A bed and use of a bed

Abstract

 Disclosed is a bed (1) comprising a bottom frame (2) including support means (5) for engaging an underlying ground and a top frame (3) comprising a bed surface (6) for supporting a person lying in the bed (1). The bed (1) also comprises a lifting mechanism (4) arranged between the bottom frame (2) and the top frame (3) to displace the bottom frame (2) and the top frame (3) in relation to each other, wherein the lifting mechanism (4) comprises a first lifting arm (7) being driven by a first actuator (13) and a second lifting arm (8) being driven by a second actuator (14). The lifting arms (7, 8) are rotatably connected to the bottom frame (2) in a first bottom frame point of attack (9) and a second bottom frame point of attack (10), respectively and both slidably and rotatably connected to the top frame (3) in a first top frame point of attack (11) and a second top frame point of attack (12), respectively. The first lifting arm (7) is rotatably connected to the bottom frame (2) in the first bottom frame point of attack (9) around a first bottom frame rotational axis (23) and the second lifting arm (8) is rotatably connected to the bottom frame (2) in the second bottom frame point of attack (10) around a second bottom frame rotational axis (24) and wherein the first bottom frame rotational axis (23) and the second bottom frame rotational axis (24) are substantially coaxial.

Description

Field of the invention

[0001] The invention relates to a bed comprising a bottom frame including support means for engaging an underlying ground and a top frame comprising a bed surface for supporting a person lying in the bed. The bed also comprises a lifting mechanism arranged between the bottom frame and the top frame to displace the bottom frame and the top frame in relation to each other. The invention further relates to use of a bed.

Background of the invention

[0002] Beds comprising some sort of motorised elevation mechanism for adjusting the height of the bed have been known for several years particularly for use within hospitals, retirement homes, care homes but also in private homes e.g. to enable easier access to the bed for less mobile persons and/or to ensure a good working position for a nurse or similar.

[0003] However, often a bedbound patient is so immobile that auxiliary equipment - like mobile lifts, ceiling mounted lifts etc. - has to be used to ensure that the patient can get in and out of the bed and such equipment is costly and space consuming.

[0004] Thus, from US 2010/0257672 A1 it is known to enable that the lifting mechanism of a hospital bed may also tilt the bed so that the foot of bed is lowered while the opposite end is raised while the bed surface is transformed, so that the bed more or less changes into a chair, hereby enabling that the patient is carefully raised from a lying position into a sitting position from which the patient much easier can leave the bed. But, the presented lifting mechanism has severe limitations regarding the angle in which the bed can be inclined.

[0005] From WO 2007/069912 Al it is known to form a bed with a lifting mechanism comprising two individual lifting arms actuated by two separate actuators. But this mechanism design provides little or no help in getting in and out of the bed.

[0006] An object of the invention is therefore to provide for a bed with a more advantageous lifting mechanism.

The invention

[0007] The invention provides for a bed comprising a bottom frame including support means for engaging an underlying ground and a top frame comprising a bed surface for supporting a person lying in the bed. The bed also comprises a lifting mechanism arranged between the bottom frame and the top frame to displace the bottom frame and the top frame in relation to each other, wherein the lifting mechanism comprises a first lifting arm being driven by a first actuator and a second lifting arm being driven by a second actuator. The lifting arms are rotatably connected to the bottom frame in a first bottom frame point of attack and a second bottom frame point of attack, respectively, and both slidably and rotatably connected to the top frame in a first top frame point of attack and a second top frame point of attack, respectively. The first lifting arm is rotatably connected to the bottom frame in the first bottom frame point of attack around a first bottom frame rotational axis and the second lifting arm is rotatably connected to the bottom frame in the second bottom frame point of attack around a second bottom frame rotational axis and wherein the first bottom frame rotational axis and the second bottom frame rotational axis are substantially coaxial.

[0008] Connecting two individually driven lifting arms slidably to the top frame is advantageous in that - besides enabling that the lifting arms can change the vertical position of the top frame in relation to the bottom frame - the sliding connection can also be used for displacing the top frame horizontally in relation to the bottom frame, hereby enabling that the top frame can also be moved e.g. forward in relation to the bottom frame when the front end of the bed is lowered by lowering only the front lifting arm. This is advantageous in that it enables that the front end of the bed can be moved closer to the underlying ground without colliding with the bottom frame hereby enabling easy access to and from the bed and particularly if the bed surface is transformed into a chair-like device, the seat of this chair can be arranged in a height suitable for even a relatively low person and thereby enabling easy access to and from the chair and thereby the bed.

