Lifting mechanism

Abstract

A lifting mechanism is described for a bed platform, wherein the platform is liftable relative to a fixed frame, comprising a first arm and a second arm shorter than the first arm forming with the platform and the fixed frame an articulated quadrilateral capable of guiding the platform from a lowered and horizontal position to a raised and inclined position. There are N gas springs, N >= 2, which are hinged at one end thereof to the fixed frame and at the other end are hinged to the first arm about respectively horizontal axes which are parallel to each other and parallel to the first to fourth axes.

Description

[0001] The invention relates to a lifting mechanism and a liftable articulating bed equipped with the mechanism.

[0002] Mechanisms are known for raising a bed platform, or the associated bed spring, in order to access the storage compartment underneath or simply to perform cleaning under the bed, see e.g. EP2160961. A pair of mechanisms, one on each side of the bed, is always used for proper operation, often including only a gas spring to aid manual-only lifting. Each gas spring releases an equal force, by symmetry, which can usually range from 200 N to 1350 N and above, maximum 1500 N, depending on the weight of the mattress.

[0003] Over time, the market demands mattresses with increasing weights and heights; and furniture manufacturers, for aesthetic reasons, tend to also want to lift the wooden frame surrounding the bed along with the bed spring or the bed platform, thus adding to the side mechanisms weight to be lifted.

[0004] Very often the final weight to be lifted is not known, and gas springs must be upgraded in advance with larger stems and bodies to develop forces even greater than 2000 N. Not only does the mechanism become considerably more complicated, also for the cost and handling of gas springs of various forces, but in fact this development does not always allow the necessary force of gas springs to be sized appropriately and accurately.

[0005] The main object of the invention is to improve this state of the art.

[0006] Another object is to solve or mitigate the above problem and / or to propose a liftable bed with more functionality.

[0007] Another object is to propose a safer liftable bed.

[0008] These and other objects, which will better appear later, are achieved by an apparatus and method as defined in the attached claims, where the dependent ones define beneficial variants.

[0009] One aspect of the invention relates to a lifting mechanism for a bed platform, wherein the platform is liftable relative to a fixed frame, comprising: a first arm; a second arm shorter than the first arm; the first arm being hinged at one end thereof to the fixed frame about a first axis, the second arm being hinged at one end thereof to the fixed frame about a second axis, the second arm being hinged at one end thereof to the platform about a third axis, the first arm being hinged at one end thereof to the platform about a fourth axis, the first, second, third and fourth axes being in use horizontal and parallel to each other, so as to form with the platform and fixed frame an articulated quadrilateral capable of guiding the platform from a lowered and horizontal position to a raised and inclined position; N gas springs, N >= 2, which are hinged at one end thereof to the fixed frame and at the other end are hinged to the first arm about, respectively, horizontal axes that are parallel to each other and parallel to the first to fourth axes.

[0010] One aspect of the invention relates to a gas spring mounting method in a lifting mechanism for a platform of a bed, wherein the platform is liftable relative to a fixed frame, comprising a first arm and second arm as defined above, wherein N gas springs, N >= 2, are mounted hinged at one end thereof to the fixed frame and at the other end to the first arm about, respectively, horizontal axes that are parallel to each other and parallel to the first to fourth axes.

[0011] By platform here it is meant a substantially rigid plane, such as also e.g., a bed spring, capable of supporting a mattress or at least a person lying down. The size of the platform may be variable, e.g. from a single bed to a double bed.

[0012] The mechanism and method have the advantage of being able to create combinations of forces from the gas springs customizing them to each platform weight combination, making it easier to open and close the bed platform. Combining multiple springs allows not having as many other springs in stock for the many cases that may arise. And using common gas springs costs much less than having to employ oversized gas springs.

[0013] In addition, the mechanism allows for a greater degree of safety in the event of a gas spring failure since the system, e.g. in the case of two pairs of springs, will have 25% less force instead of 50% as traditional two-spring systems. This is also given the considerable weights of the mattresses and any frame surrounding the bed.

