Forward and reverse cloth feeding assembly structure of sewing machine

Abstract

The utility model discloses a sewing machine forward and reverse direction cloth feeding assembly structure, which comprises a cloth feeding mode adjusting mechanism, a connecting rod mechanism and a rotating shaft mechanism, the cloth feeding mode adjusting mechanism comprises a first mounting column, a second mounting column, an end face cam, a swing arm component and a first mode turntable, the rotating shaft mechanism comprises a rotating shaft and a limit connecting block, and the connecting rod mechanism comprises a cloth feeding frame. The end face cam is rotated to drive the end of the upper swing arm to abut against or break away from the peripheral wall of the first mode rotary disc, when the first mode rotary disc rotates, the protrusions on the peripheral wall of the first mode rotary disc can make contact with the end of the upper swing arm and jack up the upper swing arm, the upper swing arm is made to deflect around the second installation column, the cloth feeding frame is driven to move downwards, and then the rotary shaft is driven to deflect; the movement track of the feed dog is changed at the moment of deflection, the limiting connecting block completes one-time direction change at the moment of deflection every time, the first mode rotating disc continuously rotates to enable the upper swing arm to make contact with the protrusion once at intervals, and continuous switching of forward cloth feeding and reverse cloth feeding of the sewing machine is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewing machines, in particular to a forward and reverse direction cloth feeding assembly structure of a sewing machine. Background Art

[0002] Sewing machines are widely used production equipment, mainly used in the fields of clothing, shoes and hats, luggage, etc. Traditional sewing machines mainly feed cloth through the gears at the bottom, but this method can only achieve one-way cloth feeding, that is, it can only feed cloth in the forward or reverse direction. Forward cloth feeding mainly refers to pushing the cloth to the front of the sewing machine, which is suitable for most conventional sewing needs, such as straight stitching, style stitching, etc. Reverse cloth feeding refers to pushing the cloth to the back of the sewing machine, which is mainly used for reverse stitching or locking stitches. However, there are some problems in the realization of forward cloth feeding and reverse cloth feeding in existing sewing machines: 1. Switching difficulties: The current sewing machines on the market often require manual operation when switching between forward cloth feeding and reverse cloth feeding, such as pressing a switching button or lever on the machine body. This is not only cumbersome to operate, but also in the continuous sewing process, frequent switching operations may affect the sewing speed and quality. 2. Fabric slippage: When feeding in reverse, due to the friction and tension changes of the fabric, fabric slippage may occur, resulting in uneven stitches or position shifts, affecting the appearance and quality of the product. 3. Equipment wear: Frequent forward and reverse switching may increase equipment wear and affect the service life of the equipment.

[0003] Patent CN211005884U discloses a cloth feeding system, including a cloth feeding mode adjustment mechanism, a cloth feeding frame, a first rotating shaft mechanism, a connecting frame, and a lower bracket structure. The first rotating shaft mechanism includes a first rotating shaft and a limit connecting block. The limit connecting block is provided with a limit groove and is inclined. The lower bracket structure includes a cloth feeding tooth seat and a cloth feeding swing frame. One end of the connecting frame is provided with a convex column, which cooperates with the limit groove and is movably connected. The other end of the connecting frame is hinged with the cloth feeding swing frame. The reciprocating swing of the connecting frame is realized by the cam below the connecting frame and the limiting effect of the limit groove, thereby driving the cloth feeding tooth seat above the cloth feeding swing frame to reciprocate. Changing the inclination angle of the limit groove can control the movement trajectory of the cloth feeding tooth. When reversing is required, the protruding block on the cloth feeding frame is pressed to make it reverse. However, this reversing method is only transient. The protruding block needs to be pressed every time reversing, and continuous forward-reverse cloth feeding cannot be achieved.

[0004] In view of the above problems, designing a device that can easily realize the continuous switching between forward feeding and reverse feeding without affecting the sewing quality during the switching process will be an effective way to solve these problems. Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a forward and reverse direction cloth feeding assembly structure of a sewing machine.

