Device for achieving automatic shadow puppet performance through mechanical structure
Through the combination of mechanical structure and shadow puppet components, the stepping reduction motor and connecting rod mechanism are used to achieve automatic performance of shadow puppet, which solves the problems of high personnel costs and insufficient authenticity of traditional shadow puppets, and achieves dynamic shadow puppet demonstration and widespread dissemination.
Patent Information
- Application Number
- CN202422143282.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-09-02
AI Technical Summary
The physical performances of existing shadow puppets require high personnel investment costs, multimedia video display lacks authenticity and attractiveness, and traditional performance forms are single, making it difficult to spread widely.
The mechanical structure is combined with shadow puppet components, and the stepping reduction motor and connecting rod mechanism are used to achieve automatic performance. The servo controls the head piece movement, and accurately controls the movement through a programmable logic controller to achieve dynamic shadow puppet demonstration.
It saves the cost of performers, enhances the fun and authenticity of the exhibition, expands the spread range of shadow puppets, breaks through the time and space limitations of performance, and displays dynamic shadow puppet movements and movement trajectories.
Smart Images
Figure CN223127253U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of exhibition interactive exhibits in science and technology museums, and particularly relates to a device for automatically performing shadow puppetry through a mechanical structure. Background Art
[0002] At present, shadow puppets of shadow puppetry are all side views, divided into parts such as heads, bodies, arms and legs, and are composed of more than a dozen movable components. Generally, cotton threads are used to stitch the various parts of the shadow puppets together. The movements of the hands and feet of the shadow puppets are combinations of radius, center and angle. Shadow puppetry artists utilize the lever principle and control the every move of the shadow puppets through control rods to make the shadow puppets come alive, thus presenting a vivid story.
[0003] The existing displays show the movement mode of shadow puppetry in the form of physical objects and multimedia videos, etc. The physical display of shadow puppetry requires personnel input costs and has limitations; the multimedia video display of shadow puppetry lacks authenticity, has a single form, and has little attraction to the audience. Content of the Utility Model
[0004] The utility model provides a device for automatically performing shadow puppetry through a mechanical structure. The prior art has the problems that the physical display of shadow puppetry requires personnel input costs and has limitations; the multimedia video display of shadow puppetry lacks authenticity, has a single form, and has little attraction to the audience.
[0005] To solve the above problems of the utility model, the technical solutions provided by the utility model are as follows:
[0006] A device for automatically performing shadow puppetry through a mechanical structure includes a shadow puppet assembly and a base. A head piece, a large arm piece, a small arm piece, an upper body piece, a lower body piece and a leg piece are connected by hinge shafts to form the shadow puppet assembly; the bottom of a column is installed on the base, and the upper part of the column is connected to the upper body piece through a column connection assembly;
[0007] A head drive assembly is installed at the top of the column, and the head drive assembly drives the head piece to swing. An arm drive assembly and a leg drive assembly are installed on the base. The arm drive assembly drives the small arm piece to operate, and the leg drive assembly drives the leg piece to move.
[0008] Preferably, the column connection assembly includes a compression sleeve and a fixing frame. The compression sleeve is sleeved on the column and locked by bolts. A positioning pin is welded on the fixing frame. The positioning pin is connected to the compression sleeve, and the fixing frame is connected to the upper body piece.
[0009] Preferably, the head drive assembly includes a servo motor installed at the top of the column. The output shaft of the servo motor is connected to the first rotating shaft through a metal flange. A head piece, a retaining sleeve, and a first bearing are sequentially installed on the first rotating shaft. A pressure plate and the end of the first rotating shaft are connected by screws. The outer ring of the first bearing is installed in the bearing hole of the upper body part. A fixing plate, the upper body part, and a gland are connected by bolts.
[0010] Preferably, the arm drive assembly includes a stepper reduction motor installed on the base. One end of a motor spacer and a swing rod is installed on the output shaft of the stepper reduction motor. The output shaft of the stepper reduction motor and the swing rod are locked by a plug plate and bolts. The other end of the swing rod is rotatably connected to the small arm part through an arm connection assembly.
