CN113273833B - Office chair with adjustable chair back - Google Patents

Abstract

The utility model discloses an office chair with an adjustable chair back, which comprises a chair seat, a chair back and two armrests; a cross bar extending left and right is arranged on the bottom surface of the front part of the chair seat; the surface of the end part of the cross rod is provided with oblique reciprocating spline grains, and the front end of the handrail is rotatably sleeved at the end part of the cross rod and is in threaded fit with the end part of the cross rod; the armrests are lifted upwards to the upper part of the chair seat from front to back, and then are bent laterally and wound to the rear part of the chair back; the rear ends of the armrests are movably connected with the rear surface of the chair back and can transversely slide along the rear ends of the armrests; when the chair back is driven by the armrest to tilt backwards around the cross rod, the rear end of the chair seat avoids the bottom end of the chair back, and the armrests slide inwards along the cross rod transversely and synchronously when being tilted backwards, so that the distance between the two armrests is reduced. The utility model has the advantages that the safety sense of a user can be improved when the chair back tilts backwards, and the aim of relaxation is fulfilled.

Description

Office chair with adjustable chair back

Technical Field

The utility model relates to an office chair, in particular to an office chair with an adjustable chair back.

Background

In the prior art, the comfort and versatility of office chairs, such as forward and backward tilting, seat adjustment, back adjustment, etc., are increasingly in demand.

For example, prior art publication number CN109349844A discloses an office chair suitable for sedentary use, including the office chair body, the equal fixed mounting in the left and right sides of office chair body has the handrail, and the bottom fixed mounting of office chair body has the dead lever, and the one end fixed mounting that the dead lever kept away from office chair body bottom has the supporting leg, and the middle part that the dead lever one end was kept away from to the supporting leg is equipped with removes the wheel, and the inboard top fixedly connected with that just is located the office chair body left and right sides of handrail accepts the pole. This office chair suitable for family of sitting uses for a long time through the combination of slider and spout, effectively adjusts the distance between backup plate and the seat of office chair body, makes office chair body be applicable to different users' high demand, the effectual practicality that has improved equipment, and the combination through clamping screw and spacing loop bar carries out effectual fixing to the adjustment structure simultaneously, has further improved the stability of equipment in the work.

For example, prior art publication No. CN108402749A discloses an office chair with high stability, including the office chair body, ventilative foam-rubber cushion is installed to the intermediate position of the internal portion of office chair, the raising button is installed to one side of the internal portion of office chair front end, the internally mounted of one side of the office chair top has the bracing piece, fixed backplate is installed to the top of bracing piece, fixed back is installed to the rear end of the internal portion of office chair, high elastic force protection network is installed to the intermediate position of the internal portion of fixed back, the automatic groove of rolling up is installed to the rear end of the office chair body, the internally mounted in automatic groove of rolling up has the summer sleeping mat. The upper fixing frame and the lower fixing frame are of symmetrical structures, the bottom of the office chair can be stabilized through the upper fixing frame, so that larger weight can be supported, the office chair body and the ground can be stabilized through the lower fixing frame, the office chair is prevented from falling, and the office chair looks more attractive and fashionable through symmetry.

For another example, prior art publication No. CN210227506U discloses an office chair, which belongs to the field of office tables and comprises a main body support frame, a supporting plate, an armrest frame, an office chair back rest, a hydraulic support rod, a bottom support, a control rod and a roller assembly; the roller assembly comprises a roller frame, a rotating shaft and a roller; the rollers are arranged in a mode that the middle diameter is large and the two sides diameter is small; the outer circumferential surface of the roller is provided with uniform convex ribs; the back of the office chair backrest is provided with an arc-shaped groove for mounting the rotating shaft; the pivot just adopts the latch segment to compress tightly fixedly behind the embedding arc wall, and the latch segment passes through the bolt fastening at the back of office chair back. The office chair has good massage effect, well corrects sitting posture, and cuts the spine more, so that the office chair is comfortable and reliable to use; the back just adopts the latch segment to compress tightly fixedly in the pivot embedding arc wall, and the latch segment passes through the bolt fastening at the back of office chair back, ensures that wheel components's installation is reliable, and easy dismounting, and structural strength is good, and the locking dynamics is big, and joint strength is reliable.

These office chairs have the following problems: firstly, the supporting position of the chair legs on the chair seat is positioned in the middle of the chair seat, and the office chairs are used in office occasions, particularly in front of an office desk, so that most of users adopt forward sitting postures when busy working, the gravity center of the upper half body is closer to the front and is spaced from the position of the chair legs supporting the chair seat, and the problems of structural damage, aging deformation and the like are easy to occur between the chair seat and the chair legs after long-time use. Secondly, the back-bending function of the chair back is not good, the supporting force to the waist of the user is insufficient when the chair back bends backwards, the muscle fatigue of the waist is easily caused, and even the problems of the protrusion of the lumbar disc and the like are easily caused. Moreover, the adjustment function of the chair seat is also poor, and a corresponding reasonable adjustment mode is not set according to the office application environment.

