JPH06170076A - Chain stitch sewing machine - Google Patents

Abstract

PURPOSE:To properly execute sewing of the next thread by allowing a discharge member for drawing out a thread of the side linked with cloth on a throat plate after cutting a thread by a thread cutter to the lower face side of cloth from a needle hole, to be freely movable horizontally along the upper face of the throat plate. CONSTITUTION:In an end spot of sewing by one thread, after a needle 8 moves to the top dead center, a movable part of a thread cutter 15 executes a reciprocating motion an indicated with arrows 15a, 15b, and cuts a thread 36' being between a needle hole 4 and a looper 12. Subsequently, a discharge member 21 executes a reciprocating motion by its driving mechanism. In this case, in a going motion process, the discharge member 21 is guided by the guide surface 19a of a guide piece 19 and raised, passes through a position superposed to the needle hole 4 along the upper face of a throat plate 2 as indicated with an arrow 37 and moves horizontally, draws out a thread 36a left in the needle hole 4, sets a state of running along the lower face of cloth 35, and thereafter, the discharge member 21 is subjected to returning motion and returned into a recessed part. Subsequently, by a horizontal movement of an embroidery frame, a horizontal movement of one stitch portion dimensions of the cloth 35 is executed. By keeping pace therewith, a looper 12 loaded with the next sewing thread is brought right under the needle hole 4 by a horizontal movement of a looper base.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chain stitch sewing machine in which a plurality of threads are selectively used to perform chain stitch sewing on cloth.

[0002]

2. Description of the Related Art A needle plate, a needle for sewing provided above the needle plate so as to be movable up and down, a plurality of loopers arranged below the needle plate so as to be interchangeable for selective use, A chain stitch sewing machine having a structure including a thread cutting device disposed below the needle plate for cutting the thread between the needle plate and the looper is known (see, for example, Japanese Patent Publication No. 3-11239). ). In such a sewing machine, when sewing with one thread is finished, the thread is cut there and the looper is replaced, so that sewing with the next thread can be performed subsequently.

[0003]

However, when the sewing with the next thread is started, the previous thread remains in the needle hole, and therefore the thread is a fluffy thread or a plurality of thin threads. If it is a thread that is lightly twisted, the fluff of the former thread or some of the thin threads in the latter thread will be caught by the needle, which will be pulled up by the raising of the needle and There was a problem that it appeared in mixed state.

In order to solve the problem, after the sewing with one thread is finished and the thread is cut, the needle is largely raised and the end of the cut thread is pulled up from the needle hole to the upper surface side of the cloth through the cloth. Was attempted. However, if you do so, after you finish sewing all of the cloth and remove the cloth from the sewing machine,
When attempting to prevent the end of the thread used for each sewing from coming off from the side that was the lower surface of the cloth, the thread end on the side that was the upper surface of the cloth was the lower surface through the cloth. There was a problem that the troublesome work of sending it to the side was required.

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art. When sewing with one thread is finished and then sewing with the next thread is started, If you can prevent accidental pulling up of the previous thread and can properly sew with the next thread, and if you want to prevent the thread end from coming off after finishing all It is an object of the present invention to provide a chain stitch sewing machine capable of performing the work without any modification.

[0006]

In order to achieve the above object, a chain stitch sewing machine according to the present invention is provided with a needle plate, a needle for sewing vertically above the needle plate, and a needle below the needle plate. A loop provided with a plurality of loopers that are interchangeably arranged for selective use, and a thread cutting device that is arranged below the needle plate to cut the thread between the needle plate and the looper. In the sewing machine, after the thread is cut by the thread cutting device, a sweeping member for pulling out the thread on the side of the cloth on the needle plate from the needle hole to the lower surface side of the cloth is provided along the upper surface of the needle plate. It is prepared to move freely.

