Seat depth adjusting mechanism and seat

Abstract

The seat depth adjusting mechanism comprises a supporting assembly and a backrest assembly, the supporting assembly comprises a supporting piece and chair legs, the supporting piece comprises a horizontally-arranged supporting pipe and a seat height adjusting part vertically arranged at the bottom of the supporting pipe, and the seat height adjusting part is slidably connected to the chair legs in the vertical direction; the supporting pipe is of a sleeve-shaped structure, a sliding groove is formed in the hollow portion of the supporting pipe, and the backrest assembly comprises a sliding part which is slidably connected to the supporting pipe through the sliding groove. A locking assembly is arranged between the supporting pipe and the sliding piece, the locking assembly comprises a plug pin and a plurality of clamping openings, the plug pin is movably connected to one of the supporting pipe and the sliding piece, and the clamping openings are formed in the other one of the supporting pipe and the sliding piece; when the bolt is clamped in the bayonet, the sliding piece and the supporting pipe are relatively fixed; and when the bolt avoids the bayonet, the sliding piece can slide relative to the supporting pipe again. According to the seat depth adjusting mechanism and the seat, the seat depth and the seat height of the seat can be adjusted through the supporting piece, the adjusting freedom degree is high, and practicability is good.

Description

Technical Field

[0001] This utility model relates to the field of seating technology, specifically to a seat depth adjustment mechanism and a seat. Background Technology

[0002] As seating furniture that accompanies children during their studies, study chairs play a very important role in children's growth and learning process. Children's bodies grow rapidly with age, and to accommodate these changes in height, existing children's chairs feature height-adjustable seats and backrests.

[0003] Most children's chairs on the market consist of a vertical column. Both the seat and backrest have a collar on the back that engages with the column, allowing the seat and backrest to slide up and down along the column. The collar has a knob screw, and the column has multiple vertically slit holes for adjusting the seat and backrest height. Users can fix the seat and backrest height by turning the knob screw until it engages with a slit. This allows users to easily adjust the seat and backrest height according to the child's height, and the seat height adjustment is quite simple.

[0004] However, the above solution has the following problems: for children of different body sizes, the distance between their buttocks and the backrest will vary to some extent. This means that if the seat can only adjust the seat height, it will not be able to adapt to children of all body sizes, and its practicality is insufficient. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a seat depth adjustment mechanism and a seat. The support member can not only adjust the seat height by sliding up and down relative to the chair legs through the seat height adjustment part, but also adjust the seat depth by sliding back and forth within the support tube through the sliding member. That is, by setting the support member, the seat integrates seat height adjustment function and seat depth adjustment function, which not only makes the seat adjustment more flexible and practical, but also allows the seat height and seat depth adjustment operations to be completed by adjusting only the support member. This makes the seat depth adjustment mechanism structure simpler, the seat appearance more concise, and the overall manufacturing cost lower.

[0006] The effect of this utility model is achieved as follows:

[0007] In a first aspect, this application provides a seat depth adjustment mechanism, including a support assembly and a backrest assembly. The support assembly includes a support member and chair legs. The support member includes a support tube horizontally arranged on its upper side and a seat height adjustment part vertically arranged at the bottom of the support tube. The seat height adjustment part is slidably connected to the chair legs in a vertical direction. The support tube has a sleeve-like structure with a groove formed in its hollow part. The backrest assembly includes a sliding member, which is slidably connected to the support tube through the groove and drives the backrest assembly to slide back and forth relative to the support assembly. A locking assembly is provided between the support tube and the sliding member. The locking assembly includes a pin and multiple latches. The pin is movably connected to one of the support tube and the sliding member, and the multiple latches are opened in the other of the support tube and the sliding member. When the pin is engaged with the latch, the sliding member and the support tube are relatively fixed. When the pin avoids the latch, the sliding member can slide again relative to the support tube.

