Wall-mounted publicity board for classroom

Abstract

The invention belongs to the technical field of teaching aids and information display equipment, and particularly relates to a wall-mounted publicity board for a classroom, which comprises a frame body, tempered glass, an ink screen and a partition plate are sequentially connected along the frame body from front to back, and the interior of the frame body is divided into a first cavity, a second cavity and a third cavity by the tempered glass, the ink screen and the partition plate; the third cavity is adsorbed on the wall surface under negative pressure; the ink screen is elastically arranged between the first cavity and the second cavity in a sliding mode, a plurality of limiting sliding blocks arranged in a matrix mode are fixed to the back face of the ink screen, the limiting sliding blocks are in limiting sliding fit with high-pressure air cylinders, and the high-pressure air cylinders are fixed in the third cavity; the air inlet end of the high-pressure air cylinder is communicated with the air outlet end of a roots pump, one air inlet end of the roots pump is communicated with the first cavity, the other air inlet end of the roots pump is communicated with the third cavity through a one-way valve, and the first cavity is communicated with the second cavity; the air outlet end of the high-pressure air cylinder communicates with the first cavity through the pressure relief part.

Description

Technical Field

[0001] This invention belongs to the technical field of teaching aids and information display equipment, and particularly relates to a wall-mounted advertising board for classrooms. Background Technology

[0002] In modern educational environments, classrooms are not only places for imparting knowledge but also important spaces for information exchange and cultural interaction. Bulletin boards, as indispensable facilities in classrooms, bear important functions such as issuing notices, showcasing achievements, and disseminating culture. With the continuous improvement of educational informatization, traditional paper posters and printed display boards can no longer meet the modern demands for dynamic information updates, multimedia content display, and energy conservation and environmental protection. Therefore, bulletin boards using low-power electronic displays (such as e-ink screens) are gradually entering schools. They can remotely update content wirelessly, provide clear and eye-friendly displays, and have significant energy-saving advantages. However, when these electronic bulletin boards are integrated into the actual classroom environment, they face new challenges that are completely different from traditional display boards. The core contradiction lies in the fact that, on the one hand, electronic displays are relatively fragile and require robust physical protection to avoid damage from accidental collisions and scratches during students' daily activities; on the other hand, as public facilities, the installation and maintenance of bulletin boards need to be as simple as possible to avoid permanent damage to the walls or complex installation procedures.

[0003] Currently, to address the aforementioned issues, the common industry practice is to install external protective covers, such as tempered glass, on electronic display boards to provide basic physical protection. For fixing, traditional expansion screws are often used to directly fasten them to the wall. While this solution protects the screen to some extent, its inherent drawbacks are significant. First, rigid fixing lacks a buffer mechanism. When the protective cover breaks due to accidental impact, the resulting fragments or stress may be directly transmitted to the fragile internal electronic screen, causing damage and substantial economic losses. Second, traditional drilling installation methods cause irreversible damage to the wall. The installation process is cumbersome and dusty, and obvious repair marks are left when adjusting the position or replacing equipment, affecting the overall aesthetics of the classroom environment. Furthermore, existing designs are functionally limited, only providing basic display and protection, unable to detect risks and proactively respond to them, resulting in low levels of intelligence. When the outermost protective glass breaks, the safety status of the entire device becomes unknown, making it difficult for maintenance personnel to detect and address the issue promptly, leaving the expensive internal display screen continuously exposed to risk.

[0004] Therefore, there is an urgent need for a wall-mounted bulletin board for classrooms to solve this problem. Summary of the Invention

[0005] The purpose of this invention is to provide a wall-mounted advertising board for classrooms to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A wall-mounted bulletin board for classroom use includes:

[0008] A frame is provided, from front to back, to be connected in sequence to tempered glass, an e-ink screen, and a partition plate. The tempered glass, the e-ink screen, and the partition plate divide the interior of the frame into a first cavity, a second cavity, and a third cavity. The third cavity is negatively pressure adsorbed onto the wall surface.

[0009] The e-ink screen is elastically slidably disposed between the first cavity and the second cavity. A plurality of matrix-arranged limiting sliders are fixed on the back of the e-ink screen. The limiting sliders are limited and slidably coupled with a high-pressure cylinder. The high-pressure cylinder is fixed in the third cavity.

[0010] The air inlet of the high-pressure cylinder is connected to the air outlet of the Roots pump. One air inlet of the Roots pump is connected to the first chamber, and the other air inlet of the Roots pump is connected to the third chamber through a one-way valve. The first chamber and the second chamber are connected.