[0009] Connecting the lifting arms rotatably to the bottom frame in the same point is advantageous in that it enables a pendulum motion of the top frame in relation to the bottom frame which along with the possibility of horizontal displacement of the top frame enables that the front end of the bed can be moved close to the ground without colliding with the bottom frame. Furthermore, the coaxial rotational axis enables a more compact and efficient lifting mechanism design.

[0010] By the terms "The lifting arms are rotatably connected to the bottom frame in a first bottom frame point of attack and a second bottom frame point of attack, respectively" is to be understood that the lifting arms are directly or indirectly connected to the bottom frame through some sort of pivotal joint. I.e. the lifting arms does not necessary have to be directly connected to the bottom frame but could be rotatably connected through one or more further arms or one lifting arm could be rotatably connected somewhere on the other lifting arm, which then in turn would be rotatably connected to the bottom frame.

[0011] Likewise, by the term "The lifting arms are ... slidably and rotatably connected to the top frame in a first top frame point of attack and a second top frame point of attack, respectively" is to be understood that the lifting arms are directly or indirectly connected to the top frame through some sort of pivotal joint and some sort of track, guide, rails, cams or similar means allowing that a point of attack between the lifting arms and the top frame can be displaced in relation to each other to enable said sliding. I.e. the lifting arms does not necessary have to be directly connected to the top frame but could be rotatably and/or slidably connected through one or more further arms and the means allowing the connection to be rotatable does not necessary have to coincide or be arranged together with the means allowing the connection to be slidable.

[0012] In an aspect of the invention, said first actuator is connected to said first lifting arm through a first lever arm gear and/or said second actuator is connected to said second lifting arm through a second lever arm gear.

[0013] If the actuators are connected directly on the lifting arms between the respective points of attack, the rotational speed of the top frame points of attack will vary with the angle of the lifting arm - even if the actuators are operating at a constant speed. And the force required from the actuators to lift a given load on the top frame will vary much over the entire vertical stroke of the top frame. However, by connecting the actuators to the lifting arms through lever gears it is possible to counteract this speed variation and variation in force required from the actuators - at least to some degree. Obviously the actuators have to be dimensioned according to the highest load and it is therefore advantageous to connect the actuators to the lifting arms through lever arm gears that can even out the force requirement and thereby enable that actuators with a smaller capacity can actuate the lifting arm over the entire stroke of the top frame. And it is advantageous in that it also provides a more constant lifting speed over the entire vertical stroke.

[0014] It should be noted that by the term "lever arm gear" is to be understood a gearbox or a transmission that will gear the motion of the actuators in relation to the motion of the lifting arms by means of one or more lever arms. I.e. in relation to a traditional gear wheel transmission (as in a car) a lever arm gear enables that the gearing of the gear changes in accordance with the given extension of the actuators so that e.g. a 10 mm stroke of the actuators results in e.g. 100 mm vertical movement of the top frame no matter if it is at the beginning or the end of the actuator stroke. This is of course ideally but in another embodiment the lever arm gears will at least improve the ratio in relation to a design where the actuators are connected directly to the lifting arms.

[0015] In an aspect of the invention, said first actuator is rotatably connected to said bottom frame and/or said second actuator is rotatably connected to said bottom frame.

[0016] Hereby is achieved an advantageous embodiment of the invention.

[0017] In an aspect of the invention, said lifting mechanism further comprises a guide arm being rotatably connected to said first lifting arm in a first guide arm point of attack and being rotatably connected to said top frame at a second guide arm point of attack of said guide arm.

[0018] If the top frame points of attack of both lifting arms are slidably connected to the top frame additional means are needed to ensure a controlled position of the top frame in relation to the bottom frame at all times. Connecting a guide arm between a lifting arm and the top frame will in a simple and inexpensive manner ensure that the top frame cannot slide uncontrollably in relation to the lifting arms.

[0019] In an aspect of the invention, said second guide arm point of attack is located between said first top frame point of attack and said second top frame point of attack.

[0020] Connecting the guide arm to the top frame between the connection points of the lifting arms is advantageous in that it provides for a more compact lifting mechanism design and it enables a more advantageous motion pattern of the top frame in relation to the bottom frame.

