CN113616013A

CN113616013A - Foldable and unfoldable chair frame

Info

Publication number: CN113616013A
Application number: CN202110955325.5A
Authority: CN
Inventors: 陈德隆; 陈品颐; 陈品翰
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-08-19
Filing date: 2021-08-19
Publication date: 2021-11-09

Abstract

A foldable and unfoldable chair frame comprises a chair seat unit, a chair back unit, two chair leg units, two armrest units, a first connecting rod unit and two pivot rod units. The chair back unit comprises two back rods which are spaced from each other at left and right, extend up and down and are pivoted with the chair seat unit. Each chair leg unit comprises a front leg rod pivoted with one side of the chair seat unit and a rear leg rod pivoted with the front leg rod and pivoted with the same side of the chair seat unit through a penetrating piece. Each armrest unit is arranged on one of the chair foot units and is pivoted with one of the back rods. The first connecting rod unit is pivoted between the two back rods. One end of each pivot rod unit is pivoted with the first connecting rod unit, and the other end of each pivot rod unit is pivoted with one armrest unit. The invention has the characteristic of being capable of being operated from the front side to be unfolded or folded.

Description

Foldable and unfoldable chair frame

Technical Field

The invention relates to furniture or outdoor camping supplies, in particular to a foldable and unfoldable chair frame.

Background

Referring to fig. 1 to 3, taiwan patent No. I522071 discloses a foldable and unfoldable chair frame suitable for being matched with a chair cloth 11 to form a reclining chair for a user to sit on. The chair frame comprises a chair seat unit 12, a chair back unit 13 with the bottom pivoted to the chair seat unit 12 and extending upwards from the chair seat unit 12, two chair leg units 14 pivoted to the left and right sides of the chair seat unit 12 respectively, two armrest units 15 arranged at the top ends of the chair leg units 14 and pivoted to the left and right sides of the chair back unit 13 respectively, a first connecting rod unit 16 and a second connecting rod unit 17 located behind the chair back unit 13 and pivoted to the chair back unit 13, and a pull rod unit 18 pivoted between the first connecting rod unit 16 and the second connecting rod unit 17.

The seat unit 12 includes two seat bars 121 spaced apart from each other and extending forward and rearward. The back unit 13 includes two back bars 131 spaced apart from each other in the left-right direction and extending in the up-down direction.

Each leg unit 14 includes a front leg shaft 141 pivotally connected to one of the seat shafts 121, a rear leg shaft 142 terminating the front leg shaft 141 at the top, and a penetrating member 143 penetrating the rear leg shaft 142 and pivotally connected to the seat shaft 121. Each of the front leg rods 141 and the corresponding rear leg rod 142 are matched to form an inverted V shape, and are matched to provide the armrest unit 15. Each of the fitting members 143 can slide up and down with respect to the corresponding rear leg 142.

Each of the first link unit 16 and the second link unit 17 includes a pivot seat 191 between the back rods 131 and pivotally connected to the link unit 18, and two pivot rods 192 extending left and right. Each pivot rod 192 is pivotally connected between one of the back rods 131 and the pivot seat 191.

The rod unit 18 is pivotally connected between the pivoting seats 191 and can drive the pivoting seats 191 to move up and down, thereby driving the pivoting rod 192 to actuate.

Referring to fig. 2 to 4, the conventional collapsible and expandable chair frame can be changed between an expanded state suitable for the user to sit on as shown in fig. 3 and a collapsed state as shown in fig. 4.

In the unfolded state, since the pivot points of the pivot rod 192 and the left and right ends are located on the same line, which forms a dead point on the link mechanism, the first link unit 16 and the second link unit 17 can stably support the backrest unit 13 and the entire chair frame structure in the unfolded state. The pulling rod unit 18 is pulled upward to drive the pivoting seat 191 to move upward and drive the pivoting rods 192 to close in groups, so as to eliminate the dead point on the link mechanism and change the chair frame to the folding state.

By operating the rod unit 18, the chair frame can be conveniently unfolded and folded, but the disadvantage is that the rod unit 18 at the rear part needs to be operated when the chair frame is changed, and the user needs to go around the rear part of the chair frame to operate, which is slightly inconvenient.

