JP4783619B2 - sewing machine - Google Patents

Description

  The present invention relates to a sewing machine capable of adjusting a stroke of a thread hook that moves up and down together with a presser bar.

The sewing machine is provided with a needle bar, a balance, and a presser bar. A sewing needle is attached to the lower end of the needle bar, and a presser tool is attached to the lower end of the presser bar. By doing so, the cloth is stitched. The machine frame of the sewing machine is provided with a thread guide, a thread hook, a thread tension device, etc., and the thread from the spool is guided to the sewing needle via the thread guide, the thread tension device, the thread hook, a balance, etc. (For example, refer to Patent Document 1).
There are two types of conventional sewing machines, one in which the thread hanging tool moves up and down in conjunction with the vertical movement of the presser bar and the other in which the thread hanging tool is fixed to the machine frame and does not move.
Japanese Utility Model Publication No. 5-43754

  The type of sewing machine with a thread hook fixed thereto is suitable for applying a seam to a thick cloth mainly because the thread is easily tightened during sewing. The type of sewing machine in which the thread hook is interlocked with the presser bar can be used to apply a seam to a thin cloth because it can apply a loose seam. However, there has been no sewing machine that can stably apply beautiful seams to both thick and thin fabrics.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to enable a beautiful seam to be stably applied to any thickness of cloth.

  In order to solve the above problems, the invention according to claim 1 is characterized in that a presser bar which moves up and down by rotation of a main shaft of the sewing machine and has a presser foot at a lower end thereof, and a presser bar holding member fixed to the presser bar And an eccentric member that is rotatably attached to the machine frame of the sewing machine and has an eccentric shaft formed at a position that is eccentric from the rotation shaft, and one end side is connected to the presser bar holding member, and a central portion is connected to the eccentric shaft. A supported first link member, a second link member whose one end is slidably connected to the other end of the first link member, and whose center is rotatably supported by the machine frame, and an upper end is A thread hook mounting member that is slidably connected to the other end side of the second link member and is supported by the machine frame so as to move up and down; and a thread hook member fixed to the thread hook mounting member. , Rotate the eccentric member and interlock with the presser bar And adjusting a vertical stroke of the yarn hooking member to be vertically movable.

  According to the above invention, since the eccentric shaft is eccentric with respect to the rotational shaft of the eccentric member, when the eccentric member is rotated, the inclination of the first link member relative to the presser bar can be adjusted. The rotation angle of the two link members can be adjusted, and the vertical strokes of the yarn hook mounting member and the yarn hook can also be adjusted.

  According to the present invention, it is possible to adjust the vertical stroke of the yarn hooking attachment member and the yarn hooking tool by the rotation of the eccentric member, so that it is possible to adjust the tightness of the yarn according to the thickness of the cloth. Even a thick cloth can be applied stably with beautiful seams.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  As shown in FIG. 1, a main shaft 12 is rotatably provided inside a machine frame 11 of a sewing machine, and a needle bar 13 is connected to the main shaft 12 via a crank mechanism or the like, and the needle bar 13 moves up and down. It is provided as possible. The needle bar 13 extends from the inside of the machine frame 11 to the lower side outside the machine frame 11, and a sewing needle 14 is attached to the lower end of the needle bar 13. Further, a balance 15 is connected to the main shaft 12 via a balance transmission mechanism or the like, and the balance 15 extends from the inside of the machine casing 11 to the front outside. When the main shaft 12 is rotated by the sewing machine motor, the balance 15 is also moved up and down, and the sewing needle 14 is moved up and down together with the needle bar 13, whereby the cloth is stitched.

  As shown in FIG. 2, the sewing machine has a stroke adjusting device 30 for adjusting the vertical stroke amount of the thread hook 36. The stroke adjusting device 30 is provided with respect to a presser bar 21, a presser bar holding plate 31 attached to the presser bar 21, an eccentric knob 35 rotatably attached to the machine frame 11, and a rotation axis of the eccentric knob 35. A first link that is rotatable about an eccentric eccentric shaft 35a and is connected to an eccentric knob 35, and a sliding pin 31a of a presser bar holding plate 31 is slidably connected in a radial direction of the eccentric shaft 35a. A plate 32 is provided. The stroke adjusting device 30 is rotatably attached to the machine casing 11 and is coupled to the first link plate 32 so as to be slidable in the radial direction of the eccentric shaft 35a on the opposite side of the sliding pin 31a with respect to the eccentric shaft 35a. The second link plate 33 and the second link plate are supported by the machine frame 11 so as to be movable up and down, and on the opposite side of the connecting portion with the first link plate 32 with respect to the rotation shaft 33a of the second link plate 33. 33, a thread hook attaching member 34 connected to 33, and a thread hook 36 provided on the thread hook attaching member 34. In FIG. 2, the main shaft 12, the needle bar 13, and the sewing needle 14 are not shown for easy viewing of the drawing.

