Adjustable bedstead

Abstract

The utility model belongs to the technical field of sickbeds, and particularly relates to an adjustable bed frame which comprises a bottom frame, an adjustable back plate assembly and a driving mechanism, the adjustable back plate assembly comprises a mattress supporting piece and a movable connecting piece, one end of the movable connecting piece is connected with the mattress supporting piece, and the other end of the movable connecting piece is connected to the bottom frame in a sliding mode. The main body part of the driving mechanism is rotatably connected to the bottom frame, the output end of the driving mechanism is rotatably connected with the adjustable back plate assembly, and the output end of the driving mechanism stretches out and draws back to drive the mattress supporting piece to stand up and slide towards the bedside or return to the original position. The output end of the driving mechanism stretches out and draws back to drive the adjustable back plate assembly to move, so that the mattress supporting piece moves towards the bedside direction while rotating and standing up, and the trend that a human body extrudes towards the middle when the posture is changed is counteracted. The adjustable bedstead provided by the utility model can prevent the waist and abdomen of a user from being extruded in the lifting process.

Description

Technical Field

[0001] This utility model belongs to the field of hospital bed technology, specifically relating to an adjustable bed frame. Background Technology

[0002] Various types of hospital beds are available on the market, and bed frames typically feature an upper section that can be raised. However, existing bed frames often use a segmented bed board, with the lower edge of the upper bed board directly bolted to the bed frame. Raising the upper bed board serves as the user's backrest. When using this technology, the user experiences compression in the lower back and abdomen during the raising process, which is particularly unpleasant for some patients with spinal disorders. Utility Model Content

[0003] To solve the above-mentioned technical problems, it is necessary to provide an adjustable bed frame that can prevent the user's waist and abdomen from being squeezed during the lifting process.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] An adjustable bed frame includes a base frame, an adjustable backrest assembly, and a drive mechanism. The adjustable backrest assembly includes a mattress support and a movable connector. One end of the movable connector is connected to the mattress support, and the other end is slidably connected to the base frame. The main body of the drive mechanism is rotatably connected to the base frame, and its output end is rotatably connected to the adjustable backrest assembly. The output end of the drive mechanism extends and retracts to cause the mattress support to stand up and slide towards the head of the bed, or return to its original position.

[0006] The adjustable bed frame provided by this utility model features an adjustable backrest assembly whose structure alters the movement trajectory of the mattress support compared to existing technologies. During lifting, the mattress support does not rotate around the bolted connection point fixed to the bottom frame, but instead follows or drives the movable connecting parts. The output end of the drive mechanism is rotatably connected to any component of the adjustable backrest assembly, sufficient to move the mattress support. The extension and retraction of the drive mechanism's output end propels the adjustable backrest assembly, causing the mattress support to move towards the headboard while rotating and rising, thus counteracting the tendency of the body to be squeezed towards the center when changing posture. The adjustable bed frame provided by this utility model can prevent compression of the user's lower back and abdomen during lifting.

[0007] Preferably, the adjustable back panel assembly further includes a support rod with one end rotatably connected to the bottom frame and the other end rotatably connected to the movable connector. In this structure, one end of the movable connector can slide on the bottom frame, while the other end is connected to the support rod rotatably connected to the bottom frame. The support rod supports the mattress support when the mattress support is upright, making the structure more stable.

[0008] Preferably, the movable connector includes a left movable member and a right movable member, and the supporting link includes a left link and a right link. A left sliding groove is formed on the bottom frame corresponding to the left movable member, and a right sliding groove is formed corresponding to the right movable member. This structure features two sets of movable connectors and supporting links symmetrically arranged, resulting in greater structural stability.

[0009] Preferably, the mattress support includes a base rod, and the left and right movable parts each have a groove that matches the shape of the base rod. The base rod is a square tube and is connected within the groove. This structure prevents the mattress support from rotating relative to the movable parts through the fit between the groove and the square tube shape, resulting in a more stable connection between the movable parts and the mattress support.

