Sewing machine feeding tooth adjusting device and sewing machine

Abstract

The invention provides a sewing machine feed dog adjusting device and a sewing machine, the sewing machine feed dog adjusting device comprises a fixedly arranged base plate, a feed dog lifting shaft rotatably supported in the base plate, a feed dog frame, a feed dog fixed on the feed dog frame and a transmission adjusting assembly, and the transmission adjusting assembly is in transmission connection between the feed dog lifting shaft and the feed dog frame. The transmission adjusting assembly is provided with an adjusting execution part for a user to operate, a locking structure is further arranged between every two adjacent parts in the transmission adjusting assembly, and the locking structures are used for keeping the relative positions of the two adjacent parts; when a user operates the adjusting execution part, the height of the feeding teeth during follow-up operation of the sewing machine is changed, and the current relative positions of the two adjacent parts are changed, so that a turner can easily and conveniently adjust the height of the feeding teeth. The relative positions of the two adjacent parts are locked through the locking structures, so that the height of the feeding teeth is locked after each time of adjustment. The sewing machine is simple in overall structure and low in cost, the overall cost of the sewing machine is reduced, and competitiveness is improved.

Description

Technical Field

[0001] This invention relates to the field of sewing machine technology, and in particular to a sewing machine feed dog adjustment device and a sewing machine equipped with the sewing machine feed dog adjustment device. Background Technology

[0002] Flatbed sewing machines used in the sewing industry are equipped with a dog-lifting mechanism and a feeding mechanism. The dog-lifting mechanism mainly includes a dog-lifting shaft rotatably mounted in the sewing machine base plate, a dog-lifting fork-shaped crank fixed and locked to the dog-lifting shaft by screws, and a dog-lifting slider that slides in a groove with the dog-lifting fork-shaped crank. The dog-lifting slider is hinged to the dog holder by a shaft screw, and the dog holder has a feed dog fixed on it. During the operation of the flatbed sewing machine, the dog-lifting mechanism drives the dog holder and feed dog to move up and down reciprocally, causing the feed dog to protrude from the upper surface of the needle plate and press against the lower surface of the fabric. Combined with the feeding mechanism driving the dog holder and feed dog to move back and forth, it pushes the fabric on the upper surface of the needle plate.

[0003] Typically, the different heights of the feed dog protruding from the needle plate surface can adapt to different sewing conditions. Existing flatbed sewing machines are divided into thin-material and thick-material models. One of the main differences between the two models is the height at which the feed dog protrudes from the needle plate surface; in the thick-material model, the feed dog protrudes higher than the needle plate surface in the thin-material model. Thus, the feed dog in the thick-material model exerts a deeper pressure on the fabric, providing stronger fabric feeding capability.

[0004] In the sewing industry, market demand for clothing is diversified, showing a trend towards small-batch, quick-response production and a wide variety of sewing materials, resulting in users frequently needing to change styles. Changing styles usually means changing the fabric, requiring users to frequently adjust their sewing machines to adapt to the new fabrics. In particular, changes in fabric thickness typically require users to adjust the height of the feed dog above the needle plate in the sewing machine to suit the sewing conditions.

[0005] Currently, adjusting the feed dog height on a sewing machine involves first flipping the machine head over, then forcefully loosening the screw securing the feed dog fork crank, and finally adjusting the vertical position of the feed dog fork crank on the feed dog shaft to roughly adjust the feed dog height. This feed dog height adjustment procedure is generally straightforward for machine repair technicians in garment factories. However, the limited number of repair technicians means that this cannot be done promptly, necessitating adjustments by the sewing machine operators. However, garment factory sewing machine operators, predominantly women with less strength, find it very difficult to flip the machine head and loosen the screws. Furthermore, they often lack suitable tools for loosening the screws and have no clear understanding of how much feed dog height to adjust. Ultimately, when sewing machine operators need to adjust the feed dog height to adapt to new designs, the cumbersome adjustment process forces them to wait for machine repair, impacting the garment factory's operational efficiency. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a sewing machine feed dog adjustment device that can conveniently adjust the feed dog height.

[0007] To achieve the above objectives, the present invention provides a sewing machine feed dog adjustment device, comprising a fixed base plate, a feed dog lifting shaft rotatably supported in the base plate, a feed dog bracket, a feed dog fixed on the feed dog bracket, and a transmission adjustment assembly. The transmission adjustment assembly is tractively connected between the feed dog lifting shaft and the feed dog bracket. The transmission adjustment assembly has an adjustment actuator for user operation. A locking structure is also provided between two adjacent components in the transmission adjustment assembly to maintain the relative position of the two adjacent components.

[0008] When the user operates the adjustment actuator, the height of the feed dog and the current relative position of the two adjacent components change during subsequent sewing machine operation.

[0009] Furthermore, the transmission adjustment assembly includes a tooth-lifting fork-shaped crank with a tooth-lifting groove, a tooth-lifting adjustment knob, a transmission eccentric pin, and a transmission slider that slides in cooperation with the tooth-lifting groove. The tooth-lifting fork-shaped crank is fixed on the tooth-lifting shaft. The transmission eccentric pin includes an eccentrically arranged first shaft portion and a second shaft portion. The first shaft portion rotates in cooperation with the transmission slider and is fixed to the tooth-lifting adjustment knob. The second shaft portion rotates in cooperation with the tooth frame. The tooth-lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth-lifting adjustment knob and the transmission slider, or between the transmission slider and the transmission eccentric pin.

[0010] When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the relative position between the rotational fit center of the first shaft and the transmission slider, and between the rotational fit center of the second shaft and the tooth frame.

[0011] Furthermore, the transmission adjustment assembly also includes a limiting pin, one end of which is fixed in the transmission slider. The tooth lifting adjustment knob is provided with a protruding upper limit part and a lower limit part. The limiting pin is distributed in the area between the upper limit part and the lower limit part on the outer periphery of the tooth lifting adjustment knob and can abut against the upper limit part and the lower limit part.

[0012] Furthermore, the transmission adjustment assembly includes a tooth-lifting fork-shaped crank with a tooth-lifting groove, a tooth-lifting adjustment knob, a transmission eccentric pin, and a transmission slider that slides in cooperation with the tooth-lifting groove. The tooth-lifting fork-shaped crank is fixed on the tooth-lifting shaft. The tooth frame is fixedly provided with a tooth frame connecting part at one end near the tooth-lifting shaft. The transmission eccentric pin includes an eccentrically set first shaft part and a second shaft part. The first shaft part passes through the tooth frame connecting part and is fixedly connected to the tooth-lifting adjustment knob. The second shaft part is rotatably engaged with the transmission slider. The tooth-lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth-lifting adjustment knob and the tooth frame connecting part, or between the transmission slider and the transmission eccentric pin.

[0013] When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the height of the rotational fit center between the first shaft and the tooth frame connection.

[0014] Furthermore, the transmission adjustment assembly includes a tooth lifting drive crank fixed on the tooth lifting shaft, a tooth lifting fork-shaped crank rotatably fitted on the tooth lifting shaft, a tooth lifting adjustment slider, a tooth lifting drive slider, a transmission eccentric pin, and a tooth lifting adjustment knob. The tooth lifting fork-shaped crank has a tooth lifting adjustment groove that slidably engages with the tooth lifting adjustment slider and a tooth lifting drive groove that slidably engages with the tooth lifting drive slider. The transmission eccentric pin includes an eccentrically positioned first shaft portion and a second shaft portion. The first shaft portion rotatably engages with the tooth lifting drive crank and is fixed to the tooth lifting adjustment knob. The second shaft portion rotatably engages with the tooth lifting adjustment slider. The tooth lifting drive slider is hinged to the tooth frame. The tooth lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth lifting adjustment knob and the tooth lifting drive crank, or between the tooth lifting drive crank and the transmission eccentric pin.

[0015] When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the relative position between the tooth lifting drive crank and the tooth lifting fork crank.

[0016] Furthermore, the transmission adjustment assembly includes a tooth lifting drive crank, a tooth lifting connecting rod, a transmission eccentric pin, and a tooth lifting adjustment knob fixed on the tooth lifting shaft. The transmission eccentric pin includes an eccentrically arranged first shaft portion and a second shaft portion. The first shaft portion is rotatably engaged with the tooth lifting drive crank and fixed to the tooth lifting adjustment knob. The second shaft portion is rotatably engaged with one end of the tooth lifting connecting rod. The other end of the tooth lifting connecting rod is hinged to the tooth frame. The tooth lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth lifting adjustment knob and the tooth lifting drive crank, or between the tooth lifting drive crank and the transmission eccentric pin.

[0017] When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the relative position between the second shaft and the tooth lifting connecting rod.

[0018] Furthermore, the transmission adjustment assembly includes a lifting transmission crank, a lifting connecting rod, a lifting adjustment crank, a lifting adjustment knob, and a transmission eccentric pin fixed on the lifting shaft. One end of the lifting connecting rod is hinged to the lifting transmission crank, and the other end of the lifting connecting rod is fixed to the lifting adjustment crank. The transmission eccentric pin includes an eccentrically arranged first shaft portion and a second shaft portion. The first shaft portion passes through the lifting adjustment crank and the two are rotatably engaged. The second shaft portion passes through the tooth frame and the two are rotatably engaged. The lifting adjustment knob is fixedly connected to the transmission eccentric pin. The lifting adjustment knob is close to one side of the lifting adjustment crank along the axial direction of the transmission eccentric pin. The lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the lifting adjustment knob and the lifting adjustment crank, or between the lifting adjustment crank and the transmission eccentric pin.

[0019] When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates together with the tooth lifting adjustment knob, changing the relative position between the rotational fit center of the first shaft and the tooth lifting adjustment crank, and between the rotational fit center of the second shaft and the tooth frame.

[0020] Furthermore, two adjacent components in the transmission adjustment assembly that are equipped with a locking structure are defined as the first component and the second component;

[0021] The locking structure includes a positioning component and several circumferentially spaced adjustment positioning grooves. The positioning component is telescopically mounted in the first component. The several adjustment positioning grooves are provided on the surface of the second component facing the first component. The positioning component can telescopically extend or retract in the direction of approaching or moving away from the second component and is locked in any adjustment positioning groove. The height of the feed tooth corresponding to each adjustment positioning groove is different.

[0022] When the tooth lifting adjustment knob is rotated, the positioning component moves out of the current adjustment positioning slot and engages in another adjustment positioning slot.

[0023] Furthermore, the locking structure also includes a positioning pin, which is fixed in the first component, and the end of the positioning pin facing the second component has a retractable positioning bead, which constitutes the positioning component.

[0024] Furthermore, the locking structure also includes a positioning top post and a positioning spring. The positioning top post includes a support column and a positioning head fixed to the end of the support column. The positioning spring is sleeved on the support column. The support column is movably supported in the first component. The two ends of the positioning spring abut against the positioning head and the first component, respectively. The positioning head constitutes the positioning component.

[0025] The outer surface of the positioning head includes a top column positioning surface and a top column limiting plane connected to both sides of the top column positioning surface. The groove wall of the adjusting positioning groove includes a groove positioning surface and a groove limiting plane connected to both sides of the groove positioning surface. The top column positioning surface and the groove positioning surface are in surface contact with each other, and the top column limiting plane and the groove limiting plane are in surface contact with each other.

[0026] Furthermore, an adjustment lever extends integrally from the tooth lifting adjustment knob, the adjustment lever being used by the user to drive the tooth lifting adjustment knob to rotate.

[0027] Furthermore, the transmission adjustment assembly includes a tooth-lifting fork-shaped crank, a tooth-lifting adjustment knob, and a transmission slider. The tooth-lifting fork-shaped crank includes a connected bushing portion and a fork-shaped portion with a tooth-lifting groove. The tooth-lifting adjustment knob includes an eccentrically arranged third shaft portion and a fourth shaft portion. The third shaft portion passes through the bushing portion and the two are rotatably engaged. The fourth shaft portion passes through the tooth-lifting shaft and the two are rotatably engaged. The transmission slider is slidably engaged with the tooth-lifting groove and hinged to the tooth frame. The tooth-lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth-lifting adjustment knob and the bushing portion.

[0028] When the tooth lifting adjustment knob is rotated, the height of the rotational mating center of the third shaft and the bushing changes.

[0029] Furthermore, the locking structure includes a positioning pin fixed in the third shaft portion and several first positioning holes distributed circumferentially in the bushing portion. The end of the positioning pin has a retractable positioning bead. The positioning bead is retractably disposed between the third shaft portion and the bushing portion and is engaged in any of the first positioning holes. The height of the feed tooth corresponding to each first positioning hole is different.

[0030] When the tooth lifting adjustment knob is turned, the positioning bead moves out of the current first positioning hole and is inserted into another first positioning hole.

[0031] Furthermore, the transmission adjustment assembly includes a tooth-lifting fork-shaped crank with a tooth-lifting groove, a transmission slider that slides with the tooth-lifting groove, an adjustment slider, and a positioning pin. The tooth-lifting fork-shaped crank is fixed on the tooth-lifting shaft, and a sliding sleeve is fixed on the tooth frame. The adjustment slider includes a first connecting part and a second connecting part that are connected to each other. The first connecting part slides with the sliding sleeve, and the second connecting part is hinged to the transmission slider. The positioning pin is installed on the first connecting part and has a retractable positioning bead at its end. The sliding sleeve has several second positioning holes that are spaced apart along the extension direction of the sliding sleeve. The positioning bead is retractably disposed between the sliding sleeve and the first connecting part and is locked in any of the second positioning holes. The height of the feed tooth corresponding to each second positioning hole is different. The positioning bead constitutes the adjustment actuator, and the positioning bead and the second positioning hole constitute the locking structure.

[0032] When the first connecting part and the sliding sleeve part are driven to slide relative to each other, the position of the transmission slider in the tooth lifting groove changes, and the positioning bead moves out of the current second positioning hole and is inserted into another second positioning hole.

