Piece of furniture for a recreational vehicle

Abstract

Piece of furniture (1) for a recreational vehicle comprising a functional structure (2) that can be raised and / or lowered; a winding shaft (3) having an its own longitudinal extension; support means (4) to support the functional structure operatively connected to the winding shaft; the winding shaft being drivable to modify the length of the support means (4) so as to raise and / or lower the functional structure (2); an auxiliary device (5) for weight compensation of the functional structure and / or to assist the movement of the functional structure, said auxiliary device (5) being operatively connected to said winding shaft (3); wherein the auxiliary device (5) comprises a linear guide element (6), a slider (7) linearly movable along the linear guide element (6) and operatively connected to the winding shaft (3) by means of a tensile element (8), at least one force generating device (9) for supplying a force (F; F1, F2) aimed at influencing the linear movement of the slider along the linear guide element; and wherein the linear guide element (6) of the auxiliary device (5) is oriented orthogonally with respect to the winding shaft (3).

Description

PIECE OF FURNITURE FOR A RECREATIONAL VEHICLE’TECHNICAL FIELD

[0001] . The object of the present invention is a piece of furniture comprising a functional structure that can be raised and / or lowered.

[0002] . The piece of furniture according to the invention is particularly suitable for a recreational vehicle.

[0003] . The present invention also relates to a recreational vehicle comprising said piece of furniture.STATE OF THE ART

[0004] . In known recreational vehicles, such as campers or caravans, the reduced interior spaces typically require the provision of convertible furnishing structures, adapted to modify the intended use thereof, for example a sofa bed as well as tables and chairs which can be transformed, if necessary, into a bed.

[0005] . Functional structures (for example, bed or sofa) are also known, hanging from the ceiling or walls of an internal room of the recreational vehicle by means of a plurality of belts and provided with a motorized winding roller which, by winding or unwinding the belts of said plurality in a controlled manner, varies the length thereof, causing the raising as well as the lowering of the functional structure itself (bed or sofa) in the internal room of the recreational vehicle.

[0006] . The prior art document DE-102020130514 discloses an example of a raising / lowering bed structure by means of a winding roller which winds / unwinds belts hanging the functional structure itself from the ceiling. This known example further envisages that the winding roller is associated with a mechanism for weight compensation of the bed structure comprising ropes or wires which are wound around conical spools arranged at opposite ends of the roller and returned by a pulley system to an elastic device (see figure 17 of DE-102020130514).

[0007] , Such a system, although partially advantageous from some points of view such as the ability to have the elastic action of the device parallel to the rotation axis of the windingroller and flanked therewith, is extremely complex to assemble and maintain in particular if the wire or rope derails from the return pulleys on which it is wound. Furthermore, the high number of components makes the system prone to malfunctions as well as generating high friction which could tear the ropes or even just one of the two ropes. In addition, the provision of two ropes wound at opposite ends of the winding shaft necessarily imposes frequent misalignments or imbalances which tend to undesirably tilt the winding roller or even worse to generate shear forces on the roller aimed at flexing the roller itself when in operating conditions, compromising the winding capabilities of the belts.

[0008] . The need is therefore felt to provide an improved solution for moving a functional structure of a piece of furniture for a recreational vehicle, able to compensate at least in part for the weight of the functional structure itself, which is reliable and robust when in operating conditions, without thereby entailing an increased number of components with respect to known solutions.SUMMARY OF TH E INVENTION

[0009] . An object of the present invention is therefore to obviate the drawbacks complained of with reference to the state of the art.

[0010] . This and other objects are achieved with a piece of furniture according to claim 1 , as well as with a vehicle according to claim 10.

[0011] . Some advantageous embodiments are the object of the dependent claims.

[0012] . According to an aspect of the invention, a piece of furniture comprises a functional structure that can be raised and / or lowered, a winding shaft having its own longitudinal extension, support means to support the functional structure operatively connected to the winding shaft, the winding shaft being drivable to modify the length of the support means so as to raise and / or lower the functional structure.

