Abstract: An automated system and method are provided to supply a liquid toner dispersion to the printing station of a high speed electrophotographic printing press. A highly concentrated form of the liquid toner dispersion is supplied in a first container. Density measurement of the liquid toner in a process tank controls the feed of concentrate to the process tank. Liquid level switches in the process tank control toner carrier liquid flow to the process tank. Conductivity sensor monitoring of the toner in the process tank controls the flow of liquid charge control agent into the process tank. Flow rate of the liquid toner from the process tank to the printing station of the printing unit is controlled by a sensor, logic circuitry, and motorized adjustable flow valve and flow meter.

Abstract: An envelope feeder for a printing press providing a unique feeder arrangement that allows multiple parallel feeding of stacks of differently sized and shaped envelopes to be fed into the press simultaneously. An envelope vacuum pick-up arrangement is coordinated with a feed roller that grabs the envelopes from the bottom end of open-ended, independently adjustable feeder trays, that can be fed with unprinted envelopes continuously without interrupting the printing process. Electronic logic sensing and control apparatus monitors the envelope feeding process such that, in case of misfeeds, the next following printing cycle is inhibited to avoid smearing of wet ink. Timing apparatus with manual control insures precise registration of the printed image even at high speed operation. Manual switches coordinated with the electronic control allows feeding from a single or from all feeder trays.