Anti-training platform for simulating ship motion

Abstract

The invention belongs to the technical field of ship movement, and particularly relates to an anti-training platform for simulating ship movement, which comprises a mounting platform, a spherical training cavity fixedly mounted at the upper end of the mounting platform, a binding mechanism mounted in the spherical training cavity, a placement table mounted at the upper end of a lifting mechanism and hermetically connected with a through groove, and a floating ball mounted in the spherical training cavity. The lower end of the floating ball is hermetically connected with a standing table, the standing table is heavier than the floating ball, a locking mechanism connected with the floating ball is mounted at the upper end of the standing table, a buoyancy ring plate is fixedly mounted on the outer side of the floating ball, and a mounting ring is fixedly mounted in the floating ball; according to the invention, the spherical training cavity can be filled with a solution to cooperate with the sea wind simulation mechanism and the sea wave simulation mechanism to simulate the sea surface condition, so that the floating ball floats on the water surface to simulate the state of a ship, and the anti-dizziness ability of navigation personnel is trained by simulating the sea surface motion condition; therefore, the floating ball is enabled to move more truly, and more effective dizziness training is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of ship motion, and in particular relates to a defense training platform for simulating ship motion. Background Art

[0002] Motion sickness (MS), also known as motion sickness, car sickness, seasickness, airsickness, cosmic motion sickness, etc., is a series of physiological reactions caused by multiple factors that lead to the human body's incorrect perception of the state of motion. It is a syndrome dominated by vestibular and autonomic nervous system reactions such as dizziness, upper abdominal discomfort, nausea, vomiting, pale complexion, cold sweats, drowsiness, salivation, and headaches caused by the body being in a moving environment and being stimulated by inappropriate motion. The common types of motion sickness are seasickness, airsickness, and motion sickness. The incidence of seasickness is high and the symptoms are severe.

[0003] There are many seafarers who suffer from motion sickness. However, in order to work at sea, they usually experience and train the movement of the ship in a simulation cabin to avoid dizziness of the seafarers and their inability to operate the ship when the ship rotates or bumps. At the same time, the seafarers can also be trained to avoid seasickness when actually going out to sea. Therefore, an anti-dizziness training platform that simulates the movement of the ship is involved. Summary of the invention

[0004] The purpose of the present invention is to provide a defense training platform for simulating ship motion, so as to solve the problems existing in the background technology.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows: A defense training platform simulating the movement of a ship comprises a mounting platform, a spherical training cavity is fixedly mounted on the upper end of the mounting platform, a sea wave simulation mechanism and a sea breeze simulation mechanism are mounted inside the spherical training cavity, a through groove is penetrated through the upper and lower parts of the spherical training cavity, a lifting mechanism is mounted on the upper end of the mounting platform, a binding mechanism is mounted inside the spherical training cavity, the lower side of the spherical training cavity is connected with an external water source through a water pipe, a placing table sealed with the through groove is mounted on the upper end of the lifting mechanism, a floating ball is mounted inside the spherical training cavity, a standing platform is sealed with the lower end of the floating ball, the mass of the standing platform is greater than the mass of the floating ball, the size of the standing platform is smaller than the size of the placing platform, a locking mechanism connected with the floating ball is mounted on the upper end of the standing platform, a buoyancy ring plate is fixedly mounted on the outer side of the floating ball, a mounting ring is fixedly mounted inside the floating ball, a plurality of cameras are mounted inside the mounting ring, a ventilation mechanism is mounted on the top of the floating ball, and the binding mechanism is mounted on the upper end of the standing platform; The ventilation mechanism includes a slidingly connected arc plate, and a plurality of meshing teeth are installed on both sides of the arc plate. The upper end of the spherical training cavity is symmetrically rotatably connected to two gears meshing with the plurality of meshing teeth. The gears are evenly provided with a plurality of ventilation holes. The spherical training cavity is provided with through holes adjacent to the ventilation holes, and a force plate is fixedly installed on the upper end of the floating ball.

[0006] The locking mechanism includes a plurality of support rods fixedly connected to the upper end of the standing platform, and an arc rod is commonly installed on the upper ends of the support rods. The binding mechanism is installed between the support rods and the arc rods, and three of the support rods are rotatably installed with locking rods. Three locking platforms matching the locking rods are evenly installed inside the spherical training cavity, and a locking assembly is installed between the locking rod and the locking platform.

