JPH11226280A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a cushioning medium which determines a bottom dead center of a presser foot supporting bar even if thick cloth to be processed as well as thin cloth to be processed is sewn. SOLUTION: A sewing machine comprises a needlebar 3 and a presser foot supporting bar 9 which are arranged in parallel so as to rise and fall. When the falling needlebar 3 pushes down a presser foot supporting bar 9 with a pushing-down spring 18, an engaging part 15a of a coupling metal 15 fastened to the presser foot supporting bar 9 butted to a cushioning member 6 for determining a bottom dead center of the presser foot supporting bar 9, wherein the cushioning member 6 is formed in a block shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine provided with a cushioning material for determining a bottom dead center of a presser foot support rod.

[0002]

2. Description of the Related Art In a conventional sewing machine, as shown in FIG. 7, a needle bar 42 is supported by a needle bar guide hole 45a provided in a needle bar guide portion 45 of a sewing machine head body 40 in a vertically movable manner. In a support rod guide groove 46 provided in front of the guide part 45, a cloth holding support rod 44 is supported so as to be able to move up and down. Needle bar 4
An engaging fitting 47 is fixed to an upper end of the holding member 2, and a holding portion 48 provided at a front portion of the fitting 47 holds the upper end of the presser foot supporting rod 44 so as to be relatively vertically movable. I have. on the other hand,
A coupling fitting 49 is fixed to a central portion of the cloth holding support rod 44, and a central portion of the needle bar 42 is inserted into a hole 50 provided at a rear portion of the fitting 49 so as to be relatively vertically movable. In this manner, the needle bar 42 and the presser foot support bar 44 are connected to be vertically movable relatively.

A pressing spring 51 having a high elasticity is interposed between the engaging fitting 47 and the connecting fitting 49. When the needle bar 42 is lowered, the connecting fitting 49 and the connecting fitting 49 are connected via the pressing spring 51. The presser foot support rod 44 is pushed down and descends. An O-ring 52 as a cushioning material is mounted on the peripheral wall of the needle bar 42 between the upper surface of the needle bar guide 45 of the sewing machine head body 40 and the coupling fitting 49, and the O-ring 52 serves as a locking portion 49a. By contacting the lower edge of the hole 50 of the connecting fitting 49, the bottom dead center of the presser foot support rod 44 is determined.

[0004] The sewing machine constructed as described above operates as follows. First, when the needle bar 42 is lowered by the needle bar hit 53 driven up and down by a driving unit (not shown),
Along with this, the coupling fitting 49, the cloth presser support rod 44 and the cloth presser 43 are pushed down via the presser spring 51. When the locking portion 49a of the coupling fitting 49 abuts on the O-ring 52 (the position of the bottom dead center indicated by the two-dot chain line in FIG. 7), the descent of the work clamp 43 stops. After that, only the needle bar 42 further descends,
It penetrates the work cloth W. At this time, since the pressing spring 51 is compressed between the engagement fitting 47 and the coupling fitting 49 as the needle bar 42 descends, the repulsive force is applied to the O-ring 52. When the needle bar 42 reaches the bottom dead center position, the needle bar 42 starts to rise, but the cloth presser 43 urged downward by the pressing spring 51 stops at the bottom dead center position and presses the work cloth W. I have. Then, after the needle 41 comes off from the work cloth W, the cloth presser 43 and the cloth presser support rod 44 together with the needle 41 and the needle bar 42 also rise.

[0005]

However, when the coupling fitting 49 fixed to the presser foot support rod 44 descends, an impact force is applied to the O-ring 52 when the locking portion 49a comes into contact with the O-ring. Further, when the presser foot support bar 44 reaches the bottom dead center and the needle bar 42 is further lowered, a compressive force is applied to the O-ring 52. Therefore, the O-ring 5 as a cushioning material
In some cases, the needle bar 2 may be damaged or cut off. In such a case, the needle bar 42 must be temporarily removed from the sewing machine head body 1 and the O-ring 52 must be re-mounted, which causes a problem that maintenance is troublesome.

Particularly, in a sewing machine for sewing a work cloth W of a thick material (a thick cloth, a hard cloth, a leather, etc.), a pressing spring 51 having a particularly high elasticity is used.
The above problems often occur. The reason why the pressing spring 51 having a high elasticity is used is that the needle 41 is hard to be pulled out from the strong work cloth W. Therefore, if the elasticity of the pressing spring 51 is weak, the needle bar 42 will die down. This is because, when ascending from the point position, the work clamp 43 does not hold down the work cloth W, and the needle 41 and the work clamp 43 rise while the needle 41 is stuck in the work cloth W.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and even if a thick work cloth as well as a thin work cloth is sewn, the cushioning material that determines the bottom dead center of the work clamp supporting rod is hardly damaged. Its maintenance is also to provide a sewing machine which is easy to maintain.

