A towel embroidering machine head

Abstract

The application discloses a towel embroidery machine head, one end of a driving connecting rod is matched with a first connecting rod, and the other end is rotatably connected with a driving wheel assembly. The driving wheel assembly is driven to act, the driving connecting rod is matched with an arc-shaped guide groove through a guide shaft to drive the first connecting rod to act, the first connecting rod is rotatably arranged to drive a needle rod to reciprocate up and down through a second connecting rod, and the towel embroidery is realized. The distance between the guide shaft center and the other end of the driving connecting rod is the radius of the arc-shaped guide groove; when the driving wheel assembly drives the needle rod to descend to a lower stop point, the driving connecting rod is located at the center of the arc-shaped guide groove with the other end of the driving wheel assembly as the center. The driving assembly of the position switch and the switching connecting rod movably connected with the driving connecting rod are matched, the position of the upper stop point of the needle rod ascending can be infinitely adjusted according to the needs of towel embroidery, different lengths of towel hair can be embroidered without changing the position of the lower stop point of the needle rod descending, and thus the loop is beneficially formed.

Description

Technical Field

[0001] This invention relates to a towel embroidery machine head. Background Technology

[0002] Towel embroidery is used to create towel fibers, which require varying lengths and heights. Therefore, during the process, the fiber height often needs adjustment to achieve the desired length. Current towel embroidery machines typically have a drive shaft on the needle bar, which drives a linkage assembly to adjust the needle bar's highest point. This linkage mechanism changes the needle bar's travel distance, thus moving the needle bar upwards. However, in existing towel embroidery machines, the needle bar's vertical travel distance is constant. Increasing the needle bar's travel raises the upper limit of the upward movement, consequently raising the lower limit of the downward movement. This alters the engagement position between the lower limit and the looping mechanism, making looping difficult and prone to failure, thus limiting the needle bar's further upward travel. Summary of the Invention

[0003] To address the problem that adjusting the needle rod stroke during the use of existing towel embroidery machines alters the lowest point of the needle rod's descent, leading to difficulties in looping, this invention provides a towel embroidery machine head that allows for easy adjustment of the needle rod stroke without changing the lowest point of the needle rod's descent.

[0004] The technical solution of this invention to solve the existing problems is: a towel embroidery machine head, including a machine head housing, a needle bar, a drive wheel assembly for driving the needle bar, and a connecting rod assembly. As an improvement, the connecting rod assembly includes a first connecting rod, a second connecting rod for driving the needle bar, and a drive connecting rod for transmitting power to the drive wheel assembly. The first connecting rod is rotatably configured, and one end of the first connecting rod is rotatably connected to the second connecting rod. One end of the drive connecting rod cooperates with the first connecting rod, and the other end is rotatably connected to the drive wheel assembly. The first connecting rod is provided with an arc-shaped guide groove, and the drive connecting rod is provided with a guide shaft that slides in cooperation with the arc-shaped guide groove.

[0005] The distance between the center of the guide shaft and the center of the shaft at the other end of the drive linkage is the radius of the arc-shaped guide groove; when the drive wheel assembly drives the needle rod to the lower stop point, the drive linkage is located at the center of the arc-shaped guide groove at the center of the shaft at the end of the drive wheel assembly.

[0006] It also includes a position switcher for driving the drive link to change the mating position of the guide shaft and the arc-shaped guide groove, thereby adjusting the rotation angle of the second link. The position switcher is provided with a driver assembly and a switching link connected to the driver assembly. The corresponding end of the switching link is movably connected to the drive link.

[0007] As a further improvement, the needle bar is provided with a drive rod for driving the needle bar. The drive rod is arranged parallel to the needle bar on the machine head housing. A connecting block structure is provided between the drive rod and the needle bar. The drive rod is connected to a second connecting rod.

[0008] As a further improvement, the guide shaft is provided with rollers or bearings that cooperate with the guide groove; the corresponding end of the switching linkage is movably connected to the guide shaft.

[0009] As a further improvement, the first connecting rod is a bent-arm connecting rod; the rotation point is located at the bend of the bent-arm connecting rod.

