pin 17, so the lower surface of the ring presser 16 is in close contact with the upper surface of the throat plate. , cooperates with the feed dog to reliably send out the empty ring of the double chain stitch in the cloth feeding direction.

As described above, in this invention, the empty ring presser foot 16 is rotatably supported at the tip of the presser arm 14, which is rotatably supported by the presser foot 5 and has a downward pressing force always applied to the tip. Even if the fabric enters the empty ring presser 16,
The fabric can be fed smoothly without causing fabric jams, making it possible to perform the sewing work reliably, and even if the thickness of the fabric entering the lower part of the presser foot 5 changes, the empty ring is always pressed down reliably, so that the empty ring can be formed. The stitching is stable, there is no skipped stitches at the beginning or end of sewing the fabric, the seams can be reliably formed, and sewn products with high commercial value can be obtained.

In addition, the same effect can be obtained by forming the presser arm 14 itself shown as another embodiment from an elastic body and rotatably supporting the hollow ring presser 16 at its tip.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the present invention, FIG. 2 is a cross-sectional view taken from FIG. In the figure, 5 is the presser foot, 9 and 11 are the front and rear rollers, and 14
1 is a presser arm, 16 is an empty ring presser, and 18 is a spring.

Claims (1)

[Scope of Claim for Utility Model Registration] An empty ring seam presser mechanism of a sewing machine that sends out an empty ring in the cloth feeding direction in cooperation with a feed dog, and whose part is rotatably supported by a cloth presser foot and whose tip is always held at the tip. An empty ring stitch presser mechanism for a sewing machine, comprising: a presser arm 14 on which a downward pressing force acts; and an empty ring presser 16 whose base portion is rotatably supported at the tip of the presser arm 14.