Patent attributes
A flexible piston rod includes a piston and a row of elements, each having top, bottom, and lateral surfaces, the top surface of one element being connected to the bottom surface of an adjacent element by a hinge that allows the two adjacent elements to pivot from a first position, where a portion of the top surface of one element abuts a corresponding portion of the bottom surface of the adjacent element and corresponding to a rectilinear, relatively stiff configuration of the piston rod, to a second position wherein the top surface of one element is spaced from the bottom surface of the adjacent element and corresponding to a curved configuration of the piston rod. The lateral surface of each element has first and second mutually-opposed cylindrical surface portions incorporating a thread for meshing with a corresponding thread of an actuator for displacing the piston rod longitudinally.