Belt cutting device of sewing machine

Abstract

The utility model relates to clothing machinery, in particular to a sewing machine belt cutting device which comprises an upper cutter and a lower cutter which are mutually hinged to form a cutting pair, and a guide groove of the upper cutter and the lower cutter form a specific included angle with the left-right direction. The fixed plate, the linear guide rail, the sliding block, the driven plate, the driving plate and the like cooperatively operate. Compared with the prior art, only one stepping motor is needed, the movable cutter can be sequentially driven to be linearly close to the belt and automatically conduct shearing motion after reaching the designated position, the key belt cutting step is completed at a time, the driving process is greatly simplified, the belt cutting efficiency is improved, and time and energy are saved. And meanwhile, the cutter adopts a thin-sheet design and can be flexibly used in a narrow space, so that the limitation of an existing belt cutting device on a narrow operation space is effectively overcome, and a belt cutting scheme with higher adaptability is provided for the textile processing industry.

Description

Technical Field

[0001] This utility model relates to garment machinery, specifically to a sewing machine tape cutting device. Background Technology

[0002] In the field of sewing machine binding processes today, the technological development of pre-cutting tape devices plays a crucial role in improving production efficiency and product quality. Currently, most pre-cutting tape devices widely used in the market employ hot-cutting technology. This type of hot-cutting tape device has shown certain advantages in specific application scenarios, and it can be effectively used for single-bundle processes of some stiff woven tapes. However, with the continuous development of the textile industry, the processing needs for tapes of various materials and properties are becoming increasingly diversified, and existing hot-cutting tape devices have revealed significant limitations.

[0003] Among various tape materials, some softer ribbed tapes, especially thin and soft knitted ribbed tapes, pose a significant challenge to the pre-cutting process for edge binding. Existing edge binding pre-cutting devices on the market are almost ineffective at pre-cutting such soft knitted ribbed tapes. In traditional pre-cutting devices, the tape is typically cut using a heat cutter in the middle of the pull drum, and then the feeding mechanism transports the remaining tape to the outside of the pull drum head for subsequent edge binding. However, this traditional feeding mechanism struggles with thin and soft knitted ribbed tapes. Because knitted ribbed tapes are inherently too soft and lack sufficient rigidity to maintain stable transport, traditional feeding devices simply cannot smoothly deliver the remaining tape outside the pull drum. In this situation, the cutting device is forced to perform the cutting operation within an extremely limited and narrow space between the machine presser foot and the tape pull drum, which undoubtedly increases the difficulty and instability of the cutting process.

[0004] Furthermore, hot cutting presents serious drawbacks for white knitted rib tape. The high temperatures generated during hot cutting inevitably cause discoloration at the cut point, which is completely unacceptable for the modern textile processing industry, which demands extremely high product appearance quality. Therefore, for white and other color-sensitive knitted rib tapes, cold cutting is the only viable option. However, the market currently lacks cold-cutting pre-cutting devices suitable for the double-wrap processing of thin and soft knitted rib tapes. This technological gap severely restricts the production efficiency and quality improvement of related textile products, urgently requiring an innovative technical solution. Utility Model Content

[0005] The purpose of this invention is to address one or more of the deficiencies in existing technologies by providing a structurally optimized sewing machine tape cutting device. The technical solution adopted is as follows:

[0006] A sewing machine tape cutting device, comprising

[0007] The upper and lower cutters are hinged together at their rear ends to form a shearing pair.

[0008] The fixing plate is fixedly connected to the sewing machine body;

[0009] Linear guide rail, fixed on a fixed plate, with left and right directions;

[0010] The driven plate is slidably connected to the linear guide rail via the first slider;

[0011] The drive plate is linked with the driven plate and can move left and right. Its right end is slidably engaged with the guide grooves of the upper and lower cutters via a pin.

[0012] The translation of the drive plate drives the upper and lower cutters to rotate around the hinge point, thereby realizing the shearing action.

[0013] Furthermore, the upper cutter is provided with a first guide groove, the angle between its longitudinal direction and the left-right direction being +α;

[0014] The lower cutter is provided with a second guide groove, the angle between its longitudinal direction and the left and right directions is -a, and 0° < a < 45°;

[0015] The right end of the drive plate is provided with a first pin and a second pin, which slide in cooperation with the first guide groove and the second guide groove respectively.

