Cover presser device

Abstract

The technical scheme discloses a cover clamping device of a glue binding machine, which comprises a driving assembly, a first translation assembly, a second translation assembly, a cutter plate assembly and a clamping table plate. The driving assembly drives the first translation assembly and the second translation assembly to move in a step-by-step intermittent mode. The step-by-step intermittent mode refers to a single-morph relative motion mode of the two translation assemblies. The first translation assembly is provided with a cam and a clamping sliding block. The cam intermittently drives the clamping sliding block to reciprocate. The second translation assembly is provided with a driving gear and a rack. The driving gear intermittently drives the rack to reciprocate. The cutter plate assembly is provided with two cutter plate sliding blocks which are respectively fixed to the first translation assembly and the second translation assembly. The clamping table plate is provided with a sliding groove. The cutter plate sliding blocks reciprocate in the sliding groove. The technical scheme solves the technical problem of designing a cover clamping device which is driven by a single-morph step-by-step independent operation.

Description

Technical Field

[0001] This invention relates to a system for clamping books in a perfect binding machine, which is mainly used for clamping the cover and the paper. Background Technology

[0002] Perfect binding machines are specialized equipment for binding paper into books. They consist of multiple integrated devices, such as paper clamping devices, glue roller devices, and cover clamping devices. The cover clamping device is mainly used to clamp the cover to the paper. The structures for completing the clamping are varied, and existing devices are complex in structure. In addition, current cover clamping devices all use a dual-mode synchronous method to drive the front and rear blades, which requires the device to have high design and assembly precision, thus increasing the cost of the entire device. Summary of the Invention

[0003] The purpose of this invention is to provide a cover clamping device for a perfect binding machine. The technical problem to be solved is: to design a cover clamping device that adopts a single-mode, step-by-step, and independently operated driving method.

[0004] The cover clamping device for a perfect binding machine includes: The driving component drives the first translation component and the second translation component to move in a step-by-step intermittent manner. The step-by-step intermittent motion refers to driving the two translation components to form a single-mode relative motion pattern in which one component moves and the other remains stationary. The first translation component has a cam and a clamping slider, wherein the cam intermittently drives the clamping slider to reciprocate. The second translation component has a drive gear and a rack, wherein the drive gear intermittently drives the rack to reciprocate. The blade assembly has two parts, which are respectively fixed to the first translation assembly and the second translation assembly via blade sliders; The clamping plate has a groove in which the blade slide block is configured to slide back and forth.

[0005] The drive assembly includes a motor, a transmission gear set, and a transmission shaft set; the transmission gear set has multiple transmission teeth, and the transmission shaft set has multiple transmission shafts; a transmission tooth is fitted on the motor shaft and drives the remaining transmission teeth to rotate in sequence, and the remaining transmission teeth are assembled with the multiple transmission shafts one by one so that the transmission shafts and transmission teeth rotate synchronously.

[0006] The cam has a convex structure with symmetrical pressure shafts on both sides. The pressure shafts drive the clamping slider to reciprocate, which in turn drives the corresponding blade slider to slide. The cam has a gap at the corresponding position of the pressure shaft. The gap does not contact the clamping slider, thus realizing the cam intermittently drives the clamping slider to reciprocate.

[0007] There are screws and bearings between the cam and the clamping slider; the bearings are installed on the clamping slider by screws, and the pressure shaft part contacts the bearings to drive the bearings to move.

[0008] The drive gear has an arc portion and a gear portion; the arc portion and the gear portion together form the outer edge of the drive gear. The arc portion does not contact the rack, and the gear portion meshes with the rack to realize the intermittent reciprocating motion of the drive gear driving the rack.

[0009] The motor is fixed on a motor wall panel, and the two ends of the transmission shaft assembly are fitted with bearings and inner wall panels, thus forming two spaced inner wall panels. A wall panel connecting strip is installed between the two inner wall panels, and the inner wall panels can move up and down on the clamping base through multiple bearing flanges.

[0010] The clamp base is equipped with a fine-adjustment rod, on which a fine-adjustment cam is sleeved. The fine-adjustment cam is spirally protruding, thereby forming multiple platforms on its outer surface. These platforms adjust the height of a lifting base.

