Lifting white board

Abstract

A lifting white board comprises a vertical frame and a panel installed on the vertical frame, the vertical frame comprises two supporting rods arranged in a left-right spaced mode, each supporting rod comprises a fixed rod and a movable rod movably connected to the fixed rod, and the left side and the right side of the panel are in linkage connection with the two movable rods respectively; the rocking handle is arranged on the at least one fixing rod; the lifting assemblies are arranged in the two supporting rods respectively, the rocking handle and the movable rod are both connected with the lifting assemblies, and the rocking handle drives the movable rod to ascend and descend through the lifting assemblies so as to drive the panel to ascend and descend. The lifting whiteboard accords with ergonomics and use habits, and is more convenient and labor-saving to use.

Description

Technical Field

[0001] This utility model relates to the field of whiteboard technology, specifically to a liftable whiteboard. Background Technology

[0002] A whiteboard functions similarly to a blackboard, serving as a rewritable writing tool. Traditional fixed whiteboards, however, cannot be height-adjustable, failing to adequately meet the needs of users of different heights. To address this technical issue, height-adjustable whiteboards were developed.

[0003] Chinese utility model patent CN220995960U discloses a liftable whiteboard, the structure of which is as follows: Figure 1 and Figure 2 As shown, the device includes a support frame 1a and a panel 2a mounted on the support frame 1a. The support frame 1a includes a left support frame 3a and a right support frame 4a. Both the left support frame 3a and the right support frame 4a include a fixed rod 5a and a movable rod 6a that are movably connected. The movable rod 6a contains a lifting assembly 7a. The lifting assembly 7a includes a sleeve 8a, a gearbox 9a, and a lead screw 10a. The gearbox 9a is mounted on the upper end of the lead screw 10a, and the sleeve 8a is mounted on the lower end of the lead screw 10a. The gearbox 9a is fixed inside the movable rod 6a, and the sleeve 8a is fixed inside the fixed rod 5a. A rotating shaft 11a is also provided between the gearboxes 9a on the left and right sides. A rocker arm 12a is provided on one of the movable rods 6a, and the rocker arm 12a is connected to the rotating shaft 11a inside the gearbox 9a on the corresponding side. During operation, turning the crank 12a drives the rotating shaft 11a to rotate. The rotation of the rotating shaft 11a drives the gearboxes 9a on the left and right sides to rotate, causing the lead screw 10a to rotate synchronously. The lead screw 10a moves up and down relative to the sleeve 8a, causing the movable rod 6a to move up and down relative to the fixed rod 5a, thereby realizing the lifting and lowering of the panel 2a.

[0004] However, the existing lifting whiteboard still has the following technical problems: Since the crank 12a is set on the movable rod 6a, the crank 12a will rise and fall with the panel 2a, which does not conform to ergonomics and usage habits. Moreover, as the height of the crank 12a increases, it is more difficult to crank and it is inconvenient to use. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a lifting whiteboard that conforms to ergonomics and usage habits and is more convenient and labor-saving to use.

[0006] The technical solution of this utility model is: a lifting whiteboard, including a frame and a panel mounted on the frame. The frame includes two support rods spaced apart on the left and right sides. Each support rod includes a fixed rod and a movable rod movably connected to the fixed rod. The left and right sides of the panel are respectively linked to the two movable rods. It also includes...

[0007] A crank handle, which is disposed on at least one of the fixed rods;

[0008] The lifting assembly is respectively disposed in the two support rods. The crank and the movable rod are both connected to the lifting assembly. The crank drives the movable rod to rise and fall through the lifting assembly, thereby driving the panel to rise and fall.

[0009] With the above structure, this utility model has the following advantages:

[0010] This utility model of a lifting whiteboard has a crank handle mounted on a fixed rod. In conjunction with the lifting assembly, the crank handle does not move up or down with the panel, which is more ergonomic and user-friendly. Since the crank handle is always at the same height on the fixed rod, it does not increase the height during cranking, making it more convenient and effortless to use.

