JPH028759B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an empty chain sewing device for a two-needle overlock sewing machine.

[Conventional technology]

Generally, when overlocking the edge of a fabric with an overlock sewing machine, when the sewing is completed, a loop is created that connects the fabric.

For this reason, in overlock sewing machines, an empty ring holding/cutting device is usually installed in front of the needle drop section, and when sewing is completed, the operator brings the empty ring connected to the fabric to the front side. It is hung on a ring holding/cutting device to hold it and cut it from the fabric.

In this way, the empty ring held by the empty ring holding/cutting device is automatically sewn into the seam of the fabric to be sewn next, thereby preventing the seam from fraying at the beginning of sewing.

By the way, the throat plate of a two-needle overlock sewing machine is designed to prevent the work cloth from sinking into the needle groove or skipping stitches when sewing with two needles, and to make the seams plump so that the sewing product can be sewn. In order to maintain the texture, a middle claw is usually provided as shown in Figure 1. 1 is the throat plate, 2 is the middle claw, 3 is the outer claw, and 8 is the feed dog groove.

However, after sewing is completed, when the operator brings the empty ring connected to the fabric to the front side and hooks it to an empty ring holder or the like to hold it (so-called back-tuck), the empty ring is pulled by the middle claw. This not only makes it impossible to perform the back-tuck operation smoothly, but also often interferes with the smooth sewing of the formed hollow ring into the next fabric.

Therefore, in order to solve the above problem, the inner claw can be retracted toward the front from a position parallel to the outer claw, and the inner claw is configured to be held in the retracted position when not sewing. A built-in device is provided.

However, in the case of such a conventional hollow ring sewing device, in order to enable the inner claw to retreat properly, a drive mechanism constituted by a rotary solenoid or the like is provided between the drive mechanism and the inner claw. An interposed slide lever, a control device for the drive mechanism, etc. are required.

[Problem that the invention seeks to solve]

Conventional empty ring sewing devices require the above-mentioned configuration, which increases the number of parts and complicates the structure.
Problems such as occurrence of malfunctions, difficulty in maintenance services, and increase in cost arise.

[Means for solving problems]

In this invention, when the empty ring is rotated and held toward the operator side, the empty ring guide means provided at the end of the outer pawl is brought into contact with the end on the throat plate side during a so-called back-tuck. The aim is to solve the above-mentioned problems by combining the two methods.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 2 to 5.

In the figure, 1 is the throat plate, 2 is the middle claw, and 3 is the middle claw 2.
4 is an empty ring guiding means provided at the tip of the outer claw 3, and 5 is an empty ring holding/cutting device provided at the end of the throat plate 1 on the near side (operator side). be. As shown in FIG. 2, the empty ring guide means 4 has an oval lever rotatably attached to the throat plate 1 side at the tip of the outer claw 3, and the tip of the lever is normally rotated by a spring means.
It is configured to abut against the side end of the throat plate 1 facing the inside of the outer claw 3. This will be explained in more detail with reference to FIG. In this embodiment, the tip of the outer claw 3 has a notch in the left half, and an empty ring guide means 4 is provided therein.
The lever is located as follows. That is, a recess 4a is formed on the outer pawl 3 at the lower part of the notch portion as a joint portion of the lever (empty ring guide means) 4. In order for the lever 4 to rotate to the left, the recess 4a has an upper side and a left side whose bottom surfaces are on the same plane.

Further, 4b in the figure is a spring means provided on the outer claw 3 that normally biases the lever 4 so that its tip comes into contact with the side end of the throat plate 1 facing the inside of the outer claw 3. . The biasing force of the spring means 4b causes the tip of the lever 4 to come into contact with the side end of the throat plate 1 when no load is applied, and when an empty ring is formed on the outer pawl 3, the lever 4 is moved by its compressive force. It is necessary that it be in a closed state. (See FIG. 4) The following operation will be explained based on the above configuration. First, when an empty ring is not formed in the outer claw 3, the lever (empty ring guide means) 4 brings its tip end into contact with the end of the throat plate 1 on the side opposite to the outer claw 3 by the spring means 4b. I'm letting you do it.

Next, when the sewing machine is driven and the thread starts to engage with the outer claw 3, the lever (empty ring guide means) 4 is pulled toward the outer claw 3 by the binding force against the spring pressure. Joins with external claw 3. (See Fig. 4) When the sewing is completed and the fabric is stretched in the direction of movement and at the same time the hollow ring formed on the outer claw 3 is pulled out, the lever (air ring guide means) 4 is automatically activated by the spring bias. It returns to its original position, that is, the position where its tip moves leftward in FIG. 4 and abuts the side edge of the throat plate 1, and the opening to the middle claw 2 is closed. (5th
(See figure) Next, when the fabric and the ring A connected to it are brought to the operator's side, the ring A is guided by the outer surface of the lever (ring guide means) 4, which is in an inclined state, and moves extremely smoothly. engages with the tip of the outer claw 3,
The front end of the empty ring A is clamped by the empty ring holding/cutting device 5 at the same time as the cutting. (Refer to Figure 5) [Effect of the Invention] With the configuration described above, the present invention allows smooth operation by automatically closing the opening to the middle claw when necessary, even when the operator does not intend to do so. It is possible to carry out the work of holding an empty ring, and since the structure is simple and the number of parts is small, operational reliability is high, and the cost can be significantly reduced.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an example of the throat plate in the prior art, Fig. 2 is an explanatory diagram of the hollow ring guide means in the present invention, Fig. 3 is an enlarged view of the main part of Fig. 2, and Fig. 4 is an explanatory diagram of the hollow ring guide means in the present invention. An explanatory diagram showing a state in which the empty ring guide means is closed,
FIG. 5 is an explanatory diagram showing the state in which the empty ring is held after sewing is completed.

Claims (1)

[Claims] 1. An empty ring holding/cutting device is provided on the front side of the needle drop part, and an empty ring guiding means is provided at the tip of the outer claw parallel to the inner claw, and after sewing is completed, the fabric is stretched in the direction of movement to form the fabric. When the continuous empty ring is removed from the outer claw, the guide means rotates to close the opening between the outer claw side end and the opposing throat plate side end, and stretches the empty ring toward you. An empty ring sewing device for a two-needle overlock sewing machine, characterized in that the empty ring is guided so that the empty ring engages with the tip of the outer claw.