  The presser bar 21 is supported by the machine frame 11 so as to be movable up and down, and a presser 22 for pressing the cloth from above is attached to the lower end thereof. The upper end of the presser bar 21 is inserted into a presser spring 100 that presses the cloth from above with a spring force, and the other end of the presser bar 21 is abutted and attached to a presser adjusting screw for adjusting the presser pressure (not shown). When the main shaft 12 is rotated by the sewing machine motor, the feed dog of the cloth feed mechanism (not shown) rises from the needle plate upper surface 101, presses the cloth between the presser 22, and moves above the needle plate upper surface 10 in the cloth feed direction. The cloth is sent by exercising. The presser bar 21 moves up and down in conjunction with the main shaft 12 and moves up and down in conjunction with the vertical movement of the feed dog.

  The presser bar holding plate 31, the first link plate 32, the second link plate 33, and the thread hook attachment member 34 are arranged inside the machine casing 11.

  The presser bar holding plate 31 is fixed to the presser bar 21 and moves up and down together with the presser bar 21. A sliding pin 31a is provided on the right end portion of the presser bar holding plate 31 so as to project therefrom.

  The eccentric knob 35 is attached to the front surface of the machine casing 11 so as to be partially exposed from the machine casing 11, and the eccentric knob 35 can rotate about the axis in the front-rear direction with respect to the machine casing 11. An eccentric shaft 35 a is formed at a position eccentric with respect to the rotation axis of the eccentric knob 35. The eccentric shaft 35 a is connected to the intermediate portion of the first link plate 32, and the first link plate 32 can rotate around the eccentric shaft 35 a with respect to the eccentric knob 35. Since the eccentric shaft 35 a is eccentric with respect to the rotation axis of the eccentric knob 35, if the eccentric knob 35 is rotated, the eccentric shaft 35 a of the first link plate 32 turns around the rotation axis of the eccentric knob 35. It is like that.

  A long hole 32 b is formed in the left end portion of the first link plate 32 along the longitudinal direction of the first link plate 32, and a long hole 32 c is also formed in the right end portion along the longitudinal direction of the first link plate 32. Is formed. Both the long hole 32b and the long hole 32c are elongated in the radial direction of the eccentric shaft 35a. The slide pin 31a of the presser bar holding plate 31 is inserted into one of the long holes 32c, and the slide pin 31a can slide along the longitudinal direction of the long hole 32c.

  A rotation shaft 33 a is formed at the left and right intermediate portion of the second link plate 33 so as to extend forward, the rotation shaft 33 a is connected to the front surface of the machine frame 11, and the second link plate 33 is connected to the machine frame 11. On the other hand, it can rotate around the rotation shaft 33a. A sliding pin 33c is protruded from the left end of the second link plate 33. The sliding pin 33c is inserted into the elongated hole 32b of the first link plate 32, and the sliding pin 33c is the longitudinal length of the elongated hole 32b. It can slide along the direction. A sliding pin 33 b is provided on the opposite side of the rotating shaft 33 a from the sliding pin 33 c and on the right end of the second link plate 33.

  A long hole 34a elongated in the left-right direction is formed in the upper end portion of the thread hook attachment member 34, and the slide pin 33b of the second link plate 33 is inserted into the long hole 34a, and the slide pin 33b is long. It can slide along the longitudinal direction of the hole 34a.

  The thread hook attachment member 34 can be slid up and down by a guide provided inside the machine casing 11. A thread hook 36 is fixed to the lower end portion of the thread hook mounting member 34. The thread hook 36 extends from the inside of the machine casing 11 to the front side outside the machine casing 11 and is further bent downward. The yarn derived from the spool is hung on the yarn hook 36 via a yarn guide, a thread tensioner, a thread take-up spring, and the like, and then guided to the sewing needle 14 via the balance 15 and the like.