[0006] According to the first aspect of the present invention, the forward and reverse direction cloth feeding assembly structure of the sewing machine comprises a cloth feeding mode adjustment mechanism, a connecting rod mechanism, and a rotating shaft mechanism;

[0007] The cloth feeding mode adjustment mechanism comprises a first mounting post, a second mounting post, an end face cam, a swing arm assembly and a first mode dial, the end face cam being fixedly sleeved on the first mounting post, the second mounting post being located between the first mounting post and the first mode dial, the swing arm assembly being rotatably mounted on the second mounting post, the swing arm assembly comprising an upper swing arm and a lower swing arm located below the upper swing arm, the upper swing arm and the lower swing arm being synchronously rotated around the second mounting post, the first mode dial being driven to rotate by an upper shaft of the sewing machine, a protrusion being provided on an outer peripheral wall of the first mode dial, an end portion of the upper swing arm being able to contact with an outer peripheral wall of the first mode dial, the upper swing arm being provided with an abutting block for abutting against the end face cam, the swing arm assembly also comprising an elastic member for driving the abutting block to abut against the end face cam, and rotating the end face cam can drive the upper swing arm to move axially along the second mounting post;

[0008] The rotating shaft mechanism comprises a rotating shaft and a limit connecting block, wherein the limit connecting block is arranged in an inclined manner and fixedly arranged at one end of the rotating shaft, and a return torsion spring for positioning the inclined direction of the limit connecting block is sleeved on the rotating shaft;

[0009] The connecting rod mechanism includes a cloth feeding rack, the upper end of the cloth feeding rack is hinged to the lower end of the lower swing arm so that the cloth feeding rack can be driven to move up and down when the lower swing arm rotates, the lower end of the cloth feeding rack is connected to the other end of the rotating shaft and the up and down movement of the cloth feeding rack can drive the rotating shaft to rotate.

[0010] The forward and reverse direction cloth feeding assembly structure of the sewing machine according to the embodiment of the utility model has at least the following beneficial effects:

[0011] The utility model drives the upper swing arm to move axially along the second mounting post by rotating the end face cam, so that the end of the upper swing arm can abut against or disengage from the outer peripheral wall of the first mode turntable. When the first mode turntable rotates, the protrusion on the outer peripheral wall can contact the end of the upper swing arm and lift it up, so that the upper swing arm deflects around the second mounting post, and at the same time drives the lower swing arm to deflect. When the lower swing arm deflects, its lower end will generate a downward pressure force on the cloth feeding rack, thereby driving the cloth feeding rack to move downward. The downward movement of the cloth feeding rack will drive the rotating shaft to deflect, so that the cloth feeding rack fixed at the end of the rotating shaft The limit connecting block on the upper part also deflects, changing its tilting direction. At the moment of deflection, the motion trajectory of the feed dog changes. The feed dog is adjusted from front to back, or from back to front. Whenever the upper swing arm passes a protrusion, the limit connecting block deflects instantly and is quickly reset under the action of the reset torsion spring. The limit connecting block completes a direction change at the moment of deflection each time. The first mode dial rotates continuously so that the upper swing arm contacts the protrusion once every period of time, realizing the continuous switching of the forward and reverse feeding of the sewing machine. The continuous switching of the forward and reverse feeding of the feed dog can combine a variety of stitches with the motion trajectory of the needle bar, providing more diverse design elements for sewing products, helping to achieve personalized sewing effects, meeting the needs and preferences of different groups of people, and expanding the application range of sewing machines.

[0012] According to some embodiments of the utility model, the contour curve on the end face of the end face cam is a stepped structure with a smooth transition, with more than two bosses and each boss having a different height, the top of each boss being a plane, and there being a transitional curved surface between the bosses. When the end face cam is rotated, the transitional curved surface squeezes the abutment block to make the upper swing arm move axially along the second mounting column until the abutment block reaches the plane of the boss, i.e., reaches a gear position, and then continues to rotate the end face cam to make the abutment block reach a higher boss and enter another gear position. The height of the boss determines the moving distance of the upper swing arm, i.e., determines the axial position of the end of the upper swing arm on the first mode turntable. The protrusions are distributed in intervals on the outer peripheral wall of the first mode turntable, and different protrusion spacing distribution patterns are designed at different axial positions on the first mode turntable, corresponding one to one with the gear position of the end face cam. Such a design can flexibly adjust the switching timing of forward and reverse feeding. When only one-way feeding is required, the upper swing arm can be designed to move outside the first mode turntable to disengage the two.