[0033] Furthermore, the sewing machine feed dog adjustment device also includes a push plate assembly. The base plate is provided with an adjustment opening groove and push plate slide grooves on both sides of the adjustment opening groove. The push plate assembly is movably assembled in the push plate slide grooves and can open or close the adjustment opening groove.

[0034] When the user drives the push plate assembly to slide and open the adjustment opening slot, the adjustment actuator is exposed from the adjustment opening slot.

[0035] The present invention also provides a sewing machine equipped with the sewing machine feed dog adjustment device as described above.

[0036] As described above, the sewing machine feed dog adjustment device and sewing machine of the present invention have the following beneficial effects:

[0037] This application incorporates a transmission adjustment assembly between the feed dog shaft and the feed dog bracket. Users can change the feed dog height during subsequent sewing machine operation by manipulating the adjustment actuator within this assembly, allowing operators to easily and conveniently adjust the feed dog height. Furthermore, a locking structure is provided between adjacent components of the transmission adjustment assembly. This locking structure locks the relative positions of the two adjacent components, thus locking the feed dog height after each adjustment and preventing accidental changes in the feed dog height. Simultaneously, this application features a simple overall structure and low cost, which helps reduce the overall cost of the sewing machine and enhances its competitiveness. Attached Figure Description

[0038] Figures 1 to 3 These are schematic diagrams of the sewing machine feed dog adjustment device according to Embodiment 1 of this application from different perspectives.

[0039] Figure 4 for Figure 2 A structural diagram omitting the base plate, needle plate, and push plate assemblies.

[0040] Figure 5 for Figure 4 Exploded view.

[0041] Figure 6 for Figure 5 A schematic diagram of the tooth lifting adjustment knob.

[0042] Figure 7 for Figure 5 A schematic diagram of the structure of the transmission slider.

[0043] Figure 8 for Figure 5 A schematic diagram of the center positioning pin.

[0044] Figure 9 This is a schematic diagram of the adjustment of the sewing machine feed dog adjustment device according to Embodiment 1 of this application.

[0045] Figure 10 This is a schematic diagram of the structure of Embodiment 2 of the sewing machine feed dog adjustment device of this application.

[0046] Figure 11 for Figure 10 Exploded view.

[0047] Figure 12 for Figure 10 Cross-sectional view at the top positioning column.

[0048] Figure 13 and Figure 14 The diagram shows the structure of the transmission eccentric pin in this application from different perspectives.

[0049] Figure 15 for Figure 14 AA-direction cross-section diagram.

[0050] Figure 16 and Figure 17 The diagram shows the structure of the top column of this application from different perspectives.

[0051] Figure 18 for Figure 10 A schematic diagram of the structure of the transmission slider.

[0052] Figure 19 for Figure 10 A schematic diagram of the tooth lifting adjustment knob.

[0053] Figure 20 This is a schematic diagram of the adjustment of the sewing machine feed dog adjustment device according to Embodiment 2 of this application.

[0054] Figure 21 This is a schematic diagram of the structure of Embodiment 3 of the sewing machine feed dog adjustment device of this application.

[0055] Figure 22 This is a schematic diagram of the fourth embodiment of the sewing machine feed dog adjustment device of this application.

[0056] Figure 23 for Figure 22 Exploded view.

[0057] Figure 24 for Figure 22 A schematic diagram of the structure of the dental articulator at the connection point of the dental articulator.

[0058] Figure 25 This is a schematic diagram of the adjustment of the sewing machine feed dog adjustment device in Embodiment 4 of this application.

[0059] Figure 26 This is a schematic diagram of the structure of Embodiment 5 of the sewing machine feed dog adjustment device of this application.

[0060] Figure 27 for Figure 26 Exploded view.

[0061] Figure 28 for Figure 26 A schematic diagram of the tooth lifting adjustment knob.

[0062] Figure 29 for Figure 26 A schematic diagram of the structure of the lifting tooth drive crank.

[0063] Figure 30 for Figure 26 A schematic diagram of the structure of the fork-shaped crank with a lifting tooth.

[0064] Figure 31 This is a schematic diagram of the adjustment of the feed dog adjustment device of the sewing machine in Embodiment 5 of this application.

[0065] Figure 32 This is a schematic diagram of the structure of Embodiment Six of the sewing machine feed dog adjustment device of this application.

[0066] Figure 33 for Figure 32 Exploded view.

[0067] Figure 34 for Figure 32 A schematic diagram of the structure of the lifting tooth drive crank.

[0068] Figure 35 This is a schematic diagram of the adjustment of the feed dog adjustment device of the sewing machine in Embodiment Six of this application.

[0069] Figure 36This is a schematic diagram of the structure of Embodiment 7 of the sewing machine feed dog adjustment device of this application.

[0070] Figure 37 for Figure 36 Exploded view.

[0071] Figure 38 for Figure 36 End face view at the tooth lifting link.

[0072] Figure 39 for Figure 36 A schematic diagram of the structure of the lifting crank in Embodiment 1.

[0073] Figure 40 for Figure 36 A schematic diagram of the structure of the lifting crank in embodiment two.

[0074] Figure 41 for Figure 36 A schematic diagram of the structure of the eccentric pin in embodiment one of the central transmission.

[0075] Figure 42 for Figure 36 A schematic diagram of the structure of the eccentric pin in embodiment two of the central transmission.

[0076] Figure 43 This is a schematic diagram of the adjustment of the feed dog adjustment device of the sewing machine in Embodiment 7 of this application.

[0077] Figure 44 This is a schematic diagram of the structure of Embodiment 8 of the sewing machine feed dog adjustment device of this application.

[0078] Figure 45 and Figure 46 for Figure 44 Schematic diagram of the center tooth adjustment knob from different angles.

[0079] Figure 47 for Figure 44 A schematic diagram of the structure of the fork-shaped crank with a lifting tooth.

[0080] Figure 48 This is a schematic diagram of the adjustment of the feed dog adjustment device of the sewing machine in Embodiment 8 of this application.

[0081] Figure 49 This is a schematic diagram of the structure of Embodiment 9 of the sewing machine feed dog adjustment device of this application.

[0082] Figure 50 for Figure 49 A structural diagram from another perspective, omitting the base plate.

[0083] Figure 51 for Figure 50 Exploded view.

[0084] Figure 52 for Figure 50 A schematic diagram of the structure of the adjusting slider.

[0085] Figure 53 This is a schematic diagram of the adjustment of the feed dog adjustment device of the sewing machine in Embodiment 9 of this application. Detailed Implementation

[0086] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0087] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0088] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0089] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0090] This application provides a sewing machine feed dog adjustment device and a sewing machine equipped with the sewing machine feed dog adjustment device.

[0091] like Figures 1 to 4As shown, the sewing machine includes a fixed base plate 10, a feed dog 40, a feed dog 50 fixed on the feed dog 40, a lifting mechanism connected to one end of the feed dog 40, a feeding mechanism connected to the other end of the feed dog 40, and a needle plate 170 fixed on the base plate 10. The lifting mechanism has a lifting shaft 20 rotatably supported in the base plate 10, and the feeding mechanism has a feeding shaft 140 rotatably supported in the base plate 10. The lifting shaft 20 and the feeding shaft 140 are parallel. The power source driving the lifting shaft 20 and the feeding shaft 140 in the sewing machine can be the same power source or two different power sources.

[0092] For ease of description, in the following embodiments, the axial direction of the lifting tooth shaft 20 is defined as the left-right direction, and the direction of the lifting tooth shaft 20 toward the sewing machine head is defined as the left direction; the direction orthogonal to the left-right direction is defined as the front-back direction, and the direction orthogonal to the left-right direction is defined as the up-down direction. Based on this, Figure 2 In the view shown, the left and right sides of the paper are the left and right directions, the top and bottom sides are the front and back directions, and the front and back sides are the top and bottom directions.

[0093] like Figures 3 to 5 As shown, the left end of the lifting tooth shaft 20 is connected to the rear end of the tooth holder 40, and the left end of the feed shaft 140 is connected to the front end of the tooth holder 40. The sewing machine feed dog adjustment device involved in this application includes, in addition to the aforementioned base plate 10, lifting tooth shaft 20, tooth holder 40, and feed dog 50, a transmission adjustment assembly. The transmission adjustment assembly is drively connected between the rear ends of the lifting tooth shaft 20 and the tooth holder 40, and is part of the lifting tooth mechanism. Furthermore, the stroke of the transmission adjustment assembly is adjustable (including adjustable stroke size or adjustable stroke height). The transmission adjustment assembly has an adjustment actuator for user operation, and a locking structure is provided between adjacent components of the transmission adjustment assembly. The stroke of the transmission adjustment assembly is adjusted by operating the adjustment actuator, and the locking structure is used to maintain the relative position of the two adjacent components. For ease of description, the two adjacent components with the locking structure in the transmission adjustment assembly are defined as the first component and the second component. Meanwhile, the feeding mechanism also includes a feeding shaft 140 rotatably supported in the base plate 10, a tooth holder seat 150 fixed to the left end of the feeding shaft 140, and a tooth holder pin 160. The feeding shaft 140 is parallel to the tooth lifting shaft 20, and the tooth holder seat 150 is connected to the front end of the tooth holder 40 through the tooth holder pin 160.

[0094] During normal operation of the sewing machine, the lifting mechanism drives the feed dog 40 and feed dog 50 to reciprocate up and down, with the feed dog 50 performing the lifting action. Simultaneously, the feeding mechanism drives the feed dog 40 and feed dog 50 to reciprocate back and forth, with the feed dog 50 performing the feeding action. Therefore, the feed dog 50 performs a combined up-and-down and back-and-forth motion. When the feed dog 50 emerges upward from the toothed groove of the needle plate 170, it drives the fabric on the upper surface of the needle plate 170 to move forward, combining with the needle's piercing action to sew the fabric. When the height of the feed dog 50 needs to be adjusted, the sewing machine stops, and the user operates the adjustment actuator, thereby changing the stroke or stroke height of the transmission adjustment component. This changes the height of the feed dog 50 above the upper surface of the needle plate 170 during subsequent sewing machine operation, thus achieving the adjustment of the feed dog 50 height. Simultaneously, the relative positions of the first and second components in the transmission adjustment component change, and the locking structure maintains the adjusted relative positions of the first and second components, reliably maintaining the adjusted feed dog height. In this application, the operation of adjusting the feed dog 50 height is very easy and convenient; the user only needs to operate the adjustment actuator, making it convenient for garment factory workers to adjust it themselves, effectively improving the operational efficiency of the garment factory. In addition, the overall structure of this application is simple and low-cost, which helps to reduce the overall cost of the sewing machine and enhance its competitiveness.

[0095] In a sewing machine feed dog adjustment device, the transmission adjustment component has multiple structures. Based on the different structures of the transmission adjustment component, the sewing machine feed dog adjustment device has multiple embodiments. Several preferred embodiments of the sewing machine feed dog adjustment device are provided below.

[0096] Example 1 of sewing machine feed dog adjustment device

[0097] In Embodiment 1 of the sewing machine feed dog adjustment device, such as Figures 3 to 5 As shown, the transmission adjustment assembly includes a lifting fork-shaped crank 30, a lifting adjustment knob 60, a transmission eccentric pin 70, and a transmission slider 80. The lifting fork-shaped crank 30 is fixed and locked to the left end of the lifting shaft 20 by screws. At least a portion of the transmission slider 80 is disposed in the lifting groove 31 and slides in cooperation with the lifting groove 31. The transmission eccentric pin 70 includes a first shaft portion 71 and a second shaft portion 72 extending horizontally to the left and right. The first shaft portion 71 and the second shaft portion 72 are eccentrically arranged. The first shaft portion 71 passes through the transmission slider 80 and the lifting adjustment knob 60, and is rotatably engaged with the transmission slider 80 and fixed to the lifting adjustment knob 60. The second shaft portion 72 passes through the rear end of the jaw bracket 40 and is rotatably engaged with the rear end of the jaw bracket 40. The lifting adjustment knob 60 constitutes the adjustment actuator. A locking structure is provided between the lifting adjustment knob 60 and the transmission slider 80, or between the transmission slider 80 and the transmission eccentric pin 70. In this embodiment, the first component is the tooth lifting adjustment knob 60, and the second component is the transmission slider 80.

[0098] During normal operation of the sewing machine, the feed dog shaft 20 drives the feed dog holder 40 and feed dog 50 to reciprocate up and down via the feed dog fork crank 30, transmission slider 80, and transmission eccentric pin 70. When it is necessary to adjust the height of the feed dog 50, the sewing machine is stopped, and the feed dog adjustment knob 60 is turned. Figure 9 As shown, since the tooth lifting adjustment knob 60 is fixed to the first shaft portion 71 of the transmission eccentric pin 70, the transmission eccentric pin 70 rotates synchronously with the tooth lifting adjustment knob 60. The first shaft portion 71 and the second shaft portion 72 of the transmission eccentric pin 70 are eccentrically set. The rotational engagement of the first shaft portion 71 with the transmission slider 80 and the rotational engagement of the second shaft portion 72 with the tooth holder 40 cause the transmission eccentric pin 70 to rotate synchronously with the tooth lifting adjustment knob 60. After rotating around the rotational engagement center of the first shaft portion 71 and the transmission slider 80, the relative position between the rotational engagement center of the first shaft portion 71 and the transmission slider 80 and the rotational engagement center of the second shaft portion 72 and the tooth holder 40 will change. This changes the height of the feed dog 50 above the upper surface of the needle plate 170 during subsequent sewing machine operation, thus achieving the adjustment of the feed dog 50 height.