Disclosure of Invention

The utility model aims to provide an office chair with an adjustable chair back, which can improve the safety of a user when the chair back leans backwards, and achieve the purpose of relaxation.

The utility model is realized by the following technical scheme.

An office chair with an adjustable chair back comprises a chair seat, a chair back and two armrests; a cross bar extending left and right is arranged on the bottom surface of the front part of the chair seat; the surface of the end part of the cross rod is provided with oblique reciprocating spline grains, and the front end of the handrail is rotatably sleeved at the end part of the cross rod and is in threaded fit with the end part of the cross rod; the armrests are lifted upwards to the upper part of the chair seat from front to back, and then are bent laterally and wound to the rear part of the chair back; the rear ends of the armrests are movably connected with the rear surface of the chair back and can transversely slide along the rear ends of the armrests; when the chair back is driven by the armrest to tilt backwards around the cross rod, the rear end of the chair seat avoids the bottom end of the chair back, and the armrests slide inwards along the cross rod transversely and synchronously when being tilted backwards, so that the distance between the two armrests is reduced.

As a further improvement of the utility model, the left side and the right side of the cross bar at the front end of the handrail are respectively fixedly sleeved with a limiting lantern ring which can be abutted against the front end of the handrail so as to limit the transverse sliding range of the handrail along the cross bar.

As a further improvement of the utility model, a first reset pressure spring is sleeved outside the cross rod, and two ends of the first reset pressure spring are respectively supported at the front end of the handrail and the limit lantern ring in the handrail.

As a further improvement of the utility model, a circular channel extending transversely from left to right is arranged in the chair back; the back surface of the chair back is provided with two straight grooves which are bilaterally symmetrical and communicated with the circular channel, and the straight grooves incline upwards from one end close to the side edge of the chair back to one end far away from the side edge of the chair back; the rear ends of the two handrails are provided with connecting rods which extend forwards and backwards and are inserted into the corresponding straight grooves, one ends of the connecting rods, which are positioned in the circular channels, are fixedly connected with sliding rods, and the sliding rods can transversely slide left and right along the circular channels and can rotate around the axes of the sliding rods relative to the circular channels; the chair back is driven by the armrest to turn backwards around the cross rod, and synchronously turns backwards around the slide rod when turning backwards, so that the horizontal height of the bottom end of the chair back is not lower than the rear end of the chair seat.

As a further improvement of the utility model, the rear end of one of the armrests is provided with a guide rod extending left and right, and the guide rod is inserted into the rear end of the other armrest in a sliding manner.

As a further improvement of the utility model, a second return compression spring is sleeved outside the guide rod, and two ends of the second return compression spring are respectively supported at the rear ends of the two handrails.

As a further improvement of the utility model, a plastic corrugated pipe is sleeved outside the second reset pressure spring, and two ends of the plastic corrugated pipe are respectively and fixedly connected with the rear ends of the two handrails.

As a further improvement of the utility model, the handrail comprises a handrail front section, a handrail middle section and a handrail rear section; the utility model discloses a chair seat, including handrail front end, back end, connecting rod, handrail rear end, handrail front end, back end, handrail middle section, handrail front end is the vertical extension of base basis, and its front end rotates to cup joint the tip at the horizontal pole, and the rear end lifting is to the top of seat support and with the front end body coupling in handrail middle section, the handrail middle section is by front end to rear end tilt up and be used for supporting the arm, its rear end and the front end body coupling in handrail rear section, the rear end body coupling in handrail rear section the connecting rod.

The utility model has the beneficial effects that:

in the embodiment, the inclined straight groove can synchronously turn over backwards around the sliding rod positioned in the circular channel in the process that the chair back turns over backwards around the cross rod, so that the bottom end of the chair back is flush with the rear end of the chair seat and even slightly higher than the rear end of the chair seat; therefore, the waist and part of the back of the user can be better supported, and the relaxing effect can be achieved.

Drawings

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

FIG. 1 is a right side view of an office chair according to embodiment 1;

FIG. 2 is a front view of an office chair according to embodiment 1;

FIG. 3 is an enlarged partial schematic view of FIG. 1;

FIG. 4 is a top view of the embodiment 1 cross;

fig. 5 is a right side view of the office chair of embodiment 2;

FIG. 6 is an enlarged partial schematic view of FIG. 5;

FIG. 7 is a rear view of the guide post and the turning support in embodiment 2;

fig. 8 is a right side view of an office chair of embodiment 3;

FIG. 9 is a front view of the support and cross bar of embodiment 3;

FIG. 10 is a rear view of the arm rests and the seat back of embodiment 3;

fig. 11 is a rear view of the armrest of embodiment 3;

FIG. 12 is a rear view of the chair back of embodiment 3;

FIG. 13 is a sectional view of an armrest and a seatback of embodiment 3;

FIG. 14 is a right side view of an office chair of embodiment 4;

FIG. 15 is an enlarged partial schematic view of FIG. 14;

fig. 16 is a right side view of the rotation restricting mechanism of embodiment 4.

