Feeding mechanism of splicing and sewing machine

Abstract

The utility model provides a feeding mechanism of a sewing machine, and belongs to the technical field of sewing machines. The sewing machine solves the problem that when an existing sewing machine is used for splicing and sewing cloth made of different materials, the sewing quality is not high. The feeding mechanism of the splicing and sewing machine comprises a feed dog frame assembly, a main feed dog, a differential connecting rod, a differential feed dog and a feeding crank, the feeding crank comprises a horizontally-arranged hinge part and two swing parts oppositely arranged on the hinge part, and the main feed dog comprises two main half teeth arranged in a split mode; the feed dog frame assembly comprises a differential feed dog frame with the front end connected with a differential feed dog and two main feed dog frames which are arranged side by side with the differential feed dog frame, the front ends of the main feed dog frames are connected with main half teeth respectively, a hinged portion of the feeding crank is hinged to the machine shell, the feeding crank can swing around the axis perpendicular to the differential feed dog frame, and the front end of the differential connecting rod is hinged to the differential feed dog frame. The rear end of the differential connecting rod is hinged to the top of the hinge part. When the sewing machine is used for splicing and sewing cloth of different materials, the sewing quality can be effectively improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewing machines and relates to a feeding mechanism of a splicing sewing machine. Background Technique

[0002] A splicing sewing machine is a special sewing machine used to stitch two pieces of fabric together. When the sewing machine is used to sew elastic fabrics such as underwear and swimsuits, a differential feeding mechanism is provided on the sewing machine, so that the feeding speeds of the differential feed dog and the main feed dog are different, realizing differential feeding, so as to tension the elastic fabric, thereby achieving the effect of avoiding fabric wrinkling.

[0003] The differential feeding technology has been widely used at present. In the conventional technology, both the differential feed dog and the main feed dog are integrally formed. For example, a sewing machine feeding mechanism disclosed in a patent document (application number: 201510219424.1), a sewing machine step differential and tooth adjustment mechanism (application number: 202110224339.X), a sewing machine with adjustable stitch length and differential ratio, and a sewing machine adjustment method (application number: 202211249108.5). In the above patents, both the differential feed dog and the main feed dog are integrally formed.

[0004] At present, in a splicing sewing machine, a differential feeding mechanism is also provided to realize the sewing of fabrics. However, the existing conventional differential feeding mechanisms separately adjust the forward and backward movement strokes of the differential feed dog and the main feed dog. In essence, the distance between the two feed dogs to be adjusted is changed to pull and tension the fabric. For example, a stitch length adjustment structure of a sewing machine disclosed in a patent document (application number: 202322357347.9) includes a machine shell, a support arm, a differential tooth frame, and a connecting arm hinged to the differential tooth frame and capable of driving the differential tooth frame to reciprocate forward and backward. The stitch length adjustment structure further includes a driving shaft capable of driving the connecting arm to move and a transmission connecting rod sleeved on the driving shaft and capable of self-rotating. When it is necessary to adjust the stitch length of the sewing machine, rotating the handle can drive the transmission connecting rod to swing, and the transmission connecting rod drives the connecting arm to slide along the support arm. At this time, the connecting arm drives the differential tooth frame to move when sliding, so as to realize the stitch length adjustment of the differential tooth frame. This sewing machine is actually a splicing sewing machine, and there are the following deficiencies in the use process of this splicing sewing machine:

[0005] Although the stitching machine can achieve the tension of the fabric by the different feeding speeds of the differential feed dog and the main feed dog, in some cases, the stitching machine needs to stitch and sew two pieces of fabrics made of different materials together. However, fabrics made of different materials usually have different extensibility, thickness, and elasticity. Since the differential feed dog and the main feed dog of this stitching machine are integrally formed, the main feed dog acts on two fabrics with different materials at the same feeding speed, which will always cause at least one fabric to have insufficient flattening effect during stitching, resulting in problems such as wrinkling and uneven thread running during the sewing process, affecting the overall sewing quality. Summary of the Invention

[0006] The purpose of the present utility model is to address the above problems existing in the prior art and propose a feeding mechanism for a stitching machine. The present utility model solves the problem of low sewing quality when the existing stitching machine stitches and sews fabrics made of different materials.

