EP4066689A1

EP4066689A1 - Mechanism for sofas/chair beds without levers

Info

Publication number: EP4066689A1
Application number: EP22162677.3A
Authority: EP
Inventors: Giulio Manzoni
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-04-02
Filing date: 2022-03-17
Publication date: 2022-10-05
Also published as: IT202100008339A1

Abstract

Lever-free sofa/chair-bed kinematic mechanism consisting of three frames, the top and bottom frames hinged to the central frame, and a frame-backrest anchored to the top frame: the central frame rotating on the headframe to which a raising slide for the bottom frame is anchored, with the frame-backrest that, rotated and engaged to the catches thereof, acts as invisible leg for the top frame, when it is bed, and with the top frame that, when it is sofa, it is engaged to the headframe by pendulum hooks, the whole without using movement levers for the three frames and related frame-backrest, the motion of the central frame first managed by a gas spring acting between the same and the top frame until alignment thereof in almost vertical position, and then by a tensile spring managing the motion of the central frame, hinged to the bottom frame, until the horizontal alignment of all the frames in bed position.

Description

The present invention refers to a lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs.
More specifically, the present invention refers to a lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs consisting of three frames, a top frame, a central frame and a bottom frame, with the top and bottom frames being hinged to the central frame, and a frame-backrest anchored to the top frame, with the central frame rotating on the headframe on which a slide, which guides the motion of the bottom frame, is present, with the frame-backrest that, being rotated forward and engaged to the catches thereof, having invisible support leg-function for the top frame, when as a bed, and at last with the top frame which is engaged to the headframe by pendulum hooks when it is disposed as a sofa.
The motion of the central frame, which occurs after the frame-backrest lowering disengaging the pendulum hooks, is first managed by a compression gas spring acting between the top frame itself and the central frame until alignment of the two frames in almost vertical position and then by a tensile spring managing the motion of the central frame which is rear-hinged to the bottom frame until the horizontal alignment of all the three frames in bed position.
On the bottom frame is also present a securing latch which is stopped by a shear lever hinged to the bottom frame before repositioning as sofa the three frames and related frame-backrest.
The whole without using levers for moving the three frames and related frame-backrest.
The whole through simple, practical and safe movements.
The above invention, belonging to the furniture sector and, more particularly, to the sofa-bed sector, being aimed at solving, in a completely different way as nowadays addressed, the problem to have a sofa turning into a bed trough a kinematic mechanism without the common movement levers and co-adjuvated, instead of by the at least two common pairs of tensile springs, by a pair of compression gas springs and then by a pair of tensile springs and with the invisible bed legs and giving a remarkable flexibility with reference to the sofa designing, as well as a considerable low overall width and without unexpected filling element compressions.
Moreover, the found solution allows all the possible risks due to accidental sofa-bed closures/openings to be avoided, as securing systems were studied and inserted in the kinematic mechanism, such that bed accidental closures are not allowed.
The need to have products allowing to optimize always and in any case the space has always been, and still is, very popular, especially in the field of sofa-beds, the continuous research resulted in solutions more or less new and more or less complex and/or complicated, but none offers solutions of the finding, which is, in this way, completely new and innovative.
The known solutions, nowadays proposed, offer sofa-beds with three / four frames moved by more or less complex lever systems with a following "scissor" effect of the levers and related injury risk.
A further drawback of the known inventions is that the bed legs are always exposed and operated by systems of levers all of which being external to the mesh planes, thus forcing to have a considerable dimensional gap between the mesh plane and the headframe, among which the levers are housed, with a considerable subsequent side width which generates considerable both dimensional and aesthetical constraints.
A further drawback of the known inventions is that all the sofa-bed kinematic mechanisms always provide at least two pairs of tensile springs, which sometimes also are four pairs and which, however, are always only tensile springs.
A further drawback of the known inventions is that all the sofa-bed kinematic mechanisms generate large constraints relating to design since the material and mesh part protruding from the top frame is to be hidden and it is higher than the seat plane, with the need to hide the whole with armrests and backrests, thus heavily constraining the achievable design, which is therefore limited to certain models, which are often similar from each other and revealing more or less clearly to be sofa-beds.
A further drawback of the known inventions is to have different meshes having different kinematic mechanisms, depending on the height of the sofa-bed leg, thus making the product not suitable for an industrial manufacturing and then being penalized from an economical point of view.
An object of the present invention is to overcome such and other drawbacks, thus making a lever-free sofa/chair-bed kinematic mechanism moved by compression gas springs, and thus by tensile springs, with invisible bed legs.
More specifically, an object of the present invention is to make a kinematic mechanism of a sofa-bed not providing levers, thus completely eliminating the risk resulting from the "scissor" effect, which necessarily occurs in the presence of levers and, thus promoting safety.
A further object of the present invention is to make a sofa-bed kinematic mechanism having a minimal side width obtainable with a drastic reduction of the space between mesh plane and headframe and which is possible if the bed leg supports are invisible and not operated by levers, thus allowing a considerable reduction of dimensional constraints and thus promoting aesthetics.
A further object of the present invention is to make a sofa-bed kinematic mechanism offering the possibility to allow the free positioning of the backrest, wherein all the mesh frame moving is contained below the sofa seat plane, thus allowing a free choice of the design for constraint reduction, thus promoting aesthetics.
A further object of the present invention is to make a sofa-bed kinematic mechanism giving the possibility to better manage weights, with a two-steps moving and with two different types of forces: gas springs and tensile springs which do not act simultaneously, but sequentially, thus promoting lightness and fluidity of moving itself.
A further object of the present invention is to make a sofa-bed kinematic mechanism offering the possibility to easily manage forces as a function of weights using gas spring of various thrusts and tensile springs of various pre-load forces.
A further object of the present invention is to make a sofa-bed kinematic mechanism allowing to have a single mesh for different leg heights, by simply replacing a piece made with two depths, thus resulting in a competitive product, which is suitable for an industrial manufacturing and which is accordingly interesting from an economical point of view.
These and other objectives, as well as further characteristics of the lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, object of the present invention, will be better explained in the following description of a preferred, but not limiting, embodiment, with reference to the drawings where, by the way, specifying that colors are not constraining, and having the only scope to make more explanatory the drawings themselves and where reference is made to sofa-bed, but the structure and the described and illustrated considerations are obviously valid even in the case of a chair-bed and in which it is schematically represented:

