CN113142869A - Chair capable of inclining forwards and backwards - Google Patents

Abstract

The invention discloses a chair capable of inclining forwards and backwards, which comprises a base, a chair seat, a chair back frame and a turnover frame, wherein the front end and the rear end of the chair seat are respectively hinged with the upper end of the turnover frame and the middle section of the chair back frame; the rear end of the chair back frame is fixedly connected with the chair back frame; the bottom of the rear section of the base is fixedly connected with a chair foot rest; the base is inclined downwards from the front end to the rear end, so that the vertical gap between the seat and the base is gradually increased from front to back; the chair back frame inclines upwards from the front end to the rear end, so that the vertical gap between the chair seat and the chair back frame is gradually reduced from front to back; the seat is used for fixedly mounting a cushion. The invention has the beneficial effect that the comfort level can be improved.

Description

Chair capable of inclining forwards and backwards

Technical Field

The invention relates to a chair, in particular to a chair capable of inclining forwards and backwards.

Background

At present, office chairs used in office occasions or leisure chairs used for daily leisure have the functions of forward and backward inclining, locking the inclining angle and adjusting the inclining tightness.

For example, patent application publication No. CN109393798A discloses a wire control device for adjusting the tilting and tightness of the back frame of a seat. A line control device for adjusting the inclination and the tightness of a back frame of a seat comprises a back frame inclination adjusting line control device and a back frame tightness adjusting line control device which are arranged in the seat; the back frame inclination adjustment line control device comprises a back frame connecting tail plate, an inclination adjustment mechanism, an inclination pull rope and an inclination adjustment handle, wherein one end of the inclination pull rope is connected with the inclination adjustment mechanism, and the other end of the inclination pull rope is connected with the inclination adjustment handle; the back frame tightness adjusting line control device comprises a tightness adjusting control rod, a first tightness pull rope, a second tightness pull rope and a tightness adjusting mechanism. This patent application designs back of the body frame and inclines to face upward regulation drive-by-wire device and back of the body frame tight regulation drive-by-wire device, realizes through the drive-by-wire that the back of the body frame inclines to face upward, tight regulation's seat utensil, through simple mechanical mechanism, the user can easily adjust back of the body frame to comfortable angle.

And the patent application that above-mentioned prior art optimizes in the regulation elasticity, this patent application publication number is CN111528639A, discloses a seat support connecting device of adjustable back, belongs to swivel chair technical field. It comprises a chair back tightness control component; the chair back tightness control assembly comprises a control handle, a universal joint, a transmission rod, a first bevel gear, a second bevel gear, a lifting piece, a mounting seat of the lifting piece and a tightness adjusting rod which are regulated and controlled in a rotating mode. The universal joint is replaced by the original pull rope for transmission, so that the response timeliness of force transmission when the tightness of the chair back is adjusted is improved; the accuracy and the controllability of the tightness adjustment of the chair back are improved; meanwhile, the size of the force arm is effectively improved in a mode of adjusting by adopting the pull rope relatively, the force transmission size of the product during adjustment is improved, the requirement on the force transmission size is improved, the force requirement on a user is reduced, the possibility that the adjusting mechanism is damaged due to overlarge input force when the product is adjusted is effectively reduced, and the service life of the product is prolonged.

First, the above two patent applications use knobs for adjusting the tightness of the pitch, and although the stepless adjustment can be realized by rotating the knobs, so that the adjustment is finer, the adjustment method has the following three disadvantages:

firstly, the tightness degree is troublesome to adjust in a large span, a user cannot directly adjust in a spanning mode, the user needs to repeatedly rotate a knob to gradually adjust, and the use is troublesome; moreover, the fineness of the adjusting mode is in direct proportion to the rotation degree of the knob, so that the contradiction exists between the performance and the use convenience.

Secondly, the elasticity degree of knob and the elasticity degree of adjusting the front and back tilt are directly proportional, and the user is by the regulation in-process of elasticity to tightness, and the required dynamics of rotatory knob is crescent thereupon, and is relatively poor to user's experience sense.

Thirdly, the tightening devices of the two patent applications, no matter how the tightness is adjusted, all function modes of the tightening devices are gradually tightened in the process of backward bending, namely the damping is gradually increased, the effect similar to braking is achieved, and the jerking feeling caused by stopping when the tightening device is bent backwards to the maximum angle is reduced, but the damping is always existed in the process of backward bending and is in a linear relation; when the user is relaxed, for example, when the user leans back and forth (swings back and forth), especially when the swing speed is fast, the ideal experience is that the damping is small (loose) or even completely no damping during the first half of the backward tilting, and the damping is large (tight) during the second half of the backward tilting to achieve the braking effect. The two tightening devices in the prior art cannot realize the experience, if the tightening devices are adjusted loosely, the brake effect is poor due to rapid forward and backward tilting, and the pause and the contusion are strong when the tightening devices are tilted backwards to the maximum angle and stop; if the adjustment is tight, the braking effect can be ensured, but the damping of forward tilting and backward tilting is large, and the forward tilting and backward tilting cannot be rapidly performed.

