Patent ID: 7076951

Claim:
Discrete step rotary actuator ( 1 ), comprising a stationary part or stator ( 2 ), a rotary part or rotor ( 3 ) and means ( 10 , 13 , 14 ) for rotating the rotor ( 3 ) with respect to the stator ( 2 ), characterized in that said means ( 10 , 13 , 14 ) comprise at least an actuating element ( 10 ) made at least partly with a shape memory active material, which can take a shortened configuration and an extended configuration, the actuating element ( 10 ) having a first portion ( 11 ) anchored to one of said stator ( 2 ) and rotor ( 3 ), a consecutive sequence of consecutive seatings ( 14 ) arranged as a circumference around the other one of said rotor ( 3 ) and stator ( 2 ), the actuating element ( 10 ) having a second portion ( 12 ) that can engage said seatings ( 14 ) sequentially, elastic means ( 13 ) placed between the actuating element ( 10 ) and the one of said stator ( 2 ) and rotor ( 3 ) to which said first portion ( 11 ) of the actuating element ( 10 ) is anchored, where said elastic means ( 13 ) are operative for inducing a shift of said second portion ( 12 ) of the actuating element ( 10 ) between two consecutive seatings ( 14 ) of said sequence, during the passage of the active material from its shortened to its extended configuration, the passage of the active material from the extended configuration to its shortened configuration imparting the rotor ( 3 ) a rotation couple with respect to the stator ( 2 ).