A well known patent filing for a toy that is made out of a long metal coil that goes down stairs. US Patent filings are released into the public domain. That is a great source of finding imagery.
走下樓梯的金屬玩具
famous、filing、mapitize、metal、patent、pop、publicdomain、toy、upload2openclipart
著名、備案、mapitize、金屬、專利、流行的、公共區域、玩具、upload2openclipart
資料來源：openclipart ( https://openclipart.org/ )