JPH0233276B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to removing an empty ring whose tip end is captured by an empty ring trap and continues to a seam forming part from the empty ring catching device, and removing the empty ring from the empty ring trap, This invention relates to a so-called empty chain sewing device which automatically sews into the first part of a new piece of cloth in a state where it is folded back toward the front from a forming part.

BACKGROUND OF THE INVENTION The purpose of sewing a hollow ring at 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 was
As seen in Publication No. 170, 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, In addition, since a concave groove of an appropriate length is formed in the throat plate from near the needle drop toward the front of the sewing machine as a means for aligning the empty rings, the following problems occur. Ta.

Problems to be Solved by the Invention Namely, the empty ring is folded back to the underside of the new fabric and inserted into the groove formed in the throat plate and positioned, but due to the structure of the throat plate, it cannot reach the needle drop 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 hollow 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, resulting in defects such as skipped stitches. There is.

A jet from an elongated nozzle in the suction window that captures the empty ring directs the empty ring away from the sewing machine needle, and the empty ring is received by a gripping device located at a relatively distant distance and placed on the needle. Since it is fitted into the groove of the plate, 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.

Means for Solving the Problems Therefore, in order to achieve the above object, the empty chain sewing device in the overlock stitch sewing machine according to the present invention is provided at a rear position of the seam forming section, and is connected continuously from the edge of the fabric. an empty ring catcher having a cutting knife for sucking the empty ring formed through a suction window and cutting the empty ring; a presser foot provided with a guide section for guiding the empty ring; and a presser foot provided with a guide section for guiding the empty ring; It is provided on the front right side of the sewing machine main body which is in front and intersects with the cloth feeding direction, and moves in the space above the presser foot between a first position where it approaches the empty ring catcher and a second position where it moves away from the empty ring catcher. an empty ring transfer device configured to suction and receive the empty ring captured by the empty ring catcher at a first position and to transfer the received empty ring above the presser foot at a second position; An empty ring holding mechanism that captures the cut empty ring by the empty ring transfer device, transfers it above the presser foot at a second position, and holds the empty ring until a predetermined period when the sewing machine is operated after a new fabric is set. The empty ring transfer device is attached to the tip of a support whose base end is rotatably supported on the front surface of the sewing machine body, and has a suction suction device with the tip facing the right side in front of the seam forming section. The sewing machine is equipped with a nozzle and a driving air cylinder which is provided on the front right side of the sewing machine body corresponding to the base end of the support and whose rod tip is rotatably connected to the base end of the support. The present invention is characterized in that the suction nozzle is rotated between the first position and the second position by the advancing and retracting operations of the rod of the driving air cylinder.

Operation According to the above configuration, when the rod of the driving air cylinder is advanced, the suction nozzle rotates to the first position and receives the empty ring captured by the empty ring transfer device at this position. Then, when the rod is retracted, the suction nozzle is rotated to the second position on the near side, and the empty ring is transferred to this position. At this time, the suction nozzle moves in the space above the presser foot, so the empty ring is guided from the seam forming part to the guide part provided on the presser foot on the operator's side and is folded back onto the upper surface of the presser foot. It is held by a ring holding mechanism.
Then, a new cloth is inserted under the presser foot, and as sewing begins, the holding by the ring presser mechanism is released midway as the cloth moves forward. This causes the loop to move forward as the fabric moves forward, and is sewn into the seam at the beginning of the fabric.

Embodiment FIG. 1 shows an external perspective view of an overlock sewing machine equipped with a 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, there is an empty ring catcher 4 on one side of the sewing machine bed B behind the presser foot 1, as shown in FIG.
is provided. Empty ring catcher 4 is a real Kosho 54-40195
As is well known in Japanese Utility Model Publication No. 57-55820, the hollow ring formed continuously from the edge of the fabric on the throat plate claw 200 (see Figure 9) is sucked in through a suction window and cut. It has a structure with a cutting knife. 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. The suction window 41 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,
It communicates with an upper knife stand 52 which is movable up and down and which fixes an upper knife 51, so that it can be opened and closed. By opening and closing this 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 a structure in which the cutting knife is driven after an appropriate number of stitches after the trailing edge of the fabric passes through the sewing section may be used, for example. .

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. The support structure by the presser stand 11 is the 11th
As shown in the figure, a presser foot 12 is attached to the tip of the presser foot 11.
horizontal arm 1 formed at the lower end of the presser foot 12.
2a is elastically held between a presser foot body 13 and a leaf 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 main body 13, a plate piece 15 for eliminating curling of the fabric screwed to the presser foot body 13, the plate spring 14, and a base 16 of the plate 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. 13B. 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 sloped smoothly as shown in FIG. 13A, so that the hollow ring C can smoothly enter into the notch 12b. In the figure, an arrow m indicates a path through which the hollow ring C enters the notch 12b. Further, until the empty ring enters the notch 12b as described above, care is taken to prevent it from coming off the guide groove 16a.
A tall wall plate portion 16b is formed upright on the right side of the guide groove 16a.

