Abstract: An aquarium air pump includes an electromagnetic motor-operated pump unit positioned in the housing of the pump and including two vibrating arms energized by the motor and each carrying a pump diaphragm forming with a closure member of the pump unit casing a pump chamber. Each vibrating arm is positioned on the casing to be pivoted to an operative position to close the respective closure member and a non-operative position in which the arm can be removed from the casing and interchanged. The pump housing includes a bottom part and a top part connectable to each other and sealed in the connected position by a peripheral seal. Cushioning cups support the pump unit in the pump housing to absorb vibrations.

Abstract: A vent valve of an air pump typically utilized in an aquarium apparatus. The vent valve includes a wall member with a vent hole in the wall member. A valve body having a flap member closes onto the vent hole. The closure action of the flap member is regulated so that the flap is twisted under the force of air flowing through the vent hole in a direction toward the flap member and returns to a closed position against the wall member with a rolling sidewise fold-down motion when an air flow lessens. In this manner, there is a reduction in the flapping noise of the valve.