A lectern that can be raised

Abstract

A kind of liftable lectern, including table main body and inner stand, and inside them: ① provide constant lift gas strut for table main body;② by the combination of top plate, suspension straight pole, guide head, straight pipe, bottom plate, floor block, the guarantee mechanism of vertical lifting of table main body;③ by active pole, special type of fastener, lying spring, buckle cover, rotating plate, torsion spring, hinge, the mechanism of descending locking and ascending unlocking;④ signal mechanism of specific turning point position.The device is blind operation for teaching teachers, whether lifting or not, only needs to press the table top once, the table main body runs normal and stable, noiseless in the whole process of second-level lifting, maintenance-free for years, fully meets the practical requirements under the scene of primary and secondary school teaching process.

Description

Technical Field

[0001] This invention relates to classroom supplies for primary and secondary schools, specifically a height-adjustable lectern. Background Technology

[0002] In ordinary primary and secondary schools in China, the desks and chairs of students in a classroom are usually of the same standard. In order not to block the view of students in the back row, the conventional seating arrangement is that shorter students sit in the front row, so that all students can read the blackboard teaching content and the graphic content presented on the electronic whiteboard under the condition of information technology teaching.

[0003] Currently, the height of primary and secondary school desks according to the Chinese national standard (functional dimensions of school desks and chairs, GB / T 3976-2002) is 490-760cm. In practice, the height of desks widely used in grades 5-9 of ordinary primary and secondary schools is generally 68-72cm. To prevent students' seats from being too far from the blackboard, the horizontal distance between the front edge of the front row of desks and the blackboard is generally no more than 2 meters, a distance that basically meets the requirements of the national standard.

[0004] In typical primary and secondary school classrooms, the height of a lectern with a full-level desktop is generally 82-85cm, while the height of a lectern equipped with a teaching computer is generally 90-92cm. Near the center of the blackboard, there is usually a (or a movable) "lectern" on the floor, typically 18-22cm high, suitable for teachers and students to step onto. The lectern is positioned at the front center of the lectern, and the teacher often moves around in front of the blackboard. While the height of the teacher for a specific course is not predetermined in each classroom, even a shorter teacher can easily observe all students' learning progress while standing on the lectern.

[0005] The height of the lectern is significantly higher than the eye level of students in their seats, and much higher than the height of their desks. This design is based on the difference in application between teachers standing to lecture and students sitting to learn. Due to the relatively high lectern's proximity, shorter students sitting in the front rows experience visual reading difficulties on the lower part of the blackboard (including display panels in information-based teaching conditions—such as interactive whiteboards), directly impacting their learning mood and effectiveness. This phenomenon is prevalent in grades 1-9, especially in lower grades, where up to 25% of the class may have these reading difficulties. However, schools currently do not purchase lower lecterns for their classes (it is understood that there is currently no mass-produced supply of lecterns with non-traditional heights on the market).

[0006] In response to the above problems, some schools have designed student desks and chairs with height-adjustable structures. However, students in the back rows may experience additional reading difficulties when the chairs of students in the front rows are raised. It is clear that raising the chairs of individual or some students in a classroom is merely a shift in the problem rather than a substantial solution. In other words, raising the chairs is not the best approach to solving the problem.

[0007] In specific application scenarios during classroom teaching, due to considerations such as the control method of raising and lowering the lectern (which should be extremely simple), application time (which should be extremely short), operating noise (which should be noiseless), personal safety (which should be worry-free), as well as the cost level, installation difficulty, maintenance method, and appearance that the product inevitably involves, the application effect of existing raising and lowering design technologies is not ideal, or rather, there is no one that is comprehensively suitable. Summary of the Invention

[0008] The objective of this invention is to provide a height-adjustable lectern for ordinary primary and secondary school classrooms that is easy to operate and operates silently, so as to facilitate all students in the class to read all teaching content on the blackboard without any obstacles.

[0009] The present invention provides a height-adjustable lectern, comprising a main body and an inner vertical enclosure. The side of the main body closest to the blackboard forms an openable and closable outer door. The outer door, together with the other side panels, constitutes the upper enclosure of the main body. The inner vertical enclosure, corresponding to the inner side of the upper enclosure, is fixed to the lectern floor. The invention is characterized by:

[0010] 1) The pneumatic strut located between the center of the bottom side of the horizontal tabletop and the floor of the podium is in an upright position. The lower end of the pneumatic strut is fixed to the floor of the podium, and the upper end is fixedly connected to the horizontal tabletop.

[0011] 2) The lower end of the upright tube is fixed to the podium floor, and the cover is fixed to one side of the upper end of the upright tube. The cover has a horizontal bolt inside, and both ends of the bolt are sloping. The horizontal spring is located between the bolt base plate and the cover, and the two ends of the horizontal spring are respectively connected to the end plate of the cover and the middle of the bolt.

