阅读说明：本技术 靠背椅座升降平稳且锁定稳固可靠的双支撑立杆座椅 (Double-support upright rod chair with stable lifting of backrest and chair seat and stable and reliable locking ) 是由 姚宾 于 2021-05-11 设计创作，主要内容包括：本发明公开了一种靠背椅座升降平稳且锁定稳固可靠的双支撑立杆座椅,包括座椅支架、椅脚和座椅把手,座椅支架包括支撑立杆、椅座、靠背和扶手,椅座通过下锁定机构与支撑立杆连接,靠背通过上锁定机构与支撑立杆连接,上锁定机构和下锁定机构均包括立杆套、锁定支架和活动插销,锁定支架的顶部设有按钮和复位弹簧,按钮通过一拨杆组件分别与两个活动插销连接,活动插销通过插销导向座与拨杆组件连接,支撑立杆上设有外插销孔；两根支撑立杆的底部通过一连接板连接。本发明靠背和椅座的升降平稳可靠,可防止卡住,操作方便可靠；支撑立杆和椅脚通过连接板放大连接接触面,使支撑立杆与椅脚之间的连接更紧固,不容易晃动,确保使用舒适性。(The invention discloses a double-support upright rod seat with stable lifting of a backrest seat and stable and reliable locking, which comprises a seat support, seat legs and a seat handle, wherein the seat support comprises a support upright rod, a seat, a backrest and armrests; the bottoms of the two supporting vertical rods are connected through a connecting plate. The lifting of the backrest and the chair seat is stable and reliable, the clamping can be prevented, and the operation is convenient and reliable; the supporting upright stanchion and the chair leg are connected with the contact surface in an enlarged way through the connecting plate, so that the connection between the supporting upright stanchion and the chair leg is firmer, the chair leg is not easy to shake, and the use comfort is ensured.)

1. The utility model provides a back seat support goes up and down steadily and locks reliable and firm dual bracing pole setting seat, includes the seat support, installs the chair foot in seat support bottom and installs the seat handle at seat support top, its characterized in that: the seat support comprises two supporting upright rods, a seat support, a backrest and handrails, wherein the seat support is connected with the supporting upright rods through a lower locking mechanism, the backrest is connected with the supporting upright rods through an upper locking mechanism, the upper locking mechanism and the lower locking mechanism respectively comprise two upright rod sleeves matched with the supporting upright rods, a locking support arranged between the two upright rod sleeves and two movable bolts which are connected in the locking support in a sliding manner and move in opposite directions, the top of the locking support is provided with a button for driving the two movable bolts to act and a reset spring matched with the button, the button is respectively connected with the two movable bolts through a driving lever component, the movable bolts are connected with the driving lever component through a bolt guide seat, the supporting upright rods are provided with a plurality of outer inserting pin holes matched with the movable bolts, and the seat support is connected with the lower locking mechanism through a seat support connecting rod, the backrest is connected with the upper locking mechanism through a backrest mounting frame; the utility model discloses a chair, including two support posts, seat, chair foot, connecting plate, mounting screw, mounting plate's mounting groove, the inside of mounting groove is equipped with the spacing groove of cooperation connecting plate, and the seat is installed in the bottom of two support posts, and the seat handle is installed at the top of two support posts, and the bottom of two support poles sets is connected through a connecting plate, the connecting plate is connected with the chair foot through two above mounting screws, be equipped with the mounting groove of mounting plate on the chair foot, the inside of mounting groove is equipped with the spacing groove of cooperation connecting plate.

2. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 1, wherein: the driving lever assembly comprises a guide driving lever and two driving lever heads fixed at the bottoms of the front and back surfaces of the guide driving lever, a driving lever head guide groove matched with the driving lever head is arranged on the bolt guide seat, the driving lever head guide groove is obliquely arranged, and the distance between the bottom of the driving lever head guide groove and the corresponding movable bolt is smaller than the distance between the top of the driving lever head guide groove and the corresponding movable bolt.

3. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 2, wherein: the locking mechanism is characterized in that reinforcing seats are arranged inside the locking support of the upper locking mechanism and the locking support of the lower locking mechanism, button guide grooves are formed in the upper portions of the reinforcing seats, the reset springs are located in the button guide grooves, spring seats matched with the reset springs are arranged at the bottoms of the button guide grooves, bolt guide grooves matched with the bolt guide seats are formed in the middle of the reinforcing seats, and bolt guide ports matched with movable bolts are formed in the two sides of the reinforcing seats.

4. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 3, wherein: one side of the guide deflector rod is provided with a plurality of limiting grooves, and limiting plates matched with the limiting grooves are arranged inside the reinforcing seat.

5. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 1, wherein: one side of the upright rod sleeve is provided with an inner inserting pin hole matched with the movable bolt and the outer inserting pin hole, and the inner side of the upright rod sleeve is provided with a tight fit ring matched with the support upright rod.

6. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 3, wherein: a connecting rod fixing frame matched with a seat connecting rod is further arranged in the locking support of the lower locking mechanism, the back surface of the connecting rod fixing frame is opened, the seat connecting rod is fixed on the front surface of the connecting rod fixing frame, and a button guide opening matched with a button is formed in the top of the connecting rod fixing frame; the front of the connecting rod fixing frame is provided with a plurality of limiting holes, and the front side of the reinforcing seat is provided with a limiting pin matched with the limiting holes of the part.

7. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 3, wherein: the backrest mounting bracket is a double-backrest mounting bracket, the front side of the locking bracket of the upper locking mechanism is open, a plurality of mounting columns matched with the backrest mounting bracket are arranged on the front side of the reinforcing seat of the upper locking mechanism, the two backrests are arranged on the front side of the backrest mounting bracket, and the back side of the backrest mounting bracket is arranged on the reinforcing seat of the upper locking mechanism through the mounting columns.

8. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 1, wherein: the supporting upright rods are inserted into the connecting plate and welded with the connecting plate, the connecting plate is provided with an I-shaped reinforcing rib, and two sides of the I-shaped reinforcing rib respectively correspond to the two supporting upright rods; the top of mounting groove is equipped with the apron, be equipped with the guide pin bushing between support pole setting and the apron.

9. A double-support upright chair with stable lifting and stable locking of the backrest and the chair seat as claimed in claim 1, wherein: the limiting groove is formed by matching two limiting barrier strips fixed in the mounting groove with the side wall of the mounting groove; the connecting plate is provided with a plurality of screw mounting holes matched with mounting screws, the bottom of the mounting groove is provided with screw mounting hole columns matched with the screw mounting holes and a plurality of connecting plate supporting sheets matched with the connecting plate, and the side wall of the mounting groove is provided with connecting plate limiting strips matched with the connecting plate.

10. A double support pole chair with stable lifting and reliable locking as claimed in claim 8, wherein: the supporting vertical rods are steel pipes, the connecting plates are iron plates, the number of the mounting screws is four, two mounting screws are located on the front side of the I-shaped reinforcing rib, and the other two mounting screws are located on the rear side of the I-shaped reinforcing rib; the distance between the two mounting screws on the front side is greater than the distance between the two supporting vertical rods, and the distance between the mounting screws on the two sides of the rear side is less than the distance between the two supporting vertical rods.

Technical Field

The invention relates to a chair, in particular to a double-support upright chair with stable lifting of a backrest and a chair seat and stable and reliable locking.

Background

At present, in a seat support of a conventional single-support upright or double-support upright, whether a seat or a backrest is limited and locked with the support upright, a locking component is usually adopted to be singly locked with one support upright, and the locking structure is suitable for being used on a seat with the single-support upright; however, in the case of the double-support upright seat, if each support upright is locked with the seat or the backrest by using a locking component, two separate sets of locking components are required, and the operation is very troublesome; and common two pole locking Assembly is used in the seat and supports in pairs on the pole setting, and it is relatively poor to reciprocate the synchronism, and the improper easy card of operation leads to the lift stationarity and the reliability of back and seat support to obtain the guarantee, influences and uses the travelling comfort.

In addition, the conventional seat supporting upright stanchions are either single-pole or double-pole, and basically, the bottom of the single supporting upright stanchion is fixed with the chair leg through the connecting lug matched with two mounting screws, so the structure causes that the connecting contact surface between the supporting upright stanchion and the chair leg is smaller, and the connecting strength cannot be guaranteed; and the distance between two mounting screws receives the restriction of supporting pole setting cross-section size, can influence the fastening nature of being connected of supporting pole setting and chair foot, still can lead to supporting the relative chair foot of pole setting and produce and rock, influences seat quality and use travelling comfort.