Detailed Description

The utility model 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 to 4, an office chair includes a chair seat 1, chair legs 2; the chair leg 2 is connected with a support frame 11 which extends forwards and inclines upwards, and the rear end of the support frame 11 is fixedly connected with the chair leg 2 in a fixed sleeving manner. The front end of the support frame 11 is provided with a cross rod 12 extending left and right, and the bottom surface of the front part of the seat 1 is provided with a sleeve structure 13 which is rotatably sleeved on the cross rod 12, so that the seat 1 can turn over the cross rod 12 around the cross rod 12 as a rotating shaft. Be provided with movable support 3 between chair foot 2 and the seat support 1, movable support 3's bottom articulates the top at chair foot 2 to can overturn around as the center of rotation in its bottom, movable support 3's top sliding connection is in the bottom surface of seat support 1 and can follow seat support 1 and slide around.

The office chair of this embodiment, the horizontal pole 12 that sets up at the anterior bottom surface of seat support 1 not only is as the axis of rotation of front and back upset, still as the center of support of whole seat support 1, the user of especially adapted work in front of the desk, for example the user of work in front of the computer, the user of work at desk, the position all leans on forward more usually, only end is sat in the first half of seat support 1, thereby make the whole focus of user also more lean on forward roughly coincide with the position of horizontal pole 12, can avoid because user's focus and seat support 1 center of support position interval around, thereby lead to seat support 1 to be in the state of overturning forward for a long time and then the structure is impaired easily, the problem that life is influenced such as structural deformation.

When a user needs to rest and relax, the user can adjust the sitting posture to lean backwards, and can sit most parts of the chair seat 1, at the moment, the gravity center moves backwards, the upper half body of the user can shake forwards and backwards to enable the chair seat 1 to turn forwards and backwards in a reciprocating mode, and the 'leisure' function is provided for the user. The movable support between chair foot 2 and the seat support 1 has played the effect of supporting both for seat support 1 keeps better stability in the in-process of reciprocal reversal in front and back, and movable support bottom and chair foot 2 are articulated simultaneously, and top and the in-process of seat support 1 bottom surface sliding fit also makes seat support 1 reciprocal upset in front and back more smooth and easy, and movable support can not appear blocking the condition of seat support 1 and take place.

The movable support 3 comprises a movable top plate 31 and two movable support plates 32 which are formed by vertically extending the bottom surface of the movable top plate 31 and are spaced from left to right, the shape of each movable support plate 32 is approximately triangular, and the front-back length of the movable top plate 31 is slightly larger than the top edge of each movable support plate 32, so that the contact area between the movable top plate 31 and the bottom surface of the seat 1 is increased, the movable top plate can better support the seat along the front-back sliding, and the stability is improved. The top end of the chair leg 2 is provided with a mounting seat 33, and the mounting seat 33 is provided with a front seat head 331 and a rear seat head 332 which are spaced front and back; the cross pipe 34 is arranged in the mounting seat 33, the end parts of the front section 34-a and the rear section 34-b of the cross pipe 34 are respectively connected with the front seat head 331 and the rear seat head 332, the bottom ends of the two movable support plates 32 are respectively and rotatably sleeved on the left section 34-c and the right section 34-d of the cross pipe 34, through the cross structural characteristics of the cross pipe 34, the left section 34-c and the right section 34-d are used as a left limb and a right limb to realize the hinging of the movable support 3 and the mounting seat 33, and the front section 34-a and the rear section 34-b are used as a front limb and a rear limb to strengthen the structural strength of the mounting seat 33.

The top surface of the movable top plate 31 is provided with a dovetail groove extending forwards and backwards, the bottom surface of the seat 1 is fixedly connected with a mounting plate 35, the bottom surface of the mounting plate 35 is provided with a slide rail 351 extending forwards and backwards and matched with the dovetail groove in shape, and the movable top plate 31 is clamped on the slide rail 351 through the dovetail groove and can slide forwards and backwards along the slide rail 351. The mounting plate 35 and the movable top plate 31 are replaceable parts, direct contact between the movable top plate 31 and the base is avoided by arranging the mounting plate 35, replacement is convenient when the movable top plate is damaged, and replacement cost is low. The front end and the rear end of the slide rail 351 are respectively provided with a limiting block 352 which can be abutted against the movable top plate 31 to limit the front-back sliding range of the movable top plate 31, so that the range of the front-back overturning range of the seat 1 is limited, and the potential safety hazard is avoided.

