CN216059883U

CN216059883U - Stable folding chair

Info

Publication number: CN216059883U
Application number: CN202122745938.4U
Authority: CN
Inventors: 周晓峰
Original assignee: Foshan Shijing Tourism Products Co ltd
Current assignee: Foshan Shijing Tourism Products Co ltd
Priority date: 2021-07-14
Filing date: 2021-11-10
Publication date: 2022-03-18
Anticipated expiration: 2031-11-10

Abstract

The utility model discloses a stable folding chair which comprises a supporting leg assembly, a cushion supporting assembly, a locking assembly and a main rod, wherein the cushion supporting assembly is arranged on the supporting leg assembly; the supporting leg assembly is arranged at the upper end of the main rod, supporting legs of the supporting leg assembly extend downwards, and the supporting legs are used for supporting the folding chair; the cushion supporting component is arranged at the lower end of the main rod, a supporting arm of the cushion supporting component extends upwards, and the supporting arm is used for supporting a cushion; the supporting legs are hinged with the supporting arms; the locking assembly is sleeved on the outer wall of the main rod and fixedly connected with the supporting leg assembly or fixedly connected with the cushion supporting assembly. The stable folding chair is simple to fold and operate, and the problem of unstable structural support after unfolding is solved through the locking assembly.

Description

Stable folding chair

Technical Field

The utility model relates to the technical field of outdoor articles, in particular to a stable folding chair.

Background

With the rapid development of economy and society, the requirements of people on the quality of life are higher and higher, and the outdoor leisure activities such as self-driving travel are favored by people. The folding chair is necessary equipment for outdoor leisure activities, but the folding operation of the existing folding chair is complicated, and the unfolded structure is unstable, which seriously affects the experience of users.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned drawbacks, the present invention is directed to a stable folding chair, which is easy to fold and solves the problem of unstable structural support after unfolding by means of a locking assembly.

In order to achieve the purpose, the utility model adopts the following technical scheme: a stable folding chair comprises a supporting leg component, a cushion supporting component, a locking component and a main rod;

the supporting leg assembly is arranged at the upper end of the main rod, supporting legs of the supporting leg assembly extend downwards, and the supporting legs are used for supporting the folding chair;

the cushion supporting component is arranged at the lower end of the main rod, a supporting arm of the cushion supporting component extends upwards, and the supporting arm is used for supporting a cushion;

the supporting legs are hinged with the supporting arms, when the supporting leg assemblies and/or the cushion supporting assemblies move towards the middle of the main rod, the supporting leg assemblies and the cushion supporting assemblies are close to each other, the supporting legs are unfolded towards the direction far away from the main rod, and the supporting arms are unfolded towards the direction far away from the main rod;

when the supporting leg assembly and/or the cushion supporting assembly move in the direction away from the middle of the main rod, the supporting leg assembly and the cushion supporting assembly are away from each other, the supporting leg is folded in the direction close to the main rod, and the supporting arm is folded in the direction close to the main rod;

the locking assembly is sleeved on the outer wall of the main rod, the locking assembly is fixedly connected with the supporting leg assembly, or the locking assembly is fixedly connected with the cushion supporting assembly, and when the supporting leg assembly and the cushion supporting assembly are completely unfolded, the locking assembly is clamped on the outer wall of the main rod.

The supporting leg assembly further comprises a connecting fixing block, and the supporting leg is hinged to the connecting fixing block;

the connecting fixing block is fixedly arranged at the upper end of the main rod;

the cushion supporting assembly further comprises a connecting slide block, and the supporting arm is hinged with the connecting slide block;

the connecting slide block is movably sleeved at the lower end of the main rod and fixedly connected with the locking assembly.

Preferably, the locking assembly comprises an installation seat, a first limiting hole and a limiting screw rod, the outer wall of the main rod is provided with a second limiting hole, the installation seat is movably sleeved on the outer wall of the main rod, the installation seat is fixedly connected with the connecting slide block, and the side wall of the installation seat is provided with the first limiting hole;

when the supporting leg subassembly with the cushion supporting component expandes the back completely, first spacing pore pair in the spacing hole of second, spacing screw passes first spacing hole with the spacing hole of second, and will the mount pad chucking in the mobile jib.

