CN111195179B

CN111195179B - Height-adjustable bed and operation method thereof

Info

Publication number: CN111195179B
Application number: CN201811383917.9A
Authority: CN
Inventors: 卡洛斯·白林格罗斯
Original assignee: Jiaxing Sainuo Machinery Co ltd; Sino International Group Ltd
Current assignee: Tiankang Technology Co ltd; Sino International Group Ltd
Priority date: 2018-11-20
Filing date: 2018-11-20
Publication date: 2022-11-25
Anticipated expiration: 2038-11-20
Also published as: CN111195179A

Abstract

The application provides a height-adjustable's bed includes: a platform; a set of casters mounted below the platform; and a lifting system. The lift system is mounted below the platform for adjusting the height of the platform relative to the ground, the lift system being operable between a first condition and a second condition. In the first state, the set of casters is raised off the ground and the hoist system is standing on the ground to support the platform such that movement of the height-adjustable bed relative to the ground is prevented; in the second state, the set of casters contacts the ground to support the platform, and the lift system is raised off the ground such that movement of the height-adjustable bed relative to the ground is permitted.

Description

Height-adjustable bed and operation method thereof

Technical Field

The present application relates to height adjustable beds, and more particularly to a braking mechanism and a braking method for a height adjustable bed.

Background

Mobile beds are common in the medical field, such as hospital or care beds. It is desirable to facilitate moving the bed to another location or removing the bed to facilitate cleaning of the underside of the bed. Generally, a movable bed is movable because it contacts the ground through casters (wheels that can rotate about an axis).

A key requirement is that a braking system be provided which will maintain the bed in a fixed position if the bed is not intended to be moved. Typically, such braking systems are achieved by adding a mechanism to the caster for locking the caster. Such systems are commonly referred to as "braking devices". Various braking devices are known, such as pedals, which press against the wheel when pressed, preventing the wheel from rotating by friction between the wheel and the pedal.

Disclosure of Invention

The present invention provides a height adjustable bed with a novel brake arrangement.

The invention also provides a method of operating a height adjustable bed to lock or unlock the bed.

In one aspect, the present application provides a height adjustable bed comprising: a platform; a set of casters mounted below the platform; and a lifting system mounted below the platform for adjusting the height of the platform relative to the ground, the lifting system being operable between a first condition and a second condition. In the first state, the set of casters is raised off the ground, the lifting system standing on the ground to support the platform such that movement of the height-adjustable bed relative to the ground is prevented; in the second state, the set of casters contacts the ground to support the platform and the lift system is raised off the ground such that movement of the height adjustable bed relative to the ground is permitted.

In one embodiment, the lifting system includes a lifting base for contacting the ground and a lifting bar assembly mounted between the lifting base and the platform that can be folded and unfolded to adjust the height of the platform.

In an embodiment, the lift system includes a drive device mounted between the platform and the lift bar operating assembly, the drive device configured to drive the lift bar assembly to fold or unfold between the first state and the second state.

In one embodiment, the lift bar assembly comprises: the first rotating rod is provided with a lower end and an upper end, the lower end of the first rotating rod is rotatably connected with the lifting base, and the upper end of the first rotating rod is slidably connected with the platform; and the second rotating rod is provided with a lower end and an upper end, the lower end of the second rotating rod is rotatably connected with the first rotating rod, and the upper end of the second rotating rod is rotatably connected with the platform. The drive arrangement has be connected to respectively the platform with the double-phase opposite end of second dwang, drive arrangement constructs to be used for the drive the second dwang rotates, the second dwang then drives first dwang rotates.

In one embodiment, the platform comprises a support frame and a slide rail assembly, the slide rail assembly is positioned below the support frame and extends along the longitudinal direction of the platform, at least one roller is connected to the upper end of the first rotating rod, and the at least one roller is slidably supported on the slide rail assembly, so that the upper end of the first rotating rod can slide along the slide rail assembly.

In one embodiment, the slide rail assembly includes two slide rails extending along two opposite edges of the platform, the platform includes two transverse beams fixedly mounted to the supporting frame and located at two opposite ends of the slide rail assembly, two ends of each slide rail are respectively fixedly connected to the two transverse beams, and the set of casters extends downward from the two transverse beams.

In one embodiment, each transverse beam includes a central portion and two recessed end portions, and each caster wheel extends downwardly from a corresponding one of the recessed end portions.

