From Xylographs to Lead Molds; A.D. 1440-A.D. 1921 — John Shaqi
From Xylographs to Lead Molds; A.D. 1440-A.D. 1921Forster, H. C.
History
From Xylographs to Lead Molds; A.D. 1440-A.D. 1921
Forster, H. C.
Electrotyping; Printing -- History
The molded cases are suspended at regular intervals of twenty inches
from an endless chain-conveyor operating directly over the batteries.
This conveyor carries the cases edge-wise through the electrolytic
bath between two rows of anodes which are four inches apart. At the
end of each battery the conveyor automatically lifts the cases out and
over into the next battery in the series, of which there are seven.
The eighth tub contains pure running water for washing the case after
the complete deposition of the shell.
The speed of this conveyor is regulated so that when the molded case
has reached the end of its journey through the series of seven
batteries, the other factors also being regulated, a shell of uniform
thickness and texture throughout is deposited thereon.
This automatic handling of the cases in the batteries eliminates the
necessity of the battery-man pulling the case out of the bath by hand
from time to time in order to peel back a corner of the shell to see
if it is thick enough, which is the common practice. In other words,
the element of human guess-work is eliminated, and in addition, the
items of time and handling are greatly reduced.
BACKING UP THE SHELL
Backing-up the shells with the metal base, i. e., casting, is done
automatically by The Rapid Electrotype Company.
A rotary casting-table with a capacity of ten pans revolves around its
axis on a plane that brings each pan immediately below a spout through
which the required metal is automatically flowed from the bottom of
the metal pot on the tinned shell placed therein. When the required
metal backing has been flowed, the table turns to bring the next pan
with its shell under the metal-spout. The amount of metal flowed is
exactly regulated. As the casting table completes a circuit, the first
shell backed up has cooled so that it can be removed to the scrubbing
machine.
This method, of course, eliminates the hand-ladling of hot metal from
the metal-pot to the casting-table, as is the ordinary practice, and
obviates any possibility of the oxidized metal or dross on the surface
getting into the casts, besides effecting a marked economy in time and
handling. In addition, it casts the plates flat, thereby eliminating
about 75 per cent of the finishing, which, of course, means a better
printing plate. Three of these machines are used.
The Rapid Electrotype Company developed and built these
casting-machines in its own machine shop and owns the patents covering
them.
THE ALUMINOTYPE PROCESS
The development, perfection and introduction of the Aluminotype
Process for duplicating a printing surface in a solid piece is one of
the outstanding accomplishments of The Rapid Electrotype Company, and
marks a distinct step in advance of the other and older methods used
in the graphic arts, for certain classes of printing.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account