[0011] Preferably, each of the lifting components includes

[0012] A lead screw, which is located inside the fixed rod;

[0013] A sleeve, which is vertically and flexibly connected to the lead screw, and the movable rod is fixedly connected to the sleeve;

[0014] A gearbox is disposed at the lower end of the lead screw and fixed inside the fixed rod;

[0015] A rotating shaft is also connected between the two gearboxes, and the crank is linked to the rotating shaft inside the gearbox on the corresponding side;

[0016] Rotating the crank handle drives the rotating shaft to rotate, which in turn drives the gearboxes on the left and right sides to rotate, causing the lead screw to rotate synchronously. The rotation of the lead screw drives the sleeve to move up and down, and the up and down movement of the sleeve drives the movable rod to move up and down, thereby raising and lowering the panel.

[0017] The lifting assembly has a simple structure and can work well with the crank, fixed rod, and movable rod to keep the crank height constant when the movable rod is raised or lowered.

[0018] Preferably, the diameter of the movable rod is larger than the diameter of the fixed rod, so that the movable rod is movably connected to the outside of the fixed rod. Positioning the movable rod outside the fixed rod avoids interference with the lifting assembly during its movement.

[0019] Preferably, the upper end of the sleeve is fixed to the movable rod, and the lower end of the sleeve is fixed with a nut that is threadedly connected to the lead screw. The sleeve is vertically connected to the lead screw through the nut. This arrangement reliably converts the rotational motion of the lead screw into the vertical motion of the sleeve through the cooperation of the nut and the lead screw.

[0020] Preferably, the upper end of the sleeve is fixed inside the movable rod by a sixth fastener passing through both sides of the movable rod; the lower end of the sleeve is fixed with a lower end cap that closes the lower end port, and the lower end cap has a limiting groove inside, through which the nut is fixed inside the lower end cap. The lower end cap closes the lower end of the sleeve, making the installation of the nut more reliable and less likely to fall off, thus making the connection between the nut and the lead screw more secure. The sixth fastener reliably fixes the sleeve to the movable rod, thereby reliably converting the helical motion of the nut and the lead screw into the lifting motion of the sleeve and the movable rod.

[0021] Preferably, the lower end cap is snap-fitted to the sleeve, and the cross-section of the limiting groove is polygonal to restrict the rotation of the nut. The snap-fit ​​connection facilitates the assembly and disassembly of the lower end cap and the sleeve, and the polygonal cross-section of the limiting groove ensures that the nut is reliably fixed inside the sleeve when the lead screw rotates.

[0022] Preferably, the panel includes a plate body and frames fixed to at least the left and right sides of the plate body. Pre-positioning structures are respectively provided between the frames on the left and right sides and the two movable rods. Each pre-positioning structure includes a pre-hanging groove and a positioning post that can be connected to the pre-hanging groove. Both the left and right frames are provided with the positioning post, and both movable rods are provided with the pre-hanging groove; or both the left and right frames are provided with the pre-hanging groove, and both movable rods are provided with the positioning post. The side of each positioning post has a circumferentially provided annular groove, and the positioning post is connected to the pre-hanging groove through the annular groove. This design allows for easy and labor-saving installation by simply connecting the positioning post to the pre-hanging groove during panel installation, eliminating the need to lift the panel. Furthermore, the annular groove cooperates with the pre-hanging groove to limit the left and right position of the panel.

[0023] Preferably, a pen holder is provided below the panel, with both ends of the pen holder fixed to the two movable rods respectively. The pen holder also has a first limiting structure for restricting the front-to-back swing of the panel. The first limiting structure includes a limiting seat and a U-shaped groove on the top of the limiting seat, and the bottom of the panel is installed in the U-shaped groove of the first limiting structure. This arrangement can further limit the front-to-back position of the panel using the first limiting structure, thereby limiting the front-to-back and left-to-right positions of the panel. Moreover, the pen holder also makes the structure of the stand more stable. In addition, the first limiting structure is simple, easy to install with the panel, and provides reliable limiting.