[0011] The outlet of the high-pressure cylinder is connected to the first cavity through a pressure relief section.

[0012] Optionally, a sealing ring is fixed to the outer edge of the frame, and the sealing ring is positioned close to the third cavity.

[0013] Optionally, a groove is provided on the inner side of the frame, and the edge of the tempered glass is embedded in the groove.

[0014] Optionally, the pressure relief section includes:

[0015] The exhaust pipe has one end connected to the outlet of the Roots pump and the other end connected to the first cavity.

[0016] The second limiting ring is coaxially fixed inside the exhaust pipe, and the second limiting ring is disposed close to the first cavity;

[0017] A bracket is coaxially fixed inside the second limiting ring, and several through holes are provided on the bracket.

[0018] One end of the first elastic part is fixedly connected to the second limiting ring, and the other end of the first elastic part is fixedly connected to a piston slider, which is slidably disposed inside the exhaust pipe.

[0019] The piston slider has an air passage in the middle, one end of the air passage is sealed with a plug, and the other end of the plug is fixed on the bracket.

[0020] Optionally, the first elastic part includes a first spring, one end of which is fixedly connected to the second limiting ring, and the other end of which is fixedly connected to the piston slider.

[0021] Optionally, a sliding groove is provided inside the frame, a sliding rod is fixed inside the sliding groove, a slider is slidably engaged with the sliding rod, and the slider is fixed to the edge of the e-ink screen;

[0022] A second elastic portion is provided between the inner wall of the groove and the slider, and the second elastic portion is located in the first cavity.

[0023] Optionally, the second elastic part includes a second spring, one end of which is fixedly connected to the inner wall of the slide groove, and the other end of which is fixedly connected to the slider. The second spring is sleeved on the outside of the slide rod.

[0024] Optionally, the first cavity and the second cavity are connected by a connecting pipe.

[0025] Optionally, a first limiting ring is coaxially fixed inside the high-pressure cylinder, the first limiting ring is in a limiting engagement with the end of the limiting slider, and the limiting slider is in a limiting engagement with the high-pressure cylinder.

[0026] Optionally, the air inlet of the Roots pump is connected to one end of the main air inlet pipe, the other end of the main air inlet pipe is connected to the one-way valve, the middle part of the main air inlet pipe is connected to one end of the air inlet branch pipe, and the other end of the air inlet branch pipe is connected to the first cavity.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] This application provides a wall-mounted advertising board for classrooms. In terms of installation and fixation, a Roots pump simultaneously evacuates the first, second, and third chambers, creating a stable negative pressure in the third chamber. Atmospheric pressure then firmly adheres the entire frame to the smooth wall surface. This hole-free installation method completely avoids the damage to the wall caused by traditional drilling, achieving non-destructive installation and convenient disassembly. Under normal operating conditions, the operation of the Roots pump creates high pressure in the high-pressure cylinder, pushing the limit slider and its connected ink screen forward, bringing it closer to the inside of the tempered glass for easy display. When the tempered glass is accidentally broken, the pressure in the first chamber changes abruptly, triggering the pressure relief unit to quickly release the high-pressure gas in the high-pressure cylinder into the first chamber, causing a drop in its internal pressure. At this time, the ink screen smoothly and quickly retracts backward, instantly moving it away from the damaged area, thus effectively preventing damage to the ink screen. This device cleverly combines pneumatic control, mechanical transmission, and elastic elements to create a high-performance advertising board that integrates non-destructive installation, stable display, and intelligent active protection, possessing extremely high practicality and safety. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the present invention;

[0031] Figure 2 This is a cross-sectional view of the structure of the present invention;

[0032] Figure 3 This is a schematic diagram of the internal pipeline connection of the present invention;

[0033] Figure 4 For the present invention Figure 3 Enlarged view of a portion of point A in the middle;

[0034] Figure 5 For the present invention Figure 3 Enlarged view of a section at point B in the middle;

