CN109757891B - Leaning back support structure for backrest-free chair - Google Patents

Abstract

The invention discloses a leaning back support structure for a backrest-free chair, which comprises two leaning back support bodies and a back cushion, wherein the leaning back support bodies comprise clamping rods, lifting rods and fixing pieces; the clamping rod of one leaning back support body is used for clamping one side of the back cushion, and the clamping rod of the other leaning back support body is used for clamping the other side of the back cushion; the bottom of the clamping rod is connected with the top of the lifting rod, the bottom of the lifting rod is provided with a fixing piece, and the fixing piece is used for being fixed on a chair leg of the backrest-free chair. The invention can be installed on a chair without backrest for use, so that a user sitting on the chair can relax properly to relieve lumbar vertebra burden, and the chair has the advantages of simple integral structure, easy assembly, easy storage and convenient disassembly and installation.

Description

Leaning back support structure for backrest-free chair

Technical Field

The invention relates to a backrest, in particular to a backrest bracket structure for a backrest-free chair.

Background

Universities, except libraries, reading rooms in various rest rooms and classrooms, learn places with most frequent use time are too warm and convenient dormitories. Many chairs used in university dormitories are four-way benches without a backrest. Firstly, the hardness requirements of schools are unified and convenient to manage, namely, the chairs with backs are not allowed to be purchased. Secondly, the self-purchasing chair occupies too much space, and if an emergency occurs, the self-purchasing chair is convenient for various reasons such as timely escape in the narrow dormitory.

However, many students who need to sit on the bench for a long time in a bedroom feel painful, work and study for a long time all day, and when the students want to rest, the students do not lean on the bench even with an imaging point, and the students do not lean on the bench, either lean on a cold wall or lean on a thin and straight rust-generating steel tube bed ladder stand. The students who do not become office workers can learn a series of lumbar bone cervical spondylosis in advance, and work efficiency is greatly affected.

The above-mentioned problems are those which should be considered and addressed in the attachment of the backrest.

Disclosure of Invention

The invention aims to solve the technical problem of providing a leaning back support structure for a backrest-free chair aiming at the defects of the prior art, and the leaning back support structure for the backrest-free chair can be installed on the backrest-free chair for use, so that a user sitting on the chair can relax properly to relieve lumbar vertebra burden, and the leaning back support structure is simple in overall structure, easy to assemble, easy to store and simple and convenient to install and disassemble.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a leaning back support structure for a backrest-free chair, comprising two leaning back support bodies and a back cushion, wherein the leaning back support bodies comprise clamping rods, lifting rods and fixing pieces;

the clamping rod of one leaning back support body is used for clamping one side of the back cushion, and the clamping rod of the other leaning back support body is used for clamping the other side of the back cushion;

the bottom of the clamping rod is connected with the top of the lifting rod, the bottom of the lifting rod is provided with a fixing piece, and the fixing piece is used for being fixed on a chair leg of the backrest-free chair;

the utility model provides a clamp lever, including clamp lever main part, clamp lever cap, screw, front plate and back splint, the inside of clamp lever main part is hollow structure, and upper end and lower extreme are open structure, and the surface of clamp lever main part is equipped with the back pad penetration groove of two intercommunications, front plate and back splint all face-to-face are located the inboard of clamp lever main part and the inboard fixed connection of back splint and clamp lever main part, screw and the surface threaded connection of clamp lever main part and screw in can screw in the inboard of clamp lever main part and jack the front plate, thereby the front plate is used for moving to the direction that back splint place under the effect of screw makes front plate and back splint can press from both sides the back pad, the upper end and the clamp lever cap of clamp lever main part are connected, and the lower extreme is connected with the top of lifter.

As a further improved technical scheme of the invention, countersunk threaded holes are formed in the surface of the clamping rod main body, two back pad penetrating grooves are formed in two sides of the countersunk threaded through holes, a circular groove is formed in the surface of the front clamping plate, the end part of the rotary nail is circular arc-shaped, the maximum diameter of the circular arc-shaped end part of the rotary nail is larger than the diameter of the circular groove, the rotary nail is used for being screwed into the countersunk threaded through holes in the surface of the clamping rod main body, and the circular arc-shaped end part of the rotary nail is used for being embedded into and propped against the circular groove in the surface of the front clamping plate.

As a further improved technical scheme of the invention, 2 countersunk head threaded holes are formed, the number of the rotary nails is 2 in the same vertical direction, the upper end of the clamping rod main body is in threaded connection with the clamping rod cap, and friction convex ribs are arranged on the opposite surfaces of the front clamping plate and the rear clamping plate.