[0024] Preferably, an upper horizontal tube is fitted over the rotating shaft, with both ends of the upper horizontal tube fixed to the two fixed rods respectively; both ends of the upper horizontal tube are also provided with second limiting structures to restrict the left and right movement of the rotating shaft. This arrangement not only uses the upper horizontal tube to hide and protect the rotating shaft, making the overall structure simpler and the rotating shaft more reliable, but also makes the structure of the upright frame more stable; in addition, the setting of the second limiting structure can prevent the rotating shaft from moving left and right, so as not to fall out of the gearbox, ensuring the reliable connection between the rotating shaft and the gearbox, thereby making the operation of the lifting assembly more reliable.

[0025] Preferably, each end of the upper horizontal tube is provided with a first end cap, and both ends of the upper horizontal tube are fixed to the inner sides of the two fixing rods by the first end caps. The second limiting structure includes a rotating seat disposed within the first end cap. The rotating seat is fixed outside the rotating shaft and rotates synchronously with the rotating shaft. One side of the rotating seat abuts against the first end cap, and the other side abuts against the inner side of the fixing rod. This arrangement hides the second limiting structure within the first end caps at both ends of the upper horizontal tube. Furthermore, this second limiting structure requires fewer components, has a simple structure, and can reliably limit the left and right movement of the rotating shaft.

[0026] Preferably, one or more first welding nuts are provided on the fixing rod and inside the first end cap. The first end cap has a first fixing hole that mates with the first welding nut. The first fastener passes through the first fixing hole of the first end cap and is threadedly connected to the first welding nut, thereby fixing both ends of the upper horizontal tube to the two fixing rods. This arrangement allows the first welding nut to be hidden inside the first end cap, resulting in a simpler structure. Moreover, using the first welding nut makes it easier to install the first fastener onto the first end cap and the fixing rod.

[0027] Preferably, a lower horizontal tube is also provided below the upper horizontal tube, and both ends of the lower horizontal tube are respectively fixed to the two fixing rods. This arrangement further stabilizes the structure of the upright frame. Attached image description:

[0028] Figure 1 Here is a schematic diagram of the existing lift-up whiteboard;

[0029] Figure 2 This is a schematic diagram showing the connection between the lifting components and the rotating shaft of an existing lifting whiteboard.

[0030] Figure 3 This is a schematic diagram of the structure of the lifting whiteboard of this utility model;

[0031] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle;

[0032] Figure 5 for Figure 3 A magnified view of a portion of point B in the middle;

[0033] Figure 6 for Figure 3 A magnified view of a portion of point C in the middle;

[0034] Figure 7 This is a cross-sectional view of the lifting whiteboard of this utility model after the support frame has been cut open;

[0035] Figure 8 for Figure 7 A magnified view of a portion of point D in the middle;

[0036] Figure 9 for Figure 7 A magnified view of a portion of point E in the middle;

[0037] Figure 10 for Figure 7 A magnified view of a portion of point F in the middle;

[0038] Figure 11 This is an assembly diagram of the pre-positioning structure of the lifting whiteboard of this utility model;

[0039] Figure 12 This is a schematic diagram of the structure of the support for the lifting whiteboard of this utility model;

[0040] Figure 13 This is a schematic diagram showing the cooperation between the lifting component and the rotating shaft of the lifting whiteboard of this utility model;

[0041] Figure 14 This invention primarily showcases a cross-sectional view of the internal fit between the sleeve and the lead screw of the lifting whiteboard.

