A highly adaptive adjustable student desk and chair

Abstract

The application discloses a highly self-adaptive student desk and chair, which comprises a seat surface, a base, a lifting support, a telescopic pedal assembly and a descent stroke limiting assembly. The telescopic pedal assembly comprises a damping rotating rod, a telescopic assembly, a pedal and a displacement sensor, which is used to obtain the telescopic distance corresponding to the size of the lower limbs of a user. Two groups of inverted V-shaped support rods are arranged between the seat surface and the base, the lower ends of the support rods are hingedly connected with the sliding blocks in the sliding grooves, the flexible limiting belts are connected between the sliding blocks in the same group, and the middle portions of the flexible limiting belts pass around the liftable cross rod. A control module controls the lifting mechanism to adjust the height of the cross rod according to the detection signal of the displacement sensor, so as to change the maximum separation distance of the sliding blocks and limit the maximum descent stroke of the seat surface. After the lifting support is released, the seat surface is lowered to the height corresponding to the size of the lower limbs under the action of the weight of the human body, so that the deviation caused by repeated adjustment according to subjective experience is reduced, and the adaptability, stability and convenience of the seat height adjustment are improved.

Description

Technical Field

[0001] This invention relates to the field of student desks and chairs technology, specifically to a student desk and chair that can adaptively adjust the seat height according to the user's lower limb size. Background Technology

[0002] When students use desks and chairs, the seat height directly affects the support of their legs. When the seat is too high, the user's feet are likely to dangle and their legs will be compressed; when the seat is too low, the knees will bend more, which can easily lead to an unsuitable sitting posture.

[0003] Existing student chairs typically have height adjustment levers. Users adjust the seat height by operating the levers. This type of adjustment relies heavily on the user's subjective judgment. Students often don't know the seat height that best suits their lower limb size, requiring multiple attempts and adjustments. The adjustment results are also easily influenced by personal habits, making it difficult to keep the seat consistently in a position that matches the user's lower limb size.

[0004] Therefore, there is a need for student desks and chairs that can obtain the user's lower limb size information and limit the seat descent position accordingly. Summary of the Invention

[0005] The purpose of this invention is to provide a height-adaptive adjustable student desk and chair, which reduces the problem of users repeatedly adjusting the seat height based on subjective experience, and allows the seat to be lowered to a suitable position according to the user's lower limb size.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a height-adaptive adjustable student desk and chair, including a seat, a base, and a lifting support member disposed between the seat and the base, wherein the lifting support member can switch between a free extension and retraction state and a fixed position state; A retractable pedal assembly is provided on the front side of the seat surface. The retractable pedal assembly includes a damping rod, two telescopic components respectively disposed at both ends of the damping rod, a pedal connected to the two telescopic components, and a displacement sensor for detecting the telescopic distance of the telescopic components. Two sets of support components are provided between the seat surface and the base. Each set of support components includes two support rods. The upper ends of the two support rods are hinged to the bottom of the seat surface, and the lower ends are respectively hinged to sliders that are slidably disposed on the base. A flexible limiting band is connected between the two sliders in the same group. The middle part of the flexible limiting band cooperates with a liftable crossbar, which is connected to a lifting mechanism. It also includes a control module, which is signal-connected to the displacement sensor and control-connected to the lifting mechanism. The control module is used to control the lifting mechanism to adjust the height of the crossbar according to the detection signal of the displacement sensor, so as to limit the maximum separation distance between the two sliders and limit the maximum descent stroke of the seat surface.

[0007] Furthermore, each of the telescopic components includes a first telescopic rod and a second telescopic rod. One end of the first telescopic rod is connected to the damping rotating rod, and the other end is telescopically disposed inside the second telescopic rod. The ends of the two second telescopic rods away from the damping rotating rod are respectively connected to the two ends of the pedal.

[0008] Furthermore, the end of the first telescopic rod that extends into the second telescopic rod is provided with an elastic protrusion that can elastically extend and retract. The second telescopic rod is provided with a plurality of locking holes spaced apart along the axial direction. The elastic protrusion can selectively engage with the locking holes at different positions to fix the relative position of the first telescopic rod and the second telescopic rod.

[0009] Furthermore, the damping rod is arranged along the width direction of the seat surface and can drive the telescopic assembly and the pedal to rotate relative to the seat surface; the damping rod has a measuring position that positions the pedal in front of and below the seat surface, and a storage position that moves the pedal toward the bottom of the seat surface.

[0010] Furthermore, the bottom of the seat surface is provided with two hinge seats, and the upper ends of the two support rods of the same group are hinged to the same hinge seat; the base is provided with two sliding grooves corresponding to the two groups of support components respectively, and the two sliders of the same group are slidably disposed in the same sliding groove; the two support rods of the same group are arranged in an inverted V shape, and when the seat surface descends, the two support rods unfold towards each other and drive the two sliders to separate towards each other along the sliding groove.