[0012] 3) The active rod has an L-shaped structure. The upper end of its vertical section is fixed to the bottom side of the horizontal table, and the lower flat finger section acts on the outer circumference of the special ring at one end of the bolt.

[0013] 4) The hinge has a coaxial torsion spring. Its horizontal leaf is fixedly connected to the bottom side of the horizontal table, and the upper end of the rotating plate is fixedly connected to the rotating leaf of the hinge. The rotating plate has a vertical opening, and the lower end of the rotating plate corresponds to the tongue slope section of the bolt.

[0014] The fixed connection point of the upper end of the pneumatic strut on the bottom side of the horizontal table is the center of gravity of the table body.

[0015] The upper end of the suspension rod is fixed to the bottom side of the horizontal tabletop. The axis of the suspension rod is in the same line or parallel to the axis of the vertical pipe. The guide head fixed at the lower end of the suspension rod is located inside the vertical pipe, and the outer circumference of the guide head is moderately close to the inner wall of the vertical pipe.

[0016] The sound tube, which can be struck by the rotating plate, is fixed to the upper side of the upright tube.

[0017] The components, from top to bottom, are the top plate, suspension rod, guide head, upright pipe, base plate fixed at the lower end of the upright pipe, and floor plate fixed to the podium floor. These components are repeatedly set at discrete points on the bottom side of the horizontal tabletop, away from the center.

[0018] A top plate is attached and fixed to the center of the bottom side of the desktop. The upper end of the pneumatic strut, the upper end of the active strut, the upper end of the suspension strut, and the horizontal hinge are all connected to the bottom side of the desktop by fixing to the top plate.

[0019] The floorboards are fixed to the podium floor, and the lower ends of the pneumatic struts and the vertical tubes are fixed to the floorboards.

[0020] The horizontal spring consists of two parallel springs.

[0021] Corresponding to the inner side of the outer door of the main table, the inner frame has left and right sliding doors parallel to the blackboard.

[0022] This lectern design includes a main body composed of a horizontal tabletop and an upper panel, an inner vertical panel, and the following mechanisms located within them:

[0023] ① Lifting mechanism – a pneumatic strut standing upright between the center top plate on the bottom side of the table and the platform floor plate, which always outputs an upward rebound force at any moment when it is compressed (intending to push the table body back to the traditional height);

[0024] ② The mechanism for guiding the vertical lifting of the table body is a combination of the top plate, suspension rod, guide head, upright tube, floor plate fixed to the podium floor, and bottom plate fixed to the lower end of the upright tube from top to bottom. The axis of the suspension rod is in the same line or parallel to the axis of the upright tube. Whether it is set at the center of the bottom side of the table or repeatedly set at discrete points far from the center of the bottom side of the table, it provides a guarantee for the vertical lifting of the table body.

[0025] ③Lowering locking and rising unlocking mechanism - composed of a drive rod, specially constructed bolts, horizontal springs, buckles, rotating plates, and hinges carrying torsion springs. Through their organic interlocking reaction, the table body is statically locked after being lowered by a specified amount, and the table body is able to rise back to the traditional height after being unlocked, achieving a stable working state.

[0026] ④ Signal mechanism for reaching a specific turning position – This product is designed for blind operation (when the teacher deems it necessary during instruction) by pressing the tabletop (center): Under certain conditions, the rotating plate, driven by the active lever and bolt, strikes the speaker, emitting a faint single sound that only the operator (teacher) can hear. The teacher then stops pressing the tabletop, and the table body automatically returns to its stable working state after being lowered. If the operator wants to raise the table body to the traditional height, the operator presses the tabletop again. After a short descent, when the operator feels that it can no longer be lowered, the operator releases the pressure, and the table body automatically rises to the traditional working height and returns to a static state.

[0027] The lifting control system, which is composed of the above-mentioned mechanisms and located below the center of the desktop, is the core of this design.

[0028] The table's main body weight is constant. The pneumatic strut's rebound force (lift) under pressure is greater than the table's main body weight, ensuring the table, with the strut fixed to the bottom, maintains a stable height similar to a traditional lectern. When the operator's hand presses on the tabletop with a force greater than the difference between the pneumatic strut's lift and the table's main body weight, the table is in the process of lowering; conversely, if the pressure is removed, the table is in the process of rising (except in locked situations). Pneumatic struts are widely available on the market, and the difference between their lift and the table's main body weight can be preset during production.