Fig.1: a perspective view of the finding in sofa closed position.
Fig. 2: a perspective view of the rotational kinematic mechanism detail and simultaneous locking of the frame-backrest in raised position.
Fig. 3: a perspective view of the rotational kinematic mechanism detail and simultaneous locking of the frame-backrest in lowered position.
Fig. 4: a perspective view of the compression gas spring detail, and of the tensile spring with the finding in closed position.
Fig.5: a perspective view of the finding with the top frame rotated in almost vertical position.
Fig. 6: a perspective view of the finding in bed open position.
Fig.7: a perspective view of the securing latches detail, of the compression gas spring and tensile spring with the finding in open position.
Fig. 8: a perspective view of a further configuration of the finding with compression gas spring and with cable tensile spring.
Fig. 8a: a perspective view of the further configuration of the finding of fig. 8 with compression gas spring and cable tensile spring details.
Fig. 9: a perspective view of a further configuration of the finding in closed position with fixed leg and "capote" backrest.
Fig.10: a perspective view of a further configuration of the finding in sofa closed position, with the two-levers roto-translational kinematic mechanism and simultaneous frame-backrest locking.
Fig. 11: a perspective view of the further configuration of the finding of fig. 10 in sofa closed position, of the kinematic mechanism detail of two-levers roto-translation and simultaneous locking of the frame-backrest in open position.
Fig. 12: a perspective view of the further configuration of the finding of fig. 10 in bed open position, of the two-levers roto-translational kinematic mechanism detail and simultaneous locking of the frame-backrest in lowered position.

