JP2018149020A - Double chain stitch sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double chain stitch sewing machine capable of reducing a height dimension of a bed part inserted between an up and down facing faces of the interior member to an interior member facing at least a part by pinching a ridge line of a replication part which is bended less than a prior sewing machine.SOLUTION: A looper 12 for forming a stitch by cooperation of work with a needle 6, 6 is composed of a basal part 12a, and a core point part 12b, 12b. The core point parts 12b, 12b each extend from the basal part 12a in one direction, and are arranged along a horizontal and front-back direction. The basal part 12a is connected to one end of a looper table 13 positioned on the lower side of a needle plate 7. The other end extending in the right direction from one end of the looper table 13 is connected to a looper table-driving mechanism 14. The looper table 13 and the looper 12 advance and retreat in a front-back direction by driving of the looper table-driving mechanism 14 while oscillating a horizontal plane in the right-left direction, linking with rotation of a main shaft 5.SELECTED DRAWING: Figure 4

Description

The present invention relates to a double chain stitch sewing machine for sewing a vehicle interior member.
In the present invention, the front and rear refer to the front and rear directions in the direction in which the vehicle interior member is fed (hereinafter referred to as the feed direction), and the left and right refer to the left and right directions when the sewing machine is viewed from the front. The up and down direction means the up and down direction of the sewing machine.

2. Description of the Related Art Conventionally, stitches as decoration are applied to interior members (hereinafter, interior members) such as instrument panels and door trims that are mounted in a vehicle interior. This stitch is generally a main stitch, and a post bed type or cylinder bed type main stitch sewing machine is often used as a sewing machine for forming the stitch.
Since the bobbin thread of the sewing machine is supplied by the bobbin, if a long sewing member such as an interior member is sewn, the amount of bobbin thread wound around the bobbin is small, so the bobbin must be replaced frequently. Therefore, there is a problem that productivity is remarkably lowered.
Further, strictly speaking, the main seam is not formed in a straight line, and there is a problem that a high-grade feeling as a decoration is somewhat lacking. That is, in the process of forming the stitches by the main sewing machine, the stitches of one stitch per stitch are inclined with respect to the feed direction of the member to be sewn, so that the appearance is deteriorated.

Therefore, in recent years, stitches using a chain stitch sewing machine have attracted attention as decorations for interior members. A bobbin is not required to supply the bobbin thread in a chain stitch sewing machine, and the stitches of each stitch are parallel to the feed direction of the material to be sewn and the entire stitch is formed in a straight line. It will be solved.
In recent years, the shape and design of interior members have been diversified, and designs have been proposed in which stitches are difficult to sew with conventional post bed type and cylinder bed type sewing machines. As an example of the above design, the interior member has a bent portion, and at least a part of the interior member is opposed across the ridge line of the folded portion. Can be stitched along. In order to apply the stitches of the above example with a sewing machine, one of the facing surfaces of the interior member described above is directed upward, and the bed portion of the sewing machine on which the looper and bobbin are arranged is inserted between the upper and lower facing surfaces of the interior member, And it is necessary to let the needle drop in the bed part reach just below the point where you want to stitch. As a result, the conventional post bed type sewing machine known in the art cannot inevitably set the bed at a desired location due to its bed shape, and in the conventional cylinder bed type sewing machine, the height dimension of the cylinder bed portion is as described above. If it is larger than the interval between the upper and lower opposing surfaces of the interior member (hereinafter, the vertical width), the bed cannot be set at a desired location.
As a sewing machine for applying the stitches of the above-described design example, one in which the front end side of the post bed is extended in the horizontal direction has been proposed (for example, see Patent Document 1). The sewing machine of Patent Document 1 is a post bed type chain stitch sewing machine, and the post part has a shape with the tip horizontally extended to the right side. A needle drop (not shown) is formed on the upper right side of the horizontally extended post part tip. A throat plate having is fixed. In order to stitch the interior member of the above example, the ridgeline (vertex) of the bent portion is directed to the right side, the post end tip is inserted and set between the upper and lower facing surfaces, the sewing machine is driven and the interior member is The sewing is performed by feeding it in the horizontal rear direction by a known feeding means.
In the sewing machine according to the embodiment described in Patent Document 1, a looper mechanism including a rotary looper or an offset looper is employed. In the example of adopting the rotary looper, the rotary looper is attached to the tip of the rotating shaft and disposed below the needle drop, and the rotating shaft is disposed in the post portion tip along the extending direction of the post portion tip.
In an example of adopting the offset looper, a lower shaft is disposed at the bottom of a post portion formed to extend vertically in a columnar shape, and a looper arm is disposed at the post portion. The looper arm is formed to extend vertically, the base end of the looper arm is connected to the lower shaft, and an offset looper is attached to the tip of the looper arm. The offset looper is formed so that a part thereof extends to the right side and is disposed at the tip of the post portion. When the sewing machine is driven, the offset looper swings back and forth with the looper arm about the lower shaft as the center of rotation.

