A latch needle driving device of a shell type pattern sewing machine

Abstract

A latch needle drive device for a shell-shaped pattern sewing machine, belonging to the field of sewing machinery technology, includes a power module connected to the sewing machine drive source and a lower main shaft; a latch needle body for cooperating with the needle to wind and knot the thread and complete compound motion; and a vertical swing drive module and a front-back motion drive module. The vertical swing drive module drives the latch needle body to reciprocate vertically through a latch needle vertical swing cam mounted at the front end of the lower main shaft. The front-back motion drive module adopts a cam transmission structure and includes a latch needle front-back motion cam, a cam positioning sleeve, a latch needle front-back motion roller, and a latch needle front-back motion connecting rod, and drives the latch needle body to reciprocate back and forth. The amount of front-back motion of the latch needle body is controlled by adjusting the contour curve of the latch needle front-back motion cam track groove, so that the latch needle body and the needle cooperate to form different types of chain edge stitches. The dual cam drive provides a rich variety of stitches, precise power synchronization, convenient adjustment, compact structure, and strong adaptability.

Description

Technical Field

[0001] This utility model belongs to the field of sewing equipment technology, specifically relating to a tongue needle drive device for a shell-shaped pattern sewing machine. Background Technology

[0002] In the sewing processing field of footwear, bags, textiles, and apparel industries, pattern sewing machines have become core production equipment due to their ability to sew complex patterns automatically. The latch needle drive device, as a key component, directly determines the precision of the latch needle's fit with the machine needle, the thread wrapping and knotting effect, and thus affects the forming quality of the sewn pattern, the stability of the stitches, and the machine's working efficiency. Among these, shell-shaped pattern sewing machines, capable of sewing decorative and three-dimensional shell-shaped stitches, are increasingly in demand in high-end apparel decoration and shoe upper processing. With the revival of Chinese aesthetics and the rise of personalized customization trends, the market has placed higher demands on the diversified presentation and sewing adaptability of shell patterns.

[0003] However, the latch drive mechanisms of mainstream pattern sewing machines currently on the market, especially those designed for sewing shell-shaped patterns, generally have significant defects, severely restricting product performance and application range. From an industry-wide perspective, most drive mechanisms suffer from complex structural designs and dispersed power transmission paths. They rely on multiple independent power sources or multiple spindles to drive the latch's up-and-down and forward-and-backward movements, resulting in a loose equipment layout, difficult assembly, and susceptibility to latch trajectory deviation due to synchronization errors of multiple power sources, leading to stitch misalignment, needle breakage, and other malfunctions. Furthermore, the latch position adjustment lacks flexibility; the horizontal position is often fixed or requires disassembly of multiple components for fine-tuning, making it impossible to quickly adapt to sewing needs with different fabric thicknesses and thread diameters. Additionally, the transmission components lack stable limiting and support structures, making them prone to wear, vibration, and abnormal noise under long-term high-speed operation, shortening equipment lifespan and increasing maintenance costs. More importantly, the shortcomings of existing drive structures are particularly prominent in specific scenarios involving shell-shaped pattern sewing, becoming a core bottleneck restricting the realization of shell patterns and the expansion of diverse stitches. On the one hand, mainstream pattern shell sewing machines adopt a combination structure of double cams and sliding guide rails. The double cams are driven by gear meshing, and during assembly, it is necessary to strictly ensure that the gears have no misaligned teeth. Although nominally a double cam structure, it actually forms a single fixed planetary motion trajectory. This not only makes the structure complex and extremely difficult to assemble, but also has a fundamental lack of adjustability, making it impossible to adjust the latch needle movement parameters according to pattern requirements or fabric characteristics. On the other hand, the cam and crank combination structure used in flatbed pattern sewing machines, although controlling the latch needle to swing up and down through the cam and controlling the forward and backward movement through the crank, has a flaw in the motion trajectory design: the forward and backward movement of the latch needle when it moves above and below the needle is always equal, resulting in only one type of needle looping method, the edge chain stitch, which is completely unable to realize the sewing of shell patterns on a flat surface. This greatly limits the richness of stitch combinations and makes it difficult to meet the market's diverse needs for personalized shell patterns. In addition, the double cam structure of some shell sewing machines is installed in an unreasonable position, with the overall height being significantly higher than the needle plate surface. This results in the inability to form a flat operating platform around the needle plate. When sewing workpieces that require rotating operation, such as shoe uppers, the movement of the sewing material is obstructed, further limiting the processing adaptability of complex shaped sewing materials.

[0004] The combination of these problems means that existing drive devices cannot solve the industry-wide issues of structural integration, motion synchronization, and ease of adjustment, nor can they overcome the core pain points unique to shell-shaped pattern sewing, such as single stitch type, non-adjustable structure, and poor operational adaptability. Therefore, developing a shell-shaped pattern sewing machine latch drive structure with high structural integration, precise synchronous power transmission, convenient adjustment of latch motion parameters, and the ability to specifically solve the problems of shell-shaped pattern sewing and enrich stitch combinations has become the key to breaking through the industry's technical bottleneck and meeting the market's personalized sewing needs. Utility Model Content

[0005] The objective of this invention is to provide a compact, easily adjustable, and conveniently installed latch drive device for a shell-shaped pattern sewing machine. This device facilitates the expansion of stitch types through a dual-cam drive structure and effectively addresses industry pain points such as the complex structure, limited stitch types, and poor adaptability of existing shell-shaped pattern sewing machine latch drive devices. It also helps to achieve integrated power transmission and synchronized and precise control of latch movement through structural innovation.

[0006] The present invention achieves its objective as follows: a latch needle drive device for a shell-shaped pattern sewing machine, comprising: a power module, which is connected to the drive source of the pattern sewing machine, and includes a lower main shaft serving as a unified power output shaft; a latch needle body, which cooperates with the needle of the pattern sewing machine to perform thread winding and knotting actions, and is capable of performing compound movements in both vertical and horizontal directions; characterized in that it further comprises: a vertical swing drive module, which converts the rotational motion of the lower main shaft into the vertical reciprocating motion of the latch needle body, and includes a latch needle vertical movement cam mounted on the front end of the lower main shaft; and a horizontal movement drive module, which converts the rotational motion of the lower main shaft into the horizontal reciprocating motion of the latch needle body. The module adopts a cam transmission structure and includes a latch needle forward and backward movement cam that rotates synchronously with the lower main shaft, a cam positioning sleeve, a latch needle forward and backward movement roller, and a latch needle forward and backward movement connecting rod. The latch needle forward and backward movement cam is connected to the lower main shaft through the cam positioning sleeve. A latch needle forward and backward movement cam track groove is provided on the outer circumferential surface of the latch needle forward and backward movement cam. The latch needle forward and backward movement roller is installed in the latch needle forward and backward movement cam track groove and can be driven by the latch needle forward and backward movement cam to perform reciprocating motion. The latch needle forward and backward movement connecting rod is connected to the latch needle forward and backward movement roller and can drive the latch needle body to move in the forward and backward direction through the transmission component. The forward and backward movement of the latch needle body is controlled by adjusting the contour curve of the latch needle forward and backward movement cam track groove, so as to form different types of chain edge stitches when the latch needle body is in conjunction with the needle.

