A retractable writing board

Abstract

The present invention discloses a foldable writing board, wherein a rotating component is connected to one corner of the table top, so that the table top can have a vertical folded state vertically downward, a first vertical unfolded state vertically unfolded, and a second vertical unfolded state when rotating around a rotating fulcrum, and can automatically switch from the vertical unfolded state to the vertical folded state under the action of its own weight. When the table top is in a horizontally opened state, quick folding can be achieved by pushing the table top upward to the second vertical unfolded state, or by pushing the table top forward horizontally to the first vertical unfolded state, without hindering escape.

Description

Technical Field

[0001] The present invention relates to the technical field of writing boards, and in particular to a retractable writing board. Background Art

[0002] Existing retractable writing boards, such as the retractable writing boards on the backs of auditorium seats, generally have a retractable structure in which a horizontal fixing rod is arranged on the back of the seat, brackets are arranged on both sides of the bottom of the writing board, the brackets are provided with sliding holes arranged in the longitudinal direction, and the fixing rods are placed in the two sliding holes. The brackets can move relative to the fixing rods along the length direction of the sliding holes. When the writing board is in the retracted state, the writing board is in a vertical downward position, and the fixing rods are located at the upper end of the sliding holes. When the writing board needs to be opened, the writing board needs to be vertically pulled up until the fixing rods are located at the lower end of the sliding holes, and then the brackets are relatively rotated around the fixing rods until the writing board is in a horizontal state, thus completing the horizontal opening state of the writing board. The writing board needs to go through the process of being stored from a vertical downward storage state → a vertical upward opening state → then flipped to a horizontal state from being stored to being opened for use; there is only one way to store it, and in the event of a natural disaster (earthquake, fire), people have to flip the writing board from a horizontal state to a vertical upward opening state, and then convert the writing board to a vertical downward storage state in order to escape. If the writing board is not fully manipulated to the vertical downward storage state, the writing board is likely to automatically flip to a horizontal state under the action of its own weight, delaying the escape time.

[0003] It can be seen that the existing technology still needs to be improved and enhanced. Summary of the invention

[0004] In view of the above-mentioned deficiencies of the prior art, an object of the present invention is to overcome the deficiencies of the prior art and provide a retractable writing board whose table top can be quickly opened or retracted for easy operation and will not hinder escape.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The foldable writing board comprises a table top, a rotating connection seat, a rotating connection mechanism and a locking and unlocking switching mechanism; a rotating component is provided on one side corner of the table top so that the table top has a longitudinal rotational freedom along the table top direction, and the table top has a vertical storage state of vertical downward and a vertical expansion state of vertical expansion when the rotating component rotates, and the vertical expansion state includes a first vertical expansion state of vertical horizontal placement and a second vertical expansion state of vertical upward placement; the rotating connection seat is rotationally connected and cooperated with the rotating component; the rotating connection mechanism comprises a rotating connection piece connected to the rotating connection seat so that the table top has a lateral rotational freedom and a locking mechanism for locking the relative movement of the rotating connection piece, and the table top is switched between a horizontally opened state and a vertically expanded state when the rotating connection piece rotates; the locking and unlocking switching mechanism is arranged between the rotating component and the rotating connection mechanism, and is used to drive the rotating connection piece to connect with the locking mechanism through the rotating component when the table top rotates from the vertical expansion state to the vertical storage state with the rotating component, and to lock the relative movement of the rotating connection piece when the table top rotates to the vertical expansion state with the rotating component , so that when the rotating connection member disengages from the locking mechanism, the locking state of the rotating connection member is unlocked; the rotating connection mechanism also includes a fixed sleeve sleeved on the outside of the rotating connection member, the locking mechanism includes an L-shaped slot arranged on the outside of the rotating connection member, and a locking member arranged on the fixed sleeve corresponding to the L-shaped slot; the L-shaped slot includes a locking portion arranged along the axial direction of the rotating connection member, a rotating movable portion extending circumferentially at one end of the connecting locking portion, and an arc-shaped guide portion located on the inner side of one end where the locking portion and the rotating movable portion are connected to each other, when the locking member is relatively displaced along the rotating movable portion, the corresponding table plate switches between the horizontally opened state and the second vertically expanded state when the rotating connection member rotates, when the locking member is relatively displaced along the arc-shaped guide portion, the corresponding table plate switches between the horizontally opened state and the first vertically expanded state with the combined rotation of the rotating connection member and the rotating component, when the locking member is clamped into the locking member from the rotating movable portion, the relative movement of the rotating connection member is locked, and when the locking member is disengaged from the locking member to the rotating movable portion, the locking state of the rotating connection member is unlocked.