Special table 2014-520602 (Figures 1 and 4-5)

  In the sewing machine of Patent Document 1, the rotary looper rotates around the horizontal axis, and the offset looper swings around the rotation axis that is separated from the vertical axis. Therefore, when the sewing machine is driven, the looper is displaced in the vertical direction. Occurs. Therefore, the height of the post portion that accommodates the loopers is required to allow the above-described vertical displacement. Therefore, in the interior member of the above design example, when the vertical width of the bent portion is narrowed, even with the sewing machine of Patent Document 1, the post portion tip cannot be set at a predetermined position, and thus a desired stitch may not be applied. .

  Accordingly, an object of the present invention is to provide an interior member of the above design example, i.e., one of the opposing surfaces of the interior member with respect to the interior member that has a folded portion that is bent and at least partially faces the ridge line of the folded portion. In addition, stitches can be formed near the ridgeline along the ridgeline, and the height of the bed portion inserted between the upper and lower facing surfaces of the interior member can be made smaller than that of the conventional sewing machine. It is to provide a double chain stitch sewing machine.

In order to achieve the above object, a double chain stitch sewing machine of the invention according to claim 1 is:
An arm and a bed constituting the outer shell of the sewing machine;
A main shaft rotatably supported by the bed;
A needle bar supported by the arm so as to be movable up and down;
A needle attached to the lower end of the needle bar and moving up and down in conjunction with rotation of the main shaft;
A throat plate bracket having a proximal end fixed to the bed and a distal end extending laterally from the proximal end positioned below the arm;
A needle plate fixed to the tip of the needle plate bracket and provided with a needle drop hole through which the needle penetrates when the needle moves up and down;
A looper base drive mechanism that is disposed on the bed and connected to the main shaft and driven in conjunction with rotation of the main shaft;
A looper base having one end positioned below the needle plate and the looper base drive mechanism coupled to the other end extending laterally from the one end;
A looper that forms a seam in cooperation with the needle,
The looper is composed of a base and a sword tip,
The base is connected to one end of the looper base;
The sword tip extending in one direction from the base is disposed horizontally and along the front-rear direction,
The looper base and the looper move forward and backward in the front-rear direction while swinging in the horizontal direction in conjunction with the rotation of the main shaft.

The invention of claim 2 is the double chain stitch sewing machine of claim 1,
The looper base drive mechanism is
An operating piece fixed to the other end of the looper base;
A forward / backward movement mechanism connected to the operating piece and moving the looper base in the front / rear direction;
A left-right moving mechanism connected to the operating piece and moving the looper base in the left-right direction is provided.

The invention of claim 3 is the double chain stitch sewing machine of claim 2,
The forward / backward movement mechanism operates by the action of a forward / backward movement cam fixed to the main shaft,
The left-right movement mechanism is operated by the action of a left-right movement cam fixed to the main shaft.

  According to the double chain stitch sewing machine of the present invention, since the vertical displacement of the looper does not occur when the looper is driven, the bed height can be made smaller than that of the conventionally known chain stitch sewing machine. Even if the interior member has a narrow vertical width that cannot be sewn with the chain stitch sewing machine, it is possible to set the bed of the sewing machine at a predetermined position. Further, since the looper moves back and forth while swinging in the horizontal direction in the horizontal direction, it is possible to sew one of the opposing surfaces of the bent portion of the interior member and the vicinity of the ridge line of the bent portion along the ridge line. Is possible.

