Drive assembly for microfilm cartridges

In combination, a drive assembly for cartridges, particularly for microfilm cartridges adapted to be introduced into a microfilm cartridge receiving channel of a microfilm apparatus, said drive assembly comprising a drive head and a back-support wheel positioned on opposite sides of the cartridge receiving channel and aligned with each other in a direction perpendicular to the direction of introduction of the cartridge into the cartridge receiving channel, entrainment means for coupling for joint rotation and for releasing from such joint rotation said drive head and a main shaft driven by drive means, said main shaft has an end portion concentrically engaging said drive head, said entrainment means and drive head being engaged to drive a cartridge of a first predetermined type, and releasing of said entrainment means being adapted to automatically disengage said drive head from said main shaft for driving a cartridge of a second predetermined type, said drive head being resiliently biased by first energy storage means towards said cartridge receiving channel, said main shaft being resiliently biased by second energy storage means toward said cartridge receiving channel, said drive head having entrainment pins projecting from its end face and adapted to engage corresponding openings in a reel core of a cartridge of the first type when said drive head engages a receiving opening in the reel core of a cartridge of the first type, said main shaft having in one end portion said entrainment means for engaging a slit terminating in a side wall of a receiving opening provided in a reel core of a cartridge of said second type as said end portion of said main shaft enters said receiving opening in the reel core of the second-type cartridge, said back-support wheel being secured automatically by lock means against axial displacement from the cartridge receiving channel by the introduction of a cartridge of the second type so that said back support wheel engages the opposing side of a cartridge of the second type which has been introduced in said channel, said drive assembly further comprising moving means provided to axially withdraw said main shaft and drive head from said cartridge receiving channel against the force exerted by said second and first energy storage means, respectively.