Magnetic brush mixing augers

Claim 1

In a developing apparatus for use in an electrostatic copying machine, the developing apparatus having a sump for holding two-component developing material consisting of a marking constituent and a magnetic carrier constituent, a magnetic applicator means rotatably mounted in the sump for withdrawing developing material from the sump and conveying it past a photoconductive member having an electrostatic image therein so as to deposit a quantity of the marking constituent on the electrostatic image to render it visible, an elongate mixing member having opposed flat surfaces rotatably mounted in the sump for continuously mixing together the marking and carrier constituents of the developing material, the mixing member being formed from an elongate strip of rigid material which is twisted to form a helix, and means for rotating the mixing member, the improvement comprising said mixing member having (a) a helical configuration which comprises said mixing member being twisted between its end so as to have one convolution therebetween and (b) an axial edge configuration which comprises an arcuate surface portion extending between the opposed flat surfaces of said mixing member.