[0008] Furthermore, the locking assembly also includes an adjusting member, one side of which protrudes to form a pin; one side of the left and right side walls of the support tube is hollowed out to form multiple bayonets, and the other side is hollowed out to form a clearance groove extending in the front-back direction; the sliding member is hollowed out radially and has a first connecting hole; the pin passes through the clearance groove and the first connecting hole and engages with the bayonets; the adjusting member can slide left and right relative to the sliding member, and drive the pin to engage or avoid the bayonets. Adjusting the pin's insertion or avoidance of the bayonets via the adjusting member achieves gear adjustment, and pulling the adjusting member drives the sliding member to slide back and forth, making the seat depth adjustment operation simpler.

[0009] Furthermore, the adjusting component is a pin-shaped knob, and the first connecting hole is an internally threaded hole. The adjusting component is screwed to the sliding component through the first connecting hole. This not only makes the installation and disassembly of the adjusting component more convenient, but also facilitates the insertion or avoidance of the adjusting pin, further improving the ease of operation of the seat depth adjustment.

[0010] Furthermore, the sliding component includes a tubular body and a sleeve portion fitted onto the outside of the tubular body. The support tube is a square tube, and the sleeve portion also has a square structure that matches the support tube, so that the sliding component and the support tube are relatively fixed in the circumferential direction. This results in a higher connection strength between the sliding component and the support tube, thereby making the seat depth adjustment operation of the seat more stable and smooth.

[0011] Furthermore, the sleeve part has a split structure, including two symmetrical shells. Several mounting protrusions protrude from the inner side of the shells, and several second connecting holes are hollowed out on the side wall of the tube part. The tube part is clamped between the two shells, and the mounting protrusions are engaged with the second connecting holes. This makes the structure of the sliding component simpler and easier to assemble.

[0012] Furthermore, the chair legs are sleeve-shaped structures, with hollow sections forming sliding support grooves. The seat height adjustment unit is slidably connected to the chair legs through these grooves, allowing the support component to slide up and down relative to the chair legs. By designing the chair legs as sleeve-shaped structures that fit over the seat height adjustment unit, the connection strength between the support component and the chair legs is increased, thereby making the seat height adjustment operation of the seat more stable.

[0013] Secondly, this application provides a chair, including a seat, a backrest, a back support, and a seat depth adjustment mechanism. The chair includes two symmetrical legs, with a support tube on a support member supporting the bottom of the seat. The upper end of the back support is connected to the backrest, and the lower end is connected to a sliding member, so that when the sliding member slides back and forth relative to the support tube, the backrest slides back and forth relative to the seat. The support tube not only supports the seat depth adjustment but also supports the seat, making the overall structure of the chair simpler and reducing manufacturing costs. Furthermore, the chair includes two legs, meaning the bottom of the seat is supported by two support tubes, resulting in better stability.

[0014] Furthermore, the back support is a bent tubular structure, including a connecting part arranged laterally on the upper side. The connecting part is configured to connect to the backrest. The left and right ends of the connecting part are bent downward to form transition parts, and the transition parts are bent forward to form sliding parts. The sliding parts and the tubular part inside the sliding component are integrally formed. The back support structure is simple and easy to manufacture. Moreover, the sliding part extending forward on the lower side of the back support and the tubular part inside the sliding component are integrally formed, and the back support and the sliding component are connected as a whole, which makes the connection strength between the back support and the support component higher and the stability better.

[0015] Furthermore, the back support is a bent plate-like structure, including a horizontally arranged connecting part on the upper side, which connects to the backrest. The left and right ends of the connecting part bend forward and downward to form a transition section, and the transition section bends downward to form a sliding section. The sliding section has a perforated positioning hole, through which a pin passes to fix the sliding section to the sliding component. The transition section can serve as an armrest for the seat, improving its practicality. The sliding section is fixed between the handle and the support tube, and can slide back and forth along with the sliding component and the adjustment component, making the installation and removal of the back support more convenient.