[0042] Figure 15 This is an exploded view of the sleeve and lead screw of the lifting whiteboard of this utility model;

[0043] In the existing technical drawings: 1a-upright frame, 2a-panel, 3a-left upright frame, 4a-right upright frame, 5a-fixed rod, 6a-moving rod, 7a-lifting assembly, 8a-sleeve, 9a-gearbox, 10a-lead screw, 11a-rotating shaft, 12a-crank handle;

[0044] In the figures of this utility model: 1-stand, 2-panel, 3-support rod, 4-lifting assembly, 5-fixed rod, 6-movable rod, 7-handle, 8-lead screw, 9-sleeve, 10-gearbox, 11-rotating shaft, 12-plate, 13-frame, 14-pre-positioning structure, 15-pre-hanging groove, 16-positioning post, 17-annular groove, 18-pen holder, 19-limiting seat, 20-U-shaped groove, 21-upper horizontal tube, 22-first end cap, 23-rotating seat, 2 4-First welding nut, 25-First fastener, 26-Lower horizontal tube, 27-Second end cap, 28-Second welding nut, 29-Second fastener, 30-Third end cap, 31-Third welding nut, 32-Third fastener, 33-Fourth fastener, 34-Suspension piece, 35-End cap, 36-First limiting structure, 37-Fifth fastener, 38-Sixth fastener, 39-Nut, 40-Upper end cap, 41-Lower end cap, 42-Limiting groove. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] Example:

[0047] like Figures 3-15 As shown, a retractable whiteboard includes a frame 1 and a panel 2 mounted on the frame 1. The frame 1 includes two support rods 3 spaced apart on the left and right sides. Each support rod 3 includes a fixed rod 5 and a movable rod 6 movably connected to the fixed rod 5. The left and right sides of the panel 2 are respectively linked to the two movable rods 6. It also includes...

[0048] A crank 7 is mounted on at least one fixed rod 5;

[0049] The lifting assembly 4 is respectively installed in the two support rods 3. The crank 7 and the movable rod 6 are both connected to the lifting assembly 4. The crank 7 drives the movable rod 6 to rise and fall through the lifting assembly 4, thereby driving the panel 2 to rise and fall.

[0050] In this embodiment, the crank handle 7 is mounted on the fixed rod 5 for the lifting whiteboard. Combined with the lifting assembly 4, this ensures that the crank handle 7 does not move with the panel 2 when it is raised or lowered, which is more ergonomic and user-friendly. Since the crank handle 7 remains at the same height on the fixed rod 5, it does not increase in height during cranking, making it more convenient and effortless to use. In this embodiment, the up, down, left, and right directions are... Figure 7 As the standard.

[0051] Each lifting component 4 includes

[0052] The lead screw 8 is located inside the fixed rod 5;

[0053] Sleeve 9 is vertically connected to lead screw 8, and movable rod 6 is fixedly connected to sleeve 9;

[0054] The gearbox 10 is located at the lower end of the lead screw 8 and is fixed inside the fixing rod 5;

[0055] A rotating shaft 11 is also connected between the two gearboxes 10, and the crank 7 is linked to the rotating shaft 11 in the corresponding gearbox 10.

[0056] Turning the crank 7 drives the rotating shaft 11 to rotate. The rotation of the rotating shaft 11 drives the gearboxes 10 on the left and right sides to rotate, causing the lead screw 8 to rotate synchronously. The rotation of the lead screw 8 drives the sleeve 9 to move up and down. The up and down movement of the sleeve 9 drives the movable rod 6 to move up and down, thereby raising and lowering the panel 2.

[0057] The lifting assembly 4 has a simple structure and can work well with the crank handle 7, the fixed rod 5 and the movable rod 6 to ensure that the height of the crank handle 7 remains unchanged when the movable rod 6 is raised or lowered.

[0058] The diameter of the movable rod 6 is larger than that of the fixed rod 5, so that the movable rod 6 is movably connected to the outside of the fixed rod 5. Placing the movable rod 6 on the outside of the fixed rod 5 can prevent interference between the movable rod 6 and the lifting assembly 4 when the movable rod 6 is raised or lowered.

