The present invention relates to a platform with adjustable height for mattress or furniture part (e.g. for a bed, sofa-beds or cots), adapted to support a mattress and/or a person and/or a component of furniture, e.g. a chest-of-drawers or a panel (e.g. made out of wood).

For example from CN 201683466, a structure of bellows-like closing cot is known, while WO 02/34089 describes a frame for beds that is collapsible by means of legs cross-hinged to each other. The problem there to be solved was how to compact the bed or cot in a simple and effortless manner, e.g. to clear the bed-spring under a cabinet when not in use.

The construction of CN 201683466 is modular, but complicated to assemble; that of WO 02/34089 is simpler but heavy to be handled.

A cot or bed-spring, especially when part of a furniture item and/or when it should disappear inside a closet, must allow the user the most possible ease of use, without efforts. In particular, the operation of opening the legs is difficult because the user must simultaneously both lift the frame, which weighs!, and divaricate the underlying legs thereof. Likewise, to close them he still has to laboriously lift the platform to close its divaricated legs.

The known closing/opening systems are uncomfortable and too tiring for example to elderly people, for whom instead these cots, especially in a hospital or retirement environment, are used a lot.

In addition, there is the problem of accidental closing of the bed-spring or cot, when e.g. one moves it. Just a little friction with the floor is enough to close the legs and let the frame collapse.

Therefore a platform of the type above is proposed which is constructed to solve one or more of the above problems, i.e. an adjustable-height platform for a mattress or part of furniture,
comprising
a frame to obtain a support plane for the mattress or the part of furniture,
a support leg, hinged to the frame, able to swing and support the frame off the ground,
characterized by comprising
an arm on one side connected to the leg and on the other coupled to a element, rotatably-mounted on the frame, which is adapted to impose a traction or a thrust on the arm during its own rotation.

The resulting structure of the mechanism with arm and rotatable element is very simple to construct, robust and compact. The number of pieces is limited, favoring the cost, ease of installation and maintenance.
The arm and the rotatable element form an articulated mechanism which drives the legs through a lever, whose power can be amplified by easy gimmicks and thus the whole thing can be made ideal for manual use.

In particular, if the platform has two or more movable and driven legs, the advantage enhances. The simplicity and effectiveness of the mechanism allows a more than proportional saving of pieces, especially because the rotatable element can operate more than one leg simultaneously. Thus it is proposed a platform comprising a said frame and two legs as defined above, characterized in that it comprises a displacement mechanism for the legs constituted by
an element rotatably-mounted on the frame, having for instance two rotatable ends,
two arms, each hinged to a distinct leg and coupled to the rotatable element, e.g. to one of said rotatable ends, so that the rotatably-mounted element is able to impart a push or thrust in opposite directions on the arms during a rotation, or mounted so that the rotation of the rotatably-mounted element at the same time entails opposite traction or thrust on the two arms.

The mechanism is in any case open to many variations, to be used alone or combined, among which:

• the rotatably-mounted element is hinged, e.g. directly, to the frame and has an end free to swing to which an arm is hinged (simple to make and compact solution). When more legs are operated the rotatably-mounted element is hinged to the frame and can have so many ends, free to swing, as are the arms, to each of which ends being hinged an arm;
• there is a rolling element which is integral to the rotatably-mounted element (to transport the cot with little friction);
• there is a lever that is coupled or can be coupled to the rotatably-mounted element and can be gripped by a user to rotate the rotatably-mounted element. E.g. the lever can be telescopic. The effect is to increase the strength of a user to rotate the rotatable element;
• the rolling element is integral with the lever, so as to avoid that the lever touches or sticks to the floor;
• there is a rolling element mounted on a leg with rotation axis parallel to the hinging axis of the leg with respect to the frame, with the aim to ease the transport of the platform.

The rotatable element can be mounted in many ways and points, in particular it can be hinged, e.g. directly, to the frame. Its rotation/hinging/pivoting axis can be parallel or orthogonal to said support plane. These variants allow to choose not only the kinematics and trajectory of the hinging points most suitable for the application, but also to dynamically control the bulk of the mechanism (e.g. by designing the position of the hinge points located at the end-of-travel).

The rotatably-mounted element can:

• comprise or be constituted by a rod or bar coupled to the frame through rotatable pivoting, with rotation axis as defined above, inside or on a spacer element (284) spacing from the frame, and/or
• comprise on said free end a seat adapted to house the end of the arm hinged therein.

