Improvement in the Method of Drying a Coating on Zinc and Copper Plates which are Used for Etching.
Year: 1893

page_text: Date of Application, 21st Dec., 1893
Complete Specification Left, 16th Oct., 1894-Accepted, 15th Dec., 1894
PROVISIONAL SPECIFICATION.
Improvement in the Method of Drying a Coating on Zinc and
Copper Plates which are Used for Etching.
MARK SMITH Engineer Guardian Office Manchester do hereby declare the
nature of this invention to be as follows:-
1
To dispose of the uncertainty of the present method of drying the coating on the
plates. The coating is made from a solution well-known of gum or glue,
bi-chromate of ammonia & albumen. The present method of drying the coating is
over a heated plate, gas, oil or spirit flame which method is uncertain some parts of
the plate at times being overheated & preventing the solution from acting in a
proper manner. My improvement consists of a chamber heated by steam in which
I enclose the twirler which holds the plate covered with the solution. The twirler
is held in an oblique position while the plate is being covered with the solution, the
superfluous solution being allowed to run down to one corner of the plate. The
twirler & plate are then turned downwards & the twirler being fixed on a centre is
turned into the steam chamber the handle or wheel remaining outside & coming
into contact with a revolving wheel which causes the twirler to revolve inside the
steam chamber for some minutes until the plate is dry. The steam chamber may
be made any suitable shape.
Dated this 20th day of December 1893
COMPLETE SPECIFICATION.
Improvement in the Method of Drying a Coating on Zinc and
Copper Plates which are Used for Etching.
MARK SMITH Printers Engineer 20 Mayfield Road Manchester 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:-
The object of this invention is to dispose of the uncertainty of the old method of
drying. The coating or enamaline is made from a solution well known of gum,
bi-chromate of ammonia, and albumen, the old method is to dry over a heated plate,
gas or spirit flame, which method is uncertain, some parts of the plate when heated
by gas, being overheated and preventing the solution from washing out. My
improvement consists in arranging steam chamber in which, we enclose the twirler
which holds the plate covered with the solution. The twirler is held in an oblique
position, whilst the enameline solution is being flown, and, the superfluous solution
allowed to run to one corner; the twirler and plate are then turned downwards.
The twirler being fixed on a centre is turned into the steam chamber, the handle
or wheel remaining outside, and coming in contact with a revolving wheel, causes
the twirler to revolve inside the chamber for some minutes until dry.
The steam chamber may be made any suitable shape, and of any suitable
material.
In the accompanying drawing:
Fig. 1 shews a plan of the steam chamber A. with the twirler plate B 2 inside,
and its driving wheel B 1 in contact with the revolving wheel C. The bracket F

page_text: notch in the joint face H., the joints H. being kept in frictional contact by means
of the spring and screws K. The revolving wheel C may be fixed to the steam
chamber A, or to a separate fixing on a wall, in any convenient position for
driving.
Fig. 2. Section shewing the arrangement and combination of the steam
chamber A, and twirler B. D is the inlet pipe, admitting steam to the chamber A..
E is the outlet for condensed steam. M is a thick iron plate with a radial slot to
admit twirler.
Fig. 3. Eront elevation shews the twirler plate B2 turned up in position to
receive the plate and solution.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what 1
claim is :-
The combination of twirler, and steam chamber for drying a solution on zinc
and copper-plates, for half-tone & line etchings, as described and shewn by the
drawings.