Disclosure of Invention

The invention aims to: provides a chair frame which can overcome the defect of inconvenient operation in the prior art and can be folded and unfolded frontally.

The foldable and expandable chair frame comprises:

a seat unit; the chair back unit comprises two back rods which are spaced from each other at left and right, extend up and down and are pivoted with the chair seat unit; each chair leg unit comprises a front leg rod pivoted with one side of the chair seat unit, a rear leg rod pivoted with the front leg rod and a penetrating and sleeving piece capable of being sleeved on the rear leg rod in a sliding mode and pivoted with the chair seat unit, and each penetrating and sleeving piece and one front leg rod are located on the same side; each armrest unit is arranged on one of the chair leg units and is pivoted with one of the back rods; the first connecting rod unit is pivoted between the two back rods and can enable the two back rods to approach or separate from each other; and one end of the at least one pivot rod unit is pivoted with the first connecting rod unit, and the other end of the at least one pivot rod unit is pivoted with one armrest unit or one penetrating sleeve member.

Preferably, the two hinge arm units are included, one end of each hinge arm unit is pivoted with the first connecting rod unit, and the other end of each hinge arm unit is pivoted with one armrest unit or one penetrating member.

Preferably, the first link unit includes a first pivot seat located between the two back bars, and two first pivot rods, each of the first pivot rods pivotally connects one of the back bars with the first pivot seat, and includes a first rod portion and a second rod portion opposite to each other, and a middle rod portion located between the first rod portion and the second rod portion.

Preferably, the first lever portion of each first pivoting lever is pivotally connected to the first pivoting seat, the middle lever portion of each first pivoting lever is pivotally connected to one of the back levers, the second lever portion of each first pivoting lever laterally protrudes from the back lever to which the middle lever portion of each first pivoting lever is correspondingly pivotally connected, and each pivoting lever unit is pivotally connected between one of the second lever portions and the rear end portion of one of the armrest units.

Preferably, the first lever portion of each first pivoting lever is pivotally connected to the first pivoting base, the second lever portion of each first pivoting lever is pivotally connected to one of the back levers, and each pivoting lever unit is pivotally connected between one of the middle lever portions and the rear end portion of one of the armrest units.

Preferably, the first lever portion of each first pivoting lever is pivotally connected to the first pivoting seat, the middle lever portion of each first pivoting lever is pivotally connected to one of the back levers, the second lever portion of each first pivoting lever laterally protrudes from the back lever to which the middle lever portion of each first pivoting lever is correspondingly pivotally connected, and each pivoting lever unit is pivotally connected between one of the second lever portions and one of the penetrating members.

Preferably, the first lever portion of each first pivoting lever is pivotally connected to the first pivoting base, the second lever portion of each first pivoting lever is pivotally connected to one of the back levers, and each pivoting lever unit is pivotally connected between one of the middle lever portions and one of the through members.

Preferably, the first connecting rod unit further comprises a second connecting rod unit located below the first connecting rod unit, the second connecting rod unit comprises a second pivot seat located between the two back rods and two second pivot rods, and each second pivot rod is pivoted between the second pivot seat and one of the back rods.

Preferably, the foldable seat further comprises a third connecting rod unit extending up and down, and the third connecting rod unit is pivoted between the first pivoting seat and the second pivoting seat and can be linked with the first pivoting seat, the second pivoting seat, the first pivoting rod and the second pivoting rod.

Preferably, the folding chair further comprises a second connecting rod unit, wherein the second connecting rod unit comprises two second pivoting rods, and each second pivoting rod is pivoted between the first pivoting seat and one back rod.

The invention has the following effects: the pivot rod unit is pivoted to the armrest unit or the penetrating member of the chair leg unit, and the linkage of the first connecting rod unit with the armrest unit and the chair leg unit is strengthened, so that a user can drive the first connecting rod unit positioned at the rear part only by operating the armrest unit and the chair leg unit at the front part, and the integral structure is unfolded or folded conveniently.