[0011] The drive shaft is equipped with a lifting cam, which has a first lifting bottom surface and a second lifting bottom surface. The first lifting bottom surface and the second lifting bottom surface have a height difference, and the second lifting bottom surface is closer to the shaft center of the lifting cam than the first lifting bottom surface. The first lifting bottom surface and the second lifting bottom surface switch contact with the lifting base to achieve the lifting and lowering of the drive assembly, the first translation assembly, the second translation assembly, and the blade assembly.

[0012] The book clamping device of the perfect binding machine includes: The driving component drives two third translation components arranged in a symmetrical manner to move in a step-by-step intermittent manner. The step-by-step intermittent motion refers to driving the two third translation components to form a single-form relative motion mode in which one component moves and the other remains stationary. The third translation component has two sets, each set having two levers and two sliding seats arranged front and rear; each lever has two intersecting actuating supports; the sliding seat has a push rod and a seat body, the push rod being fixed on the seat body and positioned between the two actuating supports; The blade assembly has two blades, each fixed to the base of the third translation assembly via a blade slider; The clamping plate has a groove in which the blade slide block is configured to slide back and forth.

[0013] The drive assembly includes a motor, a transmission gear set, and a transmission shaft set. The transmission gear set has multiple transmission teeth, and the transmission shaft set has multiple transmission shafts. A transmission tooth is fitted onto the motor shaft, causing it to sequentially drive the remaining transmission teeth to rotate. The remaining transmission teeth are assembled with the multiple transmission shafts one by one, allowing the transmission shafts and transmission teeth to rotate synchronously. The motor is fixed to a motor wall plate, and bearings are fitted onto both ends of the transmission shaft set to install inner wall plates, thus forming two spaced inner wall plates. A wall plate connecting strip is installed between the two inner wall plates, and the inner wall plates move up and down on the clamping base via multiple bearing flanges. The clamping base is equipped with a fine-adjustment rod, on which a fine-adjustment cam is sleeved. The fine-adjustment cam is spirally protruding, forming multiple platforms on its outer surface. These platforms adjust the height of a lifting base. A lifting cam is mounted on the drive shaft. The lifting cam has a first lifting base surface and a second lifting base surface, with a height difference between the first and second lifting base surfaces. The second lifting base surface is closer to the shaft center of the lifting cam than the first lifting base surface. The first and second lifting base surfaces switch contact with the lifting base to raise and lower the drive assembly, the third translation assembly, and the blade assembly.

[0014] The beneficial effects of this invention are: This application designs the first translation component and the second translation component independently. By using the same set of drive components, the first translation component and the second translation component can move intermittently in steps, reducing the transmission correlation between the two components. This can reduce the overall precision of the corresponding components and the assembly precision between the components. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the book clamping device of a perfect binding machine; Figure 2 This is a schematic diagram of the book clamping device of the perfect binding machine from another angle, which shows more of the structure of the book clamping device of the perfect binding machine; Figure 3 This is a schematic diagram showing the interior of the book clamping device of a perfect binding machine; Figure 4 yes Figure 1 A schematic diagram of the disassembled clamping device of a perfect binding machine; Figure 5 yes Figure 4 A further disassembled schematic diagram of the book clamping device of the perfect binding machine; Figure 6 This is a schematic diagram of the assembly of the display driver component, the first translation component, and the second translation component; Figure 7 yes Figure 6 The top view of the device shows the specific location and structural assembly of the drive column, the first translation component, and the second translation component; Figure 8 yes Figure 6 The front view of the device shows how other components are lifted using lifting cams; Figure 9 yes Figure 5 The diagram shows a further disassembled version of the device, omitting the clamping plate. Figure 10 This is a schematic diagram of a cam; Figure 11 This is a schematic diagram of the drive gear; Figure 12 This is a schematic diagram showing how the lifting cam raises its center of gravity when it rotates clockwise and counterclockwise, thereby causing the two inner wall panels to rise. Figure 13 This is a schematic diagram of a different style of binding machine clamping table, which uses two third translation components instead of the first and second translation components; Figure 14 yes Figure 13 A further exploded diagram of the device, which more clearly shows the assembly relationship of the internal components; Figure 15 yes Figure 13 A further exploded view of the device from another angle, showing the assembly relationships of more internal components; Figure 16 yes Figure 13 A top view of the device; Figure 17 yes Figure 13 A schematic diagram of the lever used in the third translation component of the device; In the picture 11. First blade plate; 12. Second blade plate; 13. Clamping plate; 131. Slide groove; 14. Blade plate slider; 2. Drive assembly; 21. Motor; 22. Transmission gear set; 23. Transmission shaft assembly; 3. First translation component; 31. Cam; 311. Pressing shaft part; 3111. Pressing shaft surface; 312. Empty part; 32. Bearing; 33. Screw; 34. Translation slider; 4. Second translation component; 41. Drive gear; 411. Arc portion; 412. Gear portion; 42. Translation rack; 5. Third translation component; 51. lever; 511. first actuating support; 512. second actuating support; 52. sliding seat; 521. push rod; 522. base body; 61. Motor wall panel; 62. First inner wall panel; 63. Second inner wall panel; 64. Wall panel connecting strip; 65. Clamping base; 66. Flange bearing; 71. Fine-tuning lever; 72. Fine-tuning cam; 721. Platform; 81. Lift base; 82. Gasket; 9. Lifting cam, 91. First lifting bottom surface, 92. Second lifting bottom surface, 93. Transition surface. Detailed Implementation

