GB633991A - Apparatus for electronograph printing - Google Patents

Abstract

633,991. Printing-machines. HUEBNER, W. C. Jan. 5, 1948, No. 284. Convention date, May 15, 1947. [Class 100 (ii)] An electrical printing-machine such as is described in Specification 615,556 in which ink passes from an inked printing-cylinder 10, Fig. 7, to a web 25 held to the cylinder 10 by rollers 23, 24 under the action of electric lines of force which pass between a positively-charged element 20 insulatedly mounted within the cylinder 10 and a negatively-charged stationary or rotary element 36 is characterized in that at least one of the elements such as 36 is provided with a plurality of small area projections which extend towards and adjacent to the other element. The projections may take the form shown in Fig. 6, of a series of triangular ridges 37, or of a number of serrated discs 34, 35, Fig. 4, with the projections in staggered relation, or as shown in Fig. 1, may consist, of a number of rods 30 which may have pointed ends, and which are secured to the negatively-charged element which may be stationary or rotary. The element 20 may be replaced by a series of rods similar to 30, and the extremities of the rods 30 may be arranged in concave or convex form. As shown in Fig. 7, the web W and the ink may be electrically charged prior to the printing operation by serrated plates 61, 58 respectively, charged respectively negatively and positively to correspond with the charges on the elements 36, 20. The cylinders may be charged by leads passing axially into apertures in the cylinders, or by a contact brush 43, Fig. 7. The electrical charges are obtained from highvoltage D.C. mains, and double-pole. switches are provided which permit the direction of the currents to be reversed if desired.