PROBLEM TO BE SOLVED: To propose an ascending/descending blackboard which can be re- covered with a blackboard surface material simply at a minimum cost.;SOLUTION: In the ascending/descending blackboard in which the blackboard 1 is suspended/held against its gravity by balance springs 20a-20c installed in a blackboard holding frame body 4 and can be stopped at a vertically optional position by a dynamic balance, when the gravity of the blackboard 1 is increased, the additional fitting seats 21d and 21e of balance springs 20d and 20e to be fitted additionally to obtain a dynamic balance to the increased gravity of the blackboard 1 are provided in advance in the frame body 4.;COPYRIGHT: (C)2002,JPO
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