Patent ID: 8231288
Filing Date: 2012-07-31
Classification: B41J

Abstract:
1. A rotary shaft locking device comprising: a locking unit having a transmission gear receiving rotary torque from a power source, transmitting rotary torque to a rotary shaft as the transmission gear receives rotary torque from the power source, and locking the rotary shaft as transmission of rotary torque from the power source is cut off; and a first planetary gear and a second planetary gear provided to be meshed with a sun gear and to planetarily move around the sun gear, and displaced between a meshed position and an unmeshed position so as to be meshed with and separated from the transmission gear by the planetary movement, wherein the first planetary gear is displaced to the meshed position in accordance with rotation of the sun gear in a first direction to thereby rotate the transmission gear, and is displaced to the unmeshed position in accordance with rotation of the sun gear in a second direction, the second planetary gear is displaced to the meshed position in accordance with rotation of the sun gear in the second direction, to thereby rotate the transmission gear in a direction opposite a rotation direction by the first planetary gear, and is displaced to the unmeshed position in accordance with rotation of the sun gear in the first direction, and the locking unit locks the rotary shaft for a power cutoff time which occurs when the rotation direction of the sun gear is switched and for which the transmission gear is not meshed with both the first planetary gear and the second planetary gear, wherein the locking unit comprises: