ADJUSTABLE LIFTING WRITING BOARD

Description

TECHNICAL FIELD

The invention relates to the technical field of learning tools, in particular to an adjustable lifting writing board.

BACKGROUND ART

Writing board usually refers to a flat board used in educational and training occasions and capable of being repeatedly written and erased. In the traditional sense, teaching writing boards are not limited to black writing boards, but covers a variety of writing tools and materials.

The application of writing board is usually divided into writing stage and display stage. In the writing stage, the more comfortable area of the writing board for writers is usually near the middle of the writing board. The higher or lower area requires the writer to bend down or extend his/her arm. Writing for a long time makes the writer easy to feel tired. The existing writing board usually needs to be fixed to maintain its height or angle after being adjusted. In the writing process, it is not easy for the writer to adjust the height of the writing board when holding the pen to write, so that the writer cannot maintain a more comfortable writing posture.

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention is to provide an adjustable lifting writing board, the height of a writing panel is adjusted by synchronously adjusting the relative position of a first outer tube and a first inner tube arranged inside two vertical casings, and a knob arranged near the user's hand is used to switch the lifting, angle adjustment and locking of the device.

To solve the above technical problems, the invention adopts the following technical proposal:

• • an adjustable lifting writing board comprise a writing panel, bottom transverse frames symmetrically arranged under the writing panel and self-locking universal wheels symmetrically installed on the bottom surface of the bottom transverse frames, vertical casings are fixedly installed on the upper surfaces of the bottom transverse frames, a bottom connecting frame is fixedly connected between the bottom transverse frames, and a support plate is arranged under the writing panel;
  • a sliding tube body is arranged inside the vertical casing, a first outer tube and a first inner tube are arranged inside the sliding tube body, the first inner tube and the first outer tube are connected in a sliding way and maintain sealing, and two groups of first outer tubes and first inner tubes extend and retract synchronously so that the writing panel rises and falls;
  • a folding extension tube is arranged under the first outer tube and changes the pressure of the first outer tube and the first inner tube through folding extension, so that liquid flows inside the first outer tube and the first inner tube and then extension and retraction occur between the first outer tube and the first inner tube;
  • a connecting cross tube is arranged between the two sliding tubes, an adjusting block is arranged inside the connecting cross tube, a plurality of channels are provided inside the adjusting block for liquid flowing, adjusting plugs are symmetrically arranged inside the adjusting block, and a check valve is installed on the surface of the adjusting plug for controlling the flow direction of the liquid;
  • a rotating receiving box is fixedly connected to the top of the sliding tube body, and an incomplete inner gear ring and a gear block are arranged inside the rotating receiving box to adjust the tilt angle of the writing panel.

Further, a fixing piece is fixedly connected inside the vertical casing, the first outer tube is fixedly connected inside a first circular groove arranged on the surface of the fixing piece, a sealing plug is connected inside the first outer tube in a seal sliding way, the bottom end of the first inner tube is fixedly connected to the upper surface of the sealing plug, a second inner tube is fixedly connected inside a second circular groove arranged on the upper surface of the first inner tube, the bottom end of the second inner tube is located in a penetrating circular groove arranged on the surface of the sealing plug, the second inner tube is fixedly connected with the sealing plug, a plurality of water guide holes are uniformly provided on the surface of the first inner tube near the sealing plug, the surface of the first outer tube is fixedly connected with a supporting damping block, the supporting damping block is connected with the sliding tube body in a sliding way, a filling supporting block is fixedly connected inside the sliding tube body, the first inner tube is fixedly connected in a seventh circular groove arranged on the bottom surface of the filling supporting block, and a plurality of liquid flowing grooves are arranged inside the filling supporting block.

Further, the adjusting block is fixedly connected inside the connecting transverse tube, adjusting chambers are symmetrically arranged inside the adjusting block, the adjusting plug is rotationally connected inside the adjusting chamber, four first water chutes are symmetrically arranged on the surface of the adjusting block, the two first water chutes located on the same side are connected with the inside of the corresponding adjusting chamber, the check valve is fixedly connected in a third circular groove arranged on the surface of the adjusting plug, one first water chute located on the same side is connected with the inside of the corresponding first inner tube through a pipe, and the other first water chute is connected with the inside of the corresponding second inner tube through a pipe.

Further, the bottom surface of the fixing piece is fixedly connected with a connecting piece, a connecting bottom piece is arranged below the connecting piece, the folding extension tube is located between the connecting piece and the connecting bottom piece, the connecting piece and the connecting bottom piece are fixedly connected inside two opening of the folding extension tube respectively, a fourth circular groove connected with the inside of the folding extension tube and the fixing piece is arranged on the surface of the connecting piece, a plurality of spring rods are symmetrically arranged on the upper surface of the connecting bottom piece, and both ends of the spring rod are fixedly connected with the connecting piece and the connecting bottom piece respectively.

Further, constraint blocks are symmetrically and fixedly connected inside the bottom connecting frame, rotating rods are rotationally connected inside constraint grooves arranged on the surface of the two constraint blocks, the surface of the rotating rod is fixedly connected with a footboard, the footboard is located in a movable groove arranged on the surface of the bottom connecting frame, both ends of the rotating rod are fixedly connected with extrusion blocks respectively, and the extrusion blocks are located inside the bottom transverse frame.

Further, an adjusting cavity is arranged inside the adjusting block and is connected with the inside of the adjusting chamber, annular grooves are symmetrically arranged inside the adjusting cavity, the adjusting chambers are respectively located in the corresponding annular grooves, sealing plugs are symmetrically arranged inside the adjusting cavity, the sealing plugs are rotationally connected in the corresponding annular grooves through dynamic seal rings and first bearings, the sealing plugs are fixedly connected with the corresponding adjusting plugs respectively, the surface of the sealing plug is fixedly connected with a first bearing, a second gear is meshed between the two first bearings, the surface of the second gear is fixedly connected with a connecting column, and the connecting column is rotationally connected in a fifth circular groove arranged on the surface of the connecting transverse tube through a second bearing.

Further, a knob is fixedly connected to the end of the connecting column, a plurality of positioning tubes are fixedly connected to the surface of the connecting transverse tube in a ring array, third springs are arranged inside the positioning tubes, positioning balls are connected inside the positioning tubes in a sliding way, both ends of the third spring are fixedly connected with the third springs and the positioning balls respectively, and positioning slots corresponding to the positioning balls are arranged on one side of the knob close to the connecting transverse tube.

Further, a limit sleeve is fixedly connected to the surface of the connecting transverse tube, a second spring is arranged inside the limit sleeve, a limit sliding block is connected inside the limit sleeve in a sliding way, both ends of the second spring are fixedly connected with the limit sleeve and the limit sliding block respectively, and a restraint top block is fixedly connected to the end of the second spring.

Further, the incomplete inner gear ring is rotationally connected inside the rotating receiving box, an arc-shaped sliding groove is arranged on surface of the rotating receiving box, an arc-shaped sliding block is arranged inside the arc-shaped sliding groove, is fixedly connected with the incomplete inner gear ring, and is connected with the rotating receiving box through the arc-shaped sliding groove in a sliding way, a second connecting tube is fixedly connected to the surface of the arc-shaped sliding block, the writing panel is rotationally connected with the two second connecting tubes through two second bearings, and the gear block is meshed with the incomplete inner gear ring.

Further, a rectangular casing is fixedly connected to the bottom surface of the gear block, a sealing sliding block is connected inside the rectangular casing in a sliding way, a first spring is arranged inside the rectangular casing, both ends of the first spring are fixedly connected with the sealing sliding block and the rectangular casing respectively, two second water chutes are arranged on the surface of the adjusting block and are connected with the sealing sliding block located on the same side through a pipe, and the sealing sliding block is fixedly connected in an eighth straight slot arranged inside the rotating receiving box.

The above proposal of the invention has at least the following beneficial effects:

• • in the above proposal of the invention, the height of the writing panel is adjusted by synchronously adjusting the relative position of the first outer tube and the first inner tube arranged inside the two vertical casings, the footboard used for adjustment is arranged near the user's feet to facilitate the user to adjust when writing, and the knob arranged near the user's hand is used to switch the lifting, angle adjustment and locking of the device, so that the user can adjust the device during the writing process and always maintain a more comfortable writing posture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the schematic diagram of an overall structure provided by the invention.

FIG. 2 is the schematic diagram of a connecting transverse tube in the invention.

FIG. 3 is the schematic diagram of a rotating receiving box in the invention.

FIG. 4 is the schematic diagram of a footboard in the invention.

FIG. 5 is the schematic diagram of a gear block in the invention.

FIG. 6 is the schematic diagram of an adjusting plug in the invention.

FIG. 7 is the position diagram of a first water chute in the invention.

FIG. 8 is the schematic diagram of a sealing plug in the invention.

FIG. 9 is the enlarged view at A in FIG. 2 of the invention.

FIG. 10 is the enlarged view at B in FIG. 2 of the invention.

FIG. 11 is the enlarged view at C in FIG. 3 of the invention.

FIG. 12 is the enlarged view at D in FIG. 3 of the invention.

FIG. 13 is the enlarged view at E in FIG. 4 of the invention.

FIG. 14 is the enlarged view at F in FIG. 4 of the invention.

FIG. 15 is the enlarged view at G in FIG. 4 of the invention.

Reference signs: 101. Writing panel; 102. Bottom transverse frame; 103. Self-locking universal wheel; 104. Bottom connecting frame; 105. Vertical casing; 106. Support plate; 201. Sliding tube body; 202. Connecting transverse tube; 203. Rotating receiving box; 204. Incomplete inner gear ring; 205. Arc-shaped sliding groove; 206. Arc-shaped sliding block; 207. Second connecting tube; 208. Gear block; 209. Rectangular casing; 210. Sealing sliding block; 211. Filling supporting block; 212. First inner tube; 213. First outer tube; 214. Supporting damping block; 215. Second inner tube; 216. Sealing plug; 217. Fixing piece; 218. Connecting piece; 219. Folding extension tube; 220. Connecting bottom piece; 221. Spring rod; 222. Water guide hole; 223. First spring; 301. Adjusting block; 302. First water chute; 303. Adjusting chamber; 304. Second water chute; 305. Adjusting plug; 306. Check valve; 307. Sealing plug; 308. Adjusting cavity; 309. First gear; 310. Second gear; 311. Connecting column; 401. Limit sleeve; 402. Second spring; 403. Limit sliding block; 404. Constraint top block; 405. Knob; 406. Positioning ball; 407. Positioning slot; 408. Positioning tube; 409. Third spring; 501. Constraint block; 502. Rotating rod; 503. Footboard; 504. Extrusion block.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the disclosure are described in more detail below with reference to the drawings. Although the exemplary embodiments of the disclosure are shown in the drawings, it should be understood that the disclosure may be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the disclosure and a complete communication of the scope of the disclosure to the technicians in the field.

As shown in FIG. 1, the embodiment of the invention proposes an adjustable lifting writing board, which comprises a writing panel 101, bottom transverse frames 102 symmetrically arranged under the writing panel and self-locking universal wheels 101 symmetrically installed on the bottom surface of the bottom transverse frames, vertical casings 105 are fixedly installed on the upper surfaces of the bottom transverse frames 102, a bottom connecting frame 104 is fixedly connected between the bottom transverse frames 102, and a support plate 106 is arranged under the writing panel 101.

As shown in FIG. 1 to FIG. 15, a sliding tube body 201 is arranged inside the vertical casing 105, a first outer tube 213 and a first inner tube 212 are arranged inside the sliding tube body 201, the first inner tube 212 and the first outer tube 213 are connected in a sliding way and maintain sealing, and two groups of first outer tubes 213 and first inner tubes 212 extend and retract synchronously so that the writing panel 101 rises and falls.

