Abstract: A powder metering device for distributing powder which is stored in a hopper, the powder then being delivered by the device to distributing nozzles. The metering device comprises a roller defining an engraved periphery which receives powder from the hopper. The roller carries powder at a controlled rate to a passage where the powder is then moved with the fluid to the distributing nozzles. The chamber holding the roller is maintained under positive pressure. Gaskets are located on opposite sides of the roller and maintained by the chamber pressure against the roll side walls and in engagement with the chamber walls. These gaskets, as well as the positive pressure conditions serve to discourage seepage of powder away from the path between the hopper outlet and the passage leading to the distributing nozzles.

Abstract: A system for distributing powder which is stored in a hopper and delivered from the hopper to distributing nozzles. A metering construction is interposed between the hopper and the distributing nozzles, this construction comprising a roller which receives powder from the hopper. The roller carries powder at a controlled rate to a passage where the powder is exposed to a pressurized fluid such as air. The powder is moved with the fluid to the distributing nozzles. Separate inlets, preferably for the introduction of air at atmospheric pressure, communicate with the passage. The distributing nozzles are designed for the distribution of the powder evenly over wide sheets of paper, foil or plastic, and over the printed surfaces of a web of paper or plastic.