摘要 |
An actuator in which an output shaft can be made to stop by a simple structure and in which actuator assured restart of the output shaft can be performed. The actuator comprises a motor, an output shaft provided with an external threading, and a connecting member having an internal threading engaged with the external threading of the output shaft. The actuator further comprises a resilient member for applying a predetermined load to the output shaft when the output shaft reaches the end of its moving range. The connecting member may comprise an internal screw member having a first protrusion formed on an outer surface thereof and a gear member having a second protrusion. When the second protrusion impacts with the first protrusion, a large starting torque is obtained. Further, two PTC thermistors are provided in a protection circuit, each thermistor allows flow of a current in only one direction, so as to prevent a reduction of a starting current.
|