Original holder for a printing plate processing apparatus

摘要

An original holder for a printing plate processing apparatus for rapid exchange of an original in a vacuum frame covered by a glass plate and exposed in the exposure device of a printing plate processing apparatus. The glass plate is held in its open position by a gas pressure element to facilitate insertion of the original. Two U-shaped metal sheets serve as supports for two vacuum frames which are each evacuated following insertion of an original and closing of the glass cover plate. Swivel joints are attached at the sides of the supports which enable the original holder to be pivoted through an angle of 360 DEG and which are additionally horizontally slidable in the guides of supporting and guiding arms. The vacuum frames are individually pivotably mounted in their supports by ball guides in guide tracks. When one of the vacuum frames is in the vertical exposure position in the exposure opening in the wall of the exposure device housing and its support is secured to the housing wall by locking devices, the second vacuum frame is pivoted into the horizontal position by means of a lever so that an original can be inserted therein. The second vacuum frame is thereafter folded back again to the vertical position in its support. After exposure of the original in the first vacuum frame, the entire original holder is drawn into the change position, pivoted through 180 DEG , and the original in the second vacuum frame is moved into the exposure opening. In an alternate embodiment, the swivel joints are fixedly mounted adjacent the edges of the exposure opening, and the original holder pivots inside the exposure device.