Lower tug mechanism with cloth clamping prevention function and sewing machine

Abstract

The utility model provides a lower tug mechanism with a cloth clamping prevention function, which comprises a roller seat arranged in an opening part, a lower roller rotationally arranged in the roller seat, and a lower roller transmission unit connected between a feed dog frame seat and the lower roller, and the lower roller is exposed out of a bottom plate; a plurality of cloth clamping prevention rods are further arranged on the roller seat and arranged above the lower roller in a crossing mode. The utility model further provides a sewing machine which comprises the lower dragging wheel mechanism. The cloth clamping prevention roller seat has the advantages that the cloth clamping prevention rod is arranged on the roller seat, so that fabric can be prevented from being rolled into the roller seat, and sewing efficiency and sewing quality are prevented from being affected. The driving force of the lower dragging wheel mechanism comes from swinging of the tooth frame base, the lower dragging wheel mechanism and the feeding teeth can move synchronously, and when the lower dragging wheel mechanism is used in cooperation with the rear dragging wheel mechanism, higher cloth feeding power and better mistake-proofing performance are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewing machines, in particular to a lower tug mechanism with a cloth-preventing function and a sewing machine. Background Art

[0002] The existing lower tug mechanism includes a lower roller, which is exposed from an opening of the sewing machine bottom plate and can assist the upper roller and the feed dog in feeding when rotating. Since there is a gap between the lower roller and the opening, the fabric is easily rolled into the opening when rotating, which affects the sewing efficiency and sewing quality. Utility Model Content

[0003] The utility model aims to provide a lower tug mechanism with a cloth-blocking prevention function to solve the problems existing in the prior art.

[0004] The utility model provides a lower tug mechanism with a cloth-blocking prevention function, which is installed in a sewing machine. The sewing machine comprises a fixed bottom plate and a feeding mechanism arranged below the bottom plate, wherein the feeding mechanism comprises a feeding shaft rotatably arranged in the bottom plate and a tooth frame seat arranged at one end of the feeding shaft, and an opening portion penetrating from top to bottom is opened in the bottom plate; the lower tug mechanism comprises a roller seat installed in the opening portion, a lower roller rotatably installed in the roller seat, and a lower roller transmission unit connected between the tooth frame seat and the lower roller, wherein the lower roller is exposed from the bottom plate; a plurality of cloth-blocking prevention rods are also arranged on the roller seat, and the cloth-blocking prevention rods are straddled above the lower roller.

[0005] Preferably, a plurality of annular grooves are provided on the outer circumference of the lower roller, and the anti-stuck cloth rod is arranged directly above the annular grooves.

[0006] Preferably, the anti-stuck cloth rod comprises an arc segment and a first straight segment which are connected to each other, the arc segment is arranged on the rear side of the roller seat, and the first straight segment is arranged on the front side of the roller seat.

[0007] Preferably, the maximum height of the roller surface of the lower roller is not less than the setting height of the first straight section.

[0008] Preferably, the anti-stuck cloth rod also includes a first plug-in connected to the first straight section and a second plug-in connected to the arc section, and a first socket for inserting the first plug-in is provided on the front side of the roller seat, and a second socket for inserting the second plug-in is provided on the rear side of the roller seat.

[0009] Preferably, the arc segment is connected to the second plug-in unit via a second straight segment, and a relief groove for accommodating the second straight segment is further provided on the rear side of the roller seat, and the second plug hole is arranged in the relief groove.

[0010] Preferably, an upper swing arm is provided on the feed shaft, and a base is fixedly arranged under the bottom plate, and the lower roller transmission unit comprises a rocker arm hinged with the upper swing arm at an upper end, a rotating shaft rotatably arranged in the base, a first synchronous wheel arranged at one end of the roller shaft, a second synchronous wheel arranged at the first end of the rotating shaft, a first one-way bearing and a lower swing arm which are sequentially sleeved on the second end of the rotating shaft from the inside to the outside, the first synchronous wheel and the second synchronous wheel are connected by a synchronous member, and a sliding groove is also provided on the lower swing arm, and the sliding groove is hinged with the lower end of the rocker arm; when the tooth frame seat swings in a direction consistent with the feeding direction of the sewing machine, the first one-way bearing is locked, the first synchronous wheel rotates with the rotating shaft, and the lower roller rotates; when the tooth frame seat swings in a direction opposite to the feeding direction of the sewing machine, the first one-way bearing rotates freely, the rotating shaft is stationary, and the lower roller is stationary.