[0010] Preferably, the mattress support includes a support frame, the support frame includes a bottom rod at the bottom, the bottom rod is connected to the movable connector, and the adjustable back panel assembly further includes an intermediate connecting assembly, the intermediate connecting assembly includes a fixed rod, a rod support, and a rotating connector sleeved on the fixed rod, the rod support is connected to the bottom rod, one end of the fixed rod is connected to the rod support, and the other end is connected to the movable connector, the output end of the drive mechanism is rotatably connected to the rotating connector. In the event that a user's hand may be accidentally trapped between the bottom frame and the adjustable back panel assembly during the lifting and lowering process, this structure adds an intermediate connecting assembly. Because the rotating connector provides room for movement, even if the drive mechanism loses power or malfunctions and cannot extend or retract, the trapped part can be quickly released by manually lifting the adjustable back panel assembly, increasing safety.

[0011] Preferably, the bottom frame includes a drive mechanism support, the main body of the drive mechanism is rotatably connected to the drive mechanism support, the output end faces the head of the bed, the output end extends to drive the mattress support to stand up, and the output end shortens to drive the mattress support to return to its original position.

[0012] Preferably, the base frame includes two longitudinal bars facing each other end-to-end and a crossbar straddling the two longitudinal bars. The drive mechanism support includes a base parallel to the two longitudinal bars, the root of which is connected to the crossbar. The drive mechanism support also includes a reinforcing bar connected to the base and at least one longitudinal bar, the reinforcing bar being supported on the side of the base. In this structure, the drive mechanism support is not easily deformed.

[0013] Preferably, the mattress support includes a support frame and a back panel supported by the support frame. The shape of the back panel matches the support frame, the back panel covers the support frame, and the edge of the back panel overlaps the edge of the support frame. In this structure, the back panel is detachably connected to the support frame, and the edge of the support frame is covered by the edge of the back panel, which is more aesthetically pleasing.

[0014] Preferably, the adjustable bed frame further includes a base frame support, and the base frame is vertically and height-adjustable connected to the base frame support. In this structure, the base frame can be raised and lowered relative to the base frame support. Since the components related to back panel adjustment are all connected to the base frame, the back panel adjustment function is not affected, and the adjustable bed frame also has an overall lifting function.

[0015] Preferably, the adjustable bed frame further includes a first lifting drive mechanism and a second lifting drive mechanism movably connected to the base frame, a first support leg assembly connected to the output end of the first lifting drive mechanism, and a second support leg assembly connected to the output end of the second lifting drive mechanism; the first support leg assembly includes a first support member supported between the base frame and the base frame support, the first support member being rotatably connected to the base frame support and sliding on the base frame to adjust the support angle; the second support leg assembly includes a second support member supported between the base frame and the base frame support, the second support member being rotatably connected to the base frame support and sliding on the base frame to adjust the support angle. The first support leg assembly further includes a first connecting member, one end of which is movably connected to the output end of the first lifting drive mechanism, and the other end of which is movably connected to the first support member. The second support leg assembly further includes a second connecting member, one end of which is movably connected to the output end of the second lifting drive mechanism, and the other end of which is movably connected to the second support member. One of the output ends of the first and second lifting drive mechanisms always faces the head of the bed, and the other always faces the foot of the bed. The output end of the first lifting drive mechanism extends and retracts to adjust the support angle of the first support member, and the output end of the second lifting drive mechanism extends and retracts to adjust the support angle of the second support member. This structure includes a first lifting drive mechanism and a second lifting drive mechanism. When the first and second lifting drive mechanisms move synchronously, they drive the first and second support leg assemblies to move synchronously, causing the bottom frame to rise or fall relative to the bottom frame support. The first and second connecting members provide movement space, allowing the two drive mechanisms to move independently rather than synchronously. When the first and second lifting drive mechanisms move asynchronously, the tilt angle of the bottom frame relative to the bottom frame support changes. Attached Figure Description

[0016] The above and other objects, features, and advantages of this invention will become clearer through a more detailed description of the preferred embodiments shown in the accompanying drawings. The same reference numerals indicate the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of this invention.