[0059] The upper end of the sleeve 9 is fixed to the movable rod 6, and the lower end of the sleeve 9 is fixed with a nut 39 that is threadedly connected to the lead screw 8. The sleeve 9 is vertically connected to the lead screw 8 through the nut 39. This arrangement can reliably convert the rotational motion of the lead screw 8 into the vertical motion of the sleeve 9 through the cooperation of the nut 39 and the lead screw 8.

[0060] The upper end of the sleeve 9 is fixed inside the movable rod 6 by the sixth fastener 38 passing through both sides of the movable rod 6; the lower end of the sleeve 9 is fixed with a lower end cover 41 that closes the lower end port, and a limiting groove 42 is provided inside the lower end cover 41. The nut 39 is fixed inside the lower end cover 41 through the limiting groove 42; the nut 39 can be fixed inside the limiting groove 42 by welding, but not only by welding, but also by other fixing methods, as long as the nut 39 remains fixed relative to the sleeve 9 during the movement of the sleeve 9; the screw 8 rotates, causing the nut 39 inside the lower end cover 41 to move spirally relative to the screw 8, but since the nut 39 is fixed on the lower end cover 41 of the sleeve 9, and the sleeve 9 is fixed on the movable rod 6, and the movable rod 6 can only move up and down relative to the fixed rod 5, the spiral movement of the nut 39 relative to the screw 8 is converted into the up and down movement of the sleeve 9; in this embodiment, the limiting groove 42 is provided at the upper end of the lower end cover 41. The lower end cap 41 can be used to seal the lower end of the sleeve 9, making the installation of the nut 39 more reliable and less likely to fall off, thus making the connection between the nut 39 and the lead screw 8 more secure. The sixth fastener 38 can reliably fix the sleeve 9 to the movable rod 6, thereby reliably converting the helical motion of the nut 39 and the lead screw 8 into the lifting motion of the sleeve 9 and the movable rod 6.

[0061] The lower end cap 41 is snapped into the sleeve 9. The cross-section of the limiting groove 42 is polygonal to restrict the rotation of the nut 39. The snap-fit ​​connection facilitates the assembly and disassembly of the lower end cap 41 and the sleeve 9. The polygonal cross-section of the limiting groove 42 ensures that the nut 39 is reliably fixed inside the sleeve 9 when the lead screw 8 rotates.

[0062] Panel 2 includes a plate body 12 and frames 13 fixed to at least the left and right sides of the plate body 12. Pre-positioning structures 14 are respectively provided between the left and right frames 13 and the two movable rods 6. Each pre-positioning structure 14 includes a pre-hanging groove 15 and a positioning post 16 that can be connected to the pre-hanging groove 15. Both left and right frames 13 are provided with positioning posts 16, and both movable rods 6 are provided with pre-hanging grooves 15; or both left and right frames 13 are provided with pre-hanging grooves 15, and both movable rods 6 are provided with positioning posts 16. The side of the positioning post 16 is provided with an annular groove 17, and the positioning post 16 is connected to the pre-hanging groove 15 through the annular groove 17. In this embodiment, the plate body 12 is surrounded by the frames 13 in all directions. This arrangement allows for easy and labor-saving installation of the panel 2 by simply connecting the positioning post 16 to the pre-hanging groove 15, freeing up both hands and eliminating the need to lift the panel 2. Furthermore, the annular groove 17 cooperates with the pre-hanging groove 15 to restrict the left and right position of the panel 2.

[0063] Below the panel 2, a pen holder 18 is provided. Both ends of the pen holder 18 are fixed to two movable rods 6. The pen holder 18 also has a first limiting structure 36 for restricting the front-to-back swing of the panel 2. The first limiting structure 36 includes a limiting seat 19 and a U-shaped groove 20 on the top of the limiting seat 19. The bottom of the panel 2 is installed within the U-shaped groove 20 of the first limiting structure 36. This arrangement further restricts the front-to-back position of the panel 2 using the first limiting structure 36, thus limiting the front-to-back and left-to-right positions of the panel 2. Furthermore, the pen holder 18 makes the structure of the stand 1 more stable. In addition, the first limiting structure 36 is simple, easy to install with the panel 2, and provides reliable limiting.