[0011] Furthermore, each of the grooves is provided with two springs, which respectively cooperate with the two corresponding sliders and apply an elastic restoring force to the two sliders to bring them closer together.

[0012] Furthermore, the two ends of the flexible limiting band are respectively connected to the two sliders in the same group, the crossbar is located above the two sliders, and the middle part of the flexible limiting band goes up around the crossbar and forms an inverted U-shaped structure; when the crossbar is raised, the maximum distance that the flexible limiting band allows the two sliders to separate decreases, and when the crossbar is lowered, the maximum distance that the flexible limiting band allows the two sliders to separate increases.

[0013] Furthermore, the lifting mechanism is one of an electric screw lifting mechanism, a worm gear lifting mechanism, or an electric scissor lift mechanism. The lifting mechanism has a position holding function and is used to lock the position of the crossbar after it has moved to the target height.

[0014] Furthermore, the lifting support is a pneumatic lifting rod, and a lifting adjustment rod is provided on the lifting support. The lifting adjustment rod is connected to the control valve of the pneumatic lifting rod and is used to control the lifting support to switch between a free extension / retraction state and a fixed position state.

[0015] Furthermore, a cover is provided above the base, which covers the outside of the support rod, slider, flexible limiting band, crossbar and lifting mechanism; a backrest is provided on the rear side of the seat surface, and the backrest is connected to the seat surface through a backrest support rod.

[0016] Compared with the prior art, the present invention has the following beneficial effects.

[0017] This invention utilizes a retractable pedal assembly to achieve a retractable distance corresponding to the user's lower limb dimensions, and then adjusts the crossbar height via a control module and a lifting mechanism. The crossbar employs a flexible limiting band to restrict the maximum separation distance of the slider, further limiting the extension of the support rod and the maximum descent of the seat. After releasing the fixing of the lifting support component, the seat can descend to a suitable position under the user's own weight. This structure reduces the need for the user to repeatedly adjust the seat height based on subjective feeling, and eliminates the need for the lifting mechanism to directly raise and lower the seat and the user as a whole. Two sets of support components provide auxiliary support for the seat, the flexible limiting band provides mechanical restraint, and the spring drives the slider to reset after the seat rises, making the seat height adjustment process relatively stable. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a height-adaptive adjustable student desk and chair according to the present invention; Figure 2 This is a schematic diagram of the pedal telescopic adjustment assembly in this invention; Figure 3 This is a schematic diagram of the internal structure of the present invention after the cover is removed; Figure 4 This is a schematic diagram of the seat descent travel limiting component in this invention.

[0019] In the diagram: 1. Chair back; 2. Chair back support rod; 3. Seat surface; 4. Damping rotating rod; 5. First telescopic rod; 501. Elastic protrusion; 6. Second telescopic rod; 601. Snap-fit ​​hole; 7. Pedal; 8. Displacement sensor; 9. Lifting support component; 10. Lifting adjustment rod; 11. Hinge seat; 12. Support rod; 13. Cover; 14. Base; 15. Slide groove; 16. Spring; 17. Slider; 18. Flexible limiting band; 19. Crossbar; 20. Lifting mechanism. Detailed Implementation

[0020] like Figures 1 to 4 As shown, this embodiment provides a height-adaptive adjustable student desk and chair. For ease of explanation, the term "front side" refers to the side the user faces when sitting normally; "rear side" refers to the side closest to the backrest 1; "top" and "bottom" are determined according to the orientation of the desk and chair when normally placed. The specific dimensions of each component can be adjusted according to the student's age, seat load requirements, and installation space, but the connection and movement relationships between the components remain unchanged.

[0021] This embodiment includes a chair back 1, chair back support rods 2, a seat surface 3, a lifting support component 9, a lifting adjustment rod 10, a cover 13, and a base 14. The seat surface 3 supports the user. The chair back 1 is located above and behind the seat surface 3. The chair back 1 is connected to the seat surface 3 by two chair back support rods 2. The two chair back support rods 2 are located on the left and right sides of the rear of the seat surface 3, respectively, with their lower ends fixed to the seat surface 3 and their upper ends fixed to the chair back 1. This allows the chair back 1 to distribute the force more evenly and also facilitates movement along with the seat surface 3 when it is raised or lowered.

[0022] The base 14 is located below the seat surface 3. The base 14 is used to mount the lifting support 9, support rod 12, slider 17, flexible limiting band 18, crossbar 19, and lifting mechanism 20. The base 14 can be made of a combination of sheet metal, a metal frame, and a shell, or it can be made of engineering plastics that meet load-bearing requirements combined with a metal skeleton. The base 14 should maintain sufficient rigidity to prevent significant displacement of the slide 15 and lifting mechanism 20 under stress.

