Column type sewing machine with thread cutting mechanism

Abstract

The utility model relates to a column type sewing machine with a thread cutting mechanism, which comprises a kettle plummer block, a needle plate frame, a kettle cover, a rotating shuttle, a fixed cutter and a movable cutter, the needle plate frame and the kettle cover jointly encircle to form an accommodating space positioned on one side of the kettle plummer block, and the accommodating space is divided into a needle hole communication area and a rotating shuttle mounting area through a stop groove of the needle plate frame; the rotating shuttle is located in the rotating shuttle installation area, the fixed cutter is arranged in the needle hole communication area, so that the fixed blade part of the fixed cutter can be close to the needle hole of the needle plate frame, the movable cutter is provided with a swing arm part, an extension part and a movable blade part, the height position of the swing arm part is lower than that of the rotating shuttle, the extension part is arranged in the needle hole communication area, and the movable blade part is arranged in the needle hole communication area. Therefore, the arrangement and combination of the movable cutter and the rotating shuttle can reduce the volume jointly formed by the movable cutter and the rotating shuttle, and further a kettle cover with a smaller volume can be used for covering the movable cutter and the rotating shuttle at the same time.

Description

Technical Field

[0001] The utility model relates to a columnar sewing machine applicable to sewing shoes, bags or tubes, and particularly to a columnar automatic thread-cutting sewing machine capable of using a kettle cover with a smaller volume to simultaneously cover a movable cutter and a rotary hook. Background Art

[0002] Columnar sewing machines are usually used to sew thick curved sewing materials. In order to prevent the area outside the needle plate from interfering with the sewing material and making it impossible to turn, the columnar sewing machine will place the sewing position close to the needle holes of the needle plate to facilitate the turning of the sewing material. However, when sewing materials with a smaller sewing arc, a columnar sewing machine with a smaller diameter of the kettle shaft platform is required. In recent years, in order to improve the production efficiency of columnar sewing machines, many columnar sewing machines have been equipped with automatic thread-cutting devices to automatically cut the sewing thread. However, the installation of an automatic thread-cutting device on the columnar sewing machine will increase the diameter of the kettle shaft platform, which instead makes the columnar sewing machine unfavorable for sewing sewing materials with a smaller bending arc.

[0003] Please refer to Figure 1 As shown, after the existing columnar sewing machine 50 completes the sewing operation on the sewing object, in order to facilitate the cutting of the sewing thread, the existing columnar sewing machine 50 is equipped with a thread-cutting mechanism 51 capable of cutting the sewing thread. As shown in the figure, the thread-cutting mechanism 51 mainly has a fixed cutter 511 and a movable cutter 512. The fixed cutter 511 is connected to a kettle shaft platform 53 via a fixed cutter seat 52, and the movable cutter 512 is connected to a movable cutter shaft 54 pivotally connected to the kettle shaft platform 53. Among them, one end of the movable cutter shaft 54 away from the movable cutter 512 is connected to a driving device (not shown in the figure), so that the movable cutter shaft 54 drives the movable cutter 512 to swing reciprocally, so that the swinging movable cutter 512 first completes the thread-hooking action, and then approaches the fixed cutter 511 to complete the thread-cutting operation.

[0004] However, the movable cutter 512 of the existing columnar sewing machine 50 is disposed above a rotary hook 55 assembled on the kettle shaft platform 53, so that the height position of the movable cutter 512 is higher than the height position of the rotary hook 55. Moreover, the movable cutter shaft 54 is located outside the rotation radius range of the rotary hook 55. Therefore, the arrangement combination between the movable cutter 512 and the rotary hook 55 will increase the volume formed by the movable cutter 512 and the rotary hook 55 together. Relatively, the existing columnar sewing machine 50 will use a kettle cover with a larger volume to simultaneously cover the movable cutter 512 and the rotary hook 55, resulting in an increase in the volume of the existing columnar sewing machine 50. Summary of the Utility Model

[0005] The main object of the present utility model is to provide a cylindrical sewing machine with a thread cutting mechanism, which improves the structural form of the movable cutter to change the arrangement combination between the movable cutter and the rotary hook, so that the volume formed by the movable cutter and the rotary hook can be effectively reduced, and relatively a smaller kettle cover can be used to cover the movable cutter and the rotary hook at the same time.