[0029] When the main body of the table is not lowered, the upper panel and the inner vertical panel are joined together in the vertical direction, making the appearance of the lectern similar to that of the traditional lectern. When the main body of the table is in a stable working state after being lowered, the upper panel will cover most of the inner vertical panel, and the appearance of the lectern will still be simple.

[0030] The positive effects of this design are as follows: The upright pneumatic support rods always bear the weight of the table body, supporting its stability in both traditional and lowered working states; the combination of the top plate, suspension rods, guide heads, upright tubes, base plate, and floor plate, along with their multiple points of placement between the bottom of the horizontal tabletop and the floor of the podium, reliably ensures the normal vertical lifting and lowering of the table body; the teacher can raise and lower the table in real time according to the progress of the lesson, requiring only one press from the operator for both lowering and raising, and the table body remains stable at the preset height, making operation simple and with sub-second lifting and lowering; only a single, minimal sound is actively set during the descent process to reach the preset position, ensuring noiseless operation throughout; there are no electrical components, and apart from the pneumatic support rods, there are no other hydraulic components, resulting in low construction and installation costs and maintenance-free long-term use. This design fully meets the practical requirements of specific scenarios in the teaching process of ordinary primary and secondary school classrooms. Attached Figure Description

[0031] Figure 1a This is a visual representation of the lectern's working position at its traditional height. Figure 1b It corresponds to Figure 1a A schematic diagram of the stable working state of the pneumatic strut. Figure 1c This is a visual diagram showing the working state of the lectern after it has been lowered. Figure 1d It corresponds to Figure 1c A schematic diagram of the working state of the pneumatic strut. Figure 1e This is a simplified schematic diagram of the inner frame of the lectern in this design.

[0032] Figure 2a This is a schematic diagram showing the fixed position of the lifting control system at the center of the bottom side of the desktop. Figure 2b yes Figure 2a A visual diagram of the lifting control system in the middle. Figure 2c -d are respectively Figure 2b Exploded views of the lifting control system from different perspectives. Figure 2e yes Figure 2c Enlarged view of a portion of the A-cup. Figure 2f yes Figure 2c A magnified view of part B. Figure 2g yes Figure 2d Enlarged view of the local seeker head. Figure 2h This is a visual diagram of the suspension rod. Figure 2i This is a visual diagram of the hinge assembly. Figure 2j yes Figure 2i Exploded view of the consortium Figure 2k This is a visual diagram of a bolt and its two attached horizontal springs. Figure 2l This is a schematic diagram showing the connection between the central nail and one end of the horizontal spring. Figure 2m This is an initial static schematic diagram of a torsion spring. Figure 2n yes Figure 2b A simplified diagram illustrating the data relationships during the construction process.

[0033] Figure 3a -d are intuitive diagrams of the lifting control system's transition nodes during the process of the traditional height table body descending to a stable working state again. Figure 3e -h corresponds to Figure 3a A simplified diagram illustrating the data relationships in the -d lifting control system.

[0034] Figure 4a -d are intuitive diagrams of key nodes in the lifting control system during the process of the table body rising to the traditional height and stable working state. Figure 4e -h corresponds to Figure 4a A simplified diagram illustrating the data relationships in the -d lifting control system.

[0035] Figure 5a -c represents the installation process of the lifting control system and the vertical lifting safety mechanism, shown in the schematic diagram. Figure 5d This is a schematic diagram showing the location distribution of the lifting control system and vertical lifting protection mechanism from a top-down perspective. Detailed Implementation

[0036] Example. See also Figure 1a , Figure 1c , Figure 1e This design is a height-adjustable lectern, including a main body (11) and an inner wall (12). The side of the main body near the blackboard is an openable and closable outer door (1121). The outer door and other side walls together form the upper wall (112) of the main body. The inner wall (12) is located inside the upper wall (112). Angle steel (122) on the inner side of the inner wall (12) is fixed to the lectern floor. The inner wall (12) made of thin steel plate is fixedly connected to the angle steel (122). Obviously, the angle steel (122) ensures the stable positioning of the inner wall (12).

[0037] See Figure 1e and Figure 5d The inner enclosure (12) has interlocking running tracks (123) located on the upper and lower sides near the blackboard, with two sliding doors (121) between the upper and lower running tracks (123). Figure 1e Most of the middle and upper runway (123) has been omitted.

[0038] See Figure 1a When the lectern of this design is at its traditional height, its outer perimeter is formed by the upper panel (112) and the inner vertical panel (12) joined together in the vertical direction. See also Figure 1c When the lectern of this design is in a stable working state after being lowered, its outer perimeter is still composed of the upper panel (112) and the inner vertical panel (12) assembled in the vertical direction. However, the upper panel (112) has covered most of the height of the inner vertical panel (12) from top to bottom.