[0013] According to some embodiments of the utility model, the end face cam is provided with a first flange, the first flange is arranged along the circumference of the end face cam, the number of the first flanges is the same as the number of the bosses and the positions of the first flanges and the transition curved surface correspond one to one, and the lower end of the lower swing arm is provided with a second flange that can contact the first flange. Considering that the upper swing arm may be blocked by the protrusion when axially translating and cannot smoothly switch gears, the first flange is designed on the end face cam. When the end face cam is rotated, the first flange squeezes the second flange to make the lower swing arm and the upper swing arm deflect synchronously. At this time, the end of the upper swing arm is separated from the outer peripheral wall of the first mode dial, and the upper swing arm moves axially at the same time, so that the end of the upper swing arm smoothly crosses the protrusion to reach the next gear.

[0014] According to some embodiments of the utility model, the swing arm assembly also includes a support frame, the support frame is composed of two side walls and a bottom surface to form a "U"-shaped structure, the two side walls are sleeved on the second mounting column and the bottom surface is located below the second mounting column, so that the "U"-shaped opening of the support frame faces upward, the upper swing arm is located between the two side walls and the bottom of the upper swing arm abuts against the bottom surface of the support frame, the lower swing arm is located below the support frame and the upper end of the lower swing arm is fixed to the support frame. The support frame ensures that the upper swing arm and the lower swing arm can rotate synchronously, and enables the upper swing arm to move axially alone.

[0015] According to some embodiments of the utility model, the elastic member is a spring, which is sleeved on the second mounting column and located between the upper swing arm and the side wall of the support frame. One end of the spring abuts against the side wall of the support frame, and the other end abuts against the upper swing arm, providing the upper swing arm with a thrust against the end face cam.

[0016] According to some embodiments of the utility model, a slide groove is formed on the bottom surface of the support frame, and a limit block cooperating with the slide groove is provided at the bottom of the upper swing arm.

[0017] According to some embodiments of the utility model, the connecting rod mechanism further includes a rocker arm and a fixed frame, one end of the rocker arm is hinged to the fixed frame, and the end surface of the other end has teeth, the lower end of the cloth feeding frame is hinged to the rocker arm and the hinge point is located between the two ends of the rocker arm, and the other end of the rotating shaft is fixedly sleeved with a gear, and the gear teeth of the gear are meshed with the teeth. The up and down movement of the cloth feeding frame can drive the rocker arm to deflect, and the meshing of the gear teeth and the teeth can drive the rotating shaft to rotate.

[0018] According to some embodiments of the utility model, a knob is fixedly provided at the end of the first mounting column. Turning the knob can drive the end face cam to rotate, and a gear position mark is drawn on the knob for user convenience.

[0019] According to some embodiments of the utility model, a cloth feeding mechanism is also included, the cloth feeding mechanism includes a cloth feeding tooth seat, a cloth feeding swing frame and a connecting frame, one end surface of the limiting connecting block is provided with a limiting groove, one end of the connecting frame is fixedly provided with a convex column matched with the limiting groove, the connecting frame is movably connected with the limiting connecting block through the cooperation of the convex column and the limiting groove, a cam for driving the connecting frame to swing is provided below the convex column, the other end of the connecting frame is hinged with the cloth feeding swing frame, the cloth feeding tooth seat is located above the cloth feeding swing frame and is hinged with the cloth feeding swing frame. The reciprocating swing of the connecting frame is achieved by the limiting action of the cam and the limiting groove, thereby driving the cloth feeding tooth seat above the cloth feeding swing frame to swing back and forth, and changing the inclination angle of the limiting groove can control the movement trajectory of the cloth feeding tooth.