[0014] Halving the thrust on a bed with lifting mechanism can cause the bed platform with mattress and frame surrounding the bed to fall abruptly. In the case of failure on a bed with four or more gas springs, the bed platform will not have a sudden fall but a slower one given the presence of three still-working gas springs.

[0015] In the following are some preferred variants for the mechanism and method.

[0016] The N gas springs may all be equal, all sized to exert the same force, or they are configured to exert different forces.

[0017] In one variant, the N gas springs are gas springs different from each other.

[0018] In one variant, the N gas springs are arranged side by side in an array for compactness. Specifically, a subgroup of the N gas springs is hinged on one side of the first arm and the remaining gas springs on the opposite side of the first arm, for maximum stability, compactness, and load distribution.

[0019] Preferably, the homologous ends of all N gas springs are hinged about a same axis, horizontal in use. In particular, the homologous ends of all N gas springs hinged on the platform are hinged about a fifth axis, horizontal in use, that is substantially coplanar to the third and fourth axes, wherein the fourth axis lies between the third axis and the fifth axis. Specifically, the homologous ends of all N gas springs hinged on the first arm are hinged about a sixth axis, horizontal in use, wherein the sixth axis is located, along the first arm, between the first axis and the fourth axis.

[0020] Preferably, the mechanism comprises spacer members mounted between the ends of all N gas springs and the relative member to which they are rotatably connected. In particular, the spacer members mounted between two opposite ends of a gas spring of the N gas springs are of different lengths.

[0021] In particular, N = 2.

[0022] Preferably, the bed comprises a frame, e.g. a square or rectangular frame, formed of a front vertical wall, two side vertical walls, and a rear vertical wall that delimit an empty inner compartment, the platform being placed inside and covering the compartment.

[0023] Preferably, the mechanism is placed inside the compartment.

[0024] Preferably, the mechanism comprises two equal and mirrored specimens mounted on inner and opposite walls of the frame.

[0025] Preferably, the mechanism comprises a plate which is internally fixed / fixable on a vertical wall of the frame, on two distinct points of the plate being hinged the ends (the lower ends, in use) of the first and second arms. Preferably, such two points are spaced apart and aligned along a substantially horizontal line.

[0026] Preferably, said arms are two bars and / or straight.

[0027] Preferably, the other ends (in use the upper ends) of said arms are hinged to the platform at two separate points by an angle bracket.

[0028] Preferably, the distance between the first and second axes is greater than the distance between the third and fourth axes.

[0029] The advantages of the invention will be better elucidated by the following description of exemplary embodiments of bed, illustrated in the attached drawing where: Fig. 1 shows a three-dimensional view from above of a bed with a lowered platform; Fig. 2 shows a three-dimensional view from above of a bed with a raised platform; Fig. 3 shows a side view of a mechanism; Fig. 4 shows a front view of the mechanism in Fig. 3: Fig. 5 shows a three-dimensional view of the mechanism in Fig. 3. In the figures equal numbers indicate equal parts.

[0030] A bed MC comprises a frame 10 and a bed-plane 12 (fig. 1 and 2). The frame 10, the so-called container, is usually square or rectangular, and is formed of a front vertical wall 10b, two side vertical walls 10a, 10c, and a rear vertical wall 10d that delimit an empty inner compartment V useful for holding objects. The frame 10 does not necessarily have a bottom wall.

[0031] The bed-plane 20 is a support platform or surface, e.g. for a mattress or a person lying down, which is arranged inside and covering the compartment V. In the example shown, the bed-plane 20 is a slatted bed spring.

[0032] The bed MC also comprises a manual mechanism 30 for the guided tilting of the bed-plane 20 relative to frame 10. The mechanism 30 is used to raise the bed-plane 12 from horizontal (fig. 1), where it covers the compartment V, to a raised and tilted position (fig. 2), where it gives access to the compartment V.

[0033] Preferably, the mechanism 30 (fig. 3 et seq.) is placed inside the compartment V, and is preferably provided with two equal and specular specimens mounted on inner and opposite walls 10a, 10c of the frame 10, so as to act on opposite sides of the bed-plane 20. Only one mechanism will be described in the following for simplicity.