Drawings

Other features and effects of the present invention will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of the prior art illustrating a prior art collapsible and expandable chair frame;

FIG. 2 is a perspective view of the prior art illustrating the chair frame from a different angle than FIG. 1;

FIG. 3 is a rear elevational view of the prior art showing the seat frame in a deployed condition;

FIG. 4 is a rear elevational view of the prior art showing the chair frame in a collapsed condition;

FIG. 5 is a perspective view of the first embodiment of the present invention, illustrating a foldable and expandable chair frame in an expanded state;

FIG. 6 is a perspective view of the first embodiment of the present invention, the first embodiment being illustrated from a different perspective than FIG. 5, and in the expanded state;

FIG. 7 is a side view of the first embodiment of the present invention, illustrating the first embodiment in the deployed state;

FIG. 8 is a rear elevational view of the first embodiment of the present invention, illustrating the first embodiment in the deployed state;

FIG. 9 is a side view of the first embodiment of the present invention, illustrating the first embodiment in a collapsed state;

FIG. 10 is a rear view of the first embodiment of the present invention, illustrating the first embodiment in the collapsed state;

FIG. 11 is a rear elevational view of the second embodiment of the present invention, illustrating a second embodiment of a collapsible and expandable chair frame of the present invention in the expanded condition;

FIG. 12 is a rear view of the second embodiment of the present invention, illustrating the second embodiment in the collapsed state;

FIG. 13 is a rear elevational view of the third embodiment of the present invention, illustrating a third embodiment of a collapsible and expandable chair frame of the present invention in the expanded condition;

FIG. 14 is a rear view of the third embodiment of the present invention, illustrating the third embodiment in the collapsed state;

FIG. 15 is a rear elevational view of the fourth embodiment of the present invention, illustrating a fourth embodiment of a collapsible and expandable chair frame of the present invention in the expanded condition;

FIG. 16 is a rear view of the fourth embodiment of the present invention, illustrating the fourth embodiment in the collapsed state;

FIG. 17 is a rear elevational view of the fifth embodiment of the present invention, illustrating a fifth embodiment of a collapsible and expandable chair frame of the present invention in the expanded condition;

FIG. 18 is a rear view of the fifth embodiment of the present invention, illustrating the fifth embodiment in the collapsed state;

FIG. 19 is a rear elevational view of the sixth embodiment of the present invention, illustrating a sixth embodiment of the collapsible and expandable chair frame of the present invention;

fig. 20 is a rear view of the seventh embodiment of the present invention, illustrating a seventh embodiment of a foldable and unfoldable chair frame of the present invention.

Description of the symbols:

11: chair cloth

12: chair seat

121: unit seat rod

13: chair back unit

131: back rod

14: chair leg unit

141: front foot rod

142: rear foot bar

143: wearing set

15: armrest unit

16: first link unit

17: second link unit

18: pull rod unit

191: pin joint seat

192: pin joint rod

21 seat unit

211 seat post

22 chair back unit

221 back bar

3: chair leg unit

31 front foot bar

32 rear foot rod

33 pivot shaft

34 penetration assembly

341 sleeve body

342 is a bump

4-fork lever unit

41 fork rod set

5: armrest unit

51 handrail member

511 holding tank

52 positioning part

521 positioning groove

6 first link unit

61 first pivoting seat

62 first pivoting lever

621 first rod part

622 second rod part

623 middle rod part

7 second link unit

71 second pivot seat

72 second pivoting lever

73 the third pivoting seat

731 clamping and embedding part

8: third link unit

9 hinge arm unit

91 pivot rod piece

92 first adapting piece

And 93: a second adaptor.

Detailed Description

Referring to fig. 5 to 7, a first embodiment of the foldable and unfoldable chair frame of the present invention is suitable for being combined with a piece of chair cloth to form a reclining chair for a user to sit.

The first embodiment comprises a seat unit 21, a chair back unit 22 pivoted to the seat unit 21, two chair leg units 3 spaced left and right and respectively pivoted to left and right opposite sides of the seat unit 21, a fork rod unit 4 pivoted to a front end portion of the seat unit 21 and pivoted to a front end portion of the chair leg unit 3, two armrest units 5 respectively mounted above the chair leg units 3, a first link unit 6 and a second link unit 7 pivoted to a rear portion of the chair back unit 22 at an upper and lower interval, a third link unit 8 pivoted to a space between the first link unit 6 and the second link unit 7 in an up and down extending manner, and two pivot rod units 9 pivoted to the armrest units 5 and the first link unit 6.