[0007] The purpose of the present utility model can be achieved by the following technical solutions: A feeding mechanism for a stitching machine, the stitching machine includes a machine shell. The feeding mechanism includes a tooth frame assembly, a main feed dog, a differential feed dog, and a feed crank. The feed crank includes a horizontally arranged hinged portion and two swinging portions oppositely arranged on the hinged portion. It is characterized in that the main feed dog includes two separately arranged main half teeth. The tooth frame assembly includes a differential tooth frame connected to the differential feed dog at the front end and two main tooth frames arranged side by side with the differential tooth frame, and the front ends of the two main tooth frames are respectively connected to one of the main half teeth. The hinged portion of the feed crank is hinged to the machine shell and the feed crank can swing around an axis perpendicular to the differential tooth frame. The feeding mechanism further includes a differential connecting rod. The front end of the differential connecting rod is hinged to the differential tooth frame, and the rear end of the differential connecting rod is hinged to the top of the hinged portion. The two main tooth frames are respectively connected to the two swinging portions through stitch pitch adjusting components in one-to-one correspondence, so that when the feed crank swings, it can drive the two main tooth frames to move back and forth, and the stitch pitch adjusting components can independently adjust the stroke of the corresponding main tooth frame moving back and forth.

[0008] In this stitching machine, by splitting the main feed dog into two, forming two separately arranged main half teeth, and at the same time improving the structure of the differential component. Specifically, the differential component includes a differential tooth frame and two main tooth frames arranged side by side with the differential tooth frame. The differential feed dog is connected to the front end of the differential tooth frame, and the two main half teeth are respectively connected to the front ends of the two main tooth frames in one-to-one correspondence, so that the differential feed dog and the two main half teeth can feed independently of each other.

[0009] On this basis, in this sewing machine, the differential tooth carrier is hinged to the top of the articulated part through a differential connecting rod. In this way, when the feed crank swings back and forth, it can drive the differential connecting rod and the differential tooth carrier to move back and forth, and the differential tooth carrier can drive the differential feed dog to move back and forth. At the same time, this sewing machine also connects the two main tooth carriers to the two swing parts respectively through the stitch regulation components, so that the front and back movement strokes of the two main tooth carriers can be adjusted respectively by using the stitch regulation components, enabling the two main half teeth to feed at different feeding speeds. In this way, when facing the splicing sewing of fabrics of different materials, the feeding speeds of the two main half teeth can be adjusted respectively according to the characteristics of the fabric materials, so as to form different differential amounts to drive the movement of fabrics of different materials, enabling the two fabrics of different materials to achieve a good flattening effect, avoiding problems such as wrinkling and uneven stitching during the sewing process, and effectively improving the sewing quality of the sewing machine.

[0010] As described in the background art of this case, in the existing conventional differential feeding mechanisms, the front and back movement strokes of the differential feed dog and the main feed dog are adjusted separately, and the principle is to change the distance between the two feed dogs to be adjusted. However, the differential feeding mechanism of this case is different. Since the differential tooth carrier is hinged to the protrusion on the feed crank through a differential connecting rod in this case, the front and back movement stroke of the differential feed dog can no longer be adjusted separately, but the front and back movement strokes of the two main half teeth arranged left and right are adjusted separately. Therefore, the principle is to form a dislocation in the front and back positions between the two feed dogs (i.e., the two main half teeth), rather than changing the distance between the two feed dogs. Therefore, the feeding mechanism of this sewing machine breaks the conventional design in which the strokes of the differential feed dog and the main feed in the existing sewing machines can be adjusted separately. Compared with the existing technology, the feeding mechanism of this sewing machine is not just a simple improvement of manufacturing the main feed dog separately. Instead, on the basis of splitting the main feed dog into two, combined with the improvements of the tooth carrier assembly, the feed crank, and the differential tooth carrier drive structure, an overall technical solution is formed to solve the related technical problems. This overall technical solution is completely different from the existing conventional differential feeding mechanism in terms of structure, differential principle, and the technical effects produced, so it is not a conventional technical means in this field.

