Symbol 5013 from IEC 60417 - Title/Meaning: Bell Function/description: To identify switches which operate bells, e.g. a door bell.
Additional information: 
Published in: First edition, 1973
Own work using: iso.org/obp/graphics/grs/398662d4-35db-4fb4-87a4-002bbaff15c3 200.png
Vectorization:  Mrmw