JPH10127968A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change timing to vertically move a fabric presser in respect to a needlebar corresponding to a sewing object. SOLUTION: This sewing machine is provided with a needlebar 2 supported by a supporter so as to freely move up and down and mounting a sewing needle 10 at its lower end and a fabric presser 12 relatively supported to the needlebar 2 so as to freely move up and down, energized downward to the needlebar 2 by a fabric presser spring 5 and regulated in movement while being abutted to a lock member 6 added to the needlebar 2 and before piercing the sewing object with the sewing needle 10, a pressing part 14c of the fabric presser 12 presses the sewing object so that the sewing object can be pressed by the fabric presser 12 continuously until the sewing needle gets out of the sewing object at least. In this case, the setting of a correspondent distance between the lower end of the sewing needle 10 and the pressing part 14c on the fabric presser 12 can be changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine capable of applying lockstitches such as embroidery stitches and decorative stitches to a material to be sewn. The improvement of the structure of

[0002]

2. Description of the Related Art A conventional presser body in a lockstitch sewing machine will be described with reference to FIGS. A needle bar 42 is vertically supported on a support 40 of the sewing machine head so as to be vertically movable, and a cloth presser 44 is mounted below the needle bar 42. This cloth presser body 44
For example, by performing an integral bending process on an elongated plate material, a substantially U-shaped main body portion and a leg portion 44c extending further downward therefrom are formed. The substantially U-shaped main body portion includes upper support pieces 4 which are spaced apart in parallel as shown in the figure.
4a and a lower support piece 44b.
And the needle bar 42 through a through hole formed in the lower support piece 44b.
Are relatively slidably inserted. The leg 4
4c is downwardly coupled to the lower support piece 44b, and a holding portion 44d is formed at the lower end of the leg portion 44c.

The needle bar 42 is slidably inserted into and supported by an upper support portion 40a and a lower support portion 40b projecting horizontally and parallel to the inside of the support body 40, and the upper end of the needle bar 42 and the Needle bar holding spring 46 elastically interposed between upper support portion 40a
It is always urged upward by the elastic expansion force of the (compression coil spring). A stopper 48 is fixed to a substantially central portion of the needle bar 42, and the stopper 48 comes into contact with the upper support portion 40a, whereby the needle bar 42 is held at the top dead center position shown in FIG. A needle bar clamp 50 is fixed to the needle bar 42 slightly below the stopper 48, and a cloth presser spring 52 elastically interposed between the needle bar clamp 50 and the upper support piece 44a of the cloth presser 44. (Compression coil spring)
The presser body 44 is always urged downward, and its lower support piece 44b is in contact with a needle holder 54 fixed to the lower end of the needle bar 42 via a buffer ring 56. The sewing needle 58 is fixed to the lower end of the needle bar 42 via the needle clamp 54 so as not to be detached.

The needle bar 42 is reciprocated up and down by a needle bar drive mechanism (not shown) with an engagement pin 50a protruding horizontally from the needle bar holder 50. As the needle bar 42 descends, the presser foot 44 descends. As shown in FIG. 10, the lower support portion 40b, which protrudes horizontally inside the supporter 40, has a lower support piece. By the contact of 44b via the cushion 60, the presser body 44 is held at the bottom dead center position, and the subsequent downward movement is regulated. FIG. 10 shows a state at the moment when the presser foot 44 reaches the bottom dead center position. When the needle bar 42 further continues to descend in this state, the sewing needle 58 passes through the through hole 62 a of the needle plate 62 and reaches the bottom dead center. Next, when the needle bar 42 starts rising upward and reaches the position shown in FIG.
The lower support portion 44b is pushed up by the needle holder 54, whereby the presser body 44 starts to move up together with the needle bar 42.

