Seat table board rotation self-limiting mechanism

Abstract

The application discloses a seat table board rotary self-limiting mechanism, which comprises a supporting arm and a rotary seat, wherein the supporting arm is connected with the rotary seat through a rotating shaft pin; a supporting arm insert which is in rotary cooperation with the rotating shaft pin is installed on the supporting arm through fastening screws; a middle hole is formed in the middle of the rotary seat; a middle rotating block is arranged in the middle hole; the rotary seat is in rotary cooperation with the middle rotating block; an avoiding groove is formed in the middle rotating block; a limiting channel which is in communication with the middle hole is formed in the rotary seat; a limiting pin shaft, a limiting pin crosspiece which is in clamping cooperation with the limiting pin shaft and a return spring are arranged in the limiting channel; one end of the limiting pin shaft is in close contact with the supporting arm insert; the seat table board is self-limited in the backward direction after the supporting arm is laid flat; the whole is self-limited in the backward direction during the recovery of the supporting arm; the risk that the supporting arm cannot be self-locked after being laid flat is avoided; the seat table board can be slowly moved out and recovered; the whole structure is simple; the assembly is simple; the seat table board occupies a small space and has good reliability.

Description

Technical Field

[0001] This invention relates to the field of rotation limiting mechanism technology, specifically a self-limiting mechanism for rotating chairs and dining tables. Background Technology

[0002] Rotatable dining tables are used in seats on high-speed trains, airplanes, cruise ships, and other transportation vehicles. The rotating mechanisms used for these dining tables generally have the following drawbacks: 1. The rotating mechanism lacks a limit device, causing the support arm shaft to prematurely extend the dining table when the main shaft is screwed in or out, resulting in collisions with surrounding objects (such as flocked armrests or painted privacy covers), causing damage to the appearance of surrounding objects; 2. The limit device cannot effectively limit the dining table, with a single limiting direction, poor sensitivity at extremely small angles, or reliability issues such as limit failure or jamming after long-term use.

[0003] A search revealed a Chinese patent publication number CN103182975B for a rotating limiting mechanism for a chair / dining table. The mechanism includes a rotating bracket with a support arm, an outer sleeve, and an inner sleeve. The outer sleeve has a placement groove for holding a limiting lock head. The limiting lock head is fixed in the placement groove and has a positioning groove in which a torsion spring is placed. The rotating bracket has an inner hole with a boss. The outer sleeve, with the limiting lock head installed, is inserted into the inner hole of the rotating bracket, aligning the notch on the limiting lock head with the boss. The inner sleeve is installed in the inner hole of the outer sleeve. The fixing and rotation of the inner and outer sleeves create a clearance groove. This invention uses the fixing and rotation of inner and outer sleeves to create a clearance groove, thereby releasing the rotation lock. It adopts a convenient rotation self-limiting method to ensure that the tabletop does not collide with surrounding objects when it is rotated out. However, this technical solution has the following drawbacks: the tabletop does not self-lock when it is flat, the tabletop may tip over and cause passengers' tableware or cups to overturn, the torsion spring is prone to failure and has poor reliability, there may be problems such as jamming during rotation, the tabletop cannot be moved out and retracted slowly, and the aluminum material of the support arm and limit lock head is prone to weakening or even failure of the limit function due to long-term wear. Therefore, it is necessary to design a rotating self-limiting mechanism for the seat tabletop. Summary of the Invention

[0004] The purpose of this invention is to provide a self-limiting mechanism for rotating a chair and dining table to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a self-limiting mechanism for rotating a chair and dining table, comprising a support arm and a rotating seat, wherein the support arm is connected to the rotating seat via a pivot pin;

[0006] The support arm is fitted with a support arm insert that rotatably engages with a pivot pin via fastening screws. The rotating seat has a central hole with a central rotating block inside. The rotating seat and the central rotating block rotatably engage. The central rotating block has a clearance groove. The rotating seat has a limiting channel communicating with the central hole. The limiting channel contains a limiting pin, a limiting pin crossbar that engages with the limiting pin, and a return spring. One end of the limiting pin is in close contact with the support arm insert. When the tabletop is used, the support arm insert pushes the limiting pin to move, and the other end of the limiting pin enters the clearance groove. One end of the return spring abuts against the side of the limiting pin crossbar facing the clearance groove, and the other end of the return spring abuts against the limiting channel.