The schematic front view of the double chain stitch sewing machine which concerns on this invention. The expansion perspective view which shows the principal part of the sewing machine. The top view which shows the looper advance position of the sewing machine. The top view which shows the looper retreat position of the sewing machine. The top view which shows the principal part of the looper stand drive mechanism of the sewing machine. FIG. 3 is a schematic view showing a positional relationship among a main shaft angle of the sewing machine, front / rear / left / right moving cams, front / rear / left / right driven followers and links. Schematic which shows the main shaft angle of the sewing machine, and the positional relationship of a needle | hook and a looper. The schematic front view which shows the principal part in the sewing process of the sewing machine.

Hereinafter, a double chain stitch sewing machine according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic front view of a double chain stitch sewing machine, and FIG. 2 is an enlarged perspective view showing a main part of the sewing machine. The double chain stitch sewing machine 1 includes an arm 2 and a bed 3 that constitute an outer shell of the sewing machine. The bed 3 extends horizontally, and the main shaft 5 is supported by the bed 3 so as to be rotatable about the axis. A bed cover 3 a is attached to the upper surface of the bed 3. The column part 2a of the arm 2 stands on the upper surface on one end side in the left-right direction of the bed 3, and the arm 2 extends in parallel and in the same direction as the extension direction of the bed 3 from the column part 2a. The arm 2 is longer in the left-right direction than the bed 3. A needle bar 10 is supported by the arm 2 so as to be movable up and down below the tip of the arm 2. Two needles 6, 6 arranged side by side are attached to the lower end of the needle bar 10. The needle bar 10 is connected to a known needle bar drive mechanism (not shown) disposed in the arm 2, and the needle bar drive mechanism is connected to the main shaft 5. The needle bar 10 and the needles 6 and 6 move up and down in conjunction with the rotation of the main shaft 5.

  A needle plate 7 is disposed below the needles 6 and 6. The needle plate 7 is connected to the bed 3 via a needle plate bracket 9. The base end of the needle plate bracket 9 is fixed to the left side surface of the bed 3 with screws 8. The needle plate bracket 9 is formed to extend laterally (leftward) from the base end to below the tip of the arm 2, and the needle plate 7 is fixed to the tip of the needle plate bracket 9. The needle plate 7 is provided with needle drop holes 7a and 7a through which the needles 6 and 6 pass when the needles 6 and 6 move up and down. It is preferable that the height of the needle plate bracket 9 is made as small as possible in the vicinity of the tip portion thereof. Note that the lower side of the needle plate 7 does not have a feeding mechanism, and the interior member is fed in the rearward direction of the sewing machine along the feeding direction F by a known feeding mechanism other than the lower side of the needle plate 7.

  A looper 12 that forms a seam in cooperation with the needles 6 and 6 is disposed below the needle plate 7. The looper 12 is composed of a base 12a and sword tips 12b and 12b. Each of the sword tip portions 12b and 12b extends in one direction from the base portion 12a and is disposed horizontally and along the front-rear direction. In this embodiment, the sword tips 12b, 12b are arranged so as to extend from the base 12a to the front side. The base 12 a is connected to one end of a looper base 13 located below the needle plate 7. The other end of the looper base 13 extending from one end to the side (rightward) is connected to the looper base drive mechanism 14. By driving a looper base drive mechanism 14 to be described later, the looper base 13 and the looper 12 move back and forth in the front-rear direction while swinging in the horizontal direction in conjunction with the rotation of the main shaft 5. It is preferable that the height dimension is made as small as possible in the vicinity of the left end portion of the looper 12 or the looper base 13.

  FIG. 3 is a plan view showing the looper advance position, and FIG. 4 is a plan view showing the looper retreat position. 3 and 4 show a state in which the bed cover 3a is removed. The inner lid 15 is disposed so as to cover a part of the bed 3 and is fixed to the bed 3. A longitudinally moving cam 20 and a laterally moving cam 30 are juxtaposed and fixed to the left and right of the main shaft 5 rotatably supported by the bed 3 at a predetermined interval. The longitudinally moving cam 20 and the laterally moving cam 30 each have a cam surface 20a and a cam surface 30a on surfaces facing each other. The cam surface 20a has a reference surface 20aa and a working surface 20ab that is concave to the right from the reference surface 20aa. The cam surface 30a has a reference surface 30aa and a working surface 30ab that is concave to the left from the reference surface 30aa.