[0064] An upper horizontal tube 21 is fitted over the rotating shaft 11, with both ends of the upper horizontal tube 21 fixed to two fixed rods 5. The upper horizontal tube 21 also has second limiting structures at both ends to restrict the left and right movement of the rotating shaft 11. This design not only uses the upper horizontal tube 21 to hide and protect the rotating shaft 11, making the overall structure simpler and the operation of the rotating shaft 11 more reliable, but also makes the structure of the upright frame 1 more stable. Furthermore, the second limiting structures prevent the rotating shaft 11 from moving left and right, ensuring it does not fall out of the gearbox 10 and guaranteeing a reliable connection between the rotating shaft 11 and the gearbox 10, thus making the operation of the lifting assembly 4 more reliable.

[0065] The upper horizontal tube 21 has a first end cap 22 at each end. The two ends of the upper horizontal tube 21 are fixed to the inner sides of two fixing rods 5 through the first end caps 22. The second limiting structure includes a rotating seat 23 disposed inside the first end cap 22. The rotating seat 23 is fixed outside the rotating shaft 11 and rotates synchronously with the rotating shaft 11. One side of the rotating seat 23 abuts against the first end cap 22 and the other side abuts against the inner side of the fixing rod 5. This arrangement hides the second limiting structure inside the first end caps 22 at both ends of the upper horizontal tube 21. Moreover, the second limiting structure requires few parts, has a simple structure, and can reliably limit the left and right movement of the rotating shaft 11.

[0066] One or more first welding nuts 24 are provided on the fixing rod 5 and inside the first end cover 22. The first end cover 22 has first fixing holes that mate with the first welding nuts 24. The first fastener 25 passes through the first fixing holes of the first end cover 22 and is threadedly connected to the first welding nuts 24, thereby fixing both ends of the upper horizontal tube 21 to the two fixing rods 5. In this embodiment, two first welding nuts 24 are provided and are spaced apart vertically inside the first end cover 22. This arrangement makes the first welding nuts 24 hidden inside the first end cover 22, resulting in a simpler structure. Moreover, using first welding nuts 24 makes it easier to install the first fastener 25 onto the first end cover 22 and the fixing rod 5.

[0067] Below the upper horizontal tube 21, a lower horizontal tube 26 is also provided, with both ends of the lower horizontal tube 26 fixed to two fixing rods 5 respectively; thus forming a three-horizontal tube structure consisting of the pen holder 18, the upper horizontal tube 21, and the lower horizontal tube 26; in this embodiment, the upper horizontal tube 21 is located in the middle of the fixing rod 5, and the lower horizontal tube 26 is located at the bottom of the fixing rod 5. This arrangement further stabilizes the structure of the support frame 1.

[0068] The pen holder 18 has a second end cap 27 at each end, and the two ends of the pen holder 18 are fixed to the inner side of the two movable rods 6 through the second end cap 27. One or more second welding nuts 28 are also provided on the movable rods 6 and inside the second end cap 27. The second end cap 27 has a second fixing hole that mates with the second welding nuts 28. The second fastener 29 passes through the second fixing hole of the second end cap 27 and is threadedly connected to the second welding nut 28, thus fixing the two ends of the pen holder 18 to the two movable rods 6. In this embodiment, two second welding nuts 28 are provided and spaced vertically within the second end cap 27. This arrangement allows the second welding nuts 28 to be hidden inside the second end cap 27, resulting in a simpler structure. Furthermore, using second welding nuts 28 makes it easier to install the second fastener 29 onto the second end cap 27 and the movable rods 6.