[0010] As a further improvement, the drive wheel assembly includes a power conversion arm, a first cam and a second cam mounted on a power shaft. The power conversion arm is rotatably mounted on the head housing. The power conversion arm has a first drive arm spanning one side of the power shaft and engaging with the first cam, and a second drive arm spanning the other side of the power shaft and engaging with the second cam. The first cam has a first cam surface that drives the first drive arm to rotate in a clockwise direction, and the second cam has a second cam surface that drives the second drive arm to rotate in another clockwise direction. The first cam surface driving the first drive arm and the second cam surface driving the second drive arm alternately engage. The drive linkage is rotatably connected to a drive arm near the side where the drive linkage is located.

[0011] As a further improvement, the first cam is provided with a first transition surface, and the second cam is provided with a second transition surface. When the first cam surface cooperates with the first drive arm, the second transition surface cooperates with the second drive arm. When the second cam surface cooperates with the second drive arm, the first transition surface cooperates with the first drive arm.

[0012] As a further improvement, the first cam and / or the second cam is an outer cam.

[0013] As a further improvement, the upper end of the arc-shaped guide groove is open. The drive wheel assembly includes a drive cam or an eccentrically rotatably connected wheel to the corresponding end of the drive linkage.

[0014] As a further improvement, the driver assembly includes a drive motor, a rocker arm mounted on the drive motor shaft, and the other end of the switching link is movably connected to the rocker arm.

[0015] As a further improvement, when the lowest end of the arc-shaped guide groove is engaged with the guide shaft, the upper stop point when the driving needle bar moves upward is the lowest position of the adjustable upper stop point.

[0016] Compared with existing technologies, this invention features a drive linkage that transmits power to the drive wheel assembly. One end of the drive linkage engages with a first linkage, while the other end is rotatably connected to the drive wheel assembly. An arc-shaped guide groove is provided on the first linkage, and a guide shaft that slides along the drive linkage in conjunction with the arc-shaped guide groove is also provided. When the drive wheel assembly moves, the guide shaft of the drive linkage engages with the arc-shaped guide groove to drive the first linkage. The rotatable first linkage, via a second linkage, drives the needle bar to reciprocate up and down, thus achieving towel embroidery. The distance between the center of the guide shaft and the center of the axis at the other end of the drive linkage is the radius of the arc-shaped guide groove. When the drive wheel assembly drives the needle bar downward to its lower stop point, the drive linkage is located at the center of the arc-shaped guide groove, with the axis at the point of rotation of the drive wheel assembly as its center. The engagement position of the drive linkage and the arc-shaped guide groove can be changed by the drive assembly of the position switcher and the switching linkage that movably connects the drive linkage, thereby adjusting the rotation angle of the first linkage and, consequently, changing the upper stop point position of the needle bar via the second linkage. The setting of the center and radius of the aforementioned arc-shaped guide groove facilitates the adjustment of the upper stop point of the needle bar's upward movement, effectively ensuring that the position of the lower stop point of the needle bar's downward movement remains unchanged. The beneficial effects of this invention are its simple structure and the ability to infinitely adjust the position of the upper stop point of the needle bar's upward movement according to the needs of embroidering towel fibers, thus producing towel fibers of different lengths without altering the position of the lower stop point of the needle bar's downward movement, thereby facilitating loop stitching. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the towel embroidery machine head of the present invention.

[0018] Figure 2 This is a schematic diagram of the internal structure of the towel embroidery machine head of the present invention.

[0019] Figure 3 This is a schematic diagram of the internal structure of the towel embroidery machine head from another perspective.

[0020] Figure 4 This is a side view of the internal structure of the towel embroidery machine head of the present invention.

[0021] Figure 5 , 7 This is a structural diagram of the towel embroidery needle rod drive and switching from different perspectives of the present invention.

[0022] Figure 6 yes Figure 5 An enlarged schematic diagram of point a.

[0023] Figure 8 yes Figure 7 An enlarged schematic diagram of point b.

[0024] Figure 9 This is a perspective diagram showing the towel embroidery needle rod located at the lower stop point and the upper stop point relatively low in the travel.

[0025] Figure 10This is a perspective diagram showing the towel embroidery needle rod located at the upper stop point, with the upper stop point stroke relatively positioned at a low position.

[0026] Figure 11 The embroidery needle rod is located at the lower stop point, and the stroke at the upper stop point is relatively higher. Figure 9-10 A schematic diagram of the location.