[0011] Preferably, it also includes a tensioning eccentric pin, which includes an eccentrically arranged first shaft segment and a second shaft segment, the first shaft segment is arranged in the base, and a tensioning wheel is rotatably mounted on the second shaft segment, and the tensioning wheel abuts against the outer periphery of the synchronizer.

[0012] Preferably, a synchronous belt cover is also installed in the opening portion, and the synchronous belt cover is located directly above the first synchronous wheel.

[0013] Preferably, a retaining ring is provided on the rotating shaft, the lower swing arm is U-shaped, and the retaining ring is located between the two ends of the lower swing arm.

[0014] Preferably, it also includes a nut slidably arranged in the sliding groove, and the lower end of the rocker arm is connected to the nut through an axial screw.

[0015] The utility model also provides a sewing machine, comprising the aforementioned lower tug wheel mechanism.

[0016] The utility model is beneficial in that, by setting the anti-cloth-jamming rod on the roller seat, the fabric can be prevented from being rolled into the roller seat, which affects the sewing efficiency and sewing quality. The driving force of the lower tug mechanism comes from the swing of the tooth frame seat, which can move synchronously with the feed tooth. When used together with the rear tug mechanism, it has stronger cloth feeding power and better anti-misalignment performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional diagram of the sewing machine of the utility model;

[0018] Figure 2 It is a three-dimensional structure of the lower tugboat mechanism of the utility model. Figure 1 ;

[0019] Figure 3is the three-dimensional view of the lower idler mechanism of the present utility model Figure 2 ;

[0020] Figure 4 is the structural schematic diagram of the roller seat;

[0021] Figure 5 is the structural schematic diagram of the lower roller;

[0022] Figure 6 is the structural schematic diagram of the anti-cloth jamming rod;

[0023] Figure 7 is the exploded view of the lower idler mechanism of the present utility model;

[0024] Figure 8 is the partial cross-sectional view of the lower idler mechanism of the present utility model.

[0025] Description of component numbers:

[0026] 11 Base plate

[0027] 12 Machine housing

[0028] 13 Lifting shaft

[0029] 131 Lifting fork-shaped crank

[0030] 132 Lifting slider

[0031] 14 Feeding shaft

[0032] 141 Tooth rest

[0033] 142 Upper swing arm

[0034] 15 Tooth rest

[0035] 151 Feeding tooth

[0036] 16 Needle plate

[0037] 2 Synchronous belt housing

[0038] 3 Lower roller

[0039] 31 Roller shaft

[0040] 32 Deep groove ball bearing

[0041] 33 Annular groove

[0042] 34 Roller surface

[0043] 4 Roller seat

[0044] 41 Anti-cloth jamming rod

[0045] 411 Arc segment

[0046] 412 First straight section

[0047] 413 Second straight section

[0048] 414 First plug-in part

[0049] 415 Second plug-in part

[0050] 42 Oil-proof cover

[0051] 43 First jack

[0052] 44 Avoidance groove

[0053] 441 Second jack

[0054] 45 Groove

[0055] 5 Lower roller drive unit

[0056] 50 Synchronizer

[0057] 51 First synchronous pulley

[0058] 52 Second synchronous pulley

[0059] 531 First deep groove ball bearing

[0060] 532 Second deep groove ball bearing

[0061] 541 First one-way bearing

[0062] 542 Second one-way bearing

[0063] 55 Rotating shaft

[0064] 56 Retaining ring

[0065] 57 Third deep groove ball bearing

[0066] 58 Lower swing arm

[0067] 581 Slide groove

[0068] 59 Rocker arm

[0069] 510 Nut

[0070] 511 Axial position screw

[0071] 61 Tensioning eccentric pin

[0072] 62 Tensioning pulley

[0073] 7 Base Detailed implementation mode

[0074] The following further describes in detail the specific embodiments of the present utility model in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model.