[0007] A first damping pad is provided on one side of the intermediate rotating block, and a second damping pad is provided on the other side of the intermediate rotating block. The first damping pad and the second damping pad are in contact with the rotating seat. The first damping pad, the intermediate rotating block and the second damping pad are all provided with inner holes. A rotating fixing shaft that is fixedly connected to the seat passes through the inner holes of the first damping pad, the intermediate rotating block and the second damping pad.

[0008] The rotating fixed shaft is provided with a fastening mechanism for axially fastening the first damping pad, the intermediate rotating block and the second damping pad. The fastening mechanism is also provided with a guide pin. The first damping pad and the second damping pad have pin holes that cooperate with the guide pin.

[0009] The rotating seat is provided with a crescent-shaped guide and limiting groove in the circumference, and the guide pin passes through the pin hole on the first damping pad, the crescent-shaped guide and limiting groove, and the pin hole on the second damping pad in sequence.

[0010] In a further embodiment, the pivot pin is provided with a damping protection mechanism that cooperates with the support arm and the rotating seat. The damping protection mechanism includes a support bushing and a damping bushing respectively located at both ends of the pivot pin. The support arm and the rotating seat are each provided with mounting holes that cooperate with the support bushing and the damping bushing.

[0011] In a further embodiment, the fastening mechanism includes a positioning pin disposed on a rotating fixed shaft for fixing the first damping pad, the intermediate rotating block and the second damping pad, and the guide pin is disposed on the rotating fixed shaft.

[0012] In a further embodiment, the second damping washer has a rotating washer mounted on a rotating fixed shaft on one side, an end washer mounted on the rotating fixed shaft on one side of the rotating washer, and an anti-loosening nut that mates with the rotating fixed shaft is provided on one side of the end washer.

[0013] In a further embodiment, the limiting channel includes a convex hole and a limiting hole that are interconnected on the rotating seat. The limiting hole is engaged with one end of the limiting pin shaft. The convex hole is connected to the intermediate hole. The limiting pin crossbar is disposed in the convex hole and is slidably engaged with the convex hole.

[0014] In a further embodiment, the arm insert is provided with a limiting protrusion.

[0015] In a further embodiment, both sides of the rotating seat are provided with rotating grooves that cooperate with the first damping pad, the second damping pad, the rotating pad, and the end pad.

[0016] In a further embodiment, the crescent-shaped guide limiting groove is a quarter-circle arc groove with the center of the rotating seat as the center. When the dining table is used, the rotating seat rotates around the rotating fixed axis, and the crescent-shaped guide limiting groove rotates along the guide pin. After the rotating seat rotates 90 degrees, the support arm rotates 90 degrees around the rotating shaft pin to complete the flattening of the dining table.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] 1. The crescent-shaped guide and limiting groove ensures that the total rotation angle of the dining table is 90 degrees. The dining table and the support arm work together to drive the rotating seat to rotate 90 degrees around the fixed rotation axis. During the 90-degree rotation, the design of the first and second damping pads makes the rotating seat rotate slowly. After rotating 90 degrees, the support arm flips. When the support arm flips, the linkage support arm insert presses down the limiting pin and moves into the clearance groove of the middle rotating block. Then, the limiting pin crossbar squeezes the two return springs, which effectively ensures that the limiting pin returns to its normal position after long-term use and avoids the situation where the dining table gets stuck or even cannot be retracted.

[0019] 2. The support bushing provides support and effectively prevents the stiffness of the pivot pin from being subjected to a large overturning force when the limit state is reached. The damping bushing provides the damping required during overturning, allowing the tabletop to fall slowly.

[0020] 3. By cooperating with the rotating fixed shaft through the first damping pad, the intermediate rotating block, the second damping pad, and the rotating pad, smooth damping is ensured. During the process of the rotating seat rotating and driving the table board to move out and retract, the first and second damping pads adhere to the rotating seat, causing the rotating seat to rotate slowly, thus allowing the table board to move out and retract slowly. The first damping pad, the intermediate rotating block, and the second damping pad are fixed by the positioning pin, and the rotating fixed shaft, the first damping pad, the rotating seat, the second damping pad, and the rotating pad are fixed by the guide pin, ensuring normal operation of the whole. The whole is tightened by the cooperation of the end pad and the anti-loosening nut. The anti-loosening nut cooperates with the rotating fixed shaft to adjust the magnitude of the tightening force, thereby controlling the magnitude of the rotational damping and improving the overall reliability. The overall structure is simple, easy to assemble, and occupies little space.