In an embodiment, the sliding rail assembly includes two sliding rails extending along two opposite edges of the platform, the first rotating rod includes two parallel first rotating arms, a lower end of each first rotating arm is rotatably connected to the lifting base, an upper end of each first rotating arm is provided with a roller, the roller is slidably supported on one of the corresponding sliding rails, the second rotating rod includes two parallel second rotating arms, and each second rotating arm is rotatably connected with the platform and one of the corresponding first rotating arms.

In one embodiment, the second rotating rod comprises a connecting arm fixedly connected between the two second rotating arms and a connecting rod fixedly connected to the connecting arm, a transverse mounting beam is connected between the two sliding rails, and two opposite ends of the driving device are connected between the connecting rod and the transverse mounting beam.

In one embodiment, the transverse mounting beam is connected to an intermediate location of each slide rail, and the lift bar assembly comprises: the other first rotating rod is provided with a lower end and an upper end, the lower end of the other first rotating rod is rotatably connected with the lifting base, and the upper end of the other first rotating rod is slidably connected with the sliding rail assembly; and another second dwang, another second dwang has lower extreme and upper end, the lower extreme of another second dwang with another first dwang rotates to be connected, the upper end of second dwang with the platform rotates to be connected. The lifting system comprises a further drive arrangement having opposite ends connected to the transverse mounting beam and the further second swivelling lever, respectively, the further drive arrangement being configured to drive the further second swivelling lever in rotation, which in turn drives the further first swivelling lever in rotation; the driving means and the other driving means are installed at both sides of the transverse installation beam in the longitudinal direction of the height-adjustable bed and operate in synchronization with each other.

In one embodiment, the lifting base comprises two longitudinal bars and two transverse bars connected together to form a rectangular base frame, each transverse bar having two opposite ends, the lifting base further comprising a foot extending downwardly from each end of each transverse bar, wherein the foot is raised off the ground when the lifting system is in the second state.

In another aspect, the present application provides a method of operating a height adjustable bed. The method comprises the following steps: operating a lift system to lower a platform supported on the lift system such that a set of casters extending downwardly from the platform are in contact with the ground, wherein the lift system is stably stood on the ground such that movement of the platform is prevented until the set of casters are in contact with the ground; and after the set of castors is in contact with the ground, continuing to operate the lifting system to lift the lifting system off the ground so that the height adjustable bed becomes freely movable using the castors.

In one embodiment, operating the lift system and continuing operation of the lift system includes performing a retracting operation of a drive coupled between the platform and a lift bar assembly of the lift system, the retracting operation of the drive causing a folding operation of the lift bar assembly.

In another aspect, the present application provides a method of operating a height adjustable bed. The method comprises the following steps: operating the hoist system to lower the hoist system so that the hoist system stands firmly on the ground, wherein a set of casters extending downwardly from a platform supported on the hoist system stand on the ground to carry the full weight of the height adjustable bed before the hoist system comes into contact with the ground, such that movement of the height adjustable bed with the casters is permitted; and after the lifting system is firmly standing on the ground, continuing to operate the lifting system to raise the platform and raise the set of casters off the ground so that the height-adjustable bed becomes locked from movement on the ground.

In one embodiment, operating the lift system and continuing to operate the lift system includes extending a drive coupled between the platform and a lift bar assembly of the lift system, the extending of the drive causing an extending operation of the lift bar assembly.

In summary, the present application provides a novel braking system for a height adjustable bed. The locking and unlocking of the bed can be realized by adjusting the height of the bed without adding an additional mechanism on the caster. This simplifies the design of the braking device and makes the operation of the bed easier.

Drawings

FIG. 1 is a schematic view of a height adjustable bed according to an embodiment of the present invention, shown in a locked position.

Fig. 2 shows the height-adjustable bed of fig. 1 in a released state.

Fig. 3 shows the height-adjustable bed of fig. 1 in an intermediate state.

FIG. 4 is a perspective view of a height adjustable bed according to an embodiment of the present invention, shown in a locked state.

Fig. 5 is a perspective view of the height adjustable bed of fig. 4 from another perspective.

Fig. 6 is a side view of the height adjustable bed of fig. 4.

Fig. 7 is a partial perspective view of the height adjustable bed of fig. 4 with the upper support frame removed.

Fig. 8 is a side view of the height adjustable bed of fig. 4 in an intermediate state.