[0017] Figure 1 A schematic diagram of the overall structure of a preferred embodiment of an adjustable bed frame;

[0018] Figure 2 This is a schematic diagram of the bed frame in a preferred embodiment;

[0019] Figure 3 A bottom view of a preferred embodiment of the adjustable bed frame;

[0020] Figure 4 This is a schematic diagram of the adjustable backplate assembly (backplate not shown).

[0021] In the diagram: bottom frame 1, vertical bar 101, horizontal bar 102, left slide rail 111, right slide rail 112, drive mechanism support 12, base 121, reinforcing bar 122, adjustable back panel assembly 2, mattress support 21, support frame 211, bottom bar 2110, back panel 212, intermediate connecting assembly 22, fixed bar 221, bar support 222, rotating connector 223, left movable part 231, right movable part 232, left connecting rod 241, right connecting rod 242, drive mechanism 3, bottom frame support 4, first lifting drive mechanism 51, second lifting drive mechanism 52, first leg assembly 61, first support 611, first connector 612, second leg assembly 62, second support 621, second connector 622. Detailed Implementation

[0022] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be given below with reference to the accompanying drawings.

[0023] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to and integrated with the other element, or there may be an intervening element present. The terms "mounted," "one end," "the other end," and similar expressions used herein are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] refer to Figure 1 ,refer to Figure 1The present invention discloses an adjustable bed frame, comprising a base frame 1, an adjustable back panel assembly 2, and a drive mechanism 3. The adjustable back panel assembly 2 includes a mattress support 21 and a movable connector. One end of the movable connector is connected to the mattress support 21, and the other end is slidably connected to the base frame 1. The main body of the drive mechanism 3 is rotatably connected to the base frame 1, and the output end is rotatably connected to the adjustable back panel assembly 2. The output end of the drive mechanism 3 extends and retracts to cause the mattress support 21 to stand up and slide towards the head of the bed, or return to its original position.

[0026] In the adjustable bed frame provided by this utility model, the structure of the adjustable back panel assembly 2 makes the movement trajectory of the mattress support 21 different from that in the prior art. During the lifting process, the mattress support 21 does not rotate around the bolt point fixed on the bottom frame 1, but follows or drives the movement of the movable connecting parts. The output end of the drive mechanism 3 is rotatably connected to any component of the adjustable back panel assembly 2, which can drive the mattress support 21 to move. By extending and retracting the output end of the drive mechanism 3 to drive the adjustable back panel assembly 2 to move, the mattress support 21 moves towards the head of the bed while rotating and standing up, counteracting the tendency of the human body to be squeezed in the middle when changing posture. The adjustable bed frame provided by this utility model can avoid the user's waist and abdomen being squeezed during the lifting process.

[0027] In the preferred embodiment, the drive mechanism 3 is connected to the bottom surface of the base frame 1, with its output end facing the headboard. The extended output end pushes the mattress support 21 towards the headboard and causes it to stand upright. In other embodiments, the drive mechanism 3 can also be connected to the headboard end of the base frame 1, with its output end shortening to pull the mattress support 21 towards the headboard and cause it to stand upright. In the preferred embodiment, the base frame 1 has a groove that mates with the movable connector. One end of the movable connector is connected to the groove by a screw. In other embodiments, one end of the movable connector can be slidably connected to the base frame 1 in other ways, such as the cooperation of a slide rail and a slider. In the preferred embodiment, two movable connectors are symmetrically arranged. In other embodiments, only one movable connector located in the middle of the mattress support 21 can be used, or more movable connectors can be used.

[0028] In a preferred embodiment, the adjustable back panel assembly 2 further includes a support rod with one end rotatably connected to the bottom frame 1 and the other end rotatably connected to the movable connector. In this structure, one end of the movable connector can slide on the bottom frame 1, while the other end is connected to the support rod rotatably connected to the bottom frame 1. The support rod supports the mattress support 21 when it is upright, making the structure more stable.