[0011] Preferably, the small arm part connection assembly includes a spherical plain bearing. The outer ring, a hole retaining ring, and a shaft retaining ring of the spherical plain bearing are installed in the bearing installation hole of the swing rod. One end of a second rotating shaft is installed in the inner ring of the spherical plain bearing, and the other end is installed in the inner ring of a second bearing. The outer ring of the second bearing is installed in the bearing installation hole of the small arm part. The end of the second rotating shaft and the second bearing are locked by screws. A fixing plate, the small arm part, and a gland are connected by bolts.
[0012] Preferably, a motor connection seat is installed on the base, and the stepper reduction motor is installed on the motor connection seat.
[0013] Preferably, the leg drive assembly includes a stepper reduction motor installed on the base. One end of a motor spacer and a driving link are installed on the output shaft of the stepper reduction motor. The output shaft of the stepper reduction motor and the driving link are locked by a plug plate and bolts. The other end of the driving link is connected to one end of a connecting rod through a driving connection assembly. The other end of the connecting rod is connected to the leg part through a leg part connection assembly.
[0014] Preferably, the driving connection assembly includes a spherical plain bearing. The outer ring, a hole retaining ring, and a shaft retaining ring of the spherical plain bearing are installed in the bearing installation hole of the connecting rod. One end of a third rotating shaft is installed in the inner ring of the spherical plain bearing, and the other end is installed in the inner ring of a third bearing. The outer ring of the third bearing is installed in the bearing installation hole of the driving link. The end of the third rotating shaft and the third bearing are locked by a short spacer sleeve and screws.
[0015] Preferably, the leg connecting component includes a spherical plain bearing. The outer ring, the hole retaining ring and the shaft retaining ring of the spherical plain bearing are installed in the bearing installation hole of the connecting rod. One end of the second rotating shaft is installed in the inner ring of the spherical plain bearing, and the other end is installed in the inner ring of the second bearing. The outer ring of the second bearing is installed in the bearing installation hole of the leg. The end of the second rotating shaft and the second bearing are locked by screws. The fixing plate, the leg and the gland are connected by bolts.
[0016] Preferably, the large arm member, the short-distance sleeve, the upper body member, the short-distance sleeve and the large arm member are sequentially sleeved on the articulated long shaft, and both ends of the articulated long shaft are locked by a cover plate and screws to lock the articulated long shaft and the large arm member.
[0017] The above technical solution has at least the following beneficial effects compared with the prior art:
[0018] In the above solution, the device combines a mechanical structure with shadow puppetry, breaks through the limitations of performance time and space in a new production method and performance form, restores the form of shadow puppetry performances, enhances the interest of exhibition exhibits, and enables the audience to feel the brilliant sparks generated by the collision between shadow puppetry and contemporary science and technology; the device uses a stepper reduction motor and a connecting rod mechanism to realize the actions of swinging the arm and lifting the leg. The connecting rod mechanism is more in line with the joystick used in real shadow puppetry performances. The head member is controlled by a servo motor, which can realize the nodding action and can realize automatic demonstration, presenting the dynamic shadow puppetry actions and the trajectories and characteristics of the movements of each component of the shadow puppetry to the audience; it saves the input cost of performers and is more convenient and fast for shadow puppetry performances and dissemination; it changes the performance limitations of traditional shadow puppetry and expands the dissemination scope of shadow puppetry; bearings are used at all joint parts, which can rotate flexibly; the pulses output by the programmable logic controller can accurately control the swing amplitude; the stepper reduction motor itself has a reducer, which increases the torque and can stop at any point without displacement. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0020] Figure 1 is the front view of the device for automatically performing shadow puppetry through a mechanical structure of the present invention;
[0021] Figure 2 is the left view of the device for automatically performing shadow puppetry through a mechanical structure of the present invention;
[0022] Figure 3 is Figure 2 the enlarged view of part I;
[0023] Figure 4 is Figure 2 the enlarged view at II of
[0024] Figure 5 is Figure 2 the enlarged view at III of
[0025] Figure 6 is Figure 2 the enlarged view at IV of
[0026] Figure 7 is Figure 3 the enlarged view at VI of
[0027] Figure 8 is Figure 3 the enlarged view at VII of
[0028] Figure 9 is the control diagram of the device for automatically performing shadow puppetry through a mechanical structure of the present utility model.
