Improved Process for the Production of Matrices from Type.
Year: 1889

page_text: Date of Application, 31st Oct., 1889
Complete Specification Left, 30th July, 1890-Accepted, 6th Sept., 1890
PROVISIONAL SPECIFICATION.
Improved Process for the Production of Matrices from Type.
JAMES STUBROCK Advertiser Office, Bank Street Dundee, N.B. Cashier, and
GEORGE DUNCAN MACDOUGALD, 82 High Street, Dundee, N.B. Public Analyst, do
hereby declare the nature of this invention to be, as follows:-
Certain well known processes exist for the production of matrices from type which
may be summed up under the following heads, 1st. By pressing prepared paper in
the moist condition on the type, thereafter heating the type and matrix in a hot press
with the object of drying the matrix in contact with the type. 2nd. By proceeding
as before with the prepared paper and after its removal in the moist condition from
the type, drying the matrix in an oven. The objection to the first method of
procedure is the heating of the type, and the objection to the 2nd is a loss of
sharpness which although unimportant in certain kinds of letterpress, is important
when woodcut or newspaper line work is attempted.
•
Our improved process has for its object the securing of the sharpness obtained by
drying in contact with the type without subjecting the type to an objectionable
amount of heat.
We effect our object in the following manner;
After having in the usual way pressed the soft and moist matrix material on the
type, we place the type with the moist matrix in contact with it in an air tight vessel,
applying heat to the back of the matrix as it lies on the type within the vessel by a
heated plate or steam chest or other convenient means. Previous to or simultaneously
with, or after the application of heat to the matrix we exhaust the air from said vessel
more or less perfectly while the vessel is kept cold by water or other convenient
means. Under these conditions we have found that drying takes place very
rapidly and a good and sharp matrix is produced, the type being left at a low
temperature.
Dated this Thirtieth day of October 1889.
JAMES STURROCK.
G. D. MACDOUGALD.
COMPLETE SPECIFICATION.
Improved Process for the Production of Matrices from Type.
We, JAMES STURROCK, Cashier "Dundee Advertiser" Office, Bank Street, Dundee
in the County of Forfar, North Britain, and GEORGE DUNCAN MACDOUGALD, Chemist,
High Street, Dundee, aforesaid, 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, that is to say :-
Our said invention has for its object to obtain satisfactory results in an expeditions
manner in producing matrices from type with which to form stereotypes, and to
avoid objections believed to appertain to certain existing processes for the same
purpose.
In one existing process prepared paper in a moist condition is pressed on the
type, and the matrix whilst still on the type is heated so as to dry the matrix in
contact with the type. In a second existing process the matrix is dried by means
of heat after having been separated from the type. The first process is considered
to be objectionable because of the heating of the type, whilst with the second process
there is a want of sharpness in the matrix, which although perhaps unimportant in
•

page_text: some kinds of letterpress is important when woodcut or newspaper line work is
attempted.
Our improved process is designed to secure the sharpness obtained by drying the
matrix in contact with the type without subjecting the type to an objectionable
amount of heat; and the time occupied in the process is much shortened.
In carrying out our invention after having in the usual way pressed the soft and
moist matrix material on the type, we place the type with the moist matrix still in
contact with it, within a vessel which can be closed airtight; and we apply heat to
the back of the matrix by means of a plate heated by steam or otherwise or by other
convenient means. Previously to, or simultaneously with, or after applying heat we
exhaust the air from the vessel to a greater or less extent, whilst the type are kept
cold by means of water or otherwise.
Under these conditions the drying takes place very rapidly and a good and sharp
matrix is produced, whilst the type remains at a low temperature.
The constructive details of apparatus to be used for applying our improved process,
may be largely modified, we however show a simple and convenient example of such
apparatus on an accompanying sheet of explanatory drawings, of which Figure, 1, is
a sectional end elevation, and Figure, 2, is a longitudinal vertical section.
The matrix drying vessel consists of a rectangular metal frame, A, having fixed
down upon it a cover, B, the latter being shown in section in Figure, 1, as well as
in Figure, 2. The bottom of the vessel is formed by a plate, C, which is made hollow
to allow of cold water circulating through it, and which is attached to the frame, A,
by means of a sheet, D, of rubber cloth or other suitable airtight and flexible
material. The edges of the sheet, D, are secured between the bottom of the frame, A,
and a lower frame, E, fixed to the frame, A, by screws. In its lowest position the
bottom plate, C, rests by flanges upon a seat formed, for it on the inner sides of the
frame, A; and when the bottom plate, C, is in its lowest position its top is flush with
the bottom of an opening, F, in one end (the right-hand end in Figure 2) of the
frame, A. A door, G, is provided for closing the opening, F, and when this door
is turned down into the open position in which it is shown in Figure, 2, its then
upper surface is flush with the top of the bottom plate, C, and also with the top
of a table, H, on which the type forme rests when the matrix material is being
applied to it. As soon as the type forme is ready with the matrix material on it,
it is made to slide off the table, H, into the drying vessel where it is shown at, J,
in Figure, 2. The door, G, is then closed, being made sufficiently airtight by a
rubber strip fixed round the opening, F.
The heat is applied by means of a movable plate, K, which, having been heated
in a stove, is entered into the drying vessel through an opening, L, at the other end,
the left-hand end in Figure, 2. This hot plate, K, rests by its edges upon the top
of the frame, A, within a recess formed for it in the cover, B. A door, M, is
provided for closing the opening, L, and is made sufficiently airtight when closed, by
a strip of rubber which is fixed round the opening.
The air and moisture is exhausted from the vessel, through a pipe, N, fixed to the
cover, B, and connected to a vessel or chamber in which a vacuum is formed by
means of a pump or in any other convenient way, the pipe, N, being provided with
a stopcock for closing and opening the communication as required.
Pipes, P, Q, are shown for leading water to and from the interior of the hollow
bottom plate, C, we may however mention that it may not always be necessary to
apply water in this way for cooling the plate, C, as the drying action is so rapid that
there is not time for the type forme, J, to become much heated, but when a large
number of matrices have to be made and dried in quick succession the action of
cooling water will be advantageous.
When the type forme, J, with the matrix material on it is entered into the drying
vessel there is a clear space between it and the bottom of the hot plate, K, but as
soon as the vacuum communication is opened after the doors, G, M, have been closed

page_text: atmospheric pressure lifts up the bottom plate, C, and thereby raises the type
forme, J, up into contact with the hot plate, K.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
:―
1. The improved process for the production of matrices from type, in which the
drying of the matrix material is effected in a closed vessel from which air is exhausted,
and in which heat is applied to the back of the matrix material substantially as
hereinhefore described.
2. In the improved process in which a matrix is dried in a closed vessel with the
aid of a vacuum and of heat applied to the back of the matrix, applying a cooling
fluid for preventing injurious heating of the type forme substantially as hereinbefore
described.
Dated this Twenty-ninth day of July 1890
EDMUND HUNT,
Applicants' Agent.