[0021] In an aspect of the invention, said second guide arm point of attack is located substantially half way between said first top frame point of attack and said second top frame point of attack when said top frame is parallel with said bottom frame.

[0022] Connecting the guide arm to the top frame somewhere around the middle between the top frame points of attack of the lifting arms - when the top frame is horizontal or at least parallel with the bottom frame - is advantageous in that it ensures a the lifting mechanism does not wedge and it ensures that when the actuators are extending simultaneously and uniformly the top frame will only move up (or down) and substantially not move back or forth horizontally.

[0023] This is advantageous in that it hereby is simpler to only move the top frame up and down.

[0024] In an aspect of the invention, said first guide arm point of attack is placed between 10% and 90%, preferably between 25% and 75% and most preferred between 40% and 60% of the distance between said first bottom frame point of attack and said first top frame point of attack of said first lifting arm from said first bottom frame point of attack of said first lifting arm.

[0025] If the guide arm is not connected to the lifting arm around the middle between the top frame point of attack and the bottom frame point of attack the lifting mechanism will have a tendency to wedge and/or the top frame cannot move only vertically if the actuators are extending simultaneously and uniformly. The present placement ranges therefore provides for an advantageous relationship between efficiency and functionality.

[0026] In an aspect of the invention, the distance between said first guide arm point of attack and said second guide arm point of attack of said guide arm is between 10% and 90%, preferably between 25% and 75% and most preferred between 40% and 60% of the of the distance between said first bottom frame point of attack and said first top frame point of attack of said first lifting arm.

[0027] Forming the guide arm so that the distance between its respective points of attack is approximately half the length of the distance between the outer points of attack of the lifting arm - i.e. it is approximately half as long as the lifting arm - is advantageous in that it enables a more simple and uncomplicated lifting mechanism in that the top frame will substantially only move vertically when the two lifting arms are moving synchronously.

[0028] In an aspect of the invention, the distance between said first bottom frame point of attack and said first top frame point of attack of said first lifting arm is substantially identical with the distance between said second bottom frame point of attack and said second top frame point of attack of said second lifting arm.

[0029] Arranging the outer points of attack of the lifting arms in identical distances is advantageous in that provides for a more simple lifting mechanism regarding simple vertical elevation of the top frame and it enables identical or at least symmetrical design of the lifting arms hereby reducing manufacturing and assembly time and cost.

[0030] In an aspect of the invention, said bed surface comprises two or more joints extending transversely in relation to the longitudinal extend of said bed wherein said joints allow said bed surface to be transformed into a chair-like device.

[0031] Providing joints that allow the bed to be transformed into a chair-like device is advantageous in that it enables that a person using the bed can easily and gently get in and out of the bed even if this person mobility is impaired or if the transition between lying and sitting (or standing up) is normally related with much pain.

[0032] In an aspect of the invention, said first actuator and said second actuator are electrical linear actuators comprising an electrical motor and a spindle drive.

[0033] Hereby is achieved an advantageous embodiment of the invention.

[0034] In an aspect of the invention, said first actuator has a longer stroke than said second actuator.

[0035] To move the top frame horizontally up and down the strokes of the actuators only need to be similar but when the top frame is tilted the stroke of one actuator needs to be considerably larger than the outer. It is therefore advantageous to provide the lifting mechanism with actuators having different strokes.

[0036] In an aspect of the invention, the shape of said first lifting arm is a substantial identical mirror-inverted shape of said second lifting arm which enables reduced manufacturing and assembly costs.

[0037] The invention provides for use of a bed according to any of the previously described beds for bringing a person lying in said bed into a sitting position.

[0038] Using a bed according to the present invention to move a person lying in the bed into a sitting position is advantageous in that a bed according to the present invention is particularly suited for tilting a bed surface so that one end of the bed is close to the ground hereby enabling that this person may enter a sitting position while remaining in the bed. This enables that the person can more easily and gently get in and out of bed.

Figures

[0039] The invention will be described in the following with reference to the figures in which

fig. 1

illustrates a bed according to the invention in a bottom position, as seen from the side,

fig. 2

illustrates a bed in an elevated position, as seen from the side,

fig. 3

illustrates a bed in a chair-like position, as seen in perspective,

fig. 4

illustrates a circular cross section in a bed in an elevated position, as seen from the side,

fig. 5

illustrates a bed with elevated parts of the bed surface, as seen from the side,

fig. 6

illustrates a bed transforming into a chair-like position, as seen from the side,

fig. 7

illustrates a bed in a low chair-like position, as seen from the side, and

fig. 8

illustrates a bed in a high chair-like position, as seen from the side.