[0007] In a specific embodiment of this utility model, the forward and backward movement cam of the latch is a first-type cam, and the track groove of the forward and backward movement cam is a closed-loop curved groove extending circumferentially along the outer peripheral surface of the first-type cam; and the contour curve of the track groove of the forward and backward movement cam of the latch includes a large stroke segment and a small stroke segment, the large stroke segment and the small stroke segment are two reciprocating motion segments with different radial displacements and are alternately distributed along the circumferential direction of the forward and backward movement cam of the latch; the radial offset of the contour curve of the large stroke segment corresponds to the large stroke movement of the latch body, and the radial offset of the contour curve of the small stroke segment corresponds to the small stroke movement of the latch body; and the large stroke segment and the small stroke segment... The stroke segments are connected end to end by smoothly transitioning curved segments to form a continuous closed loop track; when the forward and backward movement cam of the latch needle rotates with the lower main shaft, the large stroke segment and the small stroke segment of the track groove of the forward and backward movement cam of the latch needle coordinate with the up and down movement cam of the up and down swing drive module, so that the latch needle body performs a large stroke above the needle to penetrate the sewing loop and performs a small stroke below the needle to avoid penetrating the sewing loop; or the forward and backward movement cam of the latch needle rotates 180° relative to the up and down movement cam of the latch needle and then the two coordinate, so that the latch needle body performs opposite movements in the up and down directions, thereby forming different types of chain edge stitches.

[0008] In another specific embodiment of this utility model, the latch needle forward and backward movement cam is a second type of cam, and the latch needle forward and backward movement cam track groove is a closed-loop curved groove extending circumferentially along the outer peripheral surface of the second type of cam; the contour curve of the latch needle forward and backward movement cam track groove includes two equidistant movement segments with equal radial displacement, the radial offset of the contour curves of the two equidistant movement segments is consistent, and the two are symmetrically distributed along the axial axis of the latch needle forward and backward movement cam, and the two equidistant movement segments are connected by a smooth transition curve segment to form a continuous closed-loop track; when the latch needle forward and backward movement cam rotates with the lower main shaft, the two sets of equidistant movement segments of the latch needle forward and backward movement cam track groove cooperate with the latch needle up and down movement cam of the up and down swing drive module to make the latch needle body perform equal stroke movements above and below the needle to penetrate the sewing loop, thereby forming a compound loop chain edge stitch.

[0009] In another specific embodiment of this utility model, the tongue needle forward and backward movement cam of the forward and backward movement drive module is fixedly installed at the middle position of the lower main shaft along its length. The tongue needle forward and backward movement cam is axially positioned by a cam positioning sleeve to prevent it from shifting during the rotation of the lower main shaft. A vertically arranged tongue needle forward and backward movement roller pin is also inserted in the tongue needle forward and backward movement roller. The top end of the tongue needle forward and backward movement roller pin is hinged to the tongue needle forward and backward movement connecting rod, realizing the transmission connection between the tongue needle forward and backward movement roller and the tongue needle forward and backward movement connecting rod. This allows the rotational motion of the tongue needle forward and backward movement cam to be converted into the reciprocating oscillation of the tongue needle forward and backward movement connecting rod through the tongue needle forward and backward movement roller. The tongue needle forward and backward movement connecting rod has a rod-shaped structure, and one end of the tongue needle forward and backward movement connecting rod along its length is connected to the tongue needle forward and backward movement roller. The front and rear moving roller pins of the latch needle are connected, and the other end of the latch needle front and rear moving linkage in the length direction is hinged to the transmission component through a latch needle front and rear moving linkage pin to ultimately drive the latch needle body to move in the front and rear direction. At the end of the latch needle front and rear moving linkage away from the latch needle front and rear moving roller pin, a latch needle front and rear stroke adjustment groove is also provided. By adjusting the installation position of the latch needle front and rear moving linkage pin in the latch needle front and rear stroke adjustment groove, the front and rear stroke range of the latch needle body can be adjusted. At the upper position of the latch needle front and rear moving linkage, a moving linkage positioning bracket is also provided. The moving linkage positioning bracket is a fixed support and is installed in the sewing machine base. The moving linkage positioning bracket is rotatably connected to the latch needle front and rear moving linkage through a hinge shaft to provide a swing positioning reference for the latch needle front and rear moving linkage.

[0010] In another specific embodiment of this utility model, the power module is connected to a drive shaft disposed within the pattern sewing machine; the power module further includes an upper synchronous pulley, a synchronous belt, and a lower synchronous pulley. The upper synchronous pulley is fixedly mounted on the main drive shaft of the pattern sewing machine and can rotate synchronously with the drive shaft. The lower synchronous pulley is fixedly mounted at the rear of the lower main shaft body. The synchronous belt is sleeved between the outer circumferential surfaces of the upper and lower synchronous pulleys and transmits power synchronously through meshing. Both the upper synchronous pulley and the drive shaft of the power module are mounted on... In the hollow cavity of the sewing machine head, a base is fixedly installed at the lower part of the sewing machine head. The middle part of the base forms a hollow base platform, and the front end of the base forms a base head for holding shoes. The synchronous belt of the power module extends downward from the hollow cavity of the sewing machine head and enters the interior of the base. The lower spindle and the up-and-down swing drive module are also located inside the base. The lower spindle has a front bearing, a middle bearing, and a rear bearing, which are installed in the base and used to support the lower spindle.

[0011] In another specific embodiment of this utility model, the latch needle drive device of the shell-shaped pattern sewing machine further includes a latch needle linkage component. The latch needle linkage component is connected to the front and back motion drive module and the latch needle body respectively, and is used to transmit the front and back motion power so that the latch needle body forms a composite motion trajectory of up and down and front and back under the coordinated action of the up and down swing drive module and the front and back motion drive module.

[0012] In a further specific embodiment of this utility model, the needle is connected to and driven by the front end of the power shaft; a needle bar crank, a needle bar connecting rod, a needle bar connector, and a needle bar body are also provided at the front end of the power shaft. The needle bar crank is fitted and installed at the front end of the power shaft, and the needle bar crank is driven by the needle bar connecting rod through a hinge pin. The needle bar body is vertically arranged and the needle is fixedly installed at the bottom of the needle bar body. The needle bar connector is fixedly fitted at the middle of the needle bar body and is also driven by the needle bar connecting rod, so that the power shaft body can drive the needle bar body and the needle to move.

[0013] In a further specific embodiment of this utility model, the up-and-down swing drive module includes a tongue needle up-and-down movement cam, which is fixedly installed at the front end of the lower main shaft and can rotate synchronously with the lower main shaft. A tongue needle up-and-down movement cam track groove is formed on the outer circumferential surface of the tongue needle up-and-down movement cam; a tongue needle up-and-down movement roller, which is embedded in the tongue needle up-and-down movement cam track groove of the tongue needle up-and-down movement cam and can reciprocate with the tongue needle up-and-down movement cam; and a tongue needle up-and-down movement rocker arm, the lower end of which is fixedly connected to the tongue needle up-and-down movement roller via a tongue needle up-and-down movement roller pin; the tongue needle... The oscillating shaft of the oscillating needle is fixedly connected at one end along its length to the upper end of the oscillating rocker arm. The oscillating shaft can oscillate synchronously with the oscillation of the oscillating rocker arm. A oscillating shaft bracket and a oscillating shaft sleeve are also fixedly installed on the oscillating shaft. The oscillating shaft bracket can limit the movement of the oscillating shaft body. The oscillating frame of the oscillating needle is installed at the other end of the oscillating shaft away from the oscillating rocker arm along its length. A pair of oscillating frame mating sections protruding from the body and symmetrically arranged are formed on the oscillating frame.

