Device for adjusting the tilt of a backrest or seat of a chair

Abstract

Device ( 1 ) for adjusting the tilt of at least one movable component of a chair, of the type comprising at least one cam ( 16, 17 ), constrained in a rotation manner to a bracket ( 2 ), and at least one follower ( 15 ) constrained in a sliding manner on the profile ( 23 ) of said cam, the movable component being integral with the follower and the bracket being fixed with respect to the follower or vice versa. The device furthermore comprises means ( 13, 18 ) to constrain the follower to the bracket, the above-mentioned means ( 13, 18 ) and the above-mentioned cam ( 16, 17 ) being configured so that the constraint reaction of the follower on the cam is substantially always directed towards the centre of instantaneous rotation of the latter.

1 . Device for adjusting the tilt of at least one movable component of a chair, of the type comprising at least one cam, constrained in a rotating manner to a bracket, and at least one follower constrained in a sliding manner on the profile of said at least one cam, said movable component being integral with said at least one follower and said bracket being fixed with respect to the follower or, vice versa, said movable component being integral with said bracket and said at least one follower being fixed with respect to the bracket, characterised in that it comprises means for constraining said at least one follower to said bracket, said means and said at least one cam being configured so that the constraint reaction of said at least one follower on said at least one cam is substantially always directed towards the centre of instantaneous rotation of said at least one cam. 
     
     
         2 . Device as claimed in  claim 1 , characterised in that said means to constrain said at least one follower to said bracket comprise at least one lever hinged to said bracket, said lever being constrained to said follower. 
     
     
         3 . Device as claimed in  claim 2 , wherein said follower is a driven rod integral with said lever. 
     
     
         4 . Device according to  claim 2 , wherein said movable component is integral with said lever. 
     
     
         5 . Device according to  claim 1 , characterised in that said means to constrain said at least one follower to said bracket comprise at least one linear guide within which said follower slides. 
     
     
         6 . Adjustment device according to  claim 1 , characterised in that said at least one follower is constrained to said bracket, or vice versa, in a sliding and/or rotating manner on a plane parallel to or coinciding with the rotation plane of said at least one cam. 
     
     
         7 . Adjustment device according to  claim 1 , characterised in that said at least one follower is furthermore constrained in a sliding manner on the profile of said at least one cam, in a groove which defines said cam profile. 
     
     
         8 . Adjustment device according to  claim 1 , characterised in that it comprises two cams on the profile of which at least one follower is constrained in a sliding manner. 
     
     
         9 . Adjustment device according to  claim 1 , characterised in that said at least one cam is driven by a rod. 
     
     
         10 . Adjustment device as claimed in  claim 9 , characterised in that it comprises a knob integrally constrained to said rod. 
     
     
         11 . Adjustment device according to  claim 1 , characterised in that said movable component is a seat or backrest of a chair.