Vislok
Maker of a design of locking nut, of Salisbury Sq, London (1916)
of Market Harborough.
1913 Vislok nuts first offered for sale.
1914 Company formed.
1914 A patent single lock-nut had been put on the market by Vislok of 3 St. Bride's House, Salisbury-square, Fleet-street, London. The Vislok lock-nut supersedes two ordinary nuts, but occupies less space[1]
1916 Offered a range of safety nuts which were used by a wide range of clients[2]. Based on the coincidence of address, and the fact that the advertising was handled by Haddon Advertising[3] it seems likely this company was part of Haddon group of companies
1922 Walter Haddon was managing director
1926 Vislok were used in Tungstone batteries[4]
1928 Patent with William Haddon on "Improvements in the manufacture of cap nuts"