[0007] Furthermore, the locking piece is connected to the rotating movable part along one end of the locking part to the other end of the locking part, and the corresponding table top rotates 180 degrees along the rotating component; the locking piece is connected to the arc-shaped guide part along one end of the locking part to the other end of the locking part, and the corresponding table top rotates 90 degrees along the rotating component; the locking piece is connected to the arc-shaped guide part along one end of the locking part to the other end of the arc-shaped guide part, and the corresponding table top rotates 45 degrees along the rotating connection piece and the rotating component respectively.

[0008] Furthermore, the rotating connection mechanism also includes a fixed sleeve mounted on the outside of the rotating connection member, and the locking mechanism includes an L-shaped slot arranged on the outside of the rotating connection member, and a locking member arranged on the fixed sleeve corresponding to the L-shaped slot; the L-shaped slot includes a locking portion arranged along the axial direction of the rotating connection member, and a rotating movable portion extending circumferentially along one end of the locking portion, and when the locking member is relatively displaced along the rotating movable portion, the table top is switched between a horizontally opened state and a vertically expanded state as the rotating connection member rotates, and when the locking member is engaged with the locking member from the rotating movable portion, the relative movement of the rotating connection member is locked, and when the locking member is disengaged from the locking member to the rotating movable portion, the locked state of the rotating connection member is unlocked; through such a setting, the locking mechanism is simply set up, and the effect of locking the lateral rotation freedom of the rotating connection member is good.

[0009] Furthermore, the rotating connection structure also includes an elastic driving device that is transmission-connected to the rotating connection member. When the table top is rotated from the vertical storage state to the vertical expansion state, the elastic driving device drives the rotating connection member to make the locking member disengage from the locking portion and enter the rotating movable portion. Through such an arrangement, when the table top is switched from the vertical storage state to the vertical expansion state, the locking member is automatically disengaged from the locking portion and unlocked by the elastic driving device.

[0010] Furthermore, the elastic driving device is an elastic member arranged at the inner end of the fixed sleeve and abutting against the rotating connecting member; through such an arrangement, the elastic driving device is simply arranged and the manufacturing cost is low.

[0011] Furthermore, the locking and unlocking switching mechanism includes a guide structure arranged between the rotating connection piece and the rotating member, and the guide structure enables the rotating connection piece to move along the axial direction of the fixed sleeve when the rotating member rotates relatively to achieve the locking piece to be engaged with or disengaged from the locking part; through such an arrangement, through the guide structure, it is better to achieve driving the locking piece to be engaged with or disengaged from the locking part when the table top is switched between the vertical storage state and the vertical expansion state.

[0012] Furthermore, the guide structure includes a guide track groove provided on the rotating component and a guide slide corresponding to the rotating connecting member and the guide track groove, and the distance between the guide track groove and the rotation center of the rotating component gradually increases from one end to the other end along the circumferential direction; through such an arrangement, the guide structure is simply arranged and convenient for production and manufacturing.

[0013] Furthermore, the end of the guide track groove close to the rotation center of the rotating component is provided with a positioning groove cooperating with the guide slide; through this arrangement, the guide slide plays a basic positioning role when it moves to the end close to the rotation center of the rotating component.

[0014] Furthermore, a receiving groove is provided at the outer end of the rotating connector, the rotating component is placed in the receiving groove, and the guide slide passes through both sides of the rotating connector through the guide track groove and both ends are connected to the two opposite inner walls of the receiving groove; through such an arrangement, the guide slide connection structure is stable and reliable to use.

[0015] Furthermore, the rotating connection mechanism also includes a movable sleeve arranged in the fixed sleeve, the locking mechanism and the rotating connection piece are arranged in the movable sleeve, the movable sleeve is connected to the rotating connection seat, and the movable sleeve is provided with an avoidance movable hole corresponding to the locking piece along the circumferential direction; through such an arrangement, the rotating connection mechanism has a compact structure and a reasonable structural design.

[0016] Furthermore, it also includes a bracket, the rotating connection mechanism is arranged between the rotating connection seat and the bracket, the bracket is provided with a storage cavity located on the inner side, and when the table top is rotated to a vertical storage state along with the rotating component, the table top is placed in the storage cavity; through such an arrangement, the table top can be better stored in the receiving groove, thereby ensuring the safety and reliability of the product.