Secondly, in the two patent applications, the locking of the front and back inclination angles is realized in a plug-in fit mode through the arc-shaped plate-shaped structures, the arc-shaped plate-shaped structures occupy the space in the vertical direction, so that almost no structural gap is formed between the seat positioned above and the base positioned below, the base is basically and directly supported on the bottom surface of the seat, the seat is of a rigid structure, when a user sits on the cushion, the pressure applied to the seat is gradually increased from the edge to the center, and therefore the seat is sunken downwards to form a pit-shaped deformation trend, and the seat is hard at the center of the cushion due to no deformation buffer room and is not good in comfort; since there is no gap, the sheet is likely to be stuck when aged and deformed locally after long-term use. In addition, in the prior art CN111528639A, the seat (seat connecting part) and the base (tray) are connected, so the seat cannot be tilted back and forth synchronously, and the user experience is poor.

Disclosure of Invention

The invention aims to provide a chair capable of inclining forwards and backwards, which can improve the comfort level.

The invention is realized by the following technical scheme.

A chair capable of inclining forwards and backwards comprises a base, a chair seat, a chair back frame and a turnover frame, wherein the front end and the rear end of the chair seat are respectively hinged with the upper end of the turnover frame and the middle section of the chair back frame; the rear end of the chair back frame is fixedly connected with the chair back frame; the bottom of the rear section of the base is fixedly connected with a chair foot rest;

the base is inclined downwards from the front end to the rear end, so that the vertical gap between the seat and the base is gradually increased from front to back; the chair back frame inclines upwards from the front end to the rear end, so that the vertical gap between the chair seat and the chair back frame is gradually reduced from front to back; the seat is used for fixedly mounting a cushion.

As a further improvement of the invention, the base is of a hollow box-packed structure, the left side wall and the right side wall of the base are respectively provided with a first hinge point at the upper part of the rear section, the two chair back frames are provided, and the upper parts of the front ends of the two chair back frames are respectively hinged with the two first hinge points; the lower parts of the front ends of the two back frames are connected with swing rods extending left and right, and the left side wall and the right side wall of the base are respectively provided with arc-shaped grooves which allow the swing rods to pass through and limit the forward and backward swing range of the swing rods.

As a further improvement of the invention, a main push rod extending forwards and backwards is arranged in the base, the front end of the main push rod penetrates through a first loop structure arranged in the base in a sliding manner, and the rear end of the main push rod is movably connected with the swinging rod; the main push rod is sleeved with a first elastic compression structure, and two ends of the main push rod are respectively supported on the first sleeve structure and the swinging rod.

As a further improvement of the present invention, the seat back frame is unfolded laterally from the front end to the rear end so that the left-right distance between the two seat back frames gradually increases from front to rear and defines the width of the seat back frame.

As a further improvement of the invention, the chair back frame comprises two chair back connecting sections which are fixedly connected with the rear end of the chair back frame and extend along the extending direction of the chair back connecting sections, two side frames which extend upwards from the rear ends of the two chair back connecting sections, a top frame which extends transversely from the top ends of the two side frames and is folded, and a bottom frame which is connected between the bottom ends of the two side frames; the side frame inclines forwards from the bottom end to the middle part and inclines backwards from the middle part to the top end; the top frame inclines backwards from two sides to the middle; the top frame, the top frame and the two side frames are encircled to form a frame structure for fixing the back of the chair.

As a further improvement of the invention, the chair back connecting section and the outer side edge from the bottom end to the middle part of the side frame are fixedly connected with armrest fixing frames extending along the extending direction of the chair back connecting section and the side frame, and the top ends of the armrest fixing frames are fixedly connected with armrests extending forwards.

As a further improvement of the invention, the chair seat is of a flat-laid plate-shaped structure, the rear ends of the left side and the right side of the chair seat are respectively provided with a third hinge joint, the middle section of the chair back frame is provided with a support extending towards the side of the chair back frame, and the end parts of the two supports are hinged with the two third hinge joints.

As a further improvement of the invention, the front ends of the left and right side walls of the base are respectively provided with a second hinge point, and the front ends of the left and right sides of the seat are respectively provided with a fourth hinge point; the roll-over stand is provided with two, and its lower extreme, upper end are articulated with second pin joint, fourth pin joint respectively.

As a further improvement of the invention, a cushion supporting plate is fixed on the top surface of the chair seat, and the area of the cushion supporting plate is larger than that of the chair seat; the bottom surface of the cushion supporting plate is provided with an installation surface which is formed by inwards sinking, and the seat is embedded into the installation surface; the top surface of cushion backup pad is fixed the cushion.

As a further improvement of the invention, the whole front end of the cushion supporting plate and the cushion is curved downwards in an arc shape.

The invention has the beneficial effects that:

according to the invention, the base, the chair back frame, the chair seat and the turnover frame are arranged into the inverted triangular integral structure, so that a larger gap is formed between the chair seat positioned above and the base and the chair back frame positioned below, and the maximum range of the chair back frame capable of being tilted backwards can be increased; but also the chair seat has a space which is deformed and sunken downwards, thereby giving a certain buffer room when a user sits down and improving the comfort.

