Thread hooking assembly and shuttle mechanism and sewing machine having the same

Abstract

The present application relates to sewing technical field, particularly to a thread hooking assembly, a shuttle mechanism, a sewing machine, a sewing method and a lock stitch; the thread hooking assembly comprises a first thread hooking part and a second thread hooking part, the first thread hooking part and the second thread hooking part can be used for thread hooking and thread unhooking; the thread hooking parts extend along the circumference of the bearing seat and are respectively formed at different positions of the outer edge of the bearing seat. In one rotation cycle, the thread hooking assembly provided by the present application can form two needle traces, the efficiency is higher, the rotation speed requirement of the shuttle mechanism is lower, the shuttle mechanism with lower rotation speed has lower cost and longer service life; and the same thread hooking assembly can hook and unhook threads in two directions, solves the problem that the inclined directions of the needle traces are inconsistent when the pattern sewing and the back sewing are performed due to the one-way skew of the needle traces, and greatly improves the appearance of the needle traces on the sewing material.

Description

Technical Field

[0001] This invention relates to the field of sewing technology, and in particular to a hook assembly, a shuttle mechanism having the hook assembly, and a sewing machine. Background Technology

[0002] Sewing machines are usually equipped with a shuttle mechanism, which contains a thread hooking component. When the top thread is driven by the needle, it passes through the fabric and needle plate, and rises a certain distance from the bottom dead center to form a thread loop. The thread hooking component is used to hook the thread loop. The thread loop and the bottom thread interweave to form a stitch unit. A stitch contains multiple stitch units.

[0003] Currently, the hook assembly can hook the thread clockwise and counterclockwise. However, on the same sewing machine, the hooking direction of the same hook assembly is unidirectional, resulting in multiple stitches that are all tilted in the same direction. This causes two adjacent stitches formed by hooking in the same direction to form a skewed stitch unit on the fabric, meaning the stitch unit is not parallel to the feed direction. This results in a significant defect in the lockstitch, causing the stitches formed by the sewing machine's forward stitch and backward stitch to have opposite tilt directions, severely affecting the appearance of the fabric. Furthermore, the shuttle mechanism can only form one stitch unit per complete reciprocating cycle, resulting in low efficiency. Summary of the Invention

[0004] In view of this, in order to solve the above-mentioned technical problems, it is necessary to provide a hook assembly, a shuttle mechanism having the hook assembly, and a sewing machine.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0006] A hook-and-loop assembly is provided for hooking a loop formed after the top thread passes through the fabric. When the hook-and-loop assembly rotates, it interweaves with the bottom thread to form a stitch, and two adjacent stitches are sewn onto the fabric to form a stitch unit. The hook-and-loop assembly includes a hook-and-loop component and a support base fixed to each other. The support base can drive the hook-and-loop component to rotate. The hook-and-loop component includes a first hook-and-loop portion and a second hook-and-loop portion, which extend circumferentially along the support base and are respectively formed on the outer edge of the support base. The hook-and-loop directions of the first hook-and-loop portion and the second hook-and-loop portion are opposite. When the support base rotates clockwise, the first hook-and-loop portion hooks a first loop, and the first loop disengages from the hook-and-loop assembly at the position of the second hook-and-loop portion. When the support base rotates counterclockwise, the second hook-and-loop portion hooks a second loop, and the second loop disengages from the hook-and-loop assembly at the first hook-and-loop portion.

[0007] In one embodiment, the first hook portion and the second hook portion are arranged symmetrically.

[0008] In one embodiment, the angle formed by the line connecting the first hook portion and the second hook portion with the axis of the bearing seat is in the range of 150° to 240°.

[0009] In one embodiment, the hook member is provided with a line-blocking part, and the line-blocking part is respectively provided in one-to-one correspondence with the first hook part and the second hook part.

[0010] In one embodiment, the two line-blocking portions corresponding to the first line-hooking portion and the second line-hooking portion are arranged symmetrically along an axis.

[0011] In one embodiment, the first hook portion and the second hook portion respectively form a wire receiving groove with the corresponding wire blocking portion.

[0012] In one embodiment, the groove is an arc-shaped groove.

