JP2003144785A - Sewing machine provided with thread feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leak of oil and invasion of dust, secure safety for a worker, responde to high speed sewing, and facilitate assembling a needle bar by dispensing with a needle thread way at an upper end part of the needle bar and a movable thread feeding member protruded sideways to close a machine arm part. SOLUTION: A vertical reciprocation range of the needle bar 3 supported on a tip part 1A of the machine arm part 1 to be capable of vertically reciprocating through a drive mechanism such as a crank mechanism is set in such a range that an upper end part of the needle bar is not protruded above an upper wall part 1a of the tip part 1A of the machine arm part 1 when it is moved up to an upper dead point. At the upper wall part 1a of the tip part 1A of the machine arm part 1, a needle bar assembling opening 18 is formed in which a removable cap 19 is engaged to close it in normal usage of this sewing machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine with a thread take-up device applied to flat stitch sewing machines and double chain stitch sewing machines.
Specifically, a needle bar that reciprocates in the vertical direction via a drive mechanism that includes a drive spindle that is inserted and supported in the horizontal portion of the sewing machine arm, and at least one needle attached to the lower end of the needle bar. , A part including the looper that constitutes the sewing and is accommodated in the front end portion of the sewing machine bed, a thread tensioner that adjusts the tension of the needle thread and the looper thread supplied to the needle and the looper, and the thread tensioner and the stationary thread. The present invention relates to a sewing machine with a thread take-up device, which includes a thread take-up device that pays out a needle thread supplied to a needle via a needle thread path.

[0002]

2. Description of the Related Art In a conventional sewing machine with a thread take-up device of this type, a needle thread take-up member is provided on the outside of the front surface of the horizontal portion of the sewing machine arm in order to control the take-out of the needle thread necessary for maintaining a good sewing condition. A movable thread take-up device having the needle is provided, and a needle is provided at the upper end of a needle bar that penetrates through the upper wall of the tip of the sewing machine arm and projects upward, so as to reciprocate vertically in synchronization with the needle bar. A means for fixing the yarn path was also used (see, for example, Patent Document 1).

Further, the needle thread path is fixed to the upper end portion of the needle bar protruding upward from the sewing machine arm portion, and a vertical elongated hole is formed in the side wall portion of the sewing machine arm portion. The movable arm member with the needle thread control hole fixed to the middle portion is projected laterally, and the needle thread path and the movable arm member are reciprocally moved up and down in synchronization with the needle bar so that the thread winding function is exerted. There are also known products (for example, refer to Patent Document 2).

[0004]

[Patent Document 1] US Pat. No. 5,138,961 (FIG. 2)

[Patent Document 2] Japanese Patent Application Laid-Open No. 7-155488 (4th
(Page, Figure 1)

[0005]

In the case of the conventional sewing machine with a thread reeling device disclosed in the above-mentioned Patent Document 1, in order to fix the needle thread path to the upper end portion of the needle bar, the upper end portion of the sewing machine arm portion is fixed. There is a through hole on the wall where the needle bar protrudes upward, and there is a risk of oil leakage and dust intrusion through this through hole, and the needle bar upper end protruding above the tip of the sewing machine arm. Since the portion and the needle thread passage fixed to the portion reciprocate up and down at high speed in synchronization with the needle bar, it is not preferable in terms of safety for workers and the like. Moreover, since the needle bar is long and the weight of the needle thread passage fixed to the upper end is added to increase the weight of the entire needle bar, there is a limit to the increase in sewing speed.

Further, in the case of the conventional sewing machine with the thread reeling device disclosed in the above-mentioned Patent Document 2, since holes are formed in both the upper wall portion and the side wall portion of the sewing machine arm, the holes are formed through these holes. Problem of oil leakage and dust intrusion, safety problem due to needle thread path and / or movable arm member reciprocating up and down at high speed, and problem of difficulty in increasing speed due to increased weight of needle bar Was inevitable.

The present invention has been made in view of the above situation, and eliminates the use of the needle thread passage attached to the upper end portion of the needle bar and substantially seals the sewing machine arm portion to prevent oil leakage and dust intrusion. A sewing machine with a thread take-up device, which can improve safety for workers and can easily cope with high-speed sewing, and can easily assemble the needle bar into the sewing machine arm, facilitating overall assembly and manufacturing. Is intended to provide.

