Thread sweeping mechanism of sewing machine

Abstract

The thread sweeping mechanism comprises a machine head, an air cylinder and a compressor, the air cylinder and the compressor are arranged in the machine head, the air cylinder is connected with the compressor, when a piston rod of the air cylinder is pushed, a thread sweeping rod can be driven to rotate to achieve thread sweeping, an opening is formed in the upper end of the air cylinder, and an air cylinder cover for blocking the opening is connected to the opening. A piston and a piston rod connected with the piston are arranged in the air cylinder, a spring is arranged between the piston and the inner wall of the air cylinder, and when the spring is in an initial state, the thread sweeping rod is in a non-triggered state; and a transmission mechanism is arranged between the piston rod and the thread sweeping rod. According to the scheme, the problems that an existing thread sweeping mechanism is not buffered in the action process, impact force on a thread sweeping rod is large, and loosening and deformation are caused are solved.

Description

Technical Field

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

[0002] During the sewing process, thread collection, release, and organization are crucial. The thread sweeping mechanism's primary function is to quickly and accurately gather excess thread into a designated location after the machine completes sewing. This prevents thread entanglement, accumulation, and interference with subsequent sewing, thereby ensuring a smooth sewing process and high-quality finished products.

[0003] At present, the thread sweeping mechanism commonly used in sewing machines mainly uses a cylinder as a driving device, which converts the linear motion of the piston rod into the rotational motion of the thread sweeping rod through a specific mechanical structure, thereby realizing the thread sweeping function.

[0004] As the piston rod in the cylinder moves up and down, its velocity and acceleration change very linearly and directly, without any buffering mechanism. When the piston rod moves rapidly to the end of its stroke, it generates a large impact force, which is directly transmitted to the thread-wiping rod and the entire thread-wiping mechanism. This causes increased wear and shortens the lifespan of the mechanism, leading to loosening, deformation, or even failure. Therefore, a new thread-wiping mechanism drive method is urgently needed to improve the performance and service life of sewing machine thread-wiping mechanisms. Utility Model Content

[0005] The utility model aims to provide a thread sweeping mechanism for a sewing machine, so as to solve the problems of the existing thread sweeping mechanism in that the action process has no buffer, the impact force on the thread sweeping rod is relatively large, and the looseness and deformation are caused.

[0006] The utility model is achieved through the following technical solutions:

[0007] A thread-wiping mechanism for a sewing machine comprises a machine head and a cylinder and a compressor arranged inside the machine head. The cylinder is connected to the compressor, and when the piston rod of the cylinder is pushed, it can drive the thread-wiping rod to rotate to achieve thread sweeping. An opening is provided at the upper end of the cylinder, and a cylinder cover for sealing the opening is connected to the opening; a piston head and a piston rod connected to the piston head are provided in the cylinder, and a spring is provided between the piston head and the inner wall of the cylinder. When the spring is in an initial state, the thread-wiping rod is in an untriggered state; a transmission mechanism is also provided between the piston rod and the thread-wiping rod.

[0008] In order to better realize the solution of the utility model, it also includes an intake pipe, which is connected to the interior of the cylinder head. The cylinder head is also provided with an end cover that matches the inner wall of the cylinder head.

[0009] In order to better implement the solution of the present invention, a dustproof annular groove and a sealing annular groove are provided on the side of the end cover from top to bottom along the axial direction of the end cover; a dustproof ring is provided in the dustproof annular groove, and a sealing ring is provided in the sealing annular groove.

[0010] In order to better implement the solution of the utility model, a cylindrical boss is provided at the lower end of the piston head, and the boss coincides with the axis of the piston head; the spring is sleeved on the outer edge of the boss.

[0011] In order to better implement the solution of the present invention, a cavity is provided inside the piston head, the upper end of the piston rod passes through the boss and a protrusion matching the cavity is provided at the end.

