JP7510293B2 - Guide mechanism for interlock stitch machines - Google Patents

Description

The present invention relates to a guide mechanism for an interlock stitch machine.

An interlock stitch sewing machine can form a plurality of stitches along the feed direction using a plurality of sewing needles (see, for example, Japanese Patent Application Laid-Open No. 2003-233634).
Such an interlock stitch machine is used to sew together two pieces of fabric with their edges butted together.

JP 2006-212135 A

As mentioned above, when sewing together two pieces of fabric with their edges butted together, if the stitch deviates from the edges of the fabric being butted together, the sewing quality drops significantly, so the sewing work requires skill.

SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a guide mechanism for an interlock stitch sewing machine which can easily achieve high-quality sewing.

The invention described in claim 1 is a guide mechanism for a flat stitch sewing machine,
A guide pin for the workpiece protruding from an upper surface of a needle plate of a flat stitch sewing machine that sews together the edges of two pieces of workpieces toward a presser foot that holds the workpiece on the needle plate;
an insertion portion provided on the presser foot into which the guide pin can be inserted,
The guide pin is disposed upstream of the needle hole in the feed direction of the sewing workpiece, and is disposed adjacent to the needle hole in the feed direction of the sewing workpiece,
The guide pin is round bar-shaped and is positioned adjacent to the needle hole formed in the needle plate in the feed direction of the workpiece , and is positioned between the butted edges of the two workpieces during sewing .

The invention described in claim 2 is a guide mechanism for a flat stitch sewing machine,
A guide pin for a workpiece protruding from a lower surface of a presser foot that holds the workpiece on a needle plate of a flat stitch sewing machine for sewing together the edges of two pieces of workpiece, toward the needle plate;
an insertion portion provided on the needle plate into which the guide pin can be inserted,
the insertion portion is disposed adjacent to a needle hole formed in the needle plate in a feed direction of the sewing material ,
the guide pin is disposed upstream of the needle hole in a feed direction of the sewing material,
The guide pin is a round bar and is positioned between the butted edges of the two pieces of workpiece when they are sewn .

The invention described in claim 3 is a guide mechanism for a flat stitch sewing machine according to claim 1 or 2,
The guide pin is characterized by comprising an adjustment portion for adjusting the amount of protrusion of the guide pin.

The invention described in claim 4 is the guide mechanism for a sewing machine according to any one of claims 1 to 3 ,
The guide pin is disposed between a feed dog located on the upstream side in the feeding direction of the sewing material and a feed dog located on the downstream side.

The guide mechanism of the present invention is equipped with a guide pin that protrudes from the upper surface of the needle plate toward the presser foot and an insertion part provided on the presser foot, and since the guide pin is located next to the needle hole, it is possible to guide the edges of the two items to be sewn very close to the needle drop position, and even if the edges of the items to be sewn are not linear, it is possible to guide them along the path they should pass. This makes it possible to prevent gaps from occurring between the edges of the items to be sewn and achieve high-quality sewing.
Furthermore, since the guide mechanism guides the edges of the two items to be sewn, high skill is not required for sewing, and the sewing work load can be reduced.

1 is a perspective view of a guide mechanism of a sewing machine according to an embodiment of the present invention; FIG. 4 is a perspective view showing the configuration of the needle plate side of the guide mechanism. FIG. 4 is a cross-sectional side view of a presser foot and a needle plate provided with a guide mechanism. FIG. 4 is an enlarged cross-sectional view of the periphery of a guide pin. FIG. 13 is a cross-sectional side view of a presser foot provided with a guide mechanism according to a comparative example. FIG. 13 is a perspective side view of a presser foot provided with a guide mechanism as a comparative example. FIG. 13 is a plan view of the left and right cloths showing the state in which interlock stitching has been performed using the guide mechanism of the embodiment. FIG. 13 is a plan view of the left and right cloths showing the state in which interlock stitching has been performed using a guide mechanism as a comparative example. 13 is a cross-sectional side view of a presser foot and a needle plate provided with a guide mechanism according to another example. FIG.

