Patent ID: 7472622

Claim:
A linkage system comprising: an input member disposed on an input side; an output member disposed on an output side; and three or more link mechanisms, each link mechanism consisting of end links rotatably coupled to the input member and the output member, respectively, a center link rotatably coupled to the end links on the input side and the output side, and four revolute joints by which the end links are rotatably coupled to the input and output members, and to the center link, the link mechanism being geometrically identical with respect to a center cross-sectional plane relative on the input and output sides, wherein each of the revolute joints of the link mechanism includes bearings that support at both ends of the revolute joint, and the orientation of the output member is determined from an equation representing the correlation between the orientation of the output member defined by a bending angle θ and a revolution angle φ and rotation angles βn of the end links on the input side: cos(θ/2)sin β n −sin(θ/2)sin(φ+δ n )cos β n +sin(γ/2)=0 where γ is an axial angle between the two coupling shafts at both ends of the center links, and δ is a distance angle of circumferential distance of each end link from a reference end link.