[0012] In order to better implement the solution of the present utility model, the transmission mechanism includes a fixed bracket, a rack segment, a gear and a rotating shaft. The rack segment is arranged on the outer surface of the lower section of the piston rod, the gear is movably connected to the fixed bracket, the rotating shaft and the gear are coaxially connected, one end of the rotating shaft is connected to the gear, and the other end of the rotating shaft movably passes through the fixed bracket. A limit block is provided on the end surface of the rotating shaft extending out of the fixed bracket, and a wire sweeping rod is fixedly connected to the limit block.

[0013] In order to better implement the solution of the present invention, the inner diameter of the cylinder head is smaller than the inner diameter of the cylinder, a first buffer ring is provided between the upper end of the piston head and the lower end of the cylinder head, and a second buffer ring is provided between the lower end of the spring and the inner lower end of the cylinder.

[0014] In order to better implement the solution of the present utility model, a guide tube for guiding the piston rod is connected to the lower end of the cylinder.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: the present invention provides a spring inside the cylinder, and when the piston head moves, the spring can effectively absorb the impact force generated by the movement of the piston head, play a buffering role, thereby reducing movement impact and noise, and extending the service life. At the same time, an opening is provided at the upper end of the cylinder and is connected to the cylinder head. The cylinder head can prevent dust and impurities from entering the interior of the cylinder, ensure the airtightness of the cylinder, avoid compressed air leakage, ensure the stability of the internal pressure, and improve the speed and force output of the piston head movement. In addition, a transmission mechanism is provided between the piston rod and the thread sweeping rod, which efficiently converts the linear motion of the piston rod into the rotational motion of the thread sweeping rod, ensuring the reliability and stability of the thread sweeping action. Therefore, this solution effectively solves the problems of large movement impact, high noise, insufficient precision and stability in the existing cylinder-driven thread sweeping mechanism, and significantly improves the performance and service life of the sewing machine thread sweeping mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0017] Figure 1 This is a schematic diagram of the overall structure of the sewing machine of the present utility model;

[0018] Figure 2 forFigure 1 Enlarged view of A in Fig.

[0019] Figure 3 Structure diagram of the thread sweeping mechanism of the sewing machine;

[0020] Figure 4 Partial cross-sectional view of the thread sweeping mechanism, aiming to show the internal structure of the air cylinder.

[0021] The signs represented by the reference signs are:

[0022] 1, the head,

[0023] 2, the air cylinder, 21, the air cylinder cover, 22, the air inlet pipe, 23, the guide cylinder,

[0024] 3, the piston rod, 31, the piston head, 33, the first buffer ring, 34, the second buffer ring, 35, the end cover, 351, the sealing ring, 352, the dustproof ring,

[0025] 4, the rotating shaft, 41, the gear, 42, the limiting block,

[0026] 5, the thread sweeping rod,

[0027] 6, the fixed support. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme of the embodiments of the utility model will be described clearly and completely below in combination with the drawings of the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the described embodiments of the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the utility model. The illustrative embodiments of the utility model and their descriptions are only used to explain the utility model, and not as a limitation of the utility model. It should be noted that the utility model is already in the actual research and development stage.

[0029] Unless otherwise defined, the technical terms or scientific terms used in the utility model should be understood as the usual meaning by those of ordinary skill in the art to which the utility model belongs. The "first", "second" and similar words used in the utility model do not represent any order, quantity or importance, but are only used to distinguish different components. "Include" or "contain" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0030] Embodiment 1:

[0031] As Figure 1、 Figure 2 With Figure 4 As shown in the figure, a sewing machine thread sweeping mechanism, comprising a head 1 and a cylinder 2 and a compressor arranged inside the head 1, the cylinder 2 and the compressor are connected, when the piston rod 3 of the cylinder 2 is pushed, it can drive the thread sweeping rod 5 to rotate to realize thread sweeping, the upper end of the cylinder 2 is provided with an opening, the opening is connected with a cylinder cover 21 for blocking the opening; the cylinder 2 is provided with a piston head 31 and a piston rod 3 connected with the piston head 31, a spring is arranged between the piston head 31 and the inner wall of the cylinder 2, when the spring is in the initial state, the thread sweeping rod 5 is in the untriggered state; a transmission mechanism is further arranged between the piston rod 3 and the thread sweeping rod 5.

