Abstract: A pellet feeder (A) feeds pellets of vulcanized rubber or other materials and water or another fluid at controlled rates into a mixing tank (30). An agitator (32) mixes the pellets and fluid into a slurry. The slurry is pumped from the mixing tank to a mill (C) by a pump (34). The mill has a receiving region (70) defined between a stator (48) and a rotor (68) for receiving the slurry. The stator and rotor define a peripheral grinding zone (72) around the slurry receiving region. An impeller (74) has vanes which extend from the upper surface of the rotor to an abrasive surface (82) of the stator such that the impeller vanes are ground at the same rate as the stator and rotor wear to maintain a fluid seal around the impeller blades. Fluid cylinders (50, 52) maintain a constant pressure between the stator and rotor. The stator has a plurality of recesses (86, 86') which preferably have downstream extending relief areas (214).

Abstract: In accordance with the present invention there is provided an electrographic recording apparatus for recording on an electrostatic charge retentive record medium and a driver circuit suitable for use therein. The apparatus comprises a plurality of recording electrodes mounted in close proximity to the record medium. A plurality of complementary electrodes are mounted in electrical cooperative relationship with the recording electrodes. Improved driver circuits are provided for applying a voltage to the electrodes. The driver comprises a current branch to which the electrode is connected. A current control is provided for supplying a current through the current branch, which current biases diodes to force the electrode to a reference potential. The current further charges an electrical storage element. To apply a high voltage to an electrode, the current control blocks the current flow. The potential stored in the storage element which causes a base-emitter current flow to forward bias the transistor.

Abstract: An electrographic writing system including an electrographic writing head operatively connected to a switching system is disclosed. The electrographic writing head includes a plurality of electrically conducting styluses arranged to produce an electrostatic charge on a record medium which is normally dielectric coated paper. The styluses are supported by an insulating material, and one of the ends of each of the styluses is either substantially flush with one end of the writing head or slightly recessed. The other ends of the styluses act as part of a connecting means to the switching system. The switching system includes a plurality of diode assemblies. Each diode assembly has a sequence of diode switching circuits including a first high stored charge or slow diode, a second low stored charge or fast diode in series therewith and a capacitor. The capacitor has one end connected between the diodes and the other end to ground or a dynamic voltage.