Synthesis of a Spatial 3-dof Deployable Mechanism to Grasp Stacked Non-Rigid Materials

The paper deals with the synthesis of a novel deployable mechanism with three decoupled degrees of freedom for the handling of large plies of non-rigid material stacked on a beam. The gripper structure is made up of a repeated deployable unit. This basic mechanism is an assembly of Sarrus and scissor linkage: the first to move the unit in three independent directions and the other to transmit the motion to adjacent elements. The particular shape of the beam requires a symmetrical transmission of motion solved by adding linkages of the same type. The final assembly keeps decoupled the three degrees of freedom, which actuated are able to make an anisotropic scaling of the whole on a skew but symmetrical surface. Moreover, the kinematics analysis highlights the scale transformation of the structure and simulations are performed to verify the reconfigurability.