[0032] The head 1 is the core component of the sewing machine, and the cylinder 2 and the compressor are arranged inside. The head 1 provides mounting space and support for the whole thread sweeping mechanism. The cylinder 2 is connected with the compressor through a pipeline, and the compressor provides compressed air for the cylinder 2, so that the piston rod 3 makes linear reciprocating motion in the cylinder 2. The upper end of the cylinder 2 is provided with an opening, and the cylinder cover 21 is used to block the opening to prevent dust and impurities from entering the inside of the cylinder 2, while ensuring the sealing of the cylinder 2. The piston head 31 makes reciprocating motion in the cylinder 2, the piston rod 3 is connected with the piston head 31 and extends out of the cylinder 2, and the movement of the piston rod 3 is the driving force source of the thread sweeping action. The spring is arranged between the piston head 31 and the inner wall of the cylinder 2, when the piston rod 3 is not affected by the compressed air, the spring is in the initial state (natural elongation state), at this time the thread sweeping rod 5 is in the untriggered state. A transmission mechanism is arranged between the piston rod 3 and the thread sweeping rod 5, for converting the linear motion of the piston rod 3 into the rotary motion of the thread sweeping rod 5.

[0033] Working process:

[0034] Initial: when the compressor does not supply air to the cylinder 2, the spring is in the initial state, the piston head 31 is located at the bottom of the cylinder 2, and the thread sweeping rod 5 is in the static state.

[0035] Start: the compressor starts to supply air to the cylinder 2, and the compressed air pushes the piston head 31 to move downward. The piston rod 3 moves downward under the driving of the piston head 31, and converts the linear motion into the rotary motion of the thread sweeping rod 5 through the transmission mechanism, realizing the thread sweeping function.

[0036] Buffering: in the process of the piston head 31 moving downward, the spring is compressed, absorbing part of the impact force generated by the movement of the piston head 31, playing a buffering role, reducing the impact on the thread sweeping rod 5 and the whole mechanism, reducing noise, prolonging the service life of the mechanism.

[0037] End: when the piston head 31 moves to the bottom of the cylinder 2, the compressed air stops supplying, the spring pushes the piston head 31 back to the initial position, the thread sweeping rod 5 resets, preparing for the next thread sweeping action.

[0038] It should be noted that the buffering effect of the spring effectively reduces the impact force when the piston head 31 moves to the end of the stroke, reduces the wear and tear of the mechanism, and prolongs the service life; the buffering effect also reduces the noise during the operation of the mechanism, improves the working environment; the buffering effect of the spring makes the movement of the piston head 31 more stable, improves the precision and stability of the line sweeping action.

[0039] As Figure 3 With Figure 4 As shown in the embodiment, there is a better solution, which further includes an air inlet pipe 22 connected to the inside of the cylinder head 21, and the inside of the cylinder head 21 is further provided with an end cover 35 matched with the inner wall of the cylinder head 21.

[0040] It should be noted that the end cover 35 is installed inside the cylinder head 21 and matched with the inner wall of the cylinder head 21; the function of the end cover 35 is to close the internal space of the cylinder head 21, prevent dust and impurities from entering the inside of the cylinder 2, guide compressed air into the inside of the cylinder 2, and ensure smooth and stable airflow.

[0041] As Figure 4 shown, the embodiment has a better solution, along the axis direction of the end cover 35, from top to bottom, a dustproof annular groove and a sealing annular groove are arranged on the side surface of the end cover 35; a dustproof ring 352 is arranged in the dustproof annular groove, and a sealing ring 351 is arranged in the sealing annular groove.