[0007] The locking assembly includes a sliding plate, a sliding groove is provided inside the locking rod and is slidably connected to the sliding plate, a T-shaped block is fixedly installed on the side of the sliding plate close to the support rod, a first spring is installed between the T-shaped block and the sliding groove, a triangular push block is installed on the other side of the sliding plate, the locking rod is elastically rotatably connected to the limit rod, the locking rod and the locking platform are both provided with an arc groove matching the limit rod, and the sliding plate and the locking rod are provided with a threaded groove on the side close to the arc rod, and the threaded groove is threadedly connected to the threaded rod.

[0008] The sliding plate is fixedly connected with an extended abutment plate, and a gripping rod is fixedly installed between the locking platform and the mounting ring.

[0009] An annular water storage tank is provided at the lower side of the floating ball, and a connecting rod is sealingly and slidably connected to the annular water storage tank, a counterweight is fixedly installed at the lower end of the connecting rod, and the connecting rod is fixedly installed with the arc plate.

[0010] The floating ball is provided with a circular arc groove connected to the annular water storage tank, the circular arc groove is sealingly and slidably connected with a piston fixedly installed on the connecting rod, the floating ball and the mounting ring are jointly provided with a one-way inflow channel connected to the circular arc groove, the circular arc groove is installed with a one-way valve connected to the annular water storage tank, and the mounting ring is installed with a nozzle connected to the one-way inflow channel.

[0011] A one-way drainage channel connected to the annular water storage tank is provided in the middle of the circular arc groove.

[0012] A sealing pad fixedly mounted on the lower end of the standing platform and fixedly mounted on the floating ball, a positioning pin fixedly mounted on the lower end of the sealing pad, and a limiting hole matching the positioning pin is opened on the upper end of the placing platform.

[0013] The present invention can fill the spherical training cavity with a solution and cooperate with a sea breeze simulation mechanism and a sea wave simulation mechanism to simulate the conditions of the sea surface, thereby making the floating ball float on the water surface to simulate the state of a ship. By simulating the movement of the sea surface, the anti-vertigo ability of the sailors can be trained, and the movement of the floating ball can be made more realistic, thereby achieving more effective vertigo training. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is further illustrated by means of the non-limiting examples given in the accompanying drawings.

[0015] Figure 1 This is a structural schematic diagram of a defense training platform for simulating ship motion according to the present invention; Figure 2 This is a schematic diagram of the first cross-sectional structure of a defense training platform for simulating ship motion according to the present invention; Figure 3 This is a schematic diagram of the second cross-sectional structure of a defense training platform for simulating ship motion according to the present invention; Figure 4 for Figure 3 A schematic diagram of the enlarged structure at A in the middle; Figure 5 This is a schematic diagram of the third cross-sectional structure of a defense training platform for simulating ship motion according to the present invention; Figure 6 for Figure 5 A schematic diagram of the enlarged structure at B in the middle; Figure 7 This is a schematic diagram of the fourth cross-sectional structure of a defense training platform for simulating ship motion according to the present invention; Figure 8 for Figure 7 Schematic diagram of the enlarged structure at point C in the middle.