Next, the operation will be described.
When the user rotates the eccentric knob 35, the eccentric shaft 35 a is positioned on the lower left side of the rotational axis of the eccentric knob 35 as shown in FIGS. 2 (a) and 2 (b). In this state, when the presser bar 21 is moved up and down by the rotation of the main shaft 12, the first link plate 32 rotates around the eccentric shaft 35a as shown in FIGS. 2 (a) and 2 (b). The second link plate 33 rotates about the rotation shaft 33 a, and the yarn hook attachment member 34 moves up and down together with the yarn hook 36.

  As shown in FIG. 2A, in a state where the presser bar 21 is positioned at the lower end within the vertical movement range, the first link plate 32 is inclined with respect to the presser bar 21, and the second link plate 33 is It becomes almost horizontal. In the state of FIG. 2A, the yarn hooking attachment member 34 and the yarn hooking tool 36 are at the lowest position of the vertical stroke.

  When the presser bar 21 rises from the state shown in FIG. 2A, the first link plate 32 rotates counterclockwise in the illustrated direction of FIG. 2, and the inclination of the first link plate 32 with respect to the presser bar 21 increases. Thus, the second link plate 33 rotates counterclockwise, the inclination of the second link plate 33 with respect to the horizontal plane increases, and the thread hook attachment member 34 rises together with the thread hook 36. Here, when the presser bar 21 moves up, the sliding pin 31a slides so as to relatively approach the eccentric shaft 35a, and the sliding pin 33c also slides so as to relatively approach the eccentric shaft 35a.

  2B, when the presser bar 21 is positioned at the upper end within the vertical movement range, the inclination of the first link plate 32 with respect to the presser bar 21 is greater than the inclination in the state of FIG. 2A. The inclination of the second link plate 33 with respect to the horizontal plane is smaller than that in the state of FIG. 2A, and the thread hook attachment member 34 and the thread hook 36 are at the uppermost position of the vertical stroke. When the presser bar 21 is lowered, the first link plate 32 is rotated clockwise, the inclination of the first link plate 32 with respect to the presser bar 21 is reduced, and the second link plate 33 is rotated clockwise. The inclination of the second link plate 33 with respect to the horizontal plane is reduced, and the yarn hook attachment member 34 is lowered together with the yarn hook 36.

  As described above, when the eccentric shaft 35a of the first link plate 32 is positioned at the lower left of the rotation shaft of the eccentric knob 35, the vertical stroke amount of the thread hook 36 is δ1. This stroke amount δ1 is substantially equal to the stroke amount of the vertical movement of the presser bar 21.

  When the user rotates the eccentric knob 35, the eccentric shaft 35 a is positioned on the upper right side of the rotational axis of the eccentric knob 35 as shown in FIGS. 3 (a) and 3 (b). In this state, when the presser bar 21 is moved up and down by the rotation of the main shaft 12, the first link plate 32 rotates around the eccentric shaft 35a as shown in FIGS. 3 (a) and 3 (b). The second link plate 33 rotates about the rotation shaft 33 a, and the yarn hook attachment member moves up and down together with the yarn hook 36.

  As shown in FIG. 3A, in a state where the presser bar 21 is positioned at the lower end within the vertical movement range, the first link plate 32 is inclined with respect to the presser bar 21, and the second link plate 33 is moved. It will be in a state inclined with respect to the horizontal plane. In the state of FIG. 3A, the thread hook attachment member 34 and the thread hook 36 are at the lowest position of the vertical stroke. 2 (a) and FIG. 3 (a) are compared, the inclination of the first link plate 32 with respect to the presser bar 21 is the state of FIG. 3 (a) rather than the state of FIG. 2 (a). Is smaller.

  When the presser bar 21 rises from the state shown in FIG. 3A, the first link plate 32 rotates counterclockwise in the direction shown in FIG. 3, and the inclination of the first link plate 32 with respect to the presser bar 21 increases. Thus, the second link plate 33 rotates counterclockwise, the inclination of the second link plate 33 with respect to the horizontal plane is reduced, and the thread hook attachment member 34 is raised together with the thread hook 36.

