| 摘要 |
An elongated lifting rail (8) is displaceable to collectively pivot a plurality of damper levers (91). An actuator (552) is provided beside or underneath the lifting rail for automatically displacing the lifting rail. The lifting rail is displaced, in response to driving of the actuator, to displace the damper levers so that the dampers (6) are moved away from contact with sounding members (4). Further, a position sensor (555) is provided for detecting a displaced position of the lifting rail, so that position data detected by the position sensor is used for operating position control and/or operating position recording of the dampers. |