The front section 34-a and the rear section 34-b of the cross pipe 34 respectively penetrate through the front seat head 331 and the rear seat head 332 and can slide along the mounting seat 33 in the front-back direction, and the front seat head 331 and the rear seat head 332 can abut against the cross part 34-e of the cross pipe 34 to limit the front-back sliding range of the cross pipe 34. The front section 34-a of the cross pipe 34 is sleeved with a reset compression spring 36, the front end and the rear end of the cross pipe are respectively supported on the front seat head 331 and the cross part 34-e, and the cross part 34-e and the rear seat head 332 can be abutted by the elasticity of the reset compression spring 36. On the premise that the limiting block 352 limits the preliminary range of the front-back overturning range of the seat 1, the front-back sliding of the cross pipe 34 can also continuously amplify the front-back overturning range of the seat 1 in a smaller range. For example, when the seat 1 is turned backwards, due to the action of the reset compression spring 36, the cross part 34-e of the cross pipe 34 is pressed by the reset compression spring 36 to abut against the rear seat head 332, firstly, the movable top plate 31 slides forwards along the sliding rail 351 until abutting against the limiting block 352 at the front end, then, the cross pipe 34 slides forwards to continue turning backwards, in the process, the reset compression spring 36 is gradually compressed to gradually increase the damping of the backward turning of the seat 1 until stopping, so that the experience of a user can be improved, in the process that the movable top plate 31 slides forwards and backwards along the sliding rail 351, the damping is very small to enable the turning of the seat 1 to be flexible, the seat is suitable for the user to relax, when the seat 1 is turned backwards continuously (the cross pipe 34 slides forwards), the reset spring plays a role in buffering, and the safety is improved.

The root part of the rear section 34-b of the cross pipe 34, which is close to the cross part 34-e, is fixedly sleeved with an elastic gasket 37, the elastic gasket 37 is supported between the cross part 34-e and the rear seat head 332 when the cross part 34-e abuts against the rear seat head 332, and when the seat support 1 is turned forwards under the action of the reset compression spring 36, the cross pipe 34 is reset to enable the cross part 34-e to abut against the rear seat head 332, and at the moment, the elastic gasket 37 plays a role in buffering, so that the user is prevented from being subjected to pause and contusion, and the comfort level is improved.

The thickness of the chair seat 1 is gradually widened from the front end to the middle rear part and then gradually reduced from the middle rear part to the rear end to be folded; the top of the said movable support 3 slides in the front and back of the bottom surface of the seat 1 and is the inclined plane, and incline downward from front to back, when the user relaxes using the function of "free" and uses the horizontal rod 12 in the front of the seat 1 as the axis of rotation, the impact force received by the middle and back of the seat 1 is large, therefore, for the seat 1, the structural strength of the middle and back part needs to be strengthened, in this embodiment, through increasing the thickness of the seat 1 gradually from front to back, the inside of the middle and back part of the seat 1 can be provided with structures such as reinforcing ribs to strengthen its structural strength, correspondingly, the top of the movable support 3 slides in the front and back of the bottom surface of the seat 1 and is the inclined plane, and the function of the movable support 3 will not be affected.

The chair leg 2 comprises a chair leg frame 21 extending to the periphery and provided with walking wheels, a sleeve 22 vertically and fixedly connected to the center of the chair leg frame 21, and a support shaft 23 inserted in the sleeve 22 and extending upwards, the rear end of the support frame 11 is fixedly sleeved on the upper part of the support shaft 23, and the mounting seat 33 is arranged on the top end of the support shaft 23 and is of an integral structure. Means for height adjustment may be provided between the sleeve 22 and the support shaft 23 so that the height of the seat 1 may be adjusted.

Example 2:

referring to fig. 5 to 7, an office chair comprises a chair seat 1 and chair legs; the chair legs are connected with a support frame 11 which extends forwards and inclines upwards, the front end of the support frame 11 is provided with a cross rod 12 which extends leftwards and rightwards, the bottom surface of the front part of the chair seat 1 is provided with a sleeve pipe structure which is rotatably sleeved on the cross rod 12, and the structure is the same as that of the embodiment 1.

In this embodiment, the rear end of the supporting frame 11 is connected to a jacket structure 41, a vertically extending guide post 42 is slidably inserted into the jacket structure 41, the jacket structure 41 is provided with a manual driving mechanism to drive the guide post 42 to slide up and down, a turning support 43 is arranged between the top end of the guide post 42 and the seat 1, the middle or lower portion of the turning support 43 is hinged to the top end of the guide post 42 and can be turned back and forth with the bottom end thereof serving as a rotation center, and the top end of the turning support 43 is fixedly connected to the bottom surface of the seat 1.