[0006] The secondary object of the present utility model is to provide a cylindrical sewing machine with a thread cutting mechanism, which improves the installation position of the thread cutting mechanism in the cylindrical sewing machine, so that the fixed cutter of the thread cutting mechanism is close to the needle hole of the needle plate holder. After the movable cutter of the thread cutting mechanism cooperates with the fixed cutter to cut the sewing thread, the length of the remaining thread on the surface of the sewn object is shorter, and thus the need for a second trimming of the thread head can be avoided, thereby shortening the operation time and increasing the production volume.

[0007] Another object of the present utility model is to provide a cylindrical sewing machine with a thread cutting mechanism, which improves the connection object of the fixed cutter in the thread cutting mechanism, so that when the needle plate is separated from the kettle shaft platform, the relative position between the fixed cutter and the rotary hook will not change due to the disassembly or assembly of the needle plate. Therefore, the sewing operator can not only conveniently replace the needle plate, but also easily adjust the relative position between the fixed cutter and the rotary hook.

[0008] Another object of the present utility model is a cylindrical sewing machine with a thread cutting mechanism, and the connection manner between the movable cutter and the movable cutter seat enables the movable cutter to move relative to the movable cutter seat to adjust the relative position relationship between the movable cutter and the movable cutter seat. Thus, the movable cutting edge of the movable cutter can be far away from the rotary hook to increase the rotation radius of the movable cutter, or the movable cutting edge of the movable cutter can be close to the rotary hook to shorten the rotation radius of the movable cutter.

[0009] To achieve the foregoing objects, the present utility model provides a cylindrical sewing machine with a thread cutting mechanism. The cylindrical sewing machine with a thread cutting mechanism includes: a base, a rotary hook and a thread cutting mechanism.

[0010] The base has a kettle shaft platform, a needle plate holder and a kettle cover. The needle plate holder and the kettle cover are both connected to the kettle shaft platform, so that the needle plate holder and the kettle cover jointly form an accommodation space on one side of the kettle shaft platform. The needle plate holder is recessed to form a stop groove in the accommodation space, and the accommodation space is divided into a needle hole communication area and a rotary hook installation area through the stop groove. The needle hole communication area communicates with a needle hole of the needle plate holder.

[0011] The rotary hook is located in the rotary hook installation area and has an outer kettle that can rotate relative to the needle plate holder and an inner kettle assembled inside the outer kettle. The inner kettle extends to form an inner kettle stop block that can abut against the stop groove, so that the inner kettle cannot rotate with the outer kettle.

[0012] The tangent mechanism has a fixed cutter and a movable cutter. The fixed cutter is disposed in the needle hole communication area such that a fixed cutting edge of the fixed cutter can be close to the needle hole. The movable cutter is sequentially provided with an arm portion having a height position lower than that of the bobbin case, an extension portion located inside the needle hole communication area, and a movable cutting edge portion located inside the needle hole communication area. The movable cutter can reciprocate inside the accommodation space such that the arm portion can drive the movable cutting edge portion to approach or move away from the fixed cutting edge portion through the extension portion.

[0013] In a preferred embodiment, the cylindrical sewing machine having the tangent mechanism further has a feed wheel that can rotate. The feed wheels are arranged at intervals inside the needle hole communication area relative to the bobbin case. When the movable cutter reciprocates inside the accommodation space, the extension portion can pass between the feed wheel and the bobbin case.

[0014] In addition, the tangent mechanism further has a movable cutter seat located inside the accommodation space. The arm portion is provided with a movable cutter connecting portion at one end away from the extension portion. The movable cutter connecting portion is provided with a movable convex block to movably connect to a movable groove of the movable cutter seat such that the movable cutter can move relative to the movable cutter seat to adjust the relative positional relationship between the movable cutter and the movable cutter seat. Furthermore, the movable cutting edge portion can selectively approach or move away from the bobbin case.

[0015] Wherein, the needle plate holder has a needle plate provided with the needle hole and the stop groove, and a needle plate seat connected between the needle plate and the kettle shaft platform. The fixed cutting edge portion is disposed between the needle hole and the stop groove such that the fixed cutting edge portion is close to the needle plate. Furthermore, the height position of the fixed cutting edge portion is close to the height position of the inner kettle stopper.

[0016] Moreover, the tangent mechanism further has a fixed cutter seat connected to the kettle shaft platform. The fixed cutter is connected to the fixed cutter seat such that the fixed cutter is close to the needle hole through the fixed cutter seat. Wherein, the tangent mechanism further has a thread clamping spring piece. One end of the thread clamping spring piece is connected to the fixed cutter seat, and the other end of the thread clamping spring piece abuts against the bottom surface of the movable cutting edge portion.