A folding extension tube 219 is arranged under the first outer tube 213 and changes the pressure of the first outer tube 213 and the first inner tube 212 through folding extension, so that liquid flows inside the first outer tube 213 and the first inner tube 212 and then extension and retraction occur between the first outer tube 213 and the first inner tube 212.

A connecting cross tube 202 is arranged between the two sliding tubes 201, an adjusting block 301 is arranged inside the connecting cross tube 202, a plurality of channels are provided inside the adjusting block 301 for liquid flowing, adjusting plugs 301 are symmetrically arranged inside the adjusting block 301, and a check valve 306 is installed on the surface of the adjusting plug 305 for controlling the flow direction of the liquid.

A rotating receiving box 203 is fixedly connected to the top of the sliding tube body 201, and an incomplete inner gear ring 204 and a gear block 208 are arranged inside the rotating receiving box to adjust the tilt angle of the writing panel 101.

In the embodiment, when the height of the writing panel 101 needs to be adjusted, the first inner tubes 212 and the first outer tubes 213 are filled with liquid, and the first inner tubes 212 inside the two first outer tubes 213 slide synchronously by changing the liquid pressure inside the first inner tubes 212 and the first outer tubes 213, and then the height of the writing panel 101 is changed; the direction of the water outlet end of the check valve 306 is changed by turning the adjusting plug 305, and then the flow direction of the liquid in the two first water chutes 302 located on the same side is changed to control the extension or retraction of the first inner tube 212 and the first outer tube 213; the tilt angle of the writing panel 101 is controlled by controlling the engagement and separation of the incomplete inner gear ring 204 and the gear block 208.

As shown in FIG. 1, FIG. 11, FIG. 13, FIG. 14 and FIG. 15, a fixing piece 217 is fixedly connected inside the vertical casing 105, the first outer tube 213 is fixedly connected inside a first circular groove arranged on the surface of the fixing piece 217, a sealing plug 216 is connected inside the first outer tube 213 in a seal sliding way, the bottom end of the first inner tube 212 is fixedly connected to the upper surface of the sealing plug 216, a second inner tube 215 is fixedly connected inside a second circular groove arranged on the upper surface of the first inner tube 212, the bottom end of the second inner tube 215 is located in a penetrating circular groove arranged on the surface of the sealing plug 216, the second inner tube 215 is fixedly connected with the sealing plug 216, a plurality of water guide holes 222 are uniformly provided on the surface of the first inner tube 212 near the sealing plug 216, the surface of the first outer tube 213 is fixedly connected with a supporting damping block 214, the supporting damping block 214 is connected with the sliding tube body 201 in a sliding way, a filling supporting block 211 is fixedly connected inside the sliding tube body 201, the first inner tube 212 is fixedly connected in a seventh circular groove arranged on the bottom surface of the filling supporting block 211, and a plurality of liquid flowing grooves are arranged inside the filling supporting block 211.

In the embodiment, when the liquid enters between the second inner tube 215 and the first inner tube 212 from the inside of the second inner tube 215 under the action of pressure and enters between the first inner tube 212 and the first outer tube 213 through the water guide hole 222, the sealing plug 216 enables the first inner tube 212 to move downward relative to the first outer tube 213 under the action of the larger liquid pressure above; when the liquid moves in reverse direction, the first inner tube 212 moves upward relative to the first outer tube 213; during the movement of the first inner tube 212, the filling supporting block 211 fixedly connected to the first inner tube 212 and the sliding tube body 201 enables the sliding tube body 201 to move synchronously inside the vertical casing 105.