Detailed description

[0040] Fig. 1 illustrates a bed 1 according to the invention in a bottom position, as seen from the side and fig. 2 illustrates the bed 1 shown in fig. 1 in an elevated position, also seen from the side.

[0041] In this embodiment the top frame 3 - provided with a bed surface 6 for supporting a person (not shown) lying in the bed 1 - can be moved up and down while being maintained parallel with the bottom frame 2 i.e. if the bottom frame 2 is arranged on a level horizontal ground the top frame 3 also remains horizontal while being elevated or lowered.

[0042] The vertical movement of the top frame 3 is facilitated by a lifting mechanism 4 arranged between the bottom frame 2 and the top frame 3.

[0043] In this embodiment the lifting mechanism 4 comprises a first lifting arm 7 and a second lifting arm 8 each driven by an actuator 13, 14 connected to the bottom frame 2. However, in another embodiment at least one of the actuators 13, 14 could be extending between both lifting arms 7, 8, one or both actuators 13, 14 could be connected to the top frame 3 or one or both actuators 13, 14 could be connected to a device external to the bed 1.

[0044] In another preferred embodiment the bed surface 6 would further comprise a mattress for cushioning a person (not shown) lying in the bed 1.

[0045] In this embodiment the bottom frame 2 comprises support means 5 for engaging an underlying ground in the form of four wheels arranged substantially at each of the four corners of the bottom frame 2 hereby enabling that the bed 1 can easily be moved around. However in another embodiment the bed 1 could be formed more stationary if the support means 5 were formed as legs, feet or similar or the bottom frame 2 could comprise a combination of wheels and feet.

[0046] Fig. 3 illustrates a bed 1 in a chair-like position, as seen in perspective.

[0047] In this embodiment of the invention the two lifting arms 7, 8 are not operating synchronously enabling that the top frame 3 is tilted forward. This functionality will be discussed in more details later.

[0048] In this embodiment the bed surface 6 is provided with a number of transversal joints 22, which together with the tilt function of the top frame 3 enables that the bed 1 is transformed into a chair like device.

[0049] In this embodiment of the invention the first actuator 13 is driving the first lifting arm 7 through a first lever arm gear 17 and the second actuator 14 is driving the second lifting arm 8 through a second lever arm gear 18. However in another embodiment one or both actuators 13, 14 could be connected directly to the respective lifting arms 7, 8.

[0050] In this embodiment both the actuators 13, 14 are electrical linear actuators comprising an electrical motor and a spindle drive but in another embodiment of the invention the actuators 13, 14 could be motors, hydraulic or pneumatic cylinders or the motor driving the linear actuator could be powered by other means that electricity.

[0051] In this embodiment the electrical motors of the two actuators 13, 14 are identical and the pitch of the spindles are identical so that when the two actuators 13, 14 are activated simultaneously, they will extend or contract uniformly hereby enabling that the bed surface 6 can be maintained in the same angle in relation to the bottom frame 2 during the entire elevation or contraction process of the lifting mechanism 4 - if so desired.

[0052] However, in another embodiment of the invention it could be advantageous if the electrical motors of the two actuators 13, 14 were not identical or if the spindles had different pitch e.g. to compensate for asymmetry in the lifting mechanism 4 or to provide further functionality.

[0053] In this embodiment the first lifting arm 7 actually consist of a pair of identical arms that are mutually axially displaced on the first bottom frame rotational axis 23 and the second lifting arm 8 actually also consist of a pair of identical arms that are mutually axially displaced on the second bottom frame rotational axis 24. However, in another embodiment the first lifting arm 7 and/or the second lifting arm 8 would only comprise one arm or one or both lifting arms 7, 8 would comprise more parallel arranged arms such as three, four, five or more arms.

[0054] Fig. 4 illustrates a circular cross section in a bed 1 in an elevated position, as seen from the side.

[0055] In this embodiment the first lifting arm 7 and the second lifting arm 8 are rotatably connected to the bottom frame 2 in a first bottom frame point of attack 9 and a second bottom frame point of attack 10 around a first bottom frame rotational axis 23 and a second bottom frame rotational axis 24, respectively. In this case the rotational axis 23, 24 are coaxial in that both lifting arms 7, 8 are connected to the same bottom frame lifting arm shaft 25. In another embodiment the first bottom frame point of attack 9 and a second bottom frame point of attack 10 - and thereby the first bottom frame rotational axis 23 and the second bottom frame rotational axis 24 - may be spaced apart so that the lifting arms 7, 8 are also spaced apart or so that the lifting arms 7, 8 crosses each other as seen from the side.