[0034] The mechanism 30 comprises an (optional) plate 32 fixed / fixable internally to a vertical wall 10a, 10c of the frame 10. On two separate points of the plate 32 are hinged the ends (the lower ends in use) of two rigid lifting arms 40, 50. These two points are spaced apart and aligned along a substantially horizontal line.

[0035] The arms 40, 50 are preferably two bars and / or straight.

[0036] The other ends (the higher ends in use) of the arms 40, 50 are hinged at two separate points to the plane 20, preferably by means of an angle bracket 90 that allows easier coupling between them.

[0037] The arms 40, 50 have hinging axes that are all horizontal and parallel to each other. Specifically: one end of the arm 40 is hinged to the plate 32 about an X1 axis; the other end of the arm 40 is hinged to the angle bracket 90 about an X4 axis; one end of the arm 50 is hinged to the plate 32 about an X2 axis; the other end of the arm 50 is hinged to the angle bracket 90 about an X3 axis.

[0038] The distance between the X1, X2 axes is greater than the distance between the X3, X4 axes.

[0039] The arms 40, 50 have different lengths; in particular, the arm 40 is longer than the arm 50, which is placed in the portion of the bed-plane 12 that, when tilted, remains lower.

[0040] The arms 40, 50 as a whole form, with the frame 10 and the angle bracket 90 (or the plane 20 when the angle bracket 90 is absent), an articulated quadrilateral capable of guiding the bed plane 20 in order to tilt it relative to the frame 10. Figures 1 and 2 show the different tilt achievable.

[0041] To counteract the weight of the bed-plane 20 and help the lifting maneuver, between the arm 40 and the angle bracket 90 there is installed a pair of gas springs 86, 88 that on one side are hinged to the arm 40 and to the angle bracket 90 on the other.

[0042] The homologous ends of the gas springs 86, 88 are preferably hinged about the same horizontal axis, but not necessarily.

[0043] In particular, the gas spring 88 has one end 88a hinged to the angle bracket 90 and one end 88b hinged to the arm 40; and the gas spring 86 has one end 86a hinged to the angle bracket 90 and one end 86b hinged to the arm 40.

[0044] The ends 86a, 88a are hinged about the same horizontal axis X5; the ends 86b, 88b are hinged about the same horizontal X6 axis.

[0045] The X4 axis is placed between the X3 axis and the X5 axis to compress the gas springs 86, 88 when the bed plate 12 is lowered and made horizontal, and preferably the X3, X4, and X5 axes are substantially coplanar.

[0046] The X6 axis is offset from the X1 axis, and placed between the X1 axis and the X4 axis, but not necessarily. In particular, the X6 axis is placed in proximity of, or coincident with, the X1 axis.

[0047] The hinging of the four ends 86a, 88a, 86b, 88b is preferably done by means of spacer members with respect to the relative member to which they are rotationally connected, with the advantage of ensuring constant parallelism between the gas springs 86, 88 and the rest of the mechanism 30, and also of separating the gas springs 86, 88 from each other. The resulting gap between the gas springs 86, 88 is useful for accommodating the arm 40 when the bed-plate 12 is lowered and horizontal, a condition in which the arm 40 and the gas springs 86, 88 are parallel and coplanar.

[0048] Preferably, the spacer members comprise: a spacer member 70 mounted between the end 88a and the arm 40 to space them apart along the X5 axis; a spacer member 72 mounted between the end 86a and the arm 40 to space them apart along the X5 axis; a spacer member 74 mounted between the end 88b and the arm 40 to space them apart along the X6 axis; a spacer member 76 mounted between end 86b and the arm 40 to space them apart along the X6 axis.

[0049] The spacer members 70, 72, 74, 76 in general may have equal length.

[0050] To avoid and correct a slight misalignment between the arm 40 and the gas springs 86, 88 due to the thicknesses of the parts in correspondence of the X4 axis, preferably the spacer member 70 is longer (shorter) than the spacer member 74 and the spacer member 72 is longer (shorter) than the spacer member 76, depending on the side of application with respect to the arm 40.