[0016] The third pin and the fourth pin are respectively fixed in the middle and right end of the driven plate, and the fourth pin is simultaneously hinged to the upper cutter and the lower cutter.

[0017] The drive plate is provided with a third guide groove and a fourth guide groove, which slide in cooperation with the third pin and the fourth pin respectively;

[0018] If the stroke of the drive board is defined as L1, the lengths of the projections of the first guide groove and the second guide groove on the horizontal plane are equal and are L2, and the lengths of the third guide groove and the fourth guide groove are equal and are L3, satisfying L1≥L2+L3.

[0019] Furthermore, the driven plate is punched and folded in the middle to form a driven folding plate, and a driven screw hole with the axial direction in the left and right direction is opened on the driven folding plate; the left end of the drive plate is punched and folded to form an active folding plate, and an active guide hole with the axial direction in the left and right direction is opened on the active folding plate; the guide rod is screwed to the driven screw hole and slidably engaged with the active guide hole, and a first spring is sleeved on the guide rod, with one end of the first spring abutting against the active folding plate and the other end abutting against the driven folding plate.

[0020] Furthermore, the third pin is screwed to the driven plate; the fourth pin passes through the pin holes at the left ends of the upper and lower cutters, then passes through the driven plate, and finally is screwed to the nut. A second spring is fitted on the fourth pin, and the two ends of the second spring abut against the pin head and the upper cutter, respectively.

[0021] Furthermore, the left end of the driven plate is punched and folded to form a baffle, and the middle part of the fixed plate is punched and folded to form a fixed folding plate. An adjustment screw hole with the axial direction in the left and right direction is opened on the fixed folding plate. An adjustment screw is screwed into the adjustment screw hole, and a back tightening nut is screwed into the adjustment screw. The rod end of the adjustment screw abuts against the baffle. The limit position of the driven plate to the right is adjusted by adjusting the screwing amount.

[0022] Furthermore, the driving device includes a cylinder, a hydraulic cylinder, a push-pull electromagnet, a rotary electromagnet, or a motor.

[0023] Furthermore, when the driving device is a cylinder, a hydraulic cylinder, or a push-pull electromagnet, the actuator of the cylinder, hydraulic cylinder, or push-pull electromagnet is directly connected to the driving plate, the linear motion direction is left and right, and the stroke is ≥ L2 + L3.

[0024] Furthermore, when the driving device is a rotary electromagnet or a motor, its rotary output shaft is fixed to the center of the flywheel, and the second slider is mounted at the eccentric position of the flywheel; a fifth guide groove with the longitudinal direction being up and down is opened on the driving plate, and the second slider is slidably engaged with the fifth guide groove; the eccentricity of the second slider is ≥ (L2+L3) / 2.

[0025] Furthermore, the portion to the right of the hinge pin of the upper and lower cutters extends into the narrow space between the machine presser foot and the belt puller.

[0026] Furthermore, a receiving end of a photoelectric switch is installed on the left end of the driven plate, and a transmitting end of a photoelectric switch is installed above the fixed plate. The photoelectric switch is used to detect the zero position of the driven plate.

[0027] Compared with the prior art, this utility model has the following beneficial technical effects:

[0028] High-efficiency tape cutting operation: Only one stepper motor is needed to drive two movable blades to move in a straight line towards the tape. After reaching the designated position, the fixed blade and the movable blade stop their straight line movement and begin the cutting motion. The two key steps of bringing the cutter close to the tape and cutting the tape are completed in one go by a single motor, which greatly simplifies the driving process and improves tape cutting efficiency. Compared with the traditional multi-step, multi-drive tape cutting method, it is more efficient in terms of time and energy utilization.

[0029] Adaptable to narrow spaces: The overall structure of the cutter is designed to be thin, which enables it to be used flexibly in narrow spaces. This effectively solves the limitations of existing tape cutting devices when facing narrow operating spaces. It is especially suitable for production scenarios with strict requirements on equipment installation space, and provides a more adaptable tape cutting solution for the textile processing industry.

[0030] Diverse Power Options: The structure offers wide applicability to various drive methods, including electric motors, electromagnets, and cylinders. This versatility allows users to flexibly choose the most suitable power drive method based on actual production needs, equipment compatibility, and cost considerations, enhancing the device's versatility and operability in different production environments.