[0035] The components are as follows: 1. Frame; 2. Tempered glass; 3. Sealing ring; 4. First cavity; 5. Second cavity; 6. Third cavity; 7. Partition plate; 8. Connecting pipe; 9. High-pressure cylinder; 10. Roots pump; 11. First limiting ring; 12. Limiting slider; 13. Main intake pipe; 14. Intake branch pipe; 15. One-way valve; 16. Exhaust pipe; 17. Piston slider; 18. Air passage; 19. Second limiting ring; 20. Through hole; 21. Bracket; 22. Block; 23. First spring; 24. Slide groove; 25. Slide rod; 26. Slider; 27. Second spring; 28. E-ink screen. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Reference Figures 1 to 5 This invention discloses a wall-mounted bulletin board for classroom use, comprising:

[0039] The frame 1 is connected in sequence from front to back by tempered glass 2, e-ink screen 28 and partition plate 7. The tempered glass 2, e-ink screen 28 and partition plate 7 divide the interior of the frame 1 into a first cavity 4, a second cavity 5 and a third cavity 6. The third cavity 6 is negatively pressure adsorbed onto the wall surface.

[0040] The e-ink screen 28 is elastically slidably disposed between the first cavity 4 and the second cavity 5. Several matrix-arranged limiting sliders 12 are fixed on the back of the e-ink screen 28. The limiting sliders 12 are limited and slidably coupled with a high-pressure cylinder 9, which is fixed in the third cavity 6.

[0041] The air inlet of the high-pressure cylinder 9 is connected to the air outlet of the Roots pump 10. One air inlet of the Roots pump 10 is connected to the first chamber 4, and the other air inlet of the Roots pump 10 is connected to the third chamber 6 through the one-way valve 15. The first chamber 4 and the second chamber 5 are connected.

[0042] The outlet of the high-pressure cylinder 9 is connected to the first cavity 4 through the pressure relief section.

[0043] In use, the Roots pump 10 is started. The two air inlets of the Roots pump 10 draw air from the first chamber 4 and the third chamber 6 into the high-pressure cylinder 9. Since the first chamber 4 and the second chamber 5 are connected, the first chamber 4, the second chamber 5, and the third chamber 6 are all under negative pressure. The third chamber 6 is in contact with the wall surface and is adsorbed onto the wall surface by negative pressure. The wall surface is a smooth wall surface or a smooth blackboard surface. Since the third chamber 6 is connected to the Roots pump 10 through the one-way valve 15, the one-way valve 15 can prevent gas from flowing into the third chamber 6, thereby maintaining the negative pressure adsorption state between the third chamber 6 and the wall surface. At the same time, since the first chamber 4 and the second chamber 5 are also under negative pressure, the high-pressure cylinder 9 is under high pressure. This air pressure pushes the limit slider 12 and moves the ink screen 28 closer to the tempered glass 2 for easy viewing.

[0044] When the tempered glass 2 is accidentally broken, the first cavity 4 is connected to the atmosphere through the crack in the tempered glass 2. At this time, the negative pressure state in the first cavity 4 is broken and reaches the standard atmospheric pressure. The second cavity 5 is connected to the first cavity 4 and is also at normal pressure. The pressure relief part detects the pressure change in the first cavity 4 and discharges the gas in the high-pressure cylinder 9 into the first cavity 4. The air pressure in the high-pressure cylinder 9 decreases. Under the action of air pressure, the ink screen 28 is pushed away from the tempered glass 2. While the ink screen 28 moves, the first cavity 4 and the second cavity 5 will automatically balance the air pressure due to their connection. At the same time, the negative pressure in the third cavity 6 is kept constant due to the one-way valve 15, ensuring the connection between the frame 1 and the wall. This setting can immediately move the ink screen 28 away from the tempered glass 2 when the tempered glass 2 is accidentally broken, preventing damage to the surface of the ink screen 28. At the same time, because the internal and external pressure of the tempered glass 2 is balanced, it can also prevent the tempered glass 2 from breaking outward under uneven air pressure.

[0045] This application provides a wall-mounted advertising board for classrooms. In terms of installation and fixation, a Roots pump 10 simultaneously pumps air from the first chamber 4, the second chamber 5, and the third chamber 6, creating a stable negative pressure within the third chamber 6. Atmospheric pressure then firmly adheres the entire frame 1 to the smooth wall surface. This hole-free installation method completely avoids the damage to the wall caused by traditional drilling, achieving non-destructive installation and convenient disassembly. Under normal operating conditions, the operation of the Roots pump 10 creates high pressure within the high-pressure cylinder 9, pushing the limit slider 12 and its connected ink screen 28 forward, bringing it closer to the inside of the tempered glass 2 for easy display. When the tempered glass 2 is accidentally broken, the pressure in the first chamber 4 changes abruptly, triggering the pressure relief mechanism. This quickly releases the high-pressure gas from the high-pressure cylinder 9 into the first chamber 4, causing a drop in its internal pressure. At this time, the ink screen 28 smoothly and quickly retracts backward, instantly moving it away from the damaged area, effectively preventing damage to the ink screen 28. This device ingeniously combines pneumatic control, mechanical transmission, and elastic elements to create a high-performance advertising board that integrates non-destructive installation, stable display, and intelligent active protection, making it highly practical and safe.