[0011] In the feeding mechanism of the above sewing machine, this feeding mechanism further includes a lifting connecting rod that can move up and down. The rear end of the differential tooth carrier is hinged to the lifting connecting rod. The rear ends of the two main tooth carriers both have an upper clamping part and a lower clamping part that are arranged vertically opposite to each other. The rear end of the differential tooth carrier is clamped between the upper clamping part and the lower clamping part of one of the main tooth carriers, and the upper clamping part or the lower clamping part of this main tooth carrier is clamped between the upper clamping part and the lower clamping part of the other main tooth carrier.

[0012] In this sewing machine, upper and lower clamping parts which are opposite to each other up and down are arranged at the rear ends of two main tooth carriers, so that the rear end of the differential tooth carrier is clamped between the upper and lower clamping parts of one of the main tooth carriers, and the upper or lower clamping part of this main tooth carrier is clamped between the upper and lower clamping parts of the other main tooth carrier. In this way, when the number of tooth carriers increases, the differential tooth carrier and the rear ends of the two main tooth carriers in the differential tooth carrier assembly can be joined together and linked with the same lifting connecting rod within a limited space. In this way, relying on the same lifting connecting rod to drive the differential tooth carrier and the two main tooth carriers to swing up and down synchronously, so that the swinging of the differential feed dog and the two main half teeth in the up and down direction is synchronized, ensuring that both pieces of fabric to be sewn together can be smoothly fed under the sewing needle during the sewing process, guaranteeing the consistency and flatness of the sewing stitch, and thus ensuring the sewing quality.

[0013] In the feeding mechanism of the above-mentioned sewing machine, the two main tooth carriers are respectively arranged on both sides of the differential tooth carrier, and the upper and lower clamping parts on each main tooth carrier are both located on the side wall facing the other main tooth carrier. The lifting connecting rod is connected to the differential tooth carrier, and when the lifting connecting rod moves up and down, it drives the differential tooth carrier to swing up and down. At this time, since the upper and lower clamping parts on each main tooth carrier are both located on the side wall facing the other main tooth carrier, the differential tooth carrier can be in the middle position between the two main tooth carriers to drive the two main tooth carriers to swing up and down. In this way, it has better balance, enabling the differential tooth carrier to apply external force more evenly to the two main tooth carriers, ensuring that when the differential tooth carrier drives the two main tooth carriers to swing up and down, there will be no tilt or deviation, improving the stability and synchronism of the differential tooth carrier and the two main tooth carriers when swinging up and down, and further improving the sewing quality.

[0014] In the feeding mechanism of the above-mentioned splicing machine, the hinged part is columnar and perpendicular to the differential tooth carrier. The top of the hinged part has a protrusion, and the rear end of the differential connecting rod is hinged to the protrusion. When the feeding crank swings back and forth, the protrusion swings back and forth together, thereby driving the differential connecting rod and the differential tooth carrier to move back and forth. Through the setting of the protrusion, the rear end of the differential connecting rod is hinged to the protrusion, making it more convenient to connect the differential connecting rod with the feeding crank. The hinged part is perpendicular to the differential tooth carrier, and the feeding crank can swing around the axis of the hinged part, enabling the feeding crank to swing back and forth, and thus driving the differential tooth carrier to move back and forth by the action of the differential connecting rod. The differential connecting rod that drives the differential tooth carrier to move back and forth is hinged to the protrusion. At this time, the two swinging parts on the feeding crank can be respectively connected to the two main tooth carriers through the stitch regulator assembly, so that the feeding crank can also drive the two main tooth carriers to move back and forth. Therefore, this design can drive the differential tooth carrier and the two main tooth carriers to move back and forth synchronously by relying on the same feeding crank, ensuring that the differential feed dog and the two main half teeth move synchronously in the front and back directions, ensuring that both pieces of fabric to be spliced and sewn can be smoothly fed under the sewing needle during the sewing process, ensuring the consistency and flatness of the sewing stitch, and thus ensuring the sewing quality.

