JP4616512B2 - Needle plate structure in flat stitched multi-needle sewing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a needle plate structure in a flat-sewing multi-needle sewing machine that can cut a sewing thread end as short as possible when cutting an upper thread and a lower thread after sewing that are sewn on a sewing fabric. is there.
[0002]
[Prior art]
FIGS. 14 and 15 each show a conventional thread cutting device in a flat stitch two-needle sewing machine, where 1 is a stitch by using three threads, 2 is an upper thread, 3 is a lower thread, Is an upper thread sewing loop by upper thread 2, 5 is a lower thread sewing loop by lower thread 3, 6 is a sewing needle, 7 is a looper, 85 is a needle plate, 86 is a needle hole, and 87 is a nail provided on needle plate 85. is there.
[0003]
Reference numeral 88 denotes a thread cutting device which is positioned below the horizontal surface of the needle plate 85, 89 is an appropriately fixed upper blade, 90 is a reciprocating lower blade, and a lower thread cutting lower blade 91 and upper thread cutting. When cutting the end of the sewing thread at the end of sewing, the lower blade 90 is reciprocated in the direction of the arrow indicated by the dotted line as shown in FIG. To cut.
[0004]
That is, when the lower blade 90 reciprocating as shown in FIG. 15 returns to the original position, the upper blade 89 and the lower blade 90 return to the original position while appropriately concentrating the upper threads 2, 2 and the lower thread 3. The upper thread 3 and the lower thread 2 are cut through the blades 91 and 92, respectively.
[0005]
[Problems to be solved by the invention]
However, when the sewing thread is cut using the sewing thread cutting device 88 as described above, the lower blade 90 is moved to the position of the upper blade 89 far from the position of the needle hole 86 for cutting, so that the needle hole 86 and the sewing thread cutting device are used. The distance between 88 becomes longer, and the cutting ends (sewing ends) of the upper thread 2 and the lower thread 3 become longer.
[0006]
Further, in the case of the conventional throat plate 85, the thickness thereof is formed to be thick (about 2.5 to 3.0 mm), so that the sewing thread cutting end of the upper thread 2 is excessive by the thickness of the throat plate 85. Eventually, the length of the yarn end becomes approximately 7 to 9 mm, which is obtained by adding the thickness of the needle plate 85 to the distance between the needle hole 86 and the sewing thread cutting device 88 described above. For this reason, the appearance of the sewn product is deteriorated and the quality of the sewn product is deteriorated. Therefore, if the cutting end of the upper thread 2 is to be cut as short as possible, a manual cutting operation is required, which causes a disadvantage of reducing the efficiency of the sewing operation.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a movable claw that is slidable separately from a single needle plate having a needle hole and a fixed claw, instead of a conventional needle plate formed in a single layer. It is provided on the back of the needle plate and has a double structure. An upper blade is provided on the neck of the fixed claw, a lower blade is provided on the movable claw, and the movable claw is slid to sew. It has a function to cut the sewing thread after wearing. Therefore, it is possible to cut the end of the sewing thread as short as possible, saving the trouble of cutting the end of the sewing thread having a long bristle as before. This can contribute to improvement of the sewing efficiency and improvement of the quality of the sewing product.
[0008]
Further, in the present invention, a movable claw that is slidable separately from a single throat plate having a needle hole and a fixed claw is provided on the back surface of the throat plate to form a double structure, so that compared to the case of a conventional thick throat plate. In the present invention, it is possible to make the thickness of the needle plate as thin as possible. Therefore, by further shortening the distance between the sewing fabric and the thread cutting portion of the upper thread, the cutting thread end of the upper thread becomes shorter and the quality is improved. It is possible to obtain an excellent sewing product.
[0009]
[Action]
In the present invention, a movable claw that is slidable separately from a single throat plate having a needle hole and a fixed claw is provided on the back surface of the needle plate, an upper blade is provided on the neck portion of the fixed claw, and a lower claw is provided on the movable claw. By providing a blade and sliding the movable claw to cut the upper thread and lower thread after sewing at the position of the needle hole, the thread end of the sewing thread can be cut as short as possible. The efficiency is improved and the quality of the sewing product is improved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view showing a formation state of a stitch 1 by using three threads in a flat stitch two-needle sewing machine. 2, 2 is an upper thread, 3 is a lower thread, 4 is an upper thread sewing loop by an upper thread 2. Reference numeral 5 denotes a lower thread sewing loop with the lower thread 3, 6 a sewing needle, and 7 a looper. FIG. 2 is a schematic plan view of a needle plate 10 in a flat-sewing two-needle sewing machine, 11 is a needle hole, 12 and 13 are side grooves and rear grooves provided in series in the needle plate 10, respectively. The side grooves 12 and 12 are provided so as to communicate with the needle holes 11 and 11, respectively, 14, 14... Are notched holes, and a feed for feeding the cloth (not shown) is placed in the hole 14. It is provided so as to be able to appear and retract so that the sewing fabric is fed backward, and 15 is a fixed claw provided on the needle plate 10.