Fig. 9 is a perspective view of the height adjustable bed of fig. 8.

FIG. 10 is a side view of the height adjustable bed of FIG. 4 in a relaxed state.

Detailed Description

Before the embodiments are described in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in other forms of implementation. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," "having," and the like, herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. In particular, when "a certain element" is described, the present invention is not limited to the number of the element being one, and may include a plurality of the elements.

Fig. 1 to 3 illustrate a height adjustable bed 100 according to an embodiment of the present invention. The bed 100 includes a platform 102 for supporting a user, a set of casters 104 mounted beneath the platform 102, and a lift system or height adjustable base 106 mounted beneath the platform 102 for adjusting the height of the platform 102 relative to a ground 108.

In the illustrated embodiment, four legs extend downwardly from the corners of the platform 102, and casters 104 are mounted at the bottom ends of the legs.

The lift system 106 includes various components operable to vary the vertical dimension of the lift system 106 to raise or lower the platform 102. The term "vertical dimension" is used herein to refer to the overall dimension of the hoist system 106 in a direction perpendicular to the ground 108, and the height of the bed is adjusted by changing the vertical dimension of the hoist system 106.

The lift system 106 is operable between a first state and a second state. Fig. 1 shows lift system 106 in a first state, in which casters 102 are clear of ground 108, and lift system 106 is standing on ground 108 to support platform 102 such that movement of height-adjustable bed 100 relative to ground 108 (i.e., movement parallel to the ground) is prevented. In this state, the height-adjustable bed 100 is braked, i.e., the brake is turned on.

Fig. 2 shows lifting system 106 in a second state, in which casters 104 are in contact with ground 108 and lifting system 106 is off of ground 108, such that movement of height-adjustable bed 100 relative to ground 108 is permitted. In this state, the height adjustable bed 100 releases the brakes, i.e., the brakes are closed.

Fig. 3 shows an intermediate state between the first state and the second state, in which both the caster 102 and the lift system 106 are in contact 108 with the ground. In this state, depending on the operation of lifting system 106, the load of height-adjustable bed 100 is transferred from casters 104 to lifting system 106, or from lifting system 106 to casters 104. Specifically, as the hoist system 106 moves from the condition of fig. 1 to the condition of fig. 2 to reduce its vertical dimension, the load of the bed is transferred from the hoist system 106 to the castors 104 as this intermediate condition is passed. While passing through this intermediate state, the load of the bed is transferred from the castors 104 to the lifting system 106, as the lifting system 106 moves from the state of fig. 2 to the state of fig. 1 to increase its vertical dimension.

In this intermediate state, the height of the platform 102 or bed is H1, as shown in FIG. 3. When the vertical dimension of the lifting system 106 is greater than H1 (when discussing the dimensional relationship, the thickness of the platform 102 is disregarded), such as the state shown in fig. 1, the bed 100 is braked from moving on the ground 108; when the vertical dimension of the lifting system 106 is less than H1, the bed 100 is released from the brakes and is free to move over the ground.

In fig. 1-3, two rectangular boxes B1 and B2 are used to represent two components of the lift system 106. The two components B1 and B2 are relatively movable to change the vertical dimension of the lifting system 106. It should be noted that these two rectangular frames are merely used to illustrate the concept of the lifting system 106 being adjustable in vertical dimension, and the lifting system 106 should not be limited to a two-piece design. Additionally, the components of the lift system 106 may move in various ways as long as the movement of the components thereof can cause a change in the vertical dimension of the lift system 106. Different forms of activity will result in different lift system configurations. Examples of the lifting system 106 include, but are not limited to, a scissor (single or double scissor) system or a telescoping tube system. Hereinafter, a specific configuration of the above-described height-adjustable bed 100 will be exemplified in conjunction with a scissor lift system.

Referring to fig. 4 to 7, a height-adjustable bed according to an embodiment of the present invention includes a platform 10, a set of casters 12 installed under the platform 10, and a hoist system 14 installed under the platform 10 for adjusting the height of the platform 10 with respect to the ground (not shown). Lift system 14 is operable between a first state (fig. 4-7) and a second state (fig. 10). In the first state, the casters 12 are off the ground and the hoist system 14 is standing on the ground to support the platform 10 such that movement of the height adjustable bed relative to the ground is prevented. In the second state, the casters 12 are in contact with the ground to support the platform 10, while the hoist system 14 is off the ground so that movement of the height adjustable bed relative to the ground is permitted.