Specifically, locking Assembly includes fixed plate and self-locking plate, the fixed plate movable sleeve is located the outer wall of mobile jib, the fixed plate with joint block fixed connection, the self-locking version with the fixed plate is articulated, works as the supporting legs subassembly with the cushion supporting component expandes the back completely, just the supporting legs subassembly with when the cushion supporting component keeps away from each other, the self-locking plate chucking in the outer wall of mobile jib.

It is worth to say that the self-locking plate is provided with a self-locking hole, the main rod is arranged in the self-locking hole, and the area of the self-locking hole is larger than the cross-sectional area of the main rod;

when the supporting legs subassembly with when the cushion supporting component keeps away from each other, from the jam plate around its self with articulated shaft between the fixed plate toward the direction in mobile jib middle part rotates, from the preceding inner wall of lockhole with the preceding outer wall contact of mobile jib, from the back inner wall of lockhole with the back outer wall contact of mobile jib.

Optionally, an elastic mechanism is arranged on a hinge shaft between the self-locking plate and the fixing plate;

under the elastic force action of the elastic mechanism, the self-locking plate has the tendency of rotating around the direction of the middle part of the hinged axial main rod.

Specifically, the outer wall of the main rod is provided with a limiting groove, and the limiting groove is arranged along the length direction of the main rod;

the fixed plate is provided with a limiting pin, and the limiting pin penetrates through the fixed plate and then is movably arranged in the limiting groove.

Preferably, a gasket is arranged between the outer wall of the main rod and the inner wall of the self-locking hole.

Optionally, the supporting legs are arranged on the connecting fixing block in a pairwise symmetrical manner, and the supporting arms are arranged on the connecting sliding block in a pairwise symmetrical manner.

Preferably, the support arm comprises an elastic telescopic mechanism, a plurality of straight pipes and a plurality of two-way joints, and every two adjacent straight pipes are connected through the two-way joints;

the elastic telescopic mechanism is arranged inside the straight pipe and the two-way joint in a penetrating manner;

one end of the elastic telescopic mechanism is fixedly connected with the straight pipe, and the other end of the elastic telescopic mechanism is fixedly connected with the two-way joint.

One of the above technical solutions has the following beneficial effects: in the stable folding chair, the supporting legs and the supporting arms are hinged through the supporting leg and the supporting arm linkage structure, and the supporting legs and the supporting arms can be folded and unfolded simultaneously only by pushing and pulling the supporting legs or the supporting arms, so that the folding, storage and unfolding functions are realized, and the operation is simple. Locking Assembly is in the supporting legs with after the support arm expandes, can effective chucking the outer wall of mobile jib avoids the user in the in-process of using the folding chair draws in suddenly, has improved bearing structure's after the folding chair expandes stability has improved user's use experience.

Drawings

FIG. 1 is a schematic view of a folding chair according to one embodiment of the present invention shown in a folded configuration;

FIG. 2 is a schematic view of the folding chair in an unfolded configuration in accordance with one embodiment of the present invention;

FIG. 3 is a schematic view of the locking assembly and the primary bar of the folding chair in an unfolded configuration in accordance with one embodiment of the present invention;

FIG. 4 is a schematic view of the locking assembly and the primary bar of the folding chair of one embodiment of the present invention;

FIG. 5 is a schematic view of a folded support arm according to an embodiment of the present invention;

FIG. 6 is a schematic view of the folding chair of another embodiment of the present invention shown folded;

