IM- PROVEMENTS IN THE METHOD OF AND APPARATUS FOR PRODUCING FAC- SIMILE' OR CORRESPONDING PRINTING-PLATES OR PRINTING-STONES IN REDUCED OR ENLARGED SCALE FROM ORIGINAL PRINTING-PLATES OR PRINTING-STONES
Year: 1879

page_text: LETTERS PATENT to Friedrich Hermann Felix Engel, Civil Engineer and
Patent Agent, in the City of Hamburg, Germany, for the Invention of "IM-
PROVEMENTS IN THE METHOD OF AND APPARATUS FOR PRODUCING FAC-
SIMILE' OR CORRESPONDING PRINTING-PLATES OR PRINTING-STONES IN
REDUCED OR ENLARGED SCALE FROM ORIGINAL PRINTING-PLATES OR
PRINTING-STONES." A communication from Gustav Wilhelm Seitz, of
Wandsbeck, in the German Empire.
Scaled the 4th July 1879, and dated the 11th January 1879.
PROVISIONAL SPECIFICATION left by the said Friedrich Hermann Felix
Engel at the Office of the Commissioners of Patents on the 11th January
1879.
"
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hamburg, Germany. IMPROVEMENTS IN THE METHOD OF AND
APPARATUS FOR PRODUCING 'FAC-SIMILE' OR CORRESPONDING PRINTING-PLATES
OR PRINTING-STONES IN REDuced or Enlarged Scale FROM ORIGINAL PRINTING-
PLATES OR PRINTING-STONES." A communication from Gustav Wilhelm Seitz, of
Wandsbeck, in the German Empire.
The purpose of this Invention is the production of facsimile printing-plates or
printing-stones in reduced or enlarged scale from original printing-plates or
printing-stones used for the production of chromo pictures and such like. Hitherto
such new printing-plates or printing-stones were made by copying the original
prints by hand to the required scale, and as one chromo picture often requires 20 and
more corresponding printing-plates or stones this manner of reproduction is very
troublesome, takes a long time, and requires skilled artists, while with this Inven-
tion the new printing-plates or printing-stones can be produced of thorough
exactness and very rapidly in a mechanical manner.
This Invention consists of improvements founded upon Lewis's automatic panto-
graph, by means of which this instrument is rendered applicable for the reproduc-
tion of corresponding printing-plates or printing-stones of the required exactness on
reduced or enlarged scale. Formerly reduced or enlarged copies produced by this
instrument always showed more or less distortion from the original, and in
consequence the instrument was not applicable for the purpose in question.
The inaccuracy of former products of this apparatus resulted mainly from the
manner of connecting the india rubber transfer surface to the tension frame, and
I Drine 1

page_text: further from the manner of copying or transferring the reduced or enlarged
impression from the india rubber transfer surface on to the plate or stone under
treatment or preparation. The india-rubber transfer surface of the automatic
pantograph hitherto constructed was furnished with holes on its outer edge, and
was, by means of hooks, attached to the expanding or tension-frame. This manner
of connection had the disadvantage of an unequal alteration (stretching or con-
traction) of the dimensions of the india rubber transfer surface when the tension
frame was extended or diminished in size.
In this improved apparatus the india rubber transfer surface is furnished with a
strong rim all round, and by means of attachment or binder screws it is connected
to the tension frame. By this means a thoroughly equal extension or reduction of
the surface, and consequently of the print impressed on it from the original
stone or plate is attained, and the reduced or enlarged print is not distorted as was
formerly the case.
For impressing the reduced or enlarged print from the india rubber surface upon
the now plate or stone the latter is placed on a stable foundation or bed plate, and
is covered with the frame and transfer surface of the pantograph. A strong metal
plate is then placed on the back of the transfer surface, and a heavy iron roller,
which is suspended in a hanging frame above the foundation, is lowered on to the
metal plate. This roller is carefully worked over the plato in different directions,
and the impression is given off from the india rubber surface on to the new plate
or stone, such impression being of complete accuracy and clearness.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Friedrich Hermann Felix Engel in the Great Seal Patent Office on
the 10th July 1879.
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hamburg, Germany. "IMPROVEMENTS IN THE METHOD OF AND
APPARATUS FOR PRODUCING 'FAC-SIMILE' OR CORRESPONDING PRINTING PLATES
OR PRINTING-STONES IN REDUCED OR ENLARGED SCALE FROM ORIGINAL PRINTING
PLATES OR PRINTING STONES." A communication from Gustav Wilhelin Seitz, of
Wandsbeck, iu the German Empire.
The purpose of this Invention is the production of fac-simile printing-plates or
printing stones in reduced or enlarged scale from original printing plates or
printing stones used for the production of chromo pictures and such like.
Hitherto
such new printing plates or printing stones were made by copying the original
prints by hand to the required scale, and as one chromo picture often requires
twenty and more corresponding-printing-plates or stones, this manner of reproduc-
tion is very troublesome, takes a long time, and requires skilled artists, while with
this Invention the new printing plates or printing stones can be produced of
thorough exactness and very rapidly in a mechanical manner.
This Invention consists of improvements founded upon Lewis's automatic panto-
graph, by means of which this instrument is rendered applicable for the reproduc-
tion of corresponding printing-plates or printing stones of the required exactness
on reduced or enlarged scale. Formerly reduced or enlarged copies produced by
this instrument always showed more or less distortion from the original, and in
consequence the instrument was not applicable for the purpose in question.
The inaccuracy of former products of this apparatus resulted mainly from the
manner of connecting the india rubber transfer surface to the tension frame and
further from the manner of copying or transferring the reduced or enlarged im-
pression from the india rubber transfer surface on to the plate or stone under
treatment or preparation. The india rubber transfer surface of the automatic
pantograph hitherto constructed was furnished with holes on its outer edge, and
was, by means of hooks, attached to the expanding or tension-frame. This manner
of connection had the disadvantage of an unequal alteration (stretching or contrac-
tion) of the dimensions of the india rubber transfer surface when the tension frame
was extended or diminished in size.
In this improved apparatus the india rubber transfer surface is furnished with a
strong rim all round, and by means of attachment or binder screws it is connected
to the tension frame. By this means a thoroughly equal extension or reduction of
the surface, and consequently of the print impressed on it from the original stone
or plate is attained, and the reduced or enlarged print is not distorted as was
formerly the case.
For impressing the reduced or enlarged print from the india rubber surface upon
the new plate or stone, the latter is placed on a stable foundation or bed plate,
and is covered with the frame and transfer surface of the pantograph. A strong
metal plate is then placed on the back of the transfer surface, and a heavy iron
roller, which is suspended in a hanging frame above the foundation, is lowered onto
the metal plate. This roller is carefully worked over the plate in different direc-
tions, and the impression is given off from the india rubber surface onto the new
plate or stone, such impressions being of complete accuracy and clearness.
In the accompanying Drawings,—
Fig. 1 is a ground plan of the tension frame and transfer surface A.
Fig. 2 is a side elevation of the apparatus.
Figa 3 and 4. side view and ground plan respectively of the connecting parts