[0099] Furthermore, such as Figure 4 , Figure 5 and Figure 7As shown, the transmission adjustment assembly also includes a positioning pin 120 fixed in the tooth lifting adjustment knob 60. The positioning pin 120 has a positioning bead 121 that can extend and retract left and right at its right end facing the transmission slider 80, forming a positioning component. Several circumferentially spaced adjustment positioning grooves 81 are provided on the end face of the transmission slider 80 facing the tooth lifting adjustment knob 60. The positioning bead 121 can extend and retract in the direction approaching or away from the transmission slider 80 and be engaged in any adjustment positioning groove 81. The height of the feed tooth corresponding to each adjustment positioning groove 81 is different; that is, the positioning bead 121 engaging in different adjustment positioning grooves 81 corresponds to different feed tooth heights. The positioning bead 121 and the several adjustment positioning grooves 81 combine to form a locking structure. During the process of adjusting the height of the feed tooth 50 by rotating the tooth lifting adjustment knob 60, the positioning bead 121 can be moved out of the current adjustment positioning groove 81 and locked into another adjustment positioning groove 81 by the extension and retraction of the positioning bead 121. The engagement of the positioning bead 121 with the adjustment positioning groove 81 provides positioning for the rotation of the tooth lifting adjustment knob 60, that is, it provides positioning and self-locking for the operation of adjusting the height of the feed tooth 50, making the operation of adjusting the height of the feed tooth 50 very easy and convenient, allowing garment factory workers to adjust it themselves, effectively improving the work efficiency of the garment factory. Furthermore, when the user rotates the tooth lifting adjustment knob 60, the positioning pin 120 rotates with the tooth lifting adjustment knob 60. During the rotation, the positioning bead 121 is squeezed by the left end face of the transmission slider 80 and will first retract to the left, disengaging from the current adjustment positioning groove 81, until the positioning bead 121 extends to the right and locks into the next adjustment positioning groove 81. When the height of the feed tooth 50 is not adjusted, the positioning bead 121 is always locked in an adjustment positioning groove 81, which more reliably ensures that the relative position of the tooth lifting adjustment knob 60 and the transmission slider 80 does not change.

[0100] Preferably, such as Figure 8 As shown, the positioning pin 120 also includes a housing 122 and a spring 123 housed in the housing 122. The housing 122 is fixed in the tooth lifting adjustment knob 60, thereby fixing the positioning pin 120 as a whole in the tooth lifting adjustment knob 60. The left and right ends of the spring 123 are connected to the housing 122 and the positioning bead 121 respectively, thereby realizing the left and right extension and retraction of the positioning bead 121. Figure 6 As shown, the tooth lifting adjustment knob 60 has a first hole 64 and a second hole 65 that are both through to the left and right. The first hole 64 is used to accommodate the first shaft 71, and the second hole 65 is used to accommodate the positioning pin 120.

[0101] Furthermore, such as Figure 4 and Figure 5As shown, along the axial direction of the transmission eccentric pin 70, the feed adjustment knob 60, the transmission slider 80, and the feed dog 40 are arranged side by side from left to right. The sewing machine feed adjustment device also includes two fastening screws 110 threaded into the feed adjustment knob 60. The ends of the fastening screws 110 abut against the outer circumference of the first shaft portion 71, thereby fixing the feed adjustment knob 60 to the left end of the first shaft portion 71. In addition, the feed adjustment knob 60 and the feed dog 40 abut against the left and right sides of the transmission slider 80, respectively, effectively limiting the left and right movement of the transmission slider 80 along the axial direction of the transmission eccentric pin 70, without affecting the rotational movement between the transmission slider 80 and the first shaft portion 71 of the transmission eccentric pin 70.

[0102] Furthermore, such as Figure 1 , Figure 2 and Figure 6 As shown, the tooth lifting adjustment knob 60 has a rotating operating part exposed on the base plate 10. The rotating operating part is an adjusting wrench part 61 integrally extended from the tooth lifting adjustment knob 60. The adjusting wrench part 61 extends radially along the first shaft part 71. An adjusting opening groove 101 is provided on the base plate 10. The adjusting opening groove 101 extends to the left edge of the base plate 10 and is distributed on the left side of the needle plate 170. The adjusting wrench part 61 is exposed in the adjusting opening groove 101. Based on the structure that the adjusting wrench part 61 can be exposed on the base plate 10, and the structure that the height of the feed tooth 50 can be adjusted by driving the tooth lifting adjustment knob 60 to rotate through the adjusting wrench part 61, it is convenient to drive the tooth lifting adjustment knob 60 to rotate, and the operation of adjusting the height of the feed tooth 50 is more convenient. Meanwhile, the sewing machine feed dog adjustment device also includes a push plate assembly 90. The base plate 10 has push plate slide grooves 102 extending horizontally on both the front and rear sides of the adjustment opening groove 101. The push plate assembly 90 is movably mounted in the push plate slide grooves 102. When the feed dog height 50 does not need adjustment, the push plate assembly 90 covers and closes the adjustment opening groove 101, preventing dust, yarn, and other impurities from entering the sewing machine through the adjustment opening groove 101. When the feed dog height 50 needs adjustment, the user drives the push plate assembly 90 to slide to the left, opening the adjustment opening groove 101, and the adjustment lever part 61 protrudes from the adjustment opening groove 101. Figure 2 As shown, at this time, the user can apply the adjusting wrench 61 to drive the tooth lifting adjustment knob 60 to rotate, which greatly facilitates the operation of adjusting the height of the feed tooth 50. After the adjustment is completed, the user drives the push plate assembly 90 to slide to the right, re-closing the adjusting opening slot 101.

[0103] Furthermore, such as Figure 5 and Figure 7As shown, there are three adjusting positioning grooves 81: a standard gear groove 82, a high gear groove 83, and a low gear groove 84. The high gear groove 83 and low gear groove 84 are located on either side of the standard gear groove 82. The height of the feed dog 50 corresponding to the high gear groove 83, the standard gear groove 82, and the low gear groove 84 gradually decreases. Furthermore, the height of the feed dog 50 corresponding to the standard gear groove 82 is the height of a feed dog 50 used for standard sewing, the height of the feed dog 50 corresponding to the high gear groove 83 is the height of a feed dog 50 used for sewing thick materials, and the height of the feed dog 50 corresponding to the low gear groove 84 is the height of a feed dog 50 used for sewing thin materials. Figure 5 and Figure 9 In the schematic diagram shown, the positioning bead 121 is engaged in the conventional gear slot 82. The high gear slot 83 is located on the clockwise side of the conventional gear slot 82, and the low gear slot 84 is located on the counterclockwise side of the conventional gear slot 82. When the height of the feed tooth 50 needs to be adjusted, push the push plate assembly 90 to the left, exposing the adjusting lever 61 on the tooth lifting adjustment knob 60. When the user inserts a finger or uses other tools to pull the adjusting lever 61 upward, the tooth lifting adjustment knob 60 rotates clockwise, and the positioning bead 121 moves out of the conventional gear slot 82 and into the high gear slot 83. This adjusts the height of the feed tooth 50. Conversely, when the user inserts a finger or uses other tools to pull the adjusting lever 61 downward, the tooth lifting adjustment knob 60 rotates counterclockwise, and the positioning bead 121 moves out of the conventional gear slot 82 and into the low gear slot 84. This adjusts the height of the feed tooth 50. This structure provides a tactile feedback when the user adjusts the height of the feed tooth 50, making it easier for the machinist to adjust the height of the feed tooth 50 more precisely and conveniently.

[0104] Furthermore, such as Figure 4 and Figure 5 As shown, the sewing machine feed dog adjustment device also includes a limit pin 130. The limit pin 130 is a spring pin, and its right end is fixed in the transmission slider 80. The feed dog adjustment knob 60 has a protruding upper limit part 62 and a lower limit part 63 on its outer periphery. The limit pin 130 is distributed in the area between the upper limit part 62 and the lower limit part 63 on the outer periphery of the feed dog adjustment knob 60. When the adjustment lever 61 is turned upward to drive the feed dog adjustment knob 60 to rotate clockwise, the upper limit part 62 rotates toward the limit pin 130 and can abut against the limit pin 130; when the adjustment lever 61 is turned downward to drive the feed dog adjustment knob 60 to rotate counterclockwise, the lower limit part 63 rotates toward the limit pin 130 and can abut against the limit pin 130. In this way, the rotation range of the tooth lifting adjustment knob 60 can be limited, preventing the tooth lifting adjustment knob 60 from being over-rotated, thus ensuring that the positioning bead 121 can correctly enter the corresponding adjustment positioning groove 81 on the transmission slider 80.

[0105] Furthermore, such as Figure 5 and Figure 7 As shown, the transmission slider 80 includes a slider body 85 and slider end plates 86 fixed at the left and right ends of the slider body 85. The slider body 85 is movably disposed in the tooth-lifting groove 31 and contacts and engages with the groove wall surface of the tooth-lifting groove 31. The left and right slider end plates 86 respectively abut against the left and right sides of the tooth-lifting fork-shaped crank 30. In addition, the transmission slider 80 has a third hole 87 and a fourth hole 88. The third hole 87 extends through the slider body 85 and the two slider end plates 86 and is used to accommodate the first shaft 71. The fourth hole 88 extends through the left slider end plate 86 and is used to accommodate the limiting pin 130.

[0106] Example 2 of sewing machine feed dog adjustment device

[0107] In Embodiment 2 of the sewing machine feed dog adjustment device, such as Figure 10 and Figure 11 As shown, the transmission adjustment assembly includes a lifting fork-shaped crank 30, a lifting adjustment knob 60, a transmission eccentric pin 70, and a transmission slider 80. The lifting fork-shaped crank 30 is fixed and locked to the left end of the lifting shaft 20 by screws. At least a portion of the transmission slider 80 is disposed in the lifting groove 31 and slides in cooperation with the lifting groove 31. The transmission eccentric pin 70 includes a first shaft portion 71 and a second shaft portion 72 extending horizontally to the left and right. The first shaft portion 71 and the second shaft portion 72 are eccentrically arranged. The first shaft portion 71 passes through the transmission slider 80 and the lifting adjustment knob 60, and is rotatably engaged with the transmission slider 80 and fixed to the lifting adjustment knob 60. The second shaft portion 72 passes through the rear end of the jaw bracket 40 and is rotatably engaged with the rear end of the jaw bracket 40. The lifting adjustment knob 60 constitutes the adjustment actuator. A locking structure is provided between the lifting adjustment knob 60 and the transmission slider 80, or between the transmission slider 80 and the transmission eccentric pin 70. In this embodiment, the first component is the transmission slider 80, and the second component is the transmission eccentric pin 70.

[0108] Furthermore, such as Figure 10 , Figure 16 and Figure 17 As shown, the positioning top post 180 includes a support post portion 181 and a positioning head 182 integrally formed at the end of the support post portion 181. The support post portion 181 is movably supported in the transmission slider 80. Figures 10 to 15As shown, the outer circumferential surface of the first shaft portion 71 is provided with several circumferentially spaced adjustment positioning grooves 81. The positioning spring 190 is a compression spring and is sleeved on the support column portion 181. The two ends of the positioning spring 190 abut against the positioning head 182 and the transmission slider 80, respectively. Both the support column portion 181 and the positioning spring 190 are arranged radially along the first shaft portion 71. The positioning head 182 at the end of the positioning top post 180 is pressed against one of the adjustment positioning grooves 81 under the action of the positioning spring 190, and the positioning head 182 constitutes a positioning component. The positioning spring 190 allows the positioning top post 180 to extend and retract in the direction away from or towards the adjustment positioning groove 81, thereby allowing the positioning head 182 to move out of the adjustment positioning groove 81 and to engage in the adjustment positioning groove 81. When the positioning head 182 is engaged in different adjustment positioning grooves 81, it corresponds to different feed tooth heights. The positioning pin 180, positioning spring 190, and several adjusting positioning grooves 81 combine to form a locking structure. Specifically, the outer surface of the positioning head 182 includes a pin positioning surface 183 and pin limiting planes 184 connecting both sides of the pin positioning surface 183; the pin positioning surface 183 and the pin limiting planes 184 are not coplanar. Each adjusting positioning groove 81 includes a groove positioning surface 816 and groove limiting planes 817 connecting both sides of the groove positioning surface 816; the groove positioning surface 816 and the groove limiting planes 817 are not coplanar. When the positioning head 182 is pressed into the adjusting positioning groove 81, the pin positioning surface 183 contacts the groove positioning surface 816 of the adjusting positioning groove 81, and the pin limiting planes 184 and 817 of the adjusting positioning groove 81 contact each other. Preferably, both the pin limiting planes 184 and 817 are planes extending radially along the first shaft portion 71.

[0109] During normal operation of the sewing machine, the lifting pin 20 drives the feed dog 40 and feed dog 50 to reciprocate up and down via the lifting fork crank 30, the transmission slider 80, and the transmission eccentric pin 70. When it is necessary to adjust the feed dog height, the sewing machine is stopped, the lifting adjustment knob 60 is turned, and at the same time, the support column 181 of the positioning top column 180 is pulled out radially. Figure 20As shown, since the tooth lifting adjustment knob 60 is fixed to the first shaft portion 71 of the transmission eccentric pin 70, the transmission eccentric pin 70 rotates synchronously with the tooth lifting adjustment knob 60. The first shaft portion 71 and the second shaft portion 72 of the transmission eccentric pin 70 are eccentrically positioned. The rotational engagement of the first shaft portion 71 with the transmission slider 80 and the rotational engagement of the second shaft portion 72 with the tooth holder 40 causes the transmission eccentric pin 70 to rotate synchronously with the tooth lifting adjustment knob 60. After rotating around the rotational engagement center of the first shaft portion 71 and the transmission slider 80, the relative position between the rotational engagement center of the first shaft portion 71 and the transmission slider 80 and the rotational engagement center of the second shaft portion 72 and the tooth holder 40 is changed. This changes the relative position of the transmission slider 80 and the second shaft portion 72, thereby changing the height of the feed dog 50 above the upper surface of the needle plate 170 during subsequent sewing machine operation, thus achieving feed dog height adjustment. This adjustment structure is simple and easy to implement, especially convenient for sewing machine operators to easily and conveniently adjust the feed dog height.

