Four-thread embroidery machine

Abstract

This invention relates to a mechanical embroidery machine capable of processing four embroidery threads simultaneously, thus producing intricate embroidery patterns with multi-color gradients. The embroidery machine of this invention incorporates an improved system that can synchronize components, manage thread tension, and prevent thread tangling, while simultaneously enabling precise control of needle and fabric movement through a novel J-shaped bending arm mechanism. The embroidery machine of this invention is equipped with specific rotary hooks and gears that coordinate movements and optimize embroidery precision and quality, while also aiding in the adjustment of thread tension and pressure.

Description

[Technical Field]

[0001] This invention relates to the field of textile machinery technology, and more particularly to an industrial or manual embroidery machine for producing embroidery patterns on various textile materials. This invention belongs to the subfield of mechanical embroidery machines and can process four embroidery threads simultaneously, thus producing intricate and multi-colored embroidery patterns without frequent manual intervention. [Previous Technology]

[0002] Mechanical embroidery machines rely on purely mechanical systems without human assistance, creating patterns on fabric through the coordinated movement of the needle and embroidery frame. One of the most famous innovations in this field is the development of embroidery machines capable of producing chain stitch and bouquet stitch, providing a variety of textures and raised patterns on fabric.

[0003] Among these machines, one particular type has brought about a significant change to mechanized embroidery: the manually guided (hand-guided) embroidery machine. This type of machine is used to produce continuous stitches such as the Beauvais stitch (or chain stitch), which are known for their ability to follow patterns drawn on the fabric manually. The fabric is positioned using a crank or foot pedal system, and the needle movement is synchronized with the embroidery frame, allowing for a level of freedom of movement rarely seen in traditional mechanical machines. This mechanism operates on a universal drive, with the operator guiding the fabric beneath the needle to form the pattern, resulting in designs that are more in line with traditional craftsmanship and handcrafting techniques, while also offering the benefits of machine assistance and ensuring consistent stitch patterns.

[0004] A key pattern in this field is that the machine excels at "undercut" and chain stitches, and is highly regarded for adding fine cords, beads, and other complex decorative elements. This pattern is equipped with an additional rotary hook that can hook the embroidery thread and weave it around the needle to form continuous loops or delicate decorative edges.

[0005] The principle of this type of embroidery machine is based on the ability to precisely repeat needle movements mechanically to produce standard patterns with variations in stitches. In addition, some modes can perform towel stitch or osmanthus stitch, using multiple layers of embroidery thread to provide distinctly different three-dimensional effects.

[0006] The main feature of this type of machine is that it includes a manual fabric feeding system located below the machine and controlled by a handle, allowing the operator to guide the embroidery frame according to the desired pattern. Some machines also include accessories for sewing sequins, braiding threads, and even performing beadwork, thus enhancing their versatility and ability to produce outstanding embroidery through manual control.

[0007] Although digital embroidery machines have been introduced, mechanical embroidery machines continue to be used because they are capable of replicating the unique appearance, high time-tested quality, and high precision of hand embroidery. In situations where the tactile feel and detail quality are paramount, such as in uniform production or decorative embroidery on delicate fabrics, mechanical embroidery machines remain the better choice.

[0008] This type of embroidery machine embodies the balance between handicrafts and mechanization, allowing embroidery to retain the charm and precision of handmade products while also benefiting from the efficiency of mechanization to mass-produce without sacrificing the quality of the finished product.

[0009] Moroccan embroidery is an ancient technique, distinguished by its richness and diversity, and deeply embedded in the country's clothing and religious traditions. Traditional Moroccan garments, such as the khaftan, djerraba, and short-sleeved robes, are adorned with intricate embroidery, varying according to religion, city, and even family. Each embroidery tells a story, conveying the unique symbols, beliefs, and cultural elements of each group. These patterns are often inspired by nature, Islamic geometric patterns, or calligraphic symbols, reflecting the influence of Islamic and Andalusian art permeating Moroccan identity.

[0010] Each region of Morocco has its own unique embroidery style, distinguishing different traditional garments. For example, Fez is known for its floral embroidery using silk thread, creating exquisite and intricate patterns on high-quality fabrics. In contrast, Meknes stands out for its rigorous geometric patterns, often using gold and silver thread to symbolize rigor and stability. Tetouan's embroidery is unaffected by Andalusian art, using specific stitches to create designs reminiscent of the Arabesque (vine) style; Rabat's embroidery incorporates more abstract designs, emphasizing a freer and more contemporary style.