As a further improved technical scheme of the invention, the lifting rod comprises a lifting buckle structure, an upper lifting rod and a lower lifting rod, wherein the inside of the lower lifting rod is of a hollow structure, the upper end of the lower lifting rod is of an opening structure, the upper lifting rod extends into the lower lifting rod from the upper end of the lower lifting rod, the upper lifting rod can freely slide in the lower lifting rod, the upper end of the upper lifting rod is in threaded connection with the lower end of the clamping rod main body, and the lifting buckle structure is arranged at the upper end of the lower lifting rod and is used for fixing the relative positions of the upper lifting rod and the lower lifting rod.

According to the technical scheme, the lifting buckle structure comprises a lifting buckle main body, a closing switch, a bolt nail, a nut and a clamping gasket, wherein a notch is formed in one side surface of the lifting buckle main body, connecting lugs are connected to the top and the bottom of the notch, the clamping gasket is located at the notch, an elliptic cylinder section of the closing switch is located between the two connecting lugs, the bolt nail sequentially penetrates through the center of one connecting lug, the center of the elliptic cylinder section and the center of the other connecting lug, the bolt nail is connected with the nut so that the elliptic cylinder section is clamped between the two connecting lugs, a handle section of the closing switch and the elliptic cylinder section are connected into an integral structure, the handle section is used for driving the elliptic cylinder section to rotate between the two connecting lugs so that the elliptic cylinder section is propped against the clamping gasket at the notch or is separated from the clamping gasket at the notch, a limit bulge is arranged on the inner side wall of the clamping gasket, a through groove matched with the limit bulge is formed in one side surface of the upper end of the lower lifting rod, the limit bulge of the clamping gasket is embedded in the through groove of the lower lifting rod, and the clamping bulge of the clamping gasket is used for pressing the lifting rod by the lifting rod.

According to the technical scheme, the fixing piece comprises a U-shaped metal shell, a rubber belt, a rotary support bolt, a clamping screw and a fixing buckle, wherein a first through hole penetrating horizontally is formed in the bottom of a lower lifting rod, a second through hole is formed in the middle lower portion of the left side face and the right side face of the U-shaped metal shell, the bottom of the lower lifting rod is located on the inner side of the U-shaped metal shell, the first through hole on the lower lifting rod is rotationally connected with the two through holes on the U-shaped metal shell through the rotary support bolt, a clamping threaded hole and a clamping through hole are formed in the middle upper portion of the left side face and the middle upper portion of the right side face of the U-shaped metal shell respectively, one end of the clamping screw sequentially penetrates through the clamping through hole and the clamping threaded hole and is in threaded connection with the clamping screw, one side of the lower lifting rod is located between the front side face of the U-shaped metal shell and the clamping screw, one side of the rubber belt is fixedly connected with the left side face of the U-shaped metal shell, the fixing buckle is fixedly connected with the right side face of the U-shaped metal shell and is fixedly used for fixing or loosening the other end of the rubber belt, and the rubber belt is fixedly connected with the fixing seat and the backrest.

As a further improved technical scheme of the invention, the fixing piece further comprises a rubber gasket, and the rubber gasket is fixedly connected with the front side surface of the U-shaped metal shell; the upper middle-upper part of the left side surface of the U-shaped metal shell is provided with two clamping threaded holes, the upper middle-upper part of the right side surface is provided with two clamping through holes, the two clamping threaded holes of the left side surface are positioned on the same circle taking the second through hole of the left side surface as the center of a circle, and the two clamping through holes of the right side surface are positioned on the same circle taking the second through hole of the right side surface as the center of a circle.

As a further improved technical scheme of the invention, the surface of the lower lifting rod is provided with a clamping groove matched with the outer wall of the clamping screw in shape, and the lower lifting rod is used for rotating at the inner side of the U-shaped metal shell through a rotating bracket bolt, and the clamping groove can be clamped with the outer wall of the clamping screw.

As a further improved technical scheme of the invention, one side of the rubber belt is fixedly connected with the left side surface of the U-shaped metal shell through a connecting piece, the connecting piece comprises a connecting frame and a first bolt, the connecting frame is fixedly connected with the left side surface of the U-shaped metal shell, one side of the rubber belt is positioned on the inner side of the connecting frame, and one side of the rubber belt is fixedly connected with the connecting frame through the first bolt.

As a further improved technical scheme of the invention, the fixing buckle comprises a U-shaped clamping frame, a clamping switch and a second peg, wherein the U-shaped clamping frame is fixedly connected to the right side face of the U-shaped metal shell, the clamping switch is tightly connected with the U-shaped clamping frame through the second peg and can rotate on the U-shaped clamping frame through external force, a rake-shaped protrusion is arranged on the inner side of the clamping switch, and the other side of the rubber belt is used for penetrating through a gap between the clamping switch and the U-shaped clamping frame and enabling the rake-shaped protrusion to clamp the rubber belt through external force.

