Adjustable damped snap-acting hinge

An adjustable damped snap-acting hinge, comprising:

• a first articulated quadrilateral which comprises a coupling element which is configured to be associated with a fixed element, a first portion of a first lever and a third lever which are associated in an articulated manner with said coupling element, and a first portion of a second lever, which is interposed between the first and third levers and is articulated thereto,
• a second articulated quadrilateral which comprises a fixing element which is configured to be associated with an element that can move with respect to said fixed element, a second portion of said second lever and a fourth lever which are associated in an articulated manner with said fixing element, and a second portion of said first lever which is interposed between the preceding levers and is articulated thereto,
• the hinge being adapted to assume alternately an open configuration and a closed configuration, said first, second, third and fourth levers rotating about respective articulation pivots which are substantially mutually parallel, and said fixing element varying arrangement thereof by an angle of aperture during a movement between the open and closed configurations,
• the hinge being further provided with first elastic compression means associated with the first quadrilateral and with second elastic compression means associated with the second quadrilateral,
• wherein either or both of said first and second elastic means is interposed between said coupling element or said fixing element and an abutment element associated with at least one of the levers of said first or second quadrilateral, and further comprising at least one adjustment assembly for adjusting a preloading of said first or second elastic means, which comprises a movable element supporting said abutment element and associated with at least one of the levers of said first or second quadrilateral, and at least one pusher element interposed between said third or fourth lever and said movable element, a variation of the position of the movable element that is actuated via the pusher element being adapted to modify the preloading of the first or second elastic means.