[0015] In the feeding mechanism of the above-mentioned splicing machine, each stitch regulator assembly includes a main connecting rod. The front end of the main connecting rod is hinged to the corresponding main tooth carrier and the rear end is connected to the corresponding swinging part, and the height position of the rear end of the main connecting rod on the swinging part can be adjusted. When the feeding crank swings back and forth, the higher the position on the swinging part, the greater the swing amplitude. Therefore, by adjusting the height position of the rear end of the main connecting rod on the swinging part, the stroke of the main connecting rod moving back and forth can be adjusted, and further the stroke of the main tooth carrier and the main half teeth on the main tooth carrier moving back and forth can be adjusted.

[0016] In the feeding mechanism of the above-mentioned splicing machine, a hinge shaft is passed through the hinged part. Both ends of the hinge shaft are fixedly connected to the machine shell, and the hinged part can rotate relative to the hinge shaft. The hinged part is hinged to the machine shell through the hinge shaft, ensuring that the feeding crank can swing back and forth stably, and this hinged method has the advantages of low cost and convenient installation.

[0017] In the feeding mechanism of the stitching machine described above, two swinging parts are provided with strip grooves extending up and down, and the rear end of each main connecting rod is fixedly connected to a slider located in the strip groove, and the stitch length adjustment assembly also includes a lifting connecting rod and an L-shaped crank, and the corner of the L-shaped crank is rotatably sleeved on the hinge shaft, one end of the lifting connecting rod is hinged to the corresponding main connecting rod, and the other end of the lifting connecting rod is hinged to one end of the corresponding L-shaped crank, and the housing is also provided with an adjustment knob connected to the other end of the L-shaped crank and capable of driving the L-shaped crank to swing and position after swinging. The adjustment knob can drive the L-shaped crank to rotate around the hinge shaft, so that the end of the L-shaped crank connected to the lifting connecting rod can swing upward or downward, and then push upward or pull downward the main connecting rod, so that the position of the slider at the rear end of the main connecting rod in the strip groove can be changed, so that the stroke of the main connecting rod moving forward and backward can be adjusted, and then the stroke of the main tooth rack and the main half tooth on the main tooth rack moving forward and backward can be adjusted.

[0018] In the feeding mechanism of the above-mentioned stitching machine, the adjustment knob includes a knob disk fixedly connected to the outer wall of the casing, the inner side of the knob disk is provided with a toggle crank rotatably connected to the knob disk, the other end of the L-shaped crank is provided with a long strip of sliding groove, the toggle crank has a convex column located in the sliding groove, and the outer side of the knob disk is also provided with a lever connected to the toggle crank and capable of driving the toggle crank to swing. The knob disk and the toggle rod are both located outside the casing, which can facilitate the staff to operate the toggle rod to realize the adjustment function. Specifically, when the toggle rod is rotated, the toggle crank rotates with the toggle rod, and then the convex column on the toggle crank drives the L-shaped crank to rotate, and finally the adjustment of the stroke of the main half tooth moving forward and backward is realized. After the adjustment is completed, the toggle rod can be tightened by bolts to fix its position, thereby fixing the position of the slider in the strip groove.

[0019] In the feeding mechanism of the stitching machine, two swing parts are respectively arranged at the top of both ends of the hinge part, and the two swing parts are parallel to each other and perpendicular to the hinge part. This structure makes the two swing parts symmetrical, which not only makes it easy to manufacture the feeding crank, but also the two swing parts can match the needle distance adjustment components of the same structure to achieve the adjustment of the forward and backward movement stroke of the corresponding main connecting rod, so that the equipment is easy to assemble and the manufacturing cost is reduced.

[0020] Compared with the prior art, the feeding mechanism of this stitching machine has the following advantages:

[0021] 1. This stitching machine is equipped with a stitch length adjustment component to separately adjust the forward and backward movement strokes of two main tooth carriers, enabling the two main half teeth to feed at different speeds. In this way, when facing the stitching of fabrics with different materials, the feeding speeds of the two main half teeth can be adjusted according to the characteristics of the fabric materials, thereby forming different differential amounts to drive the movement of fabrics with different materials, ensuring that two fabrics with different materials can achieve a good flattening effect, avoiding problems such as wrinkling and uneven thread running during the sewing process, and effectively improving the sewing quality of the stitching machine.