[0013] The present invention also provides a shuttle mechanism, including any of the hook assembly described above.

[0014] In one embodiment, the shuttle mechanism further includes a shuttle holder for driving the hook assembly to rotate; the shuttle holder has a pushing part corresponding to the first hook part and the second hook part; the hook member is provided with a line-blocking part, the line-blocking part and the corresponding first hook part respectively forming a line-receiving groove; the pushing part is received in the line-receiving groove.

[0015] The present invention also provides a sewing machine including a shuttle mechanism, wherein the shuttle mechanism is any of the shuttle mechanisms described above.

[0016] The hook assembly and shuttle mechanism provided by the present invention have the following advantages compared with the prior art:

[0017] The thread hook assembly provided by this invention has a first hooking part and a second hooking part at both ends, capable of hooking and unhooking the thread, thus providing bidirectional hooking and unhooking functionality. In one rotation cycle, the thread hook assembly rotates clockwise for half a cycle, with the first hooking part hooking the thread in the forward direction to form a stitch. Then, the thread hook assembly rotates counterclockwise for half a cycle, with the second hooking part hooking the thread in the reverse direction to form another stitch. Therefore, two stitches can be formed in one rotation cycle. In contrast, existing sewing machines can only form one stitch in one rotation cycle. This demonstrates that the thread hook assembly of this invention is more efficient and requires a lower rotational speed from the shuttle mechanism. A lower-speed shuttle mechanism is less expensive, has a longer lifespan, and is less prone to damage.

[0018] Because the bobbin thread passes through the loop in one direction, the loop is pulled in a single direction by the bobbin thread, resulting in a stitch that is tilted in one direction. On the same sewing machine, the hook assembly of this application can achieve both forward and reverse hooking. The stitches formed by forward and reverse hooking are in opposite directions. Therefore, forward hooking is used when the sewing machine is sewing forward, and reverse hooking is used when the sewing machine is sewing backward. The stitches formed by forward and backward sewing are in the same tilt direction, solving the problem of inconsistent stitch tilt direction during pattern sewing and backward sewing caused by unidirectional stitch skew, and greatly improving the aesthetics of the stitches on the fabric.

[0019] Furthermore, since the stitches formed by forward and reverse stitching are in opposite directions, if a stitch unit is formed by stitches formed by forward and reverse stitching, the top line between the two stitches is subjected to pulling forces from the bottom line in two opposite directions. These two pulling forces cancel each other out, thus preventing stitch skewing in the resulting stitch unit. Therefore, the stitches formed by the stitching assembly provided in this application through alternating forward and reverse stitching do not have a skewing problem.

[0020] Even better, since the hook assembly provided by the present invention can hook along any forward and reverse direction on the same sewing machine, it can form a variety of more beautiful and superior new lockstitches on the fabric, satisfying users' aesthetic needs for stitches and having a wider range of applications. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the hook assembly in the initial hook state in the prior art (the needle reaches the bottom dead center, and the top thread passes through the sewing material to form a loop);

[0022] Figure 2 A schematic diagram of the hooking assembly in the prior art;

[0023] Figure 3 This is a schematic diagram of the existing hook assembly when it has rotated half a cycle (the loop disengages from the hook assembly);

[0024] Figure 4 This is a schematic diagram of stitch formation in the prior art (the loop tightens, the top and bottom threads interweave to form a stitch, and at this time the hook assembly rotates to return to its initial position);

[0025] Figure 5 This is a schematic diagram of the structure of a shuttle mechanism provided in one embodiment of the present invention;

[0026] Figure 6 for Figure 5 A schematic diagram of the shuttle mechanism in the image, with the shuttle core and shuttle cover removed;

[0027] Figure 7 This is a schematic diagram of the structure of a hook assembly provided in one embodiment of the present invention;

[0028] Figure 8 This is a schematic diagram of the initial state of the hook-and-loop assembly (the needle reaches the bottom dead center, and the top thread passes through the fabric to form the first loop).

[0029] Figure 9 A schematic diagram of the first hooking part of the hooking assembly in the forward hooking direction;

[0030] Figure 10 A schematic diagram showing the forward rotation of the hook assembly until the hook loop disengages from the second hook section from the shuttle mechanism;

[0031] Figure 11 This is a schematic diagram of the hook assembly rotating clockwise for half a cycle (the loop tightens, and the top and bottom threads interweave to form the first stitch).