[0039] See Figure 1b , Figure 1d and compare Figure 1a , Figure 1c The pneumatic strut (2) mainly includes a pressure cylinder (21) and a piston rod (22), etc., and its maximum and minimum height states are as follows: Figure 1b , Figure 1d As shown, this is actually a limit for the lifting of the table body (11) supported by it. The pneumatic strut (2) can be used normally in a temperature environment of [-35°, +60°]; under pressure, the pneumatic strut (2) maintains a constant lifting force, and its rebound force is output in a slow release manner; these performance characteristics are suitable for use in the lifting of the lectern in a classroom environment. Obviously, the pressure of the operator's hand on the tabletop (111) only needs to be greater than the difference between the lifting force of the pneumatic strut (2) and the weight of the table body (11) for the table body (11) to descend.

[0040] See Figure 2a -b and Figure 2c-d: The upper ends of the active rod (5), pneumatic strut (2), and suspension rod (32), as well as the horizontal hinge (622) in the combination of the rotating plate (61) and hinge (62), are all connected to the bottom side of the horizontal tabletop (111) through the connection with the top plate (31). The vertical section of the active rod (5), the axis of the pneumatic strut (2), the center line of the suspension rod (32), and the vertical section of the rotating plate (61) are all perpendicular to the horizontal tabletop (111). The pneumatic strut (2) and the upright tube (34) are both perpendicular to the ground, and their lower ends are fixed to the podium floor by connecting with the floor plate (35). In particular, the upper and lower ends of the pneumatic strut (2) are connected to the top plate (31) and the floor plate (35) by screws.

[0041] exist Figure 5a In -c, each top plate (31) is actually fixedly connected to the bottom side of the horizontal tabletop (111) of the main table body. For the convenience of related explanations, the main table body (11) is omitted in the figure.

[0042] See Figure 5a And compare Figure 2a -b: Several discrete points off-center on the desktop (e.g.) Figure 5a (3 locations in the middle), the suspension rod (32) is vertically fixed to the top plate (31), and the lower end of the suspension rod (32) is inserted and fixed with a guide head (33). Push up each upright pipe (34) to make it fit the corresponding guide head (33) (that is, the inner wall of the upright pipe (34) fits the outer periphery of the guide head (33), and overlaps more with the suspension rod (32) (this state should be temporarily stabilized, such as the upper and lower ends of the tape are respectively pasted on the suspension rod (32) and the upright pipe (34)). During the product installation process, the table body (11) is lifted horizontally (that is, Figure 5a Each top plate (31), the connecting plate (8), the suspension rods (32) attached to the lower side of each top plate (31), the guide head (33), and the upright pipe (34) temporarily fitted with the guide head are lifted as a whole. Then, the guide head (33) below the center point of the table is first inserted into the corresponding center position upright pipe (34) to obtain Figure 5b The state shown. Afterwards (removing the temporary fixation of the uprights (34) relative to the suspension rods (32), for example, by tearing off the tape), allow the other uprights (34) at non-central positions to fall freely (actually still constrained by the guide head (33) fixed at the lower end of the suspension rods (32) attached to their inner walls). The base plate (341) fixed at the lower end of the uprights (34) will roughly overlap the corresponding floor plate (35). The product installer can then apply strong adhesive across the entire area between the base plate (341) and the floor plate (35) to achieve reliable fixation between them. The overall structural state has then changed to... Figure 5c .

[0043] The thin plate of the horizontal tabletop (111) is obviously not strong enough. Figure 5a In -c, with the help of the top plate (31) at the center and the top plates (31) at other locations, and with the help of the strip plate (8) to connect the top plates (31) in an integrated manner, it helps the product lifting control system to be assembled accurately and qualifiedly, helps the relative and accurate positioning between the top plates (31), helps the table body (11) to be more resistant to the teacher's hand operation during lifting, and facilitates the overall and rapid installation of the product at the customer's site.

[0044] Figure 5d This is a top-down view of the lifting control system and the various vertical lifting safety mechanisms relative to the upper enclosure (112) and the inner enclosure (12), showing a possible distribution. It can be seen that an additional vertical lifting safety mechanism could be added at position ④. The upper left corner of the desktop can be opened to accommodate a teaching computer monitor. Figure 5d In the middle, we can see the relative positional relationship between the vertical lifting support mechanism at positions ①-④ and the angle steel (122) (the direct function of the angle steel is to fix the inner enclosure (12) on the podium ground). We can also see the relative positional relationship between the double-opening outer door (1121), the inner left and right sliding doors (121), and the runway (123).