[0016] Furthermore, a connecting groove is recessed at the bottom of the seat, through which the support tube is snapped into the bottom of the seat. This not only increases the connection strength and stability between the seat and the support component, but also makes the support tube appear as a single unit with the seat, resulting in a more integrated and streamlined appearance for the chair.

[0017] The seat depth adjustment mechanism and seat provided in this application utilize a sleeve-shaped support tube on a support member. The backrest assembly slides relative to the support tube via a sliding member, thereby adjusting the fore-and-aft position of the backrest assembly, i.e., adjusting the seat depth. Thus, the support member can not only adjust the seat height by sliding the seat height adjustment part up and down relative to the chair legs, but also adjust the seat depth by sliding the sliding member back and forth within the support tube. In other words, by incorporating the support member, the seat integrates both seat height and seat depth adjustment functions. This not only provides a high degree of freedom in seat adjustment and good practicality, but also simplifies the seat depth adjustment mechanism structure and makes the seat appearance more streamlined, while reducing overall manufacturing costs. Furthermore, the sliding distance of the sliding member is adjusted through a pin and latch engagement mechanism, thereby achieving seat depth level adjustment with good stability. Attached Figure Description

[0018] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0019] Figure 1 A three-dimensional structural schematic diagram of the seat depth adjustment mechanism provided in the embodiments of this application;

[0020] Figure 2 This is a schematic diagram of the connection structure between the slider and the support provided in an embodiment of this application;

[0021] Figure 3 This is a schematic diagram of the internal structure of the slider provided in the embodiments of this application;

[0022] Figure 4 This is a schematic diagram of the internal structure of the adjusting member provided in the embodiments of this application;

[0023] Figure 5 A cross-sectional structural schematic diagram of the seat depth adjustment mechanism when adjusted to the foremost position according to an embodiment of this application;

[0024] Figure 6 A cross-sectional structural schematic diagram of the seat depth adjustment mechanism when the pin disengages from the bayonet, provided in an embodiment of this application;

[0025] Figure 7 A cross-sectional structural schematic diagram of the seat depth adjustment mechanism when adjusted to the very end, as provided in the embodiments of this application;

[0026] Figure 8 This is a schematic diagram of the connection structure between the support member and the chair leg provided in an embodiment of this application;

[0027] Figure 9 A three-dimensional structural diagram of the seat when the back support is a tubular structure, as provided in the embodiments of this application;

[0028] Figure 10 A schematic diagram of the connection structure between the back support and the seat depth adjustment mechanism when the back support is a tubular structure according to an embodiment of this application;

[0029] Figure 11 This is a schematic diagram illustrating the changes in the seat when the back support is a tubular structure, as provided in the embodiments of this application.

[0030] Figure 12 A three-dimensional structural diagram of the seat when the back support is a plate-like structure, as provided in the embodiments of this application;

[0031] Figure 13 A schematic diagram of the connection structure between the back support and the seat depth adjustment mechanism when the back support provided in the embodiment of this application is a plate-shaped structure;

[0032] Figure 14 A schematic diagram of the connection structure between the sliding part and the support member when the back support provided in the embodiment of this application is a plate-shaped structure;

[0033] Figure 15 This is a schematic diagram of the connection structure between the support member and the seat provided in an embodiment of this application.

[0034] The reference numerals in the attached drawings are as follows: 1-Support member, 110-Support tube, 111-Slide groove, 112-Bayonet, 113-Allowing groove, 120-Seat height adjustment part, 130-Angle iron, 2-Sliding member, 210-Tube body part, 211-First connecting hole, 212-Second connecting hole, 220-Housing shell, 221-Mounting protrusion, 3-Adjusting member, 310-Pin, 320-Handle part, 321-Mounting hole, 330-Fixing part, 331-Through hole, 340-Spring, 4-Chair leg, 401-Sliding support groove, 5-Chair seat, 510-Connecting groove, 6-Backrest, 7-Backrest bracket, 710-Connecting part, 720-Transition part, 730-Sliding part, 731-Positioning hole. Detailed Implementation

[0035] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the scope of the utility model. Furthermore, it should be noted that, for ease of description, only the parts relevant to the utility model are shown in the accompanying drawings.

