JPH04338487A - Upper thread supply structure in sewing machine - Google Patents

Abstract

PURPOSE:To enable an upper thread to be supplied toward a thread regulator without generating a loop-like twist by providing a hollow thread erector to guide the upper thread drawn out of a bobbin to the thread regulator through the hollow thread erector and a hollow pipe connected thereto. CONSTITUTION:An upper thread 29 wound around a bobbin 28 is drawn out of the outer peripheral part thereof sequentially to enter a thread inlet 20 through a slight distance. Then, the upper thread 29 is drawn out of the surface of the upper thread 29 yet wound around the bobbin 28 to be separated therefrom by a thread guide 23. Thus, the thread 29 excessively unwound from the bobbin 28 is prevented from an accident of entangling with the drawn-out thread. The upper thread 29 entering the thread inlet 20 is guided to a thread regulator 6 through the hollow thread erector 14 and hollow pipe 24.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle thread supply structure for a sewing machine, which supplies needle thread toward a needle for use in sewing.

0002

[Prior Art] As shown in FIG. 3, a sewing machine frame 3f
A thread stand 14f is provided in the form of a tree, and an upper thread bobbin 28f is inserted into the thread stand 14f. In order to smoothly pull out the needle thread 29f wound around the bobbin 28f, a thread guide 41 is provided at a location on the extension direction side (in this example, on the upper side) of the axis of the thread stand 14f.

0003

[Problems to be Solved by the Invention] With the needle thread supply structure in this conventional sewing machine, when sewing, the needle thread 29f
is smoothly pulled out from the bobbin 28f, and passed through the thread guide 41 and other thread guides 42 to the thread adjuster 6f.
You will be guided to. However, in this case, if the upper thread 29f wound around the bobbin 28f suddenly unravels from its outer circumference due to vibrations of the sewing machine during sewing, the distance from the bobbin 28f to the thread guide 41 above it is long, When the needle thread is a strongly twisted needle thread, the needle thread 29f between the bobbin 28f and the thread guide 41 is twisted into a loop shape as shown by the reference numeral 43, and the needle thread that remains twisted in the loop shape is used for thread adjustment. There is a problem in that the thread is fed toward the thread adjuster 6f, and gets caught somewhere along the way from the thread adjuster 6f to the thread take-up lever 8f to the needle 5f, interrupting the sewing process. In order to prevent the above-mentioned loop-like twist, the thread guide 41 should be connected to the bobbin 28f.
Although it is conceivable to arrange the bobbin 28f close to the thread stand 14f, there is a problem that it becomes difficult to insert and remove the bobbin 28f from the thread stand 14f.

The present invention was made in order to solve the problems (technical problems) of the prior art described above, and the thread stand is made hollow, and the upper thread pulled out from the bobbin is passed through the hollow thread stand and the threads connected to it. By guiding the needle thread to the thread regulator with a hollow tube, even if the needle thread is strongly twisted, the needle thread can be fed toward the thread regulator without creating a loop-like twist, resulting in smooth sewing. To provide an upper thread supply structure for a sewing machine in which the bobbin can be moved forward, and furthermore, a location on the extension direction side of the axis of the thread stand can be made into an open space, and the bobbin can be easily inserted into and removed from the thread stand. The purpose is to

[0005]

[Means for Solving the Problems] In order to achieve the above object, the upper thread supply structure of the sewing machine according to the present invention includes a machine frame equipped with a vertically movable sewing needle, and a needle thread supply structure in a sewing machine according to the present invention. The machine frame is equipped with a rod-shaped thread stand for standing up the bobbin by passing through the core of the bobbin around which the upper thread for supplying the needle is wound. , a thread regulator for applying tension to the upper thread supplied from the bobbin toward the needle, and a vertically movable thread take-up for pulling up the upper thread between the thread regulator and the needle. In the sewing machine, the thread stand is constituted by a hollow cylinder whose upper and lower ends are open so that the upper thread can pass through from the upper end to the lower end, and at the lower end of the hollow thread stand, One end of a hollow tube for guiding the needle thread, which is open at both ends, is communicated with the other end of the hollow tube, and the other end of the hollow tube is located near the thread adjuster.

[0006]

[Operation] The upper thread pulled out from the bobbin enters the inside of the hollow thread stand from the upper end thereof, and is guided to the thread adjuster via the thread stand and the hollow tube connected thereto.

