Piccardi
{{PatentInfo |Inventor=William P. De Witt |Assignee=William P. De Witt |Country=US |ApplicationNum=568469 |ApplicationDate=1922-06-15 |PatentNum=1463803 |PatentDate=1923-08-07 |PriorityDate=1922-06-15 |Titolo=Pencil with adjustable lead |Marca=De Witt...