[0023] The lifting support 9 is vertically positioned between the seat surface 3 and the base 14. The lower end of the lifting support 9 is fixed to the middle of the base 14, and the upper end is connected to the bottom of the seat surface 3. In this embodiment, the lifting support 9 is a pneumatic lifting rod with a control valve. The lifting adjustment rod 10 is connected to the control valve of the pneumatic lifting rod. When the lifting adjustment rod 10 is moved, the control valve opens, and the lifting support 9 enters a free extension / retraction state; after releasing or resetting the lifting adjustment rod 10, the control valve closes, and the lifting support 9 maintains its current length.

[0024] When there is no load on the seat surface 3, or when the user gets up to reduce the load on the seat surface 3, the lifting support 9 extends under the action of internal gas, causing the seat surface 3 to rise. When the user sits on the seat surface 3 and opens the control valve, the weight of the user body causes the lifting support 9 to gradually shorten, and the seat surface 3 lowers accordingly. The lifting support 9 mainly undertakes the lifting and lowering of the seat surface 3 and provides basic support. Two sets of support components are set between the seat surface 3 and the base 14 to cooperate with the movement of the seat surface 3 and limit the lowest position of the seat surface 3.

[0025] A retractable pedal assembly is provided on the front side of the seat surface 3. The retractable pedal assembly includes a damping rod 4, two sets of telescopic components, a pedal 7, and a displacement sensor 8. The damping rod 4 is arranged along the width direction of the seat surface 3. The two ends of the damping rod 4 are rotatably mounted on the left and right sides of the seat surface 3, respectively. A damping engagement is provided between the damping rod 4 and the seat surface 3, so that the damping rod 4 can rotate when subjected to external force, and can maintain the current angle after the external force is removed, and will not swing on its own under the weight of the pedal 7 and the user's feet.

[0026] The damping lever 4 has both a measuring position and a retracted position. When measuring lower limb dimensions, rotate the damping lever 4 forward and downward so that the pedal 7 is positioned in front of and below the seat surface 3. At this point, the user can sit on the seat surface 3 and place both feet on the pedal 7. After adjusting the seat height, rotate the damping lever 4 backward and upward so that the two telescopic components and the pedal 7 are close to the bottom of the seat surface 3. When retracted, the pedal 7 no longer occupies the main activity space in front of the seat surface 3, allowing the user to easily tuck their legs and stand up.

[0027] To ensure consistent reference angles during each measurement, a rotation stop point can be set at the measurement position for the damping rod 4. Once the damping rod 4 reaches this position, its rotation is limited by the rotation stop point and maintained by damping. A corresponding stop point can also be set at the storage position. The rotation stop point can be formed by the limiting surface at the end of the damping rod 4 and the mating surface on the seat surface 3, eliminating the need for a separate, complex structure.

[0028] Two sets of telescopic components are respectively installed at both ends of the damping rotating rod 4. Each set of telescopic components includes a first telescopic rod 5 and a second telescopic rod 6. One end of the first telescopic rod 5 is fixedly connected to the damping rotating rod 4, and the other end extends into the second telescopic rod 6. The cross-sectional shapes of the first telescopic rod 5 and the second telescopic rod 6 are matched to each other, allowing them to move relative to each other along the axial direction and limiting significant circumferential sway. The ends of the two second telescopic rods 6 away from the damping rotating rod 4 are respectively connected to the left and right ends of the pedal 7.

[0029] The pedal 7 can be made into a long strip. The length of the pedal 7 is suitable for supporting both of the user's feet simultaneously. The upper surface of the pedal 7 can be provided with anti-slip texture or anti-slip mat. Two second telescopic rods 6 form a rigid connection with the pedal 7, so that the pedal 7 remains basically horizontal during adjustment. The first telescopic rods 5 and the second telescopic rods 6 on both sides are of the same specification, and their locking positions correspond to each other, so that the two sets of telescopic components maintain the same extension length.

[0030] A resilient protrusion 501 is provided at one end of the first telescopic rod 5 that extends into the second telescopic rod 6. The resilient protrusion 501 is arranged radially along the first telescopic rod 5. The inner end of the resilient protrusion 501 can be connected to a compression spring, and the outer end can protrude from the through hole on the first telescopic rod 5. A plurality of locking holes 601 are spaced apart along the axial direction on the second telescopic rod 6. The diameter of each locking hole 601 matches the outer end of the resilient protrusion 501.

[0031] When the position of pedal 7 needs to be changed, first press the elastic protrusion 501 to retract it and exit the current locking hole 601. Then pull or push pedal 7 to move the second telescopic rod 6 relative to the first telescopic rod 5. After pedal 7 has moved to the appropriate position, release the elastic protrusion 501. Continue to move the second telescopic rod 6 slightly until the elastic protrusion 501 is aligned with the adjacent locking hole 601. Under the action of internal elastic force, the elastic protrusion 501 extends into the locking hole 601, thereby fixing the relative position of the first telescopic rod 5 and the second telescopic rod 6.

