AUXILIARY NEGATIVE GAGE PRESSURE DEVICE
Original Publication Date: 1980-Aug-31
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
Toner contamination of electrostatographic reproducing apparatus outside the developer housing can be reduced by lowering the pressure within the developer housing thereby reducing the amount of toner which escapes from the developer housing. The figure illustrates a device which applys the Venturi effect to air flow in a free field to achieve lower pressure. In the device, a funnel-shaped conduit 10 is inserted in the much larger fuser exhaust duct 12, for example, one which has a constant fluid flow within it. The funnel-shaped conduit necks down to a much smaller diameter tube 14 resulting in greatly increased air velocity at this point thereby creating a high pressure drop. At this point the tube 14 is connected by conduit 16 to developer housing 18 thereby reducing the pressure within the developer housing and the resulting machine contamination due to toner escaping from the developer housing.