IMPROVED MODE AND APPARATUS FOR MAKING STEREO- TYPE PLATES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Carl Pieper at the Office of the
Commissioners of Patents on the 1st February 1881. A communication
from Alexander Faber, Gentleman, of Magdeburg, Prussia.
CARL PIEPER, Civil Engineer and Patent Agent, of 100/110, Gneisennustrasse,
Berlin, S.W., Prussia. "IMPROVED MODE AND APPARATUS FOR MAKING STEREO-
TYPE PLATES." A communication from Alexander Faber, Gentleman, of Magdeburg,
Prussia.
This Invention relates to an improved mode of making stereotype-plates, and
more especially of the matrices in which they are cast, as also to an apparatus in
which the matrices for such plates are dried.
The matrice is made of several layers of paper or of thin card-board, as usual, but
for the purpose of causing the same to be flexible to a certain degree after having
been dried, the sheets of paper &c., are pasted together by means of a paste con-
sisting of starch, glue, glycerine, ground chalk (or whiting) and water. A small
quantity of turpentine may in certain cases be added with advantage.
material thus prepared is laid on the composition, and the impression is taken as
usual by means of rollers, brushes, or otherwise.
Tho
The matrice is hereupon removed from the composition and placed with the
impressed side upward into a cradle of perforated sheet iron. For the purpose of
allowing the matrice to be handled in its moist state, a sheet of wire gauze is used,
which is strengthened at two opposite edges by means of a metallic ledge to which
another ledge is hinged upon its whole length. The gauze having been placed on
the matrice, the edges of the latter are turned up, and the hinged ledges of the
gauze are folded over them, so that the matrice may now be lifted off the com-
position and turned over, together with the gauze, whereupon it is laid into the said
cradle which, in this case, may consist of strong wire gauze, if preferred. The
cradle, with the matrice is thereupon put into a drying-stove. When the matrices
are of small size, they may be lifted off the composition without the use of the
gauze. In this case their edges are pressed against the cradle by ledges hinged to
the cradle.
The drying apparatus which the inventor employs consists of a muffle corre-
sponding to the shape of the cradle, and of sufficient size to leave a free space
around the cradle, which is provided with legs. This muffle, which is closed in

page_text: front by a door, is placed in a stove in such a manner that the heating gases can
circulate uniformly around the same. The top of the muffle is provided with holes
for the egress of the vapour from the matrice. For promoting the drying process,
a current of air is admitted by a perforated tube extending lengthwise into the
muffle, the air being caused to pass into the said muffle and out through the holes
in its top by the draught of the chimney or by a mechanical contrivance. The
air-current thus produced serves to carry off the vapours rising from the matrice.
The air is preferably heated previous to its admission into the apparatus by passing
it through tubes or channels suitably arranged in the flues of the stove.
The temperature of the apparatus may be controlled by deflecting a part of the
combustion gases into the chimney before their entrance into the muffic-chamber,
or by admission of cold air into the flue leading to the said chamber.
For the purpose of allowing the muffle to be removed, the top of the stove
is so arranged that it can be lifted off; but if preferred, the muffle may be made
a fixture, or, instead of the same, a fixed drying space may be built into the
stove.