WO2009008011A1

WO2009008011A1 - Mechanical device for opening and closing sofa beds

Info

Publication number: WO2009008011A1
Application number: PCT/IT2007/000474
Authority: WO
Inventors: Graziantonio Cannito
Original assignee: Altaflex S.R.L.
Priority date: 2007-07-12
Filing date: 2007-07-12
Publication date: 2009-01-15
Also published as: EP2166900A1

Abstract

Mechanical device for opening and closing sofa beds, comprising a plurality of rods and articulated joints, capable of positioning a frame of a sofa bed in two configurations, so-called 'open' and 'closed' configurations, and characterised in that the number of rods in the quadrilateral (A) is not greater than three and the number of rods in the quadrilateral (B) is not greater than two. The change between the two positions is obtained without having to remove the seat and back cushions, and with a single movement. Said system moreover comprises an anti-foldover block, which prevents the frame from accidentally closing if loaded beyond limits. Finally, the cushion exit system is obtained with only two rods.

Description

Mechanical device for opening and closing sofa beds

DESCRIPTION

A mechanical device for opening and closing sofa beds forms the object of the present finding. Normally, sofa beds comprise a fixed structure and a plurality of movable frames which are consecutively bound to each other. Said frames can be moved through rototranslation motions from a so-called "closed" position, in which they are folded in an orderly manner and substantially contained in the volume formed by the fixed structure, to a so-called "open" position according to which the movable frames are consecutively aligned with each other, outside said volume, and define a rest surface. This movement is made possible by one or more kinematic mechanisms interposed between the fixed structure and the frames themselves. Numerous embodiments of similar devices are known at the state of the art. Almost all, by now, permit carrying out the opening and closing operations by means of a single movement, without having to remove the seat cushions before carrying out the aforesaid operations. Notwithstanding the technical progress, the known applications still have several disadvantages. Firstly, said devices are complex and require a large number of levers and articulations. Moreover, they do not avoid the possibility of accidental closure. In fact, in the cases in which, with the sofa in open position, the user sits near the articulation point between two adjacent frames, an accidental closure of the bed itself can occur.

The finding, object of the present invention, resolves the above mentioned problems since it regards a mechanical device for opening and closing sofa beds comprising a framework structure and a plurality of movable frames, consecutively bound to each other and movable through rototranslation motions; said device moreover comprises at least one first articulated quadrilateral (A) and at least one second articulated quadrilateral (B), interlocked and driven by said movement, and is characterised in that the number of rods in the quadrilateral (A) is not greater than three and the number of rods in the quadrilateral (B) is not greater than two.

According to another object, the finding is equipped with an anti-foldover block (K) which prevents the structure in open position from accidentally closing, if loaded beyond the limits with either concentrated or distributed load.

These and other advantages will be clearer from the detailed description of the invention, which will make specific reference to tables 1/3, 2/3 and 3/3 in which a preferential implementation diagram is represented which is entirely exemplifying and non- limiting. In particular:

• Fig. 1 represents the structure of the device with all its main components, according to a configuration which attains the opening of the sofa bed; • Figs. 2a, 2b and 2c show the three innovative components of the mechanical device, i.e. the quadrilaterals (A) and (B) and the mechanical stop (K);

• Fig. 3 shows the quadrilateral C;

• Figs. 4a-e schematically represent the functioning of the mechanical stop;

• Figs. 5a and 5b represent the device in configurations according to which they respectively attain an intermediate position and a closed position of the sofa bed;

• Fig. 6 represents a second embodiment of the device. With reference to the aforesaid figures and in particular to fig. 1, the structure of the device is composed of a quadrilateral A comprising the rods (1, 2, 3), a quadrilateral B comprising the rods (4, 5), a quadrilateral C comprising the rods (17, 18), and a mechanical stop K. Said device moreover comprises: a head frame tube (7) and a plate (6) fixed on said tube, a central frame tube (9) and an articulated joint (8) between said head frame tube and foot frame tube (15), a return rod (10) of said foot frame tube, a fixed plate (11), an articulated joint between central frame tube and foot frame tube (12), a first return rod (13) of said foot frame tube and foot support, a second return rod (14) of said foot frame tube and foot support, a rod of foot support (16) and back frame support, a shaped foot (19), a back frame (20), a support base (21) of the quadrilaterals A, B and the mechanical stop K, a first return spring (22) between the rod (3) and the articulated joint (8) and a second return spring between the rod (3) and the rod (4).

The mechanical device, according to the present invention and due to a series of rods and articulated joints, permits positioning of the framework structure in two configurations, said open and closed configurations. In the closed configuration, the framework structure can be inserted in a sofa and serve as a support for sitting, in the open configuration the same serves as support for a bed mattress of considerably height (even 14 cm). The change between the two positions is obtained by means of a single movement, without having to remove the seat and back cushions.

