According to Purvis, his updated design of the fountain pen was intended to provide a simple, durable, and cheaper construction so the pen could be carried in someone's pocket. Purvis set an elastic tube between the pen nib and the ink reservoir, enabling the tube to return the excess ink to the reservoir. After this improvement, the new pen could evenly distribute the ink when being used. For this design, Purvis received U.S. Patent 419,065 on January 7, 1890.
