IMPROVEMENTS IN THE MANUFACTURE OF COPPER ROLLERS FOR PRINTING PURPOSES
Year: 1879

page_text: LETTERS PATENT to Peter Jensen, of 33, Chancery Lane, London, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF COPPER ROLLERS FOR
PRINTING PURPOSES." A communication from abroad by Georg Höper, of
Iserlohn, in the German Empire.
Sealed the 28th May 1880, and dated the 29th November 1879.
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the Office of
the Commissioners of Patents on the 29th November 1879.
PETER JENSEN, of 33, Chancery Lane, London. "IMPROVEMENTS IN THE
MANUFACTURE OF COPPER ROLLERS FOR PRINTING PURPOSES." (A communication
from abroad by Georg Höper, of Iserlohn, in the German Empire.)
Those who are acquainted with the refining and casting of copper are aware of
the general rule that any marked reduction in the amount of impurities contained
in a certain copper produces a marked increase of softness in the castings produced
from such copper.
I would also mention that it has for years but vainly been attempted to produce
printing rollers by depositing electrolytical copper (that is copper deposited pure,
or nearly so, by the electric current) direct on a core; this process is unsafe and
circumstantial.
Now the communicator has by experiments found that the general rule above
alluded to, which holds good with copper refined in furnaces, does not apply to
electrolytical copper, inasmuch as he has found that castings produced from the
latter material are harder than castings from furnace copper of inferior purity (that
is, having a marked proportion of the sort of impurities usually found in furnace
copper, say, up to about per cent. of the total weight of such copper.)
This hardness is an advantage in printing rollers cast from such electrolytical
copper, because it ensures a greater durability to the patterns that are to be
engraved on the surface of such rollers.
According to this Invention rollers for printing purposes are cast from electro-
lytical copper. It has been found advantageous to add a certain proportion of
phosphorus to the molten electrolytical copper in the manner now well known,
and in a quantity sufficient to cause the castings to contain about per cent of
phosphorus. The clasticity of the copper is thereby increased, and the edges of
the engraved lines come up sharper and clearer.
The fusion of a proportion of electrolytical copper with other copper will impart
to the latter proportionally the peculiar qualities described above.
Castings or ingots produced according to this Invention are finished or made into
rollers for printing purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Peter Jensen in the Great Seal Patent Office on the 28th May
1880.
PETER JENSEN, of 33, Chancery Lane, London. "IMPROVEMENTS IN THE
MANUFACTURE OF COPPER ROLLERS FOR PRINTING PURPOSES." (A communication
from abroad by Georg Höper, of Iserlohn, in the German Empire.)
Those who are acquainted with the refining and casting of copper are aware
of the general rule that any marked reduction in the amount of impuritics con-
tained in a certain copper produces a marked increase of softness in the castings
produced from such copper.
I would also mention that it has for years but vainly been attempted to produce
printing rollers by depositing electrolytical copper (that is copper deposited pure,
or nearly so, by the electric current) direct on a core; this process is unsafe and
circumstantial
Now the communicator has by experiments found that the general rule above
alluded to, which holds good with copper refined in furnaces, does not apply to
electrolytical copper, inasmuch as he has found that castings produced from the
latter material are harder than castings from furnace copper of inferior purity
(that is, having a marked proportion of the sort of impurities usually found in
furnace copper, say, up to about per cent. of the total weight of such copper).
The communicator has also by experiments found that a copper roller ingot cast
from the raw material known as "best selected" copper, which contains impurities
to the extent of about one quarter per cent., can be stretched in the cold state
under a 35 cwt. steam hammer up to an increase of ten per cent. in length, whereas
a copper roller ingot cast from electrolytical copper under the same conditions
will not stretch to nearly the same extent.
The aforesaid hardness is an advantage in printing rollers cast from such
electrolytical copper, because it ensures a greater durability to the patterns that are
to be engraved on the surface of such rollers.
According to this Invention rollers for printing purposes are cast from electro-
lytical copper. It has been found advantageous to add a certain proportion of
phosphorus to the molten electrolytical copper in the manner now well known,
and in a quantity sufficient to cause the casting to contain about one quarter por
cent of phosphorus. The elasticity of the copper is thereby increased, and the
edges of the engraved lines come up sharper and clearer.
The fusion of a proportion of electrolytical copper with other copper will impart
to the latter proportionally the peculiar qualities described above.
If about two thirds of electrolytical copper be mixed in casting with about one
third of ordinary copper, a roller is produced of marked superiority as regards
hardness, elasticity, purity, and evenness, compared with rollers cast from the
ordinary material.
What I mean by ordinary material is copper such as is obtained from old
printing rollers, and which contain up to about & per cent. of impurities.
Castings or ingots produced according to this Invention are finished or made
into rollers for printing purposes in the ordinary way.
And having thus described and ascertained the nature of this Invention com-
municated to me, I declare that I do not claim the manufacture of copper printing
rollers by causing pure electrolytical copper to be deposited round a cylindrical
core, but I clain,

page_text: Firstly. The employment of electrolytical copper in and for the casting of rollers
for printing purposes, as set forth.
Secondly. In the manufacture of rollers for printing purposes, casting the ingots
of such rollers wholly or mainly from electrolytical copper with or without the
addition of phosphorus, as described.
In witness whereof, I, the said Peter Jensen, have hereunto set my hand
and seal, this Twenty seventh day of May, in the year of our Lord One
thousand eight hundred and eighty.
TONARN