GB228116A - Improved apparatus for producing perforated written matter - Google Patents

Abstract

228,116. Brevetti Elettrograph, S. A. S., (Assignees of Barbieri, A.). Jan. 25, 1924, [Convention date]. Electric pens and pencils; reservoir pens.-To prevent alteration of matter written by a pen or pencil, the matter is perforated during writing by electric sparks passing between the pen or pencil and a metal plate supporting the paper or other material written upon. Figs. 1 and 2 show apparatus for connection by a plug 17 to alternating or direct current supply. A casing 14 on a base plate 1 contains a rheostat 15, a Ruhmkorff coil 21. a make-and-break switch 16. and a condenser 20. The casing is provided on the outside with a knob 6 and indicator 2 for controlling the rheostat, a switch 3 co-operating with integral contacts 17, 18, 19, and a safety spark gap 4 connecting with internal contacts 22. Terminals 13 are connected by a lead 10 to a box 9 provided with projecting arms 8, a press-button switch 11, and a lead 12 for attachment to a pen or pencil, which is normally supported in the arms 8 and holds down the switch 11 to break the circuit. The metal plate for supporting the paper is mounted on an insulating base provided with two contact studs for connection to the arms 8 of the box 9, one stud being connected by a lead to the metal plate. Fig. 3 shows a stylographic pen comprising a reservoir 29 of insulating material, a metal writing point 25 in a metal end piece 27, a finger-piece 28 of insulating material, and a cap 31 of insulating material provided with a vent hole 33 and enclosing a spring contact 32 making electric connection between the lead 12 from the box 9 and the writing point 25.