Patent ID: 7435234

Claim:
A hinge having a variable center of rotation comprising: a. an inner shell, a middle shell, and an outer shell, said middle shell rotatably engaged to said inner shell and having an inner-middle shell co-axis and middle shell rotation whereby said middle shell rotates relative to said inner shell, and said outer shell rotatably engaged to said middle shell and having a middle-outer shell co-axis and outer shell rotation whereby said outer shell rotates relative to said middle shell, wherein said inner shell does not rotate, and wherein said inner-middle shell co-axis is located at the center of the inner shell, and said middle-outer shell co-axis is located off-center of said middle shell; b. said inner shell further comprising an inner shell protuberance; c. said middle shell further comprising a middle shell protuberance, and a middle shell slot through which said inner shell protuberance tracks, wherein said inner shell protuberance tracking constrains said middle shell rotation of said middle shell relative to said inner shell; d. said outer shell further comprising an outer shell slot through which said middle shell protuberance tracks, wherein said middle shell protuberance tracking constrains said outer shell rotation of said outer shell relative to said middle shell; e. a motion constraining element to prevent rotation of said middle shell relative to said inner shell over a first flexion range as said outer shell rotates relative to said middle shell over said first flexion range and to prevent rotation of said outer shell relative to said middle shell over a second flexion range as said middle shell rotates relative to said inner shell, wherein said second flexion range does not overlap said first flexion range.