[0046] As an optional implementation, a sealing ring 3 is fixed to the outer edge of the frame 1, and the sealing ring 3 is positioned close to the third cavity 6.

[0047] When the Roots pump 10 is started, the frame 1 is tightly fitted to the wall surface through the sealing ring 3 on its outer edge. The sealing ring 3 is located around the third cavity 6, which effectively ensures the airtightness of the interface between the frame 1 and the wall surface, thereby ensuring the stability and reliability of the negative pressure adsorption force in the third cavity 6 and making the frame 1 firmly fixed.

[0048] As an optional implementation, a groove is provided on the inner side of the frame 1, and the edge of the tempered glass 2 is embedded in the groove.

[0049] During installation, the edge of the tempered glass 2 is precisely embedded into the groove on the inner side of the frame 1, forming a stable and secure connection. This structure not only provides reliable mechanical support for the tempered glass 2, ensuring its stability during use, but also enhances the overall structure's sealing and impact resistance through the limiting effect of the groove, effectively preventing the glass from shifting or loosening due to external forces.

[0050] Meanwhile, the tempered glass 2 has strong impact resistance, but the edges are prone to breakage when impacted. Protecting the edges of the tempered glass 2 with the frame 1 helps reduce the risk of breakage.

[0051] As an optional implementation, the pressure relief section includes:

[0052] One end of the exhaust pipe 16 is connected to the outlet end of the Roots pump 10, and the other end of the exhaust pipe 16 is connected to the first chamber 4.

[0053] The second limiting ring 19 is coaxially fixed inside the exhaust pipe 16, and the second limiting ring 19 is set close to the first cavity 4;

[0054] The bracket 21 is coaxially fixed inside the second limiting ring 19, and several through holes 20 are opened on the bracket 21.

[0055] One end of the first elastic part is fixedly connected to the second limiting ring 19, and the other end of the first elastic part is fixedly connected to the piston slider 17. The piston slider 17 is slidably disposed inside the exhaust pipe 16.

[0056] The piston slider 17 has an air passage 18 in the middle. One end of the air passage 18 is sealed with one end of the plug 22, and the other end of the plug 22 is fixed on the bracket 21.

[0057] As an optional implementation, the first elastic part includes a first spring 23, one end of which is fixedly connected to the second limiting ring 19, and the other end of which is fixedly connected to the piston slider 17.

[0058] During normal operation, the Roots pump 10 runs continuously, maintaining a high air pressure in the exhaust pipe 16 and on the side of the piston slider 17 closest to the Roots pump 10. Simultaneously, because the first chamber 4 is under negative pressure, this pressure difference generates a pushing force, causing the piston slider 17 to tend to move towards the first chamber 4. At this time, the first spring 23 is compressed, and its elastic restoring force is opposite to the thrust generated by the air pressure difference. Through precise mechanical design, it is ensured that under normal negative pressure operation, the piston slider 17 can move towards the second limiting ring 19, allowing the plug 22 to insert into the air passage 18 to form a seal, preventing high-pressure gas from leaking through this gap. The entire high-pressure air circuit is in a closed state, the system remains stable, and the pressure in the high-pressure cylinder 9 is maintained, thereby pushing the e-ink screen 28 tightly against the tempered glass 2. Subsequently, the Roots pump 10 stops working; the Roots pump 10 has an anti-backflow function, and the air pressure in the high-pressure cylinder 9 is maintained.

