Latch drive device for a pattern sewing machine

Abstract

A tongue needle driving device for pattern sewing machine belongs to the technical field of sewing machine. It includes tongue needle power unit, tongue needle body, tongue needle up and down swing driving unit, tongue needle front and back action driving unit and tongue needle linkage assembly. The tongue needle power unit is connected with the power driving source of the sewing machine and is provided with a lower main shaft which can rotate around its own axis. The tongue needle body cooperates with the needle to realize winding knotting and can complete the up and down and front and back compound motion. The tongue needle up and down swing driving unit is transmission connected with the lower main shaft to convert the rotary motion into the up and down reciprocating motion of the tongue needle body. The tongue needle front and back action driving unit is transmission connected with the lower main shaft to convert the rotary motion into the front and back action of the tongue needle body. The tongue needle body realizes the up and down and front and back compound motion efficiently and stably, the synchronous precision of each unit motion is high, the stitch quality is stable, it can adapt to different fabrics and threads, the structure is modular, the maintenance is convenient, the parts are wear-resistant and durable, the sewing stability and quality are greatly improved, the adaptability is strong, and the application range is wide.

Description

Technical Field

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

[0002] In the sewing processing field of footwear, bags, textiles, and apparel industries, pattern sewing machines are widely used because they can automate the sewing of complex patterns. Their core function relies heavily on the precise coordination between the latch and the needle, and the specific movement of the latch completes the thread winding and knotting, directly determining the accuracy of the sewn pattern, the stability of the stitches, and the overall efficiency of the equipment. Currently, the latch drive devices of mainstream pattern sewing machines on the market generally suffer from complex structural designs and dispersed power transmission paths. Most devices rely on multiple independent power sources or multiple spindles to drive the up-and-down and back-and-forth movements of the latch, resulting not only in a loose internal layout and difficult assembly, but also in susceptibility to synchronization errors among multiple power sources, causing the latch's movement trajectory to deviate, leading to stitch irregularities, broken needles and threads, and other malfunctions, significantly reducing sewing quality and production efficiency. Meanwhile, existing latch needle drive devices lack sufficient adjustment flexibility. The relative distance between the latch needle and the machine needle directly affects the thread winding and knotting effect. In traditional devices, the horizontal position of the latch needle is often fixed or requires disassembly of multiple parts for fine-tuning, making operation cumbersome and adjustment accuracy difficult to guarantee. This makes it impossible to quickly adapt to the sewing needs of different fabric thicknesses and thread diameters, limiting the device's applicability. Furthermore, some drive devices lack stable limiting and support structures in their transmission components, which can easily lead to component wear, vibration, and abnormal noise under long-term high-speed operation. This shortens the device's lifespan, increases maintenance costs and downtime, and fails to meet the high requirements for equipment stability and durability in industrial production.

[0003] Therefore, developing a highly integrated, synchronously precise, conveniently adjustable, and stable latch drive device for pattern sewing machines has become a key requirement for addressing current industry pain points and improving the performance of pattern sewing machines. In response to these needs, the applicant has developed a beneficial design, and the technical solution described below arose from this context. Utility Model Content

[0004] The objective of this invention is to provide a compact, precise, and easily adjustable latch needle drive device for pattern sewing machines. This device facilitates efficient control and precise positioning of the latch needle's compound motion through multi-unit coordinated transmission via structural innovation. Furthermore, it optimizes the transmission structure to achieve synchronous driving of the latch needle's up-and-down swing unit and the latch needle's forward-and-backward motion drive unit, thereby effectively improving power output efficiency.

[0005] The present invention achieves its objective as follows: a latch needle drive device for a pattern sewing machine, comprising: a latch needle power unit, which is connected to the power drive source of the pattern sewing machine, and includes a lower main shaft that can rotate around its own axis and serve as a power output shaft; a latch needle body, which is used to cooperate with the needle of the pattern sewing machine to wind and knot the thread, and is capable of performing compound movements in the up-down and back-forward directions; a latch needle up-down swing drive unit, which is connected to the lower main shaft and is used to convert the rotational motion of the lower main shaft into the up-down reciprocating motion of the latch needle body; a latch needle back-and-forth motion drive unit, which is also connected to the lower main shaft and is used to convert the rotational motion of the lower main shaft into the back-and-forth reciprocating motion of the latch needle body; and a latch needle linkage assembly, which connects the latch needle back-and-forth motion drive unit to the latch needle body and is used to transmit the back-and-forth motion power.

