Tangent structure and double needle sewing machine

Abstract

The present application relates to a kind of tangent structure and double needle sewing machine.The tangent structure is used to cooperate with rotating shuttle and needle to cut off the seam, including support, moving knife, fixed knife and bottom thread holding spring, moving knife is slidably connected with support along second direction, bottom thread holding spring and fixed knife are respectively located on the two sides of moving knife along first direction and are fixed with support;Hooking slot is opened in the side of moving knife along third direction close to the side surface of rotating shuttle, hooking slot penetrates moving knife along first direction, the side of moving knife along first direction close to bottom thread holding spring is provided with blocking piece, blocking piece is fixed on moving knife and is located on the side of hooking slot along second direction close to moving knife head, the side of blocking piece along second direction away from moving knife head has blocking surface;The interval between blocking surface and bottom thread holding spring along second direction under retraction station is 0.3mm-1.5mm;While ensuring that blocking piece effectively hooks face thread and bottom thread, moving knife is retracted to avoid collision interference with bottom thread holding spring.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewing machine related technical field, in particular to a cutting thread structure and a double needle sewing machine. BACKGROUND

[0002] The double needle machine is a horizontal shuttle type sewing machine, and the stitch is a lock stitch. Due to the basic characteristics of the lock stitch, the face thread must pass through a circle under the shuttle needle and cross the bottom thread to form a stitch.

[0003] After the conventional double needle sewing machine finishes cutting the thread, the face thread on the needle is pulled away from the bottom thread holding spring. However, due to the intersection of the face thread and the bottom thread, the intersection part acts as a force point during the process of pulling away the face thread, which makes the face thread easy to pull the bottom thread out of the thread clamp, resulting in that the previous needle sewing cannot be sewn on the next time, and even the whole stitch is off the bottom thread.

[0004] Currently, there are some solutions to avoid the bottom thread from being pulled out by changing the moving knife structure. However, due to the small gap between the moving knife, the bottom thread holding spring, the fixed knife and the shuttle in the sewing machine, most of the moving knife structures cannot avoid interference between the components while ensuring good anti-thread-off effect. SUMMARY

[0005] Therefore, it is necessary to provide a cutting thread structure and a double needle sewing machine with good anti-thread-off effect and without interference with other components to solve the problem that the current cutting thread structure cannot avoid interference between components while ensuring good anti-thread-off effect.

[0006] The present application first provides a cutting thread structure for cutting off the sewing material in cooperation with the shuttle and the needle, which comprises a bracket, a moving knife, a fixed knife and a bottom thread holding spring. The moving knife is slidably connected with the bracket along a second direction to move between an extended position and a retracted position. The bottom thread holding spring and the fixed knife are respectively located on both sides of the moving knife along a first direction and are fixed with the bracket to clamp and cut off the sewing thread when the moving knife moves to the retracted position. A hooking groove is formed on the side of the moving knife close to the side surface of the shuttle along a third direction. The hooking groove penetrates through the moving knife along the first direction. A blocking piece is arranged on the side of the moving knife close to the bottom thread holding spring along the first direction. The blocking piece is fixed to the moving knife and located on the side of the hooking groove close to the moving knife head along the second direction. The blocking piece has a blocking surface on the side away from the moving knife head along the second direction. The distance between the blocking surface and the bottom thread holding spring along the second direction is 0.3mm-1.5mm in the retracted position.

[0007] The tangent structure can limit the gap between the blocking surface and the bottom thread retaining spring in the second direction to 0.3mm-1.5mm, so as to avoid the collision between the moving cutter and the bottom thread retaining spring when the moving cutter retracts.

[0008] In one of the embodiments, the gap between the blocking surface and the bottom thread retaining spring in the second direction is 0.5mm.

[0009] In one of the embodiments, the first supporting position is away from one end of the rotating hook, and the second supporting position is close to the other end of the rotating hook. The gap between the first supporting position and the bottom thread retaining spring in the second direction is 0.3mm-1.5mm.

[0010] In one of the embodiments, the side surface of the bottom thread retaining spring close to the blocking piece is parallel to the blocking surface.

[0011] It can be understood that the parallel arrangement makes the gap between the side surface of the bottom thread retaining spring close to the blocking piece and the blocking piece equal everywhere, and meets the gap range of 0.3mm-1.5mm, further reducing the possibility of interference between the moving cutter 10 and the bottom thread retaining spring.

