Sound level regulation of alarm bell - uses bell shells mounted on strip deformed to move away from striker

摘要

A mechanical alarm bell is designed to allow the sound level to be easily varied. Two hemispherical shells are struck by an oscillating hammer located between them. The hemispherical shells are mounted on a common strip of deformable material (6, 7). An eccentric (13) may be rotated to cause the strip to deflect and so move the shells away from the striker. The sound generated is therefore varied accordingly. The plate (3) is fixed to the baseplate (12) by screws (8, 9) and similar screws (4, 5) are fitted to the centres of the hemispherical shells (1, 2).