H-shaped double-split electric lifting bed

Abstract

An H-shaped double-split electric lifting bed comprises a middle frame, the middle frame comprises a connecting frame and two fixing frames arranged at the left end and the right end of the connecting frame respectively, and each fixing frame is correspondingly matched with a bed head unit and a bed tail unit; wherein each bedside unit comprises a bedside frame and a bedside electric push rod for driving the bedside frame to act, and each bedside frame can be independently driven by one bedside electric push rod to act relative to the middle frame; each bed tail unit comprises a bed tail frame, a linkage frame and a bed tail electric push rod for driving the bed tail frame and the linkage frame to move, each bed tail electric push rod can independently control the bed tail frame and the linkage frame to move relative to the fixing frame, and independent adjustment of leg and back postures of different users is achieved through the structure; therefore, the adjusting requirements of two persons on different use postures are met.

Description

Technical Field

[0001] This utility model relates to the field of electric bed technology, specifically to an H-type double-split electric lifting bed. Background Technology

[0002] The electric bed uses electric control to move the folding mechanism, changing the user's position on the bed to meet the user's needs in different scenarios.

[0003] Referring to the technical solutions in announcement numbers CN221599614U and CN222707896U, existing electric beds typically use a mattress cover to fix the mattress to the outside of the electric bed frame to prevent the mattress from shifting after movement. However, this type of electric bed has certain inconveniences when used as a double bed. For example, the adjustment method of the electric bed is usually to adjust the head or foot of the bed as a whole. The electric bed cannot adjust the head or foot of the bed for each person individually. This adjustment method means that when one person adjusts the head or foot of the bed to tilt or flatten, the other person feels very uncomfortable. Therefore, the electric bed cannot meet the different body positions of two people on the electric bed. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, this utility model provides an H-type double split electric lifting bed.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] An H-type double-split electric lifting bed includes a middle frame, characterized in that: the middle frame includes a connecting frame and two fixed frames respectively disposed at the left and right ends of the connecting frame, each fixed frame corresponding to a headboard unit and a footboard unit;

[0007] Each headboard unit includes a headboard frame and a headboard electric actuator that drives the headboard frame. The front end of the headboard frame is hinged to the rear end of the fixed frame, and the two ends of the headboard electric actuator are respectively hinged to the headboard drive seat on the fixed frame and the headboard follower seat on the headboard frame.

[0008] Each footboard unit includes a footboard frame, a linkage frame, and a footboard electric push rod that drives the footboard frame and linkage frame. The front and rear ends of the linkage frame are respectively hinged to the front end of the fixed frame and the rear end of the footboard frame. The two ends of the footboard electric push rod are respectively hinged to the footboard drive seat on the fixed frame and the footboard follower seat on the linkage frame.

[0009] In this invention, each of the fixing frames is provided with a bottom balance bar at the bottom.

[0010] In this utility model, the bed end frame includes a bed end upper frame, a bed end front bracket, and two bed end side brackets. The bed end front bracket is fixedly installed at the bottom front end of the bed end upper frame. The two bed end side brackets are respectively located at the bottom of the left and right ends of the bed end upper frame, and the upper ends of the bed end side brackets are fixedly connected to the bed end upper frame.

[0011] In this utility model, the linkage frame includes an upper linkage and a lower linkage. The rear end of the upper frame at the foot of the bed is fixed with an upper foot hinge seat, which is hinged to the hinge part at the front end of the upper linkage via a first shaft assembly. The fixed frame includes an intermediate top frame, the front end of which is fixed with a first upper hinge seat, which is hinged to the hinge part at the rear end of the upper linkage via a second shaft assembly. The front and rear ends of the lower linkage are respectively hinged to the lower rear end of the foot frame and the lower front end of the fixed frame.

[0012] In this utility model, each headboard includes a headboard frame, a headboard rear support, and two headboard side supports. The upper front part of the headboard frame is hinged to the upper rear part of the fixed frame. The headboard rear support is fixedly installed at the bottom rear end of the headboard frame. The two headboard side supports are located at the left and right ends of the bottom of the headboard frame, respectively. The upper ends of the headboard side supports are fixedly connected to the headboard frame.