In the illustrated embodiment, the platform 10 includes a generally rectangular upper support frame 16 and a slide rail assembly 18 positioned below the support frame 16. The upper support frame 16 is used for supporting a bed plate or a mattress, for example. In some embodiments, at least a portion of the support frame 16 may be rotated or folded to provide better postural positioning for a user lying in the bed. The skid assembly 18 extends longitudinally of the platform 10. Specifically, the track assembly 16 includes two tracks 20 extending along opposite edges of the platform 10. Platform 10 further includes two transverse beams 22 at opposite ends of rail assembly 18. Each transverse beam 22 is fixedly mounted to the support frame 16. Both ends of each slide rail 22 are fixedly connected to two transverse beams 22, respectively. That is, the slide rails 20 are fixedly mounted to the upper support frame 16 by two transverse beams 22.

A transverse mounting beam 23 is connected between the two slide rails 20. In the illustrated embodiment, a transverse mounting beam 23 is attached to a middle portion of each slide rail 20.

The set of casters 12 extends downwardly from the platform 10. Specifically, the set of casters 12 includes four casters 12 located at the four corners of the platform 10 and extending downwardly from two transverse beams 22. Two of the casters 12 extend from opposite ends of one of the transverse beams 22, and the other two casters 12 extend from opposite ends of the other transverse beam 22. Each transverse beam 22 includes a central portion 24 and two opposing recessed end portions 26. The top surface of the recessed end 26 is fixedly mounted to the support bracket 16. Accordingly, the middle portion 24 projects into the support frame 16 in the height direction of the bed relative to the end portions 26. The caster 12 extends downwardly from the recessed end 26. In the illustrated embodiment, the caster 12 extends downwardly from the bottom surface of the recessed end 26.

The lift system 14 includes a lift block 30 for contacting the ground, and a lift rod assembly 32 mounted between the lift block 30 and the platform 10. The lift pin assembly 32 can be folded or unfolded to adjust the height of the platform 10. Thus, the height of the platform 10 is achieved through the folding and unfolding operations of the lift bar assemblies 32.

In the illustrated embodiment, the lift block 30 includes two longitudinal bars 34 and two transverse bars 36. Two longitudinal bars 34 and two transverse bars 36 are connected together to form a rectangular frame. Each transverse bar 36 has opposite ends 38. The lift block 30 also includes support legs 40 extending downwardly from each end 38 of each cross bar 36. In the illustrated embodiment, a total of four support legs 40 are provided. When the lifting system 14 is in the second state, the support leg 40 is lifted off the ground.

In the illustrated embodiment, the lift bar assembly 32 includes two identical sections aligned along the longitudinal direction of the height adjustable bed, each supporting one of the lateral ends of the height adjustable bed. It should be understood that this two-piece design of the lift bar assembly 32 is for illustrative purposes only and the invention should not be limited thereto. Since the two parts are identically constructed, only the details of one of the parts are described below. Each section includes a first rotatable lever 42 and a second rotatable lever 44 foldably connected together. One end of the first rotating lever 42 is rotatably connected to the lifting base 30 and the other end is rotatably connected to the platform 10. The lift rod assembly 32 can be folded and unfolded by rotation of the first and

second rotation rods

42, 44.

In the illustrated embodiment, the lift system 14 further includes at least one drive device 46 coupled between the platform 10 and the lift bar assembly 32. The drive device 46 is configured to drive the lift bar assembly 32 to fold or unfold between the first and second states. In the embodiment shown, the drive means 46 is a push-pull linear actuator. In the illustrated embodiment, the lift system 14 has two linear actuators that drive two portions of the lift rod assembly 32, respectively. In other embodiments, the drive device 46 may be other suitable forms of drive devices, such as hydraulic or pneumatic drive devices.

In more detail, as shown in fig. 7, the first rotation lever 42 includes two parallel first rotation arms 48. The lower end of each first swivel arm 48 is pivotally connected to the lifting base 30, in particular to one of the transverse bars 36. The upper end of each first rotation arm 38 is slidably connected to a corresponding one of the slide rails 20. A roller 50 is attached to the upper end of each of the arms 48. Each roller 50 is slidably supported on a corresponding one of the slide rails 20. Each track rail 20 includes a track wall 52. The two rail arms 52 of the two sliding rails 20 are parallel to each other. The upper and lower edges of the track wall 52 extend toward the other track rail 20 with an upper flange 54 and a lower flange 56, respectively. The roller 50 is disposed in a space between the upper flange 54 and the lower flange 56, and is slidably supported on the lower flange 56. Once the first rotating lever 42 is rotated with respect to the lifting socket 30, the upper end of the first rotating lever 42 slides along the slide rail 20 by means of the roller 50.