  The looper base drive mechanism 14 is connected to the operating piece 16 fixed to the other end of the looper base 13, a longitudinal movement mechanism 19 connected to the operating piece 16 and moving the looper base 13 in the front-rear direction, and connected to the operating piece 16. A left-right moving mechanism 27 that moves the table 13 in the left-right direction is provided. The forward / backward movement mechanism 19 operates by the action of the forward / backward movement cam 20 described above, and the left / right movement mechanism 27 operates by the action of the left / right movement cam 30 described above. Hereinafter, the longitudinal movement mechanism 19 and the lateral movement mechanism 27 will be described.

First, the main configuration of the longitudinal movement mechanism 19 will be described.
The longitudinally driven follower 21 is formed in a cylindrical shape, and is arranged so that a part of the circumferential side surface thereof is pressed against the cam surface 20 a by the coil spring 40. One end of the link 22 is connected to the upper surface of the longitudinally driven follower piece 21 via a screw 23a so as to be rotatable around the vertical axis. The link 22 is formed in an L-shaped plate shape and is positioned below the inner lid 15. Further, the link 22 is exposed from the inner lid 15 at the connecting portion with the above-described longitudinally driven follower 21, but the other portion is covered by the inner lid 15. The link 22 is connected to the lower surface of the inner lid 15 by a screw 23b at an L-shaped corner. The link 22 is swingable about an axis about the screw 23b. One end of the link 24 is connected to the other end of the link 22 by a screw 23c. The link 24 is formed in a straight plate shape. The other end of the link 24 is connected to the base end of the operating piece 16 via a screw 23d through a hole 15a penetrating the inner lid 15 up and down. The operating piece 16 is formed and arranged to extend to the left from the base end, and the other end of the looper base 13 is fixed to the front end thereof with screws 17 and 17.

Next, the main structure of the left-right moving mechanism 27 will be described.
The left / right driven piece 31 is formed in a cylindrical shape, and is arranged so that a part of the circumferential side surface thereof is pressed against the cam surface 30 a by the coil spring 40. One end of a link 32 is connected to the upper surface of the left / right driven piece 31 via a screw 33a so as to be rotatable around the vertical axis. The link 32 is formed in a straight plate shape and is positioned below the inner lid 15. The link 32 is exposed from the inner lid 15 at a portion where the link 32 is connected to the left and right driven piece 31 described above, but the other portion is covered by the inner lid 15. The link 32 is connected to the lower surface of the inner lid 15 by a screw 33b in the middle part. The link 32 is swingable about an axis about the screw 33b. In the middle of the operating piece 16 in the left-right direction, a long hole 16b extending in the left-right direction and a protrusion 16a partially protruding backward are formed. The other end of the link 32 is connected to the protrusion 16a of the operating piece 16 through a hole 33b passing through the inner lid 15 in the vertical direction via a screw 33c. A square piece 35 is slidably inserted into the elongated hole 16 b of the operating piece 16. The operating piece 16 is movable in the range of the long hole 16b by being guided by the square piece 35 in the long hole 16b. A presser plate 36 is disposed on the upper surface of the square piece 35, and a part of the operating piece 16 and the square piece 35 are sandwiched between the presser plate 36 and the inner lid 15. The screw 37 is inserted through the presser plate 36 and the square piece 35, and the presser plate 36 is fixed to the inner lid 15 by the screw 37. The square piece 35 sandwiched between the inner lid 15 and the presser plate 36 is rotatable about a screw 37 as a rotation center.

