| 摘要 |
PURPOSE:To secure a necessary strength without increasing the thickness of members and the number of reinforcing plates, by bending both the lateral parts of an auxiliary plate toward a main plate and orienting reinforcing ribs in such directions as to nearly bisect the internal angle between the bent lateral part and central part of the auxiliary plate. CONSTITUTION:The central part 4a of anauxiliary plate 4 is made nearly parallel with a main plate 3. Both the lateral parts of the auxiliary plate 4 are bent toward the main plate 3. Reinforcing ribs 6 are provided between the main plate 3 and the auxiliary plate 4 so that each rib extends in such a direction as to nearly bisect the internal angle theta between the bent lateral part of the auxiliary plate 4 and its central part 4a. As a result, the water pressure which acts on the surface of the auxiliary plate 4 toward the main plate 3 when a valve element 2 is opened is equally carried by constituent plates, so that local reinforcement is not needed. For that reason, a necessary strength is secured without increasing the thickness of members and the number of reinforcing plates. |