[0006] In a specific embodiment of this utility model, the latch needle power unit is connected to a drive shaft disposed in the pattern sewing machine; and the latch needle power unit further includes an upper latch needle synchronous pulley, a latch needle power synchronous belt, and a lower latch needle synchronous pulley. The upper latch needle synchronous pulley is fixedly mounted on the drive shaft of the pattern sewing machine and can rotate synchronously with the drive shaft. The lower latch needle synchronous pulley is fixedly mounted at the rear of the lower main shaft body, and the latch needle power synchronous belt is sleeved between the outer circumferential surfaces of the upper and lower latch needle synchronous pulleys and achieves synchronous power transmission through meshing transmission.

[0007] In another specific embodiment of this utility model, the needle is connected to the front end of the main force shaft and is driven therethrough. 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 main force shaft. The needle bar crank is fitted and installed at the front end of the main force shaft, and is driven through a hinge pin to the needle bar connecting rod. The needle bar body is vertically oriented, and the needle is fixedly installed at the bottom of the needle bar body. The needle bar connector is fixedly fitted into the middle of the needle bar body, and is also driven through the needle bar connecting rod, thereby enabling the main force shaft body to drive the needle bar body and the needle to move.

[0008] In another specific embodiment of this utility model, the synchronous pulley on the latch of the latch power unit and the driving shaft are both installed 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 mounting shoes. The latch power synchronous belt of the latch power unit extends downward from the hollow cavity of the sewing machine head and penetrates into the interior of the base. The lower spindle and the latch swing drive unit are also located inside the base. A front bearing, a middle bearing, and a rear bearing are respectively installed on the shaft of the lower spindle. The front bearing, the middle bearing, and the rear bearing are installed in the base and used to support the lower spindle.

[0009] In another specific embodiment of this utility model, the tongue needle up-and-down swing drive unit 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.

[0010] 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 driven by the latch needle to swing up and down. The tongue needle linkage assembly enables transmission and drives the tongue needle body to move synchronously up and down and back and forth. The front and rear ends of the tongue needle rod are respectively installed in the mating sections of the tongue needle swing frame, thereby connecting 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 assembly. The tongue needle rod can move synchronously up and down under the drive of the tongue needle swing frame, and can also move synchronously back and forth under the drive of the tongue needle linkage assembly, thereby driving the tongue needle body to form a composite motion trajectory of up and down and back and forth.

[0011] In a further specific embodiment of this utility model, the tongue needle forward and backward movement drive unit includes: a power arc gear, which is fixedly installed in the middle of the lower main shaft and can rotate synchronously with the lower main shaft; a gear shaft, which extends vertically and has a gear portion at its bottom meshing with the power arc gear and rotating under the drive of the power arc gear; an active arc gear, which is fixedly sleeved on the top end of the gear shaft and can move synchronously with the rotation of the gear shaft; a passive arc gear, which is horizontally positioned above the active arc gear and meshes with the active arc gear and can rotate under the drive of the active arc gear; and an arc gear bracket, which is fixedly installed on the pattern sewing machine. The upper end of the gear shaft passes through the bottom panel of the arc gear bracket and rotates with the arc gear bracket through a bearing. Both the active arc gear and the passive arc gear are fitted into the arc gear bracket. In a further specific embodiment of this utility model, the tongue needle forward and backward movement drive unit further includes a tongue needle forward and backward movement drive crank shaft and a tongue needle forward and backward movement crank; wherein, the tongue needle forward and backward movement drive crank shaft extends horizontally and passes through the central hole of the driven arc gear and the left and right sides of the arc gear bracket, and the tongue needle forward and backward movement drive crank shaft is fixedly connected to the driven arc gear and rotates with the arc gear bracket through bearings, and the tongue needle forward and backward movement drive crank shaft can move synchronously with the rotation of the driven arc gear; the tongue needle forward and backward movement crank is fixedly sleeved on the other end of the tongue needle forward and backward movement drive crank shaft away from the arc gear bracket in the length direction, and the tongue needle forward and backward movement crank is provided with an eccentric pin, the axis of the eccentric pin is parallel to and does not coincide with the axis of the tongue needle forward and backward movement drive crank shaft, and the tongue needle forward and backward movement crank is connected to the tongue needle linkage assembly through the eccentric pin.

