JP4674708B2 - Staggered sewing machine - Google Patents

Description

  The present invention relates to a staggered sewing machine that forms zigzag stitches on the surface of a sewing fabric.

  The staggered sewing machine moves up and down alternately to a position that is swung appropriately in the left-right direction, and passes through the sewing fabric on the throat plate, and rotates at the lower position of the throat plate to be wound around the bobbin thread bobbin. A hook for feeding out the lower thread, and a loop of an upper thread that is fed by the downward movement of the needle and penetrates the sewing fabric and is alternately formed on the lower side of the sewing fabric. It is configured to catch with the provided sword tip and cause entanglement with the lower thread.

  In such a staggered sewing machine, the needle may bend due to the action of various external forces applied during the sewing operation, and there is a risk that the needle tip of the needle and the trajectory of the sword tip may be displaced. There is a risk that various troubles that hinder normal sewing, such as a catching error of the needle and a collision between the needle and the sword tip, may occur. Therefore, conventionally, the hook is provided with a needle holder that rotates integrally with the hook, and the needle tip of the needle that is lowered by the needle holder is supported and properly positioned with respect to the trajectory of the sword. While capturing, it prevents the above-mentioned trouble from occurring (for example, see Patent Document 1).

The needle guard is formed by punching a part of the needle catch plate integrally fixed to one surface of the hook into a rectangle leaving one side on the center side, and bending and forming the remaining one side toward the hook as a leg. It is configured to stand up substantially parallel to one surface.
Japanese Utility Model Publication No. 3-13976

  In the staggered sewing machine, as described above, since the lowering of the needle occurs with an appropriate width from side to side, the needle receiver needs to be configured so that the needle tip can be reliably supported at the respective lowering positions. There is. In Patent Document 1, the support surface provided on the needle receiver so as to support the needle tip at the left and right lowered positions, and the lead surface for guiding the needle tip to the support surface are appropriately inclined with respect to one surface of the hook. The problem is solved by forming with an angle.

  On the other hand, the lower part of the needle plate also has a dimensional error of many parts interposed between the shuttle that rotates in the sewing machine bed and the needle that is suspended from the tip of the sewing machine arm on the needle plate. Since a relative position error occurs due to the accumulation, assembly adjustment for eliminating the position error is individually performed when the sewing machine is assembled.

  However, even after such assembly adjustment is performed, a position error within a predetermined tolerance range remains between the hook and the needle, so that the support surface and the lead surface as disclosed in Patent Document 1 are provided. Even if the needle guard is adopted, in order to properly support the needle tip at the left and right lowered positions, it is necessary to adjust the contact to optimize the contact state between the needle and the needle guard. A highly accurate angle setting on the lead surface is meaningless.

  Also, at the sewing site, needles with different needle tip shapes may be used depending on the type of sewing fabric in order to achieve good stitch formation. In this case, the positional relationship between the needle and the needle guard is re-established. In order to adjust, it is necessary to correct the angles of the support surface and the lead surface of the needle receiver, and it is desired to make this correction easily.

  The present invention has been made in view of such circumstances, and makes it possible to easily adjust the contact between the needle and the needle receiver, and appropriately adjust the relative position of the needle with respect to the sword tip rotating together with the hook at the left and right lowered positions. It is an object of the present invention to provide a staggered sewing machine capable of performing staggered stitching with good quality.

A staggered sewing machine according to a first aspect of the present invention is formed by molding a part of a needle receiving plate fixed to one surface of a hook rotating at a lower portion of a needle plate along one surface of the hook, In a staggered sewing machine provided with a support surface that supports a needle tip of a needle that passes through a sewing fabric and a needle surface that has a lead surface that guides the needle tip to the support surface, the needle receiver includes the needle support. Displacement in a direction in which a part of the support surface is cut away on the side of the leg portion that communicates with the needle receiving plate, the support surface is deformed with respect to the lead surface, and contacts and separates from one surface of the hook. It is characterized by having a notch portion that enables this.

In the present invention, a part of the support surface of the needle receiver that supports the needle tip of the needle descending below the needle plate is provided with a notch formed by cutting out on the side of the leg that communicates with the needle receiver plate. By utilizing the notch and deforming the support surface with respect to the lead surface, the contact adjustment with the needle tip can be easily performed.

  A staggered sewing machine according to a second aspect of the present invention is characterized in that the notch portion according to the first aspect of the invention includes the leg portion.

  In this invention, a notch formed by notching a part of the support surface is formed including a leg portion that supports the corresponding part of the support surface on the needle receiving plate, and the bottom dead center is obtained under the support state by the support surface. Avoiding the possibility of the needle tip of the reaching needle colliding with the leg.