[0011] Embroidered clothing occupies a central position in religious and festive events, such as weddings, religious ceremonies, and major celebrations. Hand-embroidered patterns using silk, gold, and silver threads add a unique brilliance to garments. These embroideries not only adorn clothing but also strengthen spiritual and cultural connections, as each design and thread carries meaning and symbolism. However, due to the complexity of these embroideries, they often require rare handcraft skills passed down through generations. While the beauty of hand-embroidered patterns is undeniable, modernization and growing demands have pushed handcrafting towards embroidery machines. Classic mechanical embroidery machines, such as those used in the 19th century, have accelerated the embroidery process while maintaining a certain level of craftsmanship. However, these machines cannot always capture the accuracy and authenticity of traditional Moroccan patterns, limiting their use to replicating embroideries intended for special occasions.

[0012] Therefore, it is extremely important to develop machines specifically designed for Moroccan embroidery. These machines must not only faithfully reproduce complex patterns but also respect the uniqueness of the region and the technical requirements of each embroidery type. For example, the tight stitches and intricate patterns of Fez embroidery require precise control of thread tension and execution speed; while the abstract designs of Rabat embroidery require more flexibility in stitch selection. Current embroidery machines are often designed for standard embroidery and cannot meet these specific needs.

[0013] Developing mechanized embroidery machines adapted to Moroccan handicrafts helps preserve historical heritage while meeting modern production needs. These machines can be equipped with hand-guided systems and mechanical adjustments to help complete intricate multi-threaded patterns and maintain the fidelity of handcrafted works. Innovations in needle design, shuttle, and transmission mechanisms also allow for the use of a variety of different fabrics and threads, respecting the techniques and intricacies of traditional embroidery.

[0014] For example, one of the prior art, Moroccan patent application No. 67481, describes an embroidery machine including at least one needle operably connected to a needle bar to form embroidery stitches on fabric; a presser foot guide arm with a U-shaped lower end is mounted to move vertically parallel to the needle bar and slidably accommodates the needle bar therein. The presser foot guide arm can descend synchronously with the needle bar, pressing the fabric at the position where the needle passes through the fabric; the presser foot guide arm is also mounted to move horizontally when the needle rises, moving the fabric by pressing around the needle.

[0015] This type of embroidery machine includes a gearbox operated by a presser foot slider crank; a series of keyed gears are mounted on the main shaft and connected to a carriage; the gearbox interacts with the carriage. This gearbox can engage with the gear set mounted on the main shaft, allowing the operator to adjust the embroidery speed and stitch length.

[0016] For example, French Patent No. FR730878 relates to a crank-driven mechanical embroidery machine designed for running satin stitch, satin stitch, and zigzag stitch. This embroidery machine includes a special needle capable of lateral skipping while simultaneously maintaining its vertical position. This feature allows for the creation of intricate embroidery patterns with adjustable skipping amplitude during operation. This embroidery machine uses a control lever for lateral needle movement and a specific guide system, which can be adjusted according to embroidery needs. Furthermore, the embroidery machine incorporates a differential mechanism that synchronizes needle movement with the thread hook to ensure the thread hook tip is in the correct position relative to the needle.

[0017] British Patent No. GB2121445 describes an embroidery machine including a standby mechanism that retracts and resets important components, such as the needle, presser foot guide arm, and presser foot guide, when the embroidery process is paused. This system uses a slotted cam and a swing arm to synchronize the vertical movement of these components, allowing them to rise from the work area and return to the operating position when embroidery resumes. Furthermore, the invention includes a mechanism that can change the needle height to adjust the thread loop length, thus allowing precise control over the consistency of the stitches.

[0018] Finally, US Patent No. 1670978 relates to an improvement on a crank-type embroidery, sewing, and openwork machine. Its characteristic is that it includes a presser foot securely mounted on a rod that swings about two mutually perpendicular axes X and YY, guided by a hinge mounted on a vertical tube for vertical reciprocating motion. This hinge, along with a robust element, ensures smooth, jump-free movement, providing system stability and preventing unwanted lateral displacement. This mechanism, based on the gimbal suspension principle, allows for multi-axis swinging while maintaining a fixed point on the vertical axis (ZZ), thereby improving system durability and accuracy while reducing wear. [Summary of the Invention]

[0019] This invention relates to improvements to embroidery machines, particularly improvements designed for Moroccan hand-stitched crank embroidery and openwork. More precisely, the improvements of this invention target synchronization mechanisms and pivot element mechanisms that allow the presser foot to move vertically and guide the fabric. This improvement facilitates multi-thread embroidery, including two embroidery threads or braided threads and two additional sewing threads. The purpose of these mechanisms is to increase the number of usable threads and modify embroidery machine components to prevent thread tangling under the needle plate, thread breakage, and fabric wrinkling, while introducing needle holder modifications and optimizing the synchronization of parts.

