A motion-stable presser foot drive and an embroidery machine

Abstract

The application discloses a motion-stable presser foot driving device and an embroidery machine, and relates to the technical field of embroidery equipment, which avoids the separation of the roller and the cam, and affects the stability of the operation of the presser foot driving device. The presser foot driving device comprises a presser foot driving cam, a first transmission member, a second transmission member and an elastic supporting member which are installed on a main shaft, and the presser foot driving cam is provided with an inner cam surface and an outer cam surface. The first transmission member is provided with a first rotating part, a first roller and a second rotating fulcrum, and the first rotating part is rotationally matched with the fixed first rotating fulcrum. The second transmission member is provided with a second rotating part and a second roller. The first roller and the outer cam surface are rollingly matched, the second roller and the inner cam surface are rollingly matched, the elastic supporting member is connected with the first transmission member and the second transmission member, and the elastic supporting member elastically drives the relative rotation of the first transmission member and the second transmission member, so that the first roller is attached to the outer cam surface and the second roller is attached to the inner cam surface.

Description

Technical Field

[0001] This application belongs to the technical field of embroidery equipment, specifically relating to embroidery machines. Background Technology

[0002] In the field of embroidery machine technology, the presser foot is driven in two ways: one is combined with the needle bar movement, in which the needle bar drives the presser foot to reciprocate up and down; the other is an independent presser foot, which is driven by an independent power source to reciprocate up and down. The reciprocating up and down movements of the independent presser foot and the needle bar do not interfere with each other.

[0003] Patent application CN120443427A discloses a conjugate cam presser foot drive device and an embroidery machine. The conjugate cam presser foot drive device includes a conjugate linkage assembly driven by a conjugate cam. The conjugate cam has an inner cam surface and an outer cam surface. The conjugate linkage assembly includes a conjugate linkage rotatably connected to a first conjugate linkage pin and a presser foot drive linkage rotatably connected to a second conjugate linkage pin. The conjugate linkage has a first transmission part and a second transmission part, and the presser foot drive linkage has a presser foot drive part. The first transmission part engages with the inner cam surface, and the second transmission part engages with the outer cam surface. Thus, the conjugate cam drives the conjugate linkage to rotate through the first and second transmission parts, and the conjugate linkage drives the presser foot drive linkage to rotate. The presser foot drive part is located below the presser foot positioning block, which is connected to the presser foot. When driving the presser foot, the presser foot drive linkage moves synchronously with the presser foot's lifting and lowering, ensuring that the presser foot drive part remains in contact with the bottom surface of the presser foot positioning block. Both the first and second transmission parts are rollers. In theory, the roller should fit the cam perfectly. However, due to machining errors in the cam and wear between the roller and the cam during use, a gap (large gap) may occur between the roller and the cam. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by this application is to provide a presser foot drive device and embroidery machine with stable motion, so as to avoid the roller and cam from separating and affecting the stability of the presser foot drive device.

[0005] To solve the above-mentioned technical problems, this application adopts the following technical solution: Firstly, a motion-stabilized presser foot drive device is provided for driving the presser foot to rise or fall. The presser foot drive device includes a main shaft and: A pressure foot drive cam mounted on the spindle, the pressure foot drive cam having an inner cam surface and an outer cam surface; A first transmission component is provided with a first rotating part, a first roller, and a second rotating fulcrum, wherein the first rotating part is rotatably engaged with the fixedly provided first rotating fulcrum. The second transmission component is provided with a second rotating part and a second roller; The first roller and the outer cam surface roll into each other, causing the first transmission component to rotate around the first rotation fulcrum in the first direction, thereby driving the pressure foot to descend; the second roller and the inner cam surface roll into each other, and the second transmission component rotates with the second rotation fulcrum through the second rotation part, causing the first transmission component to rotate around the first rotation fulcrum in the second direction, thereby driving the pressure foot to rise. An elastic support member is provided, which connects a first transmission member and a second transmission member and elastically drives the first transmission member and the second transmission member to rotate relative to each other, so that the first roller is in contact with the outer cam surface and the second roller is in contact with the inner cam surface.

[0006] Preferably, the first transmission component includes a first connecting rod, the first rotating part is disposed at the first end of the first connecting rod, the second rotating fulcrum is disposed at the middle of the first connecting rod, and the first roller is disposed between the first rotating part and the second rotating fulcrum. The second transmission component includes a second connecting rod, the second roller is disposed at the first end of the second connecting rod, the second rotating part is disposed at the second end of the second connecting rod, the first end of the elastic support is connected to the first connecting rod at the position between the second rotating fulcrum and the first roller, and the second end of the elastic support is connected to the middle of the second connecting rod.

[0007] Preferably, the elastic support includes a guide rod and an elastic element movably nested on the guide rod. One end of the guide rod is fixed to the first transmission element and the other end is movably connected to the second transmission element. The elastic element is elastically supported between the first transmission element and the second transmission element.

[0008] Preferably, the first transmission member and the second transmission member are located on opposite sides of the pressure foot drive cam. The first transmission member has a first lug on its side facing the second transmission member. The first lug has a U-shaped groove that is fixedly connected to the guide rod, and the opening of the U-shaped groove faces the second transmission member. The second transmission member has a second lug on its side facing the first transmission member. The second lug has a through hole that is movably connected to the guide rod. The elastic member is elastically supported between the first lug and the second lug.

