Stacked microfilm card packet - has profiled edge on bottom towards film platform of viewing instrument

摘要

The packet of film cards comprising card mountings for stacking together, particularly for microfilms. It has a profiled edge forming a slide moving in two directions and engaging with and sliding along a mating profiled edge on the film platform of a viewer. The platform is movable at right angles to its profiled edge. The first profiled edge (1e-1g) is on the bottom part, towards the film platform (5,3), of a support for other card mountings, which can be stacked and strung together via openings (2a-2d) on bosses (1a-1d) on the support.