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 24 with a long hole 24a with a suction nozzle 23 fixed to the tip thereof is fixed. pin 25
A pin 27, which is rotatably supported around the periphery of the drive air cylinder 22 and is further provided upright on a bracket 26 at the tip of the rod of the driving air cylinder 22, is pushed through long holes 21a and 24a formed in the brackets 21 and 24. There is a structure. 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 is
It moves between the state shown in Figure A and the state shown in Figure B. In this case, by appropriately selecting the length and bending shape of the suction nozzle 23, the suction nozzle 23 can be placed in the first position where it approaches the empty ring catcher 4 as shown in FIG. He is trying to move between it and a second position located in front of the seam forming part D. 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 a flexible hose 28
It is connected to a vacuum pump (not shown) via. Therefore, at the first position, the suction nozzle 23 receives the empty ring captured by the empty ring trap 4 by suction, and can 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, 2
A speed controller (not shown) is interposed in 2b, and controls the first position and the second position of the suction nozzle 23.
It is designed to make it easier to time the movement to the desired location.

As shown in FIG. 1, the ring holding mechanism 3 includes a ring holding tool 33 at the tip of the rod of an air cylinder 32 attached to the sewing machine arm A via a bracket 31.
It is configured by installing. Air cylinder 32
The mounting position of the air cylinder 32 is selected so that the guide groove 16a formed on the upper surface of the presser foot 1 is present at the lowered position of the ring presser 33 due to the advancement of the ring presser 33, and the tip of the ring presser 33 is located in the guide groove 16a. Groove 1
It is formed into a wedge shape so that it can be fitted into the hole 6a. Like the driving air cylinder 22, the air cylinder 32 also uses a double-acting cylinder, and has speed controllers (not shown) interposed in each of the air supply pipes 32a and 32b. 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.
The ring can be adjusted to fit into the ring 6a with an appropriate pressure.

With the above configuration, the series of steps to sew in 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. (outside) counts the number of needle movements, and when a suitable count value is reached, a fixed position stop device for the looper etc. is activated, and the upper looper does not come out above the throat plate, and the upper knife is in the movement path of the suction nozzle 23. The sewing machine stops at the wrong position. Since the empty ring catcher 4 is in operation until the sewing machine stops, the empty ring C is cut by the cutting knife while being sucked into the suction window 41 as shown in FIG. Simultaneously with the stopping of the sewing machine, the empty ring catcher 4 stops operating, and 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 trap 4 as shown in FIG. In order to ensure safety, it is desirable to provide a sewing machine start stabilizing device that forcibly stops the sewing machine when the suction nozzle 23 is in the first position. Such a safety device and a fixed position stop device such as the looper can be easily implemented by those skilled in the art.

When the suction nozzle 23 is in the first position, the empty ring C
When it adsorbs, 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. Subsequently, the ring presser mechanism 3 operates to lower the ring presser 33. Thus, as shown in FIG. 5, 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 16a is released. The inner ring moves forward and is sewn into the first part of the fabric E as shown in FIG. The sewn-in state is shown in Figure 12B.

By the way, the second aspect of the present invention is one in which an air ring sprayer is provided in addition to the above configuration. The ring sprayer is designated by the numeral 9 in FIG. In the illustrated example, the empty ring sprayer is composed of a metal pipe, which is attached to a holding table 1 by a bracket 91.
It is kept at 1. It is desirable that the operation timing of the empty ring spray device 9 starts when the suction action of the suction nozzle 23 stops, or at a slightly later time, as shown in FIG. 14l. If the empty ring sprayer 9 operates at this timing, the free end side of the empty ring C protruding from the end of the guide groove 16a will be in a state where the empty ring is pressed into the guide groove 16a by the empty ring presser 33. As shown in Figure 6, the upper knife 5
It is sprayed in one direction. Then, when a new fabric E is set and the sewing machine resumes operation, the upper knife 51 also operates, so the upper knife 51
The free end side of the empty ring that is being blown in the direction of is the seventh
As shown in FIGS. 11 and 12A, the upper knife 51 is used to cut it. The metal pipe is connected within a bracket 91 to a flexible hose 92. 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, the front end portion of the guide groove 16a has an arcuate notch groove 1 as shown in FIG.
6c is formed. 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 1.
6c, it is sprayed in the direction of the upper knife 51 over the shortest distance, 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 hollow ring C slides forward within the guide groove 16a and is sewn into the first part of the fabric (see FIG. 12B).

In Figure 1, 100 indicates that the sewing machine is "empty ring" or "sewing".
This is a thread loosening device equipped with thread tension devices 101 and 102 that are used when the thread tension is in any of the following states. FIG. 14h shows the timing of switching the device 100 between the empty ring state and the sewing state. 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 it is also possible to provide a foot switch and a knee switch to operate these switches. It can also be carried out by a so-called semi-automatic control method in which a predetermined operation is sometimes performed.

