Sewing thread clamping device of sewing machine

Abstract

The utility model discloses a sewing thread clamping device of a sewing machine. The sewing thread clamping device comprises a driving motor, a buffering piece, a connecting rod, a pull rod, a thread clamping piece and a fixing block. The driving motor is connected with a fixed shaft sleeve, the connecting rod is linked with the fixed shaft sleeve, the buffer piece is respectively connected with the connecting rod and the fixed shaft sleeve, the other end, far away from the fixed shaft sleeve, of the connecting rod is movably connected with one end of the pull rod, and the other end of the pull rod is connected with the thread clamping sheet; the thread clamping piece comprises a thread clamping connecting part and a thread clamping clamping part, a rotating shaft is arranged between the thread clamping connecting part and the thread clamping clamping part, the fixing block is arranged below a machine needle and is adjacent to the thread clamping piece, and the thread clamping clamping part rotates around the rotating shaft and abuts against the fixing block to clamp a sewing thread. According to the utility model, the sewing stability can be effectively improved, and the sewing off-line and bird nest phenomena are reduced.

Description

Technical Field

[0001] This utility model relates to the field of sewing equipment, and in particular to a sewing machine thread clamping device. Background Technology

[0002] Seam fraying and bird's nesting are common problems in sewing, primarily occurring on the back of the fabric where the bottom thread forms a clump of yarn, known as a "bird's nest." The main cause of seam fraying is improper tension of the take-up spring. If the spring is too strong, the stitch is too tight, making it prone to fraying during seam fraying; conversely, if the spring is too weak, the stitch is too loose, also leading to fraying. Therefore, current seam fraying technology is not stable enough, easily resulting in seam fraying and bird's nesting, severely affecting the appearance and quality of textiles. Improving the structure to reduce seam fraying and bird's nesting is an urgent technical problem to solve. Utility Model Content

[0003] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a sewing machine thread clamping device that can effectively improve the stability of starting the sewing and reduce thread breakage and bird nest phenomenon.

[0004] To achieve the above objectives, this utility model provides a sewing machine thread clamping device, including a drive motor, a buffer, a connecting rod, a pull rod, a thread clamping plate, and a fixing block;

[0005] The drive motor is connected to a fixed bushing, the connecting rod is linked with the fixed bushing, the buffer is connected to the connecting rod and the fixed bushing respectively, the other end of the connecting rod away from the fixed bushing is movably connected to one end of the pull rod, and the other end of the pull rod is connected to the clamping piece;

[0006] The suture clamp includes a suture clamping connection part and a suture clamping part. A rotating shaft is provided between the suture clamping connection part and the suture clamping part. The fixing block is located below the needle and adjacent to the suture clamp. The suture clamping part rotates around the rotating shaft and abuts against the fixing block to clamp the suture.

[0007] Furthermore, the connecting rod includes a first connecting arm and a second connecting arm. The first and second connecting arms are angled to form an "L" shape. A first movable shaft hole is provided at the connection between the first and second connecting arms. The connecting rod is movably connected to one end of the pull rod through this first movable shaft hole and a provided linkage shaft. By rigidly connecting the first and second connecting arms at an angle to form an L-shaped integrated structure, the rigidity of the transmission is ensured while effectively reducing the space occupied by the components, realizing a miniaturized layout of the transmission mechanism. This is particularly suitable for the precision assembly requirements within the limited space of a sewing machine. The connection between the pull rod and the connecting rod is located between the first and second connecting arms, with the outer edge bent beforehand. This allows force to be quickly transmitted to the pull rod regardless of whether the first or second connecting arm rotates, achieving linkage of the thread clamping plate.

[0008] Furthermore, the upper end of the fixed bushing extends to form a bushing connecting shaft, and the end of the first connecting arm is sleeved on the bushing connecting shaft to achieve a movable connection. A limit screw is provided on one side of the bushing connecting shaft, so that when the fixed bushing rotates, the limit screw abuts against the side edge of the first connecting arm and pushes the connecting rod to rotate. Thus, through the locking linkage between the drive motor and the fixed bushing, the fixed bushing and the connecting rod are movable components. When the fixed bushing rotates, the abutment between the limit screw and the first connecting arm drives the connecting rod to pull the pull rod and the clamping plate. With the addition of the buffer component, even when the clamping plate is locked or released to its limit, the drive motor can still move a certain distance, which plays a buffering role.