[0032] Figure 12 A schematic diagram showing the second hooking part of the hooking assembly in the hooking state when the fabric is moved by one stitch length (the needle reaches the bottom dead center again, and the top thread passes through the fabric to form a second loop).

[0033] Figure 13 This is a schematic diagram showing the state of the second hook of the hook assembly when it is hooked in the reverse direction.

[0034] Figure 14 A schematic diagram showing the reverse rotation of the hook assembly until the hook loop disengages from the first hook part from the shuttle mechanism;

[0035] Figure 15 This is a schematic diagram of the hook-and-loop assembly rotating clockwise for one cycle; (the loop tightens, and the top and bottom threads interweave to form the second stitch); Figure 16 This is a schematic diagram of a novel straight-line lockstitch A provided in one embodiment of the present invention;

[0036] Figure 17 This is a schematic diagram of the zigzag lockstitch B formed when the sewing machine is sewing forward in one embodiment of the present invention;

[0037] Figure 18 This is a schematic diagram of the zigzag lockstitch C formed when the sewing machine backstitches in one embodiment of the present invention;

[0038] Figure 19 This is a schematic diagram of the straight-line lockstitch numbered 301 in the prior art;

[0039] Figure 20 This is a schematic diagram of the zigzag lockstitch numbered 304 in the prior art.

[0040] Explanation of main component symbols

[0041]

[0042]

[0043] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] It should be noted that when a component is said to be "mounted on" another component, it can be directly mounted on the other component or may be interspersed with a component. When a component is said to be "set on" another component, it can be directly set on the other component or may be interspersed with a component. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or may be interspersed with a component.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] A sewing machine is a machine that uses one or more sewing threads to form a loop of stitch units on the fabric by self-connecting, interconnecting, or interlacing the sewing threads. Multiple stitch units form one or more stitches on the fabric, allowing one or more layers of fabric to be interlaced or sewn together.

[0048] The sewing machine provided in one embodiment of the present invention (not shown in the figure) mainly includes a machine head (not shown in the figure) and a machine base (not shown in the figure). The machine base is used to support the machine head and to be used as a workbench during sewing operations. The machine head is equipped with a feeding mechanism (not shown in the figure), a shuttle mechanism 100, a thread take-up mechanism (not shown in the figure), a feeding mechanism (not shown in the figure), and other mechanisms. The movements of each mechanism are reasonably coordinated and work in a cycle to sew the fabric together.

[0049] The needle piercing mechanism includes a needle 13, which is used to pierce the fabric and drive the top thread through the fabric and guide the top thread to form a loop; the shuttle mechanism 100 is used to hook the loop so that the loop covers the bottom thread; the take-up mechanism pulls the loop tight so that the loop and the bottom thread interweave in the fabric to form a stitch; the feed mechanism drives the fabric to move one stitch length; the sewing machine repeats the above steps to form another stitch; two adjacent stitches form a stitch unit 40 on the fabric; multiple stitch units 40 form a lockstitch.

[0050] Please see Figure 5-7 An embodiment of the present invention provides a shuttle mechanism 100, which includes a hook assembly 15. The hook assembly 15 is used to hook the thread loop formed after the top thread passes through the sewing material. When the hook assembly 15 rotates, the thread loop can interweave with the bottom thread to form a stitch. Two adjacent stitches are sewn onto the sewing material to form a stitch unit.

[0051] The shuttle mechanism 100 also includes a shuttle holder 11, a first shuttle shaft 12, a bobbin (not labeled in the figure), and a bobbin case. The hook assembly 15 has a second shuttle shaft 153, with the bobbin thread wound around the bobbin's spindle. The bobbin is rotatably mounted on the first shuttle shaft 12, and the bobbin case covers the bobbin. The hook assembly 15 is mounted on the shuttle holder 11, which is installed on the first shuttle shaft 12 and can rotate with it. The shuttle holder 11 supports and drives the hook assembly 15 to rotate and hook the thread.