[0036] Please refer to the attached document. Figure 1-8This application provides a seat depth adjustment mechanism, including a support assembly and a backrest assembly. The support assembly includes a support member 1 and chair legs 4. The support member 1 includes a horizontally arranged support tube 110 on its upper side and a seat height adjustment part 120 vertically arranged at the bottom of the support tube 110. The seat height adjustment part 120 is slidably connected to the chair legs 4 in the vertical direction. The support tube 110 has a sleeve-like structure and its hollow part forms a groove 111. The backrest assembly includes a slider 2, which is slidably connected to the support tube 110 through the groove 111 and drives... The backrest assembly slides back and forth relative to the support assembly; a locking assembly is provided between the support tube 110 and the sliding member 2, the locking assembly including a pin 310 and multiple slots 112, the pin 310 is movably connected to one of the support tube 110 and the sliding member 2, and the multiple slots 112 are opened in the other of the support tube 110 and the sliding member 2; when the pin 310 is engaged with the slot 112, the sliding member 2 and the support tube 110 are relatively fixed; when the pin 310 avoids the slot 112, the sliding member 2 can slide again relative to the support tube 110.

[0037] In this embodiment, by providing a sleeve-shaped support tube 110 on the support member 1, the backrest assembly slides relative to the support tube 110 via the slider 2, thereby adjusting the fore-and-aft position of the backrest assembly, i.e., adjusting the seat depth. Thus, the support member 1 can not only adjust the seat height by sliding the seat height adjustment part 120 up and down relative to the chair leg 4, but also adjust the seat depth by sliding the slider 2 back and forth within the support tube 110. In other words, by providing the support member 1, the seat integrates both seat height and seat depth adjustment functions, not only providing a high degree of freedom in seat adjustment and good practicality, but also simplifying the seat depth adjustment mechanism structure and making the seat appearance more streamlined, while reducing overall manufacturing costs. Furthermore, the sliding distance of the slider 2 is adjusted by the engagement of the pin 310 and the latch 112, thereby achieving seat depth adjustment at different levels, resulting in good stability.

[0038] The support tube 110 and the seat height adjustment part 120 are fixed by welding, which makes the support 1 have high overall strength and good stability.

[0039] Please refer to the attached document. Figure 2 In some embodiments of this application, the locking component further includes an adjusting member 3, one side of which protrudes to form a pin 310; one side of the left and right side walls of the support tube 110 is hollowed out to form multiple slots 112, and the other side is hollowed out to form a relief groove 113 extending in the front-back direction; the sliding member 2 is hollowed out in the radial direction and has a first connecting hole 211; the pin 310 passes through the relief groove 113 and the first connecting hole 211 and is engaged in the slot 112; the adjusting member 3 can slide left and right relative to the sliding member 2, and drive the pin 310 to engage or avoid the slot 112.

[0040] In this embodiment, the adjustment pin 310 is inserted into or avoids the bayonet 112 by setting an adjustment member 3 exposed outside the support tube 110 to achieve gear adjustment. Furthermore, the sliding member 2 can be moved back and forth by pulling the adjustment member 3, making the seat depth adjustment operation simpler. One side of the support tube 110 is hollowed out to form an avoidance groove 113 to avoid the pin 310, and at the same time, it limits the back and forth sliding distance of the pin 310 and the adjustment member 3, thereby preventing the sliding member 2 and the adjustment member 3 from detaching from the support tube 110, resulting in better stability.

[0041] Of course, in other embodiments of this application, multiple slots 112 can be formed by hollowing out the side wall of the slider 2, and the adjusting member 3 can be slidably connected to the support tube 110 and drive the pin 310 to insert into or avoid the slots 112 on the slider 2 to achieve gear adjustment.

[0042] Please refer to the attached document. Figure 4-7 In some embodiments of this application, the adjusting member 3 is a pin knob, the first connecting hole 211 is an internal thread hole, and the adjusting member 3 is screwed to the sliding member 2 through the first connecting hole 211.

