Patent ID: 7857087

Claim:
An actuator that is used in a safety apparatus for an automobile, the actuator configured to move forward a moving member arranged at inside of a housing in a cylindrical shape along with a support rod connected to the moving member in being operated, and comprising a lock mechanism of restricting a rearward movement of the support rod moved forward; wherein: the support rod projected from a front end wall portion of the housing supports a receiving member for receiving a protection object; the support rod is plastically deformed so as to absorb a kinetic energy of the protection object when receiving the protection object by the receiving member after having moved forward; the lock mechanism comprise, a diameter enlarging deformed portion arranged at the moving member and capable of enlarging a diameter of the moving member more than an outer diameter dimension of the moving member when moving forward at inside of the housing, and a locking stepped portion arranged at a position where the moving member is located at, after having been moved at an inner peripheral face of the housing, said locking stepped portion capable of restricting a rearward movement of the moving member by locking the diameter enlarging deformed portion the diameter of which is enlarged; and the diameter enlarging deformed portion is locked by the locking stepped portion by being elastically deformed by an elastic force of the diameter enlarging deformed portion itself, or being plastically deformed by a press force of the moving member from a diameter contracting state to a diameter enlarging state when the moving member is arranged at the locking stepped portion after having been moved forward.