JP2006334264A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewing machine, wherein disturbance of a needle thread during sewing is suppressed. <P>SOLUTION: The sewing machine 1 is provided with: a balance 3 whose one end is provided so as to project outward from a sewing machine arm 2, and which has a thread put-through part 31 for putting a needle thread through formed at the one end to put out the needle thread T from a thread supply source by the vertical movement of the thread put-through part 31; a first thread guiding part 6 arranged at the jaw 2a of the sewing machine arm 2 for guiding the needle thread T put through the thread put-through part 31; a second thread guiding part 7 arranged at a needle bar 12 holding a needle 11 for guiding the needle thread T guided by the first thread guiding part 6 to the needle hole 11 of the needle 11; and a third thread guiding part 8 which guides the needle thread T continuously from the thread put-through part 31 when thread put-through part 31 is at a bottom dead point, through to the first thread guiding part 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sewing machine provided with a thread guide in an upper thread path between a balance and a sewing needle.

The sewing machine is provided with a sewing machine arm that incorporates a sewing motor serving as a driving source and a drive transmission mechanism that transmits the driving of the sewing machine motor to a needle bar and a presser. Further, the sewing machine is provided with a balance that feeds the upper thread from the thread supply source by moving up and down, and the scale is moved up and down by a drive transmission mechanism.
As shown in FIG. 3, the sewing machine arm 101 has a groove 103 that forms a movement path when the balance 102 moves up and down in the vertical direction of the sewing machine arm 101, and one end of the balance 102 is a drive transmission mechanism ( The other end 102 a is provided so as to protrude from the groove 103 to the outside of the sewing machine arm 101. Then, the upper thread 104 is fed from the thread supply source (not shown) by inserting the upper thread 104 through the other end 102a of the balance 102 and moving the balance 102 up and down.

  The upper thread 104 inserted into the other end 102 a of the balance 102 is guided by an arm thread guide 105 provided on the surface of the sewing machine arm 101, and then, on a needle bar thread guide 106 provided on the jaw part 101 a of the sewing machine arm 101. Then, it is guided by a needle bar thread hook 108 provided on the needle bar 107 and is inserted through the needle hole 109 a of the sewing needle 109. These are provided at predetermined intervals, and by applying an appropriate tension to the upper thread 104, it is possible to suppress loosening and rampage of the upper thread 104 during sewing.

In addition, as a thread guide to prevent the upper thread from becoming unfamiliar during sewing, a clamping part is provided to clamp the upper thread between the balance and the sewing needle. When the upper thread loop is captured by the rotary hook, the upper thread is There is disclosed a thread guide that clamps and releases an upper thread when supplying an upper thread and tightening the thread (see, for example, Patent Document 1).
JP-A-3-218794

  However, since all of the conventional yarn guides hold the upper yarn with a point, there is a problem that the upper yarn between the yarn guides is likely to be violated. Therefore, it is conceivable that the upper thread is pressed firmly locally by the thread guide. However, the force that causes the upper thread in the thread guide to run away escapes to the upper thread between the thread guides. There was a problem that the yarn would go wild.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sewing machine that can prevent the upper thread from moving up and down during sewing.

  In order to solve the above problems, the invention according to claim 1 is provided with a thread insertion portion in which one end of the sewing machine is provided so as to protrude outward from the sewing machine arm, and an upper thread is inserted into one end of the sewing machine. A balance formed to feed the upper thread from the thread supply source by the vertical movement of the thread insertion part, and a first thread guide that is provided on the jaw part of the sewing machine arm and guides the upper thread inserted into the thread insertion part. And a second thread guide part that is provided on a needle bar that holds the sewing needle and guides the upper thread guided by the thread guide part to the needle hole of the sewing needle, and the thread insertion part has a bottom dead center. And a third yarn guide portion for continuously guiding the upper yarn from the yarn insertion portion to the first yarn guide portion.