[0020] This invention addresses technical problems that can affect the proper functioning of embroidery machines, leading to production interruptions. One of the most common issues is mechanical jamming, which typically occurs due to poor synchronization of parts or accumulation of embroidery thread in critical areas of the machine. This problem can cause the machine to stop suddenly and often requires partial disassembly to identify the source of the problem and remove the obstructing moving parts.

[0021] Another common problem that this invention aims to solve is thread tangling, characterized by the thread becoming tangled and forming a messy ball under the needle plate. This defect is often caused by incorrect thread tension settings or improper bobbin threading.

[0022] Thread breakage is also a recurring problem, especially when the thread quality is poor, the needle is worn, or the thread is improperly passed through the tension guide. Excessive thread tension or friction with the guide can cause rapid wear and frequent thread breakage.

[0023] Fabric wrinkling is another common defect that this invention seeks to address. Often, when the embroidery thread tension is too high or the fabric is not taut enough, the embroidered product will appear wrinkled or wavy.

[0024] To overcome these challenges, the first improvement of this invention is the integration of a spring-loaded embroidery thread tensioner within the system. This tensioner is designed to swing freely around its central screw and is mounted on a support fixed to the frame. This architecture allows the tensioner to adjust the pressure on the bobbin according to the rotational speed of the bobbin post, ensuring constant thread tension under all operating conditions. The tensioner support is equipped with a screw and spring, which can automatically adjust according to speed changes, providing precise bobbin pressure control. It also includes an adjusting nut, allowing for fine-tuning of the bobbin pressure to provide flexibility for specific sewing needs.

[0025] Furthermore, the embroidery machine of the present invention is equipped with an arm (13) having a crosshead designed to allow the upper end of the arm to swing around two horizontal axes. This crosshead is characterized by two central flat surfaces, each containing a hole for aligned or parallel needle bars. The other two lateral flat surfaces of the crosshead have smooth cylindrical holes that enclose a trunnion assembly inserted therein for optimal support.

[0026] The aforementioned arm itself has a J-shaped curved shape, with a section designed to accommodate the needle holder. This unique arm design optimizes the positioning and movement of the needle stick while maintaining substantial mechanical stability, enabling the creation of precise embroidery pieces with intricate shapes.

[0027] Furthermore, the present invention employs a new tube and needle configuration to address another problem related to the entanglement of the braided thread around the needle. The tube has been extended and positioned to precisely guide the braided thread to the sewing spool, thereby eliminating the risk of work breakage or sewing defects caused by thread entanglement.

Implementation Method

[0029] The following description provides certain specific details to aid in understanding the present invention. However, it should be noted that the present invention is not limited to the specific embodiments described herein, but can be implemented in different ways. Those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the present invention is not limited to the specific embodiments described below.

[0030] The details of this invention are related to the accompanying drawings. The three-dimensional view of the embroidery machine shown in the detailed description of this invention is for better explanation. This invention can be implemented to general scale, and the examples shown in the drawings are merely illustrative and not intended to limit the scope of protection. Furthermore, the three-dimensional dimensions (length, width, and depth) in the drawings are only illustrative.

[0031] In the context of this description, the term "embroidery" refers to a decorative technique in which various decorative patterns are added to beautify textiles using embroidery threads (such as embroidery thread or braided thread). These patterns are produced mechanically using specific stitches to create intricate designs.

[0032] Referring to the figures, this invention relates to an embroidery machine designed to produce intricate decorative embroidery patterns on various textiles. The operating center of the embroidery machine is an arm that allows operation on the fabric surface while facilitating precise control of the embroidery thread. Height-adjustable presser feet firmly position the fabric, ensuring appropriate tension for even embroidery.

[0033] The solution proposed in this invention is to integrate several mechanisms to improve existing embroidery machines, especially crank-type sewing machines and embroidery machines that use four threads and are equipped with a drive mechanism to sew decorative edges on fabrics.

[0034] The object of the present invention is to provide a means by which the driving action amplitude can be easily adjusted regardless of the driving direction. The present invention also provides an improved method for carrying and actuating the pressure foot and the lifting element, so as to allow easy adjustment of the pressure exerted by the pressure foot and the lifting element on the embroidery thread.

[0035] Referring to Figures 1-18, the embroidery machine according to the first embodiment of the present invention includes a hinge or crosshead 145. When this hinge or crosshead 145 slides on a needle bar sleeve 506 to perform its upward, downward, and guiding actions, it allows the presser foot guide rod 130, driven to reciprocate, to swing around two orthogonal axes and two other intermediate axes. The crosshead 145 is characterized by having a housing having two cylindrical or spherical surfaces or a truncated spherical surface, and two flat surfaces with smooth cylindrical holes. The housing houses an assembly having two cylindrical surfaces and two flat surfaces, and is provided with trunnions 141 that engage with the smooth cylindrical holes.