[0032] Both sets of telescopic components should be adjusted to the same snap-fit ​​position. In actual operation, one side can be adjusted first, and then the other side can be adjusted to the snap-fit ​​hole 601 with the same serial number. Alternatively, the elastic protrusions 501 on both sides can be pressed simultaneously and the pedal 7 can be moved. Since the two ends of the pedal 7 are connected to the two second telescopic rods 6 respectively, the pedal 7 can provide a certain synchronous constraint on the telescopic distance on both sides, reducing the tilt of the pedal 7.

[0033] Displacement sensor 8 is positioned between damping rod 4 and pedal 7. The detection direction of displacement sensor 8 is consistent with the extension / retraction direction of the telescopic assembly. One end of displacement sensor 8 is connected to damping rod 4 or the first telescopic rod 5, and the other end is connected to pedal 7 or the second telescopic rod 6. When pedal 7 moves away from damping rod 4, the detection length of displacement sensor 8 increases; when pedal 7 moves closer to damping rod 4, the detection length of displacement sensor 8 decreases.

[0034] In this embodiment, the displacement sensor 8 can be either a linear displacement sensor or a drawstring displacement sensor. When a linear displacement sensor is used, its fixed part is connected to the damping rotating rod 4, and its movable part is connected to the pedal 7. When a drawstring displacement sensor is used, the sensor body is located near the damping rotating rod 4, and the drawstring end is connected to the pedal 7. The displacement sensor 8 does not directly measure the human body, but rather detects the extension distance of the pedal 7 in a preset measurement posture. This distance corresponds to the user's lower leg length and the required seat height.

[0035] The displacement sensor 8 is connected to the control module via signal transmission. The control module can be installed inside the cover 13 or inside the drive housing of the lifting mechanism 20. The signal line of the displacement sensor 8 can be arranged along the bottom of the damping rod 4 and the seat surface 3, with a bending allowance reserved at the rotation position to prevent the damping rod 4 from pulling on the signal line when rotating between the measuring position and the storage position. The control module is connected to the lifting mechanism 20 via control, and is used to control the lifting direction, running time, and stop position of the lifting mechanism 20.

[0036] The control module pre-stores the correspondence between the telescopic distance and the target height of the crossbar 19. This correspondence can be set according to the upper reference position of the seat surface 3, the length of the support rod 12, the position of the slide groove 15, the length of the flexible limiting band 18, and the student's sitting posture requirements. After the displacement sensor 8 detects the telescopic distance, the control module finds the target height of the crossbar 19 corresponding to that telescopic distance and sends an up or down command to the lifting mechanism 20. When the telescopic distance is large, the target height corresponding to the crossbar 19 is high; when the telescopic distance is small, the target height corresponding to the crossbar 19 is low.

[0037] The above correspondence can be implemented in a segmented manner. For example, several adjacent snap-fit ​​holes 601 correspond to a height range of the crossbar 19. This can be coordinated with the graded adjustment formed by the elastic protrusion 501 and the snap-fit ​​holes 601. Alternatively, the correspondence can be implemented using a continuous conversion method, where the control module determines the position of the crossbar 19 based on the continuous detection values ​​of the displacement sensor 8. Regardless of the method used, the control module sets the position of the crossbar 19 before the seat surface 3 descends.

[0038] To avoid frequent operation of the lifting mechanism 20 caused by the instantaneous displacement when adjusting the pedal 7, the control module can control the lifting mechanism 20 to operate only after the detection signal of the displacement sensor 8 has stabilized. After the elastic protrusion 501 is engaged with the locking hole 601, the length of the telescopic component remains unchanged, and the output of the displacement sensor 8 also tends to stabilize. At this time, adjusting the crossbar 19 can make the target position of the crossbar 19 correspond to the locked position of the pedal 7.

[0039] Two hinge seats 11 are provided at the bottom of the seat surface 3. The two hinge seats 11 are located on both sides of the lifting support 9 and are symmetrically arranged along the left and right direction of the seat surface 3. Each hinge seat 11 corresponds to a set of support components. Each set of support components includes two support rods 12. The upper ends of the two support rods 12 are hinged to the same hinge seat 11, and the two support rods 12 can rotate around the hinge position.

[0040] The base 14 has two sliding grooves 15. The two sliding grooves 15 are located on both sides of the lifting support 9 and correspond to the positions of the two hinge seats 11. Each sliding groove 15 contains two sliders 17. The lower ends of the two support rods 12 in the same group are hinged to the two sliders 17 in the same sliding groove 15. The sliders 17 are restricted by the sliding grooves 15 and can only move along the length of the sliding grooves 15.

