An inner shuttle structure for a sewing machine

Abstract

This invention provides an inner shuttle structure for a sewing machine, belonging to the technical field of sewing machine accessories. It solves the problem of thread slippage during sewing in existing technologies. The inner shuttle structure of this sewing machine includes a cylindrical inner shuttle body. The outer edge of the inner shuttle body has a needle groove and a radially protruding anti-scratch edge. The inner edge of the inner shuttle body is provided with a protrusion, and the protrusion and the anti-scratch edge are located on the same side of the inner shuttle body. The side of the protrusion closest to and furthest from the needle groove has a blocking surface and a guiding surface intersecting the inner edge surface of the inner shuttle body, respectively. The guiding surface and the blocking surface are smoothly connected, and the angle between the guiding surface and the inner edge surface of the inner shuttle body is an obtuse angle. The angle between the blocking surface and the inner edge surface of the inner shuttle body is smaller than the angle between the guiding surface and the inner edge surface of the inner shuttle body. This invention has the advantage of effectively reducing the probability of thread slippage and breakage during sewing, thereby improving sewing quality.

Description

Technical Field

[0001] This invention belongs to the technical field of sewing machine accessories, and relates to an inner shuttle structure for a sewing machine. Background Technology

[0002] The rotary hook is an important component of a sewing machine. It consists of an inner hook and an outer hook that is rotatably nested outside the inner hook. The outer hook has a hook tip, and the bobbin for supplying the bobbin thread is mounted on the central axis of the inner hook. During operation, the hook tip of the outer hook hooks onto the top thread loop and rotates and expands with it. When the hook tip, carrying the top thread, passes the lowest point of the inner hook, the take-up lever quickly rises and pulls the top thread, causing the top thread loop to slide off the hook tip and interweave with the bobbin thread in the inner hook to form a lockstitch. During this process, when the top thread loop slides off the hook tip, due to the inertia of high-speed rotation, the top thread loop will swing and self-entangle after detaching from the hook tip. The self-entangled top thread loop is then pulled by the take-up lever to form a knot, which blocks the needle eye of the fabric and cannot be completely retrieved, thus causing thread loss. In severe cases, the thread may break during the pulling process, affecting the sewing quality of the garment. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing an inner shuttle structure for a sewing machine. The technical problem this invention aims to solve is to effectively reduce the probability of thread slippage and breakage during sewing, thereby improving sewing quality.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] An inner shuttle structure for a sewing machine includes a cylindrical inner shuttle body. The outer edge of the inner shuttle body has a needle groove and a radially protruding anti-scratch edge. The inner edge of the inner shuttle body is characterized by a protrusion, with the protrusion and the anti-scratch edge located on the same side of the inner shuttle body. The protrusion has a blocking surface and a guiding surface intersecting the inner edge surface of the inner shuttle body on the side closest to and furthest from the needle groove, respectively. The guiding surface and the blocking surface are smoothly connected. The angle between the guiding surface and the inner edge surface of the inner shuttle body is obtuse, and the angle between the blocking surface and the inner edge surface of the inner shuttle body is smaller than the angle between the guiding surface and the inner edge surface of the inner shuttle body.

[0006] The inner shuttle structure of this sewing machine has a protrusion on the side where the top thread loop leaves the inner edge of the inner shuttle body. When a longer top thread loop reaches the unwinding position, it automatically fits onto the protrusion, separating the two strands of the top thread loop and preventing it from swinging or tangling. Subsequently, under the pulling action of the take-up lever, the top thread loop gradually shrinks. In addition, the guide surface and the blocking surface are smoothly connected, and the angle between the guide surface and the inner edge surface of the inner shuttle body is an obtuse angle. The angle between the blocking surface and the inner edge surface of the inner shuttle body is smaller than the angle between the guide surface and the inner edge surface of the inner shuttle body. This allows one strand of the top thread loop to be blocked and limited by the blocking surface located at the upper end of the protrusion, while the other strand gradually moves from the lower end of the protrusion to the upper end along the guide surface at the lower end of the protrusion. This allows the shrunken loop to smoothly detach from the protrusion and the inner shuttle body, effectively reducing the probability of thread slippage and breakage, thereby improving sewing quality.