[0036] In the first embodiment, the crosshead 145 is drilled with two smooth holes; the screw of the presser foot guide 130 has a cylindrical end, which engages with the smooth holes to allow the presser foot guide 130 to pivot about the X-X' axis. The crosshead 145 is supported by a bearing, in which the cylindrical pivot of the pivot assembly rotates. The bearing is securely fixed to the vertically movable sliding presser foot guide 130.

[0037] A component is mounted in a high position and is visible inside the crosshead 145. This component has two cylindrical surfaces and two flat surfaces with cylindrical trunnions. The crosshead 145 has a recess of corresponding shape, and the recess has two symmetrically arranged partial cylindrical surfaces and two flat surfaces.

[0038] It should be noted that in this structure, when the crosshead assembly swings around the XX axis and other intermediate axes, it cannot move along the YY axis or the XX axis. Moreover, when the pivot block makes vertical reciprocating motion due to machine operation, the center point O will often remain on the ZZ axis.

[0039] Please refer to Figures 8, 9, 10, 11, and 13, which show that the first embodiment of the present invention includes a supporting main control platform 100. The supporting main control platform 100 is provided with a plurality of rectangular grooves to accommodate mechanical components. The supporting main control platform 100 includes an upper frame 101 and a lower part. The upper and lower parts support a vertically movable needle bar 510. The upper end of the needle bar 510 includes a gear component 504 with an upper shaft collar and a lower shaft collar. At least one needle 513 is concentrically fixed at the lower end of the needle bar 510. The gear 504 is installed in the center of the needle bar 510. When the fabric to be embroidered is pushed forward horizontally by a fabric feeding mechanism, the rotation of a drive motor or drive pulley is transmitted to the needle bar 510 via the gear 504, causing the needle bar to rotate toward the fabric to be embroidered. A presser foot lifting guide 135 is provided at the rear of the upper end of the needle bar 510. A presser foot slider crank 109, which is capable of vertical movement, is installed at the front end of the presser foot lifting guide 135. The presser foot slider crank 109 includes a base 109a, a first driving point 109b extending laterally from the upper end, and a fork-shaped gripper element 520 that can protrude to contact and generate a clamping effect. A horizontally rotatable main cam 414 is installed on the support body. A pin 419 is provided at the rear end of the main cam 414 to contact the upper surface of the needle bar drive cam (520a).

[0040] Please refer to Figures 7, 10, and 11. According to this configuration, when the main shaft 403 of the embroidery machine rotates continuously, it drives the main cam 414 to rotate. This rotational motion is converted into the vertical movement of the lifting component 5 by the pin 419, and the needle 513 is driven by the lifting component 5 to move vertically. The upper and lower parts supporting the main control panel 100 support a vertically movable needle bar sleeve 506, which is parallel to the needle bar 510 on the right side. A second gear component 502 is fixed to the upper end of the needle bar sleeve 506. An arc-shaped cam 137 is installed at the front end of the shaft 136, and a swing rod can swing under the action of the arc-shaped cam 137.

[0041] Please refer to Figures 6, 12, and 15. The gear transmission mechanism includes a sleeve shaft 818 and a bevel gear 821 that meshes with it; the bevel gear 821 drives gears 806 and 903. Gear 903 supports a needle plate 905, which is aligned with the upper surface of the worktable 2 and vertically corresponds to the bent needle (906) that meshes with the needle 513. The bent needle 906 is connected to a vertical shaft 900 mounted in a fixed bearing sleeve 200. In the two examples shown, the needle plate 905 is driven in a conventional rotational manner by meshing with the needle via the gear (903) and its associated mechanism; the bent needle 906 is driven by gear 820 mounted on a shaft 819 mounted in the gear seat 201. The shaft 819 is provided with a key that meshes with the bevel gears 809 and 821 and is driven by the handle 813 of the hand crank transmission mechanism 8.

[0042] Please refer to Figures 6, 10, 12, and 15. With the above configuration, when the sleeve shaft 818 is rotated using the handle 813, the needle bar sleeve 506 and the holding element rotate around their axis to adjust the needle 513 as needed, allowing the direction of the embroidery stitch to be changed, and the support ring and the looper 906 are operated synchronously with them. When the shaft (819) is driven to reciprocate by the main shaft 403 via the mechanisms shown in the figures, the looper 906 can properly cooperate with the needle 513 to produce embroidery stitches during embroidery sewing. It should be understood that the machine configuration shown above, including a presser foot guide 130 which can be of a known type and operated in a known manner, or an associated mechanism, works correctly in conjunction with the other machine mechanisms shown in the figures. In a preferred configuration, as shown in the figures, the presser foot guide rod 130 is mounted on the machine using a ball joint. Through the ball joint, the presser foot guide rod 130 can be properly synchronized with the associated mechanism to raise and lower the presser foot 131.