[0027] Figure 12 The towel embroidery needle bar is located at the upper stop point, and the upper stop point stroke is relatively higher than... Figure 9-10 A schematic diagram of the location. Detailed Implementation

[0028] Drive wheel assembly 1, first cam 11, second cam 12, power conversion arm 13, second drive arm 14, first drive arm 15, first connecting rod 2, second connecting rod 20, arc-shaped guide groove 21, first shaft center 22, second center 32, drive connecting rod 3, guide shaft 31, position switcher 4, limit block 40, switching connecting rod 41, drive motor 42, connecting swing arm 43, mounting bracket 44, lead screw 45, nut slider 46, detection wheel 47, detector 48, needle bar 5, drive rod 51, connecting block structure 52, machine head housing 6.

[0029] See Figure 1-12 This embodiment of a towel embroidery machine head includes a machine head housing 6, a needle bar 5, a drive wheel assembly 1 for driving the needle bar 5, and a connecting rod assembly. It may also include a needle tip bar, a presser foot bar, and a needle tip bar drive structure and a presser foot bar drive structure.

[0030] The linkage assembly includes a first linkage 2, a second linkage 20 driving the needle rod 5, and a drive linkage 3 transmitting power to the drive wheel assembly 1. The first linkage 2 is rotatably mounted. One end of the first linkage 2 is rotatably connected to the second linkage 20. One end of the drive linkage 3 engages with the first linkage 2, and the other end is rotatably connected to the drive wheel assembly 1. The first linkage 2 is provided with an arc-shaped guide groove 21, and the drive linkage 3 is provided with a guide shaft 31 that slides in conjunction with the arc-shaped guide groove 21.

[0031] The distance between the center of the guide shaft 31 and the center of the other end of the drive link 3 is the radius of the arc guide groove 21; when the drive wheel assembly 1 drives the needle bar 5 to the lower stop point, the drive link 3 is located at the center of the arc guide groove 21, which is the center of the rotation point of the drive wheel assembly 1.

[0032] It also includes a position switcher 4 for driving the drive linkage 3 to change the mating position of the guide shaft 31 and the arc-shaped guide groove 21, thereby adjusting the rotation angle of the second linkage 20. The position switcher 4 is provided with a driver assembly and a switching linkage 41 connected to the driver assembly. The corresponding end of the switching linkage 41 is movably connected to the drive linkage 3. The switcher 4 can be equipped with a mounting bracket 44 installed on the head housing 6.

[0033] See Figure 9 , 11 In this invention, when the drive wheel assembly 1 drives the needle bar 5 downwards to the lower stop point, the drive link 3 is located at the center of the arc-shaped guide groove 21, which is the axis of rotation at the end of the drive wheel assembly 1 (denoted as the first axis 22). The distance between the axis of the guide shaft 31 (denoted as the second axis 32) and the axis of rotation at the other end of the drive link 3 is equal to the radius of the arc-shaped guide groove 21. That is, the distance between the first and second axes is equal to the radius of the arc-shaped guide groove 21. Therefore, regardless of how the position switch 4 adjusts the relative position of the guide shaft 31 and the arc-shaped guide groove 21, the guide shaft 31, moving with the drive link 3, rotates around the center of the arc-shaped guide groove 21 with the same diameter. Thus, the engagement position of the first link 2 remains unchanged, ensuring that the position of the lower stop point of the needle bar 5 remains constant. (See also...) Figure 10 , 12 When the drive wheel assembly 1 drives the needle bar 5 to move upward and disengage from the lower stop point, the first axis 22 is changed. The relative position of the guide shaft 31 and the arc-shaped guide groove 21 is adjusted by the position switch 4. The guide shaft 31, which moves with the drive link 3, cooperates with the arc-shaped guide groove 21 to drive the first link 2 to rotate, thereby changing the position of the upper stop point of the needle bar's upward stroke to achieve the requirement of adjusting the towel length.

[0034] Therefore, the structure of this invention ensures that the position of the lower stop point of the needle bar 5 remains unchanged when it moves downward, while only adjusting the position of the upper stop point of the needle bar 5 when it moves upward, so as to embroider towels of different lengths.