In one embodiment, a transverse connecting rod 58 is connected between the two first rotation arms 48 at or near the upper end of the first rotation arms 48. The provision of the transverse connecting rod 58 between the two first turning arms 48 reinforces the strength of the first turning lever 42.

In the illustrated embodiment, the first rotating lever 44 includes two parallel second rotating arms 60. Each second swivel arm 60 is pivotally connected to the platform 10 and one of the first swivel arms 48. Specifically, each second pivot arm 60 includes an upper end and a lower end, the upper end of the second pivot arm 60 being slidably coupled to the central portion 24 of one of the transverse beams 22 of the platform 10, and the lower end of the second pivot arm 60 being slidably coupled to one of the first pivot arms 48. The second rotation lever 44 includes a connecting arm 62, and the connecting arm 62 is fixedly connected between the two second rotation arms 60. A connecting rod 64 is fixedly connected to the connecting arm 62.

The drive mechanism 46 has opposite ends that are pivotally connected to the platform 10 and the lift bar assembly 32, respectively. More specifically, the opposite ends are pivotally connected to the transverse mounting beam 23 of the platform and the connecting rod 64 of the lift link assembly 32, respectively. Under the pushing or pulling operation of the driving device 46, the second rotating lever 44 is driven to rotate, and the second rotating lever 44 in turn drives the first rotating lever 42 to rotate, so that the lifting lever assembly 32 is folded or unfolded to raise or lower the bed.

In the embodiment shown, two identical parts of the lifting bar assembly 32 are arranged on both sides of the transverse mounting beam 23 in the longitudinal direction of the bed. Another portion of the lift bar assembly 32 includes another first rotating bar and another second rotating bar. Another first turning bar has a lower end rotatably connected to lifting base 30 and an upper end slidably connected to slide rail assembly 18. A further second turning bar has a lower end rotatably connected to the further first turning bar and an upper end rotatably connected to the platform 10. A further drive means 46 has opposite ends pivotally connected to the transverse mounting beam 23 and to a further second pivot lever respectively. The further drive device 46 is configured to drive a further second swivelling lever in rotation, which in turn drives a further first swivelling lever in rotation. The two parts operate in the same synchronization (i.e., fold or unfold).

It should be understood that the lift bar assembly 32 may include only one set of first and second rotating rods and that the lift system 14 may include only one drive device 46 for driving the set of first and second rotating rods. In an alternative embodiment, the lift bar assembly 32 may be implemented as other collapsible structures that adjust the height of the bed by collapsing or expanding. Alternatively, the lift bar assembly 32 may be implemented as a non-folding lift mechanism.

In operation, the height adjustable bed can be switched between a braked or locked state and a released or unlocked state by merely operating one or more of the drive means 46. As shown in fig. 4, the set of casters 12 are raised off the ground and the lift system 14 is standing on the ground to support the platform 10. The hoist system 14 is in the first state and the height adjustable bed is not movable, i.e. in a locked state. In the condition shown in fig. 4-7, the drive mechanism 46 is in an extended condition.

When the drive means 46 is retracted, the first and second

rotatable levers

42 and 44 are folded over each other to lower the platform 10 so that the castor 12 comes closer to the ground. The bed is in a locked condition until the castors 12 contact the floor. As shown in fig. 8 and 9, once the casters 12 are in contact with the ground, the casters 12 support the full weight of the bed and the platform 10 cannot be lowered further. In this intermediate state, the casters 12 and the legs 40 of the lifting base 30 simultaneously contact the ground, and the weight of the bed is gradually transferred from the lifting system to the casters 12, so that the height-adjustable bed is still immovable.

As shown in fig. 10, since the platform 10 cannot be further lowered (once the casters 12 are in contact with the ground, the platform 10 maintains the bed height), continued retraction of the drive device 46 will raise the lift base 30 of the lift bar assembly 32 toward the platform 10. As a result, the legs 40 of the lifting base 30 are raised off the ground and the bed is now free to move with the castors 12, i.e. the bed is unlocked.