Drawings

The preferred embodiments of the present invention will hereinafter be described in detail to facilitate understanding of the objects and advantages of the invention, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural diagram of a base and a backrest frame of an embodiment 1;

FIG. 2 is a schematic structural diagram of a base of embodiment 1;

FIG. 3 is a schematic view of the structure inside the base of embodiment 1;

FIG. 4 is a schematic structural diagram of the swing lever, the main push rod and the sub push rod of embodiment 1;

FIG. 5 is a schematic structural diagram of a base plate of the embodiment 1;

FIG. 6 is a schematic structural diagram of the first locking mechanism, the second locking mechanism and the base in embodiment 1;

FIG. 7 is a schematic structural diagram of the embodiment 1 with the first and second locking mechanisms engaged with the main push rod and the locking seat, respectively;

FIG. 8 is a schematic structural view of a chair capable of tilting forward and backward in accordance with embodiment 2;

FIG. 9 is a schematic side view of the base, back frame, seat, and roll-over stand of embodiment 2;

fig. 10 is a schematic view of a chair capable of tilting forward and backward in a forward tilting state according to embodiment 2;

fig. 11 is a schematic view of the chair capable of tilting forward and backward in the backward state according to embodiment 2;

FIG. 12 is a schematic structural view of a backrest frame of the chair of embodiment 2;

fig. 13 is a schematic structural view of a seat support plate and a seat cushion in embodiment 2.

Detailed Description

The invention is explained in more detail below with reference to the drawings and exemplary embodiments.

The terms of orientation of up, down, left, right, front, back, top, bottom, and the like as referred to or as may be referred to in this specification are defined with respect to the configuration shown in the drawings, and the terms "inner" and "outer" refer to directions toward and away from the geometric center of a particular component and are relative terms, and thus may be changed accordingly depending on the position and the state of use of the particular component. Therefore, these and other directional terms should not be construed as limiting terms.

Example 1:

referring to fig. 1 and 2, a chair back adjusting mechanism includes a base 1 and a chair back frame 2; the base 1 is a box-shaped structure and is used for fixedly connecting a chair seat, the two chair back frames 2 are arranged and are symmetrically arranged at the rear sections of the left side wall and the right side wall of the base 1 respectively, specifically, the upper parts of the front ends of the two chair back frames 2 are hinged with the base 1 through rotating shafts penetrating through the side walls of the base 1, swing rods 2-1 extending left and right are connected between the lower parts of the front ends of the two chair back frames 2, arc-shaped grooves 1-h allowing the swing rods 2-1 to penetrate through are formed in the left side wall and the right side wall of the base 1, and the front end and the rear end of each arc-shaped groove 1-h limit the range of the swing rod 2-1 in a front-back swinging mode.

Note that, in the present application, the front, rear, left, and right described above and below are referred to as a chair, and a direction in which the chair faces forward is defined as front, and a direction in which the chair faces backward is defined as rear.

Referring to fig. 3 and 4, a sleeve 2-11 is sleeved on a part of the swinging rod 2-1, which is positioned in the base 1, in a sliding manner, the sleeve 2-11 is fixedly connected with a main push rod 61, when the backrest frame 2 is tilted backwards, the swinging rod 2-1 correspondingly swings forwards within the range constrained by the arc-shaped grooves 1-h, the sleeve 2-11 passively rotates around the axis of the swinging rod 2-1 to drive the main push rod 61 to linearly move forwards and backwards, and the tilting of the backrest frame 2 is driven by the back leaning of the user.

Referring to fig. 3 and 4, a plurality of first locking nodes 6-a are arranged at intervals in the front and rear direction at the front section of the main push rod 61, the plurality of first locking nodes 6-a occupy 1/4-1/3 of the total length of the section of the main push rod 61, which is the length of the main push rod 61 adjusted by moving back and forth and corresponds to the arc length of the arc-shaped grooves 1-h of the base 1. A first movable locking mechanism is arranged in the base 1 and can be engaged with or disengaged from a first locking node 6-a in the movable range of the first locking mechanism. When the locking mechanism is engaged, the main push rod 61 is prevented from moving forwards and backwards, so that the backward leaning angle of the chair back frame 2 is locked; when the main push rod 61 is separated, the main push rod can move back and forth freely, so that the backward leaning angle of the chair back frame 2 can be adjusted. When the first locking mechanism is engaged with the first locking node 6-a located at the foremost and rearmost ends, the seat back frame 2 is in the state of inclining most forward and inclining most rearward.

Referring to fig. 3 and 4, a set of locking seat 73, a second elastic compression structure 72 and a movable second locking mechanism are respectively disposed in the base 1 and at the left and right sides of the main push rod 61, and the front and rear ends of the second elastic compression structure 72 are respectively supported on the locking seat 73 and the swing rod 2-1, and are made of an elastic material, and can be compressed and exert an elastic force when being subjected to the forward and backward pressing force of the locking seat 73 and the swing rod 2-1. The second locking mechanism functions similarly to the first locking mechanism and can be engaged with or disengaged from the locking seat 73. When the swing rod 2-1 swings forwards, the second elastic compression structure 72 is pressed by the locking seat 73 and the swing structure to be in a compression state, so that the elastic force is applied to the swing rod 2-1; upon separation, the second resilient compression structure 72 is not compressed and therefore does not exert a resilient force on the sway bar 2-1.