[0005]

In the above-described apparatus according to the prior art, each time the needle bar 42 reciprocates up and down one time, the cloth presser 44 also reciprocates, whereby the cloth or the like placed on the needle plate 62 is moved. The sewing object 64 is pressed and released each time one stitch is sewn. That is, at the time of needle insertion, the pressing portion 44d of the cloth pressing body 44 presses the cloth 64 before the sewing needle 58 is pierced through the cloth, and at the time of needle removal, at least until the lower end of the sewing needle 58 comes out of the cloth. The pressing portion 44d of the cloth pressing body 44 presses the cloth 64.

When the sewing object 64 has a high needle insertion resistance, for example, leather, and thus a high needle removal resistance, even after the lower end of the sewing needle 58 comes out of the leather 64, the cloth presser body can be used. 44, it may be possible to perform good sewing if the pressing and holding is performed for a while. Therefore,
As one method for setting the motion relationship between the presser foot 44 and the sewing needle 58 for the leather sewing, the leg 4 of the presser foot 44 is used.
It is proposed to set 4c a little longer. However, if the length of the leg portion 44c is increased, the lower dead center position is lowered by that amount, and the pressing portion 44d collides with the needle plate 62. It is conceivable to increase the height of the object.

In this way, when the pressing portion 44d of the cloth pressing body 44 reaches the bottom dead center, the lower end of the sewing needle 58 is still at a position separated above the pressing portion 44d. This is not corrected, and even after the lower end of the sewing needle 58 comes off from the sewing object 64 at the time of needle removal, the pressing portion 44d keeps holding the sewing object 64 for a while. This means that sewing can be properly performed on a sewing object 64 such as leather having a large needle removal resistance without thread breakage or the like.

However, in the method described above, when the needle bar 42 is at the top dead center position as shown in FIG.
The distance between the needle and the upper surface of the needle plate 62 is reduced.
Therefore, when an embroidery frame is used like an embroidery sewing machine, depending on the thickness of the embroidery frame, the pressing portion 44
d may interfere. In this case, replacement of the presser foot body 44 and other operations are required, and there is a problem that it takes much time to change the setup.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has been proposed in order to solve the above-mentioned problems in a suitable manner. It aims to provide a sewing machine.

[0010]

SUMMARY OF THE INVENTION In order to overcome the above-mentioned problems and appropriately achieve the intended object, the present invention provides a needle bar having a sewing needle mounted at a lower end thereof, which is supported to be vertically movable with respect to a support. The needle bar is supported so as to be movable up and down relatively to the needle bar, is urged downward with respect to the needle bar by a cloth presser spring, and comes into contact with a locking member attached to the needle bar to restrict movement. Before the sewing needle is pierced by the sewing object, the pressing portion of the cloth pressing body presses the sewing object, at least until the sewing needle comes out of the sewing object. In a sewing machine in which the pressing of the workpiece by the cloth presser body is continued, a lower end of the sewing needle;
It is characterized in that the setting of the distance corresponding to the presser portion of the cloth presser can be changed.

In this case, the locking member is fixed to the needle bar above the presser foot spring, and an engaging bar whose upper end is engageable with the locking member is attached to the presser body. It is preferable that a contact member capable of changing an engagement position with the locking member is attached to an upper end portion of the engagement bar. It is preferable that the locking member is attached to the lower end of the needle bar so that the fixing position can be changed. Further, it is preferable that the cloth presser body that can move up and down can adjust the bottom dead center position.

[0012]

By changing the setting of the corresponding distance between the lower end of the sewing needle and the presser portion of the cloth presser, the release timing of pressing the sewing object by the presser of the cloth presser relative to the timing of removing the sewing needle is changed. It can be changed, and the longer the setting of the corresponding distance, the longer the pressing time by the pressing section after the needle is removed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a sewing machine according to the present invention will be described.
A preferred embodiment in which this is applied to a multi-needle embroidery sewing machine will be described below with reference to the accompanying drawings. 1 to 4
Is a sewing machine head fixed to the front of the support frame
2 shows a supporting case 1 provided in each of them (not shown).
A total of six needle bars 2 are supported on this support case 1 so as to be vertically movable at predetermined intervals. A balance 3 (a total of six) arranged corresponding to each needle bar 2 is vertically moved by a balance shaft 3a. It is possible to swing to. The support case 1 is slidable in the horizontal direction (row direction of the needle bars 2) on the front surface of a sewing head (not shown), and a desired needle bar 2 and a corresponding balance 3 are selected by the sliding operation. And the selected needle bar 2
Only the combination of the balance 3 and the balance 3 is driven by a drive mechanism (not shown) of the sewing head.