[0014] In another specific embodiment of this utility model, a latch needle seat is provided on the latch needle body, and a left latch needle seat guide block and a right latch needle seat guide block are respectively provided on the left and right sides of the latch needle seat. The left and right latch needle seat guide blocks are arranged opposite to each other. Both the left and right latch needle seat guide blocks have elongated grooves extending in the horizontal direction, and both are fixedly installed on the pattern sewing machine by fasteners set in the elongated grooves. The installation positions of the left and right latch needle seat guide blocks can be adjusted through the elongated grooves to adjust the position of the latch needle seat and the latch needle body to adapt to different winding and knotting requirements. A horizontally arranged latch needle rod is also fixedly installed on the latch needle seat, and the latch needle rod is respectively connected to the up-and-down swing drive module. The block and linkage component realize the transmission connection and are used to drive the tongue needle body to move up and down and back and forth synchronously. The front and rear ends of the tongue needle rod are respectively installed in the two tongue needle swing frame mating sections of the tongue needle swing frame, thereby realizing the connection between the tongue needle swing frame and the tongue needle rod and enabling the tongue needle swing frame to drive the tongue needle rod to swing. At the middle position of the tongue needle rod, a tongue needle rod clamp is also provided for transmission connection with the tongue needle linkage component. The tongue needle rod can move up and down synchronously under the drive of the tongue needle swing frame, and can also move back and forth synchronously under the drive of the tongue needle linkage component, thereby driving the tongue needle body to form a composite motion trajectory of up and down and back and forth.

[0015] In yet another specific embodiment of this utility model, the tongue needle linkage assembly includes a linkage rod, a front rod end bearing, a rear rod end bearing, and a linkage block; wherein, the inner ring of the rear rod end bearing is fitted and installed with the front and rear action drive module, the rear end of the linkage rod is fixedly connected to the rear rod end bearing, the front rod end bearing is fixedly installed at the front end of the linkage rod, the linkage block is disposed at the front end of the linkage rod and fixedly connected to the front rod end bearing, and the linkage block is fixedly connected to the tongue needle rod, thereby achieving the transmission connection between the tongue needle linkage assembly and the tongue needle body.

[0016] The beneficial effects of this utility model are as follows: First, this device innovatively adopts a dual-cam control architecture consisting of a front-and-back action cam and a top-and-bottom action cam. By optimizing the cam profile design and motion timing program, the up-and-down movement of the latch needle body can be precisely controlled by the two cams, thereby enabling on-demand switching between two core stitches. It can form a chain-like edge stitch with a straight needle that penetrates the sewing loop at the top and does not penetrate the sewing loop at the bottom. Alternatively, it can form a composite loop-like chain-like edge stitch with both the top and bottom sewing loops through the coordinated movement of the front-and-back action cam and the top-and-bottom action cam. This completely breaks through the limitation of traditional drive mechanisms that can only achieve a single needle wrapping method, fully meeting the core needs of shell-shaped pattern sewing machines for personalized and diversified pattern sewing, and is suitable for high-end clothing decoration, shoe upper processing and other multi-scenario applications. Second, by designing a relative position adjustment structure for the front-and-back action cam and the top-and-bottom action cam, the phase angle of the two cams can be adjusted without disassembling complex parts, which can flexibly adapt to different thicknesses and elasticity of thread materials. By optimizing the cam engagement, problems such as loose thread wrapping, unraveling, or thread breakage caused by differences in thread characteristics can be effectively avoided, significantly improving the equipment's compatibility with sewing materials and reducing the difficulty of debugging under different sewing conditions. Furthermore, in addition to the relative position adjustment function of the latch needle's forward and backward movement cams and the latch needle's up and down movement cams, the latch needle's forward and backward travel adjustment groove on the latch needle's forward and backward movement linkage allows for quick and fine adjustment of the latch needle's forward and backward travel by adjusting the installation position of the latch needle's forward and backward movement linkage pin. This adapts to the needs of different fabric thicknesses and sewing densities without the need for specialized tools or complex debugging procedures. The low operating threshold and high adjustment efficiency reduce the skill requirements of operators and enable rapid response to small-batch, multi-variety production needs, further expanding the equipment's applicability. Finally, by adopting a unified lower spindle as the power output reference, the dual cams and each drive module are all based on the same power source for transmission, completely eliminating the design defects of traditional multi-power-source or multi-spindle distributed drives, and fundamentally eliminating the problem of latch needle movement trajectory deviation caused by synchronization errors of multiple power sources. The improved precision of the movement of the latch needle significantly reduces faults such as stitch misalignment, broken needles and threads, ensuring a stable and continuous sewing process and significantly improving the quality of pattern formation and stitch consistency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is an exploded view of the up-and-down swing drive module and the forward-and-backward motion drive module in this utility model. Figure 3 This is a schematic diagram showing the unfolded structure of the cam track groove for the up-and-down movement of the tongue needle in this utility model; Figure 4 This is a schematic diagram showing the unfolded structure of the cam track groove for the forward and backward movement of the tongue needle in one embodiment of the present invention; Figure 5 This is a schematic diagram showing the unfolded structure of the cam track groove for the forward and backward movement of the tongue needle in another embodiment of this utility model.

[0018] In the diagram: 1. Power module, 11. Lower spindle, 12. Upper synchronous pulley of the latch needle, 13. Timing belt of the latch needle, 14. Lower synchronous pulley of the latch needle, 111. Front bearing of the lower spindle, 112. Middle bearing of the lower spindle, 113. Rear bearing of the lower spindle; 2. Latch needle body, 21. Latch needle seat, 22. Left latch needle seat guide block, 23. Right latch needle seat guide block, 24. Latch needle rod, 241. Latch needle rod chuck; 3. Up-and-down swing drive module, 31. Tongue needle up-and-down movement cam, 311. Tongue needle up-and-down movement cam track groove, 32. Tongue needle up-and-down movement roller, 321. Tongue needle up-and-down movement roller pin, 33. Tongue needle up-and-down movement rocker arm, 34. Tongue needle up-and-down swing shaft, 341. Swing shaft bracket, 342. Swing shaft copper sleeve, 35. Tongue needle up-and-down swing frame, 351. Tongue needle up-and-down swing frame mating section; 4. Front-and-back movement drive module, 41. Tongue needle front-and-back movement cam, 4111. Tongue needle front-and-back movement cam track groove, 4111. Large stroke section, 4112. Small stroke section, 4113. Equidistant motion section, 42 43. Cam positioning sleeve; 44. Front and rear movement rollers of the latch needle; 45. Front and rear movement roller pins of the latch needle; 46. Front and rear movement connecting rods of the latch needle; 47. Front and rear stroke adjustment grooves of the latch needle; 48. Front and rear movement connecting rod pins of the latch needle; 59. Movement connecting rod positioning brackets; 50. Latch needle linkage assembly; 51. Linkage rod; 52. Front rod end bearing; 53. Rear rod end bearing; 54. Linkage block; 6. Needle; 71. Drive shaft; 72. Needle bar crank; 73. Needle bar connecting rod; 74. Needle bar connector; 75. Needle bar body; 86. Machine head; 97. Hollow cavity of the machine head; 98. Machine base; 99. Machine base platform; 90. Machine base head. Detailed Implementation

[0019] The following will provide a detailed description by way of embodiments. However, the description of the embodiments is not intended to limit the utility model solution. Any formal but not substantive equivalent transformations made based on the utility model concept should be considered within the scope of the utility model's technical solution.