With reference to the cited figures, the lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to the invention, basically has: a sofa/chair headframe (1) supporting a three-frame mesh, with the top frame (2) and the bottom frame (4) longitudinally hinged to the central frame (3), and mutually foldable from each other and provided in mutual horizontal alignment in bed position, with the central frame (3) having a pair of brackets (5,5a) pivoted on the headframe (1) in the pair of points (6,6a), with the bottom frame (4) having rearly a pair of pins (7,7a) inserted in a pair of guide slides (8,8a), anchored to the headframe (1), a pair of pins (7,7a) which during the motion cause the raising of the frame itself (4), and at last with the top frame (2) having a supporting element (9) anchorable in various positions to change the seat depth when necessary to which the fixed components are integral, on which the movable components of one or more frames-backrest (10) are pivoted, to which adjustable legs (11,11a,12,12a) sustaining the top frame (2) once positioned in bed position are suitably screwed, thus being invisible, being also covered by filling elements of the frame-backrest. The top frame (2) is also engaged, in sofa position, to a pair of grappling hooks (13,13a), integral to the headframe (1), through a pair of engaging studs (14,14a), anchored to a synchrony bar (15) within the supporting element (9) and pivoted thereto, and whose stopping is caused by the rotation of the synchrony bar (15) following the thrust applied to the pair of pins (16,16a) with related return springs (16b,16c), on the synchrony bar itself (15), the thrust due to the collision against a pair of pendulums (17,17a) on the movable brackets (19,19a) for the frame-backrest (10), whose rotation is limited in a direction by the presence of a rotation limiter (18,18a) consisting of a pair of pegs integral to the movable brackets themselves.
Movable brackets (19,19a) that, rotating on the fixed brackets (20,20a) at points (21,21a) cause the pair of anchoring studs (22,22a), pivoted at points (23,23a) on said movable brackets (19,19a), to be engaged, with the possible adjuvation of a spring, to the pair of catches (24,24a) integral to the fixed brackets (20,20a), thus immobilized in a rotated position almost parallel to the ground, together with the frame-backrest (10) with related adjustable legs (11,11a,12,12a) for the bed.
At the top frame (2) it also laterally articulates: a pair of compression gas springs (25,25a) that, on the other end, are laterally pivoted on the central frame (3) on which the top frame (2) is articulated at the top that, once disengaged from the pair of grappling hooks (13,13a) which are on the headframe, it is pushed to rotate from the pair of compression gas springs (25,25a) until being aligned with the central frame (3) against which abuts at points (26,26a).
Within the central frame (3), on the hooks (28,28a), a pair of tensile springs (29,29a) is also engaged, which are engaged, on the other end, to the front crossbar (27) integral to the headframe (1) on the hooks (30,30a), managing the rotation of the central frame (3), from almost vertical to horizontal.
Said rotation of the central frame (3), which is managed by the action of the pair of tensile springs (29,29a), is due to the motion generated by the forward rotation, until horizontal repositioning thereof, of the top frame (2), which is thus sustained in such position by the adjustable legs (11,11a,12,12a), invisible, integral to the frame-backrest (10).
Said central frame (3), being pivoted to the bottom frame (4) which is guided in the motion by the pair of pins (7,7a) inserted in the pair of guide slides (8,8a), once rotated, being repositioned horizontally raised together with the bottom frame itself (4).
Said bottom frame (4) also having a pair of securing latches (31,31a) acting between the bottom frame itself (4) and a pair of screw adjustable corresponding parts (32,32a) which are on the headframe (1), securing latches stopped by a pair of unlocking rods (33,33a), hinged the bottom frame itself (4) at points (33b,33c), and which are integral through a synchrony crossbar (34).
A disposition of said frames (2,3,4) in bed position is made, with the securing latches (31,31a) started on the screw adjustable corresponding parts (32,32a), the bottom frame (4) is blocked in horizontal position, so that, also the top frame (2) and the central frame (3) being horizontal, the whole in the absence of levers for moving said frames (2,3,4).
The finding is further characterized in that, with the securing latches (31,31a) stopped by the unlocking rods (33,33a) lowered, the back folding of the three frames (2,3,4) sofa disposed is obtained, first raising the top frame (2), so that, together with central frame (3) rotating on the headframe (1), it passes from an horizontal position to an almost vertical position due to the action of the tensile springs (29,29a) pivoted to the central frame (3) and to the front crossbar (27), and then pushing downward the top frame itself (2), sustained in the drop by the action of the compression gas springs (25,25a), until engaging the frame (2) to the grappling hooks (13,13a) which are on the headframe (1) .
The finding is also characterized in that, the frame-backrest (10) sofa-repositioned by back-rotating the movable brackets (19,19a) on the fixed brackets (20,20a), first having stopped the anchoring studs (22,22a) to the fixed brackets (20,20a) by pressure on the rod (35) synchronizing them, so that pendulums (17,17a), pivoted on the movable brackets (19,19a), bumping the pins (16,16a) on the synchrony bar (15) of the engaging studs (14,14a), do not move the above-mentioned pins (16,16a), stopping the studs themselves (14,14a), as the pendulums (17,17a) rotate in the direction avoiding them to collide with the rotation limiters (18,18a) on the movable brackets (19,19a).