[0020] According to some embodiments of the utility model, it also includes a second mode dial for adjusting the movement trajectory of the needle bar, the second mode dial is coaxially arranged with the first mode dial, the swing arm assembly also includes abutment arm, a mounting plate and a base plate, the mounting plate is sleeved on the second mounting column, the base plate is located above the support frame and abuts against the bottom surface of the support frame, the mounting plate, the base plate and the upper swing arm are integrally formed to form a "U"-shaped structure, one end of the abutment arm abuts against the outer peripheral wall of the second mode dial, and the other end is sleeved on the second mounting column and connected to the mounting plate by a fixing screw and an eccentric screw, the abutment arm is provided with a first elliptical hole for installing the fixing screw and a second elliptical hole for installing the eccentric screw, the first elliptical hole is located above the second elliptical hole, the major axis of the first elliptical hole is horizontally arranged, and the major axis of the second elliptical hole is vertically arranged. When it is necessary to fine-tune the cloth feeding distance, loosen the fixing screw, and then use a screwdriver to rotate the eccentric screw to make the upper swing arm and the lower swing arm deflect at a slight angle as a whole. Through a series of transmissions, the limit connecting block is finally driven to deflect at a slight angle. Then tighten the fixing screw. The deflection angle of the limit connecting block is fixed. The larger the deflection angle, the larger the swing amplitude of the cloth feeding tooth seat, and the single cloth feeding distance increases. The first elliptical hole plays the role of limiting the maximum deflection angle. It should be noted that the deflection angle adjusted by the eccentric screw is very subtle, which is not of the same order of magnitude as the deflection angle required by the utility model to change the cloth feeding direction by causing the limit connecting block to deflect instantly by the protrusion. The deflection angle of the limit connecting block caused by the eccentric screw is about within 5°, while the deflection angle of the limit connecting block caused by the protrusion is about more than 30°. The role of the second mode turntable in the utility model is mainly to provide a fulcrum for the deflection of the upper swing arm, so that the upper swing arm deflects relative to the abutment arm. In fact, the second mode turntable is used to adjust the movement trajectory of the needle bar in the prior art. Its adjustment method and transmission structure design are not within the scope of the present invention and will not be described in detail.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the utility model;

[0024] Figure 2 It is a structural schematic diagram of the cloth feeding mode adjustment mechanism 100 of the present invention;

[0025] Figure 3 It is a schematic diagram of the connecting rod mechanism 200, the rotating shaft mechanism 300, and the cloth feeding mechanism 400 of the utility model;

[0026] Figure 4 It is a structural schematic diagram of the end face cam 130 of the utility model;

[0027] Figure 5 It is a front view of the cloth feeding mode adjustment mechanism 100 of the present invention;

[0028] Figure 6 It is an exploded structural diagram of the swing arm assembly of the utility model.

[0029] Reference numerals: cloth feeding mode adjustment mechanism 100, first mounting column 110, second mounting column 120, end face cam 130, boss 131, transition curved surface 132, first flange 133, first mode dial 140, protrusion 141, upper swing arm 150, abutment block 151, limit block 152, mounting plate 153, bottom plate 154, abutment arm 155, fixing screw 156, eccentric screw 157, lower swing arm 1 60, second flange 161, spring 170, support frame 180, slide groove 181, knob 190, connecting rod mechanism 200, cloth feeding frame 210, rocker arm 220, fixing frame 230, rotating shaft mechanism 300, rotating shaft 310, limiting connecting block 320, reset torsion spring 330, gear 340, cloth feeding mechanism 400, cloth feeding tooth seat 410, cloth feeding swing frame 420, connecting frame 430, second mode turntable 500. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0031] Reference Figure 1-6 , a forward and reverse direction cloth feeding assembly structure of a sewing machine, comprising a cloth feeding mode adjustment mechanism 100, a connecting rod mechanism 200, a rotating shaft 310 mechanism 300 and a cloth feeding mechanism 400;

[0032] The cloth feeding mode adjustment mechanism 100 includes a first mounting post 110, a second mounting post 120, an end cam 130, a swing arm assembly and a first mode dial 140. The end cam 130 is fixedly sleeved on the first mounting post 110. The second mounting post 120 is located between the first mounting post 110 and the first mode dial 140. The swing arm assembly can be rotatably mounted on the second mounting post 120. The swing arm assembly includes an upper swing arm 150 and a lower swing arm 160 located below the upper swing arm 150. The upper swing arm 150 and the lower swing arm 160 can rotate around the first mode dial 140. The second mounting column 120 rotates synchronously, and the first mode dial 140 is driven to rotate by the upper shaft of the sewing machine. A protrusion 141 is provided on the outer peripheral wall of the first mode dial 140. The end of the upper swing arm 150 can contact the outer peripheral wall of the first mode dial 140. The upper swing arm 150 has an abutment block 151 for abutting against the end face cam 130. The swing arm assembly also includes an elastic member for driving the abutment block 151 to abut against the end face cam 130. Rotating the end face cam 130 can drive the upper swing arm 150 to move axially along the second mounting column 120.