[0009] Preferably, one end of the guide rod passes through the U-shaped groove and is connected to a limiting nut; a limiting flange is provided in the middle of the guide rod; the limiting flange and the limiting nut are located on opposite sides of the U-shaped groove and fix the guide rod to the U-shaped groove; the other end of the guide rod movably passes through the through hole and is connected to a limiting screw; and / or, the elastic element is a compression spring.

[0010] Preferably, the first connecting rod has a protrusion protruding outward from the cam surface, and the first roller is mounted on the protrusion; and / or, it further includes a third transmission member, the third transmission member including a third connecting rod, and a second connecting rod bearing is provided at each end of the third connecting rod, which is respectively hinged to the first transmission member and the pressure foot driver.

[0011] Preferably, the first pivot point includes a first pivot pin and a pin seat, the first pivot pin is disposed on the pin seat, and the pin seat is fixed to the side wall of the machine head housing.

[0012] Preferably, the pin seat is provided with a protruding post that protrudes into the inner side of the housing, the first fulcrum pin is installed on the protruding post, and the side wall of the head housing is provided with a groove to avoid the protruding post.

[0013] Preferably, the inner cam surface and the outer cam surface are respectively located on both sides of the axial direction of the presser foot drive cam; and / or, the first roller is a first bearing and the second roller is a second bearing.

[0014] In addition, this application also provides an embroidery machine, including the aforementioned motion-stabilizing presser foot drive device.

[0015] The present application adopts the above technical solution and has the following technical effects: The elastic support connects the first and second transmission components and elastically drives them to rotate relative to each other. This ensures that the first roller and the outer cam surface, and the second roller and the inner cam surface, always maintain elastic preload and gapless contact. It effectively compensates for contour errors, dimensional deviations, form and position deviations, and assembly gaps at various hinge points caused by machining of the inner and outer cam surfaces. When machining errors on the cam surface cause changes in the distance between the double rollers and the cam surface, the elastic support can adaptively adjust the relative angle and position of the first and second transmission components through its own elastic expansion and contraction. This avoids problems such as mechanism jamming, jamming, and motion stagnation caused by factors such as cam size deviation, over-positioning, and improper clearance. It ensures that the two sets of cam roller pairs always cooperate smoothly during high-speed movement, achieving stable movement and reliable operation of the presser foot drive device.

[0016] These features and advantages of this application will be disclosed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description

[0017] The following description, in conjunction with the accompanying drawings, further illustrates this application: Figure 1 This is a schematic diagram of the disassembled structure of the embroidery machine head in this application. Figure 1 (Needle bar holder not shown); Figure 2 This is a schematic diagram of the disassembled structure of the embroidery machine head in this application. Figure 2 (Needle bar holder not shown); Figure 3 This is a schematic diagram of the assembly structure of the embroidery machine head in this application (needle bar frame not shown); Figure 4 This is a front view of the presser foot drive device in this application; Figure 5This is a left view of the presser foot drive device in this application; Figure 6 This is a right view of the presser foot drive device in this application; Figure 7 This is an exploded structural diagram of the presser foot drive device in this application; Figure 8 This is a schematic diagram of the presser foot driven cam in this application. Figure 1 ; Figure 9 This is a schematic diagram of the presser foot driven cam in this application. Figure 2 ; Figure 10 This is a schematic diagram of the structure of the first transmission component in this application; Figure 11 This is a schematic diagram of the structure of the second transmission component in this application; Figure 12 This is a schematic diagram of the structure of the third transmission component in this application; Figure 13 This is a schematic diagram of the structure of the first rotational fulcrum; Figure 14 This is a schematic diagram of the structure of the mating part between the side wall of the machine head housing and the first rotation fulcrum; Figure 15 This is a schematic diagram of the installation structure of the first rotation fulcrum; Figure 16 This is an exploded structural diagram of the first transmission component, the second transmission component, and the elastic support component in this application; Figure 17 This is a schematic diagram of the assembly structure of the first transmission component, the second transmission component, and the elastic support component in this application; Figure 18 This is a partial structural schematic diagram of the presser foot drive device in this application; Figure 19 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 1 ; Figure 20 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 2 ; Figure 21 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 1 ; Figure 22 This is a schematic diagram of the fixing structure of the pressure foot driven cam in one embodiment of this application. Figure 2 ; Reference numerals: 100 for presser foot drive device, 110 for first transmission component, 111 for first rotating part, 112 for first roller, 113 for second rotating fulcrum, 114 for third rotating part, 115 for protrusion, 116 for first lug, 1161 for U-groove, 120 for second transmission component, 121 for second roller, 122 for second rotating part, 123 for second lug, 1231 for through hole, 130 for third transmission component, 131 for second connecting rod bearing, 132 for connecting rod pin, 140 for presser foot drive cam, 141 for inner cam surface. Outer cam surface 142, clamping part 143, shaft hole 144, fixed bushing 145, fixed screw hole 1451, fixed screw 1452, locking bushing 146, expansion joint 1461, clamp 147, first rotating fulcrum 150, first fulcrum pin 151, pin seat 152, protrusion 153, fixing screw 154, presser foot driver 160, elastic support 170, compression spring 171, guide rod 172, limiting flange 1721, limiting nut 173, washer 174, limiting screw 175, machine head housing 200, first rotating fulcrum mounting part 210, groove 211, fixing hole 212, guide shaft 220, needle bar drive device 230. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of this application and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of this application.

