IMPROVEMENTS IN CERTAIN MACHINES FOR ETCHING OR ENGRAVING
Year: 1856

page_text: LETTERS PATENT to James Montgomery Gilbert, of the City of Manchester,
Engraver, for the Invention of "IMPROVEMENTS IN CERTAIN MACHINES FOR
ETCHING OR ENGRAVING."
Sealed the 28th April 1857, and dated the 20th November 1856.
PROVISIONAL SPECIFICATION left by the said James Montgomery
Gilbert at the Office of the Commissioners of Patents, with his
Petition, on the 20th November 1856.
I, JAMES MONTGOMERY GILBERT, of the City of Manchester, Engraver, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN CERTAIN
MACHINES FOR ETCHING OR ENGRAVING," to be as follows:-
The first part of this Invention relates especially to the machine known as
"Taylor's pentagraph machine." Heretofore that part of the machine coin-
monly called the "floating table," moved with a sliding contact upon the
supporting surfaces. The friction was lessened by means of counterbalance
weights, a method which has been found to be both inconvenient and
injurious.
My improvement consists in substituting a rolling for a sliding contact by
means of bodies of a spherical form introduced between the moveable and the
supporting surfaces. By this means the friction is efficiently reduced without
either the inconveniences or the injury arising from the employment of the
old method.
The second part of my Invention consists in a new and improved .con-
struction of carriage, by means of which the tools or instruments for etching
or engraving can be set to any required position relatively to one another.

page_text: This end is accomplished by forming tho carriage in two parts, in such a way
that one part shall form a fixed support and guide, within or upon which the
other part shall have a certain range of movement. This improvement will
enable patterns of any required step or slash to be machined at one operation.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Montgomery Gilbert in the Great Seal Patent Office
on the 16th May 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MONTGOMERY GILDERT, of the City of Manchester, Engraver, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of November, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Iler
reign, did, for Herself, fer heirs and successors, give and grant unto me, the
said James Montgomery Gilbert, Her special license that I, the said James
Montgomery Gilbert, my executors, administrators, and assigns, or such others
as I, the said James Montgomery Gilbert, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for IMPROVEMENTS IN CERTAIN MACHINES FOR ETCHING OR ENGRAVING,"
upon the condition (amongst others) that I, the said James Montgomery
Gilbert, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the dato
of the said Letters Patent.
NOW KNOW YE, that I, the said James Montgomery Gilbert, do hereby
declare the naturo of my said Invention, and in what manner the saino is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and.
to the letters and figures marked thereon (that is to say):-
My said Invention relates, first, to the machine known as "Taylor's pen-
tagraph machine," and especially to that part of it called "the floating table."
Heretoforo the said table moved with a sliding contact upon the supporting

page_text: surfaces, the friction caused thereby being lessened by means of counter-
balance weights, the action of which was prejudicial to the accuracy of the
work, limited the range of motion, and demanded an extreme and unusual
height overhead. My first improvement consists in substituting a rolling for a
sliding contact, by introducing spheres or bodies of a spherical form between
the moveable and the supporting surfaces, thereby effecting more perfectly the
required object, and avoiding the inconveniences and injurious operation of the
old method.
The second part of my Invention relates to the construction of the tool
carriages employed in machines for etching or engraving. The effect of my
improvement is to enable tools to be applied simultaneously to the surface to
be engraved in certain positions relatively to one another, which were not
attainable by the tool carriages of the old construction. By this improved
carriage, in certain patterns, many more repeats may be engraved at one opera-
tion than was previously possible. My improved carriage is made in two
distinct parts of peculiar construction, and so that the one part, when locked
upon the tool bar, shall act as a frame or support to the other part.
And in order that the said Invention may be properly understood, I shall
now proceed to describe the Sheet of Drawings appended hereunto, which
represent certain forms under which my improvements may be judiciously
carried out in practice.
Figure 1 is a side elevation of the floating table, Figure 2 is a plan, and
Figure 3 an end elevation of the same, to which my improvements are applied.
A is the floating table, on which a cylinder B is represented as the surface to
be engraved; D is the supporting plane surface; and C, C, C, C, are the
spheres, of which four are usually employed. I prefer to place these spheres
in holes made in the light frames E, to retain them in their places, but these
light frames may be dispensed with, if preferred.
It is evident that any
convenient range of movement may be given to the floating table, and that
there will not in any part of its movement be a sliding contact between any
of the surfaces. Instead of spheres, spherical bodies may be used, having
their upper and under surfaces struck from the same centre, but with radii
of different lengths, as shewn in Figure 4, or other combinations of spherical
surfaces may be adopted.
Figure 5 is a side clevation of the carriage which forms the second part of
my Invention; and Figure 6 is a plan thereof. F represents the tool bar or
bed, which in some machines is stationary, and in others moveable; G is a
portion of the carriage which is to be locked upon the bar F. The form of
this fixture, as required in machines for engraving cylinders, is shewn in

page_text: the Drawing. It may be made of any convenient or required length in the
direction of the round of the cylinder, and instead of being placed above, as
shown, it may be placed under the cylinder. H is the carriage, to which the
tool I is immediately connected. Tho carriage shewn in the Drawing is one
of convenient construction when etching or scratching tools are used. It will
be seen that the piece I may be locked by means of the screw nut J to the
fixed part G, its range of position being limited only by the length of the slot
in the part G. The part II may also be reversed in position, as shewn, to the
right-hand side of Figure 5 in the Drawing, and thereby the range of the tool
increased. K is the picco to which the diamond or other tool is attached, and
it is pivotted at L; M is an elastic band or spring, tending to press the tool
upon the surface to be engraved. The small wheel N and band O indicate
the apparatus by which the tool may be removed from the surface when
required; this is accomplished by giving a partial revolution to the rod P,
which is in communication with a treadlo acted upon by the foot of the
workman in the usual way. The carriage may be accomodated to rollers or
cylinders of various size by means of packing pieces Q.
The construction of the carriage may be varied to suit the construction of
the different machines in use; but the foregoing description and Drawings are
sufficient to indicate the peculiar character of my Invention.
im-
Having now particularly described the nature and particulars of my
provements, I wish it to be distinctly understood that what I claim as of my
Invention is,
Firstly, the use and application of spherical bodies between the moving and
supporting surfaces of the floating table, in such a way as to substituto a rolling
for a sliding contact between such surfaces.
Secondly, I claim the peculiar compound carriage berein described, or such
modification or variation thereof as shall be similar in effect, for enabling
the tools to be fixed, with all needful conditions for working in any required
position relatively to each other, upon the surface to be engraved.
In witness whereof, I, the said James Montgomery Gilbert, have here-
unto set my hand and seal, this Fifteenth day of May, in the year of
our Lord One thousand eight hundred and fifty-seven.
OLLARD'S
JAMES M. GILDERT.
(L.D.)