The advantages of the invention will be better clarified by the following description of exemplifying embodiments of platform, illustrated in the accompanying drawing where:

• Fig. 1 shows a three-dimensional view from below of a cot or frame in open configuration;
• Fig. 2 shows a side view of the cot or frame in fig. 1;
• Fig. 3 shows a three-dimensional view from below of the cot or frame of Fig. 1 in closed configuration;
• Fig. 4 shows a side view of the cot or frame in fig. 3;
• Fig. 5 shows an enlargement of the circle C of fig. 3.
• Fig. 6 shows a three-dimensional view from above of a variant of the cot or frame in closed configuration;
• Fig. 7 shows a side view of the cot or frame in fig. 6;
• Fig. 8 shows an enlargement of the circle C1 of fig. 7;
• Fig. 9 shows an enlargement of the circle C2 of fig. 6;
• Fig. 10 shows a schematic view of a variant of the mechanism for the cot or frame;
• Fig. 11 shows a schematic view of a variant of the mechanism for the cot or frame in the closed position;
• Fig. 12 shows a three-dimensional view from below of a cot or frame in open configuration;
• Fig. 13 shows a side view of the variant of fig. 12 from below;
• Fig. 14 shows an enlargement of the circle C3 in fig. 12;
• Fig. 15 shows a three dimensional view of the variant in fig. 12 in open configuration;
• Fig. 16 shows a side view of the variant of fig. 15 from below.

In the drawings, same reference numerals indicate same or similar parts, and positional terms as "horizontal" or "vertical" in the description refer to the object when in normal use, resting on a plane or the floor.

It is to be noted that the technical variants described below can be used individually and/or combining them together, even if not expressly stated.

A bed-spring or cot 10 comprises a perimetral, e.g. rectangular and/or metal, frame 12 which serves to support in the center slats 14 (only few indicated) by (optional) socles 22.

The frame 12 is comprised in a horizontal plane H, and with the slats 14 can form a supporting plane or platform e.g. for a person laid down. The slats are 14 optional, the frame or cot 12 being able to do without for supporting something else or being filled at the center.

Two, e.g. U-shaped, legs 16 are hinged at their ends to the frame 12, nearly e.g. at equal distance from the short sides of the frame 12, about an axis X horizontal and parallel to the plane H. The legs 16 can thus swing on and with respect to the frame 12 about the axis X so as to assume two configurations: (i) close to, and e.g. in contact with, the frame 12 (fig. 3 and 4), and (ii) moved away from the frame 12 (fig. 1 and 2), so that the central part of the legs 16 can keep the frame 21 lifted from the ground.

The bed-spring or cot 10 comprises a mechanism for moving the legs 16 between the above two configurations, and for preferably keeping them rigidly in the final configuration. The mechanism can operate individually a leg 16, or two or more together, by means of symmetrical construction, as in the example, and/or can be mounted on two sides of the frame 12 (see example in fig. 11).

For simplicity, we will describe in the following only one side of the various mechanisms, the other side being e.g. equal.

The mechanism comprises a first rigid element or arm 32 and a second rotating element 34, both longitudinally elongated, e.g. like a rod or a bar.

The element 34 is hinged to the frame 12 about an axis Y1 which is vertical and perpendicular to the axis X. One end 40 of the element 34 is angularly movable (along an arc), and can swing about the axis Y1 parallel (and preferably below) the plane H. Note that the shape of the element 34 is not binding, it is enough that by turning it can impart a thrust or pull on the element 32 during a rotation.

The element 32 is hinged to the end 40, with pivoting axis Y2 parallel to Y1, and to the leg 16, with pivoting axis X2 parallel to the axis X.

An (optional) lever 30 is integral with the element 34 to rotate it manually with favorable fulcrum. The lever 30 can be fixed or sliding into a hub or block 44 integral with the element 34, so that it can be concealed under the frame 12 (fig. 5) or extracted (fig. 1) to increase the lever arm on the element 34.

To activate the mechanism, preferably one acts on the lever 30 or on element 34. One pulls the lever 30 from under the frame 12 by sliding the body thereof inside the hub 44. Then by pushing it one rotates the element 34, which pushes or pulls the element 32 which in turn pushes or pulls the connected leg 16 by rotating about the axis X. Consequently the leg 16 thus moved can move closer to the frame 12, or recede away from it and assume a position approximately orthogonal with respect to the frame 12 (fig. 2).

In the extended position (fig. 2) the alignment of the elements 32, 34 and/or the (optional) locking of the element 34 relative to the axis Y1 allows the locking of the leg 16 and prevents its accidental, backward movement. That is, the lever arm on the element 34 relative to an element 32 is designed to be, in the open position of legs 16, sufficiently small.

The pivoting axis relative to the frame 12 of the piece pulling and/or pushing the legs 16 can also be different from fig. 2. E.g. a variant of the bed-spring or cot 50 is shown in figures. 9÷6. It analogously comprises a perimetral frame 12, which e.g. can support slats (not shown) in the center. The frame 12 is comprised in a horizontal plane H, and forms as before a supporting plane or platform e.g. for a person laid down or a mattress.

As before, two U- shaped legs 16 are hinged at their ends to the frame 12, nearly e.g. at equal distance from the short sides of the frame 12, about an axis X horizontal and parallel to the plane H2. The legs 16 can thus swing with respect to the frame 12 about the axis X so as to assume two configurations as the preceding variant.

As another alternative, preferably to the legs 16 are integral pins 52 on which there are mounted wheels 54, useful to slide the bed-spring or cot on the floor and place it underneath a furniture item when the legs 16 are retracted (fig. 7).