[0011]
16 is an upper blade provided at the rear edge of the needle hole 11, that is, at the neck of the fixed claw 15, 20 is a movable claw provided on the back side of the needle plate 10, and 21 is a main part of the claw 20, 22 is a horizontal surface provided on the main body 21, 23 is a rod provided on the front side of the main body 21, and 25 and 25 are side protrusions provided on the left and right sides of the main body 21, respectively. The peripheral part is formed in a substantially trapezoidal shape.
[0012]
Reference numerals 27 and 27 respectively denote protrusions provided in a protruding shape on both the left and right sides of the movable claw 20 and are formed in a substantially triangular shape, and a concave curved portion 28 at the rear position of the protrusion 27 (the sewing fabric feed side). And a lower blade 29 is formed at the upper edge of the curved portion 28, and 30 is a curved inclined portion provided at a front position of the protruding portion 27 (on the opposite side of the curved portion 28). The protrusion 27 has a thickness approximately equal to or less than about half the thickness of the main body 21 so that the sewing loop can be easily held and rolled.
[0013]
Reference numeral 31 denotes a sewing loop detachment portion that is integrally provided at a rear position of the main body portion 21, and the step portion 32 provided on the surface of the detachment portion 31 is formed in a step shape that is one step lower than the horizontal surface 22 of the main body portion 21. 35 is an inclined portion provided on the back surface side of the sewing loop detachment portion 31, and is inclined upward toward the rear position (downstream).
[0014]
In the case of using three threads of a flat sewing two-needle sewing machine, when the stitch 1 is applied to the sewing fabric W via the upper threads 2, 2 and the lower thread 3 as shown in FIGS. 15 and the movable claw 20 are covered with the sewing fabric W and the upper thread and lower thread sewing loops 4 and 5, respectively, and when the sewing fabric W is fed to the rear position of the sewing machine in this state, the above-mentioned sewing is performed. The lower thread stitching loop 5 that is smoothly moved rearwardly of the stitch 1 through the stepped portion 32 of the loop detaching portion 31 and is locked to the inclined portion 35 of the sewing loop detaching portion 31 is the sewing fabric W. Are easily separated from the inclined portion 35 with the movement of the lens and are easily removed.
[0015]
Reference numeral 36 denotes a concave guide fixed to the back side of the needle plate 10 so as to insert and support the rod 23 of the movable claw 20. Reference numeral 37 denotes a support shaft provided on the rod 23, which swings on the support shaft 37. The upper end of the rod 40 is pivotally supported, and is further pivotally supported on a support shaft 41 provided with the swinging rod 40 as appropriate.
[0016]
Reference numeral 43 denotes an air cylinder, which is provided below the swinging rod 40 at a position where it can be rotated. 45 is a piston of the air cylinder 43. The piston 45 can be rotated at the lower end of the swinging rod 40. It is pivotally supported as appropriate.
[0017]
When a desired sewing is performed on the sewing fabric W, that is, when the sewing machine is driven, the piston 45 of the air cylinder 43 is pushed forward as shown in FIG. Accordingly, the rod 23 of the movable claw 20 is positioned at the position R as shown in FIG.
When the desired sewing is completed on the sewing fabric W (at the end of sewing), that is, when the driving of the sewing machine is stopped, the air cylinder 43 is simultaneously operated so that the piston 45 is drawn. As shown in FIG. 5, the rod 23 moves forward from the position R to the position S, and the movable claw 20 also moves forward and slides integrally.
[0018]
When the air cylinder 43 is activated and the piston 45 is retracted when sewing is completed (at the end of sewing) as described above, the piston 45 is pushed out by operating the air cylinder 43 again after a predetermined time via a timer or the like. Therefore, the rod 23 is returned from the position S to the original position R, and the movable claw 20 is similarly retracted and returned to the original position.
It should be noted that when the piston 45 is pushed out by operating the air cylinder 43 after stopping the driving of the sewing machine as described above, the air cylinder 43 may be operated again and the piston 45 may be retracted.
[0019]
Next, the operation of the present invention will be described below by taking the case of using three threads of a flat stitch two-needle sewing machine as an example.
