Thread trimming and presser foot lifting device for overlock sewing machine and overlock sewing machine

Abstract

The utility model belongs to the technical field of overlock sewing machines, and particularly relates to a thread trimming and presser foot lifting device of an overlock sewing machine and the overlock sewing machine, comprising a thread trimming mechanism, a presser foot lifting mechanism and a driving mechanism; the driving mechanism drives the presser foot lifting mechanism and the thread trimming mechanism; the thread trimming mechanism comprises a thread cutting drive plate, a thread cutting crank pin, a thread cutting crank, a thread cutting rod and a cutter; a rotation center is arranged at the middle of the thread cutting drive plate, and the thread cutting drive plate is rotatably mounted on a frame of the overlock sewing machine body with the rotation center as a reference point; a supporting end is arranged at one end of the thread cutting drive plate; the supporting end is rotatably mounted on the thread cutting drive plate, and the surface of the supporting end is a spherical surface; through the structural arrangement of the spherical surface, the transmission structure between the driving motor and the thread cutting drive plate is simplified, and the noise is reduced at the same time.

Description

Technical Field

[0001] The utility model belongs to the technical field of overlock sewing machines, in particular to a thread trimming and presser foot lifting device of an overlock sewing machine and the overlock sewing machine. Background Art

[0002] CN202210060905.2 discloses a thread trimming mechanism and presser foot lifting mechanism of a sewing machine and a sewing machine, including a housing and a motor mounted on the housing, a first cam mounted on the output shaft of the motor; and also including a thread trimming connecting rod that moves up and down, a first roller mounted on the thread trimming connecting rod, the first roller is in contact with the contour of the first cam, a scissors connecting rod is hinged at the lower end of the thread trimming connecting rod, the middle part of the scissors connecting rod is mounted on the housing through an axial bolt, a knife bar connecting rod is hinged at the other end of the thread trimming connecting rod, and a knife bar is mounted at the other end of the knife bar connecting rod. The thread trimming mechanism uses the principle of a seesaw to drive the knife bar to rotate, thereby realizing the thread trimming function, the motor directly drives the thread trimming connecting rod to move up and down through the first cam, the thread trimming connecting rod is pressed on the scissors connecting rod, and the other end of the scissors connecting rod is tilted and drives the knife bar connecting rod to swing.

[0003] The disadvantages of this technical solution are:

[0004] The overall structure is relatively complex. The main structure of the thread trimming structure adopts a seesaw transmission, but it involves many parts and has serious abnormal noises. The presser foot lifting structure is only equipped with one presser foot transmission. For some models that need to be equipped with two presser feet, the structure needs to be further improved. Utility Model Content

[0005] The utility model aims to provide a thread trimming and presser foot lifting device for an overlock sewing machine with simple structure and reliable transmission and an overlock sewing machine.

[0006] The purpose of the utility model is achieved in this way:

[0007] A thread trimming and presser foot lifting device for an overlock sewing machine, comprising:

[0008] A thread cutting mechanism, which is used to cut the sewing thread of the machine needle;

[0009] A presser foot lifting mechanism, which is used to lift or lower the presser foot assembly of the overlock sewing machine;

[0010] A driving mechanism, which is used to drive the thread trimming mechanism and the presser foot lifting mechanism;

[0011] The driving mechanism comprises a driving motor, a first transmission assembly and a second transmission assembly, wherein the first transmission assembly and the second transmission assembly are mounted on the motor shaft of the driving motor; the first transmission assembly is used to drive the presser foot lifting mechanism; and the second transmission assembly is used to drive the thread trimming mechanism;

[0012] The thread trimming mechanism includes a tangent driving plate, a tangent crank pin, a tangent crank, a tangent rod and a cutter; a rotation center is arranged in the middle of the tangent driving plate, and the tangent driving plate is rotatably mounted on the frame of the overlock sewing machine body with the rotation center as a reference point; a supporting end is installed at one end of the tangent driving plate; the supporting end is rotatably mounted on the tangent driving plate, and the surface of the supporting end is a spherical surface; the other end of the tangent driving plate is hinged to one end of the tangent crank pin, and the other end of the tangent crank pin is hinged to the tangent crank, the tangent crank is fixedly mounted on the tangent rod, the tangent rod is rotatably arranged on the frame, and a cutter is installed at the front end of the tangent rod.