Disclosure of Invention

In order to solve the defects and shortcomings in the prior art, the invention provides an upper locking mechanism for connecting a backrest and a support upright rod and a lower locking mechanism for connecting a seat and the support upright rod, which adopt a structure of a locking bracket designed between two upright rod sleeves, so that the upper locking mechanism and the lower locking mechanism can be well arranged between the two support upright rods, the operation balance is good, the up-and-down movement synchronism is good, the lifting of the backrest and the seat is stable and reliable, the backrest and the seat are not easy to shake, the locking can be prevented, the use comfort is good, meanwhile, a button is adopted to drive a bolt to stretch to realize locking or unlock so as to limit the up-and-down movement, and the operation is convenient and reliable; the supporting vertical rod and the chair legs are connected with the contact surface in an amplifying mode through the connecting plate, the connecting plate is connected with the chair legs through a plurality of mounting screws, the screw distance is larger than that of the conventional supporting vertical rod which is directly connected with the chair legs, the supporting vertical rod and the chair legs are connected tightly, the chair is not prone to shaking, the lifting of the backrest chair seat is stable, and the locking of the backrest chair seat is stable and reliable.

The technical scheme of the invention is as follows: a double-support upright rod seat with stable lifting of a backrest seat and stable and reliable locking comprises a seat support, seat legs arranged at the bottom of the seat support and a seat handle arranged at the top of the seat support, wherein the seat support comprises two support upright rods, a seat, a backrest and handrails which are connected with the two support upright rods in a lifting way, the seat is connected with the support upright rods through a lower locking mechanism, the backrest is connected with the support upright rods through an upper locking mechanism, the upper locking mechanism and the lower locking mechanism respectively comprise two upright rod sleeves matched with the support upright rods, a locking support arranged between the two upright rod sleeves and two movable bolts which are connected in the locking support in a sliding way, the top of the locking support is provided with a button for driving the two movable bolts to move and a reset spring matched with the button, and the button is respectively connected with the two movable bolts through a driving lever component, the movable bolt is connected with the deflector rod assembly through a bolt guide seat, the support upright rod is provided with a plurality of outer inserting pin holes matched with the movable bolt, the seat is connected with the lower locking mechanism through a seat connecting rod, and the backrest is connected with the upper locking mechanism through a backrest mounting frame; the utility model discloses a chair, including two support posts, seat, chair foot, connecting plate, mounting screw, mounting plate's mounting groove, the inside of mounting groove is equipped with the spacing groove of cooperation connecting plate, and the seat is installed in the bottom of two support posts, and the seat handle is installed at the top of two support posts, and the bottom of two support poles sets is connected through a connecting plate, the connecting plate is connected with the chair foot through two above mounting screws, be equipped with the mounting groove of mounting plate on the chair foot, the inside of mounting groove is equipped with the spacing groove of cooperation connecting plate.

The upper locking mechanism for connecting the backrest and the supporting upright rods and the lower locking mechanism for connecting the seat and the supporting upright rods both adopt a structure of a locking bracket designed between two upright rod sleeves, so that the upper locking mechanism and the lower locking mechanism can be well arranged between the two supporting upright rods, the operation balance is good, the up-and-down movement synchronism is good, the lifting of the backrest and the seat is stable and reliable, the rocking is not easy, the clamping can be prevented, the use comfort is good, meanwhile, the button is adopted to drive the bolt to stretch and realize locking or unlock so as to limit the up-and-down movement, and the operation is convenient and reliable; the supporting vertical rod and the chair legs are connected with the contact surface in an enlarged mode through the connecting plate, the connecting plate is connected with the chair legs through a plurality of mounting screws, the screw distance is larger than that of the conventional supporting vertical rod which is directly connected with the chair legs, the supporting vertical rod and the chair legs are connected tightly, the chair is not prone to shaking, and the quality and the use comfort of the chair are guaranteed.