According to the first aspect of the present invention, since the balance moves up and down as the sewing needle moves up and down during sewing, the upper thread between the thread insertion portion of the balance and the needle hole of the sewing needle, particularly the thread insertion portion and the The upper yarn between the one yarn guide portion is likely to be violated. Here, the third thread guide part continuously guides the upper thread from the thread insertion part to the first thread guide part when the thread insertion part is at the bottom dead center. When the yarn insertion portion descends to the bottom dead center and feeds the yarn from the yarn supply source, the upper yarn between the yarn insertion portion and the first yarn guide portion is guided over the entire area.
Thereby, since the area | region where an upper thread is guided between the thread insertion part and the needle hole of a sewing needle increases significantly, the uprising of an upper thread can be suppressed. In addition, since the state of the upper thread between the thread insertion part and the first thread guide part during sewing has the greatest influence on the quality of sewing, the third thread guide part is provided to improve the sewing quality. Can be made.

  According to a second aspect of the present invention, in the sewing machine according to the first aspect, the third yarn guide portion is provided on a surface of the sewing machine arm, and the yarn when the yarn insertion portion is at a bottom dead center. It has a tubular member that can be inserted through the upper thread with the height of the insertion part as one end and the upper part of the first thread guide part as the other end.

According to the second aspect of the present invention, since the upper thread is restricted from moving in all directions by inserting the upper thread through the tubular member, the upper thread can be reliably prevented from being violated.
Further, since the upper thread can only be removed from the tubular member by moving in the longitudinal direction of the upper thread, it can exhibit a sufficient function as a thread guide that prevents the upper thread from coming off.

  According to a third aspect of the present invention, in the sewing machine according to the second aspect, the tubular member is formed along the surface of the sewing machine arm on which the tubular member is provided.

  According to the invention described in claim 3, since the contact area of the tubular member to the sewing machine arm is increased, the attachment to the sewing machine arm is facilitated. Further, since no gap is formed between the tubular member and the sewing machine arm when the tubular member is attached, the space required for attaching the tubular member can be minimized. Moreover, since the tubular member seems to be integrated with the sewing machine arm when attached, the aesthetics when attached can be improved.

  According to a fourth aspect of the present invention, in the sewing machine according to the first aspect, the third yarn guide portion is configured so that the first yarn insertion portion is at a height from the height of the yarn insertion portion when the yarn insertion portion is at a bottom dead center. It has a through-hole which penetrates the inside of the sewing machine arm over the upper portion of the yarn guide portion and through which the upper thread can be inserted.

According to the invention described in claim 4, by forming the through hole, the height of the thread insertion part when the thread insertion part is at the bottom dead center can be reduced even if a tubular member is not provided. Thus, the upper thread can be continuously guided over the upper part of the first thread guide portion.
As a result, there is no need to provide separate parts, and the area where the upper thread is guided between the thread insertion part and the needle hole of the sewing needle is greatly increased without increasing the number of parts, thus preventing the upper thread from being ramped up. be able to.

  According to the first aspect of the present invention, since the region where the upper thread is guided between the thread insertion portion and the needle hole of the sewing needle is greatly increased, it is possible to suppress the rampage of the upper thread. In addition, since the state of the upper thread between the thread insertion part and the first thread guide part during sewing has the greatest influence on the quality of sewing, the third thread guide part is provided to improve the sewing quality. Can be made.

According to the second aspect of the present invention, since the upper thread is restricted from moving in all directions by inserting the upper thread through the tubular member, the upper thread can be reliably prevented from being violated.
Further, since the upper thread can only be removed from the tubular member by moving in the longitudinal direction of the upper thread, it can exhibit a sufficient function as a thread guide that prevents the upper thread from coming off.

  According to the invention described in claim 3, since the contact area of the tubular member to the sewing machine arm is increased, the attachment to the sewing machine arm is facilitated. Further, since no gap is formed between the tubular member and the sewing machine arm when the tubular member is attached, the space required for attaching the tubular member can be minimized. Moreover, since the tubular member seems to be integrated with the sewing machine arm when attached, the aesthetics when attached can be improved.