[0110] Furthermore, during the process of adjusting the feed tooth height by rotating the tooth lifting adjustment knob 60, under the squeezing action of the first shaft 71 on the positioning head 182, the positioning head 182 first moves out of the current adjustment positioning groove 81; when the feed tooth height is adjusted to the target value, under the action of the positioning spring 190 on the positioning head 182, the positioning head 182 is then engaged in another adjustment positioning groove 81. In this way, the engagement between the positioning head 182 and the adjustment positioning groove 81 provides positioning for the rotation of the tooth lifting adjustment knob 60, that is, provides positioning for the operation of adjusting the feed tooth height, and also provides a tactile feedback when the user adjusts the feed tooth height, making the operation of adjusting the feed tooth height easier and more convenient, allowing garment factory workers to adjust it themselves, and effectively improving the operational efficiency of the garment factory. In particular, after the feed dog height adjustment is completed, the positioning head 182 is tightly pressed against the adjusting positioning groove 81 under the action of the positioning spring 190, and the top post positioning surface 183 and the top post limiting plane 184 on the positioning head 182 are in contact with the groove positioning surface 816 and the groove limiting plane 817 of the adjusting positioning groove 81, respectively. On the one hand, the contact area between the positioning head 182 and the groove wall of the adjusting positioning groove 81 is large, so the positioning head 182 is not easy to slide relative to the adjusting positioning groove 81 during the operation of the sewing machine, and can be reliably held in the adjusting positioning groove 81. On the other hand, the abutment of the top post limiting plane 184 and the groove limiting plane 817 also restricts the accidental sliding of the positioning head 182 in the adjusting positioning groove 81. Finally, the positioning head 182 is reliably prevented from sliding relative to the adjusting positioning groove 81, thereby reliably maintaining the size of the feed dog height after adjustment and improving the stability of the sewing machine operation. Furthermore, the adjusting positioning groove 81 is formed on the outer circumferential surface of the first shaft portion 71, which in turn passes through the transmission slider 80. Therefore, the mating structure between the positioning head 182 and the adjusting positioning groove 81 is enclosed within the transmission slider 80, minimizing the impact of the external environment and preventing oil, yarn, and other contaminants from getting stuck at the engagement point between the positioning head 182 and the adjusting positioning groove 81. Simultaneously, this application features a simple overall structure and low cost, which helps reduce the overall cost of the sewing machine and enhances its competitiveness.

[0111] Furthermore, such as Figure 16 and Figure 17As shown, the top post positioning surface 183 includes a first arcuate surface segment 1831 and a first inclined surface segment 1832 tangentially connected to both sides of the first arcuate surface segment 1831. The first inclined surface segment 1832 is connected to the top post limiting plane 184, but the two are not coplanar. The slot positioning surface 816 includes a second arcuate surface segment 8161 and a second inclined surface segment 8162 tangentially connected to both sides of the second arcuate surface segment 8161. The second inclined surface segment 8162 is connected to the slot limiting plane 817, but the two are not coplanar. The first arcuate surface segment 1831 and the second arcuate surface segment 8161 are in surface contact, and the first inclined surface segment 1832 and the second inclined surface segment 8162 are in surface contact. With this configuration, the accidental sliding of the positioning head 182 in the adjusting positioning slot 81 can be more reliably restricted, and the positioning head 182 can be relatively easily rotated out of the current adjusting positioning slot 81 when the feed tooth height is adjusted.

[0112] Furthermore, such as Figure 18 As shown, the transmission slider 80 includes a slider body 89 and a slider positioning part 810 integrally formed on the left side of the slider body 89. The slider body 89 slides and is in surface contact with the toothed groove 31. The slider positioning part 810 has a fifth hole 811 and a sixth hole 812 extending radially along the first shaft 71. The diameter of the fifth hole 811 is larger than the diameter of the sixth hole 812, and a slider step 813 is formed at the junction of the two. The support column 181 passes through the fifth hole 811 and the sixth hole 812. The positioning spring 190 is housed in the fifth hole 811 and abuts against the slider step 813. In this way, the positioning top post 180 is movably assembled in the transmission slider 80.

[0113] Furthermore, such as Figure 10 and Figure 11 As shown, the sewing machine feed dog adjustment device also includes a positioning shim 200 sleeved on the first shaft 71; the transmission slider 80 has a slider flange 814 at the junction of the slider body 89 and the slider positioning part 810, and the transmission eccentric pin 70 has a pin flange 73 at the right end of the second shaft 72 away from the first shaft 71; the slider flange 814 and the positioning shim 200 respectively abut against the left and right sides of the feed dog fork crank 30, limiting the feed dog fork crank 30 in the left and right directions, effectively restricting the left and right movement of the feed dog fork crank 30; the positioning shim 200 and the pin flange 73 respectively abut against the left and right sides of the feed dog frame 40, limiting the feed dog frame 40 in the left and right directions, effectively restricting the left and right movement of the feed dog frame 40.

[0114] Furthermore, such as Figure 10 and Figure 11As shown, the tooth lifting adjustment knob 60 is fixed to the left end of the first shaft portion 71 by two fastening screws 110. At the same time, after the tooth lifting adjustment knob 60 is fixed by the two fastening screws 110, the tooth lifting adjustment knob 60 abuts against the left side of the slider positioning portion 810 along the axial direction of the first shaft portion 71, so that the tooth lifting adjustment knob 60, the transmission slider 80, the positioning washer 200, the tooth bracket 40 and the pin flange portion 73 of the transmission eccentric pin 70 are sequentially pressed together.

[0115] Preferably, such as Figure 10 , Figure 18 and Figure 19 As shown, the outer periphery of the right end of the tooth lifting adjustment knob 60 is provided with a limiting groove 66, and limiting step portions 67 are formed at both ends of the limiting groove 66. The limiting groove 66 is a segment of arc groove; the left end of the slider positioning portion 810 is provided with a limiting protrusion 815 extending to the left towards the tooth lifting adjustment knob 60. The limiting protrusion 815 is accommodated in the limiting groove 66, and the limiting protrusion 815 is distributed in the area between the two limiting step portions 67. Figure 20 Taking the view angle shown as an example, when the tooth lifting adjustment knob 60 is rotated clockwise, the limiting protrusion 815 rotates toward the limiting step 67 on the clockwise side of the limiting groove 66 and abuts against the limiting step 67; when the tooth lifting adjustment knob 60 is rotated counterclockwise, the limiting protrusion 815 rotates toward the limiting step 67 on the counterclockwise side of the limiting groove 66 and abuts against the limiting step 67. In this way, the rotation range of the tooth lifting adjustment knob 60 can be limited, preventing the tooth lifting adjustment knob 60 from being over-rotated.

[0116] Furthermore, in the second sewing machine feed dog adjustment device, such as... Figure 12 and Figure 15 As shown, the adjustment positioning groove 81 also has three sections: a standard position groove 82, a high position groove 83, and a low position groove 84. The high position groove 83 and the low position groove 84 are located on both sides of the standard position groove 82. The height of the feed dog 50 corresponding to the high position groove 83, the standard position groove 82, and the low position groove 84 gradually decreases. The feed dog height corresponding to the standard position groove 82 is the feed dog height used for standard sewing, the feed dog height corresponding to the high position groove 83 is the feed dog height used for sewing thick materials, and the feed dog height corresponding to the low position groove 84 is the feed dog height used for sewing thin materials. Figure 20In the schematic diagram, the positioning head 182 is engaged in the conventional gear slot 82. The high gear slot 83 is located on the clockwise side of the conventional gear slot 82, and the low gear slot 84 is located on the counterclockwise side of the conventional gear slot 82. When the feed tooth height needs to be adjusted, push the push plate assembly 90 to the left, exposing the adjustment lever 61 on the tooth lifting adjustment knob 60. When the user inserts a finger or uses another tool to pull the adjustment lever 61 upward, the tooth lifting adjustment knob 60 rotates clockwise, and the positioning head 182 moves out of the conventional gear slot 82 and into the high gear slot 83, thus raising the feed tooth height. Conversely, when the user inserts a finger or uses another tool to pull the adjustment lever 61 downward, the tooth lifting adjustment knob 60 rotates counterclockwise, and the positioning head 182 moves out of the conventional gear slot 82 and into the low gear slot 84, thus lowering the feed tooth height.

[0117] Furthermore, such as Figure 10 and Figure 19 As shown, the feed dog adjustment knob 60 is equipped with an adjustment lever part 61, and the second feed dog adjustment device of the sewing machine is also equipped with a push plate assembly 90. The installation structure of the push plate assembly 90 is the same as that of the first feed dog adjustment device of the sewing machine, and will not be described again here.

[0118] Example 3 of Sewing Machine Feed Dog Adjustment Device

[0119] The difference between Embodiment 3 of the sewing machine feed dog adjustment device and Embodiment 2 lies only in the assembly structure of the positioning top column 180 and the setting structure of the adjusting positioning groove 81. Specifically: Figure 21 As shown, in Embodiment 3 of the sewing machine feed dog adjustment device, the positioning top post 180 is assembled in the feed dog adjustment knob 60, that is, the support column 181 is movably supported in the feed dog adjustment knob 60. Three adjustment positioning grooves 81 are all provided on the surface of the transmission slider 80, preferably on the left end face of the transmission slider 80 facing the feed dog adjustment knob 60, that is, the three adjustment positioning grooves 81 are all provided on the left end face of the slider positioning part 810. The positioning spring 190 is sleeved on the support column 181, and both ends of the positioning spring 190 abut against the positioning head 182 and the feed dog adjustment knob 60, respectively. At this time, the support column 181 and the positioning spring 190 are both horizontally arranged in the left-right direction. Therefore, in Embodiment 3 of the sewing machine feed dog adjustment device, the locking structure is provided between the feed dog adjustment knob 60 and the transmission slider 80, with the first component being the feed dog adjustment knob 60 and the second component being the transmission slider 80.

[0120] Example 4 of Sewing Machine Feed Gear Adjustment Device

[0121] like Figure 22 and Figure 23As shown, the transmission adjustment assembly includes a tooth-lifting fork-shaped crank 30 with a tooth-lifting groove 31, which is fixedly locked to the left end of the tooth-lifting shaft 20 by screws; a tooth-lifting adjustment knob 60; a transmission eccentric pin 70; and a transmission slider 80 that slides in cooperation with the tooth-lifting groove 31. The tooth frame 40 has a tooth frame connecting portion 41 integrally provided near the rear end of the tooth-lifting shaft 20. The transmission eccentric pin 70 includes a first shaft portion 71 and a second shaft portion 72 extending straight in the left-right direction. The first shaft portion 71 and the second shaft portion 72 are eccentrically arranged. The first shaft portion 71 passes through the tooth frame connecting portion 41 and the tooth-lifting adjustment knob 60, rotatably engaging with the tooth frame connecting portion 41 and fixedly connected to the tooth-lifting adjustment knob 60. The second shaft portion 72 passes through the transmission slider 80 and rotatably engages with the transmission slider 80. The tooth-lifting adjustment knob 60 constitutes the adjustment actuator. The locking structure is located between the tooth lifting adjustment knob 60 and the tooth frame connection part 41, or between the transmission slider 80 and the transmission eccentric pin 80. In this embodiment, the first component is the tooth lifting adjustment knob 60, and the second component is the tooth frame connection part 41.

[0122] The feed dog adjustment knob 60, feed dog connector 41, and transmission slider 80 are arranged sequentially from left to right. During normal operation of the sewing machine, the feed dog shaft 20 drives the feed dog connector 40 and feed dog 50 to reciprocate up and down via the feed dog fork crank 30, transmission slider 80, and transmission eccentric pin 70. When it is necessary to adjust the height of the feed dog 50, the sewing machine is stopped, and the feed dog adjustment knob 60 is turned. Figure 22 and Figure 23 As shown, since the tooth lifting adjustment knob 60 is fixed to the first shaft 71 of the transmission eccentric pin 70, the transmission eccentric pin 70 rotates synchronously with the tooth lifting adjustment knob 60 and rotates around the rotational engagement center of the second shaft 72 and the transmission slider 80. The height of the rotational engagement center of the first shaft 71 and the tooth frame connection part 41 will change accordingly. The tooth frame 40 drives the feeding tooth 50 to move up and down, thereby realizing the height adjustment of the feeding tooth 50.

[0123] Furthermore, such as Figures 22 to 24As shown, the transmission adjustment assembly also includes a positioning pin 120 fixed in the feed adjustment knob 60. The structure of the positioning pin 120 is the same as that of the positioning pin in Embodiment 1 of the sewing machine feed adjustment device. That is, the positioning pin 120 includes a housing 122, a spring 123 disposed in the housing 122, and a positioning bead 121 installed at the right end of the housing 122 and abutting against the spring 123. The positioning bead 121 constitutes a positioning component. Multiple adjustment positioning grooves 81 are provided on the left end face of the feed dog connecting part 41 near the feed adjustment knob 60, spaced circumferentially along the feed dog connecting part 41. The positioning pin 120 is extrudeably disposed between the feed dog connecting part 41 and the feed adjustment knob 60 and is engaged in any of the adjustment positioning grooves 81. The positioning bead 121 and the multiple adjustment positioning grooves 81 combine to form a locking structure. Each adjustment positioning slot 81 corresponds to a different feed tooth 50 height. By engaging the positioning pin 120 with different adjustment positioning slots 81, the rotation angle of the tooth lifting adjustment knob 60 can be precisely controlled, thereby precisely adjusting the height of the feed tooth 50. During the rotation of the tooth lifting adjustment knob 60, the positioning pin 120 can be moved from its current adjustment positioning slot 81 to another adjustment positioning slot 81 by extending and retracting left and right, providing positioning for the feed tooth 50 height adjustment operation. This makes the feed tooth 50 height adjustment operation very easy and convenient, allowing garment factory workers to adjust it themselves and effectively improving the operational efficiency of the garment factory.