[0021] 4. By setting the limiting protrusion, after the outrigger is rotated 90 degrees and laid flat, the limiting pin is still pressed down in the clearance groove of the middle rotating block. At this time, the outrigger cannot drive the rotating seat to flip backward, realizing the self-limiting of the outrigger in the backward direction after it is laid flat, and the overall backward rotation self-limiting during the outrigger retraction process, avoiding the risk of the outrigger not being able to lock after it is laid flat. Attached Figure Description

[0022] Figure 1 This is an exploded view of the entire invention;

[0023] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 3 This is an overall sectional view of the present invention;

[0025] Figure 4 , Figure 5 and Figure 6 This is a schematic diagram of the connection between the rotating limiting mechanism of the present invention and the dining table;

[0026] The attached figures are labeled as follows: 1. Support arm; 2. Rotary seat; 3. Rotary fixed shaft; 4. First damping pad; 5. Intermediate rotating block; 6. Second damping pad; 7. Rotary pad; 8. End pad; 9. Anti-loosening nut; 10. Rotary shaft pin; 11. Support bushing; 12. Damping bushing; 13. Limiting pin shaft; 14. Limiting pin crossbar; 15. Return spring; 16. Support arm insert; 17. Fastening screw; 18. Positioning pin; 19. Guide pin. Detailed Implementation

[0027] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0028] Please see Figures 1-6 The present invention provides a technical solution: a self-limiting mechanism for rotating a chair and dining table, comprising a support arm 1 and a rotating seat 2, wherein the support arm 1 is connected to the rotating seat 2 via a pivot pin 10;

[0029] A support arm insert 16, which rotates and engages with a pivot pin 10, is installed on the support arm 1 by fastening screws 17. A central hole is provided in the middle of the rotating seat 2, and a central rotating block 5 is provided in the central hole. The rotating seat 2 and the central rotating block 5 rotate and engage. An clearance groove is provided on the central rotating block 5. A limiting channel communicating with the central hole is provided on the rotating seat 2. A limiting pin 13, a limiting pin crossbar 14 that engages with the limiting pin 13, and a return spring 15 are provided in the limiting channel. One end of the limiting pin 13 is in close contact with the support arm insert 16. When the dining table is used, the support arm insert 16 pushes the limiting pin 13 to move, and the other end of the limiting pin 13 enters the clearance groove. One end of the return spring 15 abuts against the side of the limiting pin crossbar 14 facing the clearance groove, and the other end of the return spring 15 abuts against the limiting channel.

[0030] A first damping pad 4 is provided on one side of the intermediate rotating block 5, and a second damping pad 6 is provided on the other side of the intermediate rotating block 5. The first damping pad 4 and the second damping pad 6 are in contact with the rotating seat 2. The first damping pad 4, the intermediate rotating block 5 and the second damping pad 6 are all provided with inner holes. A rotating fixing shaft 3 that is fixedly connected to the seat passes through the inner holes of the first damping pad 4, the intermediate rotating block 5 and the second damping pad 6.

[0031] The rotating fixed shaft 3 is provided with a fastening mechanism for axially fastening the first damping pad 4, the intermediate rotating block 5 and the second damping pad 6. The fastening mechanism is also provided with a guide pin 19. The first damping pad 4 and the second damping pad 6 are provided with pin holes that cooperate with the guide pin 19.

[0032] The rotating seat 2 has a crescent-shaped guide and limiting groove around its circumference. The guide pin 19 passes through the pin hole on the first damping pad 4, the crescent-shaped guide and limiting groove, and the pin hole on the second damping pad 6 in sequence.