[0035] When using the towel embroidery technique, the drive link 3 is adjusted and positioned according to the required towel length via the switching link 41 of the position switcher 4. This ensures that the guide shaft 31 of the drive link 3 engages appropriately with the arc-shaped guide groove 21 of the first link 2, allowing the first link 2 to rotate at a suitable angle. This allows the upper stop position of the needle bar 5's upward stroke to meet the required towel length. The drive link 3 can be driven by the drive wheel assembly 1 to reciprocate through a push-pull motion. Combined with the positioning of the drive link 3 by the switching link 41, the guide shaft 31 on the reciprocating drive link 3 engages with the arc-shaped guide groove 21, causing the first link 2 to reciprocate around its rotation point. The reciprocating first link 2, through the second link 20, drives the needle bar 5 to move up and down, completing the towel embroidery action.

[0036] The mating structure of the first connecting rod 2 and the second connecting rod 20, the connection drive between the second connecting rod 20 and the needle bar 5, and the structure of the needle bar 5 can all use existing technology structures. To avoid interference with the transmission of the needle tip rod, the needle bar 5 is provided with a drive rod 51. The drive rod 51 is arranged parallel to the needle bar 5 on the machine head housing 6, and a connecting block structure 52 is provided between the drive rod 51 and the needle bar 5. The drive rod 51 connects to the second connecting rod 20. Of course, depending on requirements, the machine head housing 6, the presser foot, and the presser foot drive can all adopt existing technology structures.

[0037] To facilitate the cooperation between the guide shaft 31 and the arc-shaped guide groove 21, the guide shaft 31 is provided with rollers or bearings that cooperate with the guide groove; preferably, the corresponding end of the switching link 41 is movably connected to the guide shaft 31, and the switching link 41 can be directly rotatably connected to the guide shaft 31.

[0038] The first connecting rod 2 is a bent-arm connecting rod; the rotating part is located at the bend of the bent-arm connecting rod, and the first connecting rod 2 is usually rotatably mounted on the head housing 6. Of course, the shape of the first connecting rod 2 and the positional relationship between the rotating part and the arc-shaped guide groove 21 can be set as needed. The specific structure is based on the switch 4 adjusting the position of the drive connecting rod 3 to change the matching position between the guide shaft 31 and the arc-shaped guide groove 21, thereby adjusting the rotation angle of the first connecting rod 2. It is necessary to ensure that the position where the needle bar 5 descends to the lower stop point and can normally make a ring cannot be changed.

[0039] The drive wheel assembly 1 is structured to drive the drive link 3 in a reciprocating motion, allowing the guide shaft to reciprocate by pushing and pulling the arc-shaped guide groove 21, thereby causing the first link 2 to rotate around the rotation point. The drive wheel assembly 1 includes a drive cam or an eccentrically rotatably connected wheel to the corresponding end of the drive link. The drive cam may be equipped with a cam groove that drives the drive link in a reciprocating motion, thereby causing the first link to rotate in a reciprocating motion.

[0040] The corresponding end of the drive link 3 can be rotatably connected to the cam groove or eccentrically connected to the rotating wheel. Through the rotation of the cam groove or the rotating wheel, and under the positioning of the switching link 41, a reciprocating push-pull action is realized, thereby realizing the push-pull reciprocating rotation of the first link 2 by the guide shaft of the drive link 3 located in the arc-shaped guide groove 21 of the first link 2. The drive link 3 can be a straight arm link or a bent arm link, depending on whether it is suitable for the guide shaft to drive the arc-shaped guide groove.

[0041] To reduce backlash and improve the driving accuracy and lifespan of the cam, the drive wheel assembly 1 preferably includes a power conversion arm 13, a first cam 11 and a second cam 12 mounted on a power shaft. The power conversion arm 13 is rotatably mounted on the head housing 6. The power conversion arm 13 has a first drive arm 15 spanning one side of the power shaft and cooperating with the first cam 11, and a second drive arm 14 spanning the other side of the power shaft and cooperating with the second cam 12. The first cam 11 has a first cam surface that drives the first drive arm 15 to rotate in a clockwise direction, and the second cam 12 has a second cam surface that drives the second drive arm 14 to rotate in another clockwise direction. The first cam surface drives the first drive arm 15 and the second cam surface drives the second drive arm 14 in alternating cooperation to drive the power conversion arm 13 to drive the drive link 3 to reciprocate push and pull the first link 2, causing the first link 2 to rotate, thereby driving the needle bar to move through the second link 20.

