An actuator device for actuating ejector of a scraper comprising a first actuator having a long stroke, a second actuator having a short stroke, said first and second actuators being connected and fixedly secured in series so that the piston rod of said second actuator can be brought into contact with the piston of said first actuator, and valve means which normally permits the communication between the delivery side of a hydraulic pump and a pressure chamber of said first actuator and which also permits the communication between the delivery side of said pump and the pressure chamber of said second actuator when the pressure within the pressure chamber of said first actuator has increased beyond a predetermined value.