[0012] In 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 with the outer circumferential surface of the eccentric pin of the tongue needle front and rear movement drive unit, 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.

[0013] The beneficial effects of this utility model are as follows: This technical solution achieves efficient control and precise positioning of the compound motion of the latch needle through innovative mechanical structure design and multi-unit coordinated transmission; Firstly, the deep coordination between the latch needle up-and-down swing unit and the latch needle forward-and-back motion drive unit not only solves the problem of easy conflict in multi-degree-of-freedom motion in traditional mechanisms, but also ensures that the latch needle up-and-down swing drive unit and the forward-and-back motion drive unit share the lower main shaft as a power source, and ensures the synchronization of the motion through a unified rotation reference, effectively guaranteeing the synchronicity of the latch needle's up-and-down and forward-and-back motion, and making the latch needle thread-hooking process stable, with tight and uniform stitches, reducing faults such as skipped stitches and broken stitches. First, it improves sewing quality. Second, this technical solution uses a single active power shaft to drive both the needle and the latch simultaneously. Through the cooperation of the synchronous pulley and the lower main shaft, the power is efficiently transmitted to the latch's up-and-down swing unit and the latch's forward and backward movement drive unit. Compared with the traditional multi-power source design, this technical solution effectively avoids the energy loss caused by complex transmission chains and improves power output efficiency. Third, the design of the left and right latch guide blocks on both sides of the latch seat allows the position of the latch in the pattern sewing machine to be adjusted through the long groove structure, thereby adapting to different sewing thicknesses or thread winding requirements, providing reliable technical support for complex pattern sewing. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a three-dimensional exploded view of the tongue needle power unit, tongue needle body, tongue needle up-and-down swing drive unit, tongue needle forward-and-back movement drive unit, and tongue needle linkage assembly described in this utility model.

[0015] In the diagram: 1. Latch power unit; 11. Lower spindle; 111. Front bearing of lower spindle; 112. Middle bearing of lower spindle; 113. Rear bearing of lower spindle; 12. Upper synchronous pulley of latch; 13. Timing belt of latch; 14. Lower synchronous pulley of latch; 2. Latch body; 21. Latch seat; 22. Left latch seat guide block; 23. Right latch seat guide block; 24. Latch needle rod; 241. Latch needle rod chuck; 3. Latch up and down swing drive unit; 31. Up and down movement cam; 311. Track groove of up and down movement cam of latch; 32. Roller of up and down movement of latch; 321. 33. Roller pin for up-and-down movement of the tongue needle; 34. Rocker arm for up-and-down movement of the tongue needle; 35. Swing shaft for up-and-down movement of the tongue needle; 36. Swing shaft bracket; 37. Swing shaft bushing; 38. Swing frame for up-and-down movement of the tongue needle; 39. Matching section for up-and-down swing frame; 40. Drive unit for forward and backward movement of the tongue needle; 41. Power arc gear; 42. Gear shaft; 43. Driving arc gear; 44. Driven arc gear; 45. Arc gear bracket; 46. Forward and backward drive unit for the tongue needle. 47. Crankshaft; 47. Latch needle forward and backward movement crank; 471. Eccentric pin; 5. Latch needle linkage assembly; 51. Linkage rod; 52. Front rod end bearing; 53. Rear rod end bearing; 54. Linkage block; 6. Needle; 7. Main drive shaft; 71. Needle bar crank; 72. Needle bar connecting rod; 73. Needle bar connector; 74. Needle bar body; 8. Machine head; 81. Machine head hollow cavity; 9. Machine base; 91. Machine base platform; 92. Machine base head. Detailed Implementation

[0016] 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.

[0017] 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.

