| 摘要 |
<p>PROBLEM TO BE SOLVED: To assuredly elevate and lower a suction grill with a simple control. SOLUTION: A main sensor 31 detects a magnetic reaction part, a light transmitting part or a magnetic pole part provided at prescribed intervals on a wire for elevating or lowering a suction grill. A detecting part 71 generates a detecting signal of prescribed level based on a signal from the main sensor 31. An elevation control part 72 counts the number of passings of the wire through the magnetic reaction part, the light transmitting part or the magnetic pole part by a counter 75 based on the detecting signal from the detecting part 71. A motor driver 76 is controlled based on the length of supply of the wire depending on the counted value and based on instructions from remote controllers 73 and 74 so that the suction grill is lowered or elevated, automatically elevated or temporarily stopped. Thus, the quantity of elevation or lowering or the temporary stop position of the suction grill can be accurately controlled.</p> |
