An Improved Frame or Chase for use in the Manufacture of Process Blocks..
Year: 1896

page_text: PROVISIONAL SPECIFIC
TUN.
An Improved Frame or Chase for use in the Manufacture of
Process Blocks..
We, GEORGE: EDWARD BRISCOE EYRE, WILLIAM HUGH SPOTTISWOODE, and CYRIL
ANDREW SPOTTISWOODE, trading under the Firm or style of Eyre and Spottiswoode, of
6; Middle New Street, London, E.C., Her Majesty's Printers, and EDMUND JOHN
PASSINGHAM of 56, Clarence Square, Brighton, Sussex, Photographer, do hereby
declare the nature of this Invention to be as follows:-
This Invention relates to an improved frame or chase used for locking up fine
pointed wires imposed upon a photographic relief surface for the purpose of producing
therefrom a matrix from which to obtain a stereotype or electrotype reproduction
which is formed into a printing block having a stippled or mezzotint surface by
grinding the points to a common plane.
In order to obtain the regular distribution of the wires necessary to produce a
stippled effect which will render by its gradations all the half-tones and shadows of
the subject, and to enable the mass of wires to be securely locked up so as to permit
of obtaining a matrix therefrom, it is necessary that the wires be arranged in quincunx
order so as to form perfectly regular horizontal vertical and diagonal rows throughout
the mass as any deviation from absolute regularity will prevent the equal distribution
of pressure with the result that some at least of the wires will becoine displaced or
fall out, thus rendering the whole mass useless. As it is impossible, owing to the
immense number of wires employed, to arrange them positively in the required order,
it is necessary to provide means whereby they shall be constrained to assumo their.
proper positions in the act of imposing and locking up the mass. Furthermore it is
necessary that the surfaces of the chase or frame with which the wires are in contact
should present a certain amount of roughness which will prevent the wires from.
slipping in contact with them.
The object of this Invention is to ensure the regular arrangement of the wires
necessary for an equal distribution of the pressure and by the same means to prevent
the slipping of the wires in contact with the sides of the chase or frame. This is
accomplished by lining each of two opposite sides of the chase or frame with a row of
wires identical with those of which the photo-relief counterpart is to be made, but
unpointed these wires being closely juxtaposed and permanently secured to the wall
of the chase by solder or cement. The other two sides of the chase are similarly
lined with wires but as these latter are the terminal wires of alternate horizontal rows
and likewise the terminal wires of diagonal rows it follows that they must not be
closely juxtaposed but spaced at a pitch which bears a certain known proportion to
the diameter of the wires. To enable this spacing to be regularly obtained the side
wall of the chase is accurately grooved by means of a dividing engine, with grooves of
semi-circular section in which the wires are received and permanently secured by
solder or cement. The outermost rows of wires at all four sides of the chase being

page_text: thus fixed in predetermined positions the mass of loose wires comprised within the
chase are constrained to assuine their proper positions when locked up in the chase
after being imposed on the photo-relief surface.
Dated this 29th day of December 1896.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
An Improved Frame or Chase for use in the Manufacture of
Process Blocks.
We, GEORGE EDWARD BRISCOE EYRE, WILLIAM HUGH SPOTTISWOODE, and CYRIL
ANDREW SPOTTISWOODE, trading under the Firm or style of Eyre and Spottiswoode,
of 6, Middle New Street, London, E.C., Her Majesty's Printers, and EDMUND JOHN
PASSINGHAM, of 56, Clarence Square, Brighton, Sussex, Photographer, 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 the production of process printing blocks by 'imposing
very fine conically pointed wires points downwards upon a photographic relief
surface so that the relative positions of the points of the wires are determined by the
reliefs of said surface, producing from said wire points a matrix, and from the matrix
a stereotype or electrotype reproduction of the points which is forined into a printing
block having a stippled or mezzotint surface by grinding the points to a common
plane, and the Invention consists of a chase or fraine for holding and locking up the
wires in the operations of imposing them on the photographio relief surface and
obtaining a matrix.
In order to obtain the regular distribution of the wires necessary to enable tlie 2
mass of wires to be securely locked up so as to permit of obtaining a inatrix
therefrom and to ensure the ultimate production of a regular stippled effect which
will render by its gradations all the half-tones and shadows of the subject, it is
necessary that the wires be arranged in quincunx order so as to form perfectly
regular horizontal vertical and diagonal rows throughout the mass. Any deviation a
from absolute regularity will not only impair the regularity of the stipple but will
prevent the equal distribution of pressure when the wires are locked up, with the
result that some at least of the wires will become displaced or fall out, thus rendering
the whole mass useless. As it is impossible, owing to the immense number of wires
requisite for even a small block, to arrange them positively in the required order, it 3
is necessary to provide means whereby the wires shall be constrained to assume their
proper positions in the act of imposing and locking up the mass.
The object of this Invention is to ensure the regular arrangement of the wires and
the equal distribution of the pressure required to ensure the maintenance of the
wires in place.
Reference is to be had to the accompanying drawing forming part of this
specification wherein
Figure 1 represents a perspective view of a chase and
4
Figure 2 a view of one corner thereof drawn to a highly magnified scale and
adapted for the purpose of ensuring the necessary arrangement of the wires whilst 4
imposing and holding them securely when locked up.
This is accomplished by lining the inner faces of each of two opposite sides A A
of the chase or frame with a row of wires a identical in all respects with those of
which the photo-relief counterpart is to be made, except that they are unpointed,
these wires a being closely juxtaposed and permanently secured to the wall of the50

page_text: chase by soldering. The other two sides A¹ A¹ of the chase are similarly lined with
wires a not closely juxtaposed but spaced at a pitch which bears a certain known
proportion to the diameter of the wires so that the positions they occupy will be such
that they will so to speak form the terminal wires of diagonal rows of wires and'
consequently of alternate horizontal rows of wires when the chase is filled. To enable
this spacing of the wires a¹ to be regularly obtained the side wall of the chase is
accurately grooved by means of a dividing engine, with grooves of semi-circular
section, the said grooves being spaced at the proper pitch which is ascertained by
the formula pd 3p being the pitch and d the diameter of the wire. The
grooves extend the whole height of the sides A¹ of the chase and in these grooves
the wires a are received to a depth of half their diameter and are permanently
secured therein by cement. The outermost wires at all four sides of the chase being
thus fixed in predetermined positions it follows that in filling the chase with loose
wires, and looking it up after imposing on the photo-relief surface, the loose wires
next to the fixed ones are constrained to assume their proper positions and in turn
determine the positions of the next adjacent loose wires and so on whereby the
orderly arrangement and secure locking up of the whole mass of loose wires
comprised within the chase is ensured.
The chase illustrated is supposed to be rectangular in form with its side members
arranged in pairs, each pair comprising two adjacent members rigidly connected
together with their inner faces at right angles to one another, and their free ends
which thus ineet at diagonally opposite corners being tongued together as indicated
at bb to permit of the contraction about the mass of wires necessary for locking
them up. Any suitable method (such for example as wedging up within an outer
chase Cas indicated in Figure 1) may be employed for tightening up and securing
the members of the chase.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed we declare that what we
claim is:-
A frame or chase for holding and locking up wires for the purpose specified,
having its sides lined with wires similar to those to be locked up and permanently
secured in predetermined positions such as to ensure the orderly arrangement and
secure locking up of the wires as specified.
Dated this 29th day of September 1807
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.