IMPROVEMENTS IN THE MANUFACTURE OF WROUGHT-IRON CYLINDERS FOR THE CONSTRUCTION OF ORDNANCE
Year: 1861

page_text: LETTERS PATENT to George Wightwick Rendel, of the Elswick Ordnance
Works, in the County of Northumberland, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF WROUGHT-IRON
CYLINDERS FOR THE CONSTRUCTION OF ORDNANCE"
Sealed the 23rd November 1861, and dated the 29th May 1861.
PROVISIONAL SPECIFICATION left by the said George Wightwick Rendel
at the Office of the Commissioners of Patents, with his Petition, on
the 29th May 1861.
I, GEORGE WIGHTWICK RENDEL, of the Elswick Ordnance Works, in the
County of Northumberland, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF WROUGHT-IRON
CYLINDERS FOR THE CONSTRUCTION OF ORDNANCE," to be as follows:-
The improvement consists in bringing the cylinders after they are forged to
a truly circular form, and to the diameter required, by means of an expanding
block of a circular form upon which the cylinder is placed in a heated state,
and then extended to a true round of the required diameter by the application.
of hydraulic or other pressure to produce the expansion of the block.
SPECIFICATION. in. pursuance of the conditions of the Letters Patent, filed
by the said. George Wightwick Rendel in the Great Seal Patent Office
on the 29th November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WIGHTWICK RENDEL, of the Elswick Ordnance Works, in the County of
Northumberland, Civil Engineer, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of May, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Wightwick Rendel, Her special license that I, the said George
Wightwick Rendel, my executors, administrators, and assigns, or such others as
I, the said George Wightwick Rendel, 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 THE MANUFACTURE OF WROUGHT-IRON CYLINDERS FOR THE
CONSTRUCTION OF ORDNANCE," upon the condition (amongst others) that I, the
said George Wightwick Rendel, my executors or administrators, by an in-
strument 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 calender months next and
immediately after the date of the said Letters Patent.
- NOW KNOW YE, that I, the said George Wightwick Rendel, do hereby
declare the nature of my said Invention, and in what manner. the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto annexed,
and to the figures and letters marked thereon, that is to say:
The nature of my said Invention consists in a process of enlarging the
diameter of hollow wrought-iron cylinders used in the construction of ordnance,
for the purpose of making them truly round and exactly of any given diameter
after they have previously been forged approximately true, but of a less
interior diameter than that required, and the manner in which I effect this
I proceed to describe by reference to the Drawing appended hereto.
.
A is a taper bar or block of polygonal section attached by means of a rod B
to the piston of a hydraulic press C; D, D, are loose segment pieces arranged
in a ring round the taper block A, resting on the bed plate E, and made
of any sizes to suit the diameters of cylinders required. Each segment
piece D has a plane inclined face on the back fitted to bear against and
slide upon one face of the taper block A, and a curved face on the outside
forming in section an arc of a circle of or about the interior diameter required
for the cylinder to be operated upon. The small end of the taper block A
is next the press C, and the amount of taper is such that when the block is

page_text: elevated into the position shewn in the Drawing the segment pieces D, D,
lying against the taper faces of the block may be made to converge towards
the axis of the block, and thus allow a forged cylinder of less interior diameter
than the finished size required to be passed over and round the whole of
the segment pieces; F is a cylinder placed in position to be operated upon
by the apparatus, having been first brought to a sufficient heat in a furnace
or otherwise. While the cylinder is in this position the hydraulic press is
put into operation, and the taper block A being thus drawn downwards while
the segment pieces D, D, and cylinder F remain supported by the bed
plate E, its inclined faces slide upon the inclined backs of the segment pieces,
and press the pieces out with great force radially; and so stretch the cylinder
to any required extent according to the amount of the inclination and tho
length of stroke given to the block A; G is a counterweight acting by means
of the lever H and connecting rod I to return the taper block to its original
position. I sometimes vary the thickness of the segmental pieces so as to
obtain different diameters of parallel cylinders, and I also vary the external
form so as to make the cylinders of less diameter at one end than at the other,
or of any required form.
Having thus described and explained the nature of the said Invention, and
in what manner the same is to be performed, I would observe in conclusion
that I do not claim as novel and original all the several and distinct parts
of the arrangement herein-before mentioned, neither do restrict myself to
the particular method described for producing the expansion of the blocks
or moulds which may be also effected by an arrangement of levers or screws,
or by steam pressure or other mechanical appliances, but what I consider
novel and original, and therefore claim as my Invention, is the process of
expanding, while hot, wrought-iron cylinders used in the construction of
ordnance in such a manner as to bring them accurately to any given
dimension or form by expanding apparatus, on the principle herein-before
mentioned.
In witness whereof, I, the said George Wightwick Rendel, have here-
unto set my hand and seal, this 26th day of November, in the year of
our Lord One thousand eight hundred and sixty-one.
(L.S.) G. W. RENDEL.