[0031] Solving the problem of cutting soft tapes: This invention effectively addresses the difficulty of existing hot-cutting pre-cutting devices in effectively pre-cutting thin and soft knitted rib tapes. Existing hot-cutting devices cannot stably transport soft knitted rib tapes, while the structure of this invention enables the cutting of such tapes.

[0032] Meeting appearance quality requirements: It avoids the problem of discoloration at the cut position caused by high temperature during hot cutting of white and other color-sensitive knitted ribbed tapes, and can be cut by cold cutting, meeting the high requirements of the modern textile processing industry for product appearance quality.

[0033] Filling a technological gap: This utility model can adapt to the double-wrap processing technology of thin and soft knitted ribbed tape, solving the technological gap in the current market where there is a lack of applicable cold-cutting pre-cut tape devices, which helps to improve the production efficiency and quality of related textile products. Attached Figure Description

[0034] Figure 1-3 These are schematic diagrams of the structure of this utility model from different perspectives.

[0035] Figure 4 This is a schematic diagram of the upper and lower cutting blades of this utility model.

[0036] Figure 5 This is a schematic diagram of the driven plate of this utility model.

[0037] Figure 6 This is a structural schematic diagram of the fixing plate of this utility model.

[0038] Figure 7 This is a schematic diagram of the drive board of this utility model. Detailed Implementation

[0039] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0040] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "communication" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0041] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0042] like Figure 1-7 The sewing machine tape cutting device shown includes

[0043] The upper cutter 1 and the lower cutter 2 are hinged together at their rear ends to form a shearing pair. The upper cutter 1 has a first guide groove 11 with an angle of +a between its longitudinal direction and the left-right direction. The lower cutter 2 has a second guide groove 21 with an angle of -a between its longitudinal direction and the left-right direction, and satisfies 0° < a < 45°.

[0044] Fixed plate 4 is fixedly connected to the body of the sewing machine;

[0045] Linear guide rail 5 is fixed on the fixed plate 4, and its stroke is in the left and right direction;

[0046] The first slider 6 is slidably engaged with the linear guide rail 5;

[0047] The driven plate 3 is fixedly connected to the first slider 6, with a third pin 31 fixed in the middle and a fourth pin 32 fixed at the right end.

[0048] The drive plate 7 abuts against the driven plate 3 and can move left and right under the action of the drive device. The right end is fixed with a first pin 71 and a second pin 72 arranged vertically. The first pin 71 is slidably engaged with the first guide groove 11, and the second pin 72 is slidably engaged with the second guide groove 21. At the positions corresponding to the third pin 31 and the fourth pin 32, a third guide groove 73 and a fourth guide groove 74 are respectively opened in the left and right direction along the length and are slidably engaged with the third pin 31 and the fourth pin 32. The fourth pin 32 passes through the fourth guide groove 74 and is hinged to the upper cutter 1 and the lower cutter 2.

[0049] If the stroke of the drive plate 7 is defined as L1, the lengths of the projections of the first guide groove 11 and the second guide groove 21 on the horizontal plane are equal and are L2, and the lengths of the third guide groove 73 and the fourth guide groove 74 are equal and are L3, satisfying L1≥L2+L3.

[0050] In this embodiment, the driving device is a motor 12, the rotation output shaft of the motor 12 is fixed to the center of the flywheel 13, and the second slider 14 is mounted at the eccentric position of the flywheel 13; a fifth guide groove 77 with the longitudinal direction of up and down is opened on the driving plate 7, and the second slider 14 is slidably engaged with the fifth guide groove 77; the eccentricity of the second slider 14 is ≥ (L2+L3) / 2.

[0051] Working principle: Motor 12 drives flywheel 13 to rotate. During the rotation of flywheel 13, the second slider 14, located at an eccentric position, converts the rotational motion of flywheel 13 into the left-right translational motion of drive plate 7 through sliding engagement with the fifth guide groove 77 on drive plate 7. The translational motion of drive plate 7 is further driven by the sliding engagement of first pin 71 with the first guide groove 11 of upper cutter 1, second pin 72 with the second guide groove 21 of lower cutter 2, and third pin 31 and fourth pin 32 with the third guide groove 73 and fourth guide groove 74 on drive plate 7, thus enabling upper cutter 1 and lower cutter 2 to complete the actions of approaching and cutting the tape. The length design of each guide groove and the eccentricity setting of the second slider 14 ensure that the cutter can smoothly complete the complete cycle of approaching and cutting, and the thin-plate design of the cutter makes it suitable for narrow spaces.