As shown in FIG. 5, the coil spring 40 is interposed between the link 22 and the link 32. A disc-shaped washer 28 is fixed to a side surface of the link 22 facing the link 32 by a pin screw 29, and a disc-shaped washer 38 is fixed to a side surface of the link 32 facing the link 22 by a pin screw 39. Has been. The pin screw 29 and the pin screw 39 are formed so that shaft portions extend on opposite sides, and both ends of the coil spring 40 are mounted on both shaft portions. The outer diameter of the washers 28 and 38 is set larger than the outer diameter of the coil spring 40, and the coil spring 40 presses the washers 28 and 38. With the above configuration, the longitudinally driven follower 21 is always in pressure contact with the cam surface 20a of the longitudinally movable cam 20, and the laterally driven follower 31 is always in pressure contact with the cam surface 30a of the laterally movable cam 30.
In addition, one end of the coil spring 42 is fixed near the screw 23b on the upper surface of the inner lid 15 by a screw 41a. The other end of the coil spring 42 is fixed to one end of the looper base 13 with a screw 41b, and the coil spring 42 acts to pull the looper base 13 rearward to the right.
Further, one end of a coil spring 44 is fixed to the inner side surface of the left rear portion in the bed 3 by a screw 43a. The other end of the coil spring 44 is fixed to one end of the looper base 13 with a screw 43b, and the coil spring 44 acts to pull the looper base 13 rearward.

  The drive of the looper base drive mechanism 14 configured as described above will be described below. First, when the main shaft 5 is rotated, the longitudinally moving cam 20 and the laterally moving cam 30 are rotated around the axis of the main shaft 5, and the longitudinally driven follower 21 is rotated around the vertical axis as the longitudinally moving cam 20 rotates. The cam surface 20a swings left and right along the reference surface 20aa or the action surface 20ab. Then, as the link 22 swings around the screw 23b as the center of the swing, the link 24 moves substantially back and forth. Further, the left / right driven follower 31 swings left and right along the reference surface 30aa or the action surface 30ab of the cam surface 30a while rotating around the vertical axis as the left / right moving cam 30 rotates. Then, the link 32 swings about the screw 33b as the swing center as the left and right driven follower 31 swings left and right. As the links 24 and 32 swing, the operating piece 16 swings left and right while being guided by the square piece 35 in the elongated hole 16b, and rotates and swings around the vertical axis about the screw 37. By the above-described driving of the operating piece 16, the other end of the looper base 13 and the looper 12 move forward and backward in the front-rear direction while swinging in the horizontal direction in conjunction with the rotation of the main shaft 5.

  FIG. 6 shows the positional relationship of the front / rear / left / right moving cam, the front / rear / left / right driven piece and the link connected to both driven pieces at a certain shaft angle of the main shaft 5 (hereinafter, the main shaft angle). They are (a) left side view and (b) top view which show the positional relationship of the needle | hook and looper in a certain principal axis angle. 6 and 7 are schematic views in which some configurations and symbols are omitted. In FIG. 7, only one of the pair of left and right needles and the sword tip of the looper is displayed. The main shaft angle referred to here is 0 ° when the needle is at the top dead center, and the number of rotations of the main shaft in a single rotation direction in which the main shaft rotates when the sewing machine is driven is 0 ° to 360 °. It is shown in the range of °.

When the main shaft angle is 0 °, the longitudinally driven follower 21 is engaged with the reference surface 20aa of the longitudinally moving cam 20. At this time, one end of the longitudinally driven follower 21 and the link 22 is located at the left dead center in the respective left and right swing ranges, and the base end of the link 24 and the operating piece 16 is located at the rear dead center in the forward and backward swing ranges. To do. On the other hand, the tip of the looper base 13 connected to the operating piece 16 is located at the front dead center in the front and rear swing range (see FIG. 3).
Further, the left / right driven follower 31 is engaged with the reference surface 30aa of the left / right moving cam 30. One end of the left / right driven piece 31 and the link 32 is located at the right dead center in each of the left / right swing ranges, and the operating piece 16 connected to the link 32 and the looper base 13 connected to the operating piece 16 It is located at the left dead center in the swing range (see FIG. 3).
As shown in FIG. 7, the needle 6 is located at the top dead center, the looper 12 is located at the front dead center, and the sword tip 12 b of the looper 12 is located on the left side of the engaging needle 6.