Preferably, the deflector rod assembly comprises a guide deflector rod and two deflector rod heads fixed at the bottoms of the front and back surfaces of the guide deflector rod, a deflector rod head guide groove matched with the deflector rod head is arranged on the bolt guide seat, the deflector rod head guide groove is obliquely arranged, and the distance between the bottom of the deflector rod head guide groove and the corresponding movable bolt is smaller than the distance between the top of the deflector rod head guide groove and the corresponding movable bolt.

The structure ensures that the button drives the guide deflector rod and the deflector rod head to move more stably and reliably, and the deflector rod head pushes the bolt guide seat and the movable bolt to move back and forth more stably and reliably.

Preferably, the locking support of the upper locking mechanism and the locking support of the lower locking mechanism are both provided with a reinforcing seat, the upper part of the reinforcing seat is provided with a button guide groove, the reset spring is positioned in the button guide groove, the bottom of the button guide groove is provided with a spring seat matched with the reset spring, the middle part of the reinforcing seat is provided with a bolt guide groove matched with the bolt guide seat, and the two sides of the reinforcing seat are provided with bolt guide ports matched with movable bolts.

The structure ensures the integral strength of the locking bracket, and simultaneously ensures that the button is pressed and reset stably and reliably, and the bolt guide seat and the movable bolt slide stably and reliably; further ensuring the firm assembly of the connecting rod fixing frame and the locking bracket.

Preferably, one side of the guide deflector rod is provided with a plurality of limiting grooves, and a limiting plate matched with the limiting grooves is arranged inside the reinforcing seat.

The structure ensures that the guide deflector rod moves up and down more stably and reliably.

Preferably, one side of the upright rod sleeve is provided with an inner inserting pin hole matched with the movable bolt and the outer inserting pin hole, and the inner side of the upright rod sleeve is provided with a close-fitting ring matched with the support upright rod.

The structure ensures that the assembly of the upright rod sleeve and the supporting upright rod is more compact and reliable.

Preferably, a connecting rod fixing frame matched with the seat connecting rod is further arranged in the locking support of the lower locking mechanism, the back surface of the connecting rod fixing frame is opened, the seat connecting rod is fixed on the front surface of the connecting rod fixing frame, and a button guide opening matched with a button is formed in the top of the connecting rod fixing frame; the front of the connecting rod fixing frame is provided with a plurality of limiting holes, and the front side of the reinforcing seat is provided with a limiting pin matched with the limiting holes of the part.

The structure ensures the firm assembly of the connecting rod fixing frame and the locking bracket; further ensure the firm and reliable connection of seat support connecting rod and locking support, ensure the seat support installation firm reliable, guarantee the safety in utilization.

Preferably, the backrest mounting bracket is a double-backrest mounting bracket, the locking bracket of the upper locking mechanism is openly opened, a plurality of mounting posts matched with the backrest mounting bracket are arranged on the front surface of the reinforcing seat of the upper locking mechanism, the two backrests are arranged on the front surface of the backrest mounting bracket, and the back surface of the backrest mounting bracket is arranged on the reinforcing seat of the upper locking mechanism through the mounting posts.

The structure ensures that the backrest mounting frame and the locking support are firmly and reliably connected, ensures that the backrest is firmly and reliably mounted, and ensures the use safety.

Preferably, the supporting upright posts are inserted into the connecting plate and welded with the connecting plate, the connecting plate is provided with an I-shaped reinforcing rib, and two sides of the I-shaped reinforcing rib respectively correspond to the two supporting upright posts; the top of mounting groove is equipped with the apron, be equipped with the guide pin bushing between support pole setting and the apron.

The supporting upright stanchion is welded with the connecting plate, so that the connecting strength is good; the supporting plate is reinforced by the I-shaped reinforcing ribs, so that deformation can be better prevented; further ensure the connection stability and reliability between the support upright stanchion and the chair foot.

Preferably, the limit groove is formed by matching two limit barrier strips fixed in the mounting groove with the side wall of the mounting groove; the connecting plate is provided with a plurality of screw mounting holes matched with mounting screws, the bottom of the mounting groove is provided with screw mounting hole columns matched with the screw mounting holes and a plurality of connecting plate supporting sheets matched with the connecting plate, and the side wall of the mounting groove is provided with connecting plate limiting strips matched with the connecting plate.

