Thread loosening mechanism of sewing machine

Abstract

The utility model discloses a thread loosening mechanism of a sewing machine, the sewing machine comprises a machine head, a presser foot, a presser foot driving mechanism and a thread loosening mechanism, the presser foot, the presser foot driving mechanism and the thread loosening mechanism are arranged on the machine head, and the presser foot driving mechanism is used for driving the presser foot to move up and down; the thread loosening mechanism comprises a first thread loosening ejector pin, a fixed thread clamping plate and an elastic thread clamping plate; during use, the presser foot driving mechanism can drive the driven sliding block to move up and down while normally driving the presser foot to move up and down for normal sewing work, and when the driven sliding block moves upwards, the wedge-shaped face can push the first thread loosening ejector pin to abut against the elastic thread clamping plate, so that the elastic thread clamping plate is far away from the fixed thread clamping plate; therefore, the sewing thread between the elastic thread clamping plate and the fixed thread clamping plate can be normally driven by the machine needle for sewing. Compared with the prior art, the structure is simpler; when the presser foot driving mechanism normally operates, the thread loosening mechanism can be driven to realize thread loosening and paying-off, so that higher efficiency is realized; no additional driving element is needed to control the thread loosening mechanism to loosen the thread, and more cost is saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewing machines, and in particular relates to a thread loosening mechanism for a sewing machine. Background Art

[0002] Automatic sewing machine is controlled by computer and equipped with automatic monitoring system, feeding system, automatic sewing start, sewing according to set trajectory, needle stopping, thread cutting and other functions, which can automatically complete certain sewing processes.

[0003] When the automatic sewing machine is sewing, the presser foot needs to be moved up and down by the presser foot driving mechanism. At the same time, the existing sewing machine needs to be separately provided with a thread loosening mechanism to loosen and release the thread during sewing.

[0004] Setting up a separate wire loosening mechanism will make the structure of the entire head part complicated and bloated. At the same time, a separate wire loosening mechanism also requires a separate driving element, which is more expensive. Utility Model Content

[0005] In order to solve the above problems existing in the prior art, the utility model aims to provide a thread loosening mechanism for a sewing machine, which combines a presser foot driving mechanism with a thread loosening mechanism so that the presser foot can automatically drive the thread loosening mechanism to loosen the thread while moving up and down.

[0006] The technical solution adopted by the utility model is:

[0007] A thread loosening mechanism for a sewing machine comprises a machine head and a presser foot arranged on the machine head, a presser foot driving mechanism and a thread loosening mechanism, wherein the presser foot driving mechanism is used for driving the presser foot to move up and down; the thread loosening mechanism comprises a first thread loosening ejector, a fixed thread clamping plate and an elastic thread clamping plate; the presser foot driving mechanism drives the presser foot to move up and down by driving a presser foot rod, a driven slider is connected to the presser foot rod, and a wedge-shaped surface is arranged at one end of the driven slider away from the presser foot rod; when the presser foot driving mechanism drives the presser foot to move up and down, the wedge-shaped surface of the driven slider pushes the first thread loosening ejector to press against or away from the elastic thread clamping plate, thereby pushing the elastic thread clamping plate to press against or away from the fixed thread clamping plate.

[0008] Optionally, the presser foot driving mechanism includes a driving motor, a first hinge plate, a second hinge plate and a sleeve; the power output shaft of the driving motor is connected to one end of the first hinge plate, the other end of the first hinge plate is hingedly connected to one end of the second hinge plate, and the other end of the second hinge plate is hingedly connected to the side wall of the sleeve; the sleeve is locked on the presser foot rod, and the driven slider is arranged on the sleeve.

[0009] Optionally, the wire loosening mechanism further comprises a fixing seat, which is mounted on the side wall of the machine head, and the fixing clamping plate is mounted on the fixing seat.

[0010] Optionally, a central adapter shaft is provided in the fixed seat, one end of the central adapter shaft is located in the fixed seat and has a coaxial axis hole, and the other end of the central adapter shaft has an installation gap, which divides the other end of the central adapter shaft into two halves; the elastic clamping plate is mounted on the other end of the central adapter shaft.