[0008]

In order to achieve the above-mentioned object, a sewing machine with a thread reeling device according to the present invention is provided with a drive mechanism including a drive main shaft which is inserted and supported in a horizontal portion of a sewing machine arm portion in a vertical direction. A needle bar that reciprocates, at least one needle attached to the lower end of the needle bar, a part of the sewing machine that includes the looper and is housed in the tip of the sewing machine bed, and the needle and looper respectively. A thread tension device that adjusts the tension of the supplied needle thread and looper thread, and a thread winding device that pays out the needle thread that is supplied to the needle through the thread tension device and the fixed needle thread path in accordance with the vertical reciprocating motion of the needle bar. A sewing machine with a thread take-up device comprising: a needle bar, the needle bar being supported by at least two upper and lower portions of a front end of the sewing machine arm through a bearing so as to be capable of reciprocating vertically, and the needle bar vertically reciprocating. The range of motion is set such that the upper end of the needle bar does not project upward from the upper wall portion of the tip of the sewing machine arm even when the needle bar moves up to the top dead center. On the upper wall portion of the, there is formed an opening for incorporating the needle bar into the sewing machine arm,
A cap that closes the opening when the sewing machine is normally used is detachably fitted to the assembling opening.

According to the present invention having the above-mentioned structure, the use of the needle thread passage which is used in the conventional sewing machine can be omitted, so that the through hole for projecting the upper end portion of the needle bar upward from the sewing machine arm is unnecessary. In addition, it is not necessary to form a hole in the side wall of the sewing machine arm in order to project the movable arm member with the needle thread control hole to the side, and the inside of the sewing machine arm is sealed to prevent oil leakage and dust intrusion. It is possible to reduce the number very much, and since the protrusions of the sewing machine arm upwards and sideways do not move up and down at high speed,
It is possible to secure safety for workers and the like.
Also, since the length of the needle bar is short and it is easy to reduce the weight,
Easy to speed up sewing.

In addition, since the opening for inserting the needle bar is formed in the upper wall portion of the tip end of the sewing machine arm so as to be opened and closed through the cap, the opening is made by removing the cap when assembling and manufacturing the sewing machine. By opening the needle bar, it is easy to assemble the needle bar into the sewing machine arm and facilitate the assembly and manufacturing of the entire sewing machine.However, when using a normal sewing machine, the cap is fitted to close the opening, which results in the oil leakage described above. It is possible to ensure the function of preventing intrusion of dust and the like.

While the present invention can be effectively applied to a flat stitch sewing machine, it can be effectively applied to a double chain stitch sewing machine as described in claim 2. is there.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway front view of a three-needle flat stitch sewing machine that is an example of a sewing machine to which the present invention is applied, FIG. 2 is a left side view, and FIG. 3 is a plan view of essential parts. 1 is a sewing machine arm part, and its tip part 1
A needle bar 3 is supported in A by a pair of upper and lower bearings 2 so as to be capable of reciprocating in the vertical direction, and a fabric pressing mechanism (which is well-known since it is adjacent to the needle bar 3 is described in detail. Is omitted). Three needles 8 are attached to the lower end of the needle bar 3 via a needle stopper 7, and the vertical reciprocating range of the needle bar 3 is even when the needle bar 3 moves up to a top dead center. The upper end portion is set in a range that does not project upward from the upper wall portion 1a of the tip end portion 1A of the sewing machine arm portion 1.

Further, the tip portion 1A of the sewing machine arm portion 1
An opening 18 for inserting the needle bar 3 into the sewing machine arm portion 1 is formed in the upper wall portion 1a, and this installation opening 18 has a screw for closing the opening 18 when a normal sewing machine is used. The cap 19 is detachably fitted so that the upper wall portion 1a of the tip end portion 1A of the sewing machine arm portion 1 is substantially closed during normal use of the sewing machine.