[0016] Please refer to Figures 1 to 12 The book-clamping device for a perfect binding machine shown in the figure mainly consists of a drive assembly 2, a first translation assembly 3, a second translation assembly 4, a blade assembly, and a clamping plate 13. The drive assembly 2 simultaneously drives the first translation assembly 3 and the second translation assembly 4 to perform corresponding actions, maintaining a step-by-step, intermittent motion. This step-by-step, intermittent motion refers to a single-form relative motion mode where one translation assembly is in motion while the other is stationary. The first translation assembly 3 drives the first blade 11 of the blade assembly to perform a reciprocating translational motion. The second translation assembly 4 drives the second blade 12 of the blade assembly to perform a reciprocating translational motion. The blade assembly clamps the glued book. The clamping plate 13 supports the blade assembly. In practical applications, the above components can be further optimized, such as by redesigning the shape, structure, quantity, material, and position of the components, adding additional components, or replacing existing components with equivalent replacements.

[0017] The drive assembly 2 in the diagram mainly consists of a motor 21, a transmission gear assembly 22, and a transmission shaft assembly 23. The motor 21 is a reversible motor. When it completes a forward rotation, the first translation assembly 3 and the second translation assembly 4 perform a translational movement in one direction. The directions of movement of the two assemblies are opposite; for example, the first translation assembly 3 moves to the left and stops at a set position, while the second translation assembly 4 begins to move to the right and stops at a set position. When a reverse rotation begins and is completed, the first translation assembly 3 and the second translation assembly 4 similarly perform a translational movement in one direction, but in the opposite direction to the forward rotation. The directions of movement of the two assemblies are also opposite at this time; for example, the first translation assembly 3 moves to the right and stops at a set position, while the second translation assembly 4 begins to move to the left and stops at a set position. This action provides clamping space for the book and then clamps it. The transmission gear assembly 22 in this design consists of three sequentially meshing transmission gears. One gear is mounted on the shaft of the motor 21, driving the remaining transmission gears to rotate. The remaining two gears are mounted on separate transmission shafts. The function of the aforementioned transmission gears is to utilize the rotation of the motor 21 to drive the transmission shaft to rotate, which in turn drives the first translation component 3 and the second translation component 4 to rotate. In practical applications, existing mechanisms that perform transmission functions, such as chain type, cam type 31 type, and belt type, can be used to replace the aforementioned transmission gear set 22.

[0018] The drive shaft assembly 23 in the figure has two drive shafts arranged horizontally and parallel, which rotate synchronously with the drive gears.