[0052] In traditional shuttle mechanisms, the thread hooking assembly can only hook the thread in one direction within the same sewing machine. This results in only one stitch unit being formed per complete reciprocating cycle of the shuttle mechanism, leading to low efficiency. To improve efficiency, the oscillation efficiency of the shuttle mechanism must be increased, thus requiring higher rotational speeds in current technologies. However, high-speed shuttle mechanisms often have shorter lifespans. For details on the thread hooking process of traditional assemblies, please refer to [link / reference needed]. Figure 1-4 ,like Figure 1 As shown, the needle drives the thread through the fabric and forms a loop below the fabric; Figure 2 As shown, the hook assembly rotates clockwise to hook the loop, and as the hook assembly continues to rotate clockwise, the loop slowly expands; Figure 3 As shown, when the hook section of the hook assembly rotates to the lower turning point, the loop detaches from the hook assembly and interweaves with the bobbin thread. At this point, the take-up mechanism tightens the top thread, causing the loop to tighten, and the loop and bobbin thread interweave in the fabric to form a stitch; as shown Figure 4 As shown, after the stitch is formed, the hook assembly rotates counterclockwise, causing the hook assembly to return to its original position. Figure 1The next stitching operation can only be performed in the initial state shown. Furthermore, because traditional stitching components can only perform unidirectional stitching within the same sewing machine and cannot reverse direction, the resulting stitches are crooked, affecting the aesthetics of the fabric, especially when sewing thin materials, where the stitches are particularly unsightly and have become an unsolvable industry problem. Especially when performing forward and backward stitches, the stitches of the forward and backward stitches are crooked in opposite directions, forming a figure-eight pattern on the fabric, severely impacting its appearance. Moreover, traditional stitching components can only continuously perform unidirectional stitching within the same sewing machine, resulting in a limited variety of lockstitch types that fail to meet users' aesthetic needs.

[0053] Please continue reading. Figure 5-7 In one embodiment of the present invention, a hook assembly 15 is provided, including a hook member 151 and a support base 152 fixed to each other. The support base 152 can drive the hook member 151 to rotate, and a second bobbin 153 for mounting the bobbin 13 is provided on the support base 152; the hook member 151 includes a first hook part 1511 and a second hook part 1512. The first hook portion 1511 and the second hook portion 1512 extend circumferentially along the support base 152 and are respectively formed at different positions on the outer edge of the support base 152. Both the first hook portion 1511 and the second hook portion 1512 can be used for hooking and unhooking. When the support base 152 rotates clockwise, the first hook portion 1511 can hook the first loop in the forward direction, and the first loop is released from the hook assembly 15 by the second hook portion 1512. When the support base 152 rotates counterclockwise, the second hook portion 1512 hooks the second loop in the reverse direction, and the second loop is released from the hook assembly 15 by the first hook portion 1511. The first hook portion 1511 and the second hook portion 1512 are the unhooking portions of each other, so the hook assembly 15 has the functions of bidirectional hooking and double-line unhooking.

[0054] It is understood that within one rotation cycle, the hook assembly 15 provided by the present invention rotates clockwise for half a cycle, the first hooking part 1511 hooks the thread in the forward direction, forming a stitch. Then, the hook assembly 15 rotates counterclockwise for half a cycle, the second hooking part 1512 hooks the thread in the reverse direction, forming another stitch. Thus, two stitches can be formed within one rotation cycle, while existing sewing machines can only form one stitch per rotation cycle. Therefore, the hook assembly 15 of the present invention is more efficient and requires a lower rotational speed from the shuttle mechanism 100. The lower-speed shuttle mechanism 100 is also cheaper, has a longer lifespan, and is less prone to damage.

[0055] Furthermore, the first hooking part 1511 and the second hooking part 1512 are arranged symmetrically to ensure that the first hooking part 1511 and the second hooking part 1512 are subjected to balanced force when rotating to hook the thread, and rotate smoothly. This ensures that the stitches formed by the hooking assembly 15 are uniform whether hooking the thread clockwise or counterclockwise, and that the width of the formed stitch units is uniform, preventing the stitches from becoming obviously skewed.