[0124] Furthermore, such as Figure 22 and Figure 23 As shown, the tooth lifting adjustment knob 60 is fixed to the left end of the first shaft portion 71 by two fastening screws 110. A knob washer 210 is also provided between the tooth lifting adjustment knob 60 and the tooth frame connection portion 41. Along the axial direction of the transmission eccentric pin 70, the tooth lifting adjustment knob 60, knob washer 210, tooth frame connection portion 41, and transmission slider 80 are distributed from left to right. The knob washer 210 and transmission slider 80 abut against the left and right sides of the tooth frame connection portion 41, respectively, effectively restricting the left and right movement of the tooth frame connection portion 41 along the axial direction of the transmission eccentric pin 70, but without affecting the rotational movement between the tooth frame connection portion 41 and the first shaft portion 71 of the transmission eccentric pin 70.

[0125] In addition, such as Figure 24 and Figure 25As shown, there are three adjustment positioning grooves 81 on the left end face of the tooth bracket connection part 41. These three adjustment positioning grooves 81 include a regular position groove 82, a high position groove 83, and a low position groove 84. The high position groove 83 and the low position groove 84 are distributed on both sides of the regular position groove 82. The height of the feed tooth 50 corresponding to the high position groove 83, the regular position groove 82, and the low position groove 84 gradually decreases. Furthermore, the height of the feed tooth 50 corresponding to the regular position groove 82 is the height of a feed tooth 50 used for regular sewing, the height of the feed tooth 50 corresponding to the high position groove 83 is the height of a feed tooth 50 used for sewing thick materials, and the height of the feed tooth 50 corresponding to the low position groove 84 is the height of a feed tooth 50 used for sewing thin materials. In the initial state, the positioning bead 121 is engaged in the regular gear slot 82. The higher gear slot 83 is located on the clockwise side of the regular gear slot 82, and the lower gear slot 84 is located on the counterclockwise side of the regular gear slot 82. When the height of the feed tooth 50 needs to be adjusted, the tooth lifting adjustment knob 60 is rotated clockwise, moving the positioning bead 121 from the regular gear slot 82 into the higher gear slot 83, thus raising the height of the feed tooth 50. Conversely, rotating the tooth lifting adjustment knob 60 counterclockwise moves the positioning bead 121 from the regular gear slot 82 into the lower gear slot 84, thus lowering the height of the feed tooth 50. This structure provides a tactile feedback when the user adjusts the height of the feed tooth 50, allowing the operator to adjust the height of the feed tooth 50 more precisely and conveniently.

[0126] Furthermore, the structure of the feed dog adjustment knob 60 is the same as that of the feed dog adjustment knob in Embodiment 1 of the sewing machine feed dog adjustment device. The feed dog adjustment knob 60 also has an adjustment lever part 61, an upper limit part 62, a lower limit part 63, a first hole part 64 for accommodating the first shaft part 71, and a second hole part 65 for accommodating the positioning pin 120. In addition, the sewing machine feed dog adjustment device four is also equipped with a limit pin 130 and a push plate assembly 90. The installation structure of the limit pin 130 and the push plate assembly 90 is the same as that of the sewing machine feed dog adjustment device one, and will not be described again here.

[0127] Example 5 of Sewing Machine Feed Gear Adjustment Device

[0128] like Figure 26 and Figure 27 As shown, the transmission adjustment assembly includes a tooth-lifting drive crank 220, a tooth-lifting fork-shaped crank 30, a tooth-lifting adjustment slider 230, a tooth-lifting drive slider 240, a transmission eccentric pin 70, and a tooth-lifting adjustment knob 60. The tooth-lifting drive crank 220 is fixedly locked to the left end of the tooth-lifting shaft 20 by screws. The tooth-lifting fork-shaped crank 30 is sleeved on the left end of the tooth-lifting shaft 20 and rotates in cooperation with it; as shown... Figure 27 and Figure 30As shown, the tooth-lifting fork-shaped crank 30 has a tooth-lifting adjustment groove 32 and a tooth-lifting drive groove 33, which are two independent grooves; the tooth-lifting adjustment slider 230 is movably mounted in the tooth-lifting adjustment groove 32 and the two slide in cooperation; the tooth-lifting drive slider 240 is movably mounted in the tooth-lifting drive groove 33 and the two slide in cooperation. The transmission eccentric pin 70 includes an eccentrically positioned first shaft portion 71 and a second shaft portion 72, both extending horizontally. The first shaft portion 71 passes through the tooth-lifting drive crank 220, and the two are rotatably engaged. The tooth-lifting drive crank 220 has a shaft hole that rotatably engages with the first shaft portion 71. The first shaft portion 71 is also fixed to the tooth-lifting adjustment knob 60. The second shaft portion 72 passes through the tooth-lifting adjustment slider 230, and the two are rotatably engaged. The tooth-lifting drive slider 240 is hinged to the rear end of the tooth frame 40 via left-right extending slider pins 260. The tooth-lifting adjustment knob 60 constitutes the adjustment actuator. A locking structure is provided between the tooth-lifting adjustment knob 60 and the tooth-lifting drive crank 220, or between the tooth-lifting drive crank 220 and the transmission eccentric pin 80. In this embodiment, the first component is the tooth-lifting adjustment knob 60, and the second component is the tooth-lifting drive crank 220.

[0129] During normal operation of the sewing machine, the feed dog shaft 20 drives the feed dog 40 and feed dog 50 to reciprocate up and down via the transmission adjustment assembly, and the feed dog 50 performs the feed dog lifting action. When it is necessary to adjust the feed dog lifting height, the sewing machine is stopped, and the feed dog lifting adjustment knob 60 is turned. Figure 31 As shown, since the tooth lifting adjustment knob 60 is fixed to the first shaft portion 71 of the transmission eccentric pin 70, the transmission eccentric pin 70 rotates synchronously with the tooth lifting adjustment knob 60. Since the first shaft portion 71 and the second shaft portion 72 of the transmission eccentric pin 70 are eccentrically set, when the tooth lifting adjustment knob 60 drives the transmission eccentric pin 70 to rotate around the first shaft portion 71, the position of the tooth lifting adjustment slider 230, which rotates with the second shaft portion 72, changes. The tooth lifting adjustment slider 230 slides with the tooth lifting adjustment groove 32 of the tooth lifting fork crank 30, thereby driving a change in the relative position between the tooth lifting drive crank 220 and the tooth lifting fork crank 30. The tooth lifting drive groove 33 of the tooth lifting fork crank 30 slides with the tooth lifting drive slider 240, which is simultaneously hinged to the rear end of the tooth frame 40, ultimately changing the vertical position of the tooth frame 40 and realizing the height change of the feeding tooth 50.

[0130] Furthermore, such as Figure 27As shown, in the tooth-lifting drive crank 220 and the tooth-lifting adjustment knob 60, one end face is provided with several circumferentially spaced adjustment positioning grooves 81, and the other is fixed with a positioning pin 120. The structure of the positioning pin 120 is the same as that of the positioning pin in Embodiment 1 of the sewing machine feed dog adjustment device, that is, the positioning pin 120 includes a housing 122, a spring 123 disposed in the housing 122, and a positioning bead 121 installed at the right end of the housing 122 and abutting against the spring 123. The positioning bead 121 constitutes a positioning component. The retractable positioning bead 121 at the end of the positioning pin 120 is engaged in one adjustment positioning groove 81, and the positioning bead 121 and the several adjustment positioning grooves 81 combine to form a locking structure. In this embodiment, the several adjustment positioning grooves 81 are provided on the left end face of the tooth-lifting drive crank 220, the positioning pin 120 is fixed in the tooth-lifting adjustment knob 60, and the positioning bead 121 is retractably mounted on the right end face of the tooth-lifting adjustment knob 60. Positioning beads 121 are engaged in different adjustment positioning slots 81, corresponding to different feed tooth heights 50. Thus, the engagement of positioning beads 121 with different adjustment positioning slots 81 provides positioning for the rotation of the tooth lifting adjustment knob 60, which in turn provides positioning for the operation of adjusting the feed tooth height 50. When adjusting the height of the feed tooth 50 by rotating the tooth lifting adjustment knob 60, the positioning pin 120 rotates together with the tooth lifting adjustment knob 60. During rotation, the positioning beads 121, squeezed by the left end face of the tooth lifting drive crank 220, first retract to the left, disengaging from the current adjustment positioning slot 81. As the tooth lifting adjustment knob 60 rotates along with the positioning pin 120, and with the action of the spring 123, the positioning beads 121 extend to the right and engage in the next adjustment positioning slot 81. When the height of the feed tooth 50 is not adjusted, the positioning bead 121 remains locked in the current adjustment positioning groove 81, ensuring more reliably that the relative position of the tooth lifting adjustment knob 60 and the tooth lifting drive crank 220 does not change. Furthermore, this structure provides a tactile feedback when the user adjusts the height of the feed tooth 50, allowing the machinist to adjust the height of the feed tooth 50 more precisely and conveniently.

[0131] Furthermore, such as Figure 26 and Figure 27As shown, the tooth lifting adjustment knob 60 is fixed to the left end of the first shaft portion 71 by two fastening screws 110. Along the extension direction of the transmission eccentric pin 70, the tooth lifting adjustment knob 60, the tooth lifting drive crank 220, and the tooth lifting fork crank 30 are arranged side by side from left to right. The tooth lifting adjustment knob 60 abuts against the left end of the tooth lifting drive crank 220. The first shaft portion 71 extends integrally to the left from the left end of the second shaft portion 72. Several adjustment positioning grooves 81 and positioning beads 121 are provided between the tooth lifting adjustment knob 60 and the tooth lifting drive crank 220. In addition, a retaining ring 250 is fixed on the lifting shaft 20. The lifting drive crank 220 and the retaining ring 250 abut against the left and right sides of the lifting fork crank 30 along the axial direction of the lifting shaft 20, respectively, to limit the axial movement of the lifting fork crank 30, restrict the left and right movement of the lifting fork crank 30, and ensure the reliability of the lifting of the feed tooth 50 and the accuracy of the lifting height adjustment.

[0132] Furthermore, such as Figure 29 As shown, there are three adjustment positioning grooves 81 on the left end face of the lifting drive crank 220. These three grooves are a standard gear groove 82, a high gear groove 83, and a low gear groove 84. The high gear groove 83 and the low gear groove 84 are located on either side of the standard gear groove 82. The height of the feed dog 50 corresponding to the standard gear groove 82 is the height of the feed dog 50 used for conventional sewing. The height of the feed dog 50 corresponding to the high gear groove 83 is the height of the feed dog 50 used for sewing thick materials. The height of the feed dog 50 corresponding to the low gear groove 84 is the height of the feed dog 50 used for sewing thin materials. Therefore, the heights of the feed dog 50 corresponding to the high gear groove 83, the standard gear groove 82, and the low gear groove 84 gradually decrease. In this embodiment, using... Figure 31 Taking a view angle as an example, the high-gear groove 83 is located on the clockwise side of the regular-gear groove 82, and the low-gear groove 84 is located on the counterclockwise side of the regular-gear groove 82. During regular sewing, such as... Figure 31 As shown, the positioning bead 121 is engaged in the regular position slot 82. When sewing thick materials, the height of the feed dog 50 needs to be increased. In this case, the feed dog adjustment knob 60 is rotated clockwise, and the positioning bead 121 moves out of the regular position slot 82 and into the high position slot 83. Conversely, when sewing thin materials, the height of the feed dog 50 needs to be decreased. In this case, the feed dog adjustment knob 60 is rotated counterclockwise, and the positioning bead 121 moves out of the regular position slot 82 and into the low position slot 84. This makes it easier for the operator to adjust the height of the feed dog 50.

[0133] Furthermore, the preferred structure of the lifting fork-shaped crank 30 is as follows: Figure 27 and Figure 30As shown, the lifting fork-shaped crank 30 includes a crank body 34 and a first crank arm 35, a second crank arm 36, and a third crank arm 37, all extending from the crank body 34. The crank body 34 is fitted onto the lifting shaft 20 and rotatably engages with it. A lifting adjustment groove 32 is formed between the first crank arm 35 and the second crank arm 36, and a lifting drive groove 33 is formed between the second crank arm 36 and the third crank arm 37. The lifting adjustment groove 32 and the lifting drive groove 33 are parallel. Preferably, the lifting fork-shaped crank 30 is a one-piece molded part.

[0134] Furthermore, such as Figures 26 to 28 As shown, the structure of the feed dog adjustment knob 60 is the same as that of the feed dog adjustment knob in Embodiment 1 of the sewing machine feed dog adjustment device. The feed dog adjustment knob 60 also has an adjustment lever part 61, an upper limit part 62, a lower limit part 63, a first hole part 64 for receiving the first shaft part 71, and a second hole part 65 for receiving the positioning pin 120. However, the adjustment lever part 61 extends integrally to the left from the left end face of the feed dog adjustment knob 60. In addition, the sewing machine feed dog adjustment device 5 is also equipped with a limit pin 130 and a push plate assembly 90. However, the right end of the limit pin 130 is fixed in the feed dog drive crank 220. The feed dog drive crank 220 has a fixing hole for receiving the limit pin 130. The left end of the limit pin 130 is distributed in the area between the upper limit part 62 and the lower limit part 63 on the outer periphery of the feed dog adjustment knob 60, which limits the rotation range of the feed dog adjustment knob 60 and prevents the feed dog adjustment knob 60 from being over-rotated. The installation structure of the push plate assembly 90 is the same as that of the sewing machine feed dog adjustment device, and will not be described again here.