[0075] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0076] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0077] Figure 1 The following shows a perspective view of the sewing machine of the present utility model. In the following description, the Figure 1 accompanying drawings are used as the reference basis for directions. In Figure 1 it is defined that the length direction of the bottom plate 11 is the left-right direction, and the needle plate 16 is located on the left side of the bottom plate 11; the width direction of the bottom plate 11 is the front-rear direction, and the lower roller 3 is located on the front side of the needle plate 16; the height direction of the bottom plate 11 is the up-down direction, and the machine shell 12 is located above the bottom plate 11.

[0078] The present utility model provides a lower drag wheel mechanism and a sewing machine with a function of preventing cloth jamming.

[0079] As shown in Figures 1-3As shown in the figure, the sewing machine includes a fixed base plate 11, a machine shell 12 arranged above the base plate 11, a needle plate 16 fixed on the upper surface of the left side of the base plate 11, a feeding mechanism and a tooth-lifting mechanism arranged below the base plate 11. The feeding mechanism includes a feeding shaft 14 rotatably arranged in the base plate 11 and a tooth carrier base 141 arranged at the left end of the feeding shaft 14. The front end of the tooth carrier base 141 is hinged to the front end of the tooth carrier 15. The tooth-lifting mechanism includes a tooth-lifting shaft 13 rotatably arranged in the base plate 11, a tooth-lifting fork-shaped crank 131 fixed at the left end of the tooth-lifting shaft 13, and a tooth-lifting slider 132 slidably assembled in the opening of the tooth-lifting fork-shaped crank 131. The tooth-lifting slider 132 is hinged to the rear end of the tooth carrier 15. A feeding tooth 151 is fixed on the tooth carrier 15, and the feeding tooth 151 can be exposed from the needle plate 16. When the sewing machine works, the feeding shaft 14 and the tooth-lifting shaft 13 are driven to rotate by the main shaft of the sewing machine or an independent motor. The feeding mechanism drives the tooth carrier 15 and the feeding tooth 151 to perform a reciprocating forward and backward movement, and the tooth-lifting mechanism drives the tooth carrier 15 and the feeding tooth 151 to perform a reciprocating up and down movement. Finally, the feeding tooth 151 performs a compound movement with an elliptical movement trajectory, driving the fabric to move forward and completing the feeding action.

[0080] The sewing machine further includes Figure 1 a rear drag wheel mechanism not shown in the figure. The rear drag wheel mechanism includes a rear drag wheel drive source and an upper roller driven to rotate by the rear drag wheel drive source. The upper roller is arranged above the base plate 11. An opening part penetrating up and down is formed in the base plate 11.

[0081] The lower drag wheel mechanism involved in the present invention includes a roller seat 4 detachably installed in the opening part, a lower roller 3 rotatably installed in the roller seat 4 through a roller shaft 31, and a lower roller transmission unit 5 connected between the lower roller 3 and the tooth carrier base 141. The lower roller 3 is exposed from the base plate 11, and the exposed part thereof can be in contact with the fabric placed on the base plate 11. At the same time, the lower roller 3 is arranged directly below the upper roller, that is, the lower roller 3 and the upper roller are arranged vertically opposite to each other, and the fabric passes between the upper roller and the lower roller. When the sewing machine works, the rear drag wheel drive source drives the upper roller to rotate, and the tooth carrier base 141 drives the lower roller 3 to rotate through the lower roller transmission unit 5. The lower roller 3 has a driving force to drive the fabric to move, and together with the upper roller and the feeding tooth 151, it drives the fabric on the base plate 11 to move forward. Therefore, the lower drag wheel mechanism provided by the present invention can provide sufficient feeding power, is suitable for moving thick materials, and can also avoid the problem of misalignment of the upper and lower fabrics caused by insufficient feeding power. The lower drag wheel mechanism works together with the rear drag wheel mechanism, having advantages such as strong feeding ability and good anti-misalignment performance. In addition, the driving force of the lower roller 3 comes from the forward and backward swing of the tooth carrier base 141, without the need to additionally set a power source, which helps to simplify the overall structure of the lower drag wheel mechanism and reduce the production cost.

