Device for automatically forming film-loop in a miniature movie projector

Claim 1

A combination loop-forming and film-advancing mechanism adapted to contact at a contact position a length of film which is stretched between a first guide means and a second guide means and to advance said film in an advancing direction from the first to the second guide means after forming a loop therein between the first guide means and the contact position, said mechanism comprising: a drive gear adapted for rotation in a first direction about a drive gear axis during a film-advancing operation; a swing arm mounted for rotation about the drive gear axis; a planetary gear mounted on the swing arm and meshed with the drive gear, said planetary gear having a planetary gear axis positioned eccentrically with respect to the drive gear axis; a sprocket wheel positioned coaxially with the planetary gear and united to said planetary gear for rotation therewith, said swing arm, planetary gear, and sprocket wheel being movable from a loading position to a film-advancing position as the swing arm rotates about the drive gear axis in the first direction; film engaging means on the sprocket wheel for engaging and advancing the film in response to rotation of the sprocket wheel, said film engaging means engaging the film at the contact position as the swing arm, planetary gear, and sprocket wheel move from the loading position to the film-advancing position and moving said film during said motion in a direction opposite to the advancing direction, whereby a loop is formed in said film between the first guide means and the contact position.