[0052] Work process:

[0053] Initial state: Motor 12 is initially stationary, and flywheel 13 has not yet rotated. The shearing pair formed by the hinged rear ends of upper cutter 1 and lower cutter 2 is in an open state. Drive plate 7 is in the initial position, with first pin 71 near the starting end of first guide groove 11, second pin 72 near the starting end of second guide groove 21, and third pin 31 and fourth pin 32 located at the ends of third guide groove 73 and fourth guide groove 74 near the starting direction of drive plate translation, respectively.

[0054] Motor Start-up and Extension of the Shearing Pair: Motor 12 starts, driving flywheel 13 to rotate. During rotation, the second slider 14 at the eccentric position of flywheel 13, through sliding engagement with the fifth guide groove 77 on drive plate 7, drives drive plate 7 to translate horizontally. During this process, driven plate 3 moves synchronously to the right along linear guide rail 5 via first slider 6, following drive plate 7. Third pin 31 in third guide groove 73 and fourth pin 32 in fourth guide groove 74 both slide to the right in the left-right direction, causing the shearing pair formed by upper cutter 1 and lower cutter 2 to extend to the right. However, for a distance before third pin 31 and fourth pin 32 move to the right end of third guide groove 73 and fourth guide groove 74 respectively, due to the relative positional relationship between the components, upper cutter 1 and lower cutter 2 remain stationary and do not move.

[0055] Closing phase of the upper and lower cutters: As the drive plate 7 continues to move to the right, when the third pin 31 and the fourth pin 32 move to the right end of the third guide groove 73 and the fourth guide groove 74 respectively, the first pin 71 and the second pin 72 begin to slide within their respective first guide groove 11 and second guide groove 21. Because there is an angle between the longitudinal direction of the first guide groove 11 and the second guide groove 21 and the left-right direction, this sliding causes the upper cutter 1 and the lower cutter 2 to begin to rotate relative to each other around the hinge point, gradually closing.

[0056] Tape cutting completion stage: The drive plate 7 continues to move to the right until it reaches the limit position. During this process, the first pin 71 and the second pin 72 continue to slide in the guide groove, and the upper cutter 1 and the lower cutter 2 continue to close. When the drive plate 7 reaches the limit position, the upper cutter 1 and the lower cutter 2 are completely closed, and the tape cutting operation is completed at the same time.

[0057] Reverse motion phase: Motor 12 drives flywheel 13 to continue rotating, and second slider 14 pushes drive plate 7 to begin translating to the left. At this time, third pin 31 in third guide groove 73 and fourth pin 32 in fourth guide groove 74 both slide to the left in the left-right direction, causing the shearing pair to retract to the left. During the retraction process, first pin 71 and second pin 72 slide in opposite directions in the guide groove, causing upper cutter 1 and lower cutter 2 to gradually open until drive plate 7 returns to the initial position, upper cutter 1 and lower cutter 2 are fully open, completing a complete cutting cycle. Then motor 12 continues to run to start the next round of cutting operation.

[0058] In another preferred embodiment, the driven plate 3 is punched and folded in the middle to form a driven folding plate 33, and a driven screw hole 34 with an axial direction of left and right is formed on the driven folding plate 33; the left end of the drive plate 7 is punched and folded to form an active folding plate 75, and an active guide hole 76 with an axial direction of left and right is formed on the active folding plate 75; the guide rod 8 is screwed to the driven screw hole 34 and slidably engaged with the active guide hole 76, and a first spring 9 is sleeved on the guide rod 8, with one end of the first spring 9 abutting against the active folding plate 75 and the other end abutting against the driven folding plate 33. The driven plate 3 is punched and folded in the middle to form the driven folding plate 33 and the corresponding screw hole, and the left end of the drive plate 7 is punched and folded to form the active folding plate 75 and the corresponding guide hole. The combination of the guide rod 8 and the first spring 9 provides a certain degree of elastic buffering in the connection between the drive plate 7 and the driven plate 3. During operation, the device can effectively absorb vibrations and impacts caused by motor drive and component movement, reducing component wear and extending the device's service life. At the same time, the flexible connection helps compensate for minor errors that occur during the manufacturing and installation of various components, ensuring the stability and reliability of the device's operation.