[0013] In this utility model, the U-shaped frame is fixed to the bottom of the headboard, and the tops of the two side guard rods of the U-shaped frame are fixedly connected to the bottom of the headboard. The headboard electric push rod is used to connect one end of the headboard follower seat and the bottom of the headboard follower seat, both of which are higher than the bottom of the bottom guard rod of the U-shaped frame.

[0014] In this utility model, the fixing frame includes a middle top frame and two middle side supports. The two middle side supports are respectively located on the bottom of the left and right ends of the middle top frame. The top of the middle side supports is fixedly connected to the top of the middle top frame. The bottom of the middle top frame is fixedly provided with a footboard drive seat and two headboard drive seats. The bottom of the footboard drive seat and the headboard drive seats are both higher than the bottom of the middle side supports.

[0015] In this utility model, the connecting frame consists of four connecting rods arranged in a quadrilateral shape, and the two ends of the connecting rods are respectively fixedly connected to one middle side bracket of the two fixed frames.

[0016] The beneficial effects of this utility model are as follows: The intermediate frame of this utility model includes a connecting frame and two fixed frames respectively located at the left and right ends of the connecting frame. Each fixed frame corresponds to a headboard unit and a footboard unit. Each headboard unit includes a headboard frame and a headboard electric push rod that drives the headboard frame. Each headboard frame can be driven independently by a headboard electric push rod to move relative to the intermediate frame. Each footboard unit includes a footboard frame, a linkage frame, and a footboard electric push rod that drives the footboard frame and linkage frame. Each footboard electric push rod can independently control the footboard frame and linkage frame to move relative to the fixed frame. Through the above structure, independent adjustment of the leg and back postures of different users is achieved, thereby meeting the adjustment needs of two people with different usage postures. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] Figure 1 For electric bed frames in a flat position, three-dimensional Figure 1 ;

[0019] Figure 2 For electric bed frames in a flat position, three-dimensional Figure 2 ;

[0020] Figure 3 The right view shows the electric bed frame in a laid-out position;

[0021] Figure 4 The three-dimensional bed with the foot and head units in their unfolded state. Figure 1 ;

[0022] Figure 5 The three-dimensional bed with the foot and head units in their unfolded state. Figure 2 . Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0024] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0025] Furthermore, unless otherwise explicitly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection using welding, a detachable connection using bolts, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0027] Reference Figure 1-5 An H-type double-split electric lifting bed includes a middle frame 1. The middle frame 1 includes a connecting frame 11 and two fixed frames 12 respectively located at the left and right ends of the connecting frame 11. Each fixed frame 12 is corresponding to a head unit 2 and a foot unit 3.

[0028] Furthermore, each headboard unit 2 includes a headboard frame 21 and a headboard electric actuator 22 that drives the headboard frame 21. The front end of the headboard frame 21 is hinged to the rear end of the fixed frame 12. The two ends of the headboard electric actuator 22 are respectively hinged to the headboard drive seat 13 on the fixed frame 12 and the headboard follower seat 23 on the headboard frame 21, so that each headboard frame 21 can be driven individually by a headboard electric actuator 22 to move relative to the fixed frame 12, thereby supporting the user's back and head to tilt and lift. In addition, the headboard 21 is provided with a U-shaped frame 24, and the headboard follower seat 23 passes through the encirclement of the U-shaped frame 24. The headboard electric push rod 22 is used to connect one end of the headboard follower seat 23 and the bottom of the headboard follower seat 23 are both higher than the bottom of the U-shaped frame 24. The U-shaped frame 24 can prevent the headboard follower seat 23 and the end of the headboard electric push rod 22 used to connect the headboard follower seat 23 from interfering with the mattress cover when the headboard electric push rod 22 controls the movement of the headboard 21, thereby avoiding damage to the mattress cover.