[0029] The reference numerals are explained as follows:
[0030] 1. Base; 2. Stepping reduction motor; 3. Motor connection seat; 4. Swing rod; 5. Active connecting rod; 6. Right connecting rod; 7. Left connecting rod; 8. Shadow puppet assembly; 81. Head piece; 82. Large arm piece; 83. Small arm piece; 84. Upper body piece; 85. Lower body piece; 86. Leg piece; 9. Servo motor; 10. Metal flange; 11. Rotating shaft I; 12. Bearing I; 13. gland; 14. Fixed plate; 15. Retaining sleeve; 16. Pressure plate; 18. Hinged long shaft; 19. Cover plate; 20. Short distance sleeve; 21. Fixed frame; 22. Compression sleeve; 24. Positioning pin; 25. Rotating shaft II; 26. Hole retaining ring; 27. Shaft retaining ring; 28. Spherical plain bearing; 29. Bearing II; 30. Short cushion sleeve; 31. Hinged shaft; 33. Motor spacer; 34. Plug plate; 35. Bearing cover plate; 36. Rotating shaft III; 37. Bearing III; 39. Vertical rod; Specific embodiments
[0031] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0032] Unless otherwise defined, the technical terms or scientific terms used in this utility model shall have the ordinary meanings understood by those of ordinary skill in the field to which this utility model belongs. The "first", "second" and similar terms used in this utility model do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, similar terms such as "a", "an" or "the" do not denote a quantity limitation, but mean that there is at least one. Terms such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.
[0033] It should be noted that the "upper", "lower", "left", "right", "front", "rear", etc. used in this utility model are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0034] As Figure 1 and Figure 2 shown in the figure, this embodiment provides a device for automatically performing shadow puppetry through a mechanical structure, including a shadow puppet assembly 8. The shadow puppet assembly 8 is a large shadow puppet with a height of 2 meters. Through a classic link mechanism, the large shadow puppet assembly 8 can be automatically demonstrated and can be used as part of a theme wall and a door head to attract viewers to visit the exhibition. The shadow puppet assembly 8 includes a head piece 81, a large arm piece 82, a small arm piece 83, an upper body piece 84, a lower body piece 85 and a leg piece 86. As Figure 4 and Figure 5 shown in the figure, the lower part of the head piece 81 and the upper part of the upper body piece 84 are connected by a hinge shaft 31. The upper part of the upper body piece 84 and one end of the two large arm pieces 82 are connected by a hinge shaft 31. The other end of the large arm piece 82 and one end of the small arm piece 83 are connected by a hinge shaft 31. The lower part of the upper body piece 84 and the upper part of the lower body piece 85 are connected by a hinge shaft 31. The lower body piece 85 and the two leg pieces 86 are connected by a hinge shaft 31. Specifically, as Figure 3 shown in the figure, the large arm piece 82, the short-distance sleeve 20, the upper body piece 84, the short-distance sleeve 20 and the large arm piece 82 are sequentially sleeved on the hinge long shaft 18. Both ends of the hinge long shaft 18 are locked to the large arm piece 82 by a cover plate 19 and screws. Specifically, the head piece 81, the large arm piece 82, the small arm piece 83, the upper body piece 84, the lower body piece 85 and the leg piece 86 adopt a UV printing production process, and the pattern of the shadow puppet character image is sprayed on an acrylic board, overcoming the problem of easy curling and deformation of traditional leather.
[0035] As Figure 2 and Figure 3As shown, the device further includes a base 1 and a column 39. The bottom of the column 39 is mounted on the base 1, and the upper part of the column 39 is connected to the upper body member 84 through a column 39 connection assembly. The column 39 serves as the main support to position the shadow puppet assembly 8. Specifically, the column 39 connection assembly includes a compression sleeve 22 and a fixing bracket 21. The compression sleeve 22 is sleeved on the column 39 and locked by bolts. A positioning pin 24 is welded on the fixing bracket 21. The positioning pin 24 is connected to the compression sleeve 22, and the fixing bracket 21 is connected to the upper body member 84.