[Outline of the embodiment of the invention]
A guide mechanism 10 for a sewing machine according to an embodiment of the present invention will now be described with reference to the drawings.
FIG. 1 is a perspective view of a guide mechanism 10 of a sewing machine (hereinafter simply referred to as the guide mechanism 10), FIG. 2 is a perspective view showing the configuration of the needle plate 120 side of the guide mechanism 10, and FIG. 3 is a cross-sectional side view of a presser foot 110 and the needle plate 120 provided with the guide mechanism 10.
In the following description, the cloth feed direction is defined as the X-axis direction, the direction perpendicular to the cloth feed direction on the needle plate 120 is defined as the Y-axis direction, and the vertical direction is defined as the Z-axis direction.
Additionally, the downstream side in the cloth feed direction is referred to as the "front", the upstream side in the cloth feed direction is referred to as the "rear", the left hand side when facing forward is referred to as the "left", and the right hand side when facing forward is referred to as the "right".

[Interlock stitch]
The guide mechanism 10 is mounted on a so-called interlock stitch sewing machine.
The interlock stitch sewing machine is equipped with a plurality of sewing needles 101 (four are shown as an example; see FIG. 2), a looper (not shown) whose tip is inserted into the loop of each needle thread T1 to T4 inserted through the eye of each sewing needle 101 below the needle plate 120, and a spreader (not shown) which guides decorative thread T5 along the arrangement direction of the sewing needles 101 above the needle plate 120 and intertwines it with the needle threads T1 to T4 (see FIG. 7).
The sewing machine then performs interlock stitching by forming four stitches with the needle threads T1 to T4 along the cloth feed direction, stitches with a decorative thread T5 that reciprocates along a direction intersecting the cloth feed direction on the upper surface of the sewn workpiece, and stitches with a looper thread that intertwines with the needle threads T1 to T4 on the lower surface of the sewn workpiece.

The above-mentioned interlock stitch forms stitches of the decorative thread T5 and the looper thread that run in a direction intersecting with the feed direction, so that the edges of two pieces of workpieces (left fabric LC and right fabric RC; see FIG. 7) can be sewn together.
The guide mechanism 10 guides the left cloth LC and the right cloth RC, the edges of which are to be sewn together, on the needle plate 120 of the sewing machine during the above-mentioned interlock stitching so that the cloths are fed smoothly along the shape of the edges to be sewn together when they are transported by the feed dogs 132 to 137.

[Needle plate]
The guide mechanism 10 is provided between a presser foot 110 and a needle plate 120 .
The needle plate 120 is a rectangular flat plate attached to a needle drop position on the top surface of the sewing machine bed (not shown). As shown in Figure 2, the needle plate 120 has four needle holes 121 aligned along the Y-axis direction, through which the four sewing needles 101 drop.
Furthermore, openings 122 and 123 are formed on both the left and right sides of the four pinholes 121, respectively, extending along the X-axis direction from the rear of the pinholes 121 to the front of the pinholes 121.
In addition, two openings 124, 125 along the X-axis direction are formed side by side on the rear side of the four pinholes 121, and two openings 126, 127 along the X-axis direction are formed side by side on the front side of the four pinholes 121.

Left and right feed dogs 132, 133 are arranged inside the left and right openings 122, 123, rear feed dogs 134, 135 are arranged inside the rear openings 124, 125, and front feed dogs 136, 137 are arranged inside the front openings 126, 127.
Each of the feed dogs 132 to 137 performs an elliptical motion along the XZ plane, and moves forward when protruding from the openings 122 to 127, thereby feeding the left cloth LC and the right cloth RC on the needle plate 120 forward.

[Presser foot]
As shown in FIGS. 1 and 3, the presser foot 110 is connected to a presser bar 103 via a pin 102 aligned along the Y-axis direction.
The presser foot 110 has a connecting portion 111 for connecting to the presser bar 103 on the upper surface near the front end.
Furthermore, the presser foot 110 has a flat portion 112 along the XY plane, a sloped portion 113 that slopes upward as it approaches the rear at its rear end, and a sloped portion 114 that slopes upward as it approaches the front at its front end.
Further, the flat portion 112 of the presser foot 110 has needle openings 115 formed therethrough in the vertical direction, through which the four sewing needles 101 can be loosely inserted.

