A conveying system with snake motion prevention members incorporated therein for a photo-treatment apparatus in which a variety of treatments are applied to a plurality of long length photo-sensitive sheet materials such as long length photo films, while a wide leader is adapted to lead and pull said long length photo-sensitive sheet materials which are connected to the tail portion of said leader, wherein said conveying system is provided with pendulum type snake motion prevention members of which snake motion prevention portions are energized to normally protrude into the travelling passage of the leader which proceeds along guide members and on both sides of the travelling passage of the long length photo-sensitive sheet materials which proceed along another guide and curl prevention members so that when the leader is to pass, said pendulum type snake motion prevention members are rotated outside the travelling passage of the leader by means of the front end portion thereof and then when the whole leader has passed, they protrude again on both sides of the travelling passage of the long length photo-sensitive material so as to prevent any snake motion of the same.

The auxiliary device for drawing in a lap sheet between the calender rollers includes a curved plate and a flexible flat structure secured to a rear edge of the plate. The plate is introduced into a gap between the first two calender rollers and moved about the second roller until entering the gap between the second and third rollers. The start of a lap sheet is then placed on the flexible flat structure and secured thereon and the plate and flexible flat structure then advanced until the lap issues upwardly through the gap between the second and third rollers. The auxiliary device is then removed and the leading edge of the lap sheet introduced between the third and fourth calender rollers for delivery to a winding roller.

A coupling structure capable of coupling films to a leader with high reliability. The leader has a leader body formed with first holes and second holes in its rear with respect to the feed direction of the leader. Sheet members having fingers or protrusions are provided on the leader body so that the fingers extend across the respective first holes. Films having holes formed in its leading end, are coupled to the leader body by inserting their leading ends through second holes and then into the first holes until the fingers engage in the holes formed in the films.

A leader section of a film strip having coupler holes in the leading section is inserted into a film guide concavity of a coupling table through a rear slot of a leader sheet placed on the coupling table. The film strip is continuously forced to slide along a curved surface of the film guide concavity until the front end of the leader section of the film strip passes through a front slot of the leader sheet. While the leader section moves through the front slot of the leader sheet, it pushes and bends the coupler tongues upward and lets the coupler tongues snap back and enter the coupler holes of the film strip to bring the coupler tongues into engagement with the coupler holes. Finally, by pulling back and stretching the film strip tight, the film strip is coupled to the leader sheet.

There are disclosed a leader for use in developing a film, methods for attaching the leader to the film and for detaching it therefrom, and an apparatus for automatically attaching the leader to the film and detaching it therefrom. The apparatus for automatically attaching the leader to the film includes a leader set cover for holding the leader, a leader guide defining an arcuate path, leader feed means for feeding the leader from the leader set cover to the leader guide, leader backing means for backing the leader to a leader controlling part to curve the leader, and film feed means for feeding the film toward an elongated opening of the leader.