[0045] Comparison Figure 2b and Figure 2c , Figure 2d The lifting control system of the lectern in this design includes a combination of a top plate (31), an active rod (5), a pneumatic support rod (2), a rotating plate (61), and a hinge (62). It includes a suspension rod (32) and a guide head (33) fixed at its lower end, an upright tube (34) in which the guide head (33) is always located, and a floor plate (35) fixed at the lower end of the upright tube (34). It includes a cover (41) and a sound tube (7) (the sound tube can be a section of stainless steel pipe) fixed on adjacent surfaces on the outer side of the upper end of the upright tube (34). The bolt (43) has a special structure, with one section located between the cover (41) and the upright tube (34). The two ends of the horizontal spring (42) (hereinafter referred to as the horizontal spring) are fixed to the end plate (411) of the cover and the middle plate (434) of the bolt, respectively.

[0046] One end of the bolt corresponding to the active rod (5) is a special-shaped ring (432), and the other end of the bolt corresponding to the rotating plate (61) is a tongue slope (433). Obviously, since the buckle cover (41) is fixed on the outside of the upright pipe (34), the bolt (43) can only make left and right horizontal displacements, which will correspondingly compress or stretch the horizontal spring (42).

[0047] Since the upright tube (34) (with the help of the floor plate (35)) is vertically fixed to the podium floor, the guide head (33) is always located inside the upright tube (34). The four sides of the guide head (33) are almost in contact with the inner wall of the upright tube (34), and the guide head (33) is tightly inserted by the upper suspension rod (32). The suspension rod (32) (with the help of the top plate (31)) is vertically connected to the horizontal tabletop (111). Therefore, the horizontal tabletop (111), the top plate (31) fixed on the bottom side of the tabletop, the active rod (5) vertically fixed on the bottom side of the top plate (31), the pneumatic support rod (2), the suspension rod (32), and the rotating plate (61) can only follow the guide head (33) to make vertical up-and-down movements. Obviously, the table body (11) does not rotate or tilt during the lifting process and is always in a normal state.

[0048] In the assembly of the rotating plate (61) and the hinge (62), the horizontal hinge (622) is fixedly connected to the top plate (31). When there is no lifting, the rotating plate (61) is perpendicular to the top plate (31) (this can be achieved by the upper edge of the rotating plate (61) abutting against the top plate (31), see [reference]). Figure 2n (The upper right corner of the table), during the lifting and lowering process of the table body (11), the angle between the rotating plate (61) and the top plate (31) is sometimes less than 90° (considering manufacturing and assembly errors, Figure 2n The allowable range for the horizontal and rotating pages (621) is [90°, 92°], which does not hinder the lifting and lowering operation of the table body (11).

[0049] Please refer to the attached diagram for further explanation: Figure 2n , Figure 3e -h、 Figure 4e -h stands for "simplified schematic diagram," where "simplified schematic diagram" means omitting a part (such as only...). Figure 2n The pneumatic strut (2) that has been removed from its original position is retained. The suspension rod (32), guide head (33), upright tube (34) and other irrelevant elements that do not directly represent the data relationship are hidden to simplify the original excessive overlapping lines. Only the plan view of the bolt (outline) (43), horizontal spring (42), buckle cover (41), active rod (5), rotating plate (61) and top plate (31) is retained. The few hidden lines of the remaining structural components are not blurred. The purpose is to make it easier to understand the essence of the corresponding structural data relationship.

[0050] Figure 3a -d is a 3D visualization. Figure 3e -h is a planar graph, and corresponds to Figure 3a A simplified diagram of data relationships in the lifting control system of -d, with a step-by-step comparison. Figure 3a -d and Figure 3e -h (Note) Figure 3a -d perspective and Figure 3e The relativity of the -h perspective is as follows:

[0051] ① Figure 3a and Figure 3e Comparison and interpretation (note) Figure 2b Towards Figure 3a The transformation, the same institution from Figure 2n Towards Figure 3e (Transformation):

[0052] ●When the operator presses the tabletop (111) with their hand, the pressure is transmitted to the top plate (31) fixed below the center of gravity of the table body (bottom side of the tabletop) (specifically, the top position of the pneumatic strut (2));

[0053] ●(Under the forced guidance of the table body vertical lifting and lowering guarantee mechanism composed of various suspension rods (32), guide heads (33), and upright pipes (34), each guide head (33) is attached to the inner wall of the upright pipe (34) and descends vertically) The top plate (31) along with the active rod (5) and the rotating plate (61) descends vertically until the lower end of the active rod is attached to the outer upper side of the bolt special ring (432) on one side of the flat finger (51) section;

[0054] ●Slightly earlier than the above-mentioned active rod (5) abutting against the outer upper side of the bolt special ring (432), the rotating plate (61) has already touched the bolt tongue slope (433). As the active rod (5) continues to descend before abutting against the bolt special ring (432), because the lower end of the rotating plate (61) is insufficient to push the bolt (43) supported by the relatively firm double spring (42) to move to the left, it is forced to rotate slightly to the right (about 1.5°).

