JPH0133014Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a tape feeding device used in multi-needle sewing machines, overlock sewing machines, etc.

Prior Art There is a presser foot with a tape guide provided just before the needle drop, and the elastic tape unwound from the reel is guided to this guide and sewn onto the base fabric.This is mainly used for sewing anti-stretch tape. However, in this type of tape, the tape is supplied under tension as the sewing progresses, so it is difficult to obtain sufficient elongation after sewing.

In order to prevent the tape from stretching just before sewing, a guide hole is provided at the front of the presser foot, and the tape is guided through this guide hole to the bottom surface of the presser foot, and then passed through a groove formed on the bottom surface of the presser foot continuous with the guide hole. There are some products in which the feeding resistance due to the presser foot is reduced, but even in this case, the tendency of the tape to be stretched is not eliminated, and there is still the problem that sufficient elongation of the tape cannot be obtained after sewing.

Problems to be Solved by the Invention In order to solve the above-mentioned problems, the present invention provides a tape feeding device having a feed dog for feeding the tape, and causes the feed dog to act on the tape through the cutout window of the presser foot. This method attempts to secure elongation after sewing is finished by feeding the tape, but one problem that arises in this case is when the amount of tape feed becomes greater than the feed amount of the lower feed dog (the tape has elasticity). (The same is true if the tape is attached), the tape may sag and bulge, causing the tape to get stuck at the rear and hinder sewing work.

The present invention was made with the aim of solving such problems.

Means for Solving the Problems To solve this problem, the present invention provides a protrusion at the rear end of the feed dog to guide the sagging and raised part and push it under the presser foot.

In other words, the present invention has a tape feeding device used in a sewing machine that sews tape onto base fabric, which engages in a cutout window provided in the presser foot and performs four movements consisting of back and forth movement and up and down movement, and acts on the tape. It consists of a feed dog that feeds the tape, and a protrusion that prevents the tape from bulging is provided at the rear of the feed dog.

According to the results of experiments, it is more preferable for the above-mentioned protrusion to consist of a tape holding part consisting of a horizontal part and an upwardly sloped part, and further to make the lower part of the rear wall of the cutout window of the presser foot slope. It turned out to be. This seems to be because by slanting the protrusion and the rear end wall of the cutout window, the tape can be smoothly pushed under the presser foot without getting caught on the rear end of the protrusion or the rear end of the cutout window.

The tape feeding device is provided together with the top feeding device or is provided alone, and when provided together with the top feeding device, in order to simplify the mechanism, it is preferable that a feed dog for tape feeding is provided integrally in parallel with the top feed dog.
It is operated using an upper feed device.

It is preferable that the presser foot has a guide such as a guide hole on the front part for passing the tape, and a concave groove continuing to the guide on the lower surface. This is because the feeding resistance caused by the presser foot can be reduced, and almost the same amount of presser foot pressure can be applied to the base fabric and the tape on the base fabric.Also, by making the tape guide groove a concave groove, the tape is not inserted. This makes it possible to apply sufficient presser pressure to the base fabric at times, thereby eliminating the possibility of sewing jams and preventing crooked stitches.

When providing a feed dog for feeding the tape together with a feed dog for feeding the cloth, it is desirable to take care to give the same degree of feeding action to the base fabric and the tape. To do this, it is recommended to lower the tape feed dog by the thickness of the tape so that both feed teeth are stepped, or to reduce the contact area of the tape to weaken the feed action.

Embodiment The figure shows an example in which the present invention is applied to an overlock sewing machine equipped with a differential feed mechanism and a top feed mechanism. It has three rows of notched windows 3, 3' in the feeding direction, and upper feed teeth 4 for cloth feeding in the upper feeding mechanism are provided in two rows of notched windows 3. , feed dog 5 for feeding the tape, which is integral with the upper feed dog 4, is fitted into the other notch window 3', and feeds the cloth in cooperation with the differential feed dog 7 in front of the needle 6 within each notch window. In order to perform this, four movements consisting of a back-and-forth movement and an up-and-down movement are performed in synchronization with the feed dog 7.

The presser foot 1 also has a guide hole 9 for guiding the tape on the front side in the feed direction of the cutout window 3' into which the feed dog 5 fits.
(preferably formed into a pentagonal shape as shown in the figure,
The tape is bent into a V-shaped cross section to facilitate insertion), and a concave groove 10 following the guide hole 9 is formed on the lower surface of the presser foot along the feeding direction up to near the needle drop. There is. The upper fabric A is then placed along the throat plate 2 and fed under the presser foot.
The lower fabric B and the tape T passed through the guide hole 9 into the groove 10 and overlaid on the upper fabric are held between the differential feed dog 7, the upper feed dog 4, and the feed dog 5, and are fed to the needle drop. After being sewn and sewn, the needle is held between the presser foot 1 and the main feed dog 12 at the rear of the needle and sent to the rear of the presser foot. The feed dog 5 for feeding the tape is formed at the same height as the upper feed teeth 4 in the other two rows, so it engages with the tape as deeply as the thickness of the tape T. It is shortened to make it weaker, reducing the contact area with the tape.

The feed dog 5 is also provided with a protrusion 13 that protrudes rearward to suppress the slack that occurs due to excessive supply of tape and to control the swelling from between the rear end of the feed dog and the rear end wall of the cutout window. It is set as.

As shown in FIG. 1, in the embodiment of the protrusion 13, the tape holding surface is composed of a horizontal surface 13a and an upwardly inclined inclined surface 13b, and the rear end wall of the cutout window of the presser foot also has a lower part. By tilting it backward, the horizontal surface 13a presses down the rise of the tape T, and the sloped surface 13b allows the tape T to be smoothly pushed under the presser foot without getting caught on the rear end of the protrusion. It is possible to suppress the bulge in both cases where the feed dog sag from the rear end side and when it sag from the rear end wall side of the notch window.

Effects of the invention As described above, this invention provides a feed dog for feeding the tape, and by setting the amount of tape feed by the feed dog to an appropriate amount, it is possible to secure a sufficient amount of elongation at the tape sewn part. Because of the provision of a protrusion at the rear of the feed dog to suppress tape swelling, the amount of tape feed may be greater than that of the lower feed dog, or the tape may become elastic and may become loose. Even if something like this occurs, the tape can be pushed under the presser foot, and the tape will not get stuck and interfere with sewing work.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of the present embodiment, FIG. 2 is a perspective view thereof, and FIG. 3 is a partial perspective view of the presser foot seen from the back side. 1... Presser foot, 2... Throat plate, 3, 3'... Notch window, 4... Upper feed dog, 5... Feed dog, 7... Differential feed dog, 9... Guide hole, 10... ...concave groove, 12...
Main feed dog, 13...protrusion.

Claims (1)

[Claims for Utility Model Registration] (1) In a tape feeding device used in a sewing machine that sews tape onto base fabric, the device fits into a cutout window provided in the presser foot to perform four movements consisting of back and forth movement and up and down movement. The tape feeding device consists of a feeding dog that feeds the tape by acting on the tape, and the feeding dog has a protruding portion protruding from the rear of the feeding dog that suppresses the swelling of the tape. (2) The tape feeding device according to claim 1, wherein the protrusion has a horizontal portion on the lower surface and an upwardly inclined portion following the horizontal portion. (3) The presser foot has a guide at the front for passing the tape under the presser foot, and a concave groove for guiding the tape passed through the guide to the needle drop.
Tape feeding device as described in section. (4) The tape feeding device according to claim 1, wherein the feeding teeth are integrally formed with upper feeding teeth arranged in parallel for performing upward feeding by acting on the base fabric.