  3B, when the presser bar 21 is positioned at the upper end within the vertical movement range, the inclination of the first link plate 32 with respect to the presser bar 21 is greater than the inclination in the state of FIG. 3A. The inclination of the second link plate 33 with respect to the horizontal plane is smaller than that in the state of FIG. 3A, and the thread hook attachment member 34 and the thread hook 36 are at the uppermost position of the vertical stroke. 2B and the state of FIG. 3B, the inclination of the first link plate 32 with respect to the presser bar 21 is the state of FIG. 3B rather than the state of FIG. 2B. Is smaller.

  When the presser bar 21 is lowered, the first link plate 32 is rotated clockwise, the inclination of the first link plate 32 with respect to the presser bar 21 is reduced, and the second link plate 33 is rotated clockwise. The inclination of the second link plate 33 with respect to the horizontal plane is increased, and the yarn hook attachment member 34 is lowered together with the yarn hook 36.

  As described above, when the eccentric shaft 35a of the first link plate 32 is positioned at the upper right of the rotation shaft of the eccentric knob 35, the vertical stroke amount of the yarn hook 36 is set to δ2.

  Even when the vertical stroke amount of the presser bar 21 is constant, the stroke amount δ2 of the yarn hook 36 when the eccentric shaft 35a of the first link plate 32 is located at the upper right of the rotational shaft of the eccentric knob 35 is the first The eccentric shaft 35a of the link plate 32 is smaller than the stroke amount δ1 of the yarn hook 36 when the eccentric shaft 35 is located at the lower left of the rotational shaft of the eccentric knob 35. As described above, the inclination of the first link plate 32 with respect to the presser bar 21 is adjusted by the rotation of the eccentric knob 35, the rotation angle of the second link plate 33 with respect to the vertical stroke of the presser bar 21 is adjusted, and the thread hook attachment member 34 and the vertical stroke amount of the yarn hook 36 are adjusted.

  Even if the vertical stroke amount of the presser bar 21 is constant, the vertical stroke amount of the thread hook 36 can be adjusted. Therefore, the tightness of the thread can be adjusted according to the material and thickness of the fabric. Even if it is a simple cloth, it can give a beautiful and beautiful seam. For example, by increasing the vertical stroke of the thread hook 36 for a thin fabric, it is possible to stably apply a loose seam, and for the thick fabric, the vertical stroke of the thread hook 36. By reducing the size of the seam, the seam can be stably applied.

The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
For example, if the eccentric knob 35 is brought into a state between the state of FIG. 2 and the state of FIG. 3, the vertical stroke amount of the thread hook 36 is not limited to the stroke amount δ1 of FIG. 2 and the stroke amount δ2 of FIG. It can be adjusted.
In the above embodiment, the slide pin 31 a is formed on the presser bar holding plate 31 fixed to the presser bar 21, but the slide pin 31 a may be formed directly on the presser bar 21.

It is a left view of a sewing machine. They are a front view (a) when the yarn hook is positioned at the lower end when the vertical stroke of the yarn hook is increased, and a front view (b) when the yarn hook is positioned at the upper end. They are a front view (a) when the yarn hook is positioned at the lower end when the vertical stroke of the yarn hook is reduced, and a front view (b) when the yarn hook is positioned at the upper end.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Machine frame 12 Main axis | shaft 30 Stroke adjusting device 31 Presser bar holding plate 31a Sliding pin 32 1st link board 32b, 32c Elongate hole 33 2nd link board 33a Rotating shaft 33b, 33c Sliding pin 34 Thread hook mounting member 35 Eccentric knob 35a Eccentric shaft 36 Thread hook

Claims (1)

A presser bar that moves up and down by the rotation of the main shaft of the sewing machine and has a cloth presser at its lower end;
A presser bar holding member fixed to the presser bar,
An eccentric member rotatably attached to the machine frame of the sewing machine and having an eccentric shaft formed at a position eccentric from the rotational shaft;
A first link member having one end side connected to the presser bar holding member and a center portion supported by the eccentric shaft;
A second link member having one end side slidably connected to the other end side of the first link member, and a center portion rotatably supported by the machine frame;
An upper end portion is slidably connected to the other end side of the second link member, and is supported by the machine frame so as to be movable up and down;
A thread hook member fixed to the thread hook mounting member,
A sewing machine that adjusts the amount of vertical stroke of the yarn hooking member that moves up and down in conjunction with the presser bar by rotating the eccentric member.

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