[0036] As Figure 3 and Figure 7 shown, a head drive assembly is mounted on the top of the column 39, and the head drive assembly drives the head member 81 to swing. Specifically, the head drive assembly includes a servo motor 9 mounted on the top of the column 39. The output shaft of the servo motor 9 is connected to the first rotating shaft 11 through a metal flange 10. A head member 81, a retaining sleeve 15, and a first bearing 12 are sequentially mounted on the first rotating shaft 11. The pressing plate 16 and the end of the first rotating shaft 11 are connected by screws. The outer ring of the first bearing 12 is mounted in the bearing hole of the upper body member 84. The fixing plate 14, the upper body member 84, and the gland 13 are connected by bolts. When the servo motor 9 is started, the output shaft of the servo motor 9 drives the first rotating shaft 11 to rotate through the metal flange 10. The rotation of the first rotating shaft 11 drives the head member 81 to rotate. By controlling the forward and reverse rotation of the servo motor 9, the true reverse rotation of the head member 81 is achieved, and the effect of the head member 81 nodding is achieved.
[0037] As Figure 3 and Figure 8 shown, an arm drive assembly and a leg drive assembly are mounted on the base 1, and the arm drive assembly drives the small arm member 83 to operate. The arm drive assembly includes a stepper reduction motor 2. The stepper reduction motor 2 is mounted on the base 1. Specifically, a motor connection seat 3 is mounted on the base 1, and the stepper reduction motor 2 is mounted on the motor connection seat 3. One end of a motor spacer 33 and a swing rod 53 is mounted on the output shaft of the stepper reduction motor 2. The output shaft of the stepper reduction motor 2 and the swing rod 53 are locked by a plug plate 34 and bolts. The other end of the swing rod 53 is rotatably connected to the small arm member 83 through an arm connection assembly. Specifically, the small arm member 83 connection assembly includes a spherical plain bearing 28. The outer ring of the spherical plain bearing 28, a hole retaining ring 26, and a shaft retaining ring 27 are mounted in the bearing mounting hole of the swing rod 53. One end of a second rotating shaft 25 is mounted in the inner ring of the spherical plain bearing 28, and the other end is mounted in the inner ring of a second bearing 29. The outer ring of the second bearing 29 is mounted in the bearing mounting hole of the small arm member 83. The end of the second rotating shaft 25 and the second bearing 29 are locked by screws. The fixing plate 14, the small arm member 83, and the gland 13 are connected by bolts. The large arm member 82, the small arm member 83, the swing rod 53, and the base 1 and the column 39 form a linkage mechanism. When the stepper reduction motor 2 is started, the output shaft of the stepper reduction motor 2 rotates to drive the swing rod 53 to rotate. While the swing rod 53 rotates, it drives the small arm member 83 to move, achieving the effect of the movement of the small arm member 83.