The beneficial effects of the invention are as follows: the invention has simple structure, easy assembly and easy storage. The fixing piece is fixed or detached from the chair legs of the backrest-free chair, the fixing and detaching process is simple and convenient, the fixing pieces of the two leaning back support bodies are respectively fixed on the two chair legs behind the backrest-free chair, and the clamping rods of the two leaning back support bodies are respectively clamped on two sides of the back cushion, so that a user sits on the chair and can lean on the back cushion, and the user sitting on the chair can be properly relaxed to relieve lumbar vertebra burden. In addition, the leaning back support body can adjust the self inclination angle by adjusting the positions of the clamping screws in different clamping threaded holes and clamping through holes, so that the lifting rod and the clamping rod are suitable for different requirements of users, and the lifting rod and the clamping rod are inclined to the leaning angle required by the users, so that better convenience is provided for the users. The lifting rod can be contracted to the minimum length when not in use, so that the occupied space of the lifting rod is reduced, and the lifting rod is convenient to store.

Drawings

Fig. 1 is a front view of the overall structure of the invention after deployment.

Fig. 2 is a rear view of the overall structure of the invention after deployment.

Fig. 3 is a front view of the present invention after storage.

Fig. 4 is a rear view of the structure of the present invention after storage.

Fig. 5 is a schematic structural view of the clamping bar of the present invention.

Fig. 6 is an exploded view of the structure of the clamping bar of the present invention.

Fig. 7 is a schematic structural view of the lifting rod of the present invention.

Fig. 8 is a schematic structural view of the lifting buckle structure of the present invention.

Fig. 9 is a cross-sectional view of the lifting buckle structure of the present invention.

Fig. 10 is an exploded view of the lifting buckle structure of the present invention.

Fig. 11 is a schematic structural view of the fixing member of the present invention.

Fig. 12 is an exploded view of the fastener of the present invention.

Fig. 13 is a sectional view showing a state of clamping and unclamping of the fixing buckle of the fixing member of the present invention.

Fig. 14 is a schematic structural view of the back pad of the present invention.

Detailed Description

The following further describes embodiments of the present invention with reference to fig. 1 to 14:

referring to fig. 1 and 2, a reclining back bracket structure for a chair without a backrest includes two reclining back bracket bodies including a clamp bar 1, a lifter bar, and a fixing member 5, and a back pad 6 (cloth). One clamping rod 1 of the leaning back support body is used for clamping one side of the back cushion 6, and the other clamping rod 1 of the leaning back support body is used for clamping the other side of the back cushion 6. The bottom of the clamping rod 1 is connected with the top of the lifting rod, a fixing piece 5 is arranged at the bottom of the lifting rod, and the fixing piece 5 is used for being fixed on a chair leg 7 of a backrest-free chair.

Referring to fig. 5 and 6, the clamping bar 1 includes a clamping bar main body 11, a clamping bar cap 12, a screw 13, a front clamping plate 141 and a rear clamping plate 142, the inside of the clamping bar main body 11 is of a hollow structure, the upper end and the lower end are of an open structure, two connected back pad penetrating grooves 111 are formed on the surface of the clamping bar main body 11, the front clamping plate 141 and the rear clamping plate 142 are located on the inner side of the clamping bar main body 11 face to face and fixedly connected with the inner side wall of the clamping bar main body 11 in a welding manner, the screw 13 is in threaded connection with the surface of the clamping bar main body 11, the screw 13 can be screwed into the inner side of the clamping bar main body 11 and props against the inner front clamping plate 141, the front clamping plate 141 and the rear clamping plate can clamp the back pad 6 in the direction in which the rear clamping plate 142 is located under the action of the screw 13, the upper end of the clamping bar main body 11 is connected with the clamping bar cap 12, and the lower end is connected with the top of the lifting bar.

In this embodiment, the surface of the clamping rod main body 11 is provided with a countersunk threaded hole 112, two back pad penetrating grooves 111 are located at two sides of the countersunk threaded through hole 112, the surface of the front clamping plate 141 is provided with a circular groove 1411, the end of the screw 13 is circular arc-shaped, the maximum diameter of the circular arc-shaped end of the screw 13 is larger than the diameter of the circular groove 1411, the screw 13 is used for being screwed into the countersunk threaded through hole 112 on the surface of the clamping rod main body 11, and the circular arc-shaped end of the screw 13 is used for being embedded into and propped against the circular groove 1411 on the surface of the front clamping plate 141.

When the clamping bar 1 of the embodiment needs to clamp the back pad 6, the back pad 6 passes through the two back pad penetrating grooves 111 and between the front clamping plate 141 and the rear clamping plate 142, at this time, the back pad 6 is located between the front clamping plate 141 and the rear clamping plate 142, then the rotary nails 13 are screwed, the rotary nails 13 move towards the inside of the clamping bar main body 11 under the action of external force rotation, the end parts of the rotary nails 13 prop against the circular grooves 1411 on the surface of the front clamping plate 141, and then the rotary nails 13 can push the front clamping plate 141 to move towards the rear clamping plate 142 when moving continuously, so that the back pad 6 can be clamped. When the back cushion 6 needs to be removed, the screws 13 are only needed to be reversely screwed, the screws 13 are loosened to the front clamping plate 141, and the back cushion 6 can be taken out from between the front clamping plate 141 and the rear clamping plate 142.