The bed-spring or cot 50, too, comprises a mechanism for moving the legs 16 between the two above-mentioned configurations and keeping them rigidly in the final configuration. Again the mechanism is symmetrical, i.e. it can operate individually a leg 16 or two together, by means of symmetrical construction, and/or be mounted on two sides of the frame 12.

As in fig. 2, there are a first rigid element 62 and a second rigid element 64, both longitudinally elongated, like e.g. a rod or a bar, hinged to each other at one end.

The element 64 is hinged at its center to a bracket or spacer element 60 (fig. 9), which is integral to the lower surface of the frame 12 and from that it extends perpendicular to the plane H2. The pivoting takes place around an axis Z1 parallel to the axis X. Two ends 70 of the element 64 are movable along an arc and can swing around the axis Z1 remaining in a plane orthogonal to (and preferably below) the plane H2.

The element 64 is hinged at its ends 70, with pivoting axis Z2 parallel to Z1, to the element 62, which is hinged at the other end, with a hinging axis Z3 parallel to Z1, to the leg 16.

To the element 64 is integral, through an arm 76 (fig. 9), a (optional) lever 72, useful to rotate it with favorable fulcrum. Although the lever 72 can slide inside the arm 76, it is preferred it to be fixed.

As another variant, at the end of the lever 72 (or 30) there is mounted a wheel 78, which can engage, and push against, the floor to lift the frame 12 when one wants to extract the legs 16. In particular, the wheel 78 (or equivalent rolling means) has rotation axis parallel to the axis Z2, thus by rolling it facilitates the rotation of the lever 72 or 30 and raises a little the frame 12. In fact, in the retracted position (fig. 6) the lever arm of the element 64 with respect to the elements 62 and the pole Z1 is small, and great effort is needed to raise the frame 12.

To operate the mechanism, one acts substantially as before, e.g. on the lever 70. It is rotated to rotate the element 64, which pushes or pulls the element 62 which in turn pushes or pulls the leg 16.

Another variant 90 for moving the elements as e.g. those numbered 32 and/or 62 and/or 232, is shown in fig. 10. Instead of using an elongated member and/or a coupling through hinging between a rigid element (e.g. the 32 and/or 62) and the rotatable member, the first is equipped (see segment indicated with 92 in fig. 10) with a toothing 94 on which engages a rotatable pinion 96 pivoted on the frame 12. By rotating the pinion 96 the segments 92, and consequently the legs 16, approach or move away with the same effect.

In fig. 11 a different variant 100 for the location of the mechanism is generally shown. On a rotatable shaft 102, nearly long as the width of the legs 16 and rotatably mountable under the frame 12, there are two elongated rods or brackets 104, and at the end of each rod 104 there is hinged an arm 106, to be used with the function of the arm 32 or 62. It is understood, therefore, that the pivoting P of the arms 106 to the rotatable element 102, 104 can take place also on different sides of the frame.

Fig. 12 and following show another variant of bedspring or cot 210 which exploits the concept of fig. 11 and which as before comprises a perimetral frame 12, optional slats 14 and two legs 16 hinged at their ends to the frame 12 about an axis X.

We will only describe the main differences, namely the mechanism for moving the legs 16 between the two above-mentioned configurations (see also fig. 14).

The mechanism as before is symmetrical. To operate one or two legs 16 it comprises a first rigid element or arm 232 and a rotatable element or shaft 234, both longitudinally elongated, like e.g. a rod or a bar. The arm 232 is hinged at one end to the leg 16 about an axis parallel to the axis X.

The element 234 is pivoted, by means of bushings or bearings or sleeves 284, to the frame 12 around an axis Y6 which is parallel to the plane H of the frame 12 (or, which is the same, to the X axis).

From the body of the element 234, about at the center of its length, extends radially an element 240 angularly movable (along an arc) that can swing around the axis Y6 and at the free end of which there is hinged one end of the arm 232 about an axis Y7 parallel to the axis Y6. In particular, the element 240 comprises a seat nearly as wide as or larger than the arm 232, so that during the movement, and especially in the two end-of-travel configurations (legs 16 opened or closed), the arm 232 can be embraced by the element 240 and end up inside the seat. The result is that the element 240 and the arm 232 end up arranged along the same axis (which is approximately parallel to the plane H) and reduce their overall bulk (see fig. 16). To maximize this effect the element 240 can be or comprise a bracket 242 with U-shaped section, integral to the element 234, and even more preferably the bracket 242 or the element 240 constitute part of the element 234 in correspondence of its axis.

To operate two legs 16 two elements 240 are used protruding in position diametrically opposite the element 240.

An (optional) 230 lever can be tucked into a (optional) hole of the element 234 for manually rotate it with favorable fulcrum (fig. 14).

To each leg 16 is connected an optional spring 290 adapted to pull the leg 16 to the open position. The aim is to facilitate the opening when the lever arm between the bracket 242 and the arm 232 is too small or disadvantageous, or the lowered cot 210 weighs too much.

On the legs 16 wheels can be mounted touching the ground when the legs 16 are closed and parallel to the frame 12.

To operate the mechanism, one acts as in the previous cases.