bell button vs handbell

bell button

noun
  • A button in the form of a jingle bell, used as a fastener or decoration on a piece of clothing. 

  • A small, round mechanical device which, when pressed, rings a bell to announce one's presence or call a servant, assistant, etc. 

handbell

noun
  • A small bell designed to be rung by hand. 

How often have the words bell button and handbell occurred in a corpus of books? (source: Google Ngram Viewer )