[0033] Through the above technical solution, the rotating fixed shaft 3 is fixed to the external parts, and the dining table is installed on the support arm 1. The crescent-shaped guide limiting groove ensures that the total rotation angle of the dining table is 90 degrees. The dining table and the support arm 1 cooperate to drive the rotating seat 2 to rotate 90 degrees around the rotating fixed shaft 3. During the 90-degree rotation, the design of the first damping pad 4 and the second damping pad 6 makes the rotating seat 2 rotate slowly. After rotating 90 degrees, the support arm 1 is flipped. When the support arm 1 is flipped, the linkage support arm insert 16 presses down the limiting pin 13 and moves it into the clearance groove of the middle rotating block 5. Then, the limiting pin crossbar 14 squeezes the two return springs 15, effectively ensuring that the limiting pin 13 will not be damaged after long-term use. 3. Normal return to position to avoid the tabletop getting stuck or even unable to retract. The first damping pad 4, the middle rotating block 5, and the second damping pad 6 cooperate with the rotating fixed shaft 3 to ensure smooth damping. During the process of the rotating seat 2 rotating and driving the tabletop to move out and retract, the first damping pad 4 and the second damping pad 6 adhere to the rotating seat 2, making the rotating seat 2 rotate slowly, so that the tabletop moves out and retracts slowly. The fastening mechanism ensures overall stability and improves overall reliability. The overall structure is simple, the assembly is simple, and the space occupied is small. It realizes the self-limiting of the support arm 1 in the backward direction after it is flattened, the self-limiting of the overall backward rotation during the retraction of the support arm 1, and the self-limiting of the rotation of the support arm 1 during the overall retraction process.

[0034] Both the limiting pin 13 and the support arm insert 16 are made of wear-resistant and high-strength materials to avoid wear caused by repeated friction.

[0035] In a further embodiment, the pivot pin 10 is provided with a damping protection mechanism that cooperates with the support arm 1 and the rotating seat 2. The damping protection mechanism includes a support bushing 11 and a damping bushing 12 respectively provided at both ends of the pivot pin 10. The support arm 1 and the rotating seat 2 are both provided with mounting holes that cooperate with the support bushing 11 and the damping bushing 12.

[0036] Through the above technical solution, the support bushing 11 provides support and effectively prevents the stiffness of the pivot pin 10 from being subjected to a large overturning force when the limit state is affected. The damping bushing 12 provides the damping required during the overturning, so that the table board falls slowly.

[0037] In a further embodiment, the fastening mechanism includes a positioning pin 18 disposed on the rotating fixed shaft 3 for fixing the first damping pad 4, the intermediate rotating block 5 and the second damping pad 6, and a guide pin 19 disposed on the rotating fixed shaft 3.

[0038] The above technical solution uses positioning pin 18 to fix the first damping pad 4, the intermediate rotating block 5, and the second damping pad 6, and guide pin 19 to fix the rotating fixed shaft 3, the first damping pad 4, the rotating seat 2, and the second damping pad 6, ensuring the normal operation of the whole system.

[0039] In a further embodiment, a rotating washer 7 mounted on the rotating fixed shaft 3 is provided on one side of the second damping washer 6, an end washer 8 mounted on the rotating fixed shaft 3 is provided on one side of the rotating washer 7, and an anti-loosening nut 9 that cooperates with the rotating fixed shaft 3 is provided on one side of the end washer 8.

[0040] Both the rotating washer 7 and the end washer 8 have through holes that mate with the guide pin 19.

[0041] The above technical solution uses the rotating washer 7, the end washer 8 and the anti-loosening nut 9 to fasten the whole. The anti-loosening nut 9 cooperates with the rotating fixed shaft 3 to adjust the magnitude of the fastening force, thereby controlling the magnitude of the rotational damping.

[0042] In a further embodiment, the limiting channel includes a convex hole and a limiting hole that are interconnected on the rotating seat 2. The limiting hole is engaged with one end of the limiting pin 13, the convex hole is connected to the middle hole, and the limiting pin crossbar 14 is provided in the convex hole and is slidably engaged with the convex hole.

[0043] Through the above technical solution, the convex hole and the limiting hole cooperate to facilitate the movement of the limiting pin shaft 13 to drive the limiting pin crossbar 14.

[0044] In a further embodiment, the arm insert 16 is provided with a limiting protrusion.