[0017] Beneficial effects: Compared with the prior art, the foldable writing board of the present invention has a rotating component connected to one corner of the table top, so that the table top can have a vertical storage state facing vertically downward, a first vertical expansion state facing vertically expanded, and a second vertical expansion state when rotating around a rotating fulcrum, and can automatically switch from the vertical expansion state to the vertical storage state under the action of its own weight. When the table top is in the horizontally open state, quick storage can be achieved by pushing the table top upward to the second vertical expansion state, or by pushing the table top forward horizontally to the first vertical expansion state, without hindering escape. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of a retractable writing board with the table top in a vertically retracted position.

[0019] Figure 2 This is a schematic diagram of a retractable writing board with the table top in a horizontally opened state.

[0020] Figure 3 It is a schematic diagram of a rotating connection mechanism and a rotating component.

[0021] Figure 4 It is a schematic diagram of a state where the locking member in the rotary connection mechanism is located in the locking portion.

[0022] Figure 5 It is a schematic diagram showing that the locking member in the rotary connection mechanism is placed in the rotary movable part and the corresponding table top is in the second vertically expanded state.

[0023] Explanation of the main component symbols: 1-table top, 2-rotating connecting seat, 3-rotating connecting mechanism, 4-locking and unlocking switching mechanism, 11-rotating component, 31-rotating connecting member, 32-locking mechanism, 33-fixed sleeve, 321-locking member, 322-locking part, 323-rotating movable part, 324-arc guide part, 34-elastic driving device, 41-guide track groove, 42-guide slide, 43-positioning slot, 311-accommodating slot, 35-movable sleeve, 351-avoidance movable hole, 5-bracket, 51-storage cavity, 325-L-shaped slot. DETAILED DESCRIPTION

[0024] The present invention provides a retractable writing board. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of protection of the present invention.

[0025] See also Figures 1 to 5The retractable writing board of the present invention comprises a table top 1, a rotating connection seat 2, a rotating connection mechanism 3 and a locking and unlocking switching mechanism 4; a rotating component 11 is provided at one side corner of the table top 1 so that the table top 1 has a longitudinal rotational freedom along the desktop direction, and the table top 1 has a vertical storage state vertically downward and a vertical expansion state vertically expanded when rotating with the rotating component 11, and the vertical expansion state includes a first vertical expansion state vertically horizontally placed and a second vertical expansion state vertically upward; the rotating connection seat 2 is rotationally connected and cooperated with the rotating component 11; the rotating connection mechanism 3 includes a rotating connector 31 connected to the rotating connection seat 2 so that the table top 1 has a lateral rotational freedom and a rotating connector for locking the rotating connector The table top 1 is provided with a locking mechanism 32 that is relatively movable with respect to the rotating connector 31, and when the table top 1 rotates with the rotating connector 31, the table top 1 is switched between the horizontally opened state and the vertically expanded state; the locking and unlocking switching mechanism 4 is arranged between the rotating member 11 and the rotating connecting mechanism 3, and is used for locking the rotating connecting member 31 and connecting with the locking mechanism 32 through the rotating member 11 when the table top 1 rotates from the vertically expanded state to the vertically stored state, and for unlocking the locked state of the rotating connecting member 31 when the rotating connector 31 is disengaged from the locking mechanism 32 when the table top 1 rotates with the rotating member 11 to the vertically expanded state; the rotating connecting mechanism 3 also includes a locking mechanism 32 that is sleeved on the rotating member 11 and is used for locking the rotating connecting member 31 and connecting with the locking mechanism 32 when the table top 1 rotates from the vertically expanded state to the vertically stored state; and for unlocking the locked state of the rotating connecting member 31 when the rotating connector 31 is disengaged from the locking mechanism 32 when the table top 1 rotates with the rotating member 11 to the vertically expanded state. The fixed sleeve 33 on the outside of the rotating connection member 31, the locking mechanism 32 includes an L-shaped groove 325 arranged on the outside of the rotating connection member 31, and a locking member 321 arranged on the fixed sleeve 33 and corresponding to the L-shaped groove 325; the L-shaped groove 325 includes a locking portion 322 arranged along the axial direction of the rotating connection member 31, a rotating movable portion 323 extending along the circumferential direction connected to one end of the locking portion 322, and an arc-shaped guide portion 324 located on the inner side of one end where the locking portion 322 and the rotating movable portion 323 are connected to each other and respectively connects the locking portion 322 and the rotating movable portion 323; when the locking member 321 is relatively displaced between the two ends of the rotating movable portion 323, the corresponding table top 1 moves with When the rotating connection member 31 rotates, it switches between a horizontally opened state and a second vertically expanded state; when the locking member 321 is relatively displaced between the rotating movable part 323 and the locking part 322 along the arc-shaped guide part 324, the corresponding table top 1 switches between a horizontally opened state and a first vertically expanded state due to the combined rotation of the rotating connection member 31 and the rotating component 11; when the locking member 321 is inserted into the locking part 322 from the rotating movable part 323 or the arc-shaped guide part 324, the relative movement of the rotating connection member 31 is locked, and when the locking member 321 is disengaged from the locking part 322 to the rotating movable part 323 or the arc-shaped guide part 324, the locked state of the rotating connection member 31 is unlocked.When the locking piece 321 moves relatively between the two ends along the locking portion 322, the corresponding table top 1 switches between the vertical storage state, the first vertical expansion state and the second expansion state. Specifically, when the locking piece 321 moves to the other end of the locking portion 322, the table top 1 is in the vertical storage state; when the locking piece 321 moves to the entrance of the corresponding arc-shaped guide portion 324, the table top 1 is in the first vertical expansion state; when the locking piece 321 moves to the entrance of the corresponding rotating movable portion 323, the table top 1 is in the second vertical expansion state.