[0013] , The piece of furniture further comprises an auxiliary device for weight compensation of the functional structure and / or to assist the movement of the functional structure, said auxiliary device being operatively connected to said winding shaft.

[0014] . Said auxiliary device for weight compensation of the functional structure and / or toassist the movement of the functional structure comprises a linear guide element, a slider linearly movable along the linear guide element and operatively connected to the winding shaft by means of a tensile element, at least one force generating device to supply a force aimed at influencing the linear movement of the slider along the linear guide element.

[0015] , The influence action on the slider can be a thrust action on the slider.

[0016] , The linear guide element of the auxiliary device is oriented orthogonally with respect to the winding shaft.

[0017] , The tensile element can be formed by a single belt wound in a longitudinally median portion of the winding shaft and ended on the winding shaft itself.

[0018] . The tensile means can comprise a plurality of belts wound and ended in end portions of the same winding shaft.

[0019] . The at least one force generating device can comprise two elastic elements, for example gas springs, hinged to the slider on opposite sides thereof so as to change the orientation of the force applied as a function of the position of the slider along the linear guide element. By appropriately sizing the elastic elements and the arrangement thereof with respect to the stroke of the slider, it is possible to keep the resultant of the forces acting on the piece of furniture substantially constant when the position in height of the piece of furniture varies, so that, at whatever level the bed is located, it is possible to raise or lower it, always exerting the same constant force.

[0020] . The at least one force generating device can comprise a linear actuator, for example of the nut-screw type, operatively connected to an its own electric motor.

[0021] , An electronic control unit operatively connected with said electric motor of the linear actuator can also be provided to drive the linear actuator under the control of the electronic control unit.

[0022] . Thanks to the proposed solutions, it is possible to create a vertically movable piece of furniture in which an automatic system is provided for weight compensation of the functional structure as well as for assisting the raising of the same functional structure which is at the same time compact, while being robust and reliable when in operating conditions.BRI EF DESCRI PTION OF TH E DRAWI NGS

[0023] . Further features and advantages of the invention will appear from the following description of embodiments, given by way of non-limiting example, with reference to the accompanying figures, in which:- figure 1A schematically shows in axonometry an assembly of a piece of furniture comprising a functional structure, according to an embodiment, in some operating configurations;- figure 1B pictorially shows a raised vertical view of a recreational vehicle, according to an embodiment;- figure 2 A shows in axonometric view from below an assembly of a piece of furniture comprising a functional structure, according to an embodiment, when in a lowered configuration;- figure 2B shows a detail of the assembly of figure 2 A;- figure 2C shows the assembly of figure 2 A in plan view from below;- figure 2D shows a cross section of the assembly of figure 2 A obtained according to the cutting plane indicated with the arrows D-D of figure 2C;- figure 3 A shows an axonometric view from below of the assembly of figure 2 A when in a raised configuration;- figure 3B shows a detail of the assembly of figure 3 A;- figure 3C shows the assembly of figure 3 A in plan view from below;- figure 3D shows a cross section of the assembly of figure 3 A obtained according to the cutting plane indicated with the arrows D-D of figure 3C;- figure 4 A shows in axonometric view from below an assembly of a piece of furniture comprising a functional structure, according to an embodiment, when in a lowered configuration;- figure 4B shows the assembly of figure 4 A in plan view from below;- figure 4C shows a cross section of the assembly of figure 4 A obtained according to the cutting plane indicated with the arrows C-C of figure 4B;- figure 5 A shows an axonometric view from below of the assembly of figure 4 A when in a raised configuration;- figure 5B shows the assembly of figure 5 A in plan view from below;- figure 5C shows a cross section of the assembly of figure 5 A obtained according to the cutting plane indicated with the arrows C-C of figure 5B;- figure 6 A shows in axonometric view from below an assembly of a piece of furniture comprising a functional structure, according to an embodiment, when in a lowered configuration;- figure 6B shows a detail of the assembly of figure 6 A;- figure 6C shows the assembly of figure 6 A in plan view from below;- figure 6D shows a cross section of the assembly of figure 6 A obtained according to the cutting plane indicated with the arrows D-D of figure 6C;- figure 7 A shows an axonometric view from below of the assembly of figure 6 A when in a raised configuration;- figure 7B shows a detail of the assembly of figure 7 A;- figure 7C shows the assembly of figure 7 A in plan view from below;- figure 7D shows a cross section of the assembly of figure 7 A obtained according to the cutting plane indicated with the arrows D-D of figure 7C;- figure 8 A shows in plan view from below an assembly, according to an embodiment, when in a lowered configuration;- figure 8B shows a cross section of the assembly of figure 8 A obtained according to the cutting plane indicated with the arrows B-B of figure 8 A;- figure 8C shows the assembly of figure 8 A in a plan view from below when in a raised position;- figure 8 D shows a cross section of the assembly of figure 8 C obtained according to the cutting plane indicated with the arrows D-D of figure 8 C.DETAI LED DESCRI PTION OF CERTAI N EMBODI MENTS