[0059] When the protection mechanism is triggered, i.e., the tempered glass 2 breaks, the first cavity 4 is connected to the atmosphere, and its internal pressure rapidly recovers from negative pressure to standard atmospheric pressure. This change instantly disrupts the force balance on both sides of the piston slider 17 inside the exhaust pipe 16. Specifically, the pressure on the side of the piston slider 17 closest to the first cavity 4 increases sharply, while the pressure of the high-pressure gas inside the exhaust pipe 16 on the other side of the piston slider 17 remains unchanged. At this time, the air pressure and the compressed first spring 23 work together, i.e., the thrust of the air pressure of the high-pressure cylinder 9 on the piston slider 17 is less than the thrust formed by the combination of atmospheric pressure and the elastic force of the compressed first spring 23, thus pushing the piston slider 17 to slide away from the first cavity 4. The movement of the piston slider 17 directly causes the air passage 18 to separate from the blockage 22, opening the outlet of the air passage 18. The high-pressure gas inside the high-pressure cylinder 9 then rapidly flows into the first cavity 4 through the air passage 18 and the through hole 20 on the bracket 21. This rapid depressurization process causes the pressure inside the high-pressure cylinder 9 to drop sharply, and the force that pushes the limit slider 12 disappears. Since the ink screen 28 is elastically slidably set in the first cavity 4 and the second cavity 5, the ink screen 28 is safely retracted to a position away from the broken tempered glass 2 under the action of elastic force, thus being effectively protected.

[0060] The second limiting ring 19 effectively prevents the piston slider 17 from moving excessively or detaching from the exhaust pipe 16 under the impact of high-pressure gas. The entire action response is extremely rapid, driven entirely by the physical signal of gas pressure change, without the need for electronic sensors and circuit control, resulting in high reliability and low cost.

[0061] After the protection action is completed and the system fault is cleared, a reset is required. When the tempered glass 2 is replaced and the system regains its airtightness, the Roots pump 10 is restarted, and it resumes drawing air from the first chamber 4 and the third chamber 6. As the pressure in the first chamber 4 gradually decreases, the pressure difference acting on both sides of the piston slider 17 changes again. At this time, the pressure of the rebuilt high-pressure gas in the exhaust pipe 16 on the piston slider 17, together with the suction force generated by the negative pressure on the first chamber 4, pushes the piston slider 17 to overcome the elastic force of the first spring 23, compressing the first spring 23. At this point, the outlet of the air passage 18 is sealed again at the end of the blockage 22, the pressure relief channel is completely closed, and the system returns to normal operation.

[0062] The pressure relief section, through the ingenious combination of the exhaust pipe 16, the second limiting ring 19, the bracket 21, the piston slider 17, the air passage 18, the plug 22, and the first spring 23, constitutes an integrated mechanical module that integrates pressure detection, valve core driving, high-pressure relief, and automatic reset. When the tempered glass 2 breaks, it can instantly and automatically trigger the protection action and automatically reset after the system returns to normal. The structure is simple and the operation is reliable.

[0063] As an optional implementation, a slide groove 24 is provided in the frame 1, a slide rod 25 is fixed in the slide groove 24, a slider 26 is slidably engaged with the slide rod 25, and the slider 26 is fixed to the edge of the e-ink screen 28;

[0064] A second elastic part is provided between the inner wall of the slide groove 24 and the slider 26, and the second elastic part is located inside the first cavity 4.

[0065] As an optional implementation, the second elastic part includes a second spring 27, one end of which is fixedly connected to the inner wall of the slide groove 24, and the other end of which is fixedly connected to the slider 26. The second spring 27 is sleeved on the outside of the slide rod 25.

[0066] Under normal operating conditions, the high pressure built up in the high-pressure cylinder 9 pushes the e-ink screen 28 toward the tempered glass 2 via the limiting slider 12. At this time, the slider 26, fixed to the edge of the e-ink screen 28, slides along the slide rod 25 fixed in the slide groove 24. The precise sliding engagement between the slide rod 25 and the slider 26 provides a stable and reliable guide for the large flat surface of the e-ink screen 28, effectively preventing tilting, jamming, or wobbling during movement and ensuring motion accuracy. During this process, the second spring 27, located inside the first cavity 4, between the inner wall of the slide groove 24 and the slider 26, is compressed. This second spring 27 is sleeved on the outside of the slide rod 25. The compressed second spring 27 stores elastic potential energy, but its elastic force is less than the thrust of the high-pressure cylinder 9, thus the e-ink screen 28 can be stably maintained in a display position close to the tempered glass 2.

[0067] When the protection mechanism is triggered, i.e., the pressure relief section operates and causes a sudden drop in pressure inside the high-pressure cylinder 9, the thrust of the high-pressure cylinder 9 on the e-ink screen 28 disappears. At this time, the elastic potential energy stored in the compressed second spring 27 is released, and its restoring force pushes the slider 26 to slide along the slide bar 25 away from the tempered glass 2, thereby causing the e-ink screen 28 to quickly and smoothly retract to a safe position.