The seat unit 21 includes two seat bars 211 extending in the front-rear direction and spaced apart from each other in the left-right direction.

The back unit 22 includes two back bars 221 spaced apart from each other in the left-right direction and extending in the up-down direction. The bottom of each back rod 221 is pivotally connected to the rear end of one seat rod 211 of the seat unit 21.

Each leg unit 3 includes a front leg 31 and a rear leg 32, the top ends of which are pivoted to each other and cooperate with each other to form an inverted V shape, a pivot shaft 33 for pivoting the front leg 31 and the rear leg 32 together, and a penetrating member 34 slidably penetrating the rear leg 32 and pivotally connecting one of the seat bars 211 of the seat unit 21.

Each of the front legs 31 is pivotally connected to the central portion of the seat rod 211 of the seat unit 21 located on the same side.

Each of the sleeving parts 34 includes a sleeve 341 sleeved on the corresponding rear leg 32, and a protrusion 342 integrally connected to the sleeve 341 and protruding toward the corresponding seat 211 in the left-right direction to pivotally connect the seat 211. (see fig. 6) the protrusion 342 of each of the through pieces 34 is pivotally connected to the seat bar 211 on the same side as the front leg bar 31 belonging to the same chair leg unit 3.

The fork lever unit 4 comprises two fork lever sets 41 pivotally connected to each other and cooperating in a generally X-shape. Each of the fork rod sets 41 extends from one of the left and right sides to the other of the left and right sides in a downward inclined manner, and a top end of each fork rod set 41 is pivotally connected to a front end of one of the seat rods 211 and a bottom end thereof is pivotally connected to a bottom end of the front foot rod 31 on the other side.

Each of the armrest units 5 includes an armrest member 51 adapted to support an arm of the user, and a positioning member 52 provided on a bottom side of the armrest member 51.

The inner side of the rear end of each armrest 51 is pivotally connected to one of the back bars 221 of the seat back unit 22, and a receiving groove 511 is formed to receive the pivot bar unit 9. Each positioning member 52 is inserted over the pivot shaft 33 of one of the leg units 3, and a positioning slot 521 is formed for the pivot shaft 33 to be inserted in an adjustable position.

Referring to fig. 6 to 8, the first link unit 6 is pivotally connected between the two back bars 221 of the backrest unit 22 for assisting the two back bars 221 to approach or separate from each other, and includes a first pivot seat 61 located in the middle of the two back bars 221 at the same interval from left to right as the two back bars 221, and two first pivot rods 62.

Each first pivot rod 62 includes a first rod 621 and a second rod 622 oppositely disposed, and a middle rod 623 located between the first rod 621 and the second rod 622.

Each first rod 621 is pivotally connected to the first pivot base 61. Each intermediate lever portion 623 is pivotally connected to one of the back levers 221. Each second lever portion 622 laterally protrudes in the left-right direction from the back lever 221 to which the intermediate lever portion 623 is pivotally connected. Specifically, taking fig. 8 as an example, the second rod portion 622 on the right side of the drawing protrudes to the right to form the corresponding back rod 221, and the second rod portion 622 on the left side of the drawing protrudes to the left to form the corresponding back rod 221.

The second link unit 7 is spaced below the first link unit 6, and includes a second pivot seat 71 spaced apart from the other two back bars 221, two second pivot rods 72 pivotally connected to the second pivot seat 71 and the two back bars 221 of the seat unit 21, and third pivot seats 73 for respectively pivotally connecting the second pivot rods 72 to the back bars 221.

One end of each second pivot rod 72 is pivoted to the second pivot seat 71, and the other end is indirectly pivoted to one of the back rods 221 of the seat back unit 22 through the third pivot seat 73. Each third pivot seat 73 includes a fastening portion 731 (see fig. 6 and 8) for fastening the back rod 221.