[0008]

In order to achieve the above object, a sewing machine according to the present invention comprises a needle bar and a presser foot support bar which are arranged in a vertically movable manner, and the lowering needle bar is moved through a pressing spring. When the presser foot support rod is pressed down, the sewing machine is configured to determine a bottom dead center of the presser foot support rod by an engaging portion provided on the presser foot support rod coming into contact with a cushioning material. It is characterized in that the cushioning material is formed in a block shape.

In the sewing machine of the present invention, the needle bar and the presser foot support bar are arranged so as to be able to move up and down, and when the descending needle bar pushes down the presser foot support bar via a pressing spring, the cloth bar is pressed. In a sewing machine configured such that a locking portion provided on a presser holding support rod abuts on a cushioning material to determine a bottom dead center of the cloth presser supporting rod, the cushioning material is formed in a non-ring shape, and the needle It can be mounted without removing the rod.

The cushioning material is not particularly limited as long as it can reduce the impact force. Examples of the cushioning material include resin materials such as urethane resin and rubber materials such as chloroprene (CR) rubber.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a sewing machine embodying the present invention will be described below with reference to FIGS. A needle bar guide 2 formed in a plane arc shape is provided on the front surface of the sewing machine head main body 1 of the sewing machine. The needle bar guide 2
Are provided with a plurality of needle bar guide holes 2a at regular intervals, and the needle bar 3 is inserted into each of the needle bar guide holes 2a so as to be able to move up and down. A needle 4 is attached to a lower end of the needle bar 3 by a needle stopper 22 and a screw 23, and a needle plate 20 having a needle hole 21 is provided below the needle 4. At the upper end of the needle bar 3, there is provided an engagement fitting 13 with which a needle bar tapper 7 driven up and down by driving means (not shown) is engaged. During the sewing process, the needle bar 3 to be driven up and down is circularly moved so as to sequentially come to the center of the front of the sewing machine head main body 1, and the needle bar tapping 7 is applied to the engagement fitting 13 of the needle bar 3.
Are engaged, and the needle bar 3 is raised and lowered.

Immediately in front of each needle bar guide hole 2a of the needle bar guide portion 2, a plurality of support rod guide grooves 8 are arranged at a predetermined interval, and each support rod guide groove 8 is provided in each of the support rod guide grooves 8. The cloth presser supporting rod 9 is supported so as to be able to move up and down. Presser foot support rod 9
At the substantially central portion, a fixing fitting 15 is fixed with a fixing screw 27, so that the fixing position can be adjusted up and down. A hole 16 is provided at the rear of the coupling fitting 15, and the center of the needle bar 3 is inserted into the hole 16 so as to be relatively vertically movable.
At the rear end of the coupling fitting 15, there is provided a locking portion 15 a protruding rearward, and the locking portion 15 a comes into contact with the cushioning material 6 when the pressure holding support rod 9 descends, so that the pressure The bottom dead center of the support rod 9 is determined. Further, the upper end of the cloth holding support bar 9 is held by a holding portion 14 provided at a front portion of the engagement fitting 13 so as to be relatively vertically movable.

A presser foot 10 is attached to the lower end of the presser foot support rod 9. Needle bar insertion hole 11 at the top of pressure foot 10
The lower part of the needle bar 3 is inserted so as to be movable up and down relatively, and the needle 4 can be inserted through the through hole 12 at the lower part of the presser foot 10.

A pressing spring 17 having a high elasticity is interposed between the engaging metal member 13 of the needle bar 3 and the connecting metal member 15 fixed to the presser foot supporting rod 9, and the needle bar hitting member 7 is provided. When the needle bar 3 is lowered, the cloth presser support bar 9 is pressed down via the pressing spring 17. Further, a push-up spring 18 having a low elasticity is interposed between the coupling fitting 15 and the sewing machine head main body 1.

As shown in FIG. 5, the cushioning material 6 is a long urethane resin block material which is curved and formed, and its cross section is formed in an inverted L-shape. The cushioning material 6 extends along the plurality of needle bar guide holes 2 a of the needle bar guide 2.
Is mounted in a curved groove 25 provided at an interval on the rear side. The lower surface of the engaging portion 15a of the coupling fitting 15 comes into contact with the outer peripheral wall side edge 6a of the upper surface of the cushioning material 6 when the presser foot supporting rod 9 is lowered.