An upper support 1a and a lower support 1b are formed inside the support frame 1 in a vertically parallel relationship.
Each needle bar 2 is slidably inserted and supported in each sliding hole of the upper support portion 1a and the lower support portion 1b. The sewing needle 10 inserted through the lower end of the needle bar 2 is detachably attached by a set screw 11 of a needle holder 8 provided at the lower end of the needle bar 2.
The needle holder 8 is provided with a thread guide 9.

Each needle bar 2 has an upper end portion and the upper support portion 1.
a needle bar holding spring (compression coil spring) 5 elastically interposed between the needle bar 2 and the locking member which is always urged upward by the elastic expansion force and is fixed to the center of the needle bar 2 in the vertical direction. 6 is held at the top dead center position as shown in FIG. 2 by contacting the cushion member 4 provided on the lower surface of the upper support portion 1a. A needle bar clamp 7 is fixed to the needle bar 2 directly below the locking member 6, and an engagement pin 7a protruding horizontally on the rear surface of the needle bar clamp 7 and a vertical drive member of the drive mechanism.
The needle bar 2 is reciprocally driven up and down by engagement with a needle bar (not shown). In this case, the engaging pin 7 of the needle bar 2 selected by the sliding operation of the support case 1 is used.
Only a engages with the vertical drive member. A needle plate 11 having an insertion hole 11a is horizontally arranged below the support case 1, and a sewing needle 10 of a selected needle bar 2 is inserted into the insertion hole 1a.
1a.

A cloth presser body 12 is mounted below each of the needle bars 2. The cloth presser body 12 is provided with a movable element 13 slidably mounted on the needle bar 2 and a movable element 13. And a main body 14 attached to the main body. The main body 14, as shown in FIG.
For example, it is formed by integrally bending an elongated metal plate, the upper end is connected to the mover 13 by a screw 16, and the support piece 14a at the intermediate part is slidably inserted outside the needle bar 2. ing. A leg 14b hangs down from the support piece 14a, and a holding portion 14c is formed at a lower end of the leg 14b. FIG. 2 shows a fitting portion between the support piece 14a and the needle bar 2.
The bush 15 is fitted as shown in FIG. In addition, a vertically long slot 39 is provided in the connection portion by the screw 16 at the upper end.
(See FIG. 5), the vertical mounting position with respect to the moving element 13 can be adjusted. Also, the rising portion from the support piece 14a in the main body 14 is
The support case 1 is slidably fitted in an engagement groove 17 formed in the support case 1, thereby preventing the cloth pressing body 12 from rotating.

At the upper end of the main body 14 of the cloth presser body 12, a lower end of an engaging bar 18 made of a round bar is fixed by an appropriate means (for example, brazing) and extends parallel to the needle bar 2. I have. The upper end of the engagement bar 18 is engaged with the locking member 6. That is, an insertion hole 6a is formed in the locking member 6, and the upper end of the engagement bar 18 is slidably inserted into the insertion hole 6a. A male screw is formed at the upper end of the engagement bar 18, and two nuts 20, 21 are screwed into a portion projecting upward from the insertion hole 6a.
The lower nut 20 functions as a contact member, and the upper nut 21 functions as a lock.