FIG. 7 is a schematic view of a folding chair according to another embodiment of the utility model shown in an unfolded configuration;

wherein: 1 supporting a foot assembly; 11 supporting feet; 12 connecting a fixed block; 2 a cushion support assembly; 21 supporting the arm; 211 an elastic telescopic mechanism; 212 a straight pipe; 213 two-way joint; 22 connecting the sliding block; 3, locking the assembly; 31 fixing the plate; 32 a self-locking plate; 33 self-locking hole; 34 an elastic mechanism; 35 a limiting pin; 36 a mounting seat; 37 a first limiting hole; 38 a second limiting aperture; 39 a limit screw; 4, a main rod; 41 a limiting groove; 42 shim.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

A stable folding chair according to an embodiment of the present invention will be described with reference to fig. 1 to 7, which includes a supporting leg assembly 1, a cushion supporting assembly 2, a locking assembly 3 and a main bar 4;

the supporting leg assembly 1 is arranged at the upper end of the main rod 4, a supporting leg 11 of the supporting leg assembly 1 extends downwards, and the supporting leg 11 is used for supporting the folding chair;

the cushion support component 2 is arranged at the lower end of the main rod 4, and a support arm 21 of the cushion support component 2 extends upwards, and the support arm 21 is used for supporting a cushion;

the supporting legs 11 are hinged to the supporting arms 21, when the supporting leg assemblies 1 and/or the cushion supporting assemblies 2 move towards the middle of the main bar 4, the supporting leg assemblies 1 and the cushion supporting assemblies 2 approach each other, the supporting legs 11 are unfolded towards the direction far away from the main bar 4, and the supporting arms 21 are unfolded towards the direction far away from the main bar 4;

when the supporting leg assembly 1 and/or the cushion supporting assembly 2 move in a direction away from the middle of the main bar 4, the supporting leg assembly 1 and the cushion supporting assembly 2 are away from each other, the supporting leg 11 is folded in a direction close to the main bar 4, and the supporting arm 21 is folded in a direction close to the main bar 4;

locking assembly 3 cover is located the outer wall of mobile jib 4, locking assembly 3 with supporting legs component 1 fixed connection, perhaps locking assembly 3 with cushion supporting component 2 fixed connection works as supporting legs component 1 with cushion supporting component 2 expandes the back completely, locking assembly 3 chucking in the outer wall of mobile jib 4.

In the stable folding chair, the supporting legs 11 and the supporting arms 21 can be folded and unfolded simultaneously only by pushing and pulling the supporting legs 11 or the supporting arms 21 through the linkage structure of the supporting legs 11 and the supporting arms 21, so that the folding, storage and unfolding functions are realized, and the operation is simple. Locking Assembly 3 is in supporting legs 11 with after the support arm 21 expandes, can effective chucking the outer wall of mobile jib 4 avoids the user at the in-process that uses the folding chair draws in suddenly, has improved bearing structure's after the folding chair expandes stability has improved user's use experience.

The supporting foot 11 is hinged to the supporting arm 21 to form a hinge point. When the support leg assembly 1 and the seat cushion support assembly 2 approach each other, the end of the support leg 11 close to the main lever 4 maintains a constant distance from the hinge point, and the end of the support arm 21 close to the main lever 4 maintains a constant distance from the hinge point, and the hinge point moves in the opposite direction of the main lever 4 and moves away from the main lever 4, so that the support leg 11 and the support arm 21 are unfolded. When the support leg assembly 1 and the seat cushion support assembly 2 are far away from each other, one end of the support leg 11 close to the main rod 4 keeps unchanged for a distance with the hinge point, and one end of the support arm 21 close to the main rod 4 keeps unchanged for a distance with the hinge point, and the position of the hinge point is close to the main rod 4, so that the support leg 11 and the support arm 21 are folded.

Work as locking Assembly 3 with 2 fixed connection of cushion supporting component, cushion supporting component 2 with 4 swing joint of mobile jib, just supporting legs 1 with during 4 fixed connection of mobile jib, cushion supporting component 2 drives locking Assembly 3 is followed the expansion and the drawing in of folding chair just can be realized in the motion of mobile jib 4 the folding chair expandes the back completely, 3 chucking of locking Assembly the outer wall of mobile jib 4 to the restriction the activity of cushion supporting component 2 just can make folding chair keeps stable.