[0024] , In accordance with a general embodiment, a piece of furniture 1 is provided. The piece of furniture 1 is of the type adapted to be installed on a recreational vehicle 10, such as a motorhome, a caravan, a boat, and the like.

[0025] , The piece of furniture 1 can be installed in a home.

[0026] . The piece of furniture 1 comprises a functional structure 2 that can be raised and / or lowered. The functional structure 2 can comprise, for example, a bed and / or a sofa and / or a seat which therefore can be raised and / or lowered.

[0027] , The provision of a functional structure 2 that can be raised or lowered allows to make a convertible piece of furniture and / or a recessed piece of furniture, allowing an internal room 29 of the recreational vehicle 10 to be reconfigured, if necessary. For example, in the case of a motorhome type vehicle, the functional structure 2 can be lowered if necessary to create a sleeping area.

[0028] . The functional structure 2 preferably has a body defining a longitudinal extension LON and a transverse extension TRA. For example, the body of the functional structure 2 is substantially quadrangular, although it can comprise one or more gaps, for example to conform to the features of the internal room of the recreational vehicle. The functional structure further comprises a thickness S which can be much smaller than the longitudinal LON and transverse TRA extensions and which for example is substantially constant and defined by a functional structure edge.

[0029] . The piece of furniture 1 further comprises a winding shaft 3 (or winding roller) having an its own longitudinal extension which substantially coincides with the longitudinal extension direction of said winding shaft 3. Preferably, the winding shaft 3 is oriented so that its own rotation axis is aligned with the longitudinal dimension LON of the functional structure 2.

[0030] . When in operating conditions, the winding shaft 3 is rotatable with respect to the functional structure 2, and in particular is mounted to the functional structure 2 so as to be rotatable about its own longitudinal axis. To this end, mounting brackets 20 can be provided for the winding roller or shaft 3 which are fixed to a lower surface 16 of the functionalstructure 2, so that the winding shaft 3 can rotate about its own longitudinal axis without translating its own rotation axis with respect to the functional structure 2.

[0031] , The piece of furniture 1 further comprises support means 4 to support the functional structure 2 which are operatively connected to the winding shaft 3. The winding shaft is drivable to modify the length of the support means so as to raise and / or lower the functional structure 2 as a result of the modification of the length of the support means.

[0032] . In accordance with a preferred embodiment, the support means 4 are configured to keep the functional structure 2 hanging on a ceiling or side walls of an internal room of a recreational vehicle 10. In general, in the following mention will be made for the sake of simplicity to support means for keeping the functional structure 2 hanging from a ceiling, but it must be understood that the fixing can also occur in a completely similar manner to the vertical walls of the recreational vehicle or any other horizontal, vertical or inclined fixed support structure, even inside homes. The support means 4 for example comprise substantially inextensible flexible elements, and for example a plurality of raising belts 4, for example four raising belts arranged on two opposite sides of the functional structure 2. In accordance with an embodiment, the support means 4 comprise substantially inextensible flexible elements such as cords or ropes or cables for hanging the functional structure 2 on the ceiling of the internal room of the recreational vehicle 10. The support means 4, for example raising belts 4, are preferably ended and wound in end portions 18, 19 of the winding shaft 3, and preferably two opposite support belts 4 are wound in each end portion 18, 19. The support means 4 can further comprise return elements 21 arranged on opposite sides of the functional structure 2.