The office user mentioned in embodiment 1 normally sits forward during work, especially a user working at a desk, and a part of the center of gravity of the upper half of the body is supported on the desk, for such a user, if the front end of the seat 1 is slightly tilted upward, or the seat 1 as a whole is inclined downward from the front end to the rear end, then the upper half of the body is inclined forward and the legs are too raised upward when the user sits forward, on one hand, the back is easy to rickets, the back and the waist of the user are easy to fatigue, even the pathological conditions of the spine and the lumbar are easy to occur, on the other hand, the degree of compression of the abdomen is heavy, and the user who is fat is extremely uncomfortable. Therefore, on the premise that the office chair is suitable for office users to lean on sitting postures, the driving mechanism is used for driving the guide post 42 to slide up and down, so that the inclination degree of the chair seat 1 can be adjusted, the chair seat can be matched with the sitting postures to achieve a comfortable degree, and the office chair is particularly suitable for users working at desk.

The guide post 42 has a vertically extending rack 421, and the jacket structure 41 has a notch 422 allowing the rack 421 to pass through up and down. The driving mechanism comprises bearings 441 respectively arranged at the left side and the right side of the jacket structure 41 at the notch 422, a transverse rotating shaft 442 is connected between the two bearings 441, and a gear 443 meshed with the rack 421 is fixedly sleeved on the rotating shaft 442; one end of the rotating shaft 442 is provided with a rocker 444 or a knob cover, the rocker 444 selected in this embodiment can lift the guide post 42 by rotating the rocker 444, thereby adjusting the inclination degree of the seat 1.

The part of the guide post 42, which is provided with the rack 421, is fixedly sleeved with the polygonal shell 422, the shape of the inner surface of the jacket structure 41 is matched with the polygonal shell 422, and the structure of the polygonal shell 422 enables the clamping and embedding of the guide post 42 and the jacket structure 41 to be firmer, so that the axial movement or slipping can be avoided, and the adjustment of the guide post 42 is more accurate.

The overturning support 43 comprises two overturning support plates 431 which are arranged at left and right intervals, and an overturning shaft 432 which is transversely arranged and is fixedly connected to the middle parts of the two overturning support plates 431 at two ends respectively, the overturning shaft 432 transversely penetrates through the guide pillar 42 from left to right, the two overturning support plates 431 are clamped at the left and right sides of the guide pillar 42, the top ends of the two overturning support plates 431 are fixedly connected to the bottom surface of the seat 1, the overturning support 43 rotates in a suitable manner when the inclination degree of the seat 1 is adjusted through the overturning support plates 431 and the overturning shaft 432, the guide pillar 42 is prevented from being clamped and being incapable of lifting along the radial dislocation, and the smooth degree of adjustment is improved.

The left side and the right side of the guide post 42 clamped by the two turnover support plates 431 are vertical planes flatly attached to the turnover support plates 431, so that the contact area between the turnover support plates 431 and the guide post 42 is increased, and the structural stability of the turnover support 43 is better.

The bottom surface of the seat 1 is provided with two left and right spaced lugs 433, and the top ends of the two turning support plates 431 are respectively attached to the two lugs 433 and fixedly connected through at least two fasteners.

The lower parts of the two turnover support plates 431 are respectively provided with an arc-shaped groove 434, the arc-shaped grooves 434 take the connecting point of a turnover shaft 432 on the turnover support plates 431 as the center of a circle, the guide post 42 transversely penetrates through an adjusting rod 435, two ends of the adjusting rod 435 penetrate through the two arc-shaped grooves 434 and are respectively in threaded connection with a locking nut 436 capable of clamping the two turnover support plates 431, when the inclination degree of the seat 1 is adjusted by rotating the rocker 444, if the locking nut 436 is not screwed, the turnover support 43 can be turned over back and forth in a small range due to the existence of a mechanical gap, and the seat 1 can be slightly turned back and forth when a user adjusts a sitting posture in a small range, so that the comfort level is improved; if the lock nut 436 is tightened, the seat 1 is fixed so as not to rotate back and forth, thereby improving the stability of supporting the buttocks of the user and being more suitable for the user in a fixed sitting posture.

The thickness of the seat 1 is gradually widened from the front end to the middle rear portion, and then gradually reduced from the middle rear portion to the rear end, and the top end of the overturning support 43 is fixedly connected between the middle rear portion and the rear end of the bottom surface of the seat 1, so that the supporting force of the overturning support 43 to the seat 1 is forward and upward inclined, and the supporting force points to the center of gravity of a user in a forward leaning sitting posture, and the supporting performance is better.

Example 3:

referring to fig. 8-13, an office chair comprises a seat 1, a backrest 6, two armrests 5, and legs. The structure of the chair seat 1 and the supporting legs are the same as the embodiment 1 and the embodiment 2, and the movable support of the embodiment 1 can be selected as the structure between the chair seat 1 and the supporting legs, and the guide posts and the overturning supports of the embodiment 2 can also be selected as the structures between the chair seat 1 and the supporting legs.