As shown in FIG. 3, FIG. 6, FIG. 7, FIG. 8, FIG. 13 and FIG. 15, the adjusting block 301 is fixedly connected inside the connecting transverse tube 202, adjusting chambers 303 are symmetrically arranged inside the adjusting block 301, the adjusting plug 305 is rotationally connected inside the adjusting chamber 303, four first water chutes 302 are symmetrically arranged on the surface of the adjusting block 301, the two first water chutes 302 located on the same side are connected with the inside of the corresponding adjusting chamber 303, the check valve 306 is fixedly connected in a third circular groove arranged on the surface of the adjusting plug 305, one first water chute 302 located on the same side is connected with the inside of the corresponding first inner tube 212 through a pipe, and the other first water chute 302 is connected with the inside of the corresponding second inner tube 215 through a pipe.

In the embodiment, the adjusting plug 305 is rotated in the adjusting chamber 303; when the adjusting plug 305 blocks the two first water chutes 302, the liquid inside the second inner tube 215 and the liquid inside the first inner tube 212 cannot be circulated with each other, and the shape variable of the liquid under pressure can be ignored; therefore, the relative position of the first outer tube 213 and the first inner tube 212 is not easily changes, that is, the height of the writing panel 101 remains fixed; when the adjusting plug 305 is rotated not to block the two first water chutes 302, the liquid of the check valve 306 flows to the water inlet end of the check valve 306 through the pipe between the first inner tube 212 and the second inner tube 215, flows through the water outlet end of the check valve 306, and then flows into the second inner tube 215 through the pipe from the water outlet end; in this process, the liquid above the sealing plug 216 between the first outer tube 213 and the first inner tube 212 is reduced, and then the sealing plug 216 drives the second inner tube 215 to move upward; at this time, the adjusting plug block 305 is rotated by 180 degrees, and then the liquid flows in the reverse direction, so that the sealing plug 216 drives the second inner tube 215 to move downward.

As shown in FIG. 4 and FIG. 8, the bottom surface of the fixing piece 217 is fixedly connected with a connecting piece 218, a connecting bottom piece 220 is arranged below the connecting piece 218, the folding extension tube 219 is located between the connecting piece 218 and the connecting bottom piece 220, the connecting piece 218 and the connecting bottom piece 220 are fixedly connected inside two opening of the folding extension tube 219 respectively, a fourth circular groove connected with the inside of the folding extension tube 219 and the fixing piece 217 is arranged on the surface of the connecting piece 218, a plurality of spring rods 221 are symmetrically arranged on the upper surface of the connecting bottom piece 220, and both ends of the spring rod 221 are fixedly connected with the connecting piece 218 and the connecting bottom piece 220 respectively.

In the embodiment, the folding extension tube 219 is folded and retracted by squeezing the connecting bottom piece 220, and the liquid stored inside the folding extension tube 219 is squeezed into the inside of the first outer tube 213 through the fourth circular groove on the surface of the connecting piece 218; when the direction of the water outlet end of the check valve 306 enables the liquid inside the second inner tube 215 to flow between the first inner tube 212 and the first outer tube 213, the liquid squeezed into the first outer tube 213 from the folding extension tube 219 enters the second inner tube 215 through the penetrating circular groove at the bottom of the sealing plug 216 and enters one side of the adjusting chamber 303 at the inlet end of the check valve 306 through the pipe; after passing through the adjusting chamber 303 at the outlet end of the check valve 306, the liquid enters between the first inner tube 212 and the second inner tube 215 through the pipe and enters between the first inner tube 212 and the first outer tube 213 through the water guide hole 222, so that the liquid between the first inner tube 212 and the first outer tube 213 is increased, and the sealing plug 216 drive the first inner tube 212 to move downward in the first outer tube 213; if the direction of the water outlet end of the check valve 306 enables the liquid to flow to the inside of the second inner tube 215 from the first inner tube 212 and the first outer tube 213, the sealing plug 216 drives the first inner tube 212 to move upward inside the first outer tube 213; when the squeezing of the folding extension tube 219 is finished, the connecting bottom piece 220 move in the direction away from the connecting piece 218 under the action of elastic potential energy of the spring rod 221; in this process, when the direction of the water outlet end of the check valve 306 enables the liquid inside the second inner tube 215 to flow between the first inner tube 212 and the first outer tube 213, the resetting and water absorption of the folding extension tube 219 ensure that the sealing plug 216 continues to move downward inside the first outer tube 213 until the folding extension tube 219 is reset; when the direction of the water outlet end of the check valve 306 enables the liquid to flow to the inside of the second inner tube 215 from the first inner tube 212 and the first outer tube 213, the resetting and water absorption of the folding extension tube 219 ensure that the sealing plug 216 continues to move upward inside the first outer tube 213.