[0019] Those skilled in the art will understand that, without conflict, the features in the following embodiments and implementations can be combined with each other.

[0020] The terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the application. For example, terms such as "upper," "lower," "front," "rear," and "lateral," which indicate orientation or positional relationship, are based solely on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing the application and simplifying the description. They do not indicate or imply that the device / component referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the application.

[0021] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0024] As shown in Figures 1 to 22, the embroidery machine has at least one machine head, which includes a machine head housing 200 and a needle bar holder located on the front side of the machine head housing 200. A transverse slide rail mechanism is provided between the needle bar holder and the machine head housing 200. When changing colors, the needle bar holder slides laterally along the transverse slide rail mechanism. In this embodiment, the relative direction between the needle bar holder and the machine head housing 200 is defined as the front-back direction, and the direction of movement of the needle bar holder is defined as the transverse direction, or the left-right direction. The embroidery machine has a main shaft that extends laterally and passes through each machine head housing 200. The main shaft serves as a power source to drive the needle bars on the needle bar holder to perform reciprocating lifting and lowering movements, so that the embroidery needles at the bottom of the needle bars can embroider on the embroidery fabric. A needle bar drive device 230 is provided between the main shaft and the needle bars, which can adopt a conventional cam linkage mechanism in the prior art. The presser foot is driven by a presser foot driver 160 to achieve lifting and lowering. A vertically mounted guide shaft 220 is provided on the machine head housing 200, and the presser foot driver 160 is slidably mounted on the guide shaft 220.

[0025] This embodiment uses a presser foot drive device 100 to drive the presser foot to rise or fall, including a conventional spindle and: The presser foot drive cam 140 is mounted on the spindle. The presser foot drive cam 140 has an inner cam surface 141 and an outer cam surface 142. For example, the inner cam surface 141 and the outer cam surface 142 are located on the axial sides or radial sides of the presser foot drive cam 140, respectively, that is, the outer cam surface surrounds the radial outer side of the inner cam surface. The first transmission component 110 is provided with a first rotating part 111, a first roller 112 and a second rotating fulcrum 113, and the first rotating part 111 is rotatably engaged with the fixedly provided first rotating fulcrum 150.

[0026] The second transmission component 120 is provided with a second rotating part 122 and a second roller 121, and the second rotating part 122 is rotatably engaged with the second rotating fulcrum 113.

[0027] In one embodiment, a third transmission member 130 is further included. The third transmission member 130 is hinged to the first transmission member 110 and to the pressure foot. This hinged connection to the pressure foot can be either a direct hinge or a hinge to a component connected to the pressure foot. Specifically, the first roller 112 and the outer cam surface 142 are in rolling engagement, causing the first transmission member 110 to rotate around the first rotation fulcrum 150 in a first direction, thereby causing the third transmission member 130 to lower the pressure foot. The second roller 121 and the inner cam surface 141 are in rolling engagement, and the second transmission member 120 is in rotational engagement with the second rotation fulcrum 113 via the second rotating part 122, causing the first transmission member 110 to rotate around the first rotation fulcrum 150 in a second direction, thereby causing the third transmission member 130 to raise the pressure foot. Here, the first and second directions can be considered as opposite directions; for example, if the first direction is clockwise, then the second direction is counterclockwise. Finally, the end of the third transmission component 130 that is relatively far from the end connected to the first transmission component 110 can drive the presser foot to rise or fall, in order to match the rising and falling strokes of the presser foot.

[0028] In this embodiment, the inner cam surface 141 and the outer cam surface 142 are respectively disposed on both axial sides of the presser foot drive cam. Correspondingly, the first transmission component and the second transmission component are disposed on both axial sides of the presser foot drive cam. Distributing the inner and outer cam surfaces on both axial sides of the presser foot drive cam, compared to distributing the two cam surfaces on both radial sides, avoids motion interference between the cam working surface and the transmission components, resulting in a more compact structure. It also facilitates the synchronous driving of two sets of transmission components by a single cam, simplifying the overall structure. The axial arrangement makes the cam mass distribution more uniform, easier to achieve dynamic balance, and results in less vibration and smoother operation during high-speed rotation. Furthermore, it simplifies processing and assembly, helps ensure the relative positional accuracy between the two cam surfaces, and makes the transmission control of the presser foot's rise and fall more precise and reliable.

[0029] The third transmission component 130 can be directly connected to the presser foot driver 160. The third transmission component 130 drives the presser foot to rise or fall through the presser foot driver 160. Since the presser foot driver 160 is slidably mounted on the guide shaft 220, and the presser foot is slidably mounted on the needle bar, the lifting and lowering action of the presser foot can achieve directional and precise sliding, which is suitable for the high-speed, high-precision, and high-reliability operation requirements of embroidery machine equipment.

[0030] Alternatively, the presser foot drive device 100 can be located on the left side inside the head housing 200, while the needle bar drive device 230 can be located on the right side. The inner cam surface 141 and the outer cam surface 142 are respectively located on the left and right sides of the presser foot drive cam 140. The second transmission member is located on the left side of the presser foot drive cam, and the first transmission member is located on the right side. Furthermore, the first rotating part 111 and the first roller 112 are located on the right side of the presser foot drive cam 140, while the second transmission member 120 and its second roller 121 are located on the left side of the presser foot drive cam 140, thus achieving efficient utilization of the lateral space inside the head housing 200.