[0033] . The functional structure 2 preferably comprises a lower surface 16 having a longitudinal extension and a transverse extension and the winding shaft 3 is arranged in a median portion of the lower surface of the functional structure and extends substantially for the entire longitudinal extension LON of the functional structure 2, while the linear guide element 6 extends from a transverse side of the winding shaft 3. Preferably, the force generating device 9 extends from the same transverse side of the winding shaft 3 where thelinear guide element 6 is mounted.

[0034] , The functional structure can comprise at least one functional surface 28 which forms a bed and / or a seat and which substantially faces upwards.

[0035] . Advantageously, the piece of furniture 1 further comprises an auxiliary device 5 for weight compensation of the functional structure 2 and / or to assist the movement of the functional structure 2, said auxiliary device 5 being operatively connected to said winding shaft 3. Thereby, the auxiliary device 5 cooperates with the winding shaft 3 to allow the raising and / or lowering of the functional structure 2 of the piece of furniture 1.

[0036] . The auxiliary device 5 comprises a linear guide element 6, such as a track, and a slider 7 linearly movable along the linear guide element 6.

[0037] , The slider 7 is also operatively connected to the winding shaft 3 by means of a tensile element 8. The tensile element 8 preferably comprises at least one substantially inextensible flexible elongated element, for example a belt. The tensile element 8 is preferably ended at an end thereof on the winding shaft 3.

[0038] . The auxiliary device 5 further comprises at least one force generating device 9 to supply a force F, F1 , F2 aimed at influencing the linear movement of the slider 7 along the linear guide element 6.

[0039] . When in operating conditions, to move the functional structure 2 downwards, the winding shaft 3 is moved in rotation causing the unravelling of the support means 4 (for example a plurality of support belts 4) and at the same time the winding on the same winding shaft 3 of the tensile element 8 operatively connected to the slider 7, causing a tensile action T aimed at moving the slider 7. At the same time, the force generating device 9 generates a force F, F1 , F2 on the slider 7 with an antagonistic effect with respect to the tensile action T, allowing to compensate the weight of the functional structure 2 to be moved vertically.

[0040] . When in operating conditions, to move the functional structure 2 upwards, the winding shaft 3 is moved in rotation, causing the winding of the support means 4 (for example a plurality of support belts 4) and at the same time the unravelling from the same winding shaft 3 of the tensile element 8 operatively connected to the slider 7. At the same time, the forcegenerating device 9 generates a force F, F1 , F2 on the slider 7 aimed at unravelling the tensile element 8, assisting the raising action of the functional structure 2.

[0041] . With further advantage, the linear guide element 6 of the device is oriented orthogonally with respect to the winding shaft 3. Preferably, in fact, the winding shaft is oriented in the longitudinal direction LON and the linear guide 6 is oriented in the transverse direction TRA. Preferably, the winding shaft is arranged substantially in a transversely median portion 17 of the functional structure 2 and the linear guide 6 extends from only one transverse side of the winding shaft 3. It is thereby possible to exploit the substantially two- dimensional extension of the functional structure 2 to arrange, orthogonally oriented with respect to one another, both the winding shaft 3 and the linear guide 6 of the device 5 for weight compensation of the functional structure and / or to assist the movement of the functional structure 2. Moreover, it avoids having to provide complicated systems for returning the tensile element 8 between the winding shaft 3 and the linear guide 6.

