JPH09253366A - Presser foot for lock sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the hooking and entanglement of a free chain and to smoothly perform sewing by providing a chain stitch needle location part for chain stitching, an edge sewing needle location part for edge sewing and a recessed part for guiding a free chain in a presser foot for holding cloth to be worked along with a throat plate at the upper part of a feed dog. SOLUTION: In a lock sewing machine for parallelly performing edge sewing and chain stitching, in the case that the cloth to be worked is not present at the sewing point of chain stitching, threads are entangled with each other, the free chain is formed and the free chain is fed in a cloth feeding direction by the feed dog on the throat plate 8. In this case, the chain stitching needle location part 7c where the sewing needle of chain stitching is passed through is formed at this presser foot 7 for holding the cloth to be worked, the edge sewing needle location parts 7d and 7e are formed on one side of the lower surface of the presser foot 7 on the side A of the needle location part 7c and a recessed groove 7g and the recessed part 7f are formed on the other side of the lower surface of the presser foot 7. Thus, in the case that the tree chain 12 is formed, the free chain J2 is moved along the recessed groove 7g, then displaced to the side L and kept away from the needle location parts 7d and 7e.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a presser foot of a lock sewing machine capable of simultaneously sewing overedging and chain stitching on a work cloth.

[0002]

2. Description of the Related Art Conventionally, in a lock sewing machine, there is a sewing machine in which overedging and chain stitches are sewn in parallel to a work cloth in order to secure a fray stop. The overlock stitch is configured to be sewn to the work cloth. If the work cloth is not at the sewing point of the chain stitch,
Threads used for chain stitching are intertwined with each other to form an empty ring, and the empty ring is configured to be fed on the needle plate in the cloth feeding direction by feed teeth.

Further, a presser foot having a flat surface facing the needle plate is arranged above the needle plate on which the work cloth is placed, and the work cloth is held between the needle plate and the presser foot. It is configured to be.

Further, the presser foot has an overlocking needle drop portion and a chain stitch needle drop portion through which a sewing needle for overlock stitching and a sewing needle for chain stitches pass in the vertical direction, corresponding to respective sewing points. Is formed.

[0005]

However, since the portion where the feed dog protrudes from the upper surface of the needle plate and the chain stitch needle drop are apart from each other and the holding surface of the presser foot is flat, the traveling direction of the empty ring is reduced. Was unstable. Therefore, while the empty ring is being fed by the feed dog, the traveling direction of the empty ring is squeezed due to the contraction of the empty ring, the empty ring enters the overlock needle drop portion, and further, the empty ring is pressed down by the overlock needle drop section. It may get caught on your foot, or the empty ring and the thread for overlocking may get entangled.
There is a problem that it becomes impossible to sew.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a presser foot of a lock sewing machine which prevents catching or entanglement of an empty ring and enables smooth sewing. There is.

[0007]

In order to achieve this object, the presser foot of the lock sewing machine of the present invention conveys a work cloth placed on a needle plate in a predetermined cloth feed direction by feed teeth, It is possible to sew chainwork and overlock stitching on the work cloth in parallel, and if there is no work cloth at the sewing point of the chain stitch, a lock that can form an empty ring consisting of only the thread used for the chain stitch A presser foot of a lock sewing machine which is used for a sewing machine and clamps a workpiece cloth with a needle plate above a feed dog,
The chain stitch needle drop portion formed for chain stitching and the chain stitch needle drop portion on the downstream side of the chain stitch needle drop portion in the cloth feed direction and on the sandwiching surface for sandwiching the work cloth together with the needle plate. on the right,
An overlock stitch needle drop portion formed for overlock stitching, and a recess that is formed in the area facing the feed dog and the chain stitch needle drop portion in the cloth feed direction and that guides the empty ring are provided. There is.

Therefore, in the presser foot of the lock sewing machine of the present invention, the recess defines a space extending in the cloth feed direction between the lower surface of the presser foot and the needle plate, and the space causes the chain stitch needle drop. By guiding the empty ring formed in the vicinity of the portion, it is easier to advance in the cloth feed direction than the chain stitch needle drop portion, and the shrinkage of the empty ring is eliminated.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An example in which the present invention is embodied will be described below with reference to FIGS. In the lock sewing machine, the cloth feeding direction is indicated by an arrow A, and the horizontal direction orthogonal to the cloth feeding direction is indicated by an arrow L and an arrow R.

First, the shape of the presser foot 7 will be described.
At the center of the presser foot 7, there is formed a chain stitch needle drop portion 7c through which a sewing needle of a known chain stitch passes. R on the lower surface 7b of the presser foot 7 on the A side of the chain stitch needle drop portion 7c.
On the side, overedging needle drop portions 7d and 7e through which a sewing needle of known overedging stitches pass are formed. On the L side of the overlock stitch needle drop portion 7d of the lower surface 7b, a concave groove 7g and a concave portion 7f which are concave from the surface of the presser foot 7 are formed.

The opening of the recess 7f has an elliptical shape elongated in the cloth feeding direction. The depth of the concave portion 7f gradually increases in the A direction, and gradually increases from the deepest portion. The concave groove 7g is a groove formed in the chain stitch needle drop portion 7c and the concave portion 7f so as to extend in the cloth feeding direction.