Effects of the Invention As described above, the present invention provides the following effects.

Since the empty ring is guided by a guide portion provided on the presser foot and held by the empty ring holding mechanism, the empty ring is correctly positioned in an aligned state. Since the ring is sewn into the fabric surface in such a positioned state, 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 separate from the fabric surface by the presser foot of the sewing machine, a slit for the feed dog can be provided before the needle drops, and the feed dog can be applied to the fabric. To accurately and quickly bring the edge to the needle drop and perform overlock stitching with high work efficiency.

Furthermore, 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 starting the sewing machine, 1
It is now possible to form a seam from the needle,
There is no risk of skipped stitches when sewing empty rings.

The empty ring captured by the empty ring trap is transferred to the second position while being attracted to the suction nozzle installed in the empty ring transfer device, guided by the guide section, and then moved by the empty ring holding mechanism. Since the ring is held in place, positioning of the empty ring can be performed reliably.

The empty ring transfer device includes the suction nozzle whose tip faces the right side in front of the seam forming section, and a support whose tip supports the suction nozzle and whose base end is rotatably supported on the front surface of the sewing machine body. and a driving air cylinder, which is installed on the front right side of the sewing machine main body and whose rod tip is connected to the proximal end of the support.The suction nozzle is moved to the base of the support by advancing and retracting the rod. By rotating the pivot point as a fulcrum, the suction nozzle can be moved between the first empty ring receiving position and the second position on the near side.
Since it has a mechanism configuration that converts reciprocating motion into rotational motion,
It becomes possible to move the suction nozzle over a large distance with a relatively small stroke of the rod. Therefore, compared to a mechanism in which the suction nozzle is moved only by reciprocating motion that requires a large stroke amount, there is an advantage that the mechanism structure can be made compact and the occupied space can be significantly reduced. Moreover, since the empty ring transfer device is installed on the front side of the sewing machine body, which has a wide installation space in standard sewing machines, it is easy to install the empty ring transfer device, and manufacturing and assembly costs can be significantly reduced. There is an advantage. In addition, by appropriately selecting the connection position between the rod end of the drive air cylinder and the support, the amount of rotation of the support, that is, the amount of movement of the suction nozzle, can be easily adjusted, making it easy to adjust to changes in the sewing object. It also has the advantage of being manageable.

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 loop catcher behind it (in the first position). ), there is little danger to workers.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of an overlock sewing machine equipped with the device of the present invention, FIGS. 2 to 8 are diagrams illustrating a series of empty chain stitching operations performed by the device of the present invention, and FIG. 9 10A and 10B are plan views showing the empty ring transfer device, FIG. 11 is a detailed perspective view showing the presser foot, and FIGS. A plan view showing the operation of sewing a ring in detail, 13th A is a cross-sectional view taken along the - line in the previous figure A, Figure B is a sectional view taken along the - line in the previous figure B, and Figure 14 shows a series of empty ring sewing operations. 3 is a timing chart showing the operation timing of each part in this case. 1... Presser foot, 2... Empty ring transfer device, 3... Empty ring presser mechanism, 4... Empty ring catcher, 5... Cutting knife,
12a...Horizontal arm, 12b...Notch, 16a...
... Guide groove, 16b ... Wall plate part, 22 ... Drive air cylinder, 23 ... Suction nozzle, 25 ...
...Pin, 41...Suction window, 42...Cutting knife. C...Empty ring, D...Seam forming part.

Claims (1)

[Scope of Claims] 1. An empty ring capturer that is provided at a rear position of the seam forming section and has a cutting knife that sucks the empty ring continuously formed from the edge of the fabric through a suction window and separates the empty ring. a presser foot provided with a guide portion for guiding the empty ring; and a presser foot provided on the front right side of the sewing machine body, which is in front of the seam forming portion and intersects with the cloth feeding direction, and which approaches the empty ring catcher. The presser foot is movable in the space above the presser foot between a first position where the presser foot is moved away from the presser foot, and in the first position, the empty ring captured by the empty ring catcher is sucked and received, and the empty ring that is received is movable in the space above the presser foot. an empty ring transfer device configured to transfer the ring above the presser foot in a second position; and the empty ring transfer device captures the cut empty ring and transfers the ring above the presser foot in the second position, and then transfers the ring above the presser foot to a new position. and an empty ring holding mechanism for holding the empty ring until a predetermined period of time when the sewing machine is operated after the fabric is set, and the empty ring transfer device is rotatably supported at its base end on the front surface of the sewing machine body. attached to the tip of the support,
A suction nozzle with its tip facing the front right side of the seam forming section, and a suction nozzle provided on the front right side of the sewing machine body corresponding to the proximal end of the support, and a rod tip facing the proximal end of the support. The suction nozzle is provided with a driving air cylinder that is rotatably connected to the suction nozzle, and is configured to rotate the suction nozzle between the first position and the second position by advancing and retracting the rod of the driving air cylinder. An empty chain sewing device for an overlock sewing machine, which is characterized by the following.