[0013] Preferably, a positioning pin is provided on the frame at the lower side of the tangent drive plate, and a torsion spring is mounted on the rotation center of the tangent drive plate, one end of the torsion spring rests on the positioning pin, and the other end of the torsion spring hooks the tangent drive plate.

[0014] Preferably, the presser foot lifting mechanism comprises a presser foot lifting shaft lever, a presser foot lifting first crank, a presser foot lifting second crank, a presser foot lifting shaft sleeve, a presser foot lifting lever, a presser foot lifting shaft and a presser foot lifting shaft arm;

[0015] The presser foot lifting shaft is rotatably inserted into the presser foot lifting inner shaft sleeve, the presser foot lifting inner shaft sleeve is rotatably inserted into the presser foot lifting shaft sleeve, and the presser foot lifting shaft sleeve is rotatably installed on the frame; both ends of the presser foot lifting shaft extend out of the presser foot lifting inner shaft sleeve; the first presser foot lifting crank is installed on the end of the presser foot lifting shaft facing the driving motor, and the second presser foot lifting crank is installed on the end of the presser foot lifting inner shaft sleeve facing the driving motor; a presser foot lifting shaft lever is movably sleeved on the presser foot lifting shaft or the presser foot lifting inner shaft sleeve between the first presser foot lifting crank and the second presser foot lifting crank, and the outer end of the presser foot lifting shaft lever extends to one side of the first transmission assembly and is driven by the first transmission assembly;

[0016] The other end of the presser foot lifting inner sleeve is provided with the presser foot lifting lever; the other end of the presser foot lifting shaft is provided with the presser foot lifting shaft arm;

[0017] A first abutment portion and a second abutment portion are provided on the presser foot lifting shaft lever; one side of the first crank of the presser foot lifting extends to the top of the presser foot lifting shaft lever and cooperates with the first abutment portion; one side of the second crank of the presser foot lifting extends to the bottom of the presser foot lifting shaft lever and cooperates with the second abutment portion.

[0018] Preferably, the first abutment portion is a protrusion protruding upward from the rear side of the presser foot lifting shaft lever.

[0019] Preferably, the second abutment portion is arranged below the rear side of the presser foot lifting shaft lever.

[0020] Preferably, a third abutment portion is provided on the front side of the presser foot lifting shaft lever, and the third abutment portion is a hook portion formed by extending upward from the front side of the presser foot lifting shaft lever.

[0021] Preferably, the first transmission assembly is crank 1, and a roller is installed on one side of crank 1, and the roller is used to push the presser foot lifting mechanism.

[0022] Preferably, the second transmission assembly is a cam, and the cam is used to push the thread trimming mechanism.

[0023] An overlock sewing machine comprises an overlock sewing machine body, on which the thread trimming and presser foot lifting devices of the overlock sewing machine are arranged.

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

[0025] A rotation center is arranged in the middle of the tangent drive plate of the present patent, and the tangent drive plate rotates with the rotation center as a reference point; a supporting end is installed at one end of the tangent drive plate; the supporting end is rotatably installed on the tangent drive plate, and the surface of the supporting end is a spherical surface; through the spherical structure setting, the transmission structure between the drive motor and the tangent drive plate is simplified, and the noise is reduced at the same time.

[0026] The presser foot lifting shaft of the patent can be rotatably inserted into the presser foot lifting inner shaft sleeve, and the presser foot lifting inner shaft sleeve can be rotatably inserted into the presser foot lifting shaft sleeve; then the presser foot lifting inner shaft sleeve and the presser foot lifting shaft are driven respectively by the presser foot lifting shaft lever to realize the separate transmission of the two presser feet. The structure is simple and safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of an overlock sewing machine of the utility model.