[0007]

Embodiments The drawings showing embodiments of the present application will be described below. Figure 1 shows a part of a multi-needle sewing machine, where 1 is a throat plate;
2 indicates a sewing machine head. 3 is a machine frame in the sewing machine head 2. A needle bar 4 is attached to the machine frame 3 so as to be movable up and down, and a needle 5 is attached to the lower end. A plurality of needle bars 5 are provided in a direction perpendicular to the plane of the paper in FIG. 1, and these needle bars 5 are operated interchangeably as is well known. Reference numeral 6 denotes a thread adjuster for applying tension to the needle thread fed toward the needle, and is attached to a support stand 6a attached to the machine frame 3. Reference numeral 7 indicates a thread guide, and 8 indicates a thread take-up for pulling up the upper thread between the thread regulator and the needle.

Next, the needle thread supply structure will be explained. 1
Reference numeral 2 denotes a thread stand, which in this example is attached to the machine frame 3 via a support 13. However, the sewing machine head 2 may be attached to a frame (not shown) to which the sewing machine head 2 is attached. 14
The thread stand is a rod-like structure so that it can pass through the core of the bobbin, and is attached to the thread stand stand 12 so as to be provided in the form of a tree with respect to the machine frame 3.

The thread stand 14 and related structures will be explained below with reference to FIG. 2. The thread stand 14 is constructed using a hollow cylinder with open upper and lower ends, and its lower end is fixed to the thread stand stand 12. Thread stand 1
4 is bent in a dogleg shape at the bottom in this example, but it may be straight. The above fixing structure will be explained. As shown in FIG. 2B, a thin diameter portion 15 is formed at the lower end of the thread stand 14, and a male thread is formed on the outer periphery of the thin diameter portion 15. This narrow diameter portion 15 is inserted into a through hole 16 made in the thread stand 12, and when the stepped portion 17 is in contact with the edge of the through hole 16, the nut 18 screwed onto the male screw is tightened. It is fixed to the thread stand 12. Next, the opening of the upper end 14a of the hollow thread stand 14 serves as a thread entrance 20, and the entire circumference thereof is polished to a smooth curved surface so that the upper thread will not get caught. A holder 22 is made of, for example, a synthetic resin material and is attached to the thread stand 14 so that it can be moved in the direction of the arrow. Reference numeral 23 denotes a collar-shaped thread guide which is detachably attached to the thread stand 14 and is made of a material with good sliding properties such as nylon resin, and its outer periphery is formed into a smooth curved surface. Next 2
Reference numeral 4 designates a hollow tube with both ends open for guiding the needle thread. For example, a vinyl tube is used, but any other hollow tube with a smooth inner surface may be used. One end 24a of the hollow tube 24 is placed over the lower end 14b of the thread stand 14 to communicate therewith. The opening of the other end 24b of the hollow tube 24 is the yarn outlet 25.
It is located near the thread regulator 6. In this state, a portion near the other end 24b is fixed to the support base 6a with a stopper 26. The above-mentioned vicinity refers to the yarn exit 2
The upper thread may be placed on any side of the thread regulator 6 as long as the upper thread drawn from the needle thread 5 reaches the thread regulator 6 smoothly. Further, the direction of the thread outlet 25 may be directed toward the thread adjuster 6 other than the direction shown in this example. The inner diameter of the hollow thread stand 14 and the hollow tube 24 is preferably as small as possible to allow the needle thread to pass freely in order to reliably prevent the needle thread from twisting into a loop. The thickness is selected to be about 3 to 4 mm.

[0010] Next, the supply of needle thread by the apparatus having the above structure will be explained. First, as is well known, the pedestal 30 is attached to the bobbin 28 on which the upper thread 29 is wound. This pedestal 30 is made of felt, for example, and is used to hold the outer circumferential portion of the upper thread 29 wound around the bobbin 28 so that it does not fall downward when it comes undone. Next, with the thread guide 23 in FIG. 2 not yet attached to the thread stand 14, when the bobbin 28 is placed over the thread stand 14 so that the thread stand 14 penetrates the core of the bobbin 28, The inner circumferential surface of the bobbin 28 is pressed against the outer circumferential surface of the holder 22, and the bobbin 28 is
). In this case, it is preferable to adjust the position of the holder 22 in the direction of the arrow according to the inner diameter of the bobbin 28 so that the upper end 14a of the thread stand 14 is slightly protruded from the upper end 28a of the bobbin 28, as shown in the figure. Next, the thread guide 23 is attached to a portion of the thread stand 14 near the upper end 14a. After that, the end of the upper thread 29 wound around the bobbin 28 is unwound from the bobbin 28, and the unwound upper thread 29 is passed through the thread inlet 20 using a well-known wire threading tool. 14 and further through the hollow tube 24 to the yarn outlet 25. The upper thread 29 coming out of the thread outlet 25 is passed through a thread regulator 6, thread guide 7, thread take-up 8, etc. and then to the needle 5, as is well known.

