Abstract: A module includes a housing, a sealing feature, a locking feature, and an agitator. The housing has an opening separating inner and outer surfaces and a boss that extends through the housing such that part of the outer surface forms an inner bore of the boss having a terminus pointing toward the opening. The agitator has a base, a shaft, and a mixing element coupled to the base such that the base, in cooperation with the sealing feature, circumferentially seals the opening of the housing to form a cavity defined by the inner surface. The shaft passes through the inner bore. The locking feature when engaged permits independent or simultaneous translational and rotational movement of the shaft while an area between the terminus of the boss and the shaft remains mechanically sealed during the movement against liquid or powder encroachment into a clean area of the inner bore.

Abstract: A module includes a housing, a sealing feature, a locking feature, and an agitator. The housing has an opening separating inner and outer surfaces and a boss that extends through the housing such that part of the outer surface forms an inner bore of the boss having a terminus pointing toward the opening. The agitator has a base, a shaft, and a mixing element coupled to the base such that the base, in cooperation with the sealing feature, circumferentially seals the opening of the housing to form a cavity defined by the inner surface. The shaft passes through the inner bore. The locking feature when engaged permits independent or simultaneous translational and rotational movement of the shaft while an area between the terminus of the boss and the shaft remains mechanically sealed during the movement against liquid or powder encroachment into a clean area of the inner bore.

Abstract: A module includes a housing and an agitator. The housing defines a cavity and includes a boss that extends from a first end of the housing into the interior cavity towards a second opposing end of the housing. The boss has an exterior surface and defines an inner bore. The boss includes a flange extending outwardly from the exterior surface. The agitator includes a base, a shaft, and a mixing element. The shaft of the agitator extends from the base and is slidable relative to the inner bore of the boss such that the agitator is movable between a fully retracted position, a partially extended position, and a fully extended position. The mixing element of the agitator extends from the base and includes a portion that is configured to engage the flange of the boss in a non-rotational fashion in response to the agitator being in the partially extended position.

Abstract: A module includes a housing, a sealing feature, a locking feature, and an agitator. The housing has an opening separating inner and outer surfaces and a boss that extends through the housing such that part of the outer surface forms an inner bore of the boss having a terminus pointing toward the opening. The agitator has a base, a shaft, and a mixing element coupled to the base such that the base, in cooperation with the sealing feature, circumferentially seals the opening of the housing to form a cavity defined by the inner surface. The shaft passes through the inner bore. The locking feature when engaged permits independent or simultaneous translational and rotational movement of the shaft while an area between the terminus of the boss and the shaft remains mechanically sealed during the movement against liquid or powder encroachment into a clean area of the inner bore.

Abstract: A module includes a housing, a sealing feature, a locking feature, and an agitator. The housing has an opening separating inner and outer surfaces and a boss that extends through the housing such that part of the outer surface forms an inner bore of the boss having a terminus pointing toward the opening. The agitator has a base, a shaft, and a mixing element coupled to the base such that the base, in cooperation with the sealing feature, circumferentially seals the opening of the housing to form a cavity defined by the inner surface. The shaft passes through the inner bore. The locking feature when engaged permits independent or simultaneous translational and rotational movement of the shaft while an area between the terminus of the boss and the shaft remains mechanically sealed during the movement against liquid or powder encroachment into a clean area of the inner bore.

Abstract: A module includes a housing, a sealing feature, a locking feature, and an agitator. The housing has an opening separating inner and outer surfaces and a boss that extends through the housing such that part of the outer surface forms an inner bore of the boss having a terminus pointing toward the opening. The agitator has a base, a shaft, and a mixing element coupled to the base such that the base, in cooperation with the sealing feature, circumferentially seals the opening of the housing to form a cavity defined by the inner surface. The shaft passes through the inner bore. The locking feature when engaged permits independent or simultaneous translational and rotational movement of the shaft while an area between the terminus of the boss and the shaft remains mechanically sealed during the movement against liquid or powder encroachment into a clean area of the inner bore.

Abstract: The print head of an electrographic printer is cleaned electrostatically. The printhead has a number of electrodes in an electrode array, which cooperate with a dielectric belt. Periodically, printing with the printer is interrupted (e.g. after every 100 pages of printing, or about every minute), and then substantially all of the electrodes are energized at the same time for a time period sufficient to effect burning off of contaminants from the electrodes (e.g. about the time it takes to print four pages, or about 3 seconds). A host computer controls the operation of the printer components. The printer developer unit may be moved away from the dielectric belt prior to the energization of all of the electrodes to effect cleaning.

Abstract: A magnetic brush developing system for electrostatic duplication using a monocomponent developer controls the thickness of the developer on the brush such that the necessary amount of developer is applied to the photosensitive surface which carries the latent electrostatic image. A capacitive sensor in the form of a rigid plate of conductive material is spaced closely adjacent to the surface of the roll on which the magnetic brush is formed. The dielectric constant depends on the thickness of the developer in the magnetic brush and is detected by the capacitive sensor. The capacitance of the sensor is converted, into a pulse train the duty cycle of which is modulated in accordance with the change in capacitance, by a circuit arranged on a circuit board in close proximity to the sensor to provide a compact structure which is not subject to perturbations which could effect the capacitance presented by the sensor.

Abstract: A magnetic brush developing system for electrostatic duplication uses a developer having a magnetic carrier and non-magnetic toner which is transferred by the brush to an electrostatic image. A analog signal is derived using a Hall sensor in contact with the brush and adjacent to a magnet of the brush. The location of the sensor after and downstream of the transfer point provides information in the signal both as to the absolute value of the concentration (ratio of toner to carrier by weight) as well as the rate of transfer of the toner to the electrostatic image. These signals are used to control the supplying of replenishment toner to the developer only when the concentration of toner drops below a predetermined desired value and then at a rate commensurate with the rate of transfer of toner to the electrostatic image.