From the perspective of structural shape and movement mode, the main push rod 61 is a slender structure extending back and forth, and linearly moves back and forth along the length direction thereof, and based on the characteristic, the main push rod 61 basically has only the space requirement of the front and back length for the base 1, but has lower space requirement of the upper and lower height, and only needs to meet the requirement of no mechanical interference. Therefore, the base 1 can be configured to be a flat box-shaped structure with a certain width (to satisfy the main push rod 61 and the second elastic compression structures 72 and the left rear span of the locking seat 73 located at both sides thereof), a specific length (to satisfy the length of the main push rod 61 and the movement range thereof), and a narrow thickness (only to satisfy the main push rod 61, the second elastic compression structures 72 and the locking seat 73 without mechanical interference in the up-down space), so that on one hand, more structural layout spaces can be reserved for other components of the chair (such as the seat and the cushion), and on the other hand, the seat and the cushion and other structures located above the base 1 can be more easily covered, and the appearance is more beautiful.

The two sets of locking seats 73 and the second elastic compression structure 72 are used for adjusting the tightness of the backrest frame 2 during reclining, and the tightness of reclining is adjustable in two steps by controlling whether the second locking mechanism is engaged with the locking seats 73.

Referring to fig. 3 and 4, a first collar structure 63 is arranged in the front section of the base 1, the front end of the main push rod 61 slides through the first collar structure 63, and the collar structure provides a supporting and guiding function for the front section of the main push rod 61, so that the moving direction of the main push rod 61 is kept along the axial direction thereof, and radial deflection or play is avoided when the main push rod moves back and forth. The part of the main push rod 61, which is located between the first collar structure 63 and the swing rod 2-1, is sleeved with a first elastic compression structure 62, the front end and the rear end of the first elastic compression structure 62 are respectively supported on the first collar structure 63 and the swing rod 2-1, and in the process that the swing rod 2-1 swings forwards, the first elastic compression structure 62 is compressed by the extrusion of the first collar structure 63 and the swing rod 2-1, and then the first elastic compression structure 62 applies elasticity to the swing rod 2-1. The backward elasticity of the first elastic compression structure 62 to the swinging rod 2-1 can enable the chair back frame 2 to rapidly tilt forward and reset without external force, so that forward and backward tilting is realized; in addition, the first elastic compression structure 62 is matched with the two second elastic compression structures 72, so that the backward tilting of the chair back frame 2 has three-gear tightness degree, the first elastic compression structure 62 is always in effect during the forward and backward swinging process of the swinging rod 2-1, namely, the tightness gear provided by the first elastic compression structure 62 is resident, and the two tightness gear provided by the two second elastic compression structures 72 can be selected based on the engagement or the disengagement of the second locking mechanism and the locking seat 73.

Referring to fig. 3 and 4, the plurality of second locking nodes 7-a are arranged at intervals along the front-rear direction of the locking seat 73, the second locking mechanism can be engaged with or disengaged from the second locking nodes 7-a within the movable range of the second locking mechanism, and the second locking mechanism is engaged with different second locking nodes 7-a, so that the amount of compression of the second elastic compression structure 72 when the swing lever 2-1 swings is different, and the elastic force applied to the swing lever 2-1 by the second elastic compression structure 72 is also different. Therefore, in combination with the above, the two locking seats 73 provide two adjustable large tightness steps of reclining based on the combination or separation of the second locking mechanism and the locking seats 73, and the second locking mechanism is engaged with which second locking node 7-a of the locking seats 73 to divide the large tightness steps into a plurality of selectable small tightness steps, so that the adjustment of the reclining tightness of the back frame 2 is more detailed.

The second locking mechanism may engage the second locking node 7-a at the forwardmost end of the locking seat 73 when the swing lever 2-1 is at the rearwardmost end of its range of forward and rearward swing and the second resilient compression structure 72 is in its natural state. By taking the process that the swing rod 2-1 swings forwards from the rearmost end to the frontmost end of the swing range as a reference, when the second locking mechanism is engaged with the frontmost second locking node 7-a, the second elastic compression structure 72 is always in a compressed state, and always applies an elastic force to the swing rod 2-1, wherein the magnitude of the elastic force is in direct proportion to the amplitude of forward swing of the swing rod 2-1. When the second locking mechanism is engaged with the other second locking node 7-a, the swing rod 2-1 will swing forward by a certain amount and then start to press the second elastic structure with the locking seat 73, i.e. the swing rod 2-1 will swing forward by a certain amount and then receive the gradually increasing elastic force applied by the second elastic compression structure 72. Based on this, the two locking seats 73 are combined by selecting the second locking nodes 7-A at different positions, so that the degree of tightness changes in the process of backward tilting can be differentiated, but approximately the same degree of tightness can be adjusted when the maximum backward tilting angle is approached.