[0033] The rotating shaft 310 mechanism 300 comprises a rotating shaft 310 and a limiting connection block 320. The limiting connection block 320 is tilted and fixed to one end of the rotating shaft 310. A return torsion spring 330 for positioning the tilting direction of the limiting connection block 320 is sleeved on the rotating shaft 310.

[0034] The connecting rod mechanism 200 includes a cloth feeding frame 210, the upper end of the cloth feeding frame 210 is hinged to the lower end of the lower swing arm 160 so that the lower swing arm 160 can drive the cloth feeding frame 210 to move up and down when it rotates, and the lower end of the cloth feeding frame 210 is connected to the other end of the rotating shaft 310 and the cloth feeding frame 210 can drive the rotating shaft 310 to rotate when it moves up and down;

[0035] The cloth feeding mechanism 400 includes a cloth feeding tooth seat 410, a cloth feeding swing frame 420 and a connecting frame 430. A limiting groove is provided on one end surface of the limiting connecting block 320. A convex column matched with the limiting groove is fixed on one end of the connecting frame 430. The connecting frame 430 is movably connected with the limiting connecting block 320 through the cooperation of the convex column and the limiting groove. A cam for driving the connecting frame 430 to swing is provided below the convex column. The other end of the connecting frame 430 is hinged to the cloth feeding swing frame 420. The cloth feeding tooth seat 410 is located above the cloth feeding swing frame 420 and is hinged to the cloth feeding swing frame 420. The reciprocating swing of the connecting frame 430 is realized by the limiting action of the cam and the limiting groove, thereby driving the cloth feeding tooth seat 410 above the cloth feeding swing frame 420 to swing back and forth. Changing the inclination angle of the limiting groove can control the motion trajectory of the cloth feeding tooth.

[0036] Working principle: by rotating the end face cam 130 to drive the upper swing arm 150 to move axially along the second mounting column 120, the end of the upper swing arm 150 can be made to abut against or disengage from the outer peripheral wall of the first mode dial 140. When the first mode dial 140 rotates, the protrusion 141 on its outer peripheral wall will contact the end of the upper swing arm 150 and lift it up, causing the upper swing arm 150 to deflect around the second mounting column 120, while driving the lower swing arm 160 to deflect. When the lower swing arm 160 deflects, its lower end will generate a downward pressure on the cloth feeding rack 210, thereby driving the cloth feeding rack 210 to move downward. The downward movement of the cloth feeding rack 210 will drive the rotating shaft 310 to deflect, causing the limiting connecting block 320 fixed at the end of the rotating shaft 310 to deflect as well, thereby changing its tilting direction from the original backward tilt to the forward tilt. Assuming that the limiting connecting block 320 is completely The full vertical angle is 0°, and the fixed state is tilted backward. The tilt angle can be set to -30°. Then the terminal angle of the deflection of the limit connecting block 320 should cross the vertical plane to reach above 0° before the starting direction of the movement can be changed. The terminal angle of the deflection can be designed to be +30° tilted forward. The movement trajectory of the feed dog changes at the moment of deflection. The feed dog is adjusted from front to back, or from back to front. Whenever the upper swing arm 150 passes a protrusion 141, the limit connecting block 320 will deflect instantly and be quickly reset under the action of the reset torsion spring 330. The limit connecting block 320 completes a direction change every time it deflects. The first mode dial 140 continues to rotate so that the upper swing arm 150 contacts the protrusion 141 once at a certain interval, thereby realizing the continuous switching of forward and reverse feeding of the sewing machine.

[0037] In some embodiments of the present invention, the contour curve on the end face of the end face cam 130 is a stepped structure with a smooth transition, with more than two bosses 131 and each boss 131 of a different height. The top of each boss 131 is a plane, and there are transition surfaces 132 between the bosses 131. When the end face cam 130 is rotated, the transition curved surface 132 squeezes the abutment block 151 to make the upper swing arm 150 move axially along the second mounting column 120 until the abutment block 151 reaches the plane of the boss 131, that is, reaches a gear position, and then the end face cam 130 is further rotated to make the abutment block 151 reach the higher boss 131 and enter another gear position. The height of the boss 131 determines the moving distance of the upper swing arm 150, that is, determines the axial position of the end of the upper swing arm 150 on the first mode dial 140. The protrusions 141 are distributed at intervals on the outer peripheral wall of the first mode dial 140, and different protrusion 141 spacing distribution patterns are designed at different axial positions on the first mode dial 140, corresponding to the gear positions of the end face cam 130. Such a design can flexibly adjust the switching timing of forward and reverse cloth feeding. When only one-way cloth feeding is required, the upper swing arm 150 can be designed to move outside the first mode dial 140 to make the two out of contact.