[0012] In one of the embodiments, the bottom thread retaining spring is wavy along any straight line direction in the quadrant plane.

[0013] It can be understood that the wavy bottom thread retaining spring can clamp the surface thread and the bottom thread through multi-point contact, so as to ensure the clamping force on the bottom thread while taking into account the easy pulling of the surface thread, and ensure that the bottom thread will not be taken out.

[0014] In one of the embodiments, a guide groove is arranged on the side surface of the moving cutter close to the fixed cutter in the first direction. The guide groove is in communication with one end of the hook thread groove, and the other end extends to one side of the moving cutter head in the second direction.

[0015] It can be understood that the guide groove can store a part of the surface thread and the bottom thread, so that the thread length of the surface thread connected with the needle and the bottom thread connected with the rotating hook is relatively long after the cutting is completed, so as to facilitate the subsequent re-sewing of the thread.

[0016] In one of the embodiments, the included angle between the side surface of the moving cutter away from the fixed cutter in the first direction and the blocking surface is an acute angle.

[0017] It can be understood that the acute angle can hook the surface thread after the surface thread abuts against the blocking surface, reducing the possibility of the surface thread and the blocking surface being separated, and further ensuring the blocking effect of the blocking piece.

[0018] In one of the embodiments, the blocking piece is fixed with a limiting piece protruding from the blocking piece to a side away from the cutter head of the moving cutter in the second direction; and / or, a limiting slot is opened on the side of the moving cutter away from the fixed cutter in the first direction at the intersection position of the blocking surface, and the limiting slot penetrates through the blocking piece and the moving cutter in the third direction.

[0019] It can be understood that the limiting piece or the limiting slot is beneficial to the blocking piece hooking the surface thread, thereby reducing the possibility of the surface thread being separated from the blocking surface and ensuring the blocking effect of the blocking piece.

[0020] In one of the embodiments, the blocking surface is inclined to the direction close to the cutter head of the moving cutter from the first supporting position to the second supporting position.

[0021] It can be understood that when the surface thread is pulled, the inclined blocking surface can play a certain guiding role, which is beneficial to the pulling of the bottom thread to the clamping position of the bottom thread retaining spring and the moving cutter by the pulling force of the intersection position.

[0022] The second aspect of the application provides a double-needle sewing machine comprising the thread cutting structure. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0024] Figure 1 It is a perspective view of the thread cutting structure of the prior art;

[0025] Figure 2 It is a perspective view of the thread cutting structure of the prior art when the surface thread is pulled out after the cutting of the thread is completed;

[0026] Figure 3 It is a perspective view of the moving cutter in the thread cutting structure of one of the embodiments of the application;

[0027] Figure 4 It is a perspective view of the thread cutting structure of the application;

[0028] Figure 5 It is Figure 4 It is an enlarged view of position A in FIG. 8;

[0029] Figure 6 It is Figure 3 It is a state diagram of the moving cutter in the thread cutting process of FIG. 8;

[0030] Figure 7for Figure 3 A schematic diagram showing the state of the moving blade during the wire cutting process;

[0031] Figure 8 for Figure 3 A schematic diagram showing the state of the moving blade during the wire cutting process;

[0032] Figure 9 for Figure 3 A schematic diagram showing the state of the moving blade during the wire cutting process;

[0033] Figure 10 for Figure 9 Enlarged schematic diagram of the moving part in the operating state;

[0034] Figure 11 for Figure 9 A top view of the structure under the operating state;

[0035] Figure 12 for Figure 9 A bottom-view structural diagram of the device in the operating state;

[0036] Figure 13 for Figure 11 A schematic diagram showing the hidden bottom line retaining the spring.

[0037] Figure 14 for Figure 13 A schematic diagram after the midline has been removed;

[0038] Figure 15 This is a three-dimensional structural diagram of the moving blade in a tangential structure according to another embodiment of the present invention;

[0039] Figure 16 This is a three-dimensional structural diagram of the moving blade in a tangential structure according to another embodiment of the present invention;

[0040] Figure 17 This is a three-dimensional structural diagram of the moving blade in a tangential structure according to another embodiment of the present invention;

[0041] Figure 18 This is a three-dimensional structural diagram of the moving blade in a tangential structure according to another embodiment of the present invention;

[0042] Figure 19 This is a three-dimensional structural diagram of the moving blade in the tangential structure of another embodiment of the present invention.

