A New and Useful Process for Covering Plates or Rollers with a Photographic Substance Sensible to the Action of Light.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
A New and Useful Process for Covering Plates or Rollers with a
Photographic Substance Sensible to the Action of Light.
I, ERNST ROLFFS, of Siegfeld, near Siegburg, in the Province of the Rhino,
German Empire, Manufacturer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to a process for easily and equally covering rollers and
plates with a substance sensible to the action of light so, that the rollers might
be employed for printing purposes, as described in my English Application No.
16944/1899.
This precess is a very simple one and merely consists of arranging the roller
fo le covered upon a lathe. Upon the support fixed to the mandril of this lathe
is arranged a receptacle containing the liquid for covering the roller. This
receptacle is provided with a fine opening forming an outlet for the liquid. The
roller is rotated and owing to the horizontal advancing movement of the support,
When
the liquid equally runs down upon the roller surface and covers the same.
plates are to be covered the horizontal movement of the support must be altered
Correspondingly.
The receptacle then is provided with a longitudinal slot in breadth corre
sponding to the size of the plate. When the support is advanced, the liquid
equally will cover the plate upon its whole surface.
1000
A New and Useful Process for Covering Plates or Rollers with a
Photographic Substance Sensible to the Action of Light,
I, ERNST ROLFFS, of Siegfeld, near Siegburg, in the Province of the Rhino,
German Empire, Manufacturer, 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 a process for covering printing rollers or plates to be
etched or engraved with substances sensible to light. As well known the uniform
covering even of Hat objects with a liquid substance offers great difficulties,
while the absolute uniformity is the main condition for a good result of the

page_text: These difficulties are still greater in the process, in which the finest semi-lones
are to be produced upon a printing roller by the etching or engraving of isolated
points upon a cylindrical printing roller. The applicant has now found that
this process for equally covering the roller to be etched with a substance sensible
to light becomes very easy when proceeding in the following manner:
The roller is mounted upon a lathe and a receptacle containing the said liquid
is placed upon the support longitudinally movable by the screw threaded spindle
of the lathe. When the roller is set in rotation and a cock with which the
receptacle is provided is opened, the liquid flowing down from the latter will
cover the roller in spiral lines owing to the rotation of the roller, and the simul-
tuneous advancing movement of the support and thus of the receptacle. These
spiral lines form then quito a uniform layer upon the roller.
This process also allows of a subsequent drying of the cover uniformly spread
upon the roller. The same effect can also be obtained when the receptacle does
not move in horizontal direction but stands still, while the roller besides rotating
advances simultaneously.
A spattule or the like attached to the support may be employed, which spreads
the liquid distributed upon the roller to a uniform layer.
The process can also be employed for plates in such a manner that lines are
drawn by the liquid flowing down from the small opening or narrow slit of the
receptacle, so that the lines will mix with one another and form a uniform
cover.
The process may also be carried out in such a manner that the liquid is
distributed onto the plate from a small opening or narrow slit of a receptacle
moved in such a manner over the plate or the latter being moved underneath
the small opening or narrow slit, that a uniform cover is obtained.
The apparatus for carrying out my improved process in respect of plates
when adapting the liquid receptacle to move, may consist of a frame provided
with a spindle and support, the latter being adapted to be moved longitudinally
by the said spindle as in a lathe.
This support carries the said liquid receptacle which is formed with a small
opening or narrow slit, whilst the plate to be covered is mounted upon the said
frame below the said receptacle and adapted to be moved at right angle to the
movement of the said support and receptacle.
The spindle by which the support is moved and the mechanism for imparting
movement to the plate may be worked by two different handles or by one handle
only, so that after the support has moved a certain distance and a liquid line
is drawn upon the plate by the said receptacle the plate may advance a short
distanco at right angles to the direction of the movement of the support, in
order to obtain a second, third, etc., line.
In order to make my invention more clear, an apparatus for carrying out the
process when rollers are used is illustrated in the accompanying drawing, in
which:
A is the lathe provided with a support B capable of being moved in the longi-
tudinal direction by means of a spindle A¹ provided with screw thread. Under-
neath the rotating shaft C of the lathe a heating device is arranged, as per
example a gas pipe 1 provided with perforations on its upper part. The cover-
ing of the roller is carried out by means of this apparatus in the following
manner:
The roller E is mounted upon the shaft of the lathe in a suitable manner and
the support brought into its initial position, that is to say to one extremity of
the roller. Upon the support B a receptacle containing the covering liquid,
as for instance a solution of chromic gelatine is placed and after the cock G of
the receptacle F has been opened, the lathe is set at work in such a manner,
that while the support advances, the roller rotates. As the roller only rotates
and is not moved in a longitudinal direction and on the other hand the support
upon which the receptacle is mounted, advances parallel to the axis of the roller,

page_text: the covering liquid flowing onto the roller forms fine spiral lines, which after-
wards is spread absolutely uniformly upon the whole surface.
The heating device D prevents the cover in case when chromic gelatine or the
like is used, from solidifying before the spiral lines spread over the whole
surface.
The heating device can also serve for a previously uniform heating of the
roller surface to be covered and for a subsequent drying of the cover.
Having now particularly described and ascertained the nature of my suid
invention and in what manner the same is to be performed, I declare that what
I claim is—
1st. Process for uniformly covering rollers with a substance sensible to the
action of light, in which the liquid is applied to the roller in a fine spiral line
and in which the same after being spread uniformly, is dried during the rotation
of the roller, for the purpose as described.
2nd. Process for uniformly covering rollers with a substance sensible to the
action of light, in which the liquid to be applied flows through a small opening
of a receptacle advancing parallel to the axis of the roller onto the rotating
surface of the latter, upon which the spiral liquid lines become spread so as to
form a uniform thin cover, which thereafter is dried, for the purpose as described.
3rd. Process for uniformly covering plates with a substance sensible to the
action of light, in which the liquid to be applied flows thorugh a small opening
or a narrow stit arranged in a receptacle advancing parallel above the surface of
the plate or the latter underneath the said receptacle, which latter after a line
has been drawn, is advanced in a direction perpendicular to the movement of
the support, and in which process after a number of parallel lines have been
drawn closely to each other, the latter become spread so as to form a uniform
layer, for the purposo as described.
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2000
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.