[0038] In some embodiments of the utility model, the end cam 130 is provided with a first flange 133, which is arranged along the circumference of the end cam 130, the number of the first flange 133 is the same as the number of the bosses 131, and the positions of the first flange 133 and the transition curved surface 132 correspond one to one, and the lower end of the lower swing arm 160 is provided with a second flange 161 that can contact the first flange 133. Considering that the upper swing arm 150 may be blocked by the protrusion 141 when axially translating and cannot smoothly switch gears, the first flange 133 is designed on the end cam 130. When the end cam 130 is rotated, the first flange 133 squeezes the second flange 161 to make the lower swing arm 160 and the upper swing arm 150 deflect synchronously, at this time, the end of the upper swing arm 150 is separated from the outer peripheral wall of the first mode dial 140, and the upper swing arm 150 moves axially at the same time, so that the end of the upper swing arm 150 smoothly crosses the protrusion 141 to reach the next gear.

[0039] In some embodiments of the utility model, the swing arm assembly further includes a support frame 180, which is composed of two side walls and a bottom surface to form a "U"-shaped structure, the two side walls are sleeved on the second mounting column 120 and the bottom surface is located below the second mounting column 120, so that the "U"-shaped opening of the support frame 180 faces upward, the upper swing arm 150 is located between the two side walls and the bottom of the upper swing arm 150 abuts against the bottom surface of the support frame 180, and the lower swing arm 160 is located below the support frame 180 and the upper end of the lower swing arm 160 is fixedly connected to the support frame 180. The support frame 180 not only ensures that the upper swing arm 150 and the lower swing arm 160 can rotate synchronously, but also enables the upper swing arm 150 to move axially alone.

[0040] In some embodiments of the present invention, the elastic member is a spring 170, which is sleeved on the second mounting column 120 and located between the upper swing arm 150 and the side wall of the support frame 180. One end of the spring 170 abuts against the side wall of the support frame 180, and the other end abuts against the upper swing arm 150, providing the upper swing arm 150 with a thrust to abut against the end face cam 130.

[0041] In some embodiments of the present invention, a slide groove 181 is formed on the bottom surface of the support frame 180 , and a limit block 152 cooperating with the slide groove 181 is provided at the bottom of the upper swing arm 150 .

[0042] In some embodiments of the utility model, the connecting rod mechanism 200 further includes a rocker arm 220 and a fixing frame 230. One end of the rocker arm 220 is hinged to the fixing frame 230, and the end surface of the other end has teeth. The lower end of the cloth feeding frame 210 is hinged to the rocker arm 220 and the hinge point is located between the two ends of the rocker arm 220. The other end of the rotating shaft 310 is fixedly sleeved with a gear 340, and the gear teeth of the gear 340 are meshed with the teeth. The up and down movement of the cloth feeding frame 210 can drive the rocker arm 220 to deflect, and the meshing of the gear teeth with the teeth drives the rotating shaft 310 to rotate.

[0043] In some embodiments of the present invention, a knob 190 is fixedly disposed at the end of the first mounting column 110. Rotating the knob 190 can drive the end face cam 130 to rotate, and a gear position mark is drawn on the knob 190 for user convenience.