[0043] Reference numerals: 100, top line; 200, bottom line; 10, moving knife; 11, hook groove; 12, blocking element; 121, blocking surface; 12a, first blocking position; 12b, second blocking position; 13, guide groove; 14, limiting element; 20, needle; 30, rotary hook; 31, bobbin; 32, slot; 33, rotary hook guard; 40, fixed knife; 50, bottom line retaining spring; 60, bracket. DETAILED DESCRIPTION

[0044] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the detailed description of the specific embodiments of the present application will be described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced in a variety of ways beyond the specific embodiments described herein without departing from the spirit of the present application, and that the present application is not limited to the specific embodiments disclosed below.

[0045] It is to be noted that when a component is referred to as being "on" or "disposed on" another component, it can be directly on the other component or there can be intervening components present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or there can be intervening components present. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms as used in the description of the specification are for the purpose of illustration only and do not indicate an exclusive orientation.

[0046] In addition, the terms "first", "second", and the like, are used merely to describe items that differ from one another, without necessarily implying a relative importance or a particular order. Thus, a feature specified as a "first" feature can imply, either explicitly or implicitly, that there is at least one such feature. In the description of the specification, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0047] In the present application, unless otherwise explicitly specified and limited, "on", "under", "above", and "over" of a first feature to a second feature can mean that the first feature is in direct contact with the second feature, or the first feature is in indirect contact with the second feature through an intermediate medium. Moreover, "above", "over", and "on" of a first feature to a second feature can mean that the first feature is directly above or obliquely above the second feature, or only means that the first feature is horizontally higher than the second feature. "Below", "under", and "underneath" of a first feature to a second feature can mean that the first feature is directly below or obliquely below the second feature, or only means that the first feature is horizontally lower than the second feature.

[0048] Unless otherwise defined, all technical and scientific terms used in the specification of the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in the specification of the present application includes any and all combinations of one or more of the associated listed items.

[0049] Please refer to Figure 1 and Figure 2As shown, the double needle machine is a horizontal shuttle type sewing machine, and the stitch is a lock stitch. The bottom thread P200 extends from the shuttle P30 and is connected to the fabric, and the top thread P100 extends from the needle P20 and is connected to the fabric.

[0050] The normal sewing process of the double needle machine is as follows: the needle P20 pierces the fabric, and the top thread P100 is sent to the lower side of the fabric. The top thread P100 is guided by the shuttle P30 to pass under the shuttle hook P31 of the shuttle P30 once, so as to cross the bottom thread P200. The thread tensioner drives the needle P20 to rise and tighten the top thread P100, so that the crossed top thread P100 and the bottom thread P200 form a lock stitch. The above process is repeated to complete the sewing.

[0051] The cutting thread action is to cut the top thread P100 and the bottom thread by the moving knife P10 during the normal sewing process to end the sewing.

[0052] The conventional cutting thread action of the double needle machine is as follows: after the needle P20 pierces the fabric and the top thread P100 is sent to the lower side of the fabric, the moving knife P10 cuts through the thread loop formed by the top thread P100. One side of the top thread P100 enters the hook portion P11 of the moving knife P10, and the other side of the top thread P100 is guided by the shuttle P30 to pass under the shuttle hook P31 of the shuttle P30 once, so as to cross the bottom thread P200. Then, with the upward movement of the thread tensioner, the top thread P100 is tightened, and the top thread P100 brings the bottom thread P200 into the hook portion P11 of the moving knife P10. Thus, the top thread P100 and the bottom thread P200 enter the hook portion P11 of the moving knife P10. Then, with the return of the moving knife P10, the moving knife P10 and the fixed knife P40 cut the top thread P100 and the bottom thread P200. The top thread P100 extending from the needle P20 and the bottom thread P200 extending from the shuttle P30 are clamped between the moving knife P10 and the bottom thread retaining spring P50, and the cutting thread action is completed.

