A new thread trimming and presser foot lifting self-separating device for an overlock sewing machine and an overlock sewing machine

Abstract

The invention belongs to the technical field of sewing machines, and specifically relates to a novel thread trimming and presser foot lifting self-separating device of an overlock sewing machine and the overlock sewing machine, comprising a driving motor, which is mounted on a frame and provides power for other components; a presser foot lifting mechanism, which is mounted on the frame and performs a presser foot lifting action; a thread trimming mechanism, which is mounted on the frame and performs a thread trimming action; and also comprises a presser foot lifting swing arm assembly, which is arranged at the lower part of the frame, the right end of the presser foot lifting swing arm assembly is rotatably connected to the frame, the middle part of the presser foot lifting swing arm assembly is connected to the presser foot lifting mechanism, and the left end of the presser foot lifting swing arm assembly is used to connect a pedal mechanism; a thread trimming swing arm assembly, which is arranged on one side of the presser foot lifting swing arm assembly; the middle part of the thread trimming swing arm assembly is rotatably mounted on the frame, and the right side force arm of the rotating point drives the thread trimming mechanism; a pressing portion is arranged between the left side force arm of the rotating point and the presser foot lifting swing arm assembly, and the pressing portion is used to drive the presser foot lifting swing arm assembly to move.

Description

Technical Field

[0001] The invention relates to the technical field of sewing machines, in particular to a new thread trimming and presser foot lifting self-separating device of an overlock sewing machine and the overlock sewing machine. Background Art

[0002] With the continuous improvement of the automation degree of sewing machines, sewing machines generally have automatic thread trimming mechanisms and automatic presser foot lifting mechanisms, which respectively realize the actions of automatic presser foot lifting and automatic thread trimming, thereby saving time, reducing labor and improving work efficiency.

[0003] For example, the Chinese utility model application number CN201720628787.5 discloses an integrated thread trimming and presser foot lifting mechanism for an overlock sewing machine. In this scheme, a motor is horizontally installed on the upper rear side of the machine body, and both ends of the motor shaft of the motor extend outward and are equipped with cams. The two cams drive the thread trimming and presser foot lifting mechanisms respectively.

[0004] Although the above devices can realize automatic thread trimming or presser foot lifting by the rotation of the motor, in actual operation, some sewing machine workers are accustomed to lifting the presser foot by foot control (especially workers of a certain age). For them, foot control is more effective, so it is necessary to retain the foot control function while having motor control. Summary of the invention

[0005] The purpose of the present invention is to provide a novel thread trimming and presser foot lifting self-separating device for an overlock sewing machine and an overlock sewing machine, which solves the problem that only the thread trimming and presser foot lifting mechanisms in the existing sewing machines are controlled by motors but have no foot control function through a pressing portion.

[0006] The object of the present invention is achieved by: a new thread trimming and presser foot lifting self-separating device for an overlock sewing machine, comprising

[0007] A drive motor, which is mounted on the frame and provides power to the remaining components;

[0008] A presser foot lifting mechanism, which is installed on the frame and performs a presser foot lifting action;

[0009] A thread trimming mechanism, which is mounted on the frame and performs a thread trimming action;

[0010] Also includes

[0011] The presser foot lifting swing arm assembly is arranged at the lower part of the frame, the right end of the presser foot lifting swing arm assembly is rotatably connected to the frame, the middle part of the presser foot lifting swing arm assembly is connected to the presser foot lifting mechanism, and the left end of the presser foot lifting swing arm assembly is used to connect the pedal mechanism;

[0012] A thread trimmer swing arm assembly is arranged on one side of the presser foot lifting swing arm assembly; the middle part of the thread trimmer swing arm assembly is rotatably mounted on the frame, and the right lever arm of the rotation point drives the thread trimmer mechanism; a pressing portion is arranged between the left lever arm of the rotation point and the presser foot lifting swing arm assembly, and the pressing portion is used to drive the presser foot lifting swing arm assembly to move; wherein the outer end of the left lever arm is driven by the driving motor to move up and down.

[0013] Preferably, the pressing portion is formed at the upper end of the left force arm, and the pressing portion is a pressing plate, and the pressing plate is located on the upper end surface of the presser foot lifting swing arm assembly.