[0041] When the seat surface 3 is in a higher position, the two support rods 12 of the same group are in an inverted V shape, with their upper ends close together and their lower ends also close to each other. When the seat surface 3 moves downward, the hinge seat 11 descends with the seat surface 3. The upper ends of the two support rods 12 move downward, changing the inclination angle of the support rods 12 and pushing the two sliders 17 to move in opposite directions along the slide groove 15. As a result, the two support rods 12 gradually unfold, and the two sliders 17 gradually separate.

[0042] As the seat surface 3 moves upward, the above actions are reversed. The hinged seat 11 rises, the two support rods 12 gradually retract, and the two sliders 17 move towards the center along the slide groove 15. The two sets of support components are symmetrically arranged, which can provide auxiliary guidance from both sides during the raising and lowering of the seat surface 3. Even if the user's sitting posture is slightly off, the two sets of support components can reduce the sinking and rotation of the seat surface 3 on one side.

[0043] Two springs 16 are installed within each groove 15. The two springs 16 are located on the outer sides of the two sliders 17, respectively. One end of each spring 16 abuts against or is connected to the end of the groove 15, and the other end abuts against or is connected to the corresponding slider 17. When the two sliders 17 separate, they move towards the ends of the groove 15, compressing the two springs 16. The springs 16 thus generate an elastic force that returns the sliders 17 to the center of the groove 15.

[0044] When the seat 3 rises, the outward pushing force of the support rod 12 on the slider 17 decreases. The spring 16 pushes the two sliders 17 closer together, allowing the support rod 12 to retract smoothly. The spring 16 can also keep the slider 17 in a predetermined initial position under no-load conditions, reducing the free swaying of the slider 17 within the groove 15. The elastic parameters of the two springs 16 are preferably kept consistent, so that the reset speeds of the two sliders 17 within the same groove 15 are similar.

[0045] A flexible limiting band 18 connects two sliders 17 within the same slide groove 15. The two ends of the flexible limiting band 18 are fixed to the two sliders 17 respectively. One flexible limiting band 18 is provided in each of the two slide grooves 15. The flexible limiting band 18 uses a band with minimal elongation under stress, such as a high-strength fiber woven band or a composite band with a reinforcing layer. The flexible limiting band 18 can bend, but does not elongate significantly within its normal load-bearing range.

[0046] The crossbar 19 is located above the two sliding grooves 15. The crossbar 19 extends along the direction between the two sliding grooves 15 and simultaneously engages with two flexible limiting bands 18. The middle of each flexible limiting band 18 wraps upward around the crossbar 19, forming an inverted U-shape. The crossbar 19 may have an arc-shaped support surface or an annular limiting groove at the contact position with the flexible limiting band 18, so that the flexible limiting band 18 is held in the corresponding position when under force, preventing the two flexible limiting bands 18 from getting close to each other or coming off the end of the crossbar 19.

[0047] The length of the flexible limiting band 18 remains constant after installation. When the crossbar 19 moves upward, the length of the two sections of the flexible limiting band 18 between the slider 17 and the crossbar 19 increases. Since the total length of the flexible limiting band 18 remains constant, the length available for the two sliders 17 to separate horizontally decreases. Therefore, the higher the crossbar 19, the smaller the maximum distance the two sliders 17 can separate. The angle at which the support rod 12 can unfold also decreases, and the stroke by which the seat surface 3 can descend decreases accordingly.

[0048] As the crossbar 19 moves downward, the length occupied by the flexible limiting band 18 between the slider 17 and the crossbar 19 decreases, increasing the distance that the two sliders 17 can separate. At this time, the support rod 12 can extend to a greater angle, and the seat surface 3 can descend a longer stroke. The height of the crossbar 19 is determined by the pedal extension distance detected by the displacement sensor 8, thereby converting the extension / retraction adjustment of the pedal 7 into a limitation on the descent stroke of the seat surface 3.

[0049] In the initial stage of seat 3 descent, the two sliders 17 move outward under the push of the support rod 12, and the flexible limiting band 18 is gradually tensioned. When the two sliders 17 reach the maximum separation position allowed by the current height of the crossbar 19, the flexible limiting band 18 is in a taut state. The flexible limiting band 18 restricts the two sliders 17 from moving outward further, the support rod 12 cannot continue to unfold, and the seat 3 cannot continue to descend. The limiting position formed at this time is the seat descent position corresponding to the current user.

[0050] The lifting mechanism 20 is mounted on the base 14 and located below the crossbar 19. This embodiment preferably employs an electric scissor lift mechanism. The lifting mechanism 20 includes an extendable and retractable scissor support and an electric drive unit for driving the scissor support. The lower part of the scissor support is connected to the base 14, and the upper part is connected to the crossbar 19. When the electric drive unit operates, the scissor support extends or retracts, thereby causing the crossbar 19 to move vertically.

