JP3118990B2 - Needle bar holding device in multi-needle sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a needle bar holding device for holding a needle bar at a standby rising position in a multi-needle sewing machine such as an embroidery sewing machine.

[0002]

2. Description of the Related Art Conventionally, as a prior art of a needle bar holding device in a multi-needle sewing machine of this kind, Japanese Patent Application Laid-Open No. 4-51991 discloses a slide for supporting a balance and a needle bar in a vertically movable manner. A pair of upper and lower horizontal guides which are mounted so that the case can be moved to the left and right with respect to the sewing machine head, and the slide case is inserted into the slide case so as to guide the lower part of each of the needle bars and the middle part of the needle bar up and down freely. A portion is provided, and between each pair of guide portions, each needle bar is provided with a needle holder for raising and lowering each needle bar, and a coil spring fitted on each needle bar is provided at the upper end of each needle bar. A configuration is disclosed in which the needle bar is positioned between a spring receiver and an upper guide portion and is urged upward to raise each needle bar to a standby position.

[0003]

By the way, each needle bar in a multi-needle sewing machine for embroidery or the like moves up and down at the position where the needle bar is lowered during sewing operation, and conversely stands by so as not to sew. The sewing position must be held at a high position where the lower end of the sewing needle attached to the lower end of each needle bar is disengaged from the workpiece.

However, as described above, when the coil spring for urging each needle bar upward is located between the spring receiver at the upper end of each needle bar and the upper guide portion, the sewing operation is not performed. Regardless of the presence of the coil spring compressed inside (during the lowering of the needle bar), the length of the needle bar must be increased to allow the needle bar to move up and down. There is a problem that the head of the sewing machine becomes bulky due to the large size.

In addition, a spring receiver for supporting the upper end of the coil spring to be fitted needs to be integrally or detachably provided at the upper end of each needle bar. You have to do extra processing on the rod,
From this point, there is a problem that the manufacturing cost is increased. The present invention has been made to solve these problems, and has as its object to provide a needle bar holding device for a multi-needle sewing machine that is compact and inexpensive to manufacture.

[0006]

In order to achieve the above object, a needle bar holding device of a multi-needle sewing machine according to the present invention comprises a plurality of slide cases mounted on a slide case slidably mounted on a front surface of a sewing head. The needle bar and the balance corresponding thereto are arranged at regular intervals, and the sewing machine head is provided with a drive mechanism for vertically driving one needle bar and the balance selected by moving the slide case left and right. A needle used for a multi-needle sewing machine, wherein the slide case includes a pair of upper and lower guides for guiding the upper and lower intermediate portions of the respective needle bars slidably up and down, and needles attached to the respective needle bars. A bar hanger is positioned between the upper and lower guides, and a coil spring that is fitted to each of the needle bars and urges upward is disposed between the needle bar hanger and the upper surface of the lower guide. It is.

[0007]

Next, an embodiment of the present invention will be described. FIG. 1 is a plan view of an embroidery multi-head, multi-needle sewing machine in which a plurality of sewing arms 1 are arranged in parallel with a table 2. A common horizontal shaft 4 penetrating in a lateral direction through a hollow cylindrical bracket 3 detachably provided at the rear end of each sewing machine arm 1 is rotationally driven by one drive motor 5, and transmitted via a transmission mechanism in each bracket 3. Power is transmitted to the upper shafts 6 arranged in the respective sewing machine arms 1.

On the table 2, a cloth presser frame (not shown) for holding a cloth (not shown) to be sewn is arranged, and the cloth presser frame moves with the X motor in the X direction. Mechanism and Y
It is intermittently moved in a predetermined XY direction by a motor and a Y-direction moving mechanism. Further, control means (not shown) controls the intermittent operation of the X motor and the Y motor in the forward and reverse rotations based on the embroidery pattern.

In the base (rear part) of each sewing machine arm 1, the bed 2 is moved from the upper shaft 6 via the bevel gear pair and the vertical shaft.
(a) Power is transmitted to a lower shaft (not shown) located below and rotates a shuttle (not shown) having a known structure. A rectangular frame-shaped slide case 7 as viewed from the front is supported movably on the front surface of a hollow and open front sewing machine head 1a which is the tip of each sewing machine arm 1, and a lower guide portion 7a of the slide case 7 is provided. And the upper guide portion 7 formed in the middle position in the vertical direction
b is a large number (12 in this embodiment) arranged in a horizontal line.
The lower part of the needle bar 9 and the middle part of the needle bar 9 are vertically slidably supported, and a sewing needle 8 is attached to the lower end of each needle bar 9 (see FIGS. 3 and 4).

Next, with reference to FIGS. 4 and 5, a description will be given of a drive mechanism for vertically driving one needle bar 9 and balance 10 selected by the lateral movement of the slide case 7. FIG. On the upper side in the slide case 7, the needle bars 9
The balances 10 arranged in a row in a horizontal direction are supported by a horizontal shaft 11 so as to be vertically rotatable, and each balance 10 is provided with an urging spring 1.
8 is set to the upward position. As shown in FIG. 5, the driven cam 13 is driven by a cam groove 12a of a balance driving cam 12 attached to the tip of the upper shaft 6 in the sewing head 1a.
Are slidably fitted to each other, and a swing arm 14 to which the driven cam 13 is attached is fixed so as to rotate integrally with a rotation shaft 15. Then, the rotation of the upper shaft 6 causes the rotation shaft 15 to reciprocate by an appropriate angle. This rotating shaft 1
The fan-shaped drive gear 16 fixed to 5 selectively meshes with a fan-shaped driven gear 17 provided on the balance 10 at the sewing position due to the lateral movement of the slide case 7, and moves only the balance 10 up and down. Rock it.

