JPH01250297A - Apparatus for sewing string of loop by hem-overlock machine - Google Patents

Abstract

PURPOSE:To remove friction between a string of loops and cloth, to confirm whether seam formation is proper, and to settle the holding position of a string of the loops, by a method wherein a string of the loops is received by a suction nozzle at the first place and transferred through the space above a pressor foot to the second position, and a string of the loops left over is blown on a hem cutting knife, and the next cloth is inserted under the presser foot, and then sewing is started. CONSTITUTION:When a sewing machine is stopped, a loop catcher 4 is also stopped. At the same time, a nozzle 23 of a loop transfer device 2 starts sucking. After the suction nozzle 23 sucks a string of loops (C) at the first position, it (23) returns to the second position in that state. A string of the loops (C) is folded by this operation above a presser foot 1. As soon as the suction nozzle 23 stops sucking, a loop blowing device 9 is operated. When a string of the loops (C) is depressed by a loop depressing bar 33 on a guide groove 16a, the play end of the loops (C) which is left out of the end part of the guide groove 16a, is blown to the direction of an upper cutting knife 51, and the next new cloth E is set, and then the sewing machine is restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is to remove the empty ring that continues to the seam forming part with its tip captured by the empty ring catcher from the empty ring catcher, and then sew the empty ring. This invention relates to a so-called empty chain sewing device which automatically sews into the first part of a new cloth in a state where it is folded back toward the front from the stitch forming part.

The reason why the hollow ring is sewn into the beginning of the fabric as described above is to prevent the stitches at the beginning of the fabric from loosening and unraveling.

Therefore, in order to automatically sew an empty ring to the beginning of the fabric in this way, it is necessary to at least have an empty ring catcher for separating and capturing the empty ring, and to take out the caught empty ring and sew it. It is necessary to provide means for orienting the ring toward the front from the forming part and means for positioning the orientated empty ring in an aligned state. Hole ring sewing devices equipped with such various means have conventionally existed.

However, the conventional hollow ring sewing device is
As seen in Publication No. 0, as a means for directing the empty ring toward the front from the seam forming part, a configuration in which an elongated nozzle is provided in a sewn-in window that captures the empty ring is used, and As a means for positioning the empty rings in an aligned state, a configuration in which a concave groove of an appropriate length is temporarily formed on the needle from near the course toward the front of the sewing machine is used, which causes the following problems. In other words, the empty ring is folded back to the underside of the new fabric and inserted into the groove formed on the needle and positioned, but due to the structure of the throat plate, it cannot reach the needle position. Since the concave groove cannot be extended, it is not possible to eliminate the friction with the fabric that affects the retention of the empty ring, which limits the workability.

■Since the empty ring is folded back and sewn into the underside of the fabric where it cannot be seen by the worker, it is not possible to check whether the seam is formed properly or not, which causes problems such as skipped stitches and other defects. be.

■The jet from the elongated nozzle installed in the suction window that captures the empty ring directs the empty ring toward you from the sewing machine needle, and it is received by a gripping device located relatively far away and placed on the throat plate. Since the hollow ring is fitted into the groove, the holding position of the empty ring becomes unstable and it is difficult to properly position it.

An object of the present invention is to provide an effective means for solving the above-mentioned problems in conventional devices.

Therefore, in order to achieve the above-mentioned object, the hollow ring sewing device of the overlock stitch sewing machine according to the present invention sucks the hollow ring continuously formed from the edge of the fabric through the suction window. an empty ring catcher having a cutting knife for cutting off the empty ring; a first position provided in front of the seam forming part and having a tip thereof close to a suction window of the empty ring catcher; a suction nozzle rotatably supported around a rotation axis provided on the front side of the sewing machine frame so as to be movable in an empty ring above the presser foot between a second position existing on the front side; a driving air cylinder that acts on the suction nozzle so as to suction and receive the empty ring captured by the empty ring catcher at a first position and transfer the received empty ring above the presser foot at a second position; The suction nozzle is provided on the side, and the suction nozzle captures the cut empty ring and transfers it to the upper part of the presser foot in a second position, and after a new fabric is set, the sewing machine is operated to hold the empty ring for a predetermined period of time. an empty ring holding mechanism that holds the empty ring; and an empty ring sprayer that sprays the empty ring toward a cutting knife provided for trimming one side of the fabric so that the length of the empty ring held by the empty ring holding mechanism is even. It is characterized by having the following.