[0056] The angle formed by the line connecting the first hook portion 1511 and the second hook portion 1512 to the axis of rotation of the support 152 is in the range of 150° to 240°, ensuring that the loop can smoothly unwind when the first hook portion 1511 and the second hook portion 1512 hook the line and rotate to the next turning point. In this embodiment, it is preferable that the first hook portion 1511 and the second hook portion 1512 are on the same straight line as the axis of rotation of the support 152. Of course, in other embodiments, this angle range is not limited to the range described above, and may be less than 150° or greater than 240°.

[0057] Furthermore, the hook member 151 is provided with two line-blocking portions 1513. The two line-blocking portions 1513 are respectively configured to correspond one-to-one with the first hook portion 1511 and the second hook portion 1512, and the first hook portion 1511 and the second hook portion 1512 respectively form a line-receiving groove 1514 with the corresponding line-blocking portion 1513. Specifically, the first hook portion 1511 or the second hook portion 1512 hooks the line loop, and the line-blocking portion 1513 blocks the line loop, ensuring that the line loop remains confined within the line-receiving groove 1514 until the hook member 151 rotates to the next turning point, preventing the line loop from prematurely detaching from the hook assembly 15.

[0058] Furthermore, the shuttle 11 has a pushing part 111 corresponding to the first hook part 1511 and the second hook part 1512; the two pushing parts 111 are respectively housed in the wire receiving groove 1514, and there is a gap between the pushing part and the wire receiving groove for the wire ring to pass through; when the shuttle rotates, the pushing part applies a thrust to the corresponding wire receiving groove, thereby pushing the corresponding first hook part 1511 or second hook part 1512 to rotate. By extending the pushing part 111 into the corresponding wire receiving groove 1514, the pushing part 111 is difficult to disengage from the wire receiving groove 1514 when the shuttle 11 rotates, thus making it safer and more stable for the pushing part 111 to push the hook assembly 15.

[0059] Since the first hook section and the second hook section are each other's unhooking sections, a gap is formed between the pushing part 111 and the corresponding thread receiving groove 1514 for hooking and unhooking. It can be understood that the hooking gap corresponding to the first hook section is the unhooking gap of the second hook section, and vice versa. Specifically, after the first hook section hooks the thread loop, the thread loop enters the thread receiving groove from the hooking gap at the first hook section. The thread loop gradually expands until it wraps around the shuttle housing, until it moves out of the space between the driving member and the shuttle housing. After the thread loop continues to tighten, it unhooks from the unhooking gap at the second hook section and disengages from the shuttle mechanism.

[0060] Specifically, in one embodiment, see [reference] Figure 3 The shuttle 11 includes a radially extending crank arm 112 and an arc-shaped drive member 113 disposed on the outer edge of the crank arm 112. Pushing parts 111 are respectively disposed at both ends of the drive member 113. The crank arm 112 is rotatably mounted on the first shuttle shaft 12. The two ends of the arc-shaped drive member 113 correspond one-to-one with the two line-receiving grooves 1514 of the hook member 151. When the drive member 113 rotates, the pushing parts 111 at both ends of the drive member 113 respectively push the hook member 151 to achieve smooth rotation.

[0061] Further, see Figure 3 The two line-blocking parts 1513, which correspond to the first line-hooking part 1511 and the second line-hooking part 1512 respectively, are arranged symmetrically to ensure that the line-hooking assembly 15 has a symmetrical structure, the force is balanced when the line is rotated, and the line is hooked smoothly to form a neat and uniform line unit.

[0062] As a preferred option, see [reference] Figure 6 , 7 The thread-receiving groove 1514 is an arc-shaped groove, so when the first hooking part 1511 and the second hooking part 1512 hook the thread loop into the thread-receiving groove 1514, the thread loop contacts the arc-shaped groove wall, which can prevent the groove wall from wearing down the thread loop. If the groove wall has sharp edges, the thread loop will easily wear down when sliding in the thread-receiving groove. Since the hooking assembly 15 provided by the present invention can rotate clockwise for forward hooking and counterclockwise for reverse hooking, a variety of new lockstitches can be formed on the same sewing machine by using the hooking assembly 15 provided by the present invention, and the application range is wider; while the hooking assemblies in the prior art cannot form the new lockstitches formed in this application.