[0014] Preferably, it also includes a foot pedal mechanism, the left end of the presser foot lifting swing arm assembly is connected to the foot pedal mechanism and is used to perform the presser foot lifting action, the middle part of the thread trimming swing arm assembly is rotationally arranged on the rotation point of the presser foot lifting swing arm assembly, and the rotation points of the presser foot lifting swing arm assembly and the thread trimming swing arm assembly are concentrically arranged.

[0015] Preferably, a pushing portion is provided at the upper end of the right lever arm, and when the right lever arm swings from top to bottom to a set position, the pushing portion drives the thread trimming mechanism and performs thread trimming; when the right lever arm moves in the opposite direction to the set position, the pushing portion is separated from the thread trimming mechanism.

[0016] Preferably, a crank is provided at the rear end of the thread trimming shaft of the thread trimming mechanism, an axle pin is provided on the crank, and a wear-resistant sleeve is installed on the outer periphery of the axle pin. When trimming the thread, the wear-resistant sleeve rotates with the pushing part to perform thread trimming;

[0017] The frame is provided with an adjustable bracket, and the bracket is provided with a supporting portion for limiting the position of the crank; after the pushing portion leaves the shaft pin, the crank is pressed against the supporting portion under the action of a reset spring.

[0018] Preferably, a thread trimmer abutment seat extends from the lower side of the crank, the thread trimmer abutment seat cooperates with the abutment portion, and the abutment portion is a rubber pad.

[0019] Preferably, the bracket is provided with a transverse strip-shaped fixing hole, and a fastener passes through the strip-shaped fixing hole so that the bracket can be adjusted left and right to be set on the rack.

[0020] Preferably, the drive motor is installed transversely on the upper part of the frame, and a swing rod is installed on the motor shaft of the drive motor; transmission is transmitted between the outer end of the swing rod and the end of the left force arm through a universal ball head connecting rod.

[0021] Preferably, the right side force arm is triangular, the length of the left side force arm is greater than that of the right side force arm, and the rotation point is arranged at the intersection of the two force arms.

[0022] Preferably, a hook is provided at the right end of the presser foot lifting swing arm assembly, the other end of the hook is connected to and drives the presser foot lifting mechanism, and a groove for the hook to move is provided on the thread trimming swing arm assembly.

[0023] An overlock sewing machine comprises a thread trimmer, a presser foot lifter and a pedal mechanism.

[0024] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects:

[0025] 1. The present invention can control the presser foot lifter by a motor or by foot, which can meet the needs of some users. In addition, since the presser foot lifter swing arm assembly is separately arranged from the motor and the thread trimming mechanism and has no direct connection relationship, the thread trimming swing arm assembly and the presser foot lifter swing arm assembly have a linkage effect through the pressing portion. Therefore, when the presser foot lifter mechanism is controlled by foot, the motor and the thread trimming mechanism will not hinder the operation of the foot-operated presser foot lifter, and there is no resistance, so it is more accurate, smooth and labor-saving to use.

[0026] 2. The present invention adopts the design of the pressing part. When the left force arm rotates downward, the presser foot lifting swing arm assembly will be driven to move through the pressing plate at the same time, thereby realizing the motor-controlled presser foot lifting function, without manual control, and easy operation.

[0027] 3. The present invention adopts the design of the foot-operated mechanism, so that the operator can control the operation of the presser foot lifting mechanism by stepping on the foot-operated mechanism, thereby manually controlling the presser foot lifting operation by stepping on the foot, so as to meet the operation requirements of some staff members.

[0028] 4. The present invention provides a pushing part on the right lever arm to intermittently drive the corresponding thread cutting mechanism. Compared with the old overlock sewing machine, fewer parts need to be replaced, which is suitable for upgrading.

[0029] 5. The present invention adopts the design of an adjustable bracket. When the bracket is moved to the right, the swing amplitude of the crank can be reduced, and the swing frequency of the scissors can be reduced; when the bracket is moved to the left, the swing amplitude of the crank can be increased, and the swing frequency of the scissors can be increased, and the adjustment is convenient.

[0030] 6. The driving motor of the present invention is installed horizontally on the upper part of the frame, and directly drives the swing arm assembly through the universal ball joint connecting rod, without the need for a complex transmission structure, with good stability, low cost and easy maintenance.

[0031] 7. The right side arm of the present invention is triangular in shape, and the structure is more stable. The length of the left side arm is greater than that of the right side arm. The rotation point is set at the intersection of the two arm. The thread trimming swing arm assembly acts as a labor-saving lever, which reduces and improves the working efficiency of the motor and the stability of the entire structure.

