Rotating hook with needle protection function and sewing machine

Abstract

The application provides a rotating hook with a needle protection function and a sewing machine. The rotating hook comprises a hook frame with a needle falling groove. The needle falling groove extends along the circumference of the hook frame and is used for allowing a needle in the sewing machine to pass through. Along the axial direction of the rotating hook, the hook frame is provided with a left needle protection surface and a right needle protection surface in the needle falling groove. The left needle protection surface and the right needle protection surface are respectively adjacent to the left side and the right side of the needle. The left needle protection surface is newly added and is adjacent to the left side of the needle. The left needle protection surface and the right needle protection surface cooperate to effectively limit the deformation of the needle within a certain range and reduce the amplitude of the needle. In particular, when the needle with a sewing thread passes through the needle falling groove and rises upward from the lowest point, the left needle protection surface drives the part of the sewing thread on the left side of the needle to move to the right side of the needle, the thread loop on the right side of the needle becomes larger, the hook tip of the rotating hook is easily and effectively hooked into the thread loop on the right side of the needle, and the probability of faults such as thread jumping, thread splitting and thread breaking is reduced.

Description

Technical Field

[0001] This invention relates to the field of sewing machine technology, and in particular to a rotary hook with a needle guard function, and a sewing machine equipped with the rotary hook. Background Technology

[0002] The rotary hook is an important component of a sewing machine. It is fixed to the end of the rotating lower shaft in the sewing machine and is used to hook the thread. The rotary hook and the needle in the sewing machine work together to form a stitch on the fabric.

[0003] like Figure 1 As shown, the rotary shuttle 10 mainly includes a shuttle frame 20 and a shuttle bed 30 assembled on the outer periphery of the shuttle frame 20. The right end of the shuttle bed 30 is fixed to the end of the lower shaft by several screws. The shuttle bed 30 is also integrally provided with a shuttle tip for hooking the thread. A needle groove 21 is provided on the left end of the shuttle frame 20, which allows the needle 40 to pass through vertically. Figure 1 In the rotary hook shown, the right side of the needle drop groove 21 is the right needle guard plane, which extends straight along the axis of the rotary hook. The left side of the needle drop groove 21 has no needle guard structure, that is, this side is far away from the needle and only forms an empty area between it and the needle, which is prone to faults such as large needle amplitude, skipped stitches, and broken stitches.

[0004] Specifically, during normal operation, to ensure good stitches and prevent skipped stitches, thread breaks, and other malfunctions, the gap between the shuttle hook tip and the needle along the lower axis, as well as the shuttle hooking time, must be maintained in a controlled manner. Therefore, sewing machines are pre-set with the needle type based on common customer scenarios at the factory, and the gap between the shuttle hook tip and the needle is adjusted to the optimal state, minimizing the probability of skipped stitches. However, after sewing machines enter the market, due to seasonal changes and drastic variations in clothing styles and fabric thickness, the thread and needle are frequently adjusted to meet customer needs. However, changing to different needle types (with varying thicknesses) alters the gap between the shuttle hook tip and the needle; changing to thinner or thicker fabrics changes the friction between the fabric and the thread, causing changes in the size of the hook loop. This causes the sewing machine to lose its optimal operating conditions, leading to frequent skipped stitches, thread breaks, and thread splits.

[0005] To address issues like skipped stitches, thread breakage, and splitting threads, the industry typically employs the following solution: After replacing the needle with a different model (of varying thickness), to ensure minimal or no skipped stitches, the gap between the shuttle hook tip and the needle, as well as the hook-up time, must be rechecked and adjusted. If necessary, the needle's return height may also be adjusted. Adjusting this process requires loosening the three screws securing the shuttle to the lower shaft, moving the shuttle in four directions (front, back, left, and right) to adjust its position until the optimal installation is found, and then tightening the screws again. This adjustment process is quite cumbersome. In particular, controlling the gap between the shuttle hook and the needle is the most critical step and technical requirement in sewing machine assembly. It necessitates stopping the sewing machine and requires operators with advanced sewing machine maintenance skills, thus impacting sewing efficiency and increasing operating and maintenance costs. Meanwhile, because the fabrics sewn by sewing machines are incredibly diverse, with varying thicknesses and complex, frequent changes, sewing machines struggle to adapt. This leads to frequent problems like skipped stitches, broken threads, and split threads, reducing sewing quality. The adjustment and repair of sewing machines is also a significant undertaking, increasing after-sales service costs. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a rotary hook with a needle protection function, which reduces the amplitude of the needle and enables the hook tip to effectively hook the thread loop.

[0007] To achieve the above objectives, the present invention provides a rotary shuttle with a needle protection function, comprising a shuttle frame with a needle drop groove, the needle drop groove extending circumferentially along the shuttle frame to allow the needle in the sewing machine to pass through; along the axial direction of the rotary shuttle, the shuttle frame has a left needle protection surface and a right needle protection surface in the needle drop groove, the left needle protection surface and the right needle protection surface being distributed adjacent to each other on the left and right sides of the needle, respectively.

[0008] Optionally, the left side wall of the needle groove may partially or entirely form a left needle guard surface, and the right side wall of the needle groove may partially or entirely form a right needle guard surface.

[0009] Optionally, the shuttle frame further includes a movable needle guard baffle, which is movably mounted on the shuttle frame along the axis of the shuttle. The right side wall of the needle drop groove partially or entirely constitutes the right needle guard surface, and the left needle guard surface is fixed on the movable needle guard baffle.