  In the staggered sewing machine according to the first aspect of the present invention, a part of the support surface that supports the needle tip of the needle is cut out on the leg side, so that the support surface is deformed with respect to the lead surface, It is possible to easily adjust the contact state of the needle by moving it in the direction of contact and separation, and it is possible to optimize the descent position of the needle with respect to the trajectory of the hook tip of the hook and perform zigzag stitching with good quality It becomes.

  Further, in the staggered sewing machine according to the second invention, since the notch portion of the support surface is formed including the corresponding portion of the leg portion, the needle tip of the needle that reaches the bottom dead center under the support by the support surface is formed in the leg portion. The present invention has excellent effects such as avoiding the possibility of collision and preventing the occurrence of a needle breakage accident due to the collision.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is an external perspective view of a zigzag stitch sewing machine according to the present invention. A sewing machine arm 11 extends substantially parallel to the upper surface of the sewing machine bed 1 at the upper end of a leg 10 standing on one side of the sewing machine bed 1. It has. A needle bar 20 and a presser bar 30 are suspended from the tip of the sewing machine arm 11, a needle 2 is attached to the lower end of the needle bar 20, and a presser foot 3 is attached to the lower end of the presser bar 30. Yes. Further, a needle plate 4 is installed on the upper surface of the sewing machine bed 1 facing the front end of the sewing machine arm 11 from below.

  FIG. 2 is an enlarged perspective view showing the vicinity of the needle plate 4. The needle plate 4 is formed with a plurality of feed dog holes 40, 40... In the form of elongated holes extending in the width direction (front-rear direction) of the sewing machine bed 1. The feed dog configured to transmit is protruded and configured to perform a predetermined feed operation that moves backward.

  On the needle plate 4, the presser foot 3 attached to the lower end of the presser bar 30 abuts. The presser foot 3 moves up and down in response to the lifting and lowering operation of the presser bar 30. When the presser foot 3 moves downward, the presser foot 3 descends onto the needle plate 4 as shown in the figure, and grips the sewing fabric (not shown) fed onto the needle plate 4. Make.

  The needle 2 attached to the lower end of the needle bar 20 moves in the longitudinal direction (left-right direction) of the sewing machine bed 1 and the sewing machine arm 11 according to the movement of the needle bar 20 by transmission from a needle bar drive mechanism (not shown) inside the sewing machine arm 11. ) Are alternately moved up and down at a position that is swung by a predetermined width, and a known operation of feeding the upper thread is performed. Such a needle 2 is lowered to the inside of the sewing machine bed 1 through a needle drop hole 31 formed in the presser foot 3 on the left and right and a needle drop hole (not shown) similarly formed in the needle plate 4. To do.

  As shown in FIG. 2, a hook 5 for feeding the lower thread is disposed inside the sewing machine bed 1 below the needle plate 4. The shuttle 5 rotates around an axis extending in the front-rear direction at the lower position of the needle plate 4 and has a known structure for feeding the lower thread. The hook 5 is fed by the downward movement of the needle 2 and is sewn on the needle plate 4. A sword tip 50 is provided which penetrates the fabric and captures a loop of an upper thread formed alternately on the left and right sides of the sewing fabric.

  In the sewing by the staggered sewing machine configured as described above, the sewing fabric supplied onto the needle plate 4 from the front side of the sewing machine bed 1 is held between the presser foot 3 that is lowered by the downward movement of the presser bar 30, and this A feed toward the rear side of the sewing machine bed 1 is applied to the sewing fabric by an operation of a feed dog (not shown) protruding from the feed dog holes 40, 40... The needle 2 and the lower thread are entangled by the synergistic action of the needle 2 that alternately moves up and down to the position that is swung to the proper width and the shuttle 5 that rotates fully at the lowering position of the needle 2 below the needle plate 4. It is done prematurely.

  The staggered sewing machine according to the present invention is characterized by the configuration of a needle receiver provided in the shuttle 5 to support the needle tip of the needle 2 that descends below the needle plate 4 during the above-described sewing. FIG. 3 is an exploded perspective view of the hook 5. As shown in the figure, the shuttle 5 is a disk-shaped member having a cylindrical boss 51 for fixing to the rotating shaft. The sword tip 50 has a pointed tip toward one side in the circumferential direction, and is extended so as to bend along the outer periphery. The hook 5 is indicated by an arrow in the figure by transmission from the rotating shaft. In this way, the blade tip 50 rotates in a direction in which the tip of the sword tip 50 faces to catch an upper thread loop (not shown).

  A needle receiving plate 6 having a substantially semicircular shape covering the formation portion of the sword tip 50 as a substantially center is integrally fixed to one surface of the hook 5 by fastening a fixing screw 6a. In this needle receiving plate 6, the downstream side in the rotational direction of the tip of the sword tip 50 is punched into a rectangle with a predetermined width leaving one side on the center side, and the remaining one side is bent toward the opposite side to the hook 5. The needle receiver 7 is formed by bending and bending so as to rise substantially parallel to one surface of the hook 5 while leaving the leg portion 60 of an appropriate width.