[0031] like Figure 9 As shown, in one embodiment, a clamping part 143 is provided on the right side of the center of the presser foot drive cam 140, and the clamping part 143 is integrally formed with the presser foot drive cam 140. A shaft hole 144 is provided at the center of the presser foot drive cam 140, and part of the shaft hole 144 is located within the clamping part 143. The shaft hole 144 mates with the main shaft and is clamped and fixed by the clamping part 143. Figure 19 and Figure 20 As shown, in one embodiment, a fixed bushing 145 is provided on the right side of the center of the presser foot drive cam 140. The fixed bushing 145 is integrally formed with the presser foot drive cam 140, and the inner hole of the fixed bushing is part of the shaft hole. The fixed bushing 145 is provided with at least one fixing screw hole 1451, for example, two fixing screw holes 1451, and a fixing screw 1452 is connected to it. The fixing screw 1452 is locked and fixed to the spindle. Figure 21 and Figure 22 As shown, in one embodiment, a locking bushing 146 is provided on the right side of the center of the presser foot drive cam 140. The locking bushing 146 is integrally formed with the presser foot drive cam 140. The inner hole of the locking bushing is part of the shaft hole. The locking bushing has expansion joints 1461 distributed circumferentially. The outer side of the locking bushing is provided with a separate clamp 147, which locks and fixes the locking bushing 146 to the main shaft.

[0032] In this embodiment, the presser foot drive device 100 designates the two axial sides of the presser foot drive cam 140 as inner and outer cam surfaces, enabling the presser foot to move in both upward and downward strokes with a single cam. By clearly defining the transmission functions of the inner and outer cam surfaces—outer cam surface 142 + first roller 112 corresponding to the presser foot's downward stroke, and inner cam surface 141 + second roller 121 corresponding to the presser foot's upward stroke—the two core strokes of the presser foot are precisely matched one-to-one with the cam hyperboloid and rollers. This results in a clearer transmission logic, well-defined division of labor among the transmission components, and a more direct response to the presser foot's upward / downward movements, reducing the likelihood of stroke interference. The use of the first roller 112 / second roller 121 in rolling contact with the outer / inner cam surfaces transforms sliding friction into rolling friction, significantly reducing wear on the cam surface and transmission components, and extending the device's lifespan. Simultaneously, the precise contact between the rollers and the cam surface ensures precise mechanical control of the presser foot's upward / downward strokes, preventing stroke deviations.

[0033] The intermediate transmission structure downstream of the presser foot drive cam 140 is simplified into a three-piece core structure consisting of a first transmission component 110, a second transmission component 120, and a third transmission component 130. The power transmission path is: presser foot drive cam 140 → first transmission component 110 / second transmission component 120 → third transmission component 130 → presser foot driver 160 → presser foot. The first roller 112, in conjunction with the outer cam surface 142, drives the first transmission component 110 to rotate in the first direction (presser foot down). The second roller 121, in conjunction with the inner cam surface 141, drives the second transmission component 120 to rotate, and through the second rotation fulcrum 113, the first transmission component 110 rotates in the second direction (presser foot up). Both rotations occur around the same fulcrum, and the third transmission component drives the presser foot's lifting and lowering motion, achieving directional and offset-free control of the presser foot's lifting and lowering motion. Due to the fewer components, the number of hinge points is significantly reduced. Power is directly transmitted from the cam to the presser foot driver 160 via the three-stage transmission components, reducing power loss caused by multiple hinge points and improving overall transmission efficiency. A single presser foot drive cam 140 is adopted, and inner and outer double cam surfaces are integrated on both sides of its axis, replacing the design of two independent cams in the traditional technology, thus simplifying assembly from the core component level.

[0034] The core transmission component assembly can be completed simply by coaxially mounting a single cam onto the spindle. The inner and outer cam surfaces are integrally formed structures of the cam body, and their relative positions and contour accuracy are determined during the machining stage. No additional adjustments to the fit between the two working surfaces are required during assembly, eliminating the need for alignment and adjustment of the cam working surfaces. Direct clamping ensures the fit accuracy of subsequent transmission components. Furthermore, the connections between the first transmission component 110 and the first rotating fulcrum 150, between the first transmission component 110, the second transmission component 120, and the third transmission component 130, and between the third transmission component 130 and the pressure foot driver 160 are all rotatable. A fully articulated connection design can be adopted, allowing for simple split-type connection operations and detachable assembly processes. This makes assembly operations faster and process connections more flexible, while improving the assembly qualification rate. Standardized articulated pairs enhance component interchangeability, and point connections are suitable for confined assembly spaces. This design meets the assembly needs of industrial mass production while also ensuring ease of assembly for later maintenance. Therefore, it facilitates assembly, and after assembly, only a simple trial run is needed to ensure the accuracy of the presser foot lifting stroke. There is no need for long-term trial, debugging, and calibration, which greatly shortens the cycle from assembly to finished product.

