Espacenet Patent Search - largest free Worldwide patent database Patent search: Espacenet offers free access to more than 70 million patent documents worldwide, containing information about inventions and technical developments from 1836 to today. in Public bookmarkswith patent_databasepatent_officepatent_search Note: Patent search: Espacenet offers free access to more than 70 million patent documents worldwide, containing information about inventions and technical developments from 1836 to today.