[0059] In another preferred embodiment, the third pin 31 is screwed to the driven plate 3; the fourth pin 32 passes through the pin holes at the left ends of the upper cutter 1 and the lower cutter 2, then passes through the driven plate 3, and is finally screwed with a nut. A second spring 10 is fitted on the fourth pin 32, with its two ends abutting against the pin head and the upper cutter 1, respectively. The screwing of the third pin 31 to the driven plate 3 facilitates installation and disassembly, and makes it easier for later maintenance and component replacement. The fourth pin 32 passes through the relevant components and is screwed with a nut, which, together with the second spring 10, provides elastic support for the upper cutter 1. During the tape cutting process, the second spring 10 generates continuous pressure, ensuring that the upper cutter 1 and the lower cutter 2 maintain stable pressure when contacting the tape, thus ensuring stable tape cutting.

[0060] In another preferred embodiment, the left end of the driven plate 3 is punched and folded to form a baffle 35, and the middle part of the fixed plate 4 is punched and folded to form a fixed folding plate 41. An adjusting screw hole 42 with an axial direction of left and right is provided on the fixed folding plate 41. An adjusting screw 15 is screwed into the adjusting screw hole 42, and a back-tightening nut 16 is screwed into the adjusting screw 15. The rod end of the adjusting screw 15 abuts against the baffle 35. The limit position of the rightward displacement of the driven plate 3 can be adjusted by adjusting the screwing depth of the adjusting screw 15. By adjusting the screwing depth of the adjusting screw 15, the limit position of the rightward displacement of the driven plate 3 can be precisely controlled. This allows the device to flexibly adjust the working position of the cutter according to strips of different thicknesses and materials, enhancing the adaptability of the device to diverse processing needs and improving the accuracy and quality of strip cutting.

[0061] In another preferred embodiment, the drive device includes a cylinder, a hydraulic cylinder, a push-pull electromagnet, a rotary electromagnet, or a motor 12. This variety of choices meets the needs of different users in different working scenarios. For example, a push-pull electromagnet can be used in situations requiring high power response speed; a hydraulic cylinder is more suitable when greater driving force is needed; and the motor 12 provides stable and precise power output. When the drive device is a cylinder, hydraulic cylinder, or push-pull electromagnet, its actuator is directly connected to the drive plate 7, and the stroke requirement is met, which simplifies the device structure, improves power transmission efficiency, and ensures efficient execution of the tape cutting action.

[0062] In another preferred embodiment, the right-hand portion of the hinge pins of the upper cutter 1 and the lower cutter 2 extends into the narrow space between the machine presser foot and the tape puller. This design specifically addresses the needs of operating in such confined spaces, enabling the tape cutting device to complete the tape cutting operation within a limited space. This meets the tape cutting requirements of specific sewing machine working environments, broadens the application range of the device, and is particularly suitable for textile processing equipment with strict limitations on equipment space layout.

[0063] In another preferred embodiment, a receiver of a photoelectric switch is installed at the left end of the driven plate 3, and a transmitter 17 of a photoelectric switch is installed above the fixed plate 4. The photoelectric switch is used to detect the zero-point position of the driven plate 3. This arrangement provides precise position feedback for the automated operation of the device, enabling the equipment control system to accurately grasp the initial position of the driven plate 3, thereby ensuring the consistency and accuracy of each tape cutting action. This facilitates precise control in the automated production process and improves production efficiency and product quality stability.

[0064] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A sewing machine tape cutting device, characterized in that, include The upper cutter (1) and the lower cutter (2) are hinged together at their rear ends to form a shearing pair; The fixing plate (4) is fixedly connected to the sewing machine body; Linear guide rail (5) is fixed on the fixed plate (4) and its direction is left and right; The driven plate (3) is slidably connected to the linear guide rail (5) via the first slider (6); The drive plate (7) is linked with the driven plate (3) and can move left and right. Its right end is slidably engaged with the guide grooves of the upper cutter (1) and the lower cutter (2) through a pin. The translation of the drive plate (7) drives the upper cutter (1) and the lower cutter (2) to rotate around the hinge point, thereby realizing the shearing action.