[0035] like Figure 8 and Figure 9As shown, to design the inner cam surface 141 and the outer cam surface 142, the presser foot drive cam 140 has an inner cam groove and an outer cam boss on its axial sides, respectively. The inner cam surface 141 is a curved working surface formed by the inner wall of the inner cam groove in the presser foot drive cam 140, which mates with the second roller 121. This inner wall is the core transmission surface of the inner cam groove, and its curved profile is designed according to the stroke law of the presser foot's lifting and lowering. Through rolling contact with the second roller 121, it transmits the power of the cam rotation to drive the presser foot to complete the corresponding stroke action. The outer cam surface 142 is a curved working surface formed by the outer wall of the outer cam boss in the presser foot drive cam 140, which mates with the first roller 112. This outer wall is the core transmission surface of the boss, and its curved profile is also designed according to the stroke requirements of the presser foot's lifting and lowering. It forms a conjugate fit with the inner cam surface 141, and through rolling contact with the first roller 112, it collaboratively achieves the complete power transmission for the presser foot's lifting and lowering. The inner cam surface 141 and the outer cam surface 142 are two conjugate curved working surfaces on the presser foot drive cam 140. The inner cam surface is responsible for driving the presser foot upwards, while the outer cam surface is responsible for driving the presser foot downwards. They are matched, connected, and do not conflict with each other in terms of timing, stroke, and speed, together forming a complete, continuous, and coordinated lifting and lowering cycle of the presser foot. The inner cam surface 141 and the outer cam surface 142 are formed based on the inner cam groove and outer cam boss structure of the cam, respectively. Through precise cooperation with different transmission components, they drive the presser foot to complete different strokes of upward and downward movement, jointly achieving continuous and precise control of the presser foot lifting and lowering action. It can be understood that the inner cam surface 141 and the outer cam surface 142 can also both be formed from the inner wall of the cam groove.

[0036] The first roller 112 and the second roller 121 can be elastic rollers, such as rollers with an outer ring made of elastic polyurethane material. In some embodiments, the first roller 112 is a first bearing and the second roller 121 is a second bearing. Preferably, the first and second bearings are deep groove ball bearings, but other bearings can also be used. Bearings are industrial standard parts, and their dimensional accuracy and rotational coaxiality are much higher than those of customized roller structures. By setting the first and second rollers as bearings, the contact gap between the first bearing and the outer cam surface 142, and between the second bearing and the inner cam surface 141, is more uniform, ensuring precise synchronization between the presser foot's downward / upward stroke and the cam rotation, thus improving the precision of the embroidery process. Since bearings are general-purpose standardized industrial parts, their procurement cost is much lower than that of customized rollers. Moreover, during later maintenance, if the bearings are worn or malfunction, they can be directly disassembled and replaced with standard bearings of the same model, making maintenance more convenient and significantly reducing operating costs.

[0037] Because the first bearing is less constrained by space, its diameter is larger than that of the second bearing. The presser foot descent is the core working stroke of the embroidery operation. During descent, it directly presses against the embroidery fabric, overcoming the elastic resistance of the fabric and the preload of the presser foot spring. Simultaneously, it drives the presser foot driver 160 to descend synchronously. The radial pressure and friction of the outer cam surface 142 on the first bearing are much greater than those during the upward stroke. The larger diameter first bearing offers several advantages: firstly, it provides a larger contact area, dispersing the contact stress between the cam surface and the bearing, preventing cam surface crushing and bearing outer ring wear caused by localized stress concentration; secondly, it enhances the bearing's radial load-bearing capacity, adapting to the large load of the descent stroke and preventing bearing failures such as rolling element breakage and inner ring deformation due to overload; thirdly, the rotational inertia of the larger diameter bearing is better suited to the rapid movement requirements of the presser foot descent, ensuring precise synchronization with the cam rotation and preventing problems such as jamming during the descent stroke and insufficient fabric pressing. Of course, depending on the needs, the diameter of the first bearing can also be smaller than or equal to that of the second bearing.

[0038] In some embodiments, the pressure foot drive cam 140 is provided with weight reduction holes. It is understood that the weight reduction holes follow the design principle of "opening holes in non-stressed areas and retaining them in the core stress areas." The connection between the cam and the spindle, and the force transmission areas of the inner / outer cam surfaces, maintain a complete solid structure. Weight reduction holes are only opened on the end face of the cam and in non-fitting edge areas. For example, they can extend through both axial sides of the pressure foot drive cam 140, with partial openings on the outer cam boss, and at a considerable distance from the outer cam surface 142. Providing weight reduction holes can reduce the rotational inertia of the cam, improve the motion response speed and stability of the pressure foot drive, and also reduce the power load on the spindle and drive motor, achieving energy saving and consumption reduction.

[0039] like Figure 10As shown, the first transmission member 110 includes a first connecting rod, and a first rotating part 111 is disposed at the first end of the first connecting rod. The first rotating part 111 can be a first connecting rod bearing and is connected to a first fulcrum pin 151 on the first rotating fulcrum 150. The second rotating fulcrum 113 is disposed in the middle of the first connecting rod and is provided with a pin. The first roller 112 is disposed between the first rotating part 111 and the second rotating fulcrum 113. The second end of the first connecting rod is provided with a third rotating part 114, which is hinged to the third transmission member 130. The second transmission member 120 is disposed on the left side of the first transmission member 110, the second rotating fulcrum 113 is correspondingly disposed on the left side of the first transmission member 110, and the third transmission member 130 is disposed on the right side of the first transmission member 110. The segmented layout of the first rotating part 111, the second rotating fulcrum 113, the first roller 112, and the third rotating part 114 located at the first end, middle, both sides of the middle section, and the second end of the connecting rod is to achieve cooperation with the first rotating fulcrum 150, the second transmission component 120, the pressure foot drive cam 140, and the third transmission component 130.