[0043] In this embodiment, the adjusting member 3 includes an outer handle portion 320 and a fixing portion 330. The fixing portion 330 has an external thread and is threadedly engaged with the first connecting hole 211. The front end of the handle portion 320 is recessed and has a mounting hole 321. The rear side of the fixing portion 330 and the mounting hole 321 are both hexagonal structures, allowing the handle portion 320 to move axially relative to the fixing portion 330 and be relatively fixed in the circumferential direction. A through hole 331 is hollowed out in the middle of the fixing portion 330. The pin 310 passes through the through hole 331 and is fixed to the handle portion 320, allowing the handle portion 320 to drive the pin 310 to slide relative to the fixing portion 330. A spring 340 is provided between the pin 310 and the fixing portion 330, and the pin 310 always tends to engage with the latch 112 due to the elasticity of the spring 340. Please refer to the appendix. Figure 5-6 When adjusting the seat depth, the user simply pulls out the handle 320 to disengage the pin 310 from the latch 112. Then, the handle 320 can be dragged back and forth to move the slider 2 and adjust the seat depth. Please refer to the attached document. Figure 7 When a fixed seat depth is required, simply loosen the handle 320. The pin 310, under the elastic force of the spring 340, automatically engages with the slot 112, thereby fixing the sliding member 2 to the support tube 110. Thus, by setting the adjusting member 3 as a pin-knob, not only is the installation and disassembly of the adjusting member 3 more convenient, but it also facilitates adjusting whether the pin 310 engages with or avoids the slot 112, further improving the ease of seat depth adjustment.

[0044] Please refer to the attached document. Figure 3In some embodiments of this application, the sliding member 2 includes a tubular tube portion 210 and a sleeve portion fitted onto the outside of the tube portion 210. The support tube 110 is a square tube, and the sleeve portion also has a square structure that matches the support tube 110, so that the sliding member 2 and the support tube 110 are relatively fixed in the circumferential direction. This makes the connection strength between the sliding member 2 and the support tube 110 higher, thereby making the seat depth adjustment operation of the seat more stable and smooth.

[0045] Please refer to the attached document. Figure 3 In some embodiments of this application, the sleeve part is a split structure, including two shells 220 that are symmetrical on the left and right. A plurality of mounting protrusions 221 protrude from the inner side of the shell 220. A plurality of second connecting holes 212 are hollowed out on the side wall of the tube part 210. The tube part 210 is clamped between the two shells 220, and the mounting protrusions 221 are engaged with the second connecting holes 212.

[0046] In this embodiment, the sleeve part is connected to both sides of the tube part 210 by two housings 220, and the housings 220 are snapped into the tube part 210 by mounting protrusions 221, making the structure of the sliding member 2 simpler and easier to assemble.

[0047] Please refer to the attached document. Figure 8 In some embodiments of this application, the chair leg 4 is a sleeve-like structure, with its hollow portion forming a sliding support groove 401. The seat height adjustment part 120 is slidably connected to the chair leg 4 through the sliding support groove 401, allowing the support member 1 to slide up and down relative to the chair leg 4. By setting the chair leg 4 as a sleeve-like structure fitted onto the seat height adjustment part 120, the connection strength between the support member 1 and the chair leg 4 is increased, thereby making the seat height adjustment operation of the seat more stable.

[0048] Preferably, the seat height adjustment unit 120 and the chair leg 4 are adjusted by a screw mechanism commonly used in the prior art, which is a stepless adjustment, making the seat height adjustment operation more stable and smooth. This patent will not elaborate further.

[0049] Please refer to the attached document. Figure 9-15 This application embodiment also provides a seat, including a seat 5, a backrest 6, a back support 7, and a seat depth adjustment mechanism. The seat includes two symmetrical chair legs 4. A support tube 110 on the support member 1 supports the bottom end of the seat 5. The upper end of the back support 7 is connected to the backrest 6, and the lower end is connected to the sliding member 2, so that when the sliding member 2 slides back and forth relative to the support tube 110, the backrest 6 slides back and forth relative to the seat 5.