In this embodiment, 2 countersunk threaded holes 112 are formed, and in the same vertical direction, 2 rotary nails 13 are formed, the upper end of the clamping rod main body 11 is in threaded connection with the clamping rod cap 12, and friction ribs are formed on opposite surfaces of the front clamping plate 141 and the rear clamping plate 142. The texture direction of the friction ribs on the front clamping plate 141 is crossed with the texture direction of the friction ribs on the rear clamping plate 142. The friction ribs may increase friction with the back pad 6 when the front and rear clamping plates 141 and 142 clamp the back pad 6.

In this embodiment, referring to fig. 1 and 2, the lifting rod includes a lifting buckle structure 2, an upper lifting rod 3, and a lower lifting rod 4. Referring to fig. 7, the lower lifting rod 4 is hollow and has an open upper end, the upper lifting rod 3 extends into the lower lifting rod 4 from the upper end of the lower lifting rod 4, and the upper lifting rod 3 can slide freely in the lower lifting rod 4, the upper end of the upper lifting rod 3 is in threaded connection with the lower end of the clamping rod body 11 (the lower end of the clamping rod body 11 is provided with external threads, the inner side of the upper end of the upper lifting rod 3 is provided with internal threads, and further the threaded connection of the upper lifting rod and the lower lifting rod is realized), and the lifting buckle structure 2 is installed at the upper end of the lower lifting rod 4, and the lifting buckle structure 2 is used for fixing the relative positions of the upper lifting rod 3 and the lower lifting rod 4.

In this embodiment, referring to fig. 8, 9 and 10, fig. 8 (a) is a schematic structural diagram of the lifting buckle structure 2 when the closing switch 22 is released, and when the closing switch is released, the length of the lifting rod is adjustable; fig. 8 (b) is a schematic structural diagram of the lifting buckle structure 2 when the closing switch 22 is closed, and when the closing switch is closed, the length of the lifting rod is not adjustable; fig. 9 (a) is a sectional view of the lifting buckle structure 2 when the closing switch 22 is released; fig. 9 (b) is a sectional view of the lifting/lowering buckle structure 2 when the closing switch 22 is closed; the lifting buckle structure 2 comprises a lifting buckle main body 21, a closed switch 22, a bolt 23, a nut 24 and a clamping gasket 25, wherein a notch 211 is formed in one side surface of the lifting buckle main body 21, the top and the bottom of the notch 211 are connected with the connecting lugs 212, the clamping gasket 25 is positioned at the notch 211, an elliptic column section 221 of the closed switch 22 is positioned between the two connecting lugs 212, the bolt 23 sequentially penetrates through the center of one connecting lug 212, the center of the elliptic column section 221 and the center of the other connecting lug 212, the bolt 23 is connected with the nut 24 so that the elliptic column section 221 is clamped between the two connecting lugs 212, a handle section 222 of the closed switch 22 and the elliptic column section 221 are connected into an integral structure, a means 222 is used for driving the elliptic column section 221 to rotate between the two connecting lugs 212 through external force so that the elliptic column section 221 is tightly propped against the clamping gasket 25 at the notch 211 or is separated from the clamping gasket 25 at the notch 211, one side of the inner side wall of the clamping gasket 25 is provided with a limit bulge 251, one side surface of the upper end of a lower lifting rod 4 is provided with a limit protuberance 251 which is matched with the clamping groove 25 in the lifting rod 4 through a clamping groove 251 (a 3 in the lifting section of the lifting rod 4) and the clamping groove 251 is embedded in the section of the lifting rod 4.