[0040] Furthermore, the first connecting rod is provided with a protrusion 115 protruding outward from the cam surface 142. The first roller 112 is mounted on the protrusion 115. In the lateral projection of the first transmission member 110, the centers of the first rotating part 111, the second rotating fulcrum 113, and the third rotating part 114 are on the same straight line, while the first roller 112 deviates outward from this straight line, so that a certain gap space is formed between the main body of the first transmission member 110 and the outer cam surface 142. The outer cam surface 142 is formed by the outer wall of the cam boss. The boss is a structure in which the cam body protrudes outward. The first roller 112 needs to actively conform to the cam boss to achieve rolling contact with the outer cam surface 142. Therefore, the protrusion 115 protruding outward from the cam surface 142 is provided on the first connecting rod to allow the first roller 112 to have the space to conform to the outer cam surface 142, avoid the connecting rod body from blocking or interfering with the boss structure, and ensure a gapless fit between the roller and the outer cam surface 142.

[0041] In order to coordinate with the design of the first link, such as Figure 11 As shown, the second transmission component 120 includes a second connecting rod, a second roller 121 at the first end, and a second rotating part 122 at the second end. The second rotating part 122 can be a clamp-type pin hole, connected to a pin on the second rotating fulcrum 113. Figure 10As shown, the third transmission component 130 includes a third connecting rod, with a second connecting rod bearing 131 at each end of the third connecting rod, which is hinged to the first transmission component 110 and the pressure foot driver 160, respectively. The second connecting rod bearing 131 includes an integrally formed connecting rod pin 132 as the bearing inner ring, thus eliminating the need for a separate bearing inner ring. Correspondingly, the third rotating part 114 and the pressure foot driver 160 can be provided with clamp-type pin holes to hinge with the connecting rod pin 132 of the second connecting rod bearing 131.

[0042] The three-piece core structure of the aforementioned first transmission component 110, second transmission component 120, and third transmission component 130 adopts a conventional linkage mechanism, which is combined through hinges, simplifying the structure and facilitating assembly. The design of the first and second connecting rod bearings 131 ensures transmission accuracy. Moreover, due to rolling friction, the coefficient of friction (typically 0.01~0.05) is much lower than that of sliding friction (typically 0.1~0.3), directly reducing frictional resistance at the source, reducing wear on metal surfaces, lowering the wear rate of components, and extending service life.

[0043] like Figure 13 and Figure 15 As shown, in some embodiments, the first pivot point 150 includes a first pivot pin 151 and a pin seat 152, the first pivot pin 151 is disposed on the pin seat 152, and the pin seat 152 is fixed to the side wall of the head housing 200.

[0044] Specifically, taking the presser foot drive device 100 located on the left side of the machine head housing 200 as an example, the pin seat 152 is fixed to the left side wall of the machine head housing 200. The pin seat 152 has a protruding post 153 protruding inwards from the machine head housing. The first fulcrum pin 151 is installed on the protruding post 153, that is, the protruding post 153 protrudes to the right, and the first fulcrum pin 151 extends to the right. The protruding post 153 is cylindrical, and it has a flat structure on the side facing the presser foot drive cam, which can form a clearance space to avoid the presser foot drive cam in a limited space. The side wall of the machine head housing 200 is provided with a first rotating fulcrum mounting part 210, including a groove 211 for avoiding the protruding post 153 and a fixing hole 212. The pin seat 152 is connected to the fixing hole 212 by a fixing screw 154, thereby fixing the pin seat 152 to the side wall of the machine head housing 200. The internal space of the machine head is extremely valuable. Fixing the pin seat 152 to the side wall of the machine head housing 200 makes full use of the side wall space, eliminating the need to reserve additional installation space for the rotation fulcrum inside the machine head housing 200, thus maximizing the utilization rate of the internal space of the machine head housing 200. The design of the protrusion 153 is to place the first fulcrum pin 151 on the right side of the pressure foot drive cam 140, so as to cooperate with the first rotating part 111. The protrusion 153 is a precisely oriented protrusion structure. Its protrusion height and radial dimension are shaped according to the internal space of the machine head, and it only extends the necessary length at the required position, avoiding excessive protrusion of the protrusion 153 that would occupy space.

[0045] After the presser foot drive device is assembled, theoretically the two rollers should be perfectly aligned with the corresponding cam surfaces. However, due to inherent machining and assembly errors in the inner and outer cam surfaces, the first transmission component, and the second transmission component, gaps may occur between the rollers and the cam surfaces. Therefore, in some embodiments, an elastic support component 170 can be added, such as... Figures 16 to 18As shown, the elastic support 170 connects the first transmission member and the second transmission member, and elastically drives the first transmission member and the second transmission member to rotate relative to each other, so that the first roller fits against the outer cam surface and the second roller fits against the inner cam surface. After the first transmission member and the second transmission member are assembled, under the action of the elastic support 170, the first transmission member and the second transmission member can rotate relative to each other, so that the first roller and the second roller respectively fit against the outer cam surface and the inner cam surface. This ensures that the first roller and the outer cam surface, and the second roller and the inner cam surface, always maintain elastic preload and a gapless fit. This effectively compensates for contour errors, dimensional deviations, form and position deviations, and assembly gaps at various hinge points caused by machining. When machining errors or wear on the cam surface cause changes in the distance between the two rollers and the cam surface, the elastic support 170 can adaptively adjust the relative angle and position of the first and second transmission components through its own elastic extension and contraction. This avoids problems such as mechanism jamming, jamming, and motion stagnation caused by cam size deviations, over-positioning, or improper clearances, ensuring smooth cooperation between the two cam-roller pairs during high-speed movement and achieving stable and reliable operation of the presser foot drive device. The elastic support 170 can be made of springs, such as compression springs or torsion springs, or other elastic materials, such as U-shaped metal springs.