[0056] In this embodiment the arms 7, 8 are rotatably connected to the shaft 25 through bottom frame journal bearings 26 ensuring that the lifting arms 7, 8 may rotate with very little friction. In another embodiment these and other rotatable connections may be formed simply by making the arms at least partly enclose the shaft, by means of ball bearings, roller bearings or any other type of bearings enabling that an arm may be connected to a shaft-like device and still be able to rotate around this device.

[0057] In this embodiment the first lifting arm 7 and the second lifting arm 8 are also rotatably connected to the top frame 3 in a first top frame point of attack 11 and a second top frame point of attack 12 and in this embodiment the lifting arms 7, 8 are also slidably connected to the top frame 3 in that the lifting arms 7, 8 are rotatably connected to a first slide 27 and a second slide 28 respectively, which may slide back and forth in the first guide 29 and the second guide 30, respectively.

[0058] However, in another embodiment of the invention the sliding functionality may be facilitated by means of one or more rails mounted on the top frame 3, one or more tracks formed in or on the top frame 3 or by other means enabling that the connection point of the lifting arms 7, 8 may be displaced back and forth in relation to the top frame 3.

[0059] In this embodiment the guides 29, 30 are straight, hereby enabling only linear displacement of the top frame points of attack 11, 12. However in another embodiment the guides 29, 30 could comprise a more complex shape e.g. to guide the top frame points of attack 11, 12 along a more complex curve.

[0060] Furthermore, in this embodiment the two guides 29, 30 are arranged to displace the top frame points of attack 11, 12 linearly in the same direction, wherein this direction is substantially parallel with the bed surface 6 - when the bed surface 6 is arranged in a bed configuration i.e. flat - but in another embodiment the guides 29, 30 could extend in different directions and/or one or both guides 29, 30 could extend in directions that was not parallel with the flat bed surface 6.

[0061] In this embodiment of the invention the lifting mechanism 4 also comprises a guide arm 19, which is rotatably connected to the first lifting arm 7 in a first guide arm point of attack 20 and rotatably connected to the top frame 3 in a second guide arm point of attack 21.

[0062] If the guide arm 19 was not present, the top frame 3 could slide more or less freely back and forth in the guides 29, 30. This could be advantageous if easy manual (or motorized) horizontal displacement of the top frame 3 in relation to the bottom frame 2 was desired or if it was desired that when the lifting mechanism 4 tilts the top frame 3 (as disclosed in figs. 3 and 6-8), the top frame 3 would always extend furthest in the direction of the lowest end of the bed 1 due to gravity pulling in the top frame 3.

[0063] However, by providing a guide arm 19 with approximately half the length of the first lifting arm 7 and connect it at approximately at the middle of the lifting arm in one end and approximately in the middle between the two top frame points of attack 11, 12 in the other end - as defined when the top frame 3 is parallel with the bottom frame 2 i.e. not tilted - the guide arm 19 will control the horizontal position of the top frame 3 to be substantially the same at all times - in relation to the bottom frame 2 - when the two lifting arm 7, 8 are moving up and down simultaneously and synchronously.

[0064] However, connecting a guide arm 19 of a different length in the same way or connecting a guide arm 19 of the same length differently or a combination thereof is also feasible and possibly desirable. I.e. the guide arm 19 could e.g. be formed shorter than half the length of the lifting arm 7 and maybe be connected differently to enable that the top frame 3 was displaced forward while moving vertically upwards to ensure sufficient clearance to the bottom frame 2 when the top frame 3 is tilted.

[0065] In this embodiment of the invention the lifting arms 7, 8 and the guide arm 19 are not running in a straight line between the respective connection points 9, 10, 11, 12, 20, 21 i.e. the arms 7, 8, 19 are not formed straight. The specific shapes of the arms 7, 8, 19 are in this case defined by other devices, shafts, beams and other on the bed 1 demanding that the arms 7, 8, 19 have to be formed non-linearly to enable that the lifting mechanism can be formed so compact, that in lowest position the top frame 3 may almost be in contact with the bottom frame 2.