[0009] Furthermore, the end of the first connecting arm is a first connecting portion, on which a first connecting hole matching the bushing connecting shaft is provided. A first inward bend matching the size of the limiting screw is provided between the first connecting portion and the main body of the first connecting arm. During assembly, this first inward bend is positioned on the movement trajectory of the limiting screw. The use of the first inward bend ensures a closer fit between the limiting screw and the first connecting arm, resulting in better linkage performance between the two.

[0010] Furthermore, a first connecting member is provided on the side edge of the fixed bushing, and a downwardly positioned second connecting member is provided at the end of the second connecting arm. The two ends of the buffer member are respectively connected to the first connecting member and the second connecting member. This achieves linkage between the side edge of the fixed bushing and the second connecting arm. Regardless of whether the fixed bushing rotates forward or backward, even when the clamping plate is locked or released to its limit, the stepper motor can still move a certain distance, and the buffer member can play a certain buffering role.

[0011] Furthermore, a sensor for sensing the position of the second connector is provided below the second connector. By using the sensor in conjunction with the operation, the accuracy of each action is improved.

[0012] Furthermore, the buffer element is a buffer spring.

[0013] Furthermore, the pull rod includes a second connecting part, a first bent part, a third connecting part, a second bent part, and a fourth connecting part connected in sequence. The end of the second connecting part is provided with a second connecting hole for linkage with the connecting rod. Both the first and second bent parts are bent at 90°, causing the second and third connecting parts, as well as the third and fourth connecting parts, to intersect perpendicularly. At the end of the fourth connecting part, there is a linking protrusion with an upward protrusion for connection with the thread clamping connecting part. The arrangement of the first and second bent parts allows the second and fourth connecting parts to be arranged in parallel, ensuring linear force transmission. It also adapts to different positions to fit the internal structure of the sewing machine, resulting in better and more rational space utilization.

[0014] Furthermore, the thread clamping part includes a thread clamping connecting arm and a wrapping arm connected to the thread clamping connecting arm. The wrapping arm has an arc structure and matches the outer edge of the fixing block. This allows the clamping part to rotate around a rotation axis, thus clamping the thread in conjunction with the fixing block.

[0015] Furthermore, the front end of the fixing block is an arc surface. This arc surface allows for a better and tighter contact with the clamping part, resulting in a better clamping effect on the stitching.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The drive motor and the fixed bushing of this utility model are locked together, while the fixed bushing and the connecting rod are movably connected. With the cooperation of the limit screw and the spring, the stepper motor can still move a certain distance when the clamping plate is locked or released to the limit state, which plays a buffering role. This can effectively improve the stability of the seam and reduce the seam slippage and bird nest phenomenon. Attached Figure Description

[0018] To more clearly illustrate the technology in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a sewing machine thread clamping device according to the present invention;

[0020] Figure 2 yes Figure 1 A schematic diagram of the decomposition process;

[0021] Figure 3 This is a structural schematic diagram of the fixed bushing of this utility model;

[0022] Figure 4 This is a schematic diagram of the connecting rod of this utility model;

[0023] Figure 5 This is a schematic diagram of the structure of the pull rod of this utility model;

[0024] Figure 6 This is a schematic diagram of the structure of the clamping piece of this utility model;

[0025] Figure 7 This is an assembly diagram of the present invention installed on the lower base;

[0026] Figure 8 This is a schematic diagram of the operating trajectory of the present invention when it enters the clamping state;

[0027] Figure 9 This is a schematic diagram of the operating trajectory of this utility model when it enters the disengagement state.