[0082] Such as Figures 2-6As shown, a plurality of anti-cloth jamming rods 41 are provided on the roller seat 4 at intervals in the left-right direction. The anti-cloth jamming rods 41 straddle above the lower roller 3 and are used to prevent the fabric from being rolled into the roller seat 4 as the lower roller 3 rotates, and they do not hinder the contact between the lower roller 3 and the fabric.

[0083] In a specific embodiment of the present utility model, an annular groove 33 with the same number as the anti-cloth jamming rods 41 is further provided on the lower roller 3. The plurality of annular grooves 33 divide the outer surface of the lower roller 3 into a plurality of roller surfaces 34 for contacting the fabric, and each anti-cloth jamming rod 41 is arranged above the annular groove 33. The anti-cloth jamming rod 41 includes a first plug-in part 414, a first straight section 412, an arc section 411, a second straight section 413, and a second plug-in part 415 connected in sequence. Among them, the first plug-in part 414 and the second plug-in part 415 extend vertically in the up-down direction, and the first straight section 412 and the second straight section 413 extend horizontally in the front-back direction. A slot 45 for installing the lower roller 3 is provided in the roller seat 4. A plurality of first jacks 43 for inserting the first plug-in part 414 are provided on the front side of the slot 45, and a plurality of avoidance grooves 44 for accommodating the second straight section 413 are provided on the rear side of the slot 45. A second jack 441 for inserting the second plug-in part 415 is further provided in the avoidance groove 44. Through the cooperation of the first plug-in part 414 and the first jack 43, and the second plug-in part 415 and the second jack 441, the anti-cloth jamming rod 41 can be installed in the roller seat 4, so that the first straight section 412 and the arc section 411 straddle above the lower roller 3. Among them, the arc section 411 is arranged at the rear side of the roller seat 4, and its shape matches the shape of the rear side of the annular groove 33; the first straight section 412 is arranged at the front side of the roller seat 4, and the maximum height of the roller surface 34 of the lower roller 3 is not less than the installation height of the first straight section 412. When the lower roller 3 rotates from the rear to the front for feeding, the arc section 411 cooperates with the annular groove 33 to avoid the rear side of the roller surface 34, and the rear half of the roller surface 34 can be in full contact with the fabric to drive the fabric to move forward. The second straight section 413 arranged in the avoidance groove 44 simultaneously avoids the fabric and the rear half of the roller surface 34, and it does not interfere with the contact between the fabric and the rear half of the roller surface 34. During the feeding process of the lower roller 3, the arc section 411 can prevent the rear side of the fabric from being rolled into the roller seat 4, and the first straight section 412 can support the front side of the fabric to prevent the front side of the fabric from being rolled into the roller seat 4.

[0084] As Figures 2-3 、 Figures 7-8As shown in the figure, an upper swing arm 142 is provided on the above-mentioned feeding shaft 14, and a base 7 is fixedly arranged below the bottom plate 11. The lower roller transmission unit 5 includes a rocker arm 59 whose upper end is hinged to the upper swing arm 142 by an axially-positioned screw, a rotating shaft 55 rotatably arranged in the base 7, a first synchronous pulley 51 arranged at the left end of the roller shaft 31, a second synchronous pulley 52 arranged at the left end (i.e., the first end) of the rotating shaft 55, a first one-way bearing 541 and a lower swing arm 58 sleeved on the right end (i.e., the second end) of the rotating shaft 55 in sequence from inside to outside. The first synchronous pulley 51 and the second synchronous pulley 52 are connected by a synchronous member 50. A chute 581 is also formed on the lower swing arm 58, and the lower end of the rocker arm 59 is hinged to the chute 581. When the bracket base 141 swings forward in the direction consistent with the sewing machine feeding direction, the first one-way bearing 541 locks, and the first one-way bearing 541 makes the second synchronous pulley 52 and the first synchronous pulley 51 rotate with the rotating shaft 55, the roller shaft 31 rotates, and the lower roller 3 rotates accordingly. When the bracket base 141 swings backward in the direction opposite to the sewing machine feeding direction, the first one-way bearing 541 rotates freely, the first one-way bearing 541 makes the rotating shaft 55 stationary, and the lower roller 3 is stationary.