[0055] ● The two horizontal springs (42) between the buckle cover (41) and the bolt base plate (431), which are fixed at both ends to the buckle cover end plate (411) and the bolt middle plate (434) respectively, remain in a static state (no compression and no tension).

[0056] ② Figure 3b and Figure 3f Comparison and interpretation (note self) Figure 3e Towards Figure 3f (Transformation):

[0057] ●The operator's hand is still pressing the tabletop (111): the active rod flat finger (51) continues to slide down along the outer upper side of the bolt special ring (432) (actually, the bolt (43) is pushed by the active rod flat finger (51) and moves horizontally to the right).

[0058] ● The horizontally right-moving bolt tongue slope (433) pushes the rotating plate (61) to continue rotating to the upper right (e.g., rotating to the right for about 21°). At this time, the bolt tongue slope (433) has completely fallen into the projection of the rotating plate opening () on the vertical plane. That is, (as the top plate (31) continues to descend) the rotating plate bottom bar (612) is clearly located below the bottom surface of the bolt (43) (this state only exists momentarily and is about to change).

[0059] ●At this point, the two horizontal springs (42) between the buckle cover (41) and the bolt base plate (431), which are fixed at both ends to the buckle cover end plate (411) and the bolt middle plate (434) respectively, have been compressed to the maximum extent (the length is about 4 / 9 of the static length).

[0060] To clearly show the position and state of the compressed spring (42), Figure 3b The buckle (41) in the middle is cut off, leaving only a small section for illustration.

[0061] ③ Figure 3c and Figure 3g Comparison and interpretation (note self) Figure 3f Towards Figure 3g (Transformation):

[0062] ●Previously, the rotating plate (61) rotated to the right and compressed the torsion spring (63) carried by the hinge (62). Now, due to the lack of any obstruction, the rebound force released by the torsion spring (63) pushes the rotating plate (61) to rotate to the left quickly, and the rotating plate upright opening (611) engages the bolt tongue slope (433) section.

[0063] ●The rapidly left-rotating turntable strikes the sound tube (7) (See and compare for details) Figure 3b and Figure 3c When the operator hears a tiny single tone from the microphone (7), he removes the pressure from the tabletop (111).

[0064] ● At this time, the two horizontal springs (42) between the buckle cover (41) and the bolt base plate (431), which are fixed at both ends to the buckle cover end plate (411) and the bolt middle plate (434) respectively, are compressed as above.

[0065] ④ Figure 3d and Figure 3h Comparison and interpretation (note self) Figure 3g Towards Figure 3h (Transformation):

[0066] ●The operator has removed the pressure on the tabletop (111). Since the constant lift of the pneumatic strut (2) is greater than the weight of the table body (11), the pneumatic strut (2) pushes the table body (11) to rise in a straight line (short stroke) until the bottom bar (612) at the lower end of the rotating plate (61) is locked by the bottom side of the bolt (43). At this time, the mechanism is self-locking - the table body (11) achieves a stable working state again after being lowered.

[0067] ● At this time, the two horizontal springs (42) between the buckle cover (41) and the bolt base plate (431), which are fixed at both ends to the buckle cover end plate (411) and the bolt middle plate (434) respectively, are still compressed (the length is about 7 / 9 of the static length).

[0068] To cancel the working state of the table body (11) after it has been lowered, please refer to the cancellation process. Figure 4a -d stereoscopic visualization, and corresponding Figure 4a Simplified diagram of data relationships in the -d lifting control system Figure 4e -h (Note) Figure 4a -d perspective and Figure 4e -The relativity of the h-perspective):

[0069] ⑤ Figure 4a and Figure 4e Comparison and interpretation (note self) Figure 3d Towards Figure 4a (Transformation):

[0070] ● The operator presses down on the center of gravity of the table (111) again, and the pressure is directly transmitted to the fixed top plate (31) (specifically the upper apex of the pneumatic strut (2)) (the bottom side of the table); the active rod (5), the rotating plate (61), and the top plate (31) fixed to the top plate (31) descend vertically until: the lower end of the active rod (5) is completely below the special ring (432) of the bolt (e.g., 1cm away from the lowest line of the special ring (432); the rotating plate (61) remains upright in space, and the upper edge of the vertical opening (611) is still above the upper side of the bolt (43); the piston rod (22) of the pneumatic strut (2) is just fully pressed into the pressure cylinder (21) and cannot descend further;

[0071] ●When the operator's hand pressure reaches its limit, immediately release the pressure on the horizontal tabletop (111) (at this point, the mechanism cannot stabilize itself and is about to change).