[0051] The electric drive unit can be a combination of a motor and a lead screw. The motor drives the lead screw to rotate, and the lead screw pushes the scissor lift bracket to change its deployment degree. The lead screw drive has the ability to hold its position after stopping, so that the crossbar 19 can still be maintained at the set height under the tension of the flexible limiting band 18. The lifting mechanism 20 can also adopt an electric lead screw direct lifting structure or a worm gear lifting structure, as long as it can drive the crossbar 19 to move up and down and maintain the position of the crossbar 19 after stopping.

[0052] The two ends of the crossbar 19 are preferably kept at the same height. The lifting mechanism 20 is located in the middle of the crossbar 19, or supports the crossbar 19 through synchronous left and right support positions to reduce the tilting of the crossbar 19 under force. The crossbar 19 simultaneously adjusts the two flexible limit bands 18 so that the maximum separation distance of the two sets of sliders 17 changes synchronously. This makes the descent stroke of the left and right sides of the seat surface 3 basically the same.

[0053] The lifting mechanism 20 can be set with upper and lower travel limits. When the crossbar 19 moves to the highest or lowest permissible position, the lifting mechanism 20 stops operating to prevent the crossbar 19 from exceeding the engagement range of the flexible limit band 18 and the support rod 12. The control module and the lifting mechanism 20 can be powered by a low-voltage power supply located in the base 14. The power supply only provides power when detecting and adjusting the crossbar 19; the actual descent of the seat surface 3 is still accomplished by the user's own weight and the extension and retraction of the lifting support 9.

[0054] The cover 13 is installed above the base 14 and covers the slide groove 15, spring 16, slider 17, flexible limiting band 18, crossbar 19, and lifting mechanism 20. The cover 13 can be a split structure for easy disassembly and maintenance. The cover 13 is provided with a clearance area for the lifting support 9 and support rod 12 to move. A gap is left between the clearance area and the moving parts to prevent friction or jamming of the seat surface 3 when it is raised or lowered.

[0055] The cover 13 reduces the entry of dust, paper scraps, and other debris into the slide 15, and also isolates moving parts such as the slider 17, spring 16, and flexible limiting band 18. This reduces the possibility of clothing or shoelaces coming into contact with the moving structure. The cover 13 does not bear the main load of the seat surface 3, and its shape can be set according to the range of motion of the base 14, support rod 12, and lifting mechanism 20.

[0056] When using this embodiment, first turn the damping lever 4 to the storage position and confirm that there is no obstruction above the seat surface 3. The user stands up or reduces the load on the seat surface 3, and simultaneously moves the lifting adjustment lever 10 to allow the lifting support 9 to enter a free extension / retraction state. The lifting support 9 extends and drives the seat surface 3 to rise. When the seat surface 3 reaches the preset upper reference position, release the lifting adjustment lever 10 to fix the lifting support 9 in that position.

[0057] Then, rotate the damping lever 4 to the measuring position. The user sits on the seat 3, with their buttocks close to the back of the seat 3, thighs supported by the seat 3, lower legs naturally downward, and feet placed on the pedal 7. Press the elastic protrusions 501 on both sides to adjust the relative length of the first telescopic rod 5 and the second telescopic rod 6, so that the pedal 7 fits against the soles of the feet and the knees remain naturally bent. After adjustment, engage the elastic protrusions 501 on both sides into the corresponding locking holes 601.

[0058] At this time, displacement sensor 8 detects the distance between damping rod 4 and pedal 7 and sends the detection signal to the control module. After the detection signal stabilizes, the control module determines the target height of the crossbar 19. If the current crossbar 19 is below the target height, the control module controls the lifting mechanism 20 to raise the crossbar 19; if the current crossbar 19 is above the target height, the control module controls the lifting mechanism 20 to lower the crossbar 19. Once the crossbar 19 reaches the target height, the lifting mechanism 20 stops and maintains that position.

[0059] After the position of the crossbar 19 is set, the lifting adjustment lever 10 is moved again to allow the lifting support 9 to enter a free extension and retraction state. The user maintains a normal sitting posture, and the seat 3 slowly descends under the weight of the user. As the seat 3 descends, the two hinged seats 11 move down simultaneously. Each set of two support rods 12 gradually unfolds, pushing the corresponding two sliders 17 to separate. When the sliders 17 move outward, they compress the spring 16, simultaneously pulling the two ends of the flexible limiting band 18.

[0060] Once the slider 17 has separated to the maximum allowable distance of the flexible limiting band 18, the flexible limiting band 18 becomes taut. The crossbar 19 remains stationary, the flexible limiting band 18 can no longer extend its effective length, and both sliders 17 stop moving outward. The support rod 12 stops extending, and the seat surface 3 stops descending. The lifting adjustment rod 10 is then released, allowing the lifting support 9 to re-enter its fixed position. The seat surface 3 remains at a height corresponding to the current pedal extension distance.