[0050] In this embodiment, the support tube 110 not only supports the seat depth adjustment, but also supports the seat 5, making the overall structure of the seat simpler and the manufacturing cost lower. In addition, the seat includes two legs 4 on the left and right, that is, the bottom of the seat 5 is supported by two support tubes 110 on the left and right, which provides good stability.

[0051] Among them, the inner side of the support tube 110 is screwed with several angle irons 130, and the support member 1 is screwed to the seat 5 through the angle irons 130. This not only provides a high connection strength, but also makes it easy to install and remove.

[0052] Please refer to the attached document. Figure 9-11 In some embodiments of this application, the back support 7 is a bent tubular structure, including a connecting part 710 arranged laterally on the upper side. The connecting part 710 is configured to connect to the backrest 6. The left and right ends of the connecting part 710 are bent downward to form a transition part 720. The transition part 720 is bent forward to form a sliding part 730. The sliding part 730 and the tubular part 210 inside the sliding member 2 are integrally formed.

[0053] In this embodiment, by setting the back support 7 as a bent tubular structure, the structure is simple and easy to process. The sliding part 730 extending forward on the lower side of the back support 7 and the tubular part 210 inside the sliding member 2 are integrally formed, and the back support 7 and the sliding member 2 are connected as a whole, which makes the connection strength between the back support 7 and the support member 1 higher and the stability better.

[0054] Please refer to the attached document. Figure 12-14 In some embodiments of this application, the back support 7 may have other structures and connection methods with the sliding member 2. For example, the back support 7 is a bent plate structure, including a connecting part 710 arranged horizontally on the upper side. The connecting part 710 is configured to connect to the backrest 6. The left and right ends of the connecting part 710 are bent forward and downward to form a transition part 720. The transition part 720 is bent downward to form a sliding part 730. The sliding part 730 is provided with a positioning hole 731. The pin 310 passes through the positioning hole 731 and fixes the sliding part 730 to the sliding member 2.

[0055] In this embodiment, by setting the back support 7 as a plate-like structure, with the transition portion 720 bent forward and downward and the sliding portions 730 on both sides fitting against the outer sides of the two support tubes 110, the transition portion 720 can serve as the armrest of the seat, improving its practicality. The fixing portion 330 of the adjusting member 3 passes through the positioning hole 731 and is screwed into the first connecting hole 211 of the sliding member 2. The sliding portion 730 is fixed between the handle portion 320 and the support tube 110, and can slide back and forth together with the sliding member 2 and the adjusting member 3, making the installation and removal of the back support 7 more convenient.

[0056] Please refer to the attached document. Figure 15In some embodiments of this application, a connecting groove 510 is recessed at the bottom of the seat 5, and the support tube 110 is snapped into the bottom of the seat 5 through the connecting groove 510. This not only makes the connection between the seat 5 and the support member 1 stronger and more stable, but also makes the support tube 110 and the seat 5 appear as a whole, making the seat look more integrated and simple.

[0057] The connecting groove 510 has openings on its rear side and on the side near the clearance groove 113 to avoid the sliding part 730 of the back support 7 and the adjusting member 3.

[0058] It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used above to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means three or more.

