JPH0243339Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a feed dog in a differential feed sewing machine, and is particularly concerned with preventing a gap between the main feed dog and the sub-feed dog. It is a feature.

[Prior Art] Conventionally, in order to eliminate the gap between the main feed dog and the sub-feed dog, the feed dog of this type of sewing machine has a main feed dog M in the cloth feeding direction, as shown in Fig. 4. The front end hangs downward to prevent fluffy items such as sweater fabric from getting caught on the tips of the feed dog teeth, and to prevent fabric from falling between the main feed dog M and the sub feed dog S. Ta.

[Problems that the invention aims to solve] However, when the tip of the main feed dog is lowered, it hits the looper, etc., so it cannot be lowered sufficiently, and the fabric gets stuck to the teeth of the main feed dog. It was not possible to completely prevent fabric from entering between the main feed dog and the sub feed dog.

[Means for Solving the Problems] In order to eliminate the drawbacks of the conventional techniques described above, the present invention provides an extending portion extending in the cloth feeding direction on either the main feeding dog or the auxiliary feeding dog. By loosely fitting this extension into the groove of the opposing feed dog and flattening either the top surface around the feed dog groove or the top surface of the feed dog extension, fabric can be prevented from catching or falling. Problem solved.

[Function] In cooperation with the presser foot, the fabric fed in the cloth feeding direction by the teeth of the sub-feed dog is placed on the upper surface of the extension provided on either the main feed dog or the sub-feed dog. The fabric is further fed in the fabric feeding direction by the presser foot and the teeth of the main feeding dog.

[Example] An example of the present invention will be explained with reference to FIG. 1.
is a main feed base, one end of which is pivotally connected to the upper end of a feed arm 3 which is fixed to a horizontal feed shaft 2 which swings by a known mechanism. Reference numeral 4 denotes a sub-feed table, one end of which is connected to a tube body 5 rotatably fitted to the horizontal feed shaft 2.
It is pivotally connected to an arm 6 that is integrated with the arm 6. 7 and 8 are 2 formed at the other ends of the main feed table 1 and the sub feed table 4, respectively.
A feed angle piece (not shown) is fitted into the bifurcated portion to give vertical movement to the main feed table 1 and the sub feed table 4.

9 is a main feed dog and a sub feed dog which are screwed onto the main feed table 1 and 10 are screwed onto the sub feed table 4, respectively. The main feed dog 9 has a tooth portion 9a on the upper surface, and a groove 9 extends from the cloth feed direction side to the cloth feed direction front side to the cloth feed direction.
b. The sub-feed dog 10 has a tooth portion 10 on the upper surface.
An extending portion 10b having a flat upper surface is provided which extends in the cloth feeding direction and fits loosely into the groove 9b of the main feeding dog 9.

In the differential sewing machine described above, when the sewing machine rotates, the main feed table 1 and the sub feed table 4 move back and forth and up and down by a known mechanism. In general, the back and forth momentum, that is, the amount of cloth feed is
Based on the cloth feed amount (hereinafter referred to as main feed),
The cloth feed amount of the sub-feed table 4 (hereinafter referred to as sub-feed) is set to increase or decrease.

When the ratio of the sub-feed to the main feed, the so-called differential ratio, is set to 1 or more, that is, the main feed is set larger than the sub-feed, the portion of the fabric fed by the main feed will have a larger feed amount than the portion of the sub-feed. Because of the bulk, the fabric is fed under tension.

On the other hand, if the ratio of the sub-feed to the main feed base 1 is set to 1 or less, the fabric portion of the sub-feed is fed more than the fabric portion of the main feed, and shirring is performed. When the ratio of the sub-feed to the main feed table 1 is changed, the distance between the front side surface of the groove 9b of the main feed dog 9 in the cloth feeding direction and the side end surface of the extending portion 10b of the sub feed dog 10 changes.

The fabric is fed in the fabric feeding direction by the tooth portion 10a of the sub-feed dog 10 in cooperation with a presser foot (not shown), and is placed on the upper surface of the extension portion 10b of the sub-feed dog 10, and also on the main feed dog 9. It is further pushed in the cloth feeding direction by the toothed portion 9a. At this time, the extending portion 10b of the sub-feed dog 10 fits loosely into the groove 9b of the main feed dog 9, so that there is no gap between the main feed dog 9 and the sub-feed dog 10, and the extending portion of the sub-feed dog 10 Since the fabric is placed on the upper surface of the main feed dog 10b, the fabric can be reliably fed in the fabric feeding direction without entering between the main feed dog 9 and the sub feed dog 10 or getting caught by the tooth portion 9a of the main feed dog 9.

Note that a toothed portion is provided on the upper surface of the extending portion 10b, and a groove 9b
The upper surface of the periphery may be made flat.

[Other Embodiments] The feed dog shown in FIG. 2 is another embodiment of the present invention, 11 is a main feed dog, and the upper surface has a tooth portion 11.
a, and a notch 11b is formed in the front right hand side. 12 is a sub-feed dog, and a tooth portion 12a is provided on the upper surface.
At the same time, it extends from the right side in the cloth feeding direction,
An extending portion 12b having a flat upper surface is formed to loosely fit into the groove 9b of the main feed dog 9.

Further, as shown in FIG. 3, a tooth portion 13a is provided on the upper surface of the main feed dog 12, and a tooth portion 13a is provided on the upper surface of an extending portion 13b of the main feed dog 13 that extends toward the front in the cloth feeding direction.
c, and the sub-feed dog 14 is provided with a tooth portion 14a on its upper surface to form a groove 14b into which the extending portion 13b of the main feed dog 13 fits loosely, and the upper surface of the peripheral portion of the groove is made flat; The same effect occurs.

[Effects of the invention] As explained above, according to the invention, an extending portion extending in the cloth feeding direction is provided on either the main feeding dog or the sub-feeding dog, and the groove into which this extending portion loosely fits is provided opposite to the groove. By forming the main feed dog or the sub-feed dog with a flat top surface of the extension part or the top surface of the peripheral part of the groove, there is no gap between the main feed dog and the sub-feed dog, and the presser foot The fabric fed in the fabric feeding direction by the sub-feeding dog is placed on the extending part of the feeding dog in cooperation with the auxiliary feeding dog, and the fabric is surely fed in the fabric feeding direction by the tooth part of the main feeding dog, so that the fabric is A clean stitch can be obtained without entering the gap between the main feed dog and the sub feed dog or getting caught in the teeth of the main feed dog.

[Brief explanation of drawings]

FIG. 1 shows a perspective view of an embodiment of the present invention, and FIG.
FIG. 3 shows a perspective view of a feed dog of another embodiment. FIG. 4 shows the main parts of the conventional example. In the figure, 1...Main feed stand, 4...Sub feed stand, 9,
11, 13... Main feed dog, 10, 12, 14...
Secondary feed dog.

Claims (1)

[Scope of utility model registration request] A groove or notch formed along the cloth feeding direction and an extension portion that loosely fits into this groove or notch and has a flat top surface are placed between the main feed dog and the sub feed dog which are arranged before and after in the cloth feeding direction. A feed dog in a differential feed sewing machine characterized by being formed relatively.