[0069] The lower horizontal tube 26 has a third end cap 30 at each end, and the two ends of the lower horizontal tube 26 are fixed to the inner side of two fixing rods 5 through the third end cap 30. One or more third welding nuts 31 are also provided on the fixing rods 5 and inside the third end cap 30. The third end cap 30 has a third fixing hole that mates with the third welding nut 31. The third fastener 32 passes through the third fixing hole of the third end cap 30 and is threadedly connected to the third welding nut 31, thereby fixing the two ends of the lower horizontal tube 26 to the two fixing rods 5. In this embodiment, two third welding nuts 31 are provided and are spaced apart vertically inside the third end cap 30. This arrangement makes the third welding nuts 31 hidden inside the third end cap 30, resulting in a simpler structure. Moreover, using third welding nuts 31 makes it easier to install the third fastener 32 onto the third end cap 30 and the fixing rods 5.

[0070] The fourth fastener 33 passes through the side of the rotating seat 23 and is tightened onto the rotating shaft 11, thus fixing the rotating seat 23 and the rotating shaft 11 together. In this embodiment, the rotating seat 23 is cylindrical with one end having a larger diameter than the other end, thereby forming an annular limiting step on the rotating seat 23. The small end of the rotating seat 23 passes through the first end cap 22, and the annular limiting step abuts against the first end cap 22. The end face of the large end abuts against the inner side of the fixing rod 5. The fourth fastener 33 passes through the side of the large end of the rotating seat 23. This fixing structure between the rotating seat 23 and the rotating shaft 11 is simple and easy to assemble and disassemble.

[0071] In this embodiment, both the left and right frames 13 are provided with positioning posts 16, and both movable rods 6 have pre-hanging slots 15. The rotating shaft 11 is a hexagonal drive shaft. The pre-positioning structure 14 also includes a suspension plate 34, which is fixedly connected to the frame 13, and one end of the positioning post 16 is fixed to the suspension plate 34. An annular groove 17 is provided at the other end of the positioning post 16. The movable rod 6 and the fixed rod 5 are hollow inside. The pre-hanging slot 15 is U-shaped and is provided on the inner side of the movable rod 6. The positioning post 16 is suspended from top to bottom to the pre-hanging slot 15 and is limited by the end cap 35 at the top of the movable rod 6. Inside the groove 15; the gearbox 10 is fixed to the fixed rod 5 by the fifth fastener 37; the upper and lower movable sleeve structure of the fixed rod 5 and the movable rod 6 can adopt the existing technology; the transmission structure of the gearbox 10 and the lead screw 8 can adopt the existing technology; the upper end of the sleeve 9 is also fixedly provided with an upper end cover 40 to close the upper end port, and a nut 39 is also fixedly provided inside the upper end cover 40 and located at the lower end. The nut 39 inside the upper end cover 40 can be threadedly connected to the top of the lead screw 8. The sixth fastener 38 passes through the upper end of the sleeve 9 and the upper end of the upper end cover 40, and the upper end cover 40 is snapped to the sleeve 9.

Claims

1. A retractable whiteboard, comprising a frame (1) and a panel (2) mounted on the frame (1), wherein the frame (1) comprises two support rods (3) spaced apart on the left and right, each support rod (3) comprising a fixed rod (5) and a movable rod (6) movably connected to the fixed rod (5), and the left and right sides of the panel (2) are respectively linked to the two movable rods (6); characterized in that: Also includes A crank (7) is disposed on at least one of the fixed rods (5); The lifting assembly (4) is respectively disposed in the two support rods (3). The crank (7) and the movable rod (6) are both connected to the lifting assembly (4). The crank (7) drives the movable rod (6) to rise and fall through the lifting assembly (4), thereby driving the panel (2) to rise and fall.