[0043] Referring to Figure 11, as previously noted, the needles 513 pass downward through the holding element and have a considerable length due to the presence of a support; the support 511 of the needles is held only at its upper end by a clamping element 512. The needle 513 is shown in the figure as an example of a sewing machine needle, and its lower end slides through a guide, which is part of or mounted on an adjustable support. This sliding joint can be an open dovetail joint and is secured in its adjusted position with a screw; the screw can be used to clamp the joint within the dovetail groove. This joint is flat and is secured in its adjusted position with one or more adjusting screws. In any case, the needle mounting head can be equipped with an annular flange; the flange can slide onto a collar 509 and be secured there with, for example, an adjusting screw, the collar 509 itself also being secured to a needle bar sleeve 506 with an adjusting screw.

[0044] Please refer to Figures 10, 12, and 17. When the embroidery machine described above is operated, power can be supplied from any suitable power source to the belt drive system 402 to rotate the main shaft 403, thereby causing the presser foot guide rod 130 and the needle 513 it supports to reciprocate in the vertical direction relative to the needle bar 510. At the same time, the needle plate 905 and the curved needle 904 are appropriately actuated synchronously with the needle 513 to form embroidery stitches.

[0045] Please refer to Figures 11 and 17. During the above-described operation, the needle guide, associated components, presser foot guide arm, and presser foot 131 all rise and fall accordingly to achieve proper synchronization with the operation of the needle 513. At the same time, the presser foot guide 130 is also actuated in the usual manner, cooperating with the aforementioned components. When the needle bar sleeve 506 moves up and down during these operations, the presser foot guide 130 moves up and down accordingly, and its movement is transmitted to the presser foot lifting guide 135 and the presser foot slider crank (109).

[0046] Please refer to Figures 3, 10, 11, 13, and 18. Simultaneously, the cam 416, in conjunction with the pin 416a, tilts the pull rod 307, thereby controlling the embroidery thread to pass through the opening of the pull rod 307. At the same time, the auxiliary lifter mounted on the support participates in the rotational action through the gear 706 of the support, cooperating with the lifting rod to appropriately control the embroidery thread according to the spacing of the needles 513. It should be understood that the embroidery machine can be equipped with multiple needles spaced apart from each other. The needle spacing refers to the distance between the lower ends of the needles. When the handle 813 is not operated, the embroidery stitches produced by the embroidery machine will extend in a straight line along a specified direction. If the hand crank is manually rotated, the mechanism driven by the handle 813 will cause the presser foot guide arm 13 and the presser foot 131, along with the needles 513, to rotate, changing the direction of the aforementioned embroidery stitches and allowing the stitches to form along arcs or other directions deviating from a straight line.

[0047] In a preferred embodiment of the present invention, the binding thread can be wound under tension around the embroidery thread or braided thread to form a decorative thick thread. In such conventional embroidery machines, the tension of the binding thread when wound around the embroidery thread is kept at a constant value, so the thickness or diameter of the resulting thick thread can be consistent throughout its entire length.

[0048] Another advantage of the present invention is that, when performing the binding wire winding operation, the tension of the binding wire can be automatically changed at fixed time intervals, so that the resulting decorative thick wire has a variable thickness or diameter along its entire length.

[0049] However, the present invention can be applied to other types of embroidery machines, using binding thread to wrap the embroidery thread to form decorative thick thread. It should be understood that the term "embroidery thread" as used herein is broad and therefore includes sewing thread and other types of thread used as embedding thread. The phrase "two or three thread binding" describes such machines.

[0050] Please refer to Figures 3 and 11. The machine embroidery of the present invention also includes a thread reel mechanism 7. The thread reel mechanism 7 has a bobbin guide rod 701 connected to a pivot crank 704 to support two forks 703 and 703'. Each fork carries a bobbin 702, on which embroidery thread or braided thread is wound. The bobbin rotates freely on the winding rod, unwinds the braided thread, and can be removed from the fork along with the embroidery thread or braided thread. The braided thread is guided from the bobbin through a bobbin guide rod 701, enters an opening extending downward from the pivot crank 704, descends towards the upper part of the presser foot guide rod 130, and extends downward along the longitudinal side recess of the needle bar 510 to the lower section of the presser foot ring 132, passes through the oblique hole in the lower section, and extends outward and downward along a guide bushing. The guide bushing is a pin that is locked into the lower part of the presser foot guide rod support arm from the lower end of the presser foot bar section. The pin has a central through hole for the use of the needle and a collar.