[0042] Referring to the attached diagram, when the drive wheel assembly 1 rotates, the first cam surface of the first cam 11 drives the first drive arm 15, making the first drive arm 15 the active drive arm. This causes the entire rotatable power conversion arm 13 to rotate in the corresponding clockwise direction. The first drive arm 15 pushes the drive link 3. Under the action of the switching link 41, the drive link 3, through the cooperation of the guide shaft 31 and the arc-shaped guide groove 21, pushes the first link 2 to rotate. The rotating first link 2 drives the second link 20 at the other end to drive the needle bar upward. At this time, the second drive arm 14 rotates passively.

[0043] As the drive wheel assembly 1 continues to rotate, when the second cam surface of the second cam 12 drives the second drive arm 14, the second drive arm 14 becomes the active drive arm, causing the entire rotatable power conversion arm 13 to rotate in the opposite direction. At this time, the first drive arm 15 rotates passively. The passively rotating first drive arm 15 pulls the drive linkage 3. Under the action of the switching linkage 41, the drive linkage 3, through the cooperation of the guide shaft 31 and the arc-shaped guide groove 21, pulls back the first linkage 2 to rotate in the opposite direction. The reverse-rotating first linkage 2 drives the second linkage 20 at the other end to drive the needle bar downward. This realizes the towel embroidery action.

[0044] The drive link 3 is rotatably connected to a drive arm near the side where the drive link 3 is located, as shown in the figure where the drive link 31 is rotatably connected to the nearby first drive arm 15. The power shaft can be the main shaft of the towel embroidery drive.

[0045] The first cam 11 has a first transition surface, and the second cam 12 has a second transition surface. When the curved surface of the first cam engages with the first drive arm 15, the second transition surface engages with the second drive arm 14, and the second transition surface is the trajectory surface at the engagement point of the second drive arm 14. When the curved surface of the second cam engages with the second drive arm 14, the first transition surface engages with the first drive arm 15, and the first transition surface is the trajectory surface at the engagement point of the first drive arm 15. Other transition surfaces may also be provided on the first and second cams. For example, when the power shaft rotates continuously to complete the action of the presser foot or needle rod, other transition surfaces of the first and second cams that rotate with the power shaft engage with the corresponding power arms to keep the power conversion arm 13 stationary.

[0046] The first and second cam surfaces are both precision-machined surfaces, which can accurately drive the power conversion arm 13 to rotate. The first and second transition surfaces are only for completing the corresponding cams into complete cams. When the corresponding drive arm is passive, the trajectory of the corresponding drive arm at the mating point is formed on the cam surface.

[0047] The first cam 11 and / or the second cam 12 are external cams. The two cams work together to drive the power conversion arm 13 in a reciprocating motion, thereby driving the drive link 3 to reciprocate push and pull the first link 2. Referring to the attached diagram, both the first and second cams are preferably external cams, which can effectively improve the cam lifespan. Of course, both cams can be selected as internal cams, or one as an external cam and the other as an internal cam, specifically designed so that the cam surface driven by one cam engages with the first drive arm 15 to drive the power conversion arm 13 to rotate clockwise, and the cam surface driven by the other cam engages with the second drive arm 14 to drive the power conversion arm 13 to rotate clockwise, ultimately enabling one drive arm of the power conversion arm 13 to drive the drive link 3 to reciprocate push and pull the second link 2.

[0048] The upper end of the arc-shaped guide groove 21 is open to facilitate the installation and adjustment of the drive linkage 3 guide shaft and the arc-shaped guide groove 12. For ease of adjustment, when the lower end of the arc-shaped guide groove 21 is engaged with the guide shaft 31, the upper stop point of the driving needle bar 5 during upward movement is the lowest adjustable upper stop point. Therefore, when the guide shaft 31 is located at the lower end of the arc-shaped guide groove 21, the upper stop point of the driving needle bar stroke is at its lowest position. If it is necessary to increase the height of the upper stop point of the needle bar stroke, the position switch 4 must drive the guide shaft 31 to slide upward within the arc-shaped guide groove 21.

