Description
Class F21K : LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
Subclass 5/04: Light sources using charges of combustible material, e.g. illuminating flash devices (explosive or thermic compositions C06B; fireworks F42B 4/00; photographic flash units G03B 15/03) Plural charges, e.g. associated for sequential ignition (F21K 5/06, F21K 5/12 take precedence)