A coil spring 20 is fitted between the needle bar holder 19 fixed to each of the needle bars 9 and the lower guide portion 7a of the slide case 7 to set each of the needle bars 9 at the raised position. A needle bar connector 23, which is vertically movable and rotatably mounted on a guide shaft 22 via a connecting rod 21 eccentrically attached to the tip of the balance drive cam 12, is driven to move up and down. The engagement pin 25 of the needle bar holder 19 fixed to the needle bar 9 at the sewing position is selectively engaged with the engagement groove 24 of the body 23, and only the needle bar 9 at that position is raised and lowered to the sewing state. Drive.

As shown in FIGS. 3 and 4, a vertical hole 2 formed in a cover plate 27 covering the front surface of the slide case 7 is provided.
The balance 6 is configured so that the tip of each balance 10 protrudes. As shown in FIG. 2, a guide portion 31 for guiding the upper thread F of a different color supplied from a supply table (not shown) is provided on the front surface of the thread tension table 30 to detect a thread break. Rotating body 32, thread tension 3 for applying tension to upper thread F
The upper thread F supplied from the thread tension table 30 side is inserted through the balance 10 into the sewing needle 8 attached to the lower end of the predetermined needle bar 9.

With such a configuration, the unselected needle bar 9 is moved upward by the upward biasing force of the coil spring 20.
The upper surface of the needle bar holder 19 is held at the maximum ascending position where it comes into contact with the lower surface of the upper guide portion 7b. When the slide case 7 is moved laterally in the sewing operation, the needle bar connector 23 is moved up along the guide shaft 22 by an interlocking mechanism (not shown). When the engaging pin 25 of the needle bar holder 19 comes into contact with the inclined surface 23a of the needle bar connector 23 during this ascent, the needle bar connector 23 resists the urging force of a built-in torsion spring (not shown). When the engagement pin 25 reaches the position of the engagement groove 24 in the needle bar connector 23, the needle bar connector 23 is rotated by the force of the torsion spring. Is rotated in the direction of the arrow A to engage the groove 2
The engagement pin 25 fits into the pin 4.

The needle bar 9 thus selected moves up and down by a predetermined rotation of the upper shaft 6. The balance 10 selected in synchronization with this is the balance driving cam 12 and the driven cam 1 described above.
3, the swinging arm 14, the rotating shaft 15, the driving gear 16, the driven gear 17, and the like are swung up and down to perform the sewing operation. Needless to say, the present invention can be applied to a single-head type multi-needle sewing machine, and the drive mechanism of the needle bar 9 up and down and the balance 10 may have other known forms.

[0015]

As described in detail above, according to the needle bar holding device of the multi-needle sewing machine of the present invention, a plurality of slide cases are mounted on a slide case which is slidably mounted on the front surface of the sewing machine head. The needle bar and the balance corresponding thereto are arranged at regular intervals, and the sewing machine head is provided with a drive mechanism for vertically driving one needle bar and the balance selected by moving the slide case left and right, and The slide case is provided with a pair of upper and lower guides that guide the upper and lower intermediate portions of each of the needle bars slidably up and down, and a needle bar holder attached to each of the needle bars is interposed between the upper and lower pairs of guides. On the other hand, since the coil springs that are fitted on the respective needle bars and urge upwardly are arranged between the needle bar holder and the upper surface of the lower guide portion, the length of each needle bar decreases. The upper end of the needle bar is in the position of the upper guide section It will be good but the degree of short that exhibits the ability to shorten the length of the needle bar, the height of the slide case, an effect of forming a compact by thus shortening the height of the machine head portion.

Further, since the upper end of the coil spring fitted on each needle bar contacts the lower surface of the needle holder attached to the needle bar, the needle holder also serves as a locking portion of the upper end of the coil spring. Can be. Therefore, according to the present invention, there is no need to form or attach a flange-shaped member such as a spring receiver on the upper end of the needle bar as in the related art, and the structure of the needle bar can be extremely simplified, so that the manufacturing cost can be reduced. This has a remarkable effect that it can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a multi-head, multi-needle sewing machine.

FIG. 2 is a partially cutaway side view of the multi-needle sewing machine.

FIG. 3 is a front view of the multi-needle sewing machine.

FIG. 4 is a side sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a perspective view of a drive mechanism of the needle bar and the balance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sewing arm 1a Sewing head 2a Bed 7 Slide case 7a Lower guide part 7b Upper guide part 8 Sewing needle 9 Needle bar 10 Balance F Upper thread 19 Needle bar holder 20 Coil spring 23 Needle bar connector

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-96788 (JP, A) JP-A-63-73988 (JP, A) JP-A-51-4549 (JP, U) Patent 2752453 (JP, A B2) Tokiko Hei 3-34958 (JP, B2) (58) Fields studied (Int. Cl. ⁷ , DB name) D05B 55/00-55/16 D05C 11/06

Claims (1)

(57) [Claims] 1. A plurality of needle bars and a balance corresponding thereto are arranged at regular intervals in a slide case mounted to be slidable left and right with respect to the front surface of a sewing machine head. In the multi-needle sewing machine provided with a drive mechanism for vertically driving one of the needle bars and the balance selected by the left and right movement of the needle bar, the slide case is provided with a vertically movable part of each of the needle bars which is vertically slidable. A pair of upper and lower guide portions for guiding the needle bar, and a needle bar hanger attached to each needle bar is positioned between the upper and lower pair of guide portions, and a coil spring that is fitted on each of the needle bars and urges upward. Is disposed between the needle bar holder and the upper surface of the lower guide portion.