The empty ring captured by the empty ring trap for work-111 is received at the first position by the suction nozzle and transported as it is to the second position. At this time, since the suction nozzle moves in the space above the presser foot, the empty ring is folded back from the seam forming portion to the entire upper surface of the presser foot on the operator's side.

In this state, an extra empty ring is sprayed onto the cloth edge cutting scalpel by the empty ring sprayer. The new fabric is then inserted into the presser foot and sewing begins. As a result, the free end of the empty ring is cut by the fabric edge cutting knife. Also, new fabric moves forward from the start of sewing. As the fabric moves forward, the holding of the ring by the ring holding mechanism is released midway.

This causes the ring to move forward as the fabric moves forward, and is sewn into the seam of the first part of the fabric.

Figure 1 shows an external perspective view of an overlock sewing machine equipped with the device of the present invention, in which 1 is a presser foot, 2 is an empty ring transfer device, and 3 is an empty ring presser mechanism. Although not shown in FIG. 1, an empty ring catcher 4 is provided on one side of the sewing machine bed B behind the presser foot 1, as shown in FIG. As is well known in Japanese Utility Model Publication No. 54-40195 and Japanese Utility Model Publication No. 57-55820, the empty ring catcher 4 is formed continuously from the edge of the fabric on the throat plate claw 200 (see Fig. 9). It has a structure that includes a cutting knife that sucks in the cut ring through a suction window and cuts it. In FIG. 9, numeral 41 indicates a suction window. 42 is a cutting knife. The cutting knife 42 is provided inside the suction window 41. Suction window 4
1 is connected to a vacuum pump via an air suction pipe (not shown).

On the other hand, the cutting knife 42 is composed of two cutter blades, which are opened and closed in conjunction with a vertically movable upper knife stand 52 to which an upper knife 51 is fixed. By opening and closing the cutter blade, the empty ring C sucked into the suction window 41 is cut. A lower knife (not shown) is fixedly provided on the sewing machine bed below the upper knife 51, and together they constitute a cutting knife 5 for trimming one side of the fabric. The structure of this cutting knife is also well known in overlock sewing machines. In this embodiment, the cutting knife is driven in conjunction with the upper knife, but
For example, it is possible to use a configuration in which the needle is driven after an appropriate number of stitches after the trailing edge of the fabric passes through the sewing section.

In FIG. 1, the presser foot 1 is positioned on the throat plate 8 of the sewing machine bed B while being supported by the tip of a presser foot 11 having a rotation center P on the back side of the sewing machine arm A. Presser foot 11
As shown in FIG.
A presser foot 12 is fixed to the tip of the presser foot 12, and a horizontal arm 12a formed at the lower end of the presser foot 12 is elastically held between a presser foot body 13 and a temporary spring 14. Therefore, presser foot 1 is horizontal arm 1
It can be raised and lowered around 2a. The presser foot 1 is composed of a presser foot body 13, a plate piece 15 for eliminating curls in the fabric screwed to the presser foot body 13, the plate spring 14, and a base 16 for the temporary spring 14.

A guide groove 16a for guiding the hollow ring C is formed near the right end of the pedestal 16. The guide groove 16a is clearly shown in FIG. 13(b). This figure shows a sectional view taken along the line ■--■ in FIG. 12(b). A notch 12b is formed from below in the horizontal arm 12a located behind the guide groove 16a. This cut 12b serves to prevent the hollow ring C from wobbling and coming off the seam.