In the process of rotating the main shaft 5 from the main shaft angle 0 ° to the main shaft angle 90 °, the front / rear follower piece 21 engages with the action surface 20ab of the front / rear cam 20 to rotate itself around the screw 23a. Move to the right. Then, the link 22 rotates clockwise around the screw 23b when viewed from above, and the proximal end of the operating piece 16 connected to the link 22 via the link 24 rotates clockwise when viewed from above with the screw 37 as the center. Rotate in the direction. At this time, since the spring 44 acts to pull one end of the looper base 13 connected to the operating piece 16 backward, the operating piece 16 described above is smoothly rotated.
Further, when the left / right driven piece 31 is engaged with the action surface 30ab of the left / right moving cam 30, it moves to the left while rotating about the screw 33a. Then, the link 32 rotates counterclockwise around the screw 33b as viewed from above, and the operating piece 16 moves to the right while being guided by the square piece 35 in the elongated hole 16b. At this time, since the spring 42 acts to pull one end of the looper base 13 connected to the operating piece 16 to the right rear, the movement of the operating piece 16 described above is performed smoothly.
In the process of the main shaft angle from 0 ° to 90 ° by the action of the two cams 20 and 30 described above, the looper base 13 connected to the operating piece 16 and the operating piece 16 is a clock as viewed from above with the screw 37 as the center. Move in the right direction while rotating in the turning direction. At this time, the needle 6 descends from the top dead center, and the sword tip 12b of the looper 12 moves backward while moving from the left side to the right side of the engaging needle 6. When the main shaft angle is 90 °, the tip of the needle 6 is positioned below the looper 12, and the looper 12 is positioned at the right dead center in the left-right swing range.

When the main shaft angle is 180 °, the longitudinally driven follower 21 is continuously engaged with the action surface 20ab of the longitudinally moving cam 20. The left and right positions of the working surface 20ab are rightmost, and therefore one end of the longitudinally driven follower 21 and the link 22 is positioned at the right dead center in the left and right swing range and operates together with the link 24 connected to the link 22. The base end of the piece 16 is located at the front dead center in the longitudinal swing range. On the other hand, the tip of the looper base 13 connected to the operating piece 16 is located at the rear dead center in the front and rear swing range (see FIG. 4).
Further, the left / right driven follower 31 is engaged with the reference surface 30aa of the left / right moving cam 30. One end of the left / right driven piece 31 and the link 32 is positioned at the right dead center in the left / right swing range, and the operating piece 16 connected to the other end of the link 32 is positioned at the left dead center in the left / right swing range. (See FIG. 4).
At this time, the needle 6 is located at the bottom dead center, the looper 12 is located at the rear dead center, and the tip 12b of the looper 12 is located on the left side of the engaging needle 6.

In the process of rotating the main shaft 5 from the main shaft angle 180 ° to the main shaft angle 225 °, the longitudinally driven follower 21 is continuously engaged with the operating surface 20ab of the longitudinal cam 20 and the left and right positions of the operating surface 20ab are gradually increased. As it moves to the left, the longitudinally driven follower 21 moves to the left while rotating about the screw 23a. Then, the link 22 rotates counterclockwise around the screw 23b when viewed from above, and the proximal end of the operating piece 16 connected to the link 22 via the link 24 is counterclockwise when viewed from above with the screw 37 as the center. Rotate clockwise.
Further, the left / right driven follower 31 is engaged with the reference surface 30aa of the left / right moving cam 30. One end of the left / right driven piece 31 and the link 32 holds the position of the right dead center in the left / right swing range, and the operating piece 16 connected to the link 32 is positioned at the left dead center in the left / right swing range.
Due to the action of both cams described above, the operating piece 16 and the looper base 13 connected to the operating piece 16 rotate counterclockwise around the screw 37 as viewed from above. At this time, the needle 6 rises from the bottom dead center, and the sword tip 12b of the looper 12 advances forward on the left side of the engaging needle 6. When the sword tip 12b of the looper 12 passes the left side of the needle 6, the looper 12 captures a needle thread loop (not shown) generated by the needle 6 being lifted.