[0010] Optionally, the movable needle guard includes a guard body, a connecting part, and a needle guard part that are integrally connected in sequence. A clearance notch is formed between the guard body, the connecting part, and the needle guard part to allow the needle groove to be exposed. The guard body is movably mounted on the shuttle frame. The needle guard part is distributed on the left side of the needle. The side portion of the needle guard part facing the needle or the whole of the needle guard part constitutes the left needle guard surface.

[0011] Optionally, the shuttle frame further includes an adjusting screw. A guide rail that slides with the baffle body is fixed on the outer circumferential surface of the shuttle frame. An adjusting groove is provided in the baffle body. The guide rail and the adjusting groove extend straight along the moving direction of the movable needle guard baffle. The baffle body and the shuttle frame are fixed together by the adjusting screw, which passes through the adjusting groove.

[0012] Optionally, both the left and right needle guard surfaces are radial planes that extend straight along the radial direction of the shuttle frame.

[0013] Optionally, at least one of the left and right needle guard surfaces is provided with an inclined section, the inclined section extending obliquely in the extending direction of the needle groove, the inclined section causing the working gap between the left and right needle guard surfaces to have different axial widths.

[0014] Optionally, both the left and right needle guard surfaces are provided with the inclined section.

[0015] Optionally, the inclined section of the left needle guard surface is a left inclined section, and the inclined section of the right needle guard surface is a right inclined section; along the extension direction of the needle groove, the left needle guard surface further includes a first left straight section and a second left straight section respectively provided at both ends of the left inclined section, and the right needle guard surface further includes a first right straight section and a second right straight section respectively provided at both ends of the right inclined section, wherein the first left straight section, the second left straight section, the first right straight section and the second right straight section all extend straight along the circumference of the shuttle frame.

[0016] Optionally, the tilting direction of the left tilting segment is opposite to the tilting direction of the right tilting segment.

[0017] Optionally, the tilt angle of the left tilt segment is greater than the tilt angle of the right tilt segment.

[0018] Optionally, the rotary shuttle further includes a gap adjustment assembly, which is connected to the shuttle frame and is used to drive the shuttle frame to rotate around its own axis.

[0019] Optionally, the gap adjustment assembly includes an adjustment positioning plate that is radially movable along the shuttle frame. The adjustment positioning plate is provided with a positioning hook, and an adjustment positioning groove is provided on the outer edge of the shuttle frame. The positioning hook engages with the adjustment positioning groove.

[0020] Optionally, the gap adjustment assembly further includes a fixed guide pin, and the adjustment positioning plate has a guide groove extending straight along its moving direction, with the guide pin passing through the guide groove and the two slidingly engaged.

[0021] Optionally, the adjustment positioning plate is provided with a scale, which is used to characterize the size of the working gap between the left and right needle guard surfaces directly below the needle.

[0022] Optionally, the outer ends of both the left and right needle guard surfaces are provided with chamfered portions, which are either arc surfaces or beveled surfaces.

[0023] Optionally, the gap between the left needle guard and the needle in the direction of the rotary hook is 0.15±0.15mm, and the gap between the right needle guard and the needle in the direction of the rotary hook is 0.15±0.15mm.

[0024] This application also provides a sewing machine equipped with a rotary hook as described above.

[0025] As described above, the rotary hook and sewing machine with needle protection function of the present invention have the following beneficial effects:

[0026] In this application, the rotary hook features a newly added left needle guard surface located adjacent to the left side of the needle. Thus, during normal sewing machine operation, because the left and right needle guard surfaces are adjacent to each other on both sides of the needle, they work together to limit the needle's vibration and offset in the left-right direction, effectively limiting needle deformation within a certain range and reducing needle amplitude, thereby protecting the needle. In particular, when the needle, carrying the thread, rises from its lowest point through the needle groove, the left needle guard surface exerts a certain compressive force on the thread on the left side of the needle, driving this portion of the thread to move to the right side of the needle. This enlarges the thread loop on the right side of the needle, allowing the rotary hook tip to more easily and effectively hook into the thread loop on the right side of the needle, significantly reducing the probability of skipped stitches, thread splits, and thread breaks. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a rotary shuttle in the prior art.

[0028] Figure 2 This is a schematic diagram of the structure of the rotary hook embodiment one in this application. The gap adjustment component is omitted from the diagram.

[0029] Figure 3 for Figure 2 Top view.

[0030] Figure 4 for Figure 2 A schematic diagram of the middle shuttle frame.

[0031] Figure 5 for Figure 4 Top view.

[0032] Figures 6a to 6d This figure shows four preferred embodiments of the left and right needle guard surfaces in Embodiment 1 of the rotary hook, and is a top view.

[0033] Figure 7 This is a schematic diagram showing the interaction between the rotary hook and the needle in Embodiment 1 of this application.

[0034] Figure 8 This is a schematic diagram of the structure of the rotary shuttle in Embodiment 1 of this application.

[0035] Figure 9 This is a schematic diagram of the structure of the adjusting positioning plate in this application.

[0036] Figure 10 This is a schematic diagram of the structure of Embodiment 2 of the rotary hook in this application.

[0037] Figure 11 for Figure 10 A schematic diagram of the structure of the movable needle guard.

[0038] Figures 12a to 12c This figure shows three preferred embodiments of the left and right needle guard surfaces in embodiment two of the rotary hook, and is a top view.

