Lifting device for articulated folding structures of sofa-beds and sofa-bed containing such a device

Abstract

A lifting device for articulated folding structures of sofa-beds comprises a fixed support framework ( 2 ) and a pantograph leverage ( 4 ) operatively active between a first main movable frame ( 3 ) of an articulated folding structure of a sofa-bed and the fixed support framework ( 2 ), to move the first main movable frame ( 3 ) in a vertical direction between a first position at which it is housed at the bottom of the fixed support framework ( 2 ) and a second position at which it is raised relative to the framework itself ( 2 ). The lifting device further comprises first and second means ( 8, 10 ) for connecting the pantograph leverage ( 4 ) with the first main movable frame ( 3 ), which means consists of at least one oscillating link ( 9, 11 ).

What is claimed is:  
     
         1 . A lifting device for articulated folding structures of sofa-beds, comprising: 
 a fixed support framework ( 2 );    a pantograph leverage ( 4 ) operatively active between a first main movable frame ( 3 ) of an articulated folding structure of a sofa-bed and the fixed support framework ( 2 ), to move the first main movable frame ( 3 ) in a substantially vertical direction between a first position at which it is housed in the fixed support framework ( 2 ) and a second position at which it is raised relative to the fixed support framework ( 2 );    first means ( 8 ) for connecting the pantograph leverage ( 4 ) with the first main movable frame ( 3 );    second means ( 10 ) for connecting the pantograph leverage ( 4 ) with the fixed support framework ( 2 );    characterised in that said first or second connecting means ( 8 ;  10 ) comprises at least one respective oscillating link ( 9 ;  11 ).    
     
     
         2 . The lifting device as claimed in  claim 1 , wherein the pantograph leverage ( 4 ) comprises: 
 a first lifting rod ( 6 ) having a first end ( 6   a ) hinged on the fixed support framework ( 2 ) and a second end ( 6   b ) kinematically connected to the first main movable frame ( 3 );    a second lifting rod ( 7 ) centrally hinged on the first lifting rod ( 6 ) and having a first end ( 7   a ) hinged on the first main movable frame ( 3 ) and a second end ( 7   b ) kinematically connected to the fixed support framework ( 2 ).    
     
     
         3 . The lifting device as claimed in  claim 2 , wherein the first connecting means ( 8 ) comprises a first oscillating link ( 9 ) having a first end ( 9   a ) hinged on the first main movable frame ( 3 ) and a second end ( 9   b ) hinged on the first lifting rod ( 6 ), preferably at the second end ( 6   b ) of said first rod ( 6 ).  
     
     
         4 . The lifting device as claimed in  claim 2 , wherein the second connecting means ( 10 ) comprises a second oscillating link ( 11 ) having a first end ( 11   a ) hinged on the fixed support framework ( 2 ) and a second end ( 11   b ) hinged on the second lifting rod ( 7 ), preferably at the second end ( 7   b ) of said second rod (V).  
     
     
         5 . The lifting device as claimed in  claim 2 , further comprising elastic means ( 12 ) preferably defined by a draw-spring, operatively active between the first end ( 6   a ) of the first rod ( 6 ) and the second end ( 7   b ) of the second rod ( 7 ), to facilitate lifting of the first main movable frame ( 3 ).  
     
     
         6 . A lifting device as claimed in  claim 5 , comprising a first tailpiece  13  rigidly extending from the first lifting rod  6  and a second tailpiece  14  rigidly connected to the second oscillating link  11 ; the elastic means  12  comprising a spring connected, at a first end  12   a  thereof, to the first tailpiece  13  and, at a second end  12   b  opposite to the first one  12   a , to the second tailpiece  14 .  
     
     
         7 . A sofa-bed with an articulated folding structure, comprising: 
 a fixed support framework ( 2 );    a first main movable frame ( 3 ) kinematically connected to the fixed support framework ( 2 ) and movable between a first position at which it is housed at the bottom of the fixed support framework ( 2 ) and a second position at which it is raised relative to the fixed support framework ( 2 );    a first lifting rod ( 6 ) having a first end ( 6   a ) hinged on the fixed support framework ( 2 ) and a second end ( 6   b ) kinematically connected to the first main movable frame ( 3 );    a second lifting rod ( 7 ) centrally hinged on the first lifting rod ( 6 ) and having a first end ( 7   a ) hinged on the first main movable frame ( 3 ) and a second end ( 7   b ) kinematically connected to the fixed support framework ( 2 ).    a first auxiliary movable frame ( 16 ) consecutively and rotatably in engagement with the first main movable frame ( 3 ) at a first hinging axis ( 15 );    a second main movable frame ( 17 ) consecutively and rotatably in engagement with the first auxiliary movable frame ( 16 ) at a second hinging axis ( 18 );    a second auxiliary movable frame ( 19 ) consecutively and rotatably in engagement with the second main movable frame ( 17 ) at a third hinging axis ( 20 );    a third main movable frame ( 21 ) consecutively and rotatably in engagement with the second auxiliary movable frame ( 19 ) at a fourth hinging axis ( 22 );    characterized in that it comprises a first oscillating link ( 9 ) having a first end ( 9   a ) hinged on the first main movable frame ( 3 ) and a second end ( 9   b ) hinged on the second end ( 6   b ) of the first lifting rod ( 6 ), and a second oscillating link ( 11 ) having a first end ( 11   a ) hinged on the fixed support framework ( 2 ) and a second end ( 11   b ) hinged on the second end ( 7   b ) of the second lifting rod ( 7 ).