[0029] In a preferred embodiment, the movable connector includes a left movable member 231 and a right movable member 232, and the supporting link includes a left link 241 and a right link 242. A left sliding groove 111 is formed on the bottom frame 1 corresponding to the left movable member 231, and a right sliding groove 112 is formed corresponding to the right movable member 232. This structure features two sets of movable connectors and supporting links symmetrically arranged, resulting in greater structural stability.

[0030] In a preferred embodiment, the mattress support 21 includes a base rod 2110. The left movable member 231 and the right movable member 232 each have a slot that matches the shape of the base rod 2110. The base rod 2110 is a square tube and is connected within the slot. This structure prevents the mattress support 21 from rotating relative to the movable members through the fit between the slots and the square tube shape, resulting in a more stable connection between the movable members and the mattress support 21.

[0031] In a preferred embodiment, the mattress support 21 includes a support frame 211, which includes a bottom rod 2110 located at the lowest point. The bottom rod 2110 is connected to the movable connector. The adjustable back panel assembly 2 further includes an intermediate connecting assembly 22, which includes a fixed rod 221, a rod support 222, and a rotating connector 223 sleeved on the fixed rod 221. The rod support 222 is connected to the bottom rod 2110. One end of the fixed rod 221 is connected to the rod support 222, and the other end is connected to the movable connector. The output end of the drive mechanism 3 is rotatably connected to the rotating connector 223. During the lifting and lowering process, the user's hand may be accidentally trapped between the bottom frame 1 and the adjustable back panel assembly 2. This structure adds an intermediate connecting assembly 22. Because the rotating connector 223 provides room for movement, even if the drive mechanism 3 loses power or malfunctions and cannot extend or retract, the trapped part can be quickly released by manually lifting the adjustable back panel assembly 2, increasing safety.

[0032] In a preferred embodiment, the bottom frame 1 includes a drive mechanism support 12, and the main body of the drive mechanism 3 is rotatably connected to the drive mechanism support 12. The output end faces the head of the bed, and when the output end extends, it drives the mattress support 21 to stand up. When the output end shortens, it drives the mattress support 21 to return to its original position.

[0033] In a preferred embodiment, the base frame 1 includes two longitudinal bars 101 facing each other end-to-end and a crossbar 102 spanning the two longitudinal bars 101. The drive mechanism support 12 includes a base 121 parallel to the two longitudinal bars 101, the root of which is connected to the crossbar 102. The drive mechanism support 12 also includes a reinforcing bar 122 connected to the base 121 and at least one longitudinal bar 101, the reinforcing bar 122 being supported on the side of the base 121. In this structure, the drive mechanism support 12 is not easily deformed.

[0034] In a preferred embodiment, the mattress support 21 includes a support frame 211 and a back panel 212 supported by the support frame 211. The shape of the back panel 212 matches the support frame 211, and the back panel 212 covers the support frame 211, with the edge of the back panel 212 covering the edge of the support frame 211. In this structure, the back panel 212 is detachably connected to the support frame 211, and the edge of the support frame 211 is covered by the edge of the back panel 212, resulting in a more aesthetically pleasing appearance.

[0035] In a preferred embodiment, the adjustable bed frame further includes a base frame support 4, and the base frame 1 is vertically and height-adjustably connected to the base frame support 4. In this structure, the base frame 1 can be raised and lowered relative to the base frame support 4. Since the components related to the adjustment of the back panel 212 are all connected to the base frame 1, the adjustment function of the back panel 212 is not affected, and the adjustable bed frame also has an overall lifting function.