[0044] In some embodiments of the utility model, a second mode dial 500 for adjusting the needle bar motion trajectory is also included. The second mode dial 500 is coaxially arranged with the first mode dial 140. The swing arm assembly also includes an abutment arm 155, a mounting plate 153 and a bottom plate 154. The mounting plate 153 is sleeved on the second mounting column 120. The bottom plate 154 is located above the support frame 180 and abuts against the bottom surface of the support frame 180. The mounting plate 153, the bottom plate 154 and the upper swing arm 150 are integrally formed to form a " The abutment arm 155 has a U" shaped structure, one end of the abutment arm 155 abuts against the outer wall of the second mode dial 500, and the other end is sleeved on the second mounting column 120 and connected to the mounting plate 153 through a fixing screw 156 and an eccentric screw 157. The abutment arm 155 is provided with a first elliptical hole for installing the fixing screw 156 and a second elliptical hole for installing the eccentric screw 157. The first elliptical hole is located above the second elliptical hole, the major axis of the first elliptical hole is horizontally arranged, and the major axis of the second elliptical hole is vertically arranged. When it is necessary to fine-tune the cloth feeding distance, loosen the fixing screw 156, and then use a screwdriver to rotate the eccentric screw 157, so that the upper swing arm 150 and the lower swing arm 160 are deflected by a slight angle as a whole, and finally drive the limit connection block 320 to deflect by a slight angle through a series of transmissions, and then tighten the fixing screw 156, the deflection angle of the limit connection block 320 is fixed, the larger the deflection angle, the larger the swing amplitude of the cloth feeding tooth seat 410, and the single cloth feeding distance increases, wherein the first elliptical hole plays the role of limiting the maximum deflection angle. It should be noted that the deflection angle adjusted by the eccentric screw 157 is very slight, and is not of the same order of magnitude as the deflection angle required for the utility model to change the cloth feeding direction by causing the limit connection block 320 to deflect instantly by the protrusion 141. The deflection angle of the limit connection block 320 caused by the eccentric screw 157 is approximately within 5°, while the deflection angle of the limit connection block 320 caused by the protrusion 141 is approximately above 30°. The second mode dial 500 in the present invention mainly serves to provide a fulcrum for the deflection of the upper swing arm 150, so that the upper swing arm 150 deflects relative to the abutment arm 155. In fact, the second mode dial 500 is used to adjust the needle bar motion trajectory in the prior art, and its adjustment method and transmission structure design are not within the scope of the present invention, and will not be described in detail.

[0045] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A forward and reverse cloth feeding assembly structure for a sewing machine, characterized in that: It comprises a cloth feeding mode adjustment mechanism (100), a connecting rod mechanism (200), and a rotating shaft (310) mechanism (300); The cloth feeding mode adjustment mechanism (100) comprises a first mounting post (110), a second mounting post (120), an end face cam (130), a swing arm assembly and a first mode dial (140); the end face cam (130) is fixedly sleeved on the first mounting post (110); the second mounting post (120) is located between the first mounting post (110) and the first mode dial (140); the swing arm assembly can be rotatably mounted on the second mounting post (120); the swing arm assembly comprises an upper swing arm (150) and a lower swing arm (160) located below the upper swing arm (150); the upper swing arm (150) and the lower swing arm (160) can be rotatably mounted on the second mounting post (120); The second mounting column (120) rotates synchronously, the first mode dial (140) is driven to rotate by the upper shaft of the sewing machine, a protrusion (141) is provided on the outer peripheral wall of the first mode dial (140), the end of the upper swing arm (150) can contact the outer peripheral wall of the first mode dial (140), the upper swing arm (150) has an abutment block (151) for abutting against the end face cam (130), the swing arm assembly also includes an elastic member for driving the abutment block (151) to abut against the end face cam (130), and the rotation of the end face cam (130) can drive the upper swing arm (150) to move axially along the second mounting column (120); The rotating shaft (310) mechanism (300) comprises a rotating shaft (310) and a limiting connection block (320); the limiting connection block (320) is arranged in an inclined manner and fixed to one end of the rotating shaft (310); and a return torsion spring (330) is sleeved on the rotating shaft (310) for positioning the inclined direction of the limiting connection block (320); The connecting rod mechanism (200) comprises a cloth feeding frame (210), the upper end of the cloth feeding frame (210) being hinged to the lower end of the lower swing arm (160) so that when the lower swing arm (160) rotates, the cloth feeding frame (210) can be driven to move up and down, the lower end of the cloth feeding frame (210) is connected to the other end of the rotating shaft (310), and the cloth feeding frame (210) can drive the rotating shaft (310) to rotate when it moves up and down.

2. The forward and reverse cloth feeding assembly structure of a sewing machine according to claim 1, characterized in that: The profile curve on the end face of the end face cam (130) is a smoothly transitioned stepped structure, having more than two bosses (131) and each boss (131) having a different height, the top of each boss (131) being a plane, and transitional curved surfaces (132) being provided between the bosses (131).