The structure ensures that the limiting groove is convenient to arrange, further ensures that the process is simple and the manufacture is convenient; further ensure the assembly stability and reliability between the connecting plate and the chair feet.

Preferably, the supporting vertical rod is a steel pipe, the connecting plate is an iron plate, the number of the mounting screws is four, two of the mounting screws are positioned on the front side of the I-shaped reinforcing rib, and the other two mounting screws are positioned on the rear side of the I-shaped reinforcing rib; the distance between the two mounting screws on the front side is greater than the distance between the two supporting vertical rods, and the distance between the mounting screws on the two sides of the rear side is less than the distance between the two supporting vertical rods.

The structure ensures the strength and the assembling firmness of the supporting upright stanchion and the connecting plate; further ensuring the assembly firmness between the connecting plate and the chair leg.

The upper locking mechanism for connecting the backrest and the supporting upright rods and the lower locking mechanism for connecting the seat and the supporting upright rods both adopt a structure of a locking bracket designed between two upright rod sleeves, so that the upper locking mechanism and the lower locking mechanism can be well arranged between the two supporting upright rods, the operation balance is good, the up-and-down movement synchronism is good, the lifting of the backrest and the seat is stable and reliable, the rocking is not easy, the clamping can be prevented, the use comfort is good, meanwhile, the button is adopted to drive the bolt to stretch and realize locking or unlock so as to limit the up-and-down movement, and the operation is convenient and reliable; the supporting vertical rod and the chair legs are connected with the contact surface in an enlarged mode through the connecting plate, the connecting plate is connected with the chair legs through a plurality of mounting screws, the screw distance is larger than that of the conventional supporting vertical rod which is directly connected with the chair legs, the supporting vertical rod and the chair legs are connected tightly, the chair is not prone to shaking, and the quality and the use comfort of the chair are guaranteed.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of the upper and lower locking mechanisms of the present invention with the locking bracket shell and the rear half reinforcing seat removed;

FIG. 3 is a schematic structural view of the lower locking mechanism of the present invention with the locking bracket shell removed and the seat link rod connected thereto;

FIG. 4 is a schematic view of the push button toggle assembly of the present invention;

FIG. 5 is a schematic structural view of a movable plug pin with a plug pin guide seat according to the present invention;

FIG. 6 is a schematic structural view of a front half of a reinforcing base according to the present invention;

FIG. 7 is a schematic view of the locking state of the upper and lower locking mechanisms according to the present invention;

FIG. 8 is a schematic view of the construction of the lower locking mechanism of the present invention;

FIG. 9 is a schematic view of the connection between the vertical support rod and the chair leg;

FIG. 10 is an exploded view of the support upright of the present invention connected to a chair leg;

in the figure, 1, a supporting upright rod, 2, an outer inserting pin hole, 3, a seat, 4, a backrest, 5, an upper locking mechanism, 6, a lower locking mechanism, 7, a backrest mounting frame, 8, a mounting column, 9, an inner inserting pin hole, 10, a tight fit ring, 11, an upright rod sleeve, 12, a locking bracket, 13, a seat connecting rod, 14, a movable bolt, 15, a button, 16, a bolt guide seat, 17, a guide rod, 18, a rod head, 19, a rod head guide groove, 20, a reinforcing seat, 21, a button guide groove, 22, a spring seat, 23, a bolt guide groove, 24, a bolt guide port, 25, a connecting rod fixing frame, 26, a button guide port, 27, a limiting hole, 28, a limiting pin, 29, a limiting groove, 30, a limiting plate, 31, a seat handle, 32, a seat foot, 33, a connecting plate, 34, a mounting groove, 35, an I-shaped reinforcing rib, 36, a limiting groove, 37, a limiting blocking strip, 38, a screw mounting hole, 39. the bolt is installed the hole post, 40, the connecting plate backing sheet, 41, the connecting plate spacing strip, 42, the apron, 43, the guide pin bushing, 44, the handrail.

Detailed Description

The present invention will be described in further detail with reference to the attached drawings, but the present invention is not limited thereto.