[0135] Example 6 of Sewing Machine Feed Gear Adjustment Device

[0136] like Figure 32 and Figure 33 As shown, the transmission adjustment assembly includes a tooth-lifting drive crank 220, a tooth-lifting connecting rod 270, a transmission eccentric pin 70, and a tooth-lifting adjustment knob 60. The tooth-lifting drive crank 220 is fixedly locked to the left end of the tooth-lifting shaft 20 by screws. The transmission eccentric pin 70 includes an eccentrically positioned first shaft portion 71 and a second shaft portion 72, both extending horizontally. The first shaft portion 71 rotatably engages with the tooth-lifting drive crank 220 and is fixed to the tooth-lifting adjustment knob 60. The second shaft portion 72 rotatably engages with one end of the tooth-lifting connecting rod 270, and the other end of the tooth-lifting connecting rod 270 is hinged to the rear end of the tooth carrier 40. The tooth-lifting adjustment knob 60 constitutes the adjustment actuator. A locking structure is provided between the tooth-lifting adjustment knob 60 and the tooth-lifting drive crank 220, or between the tooth-lifting drive crank 220 and the transmission eccentric pin 70. In this embodiment, the first component is the tooth lifting adjustment knob 60, and the second component is the tooth lifting drive crank 220.

[0137] During normal operation of the sewing machine, the feed dog shaft 20 drives the feed dog 40 and feed dog 50 to reciprocate up and down via the transmission adjustment assembly, and the feed dog 50 performs the feed dog lifting action. When it is necessary to adjust the feed dog lifting height, the sewing machine is stopped, and the feed dog lifting adjustment knob 60 is turned. Figure 35 As shown, since the tooth lifting adjustment knob 60 is fixed to the first shaft portion 71 of the transmission eccentric pin 70, the transmission eccentric pin 70 rotates synchronously with the tooth lifting adjustment knob 60 rotating around the first shaft portion 71. Since the first shaft portion 71 and the second shaft portion 72 of the transmission eccentric pin 70 are eccentrically set, when the tooth lifting adjustment knob 60 drives the transmission eccentric pin 70 to rotate around the first shaft portion 71, the relative position of the second shaft portion 72 of the transmission eccentric pin 70 and the tooth lifting connecting rod 270 changes, thereby changing the vertical position of the tooth frame 40 hinged to the tooth lifting connecting rod 270, and thus the height of the feeding tooth 50 also changes, realizing the height adjustment of the feeding tooth 50.

[0138] Furthermore, such as Figure 33 As shown, the feed tooth drive crank 220 and the feed tooth adjustment knob 60 each have several circumferentially spaced adjustment positioning grooves 81 on their end faces, while the other has a fixed positioning pin 120. The structure of the positioning pin 120 is the same as that of the positioning pin in Embodiment 1 of the sewing machine feed tooth adjustment device, that is, the positioning pin 120 includes a housing 122, a spring 123 disposed in the housing 122, and a positioning bead 121 installed at the right end of the housing 122 and abutting against the spring 123. The positioning bead 121 constitutes a positioning component. The positioning bead 121 can extend and retract in the direction of approaching or moving away from the adjustment positioning groove 81 and is locked in any adjustment positioning groove 81. The height of the feed tooth 50 corresponding to each adjustment positioning groove 81 is different. The positioning bead 121 and the several adjustment positioning grooves 81 combine to form a locking structure. When adjusting the height of the feed tooth 50 by rotating the tooth lifting adjustment knob 60, the positioning pin 120 rotates together with the knob. During rotation, the positioning bead 121, pressed by the left end face of the tooth lifting drive crank 220, first retracts to the left into the housing, disengaging from the current adjustment positioning slot 81. As the tooth lifting adjustment knob 60 rotates along with the positioning pin 120, and with the action of the spring 123, the positioning bead 121 extends to the right and engages in the next adjustment positioning slot 81. When the height of the feed tooth 50 is not adjusted, the positioning bead 121 remains engaged in the current adjustment positioning slot 81, more reliably ensuring that the relative position of the tooth lifting adjustment knob 60 and the tooth lifting drive crank 220 does not change. Furthermore, this structure provides a tactile feedback when the user adjusts the height of the feed tooth 50, facilitating more precise and convenient height adjustment by the machinist.

[0139] Furthermore, such as Figures 32 to 34As shown, the lifting drive crank 220 includes a crank body 221 and a pair of crank arms 222 extending from the crank body 221. The pair of crank arms 222 are arranged side by side. One end of the lifting connecting rod 270, which is connected to the second shaft 72, abuts against the pair of crank arms 222. The first shaft 71 has two sections, left and right, which are rotatably inserted into the pair of crank arms 222. The second shaft 72 is connected between the two sections of the first shaft 71, thereby realizing the connection between the lifting drive crank 220, the lifting connecting rod 270, and the transmission eccentric pin 70. In addition, the pair of crank arms 222 of the lifting drive crank 220 can limit the lateral movement of the lifting connecting rod 270, ensuring the reliability of the lifting of the feed tooth 50 and the accuracy of the lifting height adjustment.

[0140] Furthermore, such as Figure 34 As shown, there are three adjustment positioning grooves 81 on the left side of the outer end of the lifting drive crank 220. These three grooves are a standard gear groove 82, a high gear groove 83, and a low gear groove 84. The high gear groove 83 and the low gear groove 84 are located on either side of the standard gear groove 82. The height of the feed dog 50 corresponding to the standard gear groove 82 is the height of the feed dog 50 used for conventional sewing. The height of the feed dog 50 corresponding to the high gear groove 83 is the height of the feed dog 50 used for sewing thick materials. The height of the feed dog 50 corresponding to the low gear groove 84 is the height of the feed dog 50 used for sewing thin materials. Therefore, the heights of the feed dog 50 corresponding to the high gear groove 83, the standard gear groove 82, and the low gear groove 84 gradually decrease. In this embodiment, using... Figure 35 Taking a view angle as an example, the high-gear groove 83 is located on the clockwise side of the regular-gear groove 82, and the low-gear groove 84 is located on the counterclockwise side of the regular-gear groove 82. During regular sewing, such as... Figure 35 As shown, the positioning bead 121 is engaged in the regular position slot 82. When sewing thick materials, the height of the feed dog 50 needs to be increased. In this case, the feed dog adjustment knob 60 is rotated clockwise, and the positioning bead 121 moves out of the regular position slot 82 and into the high position slot 83. Conversely, when sewing thin materials, the height of the feed dog 50 needs to be decreased. In this case, the feed dog adjustment knob 60 is rotated counterclockwise, and the positioning bead 121 moves out of the regular position slot 82 and into the low position slot 84. This makes it easier for the operator to adjust the height of the feed dog 50.

[0141] Preferably, such as Figures 32 to 34As shown, in the transmission eccentric pin 70, the diameters of the right first shaft portion 71, the second shaft portion 72, and the left first shaft portion 71 decrease sequentially. Thus, in the lifting crank 220, the shaft hole in the right crank arm portion 222 that rotatably engages with the right first shaft portion 71 is a large hole, while the shaft hole in the left crank arm portion 222 that rotatably engages with the left first shaft portion 71 is a small hole. The lifting adjustment knob 60 abuts against the left side of the end of the lifting crank 220 along the extension direction of the transmission eccentric pin 70. Several adjustment positioning grooves 81 are provided on the left end face of the lifting crank 220, and positioning beads 90 are retractably mounted on the right end face of the lifting adjustment knob 60.

[0142] Furthermore, such as Figure 32 and Figure 33 As shown, two fastening screws 110 are threaded into the tooth lifting adjustment knob 60. The left section of the first shaft 71 extends from the tooth lifting drive crank 220 and passes through the tooth lifting adjustment knob 60. The tooth lifting adjustment knob 60 has a shaft hole for accommodating the first shaft 71. The ends of the fastening screws 110 abut against the outer circumference of the first shaft 71, thereby fixing the tooth lifting adjustment knob 60 to the left end of the first shaft 71. A rivet 280 is riveted into the tooth frame 40. The rivet 280 passes through the tooth lifting connecting rod 270 and rotates with the tooth lifting connecting rod 270, thereby hinged the tooth lifting connecting rod 270 to the rear end of the tooth frame 40.

[0143] Furthermore, the feed dog adjustment knob 60 is provided with an adjustment lever part 61, which extends integrally to the left from the left end face of the feed dog adjustment knob 60. The sewing machine feed dog adjustment device six is ​​also equipped with a push plate assembly 90, and the installation structure of the push plate assembly 90 is the same as that of the sewing machine feed dog adjustment device one, and will not be described again here.

[0144] Example 7 of Sewing Machine Feed Gear Adjustment Device

[0145] like Figure 36 and Figure 37As shown, the transmission adjustment assembly includes a lifting drive crank 290, a lifting connecting rod 270, a lifting adjustment crank 310, a lifting adjustment knob 60, and a transmission eccentric pin 70, all fixed to the lifting shaft 20. One end of the lifting connecting rod 270 is hinged to the lifting drive crank 290, and the other end is fixed to the lifting adjustment crank 310. The transmission eccentric pin 70 includes an eccentrically positioned first shaft portion 71 and a second shaft portion 72, both extending laterally. The second shaft portion 72 extends integrally to the right from the left end of the first shaft portion 71. The first shaft portion 71 passes through the lifting adjustment crank 310, and the two are rotatably engaged. The second shaft portion 72 passes through the rear end of the tooth frame 40, and the two are rotatably engaged. The lifting adjustment knob 60 is fixedly connected to the transmission eccentric pin 70. The lifting adjustment knob 60 constitutes the adjustment actuator. The locking structure is located between the tooth lifting adjustment knob 60 and the tooth lifting adjustment crank 310, or between the tooth lifting adjustment crank 310 and the transmission eccentric pin 80. In this embodiment, the first component is the tooth lifting adjustment knob 60, and the second component is the tooth lifting adjustment crank 310.

[0146] During normal operation of the sewing machine, the tooth lifting adjustment knob 60 does not rotate. The tooth lifting shaft 20 drives the tooth holder 40 and the feed tooth 50 to reciprocate up and down through the tooth lifting transmission crank 290, the tooth lifting connecting rod 270, the tooth lifting adjustment crank 310 and the transmission eccentric pin 70. The feed tooth 50 performs the tooth lifting action. The tooth lifting transmission crank 290 and the tooth holder 40 always maintain the current transmission relationship. When the feed dog height needs to be adjusted, the sewing machine is stopped, and the feed dog adjustment knob 60 is rotated. Since the feed dog adjustment knob 60 is fixedly connected to the transmission eccentric pin 70, the transmission eccentric pin 70 rotates together with the feed dog adjustment knob 60. Based on the eccentric setting of the first shaft portion 71 and the second shaft portion 72 of the transmission eccentric pin 70, after the transmission eccentric pin 70 rotates, it changes the relative position between the rotational engagement center of the first shaft portion 71 and the feed dog adjustment crank 310, and the rotational engagement center of the second shaft portion 72 and the feed dog holder 40. That is, the hole on the feed dog adjustment crank 310 that rotates with the first shaft portion 71 and the hole on the feed dog holder 40 that rotates with the second shaft portion 72 change the relative position of the two holes, and the transmission relationship between the feed dog adjustment crank 310 and the feed dog holder 40 changes, thereby changing the height of the feed dog 50 above the upper surface of the needle plate 170 when the sewing machine is running, thus realizing the adjustment of the feed dog height.

[0147] Furthermore, such as Figure 36 and Figure 37As shown, the sewing machine feed dog adjustment device also includes a positioning pin 120 installed on the feed dog adjustment knob 60. The feed dog adjustment knob 60 is located close to the left side of the feed dog adjustment crank 310 along the axial direction of the transmission eccentric pin 70. The structure of the positioning pin 120 is the same as that of the positioning pin in Embodiment 1 of the sewing machine feed dog adjustment device, that is, the positioning pin 120 includes a housing 122, a spring 123 disposed in the housing 122, and a positioning bead 121 installed at the right end of the housing 122 and abutting against the spring 123. The positioning bead 121 constitutes a positioning component. Figure 39 As shown, the tooth lifting adjustment crank 310 has several adjustment positioning grooves 81 on its left end face facing the tooth lifting adjustment knob 60. These grooves are spaced apart circumferentially along the transmission eccentric pin 70. Positioning beads 121 are embedded in one of the adjustment positioning grooves 81, forming a locking structure. When the positioning beads 121 are embedded in different adjustment positioning grooves 81, different feed tooth heights are corresponding to them. During the adjustment of the feed tooth height, under the action of the spring 123 and the external force of rotating the tooth lifting adjustment knob 60 and the transmission eccentric pin 70, the positioning bead 121 is squeezed by the tooth lifting adjustment crank 310 and moves out of the current adjustment positioning groove 81 and retracts to the left into the housing 122. When the tooth lifting adjustment knob 60 and the transmission eccentric pin 70 are rotated to the next position, the positioning bead 121 extends to the right from the housing 122 and re-engages into another adjustment positioning groove 81, reliably keeping the position of the tooth lifting adjustment knob 60 and the transmission eccentric pin 70 relative to the tooth lifting adjustment crank 310 unchanged.

[0148] Preferably, the adjustment positioning groove 81 can have 2-4 grooves, which can be set by the user according to actual needs.

[0149] For example: Figure 39 As shown, there are two adjusting positioning grooves 81, namely a regular position groove 82 and a high position groove 83. The feed dog height corresponding to the high position groove 83 is greater than the feed dog height corresponding to the regular position groove 82, and the high position groove 83 is located above the regular position groove 82. The feed dog height corresponding to the regular position groove 82 is the feed dog height used for regular sewing, and the feed dog height corresponding to the high position groove 83 is the feed dog height used for sewing thick materials. Thus, with Figure 43 Taking the view angle shown as an example, when the tooth lifting adjustment knob 60 is turned counterclockwise upwards, the positioning bead 121 moves out of the normal gear slot 82 and is engaged in the high gear slot 83, which is to adjust the height of the feeding tooth; when the tooth lifting adjustment knob 60 is turned clockwise downwards, the positioning bead 121 moves out of the high gear slot 83 and is engaged in the normal gear slot 82, which is to adjust the height of the feeding tooth.

