Patent ID: 8646839
Filing Date: 2014-02-11
Classification: A47C

Abstract:
1. An adjustment device for chairs, comprising: a main body structured to be engaged onto a supporting shank of a chair; a seat support mounted above said main body and structured to be associated to a seat for a user; a backrest mounted onto said main body and structured to be associated to a back for a user; and articulation means for movably engaging the backrest and the seat support to the main body, wherein said articulation means comprise a lever hinged to said main body in a first mounting site and having two opposite lever portions hinged to the seat support in a second mounting site and to the backrest in a third mounting site, respectively, so as to obtain a relative movement between said backrest and said seat support wherein said articulation means further comprises a first swinging arm hinged to the main body and to the seat support and a second swinging arm hinged to the main body and to the backrest, said first swinging arm defining together with said lever, said seat support and said main body a first hinged quadrilateral and said second swinging arm defining together with said lever, said backrest and said main body a second hinged quadrilateral, and wherein said lever defines an angular portion turnably engaged to said main body in said first mounting site; said angular portion being placed between said lever portions of the lever.