[0068] During troubleshooting and system reset, the Roots pump 10 restarts, the high-pressure cylinder 9 builds up pressure again and pushes the e-ink screen 28 forward, overcoming the elasticity of the second spring 27 and recompressing it until the e-ink screen 28 is once again pressed against the tempered glass 2, and the system returns to its initial working state. This guiding and elastic reset mechanism not only ensures the realization of the core protection function, but its purely mechanical design also has the advantages of high reliability and long service life.

[0069] As an optional implementation, the first cavity 4 and the second cavity 5 are connected by a connecting pipe 8.

[0070] The connecting pipe 8 ensures that the air pressure in the first chamber 4 and the second chamber 5 is always balanced. When the Roots pump 10 is working, the pressure of both chambers changes synchronously; when the tempered glass 2 breaks and causes the first chamber 4 to lose pressure, the second chamber 5 responds quickly through the connecting pipe 8, and the pressure synchronously returns to normal pressure, thus providing a consistent air pressure environment for the safe retraction of the e-ink screen 28.

[0071] As an optional implementation, a first limiting ring 11 is coaxially fixed inside the high-pressure cylinder 9. The first limiting ring 11 is in a limiting engagement with the end of the limiting slider 12, and the limiting slider 12 is in a limiting engagement with the high-pressure cylinder 9.

[0072] The first limiting ring 11 inside the high-pressure cylinder 9 engages with the end of the limiting slider 12, while the limiting slider 12 also engages with the inner wall of the high-pressure cylinder 9. This structure ensures that during the pushing process of high-pressure gas or the pull-back process of spring force, the stroke of the limiting slider 12 is always limited within a safe range between the first limiting ring 11 and the end of the cylinder, preventing the ink screen 28 from being dislodged or damaged due to overshoot, and ensuring the reliability and service life of the moving parts.

[0073] As an optional implementation, the air inlet of the Roots pump 10 is connected to one end of the air inlet manifold 13, the other end of the air inlet manifold 13 is connected to the one-way valve 15, the middle part of the air inlet manifold 13 is connected to one end of the air inlet branch pipe 14, and the other end of the air inlet branch pipe 14 is connected to the first cavity 4.

[0074] The intake manifold 13 serves as the main airflow channel. One end of it is connected to the third chamber 6 via a one-way valve 15, and the other end is connected to the intake end of the Roots pump 10. The intake branch pipe 14 is connected from the middle of the intake manifold 13, and the other end is connected to the first chamber 4.

[0075] When the Roots pump 10 starts, the suction it generates acts simultaneously on the first chamber 4 and the third chamber 6 through the main intake pipe 13 and the branch intake pipe 14, rapidly bringing both chambers to the required negative pressure state. At the same time, the one-way valve 15 integrated on the main intake pipe 13 effectively prevents gas from flowing back into the third chamber 6 when the pump operates intermittently or stops, thereby maintaining a stable negative pressure suction force in that chamber and ensuring the reliability of the advertising board's fixation.

[0076] In this device, the Roots pump, a positive displacement rotary vacuum pump, gets its name from its core components—two figure-eight shaped rotors, often referred to as Roots rotors or impellers. In this application, the Roots pump 10 is the power heart of the entire pneumatic system, and its performance directly determines the reliability and response speed of the pump. Structurally, the Roots pump 10 mainly consists of a pump body, a pair of high-precision machined synchronous gears, and two meshing but non-contacting figure-eight shaped rotors. These two rotors are mounted parallel within the pump chamber and driven by a pair of precision synchronous gears, ensuring they rotate in opposite directions at the same angular velocity, maintaining a small gap during rotation without any mechanical contact.

[0077] The working principle of a Roots pump can be clearly divided into four stages: intake, isolation, delivery, and discharge. When the motor drives the synchronous gear to rotate the two rotors, the cavity on the inlet side gradually increases with the rotation of the rotors. This volume expansion creates a vacuum effect, drawing gas from the intake manifold 13 into the pump chamber—this is the intake process. As the rotors continue to rotate, the intake gas is isolated by the closed space formed by the convex corner of the rotor and the inner wall of the pump chamber, forming an "air bag," thus achieving gas isolation. The continuous rotation of the rotor pushes this isolated "air bag" along the inner wall of the pump chamber from the inlet side to the outlet side, achieving gas delivery. When the convex corner of the rotor passes the outlet, the delivered "air bag" connects with the outlet side. At this time, due to the higher pressure on the outlet side, the gas is rapidly compressed and discharged from the pump body, completing the discharge process. These four processes cycle continuously, thereby creating a stable negative pressure at the pump's inlet end and simultaneously establishing the required high pressure at the outlet end.