[0039] Component designation explanation

[0040] 10. Rotary Shuttle

[0041] 20 shuttles

[0042] 21. Needle groove

[0043] 22 Left needle side

[0044] 221 Left-leaning segment

[0045] 222 First Left Straight Section

[0046] 223 Second Left Straight Segment

[0047] 23 Right side of the needle

[0048] 231 Right-sloping segment

[0049] 232 First Right Straight Section

[0050] 233 Second right straight section

[0051] 24 Inclined Section

[0052] 25 Adjust the positioning groove

[0053] 26. Chamfered edge

[0054] 27 Front arc surface

[0055] 28. Rear arc surface

[0056] 29 guide rails

[0057] 30 shuttle bed

[0058] 31 Spindle Tip

[0059] 40 needles

[0060] 50 Adjustable positioning plate

[0061] 51 Positioning Hook

[0062] 52 Guide groove

[0063] 53 graduations

[0064] 60 guide pins

[0065] 70 Conductor Board

[0066] 80 shuttle plate

[0067] 90 Active needle guard

[0068] 91. Main body of the baffle

[0069] 92 Connecting part

[0070] 93. Needle plate section

[0071] 94. Avoidance gap

[0072] 95 Adjustment slot

[0073] 110 Adjusting screw Detailed Implementation

[0074] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0075] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0076] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0077] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0078] This application provides a rotary hook 10 with a needle guard function, and a sewing machine equipped with the rotary hook 10. Typically, such as... Figure 7 As shown, the sewing machine includes a lower shaft rotatably mounted in the sewing machine base plate and a needle 40 that can move up and down. For ease of description, in the following embodiments, the axial direction of the lower shaft is defined as the left-right direction, and the direction of the lower shaft toward the sewing machine head is the left direction, and the direction of the lower shaft toward the sewing machine tail is the right direction; the direction intersecting the left-right direction in the horizontal plane is defined as the front-back direction. Thus, Figure 3 and Figure 5 In the view shown, the left and right sides of the paper represent the left and right directions, respectively, while the top and bottom sides represent the front and back directions, respectively.

[0079] like Figure 2 , Figure 3 and Figure 7 As shown, the rotary shuttle 10 includes a shuttle frame 20, a shuttle bed 30 assembled on the outer periphery of the shuttle frame 20, and a guide plate 70 and a shuttle plate 80 fixed on the outer periphery of the shuttle bed 30. A shuttle tip 31 is integrally provided on the left section of the shuttle bed 30, and the shuttle tips 31 are distributed on the outer periphery of the shuttle frame 20. The right section of the shuttle bed 30 is fixed to the left end of the lower shaft by several screws, thereby fixing the rotary shuttle 10 as a whole to the left end of the lower shaft. The axial direction of the rotary shuttle 10 is consistent with the axial direction of the lower shaft, and the axial direction of the rotary shuttle 10 is also the axial direction of both the shuttle frame 20 and the shuttle bed 30, both in the left-right direction.

[0080] like Figures 2 to 5 ,as well as Figure 7As shown, the shuttle frame 20 has a needle groove 21 extending circumferentially along the shuttle frame 20, which allows the sewing machine needle 40 to pass through. Specifically, the shuttle frame 20 has a left needle guard surface 22 and a right needle guard surface 23 within the needle groove 21; along the axial direction of the rotary hook 10, i.e., in the left-right direction, the left needle guard surface 22 is adjacent to the left side of the needle 40, and the right needle guard surface 23 is adjacent to the right side of the needle 40. In this application, the left-right gap between the left needle guard surface 22 and the needle 40 in the axial direction of the rotary hook 10 is 0.15±0.15mm, thus ensuring the left needle guard surface 22 is adjacent to the left side of the needle 40; similarly, the right needle guard surface 23 is also adjacent to the right side of the needle 40 in the axial direction of the rotary hook 10. Compared with the prior art, the rotary hook 10 involved in this application has an additional left needle guard surface 22 that is distributed close to the left side of the needle 40. The left needle guard surface 22 and the right needle guard surface 23 cooperate with each other, which makes the rotary hook 10 involved in this application have at least the following advantages.

[0081] 1. When the sewing machine is working normally, the needle 40 will deform, bend, and vibrate due to the resistance it experiences during high-speed piercing of the fabric and the lateral tension of the sewing thread. In this application, a left needle guard surface 22 and a right needle guard surface 23 are respectively provided on the left and right sides of the needle 40, which are close to the needle 40. The left needle guard surface 22 and the right needle guard surface 23 work together to limit the vibration deviation of the needle 40 in the left and right directions, effectively limiting the deformation of the needle 40 within a certain range. This reduces the vibration amplitude of the needle 40 under high-speed movement, providing better needle protection. This ensures that the needle 40 of different models is well protected, and always prevents the needle 40 from colliding with the shuttle tip 31 of the rotary hook 10, greatly reducing the probability of the shuttle tip 31 colliding with the needle 40.

[0082] 2. When the needle 40, carrying the thread, passes through the needle groove 21 and rises from the lowest point, under the same adjustment of the needle 40's rise parameters, the left needle guard 22 exerts a certain squeezing force on the part of the thread on the left side of the needle 40, driving the part of the thread on the left side of the needle 40 to move to the right side of the needle 40. This causes the thread loop on the right side of the needle 40 to become larger, forming a larger thread loop on the right side of the needle 40. This allows the hook tip 31 of the rotary hook 10 to more easily and effectively hook into the thread loop on the right side of the needle 40, thereby greatly reducing the probability of skipped stitches, split threads, broken threads, and other malfunctions.

[0083] 3. After the thread loop on the right side of the needle 40 is enlarged, the return height of the needle 40 can be reduced under the same conditions, so that the hooking time of the rotary hook 10 can be advanced, and the sewing machine can work in the best condition.

