Development station with improved mixing and feeding apparatus

Claim 1

A development station for a reproduction apparatus, the station comprising: a housing defining a sump for a supply of developer material comprising carrier particles and toner particles, the sump being elongate and generally cylindrical in shape and having first and second end portions, the housing having a first housing opening in the first end portion thereof and a second housing opening in the second end portion thereof, a cartridge mounting member secured to the housing at the first end portion thereof with the member located directly above and communicating with the first housing opening so that toner particles from a cartridge supported by the member can fall through the member and mix with carrier particles in the first end portion of the sump, a developer applicator located above the housing, axially spaced from a received cartridge and generally aligned with the second housing opening for receiving developer material from the housing, a generally cylindrical tube coaxially positioned within the sump and extending substantially the entire length thereof, the tube having a first tube opening therein positioned below the first housing opening so that carrier particles with fresh toner particles delivered into the housing through the cartridge mounting member can enter the tube, and the tube having a second tube opening therein along the bottom of the tube generally beneath the applicator, a feed screw positioned within the tube for positively driving developer material along the tube from the first tube opening to the second tube opening, a ribbon blender rotatably mounted within the housing coaxial with the tube and between the tube and the housing, drive means for rotating the screw in a direction for moving developer material including both carrier particles and toner particles from the first end portion of the housing toward the second end portion thereof and for rotating the ribbon blender in a direction for moving developer material from the second end portion of the housing to the first end portion thereof where said developer receives fresh toner particles directly through the first housing opening thereby providing a continuous mixing cycle including the portion of housing and tube under the cartridge, and means for feeding developer material delivered into the sump from the tube to the applicator.