[0053] After cutting the thread, the user needs to remove the fabric, which will remove the top thread P100 on the needle P20 from between the bottom thread retaining spring P50 and the moving knife P10. However, since the top thread P100 and the bottom thread P200 cross, the crossing part acts as a force point during the removal of the top thread P100, and the top thread P100 easily pulls the bottom thread P200 out from between the bottom thread retaining spring P50 and the moving knife P10. This will cause the first few stitches to fail to thread during the next sewing, and in severe cases, the bottom thread P200 will be completely lost.

[0054] Please refer to Figure 3 , Figure 4 and Figure 5As shown, the application first provides a thread cutting structure for cutting the thread of the sewing material cooperated with the rotating hook 30 and the needle 20, which comprises a support 60, a moving cutter 10, a fixed cutter 40 and a bottom thread retaining spring 50. The moving cutter 10 is slidably connected with the support 60 along the second direction 2 to move between the extended position and the retracted position. The bottom thread retaining spring 50 and the fixed cutter 40 are respectively located on both sides of the moving cutter 10 along the first direction 1 and are fixed with the support 60 to clamp and cut the thread when the moving cutter 10 moves to the retracted position. The moving cutter 10 is provided with a thread hooking groove 11 on the side close to the side surface of the rotating hook 30 along the third direction 3. The thread hooking groove 11 penetrates the moving cutter 10 along the first direction 1. The moving cutter 10 is provided with a blocking piece 12 on the side close to the bottom thread retaining spring 50 along the first direction 1. The blocking piece 12 is fixed to the moving cutter 10 and located on the side of the thread hooking groove 11 close to the cutter head of the moving cutter 10 along the second direction 2. The blocking piece 12 is provided with a blocking surface 121 on the side away from the cutter head of the moving cutter 10 along the second direction 2. The distance between the blocking surface 121 and the bottom thread retaining spring 50 along the second direction 2 is 0.3mm-1.5mm in the retracted position.

[0055] Wherein, the first direction 1, the second direction 2 and the third direction 3 are perpendicular to each other. The first direction 1 is the direction of the reciprocating movement of the needle 20. The second direction 2 is the direction of the reciprocating movement of the moving cutter 10. The bottom thread 200 extends from the rotating hook 30 and is connected with the sewing material. The face thread 100 extends from the needle 20 and is connected with the sewing material.

[0056] In the application, the blocking piece 12 can block the face thread 100 and the bottom thread 200, thereby reducing or even avoiding the possibility that the face thread 100 pulls out the bottom thread 200 from the bottom thread retaining spring 50 and the moving cutter 10.

[0057] It should be noted that if the gap between the blocking surface 121 and the bottom thread retaining spring 50 along the second direction 2 in the retracted position is too small, the moving cutter 10 may interfere with the bottom thread retaining spring 50 due to external factors such as equipment vibration and tolerance fluctuation when it is retracted.

[0058] In addition, the thread cutting structure of the application blocks the face thread 100 by the blocking piece 12 to avoid the face thread 100 pulling out the bottom thread 200 from the bottom thread retaining spring 50. The larger the gap between the blocking surface 121 and the bottom thread retaining spring 50 along the second direction 2, the closer the direction of the face thread 100 when it is pulled out to the state when the blocking piece 12 is not provided, which may cause the blocking surface 121 to fail to block the face thread 100 and the bottom thread 200.

[0059] By limiting the gap between the blocking surface 121 and the bottom thread retaining spring 50 along the second direction 2 in the retracted position to 0.3mm-1.5mm, the application can effectively block the face thread 100 and the bottom thread 200 by the blocking piece 12 while avoiding the collision and interference between the moving cutter 10 and the bottom thread retaining spring 50 when the moving cutter 10 is retracted.

[0060] The thread cutting action of the present application's moving knife 10 is the same as the prior art, but due to the difference in the structure of the moving knife 10, when the moving knife 10 of the present application completes thread cutting and separates from the seam, the position and stress state of the top thread 100 and the bottom thread 200 are different from those of the prior art. The specific hooking and thread cutting actions of the present application are as follows:

[0061] First step, please refer to Figure 6 , the shuttle 30 hooks and drives a section of the top thread 100 extending from the needle 20 to rotate, so that the thread loops of the two sections of the top thread 100 gradually expand. In this process, the moving knife 10 cuts through the thread loops. When the moving knife 10 reaches the limit position (i.e. the extended working position), it remains stationary. Then, with the rotation of the shuttle 30, the thread loops continue to expand. At this time, the section of the top thread 100 extending from the needle 20 (i.e. the section of the top thread 100 hooked and driven by the shuttle 30) is located on one side of the moving knife 10, and the section of the top thread 100 extending from the seam and the bottom thread 200 are both located on the other side of the moving knife 10.

