Tungstone Products
Tungstone Accumulator Co, of Salisbury Sq, Fleet St, London
Tungstone Products Ltd, of Market Harborough
Pre-WWI Walter Haddon discovered a material he called "Tungstone", which was described as the "next hardest thing to metal", which he used for making the frames and furniture for the standardised type which his firm, John Haddon and Co supplied to the printing trade.
1925 The Tungstone Accumulator Company, of 3, St. Bride's House, Salisbury-square, London EC introduced a new design of accumulator, using plates made from pure lead (rather than a lead-antimony alloy) and replacing the wood widely used for spacers by a more durable material (presumably Tungstone)[1]
1925 Tungstone accumulators were entirely manufactured by machines[2]
1925 Walter Haddon of London patented a design of accumulator casing and, with James McDonald Burnett of Weston by Welland, patented a design of plate/grid for accumulators
1928 Accumulators were made at the Tungstone High-Pressure Die Casting Works at Market Harborough[3]
1938 Private company formed: Tungstone Products.
1953 Became part of Haddon Group
1962 Tungstone Products Ltd, part of the Haddon Group, supplied stationary lead-acid cells and components for powering communications, to the General Post Office[4]
1963 Motor Show exhibitor. Batteries
1966 Haddon were acquired by London Merchant Securities
1984 Hawker Siddeley acquired its owner, Carlton Industries
By 1986 was part of Hawker Siddeley[5]
1992 Part of BTR Industrial Holdings[6]