[0051] Please refer to Figures 8 and 11. A spring 120 is provided between the collar 133 of the tube connector and the flange at the upper end of the presser foot lifting guide 135 (the guide bushing presses against the lower end of the presser foot bar). The spring 120 acts as a buffer spring for the tube connector and can be adjusted to continuously push the braiding thread forward according to the operation requirements. The lower section of the presser foot guide 130 is guided through the sleeve-shaped upper end located in the upper part of the presser foot guide 130, and the upper part of the presser foot guide 130 is clamped to the needle bar by the shaft pin 134. The aforementioned lower section retracts when the needle bar descends; and the lower section moves downward due to gravity when the needle bar rises. The needle passes through the center of the braiding thread, placing the braiding thread evenly on the fabric. The braiding thread is guided forward along the needle bar, the presser foot 131, and the tube connector, and is unfolded by the latter together with the fabric feeding mechanism on the embroidery machine that pushes the fabric forward.

[0052] Referring to Figure 13, the rod 303 of the braking element is slidably disposed within the bore 3052 of a block 305. The block is embedded at its front end and equipped with an arc-shaped extended support portion 3051, which forms a recess and support portion for fitting onto the outer periphery of a collar. A bolt 310 passes through the support portion 3051, securing the block 305 to the collar. A helical spring 301 is installed within the bore 3052 and is held in place by an adjustable helical plug 302. The helical spring 301 engages with the rear end face of the rod 303, elastically resisting the rod's retraction within the bore when the braking element engages the flange. The rod 303 has a groove to accommodate an adjusting screw, used to guide the rod and prevent rotational movement. A stop 304 abuts against the screw at the end of the rod to keep the rod within the bore 3052. A relatively light helical spring 311 is provided on the outer periphery of the rod 303 and is engaged between the brake and the front end of the block to apply an initial tension to the flange.

[0053] When the binding line is wrapped around the perimeter of the fabric, the embroidery thread is pulled out from the bobbin under a constant tension set by a conventional tension joint. During each rotation of the bobbin, the outer periphery of the flange engages with the braking element; the braking element tends to elastically resist the rotation of the bobbin. At the initial engagement, the helical spring 311 provides slight resistance to the retraction of the rod 303, causing the braking element to gradually slow down the rotation of the bobbin. Therefore, when the binding line is wrapped around the edge of the fabric, only a slight constraint is applied to the binding line, so that the binding line wraps more tightly around the periphery of the fabric edge in a gradually thinning manner.

[0054] In a preferred embodiment of the present invention, the embroidery machine 1 includes a drive rod; the drive rod carries a movable feed foot and is configured to control the feed foot in a normal manner using a feed foot slider crank. A feature of the present invention is that it actuates a cam element of the feed foot slider crank; this cam element has multiple cam surfaces with continuously varying inclination angles and is cyclically adjustable so that the cam surfaces engaged with the feed foot slider crank can transmit the desired movement amplitude to the feed foot.

[0055] The lifting element of the drive rod is supported by an axially movable tubular rod or sliding presser foot guide arm, which contains a spring. The pressure of the spring can be adjusted by a suitable plug adjustment element. These elements are actuated in a unidirectional positive direction by a cam mounted on the control shaft of the embroidery machine and returned by a spring.

[0056] Referring to Figure 11, the lifting member 5 carrying the needle 513 is restricted to rotation and vertical movement within a cylindrical body, as is known in the art. The lifting member 5 is provided with a needle bar long sleeve 506 with a grooved periphery; the needle bar long sleeve 506 slides on the cylindrical body and is clamped by the forked end of a forked gripper element 520 extending from the control element 501, while the lifting member 5 slides vertically within the guide of the frame 101. The control element 501 receives a reciprocating motion in a conventional manner.

[0057] Please refer to Figures 3, 4, and 5. The needle is engaged with the thread reel mechanism 7. The thread reel mechanism 7 is supported on the guide sleeve 705, which can rotate together with the gear 706. The gear 706 meshes with the shaft 707 guided on the guide sleeve 705. The shaft 708 is a shaft that pivots on the main control panel 100 of the embroidery machine support.

[0058] Please refer to Figures 3 and 6. The crank arm 812 rotates within a bearing below the worktable 2, and the crank arm 812 carries a crank 811. The cylinder 720 and the guide sleeve 705 are manually rotated by operating the crank 811. The shaft 810 meshes with a shaft 815 via a gear, and the shaft 815 meshes with a shaft 816 via a gear 802; the shaft 810 carries a gear 803 that meshes with a gear 804, so the sleeve can be rotated without affecting its oscillating coil-hooking action. The shaft 810 drives the shaft 708 to pivot within the support arm via multiple meshing gears. A gear 706 is carried on the shafts 708 and 709, and the gear 706 meshes with a gear 706a. When the gear 706a is installed, it can pivot around the XX' axis via an eccentric crank at its end, allowing the shuttle bed guide rod 701 to rotate.