When sewing is performed with the needle thread threaded as described above, the needle thread 29 wound around the bobbin 28 is sequentially pulled out from the outer circumference and enters the thread inlet 20 after a short distance. . In this case, due to the presence of the thread guide 23, the upper thread 29 is pulled out away from the surface of the upper thread that is still wound around the bobbin 28. That is, the upper thread, which is still wound around the bobbin 28, is pulled out without rubbing the surface thereof. This prevents the occurrence of an accident in which the upper thread 29 excessively unravels from the bobbin 28 and the unraveled thread becomes entangled with the above-mentioned pulled out thread. The upper thread entering the thread inlet 20 is guided to the thread regulator 6 through the hollow thread stand 14 and the hollow tube 24. During its guidance, the upper thread is always restrained by the thread stand 14 and the hollow tube 24.
Even if the needle thread is highly twisted, it is prevented from forming a loop. Further, even if a plurality of bobbins 28 are arranged side by side as shown in FIG. 1, an accident in which the needle threads 29 supplied from each bobbin 28 become entangled with each other can be prevented.

Next, if the needle thread 29 is relatively smooth and the upper end 28a of the bobbin 28 is smooth, the use of the thread guide 23 may be omitted. In that case, the bobbin 28 may be attached to the thread stand 14 such that the upper end 14a is located closer to the inside of the bobbin 28 than the upper end 28a of the bobbin 28.

[0013]

As described above, in the present invention, when sewing, the needle thread 29 pulled out from the bobbin 28 can of course be guided toward the thread adjuster 6.

0014
] When guiding the upper thread 29, the upper thread 29 pulled out from the bobbin 28 enters the hollow thread stand 14 over a short distance, and is restrained by the thread stand 14 and the hollow tube 24 following it. It has the feature that it is guided to the thread adjuster 6 while being prevented from protruding laterally. This means that even if the needle thread 29 is strongly twisted, it can be guided in a state where loop-like twists are prevented from occurring as in the prior art, and the sewing can be carried out without the needle thread getting caught. It is useful in facilitating smooth progress.

Furthermore, since the needle thread pulled out from the bobbin 28 is passed through the hollow thread stand 14 as described above, there is no need for a position on the extending direction of the axis of the thread stand 14 as in the prior art. There is no need for a thread guide, so the space can be made into an open space, and the bobbin 28 can be easily inserted into and removed from the thread stand 14 without any obstacles.

[Brief explanation of drawings]

FIG. 1 is a side view of a sewing machine.

2(A) is a partially cutaway enlarged view showing a structure related to one thread stand in FIG. 1, and (B) is an enlarged view of portion B in (A).

FIG. 3 is a side view showing a conventional sewing machine.

[Explanation of symbols]

5 needle 6 Thread regulator 8 Balance 14 Thread stand 24 Hollow tube 29 Upper thread

Claims (1)

[Claims] [Claim 1] The machine frame is provided with a sewing needle that can freely move up and down, and the machine frame is provided with a core of a bobbin on which a needle thread for supplying to the needle is wound. A rod-like thread holder is provided in a tree shape for standing up the bobbin, and the machine frame is further provided with a thread regulator for applying tension to the upper thread supplied from the bobbin toward the needle. and a vertically movable thread take-up for pulling up the needle thread between the thread adjuster and the needle, the thread stand is capable of passing the needle thread from its upper end through the inside toward its lower end. The lower end of the hollow thread holder is connected to one end of a hollow tube for guiding the upper thread, which is open at both ends, and the inside thereof is connected to the lower end of the hollow thread stand. An upper thread supply structure for a sewing machine, characterized in that the other end of the empty tube is located near the thread regulator.