[0084] 4. Effectively extends the length of thread that does not break when the horizontal rotary hook 10 sewing machine is working at high speed, improving work efficiency and stitch quality.

[0085] 5. The application scenarios of silk thread have been optimized and expanded.

[0086] 6. At the moment the needle 40 completes puncture, the needle tip generates high temperature due to friction with the pressed fabric. Normally, this temperature rise gradually accumulates until the needle 40 reaches the melting point of the thread (230-300°C), at which point the thread (especially synthetic threads) will melt and break. This application incorporates a left needle guard surface 22 and a right needle guard surface 23. Due to vibration, the needle 40 comes into contact with these surfaces, transferring the instantaneously generated heat to the rotary hook 10 while simultaneously lowering its own temperature. This keeps the needle 40 temperature consistently below the thread's melting point, thereby increasing the maximum sewing speed for synthetic threads.

[0087] Furthermore, the left needle guard surface 22 and the right needle guard surface 23 can be arranged in various ways on the shuttle frame 20. Based on different arrangements, the shuttle frame 20 has multiple embodiments, which in turn leads to multiple embodiments of the rotary shuttle. Two preferred embodiments of the rotary shuttle are provided below.

[0088] Rotary shuttle example 1

[0089] In embodiment one of the rotary shuttle, as Figure 4 and Figure 5 As shown, the left side wall of the needle groove 21 forms the left needle guard surface 22, and the right side wall of the needle groove 21 forms the right needle guard surface 23. Both the left and right needle guard surfaces 22 and 23 are integrally formed on the shuttle frame 20. The front end of the left needle guard surface 22 is connected to the front end of the right needle guard surface 23 via a front arc surface 27, and the rear end of the left needle guard surface 22 is connected to the rear end of the right needle guard surface 23 via a rear arc surface 28. The front and rear arc surfaces 27 and 28 respectively form the front and rear side walls of the needle groove 21. Furthermore, both the left and right needle guard surfaces 22 and 23 are radial planes extending straight along the radial direction of the shuttle frame 20, meaning they are perpendicular to the axial direction of the rotary hook 10. Of course, in other embodiments, a portion of the left side of the needle groove 21 may form the left needle guard surface 22, and a portion of the right side of the needle groove 21 may form the right needle guard surface 23.

[0090] Furthermore, such as Figure 4 As shown, the outer end of the left needle guard 22 is distributed on the outer periphery of the right needle guard 23. In other words, the outer end of the left needle guard 22 protrudes outward from the outer end of the right needle guard 23, which improves the effect of the left needle guard 22 in squeezing the thread on the left side of the needle 40 to the right side of the needle 40. This further improves the accuracy of the shuttle tip 31 of the rotary hook 10 hooking the thread loop on the right side of the needle 40, thus ensuring the sewing quality.

[0091] Preferably, such as Figure 4 and Figure 5 As shown, both the left needle guard surface 22 and the right needle guard surface 23 have chamfered portions 26 at their outer ends. The chamfered portion 26 can be an arc surface formed by rounding corners, or it can be a bevel surface formed by chamfering angles. The chamfered portions 26 at the outer ends of the left needle guard surface 22 and the right needle guard surface 23 can both be arc surfaces, or both be bevel surfaces, or one can be an arc surface and the other a bevel surface. Figure 4 and Figure 5 In the embodiment shown, the chamfer 26 at the outer end of the left needle guard 22 is an arc surface formed by rounding, and the chamfer 26 at the outer end of the right needle guard 23 is a bevel surface formed by chamfering.

[0092] Furthermore, the rotary hook 10 involved in this application also has the function of stepless adjustment of the gap, that is, the size of the working gap formed between the left guard needle surface 22 and the right guard needle surface 23 in the left-right direction can be steplessly adjusted. Specifically, as Figure 4 and Figure 5 As shown, at least one of the left needle guard surface 22 and the right needle guard surface 23 is provided with an inclined section 24. The inclined section 24 extends obliquely in the extending direction of the needle drop groove 21. The inclined section 24 makes the working gap between the left needle guard surface 22 and the right needle guard surface 23 have different axial widths in the left and right directions. Thus, by driving the shuttle 20 to rotate around its central axis by an angle, the axial width of the working gap directly below the needle 40 can be adjusted. This means that the left-right gap between the left needle guard 22 and the needle 40, as well as the left-right gap between the right needle guard 23 and the needle 40, can be infinitely adjusted, so that the needle 40 is in the optimal working gap. This ensures that different types of needles 40 with different thicknesses can perform these two functions well: reducing the amplitude by being limited left and right by the left and right needle guards 22 and 23, and increasing the thread loop on the right side of the needle 40 by the left needle guard 22 squeezing the thread loop on the left side of the needle 40. This allows the sewing machine to stably achieve the hooking function when sewing different fabrics and using different types of needles 40, innovatively and effectively improving the application range and sewing performance of the sewing machine.

[0093] Furthermore, the shuttle frame 20 of the rotary shuttle 10 may have an inclined section 24 provided only on the left needle guard surface 22, or only on the right needle guard surface 23, or both on the left and right needle guard surfaces 22 and 23. Based on the different arrangements of the inclined section 24, the shuttle frame 20 has several preferred embodiments. Four preferred embodiments of the shuttle frame 20 are provided below.