Locking of the bed can be achieved simply by reversing the operation of the drive means (i.e. the extension operation). At the beginning of the extension operation of the drive means 46, the lifting base 30 is moved away from the platform 10 and towards the ground. The bed is maintained in the unlocked state until the legs 40 of the lifting base 30 are in contact with the ground. Once the legs 40 contact the ground, the lift bar assembly 32 supports the entire weight of the bed, and the bed becomes locked. Further extension of the drive means 46 raises the platform with the castors 12 together to adjust the height of the bed whilst the bed remains locked.

Accordingly, the present invention provides a method of operating a height adjustable bed. The detailed structure of the height adjustable bed has been described above.

In one embodiment, the method includes operating the lift system 14 to lower the platform 10 supported on the lift system 14 such that a set of casters 12 extending downwardly from the platform 10 are in contact with the ground, wherein the lift system 14 is stably standing on the ground such that movement of the platform 10 is prevented until the set of casters 12 are in contact with the ground; after the set of casters 12 contacts the ground, the hoist system 14 continues to be operated to lower the hoist system 14 off the ground so that the height adjustable bed becomes free to move with the casters 12.

Specifically, in one embodiment, operating the lift system 14 and continuing operation of the lift system 14 includes retracting the drive 46 coupled between the platform 10 and the lift bar assembly 32 of the lift system 14, the retracting operation of the drive 46 causing the folding operation of the lift bar assembly 32. More specifically, the retracting operation of the driving means 46 drives the second rotating lever 44 to rotate, and the second rotating lever 44 in turn drives the first rotating lever 42 to rotate.

In another embodiment, the method includes operating the hoist system 14 to lower the hoist system 14 such that the hoist system 14 stands firmly on the ground with a set of casters 12 extending downwardly from the platform 10 supported on the hoist system 14 standing on the ground to carry the full weight of the height adjustable bed such that movement of the height adjustable bed with the casters 12 is permitted before the hoist system 14 contacts the ground; after the lifting system 14 is firmly standing on the ground, the lifting system 14 continues to be operated to raise the platform 10 and raise the set of casters 12 off the ground so that the height adjustable bed becomes locked from movement on the ground.

Specifically, in one embodiment, operating the lift system 14 and continuing to operate the lift system 14 includes extending operation of a drive device 46 coupled between the platform 10 and the lift bar assembly 32 of the lift system 14, the extending operation of the drive device 46 causing the extending operation of the lift bar assembly 32. More specifically, the extension operation of the drive device 46 drives the second rotating lever 44 to rotate, and the second rotating lever 44 in turn drives the first rotating lever 42 to rotate.

In summary, the present invention provides a novel braking system for a height adjustable bed. The locking and unlocking of the bed can be realized by adjusting the height of the bed without adding an additional mechanism on the caster. This simplifies the design of the braking device and makes the operation of the bed easier.

The concepts described herein may be embodied in other forms without departing from the spirit or characteristics thereof. The particular embodiments disclosed should be considered illustrative rather than restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. Any changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A height adjustable bed comprising:

a platform comprising a support frame and a track assembly positioned below the support frame and extending longitudinally of the platform, the track assembly comprising two tracks extending along opposite edges of the platform, a transverse mounting beam connected between the two tracks, the transverse mounting beam connected to a middle of each track;

a set of casters mounted beneath the platform; and

a lifting system mounted below the platform for adjusting the height of the platform relative to the ground, the lifting system operable between a first condition and a second condition,

wherein in the first state the set of castors are raised off the ground and the lifting system is standing on the ground to support the platform such that movement of the height adjustable bed relative to the ground is prevented; in the second state, the set of casters contacts the ground to support the platform, the lifting system is raised off the ground such that movement of the height adjustable bed relative to the ground is permitted, the lifting system includes a lifting base for contacting the ground and a lift bar assembly mounted between the lifting base and the platform, the lift bar assembly is collapsible and expandable to adjust the height of the platform, the lifting system includes a drive device mounted between the platform and the lift bar assembly, the drive device is configured to drive the lift bar assembly to collapse or expand between the first state and the second state, the lift bar assembly includes:

the first rotating rod is provided with a lower end and an upper end, the lower end of the first rotating rod is rotatably connected with the lifting base, and the upper end of the first rotating rod is slidably connected with the platform; and

