摘要 |
1,268,326. Coated wire. GTE SYLVANIA Inc. 7 Dec., 1970 [22 Dec., 1969], No. 58069/ 70. Heading B2E. [Also in Divisions C7 and G2] An anvil wire for the primer of a percussive flashbulb is provided with a coating of fulminating material intermediate its ends by a process which includes the steps of 'dipping the wire into a liquid, preferably aqueous, suspension of fulminating material to a given depth, withdrawing and drying the wire to produce a coating which extends for a given distance along the wire, and removing the end section of the coating by electrolytic means. In a preferred embodiment the fulminating material consists of a mixture of red phosphorus, potassium chlorate and powdered zirconium and the end section of the coating is removed by dipping the wire into an electrolytic bath and passing a current (A.C. or D.C.) using the wire as one of the electrodes. The bath is composed basically of water and contains a salt such as potassium chlorate or sodium chloride, an alkaline cleaner such as ammonium bicarbonate or trisodium phosphate, a wetting agent such as sodium alkyl benzene sulphonate or sodium 2-ethylhexylsulphate, and possibly an anti-foaming agent. Reference is also made to the use of baths containing sodium or ammonium bicarbonate or sodium perchlorate or potassium nitrate. The bath is maintained at a temperature of 50‹C. |