[0094] Example 1 of shuttle frame 20 Figure 6aAs shown, both the left needle guard surface 22 and the right needle guard surface 23 are provided with inclined sections 24. The inclined section 24 on the left needle guard surface 22 is defined as the left inclined section 221, and the inclined section 24 on the right needle guard surface 23 is defined as the right inclined section 231. The left inclined section 221 is inclined in a manner that extends further forward and further to the left, while the right inclined section 231 is inclined in a manner that extends further forward and further to the right. Therefore, the inclination direction of the left inclined section 221 is opposite to that of the right inclined section 231. Furthermore, the inclination angle of the left inclined section 221 is greater than that of the right inclined section 231.

[0095] Furthermore, such as Figure 6a As shown, along the extension direction of the needle groove 21, the left needle guard surface 22 also includes a first left straight section 222 and a second left straight section 223 respectively located at the front and rear ends of the left inclined section 221. The right needle guard surface 23 also includes a first right straight section 232 and a second right straight section 233 respectively located at the front and rear ends of the right inclined section 231. The first left straight section 222, the second left straight section 223, the first right straight section 232, and the second right straight section 233 all extend straight forward and backward along the circumference of the shuttle frame 20. Therefore, the left inclined section 221 is approximately located at the front and rear middle position of the left needle guard surface 22, and the right inclined section 231 is approximately located at the front and rear middle position of the right needle guard surface 23. The left tilting section 221 and the right tilting section 231 cause the working gap between the left needle guard surface 22 and the right needle guard surface 23 to change in the following manner: the front part is the same size and has a larger gap; the middle part gradually decreases in size from front to back and can change continuously; and the rear part is the same size and has a smaller gap.

[0096] Example 2 of shuttle frame 20 Figure 6b As shown, both the left needle guard surface 22 and the right needle guard surface 23 are provided with inclined sections 24. The inclined section 24 on the left needle guard surface 22 is defined as the left inclined section 221, and the inclined section 24 on the right needle guard surface 23 is defined as the right inclined section 231. The left inclined section 221 is inclined in a manner that extends further forward and further to the right, while the right inclined section 231 is inclined in a manner that extends further forward and further to the left. Therefore, the inclination direction of the left inclined section 221 is opposite to that of the right inclined section 231. Furthermore, the inclination angle of the left inclined section 221 is greater than that of the right inclined section 231.

[0097] Furthermore, such as Figure 6bAs shown, along the extension direction of the needle groove 21, the left needle guard surface 22 also includes a first left straight section 222 and a second left straight section 223 respectively located at the front and rear ends of the left inclined section 221. The right needle guard surface 23 also includes a first right straight section 232 and a second right straight section 233 respectively located at the front and rear ends of the right inclined section 231. The first left straight section 222, the second left straight section 223, the first right straight section 232, and the second right straight section 233 all extend straight forward and backward along the circumference of the shuttle frame 20. Therefore, the left inclined section 221 is approximately located at the front and rear middle position of the left needle guard surface 22, and the right inclined section 231 is approximately located at the front and rear middle position of the right needle guard surface 23. The left tilting section 221 and the right tilting section 231 cause the working gap between the left needle guard surface 22 and the right needle guard surface 23 to change in the following manner: the front part is the same size and has a small gap; the middle part gradually increases in size from front to back and can change continuously; and the rear part is the same size and has a large gap.

[0098] Example 3 of shuttle frame 20 Figure 6c As shown, an inclined section 24 is provided only on the left needle guard surface 22, and this inclined section 24 is defined as the left inclined section 221. The left inclined section 221 is inclined in a manner that extends further forward and further to the left. Along the extension direction of the needle groove 21, the left needle guard surface 22 also includes a first left straight section 222 and a second left straight section 223 respectively provided at the front and rear ends of the left inclined section 221. The first left straight section 222, the second left straight section 223, and the entire right needle guard surface 23 all extend straight forward and backward along the circumference of the shuttle frame 20. Therefore, the left inclined section 221 makes the working gap between the left needle guard surface 22 and the right needle guard surface 23 change in the following way: the size of the front part is the same and is a larger gap; the size of the middle part gradually decreases from front to back and can be continuously varied; and the size of the rear part is the same and is a smaller gap.

[0099] Example 4 of shuttle frame 20 Figure 6d As shown, an inclined section 24 is provided only on the right needle guard surface 23, and this inclined section 24 is defined as the right inclined section 231. The right inclined section 231 is inclined in a manner that extends further forward and further to the left. Along the extension direction of the needle groove 21, the right needle guard surface 23 also includes a first right straight section 232 and a second right straight section 233 respectively provided at the front and rear ends of the right inclined section 231. The first right straight section 232, the second right straight section 233, and the entire left needle guard surface 22 all extend straight forward and backward along the circumference of the shuttle frame 20. Therefore, the right inclined section 231 makes the working gap between the left needle guard surface 22 and the right needle guard surface 23 change in the following way: the size of the front part is the same and the gap is small; the size of the middle part gradually increases from front to back and can change continuously; and the size of the rear part is the same and the gap is large.

[0100] Furthermore, such as Figure 8As shown, the first embodiment of the rotary hook 10 also includes a gap adjustment component. The gap adjustment component is connected to the shuttle frame 20 and is used to drive the shuttle frame 20 to rotate around its own axis, thereby adjusting the size of the working gap directly below the needle 40. That is, it adjusts the left-right gap between the left needle guard surface 22 and the needle 40, as well as the left-right gap between the right needle guard surface 23 and the needle 40 for different models of needles 40, so that different models of needles 40 can work under the optimal working gap conditions, reducing the probability of common faults such as thread splitting, thread breakage, and skipped needles.