[0042] , In accordance with a preferred embodiment, the tensile element 8 is formed by a single belt 8. Said single belt 8 is preferably wound around a median portion 17 of the longitudinal extension of the winding shaft 3 and is fixed thereto. Preferably, said median portion 17 is substantially equidistant from the ends 18, 19 of the winding shaft 3 and is substantially equidistant from the edges of the functional structure 2. The provision of the tensile belt 8 arranged wound around the median portion 17 of the winding shaft 3 allows to minimize the length of the tensile belt 8, making a robust and reliable solution. Furthermore, the provision of the tensile belt 8 wound around the median portion 17 of the winding shaft 3 avoids bending stress on the end portions 18, 19 of the winding shaft 3 where the support belts 4 are already ended.

[0043] , The tensile belt 8 is preferably ended at an end 27 thereof and at least one return element 22 integral with the slider can be provided to return the tensile belt 8 towards the end 27 thereof. The end can be fixed with respect to the functional structure 2. The arrangement of the end 27 in combination with the at least one return element 22 makes it possible to determine the advancement direction of the slider, as well as it makes it possibleto reduce the stroke of the slider with respect to the vertical stroke of the functional structure2 and to make a compact guide 8.

[0044] . In accordance with a preferred embodiment, the at least one force generating device 9 comprises two elastic elements 11 , 12, for example gas springs, which are hinged to the slider 7 on opposite sides thereof so as to modify the orientation of the force F1 , F2 applied individually by each elastic element 11 , 12 as a function of the position of the slider 7 along the linear guide element 6. The resultant of the forces F1 and F2 is preferably always aligned with the tensile force T of the tensile belt 8.

[0045] . For example, the slider 7 is hinged with the respective elastic elements 11 , 12 by providing two opposite hinges 23, 24. At the opposite end, the elastic elements 11 , 12 can be hinged by means of the hinges 25, 26 to a mounting bracket 13 which is fixed to the functional structure 2. It is thereby possible to discharge the forces on the functional structure 2, avoiding bending (cutting) overloading the winding shaft 3. Said support bracket 13 is preferably arranged parallel to the winding shaft 3 and next to it on the lower surface 16 of the functional structure 2.

[0046] . The linear guide 6 can comprise two opposite tracks for the slider, arranged on longitudinally opposite sides of the linear guide 6. For example, the linear guide 6 is formed by a profiled element which receives rolling members (wheels) of the slider 7 in a transversely directed guide cavity thereof.

[0047] , Said two elastic elements 11 , 12 are configured to be loaded in compression when the functional structure 2 is lowered, i.e., moved downwards and consequently to extend when the functional structure 2 is raised, i.e., moved upwards.

[0048] . When in operating conditions, the functional structure 2 can be in a lowered configuration (figures 2 A-D) which causes the at least partial unravelling of the support belts 4 with respect to the winding shaft 3, and consequently causes the contextual winding of the tensile belt 8 of the device 5 for weight compensation which then pulls the slider 7 against the action of the elastic elements 11, 12, compressively loading said elastic elements, which therefore allow the elastic force F1 , F2 to be supplied to compensate theweight of the functional structure 2. From a lowered configuration, the functional structure 2 can be raised and be in a raised configuration (figures 3 A-D) in which the tensile belts 4 are wound around the winding shaft 3 and at the same time the tensile belt 8 is at least partially unwound, i.e., unravelled from the winding shaft 3, causing a movement of the slider 7 pushed by the action of the elastic elements 11 , 12. In this case the device 5 cooperates to assist the raising of the functional structure 2.

[0049] . The angles a, p formed by each elastic force F1 , F2 of said elastic devices 11, 12 and the direction of the tensile force T supplied by the tensile belt 8 can be equal to each other in both the raised configuration and in the lowered configuration, even if in accordance with an embodiment said angles are different, and for example differ by about 5°-10°. The angular excursion between a raised configuration and a lowered configuration can be about 20°, and for example said angle a is about 60° when the functional structure is in a lowered configuration and is about 45° when the functional structure is in a raised configuration. The angles a, are preferably equal to each other.