[0032] 8. The groove design of the present invention ensures that when the presser foot lifting swing arm assembly swings, the thread trimming swing arm assembly will not interfere with the movement of the hook, and the operation is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the thread trimming and presser foot lifting mechanism installed on the frame.

[0034] Figure 2 Schematic diagram of the thread trimming and presser foot lifting mechanism Figure 1 .

[0035] Figure 3 Schematic diagram of the thread trimming and presser foot lifting mechanism Figure 2 .

[0036] Figure 4 This is a schematic diagram of the exploded structure of the thread trimming and presser foot lifting mechanisms.

[0037] Figure 5 It is a schematic diagram of the cooperation between the crank and the abutment part.

[0038] Figure 6 It is a schematic structural diagram of the pushing portion at the upper end of the right lever arm of another embodiment.

[0039] Reference numerals: 1-frame; 2-rotation point; 3-reset spring; 10-driving motor; 11-motor shaft; 12-rocker; 13-universal ball head connecting rod; 20-presser foot lifting mechanism; 21-lifting and pressing sleeve; 22-lifting and pressing lever;

[0040] 30-thread trimming mechanism; 31-thread trimming shaft; 32-crank; 33-axle pin; 34-extension handle; 35-hook portion;

[0041] 36-bolt assembly; 37-thread trimmer abutment seat; 40-pedal mechanism; 50-presser foot lifting swing arm assembly; 51-hook; 60-thread trimmer swing arm assembly; 61-left force arm; 62-right force arm; 63-pressing portion; 64-groove; 65-pushing portion; 70-bracket; 71-abutment portion; 73-strip fixing hole; 74-fastener. DETAILED DESCRIPTION

[0042] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0043] Embodiment 1, as Figure 1 As shown, a novel thread trimming and presser foot lifting self-separating device of an overlock sewing machine includes a driving motor 10, which is mounted on a frame 1 and provides power for other components;

[0044] A presser foot lifting mechanism 20, which is mounted on the frame 1 and performs a presser foot lifting action;

[0045] A thread trimming mechanism 30, which is mounted on the frame 1 and performs a thread trimming action;

[0046] Also includes

[0047] A pedal mechanism 40, used for performing a presser foot lifting action;

[0048] The presser foot lifting swing arm assembly 50 is arranged at the lower part of the frame 1, the right end of the presser foot lifting swing arm assembly 50 is rotatably connected to the frame 1, the middle part of the presser foot lifting swing arm assembly 50 is connected to the presser foot lifting mechanism 20, and the left end of the presser foot lifting swing arm assembly 50 is connected to the pedal mechanism 40, so that in actual use, the operator can control the operation of the presser foot lifting mechanism 20 by stepping on the pedal mechanism 40, thereby manually controlling the presser foot lifting operation by stepping on the pedal mechanism 40;

[0049] A thread trimming swing arm assembly 60 is provided on one side of the presser foot lifting swing arm assembly 50; the middle part of the thread trimming swing arm assembly 60 is rotatably arranged on the rotation point 2 of the presser foot lifting swing arm assembly 50, and the right side force arm 62 of the rotation point 2 drives the thread trimming mechanism 30;

[0050] Combination Figure 2 A pressing portion 63 is provided between the left side force arm 61 of the rotation point 2 and the presser foot lifting swing arm assembly 50, and the pressing portion 63 is used to drive the presser foot lifting swing arm assembly 50 to move; wherein, the outer end portion of the left side force arm 61 is driven by the driving motor 10 to move up and down. During actual operation, when the driving motor 10 drives the thread trimming swing arm assembly 60 to rotate the left side force arm 61 downward, the pressing portion 63 will drive the presser foot lifting swing arm assembly 50 to move, thereby controlling the presser foot lifting through the motor.

[0051] It can be seen that the present invention can control the presser foot lifter by both the motor and the foot, which can meet the needs of some users. In addition, since the presser foot lifter swing arm assembly 50 is separated from the motor and the thread trimming mechanism and has no direct connection relationship, the thread trimming swing arm assembly 60 and the presser foot lifter swing arm assembly 50 have a linkage effect through the pressing portion 63. Therefore, when the presser foot lifter mechanism is controlled by the foot, the motor and the thread trimming mechanism will not hinder the operation of the foot-operated presser foot lifter, and there is no resistance, so it is more accurate, smooth and labor-saving to use.