A presser spring 22 composed of a compression coil spring is provided between the movable element 13 of the presser body 12 and the needle bar holder 7.
Are elastically interposed, and the elastic force of the elastic
Is always urged downward with respect to the needle bar 2. The movement of the cloth presser body 12 is regulated by the lower nut (contact member) 20 provided on the engagement bar 18 abutting on the locking member 6. Here the lock nut 21
Is loosened and the position of the lower nut (contact member) 20 is adjusted, so that the vertical position of the cloth presser body 12 with respect to the needle bar 2 can be adjusted. For example, as the position of the nut 20 is moved upward, the cloth presser body 12 will move downward,
Accordingly, as shown in an enlarged manner in FIG. 6, the corresponding distance S between the lower end of the sewing needle 10 and the pressing portion 14c of the cloth pressing body 12 is increased. The adjustment is possible within a range in which the support piece 14a of the cloth presser body 12 does not abut on the needle holder 8 or the lower surface of the support case 1. In this embodiment, the corresponding distance S is set to be larger than usual.

Next, the operation of the sewing machine according to this embodiment will be described. FIG. 3 shows a state where the cloth presser body 12 has reached the bottom dead center position. That is, the presser foot 12 descends with the lowering of the needle bar 2, and the support piece 14a of the presser foot 12
Are in contact with the cushioning material 19 on the upper surface of the lower support portion 1b of the support case 1. At this bottom dead center position,
The presser portion 14c of the cloth presser body 12 is located at a position slightly separated upward from the upper surface of the needle plate 11, and is set so as to press the sewing object 32 on the needle plate 11. The position of the bottom dead center is the position of the movable element 13 of the main body 14 in the work clamp body 12.
Can be changed by adjusting the position with respect to.

The needle bar 2 further descends and descends to a bottom dead center position shown in FIG. 4. When the needle bar 2 further descends from the state shown in FIG. Since the movement of the nut 20 is already restricted, the locking member 6 is separated from the nut 20 as the needle bar 2 descends. Next, when the needle bar 2 rises from the bottom dead center position shown in FIG. 4 to the position shown in FIG.
Abuts on the nut 20 functioning as a contact member, so that the cloth presser body 12 starts to rise together with the needle bar 2 via the engaging bar 18 from this point.

Therefore, as is apparent from FIG.
When the sewing needle 10 is inserted, the sewing object 32 has been pressed by the pressing portion 14 c of the cloth pressing body 12 long before the sewing needle 10 pierces the sewing object 32 placed on the needle plate 11. When the sewing needle 10 is removed, the sewing needle 1
For a while after 0 is removed from the sewing object 32, the sewing object 32 is pressed by the pressing portion 14 c of the cloth pressing body 12. This is, as described above, the sewing needle 1
0 and the corresponding distance S between the presser portion 14c of the presser body 12
Is set to be larger than usual.

As described above, setting the corresponding distance S large is advantageous in the case where the needle insertion resistance is large (therefore, the needle removal resistance is large), for example, in the case of leather (the sewing object 32) having a relatively large thickness. . That is, at the time of needle insertion, since the sewing object 32 is pressed early, it is possible to insert the needle while the fluttering of the sewing object 32 is almost completely suppressed. The disadvantage of being pulled up by the sewing needle 10 is avoided. As a result, good sewing is achieved without causing thread breakage.

If the height of the presser foot portion 14c of the presser foot 12 is low due to the change of the sewing operation, the nut 20 of the engaging bar 18 is adjusted with respect to the presser foot 12. By doing so, the corresponding distance S is set to be small. Thereby, the holding portion 14c
The distance between the needle plate 11 and the needle plate 11 is increased, and for example, a change can be made such that a tall holding frame (not shown) of the work 32 can be used. Even if the corresponding distance S is changed, the bottom dead center of the cloth presser body 12 does not change. When the bottom dead center of the presser foot 12 is changed, the position of the main body 14 of the presser foot 12 with respect to the mover 13 is changed. There is no.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention. In this embodiment, the needle holder 8 in the above embodiment is not used. That is, instead of using the needle holder 8, the sewing needle 10 is fixed by the set screw 25 directly screwed to the needle bar 2, and the thread guide 9 is also directly attached to the needle bar 2. In the present embodiment, the presser portion 14c of the cloth presser
There is an advantage that a corresponding distance between the sewing machine 10 and the lower end of the sewing needle 10 can be changed and set widely.