A drive spindle 4 for vertically reciprocating the needle bar 3 through a well-known crank mechanism or the like is inserted and supported inside the horizontal portion 1B of the sewing machine arm 1. 5 is a sewing machine bed portion, and the above-mentioned sewing machine arm portion 1
A part extending from the lower part of the base end part of the sewing machine arm 1 to the left side in parallel with the sewing machine arm part 1, and the tip end part of which constitutes sewing such as a needle plate, a pressing mechanism, a looper and a feeding mechanism ( The sewing machine bed portion 5 and the sewing machine arm portion 1 form a sewing machine frame body 6 of the flat stitch sewing machine.

Numeral 11 is a thread tension device, and three needle threads 9 and 1
The looper thread 12 of a book is sandwiched between a pair of thread tension discs (not shown), and the tension of each thread 9, 12 can be adjusted by rotating and operating the thread tension spring cap 11a. 13 is a stationary needle thread guide, which is the sewing machine arm 1
Is fixed to the front side surface of the needle thread 9 and regulates their movement path through the needle thread 9 led out from the thread tensioner 11. Two
Reference numeral 0 is an example of a thread reeling device, which is provided outside the front side of the sewing machine arm portion 1 of the sewing machine frame body 6.

As shown in FIG. 4, for example, the thread take-up device 20 has through holes 21a for the three needle threads 9 immediately after passing through the stationary needle thread path 13 at the upper end, and the stationary needle thread is provided. Three pipe-shaped needle threads that are movably fixed in the vertical direction via a screw 23 to a thread holder 22 that is fixed to the path 13 so that the positions of the through holes 21a can be adjusted individually in the vertical direction. The hole member 21 and the thread reel shaft 16 that is exposed to the outer side of the sewing machine arm portion 1 of the sewing machine frame body 6 in association with the drive spindle 4 are reciprocally rotated in the up-and-down direction via the needle thread guide 25. The movable needle thread take-up member 24, which is driven and rocked, is provided at the tip of the movable needle thread take-up member 24.
The intermediate portion of the three needle threads 9 that are bridged between the through hole 21a at the upper end of the needle thread and the needle thread guide member 17 fixed to the lower end of the tip portion 1A of the sewing machine arm 1. The needle thread reeling holes 24a and 24b are formed by shifting the position in the longitudinal direction of the movable needle thread reeling member 24. The movable needle thread guide member 24 is slidably fixed to the needle thread guide base 25 in the longitudinal direction through a long hole 26 and a fixture 27 formed on the base end side of the movable needle thread guide member 24. The thread tension of the three needle threads 9 can be properly set and changed even by fixing.

According to the three-needle flat stitch sewing machine having the above-mentioned structure, the three needle threads 9 are tension-adjusted by the thread tensioner 11 and then passed through the stationary needle thread path 13 to move. After the path is regulated, the three needle thread hole members 21 of the thread winding device 20 are passed through the through holes 21a, the needle thread winding holes 24a and 24b at the tip of the movable needle thread winding member 24, and the needle thread guide member 17 to form three yarns. Will be supplied to the needle 8. At this time, the three needle thread hole members 21 are separately moved and fixed in the vertical direction to adjust the vertical positions of the through holes 21a at their upper ends, and the movable needle thread winding member 2
By slidingly fixing 4 in the longitudinal direction via the long hole 26 and the fixture 27, the thread tension of each of the three needle threads 9 can be individually and appropriately set and changed.

In this state, when the needle bar 3 is reciprocally driven up and down, the movable needle thread take-up member 24 of the thread take-up device 20 reciprocally swings up and down in synchronization with this.
The feeding of each needle thread 9 is appropriately controlled without slackening or applying excessive tension to the needle thread 9. Here, the needle bar 3
Is only reciprocally driven up and down within a set range in the tip end portion 1A of the sewing machine arm portion 1, and the upper end of the needle bar 3 projects upward from the sewing machine arm portion 1 even in the ascending movement state to the top dead center. Not a composition. Therefore, when a normal sewing machine is used, a cap 19 is fitted into the assembling opening 18 to close the upper wall portion 1a of the tip end portion 1A of the sewing machine arm portion 1 to substantially seal the sewing machine arm portion 1. It is possible to maintain the configuration, prevent oil leakage and intrusion of dust, and prevent the protrusions from moving up and down at a high speed on the upper part of the sewing machine arm portion 1, thus ensuring safety for workers and the like. Further, since the length of the needle bar 3 is short and the weight is light, it is possible to sufficiently cope with speeding up of sewing.