[0052] Combination Figure 2 and Figure 3 The upper end of the left side force arm 61 is formed with the pressing portion 63, which is a pressure plate. The pressure plate is located on the upper end surface of the presser foot lifting swing arm assembly 50. Therefore, when the left side force arm 61 rotates downward, the presser foot lifting swing arm assembly 50 will be driven to move through the pressure plate, thereby realizing the motor-controlled presser foot lifting function.

[0053] Combination Figure 1 Figure 2A hook 51 is provided at the right end of the presser foot lifting swing arm assembly 50, and the other end of the hook 51 is connected to and used to drive the presser foot lifting mechanism 20. A groove 64 for the hook 51 to move is provided on the thread trimming swing arm assembly 60. When the presser foot lifting swing arm assembly 50 swings, the thread trimming swing arm assembly 60 will not interfere with the movement of the hook 51.

[0054] Combination Figure 1 and Figure 5 A pushing portion 65 is provided at the upper end of the right lever arm 62. When the right lever arm 62 swings from top to bottom to a set position, the pushing portion 65 drives the thread trimming mechanism 30 and performs thread trimming. When the right lever arm 62 moves in the opposite direction to the set position, the pushing portion 65 is separated from the thread trimming mechanism 30. Compared with the existing thread trimming and presser foot lifting design, this solution is simpler and more stable.

[0055] The rear end of the thread trimming shaft 31 of the thread trimming mechanism 30 is provided with a crank 32, and the crank 32 is provided with an axle pin 33;

[0056] The frame 1 is provided with an adjustable bracket 70, and the bracket 70 is provided with a supporting portion 71 for limiting the position of the crank 32; after the pushing portion 65 leaves the shaft pin 33, the crank 32 is pressed against the supporting portion 71 under the action of the return spring 3, and the design of the supporting portion 71 enables the pushing portion 65 to still push the shaft pin 33 when it swings over again.

[0057] The supporting part is a rubber pad. The rubber pad made of flexible material can effectively reduce the collision when the thread trimmer device is reset and improve the stability.

[0058] Look specifically Figure 5 The bracket 70 is provided with a strip fixing hole 73, and the fastener 74 passes through the strip fixing hole 73 so that the bracket 70 can be adjustably set on the frame 1. By moving the position of the bracket 70 to the right, the swing amplitude of the crank 32 can be reduced, and the swing frequency of the scissors can be reduced; by moving the position of the bracket 70 to the left, the swing amplitude of the crank 32 can be increased, and the swing frequency of the scissors can be increased, which is convenient for adjustment.

[0059] Look specifically Figure 5 A thread trimmer abutment seat 37 is extended from the lower side of the crank 32, and the thread trimmer abutment seat 37 cooperates with the abutment portion 71 to limit the thread trimmer's stroke. The abutment portion 71 is a rubber pad with a buffering effect. The knife has different resistance when it is subjected to thick cloth or thin cloth. The inertia force will not cause the knife to rush over and collide with the knife holder, but the thread trimmer abutment seat 37 abuts against the abutment portion 71, thereby playing a protective role.

[0060] Combination Figure 1-3The driving motor 10 is installed horizontally on the upper part of the frame 1, and a swing rod 12 is installed on the motor shaft 11 of the driving motor 10; the transmission is transmitted between the outer end of the swing rod 12 and the end of the left lever arm 61 through the universal ball head connecting rod 13. Since the overlock sewing machine is a relatively mature model, the main parts of its thread trimming and presser foot lifting mechanisms have been finalized and are not easy to change. The main parts of the presser foot lifting mechanism and the thread trimming mechanism in this solution can refer to the structure in ZL201420140236.0, so it will not be expanded. Further explanation: This solution can be compatible with the original model to the greatest extent, has a high rate of component interchangeability, and is easy to market.

[0061] Since the thread trimmer swing arm assembly and the presser foot lift swing arm assembly are separated, the ball head connecting rod design can be applied. The ball head connecting rod can directly convert the swing of the motor shaft into vertical reciprocating motion, and has a simple structure, but correspondingly, the transmission node cannot be separated, so it is suitable for this design. The universal ball head connecting rod 13 includes an upper universal joint, a middle connecting rod and a lower universal joint; the universal ball head connecting rod 13 is a mature spare part on the market; but it is the applicant's first to apply the universal ball head to the drive motor of the overlock sewing machine and directly drive the swing arm assembly. When the drive motor is installed horizontally on the upper part of the frame, the universal ball head connecting rod 13 can better transmit the torque of the motor directly to the swing arm assembly, and convert the rotational motion on the vertical plane into the swing required by the swing arm assembly, without the need for a complex transmission structure.