[0028] The diagram includes:

[0029] 1. Drive motor; 11. Motor mounting base; 12. Fixed bushing; 121. Bushing connecting shaft; 122. First coupling hole; 123. Pin hole; 124. Limit screw; 125. Fourth connecting hole; 126. Fifth connecting hole; 127. First connecting piece; 2. Buffer piece; 3. Connecting rod; 31. First connecting arm; 311. First connecting part; 312. First connecting hole; 32. Second connecting arm; 321. Sixth connecting hole; 322. Second connecting piece; 33. First movable shaft hole; 35. 4. First inner bend; 4. Pull rod; 41. Second connecting part; 411. Second connecting hole; 42. First bending part; 43. Third connecting part; 44. Second bending part; 45. Fourth connecting part; 451. Linkage protrusion; 5. Wire clamping piece; 51. Wire clamping connecting part; 511. Third connecting hole; 52. Wire clamping holding part; 521. Wire clamping connecting arm; 522. Wrapping arm; 53. Rotating shaft; 54. Wire clamping rotating shaft hole; 6. Fixing block; 7. Lower base; 8. Proximity sensor; 9. Needle plate; 10. Needle. Detailed Implementation

[0030] The technology of this embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiment is one embodiment of the present invention, and not all embodiments thereof. Based on this embodiment of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0032] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second", such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0033] Please see Figures 1 to 9 The present invention provides a sewing machine thread clamping device, including a drive motor 1, a buffer 2, a connecting rod 3, a pull rod 4, a thread clamping piece 5, and a fixing block 6;

[0034] like Figures 1 to 2 As shown, in this embodiment, the drive motor 1 is mounted on the lower base 7 of the sewing machine via a motor mounting bracket 11. The drive motor 1 is a stepper motor, the buffer 2 is a buffer spring, and the drive motor 1 is connected to a fixed bushing 12. Figure 3 As shown, a bushing connecting shaft 121 extends from the upper end of the fixed bushing 12. The center of the fixed bushing 12 is provided with a first connecting hole 122 that penetrates the fixed bushing 12. On both sides of the fixed bushing 12, there are pin holes 123 that communicate with the first connecting hole 122. After the output shaft of the drive motor 1 is inserted, the output shaft is locked in the first connecting hole 122 by a locking pin, so as to realize the locking linkage between the drive motor 1 and the fixed bushing 12.

[0035] like Figure 4 As shown, the connecting rod 3 includes a first connecting arm 31 and a second connecting arm 32. The first connecting arm 31 and the second connecting arm 32 are set at an angle so that the connecting rod 3 is in an "L" shape. A first movable shaft hole 33 is provided at the connection between the first connecting arm 31 and the second connecting arm 32. The end of the first connecting arm 31 is a first connecting part 311. A first connecting hole 312 matching the bushing connecting shaft 121 is provided on the first connecting part 311. During assembly, the first connecting hole 312 and the bushing connecting shaft 121 are aligned first, and then the first connecting hole 312 is directly put into the bushing connecting shaft 121. The first connecting hole 312 is then secured with a snap ring so that the first connecting part 311 cannot fall off. This achieves the movable connection between the first connecting arm 31 and the bushing connecting shaft 121.

[0036] To enable linkage between the bushing connecting shafts 121 and to cooperate with the buffer 2, a fourth connecting hole 125 is provided on one side of the bushing connecting shaft 121. A limit screw 124 is fixed in the fourth connecting hole 125. A first inner bend 35 matching the size of the limit screw 124 is provided between the first connecting part 311 and the main body of the first connecting arm 31. During assembly, the first inner bend 35 is placed on the movement trajectory of the limit screw 124, so that when the fixed bushing 12 rotates, the limit screw 124 abuts against the side edge of the first connecting arm 31 and pushes the connecting rod 3 to rotate.

[0037] To enable the buffer 2 to connect to both the connecting rod 3 and the fixed bushing 12, a fifth connecting hole 126 is provided on the side edge of the fixed bushing 12. A first connecting member 127 is fixedly connected to this fifth connecting hole 126. A sixth connecting hole 321 is provided at the end of the second connecting arm 32. A downwardly oriented second connecting member 322 is fixedly connected to this sixth connecting hole 321. Both ends of the buffer 2 are connected to the first connecting member 127 and the second connecting member 322, respectively. A proximity sensor 8 is provided below the second connecting member 322 to sense its position. By using the proximity sensor 8 in conjunction with the operation, the accuracy of each movement is improved.