In this embodiment, the surface of horizontal pole 12 tip has the reciprocal spline line of slant, the front end of handrail 5 rotates cup joints at the tip of horizontal pole 12 and rather than screw-thread fit, handrail 5 is by preceding to upwards lifting to the top of seat support 1 after to, and the lateral bending is again around to back of the chair 6 rear, and the rear end of handrail 5 and back of the chair 6 rear surface swing joint can be followed it and controlled horizontal slip, and the back of the chair 6 is dodged the bottom of back of the chair 6 when turning over around horizontal pole 12 is leaned on backward by handrail 5 drive around horizontal pole 12 to handrail 5 slides along horizontal inside step when turning over backward along horizontal pole 12 for the interval between two handrails 5 reduces.

When the back of a user leans against the chair back 6, the armrests 5 and the chair back 6 lean backwards and turn over with the cross rod 12 as a rotating shaft, at the moment, as the end parts of the cross rod 12 are provided with the reciprocating spline grains, the two armrests 5 slide inwards transversely, so that the distance between the two armrests 5 is reduced, the two armrests are more tightly attached to the two sides of the upper half of the user, the arms supported on the armrests 5 are also folded inwards, the user feels safe in the process of leaning backwards, the user can relax more easily, and the purpose and the effect of relaxing are achieved.

The left side and the right side of the cross rod 12, which are positioned at the front end of the armrest 5, are respectively fixedly sleeved with a limiting lantern ring 12-1 which can be abutted against the front end of the armrest 5, so as to limit the transverse sliding range of the armrest 5 along the cross rod 12, the limiting lantern ring 12-1 can limit the forward-leaning and backward-leaning amplitude of the chair back 6, and the potential safety hazard caused by over backward leaning of a user is avoided.

The outer sleeve of horizontal pole 12 has first pressure spring 12-A that resets, and the both ends of first pressure spring 12-A that resets support respectively in the front end of handrail 5 and by interior spacing lantern ring 12-1, and the effect of first pressure spring 12-A that resets is when the user sits up from the posture of lying backwards, and back of the chair 6 and handrail 5 can reset rapidly, uses more humanized.

The inside of back of the chair 6 is provided with the circular passageway 61 of horizontal extension about controlling, the rear surface of the back of the chair 6 has two bilateral symmetry and the straight flute 62 that communicates with circular passageway 61, straight flute 62 is by the one end that is close to back of the chair 6 side to keeping away from the one end tilt up of back of the chair 6 side, two the rear end of handrail 5 is provided with the front and back and extends and insert the connecting rod 51 that corresponds straight flute 62, connecting rod 51 is located the one end fixedly connected with slide bar 52 of circular passageway 61, slide bar 52 can follow circular passageway 61 about horizontal slip and can rotate around its axis for circular passageway 61, back of the chair 6 is driven by handrail 5 and is rolled over backward around slide bar 52 around the horizontal pole 12 when turning over backward for the level of the bottom of the back of the chair 6 is not less than the rear end of seat support 1.

When a user leans back, the chair back 6 turns backwards around the cross rod 12, and the situation that the bottom end of the chair back 6 is lower than the rear end of the chair seat 1 inevitably occurs, so that the waist and part of the back of the user have a sense of falling, on one hand, the user has no sense of safety, the spirit is not easy to relax completely, and the effect of relaxing and relieving the upper half of the body is greatly reduced; on the other hand, the lower half part of the backrest 6 has insufficient supporting force for the waist and part of the back, so that the muscles of the waist and part of the back are uncomfortable in a long-term lying-back posture, and even the pathological problems of lumbar vertebra and spine such as lumbar disc herniation are easy to cause. In the embodiment, the oblique straight groove 62 can synchronously turn backwards around the sliding rod 52 positioned in the circular channel 61 in the process that the chair back 6 turns backwards around the cross rod 12, so that the bottom end of the chair back 6 is flush with the rear end of the chair seat 1, even slightly higher; therefore, the waist and part of the back of the user can be better supported, and the relaxing effect can be achieved. In addition, a waist cushion can be arranged between the rear end of the chair seat 1 and the bottom end of the chair back 6, so that a user can obtain better experience.

The rear end of one handrail 5 is provided with a guide rod 53 extending left and right, the guide rod 53 is inserted into the rear end of the other handrail 5 in a sliding manner, a second reset compression spring 5-B is sleeved outside the guide rod 53, and two ends of the second reset compression spring 5-B are respectively supported at the rear ends of the two handrails 5. Through setting up guide bar 53 for stability is better when the rear end of two handrail 5 is along controlling lateral shifting, avoids taking place the drunkenness or shake, and in addition, because the span is too big between the front end of handrail 5 and the rear end, only relies on the reset action of first pressure spring 12-A that resets, the rear end of handrail 5 blocks easily when reseing, consequently sets up the second pressure spring 5-B that resets and can solve this problem, thereby makes the activity of reseing of handrail 5 more steady smooth and easy.

