Vacuum circuit interrupter with piezoelectric actuator and vacuum circuit breaker incorporating same

A vacuum circuit breaker comprising a vacuum interrupter operable between a closed state and an open state, and an actuator, wherein said actuator comprises a piezoelectric driver that is expandable and contractable along an expansion axis in response to an electrical input signal, and wherein said actuator further comprises a mechanical amplifying structure extendable along an actuation axis and being mechanically coupled to said piezoelectric driver such that expansion or contraction of said piezoelectric driver causes said amplifying structure to extend or retract along said actuation axis, said mechanical amplifying structure being coupled to said vacuum interrupter for operating said vacuum interrupter between said closed and open states,

• wherein said amplifying structure comprises a body shaped and dimensioned to define a cavity in which said piezoelectric driver is located, said body having a flexible structure extending between first and second sides of said body defining a top of said cavity, said flexible structure being flexible in a direction of said actuation axis to effect extension and contraction of said actuator,
• wherein the flexible structure comprises first and second sets of first and second rigid segments, each segment of said first and second rigid segments having a respective one end coupled to a respective one of said first and second sides by a respective hinge, a respective other end of each segment being coupled together by an intermediate segment that allows said first and second segments to pivot with respect to each other about an axis that runs parallel with said first and second sides,
• wherein said first and second sets of first and second rigid segments are stacked such that said first set of said first and second rigid segments is located between said second set of said first and second rigid segments and the cavity,
• and wherein the respective hinge that couples the respective one end of the respective first and second segments of the second set to the respective first or second side is stiffer than the respective hinge that couples the respective one end of the respective first and second segments of the first set to the respective first or second side.