[0018] Please see Figure 1 and Figure 2This invention discloses a latch needle drive device for a pattern sewing machine, comprising: a latch needle power unit 1, which is connected to the power drive source of the pattern sewing machine, and the latch needle power unit 1 includes a lower main shaft 11 that can rotate around its own axis and serve as a power output shaft; and a latch needle body 2, which is used to cooperate with the needle 6 of the pattern sewing machine to perform thread winding and knotting, and the latch needle body 2 can perform compound movements in the up-down and back-forward directions. The up-down movement of the latch needle 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 needle body 2 is used to adjust the hooking position to ensure that the needle thread can be accurately wound into the latch needle groove, and finally form a firm stitch.

[0019] The aforementioned latch drive device for a pattern sewing machine further includes a latch up-and-down swing drive unit 3, which is connected to the lower main shaft 11 and converts the rotational motion of the lower main shaft 11 into the up-and-down reciprocating motion of the latch body 2; a latch forward-and-backward motion drive unit 4, which is also connected to the lower main shaft 11 and converts the rotational motion of the lower main shaft 11 into the forward-and-backward reciprocating motion of the latch body 2; and a latch linkage assembly 5, which connects the latch forward-and-backward motion drive unit 4 to the latch body 2 and transmits forward-and-backward motion power.

[0020] In this embodiment, the aforementioned latch needle power unit 1 is connected to a drive shaft 7 disposed within the aforementioned pattern sewing machine. The drive shaft 7 is the core power source of the pattern sewing machine; its front end drives the needle 6, and its middle part is connected to the lower main shaft 11 via the latch needle power unit 1. The aforementioned latch needle power unit 1 also includes an upper latch needle synchronous pulley 12, a latch needle power synchronous belt 13, and a lower latch needle synchronous pulley 14. The upper latch needle synchronous pulley 12 is fixedly mounted on the main drive shaft 7 of the pattern sewing machine and can rotate synchronously with the drive shaft 7. The upper latch needle synchronous pulley 12 and the drive shaft 7 can be fixed together by a flat key. The aforementioned lower synchronous pulley 14 of the tongue needle is fixedly mounted on the rear part of the aforementioned lower main shaft 11. The aforementioned tongue needle power synchronous belt 13 is sleeved between the outer peripheral surfaces of the aforementioned upper synchronous pulley 12 and lower synchronous pulley 14 of the tongue needle and is vertically arranged in the vertical direction. The tongue needle power synchronous belt 13 realizes synchronous power transmission through meshing transmission. The tongue needle power synchronous belt 13 is preferably made of polyurethane synchronous belt, which has the characteristics of strong wear resistance and low elasticity, and is suitable for high-precision transmission. The tongue needle power synchronous belt 13 is sleeved in the outer peripheral tooth grooves of the upper synchronous pulley 12 and lower synchronous pulley 14 of the tongue needle, and realizes synchronous power transmission through tooth surface meshing.

[0021] When the aforementioned main drive shaft 7 rotates, it drives the synchronous pulley 12 on the tongue needle to rotate synchronously. Through the meshing transmission of the tongue needle power synchronous belt 13, the power is transmitted to the lower synchronous pulley 14 of the tongue needle, which in turn drives the lower main shaft 11 to rotate around its own axis, achieving power conversion in the vertical direction. The synchronous belt drive is a slip-free drive. Compared with the traditional gear drive, it has a more precise transmission ratio, lower operating noise, and lower maintenance cost.

[0022] 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.

[0023] In this embodiment, the timing pulley 12 of the aforementioned latch needle power unit 1 and the aforementioned drive shaft 7 are both housed in the head cavity 81 of the aforementioned pattern sewing machine head 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 latch needle power timing belt 13 of the aforementioned latch needle power unit 1 extends downward from the aforementioned head cavity 81 and penetrates into the interior of the base 9. The aforementioned lower main shaft 11 and the latch needle up-and-down swing drive unit 3... It is also located inside the base 9; and on the shaft of the aforementioned lower spindle 11, a lower spindle front bearing 111, a lower spindle middle bearing 112 and a lower spindle rear bearing 113 are respectively provided. The aforementioned lower spindle front bearing 111, lower spindle middle bearing 112 and lower spindle rear bearing 113 are installed in the aforementioned base 9 and are used to support the lower spindle 11. The three bearings installed on the aforementioned lower spindle 11 can simultaneously bear radial load and slight axial load, and the three are preferably installed in the preset bearing seat of the base 9 by interference fit, forming a three-point support structure to ensure stable and reliable use.