[0062] Second step, please refer to Figure 7 , with the rotation of the shuttle 30, the top thread 100 (the top thread 100 extending from the needle 20) above the shuttle comb 31 makes a complete loop, and the top thread 100 (the top thread 100 extending from the seam) at the bottom of the shuttle comb 31 also makes a complete loop, so that the top thread 100 and the bottom thread 200 cross each other (the reason for forming a lock stitch). At this time, the top thread 100 above the shuttle comb 31 will be detached from the clamping slot 32 on the shuttle comb 31, and thus be detached to the shuttle guard hook 33. At this time, the moving knife 10 has started to retract. With the retraction of the moving knife 10 and the continuous tightening of the top thread 100 extending from the needle 20 under the action of the thread tension lever, the top thread 100 and the bottom thread 200 on the side of the moving knife 10 close to the shuttle 30 are tightened together in the hooking slot 11 of the moving knife 10.

[0063] Third step, please refer to Figure 8 , with the continuous rotation of the shuttle 30, the top thread 100 on the shuttle guard hook 33 will further detach from the shuttle guard hook 33. At this time, the crossing of the top thread 100 and the bottom thread 200 has been formed. The moving knife 10 continues to retract, and the top thread 100 and the bottom thread 200 on the side of the moving knife 10 close to the shuttle 30 completely enter the hooking slot 11 of the moving knife 10.

[0064] Fourth step, please refer to Figure 9 , Figure 10 and Figure 11 , the moving knife 10 retracts to the limit position (i.e. the retracted working position). During this process, three actions occur simultaneously:

[0065] First, the top thread 100 extending from the needle 20 completely detaches from the rotary hook 33. On the side of the moving cutter 10 near the rotary hook 30, the top thread 100 and the bottom thread 200 will form an intersection. Due to the presence of the blocking part 12 and the pulling of the top thread 100 and the bottom thread 200 when the moving cutter 10 returns, the top thread 100 and the bottom thread 200 extending from the needle 20 will be hooked by the blocking surface 121.

[0066] Secondly, the surface line 100 and the bottom line 200 located on the upper side of the moving cutter 10 will be affected by the cutting edge of the moving cutter 10 and the fixed cutter 40 ( Figure 9 The meshing (not shown in the image) cuts off this portion of the top line 100 and the bottom line 200;

[0067] Secondly, the bottom line maintains a spring size of 50 ( Figure 9 , Figure 10 (Not shown) It will work with the lower end face of the moving blade 10 to clamp the cross-shaped surface line 100 and the bottom line 200.

[0068] Please combine Figure 12 , Figure 13 as well as Figure 14 As shown, after completing the above hooking and cutting actions, the user needs to pull away the sewing material. This will pull the top thread 100 on the needle 20 away from the bottom thread retaining spring 50 and the moving blade 10. However, since the top thread 100 and the bottom thread 200 intersect, during the process of pulling the top thread 100 away, the intersection point acts as a force point, and the top thread 100 can easily pull the bottom thread 200 out from between the bottom thread retaining spring 50 and the moving blade 10.

[0069] In this application, the blocking surface 121 can block the top thread 100 and the bottom thread 200, reducing or even avoiding the possibility that the top thread 100 will pull the bottom thread 200 out from between the bottom thread retaining spring 50 and the moving knife 10. The sewing rate reaches more than 98%, which can ensure that the bottom thread 200 is in a clamped state after each thread cutting and pulling of the top thread 100.

[0070] Specifically, the end of the blocking surface 121 away from the rotary shuttle 30 is the first support position 12a, and the end closer to the rotary shuttle 30 is the second support position 12b.

[0071] When the top thread 100 extending from the needle 20 is pulled away from the bottom thread retaining spring 50 and the moving blade 10, since the top thread 100 and the bottom thread 200 intersect, the top thread 100 will exert a pulling force on the bottom thread 200 at the intersection, which will cause the bottom thread 200 to separate from the bottom thread retaining spring 50 and the moving blade 10. In this application, the first support position 12a can serve as a force fulcrum to share and reduce part of the pulling force, thereby reducing or even avoiding the possibility that the top thread 100 will pull the bottom thread 200 out from the bottom thread retaining spring 50 and the moving blade 10.