[0016] The main component symbols are described as follows: Installation platform 1, spherical training cavity 11, wave simulation mechanism 12, sea breeze simulation mechanism 13, through groove 14, lifting mechanism 15, placement platform 16, floating ball 17, standing platform 18, buoyancy ring plate 19, installation ring 20, camera 21, arc plate 22, meshing teeth 23, gear 24, vent 25, water pipe 26, force plate 27, support rod 30, arc rod 31, locking rod 32, locking platform 33, Sliding plate 34, sliding groove 35, T-shaped block 36, first spring 37, triangular push block 38, limiting rod 39, arc groove 40, threaded groove 41, threaded rod 42, extended abutment plate 43, grip rod 44, annular water storage tank 50, connecting rod 51, counterweight block 52, circular arc groove 53, piston 54, one-way inflow channel 55, one-way valve 56, nozzle 57, one-way drainage channel 58, sealing gasket 59, positioning pin 60. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Example 1: Figure 1-8 As shown, a defense training platform for simulating ship movement of the present invention comprises a mounting platform 1, a spherical training cavity 11 is fixedly mounted on the upper end of the mounting platform 1, a wave simulation mechanism 12 and a sea breeze simulation mechanism 13 are mounted inside the spherical training cavity 11, a through groove 14 is opened through the upper and lower parts of the spherical training cavity 11, a lifting mechanism 15 is mounted on the upper end of the mounting platform 1, a binding mechanism is mounted inside the spherical training cavity 11, the lower side of the spherical training cavity 11 is connected to an external water source through a water pipe 26, and a placing table 16 sealed and connected to the through groove 14 is mounted on the upper end of the lifting mechanism 15. A floating ball 17 is installed inside the spherical training chamber 11, and a standing platform 18 is sealed and connected to the lower end of the floating ball 17. The mass of the standing platform 18 is greater than the mass of the floating ball 17, and the size of the standing platform 18 is smaller than the size of the placement platform 16. A locking mechanism connected to the floating ball 17 is installed on the upper end of the standing platform 18, a buoyancy ring plate 19 is fixedly installed on the outer side of the floating ball 17, a mounting ring 20 is fixedly installed inside the floating ball 17, and a plurality of cameras 21 are installed inside the mounting ring 20, a ventilation mechanism is installed on the top of the floating ball 17, and a binding mechanism is installed on the upper end of the standing platform 18; The ventilation mechanism includes a slidingly connected arc plate 22, and a plurality of meshing teeth 23 are installed on both sides of the arc plate 22. The upper end of the spherical training cavity 11 is symmetrically rotatably connected to two gears 24 meshing with the plurality of meshing teeth 23. The gears 24 are evenly provided with a plurality of ventilation holes 25. The spherical training cavity 11 is provided with through holes adjacent to the ventilation holes 25. A force plate 27 is fixedly installed on the upper end of the floating ball 17.

[0019] A battery can be installed inside the spherical training chamber 11 to power the electrical components inside it, and a water pump installed in the water pipe 16 can input external water into the sealed spherical training chamber 11 so that the floating ball 17 floats upward and leaves the placement table 16 under the buoyancy of the buoyancy ring plate 19, and the wave simulation mechanism 12 and the sea breeze simulation mechanism 13 are installed inside the spherical training chamber 11 using devices of the prior art, so that when the wave simulation mechanism 12 is started, it pushes the water inside the spherical training chamber 11, so that the water moves and then drives the floating ball 17 to move, and the sea breeze simulation mechanism 13 can blow air into the spherical training chamber 11, so that the force of the wind drives the force plate 27 to move, and then the floating ball 17 moves under the action of the force plate 27, so that the floating ball 17 can simulate the movement on the water surface inside the spherical training chamber 11, and then the anti-dizziness training is provided for the personnel training inside the floating ball 17; In the initial state, the placing platform 16 is located at the upper end of the installation platform 1 when the lifting mechanism 15 is not raised. At this time, the standing platform 18 is located at the upper end of the placing platform 16, so that the trainee can stand on the upper end of the standing platform 18. After the trainee stands up, the binding mechanism is used to securely fix the trainee, and then the lifting mechanism 15 is started to drive the placing platform 16 and the standing platform 18 to move upward, so that the placing platform 16 and the spherical training cavity 11 are abutted to complete the sealing. At this time, the trainee locks the standing platform 18 and the floating ball 17 through the locking mechanism, so that the standing platform 18 is sealed and connected with the floating ball 17. At this time, the water pipe 26 is used to push the water pipe 26 to the standing platform 18. The spherical training chamber 11 is supplied with water so that the floating ball 17 moves upward and floats on the water surface under the action of the buoyancy ring plate 19. At the same time, since a heavy standing platform 18 is installed at the lower end of the floating ball 17, the entire floating ball 17 is in the form of a "tumbler". When the floating ball 17 is overturned by a force from one side, the floating ball 17 will move in the opposite direction when the force disappears. After the floating ball 17 floats, the wave simulation mechanism 12 and the sea breeze simulation mechanism 13 can generate waves on the water and push the floating ball 17, thereby causing the floating ball 17 to shake inside the spherical training chamber 11 to perform dizziness training on the people inside. In the initial state, the arc plate 22 is located on one side and always keeps meshing with the gear 24. When the floating ball 17 tilts in the opposite direction to the arc plate 22, it will drive the arc plate 22 to slide to the other side, thereby driving the gear 24 and the vent 25 to rotate. During the rotation of the vent 25, the wind from the sea breeze simulation mechanism 13 will enter the floating ball 17 through the vent 25 to blow air on the trainees, and at the same time play a ventilation role to avoid the floating ball 17 being in a closed state for a long time, affecting the state of the trainees. In addition, the camera 21 installed on the inner side of the mounting ring 20 can perform all-round monitoring of the trainees during training to avoid situations where the trainees cannot control themselves, thereby improving the safety of training. At the same time, observing the trainees at all times can also synchronize the training state of the trainees.