The top of lift buckle main part 21 still is equipped with upper cover 26 and lower cover 27, lift buckle main part 21, upper cover 26 and lower cover 27 are integrated into one piece structure, and the perpendicular through-hole on the lift buckle main part 21, the perpendicular through-hole on the upper cover 26 and the perpendicular through-hole on the lower cover 27 switch on and the diameter is the same, and this perpendicular through-hole is used for passing lower lifter 4 and upper lifter 3. The bolt 23 passes through the stepped hole at the edge of the lower cover 27, the center of one connecting lug 212, the center of the elliptic cylinder section 221, the center of the other connecting lug 212 and the stepped hole 261 at the edge of the upper cover 26 in sequence and is connected with the nut 24, the head of the bolt 23 is embedded in the stepped hole on the lower cover 27, and the nut 24 is embedded in the stepped hole 261 on the upper cover 26. In this embodiment, referring to fig. 11 and 12, fig. 11 (a) is a schematic structural view of the fixing member 5 in the rightward direction, fig. 11 (b) is a schematic structural view of the fixing member 5 in the leftward direction, the fixing member 5 includes a U-shaped metal shell 51, a rubber belt 52, a rotation bracket bolt 54, a clamping screw 55 and a fixing buckle 56, a first through hole 42 (as in fig. 12) penetrating horizontally is formed at the bottom of the lower lifting rod 4, a second through hole 511 is formed at the middle and lower parts of the left side surface and the right side surface opposite to the U-shaped metal shell 51, the bottom of the lower lifting rod 4 is located inside the U-shaped metal shell 51, the first through hole 42 on the lower lifting rod 4 is connected with the two second through holes 511 on the U-shaped metal shell 51 in a free rotation manner through the rotation bracket bolt 54, a clamping threaded hole and a clamping through hole 512 are formed above the middle and upper parts of the left side surface and the right side surface of the U-shaped metal shell 51, one end of the clamping screw 55 sequentially penetrates through the clamping threaded hole 512 and the clamping threaded hole 513, the end is connected with the clamping threaded hole, the lower lifting rod 4 is located between the left side surface of the U-shaped metal shell 51 and the right side surface of the seat 51 and the fixing buckle 52, and the other end of the seat is connected with the rubber belt 52 in a fixing manner, and the fixing belt is used for fixing the seat is fixed with the other side surface of the rubber belt 52.

In this embodiment, referring to fig. 11 and 12, the fixing member 5 further includes a rubber gasket 53, where the rubber gasket 53 is fixedly connected to the front side of the U-shaped metal shell 51; two clamping threaded holes 513 are formed in the middle and upper portion of the left side face of the U-shaped metal shell 51, two clamping through holes 512 are formed in the middle and upper portion of the right side face of the U-shaped metal shell, the two clamping threaded holes 513 on the left side face are located on the same circle taking the second through hole 511 on the left side face as the center, and the two clamping through holes 512 on the right side face of the U-shaped metal shell are located on the same circle taking the second through hole 511 on the right side face as the center. The two clamping screw holes 513 and the two clamping through holes 512 are used for providing different inclination angles for the lifting rod, and the clamping screws 55 are positioned differently, so that the inclination angles provided for the lifting rod are different.

In this embodiment, referring to fig. 12, the surface of the lower lifting rod 4 is provided with a clamping groove 43 matching the shape of the outer wall of the clamping screw 55, the lower lifting rod 4 is used for rotating inside the U-shaped metal shell 51 by rotating the bracket bolt 54, and the clamping groove 43 can be clamped (jogged) with the outer wall of the clamping screw 55.

In this embodiment, referring to fig. 11 and 12, one side of the rubber belt 52 is fixedly connected to the left side surface of the U-shaped metal shell 51 through a connecting piece 57, the connecting piece 57 includes a connecting frame 571 and a first peg 572, the connecting frame 571 is fixedly connected to the left side surface of the U-shaped metal shell 51 in a welding manner, one side of the rubber belt 52 is located at the inner side of the connecting frame 571, and one side of the rubber belt 52 is fixedly connected to the connecting frame 571 through the first peg 572.

In this embodiment, referring to fig. 11 and 12, the fixing buckle 56 includes a U-shaped clamping frame 561, a clamping switch 562 and a second peg 563, the U-shaped clamping frame 561 is fixedly connected to the right side surface of the U-shaped metal shell 51 by a welding manner, the clamping switch 562 is tightly connected to the U-shaped clamping frame 561 by the second peg 563, and the clamping switch 562 can rotate on the U-shaped clamping frame 561 by an external force, a rake-shaped protrusion 5621 (the rake-shaped protrusion 5621 is used for clamping the rubber belt 52) is provided on the inner side of the clamping switch 562, and the other side of the rubber belt 52 is used for passing through a gap between the clamping switch 562 and the U-shaped clamping frame 561, and the clamping switch 562 is used for clamping the rubber belt 52 by the rake-shaped protrusion 5621 by the external force. The schematic cross section of the rubber belt 52 in the fixing member 5 of the present embodiment is shown in fig. 13 (a), and the fixing buckle 56 in fig. 13 (a) is a clamping state cross section after the rubber belt is wound around the chair leg 7; the rubber belt 52 in the fixing member 5 is schematically shown in a cross section taken out of the fixing buckle 56 in fig. 13 (b), and the fixing buckle 56 in fig. 13 (b) is a released state cross section.

Referring to fig. 13, one side of the rubber belt 52 of the present embodiment is fixed to the connection member 57, the rubber belt 52 extended to surround the leg 7 of the chair is then put into the fixing buckle 56, and the rubber belt 52 is fixed by the fixing buckle 56. The rubber gaskets 53 and 52 and the rubber belt can increase friction with the chair legs 7.

