Photographic developer processing tank wiper lips - are profiled for clean operation and to negotiate film joins

摘要

The usual kind of lips are wedge-shaped, and very thin where they contact the film. To prevent their being too easily deformed by the passing film, their tips are often made of firmer material: but then they tend to jam the film at the double-thickness sections where lengths are joined together. The modified wedge proposed by the invention does not narrow all the way to a thin edge, but terminates in a short section of constant thickness (5); this section can flex at its junction with the wedge (8), while still presenting a firm edge to the film. Behind the wedge, the material narrows to a waist (7), where again flexing is possible, but now only when a double-thickness section passes. Thus jams are eliminated without prejudicing efficient wiping action.