The tip of the horizontal arm 12a is smoothly inclined as shown in FIG. 13(A) so that the hollow ring C can smoothly enter into the notch 12b. In the figure, an arrow m indicates a path until the hollow ring C enters the notch 12b. In addition, a tall wall plate portion 1 is provided on the right side of the guide groove 16a to prevent the empty ring from coming off the guide groove 16a until it enters the notch 12b as described above.
6b is formed in an upright manner.

The empty ring transfer device 2 is constructed as shown in FIGS. 1 and 10. That is, a bracket 21 with a long hole 21a is fixed to the front side of the sewing machine arm A, a driving air cylinder 22 is fixed to this bracket 21, and a bracket 2 with a long hole 24a has a suction nozzle 23 fixed to the tip thereof.
4 is rotatably supported around a pin 25, and furthermore, a pin 27 provided upright on a bracket 26 at the tip of the drive air cylinder 220 is passed through long holes 21a and 24a formed in the brackets 21 and 24. This is a configuration that has been pushed through. When the driving air cylinder 22 is moved forward or backward, the bracket 24 is rotated around the pin 25, so that the suction nozzle 23 moves between the state shown in FIG. 10(a) and the state shown in FIG. 10(b). In this case, suction nozzle 2
By appropriately selecting the length and bending shape of the suction nozzle 23, the suction nozzle 23 can be placed in the first position approaching the empty ring catcher 4 as shown in FIG. and the second position that exists in . Further, by appropriately selecting the mounting height of the bracket 21, the suction nozzle 23 can be moved between the first position and the second position in the space above the presser foot 1. The suction nozzle 23 is connected to a vacuum pump (not shown) via a flexible hose 28.

Therefore, at the first position, the suction nozzle 23 can receive the empty ring captured by the empty ring trap 4 by adsorption, and move the empty ring to the second position. The suction nozzle 23 is constructed by bending a metal round pipe, and the tip of the nozzle is cut diagonally to form an oval opening. The purpose of the elliptical opening is to ensure that the empty ring is attracted at the first position. The driving air cylinder 22, which controls the movement of the suction nozzle 23, is a double-acting cylinder having forward and backward air pipes 22a and 22b. Both air pipes 22a.

A speed controller (not shown) is interposed in 22b to facilitate timing of movement of the suction nozzle 23 to the first position and the second position.

The empty ring presser mechanism 3 is an air cylinder 3 attached to the sewing machine arm A via a bracket 31 as shown in FIG.
An empty ring presser 33 is attached to the tip of the rond 2. Empty ring presser 33 due to advancement of air cylinder 32
A guide groove 16a formed on the upper surface of the presser foot 1 at the lowered position of
The mounting position of the air cylinder 32 is selected so that
It is formed into a model so that it can be fitted into 6a. Like the driving air cylinder 22, the air cylinder 32 also uses a double-acting cylinder, and has an air supply pipe 32a.
, 32b are each provided with a speed controller (not shown). In addition, an air pressure regulator (not shown) is interposed in the air supply pipe 32a on the side that advances the air cylinder 32, and an air ring presser 33 properly adjusts the air ring in the guide groove 6a of the presser foot 1. It can be adjusted to fit under pressure.

With the above configuration, the series of steps for sewing the empty ring can be automatically performed by operating electromagnetic valves and solenoids using a known sequence controller or the like. This series of steps will be explained according to the timing chart in Fig. 14. First, when the rear end of the fabric passes the seam forming area, the fabric detection sensor (not shown) detects this and at the same time the needle movement counter (not shown) counts the number of needle movements, and when a suitable count value is reached, a fixed position stop device for the louver etc. is activated, and the upper looper is brought out above the throat plate, and the upper knife is located at a position where it is not in the movement path of the suction nozzle 23. The sewing machine stops. Since the empty ring catcher 4 is in operation until the sewing machine stops, the empty ring C is removed from the suction window 41 as shown in FIG.
It was sucked into the bag and cut by a cutting knife. Simultaneously with the stopping of the sewing machine, the empty ring catcher 4 stops operating, and instead the empty ring transfer device 2 moves from the second position to the first position, and the nozzle 23 at its tip starts suctioning.

