Spherical Mechanism Constructed With Scissors Linkages With Control Means

The invention relates to a curved spherical scissors linkage mechanism (1) comprising at least four linkage elements (2) each having a first end (3) and a second end (4); the linkage elements are arranged to form sides of one rhombus or parallelogram, or a series, such as a network, of joined rhombus or parallelograms. Each of the linkage elements is rotationally connected to one of the other linkage elements via a revolute joint (5) at or near the first end and is rotationally connected to another one of the other linkage elements via another revolute joint at or near the second end. The linkage elements are shaped, dimensioned and arranged so that the axes of all the revolute joints coincide at one common remote centre of motion (RCM). Furthermore, the mechanism is grounded or connected or connectable to a first external member (7) at a proximal end and is rotationally connected or connectable to a second external member (9) at an opposite distal end. Hereby a spherical linkage mechanism with three DOFs is obtained. The spherical scissors linkage mechanism may further comprise a motion controlling mechanism at the proximal and/or at the distal end. It further comprises actuator means as control means.