  According to the fourth aspect of the present invention, it is not necessary to separately provide parts, and the area where the upper thread is guided between the thread insertion portion and the needle hole of the sewing needle is greatly increased without increasing the number of parts. Therefore, the upper thread rampage can be suppressed.

Hereinafter, the best mode of a sewing machine according to the present invention will be described in detail with reference to the drawings.
<Configuration of sewing machine>
As shown in FIG. 1, the sewing machine 1 is provided with a sewing machine arm 2 formed in a hollow shape. Inside the sewing machine arm 2 are housed a sewing machine motor (not shown) as a driving source, a driving mechanism (not shown) of the balance 3 that moves up and down on the right side of the sewing machine arm 2.

A through groove 21 is formed in the sewing machine arm 2 so as to extend along the vertical direction of the sewing machine arm 2 from the upper side to the upper side of the right side with respect to the front end side surface portion. Specifically, the through groove 21 is formed such that the balance 3 can be moved up and down along the movement path of the balance 3.
The balance 3 is formed in a substantially rod shape, and is provided so that one end protrudes outward from the through groove 21, and a thread insertion part 31 through which the upper thread T is inserted is formed at one end thereof, and the thread insertion part The upper thread T is fed out from a thread supply source (not shown) by the vertical movement of 31. The other end of the balance 3 is connected to a drive mechanism provided in the sewing machine arm 2, and the thread insertion portion 31 of the balance 3 is moved up and down in synchronization with the vertical movement of the sewing needle 11 as the sewing machine motor is driven. Can be done. That is, by raising the balance 3, the sewing needle 11 that has been loop-formed by the hook mechanism below the needle plate is pulled upward, the loop is eliminated, and the upper thread T is tensioned to form a seam.

On the surface of the sewing machine arm 2, a first thread tension device 4 is provided at the upper part of the right side with respect to the front end side of the sewing machine arm 2, and a second thread tension device 5 is also provided at the lower part of the right side surface. Yes.
The first thread tension device 4 and the second thread tension device 5 include a pair of thread tension plates, a spring that presses each other, and an adjustment screw that adjusts the pressing force of the springs. The upper thread T is clamped by passing the upper thread T between the thread tension plates, and tension is applied to the upper thread T fed from the thread supply source.

  Further, on the surface of the sewing machine arm 2, there are provided a first thread guide part 6 provided on the jaw part 2 a of the sewing machine arm 2 for guiding the upper thread T inserted into the thread insertion part 31 of the balance 3, and a sewing needle 11. A second thread guide section 7 for guiding the upper thread T guided by the first thread guide section 6 to the needle hole 11a of the sewing needle 11 and a thread insertion section 31 on the lower side. A tubular member 8 as a third yarn guide portion that continuously guides the upper yarn T from the yarn insertion portion 31 at the dead center to the first yarn guide portion 6, a second thread tension device 5, and A fourth thread guide portion 9 for guiding the upper thread T between the balances 3 and a fifth thread guide portion 10 for guiding the upper thread T between the fourth thread guide portions 9 and the balance 3 are provided. It has been.

The first thread guide portion 6 is provided at a substantially lower end of the jaw portion 2 a of the sewing machine arm 2, is formed in a U shape, and the upper thread T guided to the first thread guide portion 6 by the tubular member 8 is used. It guides to the 2nd thread guide part 7. FIG.
The second thread guide portion 7 is formed in a cylindrical shape and is attached to the lower end of the needle bar 12, and the upper thread T guided to the second thread guide portion 7 by the first thread guide portion 6. The guide is guided to the needle hole 11 a of the sewing needle 11.