[0020] In the following description, all directional or orientational concepts involving up, down, left, right, front, and back refer to the current situation. Figure 1 It refers to the position and state of the utility model, and therefore cannot be understood as a special limitation on the technical solution provided by the utility model.

[0021] Example 1: Please refer to Figure 1 , Figure 2 and combined Figure 3 and Figure 4The image shows a latch drive device for a shell-shaped pattern sewing machine, comprising: a power module 1, which is connected to the power drive source of the pattern sewing machine, and the power module 1 includes a lower main shaft 11 that can rotate around its own axis and serve as a power output shaft; and a latch body 2, which is used to cooperate with the needle 6 of the pattern sewing machine to achieve thread wrapping and knotting, and the latch body 2 can perform compound movements in the up-down and back-forward directions. The up-down movement of the latch body 2 is used to coordinate with the piercing rhythm of the needle 6, so that it is close to the fabric when the needle 6 descends and hooks the needle thread when the needle 6 rises. The back-forward movement of the latch body 2 is used to adjust the hooking position to ensure that the needle thread can be accurately wound into the latch groove, ultimately forming a firm stitch.

[0022] The key technical points of the present invention are as follows: The aforementioned shell-shaped pattern sewing machine's latch drive device includes a vertical swing drive module 3, which converts the rotational motion of the lower main shaft 11 into the vertical reciprocating motion of the latch body 2. This module includes a latch vertical movement cam 31 mounted on the front end of the lower main shaft 11. A front-back movement drive module 4 converts the rotational motion of the lower main shaft 11 into the front-back reciprocating motion of the latch body 2. This module employs a cam transmission structure and includes a latch front-back movement cam 41 that rotates synchronously with the lower main shaft 11, a cam positioning sleeve 42, a latch front-back movement roller 43, and a latch front-back movement connecting rod 44. The aforementioned forward and backward movement cam 41 of the latch needle is connected to the lower main shaft 11 through the cam positioning sleeve 42. A forward and backward movement cam track groove 411 is provided on the outer peripheral surface of the forward and backward movement cam 41. The forward and backward movement roller 43 of the latch needle is installed in the forward and backward movement cam track groove 411 and can be driven by the forward and backward movement cam 41 to perform reciprocating motion. The forward and backward movement linkage 44 of the latch needle is connected to the forward and backward movement roller 43 and can drive the movement of the latch needle body 2 in the forward and backward direction through the transmission component. The forward and backward movement of the latch needle body 2 is controlled by adjusting the contour curve of the forward and backward movement cam track groove 411, so as to form different types of chain edge stitches when the latch needle body 2 is engaged with the needle 6.

[0023] In this embodiment, the aforementioned forward and backward movement cam 41 of the latch needle is a first-type cam, and the aforementioned forward and backward movement cam track groove 411 of the latch needle is a closed-loop curved groove extending circumferentially along the outer peripheral surface of the first-type cam; and the contour curve of the aforementioned forward and backward movement cam track groove 411 includes a large stroke segment 4111 and a small stroke segment 4112. The aforementioned large stroke segment 4111 and the small stroke segment 4112 are two reciprocating motion segments with different radial displacements and are alternately distributed circumferentially along the forward and backward movement cam 41 of the latch needle. The radial offset of the contour curve of the aforementioned large stroke segment 4111 corresponds to the large stroke movement of the latch needle body 2, and the radial offset of the contour curve of the aforementioned small stroke segment 4112 corresponds to the small stroke movement of the aforementioned latch needle body 2; and the aforementioned large stroke segment 4111 and the small stroke segment 4112 are two reciprocating motion segments with different radial displacements and are alternately distributed circumferentially along the latch needle cam 41. The stroke segment 4112 is connected end to end by a smoothly transitioning curved segment to form a continuous closed loop track. When the aforementioned forward and backward movement cam 41 rotates with the lower main shaft 11, the large stroke segment 4111 and the small stroke segment 4112 of the aforementioned forward and backward movement cam track groove 411 work together with the up and down movement cam 31 of the up and down swing drive module 3 to make the tongue needle body 2 perform a large stroke above the needle 6 to penetrate the sewing loop and perform a small stroke below the needle 6 to not penetrate the sewing loop. Alternatively, the tongue needle forward and backward movement cam 41 can be rotated 180° relative to the up and down movement cam 31 before the two work together, so that the tongue needle body 2 performs opposite movements in the up and down directions, thereby forming different types of chain edge stitches.

[0024] By adjusting the contour curve of the cam track groove 411 for the forward and backward movement of the needle, that is, the large stroke segment 4111 corresponds to the needle passing through the sewing loop above and the small stroke segment 4112 corresponds to the needle avoiding below, different types of chain edge stitches such as single-thread chain and double-thread chain can be generated. The diversity of stitches is significantly improved, realizing high-precision and multi-functional chain edge sewing, effectively solving the problems of single stitch and poor adaptability of traditional sewing machines.

[0025] Please continue reading Figure 1 and Figure 2The aforementioned front-to-back movement drive module 4 has a tongue needle front-to-back movement cam 41 fixedly installed at the middle position of the lower main shaft 11 along its length. The tongue needle front-to-back movement cam 41 is axially positioned by a cam positioning sleeve 42 to prevent it from shifting during the rotation of the lower main shaft 11. A vertically arranged tongue needle front-to-back movement roller pin 431 is also inserted in the aforementioned tongue needle front-to-back movement roller 43. The top end of the tongue needle front-to-back movement roller pin 431 is hinged to the aforementioned tongue needle front-to-back movement connecting rod 44, realizing the transmission connection between the tongue needle front-to-back movement roller 43 and the tongue needle front-to-back movement connecting rod 44. This allows the rotational motion of the tongue needle front-to-back movement cam 41 to be converted into the reciprocating oscillation of the tongue needle front-to-back movement connecting rod 44 through the tongue needle front-to-back movement roller 43. The aforementioned tongue needle front-to-back movement connecting rod 44 has a rod-shaped structure, and one end of the tongue needle front-to-back movement connecting rod 44 along its length is connected to the tongue needle front-to-back movement roller pin. 431 is connected, and the other end of the front and rear movement linkage 44 of the latch needle is hinged to the transmission component through a front and rear movement linkage pin 45 to ultimately drive the aforementioned latch needle body 2 to move in the front and rear direction. Furthermore, a front and rear stroke adjustment groove 441 is provided at the end of the front and rear movement linkage 44 away from the front and rear movement roller pin 431 of the latch needle. By adjusting the installation position of the front and rear movement linkage pin 45 in the front and rear stroke adjustment groove 441 of the latch needle, the front and rear stroke range of the latch needle body 2 can be adjusted. Furthermore, an action linkage positioning bracket 46 is provided at the upper position of the aforementioned front and rear movement linkage 44. The action linkage positioning bracket 46 is a fixed support and is installed in the sewing machine base. The action linkage positioning bracket 46 is rotatably connected to the front and rear movement linkage 44 of the latch needle through a hinge shaft to provide a swing positioning reference for the front and rear movement linkage 44 of the latch needle.