For example, the second locking node 7-a at the forefront is set to the gear 1, and the gear 2 and the gear 3 are sequentially arranged from front to back, and two combination modes are adopted, wherein the gear 2 and the gear 4 are respectively selected by the two locking seats 73 in the first combination mode, the gear 3 is selected in the second combination mode, when the backrest frame 2 reaches the maximum backward tilting angle (the swinging rod 2-1 swings to the forefront), the damping (generated by the elastic force) of the two combination modes is approximately the same, but the variation of the damping is different in the backward tilting process: in the first combined mode, in the process that the swinging rod 2-1 swings forwards, the elastic force of the No. 2 gear intervenes first, and the elastic force of the No. 4 gear intervenes later; the time of elastic force intervention of the two No. 3 gears of the second combined mode is between the No. 2 gear and the No. 4 gear; therefore, in the first combination mode, the insertion time of the damping is earlier and the average change width of the damping is smaller, and in the second combination mode, the insertion time of the damping is later and the average change width of the damping is larger.

In conclusion, on the premise that the sum of the two gears is the same, the larger the span of the two gears is, the earlier the damping intervention time is, the more stable the damping is on the whole, the smaller the span of the two gears is, the later the damping intervention time is, and the stronger the damping is on the whole. Therefore, the user can freely select the combination of the two shift positions to adjust the tightness to the most suitable state.

Referring to fig. 3 and 4, the locking seat 73 is in a half-cylinder shape, the rear end of the locking seat is provided with a second collar structure 731, two secondary push rods 71 corresponding to the locking seat 73 are arranged in the base 1, the secondary push rods 71 extend in the front-rear direction, the rear ends of the secondary push rods 71 are fixedly connected with the sleeves 2-11, the front ends of the secondary push rods slide through the second collar structure 731, the second elastic compression structures 72 are sleeved outside the locking seat 73 and supported between the second collar structure 731 and the sleeves 2-11, the secondary push rods 71 can swing forward in the swing rod 2-1, and the second elastic compression structures 72 play a role as frameworks when being compressed, so as to prevent the second elastic compression structures 72 from bending along the radial direction of the secondary push rods 71, and make the second elastic compression structures more stable and reliable. In addition, the front end of the secondary push rod 71 is threadedly engaged with the nut 711 abutting against the second collar structure 731 to serve as a stopper for preventing the secondary push rod 71 from slipping off the second collar structure 731, and the secondary push rod 71 can pull back the locking seat 73 to be reset when the second locking mechanism is not engaged with the locking seat 73 and the swing lever 2-1 swings backward.

Referring to fig. 3, 5, 6 and 7, a support 11 is disposed between the main push rod 61 and the two sub push rods 71, and the support 11 and the base 1 are of an integral structure, are formed by protruding upward from a bottom plate of the base 1, and extend in the front-rear direction. The top of the support 11 is provided with a fixed shaft 12 extending forward and backward, and the front end and the rear end of the top of the support 11 are respectively provided with a supporting structure 111 for supporting two ends of the fixed shaft 12 and suspending the fixed shaft 12. The second locking mechanism includes a second swing arm 91, a second pull wire 93, and a second elastic restoring member 94. The second swing arm 91 crosses over the locking seat 73, one end of the second swing arm is rotatably sleeved on the fixed shaft 12, the other end of the second swing arm is provided with a second locking structure 92, the second locking nodes 7-A are arranged on one side, close to the side wall of the base 1, of the locking seat 73 at intervals along the front-back direction, the second locking structure 92 and the second locking nodes 7-A are arranged into a clamping tongue and a clamping groove, and the connection of the second locking structure 92 and the second locking nodes 7-A is realized in a clamping fit mode. The second pull wire 93 penetrates through the top plate of the base 1, one end of the second pull wire is fixedly connected with the second locking structure 92, the other end of the second pull wire is connected with a handle, and the handle can be installed on the base or a chair seat. The second elastic restoring member 94 is a torsion spring, and is sleeved on the fixed shaft 12, and one end thereof is supported on the support 11, and the other end thereof is supported on the second swing arm 91. The structure of the handle is the same as the tilt adjustment handle of the applicant's prior application publication No. CN109393798A, and will not be described herein. The second locking structure 92 can be pulled upwards by pulling the handle second pull wire 93 so as to be separated from the second locking node 7-A, and the separated state of the second locking structure 92 and the second locking node 7-A can be kept by clamping the handle after a certain angle is pulled; when the handle is pulled back to release the clamping state, the second swing arm 91 is reset and rotated under the action of the second elastic reset piece 94, so that the second locking structure 92 is in clamping fit with the second locking node 7-A.

The second locking mechanism is relatively flexible and simple to operate by using a toggle handle to control the engagement or disengagement of the second locking structure 92 and the second locking node 7-a. When the swing rod 2-1 is located at the rearmost end of the swing range, the handle is pulled and clamped to separate the two second locking structures 92 from the locking seat 73, then the swing rod 2-1 swings forwards by tilting backwards, and the handle can be pulled reversely to enable the second locking structures 92 to be engaged with the second locking node 7-A to lock the gear position at any time during the forward swing of the swing rod 2-1.