As shown in figures 1-10, a double-support upright chair with stable lifting of the backrest seat and stable locking comprises a chair support, chair legs 32 arranged at the bottom of the chair support and a chair handle 31 arranged at the top of the chair support. The seat support comprises two supporting upright posts 1, a seat 3 connected with the two supporting upright posts 1 in a lifting way, a backrest 4 and handrails 44, wherein the seat 3 is connected with the supporting upright posts 1 through a lower locking mechanism 6, the backrest 4 is connected with the supporting upright posts 1 through an upper locking mechanism 5, the upper locking mechanism 5 and the lower locking mechanism 6 respectively comprise two upright post sleeves 11 matched with the supporting upright posts 1, a locking support 12 arranged between the two upright post sleeves 11 and two movable bolts 14 which move in opposite directions and are connected in the locking support 12 in a sliding way, the top of the locking support 12 is provided with a button 15 driving the two movable bolts 14 to act and a return spring matched with the button 15, the button 15 is respectively connected with the two movable bolts through a deflector rod component, the movable bolts 14 are connected with the deflector rod component through bolt guide seats 16, the supporting upright posts 1 are provided with a plurality of outer inserting pin holes 2 matched with the movable bolts 14, the seat 3 is connected to the lower locking mechanism 6 through a seat link 13, and the backrest 4 is connected to the upper locking mechanism 5 through a backrest mounting frame 7. The deflector rod assembly comprises a guide deflector rod 17 and two deflector rod heads 18 fixed at the bottoms of the front and back surfaces of the guide deflector rod 17, a deflector rod head guide groove 19 matched with the deflector rod head 18 is formed in the bolt guide seat 16, the deflector rod head guide groove 19 is obliquely arranged, and the distance between the bottom of the deflector rod head guide groove 19 and a corresponding movable bolt is smaller than the distance between the top of the deflector rod head guide groove 19 and the corresponding movable bolt. The inside of the locking support of last locking mechanical system 5 and the locking support of lower locking mechanical system 6 all is equipped with reinforcing seat 20, and reinforcing seat 20's upper portion is equipped with button guide way 21, and reset spring is located button guide way 21, and the bottom of button guide way 21 is equipped with the spring holder 22 of cooperation reset spring, and reinforcing seat 20's middle part is equipped with the bolt guide way 23 of cooperation bolt guide way 16, and reinforcing seat 20's both sides are equipped with the bolt guide mouth 24 of cooperation activity bolt 14. Two limiting grooves 29 are formed in one side of the guide deflector rod 17, and a limiting plate 30 matched with the limiting grooves 29 is arranged inside the reinforcing seat 20. One side of the upright rod sleeve 11 is provided with an inner inserting pin hole 9 matched with the movable bolt 14 and the outer inserting pin hole 2, and the inner side of the upright rod sleeve 11 is provided with a tight fit ring 10 matched with the support upright rod 1. A connecting rod fixing frame 25 matched with the seat connecting rod 13 is further arranged in the locking support of the lower locking mechanism 6, the back surface of the connecting rod fixing frame 25 is opened, the seat connecting rod 13 is fixed on the front surface of the connecting rod fixing frame 25, and a button guide opening 26 matched with the button 15 is formed in the top of the connecting rod fixing frame 25; the front surface of the connecting rod fixing frame 25 is provided with a plurality of limiting holes 27, and the front side of the reinforcing base 20 is provided with a limiting pin 28 matched with part of the limiting holes. The backrest mounting frame 7 is a double-backrest mounting frame, the front surface of the locking support of the upper locking mechanism 5 is provided with an opening, the front surface of the reinforcing seat of the upper locking mechanism 5 is provided with a plurality of mounting columns 8 matched with the backrest mounting frame 7, the two backrests 4 are mounted on the front surface of the backrest mounting frame 7, and the back surface of the backrest mounting frame 7 is mounted on the reinforcing seat of the upper locking mechanism 5 through the mounting columns 8.