Work as supporting legs subassembly 1 with the equal fixedly connected with of cushion supporting component 2 locking component 3, just supporting legs subassembly 1 with cushion supporting component 2 all with during the 4 swing joint of mobile jib, supporting legs subassembly 1 with cushion supporting component 2 homoenergetic drives its locking component 3 edge that corresponds mobile jib 4 motion and realize folding chair's expansion and draw in folding chair expandes the back completely, the 3 chucking of locking component the outer wall of mobile jib 4, thereby the restriction the activity of cushion supporting component 2 just can make folding chair keeps stable.

Preferably, the supporting foot assembly 1 further comprises a connecting and fixing block 12, and the supporting foot 11 is hinged to the connecting and fixing block 12;

the connecting fixing block 12 is fixedly arranged at the upper end of the main rod 4;

the cushion supporting component 2 further comprises a connecting slide block 22, and the supporting arm 21 is hinged with the connecting slide block 22;

the connecting slide block 22 is movably sleeved at the lower end of the main rod 4, and the connecting slide block 22 is fixedly connected with the locking component 3.

In one embodiment, when the locking assembly 3 with supporting leg assembly 1 fixed connection, supporting leg assembly 1 with mobile jib 4 swing joint, just cushion supporting component 2 with during mobile jib 4 fixed connection, only need pass through supporting leg assembly 1's link block 22 drives locking assembly 3's fixed plate 31 is followed mobile jib 4 moves, supporting legs 11 just can for connect fixed block 12 to rotate, support arm 21 just can for link block 22 rotates, just can realize the expansion and draw in of folding chair. After the folding chair is completely unfolded, the main rod 4 is clamped by the locking assembly 3, so that the movement of the connecting slide block 22 is limited, and the folding chair can be kept stable. Connect fixed block 12 with the upper end fixed connection of mobile jib 4 can guarantee mobile jib 4 is in when the folding chair uses can not in connect the interior flexible of fixed block 12 to avoid contusion user.

It should be noted that, as shown in fig. 6 and 7, the locking assembly 3 includes an installation seat 36, a first limiting hole 37 and a limiting screw 39, the outer wall of the main rod 4 is provided with a second limiting hole 38, the installation seat 36 is movably sleeved on the outer wall of the main rod 4, the installation seat 36 is fixedly connected with the connecting slider 22, and the side wall of the installation seat 36 is provided with the first limiting hole 37;

when the supporting leg assembly 1 and the cushion supporting assembly 2 are completely unfolded, the first limiting hole 37 is aligned with the second limiting hole 38, and the limiting screw 39 passes through the first limiting hole 37 and the second limiting hole 38, and tightly clamps the mounting seat 36 to the main rod 4.

After the folding chair is completely unfolded, the mounting seat 36 is tightly clamped on the outer wall of the main rod 4 by the limit screw 39 through the first limit hole 37 and the second limit hole 38, so that the movement of the supporting leg assembly 1 and the cushion supporting assembly 2 is limited, and the folding chair can be kept stable.

Preferably, as shown in fig. 1 to 3, the locking assembly 3 includes a fixing plate 31 and a self-locking plate 32, the fixing plate 31 is movably sleeved on the outer wall of the main rod 4, the fixing plate 31 is fixedly connected to the connecting slider 22, the self-locking plate 32 is hinged to the fixing plate 31, and when the supporting leg assembly 1 and the cushion supporting assembly 2 are completely unfolded and the supporting leg assembly 1 and the cushion supporting assembly 2 are away from each other, the self-locking plate 32 is tightly clamped on the outer wall of the main rod 4.

After the folding chair is completely unfolded, the self-locking plate 32 clamps the outer wall of the main rod 4, so that the movement of the supporting leg assembly 1 and the cushion supporting assembly 2 is limited, and the folding chair can be kept stable.