Referring to fig. 3, 5, 6, and 7, the first locking mechanism, which includes a first swing arm 81, a first wire 83, and a first elastic restoring member 84, and the second locking mechanism on the left or right side share the same fixed shaft 12. One end of the first swing arm 81 is rotatably sleeved on the fixed shaft 12, the other end of the first swing arm 81 is provided with a first locking structure 82 capable of being jointed with the first locking node 6-A, and the first swing arm 81 is rotatably sleeved on one end of the fixed shaft 12 and is arranged in a branched structure to avoid the second swing arm 91, so that the first swing arm 81 and the second swing arm 91 can be simultaneously rotatably sleeved on the fixed shaft 12. The first locking structure 82 and the first locking node 6-a are also arranged to snap-fit into the cooperating catch and slot. The top of the first collar structure 63 has a support plate structure 631 extending forward to above the first locking structure 82, the first wire 83 penetrates the top plate of the base 1 and the support plate structure 631, one end of the first wire is fixedly connected to the first locking structure 82, and the other end is connected to a handle. The first elastic restoring member 84 is a compression spring, which is sleeved outside the first pull wire 83 and supported at two ends on the first locking structure 82 and the supporting plate structure 631 respectively. The operation is the same as the second locking mechanism and will not be described in detail.

The supporting seat 13 is arranged between the two supports 11 and under the first locking mechanism, the supporting seat 13 and the base 1 are of an integral structure and formed by upward protrusion of a bottom plate of the base 1 to support the front section of the main push rod 61 and apply upward force to the front section of the main push rod 61, so that downward acting force is applied to the main push rod 61 by the first locking structure 82 in a balanced manner, and the rear end of the main push rod 61 is prevented from being tilted upwards to prevent the swinging rod 2-1 from being blocked.

Be equipped with the slide rail 14 that extends from beginning to end in the base 1, slide rail 14 and base 1 structure as an organic whole, form to protruding by the bottom plate of base 1, the both sides of locking seat 73 are supported to the both sides of slide rail 14 for locking seat 73 can slide from beginning to end along slide rail 14, and slide rail 14 plays limiting displacement to locking seat 73, takes place the skew of lateral direction in order to avoid sliding in the front and back.

The middle part of the locking seat 73 is provided with a guide groove 73-h which penetrates through the upper part and the lower part and extends forwards and backwards, the bottom plate of the base 1 is provided with a guide rod 15 which is formed by upward protrusion at the middle part of the slide rail 14, and the guide rod 15 is inserted in the guide groove 73-h to play a role in guiding the locking seat 73 to slide forwards and backwards. In addition, when the guide rod 15 is positioned at the front end and the rear end of the guide groove 73-h, the second locking mechanism can be engaged with the second locking node 7-A at the front end and the rear end of the locking seat 73, and the guide rod 15 and the guide groove 73-h limit the forward and backward sliding range of the locking seat 73, so that the second locking node 7-A can be engaged with the second locking mechanism in the moving range of the second locking mechanism.

Example 2:

referring to fig. 8, a chair capable of tilting forward and backward comprises a base 1, a seat 3, a back frame 2 and a turning frame 5, wherein the front end and the rear end of the seat 3 are respectively hinged with the upper end of the turning frame 5 and the middle section of the back frame 2, and the front end and the rear end of the base 1 are respectively hinged with the lower end of the turning frame 5 and the front end of the back frame 2; the back end of the back frame 2 is fixedly connected with a back frame 4; the bottom of the rear section of the base 1 is fixedly connected with a chair foot rest. The structure of the base 1 and the backrest frame 2 is the same as that of the embodiment 1, and at least the main push rod 61, the first collar structure 63 and the first elastic compression structure 62 are arranged in the base 1, so that the chair has the function of forward tilting and resetting after being reclined.

Referring to fig. 8 and 9, the base 1, the back frame 2, the seat 3 and the roll-over stand 5 form a planar four-bar linkage structure, the seat 3 is used for fixedly mounting the cushion 32, referring to fig. 10 and 11, when the back frame 2 is tilted backwards, the seat 3 is also correspondingly and synchronously tilted backwards, so that the change range of the included angle between the cushion 32 and the back frame 4 is small, the sitting posture of a user in the process of tilting forwards and backwards can be basically kept unchanged, especially when the user freely relaxes and repeatedly swings forwards and backwards, the waist does not need to be twisted back and forth, and the comfort of the chair is improved.

The base 1 is inclined downwards from the front end to the rear end, so that the vertical gap between the seat 3 and the base 1 is gradually increased from the front to the rear, and the back frame 2 is inclined upwards from the front end to the rear end, so that the vertical gap between the seat 3 and the back frame 2 is gradually reduced from the front to the rear.

