Trans-fer′ring-ma-chine′.
（
Engraving.) This machine is used by bank-note engravers to obtain upon rollers cameo copies of engraved dies, and to transfer impressions from the rollers to the plates, from which notes, etc., may be printed.
In bank-note and similar engraving, the views, portraits, and ornaments are not engraved immediately upon the plate from which impressions are printed, but each design and ornament is engraved on a separate piece of softened steel, which forms a
die. The dies are placed in a closed crucible, with animal charcoal, brought to a red heat in a furnace, and, after cooling, are ready for the transferring-machine.
The die is placed on the adjustable bed-plate of this machine, and a softened steel roller is placed in the oscillating head above.
Arrangements are made for bringing the parts in perfect apposition, so that the roller may come in contact with the die in the required place.
The die and roller being then brought forcibly together, the roller is made to revolve over the die, and the metal of the former is pressed into all the lines of the die, making a cameo or salient impression of the engraving.
The roller is then hardened, and is ready for delivering an impression to a bank-note plate.
The pressure of the roller upon the plate in the transferring-machine is given by a system of compound levers, and is regulated by the pressure upon a treadle of the foot of the operator, or by a hand-lever.
The rolling is repeated again and again by rocking it back and forth until the steel of the roller has insinuated itself fully into every line of the die, whether heavy or light, and the larger machines can give a pressure of 35 tons.
When a bank-note is ordered, the directors make choice of the designs they require, each being on a separate piece of paper, as printed from the die. The choice being made, the arrangement is to be determined, and the rollers are then brought forward to deliver their impressions separately upon the face of the plate, which is attached to the bed-plate of the transferring-machine.
Thus each view, ornamental letter, portrait, lathework, rosette, or star is transferred to the plate.
The
lettering is then engraved upon it with the graver, or by die. By lettering is meant the name of the bank and such matters.
These completed, it is ready for the
printing-press.
See also transfer-press; bank-note engraving.
