Approximate date when Leona Chalmers patented an updated design of her menstrual
cup, this was after the rubber shortage during World War II. This redesign may
have incorporated new materials or addressed issues identified with the original
design.
Leona Chalmers files U.S. patent 2,089,113 for a 'Catamenial Receptacle',
marking a key milestone in the development and protection of her menstrual cup
design.