page_text: Figs. 5 and 6 represent the pressure apparatus for assisting in giving off the
impression.
R is the iron foundation framing of the tension frame, to which are attached four
double screws 8 connected to each other by bevil gearing actuated by means of
handle K. By turning screws 8 four bars B, of which two and two are placed in
parallel direction, and the ends of which bars B are connected to nuts r, moved by
the screws 8, and are shifted in such manner that the bars will enclose a square of
larger or smaller dimensions according to the direction in which the handle K is
turned. The two pairs of bars B crossing at right angles are kept together by
means of screw bolts and nuts c, which run in slots. To these bolts c are likewise
connected the four pantographic frames D, the same being a construction of lazy
tongs, which expand or reduce in length according to the required size of the
square.
The connection between the transfer surface A and bars B is shown in Figa 3
and 4. The india rubber surface A is furnished with a strong rim all round formed
oither by folding over the edge several times (as in Fig. 3) or in other convenient
manner, and it is in certain intervals fastened between strips or clips of metal 81; 811,
and leather m, m³, pressed together by means of screws 1. The lower strip 81 is
somewhat prolonged while the upper is bent at right angles, and the foot of this angle
rests on the lower strip. Within the prolongation of all a hook p is fastened, which
catches into a slot of a strip of sheet iron h, the other end of which is curved and
placed over the corresponding bar B. Each strip is connected to the fulcrum of
two arms of the pantographic fraines, and consequently follows the motions of the
latter.
For using the apparatus the transfer surface is tonsioned as far as required, and
the bars B are then fixed in position by the screws C. The tension frame with
transfer surface can now be lifted off from framo R.
Figs. 5 and 6 represent the printing or impressing apparatus. A represents the
transfer surface in bar frame B, and expanded or reduced to the required size on
frame R, and lifted off from same as before described; E represents a printing
stone, from which the copy is to be taken, or to which it is to be transferred; F is
the metal plate placed on the back of A; and G is the pressure roller for facilitating
the giving off of the impression; G is suspended from a crane for convenience of
manipulation, and can be lifted off or lowered by means of pulley blocks.
Having now described the naturo of the said Invention in such wise that the
same may be readily carried into practical effect I claim,―
First. The method of mechanical reproduction of "fac-simile " or corresponding
printing plates or printing stones in reduced or enlarged scale by means of the
automatic pantograph as herein set forth.
Second. The strengthening of the transfer surface A by means of the rim and A
the connections of and for the said transfer surface to the tension frame by means
of attachment-screws as herein set forth and shown by the Drawings.
Third. The roller G suspended in a movable hanging frame, and the application
of the metal plate F placed on the back of the transfer surface A for ensuring the
giving off of the impression from the said transfer surface onto the plate or stone 4
under preparation, substantially as described.
In witness whereof, I, the said Friedrich Hermann Felix Engel, have hereunto
set my hand and seal, this Eighth day of July, in the year of our Lord
One thousand eight hundred and seventy nine.