[0011] Optionally, the central adapter shaft is a stepped shaft, the outer diameters of both ends of the central adapter shaft are smaller than the outer diameter of the middle section, and the shaft hole passes through one end and the middle section of the central adapter shaft.

[0012] Optionally, a wire loosening top plate is mounted on the center adapter shaft, the elastic wire clamping plate is located between the middle section of the center adapter shaft and the wire loosening top plate, a top connecting beam is arranged at the center of the wire loosening top plate, and the top connecting beam is located in the installation gap.

[0013] Optionally, a second thread loosening ejector pin is movably installed in the axial hole, and two ends of the second thread loosening ejector pin are respectively close to the first thread loosening ejector pin and the thread loosening ejector plate.

[0014] Optionally, an adjusting rubber cap is fixedly mounted on the other end of the central adapter shaft, a stop plate is arranged on the adjusting rubber cap, the stop plate is fixedly mounted on the other end of the central adapter shaft, and a spring is arranged between the stop plate and the loose wire top plate.

[0015] As an option, the spring is arranged in a spring cover, and the spring cover is slidably mounted on the central adapter shaft.

[0016] The beneficial effects of the utility model are:

[0017] The utility model provides a thread loosening mechanism for a sewing machine, the sewing machine comprises a machine head and a presser foot arranged on the machine head, a presser foot driving mechanism and a thread loosening mechanism, the presser foot driving mechanism is used to drive the presser foot to move up and down; the thread loosening mechanism comprises a first thread loosening thimble, a fixed thread clamping plate and an elastic thread clamping plate; the presser foot driving mechanism drives the presser foot to move up and down by driving a presser foot rod, a driven slider is connected to the presser foot rod, and a wedge-shaped surface is arranged at one end of the driven slider away from the presser foot rod; when the presser foot driving mechanism drives the presser foot to move up and down, the wedge-shaped surface of the driven slider pushes the first thread loosening thimble to press against or away from the elastic thread clamping plate, thereby pushing the elastic thread clamping plate to press against or away from the fixed thread clamping plate. When in use, the presser foot driving mechanism normally drives the presser foot to move up and down to perform normal sewing work, and can drive the driven slider to move up and down, when the driven slider moves upward, the wedge-shaped surface will push the first thread loosening thimble to press against the elastic thread clamping plate, thereby making the elastic thread clamping plate away from the fixed thread clamping plate, so that the sewing thread between the elastic thread clamping plate and the fixed thread clamping plate can be normally driven by the needle, thereby performing sewing. Compared with the prior art, the utility model has a simpler structure; the presser foot driving mechanism can drive the thread loosening mechanism to loosen and release the thread while operating normally, which is more efficient; no additional driving element is required to control the thread loosening mechanism to loosen the thread, which saves more costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the machine head.

[0019] Figure 2 It is a schematic diagram of the installation position of the utility model.

[0020] Figure 3 It is a connection diagram of the thread loosening mechanism and the presser foot driving mechanism.

[0021] Figure 4 This is a schematic diagram of the installation of the driven slider in the machine head.

[0022] Figure 5 It is a schematic diagram of the structure of the presser foot driving device and the driven slider.

[0023] Figure 6 It is a cross-sectional schematic diagram of the wire loosening mechanism.

[0024] Figure 7 This is an exploded view of the wire release mechanism with the spring omitted.

[0025] Figure 8 It is a structural schematic diagram of the central adapter shaft and the loose wire top plate.