[0050] . The provision of said variable angles a, p, allows the system to self-balance so as to generate an elastic force capable of balancing the weight force for each position in height of the piece of furniture. Since the balancing force generated depends on the inclination of the elastic elements with respect to the tensile force T of the belt 8, it allows, in particular, to compensate for the fact that the resultant of the forces acting on the piece of furniture depends on the level of compression of the elastic elements and on the variation of the torque (moment) acting on the winding shaft 3 as a function of the increase of the thickness (arm) of the belt 4 or 8 wound instantaneously around the winding shaft 3 itself. In other words, it allows to balance, during the raising and / or lowering of the functional structure 2, the instantaneous variation of the torques as an effect of the increased arm of the weight force (with respect to the axis of the shaft 3) due to the increase in the number of turns on the winding shaft 3.

[0051] , For example, during the lowering phase of the functional structure 2: the raising belts4 are wound at the maximum on the winding shaft 3 whereby the arm of the force exerted bythe raising belts 4 on the winding shaft 3 is maximum; the elastic devices 11 and 12, for example gas springs, are completely extended so that the elastic force exerted by them is minimal; and the tensile belt 8 is completely unwound, it is therefore at its own minimum winding diameter and thus the arm of the force exerted by it on the winding shaft 3 is minimal. By moving the bed downwards, the raising belts 4 unwind, reducing the winding diameter and thus the arm of the force exerted by them, the elastic devices 11 and 12 are compressed, increasing the force exerted by them, the tensile belt 8 is wound on the shaft 3, increasing the winding diameter thereof and therefore the arm of the force exerted by it. Consequently, to maintain the force necessary to move the functional structure 2 constant, the resultant of the forces expressed by the elastic devices must decrease as the stroke increases in order to compensate for the other variations specified above. This occurs thanks to the change of the angles a, and during the stroke.

[0052] , The fixing bracket 13 can be arranged near or at a transverse edge of the functional structure 2.

[0053] . The tensile belt 8 can be returned by means of at least one return element 22 to move the slider 7 by pulling it towards the transverse edge (figures 4 A-C and 5 A-C) where the bracket 13 is mounted. The provision of the return element 22 allows to manage the advancement direction of the slider (for example: towards the edge or away from the edge) as well as it allows to reduce the stroke of the slider with respect to the movement stroke of the functional structure 2. Further return elements 22 can be provided to modify the ratio between the stroke of the slider 7 and the raising / lowering movement of the functional structure 2.

[0054] . In accordance with an embodiment, the at least one force generating device 9 comprises a linear actuator 14, for example an actuator of the nut-screw type, which is operatively connected to an its own electric motor 15. In this case, the force F is generated by the electric motor itself and / or by internal brakes or friction inside the linear actuator or the transmission thereof and is directed parallel to the tensile force T of the tensile belt 8.

[0055] . Preferably, an electronic control unit operatively connected with said electric motor 15is provided to drive the linear actuator 14 under the control of the electronic control unit. In this case, the piece of furniture 1 can further comprise at least one sensor to detect and / or calculate information on the current height (i.e., the current position) of the functional structure 2 operatively connected with the electronic control unit to drive the linear actuator based on the detected and / or calculated information on the current height of the functional structure. The detection or calculation of the information on the current position of the functional structure 2 can be achieved by monitoring the position of the cursor 7 inside the linear guide element 6 thereof.

[0056] . The at least one sensor can comprise at least one force sensor to detect information on the voltage supplied by the tensile element 8. The at least one sensor can comprise at least one sensor to detect the rotation speed of the winding shaft 3.

[0057] , In accordance with a general embodiment, a recreational vehicle 10 is provided comprising at least one piece of furniture 1 according to any one of the preceding claims.

[0058] . In accordance with a preferred embodiment, the recreational vehicle 10, such as a motorhome, comprises a habitable room 29 comprising side walls and / or a ceiling and the support means 4 of the piece of furniture 1 extend therefrom to the functional structure 2 that can be raised and / or lowered, and in particular up to the winding shaft 3.

[0059] . In accordance with an embodiment, the habitable room 29 comprises a substantially vertical wall, which can be a perimeter wall of the recreational vehicle, and the support means 4 of the piece of furniture 1 extend from the vertical wall of the habitable room 29 to the functional structure 2 that can be raised and / or lowered.

