Device for the developer mixture and the developer to a failed magnetbuerste an electrophotographic machine

摘要

An auger fed magnetic brush developer wherein two parallel augers continuously recirculate the developer mix and cause the mix to be enriched with toner prior to its being returned to the magnetic brush roll.PPA supply auger communicates with the brush roll along its entire length and directly elevates the mix to a lower part of the brush roll's surface. This supply auger includes four flutes of a pitch equal to one-half the length of the brush roll. This auger flute arrangement insures that a uniform supply of mix is presented to the brush roll along its entire length. In addition, this supply auger construction insures that a uniform supply of enriched mix is presented to the brush roll along its entire length, since the gradually depleting carrier tends to be presented to the brush roll a minimum number of times, for example three, prior to its exiting one end of the supply auger. PP The carrier exiting the supply auger enters a turnaround compartment whereat new toner is added. The depleted carrier and new toner is mixed by a return auger. To insure adequate triboelectric agitation, the return auger includes two flutes of a pitch equal to that of the supply auger. The two augers are rotated at different flute and pitch related speeds which insure equal flow through the augers.P PThe two augers are of equal length, and are longer than the brush roll. The two augers are mounted in axially offset fashion, with the opposite end of each auger substantially coextensive with opposite ends of the brush roll, and with the other end of each auger extending into end disposed turnaround compartments.