[0017] In addition, the fixed cutter base has a first cutter base for connecting to the kettle shaft platform and a second cutter base connected to the fixed cutter. The first cutter base is movably connected to the second cutter base, such that the second cutter base can move relative to the first cutter base to adjust the relative positional relationship between the second cutter base and the first cutter base. Further, the fixed cutter can selectively approach or move away from the needle hole.

[0018] The characteristics of the present utility model are that the movable cutter mainly has three parts: a swing arm portion, an extension portion, and a movable cutting edge portion. The height position of the swing arm portion is lower than the height position of the rotary hook, such that the swing arm portion is arranged on the lower side of the rotary hook, and the extension portion is located in the needle hole communication area of the accommodation space to be close to the needle hole of the needle plate holder, such that the extension portion is arranged on the left side of the rotary hook. Thus, the arrangement positional relationship among the swing arm portion, the extension portion, and the movable cutting edge portion relative to the rotary hook can reduce the volume jointly formed by the movable cutter and the rotary hook. Further, a kettle lid with a smaller volume can be used to cover the movable cutter and the rotary hook simultaneously.

[0019] In addition, the fixed cutter of the thread cutting mechanism is arranged inside the needle hole communication area of the accommodation space, such that the fixed cutting edge portion of the fixed cutter is close to the needle hole of the needle plate holder, and the movable cutting edge portion of the movable cutter is located inside the needle hole communication area. Thus, when the movable cutter can reciprocate inside the accommodation space, the swing arm portion can drive the movable cutting edge portion to approach the fixed cutting edge portion of the fixed cutter through the extension portion. After the movable cutter cooperates with the fixed cutter to cut the sewing thread, the length of the remaining thread on the surface of the sewn object is short. Further, the operator can avoid the need for a second trimming of the thread end, thereby shortening the operation time and increasing the production volume.

[0020] In addition, the fixed cutter of the thread cutting mechanism is connected to the kettle shaft platform via the fixed cutter base, such that the fixed cutter is close to the needle hole of the needle plate holder through the fixed cutter base. Further, when the needle plate holder is separated from the kettle shaft platform, the relative position between the fixed cutter and the rotary hook will not change due to the disassembly or assembly of the needle plate holder. Further, the operator can not only conveniently replace the needle plate of the needle plate holder but also easily adjust the relative position between the fixed cutter and the rotary hook.

[0021] Furthermore, the movable cutter of the thread cutting mechanism and the movable cutter base of the thread cutting mechanism are movably connected to each other through a movable convex block and a movable groove, such that the movable cutter can move relative to the movable cutter base to adjust the relative positional relationship between the movable cutter and the movable cutter base. Further, the movable cutting edge portion of the movable cutter can move away from the rotary hook to increase the rotation radius of the movable cutter, or the movable cutting edge portion of the movable cutter can approach the rotary hook to shorten the rotation radius of the movable cutter. Description of the Drawings

[0022] Figure 1 It is a partial schematic diagram of an existing column-type sewing machine;

[0023] Figure 2 It is a partial perspective view of the column - type sewing machine of the present utility model;

[0024] Figure 3 It is a schematic diagram of the assembly of the rotary hook mechanism, the thread - cutting mechanism and the feeding mechanism on the sewing machine body;

[0025] Figure 4 It is a partial exploded view of the sewing machine body;

[0026] Figure 5 It is an exploded view of the needle plate holder;

[0027] Figure 6 It is a partial cross - sectional view of the column - type sewing machine of the present utility model;

[0028] Figure 7 It is an exploded view of the rotary hook mechanism;

[0029] Figure 8 It is an exploded view of the thread - cutting mechanism;

[0030] Figure 9A It is a schematic diagram of the fixed cutter being away from the needle hole;

[0031] Figure 9B It is a schematic diagram of the fixed cutter being close to the needle hole;

[0032] Figure 10 It is a schematic diagram of the arrangement combination between the movable cutter and the rotary hook;

[0033] Figure 11A It is a schematic diagram of the movable cutter being away from the rotary hook;

[0034] Figure 11B It is a schematic diagram of the movable cutter being close to the rotary hook;

[0035] Figure 12 It is a schematic diagram of the feeding mechanism;

[0036] Figure 13A It is a schematic diagram of the movable cutter being at the thread - hooking position;

[0037] Figure 13B It is a schematic diagram of the movable cutter being at the preparatory cutting position;

[0038] Figure 13C It is a schematic diagram of the movable cutter being at the initial position.