[0036] In a preferred embodiment, the adjustable bed frame further includes a first lifting drive mechanism 51 and a second lifting drive mechanism 52 movably connected to the base frame 1, a first support leg assembly 61 connected to the output end of the first lifting drive mechanism 51, and a second support leg assembly 62 connected to the output end of the second lifting drive mechanism 52. The first support leg assembly 61 includes a first support member 611 supported between the base frame 1 and the base frame support 4, the first support member 611 being rotatably connected to the base frame support 4 and sliding on the base frame 1 to adjust the support angle. The second support leg assembly 62 includes a second support member 621 supported between the base frame 1 and the base frame support 4, the second support member 621 being rotatably connected to the base frame support 4 and sliding on the base frame 1. The support angle is adjusted accordingly. The first support leg assembly 61 further includes a first connecting member 612, one end of which is movably connected to the output end of the first lifting drive mechanism 51, and the other end of which is movably connected to the first support member 611. The second support leg assembly 62 further includes a second connecting member 622, one end of which is movably connected to the output end of the second lifting drive mechanism 52, and the other end of which is movably connected to the second support member 621. One of the output ends of the first lifting drive mechanism 51 and the second lifting drive mechanism 52 always faces the head of the bed, and the other always faces the foot of the bed. The output end of the first lifting drive mechanism 51 extends and retracts to drive the first support member 611 to adjust its support angle, and the output end of the second lifting drive mechanism 52 extends and retracts to drive the second support member 621 to adjust its support angle. In this structure, a first lifting drive mechanism 51 and a second lifting drive mechanism 52 are provided. When the first lifting drive mechanism 51 and the second lifting drive mechanism 52 move synchronously, they drive the first support leg assembly 61 and the second support leg assembly 62 to move synchronously, and the bottom frame 1 is raised or lowered as a whole relative to the bottom frame support 4. The first connector 612 and the second connector 622 provide movement space, allowing the two drive mechanisms to move independently rather than synchronously. When the first lifting drive mechanism 51 and the second lifting drive mechanism 52 move asynchronously, the tilt angle of the base frame 1 relative to the base frame support 4 changes.

[0037] In a preferred embodiment, the first support member 611 is bolted to the bottom frame support 4, and the bottom frame support 4 further includes a support slide rail. The second leg assembly includes a support slider that cooperates with the support slide rail. The second support member 621 is connected to the support slider and can slide along the support slide rail. In this structure, the end of the second support member 621 that is rotatably connected to the bottom frame support 4 can also slide, increasing the range of motion of the second support member 621. The distance between the first support member 611 and the second support member 621 connected to one end of the bottom frame support 4 can be shortened under the drive of the first lifting drive mechanism 51 and the second lifting drive mechanism 52. That is, the maximum upright angle of the first support member 611 and the second support member 621 increases, and the maximum height of the bottom frame 1 relative to the bottom frame support 4 increases. This structure can not only raise the bottom frame 1 to a higher height, but also, because it slides along the support rail, the movement process is smooth and gentle. Furthermore, the displacement of the bottom frame 1 in the horizontal direction can be controlled by the setting position of the support rail. For example, the support track is set near the head of the bed, and the first support member 611 is bolted near the foot of the bed. Since the bolting point of the first support member 611 is fixed, the bottom frame 1 will be naturally pulled towards the foot of the bed during the lifting process. However, nursing beds using other overall lifting schemes in the prior art may move towards the head of the bed when raised. The head of the bed is often set against the wall, which can easily cause damage to the wall. If space is reserved for movement in the direction of the head of the bed, it will affect the layout of the ward.

[0038] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0040] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An adjustable bed frame, characterized in that: The device includes a base frame (1), an adjustable back panel assembly (2), and a drive mechanism (3). The adjustable back panel assembly (2) includes a mattress support (21) and a movable connector. One end of the movable connector is connected to the mattress support (21), and the other end is slidably connected to the base frame (1). The main body of the drive mechanism (3) is rotatably connected to the base frame (1), and the output end is rotatably connected to the adjustable back panel assembly (2). The output end of the drive mechanism (3) extends and retracts to make the mattress support (21) stand up and slide towards the head of the bed, or return to its original position.

2. An adjustable bed frame according to claim 1, characterized in that: The adjustable back panel assembly (2) also includes a support rod with one end rotatably connected to the bottom frame (1) and the other end rotatably connected to the movable connector.