[0101] In this embodiment, the preferred structure of the gap adjustment component is as follows: Figure 8 and Figure 9 As shown, the gap adjustment assembly includes an adjusting positioning plate 50 that can move radially back and forth along the shuttle frame 20. The adjusting positioning plate 50 is equipped with a positioning hook 51, and an adjusting positioning groove 25 is provided on the outer edge of the shuttle frame 20. The positioning hook 51 engages with the adjusting positioning groove 25. By changing the front and rear installation position of the adjusting positioning plate 50, the circumferential angle of the shuttle frame 20 can be changed, thus changing the left and right gaps between the left needle guard surface 22 and the needle 40, as well as the left and right gaps between the right needle guard surface 23 and the needle 40. This reduces and facilitates the work of recalibrating the gap between the rotary hook 10 and the needle 40, ensuring the machine can perform the hooking action well. Furthermore, the adjustment of the front and rear movement of the adjusting positioning plate 50 can be done manually or by using a drive source such as a cylinder, electromagnet, or motor.

[0102] Preferably, such as Figure 8 As shown, the gap adjustment assembly also includes a fixed guide pin 60, which can be a screw. The adjusting positioning plate 50 has a guide groove 52 extending straight back and forth along its moving direction. The guide pin 60 passes through the guide groove 52, and the two slide in each other, improving the smoothness of the back and forth movement of the adjusting positioning plate 50, thus improving the stability of the gap adjustment. Additionally, as... Figure 9 As shown, the adjusting positioning plate 50 is also provided with a scale 53, which is used to characterize the size of the working gap directly below the needle 40, making it easy to adjust.

[0103] Rotary shuttle example two

[0104] In embodiment two of the rotary shuttle, as Figure 10 As shown, the shuttle frame 20 also includes a separately configured movable needle guard baffle 90. The movable needle guard baffle 90 is installed on the outer periphery of the shuttle frame 20 and can move left and right along the axis of the rotary shuttle 10. The right side wall of the needle drop groove 21 partially or entirely forms the right needle guard surface 23, and the left needle guard surface 22 is fixed on the movable needle guard baffle 90. Thus, the left needle guard surface 22 is separately formed on the shuttle frame 20, while the right needle guard surface 23 is integrally formed on the shuttle frame 20. In this way, the movable needle guard baffle 90 can be added to the existing rotary shuttle structure, reducing costs.

[0105] Furthermore, similar to the first embodiment of the rotary shuttle, both the left needle guard surface 22 and the right needle guard surface 23 are radial planes extending straight along the radial direction of the shuttle frame 20, that is, both the left needle guard surface 22 and the right needle guard surface 23 are perpendicular to the axial direction of the rotary shuttle 10. The outer end of the left needle guard surface 22 protrudes outward from the outer end of the right needle guard surface 23. Both the outer ends of the left needle guard surface 22 and the right needle guard surface 23 are provided with chamfered portions 26.

[0106] Furthermore, the structure of the movable needle guard 90 is as follows: Figure 11 As shown, the movable needle guard 90 includes a guard body 91, a connecting part 92, and a needle guard part 93 that are integrally connected in sequence. The connecting part 92 is integrally connected between the front edge of the guard body 91 and the front edge of the needle guard part 93, so that a clearance notch 94 is formed between the guard body 91, the connecting part 92 and the needle guard part 93 to allow the needle groove 21 to be exposed. The guard body 91 is movably mounted on the shuttle frame 20. The needle guard part 93 is distributed on the left side of the needle 40. The side of the needle guard part 93 facing the needle 40 or the whole constitutes the left needle guard surface 22, and the left needle guard surface 22 is integrally formed on the movable needle guard 90.

[0107] Preferably, such as Figure 10 and Figure 11 As shown, the shuttle frame 20 also includes an adjusting screw 110. A guide rail 29 is fixed on the outer circumferential surface of the shuttle frame 20 and slides with the baffle body 91. An adjusting groove 95 is provided in the baffle body 91. Both the guide rail 29 and the adjusting groove 95 extend straight along the moving direction of the movable needle guard baffle 90. The baffle body 91 and the shuttle frame 20 are fixed together by the adjusting screw 110, which passes through the adjusting groove 95. Through the sliding engagement of the guide rail 29 and the baffle body 91, and the sliding engagement of the adjusting screw 110 and the adjusting groove 95, the accuracy of the left and right position adjustment of the movable needle guard baffle 90 is ensured, and no forward or backward deviation occurs.

[0108] Furthermore, the second embodiment of the rotary hook also includes a gap adjustment assembly. The structure of the gap adjustment assembly is the same as that in the first embodiment of the rotary hook, including an adjusting positioning plate 50 with a positioning hook 51 and a guide pin 60, which will not be elaborated here. The left needle guard surface 22 and the right needle guard surface 23 can both extend straight forward and backward along the circumference of the shuttle frame 20, or at least one of them can have an inclined section 24. The inclined section 24 extends obliquely in the extending direction of the needle drop groove 21, and the inclined section 24 causes the working gap between the left needle guard surface 22 and the right needle guard surface 23 to have different axial widths in the left-right direction. Therefore, in Embodiment 2 of the rotary hook, when steplessly adjusting the size of the working gap formed between the left needle guard surface 22 and the right needle guard surface 23 in the left-right direction, it can be achieved by adjusting only the left-right position of the movable needle guard baffle 90, or by adjusting only the circumferential angle of the shuttle frame 20, or by simultaneously adjusting both the left-right position of the movable needle guard baffle 90 and the circumferential angle of the shuttle frame 20. The adjustment method is very flexible and can more reliably ensure that the needle 40 is in the optimal working gap, so that the left needle guard surface 22 and the right needle guard surface 23 have a very good needle protection effect on needles 40 of different thicknesses. Based on different configurations of the inclined section 24, four preferred embodiments of the shuttle frame 20 are provided below.

