Piccardi
{{PatentInfo |Inventor=Arthur O. Dahlberg |Assignee=Arthur O. Dahlberg |Country=US |ApplicationNum=399817 |ApplicationDate=1920-07-29 |PatentNum=1365463 |PatentDate=1921-01-11 |PriorityDate=1920-07-29 |Titolo=Fountain-pen indicator |Marca=Unbranded |De...