huinventors1-4, Exercise 2: Idea, builder, success

Model answer:

Loud: an early idea, patenting a rolling-ball pen in 1888 for marking leather, but it was not practical for writing.
Bíró: the builder of a working writing pen, with a suitable quick-drying ink, patented in the 1930s.
Later manufacturers (the British firm, and then Bic and others): success, turning it into a mass-market product at falling prices.

Who gets the credit depends on which of the three the teller values. Names and dates should be checked.