The tubular member 8 is provided on the surface of the sewing machine arm 2 and has a circular cross section. The tubular member 8 has a portion near the yarn insertion portion 31 when the yarn insertion portion 31 is at the bottom dead center. The vicinity of the guide portion 6 is the other end, and the upper thread T can be inserted. The tubular member 8 is formed along the surface of the sewing machine arm 2 on which the tubular member 8 is provided.
As a result, the upper thread T inserted into the thread insertion portion 31 that has reached the bottom dead center is immediately drawn into the inside from one end of the tubular member 8, and the upper thread T coming out from the other end of the tubular member 8 is immediately It is configured to be guided by the first yarn guide portion 6. Further, even if the thread insertion part 31 is at the top dead center, the upper thread T inserted through the thread insertion part 31 is drawn into the tubular member 8 in the vicinity of the bottom dead center of the thread insertion part 31, and is shown in FIG. As described above, the movement in the horizontal direction of the approximately half of the upper thread T extending from the thread insertion part 31 to the first thread guide part 6 is restricted by the tubular member 8.
It is preferable that the inner diameter of the tubular member 8 is sufficiently larger than the cross-section of the upper thread T so that the upper thread T can be easily inserted, and is within a range where the upper thread T is not greatly exposed.

The fourth thread guide 9 guides the upper thread T in a direction in which the upper thread T stretched over the thread take-up spring 51 provided in the second thread tension device 5 receives the elasticity of the thread take-up spring 51. .
The fifth yarn guide portion 10 is bent and formed in a U shape. The upper yarn T is inserted inside the fifth yarn guide portion 10 to guide the upper yarn T and prevent the upper yarn T from being loosened.

  That is, the upper thread T fed from the thread supply source is given tension to the first thread tension device 4 and the second thread tension device 5, and the upper thread T ejected from the second thread tension device 5 is The upper thread T guided by the fourth thread guide section 9 and guided by the fourth thread guide section 9 is guided by the fifth thread guide section 10 and guided by the fifth thread guide section 10. T is inserted into the thread insertion part 31, the upper thread T inserted into the thread insertion part 31 is inserted into the tubular member 8, and the upper thread T inserted into the tubular member 8 is guided to the first thread guide part 6. The upper thread T guided by the first thread guide section 6 is guided by the second thread guide section 7, and the upper thread T guided by the second thread guide section 7 enters the needle hole 11 a of the sewing needle 11. It is inserted.

<Effects of sewing machine>
According to the sewing machine 1 of the embodiment, when sewing is started, the needle bar 12 is moved up and down by driving the sewing machine motor, and the sewing needle 11 is also moved up and down by the vertical movement of the needle bar 12. The thread insertion part 31 of the balance 3 also moves up and down. The thread insertion part 31 moves up and down along the through-groove 21, and the upper thread T is also swung in the vertical direction by the vertical movement of the thread insertion part 31, so that the thread insertion part 31 of the balance 3 and the needle hole of the sewing needle 11 The upper thread T between 11a, in particular, the upper thread T between the thread insertion part 31 and the first thread guide part 6, is likely to run out because of the longest interval.
Here, the tubular member 8 is provided such that one end is positioned at the height of the thread insertion portion 31 when the thread insertion portion 31 is at the bottom dead center and the other end is positioned at the first thread guide portion 6. Therefore, when the thread insertion portion 31 of the balance 3 is lowered to the bottom dead center as the sewing needle 11 is lowered and the upper thread T is fed from the thread supply source, the upper thread T passing through the thread insertion portion 31 is immediately As soon as it enters the tubular member 8 and travels through the tubular member 8 and exits from the jaw 2 a of the sewing machine arm 2, it is guided to the first thread guide portion 6.