3. An adjustable bed frame according to claim 2, characterized in that: The movable connector includes a left movable part (231) and a right movable part (232), the support link includes a left link (241) and a right link (242), the bottom frame (1) has a left sliding groove (111) corresponding to the left movable part (231) and a right sliding groove (112) corresponding to the right movable part (232).

4. An adjustable bed frame according to claim 3, characterized in that: The mattress support (21) includes a base rod (2110). The left movable part (231) and the right movable part (232) are respectively provided with a slot that matches the shape of the base rod (2110). The base rod (2110) is a square tube and is connected in the slot.

5. An adjustable bed frame according to any one of claims 1-4, characterized in that: The mattress support (21) includes a support frame (211), the support frame (211) includes a bottom rod (2110) located at the bottom, the bottom rod (2110) is connected to the movable connector, the adjustable back panel assembly (2) also includes an intermediate connecting assembly (22), the intermediate connecting assembly (22) includes a fixed rod (221), a rod support (222) and a rotating connector (223) sleeved on the fixed rod (221), the rod support (222) is connected to the bottom rod (2110), one end of the fixed rod (221) is connected to the rod support (222), and the other end is connected to the movable connector, the output end of the drive mechanism (3) is rotatably connected to the rotating connector (223).

6. An adjustable bed frame according to claim 5, characterized in that: The bottom frame (1) includes a drive mechanism support (12). The main body of the drive mechanism (3) is rotatably connected to the drive mechanism support (12). The output end faces the head of the bed. When the output end extends, it drives the mattress support (21) to stand up. When the output end shortens, it drives the mattress support (21) to return to its original position.

7. An adjustable bed frame according to claim 6, characterized in that: The base frame (1) includes two longitudinal bars (101) facing each other and a crossbar (102) spanning the two longitudinal bars (101). The drive mechanism support (12) includes a base (121) parallel to the two longitudinal bars (101). The root of the base (121) is connected to the crossbar (102). The drive mechanism support (12) also includes a reinforcing bar (122) connected to the base (121) and at least one longitudinal bar (101). The reinforcing bar (122) is supported on the side of the base (121).

8. An adjustable bed frame according to any one of claims 1-4, characterized in that: The mattress support (21) includes a support frame (211) and a back panel (212) supported by the support frame (211). The shape of the back panel (212) matches the support frame (211), the back panel (212) covers the support frame (211), and the edge of the back panel (212) covers the edge of the support frame (211).

9. An adjustable bed frame according to any one of claims 1-4, characterized in that: The adjustable bed frame also includes a bottom frame support (4), and the bottom frame (1) is vertically and vertically connected to the bottom frame support (4).

10. An adjustable bed frame according to claim 9, characterized in that: The adjustable bed frame also includes a first lifting drive mechanism (51) and a second lifting drive mechanism (52) movably connected to the base frame (1), a first leg assembly (61) connected to the output end of the first lifting drive mechanism (51), and a second leg assembly (62) connected to the output end of the second lifting drive mechanism (52); the first leg assembly (61) includes a first support member (611) supported between the base frame (1) and the base frame support (4), the first support member (611) being rotatably connected to the base frame support (4) and being able to slide on the base frame (1) to adjust the support angle, the second leg assembly (62) including... The first leg assembly (61) includes a second support member (621) supported between the bottom frame (1) and the bottom frame support (4). The second support member (621) is rotatably connected to the bottom frame support (4) and can slide on the bottom frame (1) to adjust the support angle. The first leg assembly (61) also includes a first connector (612) whose one end is movably connected to the output end of the first lifting drive mechanism (51) and the other end is movably connected to the first support member (611). The second leg assembly (62) also includes a second connector (622) whose one end is movably connected to the output end of the second lifting drive mechanism (52) and the other end is movably connected to the second support member (621). Of the output ends of the first lifting drive mechanism (51) and the second lifting drive mechanism (52), one always faces the head of the bed and the other always faces the foot of the bed; the output end of the first lifting drive mechanism (51) extends and retracts to drive the first support member (611) to adjust the support angle, and the output end of the second lifting drive mechanism (52) extends and retracts to drive the second support member (621) to adjust the support angle.

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