[0019] The first translation component 3 in the figure has two sets distributed at the front and rear positions of the first blade plate 11, thereby driving the blade plate to reciprocate. The first translation component 3 mainly consists of a cam 31, a bearing 32, a screw 33, and a translation slider 34. The cam 31 uses its unique structural design to intermittently contact the bearing 32 and drive the bearing 32 to move. The bearing 32 is mounted on the translation slider 34 by the screw 33. The bearing 32 mainly bears the thrust of the cam 31, thereby driving the translation slider 34 to move. Since the translation slider 34 is fixed together with the first blade plate 11, when the cam 31 is driven to rotate by the transmission shaft, it can drive the first blade plate 11 to move. To achieve the above functions, the cam 31 is designed with symmetrical pressing shaft portions 311 and gap portions 312 on both sides. The pressing shaft portion 311 is a structure similar to the cam 31 extending from both sides, and it is designed with a pressing shaft surface 3111. In this way, the pressing shaft portion 311 uses the pressing shaft surface 3111 to push the bearing 32. The gap portion 312 is the part of the cam 31 that is missing relative to the cylindrical wheel and corresponds to the position of the pressing shaft portion 311. It can also be understood that the cam 31 is obtained by the cylindrical wheel passing through the chip of the gap portion 312. Since the gap portion 312 does not contact the bearing 32, when the cam 31 is in the gap portion 312 and the bearing 32 is in action, it cannot drive the first cutter plate 11 to move, thereby realizing the intermittent driving of the translation slider 34 by the cam 31. In practical applications, the bearing 32 can also be mounted on the translation slider 34 using other existing fasteners.

[0020] The second translation component 4 in the figure has two sets distributed at the front and rear positions of the second blade plate 12, thereby driving the blade plate to reciprocate. The second translation component 4 is designed with a drive gear 41 and a translation rack 42 structure. The drive gear 41 has a unique structural design. As shown in the figure, the drive gear 41 is designed with an arc portion 411 and a gear portion 412. That is, the arc portion 411 and the gear portion 412 together form the outer edge of the drive gear 41. The outer contour of the arc portion 411 is arc-shaped, so it does not contact the translation rack 42 and will not drive the translation rack 42 to reciprocate. The outer contour of the gear portion 412 has teeth, thereby realizing the intermittent drive of the translation rack 42 by the drive gear 41.

[0021] The blade assembly shown in the figure is an existing accessory for perfect binding machines. It mainly consists of a first blade 11 and a second blade 12. These two blades perform the subsequent book clamping action. The first blade 11 is assembled with the first translation component 3, and the second blade 12 is assembled with the second translation component 4.

[0022] The clamping plate 13 in the figure is an existing accessory of the perfect binding machine. It is located below the two blades and has a sliding groove 131 structure that runs through the plate. In this way, the blade slider 14 that fixes the blade can be arranged in the sliding groove 131 and move together with the blade.

[0023] To secure the motor 21, a plate-shaped motor wall panel 61 structure can be designed. To secure the drive shaft, two inner wall panels, namely the first inner wall panel 62 and the second inner wall panel 63, positioned at the front and rear, can be fitted with bearings 32 to secure the drive shaft. To secure the two inner wall panels, a wall panel connecting strip 64 can be installed between them as a support. As shown in the figure, the inner wall panels can be fitted with multiple flange bearings 66 and mounted on the clamping base 65 of the cover clamping device. In this way, except for the clamping base 65, which remains stationary, all other components can move up and down due to the action of the lifting cam 9, thus achieving the same operation as existing equipment.

[0024] To fine-tune the height of the blade, a fine-tuning rod 71 that can rotate flexibly on the side of the clamping base 65 can be designed. There are two clamping bases 65 in the figure, so there are also two fine-tuning rods 71, which are arranged symmetrically. A fine-tuning cam 72 structure is sleeved on the fine-tuning rod 71. The fine-tuning cam 72 adopts a spiral protrusion structure similar to the Archimedes curve, and forms multiple step-like platforms 721 on the outer surface. The lifting base 81 used to adjust the height of the blade can be placed on the platform 721. It should be noted that the lifting base 81 has an L-shaped structure. Its horizontal part supports the lifting cam 9, and the vertical part can be installed with a bearing 32 flange fixed to the clamping base 65, thereby realizing the movable lifting and lowering of the lifting base 81.

[0025] To enable the blade to rise and fall, lifting cams 9 are installed at both ends of the drive shaft. These lifting cams 9 rotate synchronously with the drive shaft. As shown in the figure, the lifting cam 9 is designed with a first lifting bottom surface 91, a second lifting bottom surface 92, and a transition surface 93 between the two bottom surfaces. The first lifting bottom surface 91 and the second lifting bottom surface 92 have a height difference, with the second lifting bottom surface 92 being closer to the shaft center of the lifting cam 9 than the first lifting bottom surface 91. At the same time, the first lifting bottom surface 91 and the second lifting bottom surface 92 switch contact with the lifting base 81 to achieve the lifting and lowering of the drive assembly 2, the first translation assembly 3, the second translation assembly 4, and the blade assembly.