A plastic corrugated pipe 54 is sleeved outside the second reset pressure spring 5-B, two ends of the plastic corrugated pipe 54 are respectively and fixedly connected with the rear ends of the two handrails 5, and the plastic corrugated pipe 54 protects the second reset pressure spring 5-B and the guide rod 53 inside and prevents the second reset pressure spring 5-B and the guide rod from being damaged.

The armrest 5 comprises an armrest front section 5-a, an armrest middle section 5-b and an armrest rear section 5-c, wherein the armrest front section 5-a extends vertically basically, the front end of the armrest front section is rotatably sleeved at the end of the cross rod 12, the rear end of the armrest front section is lifted above the seat 1 and integrally connected with the front end of the armrest middle section 5-b, the armrest middle section 5-b inclines upwards from the front end to the rear end and is used for supporting an arm, the rear end of the armrest middle section 5-b is integrally connected with the front end of the armrest rear section 5-c, and the rear end of the armrest rear section 5-c is integrally connected with the connecting rod 51.

Example 4:

referring to fig. 14-16, an office chair comprises a seat 1, a backrest 6, two armrests 5, and legs. The structure of the chair seat 1 and the supporting legs are the same as the embodiment 1 and 2, and the movable support of the embodiment 1 can be selected as the structure between the chair seat 11 and the supporting legs, and the guide posts and the overturning supports of the embodiment 2 can also be selected as the structure between the chair seat 11 and the supporting legs.

The front end of the armrest 5 is rotatably sleeved at the end part of the cross rod 12, the armrest 5 is lifted upwards from front to back to the upper part of the seat 1, and then the armrest is bent laterally and wound to the rear end of the armrest 5 behind the seat back 6 to be hinged with the rear surface of the seat back 6; the rear portion of seat support 1 is provided with the cross axle 71 that extends behind a left side, be provided with swing arm 72 between the tip of cross axle 71 and the side of the 6 bottoms of the back of the chair, the front end fixed connection of swing arm 72 is at the tip of cross axle 71, and the rear end is articulated at the side of the 6 bottoms of the back of the chair, back of the chair 6 is driven by handrail 5 and is rolled over backward around the rear end of handrail 5 when rolling over backward around horizontal pole 12, 1 rear portion of seat support is provided with the rotation limiting mechanism and is used for restricting the rotation range of cross axle 71.

When the user's back leaned on back of the chair 6, when falling backward handrail 5 and back of the chair 6 took horizontal pole 12 as the axis of rotation upset that leans backward, because handrail 5 rear end was articulated with back of the chair 6 rear surface this moment, and the both ends of swing arm 72 are articulated with the side of cross axle 71 and back of the chair 6 bottom respectively, consequently back of the chair 6 overturns backward around the rear end of handrail 5 in step, thereby make and keep the parallel and level between seat support 1 and the back of the chair 6, make user's waist, the sense of empting can not appear in the back, the comfort level has been improved. In addition, the rotation limiting mechanism can freely adjust the rotation range of the chair back 6, namely the maximum forward-leaning angle and the maximum backward-leaning angle of the chair back 6 can be customized, and the chair is more humanized to use.

The rotation limiting mechanism comprises an arc slide rail 81 fixed on the side surface of the rear part of the seat 1 and two limiting structures which can slide along the arc slide rail 81 and are used for locking positions, the arc slide rail 81 uses the end part of the transverse shaft 71 as a circle center, and the two limiting structures can be abutted against the swing arm 72 to limit the rotation range of the swing arm.

Specifically, the front end and the rear end of the arc slide rail 81 are fixedly connected with fixing plates 82 extending along the left-right direction respectively, the arc plates 83 fixedly connected with the two fixing plates 82 and spaced from the arc slide rail 81 are arranged between the two fixing plates 82, the arc plates 83 are provided with arc grooves 84 along the extending direction, the limiting structure comprises a sliding block 851 embedded in the arc slide rail 81 in a sliding manner, a limiting rod 852 fixedly connected with the inner end of the sliding block 851 penetrates through the arc grooves 84 and can abut against the swing arm 72, and a limiting knob 853 which is in a locking position can be pressed on the arc plates 83 and is sleeved at the outer end of the limiting rod 852 through threads. When the swing arm 72 is used, the limit knob 853 is loosened firstly, then the limit rod 852 slides along the arc slide rail 81 to adjust the position, and the limit knob 853 is screwed after the position is adjusted, so that the limit knob is pressed against the locking position of the arc plate 83, and the rotation range of the swing arm 72 can be limited.