[0007]

When the sewing with one thread is finished, the thread is cut by the thread cutting device. The thread on the side connected to the cloth after cutting is wiped by a wiping member which moves laterally along the upper surface of the needle plate. Therefore, the thread is pulled out from the needle hole and laid along the lower surface of the cloth. After that, the looper is replaced and sewing with the next thread is started.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. Reference numerals 1 to 15 show respective members in a known chain stitch sewing machine, and 1 is a bed plate which is attached to a base frame of the sewing machine. A needle plate 2 is attached to the bed plate 1 with a set screw 3. Reference numeral 4 denotes a needle hole, and 5 denotes a threading hole. 4a is a needle hole having a different diameter, and 5a is a threading hole provided corresponding to the needle hole. These are needle hole 4 and threading hole 5 by rotating needle plate 2 by 180 degrees when viewed in plan. They are used by bringing them to the position where they were. Reference numeral 6 is a lid for closing a maintenance hole formed in the bed plate, which is attached with a fixing screw 7. Reference numeral 8 is a vertically movable needle for sewing, which has a hook portion 9. 11 is a looper table, which is provided so as to be movable laterally with respect to the base frame of the sewing machine. Reference numerals 12, 12 ... Denote a plurality of loopers mounted on the looper base 11 and are arranged so as to be positioned immediately below the needle holes 4 interchangeably by lateral movement of the looper base 11. Each looper has a different type (eg color,
(Thickness, properties, etc.) is loaded. 13 is the looper stand 11
Is a drive rod for laterally driving the. Reference numeral 15 denotes a thread cutting device provided on the lower side of the needle plate 2, and a movable member for drawing the thread advances and retreats to a position between the needle hole 4 and the looper 12 as shown by arrows 15a and 15b to cut the thread. It is like this.

Next, 17 is a recess for accommodating the wiping member formed in the upper surface of the bed plate 1, and 18 is a bearing hole formed in the bed plate 1. Reference numerals 19 and 20 are guide pieces attached to the bed plate 1, and their upper surfaces are arcuate guide surfaces 19a and 20a as shown in FIGS. 7 and 6, respectively.
Reference numeral 21 denotes a wiping member, which can be laterally moved along the upper surface of the needle plate 2, and in this example, for example, is configured to perform an arc motion along the upper surface of the needle plate 2 around a shaft body 22 provided at the base portion. . You may make it move in parallel along the upper surface of the needle plate 2. The shaft body 22 is supported by the bearing hole 18 so as to be rotatable and movable in the axial direction. Reference numeral 23 shown in FIG. 4 is an urging member for urging the wiping member 21 toward the bed plate 1, for example, a spring urging downward in this example, and a spring receiving portion 24 formed by a part of the bed plate 1. And the spring seat 25 attached to the shaft 22
It is interposed between and. Reference numeral 26 is a passive lever fixed to the shaft body 22. 27 is a fitting hole formed at a position corresponding to the guide piece 20. Next, reference numeral 30 shown in FIG. 31 is a motor in the mechanism, 32 is a cam, and has a cam groove 32a in the periphery. Reference numeral 33 is a drive lever, which is axially supported by the intermediate portion 33c and has a follower provided at one end.
33a is engaged with the cam groove 32a, and the engaging piece 33b provided at the other end
Is engaged with an engaging hole 26a formed in the passive lever 26.
In this drive mechanism 30, one rotation of the cam 32 by the motor 31 causes the driving member 33 and the passive lever 26 to move the wiping member 21.
Makes one round trip in the direction of the arrow.

In the above construction, the looper 12 and the needle 8 operate in a known manner, and the thread 35 supplied through the looper 12 is used to sew the cloth 35, as shown in FIG. 7 (A). Be seen. That is, the needle 8 descends from the top dead center to the bottom dead center through the needle hole 4, and then the looper 12 rotates to hook the thread on the hook portion 9, and then the needle 8 faces the top dead center. The thread is raised and the thread is pulled up. In the process of raising, the cloth tension frame holding the cloth 35 is sewn on the bed plate 1
The cloth 35 is laterally moved by the size corresponding to the mesh, and the cloth 35 is laterally moved by the same size. Such an operation is repeated.