[0066] Other than being mirrored the first and second lifting arms 7, 8 have a substantially identical outer contour but in another embodiment the arms 7, 8 could be formed different from each other e.g. to be able to pass different obstacles or to provide different functionality.

[0067] Fig. 5 illustrates a bed 1 with elevated parts of the bed surface 6, as seen from the side.

[0068] In this embodiment of the invention the bed 1 would start out with a bed surface 6 formed as disclosed in fig. 1 i.e. flat and the top frame is arrange in its bottom position i.e. the lifting mechanism is fully contracted. However in another embodiment the transformation into the chair-like device could start with the top frame 3 in a partly or fully elevated state.

[0069] The person laying in the bed 1 or an external operator would then operate a control panel (not shown) to activate different actuators beneath the bed surface 6 so that the head end 15 of the bed surface 6 would be raised and so that a knee joint 16 is raised to form a very reclined chair-like device.

[0070] However, in another embodiment the flat bed surface 6 could also be formed in to the chair-like device through manual operation or semi-manual operation.

[0071] Fig. 6 illustrates a bed 1 transforming into a chair-like position, as seen from the side.

[0072] The operator is now operating the control panel to tilt the top frame 3 forward. This is done by only activating the first actuator 13 so that only the first lifting arm 7 is raised.

[0073] It should be noted that in all illustrated embodiments the first actuator 12 and the first lifting arm 7 are arranged at the head end 15 of the bed 1 and the second actuator 14 and the second lifting arm 8 are arranged at the opposite end of the bed 1. However, in another embodiment the arrangements could be switched around so that the second actuator 14 and the second lifting arm 8 are arranged at the head end 15 of the bed 1 or so that the first lifting arm 7 and the second lifting arm 8 are arranged substantially side by side.

[0074] It should also be noted that in all illustrated embodiments the bed 1 is provided with only one first actuator 12 and only one second actuator 13 but in another embodiment the first lifting arm 7 and/or the second lifting arm 8 could be actuated by means of two, three or more actuators that could be coupled in parallel and/or in series.

[0075] It should also be noted that in all illustrated embodiments the bed 1 is provided with only two lifting arms 7, 8 (or at least only two pairs of lifting arms 7, 8) but in another embodiment the lifting mechanism 4 could be provided with more lifting arms or lifting arm pairs such as three, four, five or more.

[0076] Fig. 7 illustrates a bed 1 in a low chair-like position, as seen from the side.

[0077] The previously flat and horizontal bed surface 6 has now transformed into a chair-like device from which the used may easily enter or exit the bed 1.

[0078] The figure also discloses that due to the design of the lifting mechanism 4, the lower end or the top frame 3 is brought forward in relation to the bottom frame 2 when the top frame is tilted forward, hereby enabling that the front end of the top frame 3 can be arranged closer to the underlying ground and thereby ensure a suitable seat height of the chair-like device.

[0079] Fig. 8 illustrates a bed 1 in a high chair-like position, as seen from the side.

[0080] Fig. 7 illustrates the chair-like device arranged with the seat in its substantially lowest position but if this position is too low the chair-like device can be raised by also activating the second lifting arm 8 as disclosed in figure 8.

[0081] The size of the stroke of the second actuator 14 is defined by how far the second actuator 14 has to extend to bring the top frame 3 from its lowest position till its top position when the two lifting arms 7, 8 and actuators 13, 14 are operating synchronously. But since the first lifting arm 7 is also used for creating the tilted position of the top frame 3, the first actuator 13 is in this embodiment provided with a longer stroke than the second actuator 14.

[0082] However in another embodiment the actuators 13, 14 would have the same stroke or the second actuator would have longer stroke than the first actuator 13.

[0083] The invention has been exemplified above with reference to specific examples of beds 1, lifting mechanisms 4, actuators 13, 14 and other. However, it should be understood that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the claims.

List

[0084] 

1.

Bed

2.

Bottom frame

3.

Top frame

4.

Lifting mechanism

5.

Support means

6.

Bed surface

7.

First lifting arm

8.

Second lifting arm

9.

First bottom frame point of attack

10.

Second bottom frame point of attack

11.

First top frame point of attack

12.

Second top frame point of attack

13.

First actuator

14.

Second actuator

15.

Head end of bed

16.

Knee joint of bed surface

17.

First lever arm gear

18.

Second lever arm gear

19.

Guide arm

20.

First guide arm point of attack

21.

