Facit - calculator
1922-1972
From the early 1930s, Swedish Facit achieved global success with its mechanical calculators and peaked in 1970 with over 14,000 employees. A year later in 1971 cheaper electronic calculators from Japan started flooding the market, making the mechanical machines obsolete. Facit refused to change and went out of business virtually overnight. Facit’s downfall is a classic cautionary tale of what happens when companies do not continuously invest in innovation.
Additional info:
Wikipedia - English article, the Swedish is much longer.
Disruptiveinnovation.se - link downloads a quality academic article in English