[0109] Example 1 of shuttle frame 20 Figure 12a As shown, both the left needle guard surface 22 and the right needle guard surface 23 extend straight back and forth along the circumference of the shuttle frame 20. Thus, when the adjusting screw 110 is loosened, the baffle body 91 moves left and right along the guide rail 29 and the adjusting groove 95, which can move the left needle guard surface 22 left and right: when the left needle guard surface 22 moves to the left, the left needle guard surface 22 moves away from the needle 40 and the right needle guard surface 23, and the gap between the left needle guard surface 22 and the needle 40 in the left and right direction becomes larger, which is suitable for the size of a larger needle size (i.e., a thicker needle) 40; when the left needle guard surface 22 moves to the right, the left needle guard surface 22 moves closer to the needle 40 and the right needle guard surface 23, and the gap between the left needle guard surface 22 and the needle 40 in the left and right direction becomes smaller, which is suitable for the size of a smaller needle size (i.e., a thinner needle) 40. After adjustment, tighten the adjusting screw 110 to achieve the best gap between the needle 40 and the needle guard plate 93, thus greatly reducing skipped stitches and achieving a good sewing effect.

[0110] Example 2 of shuttle frame 20 Figure 12bAs shown, the left needle guard surface 22 extends straight forward and backward along the circumference of the shuttle frame 20; the right needle guard surface 23 has an inclined section 24, which is defined as the right inclined section 231. The right inclined section 231 is inclined in a way that it extends forward and to the right. Furthermore, along the extension direction of the needle groove 21, the right needle guard surface 23 also includes a first right straight section 232 and a second right straight section 233 respectively located at the front and rear ends of the right inclined section 231. Both the first right straight section 232 and the second right straight section 233 extend straight forward and backward along the circumference of the shuttle frame 20, so the right inclined section 231 is roughly distributed at the front and rear middle position of the right needle guard surface 23. The right inclined section 231 makes the working gap between the left needle guard surface 22 and the right needle guard surface 23 change in the following way: the size of the front part is the same and is a larger gap; the size of the middle part gradually decreases from front to back and can change continuously; and the size of the rear part is the same and is a smaller gap.

[0111] When the adjusting screw 110 is loosened and the movable needle guard 90 is moved to the left, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction increases, accommodating the size of a larger needle size (i.e., a thicker needle) 40. When the adjusting screw 110 is loosened and the movable needle guard 90 is moved to the right, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction decreases, accommodating the size of a smaller needle size (i.e., a thinner needle) 40. When the adjusting positioning plate 50 is moved backward, causing the shuttle carriage 20 to rotate backward by an angle, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction increases, accommodating the size of a larger needle size (i.e., a thicker needle) 40. When the adjusting positioning plate 50 is moved forward, causing the shuttle carriage 20 to rotate forward by an angle, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction decreases, accommodating the size of a smaller needle size (i.e., a thinner needle) 40.

[0112] Example 3 of shuttle frame 20 Figure 12cAs shown, both the left needle guard surface 22 and the right needle guard surface 23 are provided with inclined sections 24. The inclined section 24 on the left needle guard surface 22 is defined as the left inclined section 221, and the inclined section 24 on the right needle guard surface 23 is defined as the right inclined section 231. The left inclined section 221 is inclined in a manner that extends further forward and further to the left, while the right inclined section 231 is inclined in a manner that extends further forward and further to the right. Therefore, the inclination direction of the left inclined section 221 is opposite to that of the right inclined section 231. Furthermore, the inclination angle of the left inclined section 221 is greater than that of the right inclined section 231. Along the extension direction of the needle groove 21, the left needle guard surface 22 also includes a first left straight section 222 and a second left straight section 223 respectively located at the front and rear ends of the left inclined section 221. The right needle guard surface 23 also includes a first right straight section 232 and a second right straight section 233 respectively located at the front and rear ends of the right inclined section 231. The first left straight section 222, the second left straight section 223, the first right straight section 232, and the second right straight section 233 all extend straight forward and backward along the circumference of the shuttle frame 20. Therefore, the left inclined section 221 is approximately located at the front and rear middle position of the left needle guard surface 22, and the right inclined section 231 is approximately located at the front and rear middle position of the right needle guard surface 23. The left tilting section 221 and the right tilting section 231 cause the working gap between the left needle guard surface 22 and the right needle guard surface 23 to change in the following manner: the front part is the same size and has a larger gap; the middle part gradually decreases in size from front to back and can change continuously; and the rear part is the same size and has a smaller gap.

[0113] Similarly, when the adjusting screw 110 is loosened and the movable needle guard 90 is moved to the left, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction increases, making it suitable for larger needle sizes (i.e., thicker needles) of the needle 40. When the adjusting screw 110 is loosened and the movable needle guard 90 is moved to the right, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction decreases, making it suitable for smaller needle sizes (i.e., thinner needles) of the needle 40. When the adjusting positioning plate 50 is moved backward, causing the shuttle carriage 20 to rotate backward by an angle, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction increases, making it suitable for larger needle sizes (i.e., thicker needles) of the needle 40. When the adjusting positioning plate 50 is moved forward, causing the shuttle carriage 20 to rotate forward by an angle, the gap between the left needle guard surface 22 and the needle 40 in the left-right direction decreases, making it suitable for smaller needle sizes (i.e., thinner needles) of the needle 40.