  This needle receiver 7 is provided including a position aligned with the tip of the sword tip 50 of the shuttle 5 in the circumferential direction, and is continuous with a support surface 70 located upstream in the rotational direction and downstream of the support surface 70 in the rotational direction. And a lead surface 71. The support surface 70 has an inclination in which the downstream side in the rotation direction approaches the one surface of the hook 5, and the lead surface 71 has an inclination in which the upstream side in the rotation direction approaches the one surface of the hook 5.

  The needle receiver 7 as described above is further provided with a notch formed by notching substantially half of the support surface 70 including the leg 60 on the leg 60 side for communication with the needle receiving plate 6. 72. By providing such a notch 72, the support surface 70 continues on the upstream side of the lead surface 71 with only the lead surface 71 as a support, and the boundary with the lead surface 71 indicated by a thin line in the figure. Can be bent and deformed by a comparatively small force, and can be displaced in a direction in which the hook 5 is in contact with or separated from the one surface.

  FIG. 4 is an operation explanatory view of the shuttle 5 provided with the needle receiver 7 as described above. The shuttle 5 arranged below the needle plate 4 rotates in the direction indicated by the arrow with the center of rotation between the left and right needle drop positions A and B indicated by the alternate long and short dash line in the figure. By this rotation, the needle receiver 7 provided on the needle receiving plate 6 integrated with the shuttle 5 is rotated with the lead surface 71 first, and the needle 2 that descends to the left and right needle drop positions A and B. The needle tip is received between the hook 5 and the needle receiving plate 6, first comes into contact with the lead surface 71, and is guided to and supported by the support surface 70 by the guide action of the lead surface 71. In this state, the blade is positioned with respect to the trajectory of the sword tip 50 at the position indicated by the broken line in the figure.

  In the staggered sewing machine according to the present invention, the notch 72 is provided in the support surface 70 for positioning the needle 2 as described above, and the support surface 70 is brought into contact with one surface of the shuttle 5 by the action of the notch 72. It can be displaced relatively easily in the direction of separation, and the contact state with the needle 2 is changed by this displacement, and the relative position of the needle 2 with respect to the trajectory of the sword tip 50 provided in the shuttle 5 is adjusted appropriately. As a result, the upper thread fed by the needle 2 and the lower thread fed by the hook 5 are surely entangled, and the formation of high-quality staggered stitches can be formed by suppressing the occurrence of stitch skipping. it can.

  Further, since the above-described contact adjustment is easily performed at the assembly stage, high shape accuracy is not required for the needle receiver 7 including the support surface 70 and the lead surface 71. As described above, the needle receiver 7 is formed by punching a predetermined portion of the needle receiving plate 6 into a rectangular shape and bending the punched portion. The needle receiver 7 is formed with respect to the support surface 70 and the lead surface 71. The required accuracy can be set low, and the manufacturing cost can be reduced.

  The notch 72 is provided only on a part of the support surface 70, and the rigidity of the lead surface 71 is maintained. Therefore, the positioning of the needle 2 abutted and supported on the support surface 70 can be performed with high accuracy. Thus, the positional relationship of the sword tip 50 with respect to the trajectory is accurately maintained.

  Further, since the notch 72 is formed including the corresponding portion of the leg 60 that connects the needle receiver 7 to the needle receiving plate 6, the needle 2 descending to the needle drop positions A and B in FIG. Of the needle 2 can be avoided from colliding with the leg 60 at the bottom dead center caused by contact with the support surface 70. For example, the length of the needle 2 attached to the lower end of the needle bar 20 can be reduced. Due to misadjustment, it is possible to prevent an accident in which the needle 2 collides with the leg 60 and breaks.

1 is an external perspective view of a staggered sewing machine according to the present invention. It is a perspective view which expands and shows the vicinity of a needle plate. It is a disassembled perspective view of a hook. It is operation | movement explanatory drawing of a hook.

Explanation of symbols

2 Needle 4 Needle plate 5 Hook 6 Needle support plate 7 Needle support
60 legs
70 Support surface
71 Lead surface
72 Notch

Claims (2)

A part of the needle receiving plate fixed to one surface of the hook rotating at the lower portion of the needle plate is formed along the one surface of the hook, and the needle tip of the needle descending through the sewing cloth on the needle plate is formed. In a staggered sewing machine provided with a support surface for supporting, and a needle receiver having a lead surface for guiding the needle tip to the support surface,
The needle receiver is formed by cutting out a part of the support surface on the side of a leg portion that connects the needle receiver to the needle receiver plate, deforming the support surface with respect to the lead surface, A zigzag stitch sewing machine comprising a notch that allows displacement in a direction toward and away from one surface .   The staggered sewing machine according to claim 1, wherein the notch is formed including the leg.

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