[0024] Please pay close attention. Figure 2 Please see Figure 1The aforementioned tongue needle up-and-down oscillation drive unit 3 includes: a tongue needle up-and-down 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 cam track groove 311 is formed on the outer peripheral surface of the aforementioned tongue needle up-and-down cam 31; and a tongue needle up-and-down oscillation roller 32, which is embedded in the tongue needle up-and-down cam track groove 311 of the aforementioned tongue needle up-and-down oscillation cam 31, and the tongue needle up-and-down oscillation roller 32 can rotate synchronously with the aforementioned lower main shaft 11. The cam 31, which moves up and down, reciprocates. The contour of the aforementioned cam track groove 311 is designed to meet the stability requirements of the up and down movement of the tongue needle body 2, ensuring no sudden impact during the movement. The tongue needle roller 32 is embedded in the cam track groove 311 and rolls against the groove wall, avoiding the jamming problem that is common in traditional sliding contact and reducing component wear. The lower end of the aforementioned rocker arm 33 is connected to the aforementioned tongue needle roller via a pin 321. The 32 is fixedly connected, and the rocker arm 33, which moves up and down the tongue needle, forms the intermediate link for power transmission. The tongue needle swing shaft 34 has one end fixedly connected to the upper end of the aforementioned rocker arm 33 in the longitudinal direction, and the swing shaft 34 can swing synchronously with the rocker arm 33. A swing shaft bracket 341 and a swing shaft copper sleeve 342 are also fixedly installed on the swing shaft 34. The swing shaft bracket 341 enables the control of the tongue needle's up and down swing. The movement limit of the main body of the moving shaft 34; the tongue needle swing frame 35, the aforementioned tongue needle swing frame 35 is installed at the other end of the tongue needle swing shaft 34 away from the tongue needle swing rocker arm 33 in the length direction. A pair of tongue needle swing frame mating sections 351 protruding from the main body and symmetrically arranged are formed on the tongue needle swing frame 35. The aforementioned tongue needle swing frame 35 is preferably integrally formed of high-strength material. The symmetrical mating structure on it is used to connect with the tongue needle rod 24 to ensure balanced force during power transmission.

[0025] When the aforementioned lower spindle 11 rotates, the latch needle up-and-down movement cam 31 rotates synchronously. The change in the contour of the latch needle up-and-down movement cam track groove 311 drives the latch needle up-and-down movement roller 32 to roll along the groove, which in turn drives the latch needle up-and-down movement rocker arm 33 to reciprocate the latch needle up-and-down swing shaft 34. The swing of the latch needle up-and-down swing shaft 34 drives the latch needle up-and-down swing frame 35 to move synchronously, and finally drives the latch needle rod 24 to move up and down through the cooperating structure, realizing the up-and-down reciprocating motion of the latch needle body 2. The latch needle up-and-down swing drive unit 3 precisely controls the up-and-down movement law of the latch needle through the cam contour, avoiding impact loads during the movement and effectively reducing the probability of wire breakage. At the same time, the rolling friction between the roller and the cam groove greatly reduces component wear and extends the overall service life of the drive unit. The stable support structure of the latch needle up-and-down swing shaft 34 ensures that the up-and-down movement trajectory of the latch needle body 2 is consistent, avoiding hooking deviation caused by shaft shaking.

[0026] 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 and right latch needle seat guide blocks 22 and 23 are arranged opposite to each other. Both the left and right latch needle seat guide blocks 22 and 23 have elongated grooves extending in the horizontal direction, and both are fixedly installed on the aforementioned pattern sewing machine by fasteners set in the elongated grooves. The installation positions of the left and right latch needle seat guide blocks 22 and 23 can be adjusted by adjusting the position of the fasteners in the elongated grooves, so as to realize the translation of the two, 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 aforementioned latch needle seat 21, and the latch needle rod 24 swings up and down with the aforementioned latch needle. The drive unit 3 and the tongue needle linkage assembly 5 are connected for transmission and are 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 assembly 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 assembly 5, thereby driving the tongue needle body 2 to form a composite motion trajectory of up and down and back and forth.