[0038] The other end of the connecting rod 3, away from the fixed bushing 12, is movably connected to one end of the pull rod 4 through the first movable shaft hole 33 and the provided linkage shaft. Specifically, as shown... Figure 5 As shown, in this embodiment, the pull rod 4 includes a second connecting part 41, a first bending part 42, a third connecting part 43, a second bending part 44, and a fourth connecting part 45 connected in sequence. The end of the second connecting part 41 is provided with a second connecting hole 411. The second connecting hole 411 is rotatably linked with the first movable shaft hole 33 by a screw. The first bending part 42 and the second bending part 44 are both bent at 90° so that the second connecting part 41 and the third connecting part 43 and the third connecting part 43 and the fourth connecting part 45 are perpendicularly intersecting. At the end of the fourth connecting part 45, there is an upwardly protruding linkage protrusion 451 for connecting with the clamping wire connecting part 51.

[0039] like Figure 6 As shown, the thread clamping piece 5 includes a thread clamping connecting part 51 and a thread clamping holding part 52. A thread clamping pivot hole 54 is provided between the thread clamping connecting part 51 and the thread clamping holding part 52. A rotating shaft 53 is connected to the thread clamping pivot hole 54. The rotating shaft 53 can be fixedly connected to the needle plate 9 of the sewing machine. A third connecting hole 511 matching the linkage protrusion 451 is provided on the thread clamping connecting part 51. The linkage between the pull rod 4 and the thread clamping connecting part 51 is realized through the connection of the third connecting hole 511 and the linkage protrusion 451. The fixing block 6 is located below the needle 10 and fixedly connected to the needle plate 9. The fixing block 6 is arranged adjacent to the thread clamping piece 5. The thread clamping holding part 52 rotates around the rotating shaft 53 and abuts against the fixing block 6 to clamp the sewing thread.

[0040] To further improve the accuracy of thread clamping, the front end of the fixing block 6 in this embodiment is an arc surface. The thread clamping part 52 includes a thread clamping connecting arm 521 and a wrapping arm 522 connected to the thread clamping connecting arm 521. The wrapping arm 522 has an arc structure and matches the outer edge of the fixing block 6. This allows the clamping part to rotate around the rotation axis 53, which can cooperate with the fixing block 6 to clamp the thread. The arc surface can better and more tightly abut against the clamping part, resulting in a better clamping effect on the thread.

[0041] Brief description of the working principle of this utility model: The assembly of this utility model is as follows: Figure 7 The drive motor 1 is mounted on the side wing of the lower machine base 7 of the sewing machine via the motor mounting bracket 11. The thread clamping plate 5 and the fixing block 6 are directly mounted below the needle plate 9 of the sewing machine. The pull rod 4 passes through the head of the lower machine base 7 and is linked with the thread clamping plate 5. During operation, if... Figure 1 or Figure 9 As shown, at this time, the thread clamp 5 is in the slack state, which can be regarded as the initial position. After the needle bar rises to the lowest point and returns to the set position after the first stitch (preset, the second or third stitch can be set) is started by sewing, as shown... Figure 8 As shown, the sewing machine's electronic control equipment senses the position of the second connector 322 through the proximity sensor 8 and sends a signal to drive the drive motor 1 to rotate counterclockwise (this is just an example; the actual movement can be adjusted according to the situation). The first connector 127 rotates with the fixed bushing 12, and through the buffer 2, it pulls the second connecting arm 32 of the connecting rod 3 to move to the right, causing the pull rod 4 to move to the right. The pull rod 4 then drives the thread clamping plate 5 to rotate around the rotating shaft 53. When the thread clamping part 52 moves clockwise and contacts the fixing block 6, it clamps the sewing thread.

[0042] When sewing to the second stitch (preset, can be set to the third or fourth stitch, etc.), after the needle bar reaches its lowest point and rises back to the set position, if... Figure 9 As shown, the sewing machine's electronic control equipment senses the position of the second connector 322 through the proximity sensor 8 and sends a signal again, causing the drive motor 1 to return to its original position. At this time, the fixed bushing 12 will rotate clockwise, causing the limit screw 124 to push the connecting rod 3 to move counterclockwise back to its initial position. During this process, the pull rod 4 will also move counterclockwise to reset as the connecting rod 3 is pulled. The connecting rod 3 pushes the pull rod 4 to the left, causing the thread clamping part 52 to rotate counterclockwise back to its initial position, completing the entire action.