The self-locking plate 32 is provided with a self-locking hole 33, the main rod 4 is arranged in the self-locking hole 33, and the area of the self-locking hole 33 is larger than the cross-sectional area of the main rod 4;

when supporting legs subassembly 1 with when cushion supporting component 2 kept away from each other, from the jam plate 32 around its self with articulated shaft between the fixed plate 31 toward the direction in the middle part of mobile jib 4 rotates, from the preceding inner wall of lockhole 33 with the preceding outer wall contact of mobile jib 4, from the back inner wall of lockhole 33 with the back outer wall contact of mobile jib 4.

As shown in fig. 3 and 4, when the supporting leg assembly 1 and the seat cushion supporting assembly 2 are far away from each other, the self-locking plate 32 corresponding to the locking assembly 3 fixedly connected to the supporting leg assembly 1 rotates downward around the hinge shaft, the self-locking plate 32 corresponding to the locking assembly 3 fixedly connected to the seat cushion supporting assembly 2 rotates upward around the hinge shaft, the area of the projection of the self-locking hole 33 on the cross section of the main rod 4 is reduced, and the self-locking plate 32 can be tightly clamped on the main rod 4 by the contact of the inner wall of the self-locking hole 33 and the outer wall of the main rod 4. Since the area of the self-locking hole 33 is larger than the cross-sectional area of the main rod 4, when the self-locking hole 33 is parallel to the cross-sectional area of the main rod 4, the supporting leg assembly 1 and/or the cushion supporting assembly 2 can move relative to the main rod 4.

It is worth to say that the hinge shaft between the self-locking plate 32 and the fixing plate 31 is provided with an elastic mechanism 34;

under the action of the elastic force of the elastic mechanism 34, the self-locking plate 32 has a tendency to rotate around the hinge axis toward the middle of the main lever 4.

When no external force is applied and the supporting leg assembly 1 and/or the cushion supporting assembly 2 do not tend to move away from each other, the self-locking plate 32 can clamp the main rod 4 through the elastic force of the elastic mechanism 34, so that the folding chair is more stable. When the folding chair needs to be folded, the self-locking plate 32 is pushed to move towards the direction far away from the middle part of the main rod 4 by external force overcoming the elastic force of the elastic mechanism 34 until the self-locking hole 33 is parallel to the cross section of the main rod 4, and the supporting leg assembly 1 and/or the cushion supporting assembly 2 can move along the main rod 4. The resilient means 34 is preferably a spring.

Optionally, the outer wall of the main rod 4 is provided with a limiting groove 41, and the limiting groove 41 is arranged along the length direction of the main rod 4;

the fixing plate 31 is provided with a limiting pin 35, and the limiting pin 35 penetrates through the fixing plate 31 and then is movably arranged in the limiting groove 41.

The limiting groove 41 has a function of limiting the moving length of the locking assembly 3 on the main rod 4, and the length of the limiting groove 41 is the moving length of the locking assembly 3. When the locking assembly 3 moves to the limit length, the limit pin 35 contacts with the edge of the limit groove 41, so as to limit the locking assembly 3 to move further to the current direction. The structure can avoid the situation that the supporting leg component 1 and/or the cushion supporting component 2 excessively move to separate from the main rod 4 when the folding chair is folded, and can also avoid the situation that the supporting leg component 1 and/or the cushion supporting component 2 excessively move to collide when the folding chair is unfolded.

Specifically, a gasket 42 is disposed between the outer wall of the main rod 4 and the inner wall of the self-locking hole 33.

The spacer 42 can increase the cross-sectional area of the position where the main lever 4 contacts the self-locking hole 33, thereby increasing the reaction speed of the self-locking plate 32 to clamp the main lever 4. In addition, the gasket 42 can prevent the self-locking plate 32 from scratching the outer wall of the main rod 4 when being clamped on the main rod 4.

It is worth to be noted that the supporting legs 11 are symmetrically arranged on the connecting fixing block 12 two by two, and the supporting arms 21 are symmetrically arranged on the connecting sliding block 22 two by two.

The structure can improve the stability of the folding chair in use, so that the folding chair can not shake in use.