[0020] After the training is completed, the solution inside the spherical training chamber 11 is discharged, and the floating ball 17 is in a vertical state under the action of the standing platform 18. Then, under the action of the arc of the inner cavity of the spherical training chamber 11, the floating ball 17 is in a tumbler state, so that the standing platform 18 gradually approaches the placing platform 16 during the water discharge process, until the standing platform 18 abuts against the placing platform 16. At this time, the contact locking mechanism can drive the placing platform 16 and the standing platform 18 to move downward through the lifting mechanism 15, thereby causing the trainee standing on the upper end of the standing platform 18 to move downward.

[0021] The present invention can fill the spherical training cavity with a solution and cooperate with a sea breeze simulation mechanism and a sea wave simulation mechanism to simulate the conditions of the sea surface, thereby making the floating ball float on the water surface to simulate the state of a ship. By simulating the movement of the sea surface, the anti-vertigo ability of the sailors can be trained, and the movement of the floating ball can be made more realistic, thereby achieving more effective vertigo training.

[0022] Embodiment 2: Further improvement is made on the basis of Embodiment 1, the locking mechanism includes a plurality of support rods 30 fixedly connected to the upper end of the standing platform 18, and an arc rod 31 is commonly installed on the upper ends of the plurality of support rods 30, and the binding mechanism is installed between the support rods 30 and the arc rods 31, wherein three support rods 30 are rotatably installed with locking rods 32, and three locking platforms 33 matching the locking rods 32 are evenly installed inside the spherical training cavity 11, and a locking assembly is installed between the locking rods 32 and the locking platforms 33.

[0023] In the initial state, the locking rod 32 is located inside the support rod 30 so that it will not affect the movement of the standing platform 18. During operation, the trainee stands inside the support rod 30, and then the trainee is fixed by the binding mechanism, and then the standing platform 18 is inserted into the lower end of the floating ball 17 through the lifting mechanism 15. At this time, the locking rod 32 is rotated to insert it into the locking platform 33 from bottom to top, and then the locking rod 32 and the locking platform 33 are connected through the locking assembly, and the three locking rods 32 are evenly arranged, so that the angles between the two adjacent locking rods 32 are the same. In this way, the locking rod 32 can improve the stability of the floating ball 17, avoid hard collision between the floating ball 17 and the spherical training cavity 11, and affect the structure of the floating ball 17.

[0024] The locking assembly includes a sliding plate 34, a sliding groove 35 slidably connected to the sliding plate 34 is provided inside the locking rod 32, a T-shaped block 36 is fixedly installed on the side of the sliding plate 34 close to the support rod 30, a first spring 37 is installed between the T-shaped block 36 and the sliding groove 35, a triangular push block 38 is installed on the other side of the sliding plate 34, the locking rod 32 is elastically rotatably connected to the limiting rod 39, the locking rod 32 and the locking platform 33 are both provided with an arc groove 40 matching the limiting rod 39, and the sliding plate 34 and the locking rod 32 are provided with a threaded groove 41 on the side close to the arc rod 31, and the threaded groove 41 is threadedly connected to the threaded rod 42.