[0007] In the aforementioned inner shuttle structure of a sewing machine, both the blocking surface and the guide surface are smooth surfaces. The angle between the blocking surface and the inner edge surface of the inner shuttle body is a right angle or an obtuse angle, and the blocking surface and the guide surface are inclined towards each other. By making both the blocking surface and the guide surface smooth surfaces, it is beneficial for the movement of the thread loop on the blocking surface and the guide surface, allowing the thread loop to eventually detach from the protrusion. At the same time, by making the angle between the blocking surface and the inner edge surface of the inner shuttle body a right angle or an obtuse angle, the blocking surface becomes steeper, which is beneficial for the blocking thread loop to detach outward from the protrusion. In addition, by making the blocking surface and the guide surface inclined towards each other, the protrusion has a structure that is smaller at the top and larger at the bottom, which is more reasonable and also facilitates the fitting and detachment of the thread loop.

[0008] In the aforementioned inner shuttle structure of a sewing machine, the length of the blocking surface is less than the length of the guide surface. By setting the length of the blocking surface to be less than the length of the guide surface, the structure is more reasonable, allowing the thread loop to gradually shrink to a certain extent before detaching from the protrusion, while also preventing the thread loop from being stuck on the protrusion.

[0009] In the aforementioned inner shuttle structure of a sewing machine, a transition surface exists between the guide surface and the blocking surface, and this transition surface is an arc surface. By setting the transition surface as an arc surface, the transition surface becomes smoother and has an arc apex, which facilitates the temporary positioning of the thread loop on both sides of the transition surface, while also allowing it to detach from the transition surface.

[0010] In the aforementioned inner shuttle structure of a sewing machine, the protrusion is integrally formed on the inner edge of the inner shuttle body. By integrally forming the protrusion on the inner edge of the inner shuttle body, it is possible to manufacture it in one step, while significantly improving the strength and durability of the parts.

[0011] In the aforementioned inner shuttle structure of a sewing machine, the protrusion is welded and fixed to the inner edge of the inner shuttle body. This results in high structural strength after the protrusion and inner shuttle body are connected, making it less prone to excessive deformation under external forces. Furthermore, no additional connecting parts are required, and the combined weight is lighter.

[0012] In the aforementioned inner shuttle structure of a sewing machine, the protrusion is threadedly connected to the inner edge of the inner shuttle body. This allows the protrusion and the inner shuttle body to be manufactured separately, while also offering advantages such as simple structure, reliable connection, and convenient assembly and disassembly.

[0013] In the aforementioned inner shuttle structure of a sewing machine, the inner end of the inner shuttle body has a strip-shaped base plate with an opening on each side and guide surfaces at both ends. The strip-shaped base plate serves two purposes: firstly, it can be used to set the central axis of the inner shuttle; secondly, the openings on both sides reduce the probability of collisions during the movement of the thread loop. Furthermore, the guide surfaces at both ends of the strip-shaped base plate guide the movement path of the thread loop, allowing it to move along the inner edge of the inner shuttle body. This enables longer thread loops to automatically engage with the protrusion when they reach the unwinding position.

[0014] In the aforementioned inner shuttle structure of a sewing machine, the guide wire surface is triangular in shape. The guide wire surface near the needle groove is inclined from the inside out in the direction of approaching to moving away from the needle groove, while the guide wire surface away from the needle groove is inclined from the outside in the direction of approaching to moving away from the needle groove. The guide wire surface of the above structure can better guide the top thread loop to move along the inner edge of the inner shuttle body, thereby facilitating the automatic mounting of longer top thread loops onto the protrusion when they reach the unwinding position.

[0015] In the inner shuttle structure of the sewing machine described above, there are two protrusions arranged adjacent to each other.

[0016] Compared with existing technologies, the advantages of the inner shuttle structure of this sewing machine are as follows: The inner shuttle structure of this sewing machine has a protrusion on the inner edge of the top thread loop away from the inner shuttle body. When a longer top thread loop reaches the unwinding position, it automatically fits onto the protrusion, separating the two strands of the top thread loop. This prevents the top thread loop from swinging or tangling. Subsequently, under the pulling action of the take-up lever, the top thread loop gradually shrinks. One strand of the top thread loop is blocked and limited by the blocking surface located at the upper end of the protrusion, while the other strand gradually moves from the lower end of the protrusion to the upper end along the guide surface at the lower end of the protrusion. This allows the shrunken loop to smoothly detach from the protrusion and the inner shuttle body, effectively reducing the probability of thread slippage and breakage, thus improving sewing quality. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the inner shuttle structure of the sewing machine in use in Embodiment 1.

[0018] Figure 2 This is a three-dimensional structural diagram of the inner shuttle structure and the state of the thread loop of the sewing machine in Embodiment 1.

[0019] Figure 3 yes Figure 2 A magnified view of a portion of point A in the middle.

[0020] Figure 4 This is an exploded view of the inner shuttle structure of the sewing machine in Embodiment 2.