Further, when assembling and manufacturing the sewing machine, the needle bar 3 can be easily assembled at a predetermined position in the sewing machine arm portion 1 through the opening 18 by removing the cap 19 and opening the opening 18. Is. In addition, the three needle thread hole members 2 that constitute the thread winding device 20.
1 is moved vertically and fixed appropriately to adjust the upper and lower positions of the through holes 21a at their upper ends, and the movable needle thread reeling member 24 is slidably fixed in the longitudinal direction via the elongated hole 26 and the fixture 27. Thus, it is possible to arbitrarily change the thread tension for each of the three needle threads 9 and adjust so that a predetermined thread reeling function can always be properly exerted.

In the above-described embodiment, the case of being applied to the multi-needle flat stitch sewing machine has been described, but it goes without saying that it may be applied to a double chain stitch sewing machine.

[0022]

As described above, according to the present invention, the movable arm member that is fixed to the needle thread path at the upper end of the needle bar and that is fixed to the middle portion of the needle bar, which is equipped in the conventional sewing machine, and projects laterally. By omitting the use of, it is not necessary to form a hole in the upper wall portion or side wall portion of the sewing machine arm, and the inside of the sewing machine arm can be sealed to prevent oil leakage and dust intrusion. It is possible to secure the safety for the operator without the protrusions moving up and down around the sewing machine arm at a high speed and sideways, and to shorten the length of the needle bar, and Since it is easy to reduce the weight, it is possible to easily cope with higher sewing speeds.

In addition, since the needle bar assembling opening that can be opened and closed via the cap is formed in the upper wall portion of the tip end of the sewing machine arm, the opening opened by removing the cap during assembly and manufacturing of the sewing machine. The needle bar can be easily incorporated into the sewing machine arm through the through-hole to facilitate the assembly and production of the entire sewing machine and the maintenance and inspection, but when using a normal sewing machine, the cap is fitted to close the opening. As a result, it is possible to ensure the above-described function of preventing oil leakage and dust intrusion.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a three-needle flat stitch sewing machine with a thread reeling device, which is an example of a sewing machine to which the present invention is applied.

FIG. 2 is a left side view of the same three-needle flat stitch machine with the front plate portion removed.

FIG. 3 is a plan view of an essential part of the above-described three-needle flat stitch sewing machine.

FIG. 4 is an enlarged front view showing an example of a yarn winding device.

[Explanation of symbols]

1 sewing machine arm 1A Sewing machine arm tip Horizontal part of 1B sewing machine arm 1a Upper wall portion of the tip of the sewing machine arm 2 bearings 3 needle bar 4 Drive spindle 5 Sewing machine bed section 8 needles 9 needle thread 11 Thread tension device 13 Stationary needle thread path 18 Needle bar insertion opening 19 cap 20 Threading device

Claims (2)

[Claims] 1. A needle bar that reciprocates in the vertical direction via a drive mechanism including a drive spindle that is inserted and supported in the horizontal portion of the sewing machine arm, and at least one needle bar attached to the lower end of the needle bar. A needle, a part that includes a looper and constitutes the sewing machine accommodated in the tip of the sewing machine bed, a thread tensioner that adjusts the tension of the needle thread and the looper thread supplied to the needle and the looper, and the needle bar. A sewing machine with a thread take-up device, comprising a thread tension device and a thread take-up device for paying out a needle thread supplied to a needle through a fixed needle thread path in accordance with a vertical reciprocating motion, wherein the needle bar has a tip portion of a sewing machine arm. Of the sewing machine is supported at least at two upper and lower positions via a bearing so that the needle bar can move up and down in the vertical reciprocating range even when the needle bar moves up to the top dead center. arm Is set so that it does not project upward from the upper wall portion of the tip of the sewing machine arm, and an opening is formed in the upper wall portion of the tip of the sewing machine arm to install the needle bar into the sewing machine arm. A sewing machine with a thread reeling device, wherein a cap for closing the opening is detachably fitted to the opening when the sewing machine is used normally. 2. The sewing machine with a thread reeling device according to claim 1, wherein the sewing machine to be applied is a flat stitch sewing machine or a double chain stitch sewing machine.