The finding is also characterized in that, through the simple replacement of the movable brackets (19,19a) with movable brackets of higher depth, various heights of sofa legs can be managed depending on the needs, without changing the seat depth of the sofa/chair, as the supporting element (9) of the fixed brackets (20,20a) and related movable brackets (19,19a) in various positions on the top frame (2), is anchorable.
The finding is also characterized in that, in order to promote the top frame (2) lowering, the pair of compression gas springs (25,25a), being pivoted to an end on the top frame (2), have on the other end, which is pivoted on the central frame (3), a fork engagement (36,36a) so that, the action of the compression gas springs (25,25a) initiates after the top frame (2) initiated the back rotation from the almost vertical position.
The finding is also characterized in that, according to a further configuration thereof to the central frame (3), instead the tensile springs (29,29a) to be internally pivoted, a pair of cables (49,49a) sliding on the related returning rotary drums (50,50a) is laterally pivoted, and being engaged, on the other end, to a pair of tensile springs (51,51a), that are engaged, on the other end, to a pair of pins (52,52a) integral to the headframe (1).
Said rotation of the central frame (3), from almost vertical to horizontal, which is managed by the action of the pair of tensile springs (29,29a), is due to the motion generated by the forward rotation, until horizontal repositioning thereof, of the top frame (2), which is thus sustained in such position by the adjustable legs (11,11a,12,12a), invisible, integral to the frame-backrest (10).
The finding is also characterized in that, according to a further configuration thereof, at the supporting element (9) anchored to the top frame (2) the fixed brackets (20,20a) and related movable brackets (19,19a) for the frame-backrest (10) are not integral, but a pair of legs (37,37a) supporting the top frame (2) being integral when horizontally disposed in bed position, and in that, moreover, in order to disengage the top frame (2) from the grappling hooks (13,13a) anchored to the headframe (1), a U-reversed handle (38) anchored to pins (16,16a) on the synchrony bar (15) for the engaging studs (14,14a) is present, pressing it said engaging studs (14,14a) rotate, the synchrony bar (15) being pivoted at the supporting element itself (9).
In the above-mentioned configuration the backrest can be made with a known "capote" openable load-carrying chain structure.
The finding is also characterized in that, in a further configuration thereof, at the supporting element (9), which is anchored to the top frame (2), shaped fixed supports (39,39a) coplanar to movable supports (40,40a) for one or more frames-backrest (10) are integral, against which (40,40a) they abut, and in that said fixed and movable supports (39,39a,40,40a) are connected each other by a pair of front short levers (41,41a), to which a pair of anchoring pins (42,42a) is integral, and by a pair of rear long levers (43,43a) to which shaped pendulums (44,44a) are also articulated and to which related rotation limiters (45,45a) are integral, and to which (43,43a) a pair of engaging brackets (46,46a) is also articulated to the anchoring pins (42,42a) with related positioning springs (47,47a).
The finding, always in the above-mentioned further configuration is characterized in that the frame-backrest (10) is immobilized in a rotated position almost parallel to the ground, by virtue of the roto-translation of the frame-backrest itself (10), guided by the above-mentioned pair of levers (41,41a43,43a), and by the starting at the same time of the pair of engaging brackets (46,6a) to the pair of anchoring pins (42,42a), and in that said position is reversible by pressing, to stop, on one of the engaging brackets (46,46a) synchronized by a synchrony rod (48) or on the synchrony rod itself (48).
The finding, always in the above-mentioned configuration, is finally characterized in that the rotation of the pair of rear long levers (43,43a), on which the pair of shaped pendulums (44,44a) is pivoted, causes the collision of said shaped pendulums (44,44a) against the pair of pins (16,16a) on the synchrony bar (15) thus causing the stop of the pair of engaging studs (14,14a) on the synchrony bar (15) itself.
The finding, always in the above-mentioned configuration, is also characterized in that repositioning of the frame-backrest (10) in sofa position occurs by virtue of the reverse rotation of the movable supports (40,40a) and related frames-backrest anchored thereto, after having stopped the pair of engaging brackets (46,46a) from the anchoring pins (42,42a), by pressing the synchrony rod (48) joining them.
The finding, always in the above-mentioned configuration, is finally characterized in that above-mentioned repositioning of the frame-backrest (10) in sofa position occurs without the pair of shaped pendulums (44,44a), pivoted on the rear long levers (43,43a), bumping the pair of pins (16,16a) on the synchrony bar (15) of the pair of engaging studs (14,14a), causes the rotation of the above-mentioned pins (16,16a) by stopping the studs themselves (14,14a), since the rotation the pair of shaped pendulums (44,44a) is in the way avoiding the collision against the fixed rotation limiters (45,45a) on the rear long levers (43,43a).
The invention, as described above, was merely proposed by way of example, it is understood that the same may be subjected to numerous modifications or variations, all of which falling within the scope of the present invention; on the basis of slight or more sophisticated modifications, corrections or amendments the finding may be applied to other fields, as well as to the field of furnishings for different purposes.