[0026] Please refer to Figures 13 to 17The difference between this embodiment and the above embodiment is that a third translation component 5 replaces the first translation component 3 and the second translation component 4. The position of the third translation component 5 is still consistent with the positions of the two translation components mentioned above. Also, one set of third translation components 5 is configured for each blade plate and fixed by the blade plate slider 14, thus forming two sets. The drive component 2 also drives these two sets of third translation components 5 in a step-by-step intermittent motion. Each set of third translation components 5 has two levers 51 arranged front and rear and two sliding seats 52; each lever 51 has two intersecting actuating supports; the sliding seat 52 has a push rod 521 and a seat body 522. The push rod 521 is fixed on the seat body 522 and positioned between the two actuating supports. Thus, when the lever 51 is driven to rotate by the drive shaft, the push rod 521 can be moved through the actuating supports.

[0027] It should be noted that the above embodiments describe the combination of the first translation component 3 and the second translation component 4, and the combination of two third translation components 5. In practical applications, combinations such as the first translation component 3 and the third translation component 5 or the second translation component 4 and the third translation component 5 can also be formed.

[0028] The specific embodiments described above are merely illustrative of the present technical solution and are not intended to limit the present technical solution. In the description of the present technical solution, it should be noted that terms such as "upper" and "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are only for the convenience of describing the present technical solution 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 the present technical solution.

[0029] Furthermore, in the description of this technical solution, it should be noted that, unless otherwise explicitly specified and limited, the terms "fixed" and "fitting" 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 direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this technical solution according to the specific circumstances.

[0030] Although embodiments of the present technical solution have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present technical solution, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cover clamping device for a perfect binding machine, characterized in that: include: The driving component (2) drives the first translation component (3) and the second translation component (4) to perform step-by-step intermittent motion. The step-by-step intermittent motion refers to driving the two translation components to form a single-form relative motion mode with one moving and one stationary. The first translation component (3) has a cam (31) and a clamping slider (34), wherein the cam (31) intermittently drives the clamping slider (34) to reciprocate. The second translation component (4) has a drive gear (41) and a rack (42), wherein the drive gear (41) intermittently drives the rack (42) to reciprocate. The blade assembly has two blades, which are respectively fixed to the first translation assembly (3) and the second translation assembly (4) via blade sliders (14); The clamping plate (13) has a groove (131) in which the blade slider (14) is arranged to slide back and forth.

2. The cover clamping device for a perfect binding machine according to claim 1, characterized in that: The drive assembly (2) has a motor (21), a transmission gear set (22), and a transmission shaft set (23); the transmission gear set (22) has multiple transmission teeth, and the transmission shaft set (23) has multiple transmission shafts; a transmission tooth is fitted on the rotating shaft of the motor (21) and the transmission tooth drives the remaining transmission teeth to rotate in sequence, and the remaining transmission teeth are assembled with the multiple transmission shafts one by one so that the transmission shafts and transmission teeth rotate synchronously.

3. The cover clamping device for a perfect binding machine according to claim 1, characterized in that: The cam (31) is a convex structure with symmetrical pressure shafts (311) on both sides. The pressure shafts (311) drive the clamping slider (34) to reciprocate and thus drive the corresponding blade slider (14) to slide. The cam (31) has a gap (312) at the corresponding position of the pressure shafts (311). The gap (312) does not contact the clamping slider (34), thereby realizing that the cam (31) intermittently drives the clamping slider (34) to reciprocate.

4. The cover clamping device for a perfect binding machine according to claim 3, characterized in that: There is a screw (33) and a bearing (32) between the cam (31) and the clamping slider (34); the bearing (32) is mounted on the clamping slider (34) by the screw (33), and the pressure shaft part (311) contacts the bearing (32) to drive the bearing (32) to move.