Two fixedly connected with circular arc guide bar 86 between fixed plate 82, circular arc guide bar 86 are located between circular arc slide rail 81 and the circular arc board 83, circular arc guide bar 86 all slides and runs through gag lever post 852, swing arm 72 can play the slide guide effect to gag lever post 852 and swing arm 72 through setting up circular arc guide bar 86 for no matter in the accommodation process or swing arm 72 rotate the in-process more for stable smooth.

A resetting pressure spring 87 is sleeved outside the arc guide rod 86, two ends of the resetting pressure spring 87 are respectively supported on the swing arm 72 and the fixing plate 82 positioned at the rear end, and the resetting pressure spring 87 has the function that the chair back 6 can be quickly reset when a user sits up.

Spacing knob 853 is provided with rubber pad 854 near the one end of circular arc board 83 to increase the frictional force of spacing knob 853 pressure on circular arc board 83, the frictional force of increase makes limit structure's position locking more firm stable on the one hand, and on the other hand also avoids spacing knob 853 and circular arc board 83 direct contact, reduces both damages with increase of service life.

In addition, the swing arm 72 is bent so as not to expose the top surface of the seat 1 and the front surface of the backrest 6, thereby avoiding direct collision with the trunk of the user and avoiding potential safety hazards.

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 (7)

1. An office chair with an adjustable chair back comprises a chair seat, a chair back and two armrests; the chair is characterized in that a cross bar extending left and right is arranged on the bottom surface of the front part of the chair seat; the surface of the end part of the cross rod is provided with oblique reciprocating spline grains, and the front end of the handrail is rotatably sleeved at the end part of the cross rod and is in threaded fit with the end part of the cross rod; the armrests are lifted upwards to the upper part of the chair seat from front to back, and then are bent laterally and wound to the rear part of the chair back; the rear ends of the armrests are movably connected with the rear surface of the chair back and can transversely slide along the rear ends of the armrests; when the chair back is driven by the armrest to tilt backwards around the cross rod, the rear end of the chair seat avoids the bottom end of the chair back, and the armrests slide inwards along the cross rod transversely and synchronously when being tilted backwards, so that the distance between the two armrests is reduced; a circular channel extending horizontally from left to right is arranged in the chair back; the back surface of the chair back is provided with two straight grooves which are bilaterally symmetrical and communicated with the circular channel, and the straight grooves incline upwards from one end close to the side edge of the chair back to one end far away from the side edge of the chair back; the rear ends of the two handrails are provided with connecting rods which extend forwards and backwards and are inserted into the corresponding straight grooves, one ends of the connecting rods, which are positioned in the circular channels, are fixedly connected with sliding rods, and the sliding rods can transversely slide left and right along the circular channels and can rotate around the axes of the sliding rods relative to the circular channels; the chair back is driven by the armrest to turn backwards around the cross rod, and synchronously turns backwards around the slide rod when turning backwards, so that the horizontal height of the bottom end of the chair back is not lower than the rear end of the chair seat.

2. The chair back adjustable office chair of claim 1, wherein the cross bar is fixedly sleeved with a limiting collar which can abut against the front end of the armrest on the left side and the right side of the front end of the armrest respectively, so as to limit the transverse sliding range of the armrest along the cross bar.

3. The office chair with the adjustable chair back according to claim 1, wherein a first return compression spring is sleeved outside the cross bar, and two ends of the first return compression spring are respectively supported on the front end of the armrest and a limiting lantern ring in the armrest.

4. The chair back adjustable office chair of claim 3, wherein the rear end of one of the armrests has a guide bar extending to the left and right, the guide bar being slidably inserted into the rear end of the other armrest.

5. The office chair with the adjustable chair back according to claim 4, wherein a second return compression spring is sleeved outside the guide rod, and two ends of the second return compression spring are respectively supported at the rear ends of the two armrests.

6. The office chair with the adjustable chair back according to claim 5, wherein a plastic corrugated pipe is sleeved outside the second return compression spring, and two ends of the plastic corrugated pipe are respectively and fixedly connected with the rear ends of the two armrests.

7. The chair-back adjustable office chair of claim 1, wherein the armrest comprises an armrest front section, an armrest middle section, and an armrest rear section; the utility model discloses a chair seat, including handrail front end, back end, connecting rod, handrail rear end, handrail front end, back end, handrail middle section, handrail front end is the vertical extension of base basis, and its front end rotates to cup joint the tip at the horizontal pole, and the rear end lifting is to the top of seat support and with the front end body coupling in handrail middle section, the handrail middle section is by front end to rear end tilt up and be used for supporting the arm, its rear end and the front end body coupling in handrail rear section, the rear end body coupling in handrail rear section the connecting rod.

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