[0038] As shown Figure 2 and Figure 6 in the figure, a leg driving assembly is installed on the base 1, and the leg driving assembly drives the leg member 86 to move. The leg driving assembly includes a stepper reduction motor 2, which is installed on the base 1. One end of the motor spacer 33 and the active connecting rod is installed on the output shaft of the stepper reduction motor 2. The output shaft of the stepper reduction motor 2 and the active connecting rod are locked by a plug plate 34 and bolts. The other end of the active connecting rod is connected to one end of the connecting rod through an active connecting component, and the other end of the connecting rod is connected to the leg member 86 through a leg member 86 connecting component. Specifically, the active connecting component includes a spherical plain bearing 28. The outer ring, the hole retaining ring 26 and the shaft retaining ring 27 of the spherical plain bearing 28 are installed in the bearing mounting hole of the connecting rod. One end of the rotating shaft three 36 is installed in the inner ring of the spherical plain bearing 28, and the other end is installed in the inner ring of the bearing three 37. The outer ring of the bearing three 37 is installed in the bearing mounting hole of the active connecting rod. The end of the rotating shaft three 36 and the bearing three 37 are locked by a short bushing 30 and screws. The bearing cover plate 35 abuts against the bearing three 37 and is locked by bolts. Specifically, the leg member 86 connecting component includes a spherical plain bearing 28. The outer ring, the hole retaining ring 26 and the shaft retaining ring 27 of the spherical plain bearing 28 are installed in the bearing mounting hole of the connecting rod. One end of the rotating shaft two 25 is installed in the inner ring of the spherical plain bearing 28, and the other end is installed in the inner ring of the bearing two 29. The outer ring of the bearing two 29 is installed in the bearing mounting hole of the leg member 86. The end of the rotating shaft two 25 and the bearing two 29 are locked by screws. The fixing plate 14, the leg member 86 and the gland 13 are connected by bolts. The active connecting rod, the connecting rod, the leg member 86 and the base 1 form a linkage mechanism. When the stepper reduction motor 2 is started, the output shaft of the stepper reduction motor 2 rotates to drive the active connecting rod to rotate. The rotation of the active connecting rod drives the connecting rod to move, and the movement of the connecting rod drives the leg member 86 to move, achieving the movement effect of the leg member 86. Specifically, there are 2 legs designed, and two sets of leg driving assemblies for driving the leg member 86 are provided. The connecting rods are respectively provided with a left connecting rod 2 and a right connecting rod 6 corresponding to the left and right leg members 86.
[0039] As shown Figure 9 in the figure, the device of this embodiment is controlled by a programmable logic controller. The programmable logic controller outputs PWM pulses to control 4 stepper reduction motors 2 and 1 servo motor 9 respectively, and drives the movement of 2 active connecting rods, 2 swing rods 53, 2 leg members 86 controlled by the head member 81, 2 small arm members 83 and 1 head member 81 respectively, demonstrating the movement actions of the shadow puppet, and increasing the spread of this traditional culture of shadow puppetry. At the same time, this display method is convenient for manufacturing and display and has a wide range of application scenarios.
[0040] The device of the present utility model utilizes a stepper reduction motor 2 and a linkage mechanism to achieve the actions of the swing arm and leg lifting. The linkage mechanism is more in line with the joystick used in the actual performance of shadow puppetry. The head piece 81 is controlled by a servo motor 9 to achieve the nodding action, and can realize automatic demonstration, presenting the dynamic shadow puppet actions and the movement trajectories and characteristics of each component of the shadow puppet to the audience; bearings are used at the joint parts, which can rotate flexibly; the pulses output by the programmable logic controller can accurately control the swing amplitude; the stepper reduction motor 2 itself is equipped with a reducer to increase the torque, can stop at any point without displacement; this device combines the mechanical structure with shadow puppetry, breaks through the limitations of the performance time and space in a new production method and performance form, restores the form of shadow puppet performances, enhances the interest of exhibition exhibits, and enables the audience to feel the brilliant sparks colliding between shadow puppetry and contemporary science and technology; it saves the input cost of performers and is more convenient and fast for shadow puppet performances and dissemination; it changes the performance limitations of traditional shadow puppetry and expands the dissemination scope of shadow puppetry.
[0041] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. The protection scope of the present utility model shall be subject to the protection scope of the claims.
Claims
1. An apparatus for automatically performing shadow puppetry through a mechanical structure, characterized in that, It includes a shadow puppetry component and a base. The head piece, the large arm piece, the small arm piece, the upper body piece, the lower body piece and the leg piece are connected by a hinge shaft to form the shadow puppetry component; the bottom of the vertical column is installed on the base, and the upper part of the vertical column is connected to the upper body piece through a vertical column connection component; A head drive component is installed at the top of the vertical column, and the head drive component drives the head piece to swing. An arm drive component and a leg drive component are installed on the base. The arm drive component drives the small arm piece to operate, and the leg drive component drives the leg piece to move.