2. The sewing machine tape cutting device according to claim 1, characterized in that, The upper cutter (1) is provided with a first guide groove (11), the angle between its longitudinal direction and the left and right directions is +a; The lower cutter (2) is provided with a second guide groove (21), the angle between its longitudinal direction and the left and right directions is -a, and 0° < a < 45°; The right end of the drive plate (7) is provided with a first pin (71) and a second pin (72), which are slidably engaged with the first guide groove (11) and the second guide groove (21), respectively. The third pin (31) and the fourth pin (32) are fixed at the middle and right ends of the driven plate (3), respectively. The fourth pin (32) is simultaneously hinged to the upper cutter (1) and the lower cutter (2). The drive plate (7) is provided with a third guide groove (73) and a fourth guide groove (74), which are slidably engaged with the third pin (31) and the fourth pin (32), respectively; If the stroke of the drive plate (7) is defined as L1, the lengths of the projections of the first guide groove (11) and the second guide groove (21) on the horizontal plane are equal and L2, and the lengths of the third guide groove (73) and the fourth guide groove (74) are equal and L3, satisfying L1≥L2+L3.

3. A sewing machine tape cutting device according to claim 2, characterized in that, The driven plate (3) is punched and folded in the middle to form a driven folding plate (33), and a driven screw hole (34) with the axial direction in the left and right direction is opened on the driven folding plate (33); the left end of the drive plate (7) is punched and folded to form an active folding plate (75), and an active guide hole (76) with the axial direction in the left and right direction is opened on the active folding plate (75); the guide rod (8) is screwed to the driven screw hole (34) and slidably engaged with the active guide hole (76), and a first spring (9) is sleeved on the guide rod (8), one end of the first spring (9) abuts against the active folding plate (75) and the other end abuts against the driven folding plate (33).

4. A sewing machine tape cutting device according to claim 2, characterized in that, The third pin (31) is screwed to the driven plate (3); the fourth pin (32) passes through the pin holes at the left end of the upper cutter (1) and the lower cutter (2) with a gap, then passes through the driven plate (3) with a gap, and finally screws a nut on it. A second spring (10) is sleeved on the fourth pin (32), and the two ends of the second spring (10) abut against the pin head and the upper cutter (1) respectively.

5. A sewing machine tape cutting device according to claim 2, characterized in that, The left end of the driven plate (3) is punched and folded to form a baffle (35), and the middle part of the fixed plate (4) is punched and folded to form a fixed folding plate (41). An adjustment screw hole (42) with the axial direction in the left and right direction is opened on the fixed folding plate (41). An adjustment screw (15) is screwed into the adjustment screw hole (42), and a back tightening nut (16) is screwed into the adjustment screw (15). The rod end of the adjustment screw (15) abuts against the baffle (35). The limit position of the rightward displacement of the driven plate (3) is adjusted by adjusting the screwing amount of the adjustment screw (15).

6. A sewing machine tape cutting device according to claim 1, characterized in that, The drive unit includes a cylinder, a hydraulic cylinder, a push-pull electromagnet, a rotary electromagnet, or a motor (12).

7. A sewing machine tape cutting device according to claim 6, characterized in that, When the driving device is a cylinder, a hydraulic cylinder, or a push-pull electromagnet, the actuator of the cylinder, hydraulic cylinder, or push-pull electromagnet is directly connected to the driving plate (7), the linear motion direction is left and right, and the stroke is ≥ L2+L3.

8. A sewing machine tape cutting device according to claim 6, characterized in that, When the driving device is a rotating electromagnet or a motor (12), its rotating output shaft is fixed to the center of the flywheel (13), and the eccentric position of the flywheel (13) is provided by the second slider (14); a fifth guide groove (77) with the longitudinal direction of up and down is opened on the driving plate (7), and the second slider (14) slides with the fifth guide groove (77); the eccentricity of the second slider (14) is ≥ (L2+L3) / 2.

9. A sewing machine tape cutting device according to claim 1, characterized in that, The right portion of the hinge shaft of the upper cutter (1) and the lower cutter (2) extends into the narrow space between the machine presser foot and the belt puller.

10. A sewing machine tape cutting device according to claim 1, characterized in that, A receiving end of a photoelectric switch is installed on the left end of the driven plate (3), and a transmitting end (17) of a photoelectric switch is installed above the fixed plate (4). The photoelectric switch is used to detect the zero position of the driven plate (3).

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