[0029] Furthermore, each footboard unit 3 includes a footboard frame 31, a linkage frame 32, and a footboard electric push rod 33 that drives the footboard frame 31 and the linkage frame 32. The front and rear ends of the linkage frame 32 are respectively hinged to the front end of the fixed frame 12 and the rear end of the footboard frame 31. The two ends of the footboard electric push rod 33 are respectively hinged to the footboard drive seat 14 on the fixed frame 12 and the footboard follower seat 34 on the linkage frame 32. Each footboard electric push rod 33 can independently control the movement of the footboard frame 31 and the linkage frame 32 relative to the fixed frame 12 to adjust the user's leg posture.

[0030] In a preferred embodiment, each of the fixed frames 12 is provided with a bottom balance bar 4 at its bottom. The middle side bracket 122 of the fixed frame 12 is connected to the bottom balance bar 4 by bolts. The bottoms of the middle frame 1, the footboard unit 3, and the headboard unit 2 are all lower than the bottom of the bottom balance bar 4. The bottom balance bar 4 is used to provide support for the middle frame 1, the footboard unit 3, and the headboard unit 2. Furthermore, the front end of the bottom balance bar 4 extends to the footboard unit 3, so that the bottom balance bar 4 can support the footboard unit 3 when it is in a flat position; the rear end of the bottom balance bar 4 extends to the headboard unit 2, so that the bottom balance bar 4 can support the headboard unit 2 when it is in a flat position. Furthermore, the bottom balance bar 4 is provided with at least two bottom connection holes 41. When the electric bed is placed directly on the user's original bed frame, connecting bolts can be passed through the bottom connection holes 41 to connect it to the user's original bed frame.

[0031] In a preferred embodiment, the bed end frame 31 includes an upper bed end frame 311, a front bed end support 312, and two side bed end supports 313. The front bed end support 312 is fixedly installed at the bottom front end of the upper bed end frame 311, and the bottom of the front bed end support 312 is higher than the bottom of the bottom balance bar 4, so as to prevent the front bed end support 312 from pressing on the ground after the bed end frame 31 is reset to the flat position. The two side bed end supports 313 are respectively located at the bottom of the left and right ends of the upper bed end frame 311. The upper end of the side bed end support 313 is fixedly connected to the upper bed end frame 311, and the bottom end of the side bed end support 313 is higher than or flush with the top of the bottom balance bar 4. The front end of the side bed end support 313 is fixedly connected to the front bed end support 312. The front end of the bottom balance bar 4 extends to the bottom of the side bed end support 313. When the bed end unit 3 is in the flat position, the side bed end support 313 presses on the top of the bottom balance bar 4, so that the bottom balance bar 4 supports the bed end unit 3.

[0032] In this embodiment, the upper frame 311 at the foot of the bed is provided with a footrest reinforcement frame 314. The footrest reinforcement frame 314 is H-shaped and is fixed to the upper frame 311 at the foot of the bed by welding, so that the footrest reinforcement frame 314 can enhance the structural stability of the upper frame 311 at the foot of the bed. At the same time, the top of the footrest reinforcement frame 314 is flush with or nearly flush with the top of the upper frame 311 at the foot of the bed, so that the top of the footrest reinforcement frame 314 can support the mattress cover.

[0033] In a preferred embodiment, the linkage frame 32 includes an upper linkage frame 321 and two lower linkage rods 322 distributed laterally. The front and rear ends of the lower linkage rods 322 are respectively hinged to the lower rear end of the bed end frame 31 and the lower front end of the fixing frame 12. Furthermore, when the bed end unit 3 is in a flat position, the lower linkage rods 322 press against the top of the bottom balance bar 4, thereby allowing the bottom balance bar 4 to support the bed end unit 3.