3. The forward and reverse cloth feeding assembly structure of a sewing machine according to claim 2, characterized in that: The end face cam (130) is provided with a first flange (133), the first flange (133) is arranged along the circumference of the end face cam (130), the number of the first flanges (133) is the same as the number of the bosses (131), and the positions of the first flanges (133) and the transition curved surface (132) correspond one to one, and the lower end of the lower swing arm (160) is provided with a second flange (161) that can contact the first flange (133).

4. The forward and reverse cloth feeding assembly structure of a sewing machine according to claim 1, characterized in that: The swing arm assembly also includes a support frame (180), and the support frame (180) is composed of two side walls and a bottom surface to form a "U"-shaped structure, the two side walls are sleeved on the second mounting column (120) and the bottom surface is located below the second mounting column (120), so that the "U"-shaped opening of the support frame (180) faces upward, the upper swing arm (150) is located between the two side walls and the bottom of the upper swing arm (150) is in contact with the bottom surface of the support frame (180), and the lower swing arm (160) is located below the support frame (180) and the upper end of the lower swing arm (160) is fixedly connected to the support frame (180).

5. The forward and reverse cloth feeding assembly structure of a sewing machine according to claim 4, characterized in that: The elastic member is a spring (170), and the spring (170) is sleeved on the second mounting column (120) and is located between the upper swing arm (150) and the side wall of the support frame (180).

6. The forward and reverse cloth feeding assembly structure of a sewing machine according to claim 4, characterized in that: The bottom surface of the support frame (180) is provided with a slide groove (181), and the bottom of the upper swing arm (150) is provided with a limit block (152) that cooperates with the slide groove (181).

7. The forward and reverse direction cloth feeding assembly structure of a sewing machine according to claim 1, characterized in that: The connecting rod mechanism (200) further comprises a rocker arm (220) and a fixing frame (230); one end of the rocker arm (220) is hinged to the fixing frame (230); the end surface of the other end of the rocker arm (220) is provided with teeth; the lower end of the cloth feeding frame (210) is hinged to the rocker arm (220) and the hinge point is located between the two ends of the rocker arm (220); the other end of the rotating shaft (310) is fixedly sleeved with a gear (340); the gear teeth of the gear (340) are meshed with the teeth.

8. The forward and reverse direction cloth feeding assembly structure of a sewing machine according to claim 1, characterized in that: A knob (190) is fixedly disposed at the end of the first mounting column (110).

9. The forward and reverse cloth feeding assembly structure of a sewing machine according to claim 1, characterized in that: The invention also comprises a cloth feeding mechanism (400), wherein the cloth feeding mechanism (400) comprises a cloth feeding tooth seat (410), a cloth feeding swing frame (420) and a connecting frame (430), one end surface of the limit connecting block (320) is provided with a limit groove, one end of the connecting frame (430) is fixedly provided with a convex column matched with the limit groove, the connecting frame (430) is movably connected with the limit connecting block (320) through the cooperation between the convex column and the limit groove, a cam for driving the connecting frame (430) to swing is provided below the convex column, the other end of the connecting frame (430) is hinged to the cloth feeding swing frame (420), and the cloth feeding tooth seat (410) is located above the cloth feeding swing frame (420) and is hinged to the cloth feeding swing frame (420).

10. The forward and reverse direction cloth feeding assembly structure of a sewing machine according to claim 4, characterized in that: The invention also includes a second mode dial (500) for adjusting the needle bar movement trajectory, wherein the second mode dial (500) is coaxially arranged with the first mode dial (140), and the swing arm assembly also includes an abutment arm (155), a mounting plate (153) and a bottom plate (154), wherein the mounting plate (153) is sleeved on the second mounting column (120), and the bottom plate (154) is located above the support frame (180) and abuts against the bottom surface of the support frame (180), and the mounting plate (153), the bottom plate (154) and the upper swing arm (150) are integrally formed to form a "U"-shaped structure. The abutment arm (155) has one end abutting against the outer wall of the second mode dial (500), and the other end is sleeved on the second mounting column (120) and connected to the mounting plate (153) through a fixing screw (156) and an eccentric screw (157). The abutment arm (155) is provided with a first elliptical hole for mounting the fixing screw (156) and a second elliptical hole for mounting the eccentric screw (157). The first elliptical hole is located above the second elliptical hole, the major axis of the first elliptical hole is horizontally arranged, and the major axis of the second elliptical hole is vertically arranged.

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