[0062] Look specifically Figure 4 The right side arm 62 is triangular in shape and has a more stable structure. The length of the left side arm 61 is greater than that of the right side arm 62. The rotation point 2 is arranged at the intersection of the two arm 62. The thread trimming swing arm assembly has a labor-saving lever, which reduces and improves the working efficiency of the motor and the stability of the entire structure.

[0063] Embodiment 2, as Figure 6 As shown, this embodiment is basically the same as embodiment 1, except that:

[0064] An extension handle 34 is installed at the upper end of the right lever arm 62, and the extension handle 34 is provided with the pushing portion 65 and the hook portion 35. The extension handle 34 can be replaced according to the situation, or designed in different styles;

[0065] When the thread trimming mechanism 30 is stuck by external force, the right force arm 62 moves upward and forcibly drives the shaft pin 33 to reset through the hook portion 35. The design of the hook portion 35 and the shaft pin 33 achieves a forced reset effect, which is stable and reliable. During the thread trimming process, under the operation of the reset spring 3, the shaft pin 33 always maintains a tendency to move to the left. When the thread trimming mechanism 30 is stuck and the shaft pin 33 cannot move to the left, the thread trimming mechanism can be reset by only slightly pushing the shaft pin 33 by the hook portion 35.

[0066] The lower side of the extension handle 34 is provided with a strip hole, and the bolt assembly 36 passes through the strip hole and locks the extension handle 34 on the right lever arm. This design allows the extension handle 34 to be slightly adjusted up and down to adapt to different conditions.

[0067] An overlock sewing machine comprises the thread trimming and presser foot lifting mechanism.

[0068] The patented thread trimming and presser foot lifting process:

[0069] The motor goes from the initial state to the thread trimming operation: the motor drives the left lever arm 61 to swing upward and the right lever arm 62 to swing downward through the universal ball joint connecting rod 13; the extension handle 34 on the right lever arm 62 approaches and pushes the shaft pin 33, and the shaft pin 33 drives the thread trimming mechanism; during the downward swinging of the right lever arm 62 and the thread trimming, the shaft pin 33 of the thread trimming mechanism slides along the pushing portion 65 and enters the hook portion 35;

[0070] After the thread trimming is completed, reset is performed: the reset spring 3 always gives the shaft pin 33 a force to swing to the left. When the right force arm 62 retreats upward, the shaft pin 33 will immediately swing to the left to reset. If the thread trimming device is accidentally stuck due to factors such as thread ends, the hook portion 35 can force the shaft pin 33 to move to the left to complete the reset. When the crank 32 of the thread trimming mechanism swings to the left to a certain position, the crank 32 will be close to the abutment portion 71, and the right force arm 62 and the shaft pin 33 will separate.

[0071] The motor goes from the initial state to the presser foot lifting operation: the motor drives the left force arm 61 to swing downward through the universal ball head connecting rod 13, and the left force arm 61 drives the presser foot lifting assembly 3 through the hook 51. The lifting and pressing lever 22, the lifting and pressing sleeve 21 and the lifting and pressing shaft of the presser foot lifting mechanism 20 are clutch-driven, and this structure is the prior art, so it will not be expanded, and the prior art ZL201120549101.6 can be referred to.

[0072] The presser foot lifting operation is performed by stepping on the pedal: after stepping on the pedal, one end of the presser foot lifting swing arm assembly 50 is pulled downward through the pedal mechanism 40, and the other end of the presser foot lifting swing arm assembly 50 will drive the presser foot lifting mechanism (20) to move through the hook 51, thereby realizing the presser foot lifting operation.