[0039] Description of reference numerals: 1 - Cylindrical sewing machine; 10 - Sewing machine body; 11 - Base; 12 - Lower shaft; 13 - Workbench surface; 14 - Cylindrical base; 141 - Bobbin shaft base; 141a - Rotating hook shaft hole; 141b - Cutter shaft hole; 141c - Feed shaft hole; 142 - Needle plate holder; 142a - Needle plate; 142a1 - Needle hole; 142a2 - Feed through hole; 142a3 - Cutter movement space; 142a4 - Stopper; 142a5 - Stopping groove; 142b - Needle plate base; 143 - Bobbin cover; 144 - Accommodating space; 144a - Needle hole communication area; 144b - Rotating hook installation area; 20 - Rotating hook mechanism; 21 - Rotating hook shaft; 22 - Rotating hook; 221 - Outer bobbin; 222 - Inner bobbin; 222a - Inner bobbin stopper; 23 - First bevel gear set; 30 - Thread cutting mechanism; 31 - Fixed cutter set; 311 - Fixed cutter seat; 311a - First cutter seat; 311b - Second cutter seat; 312 - Fixed cutter; 312a - Fixed cutter connecting part; 312b - Fixed cutter blade part; 32 - Movable cutter set; 321 - Movable cutter shaft; 322 - Movable cutter seat; 322a - Movable groove; 323 - Movable cutter; 323a - Movable cutter connecting part; 323b - Swing arm part; 323c - Extension part; 323d - Movable cutter blade part; 323e - Movable convex block; 33 - Thread clamping spring piece; 331 - Thread clamping connecting part; 332 - Thread clamping part; 40 - Feed mechanism; 41 - Feed shaft; 42 - Feed wheel; 43 - Feed driving source; 44 - Second bevel gear set; P1 - Hook position; P2 - Preparation cutting position; P3 - Initial position; 50 - Existing cylindrical sewing machine; 51 - Thread cutting mechanism; 511 - Fixed cutter; 512 - Movable cutter; 52 - Fixed cutter seat; 53 - Bobbin shaft base; 54 - Movable cutter shaft; 55 - Rotating hook. Detailed implementation mode

[0040] The present invention will be further described below in conjunction with specific embodiments and the drawings, and the advantages and features of the present invention will become clearer with the description.

[0041] In this drawing, the two sides of the X-axis refer to the left and right sides of the operator facing the cylindrical sewing machine 1 of the present invention, the two sides of the Y-axis refer to the front and back sides of the operator facing the cylindrical sewing machine 1 of the present invention, and the two sides of the Z-axis refer to the upper and lower sides of the operator facing the cylindrical sewing machine 1 of the present invention. Therefore, in the description of this case, directional terms such as "left", "right", "front", "back", "upper", and "lower" refer to the directions presented when the operator faces the cylindrical sewing machine 1 of the present invention.

[0042] Please refer to Figure 2 、 Figure 3 And Figure 4As shown, the column - type sewing machine 1 of the present utility model mainly consists of a sewing machine body 10, a rotary hook mechanism 20, a thread - cutting mechanism 30 and a feeding mechanism 40. The sewing machine body 10 has a headstock (not shown in the figure), a pillar (not shown in the figure) and a base 11. Inside the headstock, there is an upper shaft that can rotate around the X - axis, and inside the base 11, there is a lower shaft 12 parallel to the X - axis. The lower shaft 12 can rotate synchronously through the rotating upper shaft. Among them, the base 11 has a workbench surface 13 facing the headstock. And the base 11 forms a column - type seat 14 below the headstock along the Z - axis. The column - type seat 14 has a bobbin shaft platform 141 formed on the workbench surface 13, a needle plate holder 142 above the bobbin shaft platform 141 and a bobbin cover 143 above the bobbin shaft platform 141. As shown in the figure, the bobbin shaft platform 141 penetrates along the Z - axis direction to form a rotary hook shaft hole 141a, a cutter shaft hole 141b and a feeding shaft hole 141c. The rotary hook shaft hole 141a is located between the cutter shaft hole 141b and the feeding shaft hole 141c. The cutter shaft hole 141b is located on the right side of the bobbin shaft platform 141, and the feeding shaft hole 141c is located on the left side of the bobbin shaft platform 141. Among them, the needle plate holder 142 is located on the left side of the bobbin shaft platform 141 close to the feeding shaft hole 141c, and the bobbin cover 143 is connected to the right side of the bobbin shaft platform 141, making the bobbin cover 143 close to the cutter shaft hole 141b.