As a result, the empty ring C is received by the nozzle 23 from the empty ring catcher 4 as shown in FIG. In addition, the suction nozzle 23
In order to ensure safety, it is desirable to provide a sewing machine start stabilizing device that forcibly stops the sewing machine when the sewing machine is in the first position. Such a safety device and the louver-like fixed position stop device can be easily implemented by those skilled in the art.

When the suction nozzle 23 adsorbs the empty ring C at the first position, the empty ring transfer device 2 returns to the second position in that state. As a result, the empty ring C is folded back above the presser foot 1 as shown in FIG. Next, empty ring holding mechanism 3
is operated to lower the empty ring presser 33. Thus, the fifth
As shown in the figure, the hollow ring C is fitted into the guide groove 16a on the upper surface of the presser foot. Thereafter, when the suction nozzle 23 stops the suction action, a new fabric is set, and the sewing machine resumes operation, as the fabric moves forward, the pressure held by the empty ring presser mechanism is released midway and the guide groove is moved. The empty ring in 6a moves forward and is sewn into the first part of the fabric E as shown in FIG. The sewn-in state is shown in Fig. 12 (b).

By the way, in addition to the above configuration, the present invention is provided with an air ring sprayer. The ring sprayer is designated by the numeral 9 in FIG. In the illustrated example, the ring sprayer is constructed of a metal pipe, which is held on the presser stand 11 by a placket 91. It is desirable that the operation timing of the empty ring sprayer 9 starts when the suction action of the suction nozzle 23 stops, or at a slightly later time than that, as shown in FIG. 14(1). If the empty ring sprayer 9 operates at this timing, the empty ring will be pressed into the guide groove 1 by the empty ring presser 33.
6a, the free end side of the hollow ring C protruding from the end of the guide groove 16a is blown toward the upper knife 51 as shown in FIG. Then, when a new fabric E is set and the sewing machine resumes operation,
Since the upper knife 51 also operates, the free end side of the empty ring that is being blown in the direction of the upper knife 51 is cut by the upper knife 51 as shown in FIGS. 7, 11, and 12 (a). The metal pipe is connected to a flexible hose 92 within a bracket 91.

The flexible hose 92 is connected to an air pump (not shown). The tip nozzle portion 93 of the metal pipe faces the front end portion of the guide groove 16a on the upper surface of the presser foot.

On the other hand, an arcuate notch groove 16C is formed in the front end portion of the guide groove 16a, as shown in FIG. The purpose of forming such a groove 16C is to make the length of the empty ring short. That is, when the empty ring C protruding from the empty ring presser 33 is applied with the blowing force of the empty ring spraying device 9, the air ring C protrudes from the groove 16.
The air is sprayed in the direction of the upper knife 51 over the shortest distance through c, thereby making the length of the empty ring short. When the empty ring C is cut by the upper knife 51, there is no longer a need to spray in the direction of the upper knife, so the empty ring sprayer 9 stops operating. Thereafter, as the fabric moves forward, the empty ring C slides forward within the guide groove 6a and is sewn into the first part of the fabric (see FIG. 12(b)).

In Fig. 1, 100 is a thread tension device 1 used when the sewing machine is in either the "empty ring" or "sewing" thread tension state.
This is a thread loosening device equipped with 01 and 102. Figure 14 (h
) shows the timing of switching between the empty ring state and the sewing state of this device 100.

In the above embodiment, the series of operations for sewing the empty ring is automatically controlled based on the detection signal from the fabric edge detection device, but a foot switch or a knee switch is provided to operate these switches. It can also be implemented by a so-called semi-automatic control method in which a predetermined operation is performed when the

Come to Shubanmushijuku As described above, according to the present invention, the following effects are achieved.