As shown in FIG. 4, constraint blocks 501 are symmetrically and fixedly connected inside the bottom connecting frame 104, rotating rods 502 are rotationally connected inside constraint grooves arranged on the surface of the two constraint blocks 501, the surface of the rotating rod 502 is fixedly connected with a footboard 503, the footboard 503 is located in a movable groove arranged on the surface of the bottom connecting frame 104, both ends of the rotating rod 502 are fixedly connected with extrusion blocks 504 respectively, and the extrusion blocks 504 are located inside the bottom transverse frame 102.

In the embodiment, when the folding extension tube 219 is compressed, the footboard 503 can be treaded to ensure that the rotating rod 502 rotates at a certain angle inside the restraint block 501, and then the extrusion block 504 extrudes the connecting bottom piece 220 in the direction of compressing the folding extension tube 219 when rotating along with the rotating rod 502; when the user stops treading the footboard 503, the connecting bottom piece 220 extrudes the extrusion block 504 under the action of elastic potential energy of the spring rod 221, so that the extrusion block 504 drives the rotating rod 502 to reset, that is, the footboard 503 is reset; when the footboard 503 is periodically treaded, the folding extension tube 219 makes periodic extension and retraction movement, facilitating to adjust the height of the writing panel 101.

As shown in FIG. 6, FIG. 7, FIG. 8 and FIG. 10, an adjusting cavity 308 is arranged inside the adjusting block 301 and is connected with the inside of the adjusting chamber 303, annular grooves are symmetrically arranged inside the adjusting cavity 308, the adjusting chambers 303 are respectively located in the corresponding annular grooves, sealing plugs 307 are symmetrically arranged inside the adjusting cavity 308, the sealing plugs 307 are rotationally connected in the corresponding annular grooves through dynamic seal rings and first bearings, the sealing plugs 307 are fixedly connected with the corresponding adjusting plugs 305 respectively, the surface of the sealing plug 307 is fixedly connected with a first bearing 309, a second gear 310 is meshed between the two first bearings 309, the surface of the second gear 310 is fixedly connected with a connecting column 311, and the connecting column 311 is rotationally connected in a fifth circular groove arranged on the surface of the connecting transverse tube 202 through a second bearing.

A knob 405 is fixedly connected to the end of the connecting column 311, a plurality of positioning tubes 408 are fixedly connected to the surface of the connecting transverse tube 202 in a ring array, third springs 409 are arranged inside the positioning tubes 408, positioning balls 406 are connected inside the positioning tubes 408 in a sliding way, both ends of the third spring 409 are fixedly connected with the third springs 409 and the positioning balls 406 respectively, and positioning slots 407 corresponding to the positioning balls 406 are arranged on one side of the knob 405 close to the connecting transverse tube 202.

In the embodiment, by turning the knob 405, the connecting column 311 drives the second gear 310 to rotate at a certain angle, and the corresponding sealing plug 307 drives the adjusting plug 305 to rotate at a certain angle through the transmission of the two first gears 309 to adjust the position relationship between the adjusting plug 305 and the first water chute 302 and the direction of the water outlet end of the check valve 306, facilitating to adjust the position relationship between the first inner tube 212 and the first outer tube 213 and then adjust the height of the writing panel 101; in the rotation process of the knob 405, the positioning balls 406 in the positioning tube 408 generate the resistance for the rotation of the knob 405 through the elastic potential energy of the third spring 409 when sliding out of the positioning slot 407, so that the rotation of the knob 405 is easily sensed and positioned by the operator, thereby reflecting the direction of the check valve 306.