[0028] Figure 2 It is one of the schematic diagrams of the thread trimming and presser foot lifting device of the utility model.

[0029] Figure 3 This is the second schematic diagram of the thread trimming and presser foot lifting device of the utility model.

[0030] Figure 4 It is a schematic diagram of the thread trimming mechanism of the utility model. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with specific embodiments:

[0032] like Figure 1-4 As shown, a thread trimming and presser foot lifting device of an overlock sewing machine comprises:

[0033] A thread cutting mechanism 101, which is used to cut the sewing thread of the machine needle;

[0034] A presser foot lifting mechanism 102, which is used to lift or lower the presser foot assembly of the overlock sewing machine;

[0035] A driving mechanism 100, which is used to drive the thread trimming mechanism and the presser foot lifting mechanism;

[0036] The driving mechanism 100 includes a driving motor 10, a first transmission assembly and a second transmission assembly, wherein the first transmission assembly and the second transmission assembly are mounted on the motor shaft of the driving motor; the first transmission assembly is used to push the presser foot lifting mechanism 102; the second transmission assembly is used to push the thread trimming mechanism 101; the first transmission assembly is a crank 12, on one side of which a roller 25 is mounted, and the roller is used to push the presser foot lifting mechanism 102; the second transmission assembly is a cam 13, and the cam is used to push the thread trimming mechanism 101.

[0037] The thread trimming mechanism includes a thread cutting drive plate 16, a thread cutting crank pin 17, a thread cutting crank 18, a thread cutting rod 19 and a cutter 30; a rotation center 161 is provided in the middle of the thread cutting drive plate 16, and the thread cutting drive plate 16 is rotatably mounted on the frame of the overlock machine body 200 with the rotation center as a reference point; a support end 15 is installed at one end of the thread cutting drive plate 16; the support end is rotatably mounted on the thread cutting drive plate, and the surface of the support end is a spherical surface; the other end of the thread cutting drive plate 16 is hinged to one end of the thread cutting crank pin 17, and the other end of the thread cutting crank pin 17 is hinged to the thread cutting crank 18, and the thread cutting crank 18 is fixedly mounted on the thread cutting rod 19, and the thread cutting rod 19 is rotatably mounted on the frame, and a cutter 30 is installed at the front end of the thread cutting rod 19. The thread cutting drive plate 16 is similar to the structure of a seesaw, and when one end is pressed down, the other end is tilted, and vice versa. In the present application, the ball structure on the surface of the abutment end is utilized so that when the tangent drive plate 16 moves downward, the abutment end and the cam 13 are slightly offset in the vertical plane without affecting the transmission, thereby simplifying the structure; specifically, before performing the thread trimming, the cam 13 can be set slightly biased to the right side of the abutment end. During the thread trimming process, the cam and the abutment end move downward, and the cam also moves to the left relative to the abutment end; during the entire thread trimming process, ensure that the cam does not deviate from the spherical range of the abutment end.

[0038] Preferably, a positioning pin 29 is provided on the frame at the lower side of the tangent drive plate 16, and a torsion spring 28 is mounted on the rotation center of the tangent drive plate 16, one end 282 of the torsion spring abuts against the positioning pin, and the other end 281 of the torsion spring hooks the tangent drive plate 16. The torsion spring 28 realizes the reset of the tangent drive plate 16.