[0043] Please refer to Figure 5 As shown, the needle plate holder 142 of the column - type seat 14 has a needle plate 142a arranged at intervals above the bobbin shaft platform 141 and a needle plate base 142b connected between the needle plate 142a and the bobbin shaft platform 141. The needle plate 142a penetrates from top to bottom with a needle hole 142a1 and a feeding through - hole 142a2. And a cutter moving space 142a3 communicating with the needle hole 142a1 is recessed on the lower surface of the needle plate 142a, so that a stop block 142a4 adjacent to the cutter moving space 142a3 is formed on the needle plate 142a. Further, the cutter moving space 142a3 is located between the needle hole 142a1 and the stop block 142a4. And a stop groove 142a5 communicating with the cutter moving space 142a3 is recessed in the middle of the stop block 142a4.

[0044] Please refer to Figure 6As shown, when the needle plate holder 142 of the cylindrical base 14 and the kettle lid 143 of the cylindrical base 14 are respectively connected to the left and right sides of the kettle shaft platform 141, the needle plate holder 142 and the kettle lid 143 jointly form an accommodating space 144 above the kettle shaft platform 141. Among them, the stop block 142a4 of the needle plate 142a is located inside the accommodating space 144, so that the accommodating space 144 is divided into a needle hole communication area 144a and a bobbin case installation area 144b adjacent to each other on the left and right through the stop groove of the stop block 142a4. In this embodiment, the needle hole communication area 144a is close to the needle plate holder 142 to communicate with the needle hole 142a1 of the needle plate 142a and the feeding shaft hole 141c of the kettle shaft platform 141, while the bobbin case installation area 144b is close to the kettle lid 143 to communicate with the bobbin case shaft hole 141a and the cutter shaft hole 141b of the kettle shaft platform 141.

[0045] Please refer to Figure 3 、 Figure 6 and Figure 7 As shown, the bobbin case mechanism 20 has a bobbin case shaft 21 and a bobbin case 22. The bobbin case shaft 21 passes through the bobbin case shaft hole 141a of the kettle shaft platform 141, and the lower end of the bobbin case shaft 21 is connected to the lower shaft 12 of the sewing machine body 10 through a first bevel gear set 23, so that the lower shaft 12 drives the bobbin case shaft 21 to rotate relative to the kettle shaft platform 141 with the Z axis as the axis through the first bevel gear set 23. In addition, the bobbin case 22 is located inside the bobbin case installation area 144b of the accommodating space 144, so that the bobbin case 22 is located above the kettle shaft platform 141 of the bobbin case seat. And the bobbin case 22 has an outer case 221 for hooking the sewing thread and an inner case 222 for accommodating the bobbin thread. Among them, the outer case 221 is connected to the upper end of the bobbin case shaft 21 and can rotate inside the accommodating space 144, and the inner case 222 is assembled inside the outer case 221. And the inner case 222 extends to form an inner case stop block 222a, then the inner case stop block 222a can be caught in the stop groove 142a5 of the stop block 142a4 to limit the inner case 222 from rotating with the outer case 221.

[0046] Please refer to Figure 3 、 Figure 6 and Figure 8As shown, the tangent mechanism 30 has three parts: a fixed cutter group 31, a movable cutter group 32, and a wire clamping elastic piece 33. The fixed cutter group 31 is located in the needle hole communication area 144a of the accommodation space 144. Moreover, the fixed cutter group 31 is mainly composed of a fixed cutter base 311 and a fixed cutter 312. The fixed cutter base 311 is located above the kettle shaft platform 141 of the columnar base 14. And the fixed cutter base 311 has a first cutter base 311a connecting to the kettle shaft platform 141 and a second cutter base 311b connecting to the fixed cutter 312. The second cutter base 311b is movably connected to the first cutter base 311a. Among them, a part of the fixed cutter 312 is set as a fixed cutter connecting part 312a to connect to the second cutter base 311b, and the remaining part of the fixed cutter 312 is set as a fixed cutter blade part 312b intersecting and arranged with the fixed cutter connecting part 312a. In this embodiment, the fixed cutter blade part 312b is located inside the cutter movement space 142a3 of the needle plate 142a, so that the fixed cutter blade part 312b is arranged between the needle hole 142a1 of the needle plate 142a and the stop groove 142a5 of the needle plate 142a. Furthermore, the fixed cutter blade part 312b is close to the needle hole 142a1 of the needle plate 142a, resulting in the height position of the fixed cutter blade part 312b being close to the height position of the inner kettle stopper 222a. Thus, when the needle plate holder 142 is separated from the kettle shaft platform 141, the relative position between the fixed cutter 312 and the rotating shuttle 22 will not change due to the separation of the needle plate holder 142 from the kettle shaft platform 141. Therefore, the operator can not only conveniently replace the needle plate 142a of the needle plate holder 142, but also easily adjust the relative position between the fixed cutter 312 and the rotating shuttle 22.