As a result, the tubular member 8 guides the upper thread T between the thread insertion part 31 and the first thread guide part 6 over the entire area, and therefore the upper thread between the thread insertion part 31 and the needle hole 11 a of the sewing needle 11. The area where T is guided is greatly increased, and the upper thread T can be prevented from being ramped up. Further, since the state of the upper thread T between the thread insertion part 31 and the first thread guide part 6 at the time of sewing has the greatest influence on the quality of sewing, the quality of sewing is improved by providing the tubular member 8. Can be made.
Further, by inserting the upper thread T into the tubular member 8, the upper thread T is restricted from being violated in all directions, so that the upper thread T can be reliably prevented from being violated.
Further, since the upper thread T can only be removed from the tubular member 8 by moving in the longitudinal direction of the upper thread T, a sufficient function can be exhibited as a thread guide that does not allow the upper thread T to be removed. .
Further, since the tubular member 8 is formed along the surface of the sewing machine arm 2, the contact area of the tubular member 8 to the sewing machine arm 2 is increased, so that the attachment to the sewing machine arm 2 is facilitated. In addition, since a gap is not formed between the tubular member 8 and the sewing machine arm 2 when the tubular member 8 is attached, a space necessary for attaching the tubular member 8 can be minimized. Moreover, since it seems that the tubular member 8 is integrated with the sewing machine arm 2 when attached, the aesthetics when attached can be improved.

<Modification>
The present invention is not limited to the above embodiment.
For example, as a sewing machine 1A of a modified example, as shown in FIG. 2, the position of the sewing machine frame 2 provided with the tubular member 8 in FIG. 1, that is, the thread insertion part 31 when the thread insertion part 31 is at the bottom dead center. Instead of the tubular member 8, a through hole 8 </ b> A through which the upper thread T can be inserted may be formed over the first yarn guide portion 6 instead of the tubular member 8.

By adopting such a configuration, as described above, even if the tubular member 8 is not provided on the surface of the sewing machine arm 2, the first thread insertion portion 31 from the thread insertion portion 31 when the yarn insertion portion 31 is at the bottom dead center is used. The upper thread T can be continuously guided over the thread guide portion 6.
Accordingly, there is no need to provide additional parts, and the area where the upper thread T is guided between the thread insertion portion 31 and the needle hole 11a of the sewing needle 11 is greatly increased without increasing the number of parts. T rampage can be suppressed.

  Further, the first yarn guide portion 6 and the other end of the third yarn guide portion (tubular member 8, through hole 8A) may be provided integrally. Thereby, the number of parts can be reduced while maintaining the effect of the third yarn guide portion.

It is a perspective view of a sewing machine when a tubular member is used as a thread guide. It is a perspective view of a sewing machine when using a through hole as a thread guide. It is a perspective view of the sewing machine which shows the thread | yarn guide in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sewing machine 1A Sewing machine 2 Sewing machine arm 2a Jaw part 3 Balance 6 First thread guide part 7 Second thread guide part 8 Tubular member (third thread guide part)
8A Through hole (third thread guide)
11 Sewing needle 11a Needle hole 12 Needle bar 31 Thread insertion part T Upper thread

Claims (4)

A balance is provided so that one end protrudes outward from the sewing machine arm, and a thread insertion portion through which the upper thread is inserted is formed at one end thereof, and the upper thread is fed from the thread supply source by the vertical movement of the thread insertion portion. When,
A first thread guide provided on the jaw of the sewing machine arm for guiding the upper thread inserted through the thread insertion section;
A second thread guide provided on a needle bar for holding a sewing needle and guiding the upper thread guided by the first thread guide to the needle hole of the sewing needle;
A third yarn guide portion that continuously guides the upper yarn from the yarn insertion portion when the yarn insertion portion is at the bottom dead center to the first yarn guide portion;
A sewing machine comprising: The third thread guide portion is
The height of the thread insertion portion provided on the surface of the sewing machine arm when the thread insertion portion is at the bottom dead center is one end, the upper portion of the first thread guide portion is the other end, and the upper thread is The sewing machine according to claim 1, further comprising a tubular member that can be inserted.   The sewing machine according to claim 2, wherein the tubular member is formed along the surface of the sewing machine arm on which the tubular member is provided. The third thread guide portion is
A through-hole through which the upper thread can be inserted through the sewing machine arm from the height of the thread insertion section when the thread insertion section is at the bottom dead center to the top of the first thread guide section; The sewing machine according to claim 1, wherein:

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