[0072] In addition, the first support position 12a can also change the direction of the pulling force as a force support point, so that the bottom thread 200 has a tendency to move to the first support position 12a under the action of the pulling force at the intersection position. At this time, the bottom thread 200 will contact the second support position 12b, and the second support position 12b will block the bottom thread 200 as a force point, further reducing the possibility of the bottom thread 200 being pulled out by the pulling force of the surface thread 100. At the same time, the bottom thread 200 between the bottom thread retaining spring 50 and the moving knife 10 will move to the first support position 12a under the action of the pulling force, thereby increasing the movement stroke required for the bottom thread 200 to be separated from the bottom thread retaining spring 50, and increasing the clamping firmness of the bottom thread 200.

[0073] In some embodiments, the distance between the blocking surface 121 and the bottom thread retaining spring 50 in the second direction 2 under the retraction station is 0.5mm. At this distance, the blocking piece 12 can maximize the effect of hooking the surface thread 100 and the bottom thread 200 while avoiding collision and interference between the moving knife 10 and the bottom thread retaining spring 50 when the moving knife 10 is retracted.

[0074] In some embodiments, the end of the blocking surface 121 away from the rotating hook 30 is the first support position 12a, and the end close to the rotating hook 30 is the second support position 12b. The distance between the first support position 12a and the bottom thread retaining spring 50 in the second direction 2 under the retraction station is 0.3mm-1.5mm.

[0075] In this application, the blocking piece 12 mainly relies on the first support position 12a as a force support point to block the surface thread 100, share a part of the pulling force, and change the direction of the pulling force at the intersection position, thereby reducing or even avoiding the possibility of the surface thread 100 pulling the bottom thread 200 out from between the bottom thread retaining spring 50 and the moving knife 10. Therefore, by setting the distance between the first support position 12a and the bottom thread retaining spring 50 in the second direction 2 to be 0.3mm-1.5mm, the anti-thread falling effect can be ensured while avoiding collision and interference between the moving knife 10 and the bottom thread retaining spring 50 when the moving knife 10 is retracted.

[0076] In some embodiments, the side surface of the bottom thread retaining spring 50 close to the blocking piece 12 is parallel to the blocking surface 121. This ensures that the distance between the side surface of the bottom thread retaining spring 50 close to the blocking piece 12 and the blocking piece 12 is equal everywhere and meets the distance range of 0.3mm-1.5mm, further reducing the possibility of interference between the moving knife 10 and the bottom thread retaining spring 50.

[0077] In some embodiments, the bottom thread retaining spring 50 is wavy along any straight line direction in the quadrant plane. The wavy bottom thread retaining spring 50 can hold the surface thread 100 and the bottom thread 200 through multiple point contact, thereby ensuring the clamping force on the bottom thread 200 while taking into account the easy pulling out of the surface thread 100, and ensuring that the bottom thread 200 will not be pulled out by the surface thread 100.

[0078] Please refer to Figure 3 and Figure 9 As shown in FIG. 1, in some embodiments, the moving knife 10 is provided with a guide groove 13 on the side close to the fixed knife 40 along the first direction 1, the guide groove 13 is in communication with the one end of the hooking groove 11, and the other end extends to the side of the head of the moving knife 10 along the second direction 2.

[0079] In the third step of the hooking principle of the moving knife 10 in the present application, after the face thread 100 and the bottom thread 200 on the side close to the rotating hook 30 of the moving knife 10 completely enter the hooking groove 11 of the moving knife 10, the face thread 100 and the bottom thread 200 entering the hooking groove 11 will also enter the guide groove 13 due to the presence of the guide groove 13 on the moving knife 10; the guide groove 13 can store a part of the face thread 100 and the bottom thread 200, so that the length of the thread end of the face thread 100 connected with the needle 20 and the length of the thread end of the bottom thread 200 connected with the rotating hook 30 are relatively long after the thread cutting is completed, so as to facilitate the subsequent re-sewing of the thread.