The bottoms of the two supporting vertical rods are connected through a connecting plate 33, the connecting plate 33 is connected with the chair feet 32 through four mounting screws, mounting grooves 34 for mounting the connecting plate 33 are formed in the chair feet 32, and limiting grooves 36 matched with the connecting plate 33 are formed in the mounting grooves 34. The supporting vertical rods 1 are inserted into the connecting plate 33 and welded with the connecting plate 33, the connecting plate 33 is provided with an I-shaped reinforcing rib 37, and two sides of the I-shaped reinforcing rib 37 correspond to the two supporting vertical rods respectively. The top of the mounting groove 34 is provided with a cover plate 42, and a guide sleeve 43 is arranged between the supporting upright rod 1 and the cover plate 42. The limit groove 36 is formed by two limit bars 37 fixed in the mounting groove 34 and the side wall of the mounting groove 34. The connecting plate 33 is provided with four screw mounting holes 38 matched with mounting screws, the bottom of the mounting groove 34 is provided with four screw mounting hole columns 39 matched with the screw mounting holes 38 and four connecting plate supporting sheets 40 matched with the connecting plate 33, and the side wall of the mounting groove 34 is provided with a connecting plate limiting strip 41 matched with the connecting plate 33. The supporting vertical rod 1 is a steel pipe, the connecting plate 33 is an iron plate, two mounting screws are positioned on the front side of the I-shaped reinforcing rib, and the other two mounting screws are positioned on the rear side of the I-shaped reinforcing rib. The distance between the two mounting screws on the front side is greater than the distance between the two supporting vertical rods, and the distance between the mounting screws on the two sides of the rear side is less than the distance between the two supporting vertical rods.

The mounting groove for mounting the connecting plate can also be designed at the lower side of the chair leg, and the supporting upright rod penetrates through the whole chair leg and is fixedly connected with the chair leg through the connecting plate.

When the upper locking mechanism and the lower locking mechanism are used, the button is pressed, the two movable bolts are retracted, the two upright rods are sleeved on the two supporting upright rods of the seat, so that bolt holes in the upright rod sleeves correspond to part of bolt holes in the supporting upright rods and are tightly matched through the tight fit ring, then the button is loosened, the reset spring drives the button to reset, and the two movable bolts extend out and penetrate into the bolt holes of the corresponding supporting upright rods to be locked and limited; when the height needs to be adjusted, the button is pressed, the two movable bolts retract, the locking support and the vertical rod sleeve can slide on the supporting vertical rod to adjust the height, and after the adjustment is finished, the movable bolts correspond to the bolts on the supporting vertical rod, and the button is released.

When the button is pressed down, the button pushes the guide deflector rod and the deflector rod head to move downwards, the deflector rod head moves in the corresponding deflector rod guide groove, the deflector rod head moves downwards due to the inclined arrangement of the deflector rod guide groove to drive the bolt guide seat and the movable bolt to retract inwards, and when the movable bolt is completely separated from the bolt hole on the supporting upright rod, the locking bracket and the upright rod sleeve can slide on the supporting upright rod; otherwise, after the button is released, the reset spring drives the button to reset, so that the guide deflector rod and the deflector rod head are driven to move upwards, the deflector rod head moves in the corresponding deflector rod guide groove, the deflector rod guide groove is obliquely arranged, the deflector rod head moves upwards, the bolt guide seat and the movable bolt are driven to extend outwards, and when the movable bolt is inserted into the bolt hole in the support upright rod, the locking support and the upright rod sleeve are locked and limited on the support upright rod.

The upper locking mechanism for connecting the backrest and the supporting upright rods and the lower locking mechanism for connecting the seat and the supporting upright rods both adopt a structure of a locking bracket designed between two upright rod sleeves, so that the upper locking mechanism and the lower locking mechanism can be well arranged between the two supporting upright rods, the operation balance is good, the up-and-down movement synchronism is good, the lifting of the backrest and the seat is stable and reliable, the rocking is not easy, the clamping can be prevented, the use comfort is good, meanwhile, the button is adopted to drive the bolt to stretch and realize locking or unlock so as to limit the up-and-down movement, and the operation is convenient and reliable; the supporting vertical rod and the chair legs are connected with the contact surface in an enlarged mode through the connecting plate, the connecting plate is connected with the chair legs through a plurality of mounting screws, the screw distance is larger than that of the conventional supporting vertical rod which is directly connected with the chair legs, the supporting vertical rod and the chair legs are connected tightly, the chair is not prone to shaking, and the quality and the use comfort of the chair are guaranteed.