2. The device for automatically performing shadow puppetry through a mechanical structure according to claim 1, wherein The vertical column connection component includes a compression sleeve and a fixing frame. The compression sleeve is sleeved on the vertical column and locked by bolts. A positioning pin is welded on the fixing frame. The positioning pin is connected to the compression sleeve, and the fixing frame is connected to the upper body piece.
3. The device for automatically performing shadow puppetry through a mechanical structure according to claim 1, wherein The head drive component includes a servo motor installed at the top of the vertical column. The output shaft of the servo motor is connected to the first rotating shaft through a metal flange. The head piece, a retaining sleeve and a first bearing are sequentially installed on the first rotating shaft. A pressing plate and the end of the first rotating shaft are connected by screws. The outer ring of the first bearing is installed in the bearing hole of the upper body piece. The fixing plate, the upper body piece and the gland are connected by bolts.
4. The device for automatically performing shadow puppetry through a mechanical structure according to claim 1, characterized in that, The arm drive component includes a stepper reduction motor installed on the base. One end of a motor spacer sleeve and a swing rod is installed on the output shaft of the stepper reduction motor. The output shaft of the stepper reduction motor and the swing rod are locked by a plug plate and bolts. The other end of the swing rod is rotatably connected to the small arm piece through an arm connection component.
5. The device for automatically performing shadow puppetry through a mechanical structure according to claim 4, wherein The small arm piece connection component includes a spherical plain bearing. The outer ring, a hole retaining ring and a shaft retaining ring of the spherical plain bearing are installed in the bearing installation hole of the swing rod. One end of a second rotating shaft is installed in the inner ring of the spherical plain bearing, and the other end is installed in the inner ring of a second bearing. The outer ring of the second bearing is installed in the bearing installation hole of the small arm piece. The end of the second rotating shaft and the second bearing are locked by screws. The fixing plate, the small arm piece and the gland are connected by bolts.
6. The device for automatically performing shadow puppetry through a mechanical structure according to claim 4, wherein A motor connection seat is installed on the base, and the stepper reduction motor is installed on the motor connection seat.
7. The device for automatically performing shadow puppetry through a mechanical structure according to claim 1, characterized in that, The leg drive component includes a stepper reduction motor installed on the base. One end of a motor spacer sleeve and a driving connecting rod is installed on the output shaft of the stepper reduction motor. The output shaft of the stepper reduction motor and the driving connecting rod are locked by a plug plate and bolts. The other end of the driving connecting rod is connected to one end of a connecting rod through a driving connection component. The other end of the connecting rod is connected to the leg piece through a leg piece connection component.
8. The device for automatically performing shadow puppetry through a mechanical structure according to claim 7, characterized in that, The driving connection component includes a spherical plain bearing. The outer ring, a hole retaining ring and a shaft retaining ring of the spherical plain bearing are installed in the bearing installation hole of the connecting rod. One end of a third rotating shaft is installed in the inner ring of the spherical plain bearing, and the other end is installed in the inner ring of a third bearing. The outer ring of the third bearing is installed in the bearing installation hole of the driving connecting rod. The end of the third rotating shaft and the third bearing are locked by a short spacer sleeve and screws.
9. The device for automatically performing shadow puppetry through a mechanical structure according to claim 7, characterized in that, The leg connection assembly includes a spherical plain bearing. The outer ring of the spherical plain bearing, the hole retaining ring and the shaft retaining ring are installed in the bearing mounting hole of the connecting rod. One end of the second rotating shaft is installed in the inner ring of the spherical plain bearing, and the other end is installed in the inner ring of the second bearing. The outer ring of the second bearing is installed in the bearing mounting hole of the leg. The end of the second rotating shaft and the second bearing are locked by screws. The fixing plate, the leg and the gland are connected by bolts.
10. The device for automatically performing shadow puppetry through a mechanical structure according to claim 1, characterized in that, The large arm member, the short-distance sleeve, the upper body member, the short-distance sleeve and the large arm member are sequentially sleeved on the articulated long shaft. Both ends of the articulated long shaft are locked by a cover plate and screws to lock the articulated long shaft and the large arm member.