IMPROVEMENTS IN THE PRODUCTION OF MATERIAL FOR STEREOTYPE MATRICES
Year: 1883

page_text: LETTERS PATENT to Ludwig. Posselt and Herrmann Schimansky both of
Berlin, German Empire for an Invention of "IMPROVEMENTS IN THE
LETTERS PATENT to Ludwig, Posselt and Herrmann Schimansky both of
Berlin, German Empire for an Invention of "IMPROVEMENTS IN THE
PRODUCTION OF MATERIAL FOR STEREOTYPE MATRICES "
PROVISIONAL SPECIFICATION left by the said Ludwig Posselt and
Herrmann Schimansky at the Office of the Commissioners of Patents on the
2nd May 1883.
LUDWIG POSSELT and HERRMANN SCHIMANSKY both of Berlin German Empire
"IMPROVEMENTS IN THE PRODUCTION OF MATERIAL FOR STEREOTYPE MATRICES
>>
Our invention consists mainly in a new composition instead of the paste usually
used for pasting the separate sheets of paper together, which constitute the matrix.
This composition hardens without using a special kind of oven, in a few minutes,
when the matrices are placed on frames above the melting pot, it involves a better
flow of the metal, so that the finest engravings can be reproduced faultless and
lastly we can produce these stereotype sheets for the trade, so that any one who
wishes to take plates from wood blocks or type, is able to do so without any
appliances. This is of importance to smaller printing offices and wood engravers ·
who do not possess a stereotype establishment of their own.
We prepare our sticky composition which mostly consists of plastic materials and
proceed in the following manner as hereafter described.
We take

page_text: properly dissolved, a part of the prepared mixture is poured into a separate vessel
into which some rye flour is shaken and the whole is stirred until it becomes a
porridge as even or free from lumps as possible.
Then after this has been done, the whole is poured together, mixed together by
sharp stirring, and pressed through a fine hair sieve. After which so much cold
water is put with the finished porridge as to allow it to be regularly laid on with
a broad flat brush.
In producing the matrices we proceed in the following manner. A sheet of
printing paper is laid upon the stone plate and is smeared as evenly as possible
with the paste; then we take a sheet of the common red blotting paper, or instead
of that for better work, a sheet of copper plate printing paper and stick them
together by smoothing it (that is the blotting paper) down with the hand on the
already paste-coated sheet of printing paper. Then we carefully coat again the
blotting or copper plate printing sheet with paste and take a sheet of tissue paper
and make it as smooth as possible and then coat the latter with the paste. In the
same manner we proceed with a second sheet of tissue paper. Then we take a
third sheet of tissue paper, lay it on the second and smooth it carefully as this is
intended to be joined to the set type immediately when the matrix sheet is
laid on.
The matrix sheet thus finished must remain under a very light pressure for at
least one hour, before it can be used as a mould.
The sheet so made can now be dried by the warmth of the melting room and
put by for future use. In order to apply it as a matrix for stereotype casting it
only needs to be laid between two damp sheets of felt a short time so as to
gradually make it damp, it is then just as useful for stereotype as the fresh sheet.
The plastic masses which are contained in the binding material besides Flour
(not starch) paste, namely the clay slime take up the moisture slowly when
moistened for use and take a very sharp impression because they are not elastic
and retain their shape, when the sheet having been beaten on the wood block or
set type with a brush, is taken off.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ludwig Posselt and Herrmann Schimansky in the Great Seal Patent
Office on the 2nd November 1883.
.
LUDWIG POSSELT and HERRMANN SCHIMANSKY both of Berlin German Empire
"IMPROVEMENTS IN THE PRODUCTION OF MATERIAL FOR STEREOTYPE MATRICES
"
Our invention consists mainly in a new composition instead of the paste usually
used for pasting the separate sheets of paper together, which constitute the matrix.
This composition hardens without using a special kind of oven in a few minutes
when the matrices are placed on frames above the melting pot, it involves a better
flow of the metal, so that the finest engravings can be reproduced faultless, and
lastly we can produce these stereotype sheets for the trade, so that any one who
wishes to take plates from wood blocks or type is able to do so without any
appliances. This is of importance to smaller printing offices and wood engravers
who do not possess a stereotype establishment of their own.
We prepare our sticky composition which mostly consists of plastic materials,
and proceed in the following manner as hereafter described.
1000 parts.
All the substances with the exception of the rye flour are put in a convenient
holder and mixed with 1000 parts of cold water and stirred. When everything is
properly dissolved, a part of the prepared mixture is poured into a separate vessel
into which some rye flour is sbaken and the whole is stirred until it becomes a
porridge as even or free from lumps as possible.
Then after this has been done, the whole is poured together, mixed together by
sharp stirring, and pressed through a fine hair sieve. After which so much cold
water is put with the finished porridge as to allow it to be regularly laid on with a
broad flat brush,
In producing the matrices we proceed in the following manner. A sheet of
printing paper is laid upon the stone plate, and is smeared as evenly as possible
with the paste; then we take a sheet of the common red blotting paper, or instead
of that, for better work, a sheet of copper plate printing paper and stick them
together by smoothing it (that is the blotting paper) down with the hand on the
already paste-coated sheet of printing paper. Then we carefully coat again the
blotting or copper plate printing sheet with paste and take a sheet of tissue paper
and make it as smooth as possible and then coat the latter with the paste. In the
same manner we proceed with a second sheet of tissue paper. Then we take a
third sheet of tissue paper, lay it on the second and smooth it carefully, as this is
intended to be joined to the set type immediately when the matrix sheet is
laid on.
The matrix sheet thus finished must remain under a very slight pressure for at
least one hour, before it can be used as a mould.
The sheet so made can now be dried by the warmth of the melting room and
put by for future use. In order to apply it to a matrix for stereotype casting, it