[0043] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A sewing machine thread clamping device, characterized in that, It includes a drive motor (1), a buffer (2), a connecting rod (3), a pull rod (4), a clamping plate (5), and a fixing block (6); The drive motor (1) is connected to a fixed bushing (12), the connecting rod (3) is linked with the fixed bushing (12), the buffer (2) is connected to the connecting rod (3) and the fixed bushing (12) respectively, the other end of the connecting rod (3) away from the fixed bushing (12) is movably connected to one end of the pull rod (4), and the other end of the pull rod (4) is connected to the clamping piece (5); The suture clamp (5) includes a suture clamping connection part (51) and a suture clamping part (52). A rotating shaft (53) is provided between the suture clamping connection part (51) and the suture clamping part (52). The fixing block (6) is located below the needle (10) and adjacent to the suture clamp (5). The suture clamping part (52) rotates around the rotating shaft (53) and abuts against the fixing block (6) to clamp the suture.

2. The sewing machine thread clamping device according to claim 1, characterized in that, The connecting rod (3) includes a first connecting arm (31) and a second connecting arm (32). The first connecting arm (31) and the second connecting arm (32) are set at an angle so that the connecting rod (3) is in the shape of an "L". A first movable shaft hole (33) is provided at the connection between the first connecting arm (31) and the second connecting arm (32). The connecting rod (3) is movably connected to one end of the pull rod (4) through the first movable shaft hole (33) and the provided linkage shaft.

3. The sewing machine thread clamping device according to claim 2, characterized in that, The upper end of the fixed bushing (12) extends to form a bushing connecting shaft (121). The end of the first connecting arm (31) is sleeved on the bushing connecting shaft (121) to achieve a movable connection. A limit screw (124) is provided on one side of the bushing connecting shaft (121) so that when the fixed bushing (12) rotates, the limit screw (124) abuts against the side edge of the first connecting arm (31) and pushes the connecting rod (3) to rotate.

4. The sewing machine thread clamping device according to claim 3, characterized in that, The end of the first connecting arm (31) is a first connecting part (311). A first connecting hole (312) matching the bushing connecting shaft (121) is provided on the first connecting part (311). A first inner bend (35) matching the size of the limiting screw (124) is provided between the first connecting part (311) and the main body of the first connecting arm (31). During assembly, the first inner bend (35) is placed on the movement trajectory of the limiting screw (124).

5. A sewing machine thread clamping device according to claim 2, characterized in that, A first connector (127) is provided on the side edge of the fixed bushing (12), and a second connector (322) is provided at the end of the second connecting arm (32) and is arranged downward. The two ends of the buffer (2) are respectively connected to the first connector (127) and the second connector (322).

6. A sewing machine thread clamping device according to claim 5, characterized in that, A proximity sensor (8) for sensing the position of the second connector (322) is provided below the second connector (322).

7. A sewing machine thread clamping device according to claim 1, characterized in that, The buffer element (2) is a buffer spring.

8. A sewing machine thread clamping device according to claim 1, characterized in that, The pull rod (4) includes a second connecting part (41), a first bending part (42), a third connecting part (43), a second bending part (44), and a fourth connecting part (45) connected in sequence. The end of the second connecting part (41) is provided with a second connecting hole (411) for linkage with the connecting rod (3). The first bending part (42) and the second bending part (44) are both bent at 90° so that the second connecting part (41) and the third connecting part (43) and the third connecting part (43) and the fourth connecting part (45) are perpendicular to each other. At the end of the fourth connecting part (45), there is a linkage protrusion (451) with an upward protrusion at the end for connection with the clamping wire connecting part (51).

9. A sewing machine thread clamping device according to claim 1, characterized in that, The wire clamping part (52) includes a wire clamping connecting arm (521) and a wrapping arm (522) connected to the wire clamping connecting arm (521). The wrapping arm (522) has an arc structure and matches the outer edge of the fixing block (6).

10. A sewing machine thread clamping device according to any one of claims 1 to 9, characterized in that, The front end of the fixing block (6) is an arc surface.

Images