When a user sits on the chair cushion, the pressure applied to the chair seat 3 is gradually increased from the edge to the center, and under the action of the pressure distribution, the chair seat 3 has the deformation tendency that the center is sunken downwards to form a hollow pit. In the prior art, because there is almost no clearance between seat support 3 and the base 1, under the direct supporting action of base 1, even if cushion 32 is elastic, under the condition that seat support 3 is complete rigidity, does not have the deformation buffer room, cushion 32 is by the extruded degree along by the edge to central department increase gradually, can make cushion 32 central department texture harder, the comfort level is not good. In the application, the seat 3 is suspended except the front end and the rear end which are respectively supported by the roll-over stand 5 and the back frame 2, and the rest part of the seat 3 slightly deforms to provide a slightly deformed space for the user to play a good role in buffering when sitting down, so that the comfort is improved, and particularly for the user with large weight.

In the prior art, because almost no gap exists between the seat 3 and the base 1, the backward tilting amplitude of the backrest frame 2 is greatly limited in order to avoid mechanical interference; in addition, when the seat back frame 2 is locally aged and deformed after a long time use, the seat back frame is easily caught or interfered when it is tilted forward or backward. Compared with the prior art, the large clearance surplus exists between the base 1 and the seat 3, so that no matter the tilting amplitude is front and back, or the local aging deformation is caused after long-time use, the negative influence can not be generated.

In addition, the overall structure formed by the seat 3, the roll-over stand 5, the base 1 and the backrest frame 2 is triangular, so that the chair has better overall structural strength and structural stability.

Referring to fig. 9, the seat 3, the roll-over stand 5, the base 1 and the back frame 2 form a planar four-bar linkage structure, and two back frames 2 and two roll-over stands 5 are arranged and are in a left-right symmetrical relationship. The left side wall and the right side wall of the base 1 are respectively provided with a first hinge point J1 at the upper part of the rear section, and the upper parts of the front ends of the two backrest frames 2 are respectively hinged with two first hinge points J1; the front ends of the left side wall and the right side wall of the base 1 are respectively provided with a second hinge point J2, the front ends of the left side wall and the right side wall of the seat 3 are respectively provided with a fourth hinge point J4, and the lower ends and the upper ends of the two turnover frames 5 are respectively hinged with the two second hinge points J2 and the fourth hinge point J4; the chair seat 3 is a flat-laid plate-shaped structure, the rear ends of the left side and the right side of the chair seat are respectively provided with a third hinge joint J3, the middle section of the chair back frame 2 is provided with a support 21 extending towards the side of the chair back frame, and the end parts of the two supports 21 are hinged with two third hinge joints J3.

The roll-over stand 5 is substantially triangular in structure, and when the back frame 2 is tilted forward to the foremost end (the swing lever 2-1 is located at the rearmost end of the swing range), the lower side of the roll-over stand 5 is flush with the bottom side of the base 1.

The back of the chair frame 2 is expanded to the side by front end to rear end for left and right sides interval between two back of the chair frames 2 is by preceding crescent to back, has formed the extension structure of "eight" style of calligraphy, and defined the width of back of the chair frame 4, the width between two back of the chair frames 2 naturally passes through to the width of back of the chair frame 4 promptly, make the structure transition between them more steady, improved the overall structure intensity and the stability of back of the chair frame 2 and back of the chair frame 4, and also more pleasing to the eye. The back frame 2 and the support located in the middle section of the back frame are of an integral structure, and the support can enable the back frame 2 and the back frame 4 to fully avoid the rear end of the chair seat 3.

Referring to fig. 12, the back frame 4 includes two back connection sections 41 fixedly connected to the rear end of the back frame 2 and extending in the extending direction thereof, two side frames 42 extending upward from the rear ends of the two back connection sections 41, a top frame 43 extending laterally from the top ends of the two side frames 42 and folded, and a bottom frame 44 connected between the bottom ends of the two side frames 42; the side frame 42 inclines forwards from the bottom end to the middle part and inclines backwards from the middle part to the top end; the top frame 43 is inclined backward from two sides to the middle; the top frame 43, and the two side frames 42 form a frame structure for fixing the back of the chair (not shown). The shape change of side frame 42 makes the chair back be the forward-convex dog-ear form in vertical direction, and the first half at the chair back can support user's back well and withhold the waist, and the space between the lower half at the chair back and cushion 32 can let user's buttock deepen cushion 32 backward more to can let user straighten the waist, avoid the position of sitting of user rickets, play the guard action of correcting to waist, especially lumbar vertebrae. The shape change of the top frame 43 makes the middle of the upper half part of the back of the chair inwards concave, so that the left side and the right side of the chair have better wrapping performance on the neck of a user, and the comfort level is improved.

The outer side edges from the bottom ends to the middle parts of the chair back connecting section 41 and the side frames 42 are fixedly connected with armrest fixing frames 45 extending along the extending directions of the two, the top ends of the armrest fixing frames 45 are fixedly connected with armrests 46 extending forwards, and the armrest fixing frames 45 are fixedly connected with the chair back frame 4, so that the armrests 46 can also tilt forwards and backwards synchronously, and when the chair back is used by a user, the trunk, the upper limbs and the lower limbs can tilt forwards and backwards synchronously.