[0061] After adjusting the height, the user can remove both feet from pedal 7 and then turn the damping lever 4 to the stowed position. Since the measurement of pedal 7 has been completed, stowing pedal 7 will not change the position of the crossbar 19, nor will it change the already formed seat height. The seat surface 3 remains stable under the combined action of the lifting support 9 and the two sets of support components.

[0062] When changing users or needing readjustment, first move the lifting adjustment lever 10 to reduce the load on the seat surface 3. The lifting support 9 then raises the seat surface 3. During the rise of the seat surface 3, the two support rods 12 gradually retract. The spring 16 pushes the slider 17 back to the center of the slide groove 15, and the flexible limiting band 18 relaxes accordingly. After the seat surface 3 returns to the upper reference position, the pedal 7 can be readjusted according to the new user, and the height of the crossbar 19 can be set.

[0063] Throughout the adjustment process, the displacement sensor 8 and the lifting mechanism 20 are only used to determine the position of the crossbar 19. The lifting mechanism 20 does not need to directly lift the seat 3 that supports the user. The descent of the seat 3 is accomplished by the weight of the user, and the descent of the seat 3 is mainly accomplished by the lifting support 9. The flexible limiting band 18, the slider 17, and the support rod 12 together form a descent position limit, allowing the seat 3 to stop at a preset position.

[0064] The two sets of support components also provide auxiliary support for the seat surface 3. When the seat surface 3 is under stress, the load can be transmitted to the base 14 via the lifting support 9, or via the hinged seat 11, support rod 12, slider 17, flexible limiting band 18, and crossbar 19. The two sets of structures are symmetrical, which reduces the tilt of the seat surface 3 after it descends to the limiting position. During reset, the spring 16 continuously pushes the slider 17 inward, ensuring that the next adjustment starts from a more consistent initial state.

[0065] In this embodiment, the spacing of each snap-fit ​​hole 601, the length of the flexible limiting band 18, the length of the support rod 12, the effective stroke of the slide groove 15, and the lifting range of the crossbar 19 should be coordinated with each other. When the crossbar 19 is in the highest position, a necessary separation distance should still be maintained for the slider 17 to prevent the seat surface 3 from being completely unable to descend; when the crossbar 19 is in the lowest position, the slider 17 should not exceed the effective range of the slide groove 15. The above dimensions can be determined during manufacturing based on the highest and lowest positions of the seat surface 3 and the applicable student height range.

[0066] The flexible limiting band 18 should have sufficient tensile strength. The connection between the flexible limiting band 18 and the slider 17 should be reliably fixed. The surface of the crossbar 19 in contact with the flexible limiting band 18 should be flat, with no sharp corners to prevent wear on the band after long-term use. A low-friction bushing or wear-resistant layer may be provided between the slider 17 and the groove 15 to ensure smooth movement of the slider 17 under stress.

[0067] The hinges between the support rod 12, the hinge seat 11, and the slider 17 can be connected by pins. An anti-detachment structure is provided at the end of the pin. Appropriate gaps are maintained at each hinge to allow the support rod 12 to rotate without significant wobbling. The relative positions of the lifting support 9, the two hinge seats 11, and the two slides 15 should be symmetrical to ensure that the seat surface 3 moves vertically during lifting.

[0068] In actual manufacturing, the control module can be set with a manual reset function. When an abnormal detection signal is detected or maintenance is required, the crossbar 19 can be returned to the preset initial position first, and then the displacement sensor 8, telescopic assembly, and lifting mechanism 20 can be checked. After the lifting mechanism 20 is de-energized, the crossbar 19 should remain in its position to prevent it from descending on its own when the seat surface 3 is under load. The pneumatic lifting rod, lifting mechanism 20, and flexible limit belt 18 are all selected according to the predetermined load-bearing requirements of student desks and chairs.

[0069] The above structure ensures that the extension position of the pedal 7, the height of the crossbar 19, the maximum separation distance of the slider 17, and the maximum descent stroke of the seat 3 correspond sequentially. Users do not need to repeatedly observe the specific height of the seat 3; they only need to adjust the pedal 7 at the upper reference position to provide natural support for their feet, and then release the lifting support 9. The seat 3 will then descend under the weight of the user and stop at the position defined by the flexible limiting band 18.

