Drain cover assembly for drainage structure, has pivot arm that pivots to open position when its flow control portion is subjected to applied load through drain hole that is sufficient to overcome weight of its weighted portion

摘要

The drain cover assembly includes a closure device having a pivot arm (50) which includes a mounting portion (53), a flow control portion (52), and a weighted portion (51). The pivot arm pivots to an open position when the flow control portion is subjected to applied load through the drain hole that is sufficient to overcome the weight of the weighted portion. The closure device is operable for closing and opening a drain hole in a cover plate (23) of a drain cover unit (20). The flow control portion extends from and is disposed on a first side of the mounting portion and registered with the drain hole. The weighted portion extends from and is disposed on a second side of the mounting portion and having a weight sufficient to overcome the weight of the flow control portion so as to cause the pivot arm to pivot from an open position to a normal closed position.