[0026] In the figure: 1-machine head, 11-mounting block, 12-sliding gap, 2-thread release mechanism, 21-elastic thread clamping plate, 22-fixed thread clamping plate, 23-spring cover, 24-second thread release ejector, 25-fixed seat, 26-center adapter shaft, 261-axis hole, 262-mounting gap, 27-thread release ejector plate, 271-top crossbeam, 28-spring, 29-adjusting rubber cap, 291-stop plate, 3-presser foot driving mechanism, 31-driving motor, 32-first hinged plate, 33-second hinged plate, 34-sleeve, 4-presser foot, 41-presser foot rod, 5-needle, 6-driven slider, 61-wedge surface, 7-first thread release ejector. DETAILED DESCRIPTION

[0027] Embodiment 1:

[0028] In this embodiment, if Figures 1 to 6As shown, a thread loosening mechanism of a sewing machine, the sewing machine comprises a head 1 and a presser foot 4, a presser foot driving mechanism 3 and a thread loosening mechanism 2 arranged on the head 1, the presser foot driving mechanism 3 is used to drive the presser foot 4 to move up and down; the thread loosening mechanism 2 comprises a first thread loosening ejector pin 7, a fixed thread clamping plate 22 and an elastic thread clamping plate 21; the presser foot driving mechanism 3 drives the presser foot 4 to move up and down by driving the presser foot rod 41, the presser foot rod 41 is connected with a driven slider 6, and the end of the driven slider 6 away from the presser foot rod 41 is provided with a wedge surface 61; when the presser foot driving mechanism 3 drives the presser foot 4 to move up and down, the wedge surface 61 of the driven slider 6 pushes the first thread loosening ejector pin 7 to press against or away from the elastic thread clamping plate 21, thereby pushing the elastic thread clamping plate 21 to press against or away from the fixed thread clamping plate 22. When in use, the presser foot driving mechanism 3 can drive the presser foot 4 to move up and down to perform normal sewing work, and can drive the driven slider 6 to move up and down. When the driven slider 6 moves upward, the wedge surface 61 will push the first thread loosening pin 7 to support the elastic clamping plate 21, so that the elastic clamping plate 21 is away from the fixed clamping plate 22, so that the sewing thread between the elastic clamping plate 21 and the fixed clamping plate 22 can be driven by the needle 5 normally, so as to perform sewing. Compared with the prior art, the utility model has a simpler structure; the presser foot driving mechanism 3 can drive the thread loosening mechanism 2 to loosen and release the thread while operating normally, which is more efficient; no additional driving element is required to control the thread loosening mechanism to loosen the thread, which is more cost-effective.

[0029] In this embodiment, if Figure 4 As shown, a mounting block 11 is provided at the end of the machine head 1, and a slide groove 12 is provided on the mounting block 11. The driven slider 6 is located in the slide groove 12 and can slide up and down along the slide groove 12. Figure 5 As shown, the wedge surface 61 makes the wall thickness of the upper end of the driven slider 61 smaller than that of the lower end. When the driven slider 6 moves downward, the wedge surface 61 moves downward, so that the part of the driven slider 6 with a smaller wall thickness moves downward, and the bottom end of the driven slider 6 no longer presses against the first thread loosening pin 7. The elastic thread clamping plate 21 pushes the first thread loosening pin 7 to the upper end of the wedge surface 61 under the action of elastic force. At this time, the elastic thread clamping plate 21 presses against the fixed thread clamping plate 22 under the action of elastic force, and the sewing thread between the elastic thread clamping plate 21 and the fixed thread clamping plate 22 cannot move.

[0030] Embodiment 2:

[0031] This embodiment provides an optional solution for the specific structure of the presser foot transmission mechanism based on the first embodiment.

[0032] In this embodiment, if Figures 2 to 5As shown, the presser foot driving mechanism 3 includes a driving motor 31, a first hinge plate 32, a second hinge plate 33 and a sleeve 34; the power output shaft of the driving motor 31 is connected to one end of the first hinge plate 32, the other end of the first hinge plate 32 is hingedly connected to one end of the second hinge plate 33, and the other end of the second hinge plate 33 is hingedly connected to the side wall of the sleeve 34; the sleeve 34 is locked on the presser foot rod 41, and the driven slider 6 is arranged on the sleeve 34.

[0033] In this embodiment, the wedge surface 61 and the sleeve 34 are respectively located on both sides of the slide groove 12. The slide groove 12 guides the driven slider 6 so that when the second hinge plate 33 rotates, the driven slider 6 can only move up and down along the slide groove 12, so that the sleeve 34 drives the presser foot rod 41 to move up and down.