2. A retractable whiteboard according to claim 1, characterized in that: Each of the lifting components (4) includes The lead screw (8) is located inside the fixed rod (5); A sleeve (9) is vertically connected to the lead screw (8), and the movable rod (6) is fixedly connected to the sleeve (9); Gearbox (10), which is disposed at the lower end of the lead screw (8) and fixed inside the fixing rod (5); A rotating shaft (11) is also connected between the two gearboxes (10), and the crank (7) is linked to the rotating shaft (11) in the gearbox (10) on the corresponding side; Rotating the crank handle (7) drives the rotating shaft (11) to rotate. The rotation of the rotating shaft (11) drives the gearboxes (10) on the left and right sides to rotate, causing the lead screw (8) to rotate synchronously. The rotation of the lead screw (8) drives the sleeve (9) to move up and down. The up and down movement of the sleeve (9) drives the movable rod (6) to move up and down, causing the panel (2) to rise and fall.

3. A retractable whiteboard according to claim 1, characterized in that: The diameter of the movable rod (6) is larger than the diameter of the fixed rod (5) so that the movable rod (6) is movably connected to the outside of the fixed rod (5).

4. A retractable whiteboard according to claim 2, characterized in that: The upper end of the sleeve (9) is fixed on the movable rod (6), and the lower end of the sleeve (9) is fixed with a nut (39) that is threadedly connected to the lead screw (8). The sleeve (9) is connected to the lead screw (8) in a vertically detachable manner through the nut (39).

5. A retractable whiteboard according to claim 4, characterized in that: The upper end of the sleeve (9) is fixed inside the movable rod (6) by a sixth fastener (38) passing through both sides of the movable rod (6); the lower end of the sleeve (9) is fixed with a lower end cover (41) that closes the lower end port, and a limiting groove (42) is provided inside the lower end cover (41), and the nut (39) is fixed inside the lower end cover (41) through the limiting groove (42).

6. A retractable whiteboard according to claim 5, characterized in that: The lower end cap (41) is snapped together with the sleeve (9), and the cross-section of the limiting groove (42) is polygonal to restrict the rotation of the nut (39).

7. A retractable whiteboard according to claim 1, characterized in that: The panel (2) includes a plate (12) and frames (13) fixed on at least the left and right sides of the plate (12). The frames (13) on the left and right sides are respectively provided with pre-positioning structures (14) between them and the two movable rods (6). The pre-positioning structure (14) includes a pre-hanging groove (15) and a positioning post (16) that can be connected to the pre-hanging groove (15). The frames (13) on the left and right sides are provided with the positioning post (16), and the two movable rods (6) are provided with the pre-hanging groove (15), or the frames (13) on the left and right sides are provided with the pre-hanging groove (15), and the two movable rods (6) are provided with the positioning post (16). The side of the positioning post (16) is provided with an annular groove (17), and the positioning post (16) is connected to the pre-hanging groove (15) through the annular groove (17).

8. A retractable whiteboard according to claim 1, characterized in that: Below the panel (2) is a pen holder (18), the two ends of which are fixed to the two movable rods (6) respectively. The pen holder (18) is also provided with a first limiting structure (36) for limiting the back-and-forth swing of the panel (2). The first limiting structure (36) includes a limiting seat (19) and a U-shaped groove (20) set on the top of the limiting seat (19). The bottom of the panel (2) is installed in the U-shaped groove (20) of the first limiting structure (36).

9. A height-adjustable whiteboard according to claim 2, characterized in that: An upper horizontal tube (21) is also sleeved outside the rotating shaft (11), and the two ends of the upper horizontal tube (21) are respectively fixed on the two fixed rods (5); the two ends of the upper horizontal tube (21) are also respectively provided with a second limiting structure for restricting the left and right movement of the rotating shaft (11).

10. A retractable whiteboard according to claim 9, characterized in that: The upper horizontal tube (21) is provided with a first end cap (22) at both ends. The two ends of the upper horizontal tube (21) are fixed to the inner side of the two fixed rods (5) through the first end cap (22). The second limiting structure includes a rotating seat (23) disposed in the first end cap (22). The rotating seat (23) is fixed outside the rotating shaft (11) and rotates synchronously with the rotating shaft (11). One side of the rotating seat (23) abuts against the first end cap (22) and the other side abuts against the inner side of the fixed rod (5).

Images