the second rotating rod is provided with a lower end and an upper end, the lower end of the second rotating rod is rotatably connected with the first rotating rod, and the upper end of the second rotating rod is rotatably connected with the platform;

wherein the drive means has opposite ends connected to the platform and the second rotatable lever, respectively, the drive means being configured to drive the second rotatable lever in rotation which in turn drives the first rotatable lever in rotation, the retraction operation of the drive means causing the first and second rotatable levers to fold over one another to lower the platform when the lift system is operated from the first state to the second state; when the lift system is operated from the second state to the first state, extension operation of the drive means causes deployment operation of the lift bar assembly, the lift base moving away from the platform and towards the ground for a period of time at the beginning of extension operation of the drive means, further extension of the drive means causing the platform to rise upwardly relative to the ground once the lift base contacts the ground,

the lift bar assembly further comprises:

the other first rotating rod is provided with a lower end and an upper end, the lower end of the other first rotating rod is rotatably connected with the lifting base, and the upper end of the other first rotating rod is slidably connected with the sliding rail assembly; and

the other second rotating rod is provided with a lower end and an upper end, the lower end of the other second rotating rod is rotatably connected with the other first rotating rod, and the upper end of the second rotating rod is rotatably connected with the platform;

wherein the lifting system further comprises a further drive arrangement having opposite ends connected to the platform and the further second swivelling levers, respectively, the further drive arrangement being configured to drive the further second swivelling levers in rotation, which in turn drives the further first swivelling levers in rotation;

wherein the driving means and the other driving means are installed at both sides of the transverse installation beam in the longitudinal direction of the height-adjustable bed and operated in synchronization with each other.

2. The height adjustable bed of claim 1, wherein at least one roller is attached to the upper end of the first rotating rod, the at least one roller being slidably supported on the slide rail assembly such that the upper end of the first rotating rod is slidable along the slide rail assembly.

3. The height adjustable bed of claim 2, wherein the track assembly includes two tracks extending along opposite edges of the platform, the platform including two transverse beams fixedly mounted to the support frame at opposite ends of the track assembly, each track having opposite ends fixedly coupled to the two transverse beams, respectively, the set of casters extending downwardly from the transverse beams, each transverse beam including a central portion and two recessed end portions, each caster extending downwardly from a corresponding one of the recessed end portions.

4. The height adjustable bed as claimed in claim 2, wherein the first rotating bar comprises two parallel first rotating arms, a lower end of each first rotating arm is rotatably connected to the lifting base, an upper end of each first rotating arm is provided with a roller which is slidably supported on one of the corresponding slide rails, the second rotating bar comprises two parallel second rotating arms, each second rotating arm is rotatably connected with the platform and one of the corresponding first rotating arms; the second dwang includes fixed connection in linking arm between two second rotor arms and fixed connection to the connecting rod of linking arm, drive arrangement's double-phase opposite end is connected the connecting rod with transversely install between the roof beam.

5. A method of operating a height adjustable bed as claimed in claim 1, wherein the method comprises:

operating a lift system to lower a platform supported on the lift system such that a set of casters extending downwardly from the platform are in contact with the ground, wherein the lift system is stably standing on the ground such that movement of the platform is prevented until the set of casters are in contact with the ground;

after the set of casters contacts the floor, continuing to operate the lift system to raise the lift system off the floor so that the height adjustable bed becomes freely movable with the casters, operating the lift system and continuing to operate the lift system includes performing a retracting operation with a drive device connected between the platform and a lift bar assembly of the lift system, the retracting operation of the drive device causing a folding operation of the lift bar assembly.

6. A method of operating a height adjustable bed as claimed in claim 1, the method comprising:

operating the hoist system to lower the hoist system so that the hoist system stands firmly on the ground, wherein a set of casters extending downwardly from a platform supported on the hoist system stands on the ground to carry the entire weight of the height adjustable bed before the hoist system contacts the ground such that movement of the height adjustable bed with the casters is permitted;

after the lifting system is stably standing on the ground, continuing to operate the lifting system to raise the platform and the set of casters off the ground such that the height-adjustable bed becomes locked from moving on the ground, operating the lifting system and continuing to operate the lifting system includes performing an extending operation of a drive device connected between the platform and a lift rod assembly of the lifting system, the extending operation of the drive device causing an extending operation of the lift rod assembly.