[0080] In some embodiments, the side wall of the guide groove 13 close to the side of the head of the moving knife 10 is a cutting edge, which can cooperate with the fixed knife 40 to cut the face thread 100 and the bottom thread 200; the acute angle can hook the face thread 100 after the face thread 100 abuts against the blocking surface 121, reducing the possibility of the face thread 100 and the blocking surface 121 being separated, thereby ensuring the blocking effect of the blocking piece 12.

[0081] Please refer to Figure 15 As shown in FIG. 1, in some embodiments, the angle between the side of the moving knife 10 away from the fixed knife 40 along the first direction 1 and the blocking surface 121 is an acute angle; the acute angle can hook the face thread 100 after the face thread 100 abuts against the blocking surface 121, reducing the possibility of the face thread 100 and the blocking surface 121 being separated, thereby ensuring the blocking effect of the blocking piece 12.

[0082] Please refer to Figure 16 As shown in FIG. 1, in some embodiments, the blocking piece 12 is fixedly provided with a limiting piece 14 protruding from the blocking piece 12 away from the side of the head of the moving knife 10 along the second direction 2; and / or, the intersection position of the side of the moving knife 10 away from the fixed knife 40 along the first direction 1 and the blocking surface 121 is provided with a limiting groove, the limiting groove penetrates the blocking piece 12 and the moving knife 10 along the third direction 3.

[0083] The limiting piece 14 or the limiting groove is beneficial to the blocking piece 12 hooking the face thread 100, thereby reducing the possibility of the face thread 100 and the blocking surface 121 being separated, ensuring the blocking effect of the blocking piece 12; the limiting piece 14 is fixed to the blocking piece 12 by commonly used fixed connection methods such as riveting and welding; preferably, the limiting piece 14 is fixed to the side end surface of the blocking piece 12 away from the fixed knife 40.

[0084] Please refer to Figure 17As shown, in some embodiments, the blocking surface 121 is inclined from the first support position 12a to the second support position 12b towards the direction close to the cutter head of the moving cutter 10; therefore, when the surface thread 100 is pulled, the inclined blocking surface 121 can play a certain guiding role, which is conducive to the pulling of the bottom thread 200 to the clamping position of the bottom thread retaining spring 50 and the moving cutter 10 by the pulling force at the intersection position.

[0085] Please refer to Figure 18 As shown, in some embodiments, the second support position 12b corresponds to the middle line of the bottom thread retaining spring 50; during the process of pulling the surface thread 100, since the first support position 12a can serve as a force support point to change the direction of the pulling force at the intersection position of the surface thread 100 and the bottom thread 200, so that the bottom thread 200 has a tendency to move to the first support position 12a, and in this process, the second support position 12b will block the bottom thread 200 as a force point; in the present application, by corresponding the second support position 12b to the middle line of the bottom thread retaining spring 50, the bottom thread 200 can be pulled to the middle line position of the bottom thread retaining spring 50 under the action of the pulling force at the intersection position, at this time, the stroke required for the bottom thread 200 to escape from the bottom thread retaining spring 50 on either side of the third direction 3 is relatively long, thereby further increasing the clamping firmness of the bottom thread 200.

[0086] In some embodiments, the thickness of the blocking piece 12 is less than or equal to 1 mm; if the thickness of the blocking piece 12 is too large, since the distance between the moving cutter 10 and the rotating hook 30 of different equipment is different, there is a possibility of collision interference between the moving cutter 10 and the rotating hook 30 during the movement of the moving cutter 10 along the second direction 2, which may cause damage to the equipment; therefore, by setting the thickness of the blocking piece 12 to be less than or equal to 1 mm, the occurrence of such interference can be effectively avoided, thereby increasing the universality of the moving cutter 10 of the present application.

[0087] In some embodiments, the thickness of the blocking piece 12 is equal to 1 mm; if the thickness of the blocking piece 12 is too small, it will result in poor effect of blocking the surface thread 100 and the bottom thread 200, thereby affecting the anti-escape effect of the present application; therefore, by setting the thickness of the blocking piece 12 to be 1 mm, the universality can be maximized on the basis of ensuring the anti-escape effect.

[0088] In some embodiments, the blocking surface 121 is an arc surface, so as to facilitate the pulling out of the surface thread 100, and at the same time, the arc surface can effectively reduce the wear between the surface thread 100 and the blocking surface 121 when the surface thread 100 is pulled out, thereby reducing the possibility of the surface thread 100 being pulled off.