[0046] The first end of the elastic support 170 is connected between the first connecting rod and the first roller at the second rotation fulcrum, and the second end of the elastic support 170 is connected to the middle of the second connecting rod. This design allows the first roller to move towards the outer cam surface after the first connecting rod rotates, and the second roller to move towards the inner cam surface after the second connecting rod rotates. This enables the elastic support 170 to apply a stable elastic torque to the first and second connecting rods, ensuring that the first roller and the outer cam surface, and the second roller and the inner cam surface, always maintain an elastic pre-tight fit. Simultaneously, it can adaptively adjust the relative angle between the first and second transmission components, effectively compensating for machining errors, dimensional deviations, and assembly clearances of the inner and outer cam surfaces. This prevents the cam linkage mechanism from jamming due to over-positioning or improper clearance, ensuring reliable roller-cam surface contact, stable movement, reasonable elastic force without interfering with the transmission stroke, and a compact structural layout.

[0047] Specifically, the elastic support 170 includes a guide rod 172 and an elastic element movably nested on the guide rod 172. One end of the guide rod 172 is fixed to the first connecting rod, and the other end is movably connected to the second connecting rod. The elastic element is disposed between the first and second connecting rods and elastically supports the second connecting rod. The guide rod 172 provides directional guidance for the elastic element, preventing bending, swaying, and instability, and ensuring the stability of the elastic force direction. Simultaneously, the guide rod 172 and the second connecting rod are movably connected, allowing relative angular fluctuations between the first and second connecting rods. This effectively compensates for machining errors, dimensional deviations, and assembly gaps on the inner and outer cam surfaces, eliminates over-positioning of the mechanism, and prevents jamming or jamming. It ensures that the first and second rollers are always stably engaged with their corresponding cam surfaces, guaranteeing stable movement and reliable transmission of the pressure foot drive device.

[0048] Furthermore, the first connecting rod has a first lug 116 on its side facing the second connecting rod. The first lug 116 has a U-shaped groove 1161 fixedly connected to the guide rod 172, and the opening of the U-shaped groove 1161 faces the second connecting rod. The second connecting rod has a second lug 123 on its side facing the first connecting rod. The second lug 123 has a through hole 1231 movably connected to the guide rod 172. The elastic element is located between the first lug 116 and the second lug 123. By having the first lug 116 and the second lug 123 facing each other, a dedicated installation position is provided for the elastic support 170, allowing the elastic support 170 to be arranged in the gap between the two connecting rods. This results in a compact structure that does not occupy additional space and does not interfere with the movement of surrounding components. The first lug 116 is provided with a U-shaped groove 1161 to facilitate the quick assembly and radial positioning of the guide rod 172. Specifically, when the first and second connecting rods are assembled, they are close together, with the second rotating part and the rotating fulcrum achieving a pin-and-hole fit. Simultaneously, the guide rod 172 is inserted into the U-shaped groove 1161 through its opening. The guide rod 172 moves through the through hole 1231, allowing the guide rod 172 and the second connecting rod to slide relative to each other axially and to produce a small angular oscillation. When there are machining errors, dimensional deviations, or assembly gaps on the cam surface, the relative posture between the two connecting rods can be adaptively adjusted to avoid over-positioning, rigid jamming, or jamming, ensuring stable movement.

[0049] Specifically, one end of the guide rod 172 passes through the U-shaped groove 1161 and is connected to a limiting nut 173. A limiting flange 1721 is provided in the middle of the guide rod 172. The limiting flange 1721 and the limiting nut 173 are located on opposite sides of the U-shaped groove 1161, fixing the guide rod 172 to the U-shaped groove 1161. The other end of the guide rod 172 movably passes through the through hole 1231 and is connected to a limiting screw 175. Finally, the limiting nut 173 is tightened. A washer 174 can also be placed between the limiting nut and the outer end of the U-shaped groove. One end of the guide rod 172 passes through the U-shaped groove 1161 and is clamped and fixed on both sides of the U-shaped groove 1161 by the limiting flange 1721 and the limiting nut 173, so that the guide rod 172 is firmly connected to the first connecting rod, without loosening or moving, and is easy to assemble; the other end of the guide rod 172 moves through the through hole 1231 of the second lug 123 and is limited by the limiting screw 175, which not only ensures that the guide rod 172 can slide and swing slightly relative to the second connecting rod to compensate for cam machining errors, dimensional deviations and assembly gaps, and avoid the mechanism from being jammed due to over-positioning, but also prevents the guide rod 172 from coming off; the elastic element is stable in the direction of extension and contraction under the constraint of the limiting structure at both ends, without instability or deviation, so that the roller and the cam surface are always reliably pre-tightly fitted, the overall structure is solid, the operation is smooth, and the assembly and maintenance are simple.