[0039] Preferably, the presser foot lifting mechanism includes a presser foot lifting shaft lever 14, a presser foot lifting first crank 27, a presser foot lifting second crank 24, a presser foot lifting shaft sleeve 23, a presser foot lifting lever 22, a presser foot lifting shaft 20 and a presser foot lifting shaft arm 21;

[0040] The presser foot lifting shaft 20 is rotatably inserted into the presser foot lifting inner shaft sleeve, the presser foot lifting inner shaft sleeve is rotatably inserted into the presser foot lifting shaft sleeve 23, and the presser foot lifting shaft sleeve 23 is rotatably mounted on the frame; both ends of the presser foot lifting shaft 20 extend out of the presser foot lifting inner shaft sleeve; the first presser foot lifting crank 27 is installed on the end of the presser foot lifting shaft 20 facing the driving motor, and the second presser foot lifting crank 24 is installed on the end of the presser foot lifting inner shaft sleeve facing the driving motor; the presser foot lifting shaft 20 or the presser foot lifting inner shaft sleeve between the first presser foot lifting crank 27 and the second presser foot lifting crank 24 is movably sleeved with a presser foot lifting shaft lever 14, and the outer end of the presser foot lifting shaft lever 14 extends to one side of the first transmission assembly and is driven by the first transmission assembly;

[0041] The other end of the presser foot lifting inner sleeve is provided with the presser foot lifting lever 22; the other end of the presser foot lifting shaft 20 is provided with the presser foot lifting shaft arm 21; the presser foot lifting inner sleeve is located inside the presser foot lifting shaft sleeve, and the presser foot lifting inner sleeve and the presser foot lifting lever 22 are fixedly connected or integrally formed;

[0042] The presser foot lifting shaft lever 14 is provided with a first abutment portion 141 and a second abutment portion 142; one side of the presser foot lifting first crank 27 extends to the top of the presser foot lifting shaft lever 14 and cooperates with the first abutment portion 141; one side of the presser foot lifting second crank 24 extends to the bottom of the presser foot lifting shaft lever 14 and cooperates with the second abutment portion 142. When the presser foot lifting shaft lever 14 is pressed downward, the presser foot lifting shaft lever 14 can simultaneously drive the presser foot lifting inner shaft sleeve and the presser foot lifting shaft to achieve the common lifting of the two presser feet; accordingly, the presser foot lifting inner shaft sleeve can be lifted separately in another set of manual transmission structure and is not affected by the technical structure of this patent.

[0043] Preferably, the first abutting portion 141 is a protrusion protruding upward from the rear side of the presser foot lifting shaft lever 14 .

[0044] Preferably, the second abutment portion 142 is disposed below the rear side of the presser foot lifting shaft lever 14 .

[0045] Preferably, the front side of the presser foot shaft lifting lever 14 is provided with a third abutment portion 143, which is a hook portion extending upward and formed by the front side of the presser foot shaft lifting lever 14. The hook portion abuts against the lower side of the roller 25, and when the roller moves downward, the third abutment portion is pressed downward.

[0046] A sewing machine comprises a sewing machine body, on which the thread trimming and presser foot lifting devices of the sewing machine are arranged.

[0047] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thread trimming and presser foot lifting device for an overlock sewing machine, comprising: A thread cutting mechanism (101) for cutting the sewing thread of a machine needle; A presser foot lifting mechanism (102) for lifting or lowering a presser foot assembly of an overlock sewing machine; A driving mechanism (100), which is used to drive the thread trimming mechanism and the presser foot lifting mechanism; It is characterized in that The driving mechanism (100) comprises a driving motor (10), a first transmission assembly and a second transmission assembly, wherein the first transmission assembly and the second transmission assembly are mounted on the motor shaft of the driving motor; the first transmission assembly is used to drive the presser foot lifting mechanism (102); and the second transmission assembly is used to drive the thread trimming mechanism (101); The thread trimming mechanism comprises a thread cutting drive plate (16), a thread cutting crank pin (17), a thread cutting crank (18), a thread cutting rod (19) and a cutter (30); a rotation center (161) is arranged in the middle of the thread cutting drive plate (16), and the thread cutting drive plate (16) is rotatably mounted on the frame of the overlock sewing machine body (200) with the rotation center as a reference point; a supporting end (15) is mounted on one end of the thread cutting drive plate (16); the supporting end is rotatably mounted on the thread cutting drive plate, and the surface of the supporting end is a spherical surface; the other end of the thread cutting drive plate (16) is hinged to one end of the thread cutting crank pin (17), the other end of the thread cutting crank pin (17) is hinged to the thread cutting crank (18), the thread cutting crank (18) is fixedly mounted on the thread cutting rod (19), the thread cutting rod (19) is rotatably mounted on the frame, and a cutter (30) is mounted on the front end of the thread cutting rod (19).