[0059] Please refer to Figures 7, 8, and 10. The embroidery machine spindle 403 is equipped with a gear 404 to drive another gear 138. The gear 138, in turn, drives the shaft 136 and the cam 35. The arc-shaped cam causes the swing rod 140, mounted on a bolt, to swing. The lower arm of the pull rod 140a has a slot for a bolt to pass through; this bolt also engages with a corresponding slot on the swing rod 140, which swings around a horizontal axis. After adjusting the bolt in this slot, the swing of the pull rod 140a can be adjusted from zero to maximum. The other end of the pull rod 140a transmits a reciprocating motion to the slider, which has a fork that engages with a groove in the support main control panel 100, allowing the slider to move up and down on the support main control panel 100. The spacer wedge on the support main control panel 100 can be adjusted by a screw 121 passing through a groove on the spacer wedge.

[0060] Please refer to Figures 7, 8, and 9. The shaft 136 is provided with an arc-shaped cam 137, which can actuate the presser foot slider crank 109 in the direction of the feed rod 150; or, when the presser foot slider crank 109 is activated for replacement, it can be actuated in the opposite direction of the feed rod 150 with the assistance of the spring 120. To counteract the influence of the presser foot slider crank 109 and thereby suppress any unnecessary movement, a pivot pin 134 can be provided to allow the arm 151 to swing.

[0061] The spool bracket 700 is mounted on the frame 1a and is provided with multiple rotating spools; by means of this bracket, the rotation of the embroidery thread around the hole can be adjusted according to different positions.

[0062] Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it should be understood that the present invention is not limited to the disclosed embodiments, and the various parts and elements may be reconfigured, modified and replaced without departing from the spirit of the present invention. [Simplified Explanation of the Diagram]

[0028] Figure 1 shows a perspective view of a preferred embodiment of the embroidery machine of the present invention; Figure 2 shows a partial front view of the four-thread embroidery machine of the present invention; Figure 3 shows an exploded perspective view of the rotating bobbin column of the embroidery machine of the present invention; Figure 4 shows a perspective view of the aforementioned rotating bobbin column; Figure 5 shows an equidistant perspective view of the aforementioned rotating bobbin column from another angle; Figure 6 shows an exploded perspective view of the pressing foot rotation mechanism and manual error mechanism of the embroidery machine of the present invention; Figures 7, 8, and 9 show exploded perspective views and combined perspective views of the pressing foot drive system of the embroidery machine of the present invention; Figure 10 shows an exploded perspective view of the main shaft and transmission components of the embroidery machine of the present invention; Figure 11 shows an exploded perspective view of the needle holding system of the embroidery machine of the present invention; Figure 12 shows a schematic diagram of the embroidery machine of the present invention; Figure 13 shows an exploded perspective view of the embroidery thread tension system of the embroidery machine of the present invention; Figure 14 shows an exploded perspective view of the shaft guide bearing mechanism below the worktable of the embroidery machine of the present invention; Figure 15 shows an exploded perspective view of the transmission mechanism between the systems below and above the worktable of the embroidery machine of the present invention. Figure 16 shows the actual appearance of the embroidery machine of the present invention; Figure 17 shows an exploded perspective view of the presser foot of the embroidery machine of the present invention; and Figure 18 shows a three-dimensional assembly view of the presser foot of the embroidery machine of the present invention.

