Patent ID: 6121588
Filing Date: 2000-09-19
Classification: F03G,Y10T

Abstract:
An actuation device, comprising:at least two thermal actuators (5A,5B) which can be electrically supplied, each thermal actuator (5A,5B) comprising respective thrust means (4A,6A,4B,6B) being movable to perform a predetermined stroke;at least an actuation element (12) moved by means of said thermal actuators (5A,5B) and connected in particular with the thrust means (4B,6B) of one of said thermal actuators (5A,5B);where said actuation element (12;12A;18) can take at least three different steady working positions (I,II,III) in function of the presence of a supply to a first (5B), or a second (5A) or both said thermal actuators (5A,5B), characterized in that:said first thermal actuator (5B) is free to move with respect to said second thermal actuator (5A);means (6A,11) are provided to transfer the thrust generated by the second thermal actuator (5A) to the first thermal actuator (5B), and cause a change of the reciprocal positioning of one thermal actuator with respect to the other one.