2. The thread trimming and presser foot lifting device of an overlock sewing machine according to claim 1, characterized in that: A positioning pin (29) is provided on the frame at the lower side of the tangent drive plate (16), and a torsion spring (28) is sleeved on the rotation center of the tangent drive plate (16), one end (282) of the torsion spring abuts against the positioning pin, and the other end (281) of the torsion spring hooks the tangent drive plate (16).

3. The thread trimming and presser foot lifting device of an overlock sewing machine according to claim 1, characterized in that: The presser foot lifting mechanism comprises a presser foot lifting shaft lever (14), a presser foot lifting first crank (27), a presser foot lifting second crank (24), a presser foot lifting shaft sleeve (23), a presser foot lifting lever (22), a presser foot lifting shaft (20) and a presser foot lifting shaft arm (21); The presser foot lifting shaft (20) is rotatably inserted into the presser foot lifting inner shaft sleeve, the presser foot lifting inner shaft sleeve is rotatably inserted into the presser foot lifting shaft sleeve (23), and the presser foot lifting shaft sleeve (23) is rotatably mounted on the frame; both ends of the presser foot lifting shaft (20) extend out of the presser foot lifting inner shaft sleeve; the first presser foot lifting crank (27) is mounted on the end of the presser foot lifting shaft (20) facing the driving motor, and the second presser foot lifting crank (24) is mounted on the end of the presser foot lifting inner shaft sleeve facing the driving motor; a presser foot lifting shaft lever (14) is movably sleeved on the presser foot lifting shaft (20) or the presser foot lifting inner shaft sleeve between the first presser foot lifting crank (27) and the second presser foot lifting crank (24), and the outer end of the presser foot lifting shaft lever (14) extends to one side of the first transmission assembly and is driven by the first transmission assembly; The other end of the presser foot lifting inner sleeve is provided with the presser foot lifting lever (22); the other end of the presser foot lifting shaft (20) is provided with the presser foot lifting shaft arm (21); The presser foot lifting shaft lever (14) is provided with a first abutment portion (141) and a second abutment portion (142); one side of the presser foot lifting first crank (27) extends to the top of the presser foot lifting shaft lever (14) and cooperates with the first abutment portion (141); one side of the presser foot lifting second crank (24) extends to the bottom of the presser foot lifting shaft lever (14) and cooperates with the second abutment portion (142).

4. The thread trimming and presser foot lifting device of an overlock sewing machine according to claim 3, characterized in that: The first abutment portion (141) is a protrusion protruding upward from the rear side of the presser foot lifting shaft lever (14).

5. The thread trimming and presser foot lifting device of an overlock sewing machine according to claim 3, characterized in that: The second abutment portion (142) is arranged below the rear side of the presser foot lifting shaft lever (14).

6. The thread trimming and presser foot lifting device of an overlock sewing machine according to claim 3, characterized in that: A third abutment portion (143) is provided on the front side of the presser foot shaft lifting lever (14), and the third abutment portion is a hook portion extending upward and formed on the front side of the presser foot shaft lifting lever (14).

7. The thread trimming and presser foot lifting device of an overlock sewing machine according to claim 1, characterized in that: The first transmission component is a crank one (12), and a roller (25) is installed on one side of the crank one (12), and the roller is used to push the presser foot lifting mechanism (102).

8. The thread trimming and presser foot lifting device of an overlock sewing machine according to claim 1, characterized in that: The second transmission component is a cam (13), and the cam is used to push the thread trimming mechanism (101).

9. An overlock sewing machine, characterized in that: The invention comprises a main body of an overlock sewing machine, on which the thread trimming and presser foot lifting device of the overlock sewing machine according to any one of claims 1 to 7 is arranged.

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