(Third Embodiment) FIG. 8 shows a third embodiment of the present invention. In the present embodiment, the configuration is such that the engaging bar 18 is not provided in the cloth presser body 12 according to the first embodiment. That is, in this embodiment, the sewing needle 1
0 and a thread guide 9 are attached to the needle bar 2 in the same manner as in the second embodiment. A ring-shaped locking member 30 is attached to the lower end of the needle bar 2 with a screw 31 so that the mounting position can be adjusted, and the support piece 14a of the cloth presser body 12 is in contact with the upper surface thereof. I have. Therefore, according to the present embodiment, the corresponding distance between the pressing portion 14c and the lower end of the sewing needle 10 can be changed by changing the attachment position of the locking member 30 to the needle bar 2. The operation is the same as in the above embodiments.

[0026]

As described above, according to the sewing machine of the present invention, by changing the setting of the corresponding distance between the lower end of the sewing needle and the presser of the presser body, the presser foot with respect to the removal timing of the sewing needle can be changed. The release timing of the pressing of the sewing object by the pressing portion of the body can be changed. Therefore, when sewing on a sewn object having a large needle removal resistance, there is an excellent advantage that a good sewing can be performed by delaying the release timing of the pressing.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a support case of a sewing machine.

FIG. 2 is a longitudinal sectional view of a support case in a state where a needle bar is located at a top dead center.

FIG. 3 is a longitudinal sectional view of the support case in a state where the cloth presser is located at a bottom dead center.

FIG. 4 is a vertical sectional view of the support case in a state where the needle bar is located at a bottom dead center.

FIG. 5 is a perspective view showing a schematic structure of a cloth presser.

FIG. 6 is a partially enlarged view of FIG. 2 showing a state where a needle bar is located at a top dead center.

FIG. 7 is an enlarged sectional view of a part of a support case according to a second embodiment.

FIG. 8 is an enlarged sectional view of a part of a support case according to a third embodiment.

FIG. 9 is a longitudinal sectional view of a support case according to a conventional example,
This shows a state where the needle bar is located at the top dead center.

FIG. 10 is a longitudinal sectional view of a support case according to a conventional example, and shows a state where a cloth presser is located at a bottom dead center.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support case (support) 2 Needle bar 5 Cloth presser spring 6 Locking member 10 Sewing needle 12 Cloth presser 14c Pressing portion 18 Engagement bar 20 Nut (contact member) 32 Sewing object

Claims (4)

[Claims] A needle bar (2) supported vertically movably with respect to a support (1) and having a sewing needle (10) attached to a lower end thereof; and a needle bar (2).
Is supported so that it can move up and down relatively to
(5) The cloth presser body (12), which is urged downward with respect to the needle bar (2) and abuts on a locking member (6) attached to the needle bar (2) to restrict movement. And the sewing needle (10)
Before the cloth presser (1) is pierced by the workpiece (32).
The presser portion (14c) of 2) presses the work (32), and at least the sewing object (32) by the cloth presser (12) is pressed until the sewing needle (10) comes out of the work (32). In the sewing machine in which the press-down operation is continued, the setting of the corresponding distance between the lower end of the sewing needle (10) and the presser portion (14c) of the cloth presser body (12) can be changed. Sewing machine. 2. The holding member (6) is fixed to the needle bar (2) above the presser foot spring (5), and
(12) An engaging bar (1) whose upper end is engageable with the locking member (6).
The abutting member (20) capable of changing an engagement position with the locking member (6) is attached to an upper end of the engagement bar (18). sewing machine. 3. The sewing machine according to claim 1, wherein the locking member is attached to a lower end of the needle bar so that a fixed position can be changed. 4. The sewing machine according to claim 1, wherein the position of the bottom dead center of the cloth presser body (12) that can be moved up and down is adjustable.