[0050] Preferably, the elastic element is a compression spring 171. The compression spring 171 is movably sleeved outside the guide rod 172, and under the constraint of the guide rod 172, it can only extend and retract axially, making it less prone to lateral bending and instability, and its elastic action direction is stable. The compression spring 171 is located between the first lug 116 and the second lug 123 and continuously provides elastic thrust, thus, as... Figure 6 As shown, the first link has a tendency to rotate clockwise around the first pivot point, as... Figure 5 As shown, the second connecting rod tends to rotate counterclockwise around the second pivot point, thereby ensuring a stable pre-tight fit between the second roller and the inner cam surface, and between the first roller and the outer cam surface. Simultaneously, it can adaptively adjust its own compression to effectively compensate for cam machining errors, dimensional deviations, and assembly clearances, ensuring stable movement of the pressure foot drive device. The compression spring 171 has a simple structure, uniform force distribution, long service life, and compact installation space, facilitating assembly and adjustment. It is understood that the compression spring can also be replaced by a sleeve made of elastic material.

[0051] The above description is merely a specific embodiment of the application, but the scope of protection of the application is not limited thereto. Those skilled in the art should understand that this application includes, but is not limited to, the content described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the application will be included within the scope of the claims.

Claims

1. A motion-stabilized presser foot drive device for driving the presser foot to rise or fall, characterized in that, The presser foot drive device includes a main shaft and: A pressure foot drive cam mounted on the spindle, the pressure foot drive cam having an inner cam surface and an outer cam surface; A first transmission component is provided with a first rotating part, a first roller, and a second rotating fulcrum, wherein the first rotating part is rotatably engaged with the fixedly provided first rotating fulcrum. The second transmission component is provided with a second rotating part and a second roller; The first roller and the outer cam surface roll into each other, causing the first transmission component to rotate around the first rotation fulcrum in the first direction, thereby driving the pressure foot to descend; the second roller and the inner cam surface roll into each other, and the second transmission component rotates with the second rotation fulcrum through the second rotation part, causing the first transmission component to rotate around the first rotation fulcrum in the second direction, thereby driving the pressure foot to rise. An elastic support member is provided, which connects a first transmission member and a second transmission member and elastically drives the first transmission member and the second transmission member to rotate relative to each other, so that the first roller is in contact with the outer cam surface and the second roller is in contact with the inner cam surface.

2. The motion-stabilized presser foot drive device according to claim 1, characterized in that, The first transmission component includes a first connecting rod, a first rotating part disposed at a first end of the first connecting rod, a second rotating fulcrum disposed at the middle of the first connecting rod, and a first roller disposed between the first rotating part and the second rotating fulcrum. The second transmission component includes a second connecting rod, a second roller disposed at a first end of the second connecting rod, a second rotating part disposed at a second end of the second connecting rod, and a first end of the elastic support member connected to the first connecting rod at a position between the second rotating fulcrum and the first roller, and a second end of the elastic support member connected to the middle of the second connecting rod.

3. The motion-stabilized presser foot drive device according to claim 1, characterized in that, The elastic support includes a guide rod and an elastic element movably nested on the guide rod. One end of the guide rod is fixed to the first transmission element and the other end is movably connected to the second transmission element. The elastic element is elastically supported between the first transmission element and the second transmission element.

4. The motion-stabilized presser foot drive device according to claim 3, characterized in that, The first transmission member and the second transmission member are located on both sides of the axial direction of the pressure foot drive cam. The first transmission member has a first lug on its side facing the second transmission member. The first lug has a U-shaped groove that is fixedly connected to the guide rod, and the opening of the U-shaped groove faces the second transmission member. The second transmission member has a second lug on its side facing the first transmission member. The second lug has a through hole that is movably connected to the guide rod. The elastic member is elastically supported between the first lug and the second lug.

5. The motion-stabilized presser foot drive device according to claim 4, characterized in that, One end of the guide rod passes through the U-shaped groove and is connected to a limiting nut. A limiting flange is provided in the middle of the guide rod. The limiting flange and the limiting nut are located on opposite sides of the U-shaped groove and fix the guide rod to the U-shaped groove. The other end of the guide rod moves through the through hole and is connected to a limiting screw; and / or, the elastic element is a compression spring.

6. The motion-stabilized presser foot drive device according to claim 2, characterized in that, The first connecting rod has a protrusion that protrudes outward from the cam surface, and the first roller is mounted on the protrusion; and / or, it also includes a third transmission member, the third transmission member including a third connecting rod, and a second connecting rod bearing is provided at each end of the third connecting rod, which is respectively hinged to the first transmission member and the pressure foot driver.

7. The motion-stabilized presser foot drive device according to claim 1, characterized in that, The first pivot point includes a first pivot pin and a pin seat. The first pivot pin is disposed on the pin seat, and the pin seat is fixed to the side wall of the machine head housing.

8. The motion-stabilized presser foot drive device according to claim 7, characterized in that, The pin seat is provided with a protruding post that protrudes into the inner side of the housing. The first fulcrum pin is installed on the protruding post. The side wall of the head housing is provided with a groove to avoid the protruding post.

9. The motion-stabilized presser foot drive device according to claim 1, characterized in that, The inner cam surface and the outer cam surface are respectively located on both sides of the axial direction of the presser foot drive cam; and / or, the first roller is a first bearing and the second roller is a second bearing.

10. An embroidery machine, characterized in that, The invention includes a motion-stabilized presser foot drive device as described in any one of claims 1 to 9.

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