[0027] 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.

[0028] In this embodiment, the aforementioned tongue needle forward and backward movement driving unit 4 includes: a power arc gear 41, which is fixedly installed at the middle position of the aforementioned lower main shaft 11 and can rotate synchronously with the aforementioned lower main shaft 11; a gear shaft 42, which extends vertically and the gear portion at the bottom of the gear shaft 42 meshes with the aforementioned power arc gear 41 and can rotate under the drive of the aforementioned power arc gear 41; an active arc gear 43, which is fixedly sleeved on the top end of the aforementioned gear shaft 42 and can move synchronously with the rotation of the aforementioned gear shaft 42; and a passive arc gear 44, which is horizontally arranged above the aforementioned active arc gear 43 and the passive arc gear 44 and the aforementioned active arc gear 43 are connected. The aforementioned active arc gear 43 and passive arc gear 44 have high precision in their tooth surface engagement. Through efficient transmission, vertical rotation can be converted into horizontal reciprocating rotation, and the arc tooth surface limits the range of motion to avoid overtravel collisions. The aforementioned needle forward and backward movement drive unit 4 also includes an arc gear bracket 45, which is fixedly installed on the aforementioned pattern sewing machine. The upper end of the aforementioned gear shaft 42 passes through the bottom plate of the arc gear bracket 45 and rotates with the aforementioned arc gear bracket 45 through a bearing. The aforementioned active arc gear 43 and passive arc gear 44 are both installed in the arc gear bracket 45. The arc gear bracket 45 can provide stable support for the gear shaft 42 and ensure precise meshing transmission.

[0029] Furthermore, the aforementioned tongue needle forward and backward movement drive unit 4 also includes a tongue needle forward and backward movement drive crank shaft 46 and a tongue needle forward and backward movement crank 47; wherein, the aforementioned tongue needle forward and backward movement drive crank shaft 46 extends horizontally and passes through the central hole of the aforementioned driven arc gear 44 and the left and right sides of the aforementioned arc gear bracket 45, and the tongue needle forward and backward movement drive crank shaft 46 is fixedly connected to the aforementioned driven arc gear 44 and rotates with the aforementioned arc gear bracket 45 through bearings, and the tongue needle forward and backward movement drive crank shaft 46 can move synchronously with the rotation of the aforementioned driven arc gear 44; the aforementioned tongue needle forward and backward movement crank 47 is fixedly sleeved on the aforementioned tongue needle forward and backward movement drive unit 47. At the other end of the drive crankshaft 46, which is away from the aforementioned arc gear bracket 45 in the length direction, the aforementioned tongue needle forward and backward movement crank 47 is provided with an eccentric pin 471. The axis of the aforementioned eccentric pin 471 is parallel to and does not coincide with the axis of the aforementioned tongue needle forward and backward drive crankshaft 46. The aforementioned tongue needle forward and backward movement crank 47 is connected to the aforementioned tongue needle linkage assembly 5 through the eccentric pin 471. The eccentric pin 471 on the aforementioned tongue needle forward and backward movement crank 47 provides the basis for the conversion of the tongue needle forward and backward movement. The axis of the tongue needle forward and backward drive crankshaft 46 is offset from the axis of the tongue needle forward and backward movement crank 47, realizing the conversion from rotation to linear reciprocating motion.

[0030] The aforementioned tongue needle forward and backward movement drive unit 4 is driven by the lower main shaft 11. When the lower main shaft 11 rotates, the power arc gear 41 rotates synchronously, driving the gear shaft 42 to rotate through meshing. The gear shaft 42 drives the active arc gear 43 to rotate, which in turn drives the passive arc gear 44 to rotate. The passive arc gear 44 drives the tongue needle forward and backward movement crank shaft 46 to move synchronously. The tongue needle forward and backward movement crank 47 rotates with the tongue needle forward and backward movement crank shaft 46, and the circumferential motion of its eccentric pin 471 is converted into forward and backward reciprocating motion, which is finally transmitted to the tongue needle rod 24 through the tongue needle linkage component 5 to drive the tongue needle body 2 to move forward and backward. This drive unit adopts the arc gear transmission method, whose tooth surface contact area is larger than that of traditional spur gears, resulting in less force per unit area, slower wear, and a smoother transmission process. All multi-stage transmissions are rigidly connected without intermediate flexible links, ensuring that the forward and backward movements are synchronized with the rotation of the lower main shaft 11, avoiding lag or lead. The aforementioned arc gear bracket 45 integrates each transmission component into a rigid module, reducing the impact of independent vibration on transmission accuracy and further improving motion stability.

