Patent ID: 7685898

Claim:
A linear actuator comprising: a spindle ( 3 ) having external threads, a main nut ( 4 ) riding on the spindle and having internal threads in engagement with the external threads of the spindle, a safety nut ( 7 ) with internal threads defined by a first flank ( 8 ) and a second flank ( 9 ), said safety nut being arranged on the spindle in connection with the main nut ( 4 ), and said safety nut being designed such that, when the main nut is intact, it is not in carrying contact with the threads of the spindle, said flank ( 8 ) of the spindle nut engages the threads of the spindle when the main nut fails, and wherein the second flank ( 9 ) of the safety nut ( 7 ) forms an acute angle with a longitudinal axis of the safety nut.