Container for light-sensitive material

Claim 1

A container for light-sensitive material, said container comprising: first, second, third, and fourth rectangular panels of opaque material hingedly connected together in series along mutually parallel edges of said panels so as to be foldable at said edges to form a generally rectangular tube with four sides and two open ends; a cap associated with each end of said tube and adapted to close the container in a light-tight manner; and interlocking structure associated with said hingedly connected panel edges, said interlocking structure including (a) a first ridge having a surface on, and normal to, one panel adjacent each hinge connection, said ridge surface being spaced from the associated hinge connection by a predetermined distance, and (b) a second ridge having a surface on the other panel adjacent each hinge connection, said surface of the second ridge being substantially adjacent to its associated hinge connection and extending generally normal to its associated panel a distance substantially equal to said predetermined distance, so that when the hinge is folded such that the panels are generally normal to each other, the ridges increase the strength of the container and form a tortuous light path from the hinge to the interior of said container to inhibit any light which may leak through the hinge connection from reaching the material in the container.