Optionally, the lower end of the supporting foot 11 is provided with a non-slip mat.

The anti-slip mat has the anti-slip effect, improves the frictional force of supporting legs 11 and ground, and when using, the folding chair is difficult to skid.

Specifically, as shown in fig. 1, 2 and 5, the support arm 21 includes an elastic telescopic mechanism 211, a plurality of straight pipes 212 and a plurality of two-way joints 213, and every two adjacent straight pipes 212 are connected through the two-way joints 213;

the elastic telescopic mechanism 211 penetrates through the straight pipe 212 and the two-way joint 213;

one end of the elastic telescopic mechanism 211 is fixedly connected with the straight pipe 212, and the other end of the elastic telescopic mechanism 211 is fixedly connected with the two-way joint 213.

When the support arm is unfolded, the straight pipes 212 and the two-way plug 213 are pulled apart to extend the elastic telescopic mechanism 211, and then the straight pipes 212 are inserted into the two-way joint 213, so that two adjacent straight pipes 212 are connected through the two-way joint 213, and a linear support arm 21 is assembled.

After the straight tube 212 and the two-way joint 213 are separated, the supporting arm 21 is folded, and the length of the supporting arm 21 is shortened, which is beneficial to storage. The elastic expansion mechanism 211 is connected between the straight pipe 212 and the two-way joint 213, so that the two-way joint 213 or the straight pipe 212 is prevented from being lost during storage. The elastic stretching mechanism 211 is preferably one of an elastic band, a spring or an elastic band.

Other constructions and operation of a stabilized folding chair according to embodiments of the utility model are known to those skilled in the art and will not be described in detail herein.

In the description herein, references to the description of the terms "embodiment," "example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the utility model have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. A stable folding chair, characterized in that: comprises a supporting leg component, a cushion supporting component, a locking component and a main rod;

2. A stable folding chair as claimed in claim 1, characterized in that: the supporting leg assembly further comprises a connecting fixing block, and the supporting leg is hinged with the connecting fixing block;

3. A stable folding chair as claimed in claim 2, characterized in that: the locking assembly comprises an installation seat, a first limiting hole and a limiting screw rod, a second limiting hole is formed in the outer wall of the main rod, the installation seat is movably sleeved on the outer wall of the main rod and is fixedly connected with the connecting slide block, and the first limiting hole is formed in the side wall of the installation seat;

4. A stable folding chair as claimed in claim 2, characterized in that: the locking assembly comprises a fixed plate and a self-locking plate, the fixed plate is movably sleeved on the outer wall of the main rod, the fixed plate is fixedly connected with the connecting sliding block, the self-locking plate is hinged to the fixed plate, the supporting leg assembly and the cushion supporting assembly are completely unfolded, the supporting leg assembly and the cushion supporting assembly are clamped on the outer wall of the main rod when being far away from each other.

5. A stable folding chair as claimed in claim 4, characterized in that: the self-locking plate is provided with a self-locking hole, the main rod is arranged in the self-locking hole, and the area of the self-locking hole is larger than the cross-sectional area of the main rod;

6. A stable folding chair as claimed in claim 5, characterized in that: an elastic mechanism is arranged on a hinged shaft between the self-locking plate and the fixing plate;

7. A stable folding chair as claimed in claim 6, characterized in that: the outer wall of the main rod is provided with a limiting groove, and the limiting groove is arranged along the length direction of the main rod;

8. A stabilized folding chair as claimed in claim 7, wherein: and a gasket is arranged between the outer wall of the main rod and the inner wall of the self-locking hole.

9. A stable folding chair as claimed in claim 2, characterized in that: the supporting legs are symmetrically arranged on the connecting fixing block in pairs, and the supporting arms are symmetrically arranged on the connecting sliding block in pairs.

10. A stable folding chair as claimed in claim 1, characterized in that: the supporting arm comprises an elastic telescopic mechanism, a plurality of straight pipes and a plurality of two-way joints, and every two adjacent straight pipes are connected through the two-way joints;