[0031] In this embodiment, 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. The inner ring of the rear rod end bearing 53 is fitted with the outer circumferential surface of the eccentric pin 471 of the aforementioned tongue needle front and rear movement drive unit 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 aforementioned tongue needle linkage assembly 5 and the tongue needle body 2. Both the front rod end bearing 52 and the rear rod end bearing 53 are spherical bearings adaptable to multi-angle swing. The inner ring of the rear rod end bearing 53 fits with the eccentric pin 471. The outer ring is fixed to the rear end of the linkage rod 51, and 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 eccentric pin 471 of the aforementioned tongue needle forward and backward movement crank 47 performs reciprocating circular motion, the linkage rod 51 is pushed to perform a compound motion in the forward and backward directions through the rear rod end bearing 53. 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 in the forward and backward directions. The design of the joint bearing can adapt to the angle change in the movement of the linkage rod, avoid the rod bending or wear problem at the connection that is easy to occur in traditional rigid connections, and extend 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 forward and backward motion.

[0032] Please see Figure 1 and Figure 2The 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 upper and lower swing drive unit 3 of the drive device and the front and rear action drive unit 4 share the lower main shaft 11 as the power source. The unified rotation reference ensures the synchronization of the action. 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 tongue needle to rotate through the upper synchronous belt pulley 12 and the power synchronous belt 13 of the tongue needle, thereby driving the lower main shaft 11 to rotate synchronously. 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 tongue needle up-and-down movement drive unit 3 to rotate. The tongue needle up-and-down movement roller 32, which is 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 movement shaft 34. The tongue needle rod 24 swings synchronously with the tongue needle up-and-down movement frame 35, ultimately driving the tongue needle body 2 to move up and down. The other way is through the power arc gear 41 of the aforementioned tongue needle forward-and-back movement drive unit 4 to drive the gear shaft 42 to rotate. The gear shaft 42 further drives the active arc gear 43, the passive arc gear 44, and the crank shaft 46 to move in sequence, ultimately driving the tongue needle forward-and-back movement crank 47 to rotate. The tongue needle forward-and-back movement crank 47 then drives the tongue needle body 2 to move forward and backward through the transmission of the eccentric pin 471, the tongue needle linkage assembly 5, and the tongue needle rod 24. 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.

[0033] In summary, the technical solution provided by this utility model makes up for the shortcomings of the prior art, successfully completes the invention task, and faithfully realizes the technical effects described by the applicant in the above technical effect column.

Claims

1. A latch needle drive device for a pattern sewing machine, characterized in that, include: The system includes a latch needle power unit (1), which is connected to the power drive source of the pattern sewing machine. The latch needle power unit (1) includes a lower main shaft (11) that can rotate around its own axis and serve as a power output shaft. The system also includes a latch needle body (2), which is used to work with the needle (6) of the pattern sewing machine to wrap and knot the thread. The latch needle body (2) can perform compound movements in the up-down and back-forward directions. The system also includes a latch needle up-down swing drive unit (3), which is connected to the lower main shaft (11) and used in conjunction with the lower main shaft. The rotational motion of the lower main shaft (11) is converted into the reciprocating motion of the tongue needle body (2); the tongue needle front and back motion drive unit (4) is also connected to the lower main shaft (11) for transmission, and the tongue needle front and back motion drive unit (4) is used to convert the rotational motion of the lower main shaft (11) into the reciprocating motion of the tongue needle body (2); the tongue needle linkage assembly (5) is used to connect the tongue needle front and back motion drive unit (4) with the tongue needle body (2) and to transmit the front and back motion power.