[0045] Through the above technical solution, the setting of the limiting protrusion ensures that after the support arm 1 is rotated 90 degrees and laid flat, the limiting pin 13 is still pressed down in the clearance groove of the middle rotating block 5. At this time, the support arm 1 cannot drive the rotating seat 2 to flip backward, thus realizing the self-limiting of the support arm 1 in the backward direction after it is laid flat. During the recovery process of the support arm 1, the entire backward rotation is self-limiting, avoiding the risk that the support arm 1 cannot lock itself after it is laid flat.

[0046] In a further embodiment, rotating grooves are provided on both sides of the rotating seat 2 to cooperate with the first damping pad 4, the second damping pad 6, the rotating pad 7 and the end pad 8.

[0047] The above technical solution facilitates the installation of the first damping pad 4, the second damping pad 6, the rotating pad 7, and the end pad 8 by setting the groove, ensuring the normal operation of the whole system.

[0048] In a further embodiment, the crescent-shaped guide limiting groove is a quarter-circle arc groove with the center of the rotating seat 2 as the center. When the dining table is used, the rotating seat 2 rotates around the rotating fixed shaft 3, and the crescent-shaped guide limiting groove rotates along the guide pin 19. After the rotating seat 2 rotates 90 degrees, the support arm 1 rotates 90 degrees around the rotating shaft pin 10 to complete the flattening of the dining table.

[0049] Through the above technical solution, during the rotation of the rotating seat 2 around the rotating fixed shaft 3, the crescent-shaped guide limiting groove on the rotating seat 2 rotates with the rotating seat 2, so that the crescent-shaped guide limiting groove rotates along the guide pin 19, realizing the 90-degree rotation adjustment of the rotating seat 2. After rotating 90 degrees, the support arm 1 rotates 90 degrees around the rotating shaft pin 10, and the limiting pin 13 presses down into the clearance groove of the middle rotating block 5, realizing the flattening and self-locking of the dining table.