[0026] Compared with the prior art, the foldable writing board of the present invention has a rotating component 11 connected to one corner of the table top 1, so that the table top 1 can have a vertical storage state facing vertically downward, a first vertical expansion state facing vertically expanded, and a second vertical expansion state when rotating around a rotating fulcrum, and can automatically switch from the vertical expansion state to the vertical storage state under the action of its own weight. When the table top 1 is in the horizontally opened state, quick storage can be achieved by pushing the table top 1 upward to the second vertical expansion state, or by pushing the table top 1 forward horizontally to the first vertical expansion state. There are various storage methods and it will not hinder escape.

[0027] The locking piece 321 is connected to the rotating movable part 323 along the locking part 322 from one end to the other end of the locking part 322, and the table top 1 rotates 180 degrees along the rotating component 11; the locking piece 321 is connected to the arc guide part 324 along the locking part 322 from one end to the other end of the locking part 322, and the table top 1 rotates 90 degrees along the rotating component 11; the locking piece 321 is connected to the rotating movable part 323 along the locking part 322 from one end to the other end of the rotating movable part 323, and the table top 1 rotates 90 degrees along the rotating connecting member 31; the locking piece 321 is connected to the arc guide part 324 along the locking part 322 from one end to the other end of the rotating movable part 323 and enters the rotating movable part 323, and the table top 1 rotates 45 degrees respectively along the rotating connecting member 31 and the rotating component 11.

[0028] See also Figures 2 to 5In a further embodiment, the rotating member 11 is connected to the outer end of the rotating connection member 31, and the rotating movable part 323 is arranged at one end of the locking part 322 close to the rotating connection member 31; the rotating connection structure also includes an elastic driving device 34 that is transmission-connected to the rotating connection member 31, and the elastic driving device 34 is arranged at the inner end of the rotating connection member 31. When the table top 1 rotates from the vertical storage state to the vertical expansion state, the corresponding elastic driving device 34 drives the rotating connection member 31 to make the locking member 321 disengage from the locking part 322 and enter the rotating movable part 323; through such a setting, when the table top 1 switches from the vertical storage state to the vertical expansion state, the elastic driving device 34 drives the locking member 321 to automatically disengage from the locking part 322 for unlocking, which facilitates the automatic unlocking of the locking mechanism 32.

[0029] See also Figures 1 to 5 In one embodiment, the elastic driving device 34 is an elastic member arranged at the inner end of the fixed sleeve 33 and abutting against the rotating connecting member 31. The elastic member is preferably a reset spring. When the table top 1 rotates from the vertical expansion state to the vertical storage state along with the rotating component 11, the rotating connecting member 31 is driven by the rotating component 11 to move along the inner end of the fixed sleeve 33 to compress the elastic member, and at the same time, the locking member 321 is placed in the locking part 322. When the table top 1 rotates from the vertical storage state to the vertical expansion state along with the rotating component 11, the elastic recovery of the elastic member drives the rotating component 11 to reset outward, and at the same time, the locking member 321 is separated from the locking part 322. Through such a configuration, the elastic driving device 34 is simply arranged and the manufacturing cost is low.