[0047] Please refer to Figure 9A and Figure 9B As shown, since the second cutter base 311b of the fixed cutter base 311 is movably connected to the first cutter base 311a of the fixed cutter base 311, the second cutter base 311b can move relative to the first cutter base 311a to adjust the relative position relationship between the first cutter base 311a and the second cutter base 311b. Thus, as Figure 9A shown, the second cutter base 311b adjusts its position relative to the first cutter base 311a so that the fixed cutter blade part 312b of the fixed cutter 312 can be far away from the needle hole 142a1 of the needle plate 142a, or as Figure 9B shown, the second cutter base 311b adjusts its position relative to the first cutter base 311a so that the fixed cutter blade part 312b of the fixed cutter 312 can avoid interfering with both sides of the cutter movement space 142a3 of the needle plate 142a.

[0048] As Figure 3 , Figure 6 , Figure 8 and Figure 10As shown, the movable cutter group 32 of the tangent mechanism 30 mainly consists of a movable cutter shaft 321, a movable cutter seat 322 and a movable cutter 323. The movable cutter shaft 321 passes through the cutter shaft hole 141b of the kettle shaft table 141, and a tangent driving device (not shown in the figure) is connected to the lower end of the movable cutter shaft 321. Moreover, the upper end of the movable cutter shaft 321 is connected to the movable cutter seat 322. Among them, the movable cutter seat 322 is arranged inside the shuttle installation area 144b of the accommodation space 144. And, a movable groove 322a is formed by recessing the movable cutter seat 322. In addition, the movable cutter 323 is sequentially provided with a longitudinally arranged movable cutter connecting portion 323a, a swing arm portion 323b extending horizontally from the movable cutter connecting portion 323a, an extension portion 323c extending longitudinally from the swing arm portion 323b, and a movable cutter edge portion 323d formed at the upper end of the extension portion 323c. Among them, the movable cutter connecting portion 323a is provided with a movable convex block 323e to movably connect to the movable groove 322a of the movable cutter seat 322. And when the movable cutter connecting portion 323a is connected to the movable cutter seat 322, the height position of the swing arm portion 323b is lower than the lowest part of the outer kettle 221 of the shuttle 22, and the swing arm portion 323b straddles the shuttle installation area 144b and the needle hole communication area 144a of the accommodation space 144, so that both the extension portion 323c and the movable cutter edge portion 323d are located inside the needle hole communication area 144a. Furthermore, the extension portion 323c will be arranged on the left side of the shuttle 22 of the shuttle mechanism 20, and the movable cutter edge portion 323d is located inside the cutter moving space 142a3 of the needle plate 142a through the extension portion 323c, so that the movable cutter edge portion 323d can be close to the fixed cutter edge portion 312b of the fixed cutter 312. Thus, the arrangement position relationship among the swing arm portion 323b, the extension portion 323c and the movable cutter edge portion 323d relative to the shuttle 22 can reduce the volume jointly formed by the movable cutter 323 and the shuttle 22. Furthermore, a kettle lid 143 with a smaller volume can be used to cover both the movable cutter 323 and the shuttle 22 at the same time.

[0049] In addition, the thread clamping elastic piece 33 of the tangent mechanism 30 has elastic characteristics. And, a thread clamping connecting portion 331 and a thread clamping portion 332 are respectively provided at both ends of the thread clamping elastic piece 33. Among them, the thread clamping connecting portion 331 is connected to the fixed cutter seat 311 of the fixed cutter group 31, and the thread clamping portion 332 abuts against the bottom surface of the movable cutter edge portion 323d of the movable cutter 323, so that when the movable cutter 323 cuts the sewing thread, the movable cutter 323 and the thread clamping portion 332 can jointly clamp the sewing thread released by the shuttle 22.

