Sofa-bed with an articulated folding structure

Abstract

A sofa-bed with an articulated folding structure comprises a fixed support framework ( 2 ) kinematically connected to a first main movable frame ( 3 ), a pantograph leverage ( 4 ) operatively active between the first main movable frame ( 3 ) and the fixed support framework ( 2 ), a first auxiliary movable frame ( 16 ) consecutively and rotatably in engagement with the first main movable frame ( 3 ) and a second main movable frame ( 17 ) consecutively and rotatably in engagement with the first auxiliary movable frame ( 16 ). The sofa-bed further comprises a support frame ( 29 ) for the second main movable frame ( 17 ) hinged on a hooking frame ( 31 ) for a back ( 28 ) and a connecting leverage ( 34 ) joining the hooking frame ( 31 ) and support frame ( 29 ) to the second main movable frame ( 17 ).

What is claimed is:  
     
         1 . 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 );    a pantograph leverage ( 4 ) operatively active between the first main movable frame ( 3 ) 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 );    a second main movable frame ( 17 ) rotatably in engagement with the first main movable frame ( 3 );    a support frame ( 29 ) for the second main movable frame ( 17 ), said support frame ( 29 ) being connected to a back ( 28 ) of the sofa-bed ( 1 );    a hooking frame ( 31 ) for the back ( 28 );    a connecting leverage ( 34 ) joining the hooking frame ( 31 ) and support frame ( 29 ) with the second main movable frame ( 17 );    characterized in that the hooking frame ( 31 ) is hinged on the support frame ( 29 ) and movable between a first position at which the back ( 28 ) is substantially parallel to the support frame ( 29 ) and a second position at which the back ( 28 ) is substantially transverse to said support frame ( 29 ).    
     
     
         2 . The sofa-bed as claimed in  claim 1 , wherein the connecting leverage ( 34 ) joining the hooking frame ( 31 ) and support frame ( 29 ) with the second main movable frame ( 17 ) comprises: 
 a first connecting lever ( 35 ) hinged on the movable frame ( 17 ), preferably at a first end ( 35   a ) of said first lever ( 35 ), and on the support frame ( 29 ), preferably at a second end ( 35   b ) of said first lever ( 35 );    a second connecting lever ( 36 ) pivotally mounted on the hooking frame ( 31 ), preferably at a first end ( 36   a ) of said second lever ( 36 ), and on the first connecting lever ( 35 ), preferably at a second end ( 36   b ) of said second lever ( 36 );    a third connecting lever ( 37 ) hinged on the movable frame ( 17 ), preferably at a first end ( 37   a ) of said third lever ( 37 ), and on the second connecting lever ( 36 ), preferably at a second end ( 37   b ) of said third lever ( 37 ).    
     
     
         3 . The sofa-bed as claimed in  claim 2 , wherein the second connecting lever ( 36 ) is pivotally mounted on an intermediate point of the first connecting lever ( 35 ).  
     
     
         4 . The sofa-bed as claimed in  claim 2 , wherein the third connecting lever ( 37 ) is hinged on an intermediate point of the second connecting lever ( 36 ).  
     
     
         5 . The sofa-bed as claimed in  claim 1 , wherein the connecting leverage ( 34 ) joining the hooking frame ( 31 ) and support frame ( 29 ) with the second main movable frame ( 17 ) comprises: 
 a first connecting lever ( 35 ) hinged on the movable frame ( 17 ), preferably at a first end ( 35   a ) of said first lever ( 35 ), and on the support frame ( 29 ), preferably at a second end ( 35   b ) of said first lever ( 35 );    a plate ( 38 ) integral with the movable frame ( 17 ), said plate ( 38 ) being hinged on the hooking frame ( 31 ).    
     
     
         6 . The sofa-bed as claimed in  claim 2 , comprising an intermediate lever ( 39 ) having a first end ( 39   a ) pivotally mounted on the first auxiliary movable frame ( 16 ) and a second end ( 39   b ) hinged on the first connecting lever ( 35 ), to synchronize rotation of the back ( 28 ) with rotation of the first auxiliary movable frame ( 16 ).  
     
     
         7 . The sofa-bed as claimed in  claim 1 , further comprising a first auxiliary movable frame ( 16 ) consecutively and rotatably in engagement with the first main movable frame ( 3 ) at a first hinging axis ( 15 ); the second main movable frame ( 17 ) being consecutively and rotatably hinged on the first auxiliary movable frame ( 16 ) at a second hinging axis ( 18 ).  
     
     
         8 . The sofa-bed as claimed in  claim 1 , further comprising a locking mechanism ( 44 ) to lock said sofa-bed ( 1 ) to the first closed position.  
     
     
         9 . The sofa-bed as claimed in  claim 1 , wherein said locking mechanism ( 44 ) comprises: 
 an engagement portion ( 45 ) integral with the fixed framework ( 2 ) and placed at the rear of the back ( 28 );    rocker means ( 48 ) in engagement with the second main movable frame ( 17 ) and rotating between a disengagement position corresponding to the second position of the support frame ( 29 ), and a position of engagement with the engagement portion ( 45 ) corresponding to the first position of the support frame ( 29 );    a pusher pin ( 49 ) integral with the support frame ( 29 ) and operatively active on the rocker means ( 48 ) to rotate said rocker means ( 48 ) between the disengagement position and the engagement position.    
     
     
         10 . The sofa-bed as claimed in  claim 1 , further comprising: 
 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 four hinging axis ( 22 ).