In other embodiments of the present invention, the third pivot seat 73 can be omitted, such that each of the second pivot rods 72 is directly pivoted to the corresponding back rod 221. The advantage of the third pivot seat 73 provided in the first embodiment is that the third pivot seats 73 can be respectively provided for the back rod 221 to be locked so as to improve the stability.

The third link unit 8 is pivotally connected between the first pivot base 61 and the second pivot base 71 in an up-and-down extending manner, and drives the first pivot base 61 and the second pivot base 71 to move up and down, so that the first pivot rod 62 is linked with the second pivot rod 72.

Each pivot rod unit 9 includes a pivot rod member 91. One end of the pivot rod 91 is pivotally connected to the second rod 622 of one of the first pivot rods 62 of the first link unit 6, and the other end is pivotally connected to the rear end of one of the armrest units 5.

The first embodiment is changeable between an expanded state as shown in fig. 7 and 8 and a collapsed state as shown in fig. 9 and 10.

Referring to fig. 6, 7 and 8, in the unfolded state, each of the armrest units 5 extends back and forth, each of the first pivoting seats 61 is substantially in a shape of a straight line in cooperation with the two first pivoting rods 62, each of the second pivoting seats 71 is substantially in a shape of a straight line in cooperation with the two second pivoting rods 72, and the bottom of each of the back rods 221 is clamped in the clamping portion 731 of the corresponding third pivoting seat 73.

In the unfolded state, the user only needs to use two hands to drive the armrest units 5 to move upward and approach each other, and use two feet to clamp the front foot rods 31 inward in the left-right direction, so that the front foot rods 31 approach each other, and the first embodiment can be changed from the unfolded state to the folded state.

In the operation process, when the armrest units 5 are operated to approach each other, the pivot rod 91 of the pivot rod unit 9 is driven to move, and then the two first pivot rods 62 of the first link unit 6 are driven to swing toward each other, so as to drive the first pivot seat 61 to move upward, and the third link unit 8 drives the second pivot seat 71 of the second link unit 7 to move upward, so as to drive the two second pivot rods 72 to swing toward each other. During the process of swinging the two second pivoting rods 72 toward each other, each second pivoting rod 72 will drive each third pivoting seat 73 to pivot relative to the corresponding back rod 221, and during the process of clamping the front leg rod 31 with two legs, the fork rod set 41 of the fork rod unit 4 can be driven to operate, thereby facilitating the seat rods 211 to approach toward each other.

Referring to fig. 9 and 10, in the folded state, each of the armrest units 5 extends obliquely upward and downward, the two first pivot rods 62 of the first link unit 6 are substantially matched with each other in an inverted V shape, the two second pivot rods 72 of the second link unit 7 are also substantially matched with each other in an inverted V shape, and the bottom of each of the back rods 221 is separated from the engaging portion 731 of the third pivot seat 73.

In the folded state, if the user needs to take the first embodiment, the user only needs to press down the armrest unit 5 and drive the armrest unit 5 to move away from each other in the left-right direction, so as to link the chair leg unit 3, the pivot rod 91 of the pivot rod unit 9, the first link unit 6, and the second link unit 7, and then the present embodiment is changed to the unfolded state again for the user to take.

The first embodiment is characterized in that the user only needs to stand on the front side of the first embodiment and operate the armrest unit 5 and the front foot rod 31 to fold or unfold the first embodiment, and the user does not need to go around the rear side of the first embodiment, which is quite convenient.

Referring to fig. 11 and 12, a second embodiment of the foldable chair frame of the present invention is similar to the first embodiment except that the second rod portion 622 of each of the first pivot rods 62 is pivotally connected to one of the back rods 221 of the chair back unit 22, one end of the pivot rod 91 of each of the pivot rod units 9 is pivotally connected to the middle rod portion 623 of one of the first pivot rods 62, the other end of the pivot rod 91 of each of the pivot rod units 9 is pivotally connected to the rear end portion of one of the armrest units 5 as in the first embodiment, the rear side of the receiving slot 511 and the side facing the back rod 221 of each of the armrest units 5 are open for actuation of the corresponding pivot rod 91, the third pivot seat 73 is pivotally connected upside down, and in the folded state, the first pivot rod 62 of the first link unit 6 is generally V-shaped, the second pivot rod 72 of the second link unit 7 is also substantially V-shaped.