[0050] Please refer to Figure 11A and Figure 11BAs shown, between the movable cutter 323 of the movable cutter group 32 and the movable cutter seat 322 of the movable cutter group 32, they are movably connected to each other through the movable convex block 323e and the movable groove 322a, so that the movable cutter 323 can move relative to the movable cutter seat 322 to adjust the relative position relationship between the movable cutter 323 and the movable cutter seat 322. Furthermore, as Figure 11A shown, the movable cutting edge portion 323d of the movable cutter 323 can move away from the bobbin case 22 of the bobbin winder mechanism 20 to increase the rotation radius of the movable cutter 323, or as Figure 11B shown, the movable cutting edge portion 323d of the movable cutter 323 can move closer to the bobbin case 22 to shorten the rotation radius of the movable cutter 323, so that the movable cutting edge portion 323d can be adjusted to align with the fixed cutting edge portion 312b to obtain an appropriate cutting edge biting sharpness.

[0051] Please refer to Figure 3 、 Figure 6 and Figure 12 shown, the feeding mechanism 40 has a feeding shaft 41, a feeding wheel 42 and a feeding drive source 43. The feeding shaft 41 passes through the feeding shaft hole 141c of the kettle shaft platform 141, and the upper end of the feeding shaft 41 meshes with the feeding wheel 42. Moreover, the lower end of the feeding shaft 41 is connected to the feeding drive source 43 via a second bevel gear set 44. The feeding wheels 42 are longitudinally arranged inside the needle hole communication area 144a of the accommodating space 144. And the feeding wheels 42 are pivotally connected to the needle plate seat 142b of the needle plate holder 142, so that the feeding wheels 42 can rotate around the X axis. And the feeding wheels 42 are located inside the needle hole communication area 144a, so that a part of the feeding wheels 42 passes through the feeding through hole 142a2 of the needle plate 142a. At the same time, the feeding wheels 42 are arranged at intervals on the left side of the outer kettle 221 of the bobbin case 22. Among them, the feeding drive source 43 is connected to the base 11 of the sewing machine body 10, and the feeding drive source 43 can drive the feeding wheels 42 to rotate via the feeding shaft 41.

[0052] Please refer to Figures 13A to 13C shown, it is a specific application of the column type sewing machine 1 for thread cutting operation. As Figure 13AAs shown, when the column sewing machine 1 performs the last stitch during sewing operation, the column sewing machine 1 will start the thread cutting operation. First, the sewing needle of the column sewing machine 1 moves upward to pass a sewing thread through the sewing material. Subsequently, the thread cutting drive device drives the movable knife shaft 321 of the movable cutter group 32 to swing counterclockwise around the Z axis through the lower shaft 12. Among them, when the movable knife shaft 321 swings counterclockwise around the Z axis, the movable cutter 323 of the movable cutter group 32 swings counterclockwise inside the cutter movement space 142a3 of the needle plate 142a, so that the extension 323c of the movable cutter 323 passes between the feed wheel 42 of the feeding mechanism 40 and the outer bobbin 221 of the rotary hook 22. At the same time, the movable cutting edge portion 323d of the movable cutter 323 passes through between the stop groove 142a5 of the needle plate 142a and the needle hole 142a1 of the needle plate 142a, so that the movable cutting edge portion 323d can move away from the fixed cutting edge portion 312b of the fixed cutter 312 and reach a thread hooking position P1. At this time, the movable cutter 323 is ready to hook the sewing thread.

[0053] Please refer to Figure 13B As shown, subsequently, the movable knife shaft 321 of the movable cutter group 32 swings clockwise around the Z axis, and the movable knife shaft 321 that swings clockwise can drive the movable cutter 323 to swing clockwise from the thread hooking position P1 to a preliminary cutting position P2. Thus, the movable cutting edge portion 323d hooks back the sewing thread and is ready to jointly cut the sewing thread with the fixed cutting edge portion 312b. At the same time, the thread clamping portion 332 of the thread clamping spring piece 33 can cooperate with the movable cutter 323 to clamp the sewing thread released by the rotary hook 22 before cutting the sewing thread.