[0060] . In an embodiment, the support means 4 consist of substantially inextensible flexible elements such as belts, cords, ropes or cables and guide means are provided which are arranged longitudinally integral with the vertical walls to maintain the support means 4 in an extended vertical configuration between the functional structure 2 and a relative anchoring or fixed return point integral with the load-bearing structure (wall or ceiling).

[0061] , It is understood, however, that the foregoing is of exemplary and non-limiting value, therefore any variations of detail which may become necessary for technical and / orfunctional reasons, are considered from now on to fall within the same protective scope defined by the following claims.

Claims

CLAIMS1. A piece of furniture (1) comprising:- a functional structure (2) that can be raised and / or lowered;- a winding shaft (3) having an its own longitudinal extension and being arranged horizontally;- support means (4) to support the functional structure (2) operatively connected to the winding shaft (3); the winding shaft (3) being drivable in rotation about its own axis to cause the winding / unwinding thereon / therefrom of the support means (4) and modify the unwound length of the support means (4) so as to raise and / or lower the functional structure (2);- an auxiliary device (5) for weight compensation of the functional structure and / or to assist the movement of the functional structure, said auxiliary device (5) being operatively connected to said winding shaft (3); wherein the auxiliary device (5) comprises:- a linear guide element (6)- a slider (7) linearly movable along the linear guide element (6) and operatively connected to the winding shaft (3) by means of a tensile element (8),- at least one force generating device (9) to supply a force (F; F1 , F2) aimed at influencing the linear movement of the slider along the linear guide element (6); and wherein the linear guide element (6) of the auxiliary device (5) is oriented orthogonally with respect to the winding shaft (3).

2. Piece of furniture according to the preceding claim, wherein the tensile element (8) comprises a belt, and preferably is formed by a single belt that is wound in a longitudinally median portion (17) of the winding shaft (3) and ended on the winding shaft (3); and wherein, preferably, the tensile element (8) is returned by at least one return element (22) to reduce the movement stroke of the slider (7) with respect to the raising and / or lowering movement stroke of the functional structure.

3. Piece of furniture according to claim 1 or 2, wherein the at least one force generating device (9) comprises two elastic elements (11 , 12), for example gas springs, which are hinged to the slider (7) on opposite sides thereof so that the orientation of the force (F1 , F2) applied by the elasticelements (11 , 12) varies as a function of the position of the slider along the linear guide element(6).

4. Piece of furniture according to claim 3, wherein the two elastic elements (11 , 12) are hinged to a support bracket (13) that is fixed to the functional structure (2).

5. Piece of furniture according to claim 3, wherein the two elastic elements (11 , 12) are configured to be loaded in compression when the functional structure (2) is lowered, i.e. , moved downwards.

6. Piece of furniture according to any one of the preceding claims, wherein the at least one force generating device (9) comprises a linear actuator (14), for example of the nut-screw type, which is operatively connected to an its own electric motor (15).

7. Piece of furniture according to claim 6, further comprising an electronic control unit operatively connected with said electric motor of the linear actuator to drive the linear actuator (14) under the control of the electronic control unit; wherein, preferably, the piece of furniture further comprises at least one sensor to detect and / or calculate information on the current position of the functional structure (2), said at least one sensor being operatively connected with the electronic control unit to drive the linear actuator (14) based on the detected and / or calculated information on the current height of the functional structure; wherein, preferably, said at least one sensor comprises:- at least one sensor to detect the current position of the slider (7) with respect to the linear guide element (6); and / or- at least one force sensor to detect information on the voltage supplied by the tensile element (8); and / or- at least one sensor to detect the rotation speed of the winding shaft (3).

8. Piece of furniture according to any one of the preceding claims, wherein the functional structure (2) comprises at least one functional surface (28) forming a bed and / or a seat.

9. Recreational vehicle (10) comprising at least one piece of furniture (1) according to any one of the preceding claims.

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