[0034] In this embodiment, an upper footrest hinge seat 315 is fixed to the rear end of the upper frame 311 at the foot of the bed. The hinge portion at the front end of the upper connecting frame 321 is inserted into the footrest hinge slot of the upper footrest hinge seat 315. The upper footrest hinge seat 315 is hinged to the hinge portion at the front end of the upper connecting frame 321 via a first shaft assembly. A lower footrest hinge seat 316 is fixed to the rear end of the side support 313 at the foot of the bed. The front end of the lower connecting rod 322 is inserted into the footrest hinge slot of the lower footrest hinge seat 316. The lower footrest hinge seat 316 is hinged to the front end of the lower connecting rod 322 via a first shaft assembly. The first shaft assembly consists of bolts and nuts.

[0035] In a preferred embodiment, each headboard 21 includes a headboard top 211, a headboard rear support 212, and two headboard side supports 213. The upper front end of the headboard top 211 is hinged to the upper rear end of the fixing frame 12. The headboard rear support 212 is fixedly mounted at the bottom rear end of the headboard top 211. The two headboard side supports 213 are located at the left and right ends of the bottom of the headboard top 211, respectively. The upper end of the headboard side support 213 is fixedly connected to the headboard top 211, and the bottom end of the lower end is higher than the bottom of the headboard rear support 212. The rear end of the headboard side support 213 is fixedly connected to the headboard rear support 212. The bottom balance bar 4 extends to the bottom of one of the outer headboard side supports 213. When the headboard unit 2 is in a flat position, the outer headboard side support 213 presses on the top of the bottom balance bar 4, thereby allowing the bottom balance bar 4 to support the headboard unit 2.

[0036] In this embodiment, the headrest 23 and the U-shaped frame 24 are both welded and fixed to the bottom of the headrest 211. The tops of the two side guards of the U-shaped frame 24 are fixedly connected to the bottom of the headrest 211. The headrest electric push rod 22 is used to connect one end of the headrest 23 and the bottom of the headrest 23 is higher than the bottom of the bottom guard of the U-shaped frame 24.

[0037] In a preferred embodiment, the fixing frame 12 includes a central top frame 121 and two central side supports 122. The two central side supports 122 are located at the bottom of the left and right ends of the central top frame 121, respectively. The top of the central side supports 122 is fixedly connected to the top of the central top frame 121. A footboard drive seat 14 and two headboard drive seats 13 are fixedly mounted at the bottom of the central top frame 121. The bottom of the footboard drive seat 14 and the headboard drive seats 13 are both higher than the bottom of the central side supports 122. The connecting frame 11 consists of four connecting rods 111 arranged in a quadrilateral shape. The two ends of the connecting rods 111 are fixedly connected to one of the central side supports 122 of the two fixing frames 12, thereby realizing the combined connection between the connecting frame 11 and the two fixing frames 12.

[0038] In this embodiment, a first upper hinge seat 123 and a second upper hinge seat 124 are fixed to the front and rear ends of the intermediate top frame 121, respectively. The hinge portion at the rear end of the upper connecting frame 321 is inserted into the hinge slot of the first upper hinge seat 123, and the first upper hinge seat 123 is hinged to the hinge portion at the rear end of the upper connecting frame 321 via a second shaft assembly. The hinge portion of the headboard 211 is inserted into the hinge slot of the second upper hinge seat 124, and the second upper hinge seat 124 is hinged to the hinge portion of the headboard 211 via a second shaft assembly. Further, an intermediate hinge seat is provided at the front end of the intermediate side support 122, and the rear end of the lower connecting rod 322 is inserted into the hinge slot of the intermediate hinge seat and hinged to the intermediate hinge seat via a second shaft assembly. The second shaft assembly consists of bolts and nuts.