page_text: only needs to be laid between two damp sheets of felt a short time so as to
gradually make it damp; it is then just as useful for stereotype as the fresh
sheet.
The plastic masses which are contained in the binding material besides flour (not
starch) paste, namely the clay slime, take up the moisture slowly when moistened
for use and take a very sharp impression, because they are not elastic and retain
their shape, when the sheet, having been beaten on the wood block or set type
with a brush, is taken off. The mass before used consisting of Starch paste and
glue with a proportionately small addition of chalk slime served only to unite the
separate sheets of paper, and these latter formed themselves the principal part, but
because of their elasticity altered so much after being pulled off and while drying
that the form of the mould was not sharp, wherefore the casting could not be sharp
either.
The action of borax on liquid metals is known. We use it as an admixture in
order to facilitate the flow of the metal and to produce perfectly smooth surfaces
in the casting. The borax when used for brazing copper, brass and the like forms
a very hard and firm enamel on the surface of the metals and when used in
ironing linen it imparts to the latter a very smooth surface. The importance of
its admixture to the mould composition will thus be sufficiently demonstrated.
The red bole from its pliancy is an important addition for the same reason. These
substances have not been used for stereotype mould composition heretofore no
more than rye flour and clay slime and consequently we have here a combination
accompanied by new effects."
We do of course not confine ourselves to the manufacture of stereotype
cardboard for the trade, but apply also the newly made and not dried cardboard
directly for the production of matrices and stereotypes. These matrices will stand
up to twenty castings whereas by the use of the paste heretofore employed and
which consisted chiefly of starch flour and chalk slime at most five or six castings
could be taken. This great durability of our matrices as regards the action of the
heat of the molten metal is chiefly owing to the use of our paste which is
incombustible while the usual paste, because of its proportionately great amount
of vegetable and mineral substances, becomes rotten or brittle by the heat.
As already stated the matrices made by the process hereinbefore described may
be dried by the heat of the smelting pot, so that a special drying stove is not
required. For greater convenience and for preventing the shrinking of the matrix
when drying we use by preference the appliances shewn on the accompanying
drawing.
Figure 1 represents in plan the lower part A and Figure 2 in plan, the upper
part B of a frame which is shown in side view at Figure 3. The lower frame A
has its open central part covered with wire netting which serves to receive the
moist matrix as it comes from the type frame or form. The inner dimensions of
this frame A are such that all the type itself comes within it while the smooth
surrounding edge of the matrix comes partly on the outer part of the frame A.
The upper frame B Figure 2 is provided with buttons a a' for taking hold of it
and placing it upon the lower frame A after the latter has received the matrix
which is thus pressed between the two parts A and B. Such a pressure may
be exerted in a great many different ways and for instance by means of wedges
or screws but we prefer the means shewn on the drawing. Two crank handles
c c¹ are provided on the lower frame A and their pins fit exactly in two
corresponding notches & d in the upper part B thus ensuring that the parts A
and B come in their exact relative position. 6 e¹ are two half round ribs on the
top of the part B. The ribs are as shown in Figure 3 sloping down towards each
side thus forming half circular wedges. When the part B is placed on the part A
and the cranks c c¹ are turned towards the interior of the frame they will ride on
the wedge surfaces of e, e¹ thus pressing the parts A and B together and squeezing
the edges of the matrix fast between the two. In this way the matrix retains its
dimensions without shrinking while drying, and will be drawn perfectly smooth
"

page_text: just as a sheet of drawing paper when mounted in a damp state on a drawing
board.
The drying takes place above the melting pot C shown in Figures 4, 5 and 6 of
which Figure 4 is a vertical cross section, Figure 5 a vertical longitudinal section
and Figure 6 a plan. For conveniently effecting the drying of the matrix, the
pot C is of an elongated form, and is at the end away from the fire fitted or formed
with a fixed projecting rail 8, and with a movable rail 8' which can be shifted and
fixed in proper position on the flanger of the pot by means of pegs f according to
the width of the matrix. The rail r is for this purpose formed with holes . The
form of the pot is also suitable for removing the liquid contents of same by a
ladle. The frame A (Figures 1, 2 and 3) with the frame B and with the damp
matrix held firmly between them is taken hold of by the handles h h¹ is
pushed in between the rails 8 s¹ into the position shown where the matrix will
receive the heat from the liquid metal and thus dry in the course of some
minutes.
And having thus described and ascertained the nature of this invention and the
manner of carrying the same into effect we declare that we claim :-
First: The method of producing stereotype matrices by the employment of a
plastic sticky composition consisting mainly of rye flour, slime of clay, borax
and red bole, and applied as a paste between sheets of paper substantially as set
forth.
Second-The method of producing stereotype sheets of cardboard which may
be kept in stock as desired and are applied to the production of impressions
therefrom by previously moistening them substantially as set forth.
Third-The combined method of producing and of drying the matrices in
combination with the special means for conveniently carrying the drying into effect
substantially as set forth.
In witness whereof we the said Ludwig Posselt and Herrmann Schimansky
have hereunto set our hands and seals this Seventh day of August in the year
of our Lord One thousand eight hundred and eighty three.
LUDWIG POSSELT
(L.S.)
HERRMANN SCHIMANSKY (L.S.)