Next, after the sewing with one thread is completed, the operation when the sewing with the next thread is subsequently performed is as follows. At the end point of sewing with one thread, the needle 8 moves to the top dead center as shown in FIG. 7A without lateral movement of the embroidery frame. After that, the movable part of the thread cutting device 15 reciprocates as shown by arrows 15a and 15b, and cuts the thread 36 'existing between the needle hole 4 and the looper 12. Next payment element
21 is reciprocated by the drive mechanism 30 as described above. In this case, in the process of forward movement, first, the guide surfaces 19a, 20a of the guide pieces 19, 20 are removed from the states of FIG. 6 (A) and FIG. 7 (A).
The wiping member 21 is lifted up as shown in FIGS. 6 (B) and 7 (B). Subsequently, the paying member 21 is shown in FIG.
(C), it laterally moves along the upper surface of the needle plate 2 through the position where it overlaps with the needle hole 4. Due to this lateral movement, among the cut yarns 36, the yarns on the side connected to the cloth 35, that is, the yarns 36a remaining in the needle hole 4 as shown in FIG. ), It is pulled out from the needle hole 4 and is placed along the lower surface of the cloth 35. Accordingly, the post-payment member 21 returns to the position inside the recess 17. After that, the lateral movement of the embroidery frame is laterally moved by a size corresponding to one stitch of the cloth 35.
In parallel with these, that is, after the thread is cut by the thread cutting device 15 and before or after the lateral movement of the cloth, or at a time after that, the looper base 11 is laterally moved to immediately below the needle hole 4. The looper 12 is then loaded with the threads used for sewing. After that, the same operation as that in the case described above, that is, the vertical movement of the needle 8 and the operation of the looper 12, causes the sewing with the next thread. In addition, when the sweeping member 21 is returned, the thread 36a moves to the needle hole 4
Even if the thread 36a is brought back to the side, the thread 36a does not penetrate into the needle hole 4, so that the thread 36a is unlikely to be accidentally caught by the needle 8 during sewing with the next thread.

When all the sewing operations for the cloth are completed, the cloth 35
Is removed from the embroidery frame, and a well-known process for preventing the yarn end from unwinding on the back surface of the cloth (the surface that was the lower side), for example, in the area where the sewing (embroidery) is performed on the cloth A thin adhesive is applied to the back surface, the cloth 35 is sewn to another cloth, and the thread ends on the back surface of the cloth are wrapped.

[0013]

As described above, according to the present invention, the cloth 35
In the case of sewing, it is of course possible to select and use multiple types of threads by selecting multiple loopers 12 and, of course, finish sewing with one thread, cut the thread, and then continue. When trying to sew with a different thread, there is a feature that the previous thread remaining in the needle hole 4 can be removed from the needle hole 4 by the wiping member 21. This means that even if the previous thread is a fluffy thread or a thread in which multiple thin threads are lightly twisted, pulling up the previous thread at the start of sewing with the next thread There is an effect that it can be surely prevented and that the sewing with the next thread can be properly performed.

Moreover, even if the thread is removed from the needle hole 4 as described above, since the wiping member 21 moves along the upper surface of the needle plate 2, the removed thread 36a is placed on the lower surface side of the cloth 35. It has the feature that it can be pulled out. This means that when the thread end is to be processed on the side that has been the lower surface of the cloth 35 after all the sewing operations on the cloth have been completed, no operation is required in the sewing completed state (the upper surface as in the prior art). There is the convenience that the processing work can be performed (without the work of passing the thread on the side that was on the lower side to the side that was on the lower side).

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a chain stitch sewing machine.

FIG. 2 is a plan view showing a state near the needle plate on the upper surface of the bed plate in the chain stitch sewing machine.

FIG. 3 is an exploded perspective view showing a relationship between a wiping member, a bed plate and a needle plate.

FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG.

FIG. 5 is a mechanism diagram showing a drive mechanism of a displacing member.

6A is an enlarged sectional view taken along line VI-VI in FIG.
FIG. 6B is a cross-sectional view showing a state at the start of operation of the wiping member.

7A, 7B, and 7C are sectional views for explaining the operation of the wiping member.

[Explanation of symbols]

 2 Needle plate 4 Needle hole 8 Needle 12 Looper 15 Thread cutting device 21 Cleaning member

Claims (1)

[Claims] 1. A needle plate, a needle for sewing provided above the needle plate so as to be movable up and down, and a plurality of loopers arranged below the needle plate so as to be interchangeable for selective use. In a chain stitch sewing machine including a thread cutting device disposed below the needle plate to cut a thread between the needle plate and the looper, the thread is cut by the thread cutting device and connected to the cloth on the needle plate. A chain stitch sewing machine characterized in that a sweeping member for pulling out the thread on the side of the needle from the needle hole to the lower surface side of the cloth is provided so as to be able to move laterally along the upper surface of the needle plate.