2. The latch needle driving device for a pattern sewing machine according to claim 1, characterized in that: The latch needle power unit (1) is connected to a main power shaft (7) located in the pattern sewing machine. The latch needle power unit (1) also includes an upper latch needle synchronous pulley (12), a latch needle power synchronous belt (13), and a lower latch needle synchronous pulley (14). The upper latch needle synchronous pulley (12) is fixedly mounted on the main power shaft (7) of the pattern sewing machine and can rotate synchronously with the main power shaft (7). The lower latch needle synchronous pulley (14) is fixedly mounted at the rear of the lower main shaft (11). The latch needle power synchronous belt (13) is mounted between the outer circumferential surfaces of the upper latch needle synchronous pulley (12) and the lower latch needle synchronous pulley (14) and achieves synchronous power transmission through meshing.

3. The latch needle driving device for a pattern sewing machine according to claim 2, 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.

4. A latch needle driving device for a pattern sewing machine according to claim 2, characterized in that: The timing pulley (12) on the latch of the latch power unit (1) and the driving shaft (7) are both installed 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 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 latch power synchronous belt (13) of the latch power unit (1) is connected from the hollow cavity (81) of the head. The lower spindle (11) extends downward and penetrates into the machine base (9), and the lower spindle (11) and the tongue needle swing drive unit (3) are also located inside the machine base (9). 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 machine base (9) and are used to support the lower spindle (11).

5. A latch needle driving device for a pattern sewing machine according to claim 1, characterized in that: The tongue needle up-and-down swing drive unit (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 (311) 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 (3). 4) One 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).

6. A latch needle driving device for a pattern sewing machine according to claim 5, 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 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 long grooves. Adjusting the position of the latch needle seat (21) and the latch needle body (2) can 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 latch needle up and down swing drive unit (3) and the latch needle linkage group respectively. The component (5) enables transmission connection and drives 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.

7. A latch needle driving device for a pattern sewing machine according to claim 6, characterized in that: The tongue needle forward and backward movement drive unit (4) includes: a power arc gear (41), which is fixedly installed in the middle of the lower main shaft (11) and can rotate synchronously with the lower main shaft (11); a gear shaft (42), which extends vertically and the gear part at the bottom of the gear shaft (42) meshes with the power arc gear (41) and can rotate under the drive of the power arc gear (41); and an active arc gear (43), which is fixedly sleeved on the top end of the gear shaft (42) and can move synchronously with the rotation of the gear shaft (42). A passive arc gear (44) is horizontally positioned above the active arc gear (43), and the passive arc gear (44) meshes with the active arc gear (43) and can rotate under the drive of the active arc gear (43); an arc gear bracket (45) is fixedly mounted on the pattern sewing machine, the upper end of the gear shaft (42) passes through the bottom panel of the arc gear bracket (45) and rotates with the arc gear bracket (45) through a bearing, and the active arc gear (43) and the passive arc gear (44) are both fitted into the arc gear bracket (45).

8. A latch needle driving device for a pattern sewing machine according to claim 7, characterized in that: The tongue needle forward and backward movement drive unit (4) further includes a tongue needle forward and backward movement drive crank shaft (46) and a tongue needle forward and backward movement crank (47); wherein, the tongue needle forward and backward movement drive crank shaft (46) extends horizontally and passes through the center hole of the driven arc gear (44) and the left and right sides of the arc gear bracket (45), and the tongue needle forward and backward movement drive crank shaft (46) is fixedly connected to the driven arc gear (44) and rotates with the arc gear bracket (45) through bearings, and the tongue needle forward and backward movement drive crank shaft (46) can follow the driven arc gear The rotation of the wheel (44) makes synchronous movement; the front and rear movement crank (47) of the tongue needle is fixedly sleeved on the other end of the front and rear drive crank shaft (46) of the tongue needle away from the arc gear bracket (45) in the length direction. The front and rear movement crank (47) of the tongue needle is provided with an eccentric pin (471). The axis of the eccentric pin (471) is parallel to and does not coincide with the axis of the front and rear drive crank shaft (46) of the tongue needle. The front and rear movement crank (47) of the tongue needle is connected to the tongue needle linkage assembly (5) through the eccentric pin (471).

9. A latch needle driving device for a pattern sewing machine according to claim 8, 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 outer circumferential surface of the eccentric pin (471) of the tongue needle front and rear movement drive unit (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).

Images