[0085] The specific form of the synchronous member 50 is not limited and can be a belt or a chain, and the first synchronous pulley 51 and the second synchronous pulley 52 are correspondingly pulley wheels or sprocket wheels. The roller shaft 31 extends in the left-right direction, and the left and right ends of the roller shaft 31 are each rotatably arranged in the roller seat 4 through a deep groove ball bearing 32. The rotating shaft 55 extends in the left-right direction. Between the second synchronous pulley 52 and the lower swing arm 58, a first deep groove ball bearing 531, a second one-way bearing 542, and a second deep groove ball bearing 532 are sleeved on the rotating shaft 55 in sequence from left to right, and all three are located between the rotating shaft 55 and the base 7. Further, the lower swing arm 58 is U-shaped and includes a left end portion and a right end portion. The first one-way bearing 541 is arranged between the left end portion of the lower swing arm 58 and the rotating shaft 55, and a third deep groove ball bearing 57 is also arranged between the right end portion of the lower swing arm 58 and the rotating shaft 55. A retaining ring 56 is also arranged at the right end of the rotating shaft 55, and the retaining ring 56 is located between the two end portions of the lower swing arm 58 and is used to limit the left-right movement of the lower swing arm 58. A nut 510 is slidably arranged in the chute 581 of the lower swing arm 58, and the lower end of the rocker arm 59 is fixedly connected to the nut 510 by an axially-positioned screw 511. The lower end of the rocker arm 59 is hinged to the axially-positioned screw 511.

[0086] Further, a synchronous belt cover 2 is also installed in the opening portion. The synchronous belt cover 2 is located directly above the first synchronous pulley 51 and is adjacent to the roller seat 4. The synchronous belt cover 2 covers the upper part of the first synchronous pulley 51 and the synchronous member 50, and at the same time, the roller seat 4 only allows the lower roller 3 to be exposed. The combined effect of the two can prevent dust and wool yarn from entering the inside or below the bottom plate 11 from the opening portion.

[0087] As Figure 2 andFigure 7 As shown, the lower idler mechanism further includes a tensioning eccentric pin 61. The tensioning eccentric pin 61 includes a first shaft section and a second shaft section that are eccentrically arranged. The first shaft section is arranged in the base 7, and a tensioning wheel 62 is rotatably sleeved on the second shaft section. The tensioning wheel 62 abuts against the outer periphery of the synchronizing member 50. By rotating the first shaft section, the tensioning wheel 62 on the second shaft section can be driven to approach or move away from the synchronizing member 50, thereby adjusting the tension of the synchronizing member 50 to avoid the synchronizing member 50 being too tight or too loose and reducing the running noise. Preferably, the tensioning wheel 62 can be a needle roller bearing. As Figure 3 As shown, the lower idler mechanism further includes an oil guard 42 fixedly arranged below the lower roller 3. The oil guard 42 can be used to receive the dripping lubricating oil and impurities.

[0088] In summary, the working principle of the lower idler mechanism provided by the present utility model is as follows: When the sewing machine is working, the feed shaft 14 drives the bracket seat 141 to swing back and forth. With the cooperation of the lifter mechanism, the feed dog 151 drives the fabric to move forward. At the same time, the swinging bracket seat 141 drives the rotating shaft 55 to rotate intermittently. When the bracket seat 141 swings forward in the direction consistent with the sewing direction of the sewing machine, the lower swing arm 58 swings downward, and the first one-way bearing 541 locks. The first one-way bearing 541 causes the second synchronizing wheel 52 and the first synchronizing wheel 51 to rotate with the rotating shaft 55, the roller shaft 31 rotates, and the lower roller 3 rotates accordingly to assist in feeding. When the bracket seat 141 swings backward in the direction opposite to the sewing direction of the sewing machine, the lower swing arm 58 swings upward, the first one-way bearing 541 rotates freely, and the first one-way bearing 541 makes the rotating shaft 55 stationary and the lower roller 3 stationary.