The sewing machine constructed as described above operates as follows. First, the driving means (not shown) from the state of FIG.
When the needle bar 3 is lowered by the needle bar hit 7 driven to move up and down, the cloth presser supporting rod 9 and the cloth presser 10 are pressed down via the pressing spring 17 to move down. As shown by the solid line in FIG. 3, when the locking portion 15 a of the coupling fitting 15 comes into contact with the cushioning material 6, the lowering of the presser foot support rod 9 and the presser foot 10 stops. After that, only the needle bar 3 is further lowered as shown by a two-dot chain line in FIG. 3, and the needle 4 penetrates the work cloth W.
At this time, when the needle bar 3 is lowered, the engagement fitting 13 of the needle bar 3 is moved.
Since the pressing spring 17 is compressed between the pressing metal 17 and the fitting 15 fixed to the cloth holding support bar 9, the repulsive force is applied to the cushioning material 6. When the needle bar 3 reaches the bottom dead center position,
The needle bar 3 starts to rise, but the cloth presser 10 urged downward by the pressing spring 17 having strong elasticity stops at the bottom dead center position and presses the work cloth W. Then, after the needle 4 comes off from the work cloth W, the presser foot supporting rod 9 and the presser foot 10 rise together with the needle bar 3 and the needle 4.

According to the sewing machine configured as described above, since the cushioning material 6 is formed in a block shape, the elastic material has a high resilience that can cope with not only a thin work cloth W but also a thick work cloth W. Even when the pressing spring 17 is used, unlike the conventional O-ring, the pressing spring 17 is not damaged or cut.

Further, since the cushioning member 6 is formed in a non-ring shape, for example, when the aged cushioning member 6 is replaced, unlike the conventional one, the deteriorated cushioning member 6 can be removed without removing the needle bar 3. You can remove it and install a new one. Therefore, maintenance work can be easily performed.

Note that the present invention is not limited to the configuration of the above-described embodiment, and may be embodied by appropriately changing, for example, the following without departing from the spirit of the invention. (1) As shown in FIG. 6, the cushioning material 6 is divided and provided for each needle bar 3. In this case, the buffer material 6 can be replaced for each needle bar 3. (2) An engaging portion that contacts the cushioning member 6 is provided at another part of the joint 15 or other than the joint 15.

(3) A plurality of needle bar guide holes 2a are provided linearly at regular intervals on the front of the sewing machine head body 1,
The present invention is applied to a sewing machine of a type in which a needle bar 3 to be driven up and down during sewing is linearly moved so as to sequentially come to the front center of the sewing machine head body 1. For example, in the case of the first embodiment, the cushioning material 6 is a long block material formed linearly along the plurality of needle bar guide holes 2a.

[0021]

As described above in detail, according to the sewing machine according to the first aspect of the present invention, even when sewing not only a thin work cloth but also a thick work cloth, the bottom dead center of the presser foot support rod is provided. This has an excellent effect that the cushioning material that determines the resistance is hardly damaged.

Further, according to the sewing machine of the second aspect of the present invention, the maintenance of the cushioning material can be easily performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a sewing machine according to an embodiment of the present invention as viewed from the front side.

FIG. 2 is a side sectional view showing the sewing machine.

FIG. 3 is a side sectional view showing another state of the sewing machine.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a perspective view showing a cushioning material of the sewing machine.

FIG. 6 is a view similar to FIG. 4, showing a modified example of the sewing machine.

FIG. 7 is a side sectional view showing a conventional sewing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sewing machine head body 3 Needle bar 6 Buffer material 9 Cloth presser support bar 15a Locking part 17 Pressing spring

Claims (2)

[Claims] 1. A needle bar and a presser foot support bar are provided so as to be movable up and down, and when the descending needle bar pushes down the presser foot support bar via a pressing spring, the needle bar and the presser foot support bar are provided on the presser foot support bar. A sewing machine configured to determine a bottom dead center of the presser foot supporting rod by the engaging portion being in contact with the cushioning material, wherein the cushioning material is formed in a block shape. 2. A needle bar and a presser foot support bar are arranged side by side so as to be able to move up and down, and when the descending needle bar pushes down the presser foot support bar via a pressing spring, the needle bar and the presser foot support bar are provided on the presser foot support bar. In a sewing machine configured such that the locking portion contacts the cushioning material to determine the bottom dead center of the presser foot support rod, the cushioning material is formed in a non-ring shape, without removing the needle bar. A sewing machine characterized by being attachable.