[0150] For example: Figure 40As shown, there are three adjusting positioning grooves 81: a standard gear groove 82, a high gear groove 83, and a low gear groove 84. The high gear groove 83 and the low gear groove 84 are located on the upper and lower sides of the standard gear groove 82. The feed dog heights corresponding to the high gear groove 83, the standard gear groove 82, and the low gear groove 84 gradually decrease. The feed dog height corresponding to the standard gear groove 82 is the feed dog height used for standard sewing, the feed dog height corresponding to the high gear groove 83 is the feed dog height used for sewing thick materials, and the feed dog height corresponding to the low gear groove 84 is the feed dog height used for sewing thin materials. During normal sewing, the positioning bead 121 is locked in the middle of the regular position slot 82. When it is necessary to raise the height of the feed dog, simply turn the feed dog adjustment knob 60 counterclockwise upwards, and the positioning bead 121 will move out of the regular position slot 82 and be locked in the high position slot 83. When it is necessary to lower the height of the feed dog, simply turn the feed dog adjustment knob 60 clockwise downwards, and the positioning bead 121 will move out of the regular position slot 82 and be locked in the low position slot 84.

[0151] Furthermore, such as Figure 41 or Figure 42 As shown, the transmission eccentric pin 70 also includes a fifth shaft portion 74, which extends integrally to the left from the left end of the first shaft portion 71. The second shaft portion 72 and the fifth shaft portion 74 are respectively fixed at the right and left ends of the first shaft portion 71. The tooth lifting adjustment knob 60 is fixed to the outer periphery of the fifth shaft portion 74 by a first locking screw 321, thereby fixing the tooth lifting adjustment knob 60 to the left end of the transmission eccentric pin 70. Furthermore, a first locking plane 75 is provided on the outer peripheral surface of the fifth shaft portion 74, and the first locking screw 321 abuts against the first locking plane 75. The fifth shaft portion 74 can be configured in the following ways: Method 1, as shown... Figure 41 As shown, the fifth shaft portion 74 is eccentrically positioned relative to the first shaft portion 71, and the fifth shaft portion 74 is coaxially positioned relative to the second shaft portion 72; Method 2, as... Figure 42 As shown, the fifth shaft portion 74 is coaxially arranged with the first shaft portion 71, and the fifth shaft portion 74 is eccentrically arranged with the second shaft portion 72. At this time, the fifth shaft portion 74 and the first shaft portion 71 are merged into the same shaft portion.

[0152] Furthermore, such as Figure 36 and Figure 37 As shown, the lifting crank 310 includes a crank body 291, a pair of crank arms 292 extending from the crank body 291, and a crank groove 293 formed between the pair of crank arms 292. The crank body 291 is fixedly locked to the left end of the lifting shaft 20 by screws. The end of the lifting connecting rod 270 is located in the crank groove 293 and is hinged to the crank arms 292 by a left-right extending fixing pin 340. Preferably, as Figure 38As shown, the fixing pin 340 passes through the crank arm 292 and the two are rotatably engaged. The fixing pin 340 passes through the lifting connecting rod 270 and the two are fixed together by the second locking screw 322. The outer peripheral surface of the fixing pin 340 is provided with a second locking plane 341, and the second locking screw 322 abuts against the second locking plane 341.

[0153] Furthermore, such as Figure 38 and Figure 39 As shown, or as Figure 38 and Figure 40 As shown, a crankshaft 311 extends integrally to the left from the left end face of the lifting crank 310. The crankshaft 311 passes through the lifting connecting rod 270, and the two are fixed together by a third locking screw 323. A third locking plane 312 is provided on the outer circumferential surface of the crankshaft 311, and the third locking screw 323 abuts against the third locking plane 312, thereby fixing the lifting crank 310 and the lifting connecting rod 270. The lifting crank 310 and the lifting connecting rod 270 are two independent components, which is convenient for manufacturing.

[0154] Furthermore, the feed dog adjustment knob 60 is provided with an adjustment lever part 61, which extends integrally to the left from the left end face of the feed dog adjustment knob 60. The sewing machine feed dog adjustment device seven is also equipped with a push plate assembly 90, and the installation structure of the push plate assembly 90 is the same as that of the sewing machine feed dog adjustment device one, and will not be described again here.

[0155] Example 8 of Sewing Machine Feed Gear Adjustment Device

[0156] like Figures 44 to 47 As shown, the transmission adjustment assembly includes a lifting fork-shaped crank 30, a lifting adjustment knob 60, and a transmission slider 80. The lifting fork-shaped crank 30 includes a bushing portion 38 and a fork-shaped portion 39 connected to each other. The bushing portion 38 is fitted onto the outside of the lifting adjustment knob 60. The fork-shaped portion 39 has a lifting groove 31, in which the transmission slider 80 is slidably disposed. The lifting adjustment knob 60 includes an eccentrically positioned third shaft portion 68 and a fourth shaft portion 69. The third shaft portion 68 passes through the bushing portion 38 and the two are rotatably engaged. The fourth shaft portion 69 passes through the left end of the lifting shaft 20 and the two are rotatably engaged. The transmission slider 80 is slidably engaged with the lifting groove 31. The transmission slider 80 is also hinged to the rear end of the tooth frame 40 via left and right extending shaft screws. The lifting adjustment knob 60 constitutes the adjustment actuator. A locking structure is provided between the lifting adjustment knob 60 and the bushing portion 38.

[0157] When the sewing machine is running normally, the lifting gear shaft 20 drives the feed dog 40 and feed dog 50 to reciprocate up and down through the lifting gear adjustment knob 60, the lifting gear fork crank 30, and the transmission slider 80. When it is necessary to adjust the height of the feed dog 50, the sewing machine is stopped, and the lifting gear adjustment knob 60 is turned. Since the position of the lifting gear shaft 20 remains unchanged, the lifting gear adjustment knob 60 rotates around the rotational engagement center between the fourth shaft part 69 and the lifting gear shaft 20. The height of the rotational engagement center between the third shaft part 68 and the bushing part 38 will change, and the height of the fork part 39 connected to the bushing part 38 and the transmission slider 80 slidably disposed in the fork part 39 will change accordingly, thereby changing the height of the feed dog 40 and the feed dog 50, and realizing the adjustment of the height of the feed dog 50.

[0158] Furthermore, such as Figures 44 to 47 As shown, the transmission adjustment assembly also includes a positioning pin 120. The structure of the positioning pin 120 is the same as that of the positioning pin in Embodiment 1 of the sewing machine feed dog adjustment device. That is, the positioning pin 120 includes a housing 122, a spring 123 disposed in the housing 122, and a positioning bead 121 installed at the right end of the housing 122 and abutting against the spring 123. The positioning bead 121 constitutes a positioning component. The housing 122 of the positioning pin 120 is fixed to the shaft body of the third shaft portion 68. The bushing portion 38 is provided with a plurality of through first positioning holes 381 distributed circumferentially. The positioning pin 120 is telescopically disposed between the third shaft portion 68 and the bushing portion 38 and is engaged in any of the first positioning holes 381. The positioning bead 121 and the plurality of first positioning holes 381 combine to form a locking structure. Each first positioning hole 381 corresponds to a different feed tooth 50 height. By engaging the positioning pin 120 with different first positioning holes 381, the rotation angle of the tooth lifting adjustment knob 60 can be precisely controlled, thereby precisely adjusting the height of the feed tooth 50. During the rotation of the tooth lifting adjustment knob 60, the positioning pin 120 rotates together with the knob. The positioning bead 121, pressed by the inner wall of the bushing 38, first retracts into the outer shell 122, disengaging from its current first positioning hole 381, until it extends and moves into the next first positioning hole 381. When the feed tooth 50 height is not adjusted, the positioning bead 121 remains locked in one first positioning hole 381, reliably ensuring that the relative position of the tooth lifting fork crank 30, the limit knob 7, and the tooth lifting shaft 20 does not change. Figure 45 As shown, the third shaft portion 68 of the limit knob 7 has a mounting hole 681 on its shaft body, and the outer casing 122 is fixedly installed in the mounting hole 681.

[0159] Preferably, such as Figure 44 , Figure 47 and Figure 48As shown, there are two first positioning holes 381. These two first positioning holes 381 are a high-level positioning hole 382 and a low-level positioning hole 383 located below the high-level positioning hole 382. The height of the feed tooth 50 corresponding to the high-level positioning hole 382 is greater than the height of the feed tooth 50 corresponding to the low-level positioning hole 383; that is, the height of the feed tooth 50 corresponding to the high-level positioning hole 382 is the height of the feed tooth 50 used for thick material sewing, and the height of the feed tooth 50 corresponding to the low-level positioning hole 383 is the height of the feed tooth 50 used for regular sewing. Initially, the positioning pin 120 is engaged in the high-level positioning hole 382, ​​and the low-level positioning holes 383 are located on the clockwise side of the high-level positioning hole 382. When the height of the feed tooth 50 needs to be adjusted, the tooth lifting adjustment knob 60 is rotated clockwise, and the positioning pin 120 moves from the high-level positioning hole 382 into the low-level positioning hole 383, thus lowering the height of the feed tooth 50. This structure provides a tactile feedback when the user adjusts the height of the feed tooth 50, making it easier for the machinist to adjust the height of the feed tooth 50 more precisely and conveniently.

[0160] Furthermore, such as Figure 44 As shown, the lifting shaft 20 has an insertion hole at one end near the tooth holder 40, and the fourth shaft portion 69 is inserted into the insertion hole. When no external force is applied to the fourth shaft portion 69, there is sufficient friction between the fourth shaft portion 69 and the insertion hole, so that the relative angle between the lifting shaft 20 and the fourth shaft portion 69 is fixed, and the height of the feed tooth 50 remains unchanged. The lifting shaft 20 can drive the tooth holder 40 and the feed tooth 50 to reciprocate up and down through the lifting adjustment knob 60, the lifting fork crank 30, and the transmission slider 80. Specifically, the diameter of the third shaft portion 68 is larger than the diameter of the fourth shaft portion 69, and the bushing portion 38 is sleeved on the outside of the third shaft portion 68.

[0161] Furthermore, the left side of the sewing machine base plate 10 has an opening structure, through which the third shaft 68 of the feed dog adjustment knob 60 is exposed, making it convenient to rotate the feed dog adjustment knob 60 to adjust the height of the feed dog 50.

[0162] Example 9 of Sewing Machine Feed Dog Adjustment Device

[0163] like Figure 49 and Figure 50 As shown, the transmission adjustment assembly includes a tooth-lifting fork-shaped crank 30 fixed to the tooth-lifting shaft 20 by screws and having a tooth-lifting groove 31, a sliding sleeve 42 located in the rear section of the tooth frame 40, an adjusting slider 330, and a transmission slider 80 that slides in cooperation with the tooth-lifting groove 31. Figure 51 and Figure 52As shown, the adjusting slider 330 includes a first connecting part 331 and a second connecting part 332 connected to each other. The first connecting part 331 is slidably engaged with the sliding sleeve part 42, and a positioning bead 121 that can extend and retract left and right is installed on the first connecting part 331. The transmission slider 80 is hinged to the second connecting part 332. The side wall of the sliding sleeve part 42 is provided with a plurality of second positioning holes 43 spaced apart along the extending direction of the sliding sleeve part 42. The positioning bead 121 is telescopically disposed between the sliding sleeve part 42 and the first connecting part 331 and is engaged in any of the second positioning holes 43. Each second positioning hole 43 corresponds to a different height of the feed tooth 50. By engaging the positioning bead 121 with different second positioning holes 43, the relative position of the first connecting part 331 in the sliding sleeve part 42 can be precisely adjusted, thereby precisely adjusting the height of the feed tooth 50. The positioning bead 121 constitutes an adjusting actuator. The positioning bead 121 and the plurality of second positioning holes 43 combine to form a locking structure.

[0164] When the sewing machine is running normally, the lifting tooth shaft 20 drives the tooth holder 40 and the feed tooth 50 to reciprocate up and down via the lifting tooth fork crank 30, the transmission slider 80, and the sliding sleeve 42, and the feed tooth 50 performs the lifting action. When it is necessary to adjust the height of the feed tooth 50, the sewing machine stops. Figure 50 , Figure 52 and Figure 53 As shown, pressing the positioning bead 121 moves the positioning bead 121 from its current position in the second positioning hole 43 into another second positioning hole 43. This changes the relative position of the sliding sleeve 42 and the adjusting slider 330, as well as the position of the transmission slider 80 in the tooth-lifting groove 31. This causes the feeding tooth 50 to move up and down, thereby changing its height. The cooperation between the positioning bead 121 and the second positioning hole 43 provides positioning for the height adjustment operation of the feeding tooth 50, making the height adjustment operation very easy and convenient. This allows garment factory workers to adjust the height themselves, effectively improving the operational efficiency of the garment factory.

[0165] Furthermore, such as Figure 51 and Figure 52 As shown, the first connecting part 331 has a T-shaped cross-section, and the sliding sleeve part 42 is provided with a sliding sleeve groove 44 with a T-shaped cross-section. The first connecting part 331 is slidably disposed in the sliding sleeve groove 44. Preferably, the sliding sleeve part 42 is arc-shaped, and its front end is connected to the dental frame 40.

[0166] Furthermore, such as Figure 51 and Figure 52As shown, the front end of the first connecting part 331 is provided with a mounting hole 333, in which a spring 123 is fixedly installed. The spring 123 is connected to the positioning bead 121. By pressing the positioning bead 121, the positioning bead 121 can be disengaged from its current position in the second positioning hole 43 and retracted into the mounting hole 333. At this time, the first connecting part 331 is slid until the positioning bead 121 is aligned with another second positioning hole 43. At this time, the positioning bead 121 will extend and enter the second positioning hole 43 under the elastic restoring action of the spring 10. When the height of the feed tooth 50 is not adjusted, the positioning bead 121 is always locked in one of the second positioning holes 43, which can reliably ensure that the relative position of the sliding sleeve part 42, the first connecting part 331, and the adjusting slider 330 does not change.