[0050] Working principle: The rotating fixed shaft 3 is fixed to the external parts, and the dining table is installed on the support arm 1. The crescent-shaped guide limit groove ensures that the total rotation angle of the dining table is 90 degrees. Through the cooperation between the dining table and the support arm 1, the rotating seat 2 rotates 90 degrees around the rotating fixed shaft 3. During the 90-degree rotation, the design of the first damping pad 4 and the second damping pad 6 makes the rotating seat 2 rotate slowly. After rotating 90 degrees, the support arm 1 is flipped. When the support arm 1 is flipped, the linkage support arm insert 16 is pressed down to limit the movement. The pin 13 moves down into the clearance groove of the intermediate rotating block 5, and then, through the limit pin crossbar 14, squeezes the two return springs 15, effectively ensuring that the limit pin 13 returns to its normal position after long-term use, avoiding the situation where the tabletop gets stuck or even cannot be retracted. The support bushing 11 provides support and effectively prevents the stiffness of the rotating pin 10 from being subjected to a large overturning force when in the limit state. The damping bushing 12 provides the damping required for overturning, allowing the tabletop to fall slowly. Through the first damping pad 4, the intermediate rotating block 5, and the second... The two damping pads 6 and 7 cooperate with the rotating fixed shaft 3 to ensure smooth damping. During the rotation of the rotating seat 2, which drives the dining table to move out and retract, the first damping pad 4 and the second damping pad 6 adhere to the rotating seat 2, making the rotating seat 2 rotate slowly, so that the dining table moves out and retracts slowly. The first damping pad 4, the intermediate rotating block 5 and the second damping pad 6 are fixed by the positioning pin 18. The rotating fixed shaft 3, the first damping pad 4, the rotating seat 2, the second damping pad 6 and the swivel pad 7 are fixed by the guide pin 19 to ensure normal operation of the whole. The whole is tightened by the cooperation of the end pad 8 and the anti-loosening nut 9. The anti-loosening nut 9 cooperates with the rotating fixed shaft 3 to adjust the size of the tightening force, thereby controlling the size of the rotation damping and improving the overall reliability. The overall structure is simple, easy to assemble and occupies little space. It realizes the self-limiting of the support arm 1 in the backward direction after it is flattened, the self-limiting of the overall backward rotation during the retraction of the support arm 1, and the self-limiting of the rotation of the support arm 1 during the overall retraction process. The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A self-limiting mechanism for rotating a seat table board, characterized by, It includes a support arm (1) and a rotating seat (2), the support arm (1) is connected with the rotating seat (2) through a rotating shaft pin (10); The support arm (1) is provided with a support arm insert (16) matched with the rotating shaft pin (10) through a fastening screw (17), the rotating seat (2) is provided with a middle hole in the middle, the middle hole is provided with a middle rotating block (5), the rotating seat (2) is matched with the middle rotating block (5), the middle rotating block (5) is provided with an avoiding slot, the rotating seat (2) is provided with a limiting channel communicated with the middle hole, the limiting channel is provided with a limiting pin shaft (13), a limiting pin crosspiece (14) clamped with the limiting pin shaft (13) and a reset spring (15), one end of the limiting pin shaft (13) is in contact with the support arm insert (16), when the dining table plate is used, the support arm insert (16) pushes the limiting pin shaft (13) to move, the other end of the limiting pin shaft (13) enters the avoiding slot, one end of the reset spring (15) is in contact with the side of the limiting pin crosspiece (14) facing the avoiding slot, the other end of the reset spring (15) is in contact with the limiting channel; One side of the middle rotating block (5) is provided with a first damping washer (4), the other side of the middle rotating block (5) is provided with a second damping washer (6), the first damping washer (4) and the second damping washer (6) are in contact with the rotating seat (2), the first damping washer (4), the middle rotating block (5) and the second damping washer (6) are all provided with inner holes, the inner holes of the first damping washer (4), the middle rotating block (5) and the second damping washer (6) are penetrated by a rotating fixing shaft (3) fixedly connected with the seat; The rotating fixing shaft (3) is provided with a fastening mechanism for axially fastening the first damping washer (4), the middle rotating block (5) and the second damping washer (6), the fastening mechanism is also provided with a guide pin (19), the first damping washer (4) and the second damping washer (6) are provided with pin holes matched with the guide pin (19); The rotating seat (2) is circumferentially provided with a crescent-shaped guide limiting slot, the guide pin (19) penetrates the pin hole on the first damping washer (4), the crescent-shaped guide limiting slot and the pin hole on the second damping washer (6) in sequence; The rotating shaft pin (10) is provided with a damping protection mechanism matched with the support arm (1) and the rotating seat (2), the damping protection mechanism includes support shaft sleeves (11) and damping shaft sleeves (12) respectively arranged at both ends of the rotating shaft pin (10), the support arm (1) and the rotating seat (2) are both provided with mounting holes matched with the support shaft sleeves (11) and the damping shaft sleeves (12); The fastening mechanism includes a positioning pin (18) arranged on the rotating fixing shaft (3) for fixing the first damping washer (4), the middle rotating block (5) and the second damping washer (6), the guide pin (19) is arranged on the rotating fixing shaft (3); The second damping gasket (6) is provided with a rotating gasket (7) mounted on the rotating fixed shaft (3) on one side, the rotating gasket (7) is provided with an end gasket (8) mounted on the rotating fixed shaft (3) on one side, and the end gasket (8) is provided with a lock nut (9) matched with the rotating fixed shaft (3) on one side.

2. A self-limiting mechanism for a seat table board according to claim 1, wherein: The limiting channel comprises a convex hole and a limiting hole communicated with each other and provided on the rotating seat (2), the limiting hole is matched with one end of the limiting pin shaft (13), the convex hole is communicated with the middle hole, and the limiting pin crosspiece (14) is arranged in the convex hole and is slidably matched with the convex hole.

3. The self-limiting mechanism of claim 1, wherein: The support arm insert (16) is provided with a limiting protrusion.

4. The self-limiting mechanism of claim 1, wherein: The rotating seat (2) is provided with rotating grooves matched with the first damping gasket (4), the second damping gasket (6), the rotating gasket (7) and the end gasket (8) on both sides.

5. A self-limiting mechanism for a seat table board according to claim 1, wherein: The crescent-shaped guiding limiting groove is a quarter of a circular arc groove with the center of the rotating seat (2) as the center, when the dining table plate is used, the rotating seat (2) rotates around the rotating fixed shaft (3), the crescent-shaped guiding limiting groove rotates along the guiding pin (19), when the rotating seat (2) rotates by 90 degrees, the support arm (1) rotates by 90 degrees around the rotating shaft pin (10), and the dining table plate is flattened.

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