When the main shaft angle is 270 °, the longitudinally driven follower 21 is engaged with the reference surface 20aa of the longitudinally moving cam 20. One end of the longitudinally driven follower 21 and the link 22 is located at the left dead center in the lateral swing range. The base end of the operating piece 16 together with the link 24 connected to the link 22 is located at the rear dead center in the front and rear swing range. On the other hand, the tip of the looper base 13 connected to the operating piece 16 is located at the front dead center in the front and rear swing range.
Further, the left / right driven follower 31 is engaged with the reference surface 30aa of the left / right moving cam 30. One end of the left / right driven piece 31 and the link 32 is located at the right dead center in the left / right swing range, and the operating piece 16 connected to the link 32 is located at the left dead center in the left / right swing range.
At this time, the needle 6 is moving up, and the sword tip 12b of the looper 12 is located on the left side of the front dead center and the engaging needle 6.
In the process of advancing the main shaft angle from 270 ° to 360 °, the looper 12 does not move stationary and only the needle 6 continues to rise.

  As described above, in the double chain stitch sewing machine 1 of the present embodiment, the interior member 47 has a bent portion along the feed direction F, and at least a part of the interior member 47 sandwiches the ridge line of the bent portion. One of the opposing surfaces of the interior member 47 and the vicinity of the ridgeline can be sewn along the ridgeline. Further, according to the double chain stitch sewing machine 1 of the present embodiment, since the looper 12 is not displaced in the vertical direction when the looper 12 is driven, the bed height dimension can be made smaller than that of a conventionally known chain stitch sewing machine. Therefore, the interior member 47 is set at a predetermined position of the double chain stitch sewing machine 1 even if the interior member has a narrow vertical width that cannot be sewn by a conventionally known chain stitch sewing machine as shown in FIG. It is possible. Further, since the looper 12 moves back and forth while swinging in the horizontal direction on the horizontal plane, one of the opposing surfaces of the bent portion of the interior member 47 and the vicinity of the ridge line of the bent portion are sewn along the ridge line. It is possible.

  In addition, in the double chain stitch sewing machine 1 of the embodiment of the present invention, a two-needle double chain stitch sewing machine is illustrated, but other than this, for example, a single needle or three-needle double chain stitch sewing machine has the same function. There is an effect. The present invention is not limited to the embodiments described above, and the same effects as the embodiments can be obtained as long as they do not depart from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Double chain stitch sewing machine 2 Arm 3 Bed 3a Bed cover 5 Spindle 6, 6 Needle 7 Needle plate 9 Needle plate bracket 12 Looper 13 Looper base 14 Looper base drive mechanism 15 Inner lid 16 Actuating piece 19 Back and forth movement mechanism 20 Back and forth movement cam 21 Front-rear driven follower 27 Left-right motion mechanism 30 Left-right motion cam 31 Left-right motion driven piece 35 Square piece F Feed direction

Claims (3)

An arm and a bed constituting the outer shell of the sewing machine;
A main shaft rotatably supported by the bed;
A needle bar supported by the arm so as to be movable up and down;
A needle attached to the lower end of the needle bar and moving up and down in conjunction with rotation of the main shaft;
A throat plate bracket having a proximal end fixed to the bed and a distal end extending laterally from the proximal end positioned below the arm;
A needle plate fixed to the tip of the needle plate bracket and provided with a needle drop hole through which the needle penetrates when the needle moves up and down;
A looper base drive mechanism that is disposed on the bed and connected to the main shaft and driven in conjunction with rotation of the main shaft;
A looper base having one end positioned below the needle plate and the looper base drive mechanism coupled to the other end extending laterally from the one end;
A looper that forms a seam in cooperation with the needle,
The looper is composed of a base and a sword tip,
The base is connected to one end of the looper base;
The sword tip extending in one direction from the base is disposed horizontally and along the front-rear direction,
The double chain stitch sewing machine characterized in that the looper base and the looper move back and forth in the front-rear direction while swinging in the left-right direction in conjunction with the rotation of the main shaft. The looper base drive mechanism is
An operating piece fixed to the other end of the looper base;
A forward / backward movement mechanism connected to the operating piece and moving the looper base in the front / rear direction;
A left-right movement mechanism connected to the operating piece and moving the looper base in the left-right direction;
The double chain stitch sewing machine according to claim 1. The forward / backward movement mechanism operates by the action of a forward / backward movement cam fixed to the main shaft,
The left-right movement mechanism operates by the action of a left-right movement cam fixed to the main shaft.
The double chain stitch sewing machine according to claim 2.

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