In this embodiment, referring to fig. 14, fig. 14 (a) is a front view of the back pad 6, fig. 14 (b) is a back view of the back pad 6, the front surface of one end of the back pad 6 and the back surface of the other end are both provided with the fastening tape 61, and the fastening tape 61 on the front surface of one end of the back pad 6 and the fastening tape 61 on the back surface of the other end can be adhered or separated so as to realize the storage and unfolding of the back pad 6. The sticking buckle belt consists of a fabric with a small hook on one side and a fabric with a small plush loop on the other side, and the two sides have the characteristics of' being bonded by touching and being separated by pulling. Even if it is easy to store.

The assembly and installation process of the embodiment is as follows: the bottom of the clamping rod 1 is in threaded connection with the upper end of the upper lifting rod 3, the upper lifting rod 3 stretches into the lower lifting rod 4, the handle section 222 of the closing switch 22 of the lifting buckle structure 2 is rotated by force, the elliptical column section 221 of the closing switch 22 releases the clamping gasket 25 at the notch 211, the limiting boss 251 of the clamping gasket 25 releases the outer wall of the upper lifting rod 3 in the lower lifting rod 4, the relative position of the upper lifting rod 3 and the lower lifting rod 4 is adjusted so as to adjust the length of the lifting rod, after the length is adjusted to a proper length, the handle section 222 of the closing switch 22 of the lifting buckle structure 2 is rotated by force, the closing switch 22 is closed, at the moment, the elliptical column section 221 is tightly pressed by the limiting boss 251 of the clamping gasket 25 to tightly press the outer wall of the upper lifting rod 3 in the lower lifting rod 4, so that the length of the lifting rod is fixed, and the closing switch 22 in the embodiment must be opened or closed by force, and the phenomenon of looseness cannot occur when the closing is ensured. The click screw 55 is fitted into one of the click through hole 512 and the click screw hole 513 of the U-shaped metal shell 51 as required by itself. One side of the rubber belt 52 is wound around the chair leg 7 which is required to be installed on the backrest-free chair, then one side of the rubber belt 52 passes through the fixing buckle 56, after the chair leg 7 is tightly bound, the clamping switch 562 is rotated forcefully, the rubber belt 52 is clamped between the rake-shaped bulge 5621 of the clamping switch 562 and the U-shaped clamping frame 561, the fixing of the fixing piece 5 and the chair leg 7 is realized, the clamping switch 562 of the embodiment can rotate forcefully, the opening and the closing are realized, and the rubber belt 52 can be clamped without loosening during the closing is ensured. The two leaning back support bodies are respectively fixed on the two chair legs 7 in the above manner; one side of the back cushion 6 is clamped by a clamping rod 1 leaning against the back support body, and the other side is clamped by the clamping rod 1 leaning against the back support body, so that the assembly and the installation are completed. The user can lean against the back pad 6 for use.

The process of disassembly and storage of this embodiment is: the engaging switch 562 is forcibly turned on to take out one side of the rubber tape 52 from the fixing buckle 56, and the leg 7 is released. Loosening the rotary nails 13 on the clamping rods 1 leaning against the back support body, taking out the back cushion 6, forcibly unscrewing the handle section 222 of the closing switch 22 of the lifting buckle structure 2, loosening the clamping gasket 25 at the notch 211 by the elliptic cylinder section 221 of the closing switch 22, loosening the outer wall of the upper lifting rod 3 in the lower lifting rod 4 by the limiting bulge 251 of the clamping gasket 25, adjusting the relative positions of the upper lifting rod 3 and the lower lifting rod 4 so as to shorten the length of the lifting rod, forcibly unscrewing the handle section 222 of the closing switch 22 of the lifting buckle structure 2, locking the upper lifting rod 3, winding the back cushion 6 on the lifting rod and adhering the back cushion 6 through the adhesive tape 61 on the front side and the back side of the back cushion, and finally storing the result is shown in fig. 3 and 4. Many stools have different widths and heights, and the seat surfaces are different, and most of the seat surfaces are rectangular. Someone prefers to sit across the seating surface and someone prefers to sit upright on the seating surface. The clamping bars 1 clamp the two sides of the back cushion 6 to achieve the effect of the backrest, the positions of the clamping bars 1 clamping the back cushion 6 are the widths of the two fixing pieces 5 fixed on the chair legs 7 of the chair, the width of the back cushion 6 after clamping is required to be larger than the width before the two stool legs, and the width clamped by the back cushion 6 can be readjusted according to the body condition of the user.