[0025] In the initial state, the threaded rod 42 is threadedly connected to the threaded groove 41 close to the support rod 30. At this time, the limit rod 39 is located inside the slide groove 35 under the action of the rebound force. At this time, the triangular push block 38 is away from the limit rod 39, and then the locking rod 32 is rotated to extend into the locking platform 33, and then the threaded rod 42 is rotated to drive it to rotate out of the threaded groove 41, and then the sliding plate 34 and the T-shaped block 36 are driven to overcome the rebound force of the first spring 37 to slide, so that the triangular push block 38 is abutted against the arc surface of the two limit rods 39, and then under the action of the triangular push block 38, the two limit rods 39 are flipped outward and inserted into the arc groove 40, and then the threaded rod 42 is threadedly connected to the threaded groove 41 away from the support rod 30.

[0026] The sliding plate 34 is fixedly connected with an extended abutment plate 43, and a gripping rod 44 is fixedly installed between the locking platform 33 and the mounting ring 20. The extended abutment plate 43 limits the limit rod 39 without affecting the rotation of the limit rod 39. The gripping rod 44 can be held by the trainee during training to improve the trainee's stability. At the same time, when installing the locking assembly, the floating ball 17 can be driven to rotate by holding the gripping rod 44, thereby aligning the locking rod 32 and the locking platform 33.

[0027] An annular water storage tank 50 is provided at the lower side of the floating ball 17 , and a connecting rod 51 is sealingly and slidably connected to the annular water storage tank 50 . A counterweight block 52 is fixedly installed at the lower end of the connecting rod 52 , and the connecting rod 51 is fixedly installed to the arc plate 22 .

[0028] A water inlet valve connected to the annular water storage tank 50 is installed inside the floating ball 17, so that water can be filled into the annular water storage tank 50. In this way, when the counterweight block 52 is shaking, the floating ball 17 comes into contact with the water, which plays a buffering role for the moving counterweight block 52.

[0029] The floating ball 17 is provided with a circular arc groove 53 connected to the annular water storage tank 50. The circular arc groove 53 is sealingly and slidably connected to a piston 54 fixedly installed on the connecting rod 51. The floating ball 17 and the mounting ring 20 are jointly provided with a one-way inflow channel 55 connected to the circular arc groove 53. The circular arc groove 53 is equipped with a one-way valve 56 connected to the annular water storage tank 50. The mounting ring 20 is equipped with a nozzle 57 connected to the one-way inflow channel 55.

[0030] When the floating ball 17 shakes and tilts, the water inside the annular water storage tank 50 will enter the circular arc groove 53 from the one-way valve 56, and the counterweight block 52 will move toward the circular arc groove 53. Then, in the process of the floating ball 17 returning to its original position, the counterweight block 52 moves downward under the action of gravity, driving the piston 54 to compress the circular arc groove 53. Since the one-way valve 56 can only flow from the annular water storage tank 50 to the circular arc groove 53, the solution entering the circular arc groove 53 at this time is driven by the piston 54 to pass into the one-way inflow channel 55 for temporary storage. Since the one-way inflow channel 55 can only pass from the circular arc groove 53 to the nozzle 57, the repeated movement of the piston 54 will pass the aqueous solution into the one-way inflow channel 55 until the water level gradually rises and connects with the nozzle 57 during the repeated addition of the solution. In this way, when the piston 54 is compressed downward again, the water will be pressed out from the nozzle 57 to act on the inside of the floating ball 17, and the sea breeze simulation mechanism will simulate the situation where seawater splashes and disperses in the air.

[0031] A one-way drainage channel 58 communicating with the annular water storage tank 50 is formed in the middle of the circular arc groove 53 .

[0032] The one-way drainage channel 58 enables the excess water to be discharged preferentially from the one-way drainage channel 58 when too much water is stored in the circular arc groove 53 .

[0033] The lower end of the standing platform 18 is fixedly installed with a sealing pad 59 fixedly installed with the floating ball 17, and the lower end of the sealing pad 59 is fixedly installed with a positioning pin 60, and the upper end of the placing platform 16 is provided with a limiting hole matching the positioning pin 60. In the initial state, the positioning pin 60 is located inside the limiting hole, thereby limiting the standing platform 18 to facilitate the training personnel to stand.