[0114] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0115] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A rotary shuttle with needle protection function, comprising a shuttle frame (20) having a needle drop groove (21), the needle drop groove (21) extending circumferentially along the shuttle frame (20) for allowing a sewing machine needle (40) to pass through, characterized in that: Along the axial direction of the rotary shuttle (10), the shuttle frame (20) is provided with a left needle guard surface (22) and a right needle guard surface (23) in the needle drop groove (21), and the left needle guard surface (22) and the right needle guard surface (23) are respectively distributed close to each other on the left and right sides of the needle (40); The shuttle frame (20) also includes a movable needle guard (90), which is movably mounted on the shuttle frame (20) along the axis of the rotary shuttle (10). The right side wall of the needle drop groove (21) partially or entirely forms the right needle guard surface (23), and the left needle guard surface (22) is fixed on the movable needle guard (90). The movable needle guard (90) includes a guard body (91), a connecting part (92), and a needle guard part (93) that are integrally connected in sequence. A clearance notch (94) is formed between the guard body (91), the connecting part (92), and the needle guard part (93) to allow the needle groove (21) to be exposed. The guard body (91) is movably mounted on the shuttle frame (20). The needle guard part (93) is distributed on the left side of the needle (40). The side of the needle guard part (93) facing the needle (40) or the whole of the needle guard part (93) constitutes the left needle guard surface (22). The shuttle frame (20) also includes an adjusting screw (110). A guide rail (29) that slides with the baffle body (91) is fixed on the outer circumferential surface of the shuttle frame (20). An adjusting groove (95) is provided in the baffle body (91). The guide rail (29) and the adjusting groove (95) extend straight along the moving direction of the movable needle guard baffle (90). The baffle body (91) and the shuttle frame (20) are fixed together by the adjusting screw (110). The adjusting screw (110) passes through the adjusting groove (95).

2. The rotary hook with needle protection function according to claim 1, characterized in that: The left side wall of the needle groove (21) partially or entirely constitutes the left needle guard surface (22), and the right side wall of the needle groove (21) partially or entirely constitutes the right needle guard surface (23).

3. The rotary hook with needle protection function according to claim 1, characterized in that: The left needle guard surface (22) and the right needle guard surface (23) are both radial planes that extend straight along the radial direction of the shuttle frame (20).

4. The rotary hook with needle protection function according to claim 1 or 2, characterized in that: At least one of the left needle guard surface (22) and the right needle guard surface (23) is provided with an inclined section (24), which extends obliquely in the extension direction of the needle groove (21), and the inclined section (24) makes the working gap between the left needle guard surface (22) and the right needle guard surface (23) have different axial widths.

5. The rotary hook with needle protection function according to claim 4, characterized in that: The left needle guard surface (22) and the right needle guard surface (23) are both provided with the inclined section (24).

6. The rotary hook with needle protection function according to claim 5, characterized in that: The inclined section (24) of the left needle guard surface (22) is the left inclined section (221), and the inclined section (24) of the right needle guard surface (23) is the right inclined section (231). Along the extension direction of the needle groove (21), the left needle guard surface (22) also includes a first left straight section (222) and a second left straight section (223) respectively provided at both ends of the left inclined section (221), and the right needle guard surface (23) also includes a first right straight section (232) and a second right straight section (233) respectively provided at both ends of the right inclined section (231). The first left straight section (222), the second left straight section (223), the first right straight section (232) and the second right straight section (233) all extend straight along the circumference of the shuttle frame (20).

7. The rotary hook with needle protection function according to claim 6, characterized in that: The tilt direction of the left tilt segment (221) is opposite to that of the right tilt segment (231).

8. The rotary hook with needle protection function according to claim 6, characterized in that: The tilt angle of the left tilt segment (221) is greater than the tilt angle of the right tilt segment (231).

9. The rotary hook with needle protection function according to claim 4, characterized in that: It also includes a gap adjustment component, which is connected to the shuttle (20) and is used to drive the shuttle (20) to rotate around its own axis.

10. The rotary hook with needle protection function according to claim 9, characterized in that: The gap adjustment assembly includes an adjustment positioning plate (50) that is radially movable along the shuttle frame (20). The adjustment positioning plate (50) is provided with a positioning hook (51). An adjustment positioning groove (25) is opened on the outer edge of the shuttle frame (20). The positioning hook (51) engages with the adjustment positioning groove (25).

11. The rotary hook with needle protection function according to claim 10, characterized in that: The gap adjustment assembly also includes a fixed guide pin (60), and the adjustment positioning plate (50) has a guide groove (52) extending straight along its moving direction. The guide pin (60) passes through the guide groove (52) and the two slide together.

12. The rotary hook with needle protection function according to claim 10, characterized in that: The adjustment positioning plate (50) is provided with a scale (53), which is used to characterize the size of the working gap between the left needle guard surface (22) and the right needle guard surface (23) directly below the needle (40).

13. The rotary hook with needle protection function according to claim 1, characterized in that: The outer ends of the left needle guard surface (22) and the right needle guard surface (23) are provided with chamfered portions (26), and the chamfered portions (26) are arc surfaces or bevels.

14. The rotary hook with needle protection function according to claim 1, characterized in that: The gap between the left needle guard (22) and the needle (40) in the axial direction of the rotary hook (10) is 0.15±0.15 mm, and the gap between the right needle guard (23) and the needle (40) in the axial direction of the rotary hook (10) is 0.15±0.15 mm.

15. A sewing machine, characterized in that: The sewing machine is equipped with a rotary hook (10) as described in any one of claims 1-14.

Images