Magnetic brush developing unit for copier - has at least one roller spaced under photosensitive surface at distance set by distancing wheel

A magnetic brush developing unit is for an electrophotographic copier for developing a latent, electrostatically-charged image on a photo-sensitive surface. It has at least one magnetic brush developing roller installed under the photo-sensitive surface at a stipulated distance. This distance is defined by a distancing wheel supported on the photo-sensitive surface. The developing unit (100) can be firmly fixed to the copier housing. The developing roller (3, 4) is/are movably mounted so that the distance between it/them and the photo-sensitive surface (1a) is adjustable. This distancing wheel (16) is geared in between the developing roller(s) and the photo-sensitive surface. Pref. two developing rollers (3, 4) provided to force the developing roller(s) against the photo-sensitive surface. Pref. two developing rollers (3, 4) are installed with their spindles in parallel. The roller shafts (5, 6) are guided along movement paths so that they are inclined towards each other and the photo-sensitive surface. As they approach each other they also approach the photo-sensitive surface.