[0030] See also Figures 2 to 5 In one embodiment, the locking and unlocking switching mechanism 4 includes a guide structure provided between the rotating connection member 31 and the rotating component 11. When the rotating component 11 rotates relatively, the guide structure enables the rotating connection member 31 to move along the axial direction of the fixed sleeve 33 to achieve the locking member 321 being engaged with or disengaged from the locking portion 322. Specifically, the guide structure includes a guide track groove 41 provided on the rotating component 11 and a guide slide 42 corresponding to the rotating connection member 31 and the guide track groove 41. The guide slide 42 is placed in the guide track groove 41. The distance between the guide track groove 41 and the rotation center of the rotating component 11 gradually increases from one end to the other end along the circumferential direction, so that when the table top 1 switches between the vertical storage state and the vertical expansion state with the rotating component 11, the guide slide 42 slides along the preset track of the guide track groove 41, so that the rotating component 11 drives the rotating connection member 31 to move relatively in the fixed shaft sleeve 33; through such an arrangement, through the guide structure, it is better to achieve that when the table top 1 switches between the vertical storage state and the vertical expansion state, the locking member 321 is driven to engage in or disengage from the locking portion 322.

[0031] See also Figures 2 to 5 In one embodiment, the guide track groove 41 is provided with a positioning slot 43 that cooperates with the guide slide 42 at one end close to the rotation center of the rotating component 11; through such a setting, the guide slide 42 plays a basic positioning role when it moves to the end close to the rotation center of the rotating component 11.

[0032] See also Figures 2 to 5 In one embodiment, a receiving groove 311 is provided at the outer end of the rotating connector 31, and the rotating component 11 is placed in the receiving groove 311. The guide slide 42 passes through both sides of the rotating connector 31 through the guide track groove 41 and both ends are connected to the two opposite inner walls of the receiving groove 311. Through such a setting, the connecting structure of the guide slide 42 is stable and reliable to use.

[0033] See also Figures 2 to 5 In one embodiment, the rotating connection mechanism 3 also includes a movable sleeve 35 arranged in the fixed sleeve 33, the locking mechanism 32 and the rotating connection member 31 are arranged in the movable sleeve 35, the movable sleeve 35 is connected to the rotating connection seat 2, and the movable sleeve 35 is provided with an avoidance movable hole 351 corresponding to the locking member 321 along the circumferential direction, and the rotating member 11 is rotatably connected to the rotating connection seat 2 at its rotation center; through such an arrangement, the rotating connection mechanism 3 has a compact structure and a reasonable structural design.

[0034] Preferably, a rubber sleeve 30 is provided between the fixed shaft sleeve 33 and the rotating connecting seat 2 to reduce interference and make the rotating connecting seat 2 rotate more smoothly.

[0035] See also Figures 2 to 5 In one embodiment, the L-shaped slots 325 are symmetrically provided on both outer sides of the rotating connecting member 31, and the avoidance activity holes 351 are symmetrically provided on both sides of the movable sleeve 35. The locking member 321 is a pin fixed on the fixed sleeve 33 and passes through the two avoidance activity holes 351 and the two L-shaped slots 325 respectively; through such a configuration, the locking member 321 has a high connection strength, thereby ensuring the locking effect of the locking mechanism 32.

[0036] See also Figures 2 to 5 In one embodiment, it also includes a bracket 5, and the table top 1 is supported on the ground by the bracket 5. The rotating connection mechanism 3 is arranged between the rotating connection seat 2 and the bracket 5. The bracket 5 is provided with a storage cavity 51 located on the inner side. When the table top 1 rotates to a vertical storage state along with the rotating component 11, the table top 1 is placed in the storage cavity 51. Through such a setting, the table top 1 can be better stored in the receiving groove 311, thereby ensuring the safety and reliability of the product.

