JPS63230193A - Needle thread feeder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention forcibly supplies the needle thread consumed for stitch formation by a needle thread feeding device without using a thread take-up. This invention relates to an upper thread supply device for a sewing machine that performs only a tightening action.

[Prior art] Japanese Unexamined Patent Publication No. 159985/1985 and Japanese Patent Application No. 1.3/1982
In the sewing machine as described in No. 1090, the third
As shown in FIG. 4, a sewing needle 1, a thread take-up 2. Mitsutori spring 3
, a guide 4.5.6, a thread detection roller 7 driven by a motor that rotates independently of the main shaft of the sewing machine, and a swing support rod 9 that is pressed by a spring 8 against the feed-out roller luff. , a presser roller 1o that is brought into contact with the feed roller 8, an electromagnetic double thread gripper 11, a paste tension plate 12. An upper thread bobbin 13 is provided, and
Inside the sewing machine A, a rotary encoder 17 is provided on a main shaft 16 to which a boot 5 is attached. In the figure, 14 indicates a sewing thread, and B indicates a needle thread supply control device section, and the paste tension plate 12 does not necessarily have to be included in this section.

The rotary encoder 17 is used to detect when the threading of the cloth is finished by the thread take-up, and a thread take-up position detector provided in a so-called electronic sewing machine may be used.

The needle thread 14 from the needle thread bobbin 13 is given tension to the extent that the thread is not disturbed by the pace tension plate 12, passes through the electromagnetic needle thread gripper 11 which is in an inactive state, and then passes through the needle thread pay-out roller 7 and the presser roller. The needle thread is held between the thread take-up roller 7 and the needle thread take-up side, and the feeding amount is controlled by stopping the running of the needle thread by gripping the needle thread with the electromagnetic needle thread gripper 11, and This is done in such a way that the thread feeding roller 7 continues to rotate or the upper thread supply is stopped. The amount of needle thread supplied is determined by the amount of needle thread delivered by the feed roller 7 that rotates during the time when the electromagnetic needle thread gripper 11 is releasing the needle thread grip.

However, the thread feeding roller 7 and presser roller 10, which are the needle thread feeding portions of such a sewing machine, are pressed by a spring 8 and grip the needle thread 14, and the needle thread gripping action by the electromagnetic needle thread gripping device 11 is not effective. If the upper thread is not fed out at , and the rollers 8 and 10 are parallel to each other and clamp the upper thread 14, as shown in FIG. 5(a), then! ! ! ! Since the upper thread 14 remains in a stopped state even if the output roller continues to ruff, the presser roller 10, which is in contact only with the upper thread 14, is stopped together with the upper thread, as shown in FIG. 5(b). If the roller axis becomes inclined for some reason, the driven presser roller 10 will come into contact with the thread pay-out roller 7 and rotate even if the needle thread 14 is in a stopped state. If this happens, there is no problem because the feed roller 7 is made of a material that does not wear easily, such as iron, but the presser roller 10, which is made of a material such as rubber, wears out due to friction with the thread. There is a risk that the surface of the roller may gradually become unsuitable for holding the upper thread.

[Problems to be Solved by the Invention] As described above, the present invention has a problem in that the presser roller 10 rotates in contact with the thread feeding roller 7 which is constantly rotating even when the needle thread supply is stopped, and the pressure roller 10 rotates while the needle thread supply is stopped. This is to prevent wear caused by rubbing against each other.

[Means for Solving the Problems] The present invention is configured such that the upper thread is held and sent out between an upper thread pay-out roller that rotates the upper thread at a constant speed and a presser roller that is driven by the upper thread, and the upper thread is fed out on the upper thread supply side. In a sewing machine configured to control the upper thread payout amount by gripping the upper thread with an electromagnetic upper thread gripper installed at A thread guide is provided, and an upper thread guide is provided above the presser roller and is biased to the other side of the center than the thread guide to guide the upper thread so as to wind the presser roller, and the exit side needle thread guide is moved toward the entrance. By providing the side needle thread guide and the roller at almost symmetrical positions with respect to the center line of the roller width, the thread feeding roller This is intended to prevent the presser roller from coming into contact with each other.

[Operation: As described above, since two upper threads are present between the thread pay-out roller and the presser roller, the surfaces of both rollers are isolated from each other and contact rotation occurs.

