Fail safe redundant actuator

Claim 1

A fail-safe actuator comprising: (a) an output shaft; (b) a guide shaft receiving said output shaft; (c) first delatchable coupling means connecting said output shaft and said guide shaft; (d) power screw means for driving said guide shaft in a longitudinal direction, said power screw means comprising screw means comprising screw and nut components; (e) rotor shaft means receiving said nut component; (f) connecting means connecting said nut component to said rotor shaft means in rotationally fixed, translationally free relationship therewith; (g) second delatchable coupling means preventing translational motion of said ball nut means within said rotor shaft; (h) first and second reversable drive means for causing rotation of said rotor shaft, said first drive means being adapted to rotate said rotor means in a clockwise direction in normal operation and said second drive means being adapted to rotate said rotor shaft in a counter-clockwise direction in normal operation; (i) means for delatching said second delatchable coupling means when either of said motors are operated in the reverse direction from normal operation; and (j) means directing said ball nut into delatching engagement with said first delatching means after said second delatching means is delatched.