The lifting rod is the same as the lifting rod, and the comfort of the lifting rod can be adjusted according to the body condition of the lifting rod through the lifting buckle structure 2 on the lifting rod. The fixing part 5 is fixed on the chair leg 7, the lifting rod can be inclined backwards to 15 degrees and is supported by the clamping screw 55, the clamping screw 55 is different in position, and the inclination angle of the lifting rod is different. The angle between the lifting rod and the seat cushion of the chair serves two purposes, preventing the seated person from sliding forward and guiding the lumbar bend (including the sacral spine) against the back cushion 6. This angle is more appropriate at 115 degrees from the perspective of the human spine, which produces a shape that more closely approximates the shape of a natural waist. In sitting postures, the optimal reading angle is 101-104 degrees, and the reading angle is 105-108 degrees, so that the mind and the body are relaxed. The backrest support structure mainly can relax the lumbar vertebra burden properly during reading, and can adopt an inclination angle of 105 degrees, namely 15 degrees of backward inclination.

The scope of the present invention includes, but is not limited to, the above embodiments, and any alterations, modifications, and improvements made by those skilled in the art are intended to fall within the scope of the invention.

Claims (8)

1. A leaning back support structure for a backrest-free chair, characterized by comprising two leaning back support bodies and a back cushion (6), wherein the leaning back support bodies comprise clamping rods (1), lifting rods and fixing pieces (5);

the clamping rod (1) of one leaning back support body is used for clamping one side of the back cushion (6), and the clamping rod (1) of the other leaning back support body is used for clamping the other side of the back cushion (6);

the bottom of the clamping rod (1) is connected with the top of the lifting rod, a fixing piece (5) is arranged at the bottom of the lifting rod, and the fixing piece (5) is used for being fixed on a chair leg of a backrest-free chair;

the clamping rod (1) comprises a clamping rod main body (11), a clamping rod cap (12), a rotary nail (13), a front clamping plate (141) and a rear clamping plate (142), wherein the inside of the clamping rod main body (11) is of a hollow structure, the upper end and the lower end are of an opening structure, two communicated back pad penetrating grooves (111) are formed in the surface of the clamping rod main body (11), the front clamping plate (141) and the rear clamping plate (142) are face to face and are positioned on the inner side of the clamping rod main body (11) and are fixedly connected with the inner side of the clamping rod main body (11), the rotary nail (13) is in threaded connection with the surface of the clamping rod main body (11) and can be screwed into the inner side of the clamping rod main body (11) and props against the front clamping plate (141), the front clamping plate (141) is used for moving in the direction of the back clamping plate (142) under the action of the rotary nail (13) so that the front clamping plate (141) and the back clamping plate (6) can clamp the back pad, the upper end of the clamping rod main body (11) is connected with the upper end of the clamping rod cap (12) and the lower end of the clamping rod, and the top of the lifting rod is connected with the top of the lifting rod;

the surface of the clamping rod main body (11) is provided with countersunk threaded holes (112) and two back pad penetrating grooves (111) are positioned on two sides of the countersunk threaded holes (112), the surface of the front clamping plate (141) is provided with circular grooves (1411), the end part of the rotary nail (13) is arc-shaped, the maximum diameter of the arc-shaped end part of the rotary nail (13) is larger than the diameter of the circular grooves (1411), the rotary nail (13) is used for being screwed into the countersunk threaded holes (112) on the surface of the clamping rod main body (11), and the arc-shaped end part of the rotary nail (13) is used for being embedded into and propped against the circular grooves (1411) on the surface of the front clamping plate (141);

the lifting rod comprises a lifting buckle structure (2), an upper lifting rod (3) and a lower lifting rod (4), wherein the lower lifting rod (4) is of a hollow structure, the upper end of the lower lifting rod (4) is of an opening structure, the upper lifting rod (3) stretches into the lower lifting rod (4) from the upper end of the lower lifting rod (4) and can freely slide in the lower lifting rod (4), the upper end of the upper lifting rod (3) is in threaded connection with the lower end of the clamping rod main body (11), and the lifting buckle structure (2) is arranged at the upper end of the lower lifting rod (4) and is used for fixing the relative positions of the upper lifting rod (3) and the lower lifting rod (4).

2. The reclining back support structure for a chair without a backrest according to claim 1, wherein the number of the countersunk threaded holes (112) is 2, the number of the rotary nails (13) is 2 in the same vertical direction, the upper end of the clamping rod main body (11) is in threaded connection with the clamping rod cap (12), and the opposite surfaces of the front clamping plate (141) and the rear clamping plate (142) are provided with friction ribs.