[0072] ● At this time, the two horizontal springs (42) between the buckle cover (41) and the bolt base plate (431), which are fixed at both ends to the buckle cover end plate (411) and the bolt middle plate (434) respectively, have been compressed to the maximum extent (their length is about 4 / 9 of the static length).

[0073] (Note: To show the position and state of the compressed spring (42), Figure 4a The clasp (41) in the middle is cut apart, leaving only a small section for illustration.

[0074] ⑥ Figure 4b and Figure 4f Comparison and interpretation (note self) Figure 4a Towards Figure 4b (Transformation):

[0075] ●The lateral pressure of the active rod flat finger (51) on the bolt special ring (432) disappears, and the two horizontal springs (42) that have been compressed to the maximum extent release their rebound force, pushing the bolt (43) to the left (see Figure 4f ), until the spring (42) returns to its initial static length;

[0076] ● At the same time, the pneumatic strut (2) with constant lift pushes the table body (11) to rise in a straight line until the horizontal finger (51) of the active rod touches the inner lower inclined surface of the special ring (432) of the bolt from bottom to top (this state only exists for a moment and is about to change).

[0077] ● At this time, the bolt tongue slope (433) section is still in the rotating plate vertical opening (611) (that is, the mechanism has not been truly unlocked);

[0078] ⑦ Figure 4c and Figure 4g Comparison and interpretation (note self) Figure 4b Towards Figure 4c (Transformation):

[0079] ●The pneumatic strut (2), with its constant lift, continues to push the table body (11) upwards in a straight line;

[0080] ●The active lever (5) rises with the top plate (31), that is, the flat finger (51) section continuously touches and pushes against the inner lower side of the special ring (432) until the flat finger (51) section is completely above the special ring (432) of the bolt.

[0081] ● Simultaneously, the rising active lever (51) pushes the bolt (43) (a section contained between the buckle (41) and the upright pipe (34)) to the left (see Figure 4f );

[0082] ●The above translation of the bolt (43) completely disengages the bolt tongue slope (433) from the obstruction of the lower edge of the rotating plate vertical opening (611);

[0083] ● During the above process, the two horizontal springs are forced to stretch to their maximum length (which is approximately 11 / 9 of their initial static length);

[0084] ⑧ Figure 4d and Figure 4h Comparison and interpretation (note self) Figure 4c Towards Figure 4d (Transformation):

[0085] ●(see Figure 4g The thrust of the active lever (51) on the bolt's special ring (432) disappears again, and the two stretched springs release their rebound force, pushing the bolt (43) to the right and back to its initial static position (comparison). Figure 4g and Figure 4f );

[0086] ● At the same time, the lower edge of the rotating plate opening (611) no longer has the fastening of the bolt tongue slope (433) section. The pneumatic strut (2) with constant lifting force continues to push the top plate (31), that is, push the active rod (5) fixed below the top plate (31) and the rotating plate (61) to rise in a straight line, that is, push the table body (11) to rise in a straight line until it returns to the stable working state of the traditional height (at this time, the pneumatic strut (2) has reached the maximum height and its lifting force is zero).

[0087] Thus, the height-adjustable lectern of this design has completed the transition between two stable working states, which is a complete application cycle.

[0088] The following section continues to explain this design:

[0089] 1. See Figure 2l The middle screw (435) is a common screw that is screwed into the screw hole of the bolt base plate (431) (and glued to fix it to prevent it from rotating and unscrewing). It is a replacement for the bolt part’s local structure “middle plate (434)”, which greatly simplifies the forming and assembly of the bolt part (43).

[0090] 2. It is worth emphasizing that: one end of the horizontal spring (42) is fixed to the end plate (411) of the buckle cover, while the buckle cover (41) is fixed to the upper side of the upright tube. Therefore, this end of the horizontal spring (42) is fixed during the entire process of lifting and lowering the table body. The other end of the horizontal spring (42) is fixed to the middle plate (434) or the middle nail (435) of the bolt. The bolt (43) is always fastened between the side of the upright tube and the buckle cover (41). Under the direct action of the horizontal finger (51) of the active rod, the bolt (43) moves left or right from time to time. That is, the end of the horizontal spring (42) fixed to the middle of the bolt (43) expands and contracts with the bolt (43) as it moves. This results in the horizontal spring (42) being compressed to a large extent or stretched to a small extent. However, these compressions or stretches are all within the elastic limit of the horizontal spring (42).

[0091] 3. See Figure 2e The inner center of the cover (41) is provided with a strip (412), which isolates the horizontal springs (42) on both sides and prevents the two horizontal springs (42) from getting entangled during tension and compression.