Second guide arm point of attack

22.

Joints of bed surface

23.

First bottom frame rotational axis

24.

Second bottom frame rotational axis

25.

Bottom frame lifting arm shaft

26.

Bottom frame journal bearing

27.

First slide

28.

Second slide

29.

First guide

30.

Second guide

Claims

1. A bed (1) comprising
a bottom frame (2) including support means (5) for engaging an underlying ground,
a top frame (3) comprising a bed surface (6) for supporting a person lying in said bed (1),
a lifting mechanism (4) arranged between said bottom frame (2) and said top frame (3) to displace said bottom frame (2) and said top frame (3) in relation to each other,
wherein said lifting mechanism (4) comprises a first lifting arm (7) being driven by a first actuator (13) and a second lifting arm (8) being driven by a second actuator (14), said lifting arms (7, 8) being rotatably connected to said bottom frame (2) in a first bottom frame point of attack (9) and a second bottom frame point of attack (10) respectively, and both slidably and rotatably connected to said top frame (3) in a first top frame point of attack (11) and a second top frame point of attack (12) respectively,
wherein said first lifting arm (7) is rotatably connected to said bottom frame (2) in said first bottom frame point of attack (9) around a first bottom frame rotational axis (23) and said second lifting arm (8) is rotatably connected to said bottom frame (2) in said second bottom frame point of attack (10) around a second bottom frame rotational axis (24) and wherein said first bottom frame rotational axis (23) and said second bottom frame rotational axis (24) are substantially coaxial.

2. A bed (1) according to claim 1, wherein said first actuator (13) is connected to said first lifting arm (7) through a first lever arm gear (17) and/or said second actuator (14) is connected to said second lifting arm (8) through a second lever arm gear (18).

3. A bed (1) according to claim 1 or 2, wherein said first actuator (13) is rotatably connected to said bottom frame (2) and/or said second actuator (14) is rotatably connected to said bottom frame (2).

4. A bed (1) according to any of the preceding claims, wherein said lifting mechanism (4) further comprises a guide arm (19) being rotatably connected to said first lifting arm (7) in a first guide arm point of attack (20) and being rotatably connected to said top frame (3) at a second guide arm point of attack (21) of said guide arm (19).

5. A bed (1) according to claim 4, wherein said second guide arm point of attack (21) is located between said first top frame point of attack (11) and said second top frame point of attack (12).

6. A bed (1) according to claim 5, wherein said second guide arm point of attack (21) is located substantially half way between said first top frame point of attack (11) and said second top frame point of attack (12) when said top frame (3) is parallel with said bottom frame (2).

7. A bed (1) according to any of claim 4 to 6, wherein said first guide arm point of attack (20) is placed between 10% and 90%, preferably between 25% and 75% and most preferred between 40% and 60% of the distance between said first bottom frame point of attack (9) and said first top frame point of attack (11) of said first lifting arm (7) from said first bottom frame point of attack (9) of said first lifting arm (7).

8. A bed (1) according to any of claim 4 to 6, wherein the distance between said first guide arm point of attack (20) and said second guide arm point of attack (21) of said guide arm (19) is between 10% and 90%, preferably between 25% and 75% and most preferred between 40% and 60% of the of the distance between said first bottom frame point of attack (9) and said first top frame point of attack (11) of said first lifting arm (7).

9. A bed (1) according to any of the preceding claims, wherein the distance between said first bottom frame point of attack (9) and said first top frame point of attack (11) of said first lifting arm (7) is substantially identical with the distance between said second bottom frame point of attack (10) and said second top frame point of attack (12) of said second lifting arm (8).

10. A bed (1) according to any of the preceding claims, wherein said bed surface (6) comprises two or more joints (22) extending transversely in relation to the longitudinal extend of said bed (1) wherein said joints (22) allow said bed surface (6) to be transformed into a chair-like device.

11. A bed (1) according to any of the preceding claims, wherein said first actuator (13) and said second actuator (14) are electrical linear actuators comprising an electrical motor and a spindle drive.

12. A bed (1) according to any of the preceding claims, wherein said first actuator (13) has a longer stroke than said second actuator (14).

13. A bed (1) according to any of the preceding claims, wherein the shape of said first lifting arm (7) is the substantial identical mirror-inverted shape of said second lifting arm (8).

14. Use of a bed (1) according to any of the preceding claims for bringing a person lying in said bed (1) into a sitting position.

Drawing