[0059] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the utility model involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A seat depth adjustment mechanism characterized by, The chair comprises a support assembly and a backrest assembly, the support assembly comprises a support piece (1) and a chair leg (4), the support piece (1) comprises a horizontally arranged support pipe (110) and a seat height adjusting part (120) arranged vertically at the bottom of the support pipe (110), the seat height adjusting part (120) is connected to the chair leg (4) in a sliding manner along the vertical direction, the support pipe (110) is in a sleeve structure and a sliding groove (111) is formed in the hollow part, the backrest assembly comprises a sliding piece (2), the sliding piece (2) is connected to the support pipe (110) in a sliding manner through the sliding groove (111) and drives the backrest assembly to slide forward and backward relative to the support assembly, a locking assembly is arranged between the support pipe (110) and the sliding piece (2), the locking assembly comprises a latch (310) and a plurality of clamping holes (112), the latch (310) is movably connected to one of the support pipe (110) and the sliding piece (2), and the plurality of clamping holes (112) are arranged in the other one of the support pipe (110) and the sliding piece (2), when the latch (310) is clamped in the clamping hole (112), the sliding piece (2) and the support pipe (110) are relatively fixed, and when the latch (310) avoids the clamping hole (112), the sliding piece (2) can slide relative to the support pipe (110) again.

2. The seat depth adjustment mechanism of claim 1, wherein, The locking assembly further comprises an adjusting piece (3), one side of the adjusting piece (3) protrudes to form the latch (310), one side of the left and right side walls of the support pipe (110) is hollow to form the plurality of clamping holes (112), and the other side is hollow to form an avoiding groove (113) extending in the front and back directions, the sliding piece (2) is radially hollow to form a first connecting hole (211), the latch (310) passes through the avoiding groove (113) and the first connecting hole (211) and is clamped in the clamping hole (112), the adjusting piece (3) can slide left and right relative to the sliding piece (2) and drive the latch (310) to be clamped in or avoid the clamping hole (112).

3. A seat depth adjustment mechanism according to claim 2, wherein, The adjusting piece (3) is a latch knob, the first connecting hole (211) is an internally threaded hole, and the adjusting piece (3) is screwed to the sliding piece (2) through the first connecting hole (211).

4. The seat depth adjustment mechanism of claim 1, wherein, The sliding piece (2) comprises a tubular pipe body part (210) and a sleeve body part sleeved outside the pipe body part (210), the support pipe (110) is a square pipe, the sleeve body part is also in a square structure matched with the support pipe (110), so that the sliding piece (2) and the support pipe (110) are relatively fixed in the circumferential direction.

5. A seat depth adjustment mechanism according to claim 4, wherein, The sleeve body part is a split structure, comprising two symmetrical housings (220), a plurality of mounting protrusions (221) are protruded on the inner side of the housing (220), a plurality of second connecting holes (212) are hollowed out on the sidewall of the tube body part (210), the tube body part (210) is clamped between the two housings (220), and the mounting protrusions (221) are clamped in the second connecting holes (212).

6. The seat depth adjustment mechanism of claim 1, wherein, The chair leg (4) is a sleeve structure, and the hollow part forms a sliding support groove (401), the seat height adjusting part (120) is slidably connected to the chair leg (4) through the sliding support groove (401), so that the support part (1) can slide up and down relative to the chair leg (4).

7. A seat, characterized by The seat height adjusting part (120) is slidably connected to the chair leg (4) through the sliding support groove (401), so that the support part (1) can slide up and down relative to the chair leg (4).

8. The seat of claim 7, wherein, The back support (7) is a bent tubular structure, comprising a connection part (710) arranged transversely on the upper side, the connection part (710) is configured to connect the backrest (6), the left and right ends of the connection part (710) are bent downward to form a transition part (720), the transition part (720) is bent forward to form a sliding part (730), and the sliding part (730) and the tube body part (210) in the sliding part (2) are integrally formed.

9. The seat of claim 7, wherein, The back support (7) is a bent plate structure, comprising a connection part (710) arranged transversely on the upper side, the connection part (710) is configured to connect the backrest (6), the left and right ends of the connection part (710) are bent downward to form a transition part (720), the transition part (720) is bent downward to form a sliding part (730), the sliding part (730) is hollowed out to form a positioning hole (731), the latch (310) passes through the positioning hole (731) and fixes the sliding part (730) to the sliding part (2).

10. The seat of claim 7, wherein, The bottom end of the seat (5) is recessed to form a connecting groove (510), and the support pipe (110) is clamped in the bottom of the seat (5) through the connecting groove (510).

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