Referring to FIGS. 13 and 14, a third embodiment of the foldable chair frame of the present invention is similar to the first embodiment except that: each of the pivot rod units 9 further includes a U-shaped first adaptor 92 and a sheet-shaped second adaptor 93, the one end of the pivot rod 91 of each of the pivot rod units 9 is indirectly pivoted to the second rod portion 622 of the corresponding first pivot rod 62 through the corresponding first adaptor 92, and the other end of the pivot rod 91 of each of the pivot rod units 9 is indirectly pivoted to the through member 34 of the corresponding one of the leg units 3 through the corresponding second adaptor 93. Since the armrest unit 5 does not need to be pivoted by the pivot rod 91, each armrest member 51 omits a corresponding one of the receiving grooves 511 (see fig. 6).

Since each of the wearing members 34 is slidably disposed on the corresponding rear leg 32 and pivotally connected to the corresponding seat rod 211 of the seat unit 21, when the user operates the third embodiment to unfold or fold, each of the wearing members 34 can slidably move relative to the corresponding rear leg 32 and drive the corresponding first pivoting rod 62 to actuate, thereby driving the first link unit 6 and generating the effect similar to the first embodiment.

Referring to fig. 15 and 16, a fourth embodiment of the foldable chair frame of the present invention is similar to the second embodiment except that the other end of the hinge arm 91 of each hinge arm unit 9 is pivotally connected to the wearing member 34 of one of the leg units 3. Since the armrest unit 5 does not need to be pivoted by the pivot rod 91, each armrest member 51 omits a corresponding one of the receiving grooves 511 (see fig. 11).

Referring to fig. 17 and 18, a fifth embodiment of the foldable chair frame of the present invention is similar to the first embodiment except that the shape of the first pivoting seat 61 of the first linkage unit 6 is different, the second linkage unit 7 omits the second pivoting seats 71 (see fig. 8), each second pivoting rod 72 is pivoted to the first pivoting seat 61, and is pivoted to one back rod 221 of the chair back unit 22 through the corresponding third pivoting seat 73.

Referring to fig. 19, a sixth embodiment of the foldable chair frame of the present invention is similar to the first embodiment except that the second pivot seat 71 (see fig. 8) and the second pivot link 72 (see fig. 8) of the second link unit 7 (see fig. 8) are omitted and only one pivot link unit 9 is included in the sixth embodiment. One end of the pivot rod 91 of the pivot rod unit 9 is pivoted to the second rod portion 622 of the first pivot rod 62 on the left side of the drawing in fig. 19, and the other end is pivoted to the rear end of the armrest 51 of the armrest unit 5 on the same side of the first pivot rod 62 on the left side of the drawing.

Referring to fig. 20, a seventh embodiment of the foldable chair frame of the present invention is similar to the first embodiment except that the second link unit 7 (see fig. 8) is omitted, the first link unit 6 is changed from a middle portion where the back bar 221 is pivoted to a bottom portion where the back bar 221 is pivoted, and the seventh embodiment includes only one pivot unit 9. The hinge member 91 of the hinge unit 9 is pivotally connected to the second rod portion 622 of the first hinge rod 62 at the right side in the drawing of fig. 20, and pivotally connected to the rear end of the armrest 51 of the armrest unit 5 at the same side as the first hinge rod 62 at the right side in the drawing.

In the above embodiments and claims of the present invention, the pivot includes, in addition to the aspect of direct pivot, for example, the aspect of two objects directly pivoting with each other, the aspect of indirect pivot, for example, the aspect of two objects pivoting with each other through two pivots. Since both direct and indirect pivoting are common knowledge in the art of the present invention and are simple equivalent variations, the description and illustration of the various possible pivoting possibilities for each pivoting location is not exhaustive.

