AC energised printer with resilient impression roller - has potential transmitted to web by reactive current through dielectric covering of roller

摘要

The electrically assisted printing system includes a design cylinder rotatable about a horizontal axis and supported by an earthed metal shaft so that the surface of the design cylinder contacting the under surface of web is at earth potential. The web moves through a nip region between the design cylinder and an impression roller. A high voltage supply supplies a d.c. potential through an idler roller of conductive material to transmit the potential to an electrically conductive covering of the impression roller. The impression roller is provided with a metal core mounted for rotation on a shaft, which may be earthed. A resilient insulating layer interposed between the metal core and the conductive outer covering or sleeve.