[0022] 2. This lockstitch machine relies on the same lifting connecting rod to drive the differential tooth carrier and two main tooth carriers to swing up and down synchronously, making the up and down swings of the differential feed dog and the two main half teeth synchronous, ensuring that the two fabrics being stitched can be smoothly fed under the sewing needle during the sewing process, guaranteeing the consistency and flatness of the sewing stitch, and thus ensuring the sewing quality. Description of the Drawings

[0023] Figure 1 is a three-dimensional structure schematic diagram of this stitching machine.

[0024] Figure 2 is a three-dimensional structure schematic diagram of the feeding mechanism of this stitching machine.

[0025] Figure 3 is a connection schematic diagram of the differential tooth carrier, main tooth carrier, and lifting connecting rod in this feeding mechanism.

[0026] Figure 4 is an exploded view of the differential tooth carrier, main tooth carrier, and lifting connecting rod in this feeding mechanism.

[0027] Figure 5 is a connection schematic diagram of the differential tooth carrier and the feed crank in this feeding mechanism.

[0028] Figure 6 is a three-dimensional structure schematic diagram of the feed crank in this feeding mechanism.

[0029] Figure 7 is a partial structure diagram of this feeding mechanism.

[0030] Figure 8 is a schematic diagram of the stitch length adjustment component in this feeding mechanism.

[0031] In the figure, 1, casing; 2, main feed dog; 21, main half tooth; 3, differential feed dog; 4, lifting connecting rod; 5, differential tooth rack; 6, main tooth rack; 61, upper clamping part; 62, lower clamping part; 7, feed crank; 71, hinge part; 72, swing part; 721, strip groove; 73, protrusion; 8, differential connecting rod; 9, main connecting rod; 10, hinge shaft; 11, slider; 12, lifting connecting rod; 13, L-shaped crank; 131, slide groove; 14, adjustment knob; 141, knob plate; 142, toggle crank; 1421, boss; 143, toggle rod; 15, pin shaft; 16, rectangular through hole; 17, rectangular block; 18, feed connecting rod; 19, mounting shaft; 20, support arm; 21, linkage rod. DETAILED DESCRIPTION

[0032] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0033] Embodiment 1

[0034] like Figure 1 and Figure 2 As shown, the stitching machine includes a casing 1, and the feeding mechanism of the stitching machine includes a tooth frame assembly, a main feed tooth 2, a differential feed tooth 3 and a lifting connecting rod 4 which can move up and down. A feeding crank 7 is also provided in the casing 1. The main feed tooth 2 includes two main half teeth 21 which are separately arranged. The tooth frame assembly includes a differential tooth frame 5 whose front end is connected to the differential feed tooth 3 and two main tooth frames 6 which are arranged side by side with the differential tooth frame 5. The two main half teeth 21 are connected to the front ends of the two main tooth frames 6 in a one-to-one correspondence. The casing 1 is provided with a stitch length adjustment assembly which can adjust the forward and backward movement strokes of the two main tooth frames 6 respectively.

[0035] like Figure 3 As shown, in order to realize the installation of the tooth frame assembly, a pin shaft 15 perpendicular to the differential tooth frame 5 is fixedly provided on the casing 1, and a rectangular through hole 16 is provided near the front end of the differential tooth frame 5 and the two main tooth frames 6. A rectangular block 17 that can rotate around its axial line is rotatably provided on the pin shaft 15, and the rectangular block 17 is located in the rectangular through hole 16 and can slide in the front and rear direction relative to the rectangular through hole 16, so that the differential tooth frame 5 and the two main tooth frames 6 can move forward and backward and swing up and down relative to the pin shaft 15.

[0036] like Figure 3 and Figure 4As shown, the rear end of the differential jaw frame 5 is hinged to the lifting link 4. The rear ends of the two main jaw frames 6 both have an upper clamping portion 61 and a lower clamping portion 62 which are arranged up and down relatively. The rear end of the differential jaw frame 5 is clamped between the upper clamping portion 61 and the lower clamping portion 62 of one of the main jaw frames 6, and the upper clamping portion 61 of this main jaw frame 6 is clamped between the upper clamping portion 61 and the lower clamping portion 62 of the other main jaw frame 6. The two main jaw frames 6 are respectively arranged on both sides of the differential jaw frame 5, and the upper clamping portion 61 and the lower clamping portion 62 on each main jaw frame 6 are both located on the side wall facing the other main jaw frame 6. This structure enables the differential jaw frame 5 to be in the middle position between the two main jaw frames 6 to drive the two main jaw frames 6 to swing up and down. In this way, it has better balance, enables the differential jaw frame 5 to apply external force more evenly to the two main jaw frames 6, ensures that when the differential jaw frame 5 drives the two main jaw frames 6 to swing up and down, there will be no tilt or deviation, and improves the stability and synchronism when the differential jaw frame 5 and the two main jaw frames 6 swing up and down, thereby improving the sewing quality.