The presser bar 103 supporting the presser foot 110 is urged downward by a pressure spring (not shown) within the sewing machine arm, so that the presser foot 110 applies downward pressure to the left fabric LC and the right fabric RC on the needle plate 120.
The presser foot 110 can be pulled upward against the pressure spring, for example, by a presser release lever (not shown). Alternatively, the presser bar 103 may be connected to an actuator (not shown) and a release command may be given to allow the presser foot 110 to be pulled upward against the pressure spring.

[Guide mechanism]
As shown in Figures 1 to 3, the guide mechanism 10 includes a guide pin 20 that protrudes from the upper surface of the needle plate 120 toward the presser foot 110, and an insertion portion 30 provided on the presser foot 110, into which the guide pin 20 can be inserted.

The guide pin 20 has a round bar shape and is provided standing upward next to the four needle holes 121. The guide pin 20 is disposed immediately behind the four needle holes 121 (upstream in the feed direction).
In this case, "adjacent" refers to a state in which no other members or structures are provided between the pinhole 121 and the guide pin 20. In addition, it is desirable to arrange the pinhole 121 and the guide pin 20 as close as possible to each other in the X-axis direction.
Moreover, it is preferable that the guide pin 20 has a diameter as small as possible within a range in which the necessary strength can be ensured.

4 is an enlarged cross-sectional view of the periphery of the guide pin 20. As shown in the figure, the guide pin 20 is inserted and supported in a support hole 21 formed in the needle plate 120, and is fixed so as not to move up and down by a set screw 22, which is a headless screw screwed into the support hole 21 in a direction perpendicular to the support hole 21.
The amount of protrusion of the guide pin 20 can be adjusted up or down by loosening the set screw 22. In other words, the support hole 21 and the set screw 22 constitute an adjustment portion that adjusts the amount of protrusion of the guide pin 20.

The inserted portion 30 consists of a through hole that penetrates vertically through the flat portion 112 of the presser foot 110 and into which the guide pin 20 can be inserted, and is formed adjacent to and immediately behind the aforementioned needle opening 115 (upstream in the feed direction).
In this case, "adjacent" refers to a state in which no other members or structures are provided between the needle opening 115 and the inserted portion 30. In addition, it is desirable to arrange the needle opening 115 and the inserted portion 30 as close as possible in the X-axis direction.

A guide pin 20 extending from the needle plate 120 is inserted into the insertion portion 30 from below.
The presser foot 110 rises by the thickness of the left fabric LC or right fabric RC in the pressed state while pressing down the left fabric LC and the right fabric RC from above on the needle plate 120. When the presser foot 110 is in this raised state, the adjustment part adjusts the guide pin 20 so that it protrudes from the upper surface of the needle plate 120 by a length that prevents the guide pin 20 from easily slipping out of the insertion portion 30 during sewing.
For example, when the thicknesses of the left fabric LC and the right fabric RC are given, the protrusion amount of the guide pin 20 is adjusted so that it is equal to or greater than the sum of (the thickness of the left fabric LC or the right fabric RC) + (the thickness of the flat portion 112 of the presser foot 110) + (the maximum protrusion amount of each of the feed dogs 132 to 136 from the upper surface of the needle plate 120).
Furthermore, when the thickness of the left fabric LC or the right fabric RC is not a known value, it is preferable to set the thickness to be equal to or greater than the sum of (the expected maximum thickness of the left fabric LC or the right fabric RC) + (the thickness of the flat portion 112 of the presser foot 110) + (the maximum protrusion amount of each of the feed dogs 132 to 136 from the upper surface of the needle plate 120).

The guide pin 20 and the inserted portion 30 are disposed between the feed teeth 134, 135 located on the rear side (upstream side in the feed direction) and the feed teeth 136, 137 located on the front side (downstream side in the feed direction) in the X-axis direction.