[0078] The core characteristic of the Roots pump lies in its "dry" operation; no lubricating oil is required inside the pump chamber, avoiding oil mist contamination of the delicate air passages and ink screen environment. It also boasts a compact structure, high pumping efficiency, and the ability to maintain a stable pumping speed over a wide pressure range. These characteristics make it perfectly suited to the cleanliness, reliability, and rapid differential pressure requirements of this technical solution. Its non-contact design also results in low wear, long service life, and low operating noise, making it ideal for use in classrooms where a quiet environment is required.

[0079] In the specific gas path system of this invention, the Roots pump 10 plays a crucial dual role: it is both a vacuum source that generates strong suction force and a high-pressure source that drives the protective mechanism. This integrated "one pump, two uses" design greatly simplifies the system structure and improves energy efficiency and reliability.

[0080] Specifically, the Roots pump 10 draws air from its inlet end through a three-way inlet manifold 13. One end of the inlet manifold 13 is connected to the first chamber 4 via an inlet branch pipe 14, and the other end is connected to the third chamber 6 via a one-way valve 15. When the Roots pump 10 starts, it draws air from both chambers simultaneously. Since the first chamber 4 and the second chamber 5 maintain pressure balance through the connecting pipe 8, the Roots pump 10 is actually simultaneously evacuating the front display / protection chambers (first chamber 4 and second chamber 5) and the rear adsorption and fixing chamber (third chamber 6). This allows a stable high negative pressure to quickly form in the third chamber 6, which, through atmospheric pressure, firmly and without damage, adheres the entire advertising board to the wall or smooth blackboard. The one-way valve 15 prevents backflow of gas, ensuring that even if the pump operates intermittently or stops, the negative pressure in the third chamber 6 is maintained to the maximum extent, guaranteeing absolute reliability of the fixation.

[0081] Meanwhile, the high-pressure gas discharged from the Roots pump 10 is directly delivered to the high-pressure cylinder 9. This continuous flow of high-pressure gas pushes the limiting slider 12 within the high-pressure cylinder 9 forward, thereby overcoming the elastic force of the second spring 27 and pressing the e-ink screen 28 tightly against the tempered glass 2, achieving optimal display performance. The high pumping speed of the Roots pump 10 ensures that the system can quickly transition from its initial state to a stable operating state, i.e., rapidly complete the adsorption fixation and screen adhesion.

[0082] Choosing the Roots pump 10 as the core power component brings multiple core advantages to this technical solution and is the key to its ability to achieve high efficiency, reliability and intelligent protection.

[0083] First, there is the high efficiency and integration. This solution uses a single Roots pump 10 to simultaneously address the two functional requirements of adsorption fixation and screen pressing. Through the ingenious design of the air path, including the main air inlet pipe 13, the branch air inlet pipe 14, and the one-way valve 15, it maximizes resource utilization, resulting in a compact structure and reduced energy consumption for the entire device.

[0084] Secondly, there is the rapid dynamic response capability. When the protection mechanism is triggered and the tempered glass 2 breaks and the pressure relief section operates, the system needs to be reset quickly. The Roots pump 10 can quickly re-establish the negative pressure in the third chamber 6 and the high pressure in the high-pressure cylinder 9, driving the ink screen 28 to reset, shortening the time for the system to recover from the protection state to the working state, and improving the availability of the equipment.

[0085] Finally, and crucially, is cleanliness, reliability, and long lifespan. As a dry pump, the Roots pump 10 completely eliminates the risk of oil vapor contaminating the internal air passages and the ink screen 28, ensuring display quality and the cleanliness of the equipment's interior. Its contactless rotor operation means virtually no wear, guaranteeing extremely high reliability and a long service life under long-term, potentially frequent start-stop operating conditions, making it ideal for use in environments like schools where high equipment stability is required. In summary, the Roots pump 10 is not a generic, easily replaceable component; its structural principle is deeply aligned with the pneumatic drive and safety protection logic of this technical solution, and is one of the core technological pillars contributing to the many beneficial effects of this invention.