[0034] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A defense training platform for simulating ship movement, comprising a mounting platform, a spherical training cavity fixedly mounted on the upper end of the mounting platform, a wave simulation mechanism and a sea breeze simulation mechanism installed inside the spherical training cavity, a through groove running through the upper and lower parts of the spherical training cavity, a lifting mechanism mounted on the upper end of the mounting platform, a binding mechanism mounted inside the spherical training cavity, and the lower side of the spherical training cavity is connected to an external water source through a water pipe, characterized in that: A placing platform sealed and connected to the through groove is installed at the upper end of the lifting mechanism, a floating ball is installed inside the spherical training cavity, a standing platform is sealed and connected to the lower end of the floating ball, the mass of the standing platform is greater than the mass of the floating ball, the size of the standing platform is smaller than the size of the placing platform, a locking mechanism connected to the floating ball is installed at the upper end of the standing platform, a buoyancy ring plate is fixedly installed on the outside of the floating ball, a mounting ring is fixedly installed inside the floating ball, a number of cameras are installed inside the mounting ring, a ventilation mechanism is installed on the top of the floating ball, and the binding mechanism is installed at the upper end of the standing platform; The ventilation mechanism includes a slidingly connected arc plate, and a plurality of meshing teeth are installed on both sides of the arc plate. The upper end of the spherical training cavity is symmetrically rotatably connected to two gears meshing with the plurality of meshing teeth. The gears are evenly provided with a plurality of ventilation holes. The spherical training cavity is provided with through holes adjacent to the ventilation holes, and a force plate is fixedly installed on the upper end of the floating ball.

2. A defense training platform for simulating ship motion according to claim 1, characterized in that: The locking mechanism includes a plurality of support rods fixedly connected to the upper end of the standing platform, and an arc rod is commonly installed on the upper ends of the support rods. The binding mechanism is installed between the support rods and the arc rods, and three of the support rods are rotatably installed with locking rods. Three locking platforms matching the locking rods are evenly installed inside the spherical training cavity, and a locking assembly is installed between the locking rod and the locking platform.

3. A defense training platform for simulating ship motion according to claim 2, characterized in that: The locking assembly includes a sliding plate, a sliding groove is provided inside the locking rod and is slidably connected to the sliding plate, a T-shaped block is fixedly installed on the side of the sliding plate close to the support rod, a first spring is installed between the T-shaped block and the sliding groove, a triangular push block is installed on the other side of the sliding plate, the locking rod is elastically rotatably connected to the limit rod, the locking rod and the locking platform are both provided with an arc groove matching the limit rod, and the sliding plate and the locking rod are provided with a threaded groove on the side close to the arc rod, and the threaded groove is threadedly connected to the threaded rod.

4. A defense training platform for simulating ship motion according to claim 3, characterized in that: The sliding plate is fixedly connected with an extended abutment plate, and a gripping rod is fixedly installed between the locking platform and the mounting ring.

5. The defense training platform for simulating ship motion according to claim 1, characterized in that: An annular water storage tank is provided at the lower side of the floating ball, and a connecting rod is sealingly and slidably connected to the annular water storage tank, a counterweight is fixedly installed at the lower end of the connecting rod, and the connecting rod is fixedly installed with the arc plate.

6. The defense training platform for simulating ship motion according to claim 5, characterized in that: The floating ball is provided with a circular arc groove connected to the annular water storage tank, the circular arc groove is sealingly and slidably connected with a piston fixedly installed on the connecting rod, the floating ball and the mounting ring are jointly provided with a one-way inflow channel connected to the circular arc groove, the circular arc groove is installed with a one-way valve connected to the annular water storage tank, and the mounting ring is installed with a nozzle connected to the one-way inflow channel.

7. A defense training platform for simulating ship motion according to claim 6, characterized in that: A one-way drainage channel connected to the annular water storage tank is provided in the middle of the circular arc groove.

8. The defense training platform for simulating ship motion according to claim 1, characterized in that: A sealing pad fixedly mounted on the lower end of the standing platform and fixedly mounted on the floating ball, a positioning pin fixedly mounted on the lower end of the sealing pad, and a limiting hole matching the positioning pin is opened on the upper end of the placing platform.

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