[0089] In some embodiments, the blocking piece 12 can be integrally formed with the moving cutter 10 by casting, material reduction processing and the like, or can be fixed with the moving cutter 10 by commonly used fixed connection modes such as welding, interference fit or bolt connection, which is not specifically limited in the present application.

[0090] Please refer to Figure 19 As shown in FIG. 1, in some embodiments, the blocking piece 12 is in a columnar shape, and the movable knife 10 is provided with a pin hole along the first direction 1, and the blocking piece 12 is in interference fit with the pin hole.

[0091] In some embodiments, the blocking piece 12 is in a columnar shape, and the movable knife 10 is provided with a threaded hole along the first direction 1, and the blocking piece 12 is connected with the threaded hole through threads.

[0092] The second aspect of the present application provides a double-needle sewing machine comprising the thread cutting structure.

[0093] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, but as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0094] The above-mentioned embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation to the patent application scope. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A tangential structure for cooperating with a rotary hook (30) and a needle (20) to cut sewing material, characterized in that, The device includes a support (60), a movable blade (10), a fixed blade (40), and a bottom thread retaining spring (50). The movable blade (10) is slidably connected to the support (60) along a second direction (2) to move between an extended position and a retracted position. The bottom thread retaining spring (50) and the fixed blade (40) are located on both sides of the movable blade (10) along a first direction (1) and are both fixed to the support (60) to clamp and cut the thread when the movable blade (10) moves to the retracted position. The moving blade (10) has a hook groove (11) on the side of the rotary hook (30) along the third direction (3). The hook groove (11) passes through the moving blade (10) along the first direction (1). A blocking member (12) is provided on the side of the moving blade (10) along the first direction (1) near the bottom line retaining spring (50). The blocking member (12) is fixed to the moving blade (10) and located on the side of the hook groove (11) along the second direction (2) near the head of the moving blade (10). The blocking member (12) has a blocking surface (121) on the side of the blocking member (12) away from the head of the moving blade (10) along the second direction (2). When the workstation is retracted, the distance between the blocking surface (121) and the bottom retaining spring (50) along the second direction (2) is 0.3mm to 1.5mm.

2. The tangent structure according to claim 1, characterized in that, When the workstation is retracted, the distance between the blocking surface (121) and the bottom retaining spring (50) along the second direction (2) is 0.5 mm.

3. The tangent structure according to claim 1, characterized in that, The end of the blocking surface (121) away from the rotary hook (30) is the first support position (12a), and the end closer to the rotary hook (30) is the second support position (12b). When the device is retracted, the distance between the first support position (12a) and the bottom retaining spring (50) along the second direction (2) is 0.3mm to 1.5mm.

4. The tangent structure according to claim 1, characterized in that, The bottom retaining spring (50) is parallel to the blocking surface (121) on the side near the blocking member (12).

5. The tangent structure according to claim 1, characterized in that, The bottom retaining spring (50) is wavy along any straight line direction in the quadrant plane.

6. The tangent structure according to claim 1, characterized in that, The moving blade (10) has a guide groove (13) on its side near the fixed blade (40) along the first direction (1). The guide groove (13) is connected to the hook groove (11) at one end and extends along the second direction (2) toward the blade head of the moving blade (10) at the other end.

7. The tangent structure according to claim 1, characterized in that, The angle between the side of the moving blade (10) away from the fixed blade (40) along the first direction (1) and the blocking surface (121) is an acute angle.

8. The tangent structure according to claim 1, characterized in that, The blocking member (12) is fixedly provided with a limiting member (14) that protrudes from the blocking member (12) along the second direction (2) away from the cutting head of the moving blade (10); and / or, The moving blade (10) has a limiting groove at the intersection of the side of the fixed blade (40) away from the first direction (1) and the blocking surface (121). The limiting groove passes through the blocking member (12) and the moving blade (10) along the third direction (3).

9. The tangent structure according to claim 3, characterized in that, The blocking surface (121) is inclined from the first support position (12a) to the second support position (12b) towards the head of the moving blade (10).

10. A double-needle sewing machine, characterized in that, Includes the tangent structure as described in any one of claims 1 to 9.

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