[0063] The following example illustrates the process by which the hook assembly 15 forms a new type of lockstitch, and the differences and advantages of the new type of stitch compared to existing lockstitches.

[0064] Existing lockstitch stitches are classified according to international standards as follows: Figure 19The stitch number shown is a type 301 lockstitch 500, where the included angle between adjacent stitch units 40 is 180°, forming a straight stitch; as shown... Figure 20 The stitch number shown is 304, a type 304 lockstitch 600, which is a zigzag stitch. It can be understood that a zigzag stitch is formed by moving the needle insertion point back and forth in a Z-shape, so that the included angle between adjacent stitch units 40 is less than 180°. When the hook member 151 rotates clockwise, the first hook part 1511 hooks the first loop formed by the top thread. The hook member 151 continues to rotate until the first hook part 1511 is at the lower turning point. The first loop detaches from the hook assembly from the thread stop part 1513 and interweaves with the bobbin thread. Then, the first loop detaches from the shuttle mechanism 100 through the thread release gap at the second hook part 1512. The first loop interweaves with the bobbin thread and tightens to form the first stitch 20. After the sewing material is fed one stitch length, the hook member 151 rotates counterclockwise, and the second hook part 1512 hooks the second loop formed by the top thread in the opposite direction. The hook member 151 continues... Continue rotating until the second hook part 1512 is at the lower turning point, the second thread loop separates from the bobbin mechanism 100 from the thread release gap at the first hook part 1511 and interweaves with the bottom thread to form the second stitch 30; during sewing, the hook assembly 15 can rotate arbitrarily counterclockwise and / or clockwise to form a variety of lockstitches different from those in the prior art, which are formed by any combination of the first stitch 20 and the second stitch 30. Thus, the sewing machine using the hook assembly provided by this invention can sew a variety of new lockstitches, satisfying users' aesthetic needs for the stitches on clothing and other fabrics, and has a wide range of applications.

[0065] For details, please refer to Figure 8-18 Within one rotation cycle, the hook assembly 15 completes both forward and reverse hooking. The hooking process of the hook assembly 15 is as follows. First, as... Figure 8 As shown, after the needle 13 drives the top thread through the fabric to the bottom dead center, the needle 13 then rises a certain distance, causing the top thread to form the first loop below the fabric. At this time, the hook assembly 15 is in the position shown in the image. Figure 8 The initial state is shown; then as shown Figure 9 As shown, the hook assembly 15 rotates clockwise, and the first hook part 1511 hooks the first thread loop, causing the thread loop to enter the thread receiving groove 1514 from the hook gap at the first hook part 1511. At this time, the needle 13 continues to rise upward, while the first thread loop is blocked by the thread blocking part and located in the thread receiving groove 1514. The hook assembly 15 continues to rotate clockwise, and the first thread loop gradually expands until it wraps around the shuttle housing 14, causing the bobbin thread to intertwine with the first thread loop; as shown Figure 10 As shown, when the hook assembly rotates half a cycle to Figure 10In the state shown, the first hook section 1511 reaches the lower turning point, the first thread loop passes over the thread stop section 1513 and disengages from the hook assembly 15 at the stop tip of the thread stop section. At this time, the needle reaches the top dead center and then slowly descends again, and the hook assembly 15 remains stationary. Figure 11 At the angle shown, the feeding mechanism drives the sewing fabric to move one stitch length, and the take-up mechanism tightens the top thread, causing the first thread loop to disengage from the shuttle mechanism 100 through the thread release gap at the second hook section 1512. The thread loop interweaves with the bobbin thread to form the first stitch 20. Figure 12 As shown, the needle 13 continues to descend to the bottom dead center, forming a second thread loop. At this time, the hook assembly 15 rotates counterclockwise, and the second hook part 1512 hooks the second thread loop, causing the thread loop to enter the thread receiving groove 1514 from the hook gap at the second hook part 1511. The hook assembly 15 continues to rotate counterclockwise (as shown). Figure 13 As shown), the second loop gradually expands until it wraps around the shuttle housing 14, causing the bottom thread to intertwine with the second loop; when the hook assembly 15 rotates counterclockwise half a cycle to Figure 14 In the state shown, the second hook section 1512 reaches the lower turning point, the second thread loop crosses the thread stop section 1513 and disengages from the hook assembly 15 from the thread stop section corresponding to the second hook section 1512, at which point the needle reaches the top dead center for the second time; as shown Figure 15 As shown, the needle begins to descend slowly again, the feeding mechanism moves forward by one stitch length, the thread take-up mechanism tightens the second thread loop, so that the second thread loop is separated from the shuttle mechanism from the thread release gap at the first hook part 1511, the second thread loop and the bottom thread intertwine in the sewing material to form the second stitch 30, the hook assembly completes one rotation cycle, and the hook assembly returns to the initial state.