Claims

Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, essentially comprising: a sofa/chair headframe (1) which supports a three-frame mesh, the top frame (2) and the bottom frame (4) which are longitudinally hinged to the central frame (3), and mutually foldable from each other and provided in mutual horizontal alignment in bed position,
- the central frame (3) having a pair of brackets (5,5a) pivoted on the headframe (1) in the pair of points (6,6a),

- the bottom frame (4) having a pair of pins (7,7a) inserted in a pair of guide slides (8,8a), for the raising of the frame itself (4), anchored to the headframe (1), and then

- the top frame (2) to which it is top anchored, in various positions, a supporting element (9) for the rotational kinematic mechanism and simultaneous locking of one or more frames-backrest (10) on which bed adjustable legs (11,11a,12,12a) are screwed so as to be not visible,

- the top frame (2), which is also engaged, in sofa position, to a pair of grappling hooks (13,13a), which are integral with the headframe (1), by a pair of engaging studs (14,14a), anchored to a synchrony bar (15) within the supporting element (9) and pivoted thereto, and whose stopping is caused by the rotation of the synchrony bar (15) following the thrust applied to the pair of pins (16,16a) with related return springs (16b,16c), on the synchrony bar (15) itself, due to the collision against a pair of pendulums (17,17a), with a rotation limiter (18,18a) in a direction, on the movable brackets (19,19a) for the frame-backrest (10),

- movable brackets (19,19a) that, by virtue of the rotation thereof on the fixed brackets (20,20a) at points (21,21a) and at same time starting of the pair of the anchoring studs (22,22a), pivoted at points (23,23a) on said movable brackets (19,19a), to the pair of catches (24,24a) integral to the fixed brackets (20,20a), are immobilized in a rotated position almost parallel to the ground, together with the frame-backrest (10) with related adjustable legs (11,11a,12,12a) for the bed and with the top frame (2) to which it laterally articulates:

- a pair of compression gas springs (25,25a) that, on the other end, are laterally pivoted on the central frame (3) on which the top frame (2) is articulated whose rotation is caused by the thrust of said pair of compression gas springs (25,25a) and leading it, when disengaged, to be aligned with the central frame (3) against which abuts at points (26,26a), and on which it is also internally engaged

- a pair of tensile springs (29,29a) on hooks (28,28a) and which are, on the other end, engaged on the hooks (30,30a) to the front crossbar (27) integral to the headframe (1), with the central frame (3) whose rotation, from almost vertical to horizontal, is caused by both the motion generated by the forward rotation of the top frame (2) until horizontal repositioning thereof, there sustained by the adjustable legs (11,11a,12,12a), invisible, integral to the frame-backrest (10), and to the action of the pair of tensile springs (29,29a),

- central frame (3) that, being pivoted to the bottom frame (4) motion guided by a pair of pins (7,7a) inserted in the pair of guide slides (8,8a), once rotated, is horizontally repositioned raised together with the bottom frame itself (4),

- bottom frame (4) also having a pair of securing latches (31,31a) acting between the bottom frame itself (4) and a pair of screw adjustable corresponding parts (32,32a) which are on the which are on the headframe (1), securing latches (31,31a) which are stopped by a pair of unlocking rods (33,33a) hinged to the bottom frame itself (4) at points (33b,33c) and which are integral through a synchrony crossbar (34), bottom frame (4) thus blocked in horizontal position, so that, also the top frame (2) and the central frame (3) being horizontal, an arrangement of said frames (2,3,4) is made in bed position, the whole in the absence of levers for moving said frames (2,3,4).
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs and thus by tensile springs, with invisible bed legs, according to claim 1, characterized in that, with the pair of securing latches (31,31a) stopped by the pair of unlocking rods (33,33a) lowered, back folding of the three frames (2,3,4) occurs, which are disposed in sofa position
- by virtue of the raising of the top frame (2) that, together with the central frame (3) rotating on the headframe (1) at points (6,6a) passing from a horizontal position to an almost vertical position by the action of the pair of tensile springs (29,29a) pivoted to the central frame (3) and to the front crossbar (27)