[0054] Please refer to Figure 13C As shown, finally, the movable cutter 323 swings clockwise from the preliminary cutting position P2 to an initial position P3, so that the movable cutting edge portion 323d of the thread cutting mechanism 30 and the fixed cutting edge portion 312b of the thread cutting mechanism 30 jointly cut the sewing thread. In this embodiment, when the movable cutter 323 cooperates with the fixed cutter 312 to cut the sewing thread, since the fixed cutting edge portion 312b is close to the needle hole 142a1, a shorter length of thread head remains on the surface of the sewing material, so that the operator can avoid the need for a second trimming of the thread head, thereby shortening the operation time and increasing the production volume.

[0055] The above description is illustrative rather than restrictive to the present invention. Those of ordinary skill in the art can understand that many modifications, variations or equivalents can be made without departing from the spirit and scope defined by the claims, but all will fall within the protection scope of the present invention.

Claims

1. A cylindrical sewing machine with a tangent mechanism, characterized in that, Comprising: A base having a kettle shaft platform, a needle plate holder and a kettle lid. The needle plate holder and the kettle lid are both connected to the kettle shaft platform, so that the needle plate holder and the kettle lid jointly form a receiving space on one side of the kettle shaft platform. The needle plate holder is recessed to form a stop groove within the receiving space, and the receiving space is divided into a needle hole communication area and a rotary hook installation area through the stop groove. The needle hole communication area communicates with a needle hole of the needle plate holder; A rotary hook located in the rotary hook installation area and having an outer kettle capable of rotating relative to the needle plate holder and an inner kettle assembled inside the outer kettle. The inner kettle extends to form an inner kettle stop block capable of abutting against the stop groove, so that the inner kettle cannot rotate with the outer kettle; And A thread cutting mechanism having a fixed cutter and a movable cutter. The fixed cutter is arranged in the needle hole communication area, so that a fixed cutting edge portion of the fixed cutter can be close to the needle hole. The movable cutter is sequentially provided with a swing arm portion with a height position lower than that of the rotary hook, an extension portion located inside the needle hole communication area and a movable cutting edge portion located inside the needle hole communication area. The movable cutter can reciprocate inside the receiving space, so that the swing arm portion can drive the movable cutting edge portion to approach or move away from the fixed cutting edge portion through the extension portion.

2. The columnar sewing machine with a tangent mechanism according to claim 1, wherein: The cylindrical sewing machine with the thread cutting mechanism further has a feed wheel capable of rotating. The feed wheels are arranged at intervals with the rotary hook inside the needle hole communication area. When the movable cutter reciprocates inside the receiving space, the extension portion can pass between the feed wheel and the rotary hook.

3. The cylindrical sewing machine with a tangent mechanism according to claim 1, characterized in that: The thread cutting mechanism further has a movable cutter seat located inside the receiving space. The swing arm portion is provided with a movable knife connecting portion at one end away from the extension portion, and the movable knife connecting portion is provided with a movable convex block to be movably connected to a movable groove of the movable cutter seat, so that the movable cutter can move relative to the movable cutter seat to adjust the relative position relationship between the movable cutter and the movable cutter seat. Furthermore, the movable cutting edge portion can selectively approach or move away from the rotary hook.

4. The columnar sewing machine with a tangent mechanism according to claim 1, wherein: The needle plate holder has a needle plate provided with the needle hole and the stop groove and a needle plate seat connected between the needle plate and the kettle shaft platform. The fixed cutting edge portion is arranged between the needle hole and the stop groove, so that the fixed cutting edge portion is close to the needle plate. Furthermore, the height position of the fixed cutting edge portion is close to the height position of the inner kettle stop block.

5. The cylindrical sewing machine with a tangent mechanism according to claim 1, characterized in that: The thread cutting mechanism further has a fixed cutter seat connected to the kettle shaft platform, and the fixed cutter is connected to the fixed cutter seat, so that the fixed cutter is close to the needle hole through the fixed cutter seat.

6. The cylindrical sewing machine with a tangent mechanism according to claim 5, characterized in that: The thread cutting mechanism further has a thread clamping spring piece. One end of the thread clamping spring piece is connected to the fixed cutter seat, and the other end of the thread clamping spring piece abuts against the bottom surface of the movable cutting edge portion.

7. The cylindrical sewing machine with a tangent mechanism according to claim 5, characterized in that, The fixed cutter holder has a first cutter holder for connecting to the kettle shaft platform and a second cutter holder connected to the fixed cutter. The first cutter holder is movably connected to the second cutter holder, such that the second cutter holder can move relative to the first cutter holder to adjust the relative positional relationship between the second cutter holder and the first cutter holder. Furthermore, the fixed cutter can selectively approach or move away from the needle hole.

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