In summary, the foldable and unfoldable chair frame of the present invention has the following effects: the pivot rod unit 9 is pivotally connected to the arm rest unit 5 or the penetrating member 34 of the leg unit 3, so that the connection between the first link rod unit 6 and the arm rest unit 5 and the leg unit 3 is strengthened, and therefore, a user can drive the first link rod unit 6 located at the rear part only by operating the arm rest unit 5 and the leg unit 3 at the front part, so that the whole structure can be unfolded or folded conveniently.

The above description is only an example of the present invention, and the scope of the present invention should not be limited thereby, and the invention should also be covered by the claims in accordance with the simple equivalent changes and modifications of the claims and the specification.

Claims

1. A foldable and expandable chair frame, comprising:

a seat unit;

the chair back unit comprises two back rods which are spaced from each other at left and right, extend up and down and are pivoted with the chair seat unit;

each chair leg unit comprises a front leg rod pivoted with one side of the chair seat unit, a rear leg rod pivoted with the front leg rod and a penetrating and sleeving piece capable of being sleeved on the rear leg rod in a sliding mode and pivoted with the chair seat unit, and each penetrating and sleeving piece and one front leg rod are located on the same side;

each armrest unit is arranged on one of the chair leg units and is pivoted with one of the back rods;

the first connecting rod unit is pivoted between the two back rods and can enable the two back rods to approach or separate from each other; and

one end of the at least one pivot rod unit is pivoted with the first connecting rod unit, and the other end of the at least one pivot rod unit is pivoted with one armrest unit or one penetrating member.

2. The collapsible and expandable chair frame of claim 1, wherein: comprises two pivot rod units, wherein one end of each pivot rod unit is pivoted with the first connecting rod unit, and the other end of each pivot rod unit is pivoted with one handrail unit or one penetrating sleeve member.

3. The collapsible and expandable chair frame of claim 2, wherein: the first connecting rod unit comprises a first pivot seat positioned between the two back rods and two first pivot rods, each first pivot rod is pivoted with one back rod and the first pivot seat and comprises a first rod part and a second rod part which are opposite to each other and a middle rod part positioned between the first rod part and the second rod part.

4. The collapsible and expandable chair frame of claim 3, wherein: the first rod part of each first pivoting rod is pivoted with the first pivoting seat, the middle rod part of each first pivoting rod is pivoted with one back rod, the second rod part of each first pivoting rod laterally protrudes out of the back rod corresponding to the pivoted middle rod part, and each pivoting rod unit is pivoted between one second rod part and the rear end part of one handrail unit.

5. The collapsible and expandable chair frame of claim 3, wherein: the first rod part of each first pivoting rod is pivoted with the first pivoting seat, the second rod part of each first pivoting rod is pivoted with one of the back rods, and each pivoting rod unit is pivoted between one of the middle rod parts and the rear end part of one of the handrail units.

6. The collapsible and expandable chair frame of claim 3, wherein: the first rod part of each first pivoting rod is pivoted with the first pivoting seat, the middle rod part of each first pivoting rod is pivoted with one back rod, the second rod part of each first pivoting rod laterally protrudes out of the back rod corresponding to the pivoted middle rod part, and each pivoting rod unit is pivoted between one second rod part and one penetrating sleeve part.

7. The collapsible and expandable chair frame of claim 3, wherein: the first rod part of each first pivoting rod is pivoted with the first pivoting seat, the second rod part of each first pivoting rod is pivoted with one back rod, and each pivoting rod unit is pivoted between one middle rod part and one penetrating sleeve part.

8. The collapsible and expandable chair frame according to any one of claims 1 to 7, wherein: the first connecting rod unit comprises a first pin joint seat positioned between the two back rods and two first pin joint rods, and each first pin joint rod is pin jointed between the first pin joint seat and one back rod.

9. The collapsible and expandable chair frame of claim 8, wherein: the third connecting rod unit is pivoted between the first pivoting seat and the second pivoting seat and can be linked with the first pivoting seat, the second pivoting seat, the first pivoting rod and the second pivoting rod.

10. The collapsible and expandable chair frame of claim 3, wherein: the first connecting rod unit comprises two first pivoting rods, and each first pivoting rod is pivoted between the first pivoting seat and one back rod.