- and by virtue of the subsequent closure of the top frame (2), sustained in the lowering in the drop by the action of the pair of compression gas springs (25,25a), until engaging the same (2) to the headframe (1) through the pair of grappling hooks (13,13a) which are on the headframe (1) and the pair of engaging studs (14,14a) pivoted to the supporting element (9) by the fixed brackets (20,20a) anchored to the top frame (2).
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to one or more of the preceding claims, characterized in that repositioning of the frame-backrest (10) in sofa position by virtue of the back rotation of the movable brackets (19,19a) on the fixed brackets (20,20a) occurs, after the stop of the pair of anchoring studs (22, 22a) at the fixed brackets (20, 20a) by pressure on the rod (35) synchronizing them, so that the pair of pendulums (17,17a), pivoted on the movable brackets (19,19a), bumping the pair of pins (16,16a) on the synchrony bar (15) of the pair of engaging studs (14,14a), does not move the above-mentioned pins (16,16a) stopping the studs themselves (14,14a), since the rotation of the pair of pendulums (17,17a) is in the way avoiding the collision with the rotation limiters (18,18a) on the movable brackets (19,19a).
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to one or more of the preceding claims, characterized in that through the simple replacement of the movable brackets (19,19a) with movable brackets having higher depth, various heights of legs (37,37a,37b,37c) of the sofas can be managed depending on the needs, even maintaining the same depth of the sofa/chair seat being the supporting element (9) of the fixed brackets (20,20a) and related movable brackets (19,19a) anchorable in various positions on the top frame(2).
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to one or more of the preceding claims, characterized in that in order to promote the lowering of the top frame (2), the pair of compression gas springs (25,25a), at a pivoted end on the top frame (2), have on the other end, pivoted on the central frame (3), a fork engagement (36,36a) so that the pair of compression gas springs (25,25a) starts the operation after the top frame (2) started the lowering from the almost vertical position.
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to one or more of the preceding claims, characterized in that, in a further configuration thereof, at the central frame (3) a pair of cables (49,49a) is also laterally pivoted at points (50,50a) sliding on the respective returning rotary drum (51,51a) and which are, on the other end, engaged to a pair of tensile springs (52,52a), that, on the other end are engaged to a pair of pins (53,53a) integral to the headframe (1), with the central frame (3) whose rotation, from almost vertical to horizontal, is due to both the motion generated by the forward rotation of the top frame (2) until the horizontal repositioning thereof, there sustained by the adjustable legs (11,11a,12,12a), invisible, integral to the frame-backrest (10), and to the action of the pair of tensile springs (52,52a),
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to one or more of the preceding claims, characterized in that, in a further configuration thereof, to the supporting element (9) anchored to the top frame (2), the fixed brackets (20,20a) and related movable brackets (19,19a) for the frame-backrest (10) are not integral, but being integral to a pair of legs (54,54a) supporting the top frame (2) when disposed horizontally in bed position and wherein a U-reversed handle (38) is present, which is anchored to the pair of pins (16,16a) being on the synchrony bar (15) for the pair of engaging studs (14,14a) pivoted to the supporting element (9) itself, while the backrest may be made with a known "capote" openable load-carrying chain structure.
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to one or more of the preceding claims, characterized in that, in a further configuration thereof, to the supporting element (9) anchored to the top frame (2) shaped fixed supports (39,39a) are integral, abutting against the movable supports (40,40a) for one or more frames-backrest (10), which are coplanar to them (39,39a), and in that said supports (39,39a,40,40a) are connected each other by a pair of front short levers (41,41a), on which a pair of anchoring pins (42,42a) is present, and by a pair of rear long levers (43,43a) to which the shaped pendulums (44,44a) are also articulated and to which the related rotation limiters (45,45a) are integral, and a pair of engaging brackets (46,46a) is articulated to the anchoring pins (42,42a) with related positioning springs (47,47a), and being further characterized in that, by virtue of the roto-translation of the frame-backrest (10), guided by the above-mentioned pair of levers (41,41a-43,43a), and at same time starting the pair of engaging brackets (46,6a) to the pair of anchoring pins (42,42a), said frame-backrest (10) being immobilized in a rotated position almost parallel to the ground, pressure-reversible position, to stop, on one of the engaging brackets (46,46a) synchronized by a synchrony rod (48).
Lever-free sofa/chair-bed kinematic mechanism, moved by compression gas springs, and thus by tensile springs, with invisible bed legs, according to preceding claim 8, characterized at last in that, the starting of the pair of the pair of engaging studs (14,14a) on the synchrony bar (15) is due to the collision of the pair of shaped pendulums (44,44a), pivoted on the pair of rear long levers (43,43a) against the pair of pins (16,16a) which are on the synchrony bar itself (15), due to the rotation of the pair of rear long levers (43,43a), and also characterized in that the repositioning of the frame-backrest (10) in sofa position occurs by virtue of the reverse rotation of the movable supports (40,40a), after the stop of the pair of engaging brackets (46,46a) by the anchoring pins (42,42a), by pressure on the synchrony rod (48) synchronizing them, without that, the above-mentioned pins (16,16a) are rotated by the pair of shaped pendulums (44,44a), pivoted on the rear long levers (43,43a), bumping the pair of pins (16,16a) on the synchrony bar (15) of the pair of engaging studs (14,14a), thus stopping the studs themselves (14,14a), since the rotation of the pair of shaped pendulums (44,44a) is in the way avoiding the collision against the fixed rotation limiters (45,45a) on the rear long levers (43,43a).