Referring to fig. 13, a cushion support plate 31 is fixed to the top surface of the seat 3, the area of the cushion support plate 31 is larger than that of the seat 3, an installation surface 31-a formed by inward recess is formed on the bottom surface of the cushion support plate 31, the seat 3 is embedded into the installation surface 31-a, a cushion 32 is fixed to the top surface of the cushion support plate 31, and the installation area of the cushion support plate 31 is enlarged, so that the cushion 32 can be selected for a larger size, and a user feels more comfortable. In addition, the entire front ends of the seat support plates 31 and the seat 32 are curved downward in an arc shape, so that the lower legs of the user can hang down more naturally.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments can be modified, or some technical features can be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A chair capable of inclining forwards and backwards comprises a base (1), a chair seat (3), a chair back frame (2) and a turnover frame (5), wherein the front end and the rear end of the chair seat (3) are respectively hinged with the upper end of the turnover frame (5) and the middle section of the chair back frame (2), and the front end and the rear end of the base (1) are respectively hinged with the lower end of the turnover frame (5) and the front end of the chair back frame (2); the rear end of the chair back frame (2) is fixedly connected with a chair back frame (4); the bottom of the rear section of the base (1) is fixedly connected with a chair foot rest; it is characterized in that the preparation method is characterized in that,

the base (1) is inclined downwards from the front end to the rear end, so that the vertical gap between the seat (3) and the base (1) is gradually increased from front to rear; the chair back frame (2) inclines upwards from the front end to the rear end, so that the vertical gap between the chair seat (3) and the chair back frame (2) is gradually reduced from front to rear; the seat (3) is used for fixedly mounting a cushion (32).

2. The chair capable of leaning forward and backward as claimed in claim 1, wherein the base (1) is a hollow box-shaped structure, the left and right side walls of which are located at the upper part of the rear section and respectively have first hinge points (J1), the back frame (2) is provided with two, the upper parts of the front ends of the two are respectively hinged with the two first hinge points (J1); the lower parts of the front ends of the two chair back frames (2) are connected with swing rods (2-1) extending left and right, and the left side wall and the right side wall of the base (1) are respectively provided with arc-shaped grooves (1-h) which allow the swing rods (2-1) to pass through and limit the front and back swing range of the swing rods (2-1).

3. The chair with forward and backward inclinations according to claim 2, wherein the base (1) is provided with a main push rod (61) extending forward and backward, the front end of the main push rod slides through a first loop structure (63) arranged in the base (1), and the rear end of the main push rod is movably connected with the swinging rod (2-1); the main push rod (61) is sleeved with a first elastic compression structure (62), and two ends of the main push rod are respectively supported on the first sleeve structure (63) and the swinging rod (2-1).

4. The forward-backward tiltable chair according to claim 2, wherein the back frame (2) is unfolded sideways from the front end to the rear end so that the left-right spacing between the two back frames (2) is gradually increased from front to rear and defines the width of the back frame (4).

5. The chair capable of leaning forward and backward as claimed in claim 4, wherein the back frame (4) comprises two back connecting sections (41) fixedly connected to the rear end of the back frame (2) and extending along the extending direction thereof, two side frames (42) extending upward from the rear ends of the two back connecting sections (41), a top frame (43) extending laterally from the top ends of the two side frames (42) and being closed, and a bottom frame (44) connected between the bottom ends of the two side frames (42); the side frame (42) inclines forwards from the bottom end to the middle part and inclines backwards from the middle part to the top end; the top frame (43) inclines backwards from two sides to the middle; the top frame (43), the top frame (43) and the two side frames (42) surround to form a frame structure for fixing the back of the chair.

6. The chair capable of leaning forward and backward as claimed in claim 5, wherein the backrest connecting section (41) and the outer side edge from the bottom end to the middle part of the side frame (42) are fixedly connected with an armrest fixing frame (45) extending along the extending direction of the backrest connecting section and the side frame, and the top end of the armrest fixing frame (45) is fixedly connected with an armrest (46) extending forward.

7. The chair according to claim 2, wherein the seat (3) is a flat plate-like structure having a third hinge point (J3) at the rear end of the left and right sides, the middle section of the backrest frame (2) has a support (21) extending laterally therefrom, and the ends of the two supports (21) are hinged to the two third hinge points (J3).

8. The chair as claimed in claim 1, wherein the base (1) has second hinge points (J2) at the front ends of the left and right side walls, and the seat (3) has fourth hinge points (J4) at the front ends of the left and right side walls; the two roll-over stands (5) are respectively hinged with the second hinge point (J2) and the fourth hinge point (J4) at the lower ends and the upper ends.

9. The forward-backward tiltable chair according to claim 1, wherein a cushion support plate (31) is fixed to the top surface of the seat (3), and the cushion support plate (31) has a larger area than the seat (3); the bottom surface of the cushion supporting plate (31) is provided with an installation surface (31-A) formed by inward sinking, and the seat (3) is embedded into the installation surface (31-A); the top surface of the cushion supporting plate (31) is fixed with the cushion (32).

10. The reclining chair according to claim 9, wherein the entire front ends of the cushion support plate (31) and the cushion (32) are curved downward in an arc shape.

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