Improvements in Copying Writings or Drawings and in Apparatus Connected therewith.
Year: 1889

page_text: Date of Application, 22nd May, 1889-Accepted, 17th Aug.,
1889
COME LEIE DIEC
Improvements in Copying Writings or Drawings and in Apparatus
Connected therewith.
I, JOSEF PRASCH, of 7, Hörnesgasse, Vienna, in the Empire of Austria, Engineer,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:
This invention relates to what is termed "hectograph paper," by means of which
numerous copies of writings or drawings can be made from one original without the
aid of apparatus. Such paper is continuous, thin and strong, and is coated on one
side with a very fine layer of one of the ordinary gelatinous copying substances which
as, for instance,
possess the quality of absorbing soluble intense colouring matter, such
concentrated aniline ink, and from which a number of impressions of the transfer
may be taken on paper or other suitable material.
The composition of the copying substance employed forms no part of the present
invention. Any of the ordinary preparations, such as those containing glue, gelatine
and glycerine, may be used.
The essential features of this invention consist in the application of the copying
film or coating to continuous paper, in the method whereby such coating is applied
and in apparatus specially adapted for effecting such application.
In the accompanying drawings, Fig. 1 represents in vertical section and side
elevation the apparatns I prefer to employ for coating the paper; Fig. 2 being an
end elevation thereof.
In a suitable framework are mounted an axle A, two rollers B and C and a drum D
parallel to each other and in the order shewn. The roll of endless paper to be coated
is carried by the axle A, one end being led over the guide-rollers B and C to the
drum D, upon which the paper, then in the form of "hectograph paper," is wound.
A vessel G consisting of three separate compartments w, m and o is placed over a fire;
the compartment to containing water and serving as a heating bath for the other
two compartments. The copying substance is placed in the reservoir m, and is
liquefied by the hot bath underneath. The third compartment o communicates with
the reservoir m through an aperture x, which can be closed by means of a slide
actuated by the handle h. This compartment is formed with three side-walls only,
the fourth side being closed by a fixed screen E, between which and the compartment
the paper is passed. That side of the screen in contact with the paper is lined with
felt or other soft substance.
By turning the screws, the vessel G can be so adjusted that the open side of the
paper thereon
compartmen to presses to the requisite degree against the screen E or the
and is tightly closed thereby; the movement of the paper being, however, uninterrupted
on account of the yielding nature of the screen aforesaid.
When the aperture x is opened, the liquefied substance passes into the compart-
ment o and arrives in contact with the paper; an orifice.v in one of the side-walls
serving to regulate the level of the substance in this compartment.
If the drum D be set in motion in the direction indicated by the arrows, any
motive power being employed for the purpose, the paper is wound from the axle Å
and passes upwards past and in contact with the liquefied substance; a thin layer
of the latter being deposited on that side of the paper which is turned towards the
vessel G.
The thickness of the coating or layer of the copying substance so deposited is
regulated by reducing or increasing the rate of motion of the paper, thus giving
more or less time for the surplus copying substance to flow away.

page_text: As the liquefied substance when coagulated is adhesive, the paper coated therewith
cannot be rolled up and kept in that condition. Its adhesiveness must, therefore, first
of all be removed. This is effected-by sprinkling over the coating on the paper a fine
insoluble powder, such as asbestos, or powdered rice-starch, which adheres to the copying
...substance, and is washed off before use with a damp sponge. The powder is
contained in a sieve S placed between B and C. The sieve is constantly agitated
by any appliance connected with the motive mechanism, such as the notched wheel
shewn in the drawings. A small bar k, pivoted to the framework in the space
between C and D, is caused by projections on the drum D to strike lightly and
repeatedly-against the back of the paper; thus serving to knock off any excess of
powder.
The special advantages of the process of manufacture above described are as
follow: 1. A continuous length of prepared paper is produced. 2. The paper, being
wider than the opening o, a free margin is left on each side. 3. The coating or layer
of the copying substance is very uniform and no thicker than necessary; its thickness
being, moreover, regulated at will within certain limits. 4. By the employment of
the sprinkling and striking apparatus, the paper is so prepared that it may at once be
rolled up ready for use.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I claim :-
:―
1. The improved means for enabling copies to be taken from writings or drawings
as set forth, and consisting of a special preparation of continuous paper coated on one
side with a thin layer of gelatinous matter (such as a composition of glue or gelatine
and glycerine) which does not become hard but serves to enable the paper to receive
a negative impression from an original writing or drawing in the preparation of
which colouring matter (such as concentrated aniline ink) has been used, so that a
number of copies of the writing or design transferred may be produced on paper or
other suitable material.
2. In the preparation of paper of the kind referred to in the preceding claiming
clause, means substantially as described whereby a continuous length of paper is
drawn past and serves to close an opening in a vessel containing the liquefied copying
substance, so that the latter coagulates in a thin uniform layer upon one side of the
paper under treatment.
..3. In coating paper as and for the purpose herein referred to, the employment of
i apparatus constructed substantially as herein described and comprising an axle A
'upon which
mounted the roll of paper under treatment, a vessel G containing the
gelatinous matter to be applied to the paper, an abutment E, rolls B. and Cover
which the coated paper passes on its way to the winding drum D, a sieve S, in which
is placed the powder for preventing the coils of prepared paper sticking together,
means for agitating the sieve, and a bar or striker k for dislodging superfluous powder;
the vessel G being adjusted by the screws, and comprising an upper compartment or
reservoir m heated by the water in a lower compartment or bath and a compartment o
communicating with the reservoir m and with the continuous strip of paper.
* Dated the 16th day of May 1889.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Agent for the Applicant.