[Guide operation by guide mechanism]
When sewing with an interlock stitch sewing machine, the guide pin 20 of the guide mechanism 10 is positioned between the butted edges of the left cloth LC and the right cloth RC pressed down from above by the presser foot 110, and in this state the left cloth LC and the right cloth RC are fed forward by the feed dogs 132 to 136.
As a result, the left cloth LC and the right cloth RC are fed so that the guide pin 20 traces the edge portions of the left cloth LC and the right cloth RC. Therefore, even if the shape of the edge portions of the left cloth LC and the right cloth RC is not straight in a plan view, for example, if it is curved, the left cloth LC and the right cloth RC can be guided along that shape, and good, high-quality interlock stitching can be performed along the shape of the edge portions.

Technical Effects of the Invention Embodiments
The technical effects of the above-mentioned guide mechanism 10 will be described based on a comparison with a guide mechanism 10X as a comparative example. Figure 5 is a cross-sectional side view of a presser foot 110 provided with the guide mechanism 10X, and Figure 6 is a perspective view.

The guide mechanism 10X of the comparative example is composed of a guide plate along the X-Z plane that is interposed between the edge of the left fabric LC and the edge of the right fabric RC. Because the presser foot 110 has a function of pressing down the edge of the left fabric LC and the right fabric RC from above with the flat portion 112, the guide mechanism 10X cannot be provided on the underside of the flat portion 112, and can only be provided on the sloped portion 113 that is separated from the needle drop position.
The guide mechanism 10X differs from the guide mechanism 10 in that it is flat along the X-Z plane, that it is disposed away from the needle drop position, etc. In this case, if the edge portion of the left cloth LC and the edge portion of the right cloth RC are linear, no problem occurs. However, if the edge portions are not linear, such as curved, the edge portions of the left cloth LC and the edge portions of the right cloth RC may be guided to a position deviating from the trajectory along which they should originally pass, which may result in a deterioration in sewing quality.

FIG. 7 is a plan view of the left cloth LC and the right cloth RC showing the state where interlock stitching has been performed using the guide mechanism 10, and FIG. 8 is a plan view of the left cloth LC and the right cloth RC showing the state where interlock stitching has been performed using the guide mechanism 10X.
In the case of the guide mechanism 10, in addition to the guide pin 20 having a small width in the X-axis direction guiding the edge of the left fabric LC and the edge of the right fabric RC, the insertion portion 30 is provided on the presser foot 110 side, so that the guide pin 20 can be positioned next to the needle hole 121, and can be brought as close as possible to the needle drop position. This makes it possible to guide the edge of the left fabric LC and the edge of the right fabric RC along the trajectory that they should pass. Therefore, as shown in Figure 7, it is possible to sew the edge of the left fabric LC and the edge of the right fabric RC in a tight contact state without generating a gap between them.
In contrast, the guide mechanism 10X may guide the edge of the left fabric LC and the edge of the right fabric RC to a position deviating from the trajectory along which they should originally pass, resulting in a gap being generated between the edge of the left fabric LC and the edge of the right fabric RC, as shown in Figure 8.
In addition, in Figures 7 and 8, the edge portion of the left cloth LC and the edge portion of the right cloth RC are both shown as straight lines, but if the edge portion of the left cloth LC and the edge portion of the right cloth RC are curved, the occurrence of gaps will be more noticeable in the case of guide mechanism 10X.

In this way, the guide mechanism 10 is equipped with a guide pin 20 protruding upward from the upper surface of the needle plate 120 and an insertion portion 30 provided on the presser foot 110, and the guide pin 20 is positioned next to the needle hole 121, so that the edge of the left fabric LC and the edge of the right fabric RC can be guided very close to the needle drop position. Even if the edge of the left fabric LC and the edge of the right fabric RC are not in a straight line, they can be guided along the trajectory that they should normally pass. This prevents gaps from occurring between the edge of the left fabric LC and the edge of the right fabric RC, making it possible to achieve sewing with high quality.
Furthermore, since the guide mechanism 10 guides the edge of the left cloth LC and the edge of the right cloth RC, high skill is not required for sewing, and the sewing work load can be reduced.

Furthermore, since the guide mechanism 10 is provided with an adjustment portion that adjusts the amount of protrusion of the guide pin 20, the amount of protrusion can be appropriately adjusted.
This makes it possible to stably guide the edge portions of the left cloth LC and the right cloth RC during sewing, and when removing the left cloth LC and the right cloth RC from above the needle plate 120 at the end of sewing, for example, the amount of protrusion can be kept to a minimum so as not to interfere with the work, making it possible to achieve a balance between stability and workability during sewing.