[0037] As Figure 5 and Figure 6 shown, the feed crank 7 includes a columnar hinged portion 71 and two swing portions 72 arranged relatively on the hinged portion 71. A hinge shaft 10 is passed through the hinged portion 71, and both ends of the hinge shaft 10 are fixedly connected to the machine housing 1. The hinged portion 71 can rotate relative to the hinge shaft 10. The hinged portion 71 is perpendicular to the differential jaw frame 5. The two swing portions 72 are respectively arranged at the tops of both ends of the hinged portion 71. The two swing portions 72 are parallel to each other and both perpendicular to the hinged portion 71. The top of the hinged portion 71 has a protrusion 73. The hinged portion 71 is hinged to the machine housing 1 and the feed crank 7 can swing around the axis of the hinged portion 71. This feeding mechanism further includes a differential link 8. The front end of the differential link 8 is hinged to the differential jaw frame 5, and the rear end is hinged to the protrusion 73 on the hinged portion 71. The two main jaw frames 6 are respectively connected to the two swing portions 72 in one-to-one correspondence through stitch regulating components.

[0038] As Figure 3 shown, an installation shaft 19 and a feed link 18 capable of moving up and down are further provided in the machine housing 1. A support arm 20 is provided on the installation shaft 19. A linkage rod 21 is connected between the support arm 20 and one of the swing portions 72 on the feed crank 7. The lower end of the feed link 18 is connected to the support arm 20, so that when the feed link 18 moves up and down, it can drive the support arm 20 to swing back and forth around the axis of the installation shaft 19, and then drive the feed crank 7 to swing back and forth through the linkage rod 21, and finally drive the differential jaw frame 5 and the two main jaw frames 6 to swing back and forth.

[0039] As Figure 7 and Figure 8As shown, each stitch length adjustment assembly includes a main connecting rod 9, the front end of the main connecting rod 9 is hinged to the corresponding main tooth frame 6 and the rear end is connected to the corresponding swinging part 72, and the height position of the rear end of the main connecting rod 9 on the swinging part 72 can be adjusted. When the feed crank 7 swings back and forth, the higher the position on the swinging part 72, the greater the swing amplitude. Therefore, by adjusting the height position of the rear end of the main connecting rod 9 on the swinging part 72, the forward and backward movement stroke of the main connecting rod 9 can be adjusted, and then the forward and backward movement stroke of the main tooth frame 6 and the main half tooth 21 on the main tooth frame 6 can be adjusted.

[0040] Specifically, Figure 7 and Figure 8 As shown, the two swinging parts 72 are provided with a strip groove 721 extending up and down, and the rear end of each main connecting rod 9 is fixedly connected to a slider 11 located in the strip groove 721. The stitch adjustment assembly also includes a lifting connecting rod 12 and an L-shaped crank 13. The corner of the L-shaped crank 13 is rotatably sleeved on the hinge shaft 10. One end of the lifting connecting rod 12 is hinged to the corresponding main connecting rod 9, and the other end of the lifting connecting rod 12 is hinged to one end of the corresponding L-shaped crank 13. The casing 1 is also provided with an adjusting knob 14 which is connected to the other end of the L-shaped crank 13 and can drive the L-shaped crank 13 to swing and position it after swinging. The adjusting knob 14 includes a knob plate 141 fixedly connected to the outer wall of the housing 1, a crank 142 rotatably connected to the knob plate 141 is provided on the inner side of the knob plate 141, a long strip-shaped slide groove 131 is provided at the other end of the L-shaped crank 13, a boss 1421 is provided on the crank 142 and is arranged in the slide groove 131, and a lever 143 connected to the crank 142 and capable of driving the crank 142 to swing is also provided on the outer side of the knob plate 141.