[0086] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0087] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A wall-mounted bulletin board for a classroom, characterized by, The utility model relates to a frame (1) is connected with toughened glass (2), ink screen (28) and partition board (7) in order from front to back along the frame (1), and toughened glass (2), ink screen (28) and partition board (7) divide the frame (1) into first cavity (4), second cavity (5) and third cavity (6) in the inside, and the third cavity (6) is adsorbed on the wall surface under the negative pressure, The ink screen (28) is elastically slid between the first cavity (4) and the second cavity (5), the back of the ink screen (28) is fixed with a plurality of matrix arrangement limit sliding blocks (12), the limit sliding block (12) is limited slidingly matched with a high-pressure air cylinder (9), and the high-pressure air cylinder (9) is fixed in the third cavity (6); The air inlet end of the high-pressure air cylinder (9) is communicated with the air outlet end of a roots pump (10), one air inlet end of the roots pump (10) is communicated with the first cavity (4), the other air inlet end of the roots pump (10) is communicated with the third cavity (6) through a one-way valve (15), and the first cavity (4) and the second cavity (5) are communicated. The air outlet end of the high-pressure air cylinder (9) is communicated with the first cavity (4) through a pressure relief part. The outer edge of the frame (1) is fixed with a sealing rubber ring (3), and the sealing rubber ring (3) is arranged close to the third cavity (6).

2. A wall-mounted bulletin board for a classroom according to claim 1, wherein: The inside of the frame (1) is provided with a groove, and the edge of the toughened glass (2) is embedded in the groove.

3. A wall-mounted bulletin board for a classroom according to claim 1, wherein: The pressure relief part comprises:

4. The wall-mounted bulletin board for a classroom according to claim 1, wherein An exhaust pipe (16) is communicated with the air outlet end of the roots pump (10), and the other end of the exhaust pipe (16) is communicated with the first cavity (4); A second limiting ring (19) is coaxially fixed inside the exhaust pipe (16), and the second limiting ring (19) is arranged close to the first cavity (4); A support (21) is coaxially fixed inside the second limiting ring (19), and a plurality of through holes (20) are formed in the support (21); One end of a first elastic part is fixed to the second limiting ring (19), and the other end of the first elastic part is fixed to a piston sliding block (17), and the piston sliding block (17) is slidably arranged in the exhaust pipe (16); A gas channel (18) is formed in the middle of the piston sliding block (17), one end of the gas channel (18) is sealingly matched with one end of a plug (22), and the other end of the plug (22) is fixed to the support (21). The first elastic part comprises a first spring (23), one end of the first spring (23) is fixed to the second limiting ring (19), and the other end of the first spring (23) is fixed to the piston sliding block (17).

5. A wall-mounted bulletin board for a classroom according to claim 4, wherein A sliding groove (24) is arranged in the frame (1), a sliding rod (25) is fixed in the sliding groove (24), a sliding block (26) is slidably matched with the sliding rod (25), and the sliding block (26) is fixed to the edge of the ink screen (28); 6. A wall-mounted bulletin board for a classroom according to claim 1, wherein: A second elastic part is arranged between the inner wall of the sliding groove (24) and the sliding block (26), and the second elastic part is located in the first cavity (4). ​ 7. A wall-mounted bulletin board for a classroom according to claim 6, wherein: The second elastic part comprises a second spring (27), one end of the second spring (27) is fixedly connected with the inner wall of the sliding groove (24), the other end of the second spring (27) is fixedly connected with the sliding block (26), and the second spring (27) is sleeved outside the sliding rod (25).

8. A wall-mounted bulletin board for a classroom according to claim 1, wherein: The first cavity (4) and the second cavity (5) are communicated through a communication pipe (8).

9. A wall-mounted bulletin board for a classroom as defined in claim 1, wherein: A first limiting ring (11) is coaxially fixed in the high-pressure cylinder (9), the first limiting ring (11) is in limiting cooperation with the end of the limiting sliding block (12), and the limiting sliding block (12) is in limiting cooperation with the high-pressure cylinder (9).

10. A wall-mounted bulletin board for a classroom according to claim 1, wherein: One end of an air inlet main pipe (13) is communicated with the air inlet end of the Roots pump (10), the other end of the air inlet main pipe (13) is communicated with the one-way valve (15), one end of an air inlet branch pipe (14) is communicated with the middle part of the air inlet main pipe (13), and the other end of the air inlet branch pipe (14) is communicated with the first cavity (4).

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