[0039] In this embodiment, both the foot-of-bed follower seat 34 and the head-of-bed follower seat 23 are made of bent metal plates. Each of the foot-of-bed follower seat 34 and the head-of-bed follower seat 23 includes two follower bodies 10 spaced apart on the left and right sides, and multiple follower connecting blocks 20 integrally formed and connected to the two follower bodies 10. Each follower body 10 is provided with a follower slot 101. The square tube of the upper frame 321 is embedded into the follower slot 101 of the foot-of-bed follower seat 34 and is fixedly connected to the follower body 10 of the foot-of-bed follower seat 34 by welding. This achieves the positioning of the upper frame 321 and the foot-of-bed follower seat 34, and also facilitates the extension of the upper frame. The weld between the connecting frame 321 and the footrest follower seat 34 makes their welding and fixation more secure, ensuring the combined stability of the footrest follower seat 34 and the upper connecting frame 321. A portion of the headrest 211 is embedded in the follower slot 101 of the headrest follower seat 23 and fixedly connected to the follower body 10 of the headrest follower seat 23 by welding. This achieves positioning of the headrest 211 and the headrest follower seat 23, and also facilitates extending the weld between them, making their welding and fixation more secure and ensuring the combined stability of the headrest follower seat 23 and the headrest 211. In addition, the follower body 10 is provided with a follower lightweight hole 102 to reduce weight.

[0040] Furthermore, a follower hinge groove 101 is formed between the two follower bodies 10. The piston rod head of the foot-of-the-bed electric push rod 33 extends into the follower hinge groove 101 of the foot-of-the-bed follower seat 34 and is hinged together with the two follower bodies 10 of the foot-of-the-bed follower seat 34 using a first hinge shaft assembly, thereby achieving the hinge between the foot-of-the-bed electric push rod 33 and the foot-of-the-bed follower seat 34. The piston rod head of the head-of-the-bed electric push rod 22 extends into the follower hinge groove 101 of the head-of-the-bed follower seat 23 and is hinged together with the two follower bodies 10 of the head-of-the-bed follower seat 23 using a second hinge shaft assembly, thereby achieving the hinge between the head-of-the-bed electric push rod 22 and the head-of-the-bed follower seat 23. Both the first hinge shaft assembly and the second hinge shaft assembly include a hinge pivot, which is not shown in the accompanying drawings.

[0041] In this embodiment, both the footboard drive seat 14 and the headboard drive seat 13 are made of bent metal plates. Both the footboard drive seat 14 and the headboard drive seat 13 include two drive bodies 30 spaced apart on the left and right, and a drive connecting block 40 integrally formed and connected to the two drive bodies 30. The drive body 30 is provided with a drive slot 301. The square tube of the intermediate top frame 121 is embedded in the drive slot 301 of the footboard drive seat 14 and is fixedly connected to the drive body 30 of the footboard drive seat 14 by welding. This realizes the positioning between the intermediate top frame 121 and the drive body 30, and also facilitates the extension of the weld between the intermediate top frame 121 and the drive body 30, so that the footboard drive seat 14 and the headboard drive seat 13 are more firmly welded to the intermediate top frame 121, ensuring the combination stability of the footboard drive seat 14 and the headboard drive seat 13 with the intermediate top frame 121.

[0042] Furthermore, a drive hinge groove 301 is formed between the two drive bodies 30. The cylinder head of the footrest electric push rod 33 extends into the drive hinge groove 301 of the footrest drive seat 14 and is hinged to the two drive bodies 30 of the footrest drive seat 14 using a third hinge shaft assembly, thereby achieving the hinge between the footrest electric push rod 33 and the footrest drive seat 14. The cylinder head of the headrest electric push rod 22 extends into the drive hinge groove 301 of the headrest drive seat 13 and is hinged to the two drive bodies 30 of the headrest drive seat 13 using a fourth hinge shaft assembly, thereby achieving the hinge between the headrest electric push rod 22 and the headrest drive seat 13. Both the third hinge shaft assembly and the fourth hinge shaft assembly include hinge shafts, which are not shown in the accompanying drawings.

[0043] The above description is only a preferred embodiment of the present utility model. Any technical solution that achieves the purpose of the present utility model by essentially the same means shall fall within the protection scope of the present utility model.