[0051] Preferably, the gas springs 86, 88 are sized to release different forces, with the advantage that the mechanism 30 can be designed with an extra degree of freedom. Overall, the mechanism 30 can give off a force given by the combination of the forces of the gas springs 86, 88, which may be chosen according to the current or assumed weight of what is supported by the bed-plane 12. In addition, the constraint of using only one gas spring of standard force is waived, making it easier to open and close the bed-plane 12.

[0052] Combining the action of multiple springs in the mechanism 30 allows streamlining the stock of the manufacturer of the mechanism 30 but without the mechanism 30 having any capacity limitations, and achieving a variety of thrust combinations by installing on the mechanism 30 also gas springs of different types and / or forces.

[0053] On the mechanism 30 there can also be installed a number N of gas springs greater than two (N >= 2). For example, the N gas springs may all be installed in parallel, setting them side by side in an array as in the drawing.

[0054] If N is even, N / 2 gas springs may be installed on one side of the arm 40 and N / 2 on the other side.

[0055] If N is odd, LN / 2 +1 gas springs may be installed on one side of the arm 40 and the remaining on the other.

[0056] To facilitate a combined, collision-free swinging of the arm 40 and the gas springs 86, 88 during the displacement of the bed-plane 12, preferably spacer members are also mounted on the X2 and X1 axes.

[0057] In particular, between the arm 50 and the plate 32 is mounted a spacer member 80 that extends along the X2 axis, and between the arm 40 and the plate 32 is mounted a spacer member 82 that extends along the X1 axis.

[0058] One or each of the spacer members 70, 72, 74, 76, 80, 82 is preferably a pin or bushing.

Claims

1. Lifting mechanism for a bed platform, wherein the platform is liftable relative to a fixed frame, comprising: - a first arm; - a second arm shorter than the first arm, the first arm being hinged at one end thereof to the fixed frame about a first axis, the second arm being hinged at one end thereof to the fixed frame about a second axis, the second arm being hinged at one end thereof to the platform about a third axis, the first arm being hinged at one end thereof to the platform about a fourth axis, the first, second, third and fourth axis being in use horizontal and parallel to each other, so that said arms form, with the platform and the fixed frame, an articulated quadrilateral capable of guiding the platform from a lowered and horizontal position to a raised and inclined position; - N gas springs, N >= 2, which are hinged at one end thereof to the fixed frame and at the other end are hinged to the first arm about respectively horizontal axes which are parallel to each other and parallel to the first to fourth axes.

2. Mechanism according to claim 1, wherein the N gas springs are configured to exert different forces.

3. Mechanism according to any of the previous claims, wherein the N gas springs are gas springs different from each other.

4. Mechanism according to any of the previous claims, wherein the N gas springs are arranged in array-fashion next to each other.

5. The mechanism of claim 4, wherein a sub-group of the N gas springs is hinged on one side of the first arm and the remaining gas springs on the opposite side of the first arm.

6. Mechanism according to any one of the previous claims, wherein the homologous ends of all the N gas springs are hinged about the same, in use, horizontal axis.

7. The mechanism according to claim 6, wherein the homologous ends of all N gas springs hinged on the platform are hinged about a fifth axis, horizontal in use, which is substantially coplanar with the third and fourth axis, wherein the fourth axis lies between the third and the fifth axis.

8. Mechanism according to claim 6 or 7, wherein the homologous ends of all the N gas springs hinged on the first arm are hinged about a sixth axis, horizontal in use, wherein the sixth axis lies, along the first arm, between the first and the fourth axis.

9. Mechanism according to any one of the previous claims, comprising spacer members mounted between the ends of all N gas springs and the relevant member to which they are rotatably connected, the spacer members mounted between two opposite ends of a gas spring of the N gas springs being of different lengths.

10. Mechanism according to any of the previous claims, wherein the bed comprises a frame formed of a front vertical wall, two side vertical walls, and a rear vertical wall, which delimit an empty internal compartment, wherein the platform is positioned inside the compartment and for covering it, and the mechanism is placed inside the compartment and comprises two identical and mirror-image specimens mounted on internal and opposite walls of the frame.

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