3. The reclining back support structure for a chair of claim 1, wherein the lifting buckle structure (2) comprises a lifting buckle main body (21), a closing switch (22), a bolt nail (23), a nut (24) and a clamping washer (25), wherein a notch (211) is arranged on one side surface of the lifting buckle main body (21), connecting lugs (212) are connected to the top and bottom of the notch (211), the clamping washer (25) is positioned at the notch (211), an elliptic cylinder section (221) of the closing switch (22) is positioned between two connecting lugs (212) and the bolt nail (23) sequentially penetrates through the center of one connecting lug (212), the center of the elliptic cylinder section (221) and the center of the other connecting lug (212), the bolt nail (23) is connected with the nut (24) so that the elliptic cylinder section (221) is clamped between the two connecting lugs (212), a handle section (222) of the closing switch (22) is connected with the elliptic cylinder section (221) into an integral structure, the handle section (222) is driven by the clamping washer (221) to be positioned between the notches (25) to be separated from the elliptic cylinder section (211) by clamping the clamping washer (221), the inside wall of screens gasket (25) is equipped with spacing arch (251), upper end side of lower lifter (4) is equipped with logical groove (41) with spacing arch (251) matched with, spacing arch (251) of screens gasket (25) imbed in logical groove (41) of lower lifter (4), spacing arch (251) of screens gasket (25) are used for compressing tightly through the top force of elliptic cylinder section (221) upper lifter (3) in lower lifter (4).

4. The leaning back support structure used on a backrest-free chair according to claim 1, wherein the fixing piece (5) comprises a U-shaped metal shell (51), a rubber belt (52), a rotary support bolt (54), a clamping screw (55) and a fixing buckle (56), a first through hole (42) which penetrates horizontally is formed in the bottom of the lower lifting rod (4), a second through hole (511) is formed in the middle lower part of the left side surface and the right side surface opposite to the U-shaped metal shell (51), the bottom of the lower lifting rod (4) is located inside the U-shaped metal shell (51), the first through hole (42) on the lower lifting rod (4) is rotationally connected with the two second through holes (511) on the U-shaped metal shell (51) through the rotary support bolt (54), a clamping threaded hole (513) and a clamping through hole (512) are formed in the middle upper part of the left side surface and the right side surface of the U-shaped metal shell (51), one end of the clamping screw (55) sequentially penetrates through the clamping threaded hole (512) and the clamping threaded hole (513) and is connected with the clamping threaded hole (513), the first through hole (42) on the bottom of the lower lifting rod (4) is connected with the U-shaped metal shell (51) in a rotating mode, the two through the rotary support bolt (54) is rotationally connected with the upper through the clamping screw (55), the fixing buckle (56) is fixedly connected with the right side face of the U-shaped metal shell (51), the fixing buckle (56) is used for fixing or loosening the other end of the rubber belt (52), and the rubber belt (52) is used for being fixed with a chair leg on the backrest-free chair.

5. The reclining back bracket structure for a chair without a backrest according to claim 4, wherein the fixing member (5) further comprises a rubber spacer (53), and the rubber spacer (53) is fixedly connected with the front side of the U-shaped metal shell (51); two clamping threaded holes (513) are formed in the middle upper portion of the left side face of the U-shaped metal shell (51), two clamping through holes (512) are formed in the middle upper portion of the right side face of the U-shaped metal shell, the two clamping threaded holes (513) of the left side face are formed in the same circle taking the second through hole (511) of the left side face as the center of a circle, and the two clamping through holes (512) of the right side face are formed in the same circle taking the second through hole (511) of the right side face as the center of a circle.

6. The reclining back support structure for a chair according to claim 5, wherein the surface of the lower lifting rod (4) is provided with a clamping groove (43) matched with the outer wall shape of the clamping screw (55), the lower lifting rod (4) is used for rotating on the inner side of the U-shaped metal shell (51) through a rotating support bolt (54), and the clamping groove (43) can be clamped with the outer wall of the clamping screw (55).

7. The reclining back support structure for a chair of claim 4, wherein one side of the rubber belt (52) is fixedly connected with the left side surface of the U-shaped metal shell (51) through a connecting piece (57), the connecting piece (57) comprises a connecting frame (571) and a first bolt (572), the connecting frame (571) is fixedly connected with the left side surface of the U-shaped metal shell (51) and one side of the rubber belt (52) is located at the inner side of the connecting frame (571), and one side of the rubber belt (52) is fixedly connected with the connecting frame (571) through the first bolt (572).

8. The reclining back support structure for a chair of claim 4, wherein the fixing buckle (56) comprises a U-shaped clamping frame (561), a clamping switch (562) and a second peg (563), the U-shaped clamping frame (561) is fixedly connected to the right side surface of the U-shaped metal shell (51), the clamping switch (562) is tightly connected with the U-shaped clamping frame (561) through the second peg (563) and the clamping switch (562) can rotate on the U-shaped clamping frame (561) through an external force, a rake-shaped protrusion (5621) is arranged on the inner side of the clamping switch (562), and the other side of the rubber belt (52) is used for penetrating through a gap between the clamping switch (562) and the U-shaped clamping frame (561) and the clamping switch (562) is used for enabling the rake-shaped protrusion (5621) to clamp the rubber belt (52) through the external force.