[0026] Furthermore, the aforementioned power module 1 is connected to a drive shaft 7 located within the aforementioned pattern sewing machine; and the aforementioned power module 1 also includes an upper synchronous belt pulley 12, a synchronous belt 13, and a lower synchronous belt pulley 14. The upper synchronous belt pulley 12 is fixedly mounted on the drive shaft 7 of the pattern sewing machine and can rotate synchronously with the drive shaft 7. The upper synchronous belt pulley 12 and the drive shaft 7 can be fixedly connected by a flat key, and the lower synchronous belt pulley 14 is fixedly mounted on the drive shaft 7. At the rear of the aforementioned lower main shaft 11, the aforementioned latch power synchronous belt 13 is sleeved between the outer circumferential surfaces of the aforementioned upper latch synchronous pulley 12 and lower latch synchronous pulley 14, and achieves synchronous power transmission through meshing. The latch power synchronous belt 13 is preferably made of polyurethane, which has high wear resistance and low elasticity, making it suitable for high-precision transmission. The latch power synchronous belt 13 is sleeved within the outer circumferential tooth grooves of the upper latch synchronous pulley 12 and lower latch synchronous pulley 14, achieving synchronous power transmission through tooth surface meshing. When the aforementioned main drive shaft 7 rotates, it can drive the upper latch synchronous pulley 12 to rotate synchronously. Through the meshing transmission of the latch power synchronous belt 13, the power is transmitted to the lower latch synchronous pulley 14, thereby driving the lower main shaft 11 to rotate around its own axis, achieving vertical power conversion. The synchronous belt drive is a slip-free transmission, which, compared to traditional gear transmission, has a more precise transmission ratio, lower operating noise, and lower maintenance costs.

[0027] Furthermore, the synchronous pulley 12 on the latch of the aforementioned power module 1 and the aforementioned drive shaft 7 are both housed in the hollow cavity 81 of the head of the aforementioned pattern sewing machine 8. A base 9 is fixedly installed at the lower part of the aforementioned head 8. A hollow base platform 91 is formed in the middle of the aforementioned base 9, and a base head 92 for mounting shoes is formed at the front end of the base 9. The synchronous belt 13 of the aforementioned power module 1 extends downward from the hollow cavity 81 of the aforementioned head and penetrates into the interior of the base 9. The aforementioned lower main shaft 11 and the up-and-down swing drive module 3 are also located inside the base 9. The lower main shaft 11 is provided with a lower main shaft drive module 3 on its shaft. The lower spindle has a front bearing 111, a middle bearing 112, and a rear bearing 113. These bearings are installed in the base 9 and are used to support the lower spindle 11. The three bearings are installed in the base 9 and are used to support the lower spindle 11. The three bearings on the lower spindle 11 can simultaneously withstand radial loads and slight axial loads. Preferably, they are installed in the pre-set bearing seats of the base 9 by interference fit, forming a three-point support structure to ensure stable and reliable operation.

[0028] In this embodiment, the aforementioned shell-shaped pattern sewing machine's latch drive device further includes a latch linkage component 5. The aforementioned latch linkage component 5 is connected to the aforementioned front and rear motion drive module 4 and the aforementioned latch body 2 respectively, and is used to transmit front and rear motion power, so that the aforementioned latch body 2 forms a composite motion trajectory of up and down and front and back under the coordinated action of the up and down swing drive module 3 and the front and rear motion drive module 4.

[0029] Please continue reading Figure 1 and Figure 2 The aforementioned needle 6 is connected to the front end of the aforementioned drive shaft 7 and is transmitted to it. At the front end of the aforementioned drive shaft 7, a needle bar crank 71, a needle bar connecting rod 72, a needle bar connector 73, and a needle bar body 74 are also provided. The aforementioned needle bar crank 71 is installed at the front end of the aforementioned drive shaft 7. The needle bar crank 71 is transmitted to the needle bar connecting rod 72 through a hinge pin. The aforementioned needle bar body 74 is vertically arranged and the aforementioned needle 6 is fixedly installed at the bottom of the needle bar body 74. The aforementioned needle bar connector 73 is fixedly fitted in the middle of the aforementioned needle bar body 74 and is also transmitted to the aforementioned needle bar connecting rod 72, so that the aforementioned drive shaft 7 can drive the aforementioned needle bar body 74 and the needle 6 to move.

[0030] Furthermore, the aforementioned up-and-down swing drive module 3 includes a tongue needle up-and-down movement cam 31, which is fixedly installed at the front end of the aforementioned lower main shaft 11 and can rotate synchronously with the aforementioned lower main shaft 11. A tongue needle up-and-down movement cam track groove 311 is formed on the outer circumferential surface of the aforementioned tongue needle up-and-down movement cam 31; a tongue needle up-and-down movement roller 32, which is embedded in the tongue needle up-and-down movement cam track groove 311 of the aforementioned tongue needle up-and-down movement cam 31, and the tongue needle up-and-down movement roller 32 can reciprocate with the aforementioned tongue needle up-and-down movement cam 31; a tongue needle up-and-down movement rocker arm 33, the lower end of which is fixedly connected to the aforementioned tongue needle up-and-down movement roller 32 via a tongue needle up-and-down movement roller pin 321; and a tongue needle up-and-down swing shaft 3. 4. One end of the tongue needle swing shaft 34 along its length is fixedly connected to the upper end of the aforementioned tongue needle swing rocker arm 33. The tongue needle swing shaft 34 can swing synchronously with the swing of the aforementioned tongue needle swing rocker arm 33. A swing shaft bracket 341 and a swing shaft copper sleeve 342 are also fixedly installed on the tongue needle swing shaft 34. The aforementioned swing shaft bracket 341 can limit the movement of the tongue needle swing shaft 34. The tongue needle swing frame 35 is installed at the other end of the tongue needle swing shaft 34 along its length away from the tongue needle swing rocker arm 33. A pair of tongue needle swing frame mating sections 351 protruding from the body and symmetrically arranged are formed on the tongue needle swing frame 35.

[0031] In this embodiment, a latch needle seat 21 is provided on the aforementioned latch needle body 2, and a left latch needle seat guide block 22 and a right latch needle seat guide block 23 are respectively provided on the left and right sides of the latch needle seat 21. The left latch needle seat guide block 22 and the right latch needle seat guide block 23 are arranged opposite to each other. Both the left latch needle seat guide block 22 and the right latch needle seat guide block 23 have elongated grooves extending in the horizontal direction, and the two are fixedly installed on the aforementioned pattern sewing machine by fasteners set in the elongated grooves. The installation position of the left latch needle seat guide block 22 and the right latch needle seat guide block 23 can be adjusted through the elongated grooves to adjust the position of the latch needle seat 21 and the latch needle body 2 to adapt to different winding and knotting requirements. A horizontally arranged latch needle rod 24 is also fixedly installed on the aforementioned latch needle seat 21. The latch needle rod 24 is connected to the aforementioned up and down swing drive module 3 and linkage group respectively. Component 5 enables transmission connection and drives the aforementioned tongue needle body 2 to move synchronously up and down and back and forth. The front and rear ends of the tongue needle rod 24 are respectively installed in the two tongue needle swing frame mating sections 351 of the aforementioned tongue needle swing frame 35, thereby realizing the connection between the aforementioned tongue needle swing frame 35 and the tongue needle rod 24 and enabling the aforementioned tongue needle swing frame 35 to drive the aforementioned tongue needle rod 24 to swing. At the middle position of the tongue needle rod 24, a tongue needle rod clamp 241 is also provided for transmission connection with the aforementioned tongue needle linkage component 5. The aforementioned tongue needle rod 24 can move synchronously up and down under the drive of the aforementioned tongue needle swing frame 35, and can also move synchronously back and forth under the drive of the aforementioned tongue needle linkage component 5, thereby driving the aforementioned tongue needle body 2 to form a composite motion trajectory of up and down and back and forth.