[0042] The dustproof annular groove is located at the upper part of the end cover 35 and is used for installing the dustproof ring 352. The function of the dustproof ring 352 is to prevent external dust and impurities from entering the inside of the cylinder 2 through the gap between the end cover 35 and the cylinder head 21; the sealing annular groove is located below the dustproof annular groove and is used for installing the sealing ring 351. The function of the sealing ring 351 is to ensure the sealing between the end cover 35 and the inner wall of the cylinder head 21, and prevent compressed air from leaking. The dustproof ring 352 is usually made of wear-resistant rubber or plastic material and has a certain elasticity, which is installed in the dustproof annular groove and tightly contacts with the inner wall of the cylinder head 21; the sealing ring 351 is usually made of oil-resistant rubber or polyurethane material and has good elasticity and sealing performance, which is installed in the sealing annular groove and tightly contacts with the inner wall of the cylinder head 21. When the piston rod 3 reciprocates, the dustproof ring 352 moves with the piston rod 3 and continuously scrapes off the dust and impurities attached to the surface of the piston rod 3. The sealing ring 351 always tightly contacts with the inner wall of the cylinder head 21, and during the movement of the piston rod 3, the sealing ring 351 deforms elastically and always maintains good sealing performance to prevent compressed air from leaking.

[0043] As Figure 4As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31.

[0044] As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31.

[0045] As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31. Figure 3 As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31.

[0046] As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31.

[0047] As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31.

[0048] Embodiment 2:

[0049] As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31. Figure 4 As shown in the figure, the lower end of the piston head 31 is provided with a cylindrical boss, which coincides with the axis of the piston head 31; the spring is sleeved on the outer edge of the boss. The boss serves to provide a mounting position for the spring, increase the guiding length of the piston head 31, and improve the smoothness and stability of the movement of the piston head 31.

[0050] When the piston head 31 moves upward to the top of the cylinder 2, the first buffer ring 33 can absorb the impact force generated by the collision between the piston head 31 and the cylinder head 21, playing a buffering role. The first buffer ring 33 can also play a sealing role to prevent compressed air from leaking from the gap between the piston head 31 and the cylinder head 21; when the piston head 31 moves downward to the bottom of the cylinder 2, the second buffer ring 34 can absorb the impact force generated by the collision between the piston head 31 and the bottom of the cylinder 2, playing a buffering role. The second buffer ring 34 can also prevent the spring from directly contacting the bottom of the cylinder 2, avoiding spring wear.

[0051] The first buffer ring 33 and the second buffer ring 34 absorb the impact force generated by the collision between the piston head 31 and the cylinder head 21 and the bottom of the cylinder 2 when the piston head 31 moves to the end of the stroke, respectively, playing a bidirectional buffering role. The material of the buffer ring is usually wear-resistant rubber or polyurethane, which has good elasticity and wear resistance, can effectively absorb impact energy, and prolongs the service life of the cylinder 2 and the piston head 31.

[0052] As shown in Figure 3 As a further optimization scheme of the present embodiment, the lower end of the cylinder 2 is connected with a guide cylinder 23 for guiding the piston rod 3.

[0053] It should be noted that the main function of the guide cylinder 23 is to provide guidance for the movement of the piston rod 3, ensuring that the piston rod 3 always moves in a straight line during the up and down movement, avoiding radial deviation, swing or shaking of the piston rod 3. The guide cylinder 23 is a hollow cylindrical component with an inner diameter slightly larger than the outer diameter of the piston rod 3. One end of the guide cylinder 23 is connected with the lower end of the cylinder 2, and the other end is open, and the piston rod 3 extends out of the open end of the guide cylinder 23; the length of the guide cylinder 23 should be greater than the maximum stroke of the piston rod 3, to ensure that the piston rod 3 is always guided by the guide cylinder 23 during movement; the material of the guide cylinder 23 is usually wear-resistant metal or high-strength plastic, which has good wear resistance and corrosion resistance.