First, as shown in FIGS. 6 and 8, when the stitch 1 is applied to the sewing fabric W via the upper threads 2, 2 and the lower thread 3, the fixed claw 15 and the movable claw 20 When the sewing material W is fed to the rear position of the sewing machine in this state, it is covered with the lower thread sewing loops 4 and 5, and the lower thread sewing loop 5 is moved along with the backward movement of the sewing material W, respectively. The sewing loop detachment portion 31 is sequentially detached from the inclined portion 35 and then comes out.
[0020]
Further, as shown in FIG. 8, an upper thread sewing loop 70 that is fed out from the sewing needle 6 and passed through the sewing fabric W through the looper 7 is formed from the front part A and the rear part B, and further, the upper thread sewing loop. The upper thread sewing loop 71 formed from the parts C and D is located at the rear position 70, and similarly, the upper thread sewing loop 72 formed from the parts E and F is located at the rear position of the upper thread sewing loop 71. The upper thread sewing loops... Are successively formed and formed in the same manner.
[0021]
Further, in the case of the lower thread sewing loop inserted by the looper 7 side and drawn out by the lower thread 3, that is, in the case of the lower thread sewing loop 80 locked to the upper thread sewing loop 70, the portion B of the upper thread sewing loop 70. The loop 80 is formed via the parts J and K locked to the loops, and the loop 80 is formed via the parts G and H locked to the part A of the upper thread sewing loop 70.
[0022]
Further, at the rear position of the lower thread sewing loop 80, the lower thread sewing loop 81 formed from the parts L and M is located. Similarly, at the rear position of the lower thread sewing loop 81, the lower thread formed from the parts P and Q The sewing loop 82 is positioned, and the respective lower thread sewing loops... Are sequentially formed in the same manner.
[0023]
When the desired sewing is performed on the sewing fabric W, that is, while the sewing machine is being driven, the front end portion of the rod 23 provided on the movable claw 20 is at the position R as shown in FIGS. The protrusion 27 of the movable claw 20 is positioned at the position U.
Next, when the desired sewing is completed (at the end of sewing) and the driving of the sewing machine is stopped, the piston 45 is drawn through the operation of the air cylinder 43, so that the rod 23 advances from the position R and reaches the position S. That is, the protrusion 27 of the movable claw 20 moves from the position U to the position V as shown in FIG.
[0024]
When the protrusion 27 of the movable claw 20 moves (slids) from the position U to the position V as described above, the part A of the upper thread sewing loop 70 and the part of the lower thread sewing loop 80 as shown in FIGS. J is in a state of being locked to the curved inclined portion 30 of the protruding portion 27.
Further, the part B of the upper thread sewing loop 70, the parts G and H of the lower thread sewing loop 80 locked to the part A of the upper thread sewing loop 70, and the lower thread sewing locked to the part B of the upper thread sewing loop 70 are performed. The part K of the loop 80 is located in the concave curved part 28 of the protrusion part 27, respectively.
[0025]
Next, when the projecting portion 27 of the movable claw 20 moves (slids) from the position U to the position V as described above, the air cylinder 43 is actuated again and the piston 45 is pushed out, thereby moving the movable claw 20 as shown in FIG. The rod 23 provided in is slid from the position S back to the original position R and returned.
[0026]
That is, as described above, the portion B of the upper thread sewing loop 70 and the portions G, H, and K of the lower thread sewing loop 80 that are located in the concave curved portion 28 of the protrusion 27 are the same as those of the protrusion 27 from the position V. Through the cutting operation by the lower blade 29 provided on the upper end edge of the concave curved portion 28 and the upper blade 16 provided on the neck portion 17 of the fixed claw 15, at the same time when sliding to and returning to the position U of The part B of the upper thread sewing loop 70 and the parts G, H, and K of the lower thread sewing loop 80 are simultaneously cut.
[0027]
Note that the portion B of the upper thread sewing loop 70 and the portions G, H, and K of the lower thread sewing loop 80 that are connected to the sewing fabric W are integrally cut at the portion of the needle hole 11 as a result. Is cut very short compared to the prior art, and a beautiful sewing fabric W having excellent quality can be obtained.
[0028]
Further, in order to cut the portion B of the upper thread sewing loop 70, that is, the thread end on the upper thread side, further shorter, it is desirable to reduce the thickness of the needle plate 10 as much as possible. That is, it is optimal that the thickness Z of the throat plate 10 is in the range of 1 mm to 5 mm as shown in FIG. 5, and when the thickness Z of the throat plate 10 is 1 mm or less, the strength of the throat plate 10 becomes weak. In addition, if the thickness Z of the needle plate 10 is 5 mm or more, the end of the upper thread may be long, which is not preferable.
In addition, as a preferable application example in the present invention, there is a range that can be similarly applied to a flat stitching three-needle and a four-needle sewing machine in addition to the flat stitching two-needle sewing machine.