Further, the concave groove 7g extending from the chain stitch needle drop portion 7c to the concave portion 7f is bent once and is shifted to the L side. The portion of the groove 7g that extends in the same position as the cloth feed direction after bending is a portion that faces the feed dog 10 that protrudes from the needle plate 8. Further, the other end of the upper surface 7a of the presser foot 7 on the A side is configured to be attachable to a presser bar of a known lock sewing machine. The concave groove 7g corresponds to the concave portion of the present invention.

Next, the structure of the lock sewing machine body will be briefly described. The lock sewing machine has a known chain stitching mechanism,
A known overedging mechanism is provided on the A side of the chain stitching mechanism and on the R direction side. When the work cloth is not at the sewing point of the chain stitch, the chain stitch mechanism ties the threads together to form an empty ring 1
2 can be formed.

Further, the needle plate 8 has a chain stitch needle drop portion 8a through which a sewing needle of a known chain stitch passes, and a well-known overedging stitch on the A side of the chain stitch needle drop portion 8a. An overlock stitch needle drop portion 8b for passing the needle is formed. This edge sharpened needle drop portion 8b is wide in the LR direction,
The feed dog 10 is arranged at the edged needle drop portion 8b.

Next, the operation of the presser foot 7 when the empty ring 12 is formed will be described.

When the empty ring 12 is formed upward by the chain stitching mechanism, it reaches the end of the concave groove 7g formed in the lower surface 7b of the feed leg 7. Therefore, the wall surface of the recessed groove 7g changes the advancing direction of the empty stitch 12 from the upper direction to the horizontal direction, and as the empty stitch 12 is further formed, the empty stitch 12 is formed on the downstream side of the cloth feed along the concave groove 7g. Move toward a certain A side. When the empty stitch 12 reaches the recess 7f, the feed dog 10 pulls the empty ring 12 in the A direction, and the empty ring 12 moves on the lower surface 7b along the A direction.

Since the recess 7f and the recess groove 7g define a space extending between the needle plate 8 and the lower surface 7b in the cloth feeding direction, the hollow ring 12 is provided below the recess 7f and the recess groove 7g.
Is easy to proceed. Therefore, the traveling direction of the empty ring 12 is biased to the L side, and the empty ring 12 has the overedging needle drop portion 7d.
It is sent reliably so as to move away from 7e. Also, the empty ring 1
Since the contraction of 2 is eliminated in the space below the concave portion 7f and the concave groove 7g, the air ring 12 becomes thin. In the present embodiment, since the hollow ring 12 is guided by the concave portion 7f and the concave groove 7g, it is not necessary to provide any new component, and the entanglement between the blank ring 12 and the presser foot 7 can be prevented at low cost.

According to the embodiment of the present invention, since the concave groove 7g is partially formed leftward, the hollow ring 12 is formed.
Is reliably guided so as to be separated to the left from the overedging needle drop portions 7d and 7e. Therefore, it is further prevented that the empty ring is entangled with the presser foot and the overlocking sewing thread and the sewing becomes impossible. Therefore, sewing can be performed smoothly. Further, since it is sufficient to form the concave portion on the downstream side of the overlock stitch needle drop portion in the cloth feeding direction and on the left side of the sandwiching surface, it is possible to easily process and create.

[0019]

As is apparent from the above description, according to the presser foot of the lock sewing machine of the present invention, the empty ring is guided so as to advance in the cloth feeding direction from the chain stitch needle drop portion, The ring is prevented from being entangled with the presser foot or the overlocking suture and making it impossible to sew. Therefore, sewing can be performed smoothly. Further, since it is sufficient to form the concave portion on the downstream side of the overlock stitch needle drop portion in the cloth feeding direction and on the left side of the sandwiching surface, it is possible to easily process and create.

[Brief description of drawings]

FIG. 1 is a bottom view of a presser foot of a lock sewing machine according to the present invention.

FIG. 2 is a sectional view of the presser foot.

[Explanation of symbols]

 7c Chain stitch needle drop part 7d Edge stitching needle drop part 7e Edge stitch needle drop part 7f Recess 7g Recess groove A Cloth feed direction

Claims (1)

[Claims] 1. A cloth to be processed placed on a needle plate is conveyed by a feed dog in a predetermined cloth feeding direction, and chain stitching and overedging can be sewn on the cloth to be processed in parallel. When the cloth to be processed does not exist at the sewing point of the chain stitch, it is used in a lock sewing machine capable of forming an empty ring made of only the thread used in the chain stitch, and the cloth to be processed is provided above the feed dog. In the presser foot of the lock sewing machine that is clamped together with the needle plate, a chain stitch needle drop portion formed for the chain stitch, and a downstream side in the cloth feed direction from the chain stitch needle drop portion, and
On the right side of the chain stitch needle drop portion on the holding surface that holds the work cloth together with the needle plate, an overlock needle drop portion formed for overlock stitching, a region facing the feed dog, and A presser foot for a lock sewing machine, which has a chain stitch needle drop portion and a recess formed in the holding surface in the cloth feeding direction and guiding the empty ring.