[0054] There is a small gap between the inner diameter of the guide cylinder 23 and the outer diameter of the piston rod 3, which is generally 0.02mm-0.05mm; the gap fit can ensure that the piston rod 3 can slide freely in the guide cylinder 23, avoiding excessive frictional resistance between the piston rod 3 and the inner wall of the guide cylinder 23; the gap fit can also avoid the piston rod 3 from being stuck in the guide cylinder 23 due to dimensional changes caused by thermal expansion and contraction.

[0055] The above examples are only used to illustrate the technical solutions of the present disclosure, rather than limit them; although the present disclosure has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure. The following points need to be explained: only the structures involved in the embodiments of the present utility model are involved in the drawings of the embodiments of the present utility model, and other structures can refer to the usual design. In the case of no conflict, the features in the same embodiment and different embodiments of the present utility model can be combined with each other. The above is only a demonstrative implementation manner of the present utility model, rather than used to limit the protection scope of the present utility model, and the protection scope of the present utility model is determined by the appended claims.

Claims

1. A sewing machine thread sweeping mechanism, comprising a machine head (1) and a cylinder (2) and a compressor arranged inside the machine head (1), the cylinder (2) and the compressor being connected, and when a piston rod (3) of the cylinder (2) is pushed, the cylinder (2) can drive a thread sweeping rod (5) to rotate to achieve thread sweeping, characterized in that, an opening is arranged at an upper end of the cylinder (2), and a cylinder cover (21) is connected to the opening to block the opening; a piston head (31) and a piston rod (3) connected to the piston head (31) are arranged in the cylinder (2), a spring is arranged between the piston head (31) and an inner wall of the cylinder (2), and when the spring is in an initial state, the thread sweeping rod (5) is in an untriggered state; a transmission mechanism is further arranged between the piston rod (3) and the thread sweeping rod (5). Further comprising an air inlet pipe (22) which is communicated with an inside of the cylinder cover (21), and an end cover (35) which is matched with an inner wall of the cylinder cover (21) is further arranged in the inside of the cylinder cover (21). From top to bottom along an axial direction of the end cover (35), a dustproof annular groove and a sealing annular groove are arranged on a side surface of the end cover (35); a dustproof ring (352) is arranged in the dustproof annular groove, and a sealing ring (351) is arranged in the sealing annular groove. A cylindrical boss is arranged at a lower end of the piston head (31), and an axis of the boss coincides with an axis of the piston head (31); the spring is sleeved on an outer edge of the boss.

2. A sewing machine thread trimming mechanism according to claim 1, wherein An inside of the piston head (31) is provided with a cavity, and an upper end of the piston rod (3) penetrates the boss and is provided with a protrusion matched with the cavity at an end.

3. A sewing machine thread trimming mechanism according to claim 2, wherein The transmission mechanism comprises a fixed support (6), a rack segment, a gear (41) and a rotating shaft (4), the rack segment is arranged on an outer surface of a lower segment of the piston rod (3), the gear (41) is movably connected to the fixed support (6), the rotating shaft (4) is coaxially connected with the gear (41), one end of the rotating shaft (4) is connected with the gear (41), and the other end of the rotating shaft (4) movably penetrates the fixed support (6), a limiting block (42) is arranged on an end surface of the rotating shaft (4) which extends out of the fixed support (6), and the thread sweeping rod (5) is fixedly connected to the limiting block (42).

4. A sewing machine thread trimming mechanism according to claim 1 wherein, An inner diameter of the cylinder cover (21) is smaller than an inner diameter of the cylinder (2), a first buffer ring (33) is arranged between the upper end of the piston head (31) and a lower end of the cylinder cover (21), and a second buffer ring (34) is arranged between a lower end of the spring and an inner lower end of the cylinder (2).

5. A sewing machine thread trimming mechanism according to claim 4, wherein A guide cylinder (23) for guiding the piston rod (3) is connected to a lower end of the cylinder (2).

6. A sewing machine thread trimming mechanism according to claim 1 wherein, ​ 7. A sewing machine thread trimming mechanism according to claim 6, wherein ​ 8. A sewing machine thread trimming mechanism according to any one of claims 1 to 7, wherein ​

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