Patent GB-198913-A (GB)
Title: Improvements in electrically-operated illuminated signs for advertising and like purposes
IPC: G09G3/00
Filed: 1922-06-16
Abstract: 198,913. Hosken, S. T. June 16, 1922. Monogrammic signs. - Relates to monogrammic signs of the kind in which a field of electric lamps is selectively illuminated through contacts arranged on a table in correspondence with the lamps, and comprises the use of a conductive fluid such as mercury for closing the lamp circuits, the fluid being confined to the required channels by means of stencils, sand or the like. The lamps are screwed into a brass plate, their centre-contacts making connection with heads of solder on the ends of wires which are brought through an insulating plate mounted behind the brass plate, and are connected to contacts on the controlling table. This table may be of mild steel, as at 1, Fig. 2, and each lamp lead 5 is taken into a split metal sleeve 3 plugged with a metal plug 4 and insulated by a bush 2, the lamp circuit being closed when the mercury connects the plate 1, which is connected to the negative pole of the current source, to the sleeve 3. In a modification, the table 1 may be of insulating material, the mercury being in that case connected to the negative pole of the current source through the stencil or through a separate wire. The stencil containing the mercury may be wholly of insulating material, or may comprise an insulating plate 15, Fig. 5, surmounted by a metal plate 11, the mercury being poured into the channel 14. The stencil may be prepared on a part of the table which is free from contacts and slid into place, so as to give the effect of a moving letter in the sign. Alternatively, the stencil may be so formed that the mercury flows over the contacts successively, parts of the insulating plate 15 being left standing where parts of the plate 11 are cut away, the former being shown by shaded lines in Fig. 6, which represents the arrangement giving the letters " O X." The mercury is poured into a reservoir 18 insulated from the contact table, whence it flows along the channel 20, closing the corresponding lamp circuits, over the insulation 21, along the uninsulated channel 22, under a bridge 23 of insulating material, along channels 22<a>, 24, 24<a>, over the bridge 23, and along channels 24b, 26. Alternatively, sand or like material may be spread on the table and a pool 28, Fig. 10, of mercury formed on the part of the table where there are no contacts. The design is then traced with a finger or brush as at 29, so that the required lamp circuits are closed successively. Circuits are described in the Specification whereby a plurality of signs may be controlled from any one, of a plurality of tables, switches being arranged for cutting out any of these elements as required. According to the first Provisional Specification, the table when made of insulating material may have embedded in it a number of conducting points connected to the negative pole of the current source; the conducting fluid may comprise a solution of copper sulphate mixed with rouge so as to form a paint, the conducting parts of the table being in this case formed of copper; alternatively. a conducting chain may be laid on the table and arranged to form letters or the like; and the intensitv of the illumination may be varied bv a rheostat.