[0167] Furthermore, such as Figure 52 and Figure 53 As shown, there are three second positioning holes 43. These three second positioning holes 43 are a high-gear positioning hole 431, a normal-gear positioning hole 432, and a low-gear positioning hole 433. The high-gear positioning hole 431 and the low-gear positioning hole 433 are located on both sides of the normal-gear positioning hole 432. The high-gear positioning hole 431 is located on the side closer to the feed tooth 50, and the low-gear positioning hole 433 is located on the side closer to the transmission slider 80. The height of the feed tooth 50 corresponding to the high-gear positioning hole 431, the normal-gear positioning hole 432, and the low-gear positioning hole 433 gradually decreases. That is, the height of the feed tooth 50 corresponding to the high-gear positioning hole 431 is the height of the feed tooth 50 used for sewing thick materials, the height of the feed tooth 50 corresponding to the normal-gear positioning hole 432 is the height of the feed tooth 50 used for sewing regular materials, and the height of the feed tooth 50 corresponding to the low-gear positioning hole 433 is the height of the feed tooth 50 used for sewing thin materials. In the initial state, the positioning bead 121 is engaged in the normal gear positioning hole 432. The high gear positioning hole 431 is located in front of the normal gear positioning hole 432, and the low gear positioning hole 433 is located behind the normal gear positioning hole 432. When the height of the feed tooth 50 needs to be adjusted, pressing the positioning bead 121 drives the first connecting part 331 to move forward and retract into the sliding sleeve part 42. The positioning bead 121 moves from the normal gear positioning hole 432 into the high gear positioning hole 431, which raises the height of the feed tooth 50. Conversely, pressing the positioning bead 121 causes the first connecting part 331 to move backward and extend from the sliding sleeve part 42. The positioning bead 121 moves from the normal gear positioning hole 432 into the low gear positioning hole 433, which lowers the height of the feed tooth 50. This structure provides a tactile feedback when the user adjusts the height of the feed tooth 50, making it easier for the operator to adjust the height of the feed tooth 50 more precisely and conveniently.

[0168] Preferably, such as Figure 51 and Figure 52As shown, the transmission slider 80 is provided with a transmission slider pin 818 extending in the left-right direction. The transmission slider pin 818 passes through the transmission slider pad 819 and is hinged to the opening 334 opened on the second connecting part 332.

[0169] Furthermore, such as Figure 49 As shown, the left side of the sewing machine base plate 10 has an opening structure, through which the positioning bead 121 protrudes, making it convenient to press the positioning bead 121 to adjust the height of the feed tooth 50.

[0170] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0171] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A sewing machine feed dog adjusting device, comprising a fixed base plate, a feed dog lifting shaft rotatably supported in the base plate, a feed dog bracket, and a feed dog fixed on the feed dog bracket, characterized in that: It also includes a transmission adjustment assembly, which is tractively connected between the tooth lifting shaft and the tooth frame. The transmission adjustment assembly has an adjustment actuator for user operation. A locking structure is also provided between two adjacent components in the transmission adjustment assembly to maintain the relative position of the two adjacent components. When the user operates the adjustment actuator, the height of the feed dog and the current relative position of the two adjacent components change during subsequent sewing machine operation.

2. The sewing machine feed dog adjustment device according to claim 1, characterized in that: The transmission adjustment assembly includes a tooth-lifting fork-shaped crank with a tooth-lifting groove, a tooth-lifting adjustment knob, a transmission eccentric pin, and a transmission slider that slides in conjunction with the tooth-lifting groove. The tooth-lifting fork-shaped crank is fixed on the tooth-lifting shaft. The transmission eccentric pin includes an eccentrically positioned first shaft portion and a second shaft portion. The first shaft portion rotates in conjunction with the transmission slider and is fixed to the tooth-lifting adjustment knob. The second shaft portion rotates in conjunction with the tooth frame. The tooth-lifting adjustment knob constitutes the adjustment actuator. The locking structure is located between the tooth-lifting adjustment knob and the transmission slider, or between the transmission slider and the transmission eccentric pin. When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the relative position between the rotational fit center of the first shaft and the transmission slider, and between the rotational fit center of the second shaft and the tooth frame.

3. The sewing machine feed dog adjustment device according to claim 2, characterized in that: The transmission adjustment assembly also includes a limiting pin, one end of which is fixed in the transmission slider. The tooth lifting adjustment knob is provided with a protruding upper limit part and a lower limit part. The limiting pin is distributed in the area between the upper limit part and the lower limit part on the outer periphery of the tooth lifting adjustment knob and can abut against the upper limit part and the lower limit part.

4. The sewing machine feed dog adjustment device according to claim 1, characterized in that: The transmission adjustment assembly includes a tooth-lifting fork-shaped crank with a tooth-lifting groove, a tooth-lifting adjustment knob, a transmission eccentric pin, and a transmission slider that slides with the tooth-lifting groove. The tooth-lifting fork-shaped crank is fixed on the tooth-lifting shaft. The tooth frame is fixedly provided with a tooth frame connecting part at one end near the tooth-lifting shaft. The transmission eccentric pin includes an eccentrically set first shaft part and a second shaft part. The first shaft part passes through the tooth frame connecting part and is fixedly connected to the tooth-lifting adjustment knob. The second shaft part is rotatably engaged with the transmission slider. The tooth-lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth-lifting adjustment knob and the tooth frame connecting part, or between the transmission slider and the transmission eccentric pin. When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the height of the rotational fit center between the first shaft and the tooth frame connection.

5. The sewing machine feed dog adjustment device according to claim 1, characterized in that: The transmission adjustment assembly includes a tooth lifting drive crank fixed on the tooth lifting shaft, a tooth lifting fork-shaped crank rotatably fitted on the tooth lifting shaft, a tooth lifting adjustment slider, a tooth lifting drive slider, a transmission eccentric pin, and a tooth lifting adjustment knob. The tooth lifting fork-shaped crank has a tooth lifting adjustment groove that slidably engages with the tooth lifting adjustment slider and a tooth lifting drive groove that slidably engages with the tooth lifting drive slider. The transmission eccentric pin includes an eccentrically set first shaft portion and a second shaft portion. The first shaft portion rotatably engages with the tooth lifting drive crank and is fixed to the tooth lifting adjustment knob. The second shaft portion rotatably engages with the tooth lifting adjustment slider. The tooth lifting drive slider is hinged to the tooth frame. The tooth lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth lifting adjustment knob and the tooth lifting drive crank, or between the tooth lifting drive crank and the transmission eccentric pin. When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the relative position between the tooth lifting drive crank and the tooth lifting fork crank.

6. The sewing machine feed dog adjustment device according to claim 1, characterized in that: The transmission adjustment assembly includes a tooth lifting drive crank, a tooth lifting connecting rod, a transmission eccentric pin, and a tooth lifting adjustment knob, all fixed on the tooth lifting shaft. The transmission eccentric pin includes an eccentrically positioned first shaft portion and a second shaft portion. The first shaft portion is rotatably engaged with the tooth lifting drive crank and fixed to the tooth lifting adjustment knob. The second shaft portion is rotatably engaged with one end of the tooth lifting connecting rod. The other end of the tooth lifting connecting rod is hinged to the tooth frame. The tooth lifting adjustment knob constitutes the adjustment actuator. The locking structure is located between the tooth lifting adjustment knob and the tooth lifting drive crank, or between the tooth lifting drive crank and the transmission eccentric pin. When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates synchronously with the tooth lifting adjustment knob, changing the relative position between the second shaft and the tooth lifting connecting rod.

7. The sewing machine feed dog adjustment device according to claim 1, characterized in that: The transmission adjustment assembly includes a lifting transmission crank, a lifting connecting rod, a lifting adjustment crank, a lifting adjustment knob, and a transmission eccentric pin, all fixed on the lifting shaft. One end of the lifting connecting rod is hinged to the lifting transmission crank, and the other end is fixed to the lifting adjustment crank. The transmission eccentric pin includes an eccentrically positioned first shaft portion and a second shaft portion. The first shaft portion passes through the lifting adjustment crank and is rotatably engaged with it. The second shaft portion passes through the tooth frame and is rotatably engaged with it. The lifting adjustment knob is fixedly connected to the transmission eccentric pin and is located close to one side of the lifting adjustment crank along the axial direction of the transmission eccentric pin. The lifting adjustment knob constitutes the adjustment actuator. The locking structure is located between the lifting adjustment knob and the lifting adjustment crank, or between the lifting adjustment crank and the transmission eccentric pin. When the tooth lifting adjustment knob is rotated, the transmission eccentric pin rotates together with the tooth lifting adjustment knob, changing the relative position between the rotational fit center of the first shaft and the tooth lifting adjustment crank, and between the rotational fit center of the second shaft and the tooth frame.

8. The sewing machine feed dog adjusting device according to any one of claims 1, 2, or 4-7, characterized in that: The two adjacent components in the transmission adjustment assembly that have a locking structure are defined as the first component and the second component. The locking structure includes a positioning component and several circumferentially spaced adjustment positioning grooves. The positioning component is telescopically mounted in the first component. The several adjustment positioning grooves are provided on the surface of the second component facing the first component. The positioning component can telescopically extend or retract in the direction of approaching or moving away from the second component and is locked in any adjustment positioning groove. The height of the feed tooth corresponding to each adjustment positioning groove is different. When the tooth lifting adjustment knob is rotated, the positioning component moves out of the current adjustment positioning slot and engages in another adjustment positioning slot.

9. The sewing machine feed dog adjustment device according to claim 8, characterized in that: The locking structure also includes a positioning pin, which is fixed in the first component. The end of the positioning pin facing the second component has a retractable positioning bead, which constitutes the positioning component.

10. The sewing machine feed dog adjusting device according to claim 8, characterized in that: The locking structure further includes a positioning top post and a positioning spring. The positioning top post includes a support column and a positioning head fixed to the end of the support column. The positioning spring is sleeved on the support column. The support column is movably supported in the first component. The two ends of the positioning spring abut against the positioning head and the first component, respectively. The positioning head constitutes the positioning component. The outer surface of the positioning head includes a top column positioning surface and a top column limiting plane connected to both sides of the top column positioning surface. The groove wall of the adjusting positioning groove includes a groove positioning surface and a groove limiting plane connected to both sides of the groove positioning surface. The top column positioning surface and the groove positioning surface are in surface contact with each other, and the top column limiting plane and the groove limiting plane are in surface contact with each other.

11. The sewing machine feed dog adjusting device according to any one of claims 2 or 4-7, characterized in that: An adjustment lever extends integrally from the tooth lifting adjustment knob, which is used by the user to drive the tooth lifting adjustment knob to rotate.

12. The sewing machine feed dog adjustment device according to claim 1, characterized in that: The transmission adjustment assembly includes a tooth-lifting fork-shaped crank, a tooth-lifting adjustment knob, and a transmission slider. The tooth-lifting fork-shaped crank includes a connected bushing portion and a fork-shaped portion with a tooth-lifting groove. The tooth-lifting adjustment knob includes an eccentrically arranged third shaft portion and a fourth shaft portion. The third shaft portion passes through the bushing portion and the two are rotatably engaged. The fourth shaft portion passes through the tooth-lifting shaft and the two are rotatably engaged. The transmission slider is slidably engaged with the tooth-lifting groove and hinged to the tooth frame. The tooth-lifting adjustment knob constitutes the adjustment actuator. The locking structure is provided between the tooth-lifting adjustment knob and the bushing portion. When the tooth lifting adjustment knob is rotated, the height of the rotational mating center of the third shaft and the bushing changes.

13. The sewing machine feed dog adjusting device according to claim 12, characterized in that: The locking structure includes a positioning pin fixed in the third shaft and several first positioning holes distributed circumferentially in the bushing. The end of the positioning pin has a retractable positioning bead. The positioning bead is retractably disposed between the third shaft and the bushing and is engaged in any of the first positioning holes. The height of the feed tooth corresponding to each first positioning hole is different. When the tooth lifting adjustment knob is turned, the positioning bead moves out of the current first positioning hole and is inserted into another first positioning hole.

14. The sewing machine feed dog adjustment device according to claim 1, characterized in that: The transmission adjustment assembly includes a tooth-lifting fork-shaped crank with a tooth-lifting groove, a transmission slider that slides with the tooth-lifting groove, an adjustment slider, and a positioning pin. The tooth-lifting fork-shaped crank is fixed on the tooth-lifting shaft. A sliding sleeve is fixed on the tooth frame. The adjustment slider includes a first connecting part and a second connecting part that are connected to each other. The first connecting part slides with the sliding sleeve, and the second connecting part is hinged to the transmission slider. The positioning pin is installed on the first connecting part and has a retractable positioning bead at its end. The sliding sleeve has several second positioning holes that are spaced apart along the extension direction of the sliding sleeve. The positioning bead is retractably disposed between the sliding sleeve and the first connecting part and is locked in any of the second positioning holes. The height of the feed tooth corresponding to each second positioning hole is different. The positioning bead constitutes the adjustment actuator, and the positioning bead and the second positioning hole constitute the locking structure. When the first connecting part and the sliding sleeve part are driven to slide relative to each other, the position of the transmission slider in the tooth lifting groove changes, and the positioning bead moves out of the current second positioning hole and is inserted into another second positioning hole.

15. The sewing machine feed dog adjusting device according to claim 1, characterized in that: It also includes a push plate assembly, wherein the base plate is provided with an adjustment opening groove and push plate slide grooves provided on both sides of the adjustment opening groove, and the push plate assembly is movably assembled in the push plate slide grooves and can open or close the adjustment opening groove; When the user drives the push plate assembly to slide and open the adjustment opening slot, the adjustment actuator is exposed from the adjustment opening slot.

16. A sewing machine, characterized in that: The sewing machine is equipped with the sewing machine feed dog adjustment device according to any one of claims 1-15.

Images