As shown in FIG. 2 and FIG. 9, a limit sleeve 401 is fixedly connected to the surface of the connecting transverse tube 202, a second spring 402 is arranged inside the limit sleeve 401, a limit sliding block 403 is connected inside the limit sleeve 401 in a sliding way, both ends of the second spring 402 are fixedly connected with the limit sleeve 401 and the limit sliding block 403 respectively, and a restraint top block 404 is fixedly connected to the end of the second spring 402.

In the embodiment, the writing panel 101 is turned to turn the bottom edge of the writing panel 101 to the groove on the surface of the constraint top block 404; in this process, the bottom edge of the writing panel 101 first slides towards the groove along one of the oblique planes of the constraint top block 404, and the constraint top block 404 and the limit sliding block 403 move in the direction of compressing the second spring 402 until the bottom edge of the writing panel 101 is embedded in the groove of the constraint top block 404; at this time, the writing panel 101 remains fixed under the action of the elastic potential energy of the second spring 402; the writing panel 101 needs to be turned over, the writing panel 101 is continuously rotated so that the writing panel 101 slides out of the groove along the groove face of the constraint top block 404 against the elastic potential energy of the second spring 402, and slides out along the other oblique plane of the constraint top block 404 until the top edge of the writing panel 101 is turned into the groove.

As shown in FIG. 4, FIG. 5, FIG. 7, FIG. 8 and FIG. 13, the incomplete inner gear ring 204 is rotationally connected inside the rotating receiving box 203, an arc-shaped sliding groove 205 is arranged on surface of the rotating receiving box 203, an arc-shaped sliding block 206 is arranged inside the arc-shaped sliding groove 205, is fixedly connected with the incomplete inner gear ring 204, and is connected with the rotating receiving box 203 through the arc-shaped sliding groove 205 in a sliding way, a second connecting tube 207 is fixedly connected to the surface of the arc-shaped sliding block 206, the writing panel 101 is rotationally connected with the two second connecting tubes 207 through two second bearings, and the gear block 208 is meshed with the incomplete inner gear ring 204.

A rectangular casing 209 is fixedly connected to the bottom surface of the gear block 208, a sealing sliding block 210 is connected inside the rectangular casing 209 in a sliding way, a first spring 223 is arranged inside the rectangular casing 209, both ends of the first spring 223 are fixedly connected with the sealing sliding block 210 and the rectangular casing 209 respectively, two second water chutes 304 are arranged on the surface of the adjusting block 301 and are connected with the sealing sliding block 210 located on the same side through a pipe, and the sealing sliding block 210 is fixedly connected in an eighth straight slot arranged inside the rotating receiving box 203.

In the embodiment, when the two adjusting plugs 305 rotate simultaneously to plug the second water chute 304, the liquid inside the sealing sliding block 210 and the rectangular casing 209 cannot flow to the inside of the adjusting chamber 303, and then relative movement between the rectangular casing 209 and the sealing sliding block 210 hardly occurs, that is, the gear block 208 is meshed with the incomplete inner gear ring 204; at this time, the second connecting tube 207 fixedly connected with the incomplete inner gear ring 204 through the arc-shaped sliding block 206 cannot rotate around the central axis of the incomplete inner gear ring 204, that is, the writing panel 101 cannot be turned over; when the adjusting plug 305 no longer blocks the second water chute 304, the external force pushes the second connecting tube 207, so that the incomplete inner gear ring 204 tends to rotate inside the rotating receiving box 203 until the tooth surface of the gear block 208 slides relative to the teeth of the incomplete inner gear ring 204; in this process, the rectangular casing 209 and the sealing sliding block 210 make relative movement in the direction of compressing the first spring 223, the liquid inside the rectangular casing 209 and the sealing sliding block 210 flows to the corresponding adjusting chamber 303 through the pipe; when the gear block 208 is reengaged with the teeth of the incomplete inner gear ring 204, the rectangular casing 209 and the sealing sliding block 210 are reset under the action of the elastic potential energy of the first spring 223, so that the liquid inside the corresponding adjusting chamber 303 flows back to the inside of the rectangular casing 209 and the sealing sliding block 210 through the second water chute 304 and the pipe.