Claims

1. A height-adaptive adjustable student desk and chair, comprising a seat (3), a base (14), and a lifting support (9) disposed between the seat (3) and the base (14), wherein the lifting support (9) is capable of switching between a freely extendable state and a fixed position state, characterized in that: A retractable pedal assembly is provided on the front side of the seat surface (3). The retractable pedal assembly includes a damping rod (4), two telescopic components respectively disposed at both ends of the damping rod (4), a pedal (7) connected to the two telescopic components, and a displacement sensor (8) for detecting the telescopic distance of the telescopic components. Two sets of support components are provided between the seat surface (3) and the base (14). Each set of support components includes two support rods (12). The upper ends of the two support rods (12) are hinged to the bottom of the seat surface (3), and the lower ends are respectively hinged to sliders (17) that are slidably disposed on the base (14). A flexible limiting band (18) is connected between the two sliders (17) in the same group. The middle part of the flexible limiting band (18) is engaged with a liftable crossbar (19). The crossbar (19) is connected to the lifting mechanism (20). It also includes a control module, which is signal-connected to the displacement sensor (8) and control-connected to the lifting mechanism (20). The control module is used to control the lifting mechanism (20) to adjust the height of the crossbar (19) according to the detection signal of the displacement sensor (8) in order to limit the maximum separation distance of the two sliders (17) and limit the maximum descent stroke of the seat (3).

2. The height-adaptive adjustable student desk and chair according to claim 1, characterized in that: Each of the telescopic components includes a first telescopic rod (5) and a second telescopic rod (6). One end of the first telescopic rod (5) is connected to the damping rotating rod (4), and the other end is telescopically disposed inside the second telescopic rod (6). The ends of the two second telescopic rods (6) away from the damping rotating rod (4) are respectively connected to the two ends of the pedal (7).

3. The height-adaptive adjustable student desk and chair according to claim 2, characterized in that: The first telescopic rod (5) has an elastic protrusion (501) that can elastically extend and retract at one end of the second telescopic rod (6). The second telescopic rod (6) has a plurality of locking holes (601) spaced apart along the axial direction. The elastic protrusion (501) can selectively lock into the locking holes (601) at different positions to fix the relative positions of the first telescopic rod (5) and the second telescopic rod (6).

4. The height-adaptive adjustable student desk and chair according to claim 1, characterized in that: The damping rod (4) is arranged along the width direction of the seat surface (3) and can drive the telescopic assembly and the pedal (7) to rotate relative to the seat surface (3); the damping rod (4) has a measuring position that places the pedal (7) in front of and below the seat surface (3) and a storage position that brings the pedal (7) closer to the bottom of the seat surface (3).

5. The height-adaptive adjustable student desk and chair according to claim 1, characterized in that: The bottom of the seat (3) is provided with two hinge seats (11), and the upper ends of the two support rods (12) of the same group are hinged to the same hinge seat (11); the base (14) is provided with two sliding grooves (15) respectively corresponding to the two groups of support components, and the two sliders (17) of the same group are slidably disposed in the same sliding groove (15); the two support rods (12) of the same group are arranged in an inverted V shape. When the seat (3) descends, the two support rods (12) unfold each other and drive the two sliders (17) to separate from each other along the sliding groove (15).

6. The height-adaptive adjustable student desk and chair according to claim 5, characterized in that: Each of the slide grooves (15) is provided with two springs (16), which cooperate with the corresponding two sliders (17) and apply an elastic restoring force to the two sliders (17) to bring them closer together.

7. The height-adaptive adjustable student desk and chair according to claim 1, characterized in that: The two ends of the flexible limiting band (18) are respectively connected to the two sliders (17) in the same group. The crossbar (19) is located above the two sliders (17). The middle part of the flexible limiting band (18) goes up around the crossbar (19) and forms an inverted U-shaped structure. When the crossbar (19) is raised, the maximum distance that the flexible limiting band (18) allows the two sliders (17) to separate is reduced. When the crossbar (19) is lowered, the maximum distance that the flexible limiting band (18) allows the two sliders (17) to separate is increased.

8. The height-adaptive adjustable student desk and chair according to claim 1, characterized in that: The lifting mechanism (20) is one of an electric screw lifting mechanism, a worm gear lifting mechanism or an electric scissor lift mechanism. The lifting mechanism (20) has a position holding function and is used to lock the position of the crossbar (19) after the crossbar (19) moves to the target height.

9. A height-adaptive adjustable student desk and chair according to claim 1, characterized in that: The lifting support (9) is a pneumatic lifting rod. The lifting support (9) is provided with a lifting adjustment rod (10). The lifting adjustment rod (10) is connected to the control valve of the pneumatic lifting rod and is used to control the lifting support (9) to switch between a free extension and retraction state and a fixed position state.

10. A height-adaptive adjustable student desk and chair according to claim 1, characterized in that: A cover (13) is provided above the base (14), and the cover (13) covers the outside of the support rod (12), slider (17), flexible limiting band (18), crossbar (19) and lifting mechanism (20); a backrest (1) is provided on the rear side of the seat surface (3), and the backrest (1) is connected to the seat surface (3) through the backrest support rod (2).

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