5. The cover clamping device for a perfect binding machine according to claim 1, characterized in that: The drive gear (41) has an arc portion (411) and a gear portion (412); the arc portion (411) and the gear portion (412) together form the outer edge of the drive gear (41). The arc portion (411) does not contact the rack (42), and the gear portion (412) meshes with the rack (42) to realize the intermittent drive of the drive gear (41) to drive the rack (42) to reciprocate.

6. The cover clamping device for a perfect binding machine according to claim 2, characterized in that: The motor (21) is fixed on a motor wall plate (61). The two ends of the transmission shaft assembly (23) are fitted with bearings (32) and inner wall plates are installed, thus forming two inner wall plates with a gap. A wall plate connecting strip (64) is installed between the two inner wall plates. The inner wall plates move up and down on the clamp base (65) through multiple bearing (32) flanges.

7. The cover clamping device for a perfect binding machine according to claim 6, characterized in that: The clamp base (65) is equipped with a fine adjustment rod (71), and a fine adjustment cam (72) is sleeved on the fine adjustment rod (71). The fine adjustment cam (72) is spirally protruding, so that its outer surface forms multiple platforms (73). These platforms (73) adjust the height of a lifting base (81).

8. The cover clamping device for a perfect binding machine according to claim 2, characterized in that: The drive shaft is equipped with a lifting cam (9), which has a first lifting bottom surface (91) and a second lifting bottom surface (92). The first lifting bottom surface (91) and the second lifting bottom surface (92) have a height difference. The second lifting bottom surface (92) is closer to the shaft center of the lifting cam (9) than the first lifting bottom surface (91). The first lifting bottom surface (91) and the second lifting bottom surface (92) switch contact with the lifting base (81) to realize the lifting and lowering of the drive assembly (2), the first translation assembly (3), the second translation assembly (4), and the blade assembly.

9. A cover clamping device for a perfect binding machine, characterized in that: include: The driving component (2) drives two third translation components (5) arranged in a symmetrical form to move in a step-by-step intermittent manner. The step-by-step intermittent motion refers to driving the two third translation components (5) to form a single-form relative motion mode with one moving and one stationary. The third translation component (5) has two sets, each set having two levers (51) arranged in front and behind and two sliding seats (52); each lever (51) has two intersecting actuating supports; the sliding seat (52) has a push rod (521) and a seat (522), the push rod (521) is fixed on the seat (522) and is located between the two actuating supports; The blade assembly has two blades, which are respectively fixed to the base (522) of the third translation assembly (5) via the blade slider (14); The clamping plate (13) has a groove (131) in which the blade slider (14) is arranged to slide back and forth.

10. The cover clipping device for a perfect binding machine according to claim 9, characterized in that: The drive assembly (2) has a motor (21), a transmission gear set (22), and a transmission shaft set (23); the transmission gear set (22) has multiple transmission teeth, and the transmission shaft set (23) has multiple transmission shafts; a transmission tooth is fitted on the rotating shaft of the motor (21) and the transmission tooth drives the remaining transmission teeth to rotate in sequence, and the remaining transmission teeth are assembled with multiple transmission shafts one by one so that the transmission shafts and transmission teeth rotate synchronously; the motor (21) is fixed on a motor wall plate (61), and the two ends of the transmission shaft set (23) are fitted with bearings (32) and inner wall plates are installed, thereby forming two inner wall plates with a gap, and a wall plate connecting strip (64) is installed between the two inner wall plates, and the inner wall plates move up and down on the clamping base (65) through multiple bearing (32) flanges; the clamping base (65) is equipped with micro Adjusting rod (71), on which a fine-adjusting cam (72) is sleeved, the fine-adjusting cam (72) is spirally protruding so that its outer surface forms multiple platforms (73), these platforms (73) adjust the height of a lifting base (81); a lifting cam (9) is installed on the drive shaft, the lifting cam (9) has a first lifting bottom surface (91) and a second lifting bottom surface (92), the first lifting bottom surface (91) and the second lifting bottom surface (92) have a height difference, the second lifting bottom surface (92) is closer to the axis center of the lifting cam (9) than the first lifting bottom surface (91); the first lifting bottom surface (91) and the second lifting bottom surface (92) switch contact with the lifting base (81) to realize the lifting and lowering of the drive assembly (2), the third translation assembly (5) and the blade assembly.

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