[0034] Embodiment three:

[0035] This embodiment provides an optional solution for the specific structure of the wire loosening mechanism based on any of the above embodiments.

[0036] In this embodiment, if Figures 6 to 8 As shown, the wire loosening mechanism 2 further includes a fixing seat 25 , which is mounted on the side wall of the machine head 1 , and the fixing clamping plate 22 is mounted on the fixing seat 25 .

[0037] In this embodiment, a central adapter shaft 26 is arranged in the fixing seat 25, one end of the central adapter shaft 26 is located in the fixing seat 25 and is provided with a coaxial shaft hole 261, and the other end of the central adapter shaft 26 is provided with an installation gap 262, and the installation gap 262 divides the other end of the central adapter shaft 26 into two halves; the elastic clamping plate 21 is sleeved on the other end of the central adapter shaft 26.

[0038] In this embodiment, the central adapter shaft 26 is a stepped shaft, the outer diameters of both ends of the central adapter shaft 26 are smaller than the outer diameter of the middle section, and the shaft hole 261 passes through one end and the middle section of the central adapter shaft 26 .

[0039] In this embodiment, a wire loosening top plate 27 is also mounted on the central adapting shaft 26, the elastic clamping plate 21 is located between the middle section of the central adapting shaft 26 and the wire loosening top plate 27, a top connecting crossbeam 271 is arranged at the center of the wire loosening top plate 27, and the top connecting crossbeam 271 is located in the installation gap 262. A second wire loosening ejector pin 24 is movably mounted in the shaft hole 261, and the two ends of the second wire loosening ejector pin 24 are respectively close to the first wire loosening ejector pin 7 and the wire loosening top plate 27.

[0040] In this embodiment, an adjusting rubber cap 29 is fixedly mounted on the other end of the central adapting shaft 26, and a stop plate 291 is arranged on the adjusting rubber cap 29. The stop plate 291 is fixedly mounted on the other end of the central adapting shaft 26, and a spring 28 is arranged between the stop plate 291 and the thread loosening top plate 27. The spring 28 is arranged in the spring protective cover 23, and the spring protective cover 23 is slidably mounted on the central adapting shaft 26. When the driving force from the first thread loosening thimble 7 disappears, since the stop plate 291 is fixed, the spring 28 between the stop plate 291 and the thread loosening top plate 27 pushes the thread loosening top plate 27 away from the stop plate 291, and presses the elastic clamping plate 21 toward the fixed clamping plate 22, so that the sewing thread is compressed under the action of elastic force.

[0041] In this embodiment, a through hole (not shown in the figure) is provided on one side of the mounting seat 11 away from the sleeve 34, and the first thread-releasing ejector pin 7 is a stepped cylinder, and the end of the first thread-releasing ejector pin 7 with a larger outer diameter is located outside the through hole and close to the second thread-releasing ejector pin 24. The first thread-releasing ejector pin 7 passes through the through hole and abuts against the driven slider 6. One end of the second thread-releasing ejector pin 24 protrudes out of the fixed seat 25, and when the driven slider 6 moves upward, the wedge surface 61 moves upward, and under the guidance and push of the wedge surface 61, the first thread-releasing ejector pin 7 moves toward the second thread-releasing ejector pin 24, and the second thread-releasing ejector pin 24 moves in the shaft hole 261 and pushes the abutting crossbeam 271 of the thread-releasing ejector plate 27, pushing the thread-releasing ejector plate 27 to overcome the elastic force of the spring 28, so that the thread-releasing ejector plate 27 is away from the fixed clamping plate 22 along the installation gap 262.