[0032] In this embodiment, by adjusting the installation positions of the left latch needle seat guide block 22 and the right latch needle seat guide block 23, the installation positions of the latch needle body 2 and the latch needle seat 21 in the pattern sewing machine can be adjusted without disassembling other parts, making operation convenient. It can also adjust the distance between the latch needle body 2 and the needle 6 to accommodate different thicknesses of thread, ensuring that the thread does not slip during the hooking process and meeting various sewing needs. In addition, the latch needle bar 24 can simultaneously receive power in the up-down and back-forward directions. The swing of the latch needle swing frame 35 drives the latch needle bar 24 to move up and down, and the drive of the latch needle linkage component 5 drives the latch needle bar 24 to move back and forth. The two movements are superimposed to form a composite trajectory of the latch needle body 2, and the movement process does not interfere with each other, ensuring accurate thread winding and knotting.

[0033] Furthermore, the aforementioned tongue needle linkage assembly 5 includes a linkage rod 51, a front rod end bearing 52, a rear rod end bearing 53, and a linkage block 54; wherein, the inner ring of the aforementioned rear rod end bearing 53 is fitted and installed in conjunction with the aforementioned front and rear movement drive module 4, and the rear rod end bearing 53 is connected to the tongue needle front and rear movement connecting rod 44 through a hinge shaft; the rear end of the aforementioned linkage rod 51 is fixedly connected to the aforementioned rear rod end bearing 53, and the aforementioned front rod end bearing 52 is fixedly installed on the front end of the aforementioned linkage rod 51. The aforementioned linkage block 54 is disposed at the front end of the aforementioned linkage rod 51 and is fixedly connected to the aforementioned front rod end bearing 52. The linkage block 54 is also fixedly connected to the aforementioned tongue needle rod 24, thereby achieving the transmission connection between the aforementioned tongue needle linkage assembly 5 and the tongue needle body 2. Transmission connection; both the aforementioned front rod end bearing 52 and rear rod end bearing 53 adopt spherical bearings that can adapt to multi-angle swing. The inner ring of the rear rod end bearing 53 is fitted with the eccentric pin 471, while the outer ring is fixed to the rear end of the linkage rod 51. The outer ring of the front rod end bearing 52 is fixed to the front end of the linkage rod 51, while the inner ring is connected to the linkage block 54. The transmission is smooth and can absorb the angle deviation during the movement. When the aforementioned tongue needle front and rear action linkage 44 performs reciprocating circular motion, the rear rod end bearing 53 pushes the linkage rod 51 to perform a compound motion in the front and rear directions. The front rod end bearing 52 absorbs the swing component of the linkage rod 51 and only transmits the translational motion to the linkage block 54. The linkage block 54 drives the tongue needle rod 24, and finally drives the tongue needle body 2 to perform a reciprocating motion. The design of the spherical bearing can adapt to the angle change during the movement of the linkage rod, avoiding the rod bending or wear problem at the connection that is easy to occur in traditional rigid connections, and extending the component life. At the same time, the linkage rod 51 has high strength properties to ensure that the power transmission has no elastic deformation, which can eliminate the influence of assembly error on the motion accuracy and ensure accurate transmission of front and rear motion.

[0034] Please see Figure 1 and Figure 2 and combined Figure 4 , Figure 5The applicant briefly describes the working principle of the technical solution provided by this utility model in conjunction with the complete sewing cycle of the pattern sewing machine: The up-and-down swing drive module 3 and the front-and-back action drive module 4 of this drive device share the lower main shaft 11 as the power source. The unified rotation reference ensures the synchronization of the actions. When the sewing machine is started, the motor drives the main force shaft 7 to rotate. The main force shaft 7 completes two power outputs at the same time. One is to drive the needle bar body 74 and the needle 6 to move up and down through the needle bar crank 71 and the needle bar connecting rod 72. When the needle 6 descends, it pierces the fabric, and when it rises, it carries the needle thread out. The other is to drive the lower synchronous belt pulley 14 of the latch needle to rotate through the latch needle upper synchronous belt pulley 12 and the latch needle power synchronous belt 13, thereby driving the lower main shaft 11 to rotate synchronously.

[0035] The power of the aforementioned lower main shaft 11 is transmitted in two ways: First, the lower main shaft 11 drives the tongue needle up-and-down movement cam 31 of the up-and-down swing drive module 3 to rotate, and the tongue needle up-and-down movement roller 32 embedded in the tongue needle up-and-down movement cam track groove 311 moves accordingly, thereby driving the tongue needle up-and-down movement rocker arm 33 to swing. The tongue needle up-and-down movement rocker arm 33 drives the tongue needle up-and-down movement frame 35 to swing through the tongue needle up-and-down swing shaft 34. The tongue needle rod 24 swings synchronously with the tongue needle up-and-down swing frame 35, and finally drives the tongue needle body 2 to move up and down. The other way is through the tongue needle front-and-back movement cam 41 of the aforementioned front-and-back movement drive module 4 to drive the tongue needle front-and-back movement roller 43 to reciprocate. The tongue needle front-and-back movement connecting rod 44 is connected to the tongue needle linkage component 5 through the tongue needle front-and-back movement connecting rod pin 45, and finally drives the transmission of the tongue needle rod 24, and finally drives the tongue needle body 2 to move back and forth. After the two movements are coordinated, the latch needle body 2 forms a compound motion in the up-down and back-forward directions. The lower main shaft 11 drives the central eccentric cam to rotate, and the cam pushes the swing arm to swing up and down. The swing arm drives the latch needle body 2 to move in the vertical direction. When the needle 6 descends, the latch needle body 2 descends synchronously to be close to the fabric surface; when the needle 6 rises, the latch needle body 2 rises synchronously, and the hook groove at the head accurately hooks the needle thread brought out by the needle. The above process is repeated cyclically with the continuous rotation of the main power shaft 7. The compound motion of the latch needle body 2 and the movement of the needle 6 are precisely synchronized, ultimately forming a continuous and firm stitch on the fabric.

[0036] Example 2: Please refer to Figure 5 and combined Figure 1 and Figure 2The difference between this embodiment and embodiment 1 is that: the aforementioned front and rear movement cam 41 of the tongue needle is a second type of cam, and the aforementioned front and rear movement cam track groove 411 of the tongue needle is a closed-loop curved groove extending circumferentially along the outer peripheral surface of the second type of cam; the contour curve of the aforementioned front and rear movement cam track groove 411 includes two equidistant movement segments 4113 with equal radial displacement, the radial offset of the contour curves of the two aforementioned equidistant movement segments 4113 is consistent, and the two are symmetrically distributed along the axial axis of the aforementioned front and rear movement cam 41 of the tongue needle, and the two equidistant movement segments 4113 are connected by a smooth transition curve segment to form a continuous closed-loop track; when the aforementioned front and rear movement cam 41 of the tongue needle rotates with the aforementioned lower main shaft 11, the two sets of equidistant movement segments 4113 of the aforementioned front and rear movement cam track groove 411 cooperate with the tongue needle up and down movement cam 31 of the up and down swing drive module 3 to make the tongue needle body 2 perform equal stroke movements above and below the needle 6 to penetrate the sewing coil, thereby forming a compound loop chain edge stitch.