[0049] The driver assembly includes a drive motor 42 and a rocker arm 43 mounted on the motor shaft of the drive motor 42. The other end of the switching link 41 is movably connected to the rocker arm 43.

[0050] The position switcher 4 can also adopt other technical structures.

[0051] For example, the position switcher 4 includes a mounting bracket 44, a drive motor 42 mounted on the mounting bracket 44, and a drive shaft rotatably mounted on the mounting bracket 44. A transmission structure is provided between the drive shaft and the motor shaft of the drive motor 42. A lead screw 45 is mounted on the drive shaft, and a nut slider 46 is mounted on the lead screw 45. A limiting structure is provided on the mounting bracket 44 to limit the rotation of the nut slider 46. A switching link 41 is movably connected to the nut slider 46. The device also includes a detection component for detecting the rotational position of the drive motor and / or the drive shaft. The detection component detects the rotational position of the drive shaft and / or the drive motor to determine the position of the adjusting component of the switching link 41. The drive shaft and the lead screw 45 can be directly connected separately or connected via a coupling. Alternatively, a thread on the drive shaft that mates with the nut slider 46 can be provided to form the lead screw.

[0052] The transmission structure includes a set of gears that can mesh with each other, or a synchronous belt pulley assembly, or other existing transmission structures.

[0053] The detection assembly includes a detection wheel 47 and a detector 4848 that cooperates with the detection wheel 47. The detection wheel 47 is connected to a motor and / or a drive shaft. In use, the detection wheel 48 is mainly used to connect and cooperate with the detector 4848. The detector 48 detects the number of rotations of the detection wheel to achieve relatively accurate detection. The detection wheel is usually set as a reduction wheel to improve the detection accuracy and adapt to existing detectors 48.

[0054] The detection assembly includes a detection wheel 47 and a detector 4848 that cooperates with the detection wheel 47. The transmission structure includes a drive gear mounted on the motor shaft and a driven gear mounted on the drive shaft. The detection wheel 47 is provided with transmission teeth or a transmission gear that meshes with the drive gear and the driven gear. The number of teeth on the drive gear and the driven gear is the same. To facilitate the detection of the detector 48 and to adapt to the detectors 48 that are widely used in the industry, the number of teeth on the transmission gear or the detection wheel 47 is greater than the number of teeth on the drive gear, so as to reduce the rotational speed of the detection wheel 47 and thus more accurately detect the rotational position of the drive shaft, thereby serving as a reference for determining the position of the switching linkage 41.

[0055] The corresponding end of the switching link 41 can be directly rotatably connected to the nut slider 46. The limiting structure includes a limiting block 40 that can be installed on the mounting bracket 44. The limiting block 40 has a mounting hole for accommodating the nut slider and a movable groove for accommodating the movement of the switching link. The switching link is rotatably connected to the connecting groove.

[0056] To facilitate the connection between the switching link and the limiting structure, the nut slider 46 is provided with a connecting shaft 47, and the connecting shaft 47 is provided with a connecting groove. The switching link 41 is movably connected to the connecting groove. The limiting structure includes a limiting block 40 that can be installed on the mounting bracket 44. The limiting block 40 is provided with a mounting hole to accommodate the connecting shaft, and the limiting block 40 is provided with a movable groove to accommodate the movement of the switching link 41. The switching link 41 is rotatably connected to the connecting groove.

[0057] In practical use, a stop block can be provided on the nut slider or connecting shaft to prevent it from disengaging from the limit block 40.

[0058] The position switch of this structure can drive the lead screw 45 to rotate through the drive motor and transmission structure. The rotating lead screw 45 can slide through the limit-rotation nut slider 46 to drive the switching link 41 on the nut slider to move, thereby facilitating the adjustment of the guide shaft position by the switching link. The guide shaft is driven by the nut slider, and the nut slider and the lead screw cooperate to maintain relative stability, thereby locking the guide shaft and preventing it from being affected by the guide shaft in the opposite direction and running off course. Furthermore, the rotation position of the drive motor and / or drive shaft can be detected by the detection component, which can be used as a parameter to control the adjustment of the link, which is beneficial to further precise control of the link.