[0041] like Figure 7 and Figure 8 As shown, when it is necessary to adjust the forward and backward movement stroke of the main half-tooth 21, it is only necessary to rotate the lever 143 of the stitch adjustment assembly. When the lever 143 is rotated, the crank 142 is driven to rotate together with the lever 143, and then the L-shaped crank 13 is driven to rotate through the boss 1421 on the crank 142, so that the end of the L-shaped crank 13 connected to the lifting connecting rod 12 can swing upward or downward, and then push the main connecting rod 9 upward or pull it downward, so that the position of the slider 11 at the rear end of the main connecting rod 9 in the strip groove 721 can be changed, so that the forward and backward movement stroke of the main connecting rod 9 can be adjusted, and then the forward and backward movement stroke of the main tooth frame 6 and the main half-tooth 21 on the main tooth frame 6 can be adjusted.

[0042] In this sewing machine, the main feed dog 2 is divided into two parts to form two main half dogs 21 arranged separately. At the same time, the structure of the differential assembly is improved. Specifically, the differential assembly includes a differential dog frame 5 and two main dog frames 6 arranged side by side with the differential dog frame 5. The differential feed dog 3 is connected to the front end of the differential dog frame 5, and the two main half dogs 21 are respectively connected to the front ends of the two main dog frames 6. In this way, the differential feed dog and the two main half dogs 21 can feed independently. On this basis, this sewing machine is also provided with a stitch length adjustment assembly to respectively adjust the forward and backward movement strokes of the two main dog frames 6, so that the two main half dogs 21 can feed at different feeding speeds. In this way, when sewing the splicing of fabrics of different materials, the feeding speeds of the two main half dogs 21 can be adjusted respectively according to the characteristics of the fabric materials, so as to form different differential amounts to drive the movement of fabrics of different materials, so that two fabrics of different materials can both achieve a good flattening effect, avoiding problems such as wrinkling and uneven thread running during the sewing process, and effectively improving the sewing quality of the sewing machine.

[0043] Embodiment 2

[0044] The structure and principle of this embodiment are basically the same as those of Embodiment 1. The difference is that the rear end of the differential dog frame 5 is hinged to the lifting link 4. The rear ends of the two main dog frames 6 both have an upper clamping part 61 and a lower clamping part 62 arranged up and down relatively. The rear end of the differential dog frame 5 is clamped between the upper clamping part 61 and the lower clamping part 62 of one of the main dog frames 6, and the lower clamping part 62 of this main dog frame 6 is clamped between the upper clamping part 61 and the lower clamping part 62 of the other main dog frame 6.

[0045] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0046] Although this article uses the terms such as 1. casing; 2. main feed dog; 21. main half tooth; 3. differential feed dog; 4. lifting connecting rod; 5. differential tooth rack; 6. main tooth rack; 61. upper clamping part; 62. lower clamping part; 7. feed crank; 71. hinge part; 72. swing part; 721. strip groove; 73. protrusion; 8. differential connecting rod; 9. main connecting rod; 10. hinge shaft; 11. slider; 12. lifting connecting rod; 13. L-shaped crank; 131. slide groove; 14. adjustment knob; 141. knob plate; 142. toggle crank; 1421. boss; 143. toggle rod; 15. pin shaft; 16. rectangular through hole; 17. rectangular block; 18. feed connecting rod; 19. mounting shaft; 20. support arm; 21. linkage rod more frequently, it does not exclude the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of the present invention; any additional limitations interpreted as these terms are contrary to the spirit of the present invention.