[Example] Fig. 1 is an explanatory diagram showing the schematic structure of the present invention, Fig. 2 shows the relationship between the needle thread and the thread guide in the thread feeding roller and presser roller portion, and (a) is a perspective view. , (b) is a front view.

The needle thread supply device according to the present invention is configured to sandwich and feed the needle thread between a needle thread pay-out roller 7 that rotates the needle thread 14 at a constant speed and a presser roller 10 that is driven by the roller, and the needle thread supply device In a sewing machine configured to control the upper thread payout amount by gripping the upper thread with an electromagnetic upper thread gripper 11 provided at A side thread guide 18 is provided, and an upper thread guide 19 is provided at a position above the presser roller 10 and is biased toward the other side of the center than the thread guide 18 to guide the upper thread so as to wind the presser roller 7. Outlet side upper thread guide 2
0 is provided at a substantially symmetrical position with respect to the center line of the entrance side needle thread guide 18 and the roller width, and the other configurations are the same as those shown in FIGS. 3 and 4.

In the present invention, as shown in FIG.
Since the two threads are sandwiched between the presser roller 10 and the presser roller 10 at a symmetrical position in the roller width direction, the feed roller 7
and the driven presser roller 10 are reliably maintained with a gap between them by the two needle threads so that they do not come into contact with each other.

Therefore, when the electromagnetic needle thread gripper 11 grips and fixes the needle thread and stops feeding out the needle thread against the driving force of the needle thread payout roller 7, the driven presser roller 10 remains in a constantly rotating state. Since it is maintained in a non-contact state with the placed feeding roller, it is not subjected to the driving force of the feeding roller and comes to a halt state without causing any relative movement with the upper thread, so that the upper thread and the driven presser roller are It is possible to prevent the presser roller from being worn out due to movement and friction with the upper thread. Note that the upper thread 14 is wrapped once around the presser roller 10 via the upper thread guide 19, but since the upper thread and the presser roller are always displaced in the same way, the upper thread and the presser roller are In this case, no relative displacement occurs and no frictional wear occurs.

[Effects of the Invention] According to the present invention, the thread feeding roller and the presser roller do not come into contact with each other when the needle thread is sandwiched between them, so when the needle thread supply is stopped, the presser roller and the thread feeding roller do not come into contact with each other when the needle thread supply is stopped. A relative movement is generated between the needle thread and the presser roller, which are rotated in contact with each other and are stopped, thereby preventing the inconvenience of wear on the presser roller made of rubber or the like.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of the present invention, and FIG. 2 is a diagram showing the relationship between the needle thread and the thread guide in the thread feeding roller and presser roller portion, (a) is a perspective view, and (b) is front view, 3rd
Figure 4 is a perspective view of a sewing machine, Figure 4 is an explanatory diagram showing a schematic configuration of a conventional device, and Figure 5 is a front view showing the relationship between the needle thread and thread guide of the thread pay-out roller and presser roller in the conventional example.
(a) shows a normal state, and (b) shows an abnormal state in which the rollers are in contact with each other. A... Sewing machine, B... Needle thread supply control device part, 1... Sewing needle, 2... Take-up lever, 3...
... Mitsutori spring, 4.5.6... Guide, 7...
...Needle thread pay-out roller, 8...Spring. 10... Presser roller, 11... Electromagnetic upper thread gripper, 12... Paste tension plate, 13...
Upper thread bobbin, 14... Upper thread, 18...
・Entrance side thread guide, I9... Upper thread guide, 20.
...Exit side thread guide.

Claims (1)

[Claims] The needle thread is gripped and sent out between a needle thread pay-out roller that rotates at a constant speed and a presser roller that follows this, and the needle thread is gripped by an electromagnetic needle thread gripper installed on the needle thread supply side. In a sewing machine configured to control the amount of needle thread being fed out, an inlet-side thread guide is provided on the inlet side of the needle thread-feeding roller so as to be biased to one side from the center of the roller width, and the thread guide is provided above the presser roller. An upper thread guide is provided that is biased toward the other side of the center to guide the upper thread so as to wind the presser roller, and the upper thread guide on the exit side is approximately symmetrical with respect to the center line of the width of the roller with the upper thread guide on the entrance side. An upper thread supply device characterized in that it is provided in a biased position.