By 1873 David Brown was a specialist in gear systems and expert at machine cut gears, the company moved to Huddersfield in 1902. David Brown, grandson of the founder David Brown, became managing director of a much enlarged company in 1931 which had interests in America and Australia. Teaming up with Harry Ferguson in 1936, the Ferguson-Brown tractor. Ferguson's partnership with Fordson tractors soured the arrangement with David Brown who then launched their own tractor in 1939 that was adapted for use with the Royal Airforce during World war Two. David Brown bought Aston Martin in 1947, Lagonda in 1948 and Tickford in 1955. David Brown tractors sold out J.I. Case in 1972, the David Brown family sold its stake in the business in 1990. David Brown still manufactures heavy transmissions.