■Since the empty ring is sewn into the fabric surface while being positioned by the empty ring presser mechanism, there is no friction with the fabric surface when sewing the empty ring, and therefore, sewing can be performed at high speed. Moreover, since the empty ring is held on the front side of the sewing machine, a slit for the feed dog can be provided before the needle drop and the feed dog can be applied to the fabric, allowing the edge of the fabric to be accurately and quickly placed at the needle drop. Overlock stitching can be performed with extremely high work efficiency.

(2) In addition, since the operator can observe the holding state and sewing state of the empty ring from the outside, the positioning of the empty ring can be appropriately and easily adjusted. Therefore, when the sewing machine is started, it is possible to form a stitch from the first stitch, and there is no risk of skipped stitches when sewing an empty chain.

(2) The empty ring captured by the empty ring trap is transferred to the second position while being adsorbed by the suction nozzle, and then held by the empty ring holding mechanism, so that the empty ring is reliably positioned.

■The suction nozzle is rotatably supported around a rotating shaft provided on the front side of the sewing machine frame, making installation easy. That is, the mounting space is wide in front of the seam forming section, including the front part of the sewing machine arm, and the mounting work is easy, resulting in low manufacturing and assembly costs.

■Since the suction nozzle can move in the space above the presser foot, it does not interfere with fabric feeding, and the suction nozzle installed in front of the seam forming part is located near the empty ring catcher behind it (the first There is little danger to the worker because the machine moves between the two positions.

■Since the empty ring sprayer is provided, the empty ring is sprayed by the empty ring sprayer toward the fabric edge cutting knife, and the excess ring is cut off by the scalpel.

Therefore, it is possible to sew the fabric into the fabric with the length of the free ring always kept constant, and the appearance of the fabric can be maintained good.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of an overlock stitch sewing machine equipped with the device of the present invention, Figs. 10(A) and 10(B) are plan views showing the empty ring transfer device. FIG. 11 is a detailed perspective view showing the presser foot.
Figure 2 (a) and (b) are plan views showing details of the operation of sewing an empty ring into the beginning of the fabric, Figure 13 (a) is a sectional view taken along the line 1-1 of the previous figure (a), and Figure (b) 14 is a sectional view taken along the line II-IF in the previous figure (b), and FIG. 14 is a timing chart showing the operation timing of each part when performing a series of empty ring stitching operations. ■... Presser foot, 2... Empty ring transfer device, 3... Empty ring presser mechanism, 4... Empty ring catcher, 5... Cutting knife, 9...
...Empty ring sprayer, 16a...Guide groove, 22...
・Drive air cylinder, 23...Suction nozzle, 2
5... Bottle, 41... Suction window, 42... Cutting knife. C...Empty ring, D...Seam forming part. Patent applicant: Hegasus Sewing Machine Manufacturing Co., Ltd. Figure 9 Figure 11 (/1) Figure 12 E (b)

Claims (1)

[Claims] (1) An empty ring catcher having a cutting knife that sucks in an empty ring continuously formed from the edge of the fabric through a suction window and cuts off the empty ring; Provided on the front side of the sewing machine frame so as to be movable in the empty ring above the presser foot between a first position close to the suction window of the empty ring catcher and a second position located in front of the seam forming part. a suction nozzle rotatably supported around a rotation axis; the suction nozzle sucks and receives an empty ring captured by an empty ring catcher in a first position; and a presser holds the received empty ring in a second position; a driving air cylinder acting on the suction nozzle to transport it upward; and a driving air cylinder provided on the front side of the sewing machine, the suction nozzle capturing the cut ring and transporting it above the presser foot in a second position. After a new piece of fabric is set, the sewing machine is activated to create an empty ring holding mechanism that holds the empty ring for a predetermined period of time, and to cut one side of the fabric to match the length of the empty ring held by the empty ring holding mechanism. An empty ring sewing device for an overlock sewing machine, comprising an empty ring sprayer that sprays an empty ring toward a cutting knife provided for alignment.