Claims

1. A four-thread embroidery machine comprising at least one needle (513) operably connected to a needle bar (510) for forming embroidery stitches on a fabric; a presser foot guide arm (13) parallel to the needle bar (510), mounted to be vertically movable, wherein the presser foot guide arm (13) is internally accommodating a sliding needle bar; the presser foot guide arm (13) and the needle bar (510) are synchronously pressed through a presser foot guide arm (130); the four-thread embroidery machine is characterized by: a frame (1a); A single-line mechanism (7) is installed on the frame (1a), which has a shuttle bed guide rod (701) and two forks (703, 703'). The shuttle bed guide rod (701) is fixed to a connecting rod (704). Each fork carries a bobbin (702) on which embroidery thread or braided thread is wound, and it can rotate freely on a spindle to untie the braided thread. The braided thread is led out from the bobbin and enters the pivot crank via the shuttle bed guide rod (701). (704) An opening extending downwards and descending towards the upper part of a presser foot guide rod (130), passing through the guide slots in the guide wire parts (143) and (142) along the longitudinal recess in the needle bar sleeve (506), reaching the lower section of the presser foot ring (132), and then through the oblique hole in the lower section; the lower section is a pin screwed from the lower end of the presser foot bar section to the lower part of the presser foot guide rod support arm (13); the pin has a central through hole for the needle and a collar to pass through; four bobbins (702), two of which are used for embroidery thread (702) for embroidery or knitting and are mounted on the thread spool mechanism (7), and the other two bobbins (702) are used for binding the embroidery thread (702) of the fabric to the fabric mounted on the embroidery machine (1) or supplied from an external source to the embroidery machine (1); A shaft (136) is provided on the frame (1a) and an arc-shaped cam (137) is provided thereon. The arc-shaped cam (137) can move the presser foot slider crank (109) in the direction of the feed rod (150); or when starting to replace the presser foot slider crank, a spring (120) can be used to move the presser foot slider crank (109) in the opposite direction of the feed rod (150) to counteract the effect of the presser foot slider crank (109) and eliminate any unnecessary movement; and a presser foot guide arm (13) having a presser foot guide rod (130) with a specific curved section for accommodating the protruding lower edge of the needle bar sleeve (506).

2. As in request item 1, a four-thread embroidery machine, wherein, The main shaft (403) of the four-thread embroidery machine is provided with a gear (404); the gear (404) drives a gear (138), which in turn drives the shaft (136) and the cam (35), and the cam (35) swings the swing rod (140) mounted on the bolt; the lower arm of the pull rod (140a) is provided with a slot for a bolt to pass through; the bolt also engages with the slot provided on the swing rod (140) that swings around the horizontal axis.

3. As in request item 2, a four-thread embroidery machine, wherein, The needle bar (510) moves vertically through the upper and lower parts, and its upper end includes a gear (504) with upper and lower collars and at least one needle (513) concentrically fixed to the lower end of the needle bar (510). The pinion (504) is installed in the middle part of the needle bar (510). When a fabric feeding mechanism pushes the fabric to be embroidered in the horizontal direction, the rotation of a drive motor or drive pulley is transmitted to the needle bar (510) via the pinion (504), causing the needle bar (510) to rotate toward the fabric to be embroidered.

4. As in request item 1, a four-thread embroidery machine, wherein, The presser foot guide arm (13) includes a crosshead (145) that allows the upper end of the presser foot guide arm (13) to swing around two horizontal axes. In particular, the crosshead (145) has two flat surfaces with holes, the central axis of which is aligned or parallel to the needle bar (510) located in the center. The other two flat sides of the crosshead (145) are provided with smooth cylindrical holes, and a component with a trunnion (141) is placed and engaged in the smooth cylindrical holes.

5. As in request item 1, a four-thread embroidery machine, including: A set of cylindrical shaft (818) and mating bevel gear (821); drive gears (806) and (903); gear (903) supports a needle plate (905) aligned with the upper surface of a worktable (2), and the needle plate (905) is vertically aligned with a bent needle (906) that mates with a needle (513); the bent needle (906) is connected to a vertical shaft (900) mounted in a fixed bearing sleeve (200), and the needle plate (906) is... 5) The needle is driven in a conventional rotational manner via the gear (903) and its associated mechanism to engage with the needle; the bent needle (906) is also actuated in a conventional rotational manner via the gear (820) mounted on the shaft (819) which is spun inside the gear seat (201), wherein the shaft (819) is provided with key teeth to connect with the aforementioned bevel gear (821) and another bevel gear (809), and is driven by the handle (813) of the hand crank transmission mechanism (8).

6. As in Request 1, a four-thread embroidery machine, including: A rod (303) of a braking element is slidably disposed within a bore (3052) of a block (305); the front end of the block is embedded in a recess and equipped with an arc-shaped extension support (3051), which is used to fit around the outer periphery of a collar, and a bolt (310) penetrating the support (3051) secures the block (305) to the collar; a helical spring (301) is installed within the bore (3052) and is held and positioned by an adjustable helical plug (302); the helical spring (301) engages with the rear end face of the rod (303) to elastically resist the retraction of the rod (303) within the bore; the rod (303) is provided with a groove to accommodate an adjusting screw to guide the rod (303) and prevent the rod (303) from rotating; the stop (304) abuts against the screw at the end of the rod to keep the rod (303) within the bore (3052); a helical spring (311) is provided on the outer periphery of the rod (303) and engages between the brake and the front end of the block to apply an initial tension to the flange.

7. The belt drive system (402) of the four-thread embroidery machine of request item 1 may be replaced by a motor drive system coupled to the main shaft (403).

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