[0037] It should be noted that a nut is welded inside the fixed sleeve 33, and the bracket is fixedly connected to the fixed sleeve by the cooperation of the nut and the screw.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A retractable writing board, comprising: A table top, one side corner of which is provided with a rotating member that enables the table top to rotate longitudinally along the table top direction, and when the table top rotates with the rotating member, it has a vertical storage state of vertically downward and a vertical expansion state of vertically expanded, and the vertical expansion state includes a first vertical expansion state of vertically horizontal placement and a second vertical expansion state of vertically upward placement; The rotating connecting seat is rotatably connected and matched with the rotating component; The rotating connection mechanism includes a rotating connection piece connected to the rotating connection seat so that the table top has a horizontal rotational freedom and a locking mechanism for locking the relative movement of the rotating connection piece, so that the table top switches between a horizontally opened state and a vertically unfolded state when the rotating connection piece rotates; The locking and unlocking switching mechanism is provided between the rotating member and the rotating connection mechanism, and is used to drive the rotating connection member to connect with the locking mechanism through the rotating member when the table top rotates from the vertically extended state to the vertically stored state along with the rotating member, so as to lock the relative movement of the rotating connection member, and to release the locking state of the rotating connection member when the table top rotates from the vertically extended state along with the rotating member to the vertically extended state, so as to release the rotating connection member from the locking mechanism; The rotary connection mechanism further comprises a fixed sleeve sleeved on the outside of the rotary connection member, and the locking mechanism comprises an L-shaped slot arranged on the outside of the rotary connection member, and a locking member arranged on the fixed sleeve corresponding to the L-shaped slot; The L-shaped slot includes a locking portion arranged along the axial direction of the rotating connection piece, a rotating movable portion connected to one end of the locking portion and extending in the circumferential direction, and an arc-shaped guide portion located on the inner side of one end where the locking portion and the rotating movable portion are connected to each other. When the locking piece is relatively displaced along the rotating movable portion, the table top is switched between a horizontally opened state and a second vertically expanded state as the rotating connection piece rotates. When the locking piece is relatively displaced along the arc-shaped guide portion, the table top is switched between a horizontally opened state and a first vertically expanded state corresponding to the combined rotation of the rotating connection piece and the rotating component. When the locking piece is inserted into the locking piece from the rotating movable portion, the relative movement of the rotating connection piece is locked. When the locking piece is disengaged from the locking piece to the rotating movable portion, the locked state of the rotating connection piece is unlocked.

2. The retractable writing board according to claim 1, characterized in that: The locking member rotates 180 degrees along the rotating member from one end of the locking portion connected to the rotating movable portion to the other end of the locking portion corresponding to the table top; The locking member rotates 90 degrees along the rotating member from one end of the locking portion connected to the arc-shaped guide portion to the other end of the locking portion corresponding to the table top; The locking piece rotates 45 degrees along the rotating connecting piece and the rotating component from one end where the locking part is connected to the arc-shaped guiding part to the other end of the arc-shaped guiding part corresponding to the table top.

3. The retractable writing board according to claim 1, characterized in that: The rotating connection structure also includes an elastic driving device that is transmission-connected to the rotating connection member. When the table top is rotated from a vertical storage state to a vertical expansion state, the elastic driving device drives the rotating connection member to cause the locking member to disengage from the locking portion and enter the rotating movable portion.

4. The retractable writing board according to claim 3, characterized in that: The elastic driving device is an elastic member arranged at the inner end of the fixed sleeve and abutting against the rotating connecting member.

5. The retractable writing board according to claim 1, characterized in that: The locking and unlocking switching mechanism comprises a guide structure arranged between the rotating connector and the rotating member, and the guide structure enables the rotating connector to move along the axial direction of the fixed sleeve when the rotating member rotates relatively to realize the locking member being engaged with or disengaged from the locking portion.

6. The retractable writing board according to claim 5, characterized in that: The guide structure includes a guide track groove provided on the rotating component and a guide slide corresponding to the rotating connecting member and the guide track groove. The distance between the guide track groove and the rotation center of the rotating component gradually increases from one end to the other end along the circumferential direction.

7. The retractable writing board according to claim 6, characterized in that: One end of the guide track groove close to the rotation center of the rotating component is provided with a positioning groove matched with the guide sliding piece.

8. The retractable writing board according to any one of claims 5 to 7, characterized in that: The outer end of the rotating connector is provided with a receiving groove, the rotating member is placed in the receiving groove, the guide slide passes through both sides of the rotating connector through the guide track groove and the two ends are connected to the two opposite inner side walls of the receiving groove.

9. The retractable writing board according to any one of claims 1 to 4, characterized in that: The rotary connection mechanism also includes a movable sleeve arranged in the fixed sleeve, the locking mechanism and the rotary connection piece are arranged in the movable sleeve, the movable sleeve is connected to the rotating connection seat, and the movable sleeve is provided with an avoidance movable hole corresponding to the locking piece along the circumferential direction.

10. The retractable writing board according to any one of claims 1 to 7, characterized in that: It also includes a bracket, the rotating connection mechanism is arranged between the rotating connection seat and the bracket, the bracket is provided with a storage cavity located on the inner side, and when the table top rotates to a vertical storage state along with the rotating component, the table top is placed in the storage cavity.

Images