In addition, the guide pin 20 of the guide mechanism 10 is positioned upstream (rear) of the needle hole 121 in the feed direction of the left cloth LC and the right cloth RC, so that the guide pin 20 does not interfere with the sewing work, making it possible to perform good sewing work.

Furthermore, the guide pin 20 of the guide mechanism 10 is disposed between the feed teeth 134, 135 located upstream (rear side) in the feed direction of the left cloth LC and the right cloth RC and the feed teeth 136, 137 located downstream (front side). Therefore, the left cloth LC and the right cloth RC are fed from both the front and rear sides relative to the guide pin 20. This allows the edge portions of each cloth to be more effectively aligned with the guide pin 20, making it possible to perform sewing with higher quality.

[others]
Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and the details shown in the embodiment can be modified as appropriate without departing from the spirit of the invention.
For example, in the above embodiment, the guide pin 20 of the guide mechanism 10 is provided on the needle plate 120, and the inserted portion 30 is provided on the presser foot 110, but as shown in the guide mechanism 10A in Fig. 9, the guide pin 20A may be provided facing downward on the underside of the flat portion 112 of the presser foot 110. In this case, the inserted portion 30A may be located adjacent to and behind the needle hole 121 of the needle plate 120.
Also in this case, the guide pin 20A can be fixed in a support hole formed in the presser foot 110 by a set screw consisting of a headless screw, and the amount of protrusion of the guide pin 20A can be adjusted by loosening the set screw.
With these configurations, the guide mechanism 10A can achieve the same technical effects as the guide mechanism 10.

In addition, the insertion portion 30, 30A is a through hole into which the guide pin 20, 20A can be inserted, but it does not have to be a through hole as long as the guide pin 20, 20A can be inserted. For example, the insertion portion 30, 30A may be a bottomed hole with sufficient depth, or a notch or recess into which the guide pin 20, 20A can be inserted.

10, 10A, 10X Guide mechanism 20, 20A Guide pin 21 Support hole 22 Set screw 30, 30A Inserted portion 101 Sewing needle 110 Presser foot 112 Flat portion 113, 114 Sloped portion 115 Needle opening 120 Needle plate 121 Needle holes 122 to 127 Openings 132 to 137 Feed dog LC Left fabric (workpiece)
RC Right fabric (material to be sewn)
T1-T4 Needle thread T5 Decorative thread

Claims (4)

A guide pin for the workpiece protruding from an upper surface of a needle plate of a flat stitch sewing machine that sews together the edges of two pieces of workpieces toward a presser foot that holds the workpiece on the needle plate;
an insertion portion provided on the presser foot into which the guide pin can be inserted,
The guide pin is disposed upstream of the needle hole in the feed direction of the sewing workpiece, and is disposed adjacent to the needle hole in the feed direction of the sewing workpiece,
The guide pin is a round bar-shaped pin that is positioned adjacent to the needle hole formed in the needle plate in the feed direction of the workpiece, and is positioned between the butted edges of the two pieces of workpiece when sewing . A guide pin for a workpiece protruding from a lower surface of a presser foot that holds the workpiece on a needle plate of a flat stitch sewing machine for sewing together the edges of two pieces of workpiece, toward the needle plate;
an insertion portion provided on the needle plate into which the guide pin can be inserted,
the insertion portion is disposed adjacent to a needle hole formed in the needle plate in a feed direction of the workpiece ,
the guide pin is disposed upstream of the needle hole in a feed direction of the sewing material,
The guide mechanism for a flat stitch sewing machine is characterized in that the guide pin is round bar-shaped and positioned between the butted edges of the two pieces of workpiece during sewing . 3. The guide mechanism for a flat stitch sewing machine according to claim 1, further comprising an adjustment portion for adjusting the amount of protrusion of said guide pin. 4. The guide mechanism for a flat stitch sewing machine according to claim 1, wherein the guide pin is disposed between a feed dog located on the upstream side of the sewing material in the feed direction and a feed dog located on the downstream side of the sewing material.

Images