[0066] See Figure 16-18 When the thread-hooking assembly 15 rotates for one cycle, the first stitch 20 and the second stitch 30 connect with the fabric to form a stitch unit 40. The thread-hooking assembly 15 rotates back and forth for several cycles, alternately completing forward and reverse stitching. The first stitch 20 and the second stitch 30 are alternately formed on the fabric, meaning each stitch unit includes both a first stitch 20 and a second stitch 30. Based on this stitching process, using a straight-line sewing method, a stitch unit 40 is formed as follows: Figure 16 The straight-line lockstitch A200 shown, if stitched using a zigzag method, will form as follows: Figure 17 The example shown is the B300 zigzag lockstitch.

[0067] Alternating forward and reverse stitching has the following advantages: If there is no fabric between the top and bottom threads, or if there is no fabric under the presser foot of the sewing machine (not shown in the figure) for sewing (i.e., a no-fabric-seam condition), the needle 13 will move without fabric. In the no-fabric-seam condition, the stitch unit 40 formed by the existing stitch assembly 15 is a braid, with the top and bottom threads intertwined to form a thick rope, greatly affecting the aesthetics. In this invention, because the stitch assembly 15 can alternate between forward and reverse stitching, in the no-fabric-seam condition, the interweaving of the top thread b and bottom thread a between adjacent stitches will cancel each other out and not form stitch unit 40, avoiding the formation of braids. In addition, alternating forward and reverse stitching allows for two stitches to be completed in one rotation cycle, significantly improving sewing efficiency. Of course, in other embodiments, the stitching method of the stitch assembly 15 is not limited to the above description. For example, the stitch assembly 15 can perform any reverse and forward stitching to form more types of stitches. For example, if the hook assembly always hooks in the forward direction or always hooks in the reverse direction, it forms a 301 type lock stitch 500.

[0068] Currently, traditional hook stitch assemblies result in a lockstitch that is unidirectionally tilted. For details, please refer to [link / reference]. Figure 19 The bottom thread a passes through the loop of the top thread b to form stitch S1. The bottom thread a continues to pass through the loop of the top thread b in the same direction to form stitch S2. Both the bottom thread a and the top thread b within the stitch unit 40 formed by stitches S1 and S2 exhibit a skewed phenomenon, rather than extending forward in a straight line. In other words, the bottom thread a and the top thread b sewn onto the fabric are not aligned with the direction of fabric transport. This repeated process results in a continuous, unidirectional skewed stitch 500, which is particularly unsightly when sewing on thin fabrics, becoming an unsolvable industry problem. Since the hook assembly 15 of this invention can hook in both directions, through alternating forward and reverse hooking, see [reference needed]. Figure 16 This ensures that the top thread b and bottom thread a in the adjacent first stitch 20 and second stitch 30 extend in a straight line along the direction of fabric conveying, thus solving the industry-wide problem of skewed stitches.