[0021] Figure 5 This is a three-dimensional structural diagram of the inner shuttle structure of the sewing machine in Embodiment 3.

[0022] Figure 6 This is a three-dimensional structural diagram of the inner shuttle structure of this sewing machine when the protrusions are removed and the state of the thread loop.

[0023] In the figure, 1. Inner shuttle body; 1a. Inner edge surface; 1b. Strip base plate; 1b1. Guide surface; 1c. Opening; 1d. Needle groove; 1e. Protruding edge; 2. Protrusion; 2a. Blocking surface; 2b. Guide surface; 2c. Transition surface; 3. Outer shuttle; 3a. Shuttle tip; 4. Surface thread loop. Detailed Implementation

[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0025] Example 1

[0026] An inner shuttle structure for a sewing machine, referring to Figure 1-3 and Figure 6 The device includes a cylindrical inner shuttle body 1. The outer edge of the inner shuttle body 1 has a needle groove 1d and a radially protruding anti-damage ridge 1e. The inner edge of the inner shuttle body 1 is provided with a protrusion 2, and the protrusion 2 and the anti-damage ridge 1e are located on the same side of the inner shuttle body 1. The side of the protrusion 2 that is close to the needle groove 1d and the side that is far away from the needle groove 1d respectively has a blocking surface 2a and a guide surface 2b that intersect with the inner edge surface 1a of the inner shuttle body 1. The guide surface 2b and the blocking surface 2a are smoothly connected. The angle between the guide surface 2b and the inner edge surface 1a of the inner shuttle body 1 is an obtuse angle. The angle between the blocking surface 2a and the inner edge surface 1a of the inner shuttle body 1 is smaller than the angle between the guide surface 2b and the inner edge surface 1a of the inner shuttle body 1.

[0027] Furthermore, referring to Figure 1-3 and Figure 6 The length of the blocking surface 2a is less than the length of the guide surface 2b.

[0028] Furthermore, referring to Figure 1-3 and Figure 6The inner end of the inner shuttle body 1 has a strip-shaped base plate 1b, and there is an opening 1c on each side of the strip-shaped base plate 1b. The two ends of the strip-shaped base plate 1b have guide surfaces 1b1. The guide surfaces 1b1 are triangular in shape. The guide surfaces 1b1 near the needle groove 1d are inclined from the inside to the outside in the direction from the inside to the outside in the direction from the outside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction.

[0029] In this embodiment, both the blocking surface 2a and the guide surface 2b are preferably smooth surfaces. The angle between the blocking surface 2a and the inner edge surface 1a of the inner shuttle body 1 is a right angle or an obtuse angle, and the blocking surface 2a and the guide surface 2b are inclined towards each other. Preferably, there is a transition surface 2c between the guide surface 2b and the blocking surface 2a, and the transition surface 2c is an arc surface. Preferably, the protrusion 2 is integrally formed on the inner edge of the inner shuttle body 1.

[0030] The working principle of the inner shuttle structure of this sewing machine is explained below:

[0031] During operation, the sewing machine needle is located on the outer edge of the inner shuttle body 1, while the protrusion 2 is located on the inner edge surface 1a of the inner shuttle body 1, and is positioned on the side where the top thread loop is away. The top thread loop 4 rotates and expands around the inner shuttle body 1 under the influence of the shuttle tip 3a of the outer shuttle 3. When the shuttle tip 3a, carrying the top thread loop 4, passes the lowest point of the inner shuttle body 1, the take-up lever quickly rises to pull the top thread, causing the top thread loop 4 to slide off the shuttle tip 3a. At this time, the shuttle tip 3a of the outer shuttle 3 is below the protrusion 2, while the root of the top thread loop 4 is on the needle, i.e., above the protrusion 2 and on the outer edge of the inner shuttle body 1. Furthermore, the top thread loop 4 is relatively long and has the inertia to move around the inner edge of the inner shuttle body 1, allowing it to automatically fit onto the protrusion 2, which is smaller at the top and larger at the bottom. This temporarily positions the top thread loop 4 on the protrusion 2. Simultaneously, the two ends of the top thread loop 4... The thread loop 4 is separated by the protrusion 2, thus preventing it from swinging and tangling. Then, under the pull of the take-up lever, the thread loop 4 gradually shrinks, so that one thread of the thread loop 4 is blocked and limited by the blocking surface 2a located at the upper end of the protrusion 2. In addition, the guide surface 2b and the blocking surface 2a are smoothly connected by the transition surface 2c. The angle between the guide surface 2b and the inner edge surface 1a of the inner shuttle body 1 is an obtuse angle. The other thread of the thread loop 4 gradually moves from the lower end of the protrusion 2 to the upper end along the gentle guide surface 2b at the lower end of the protrusion 2, so that the shrinking loop can be smoothly separated from the protrusion 2 and the inner shuttle body 1. Finally, the thread loop 4 covers the bottom thread, the outer shuttle 3 reverses and resets, the take-up lever tightens the stitch, so that the intersection point of the thread loop 4 and the bottom thread is located in the center of the sewing material. The feed dog pushes the sewing material to complete one stitch length, thereby effectively reducing the probability of thread slippage and breakage and improving sewing quality.