The novelty of the finding lies in the kinematics, which allows the articulation of the device itself. In fact, in order to make the two open and closed configurations, it uses only three rods (1, 2 and 3) in the quadrilateral A (fig. 2a) and only two rods (4, 5) in the quadrilateral B (fig. 2b), having only one active degree of freedom. The quadrilateral A in addition to the three mentioned rods comprises a fourth side defined by the portion of the support base (21) comprised between the binding points (1') and (2'), while the quadrilateral B in addition to the two single rods (4) and (5) comprises a frame portion (6) comprised between the nodes (4") and (5') and a portion of the support base (21) comprised between the nodes (5") and (4').

A further innovative characteristic of the finding is the anti- foldover mechanical stop K (fig. 2c), which prevents the framework structure in open position from being accidentally closed, if loaded beyond the limits with either concentrated or distributed load. By observing the various images of figure 4, where initially (fig. 4a) the entire structure of the sofa is represented in open configuration, first (fig. 4b) the system is schematised in a position of equilibrium and the sleep surface is horizontal; if a force F is applied to the free end (with the intention, that is, of closing the bed), the rod (4) of the quadrilateral B rotates around the fixed point α in anticlockwise direction and is progressively moved away from the stop (K), permitting the closure of the sofa; if, on the other hand, a weight force P is applied from above on the sleep surface (fig. 4d), the rod (4) rotates around the fixed point α in clockwise direction, until it is stopped by the stop (K): in this manner, the accidental closure of the sofa is prevented. Alternatively, by optimising the sizing and positioning of the rod (5), if the same weight force P is applied from above on the sleep surface (fig. 4e), the same rod

(5) rotates an angle β in anticlockwise direction, arranging itself in equilibrium in a vertical position, with minimal energy. According to this solution, therefore, the stop K is no longer necessary, the same effect being obtained in avoiding accidental closures.

Finally, the cushion exit system is also innovative, obtained with only two rods (17), (18). The quadrilateral C is completed by the rod (14) and by a frame portion (15) comprised between the nodes (14") and (17'). In particular, the rod (18) is pivoted in the same point (18') in which also the rod (14) and foot support (16) are hinged together, thus reducing by one unit the pivots useful for the quadrilateral C kinematics. According to an alternative embodiment, it is possible to eliminate the base frame (21), substituting it with a more practical flank member (25). This is obtained by aligning the binding point (4') with two other fixed constraints (1') and (2').

Claims

1) Mechanical device for opening and closing sofa beds comprising a framework structure and a plurality of movable frames, consecutively bound to each other and movable through rototranslation motions; moreover comprising at least one first articulated quadrilateral (A) and at least one second articulated quadrilateral (B), interlocked and driven by said movement, and characterised in that the number of rods in the quadrilateral (A) is not greater than three and the number of rods in the quadrilateral (B) is not greater than 2.

2) Mechanical device according to claim 1, where said quadrilateral (A) comprises the rods (1, 2, 3) and a fourth side defined by the portion of the support base (21), comprised between the binding points (1') and (2'), while said quadrilateral (B) comprises the rods (4, 5) as well as a portion of the frame (6) comprised between the nodes (4") and (5') and a portion of the support base (21) comprised between the nodes (5") and (4').

3) Mechanical device according to claim 1 or 2, moreover comprising a quadrilateral (C) composed of the rods (17, 18) and completed by the rod (14) and a portion of the frame (15) comprised between the nodes (14") and (17'), a mechanical stop (K), a head frame tube (7) and a plate (6) fixed on said tube, a central frame tube (9) and an articulated joint (8) between said head frame tube and central frame tube, a foot frame tube (15), a return rod (10) of said foot frame tube, a fixed plate (11), an articulated joint between the central frame tube and foot frame tube (12), a first return rod (13) of said foot frame tube and foot support, a second return rod (14) of said food frame tube and foot support, a rod (16) of foot support and back frame support, a shaped foot (19), a back frame (20), a support base (21) of the quadrilaterals A, B and the mechanical stop K, a first return spring (22) between the rod (3) and the articulated joint (8) and a second return spring between the rod (3) and the rod (4).

4) Mechanical device according to claim 3, where said mechanical stop (K) prevents accidental closures of the sofa structure.

5) Mechanical device according to claim 4, where a force F applied to the free end of said framework structure makes the rod (4) of the quadrilateral (B) rotate around the fixed point α in anticlockwise direction and moves it away from the stop (K), permitting the closure of the sofa.

6) Mechanical device according to claim 4, where a weight force P applied from above, on the sleep surface, makes the rod (4) rotate around the fixed point α in clockwise direction until it is stopped by the stop (K), thus preventing the accidental closure of the sofa.

7) Mechanical device according to claim 4, where by optimising the sizing and positioning of the rod 5, a weight force P applied from above, on the sleep surface, makes said rod 5 rotate an angle β in anticlockwise direction, arranging it in equilibrium in vertical position, with minimal energy, thus preventing the accidental closure of the sofa. 8) Mechanical device according to any one of the preceding claims, where the cushion exit system is obtained with only two rods (17) and (18).

9) Mechanical device according to claim 8, where the rod (18) is pivoted in the same point in which also the rod (14) and the foot support (16) are hinged together.

10) Mechanical device according one of the preceding claims, where the alignment of the binding points (4'), (1') and (2') allow eliminating the support base (21), substituting it with a flank member (25).