[0042] In this embodiment, the inner diameter of the spring protective cover 23 is greater than the outer diameter of the adjusting rubber cap 29 . Therefore, when the second wire loosening ejector pin 24 pushes the wire loosening ejector plate 27 to move, the spring protective cover 23 slides along the adjusting rubber cap 29 synchronously.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0045] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A thread loosening mechanism for a sewing machine, the sewing machine comprising a machine head (1), a presser foot (4) arranged on the machine head (1), a presser foot driving mechanism (3) and a thread loosening mechanism (2), wherein the presser foot driving mechanism (3) is used for driving the presser foot (4) to move up and down; Features: The thread loosening mechanism (2) comprises a first thread loosening ejector pin (7), a fixed thread clamping plate (22) and an elastic thread clamping plate (21); The presser foot driving mechanism (3) drives the presser foot (4) to move up and down by driving the presser foot rod (41); a driven slider (6) is connected to the presser foot rod (41); and a wedge-shaped surface (61) is provided at one end of the driven slider (6) away from the presser foot rod (41); When the presser foot driving mechanism (3) drives the presser foot (4) to move up and down, the wedge-shaped surface (61) of the driven slider (6) pushes the first thread-releasing ejector pin (7) to press against or away from the elastic thread clamping plate (21), thereby pushing the elastic thread clamping plate (21) to press against or away from the fixed thread clamping plate (22).

2. A thread loosening mechanism for a sewing machine according to claim 1, It is characterized in that The presser foot driving mechanism (3) comprises a driving motor (31), a first hinge plate (32), a second hinge plate (33) and a sleeve (34); The power output shaft of the driving motor (31) is connected to one end of the first hinge plate (32), the other end of the first hinge plate (32) is hingedly connected to one end of the second hinge plate (33), and the other end of the second hinge plate (33) is hingedly connected to the side wall of the sleeve (34); The sleeve (34) is locked on the presser foot rod (41), and the driven slider (6) is arranged on the sleeve (34).

3. A thread loosening mechanism for a sewing machine according to claim 1, It is characterized in that The wire loosening mechanism (2) further comprises a fixing seat (25), wherein the fixing seat (25) is mounted on the side wall of the machine head (1), and the fixing clamping plate (22) is mounted on the fixing seat (25).

4. A thread loosening mechanism for a sewing machine according to claim 3, It is characterized in that A central adapting shaft (26) is arranged in the fixing seat (25), one end of the central adapting shaft (26) is located in the fixing seat (25) and is provided with a coaxial shaft hole (261), and the other end of the central adapting shaft (26) is provided with an installation gap (262), and the installation gap (262) divides the other end of the central adapting shaft (26) into two halves; The elastic clamping plate (21) is sleeved on the other end of the central adapting shaft (26).

5. A thread loosening mechanism for a sewing machine according to claim 4, It is characterized in that The central adapter shaft (26) is a stepped shaft, the outer diameters of the two ends of the central adapter shaft (26) are smaller than the outer diameter of the middle section, and the shaft hole (261) passes through one end and the middle section of the central adapter shaft (26).

6. A thread loosening mechanism for a sewing machine according to claim 5, It is characterized in that A wire loosening top plate (27) is also mounted on the central adapting shaft (26); the elastic wire clamping plate (21) is located between the middle section of the central adapting shaft (26) and the wire loosening top plate (27); a top connecting crossbeam (271) is arranged at the center of the wire loosening top plate (27); and the top connecting crossbeam (271) is located in the installation gap (262).

7. A thread loosening mechanism for a sewing machine according to claim 6, It is characterized in that A second thread loosening ejector pin (24) is movably mounted in the shaft hole (261), and two ends of the second thread loosening ejector pin (24) are respectively close to the first thread loosening ejector pin (7) and the thread loosening ejector plate (27).

8. A thread loosening mechanism for a sewing machine according to claim 7, It is characterized in that An adjusting rubber cap (29) is fixedly mounted on the other end of the central adapting shaft (26), a stop plate (291) is arranged on the adjusting rubber cap (29), the stop plate (291) is fixedly mounted on the other end of the central adapting shaft (26), and a spring (28) is arranged between the stop plate (291) and the wire loosening top plate (27).

9. A thread loosening mechanism for a sewing machine according to claim 8, It is characterized in that The spring (28) is arranged in a spring protection cover (23), and the spring protection cover (23) is slidably mounted on a central adapter shaft (26).

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