Assertion: ballpoint pen's ball | /r/HasProperty | free to turn in a socket
Facets:
Source sentences:
text: In 1938, László Bíró, a Hungarian newspaper editor, with the help of his brother George, a chemist, began to design new types of pens, including one with a tiny ball in its tip that was free to turn in a socket.
text: Working with his brother György, a chemist, he developed a new tip consisting of a ball that was free to turn in a socket, and as it turned it would pick up ink from a cartridge and then roll to deposit it on the paper.