[0037] Specifically, when the needle 6 descends to pierce the fabric under the drive of the main force shaft 7, the latch needle body 2 descends synchronously under the action of the latch needle up and down action cam 31. At the same time, it performs an equal amount of forward and backward stroke under the drive of the equidistant motion segment 4113 of the second type of latch needle forward and backward action cam, penetrating the sewing loop formed by the needle 6. When the needle 6 rises and carries the needle thread out, the latch needle body 2 rises synchronously and still maintains an equal amount of forward and backward motion under the action of the equidistant motion segment 4113, penetrating the sewing loop again. Through the coordination of the two penetrating actions, a continuous and tight composite loop chain edge stitch is finally formed on the fabric.

[0038] In summary, the technical solution provided by this utility model makes up for the shortcomings of the prior art, successfully completes the utility model task, and faithfully realizes the technical effects described by the applicant in the above technical effect column.

Claims

1. A latch drive device for a shell-shaped pattern sewing machine, comprising: The power module (1) is connected to the drive source of the pattern sewing machine, and the power module (1) includes a lower main shaft (11) as a unified power output shaft; a latch needle body (2), which is used to cooperate with the needle (6) of the pattern sewing machine to realize the winding and knotting action, and the latch needle body (2) can complete the compound movement in the up and down direction and the forward and backward direction; characterized in that it further includes: an up and down swing drive module (3), which is used to drive the thread... The rotational motion of the lower spindle (11) is converted into the reciprocating up-and-down motion of the tongue needle body (2), and the up-and-down swing drive module (3) includes a tongue needle up-and-down motion cam (31) mounted on the front end of the lower spindle (11); and a front-and-back motion drive module (4), which is used to convert the rotational motion of the lower spindle (11) into the reciprocating up-and-back motion of the tongue needle body (2), and the front-and-back motion drive module (4) adopts a cam transmission structure and includes a cam drive module (31) with the same cam drive module as the lower spindle (11). The system comprises a rotating latch cam (41), a cam positioning sleeve (42), a latch roller (43), and a latch linkage (44). The latch cam (41) is connected to the lower spindle (11) via the cam positioning sleeve (42). A latch track groove (411) is provided on the outer circumferential surface of the latch cam (41), and the latch roller (43) is fitted into the latch track groove (411). 1) It can be driven by the forward and backward movement cam (41) of the tongue needle to perform reciprocating motion. The forward and backward movement linkage (44) of the tongue needle is connected to the forward and backward movement roller (43) of the tongue needle and can drive the movement of the tongue needle body (2) in the forward and backward direction through the transmission component. The forward and backward movement of the tongue needle body (2) is controlled by adjusting the contour curve of the forward and backward movement cam track groove (411) of the tongue needle, so as to achieve the formation of different types of chain edge stitches when the tongue needle body (2) cooperates with the needle (6).

2. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 1, characterized in that: The forward and backward movement cam (41) of the tongue needle is a first type of cam, and the forward and backward movement cam track groove (411) of the tongue needle is a closed-loop curved groove extending circumferentially along the outer peripheral surface of the first type of cam; and the contour curve of the forward and backward movement cam track groove (411) of the tongue needle includes a large stroke segment (4111) and a small stroke segment (4112), the large stroke segment (4111) and the small stroke segment (4112) are two reciprocating motion segments with different radial displacements and are alternately distributed along the circumference of the forward and backward movement cam (41). The radial offset of the contour curve of the large stroke segment (4111) corresponds to the large stroke movement of the tongue needle body (2), and the radial offset of the contour curve of the small stroke segment (4112) corresponds to the small stroke movement of the tongue needle body (2); and the large stroke segment (4111) and the small stroke segment (4112) are two reciprocating motion segments with different radial displacements and are alternately distributed along the circumferential surface of the tongue needle. 4112) A continuous closed-loop track is formed by connecting the beginning and end of a smoothly transitioning curve segment; when the front and rear movement cam (41) of the tongue needle rotates with the lower main shaft (11), the large stroke segment (4111) and the small stroke segment (4112) of the track groove (411) of the front and rear movement cam of the tongue needle work together with the upper and lower movement cam (31) of the upper and lower swing drive module (3) to make the tongue needle body (2) perform a large stroke above the needle (6) to penetrate the sewing loop and perform a small stroke below the needle (6) to not penetrate the sewing loop; or the front and rear movement cam (41) of the tongue needle rotates 180° relative to the upper and lower movement cam (31) of the tongue needle and then the two are coordinated to make the tongue needle body (2) perform reverse movements in the upper and lower directions, thereby forming different types of chain edge stitches.

3. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 1, characterized in that: The forward and backward movement cam (41) of the tongue needle is a second type of cam, and the forward and backward movement cam track groove (411) of the tongue needle is a closed-loop curved groove extending circumferentially along the outer peripheral surface of the second type of cam; the contour curve of the forward and backward movement cam track groove (411) of the tongue needle includes two equidistant motion segments (4113) with equal radial displacement, the radial offset of the contour curves of the two equidistant motion segments (4113) is consistent and the two are symmetrically distributed along the axial axis of the forward and backward movement cam (41), the two equidistant motion segments ( The 4113) are connected by a smooth transition curve segment to form a continuous closed loop track; when the front and rear movement cam (41) of the tongue needle rotates with the lower main shaft (11), the two sets of equidistant movement segments (4113) of the front and rear movement cam track groove (411) of the tongue needle work together with the upper and lower movement cam (31) of the upper and lower swing drive module (3) to make the tongue needle body (2) perform equal stroke movements above and below the needle (6) to penetrate the sewing loop, thereby forming a compound loop chain edge stitch.

4. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 1, characterized in that: The forward and backward movement cam (41) of the forward and backward movement drive module (4) is fixedly installed at the middle position of the lower main shaft (11) in the length direction. The forward and backward movement cam (41) is axially positioned by a cam positioning sleeve (42) to prevent it from moving during the rotation of the lower main shaft (11). A vertically arranged forward and backward movement roller pin (431) is also provided in the forward and backward movement roller (43). The top of the cam (41) is hinged to the front and rear movement linkage (44) of the tongue needle, realizing the transmission connection between the front and rear movement roller (43) of the tongue needle and the front and rear movement linkage (44), so that the rotational motion of the front and rear movement cam (41) of the tongue needle is converted into the reciprocating oscillation of the front and rear movement linkage (44) of the tongue needle through the front and rear movement roller (43); the front and rear movement linkage (44) of the tongue needle has a rod-shaped structure, and one end of the front and rear movement linkage (44) of the tongue needle is connected to the pin of the front and rear movement roller of the tongue needle. (431) The connection is achieved, and the other end of the front and rear action linkage (44) of the latch needle is hinged to the transmission component through a front and rear action linkage pin (45) to finally drive the latch needle body (2) to achieve front and rear movement. A front and rear stroke adjustment groove (441) is also provided at the end of the front and rear action linkage (44) away from the front and rear action roller pin (431). The front and rear stroke range of the latch needle body (2) can be adjusted by adjusting the installation position of the front and rear action linkage pin (45) in the front and rear stroke adjustment groove (441). A motion linkage positioning bracket (46) is also provided at the upper position of the front and rear action linkage (44). The motion linkage positioning bracket (46) is a fixed support and is installed in the sewing machine base. The motion linkage positioning bracket (46) is rotatably connected to the front and rear action linkage (44) of the latch needle through a hinge shaft to provide a swing positioning reference for the front and rear action linkage (44).

5. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 1, characterized in that: The power module (1) is connected to a main drive shaft (7) located in the pattern sewing machine. The power module (1) also includes an upper synchronous pulley (12), a synchronous belt (13), and a lower synchronous pulley (14). The upper synchronous pulley (12) is fixedly mounted on the main drive shaft (7) of the pattern sewing machine and can rotate synchronously with the main drive shaft (7). The lower synchronous pulley (14) is fixedly mounted at the rear of the lower main shaft (11). The synchronous belt (13) is mounted between the outer circumference of the upper synchronous pulley (12) and the lower synchronous pulley (14) and transmits power synchronously through meshing. The upper synchronous pulley (12) and the main drive shaft (7) of the power module (1) are both located in the hollow cavity (81) of the head of the pattern sewing machine (8). A base (9) is fixedly installed at the lower part of the machine head (8). A hollow base platform (91) is formed in the middle of the base (9), and a base head (92) for mounting shoes is formed at the front end of the base (9). The tongue needle power synchronous belt (13) of the power module (1) extends downward from the hollow cavity (81) of the machine head and enters the interior of the base (9). The lower spindle (11) and the upper... The lower swing drive module (3) is also located inside the base (9); and the lower spindle (11) is provided with a front bearing (111), a middle bearing (112) and a rear bearing (113) respectively. The front bearing (111), the middle bearing (112) and the rear bearing (113) are installed in the base (9) and are used to support the lower spindle (11).

6. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 1, characterized in that: The tab drive device of the shell-shaped pattern sewing machine also includes a tab linkage component (5). The tab linkage component (5) is connected to the front and back motion drive module (4) and the tab body (2) respectively, and is used to transmit the front and back motion power so that the tab body (2) forms a composite motion trajectory of up and down and front and back under the coordinated action of the up and down swing drive module (3) and the front and back motion drive module (4).

7. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 5, characterized in that: The needle (6) is connected to the front end of the power shaft (7) and is driven thereto. The front end of the power shaft (7) is also provided with a needle bar crank (71), a needle bar connecting rod (72), a needle bar connector (73) and a needle bar body (74). The needle bar crank (71) is installed at the front end of the power shaft (7). The needle bar crank (71) is driven by the needle bar connecting rod (72) through a hinge pin. The needle bar body (74) is vertically arranged and the needle (6) is fixedly installed at the bottom of the needle bar body (74). The needle bar connector (73) is fixedly fitted in the middle of the needle bar body (74). The needle bar connector (73) is also driven by the needle bar connecting rod (72), so that the power shaft (7) can drive the needle bar body (74) and the needle (6) to move.

8. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 6, characterized in that: The up-and-down swing drive module (3) includes a tongue needle up-and-down action cam (31), which is fixedly installed at the front end of the lower main shaft (11) and can rotate synchronously with the lower main shaft (11). A tongue needle up-and-down action cam track groove (311) is provided on the outer peripheral surface of the tongue needle up-and-down action cam (311); a tongue needle up-and-down action roller (32), which is embedded in the tongue needle up-and-down action cam track groove (311) of the tongue needle up-and-down action cam (31) and can reciprocate with the tongue needle up-and-down action cam (31); a tongue needle up-and-down action rocker arm (33), the lower end of which is fixedly connected to the tongue needle up-and-down action roller (32) by a tongue needle up-and-down action roller pin (321); and a tongue needle up-and-down swing shaft (34). The end of the tongue needle swing shaft (34) along its length is fixedly connected to the upper end of the tongue needle swing rocker arm (33), and the tongue needle swing shaft (34) can swing synchronously with the swing of the tongue needle swing rocker arm (33). A swing shaft bracket (341) and a swing shaft copper sleeve (342) are also fixedly installed on the tongue needle swing shaft (34). The swing shaft bracket (341) can limit the movement of the tongue needle swing shaft (34) body. The tongue needle swing frame (35) is installed at the other end of the tongue needle swing shaft (34) along its length away from the tongue needle swing rocker arm (33). A pair of tongue needle swing frame mating sections (351) protruding from the body and symmetrically arranged are formed on the tongue needle swing frame (35).

9. The latch needle drive device of a shell-shaped pattern sewing machine according to claim 8, characterized in that: A latch needle seat (21) is provided on the latch needle body (2), and a left latch needle seat guide block (22) and a right latch needle seat guide block (23) are respectively provided on the left and right sides of the latch needle seat (21). The left latch needle seat guide block (22) and the right latch needle seat guide block (23) are arranged opposite to each other. Both the left latch needle seat guide block (22) and the right latch needle seat guide block (23) are provided with long grooves extending in the horizontal direction, and the two are fixedly installed on the pattern sewing machine by fasteners set in the long grooves. The long grooves can realize the adjustment of the installation position of the left latch needle seat guide block (22) and the right latch needle seat guide block (23), and adjust the position of the latch needle seat (21) and the latch needle body (2) to adapt to different winding and knotting requirements. A horizontally arranged latch needle rod (24) is also fixedly installed on the latch needle seat (21). The latch needle rod (24) is connected to the up and down swing drive module (3) and the linkage component (5) respectively. The transmission connection is realized and used to drive the tongue needle body (2) to move up and down and back and forth synchronously. The front and rear ends of the tongue needle rod (24) are respectively installed in the two tongue needle swing frame mating sections (351) of the tongue needle swing frame (35), thereby realizing the connection between the tongue needle swing frame (35) and the tongue needle rod (24) and enabling the tongue needle swing frame (35) to drive the tongue needle rod (24) to swing. At the middle position of the tongue needle rod (24), a tongue needle rod clamp (241) is also provided for transmission connection with the tongue needle linkage component (5). The tongue needle rod (24) can move up and down synchronously under the drive of the tongue needle swing frame (35) and can also move back and forth synchronously under the drive of the tongue needle linkage component (5), thereby driving the tongue needle body (2) to form a composite motion trajectory of up and down and back and forth.

10. The latch needle driving device of a shell-shaped pattern sewing machine according to claim 9, characterized in that: The tongue needle linkage assembly (5) includes a linkage rod (51), a front rod end bearing (52), a rear rod end bearing (53), and a linkage block (54). The inner ring of the rear rod end bearing (53) is fitted with the front and rear action drive module (4). The rear end of the linkage rod (51) is fixedly connected to the rear rod end bearing (53). The front rod end bearing (52) is fixedly installed at the front end of the linkage rod (51). The linkage block (54) is disposed at the front end of the linkage rod (51) and fixedly connected to the front rod end bearing (52). The linkage block (54) is also fixedly connected to the tongue needle rod (24), thereby achieving the transmission connection between the tongue needle linkage assembly (5) and the tongue needle body (2).

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