[0059] When using the towel embroidery, the corresponding end of the drive link 3 cooperates with the drive wheel assembly 1 according to the required length of the towel, and is positioned by the switching link 41. The drive link 3 can be driven to reciprocate through the drive wheel assembly 1. The guide shaft 31 on the reciprocating drive link 3 cooperates with the arc-shaped guide groove 21 to push and pull the first link 2 to reciprocate around the rotation point. The reciprocating first link 2 drives the needle bar 5 to reciprocate up and down through the second link 20 to complete the towel embroidery action.

[0060] In this invention, "upper," "lower," and "side" refer to the positions of each component when the towel embroidery machine head is normally installed and used.

Claims

1. A towel embroidery machine head, comprising a machine head housing, a needle bar, a drive wheel assembly for driving the needle bar, and a connecting rod assembly, characterized in that: The linkage assembly includes a first linkage, a second linkage driving the needle rod, and a drive linkage transmitting power to the drive wheel assembly. The first linkage is rotatably configured, with one end rotatably connected to the second linkage. One end of the drive linkage engages with the first linkage, and the other end is rotatably connected to the drive wheel assembly. The first linkage has an arc-shaped guide groove, and the drive linkage has a guide shaft that slides in conjunction with the arc-shaped guide groove. The distance between the center of the guide shaft and the center of the axis at the other end of the drive linkage is the radius of the arc-shaped guide groove. When the drive wheel assembly drives the needle rod downward to the lower stop point, the drive linkage is located at the center of the arc-shaped guide groove, with the axis at the end of the drive wheel assembly being the center of the axis. The assembly also includes a position switcher for driving the drive linkage to change the engagement position of the guide shaft and the arc-shaped guide groove, thereby adjusting the rotation angle of the second linkage. The position switcher includes a driver assembly and a switching linkage connected to the driver assembly, with the corresponding end of the switching linkage movably connected to the drive linkage.

2. The towel embroidery machine head as described in claim 1, characterized in that: The needle bar is provided with a drive rod for driving the needle bar. The drive rod is arranged parallel to the needle bar on the machine head housing. A connecting block structure is provided between the drive rod and the needle bar. The drive rod is connected to a second connecting rod.

3. The towel embroidery machine head as described in claim 1, characterized in that: The guide shaft is provided with rollers or bearings that cooperate with the guide groove; the corresponding end of the switching link is movably connected to the guide shaft.

4. The towel embroidery machine head as described in claim 1, characterized in that: The first link is a bent-arm link; the rotation point is located at the bend of the bent-arm link.

5. The towel embroidery machine head as described in claim 1, characterized in that: The drive wheel assembly includes a power conversion arm, a first cam and a second cam mounted on a power shaft. The power conversion arm is rotatably mounted on the head housing. The power conversion arm has a first drive arm spanning one side of the power shaft and engaging with the first cam, and a second drive arm spanning the other side of the power shaft and engaging with the second cam. The first cam has a first cam surface that drives the first drive arm to rotate in a clockwise direction, and the second cam has a second cam surface that drives the second drive arm to rotate in another clockwise direction. The first cam surface driving the first drive arm and the second cam surface driving the second drive arm alternately engage. The drive linkage is rotatably connected to a drive arm near the side where the drive linkage is located.

6. The towel embroidery machine head as described in claim 5, characterized in that: The first cam has a first transition surface, and the second cam has a second transition surface. When the first cam surface cooperates with the first drive arm, the second transition surface cooperates with the second drive arm. When the second cam surface cooperates with the second drive arm, the first transition surface cooperates with the first drive arm.

7. The towel embroidery machine head as described in claim 5, characterized in that: The first cam and / or the second cam are external cams.

8. The towel embroidery machine head as described in claim 1, characterized in that: The upper end of the arc-shaped guide groove is open.

9. The towel embroidery machine head as described in claim 1, characterized in that: The driver assembly includes a drive motor and a rocker arm mounted on the drive motor shaft, with the other end of the switching link movably connected to the rocker arm.

10. The towel embroidery machine head as described in claim 1, characterized in that: When the lowermost end of the arc-shaped guide groove is engaged with the guide shaft, the upper stop point when the driving needle bar moves upward is the lowest position of the adjustable upper stop point.

11. The towel embroidery machine head as described in claim 1, characterized in that: The drive wheel assembly includes a wheel that is eccentrically connected to the corresponding end of the drive linkage via a drive cam.

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