[0073] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A new thread trimming and presser foot lifting self-separation device for an overlock sewing machine, comprising: A driving motor (10) is mounted on the frame (1) and provides power to the remaining components; A presser foot lifting mechanism (20), which is mounted on the frame (1) and performs a presser foot lifting action; A thread trimming mechanism (30) which is mounted on the frame (1) and performs a thread trimming action; It is characterized in that Also includes A presser foot lifting swing arm assembly (50) is arranged at the lower part of the frame (1), the right end of the presser foot lifting swing arm assembly (50) is rotatably connected to the frame (1), the middle part of the presser foot lifting swing arm assembly (50) is connected to the presser foot lifting mechanism (20), and the left end of the presser foot lifting swing arm assembly (50) is used to connect to the pedal mechanism (40); A thread trimming swing arm assembly (60) is arranged on one side of the presser foot lifting swing arm assembly (50); the middle part of the thread trimming swing arm assembly (60) is rotatably mounted on the frame (1), and the right side force arm (62) of the rotation point (2) drives the thread trimming mechanism (30); a pressing portion (63) is arranged between the left side force arm (61) of the rotation point (2) and the presser foot lifting swing arm assembly (50), and the pressing portion (63) is used to drive the presser foot lifting swing arm assembly (50) to move; wherein the outer end portion of the left side force arm (61) is driven by the driving motor (10) to move up and down; The upper end of the left force arm (61) is formed with the pressing portion (63), and the pressing portion (63) is a pressing plate, and the pressing plate is located on the upper end surface of the presser foot lifting swing arm assembly (50); The invention also comprises a pedal mechanism (40), the left end of the presser foot lifting swing arm assembly (50) is connected to the pedal mechanism (40) and is used to perform the presser foot lifting action, the middle part of the thread trimming swing arm assembly (60) is rotatably arranged on the rotation point (2) of the presser foot lifting swing arm assembly (50), and the rotation points of the presser foot lifting swing arm assembly (50) and the thread trimming swing arm assembly (60) are concentrically arranged.

2. The thread trimming and presser foot lifting self-separating device of the new overlock sewing machine according to claim 1 is characterized in that: A pushing portion (65) is provided at the upper end of the right lever arm (62); when the right lever arm (62) swings downward from top to bottom to a set position, the pushing portion (65) drives the thread trimming mechanism (30) to perform thread trimming; when the right lever arm (62) moves in the reverse direction to the set position, the pushing portion (65) separates from the thread trimming mechanism (30).

3. The thread trimming and presser foot lifting self-separating device of the new overlock sewing machine according to claim 2 is characterized in that: The rear end of the thread trimming shaft (31) of the thread trimming mechanism (30) is provided with a crank (32), an axle pin (33) is provided on the crank (32), and a wear-resistant sleeve is installed on the outer periphery of the axle pin (33). When trimming the thread, the wear-resistant sleeve rotates with the pushing part (65) to perform the thread trimming. An adjustable bracket (70) is provided on the frame (1), and a supporting portion (71) for limiting the position of the crank (32) is provided on the bracket (70); after the pushing portion (65) leaves the shaft pin (33), the crank (32) is pressed against the supporting portion (71) under the action of the return spring (3).

4. The thread trimming and presser foot lifting self-separating device of the new overlock sewing machine according to claim 3 is characterized in that: A thread trimmer abutment seat (37) extends from the lower side of the crank (32), the thread trimmer abutment seat (37) cooperates with the abutment portion (71), and the abutment portion (71) is a rubber pad.

5. The thread trimming and presser foot lifting self-separating device of the new overlock sewing machine according to claim 3 is characterized in that: The bracket (70) is provided with a transverse strip-shaped fixing hole (73), and a fastener (74) passes through the strip-shaped fixing hole (73) so that the bracket (70) can be adjusted left and right and set on the frame (1).

6. The thread trimming and presser foot lifting self-separating device of the new overlock sewing machine according to claim 1 is characterized in that: The drive motor (10) is transversely mounted on the upper part of the frame (1), and a swing rod (12) is mounted on the motor shaft (11) of the drive motor (10); transmission is provided between the outer end of the swing rod (12) and the end of the left lever arm (61) via a universal ball head connecting rod (13); the right lever arm (62) is triangular in shape, the length of the left lever arm (61) is greater than the length of the right lever arm (62), and the rotation point (2) is arranged at the intersection of the two lever arms.

7. The thread trimming and presser foot lifting self-separating device of the new overlock sewing machine according to claim 1 is characterized in that: A hook (51) is provided at the right end of the presser foot lifting swing arm assembly (50), and the other end of the hook (51) is connected to and drives the presser foot lifting mechanism (20). A groove (64) for the hook (51) to move is provided on the thread trimming swing arm assembly (60).

8. An overlock sewing machine, characterized in that: The invention comprises a thread trimming and presser foot lifting self-separating device of a new overlock sewing machine as described in any one of claims 1 to 7.

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