It comprises a supporting structure (230) in which at least one arm (210 220) is slidably attached. Each arm (210 220) comprises first and second members (300, 400) hinged to each other. The first member (300) is rotatably hinged to the supporting structure (230) and it can be rotated about a longitudinal axis (L1) and the second member (400) may receive a joint having at least two degrees of freedom (550) for attaching a tool (900). The longitudinal axis (L1) of the first member (300) is substantially perpendicular to an axis (L2) joining the first member (300) and the second member (400) to each other.A simplified architecture is obtained allowing for accurate and efficient spatial movement of the tool holding arm (210 220).