[0029]
【The invention's effect】
As described above, the present invention is characterized in that, apart from a single needle plate having a needle hole and a fixed claw, a movable claw capable of sliding (reciprocating) is provided on the back surface of the needle plate to form a double structure. An upper blade is provided on the neck portion of the fixed claw and a lower blade is provided on the movable claw, and the movable claw is slid so as to have a function of cutting the sewing thread after sewing. By cutting the end of the thread at the position of the needle hole, unlike the case of cutting at a position farther away than the position of the needle hole as in the past, the end of the sewing thread at the sewing end position of the sewing fabric is cut extremely short. Is now possible.
[0030]
Further, it is possible to save the time and labor of cutting the ends of the seams with long bristles as in the prior art, which can greatly contribute to the improvement of the sewing efficiency and the quality of the sewing product. Furthermore, in the present invention, a movable claw that is slidable separately from a single throat plate having a needle hole and a fixed claw is provided on the back surface of the throat plate to form a double structure, so that the thickness of the conventional throat plate can be compared. The thickness of the needle plate according to the present invention can be further reduced. Therefore, by shortening the distance between the sewing fabric and the thread cutting portion of the upper thread, the cutting thread end of the upper thread is further shortened, and the stitches It is possible to obtain an excellent sewing product with a beautiful quality.
[Brief description of the drawings]
FIG. 1 is a perspective view when a stitch is formed by using three threads of a flat stitch two-needle sewing machine.
FIG. 2 is a schematic plan view of a needle plate of a flat-sewn two-needle sewing machine according to the present invention.
FIG. 3 is an enlarged plan view of the main part of FIG. 2;
FIG. 4 is a plan view of a movable claw in the present invention.
5 is a cross-sectional view taken along the line XX of FIG.
6 is a YY cross-sectional view of FIG.
FIG. 7 is a perspective view of a movable claw in the present invention.
FIG. 8 is a schematic cross-sectional side view showing a relationship between a stitch formation state of a flat-sewn two-needle sewing machine and a needle plate and a movable claw in the present invention.
FIG. 9 is a schematic side cross-sectional view for explaining an operation, showing a locking state between a stitch and a movable claw at the end of sewing in a flat stitch two-needle sewing machine of the present invention.
FIG. 10 is a schematic sectional side view for explaining an operation showing a cutting state of a thread end at the end of sewing in a flat stitch two-needle sewing machine of the present invention.
FIG. 11 is a schematic plan view for explaining the operation on the side of the throat plate showing an arrangement state of the stitches in the formation of the stitches of the flat stitch two-needle sewing machine according to the present invention.
FIG. 12 is a schematic plan view for explaining the operation on the throat plate side showing an arrangement state of stitches and movable claws at the end of sewing in the flat stitch two-needle sewing machine of the present invention.
FIG. 13 is a schematic plan view for explaining the operation on the side of the throat plate showing the arrangement after the stitches are cut at the end of sewing in the flat stitching two-needle sewing machine of the present invention.
FIG. 14 is a schematic perspective view of a thread cutting device for a flat-sewing two-needle sewing machine according to a conventional example.
FIG. 15 is a schematic plan view of a thread cutting device for a flat stitch two-needle sewing machine according to a conventional example.
[Explanation of symbols]
1 stitch 2 upper thread 3 lower thread 4 upper thread sewing loop 5 lower thread sewing loop 6 sewing machine needle 7 looper 10 needle plate 11 needle hole 12 lateral groove 13 rear groove 15 fixed claw 16 upper blade 20 movable claw 27 projecting portion 28 Concave curved portion 29 Lower blade 30 Inclined curved portion U Movable claw retraction position V Movable claw advance position W Fabric

Claims (3)

A needle plate structure for a sewing machine having a plurality of sewing needles arranged in parallel, each needle hole where each sewing machine needle moves up and down, and each needle hole is positioned between each of the grooves following the needle holes. In a needle plate structure of a sewing machine composed of a fixed claw formed toward the cloth feeding side and a movable claw arranged and slid below the fixed claw, an upper blade is provided on the neck of the fixed claw and A needle plate structure in a flat-sewing multi-needle sewing machine having a function of cutting a sewing thread after sewing by providing a lower blade on the movable claw and sliding the movable claw. The projecting protrusion is provided on the movable claw, the lower blade having a concave curved portion is provided toward the cloth feeding side, and the opposite side of the curved portion of the lower blade is inclined. A needle plate structure in a flat stitch sewing machine with multiple needles. The needle plate structure in the flat-sewn multi-needle sewing machine according to claim 1 or 2, wherein the thickness of the fixed claw is in a range of 1 mm to 5 mm.

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