Operating principle: during use, the user turns the knob 405 to rotate the adjusting plug 305 not to block the first water chute 302, and steps on the footboard 503 to adjust the position of the writing panel 101 to the appropriate position; when the writing area at the user's comfortable writing height is full, the user can step on the footboard 503 to raise or lower the writing panel 101 to a certain height, so that the writer can always maintain a more comfortable writing area; when the contents of the writing panel 101 are displayed after writing, the adjusting plug 305 can be turned not to block the second water chute 304; at this time, the second connecting tube 207 is rotated around the rotating receiving box 203 to an appropriate angle, the bottom edge of the writing panel 101 is always located in the groove of the constraint top block 404, and the relative position between the writing panel 101 and the second connecting tube 207 remains unchanged under the action of the elastic potential energy of the second spring 402; then, when the second connecting tube 207 is rotated, the writing panel 101 rotates along with second connecting tube 207; when the writing panel 101 is rotated to the appropriate position, the adjusting plug 305 plugs the second water chute 304 by turning the knob 405, so that the position of the writing panel 101 can be fixed; when the writing panel 101 needs to be displayed for a long time, the adjusting plug 305 can be turned to plug the first water chute 302 and the adjusting plug 305 simultaneously to keep the writing panel 101 fixed for a long time.

It should be noted that the bottom transverse frame 102, the bottom connecting frame 104, the vertical casing 105 and the connecting transverse tube are tubular, so that the parts can be easily arranged inside them; the friction between the supporting damping block 214 and the sliding tube body 201 makes the sliding tube body 201 and the loaded gravity have less influence on the liquid pressure inside the first outer tube 213, and can keep the second connecting tube 207 and the vertical casing 105 relatively stationary in the case of the adjusting plug 305 not plugging the first water chute 302, thus facilitating to adjust the height and angle of the writing panel 101; the change of the total amount of liquid inside the rectangular casing 209 and the sealing sliding block 210 can balance the increase or decrease of the liquid inside the rectangular casing 209, the sealing sliding block 210 and the adjusting block 301 without affecting the sealing properties by making the sealing plug 216 have a certain deformability; the angle between the second connecting tube 207 and the vertical direction is less than or equal to 30 degrees so that the limit of the constraint top block 404 to the writing panel 101 is in a preferred state; a convex ring is arranged on the surface of the rotating rod 502 and grips two restraint blocks 501 in order to prevent the rotating rod 502 and the restraint block 501 from axially moving along the rotating rod 502; the pipe used in the device is connected through a matching thread groove or a pipe orifice is fixedly connected in a preset groove; when being required to pass through the surface of the component, the pipe can penetrate by arranging a reserved slot, and the pipe with liquid flowing can be sealed by sealant; the use mode of the pipe is known by the prior art, which is not detailed here; when passing through the reserved slot inside the filling supporting block 211, the pipe is fixedly connected with the filling supporting block 211, so that the filling supporting block 211 supports the pipe; the vertical casing 105 is internally connected with the bottom transverse frame 102 to facilitate extrusion between the extrusion block 504 and the connecting bottom piece 220; the sliding tube body 201 is connected with the vertical casing 105 in a sliding way to ensure that the writing panel 101 rises and falls stably.

The above is the preferred embodiment of the invention. It should be noted that ordinary technicians in the technical field may also make a number of improvements and refinements without deviation from the principle of the invention, and these improvements and refinements shall also be considered as the scope of protection of the invention.