[0069] For details, please refer to Figure 17 and Figure 18 , Figure 17 This is a schematic diagram of the zigzag lockstitch B formed when a sewing machine is sewing forward. Figure 18 This is a schematic diagram of the zigzag lockstitch C formed during a backstitch. The sewing machine drives the fabric to feed and sew in a first direction (forward stitch), and then drives the fabric to feed and sew in a second direction (backstitch). The first and second directions are opposite. (See also...) Figure 17During the forward stitching, the support seat 152 rotates clockwise, and the first hooking part 1511 hooks the thread in the forward direction to form a forward stitch 21; the support seat 152 rotates counterclockwise, and the second hooking part 1512 hooks the thread in the reverse direction to form a reverse stitch 31; see reference. Figure 18 When sewing backwards, the support seat 152 rotates clockwise, and the first hooking part 1511 hooks the thread in the forward direction to form a backwards stitch 22; the support seat 152 rotates counterclockwise, and the second hooking part 1512 hooks the thread in the reverse direction to form a backwards stitch 32. The forward stitch 21 and the backwards stitch 32 have the same inclination direction, and the forward stitch 31 and the backwards stitch 22 have the same inclination direction. In other words, during sewing, as long as the hooking directions of the forward and backward stitches are exactly opposite at the corresponding positions on the fabric, the resulting stitches will have the same inclination direction and the same direction of skew, effectively solving the problem of inconsistent stitch skew directions during forward and backward sewing in the prior art.

[0070] On the fabric, Figure 17 21 and the straight crochet stitch Figure 18 The reverse hook stitch at position 32 corresponds to... Figure 17 31 and the reverse hook stitch Figure 18 The position of the reverse stitch and the forward stitch 22 corresponds to the position of the stitch, by Figure 17 , Figure 18 As can be seen from the comparison, during forward and backward stitching, the hooking directions are opposite at corresponding positions on the fabric, resulting in stitches and lines with the same tilt direction. For example, during forward stitching, the 301 type lockstitch 500 formed entirely by the hooking component 15 in the forward direction has the same tilt direction as the 301 type lockstitch 500 formed entirely by the hooking component 15 in the reverse direction during backward stitching. Therefore, it can be seen that... Figure 17 and Figure 18 The stitches shown are identical and visible to the naked eye on the fabric, solving the problem of inconsistent stitches on the fabric when sewing forwards and backwards.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any appropriate changes and variations made to the above embodiments within the essential spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A hook-and-loop assembly for hooking a loop of thread formed after the top thread passes through the fabric, the loop of thread interlacing with the bottom thread to form a stitch when the hook-and-loop assembly rotates, two adjacent stitches being sewn onto the fabric to form a stitch unit; the hook-and-loop assembly includes a hook-and-loop component and a support base fixed to each other, the support base being capable of driving the hook-and-loop component to rotate, characterized in that, The hooking component includes a first hooking portion and a second hooking portion, which are arranged symmetrically on an axis. The first hooking portion and the second hooking portion extend along the circumference of the support base and are respectively formed on the outer edge of the support base. The hooking directions of the first hooking portion and the second hooking portion are opposite. In this process, when the support seat rotates clockwise for half a cycle, the first hook part hooks the first loop, and the first loop disengages from the hook assembly at the position of the second hook part; when the support seat rotates counterclockwise for half a cycle, the second hook part hooks the second loop, and the second loop disengages from the hook assembly at the first hook part.

2. The hook assembly according to claim 1, characterized in that, The angle formed by the line connecting the first hook part and the second hook part to the axis of the bearing seat is in the range of 150° to 240°.

3. The hook assembly according to claim 1, characterized in that, The hook-and-line component is provided with a line-blocking part, which is respectively provided in one-to-one correspondence with the first hook-and-line part and the second hook-and-line part.

4. The hook assembly according to claim 3, characterized in that, The two line-blocking portions corresponding to the first line-hooking portion and the second line-hooking portion are arranged symmetrically along an axis.

5. The hook assembly according to claim 3, characterized in that, The first hook portion and the second hook portion respectively form a wire receiving groove with the corresponding wire blocking portion.

6. The hook assembly according to claim 5, characterized in that, The groove is an arc-shaped groove.

7. A shuttle mechanism, characterized in that, Includes the hook assembly as described in any one of claims 1-6.

8. The shuttle mechanism according to claim 7, characterized in that, It also includes a shuttle for driving the hook assembly to rotate; the shuttle has a pushing part corresponding to the first hook part and the second hook part. The hooking member is provided with a line-blocking part, and the line-blocking part forms a line-receiving groove with the corresponding first hooking part and the first hooking part; the pushing part is housed in the line-receiving groove.

9. A sewing machine, comprising a shuttle mechanism, characterized in that, The shuttle mechanism is the shuttle mechanism as described in claim 8.

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