Claims

1. A H-shaped two-part electric lift bed comprising a middle frame (1), characterized in that: The intermediate frame (1) comprises a connecting frame (11) and two fixed frames (12) respectively arranged at left and right ends of the connecting frame (11), each fixed frame (12) is correspondingly matched with a head unit (2) and a tail unit (3); Each head unit (2) comprises a head frame (21) and a head electric push rod (22) for driving the head frame (21) to move, the front end of the head frame (21) is hingedly connected to the rear end of the fixed frame (12), and the two ends of the head electric push rod (22) are respectively hingedly connected to a head driving seat (13) on the fixed frame (12) and a head following seat (23) on the head frame (21). Each tail unit (3) comprises a tail frame (31), a linkage frame (32) and a tail electric push rod (33) for driving the tail frame (31) and the linkage frame (32) to move, the front and rear ends of the linkage frame (32) are respectively hingedly connected to the front end of the fixed frame (12) and the rear end of the tail frame (31), and the two ends of the tail electric push rod (33) are respectively hingedly connected to a tail driving seat (14) on the fixed frame (12) and a tail following seat (34) on the linkage frame (32).

2. The H-shaped dual split electric lift bed of claim 1, wherein: The bottom of each fixed frame (12) is provided with a bottom balance bar (4).

3. The H-shaped dual split-segment electric lift bed of claim 1, wherein: The tail frame (31) comprises a tail upper frame (311), a tail front support (312) and two tail side supports (313), the tail front support (312) is fixedly arranged at the front end bottom of the tail upper frame (311), and the two tail side supports (313) are respectively arranged at the bottoms of left and right ends of the tail upper frame (311) and are fixedly connected to the tail upper frame (311) at the upper ends.

4. A H-shaped dual split electric lift bed as defined in claim 3, wherein: The linkage frame (32) comprises an upper linkage frame (321) and a lower linkage rod (322), the rear end of the tail upper frame (311) is fixedly provided with an upper tail hinged seat (315), the upper tail hinged seat (315) is hingedly connected to a hinged part at the front end of the upper linkage frame (321) through a first shaft assembly, the fixed frame (12) comprises a middle top frame (121), the front end of the middle top frame (121) is fixedly provided with a first upper hinged seat (123), the first upper hinged seat (123) is hingedly connected to a hinged part at the rear end of the upper linkage frame (321) through a second shaft assembly, and the front and rear ends of the lower linkage rod (322) are respectively hingedly connected to the rear end lower part of the tail frame (31) and the front end lower part of the fixed frame (12).

5. The H-shaped dual split-segment electric lift bed of claim 1, wherein: Each head frame (21) comprises a head upper frame (211), a head rear support (212) and two head side supports (213), the front end upper part of the head upper frame (211) is hingedly connected to the rear end upper part of the fixed frame (12), the head rear support (212) is fixedly arranged at the rear end bottom of the head upper frame (211), the two head side supports (213) are respectively arranged at the left and right ends of the bottom of the head upper frame (211), and the upper ends of the head side supports (213) are fixedly connected to the head upper frame (211).

6. A H-shaped dual-section electric lift bed as defined in claim 4, wherein: The U-shaped frame (24) is fixed on the bottom of the head frame (211), the two side guard rods of the U-shaped frame (24) are fixedly connected with the bottom of the head frame (211), and the head electric push rod (22) is used for connecting one end of the head follow-up seat (23) and the bottom of the head follow-up seat (23), which are higher than the bottom of the bottom guard rod of the U-shaped frame (24).

7. The H-shaped dual split-segment electric lift bed of claim 1, wherein: The fixed frame (12) comprises a middle top frame (121) and two middle side supports (122), the two middle side supports (122) are respectively arranged on the bottoms of the left and right ends of the middle top frame (121), the top of the middle side support (122) is fixedly connected with the top of the middle top frame (121), and the bottom of the middle top frame (121) is fixedly provided with a tail driving seat (14) and two head driving seats (13), and the bottom of the tail driving seat (14) and the head driving seat (13) is higher than the bottom of the middle side support (122).

8. A H-shaped dual-section electric lift bed as defined in claim 7, wherein: The connecting frame (11) is composed of four connecting rods (111) which are distributed in a quadrilateral shape, and the two ends of the connecting rod (111) are fixedly connected with one middle side support (122) of the two fixed frames (12) respectively.

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