Claims

1. A feeding mechanism for a stitching machine. The stitching machine includes a machine housing (1). The feeding mechanism includes a tooth carrier assembly, a main feed dog (2), a differential feed dog (3), and a feed crank (7). The feed crank (7) includes a horizontally arranged hinged portion (71) and two swing portions (72) oppositely arranged on the hinged portion (71), and is characterized in that, The main feed dog (2) includes two separately arranged main half dogs (21). The dog frame assembly includes a differential dog frame (5) with its front end connected to the differential feed dog (3), and two main dog frames (6) arranged side by side with the differential dog frame (5), and the front ends of the two main dog frames (6) are respectively connected to one of the main half dogs (21). The articulated part (71) of the feed crank (7) is articulated to the machine housing (1), and the feed crank (7) can swing around an axis perpendicular to the differential dog frame (5). This feed mechanism further includes a differential connecting rod (8). The front end of the differential connecting rod (8) is articulated to the differential dog frame (5), and the rear end of the differential connecting rod (8) is articulated to the top of the articulated part (71). The two main dog frames (6) are respectively connected to the two swing parts (72) one by one through stitch regulators, so that when the feed crank (7) swings, it can drive the two main dog frames (6) to move back and forth, and the stitch regulators can separately adjust the stroke of the corresponding main dog frame (6) moving back and forth.

2. The feeding mechanism of the sewing machine according to claim 1, wherein, This feed mechanism further includes a lifting connecting rod (4) that can move up and down. The rear end of the differential dog frame (5) is articulated to the lifting connecting rod (4). The rear ends of the two main dog frames (6) both have an upper clamping part (61) and a lower clamping part (62) arranged up and down relatively. The rear end of the differential dog frame (5) is clamped between the upper clamping part (61) and the lower clamping part (62) of one of the main dog frames (6), and the upper clamping part (61) or the lower clamping part (62) of this main dog frame (6) is clamped between the upper clamping part (61) and the lower clamping part (62) of the other main dog frame (6).

3. The feeding mechanism of the seaming machine according to claim 2, characterized in that, The two main dog frames (6) are respectively arranged on both sides of the differential dog frame (5). The upper clamping part (61) and the lower clamping part (62) on each main dog frame (6) are both located on the side wall facing the other main dog frame (6).

4. The feeding mechanism of the sewing machine according to claim 1 or 2 or 3, characterized in that, The articulated part (71) is columnar and perpendicular to the differential dog frame (5). The top of the articulated part (71) has a protrusion (73), and the rear end of the differential connecting rod (8) is articulated to the protrusion (73).

5. The feeding mechanism of the sewing machine according to claim 1 or 2 or 3, characterized in that, Each stitch regulator includes a main connecting rod (9). The front end of the main connecting rod (9) is articulated to the corresponding main dog frame (6) and the rear end is connected to the corresponding swing part (72), and the height position of the rear end of the main connecting rod (9) on the swing part (72) can be adjusted.

6. The feeding mechanism of the seaming machine according to claim 5, characterized in that, An articulated shaft (10) is penetrated in the articulated part (71). The two ends of the articulated shaft (10) are fixedly connected to the machine housing (1), and the articulated part (71) can rotate relative to the articulated shaft (10).

7. The feeding mechanism of the seaming machine according to claim 6, wherein Each swinging portion (72) is provided with a strip groove (721) extending up and down, and the rear end of each main connecting rod (9) is fixedly connected to a slider (11) located in the strip groove (721). The stitch length adjustment assembly also includes a lifting connecting rod (12) and an L-shaped crank (13). The corner of the L-shaped crank (13) is rotatably sleeved on the hinge shaft (10). One end of the lifting connecting rod (12) is hinged to the corresponding main connecting rod (9), and the other end of the lifting connecting rod (12) is hinged to one end of the corresponding L-shaped crank (13). The housing (1) is also provided with an adjustment knob (14) which is connected to the other end of the L-shaped crank (13) and can drive the L-shaped crank (13) to swing and position after swinging.

8. The feeding mechanism of the sewing machine according to claim 7, characterized in that The adjusting knob (14) comprises a knob plate (141) fixedly connected to the outer wall of the housing (1); a crank handle (142) rotatably connected to the knob plate (141) is provided on the inner side of the knob plate (141); a long strip-shaped slide groove (131) is provided on the other end of the L-shaped crank (13); the crank handle (142) has a convex column (1421) located in the slide groove (131); and a lever (143) connected to the crank handle (142) and capable of driving the crank handle (142) to swing is also provided on the outer side of the knob plate (141).

9. The feeding mechanism of the seaming machine according to claim 1 or 2 or 3, characterized in that The two swinging parts (72) are respectively arranged at the tops of both ends of the hinge part (71); the two swinging parts (72) are parallel to each other and perpendicular to the hinge part (71).

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