[0092] 4. See Figure 2m and comparison Figure 2j Torsion spring (63): The initial static torsion spring to be assembled should be as follows Figure 2m As shown, during assembly, it should be as follows: Figure 2m The single head is twisted 90° as indicated by the middle arrow, so as to strike the sound tube (7) with appropriate force during the rotation of the turntable (61) to produce an appropriate sound signal.

[0093] 5. Based on the structural condition near the top of the pneumatic strut (2) on the bottom side of the horizontal tabletop (111), it is recommended that the operator use only one hand to directly press the top of the pneumatic strut (2) on the tabletop (marked with a printed graphic or symbol in the official product).

[0094] 6. This design still allows the inner vertical enclosure (12) to be located on the outer periphery of the upper enclosure (112). During the lifting and lowering of the table body (11), the inner vertical enclosure (12) and the upper enclosure (112) still form a complete and simple outer periphery of the lectern in the height direction.

[0095] 7. The pneumatic strut (2) in this design is filled with inert gas in a sealed pressure cylinder (21). If a suitable oil or oil-gas mixture is filled into the sealed pressure cylinder (21), that is, a hydraulic strut or an oil-gas mixture strut is used instead of a pneumatic strut, the effect is similar to that of the above embodiment.

[0096] 8. Compared with the application of pneumatic struts (2) in other fields, the lifting and lowering of the lectern in the classroom may be relatively frequent, that is, most classes may require 1-2 lifting and lowering. This design still facilitates the individual replacement of the pneumatic struts (2) that are fixed to the upper and lower ends with screws when necessary.

Claims

1. A height-adjustable lectern, comprising a main body and an inner vertical enclosure, wherein the side of the main body near the blackboard is an openable and closable outer door, the outer door and other side panels forming the upper enclosure of the main body, and the inner vertical enclosure corresponding to the inner side of the upper enclosure is fixed to the lectern floor, characterized in that: 1) The pneumatic strut located between the center of the bottom side of the horizontal tabletop and the floor of the podium is in an upright position. The lower end of the pneumatic strut is fixed to the floor of the podium, and the upper end is fixedly connected to the horizontal tabletop. 2) The lower end of the upright tube is fixed to the podium floor, and the cover is fixed to one side of the upper end of the upright tube. The cover has a horizontal bolt inside, and both ends of the bolt are sloping. The horizontal spring is located between the bolt base plate and the cover, and the two ends of the horizontal spring are respectively connected to the end plate of the cover and the middle of the bolt. 3) The active rod has an L-shaped structure. The upper end of its vertical section is fixed to the bottom side of the horizontal table, and the lower flat finger section acts on the outer circumference of the special ring at one end of the bolt. 4) The hinge has a coaxial torsion spring. Its horizontal leaf is fixedly connected to the bottom side of the horizontal table, and the upper end of the rotating plate is fixedly connected to the rotating leaf of the hinge. The rotating plate has a vertical opening, and the lower end of the rotating plate corresponds to the tongue slope section of the bolt. 5) The fixed connection point of the upper end of the pneumatic strut on the bottom side of the horizontal table is the center of gravity of the table body; 6) The upper end of the suspension rod is fixed to the bottom side of the horizontal tabletop. The axis of the suspension rod is in the same line or parallel to the axis of the vertical pipe. The guide head fixed at the lower end of the suspension rod is located inside the vertical pipe, and the outer periphery of the guide head is appropriately close to the inner wall of the vertical pipe.

2. The height-adjustable lectern according to claim 1, characterized in that: The sound tube, which can be struck by the rotating plate, is fixed to the upper side of the upright tube.

3. The height-adjustable lectern according to claim 1, characterized in that: The components, from top to bottom, are a top plate, suspension rod, guide head, upright pipe, base plate fixed at the lower end of the upright pipe, and floor plate fixed to the podium floor. These components are repeatedly set at discrete points on the bottom side of the horizontal tabletop away from the center.

4. The height-adjustable lectern according to claim 1, characterized in that: A top plate is attached and fixed to the center of the bottom side of the desktop. The upper end of the pneumatic support rod, the upper end of the active rod, the upper end of the suspension rod, and the horizontal hinge are all connected to the bottom side of the desktop by fixing to the top plate.

5. A height-adjustable lectern according to claim 1, characterized in that: The floor panel is fixed to the podium floor, and the lower ends of the pneumatic struts and the vertical tubes are fixed to the floor panel.

6. A height-adjustable lectern according to claim 1, characterized in that: The horizontal spring consists of two parallel springs.

7. A height-adjustable lectern according to claim 1, characterized in that: Corresponding to the inner side of the outer door of the main table, the inner frame has left and right sliding doors parallel to the blackboard.

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