[0089] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present utility model, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present utility model.

Claims

1. A lower tug mechanism with a cloth jam prevention function, installed in a sewing machine, the sewing machine comprising a fixed bottom plate and a feeding mechanism arranged below the bottom plate, the feeding mechanism comprising a feeding shaft rotatably arranged in the bottom plate and a tooth frame seat arranged at one end of the feeding shaft, characterized in that: An opening portion extending from top to bottom is provided in the bottom plate; the lower tug mechanism includes a roller seat installed in the opening portion, a lower roller rotatably installed in the roller seat, and a lower roller transmission unit connected between the tooth frame seat and the lower roller, and the lower roller is exposed from the bottom plate; a plurality of anti-cloth rods are also provided on the roller seat, and the anti-cloth rods are straddled above the lower roller.

2. The lower tug mechanism according to claim 1, characterized in that: A plurality of annular grooves are arranged on the outer circumference of the lower roller, and the anti-stuck cloth rod is arranged just above the annular grooves.

3. The lower tug mechanism according to claim 2, characterized in that: The anti-stuck cloth rod includes an arc segment and a first straight segment connected to each other, the arc segment is arranged on the rear side of the roller seat, and the first straight segment is arranged on the front side of the roller seat.

4. The lower tug mechanism according to claim 3, characterized in that: The maximum height of the roller surface of the lower roller is not less than the setting height of the first straight section.

5. The lower tug mechanism according to claim 3, characterized in that: The anti-stuck cloth rod also includes a first plug-in connected to the first straight section and a second plug-in connected to the arc section. A first socket for inserting the first plug-in is provided on the front side of the roller seat, and a second socket for inserting the second plug-in is provided on the rear side of the roller seat.

6. The lower tug mechanism according to claim 5, characterized in that: The arc section is connected to the second plug-in unit via a second straight section, and a relief groove for accommodating the second straight section is also provided on the rear side of the roller seat, and the second plug hole is arranged in the relief groove.

7. The lower tug mechanism according to claim 1, characterized in that: An upper swing arm is provided on the feeding shaft, a base is fixedly provided under the bottom plate, the lower roller transmission unit comprises a swing arm whose upper end is hinged to the upper swing arm, a rotating shaft rotatably provided in the base, a first synchronous wheel provided at one end of the roller shaft, a second synchronous wheel provided at the first end of the rotating shaft, a first one-way bearing and a lower swing arm which are sleeved on the second end of the rotating shaft in sequence from inside to outside, the first synchronous wheel and the second synchronous wheel are connected by a synchronous member, and a slide groove is also provided on the lower swing arm, and the slide groove is hinged to the lower end of the swing arm; When the tooth frame seat swings in a direction consistent with the feeding direction of the sewing machine, the first one-way bearing is locked, the first synchronous wheel rotates with the rotating shaft, and the lower roller rotates; When the tooth frame seat swings in the direction opposite to the feeding direction of the sewing machine, the first one-way bearing rotates freely, the rotating shaft is stationary, and the lower roller is stationary.

8. The lower tug mechanism according to claim 7, characterized in that: It also includes a tensioning eccentric pin, which includes an eccentrically arranged first shaft section and a second shaft section, the first shaft section is arranged in the base, and a tensioning wheel is rotatably sleeved on the second shaft section, and the tensioning wheel abuts against the outer periphery of the synchronizer.

9. The lower tug mechanism according to claim 7, characterized in that: A retaining ring is arranged on the rotating shaft, the lower swing arm is U-shaped, and the retaining ring is located between the two ends of the lower swing arm.

10. The lower tug mechanism according to claim 7, characterized in that: It also includes a nut slidably arranged in the slide groove, and the lower end of the rocker arm is connected to the nut through an axial screw.

11. A sewing machine, characterized in that: It comprises the lower tug mechanism as described in any one of claims 1-10.

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