[0032] Example 2

[0033] This embodiment is basically the same as embodiment one in structure and principle, except that: (Refer to...) Figure 4 The protrusion 2 is threadedly connected to the inner edge of the inner shuttle body 1. A fixing plate is provided on the protrusion 2, and a positioning hole is provided on the fixing plate. A fixing hole with internal thread is provided on the side wall of the inner shuttle body 1 at the position corresponding to the positioning hole. The protrusion 2 is connected to the fixing hole of the inner shuttle body 1 by a bolt passing through the positioning hole.

[0034] Example 3

[0035] This embodiment is basically the same as embodiment one in structure and principle, except that: (Refer to...) Figure 5 There are two protrusions 2 arranged adjacent to each other.

[0036] Example 4

[0037] The structure and principle of this embodiment are basically the same as those of Embodiment 1. The difference is that the protrusion 2 is welded and fixed to the inner edge of the inner shuttle body 1 (not shown in the figure).

[0038] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. An inner shuttle structure for a sewing machine, comprising a cylindrical inner shuttle body (1), the outer edge of which has a needle groove (1d) and a radially protruding anti-scratch ridge (1e), characterized in that, The inner edge of the inner shuttle body (1) is provided with a protrusion (2), and the protrusion (2) and the anti-damage protrusion (1e) are located on the same side of the inner shuttle body (1). The side of the protrusion (2) that is close to the needle groove (1d) and the side that is far away from the needle groove (1d) respectively have a blocking surface (2a) and a guide surface (2b) that intersect with the inner edge surface (1a) of the inner shuttle body (1). The guide surface (2b) and the blocking surface (2a) are smoothly connected. The angle between the guide surface (2b) and the inner edge surface (1a) of the inner shuttle body (1) is an obtuse angle. The angle between the blocking surface (2a) and the inner edge surface (1a) of the inner shuttle body (1) is smaller than the angle between the guide surface (2b) and the inner edge surface (1a) of the inner shuttle body (1).

2. The inner shuttle structure of a sewing machine according to claim 1, characterized in that, Both the blocking surface (2a) and the guide surface (2b) are smooth surfaces. The angle between the blocking surface (2a) and the inner edge surface (1a) of the inner shuttle body (1) is a right angle or an obtuse angle, and the blocking surface (2a) and the guide surface (2b) are inclined towards each other.

3. The inner shuttle structure of a sewing machine according to claim 1, characterized in that, The length of the blocking surface (2a) is less than the length of the guide surface (2b).

4. The inner shuttle structure of a sewing machine according to claim 1, characterized in that, There is a transition surface (2c) between the guide surface (2b) and the blocking surface (2a), and the transition surface (2c) is an arc surface.

5. The inner shuttle structure of a sewing machine according to claim 1, 2, 3, or 4, characterized in that, The protrusion (2) is integrally formed on the inner edge of the inner shuttle body (1).

6. The inner shuttle structure of a sewing machine according to claim 1, 2, 3, or 4, characterized in that, The protrusion (2) is welded and fixed to the inner edge of the inner shuttle body (1).

7. The inner shuttle structure of a sewing machine according to claim 1, 2, 3, or 4, characterized in that, The protrusion (2) is threaded onto the inner edge of the inner shuttle body (1).

8. The inner shuttle structure of a sewing machine according to claim 1, 2, 3, or 4, characterized in that, The inner end of the inner shuttle body (1) has a strip-shaped bottom plate (1b), and there is an opening (1c) on each side of the strip-shaped bottom plate (1b). The two ends of the strip-shaped bottom plate (1b) have guide surfaces (1b1).

9. The inner shuttle structure of a sewing machine according to claim 8, characterized in that, The conductor surface (1b1) is triangular in shape. The conductor surface (1b1) near the needle groove (1d) is inclined from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction from the inside to the outside in the direction.

10. The inner shuttle structure of a sewing machine according to claim 1, 2, 3, or 4, characterized in that, There are two bumps (2) arranged adjacent to each other.

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