AN IMPROVEMENT OR IMPROVEMENTS IN THE MANUFACTURE OF STEAM ENGINE BOILERS, IRON SHIPS, AND BOATS, AND SUCH OTHER VESSELS AND THINGS AS ARE OR MAY BE MADE BY RIVETTING TOGETHER METAL PLATES."
Year: 1856

page_text: LETTERS PATENT to Edwin Thomas Wright, of Wolverhampton, in the
County of Stafford, Engineer, for the Invention of "AN IMPROVEMENT
OR IMPROVEMENTS IN THE MANUFACTURE OF STEAM ENGINE BOILERS, IRON
SHIPS, AND BOATS, AND SUCH OTHER VESSELS AND THINGS AS ARE OR MAY BE
MADE BY RIVETTING TOGETHER METAL PLATES."
PROVISIONAL SPECIFICATION left by the said Edwin Thomas Wright
at the Office of the Commissioners of Patents, with his Petition, on the
15th March 1856.
I, EDWIN THOMAS WRIGHT, of Wolverhampton, in the County of Stafford,
Engineer, do hereby declare the nature of the Invention of "AN IMPROVEMENT
OR IMPROVEMENTS IN THE MANUFACTURE OF STEAM ENGINE BOILERS, IRON SHIPS, AND
BOATS, AND SUCH OTHER VESSELS AND THINGS AS ARE OR MAY BE MADE BY RIVETTING
TOGETHER METAL PLATES," to be as follows:-
My said Invention consists of the method herein-after explained of arranging
and forming the rivetted joints in the manufacture of articles composed of
plates of metal rivetted together.
In the ordinary manufacture of cylindrical steam boilers, the plates are so
arranged that the rivitted joints run in lines parallel with the axis of the boiler,

page_text: and in a plane perpendicular to the said axis, and the joints running parallel
with the axis are known to be the weakest part of-an ordinary boiler.
My said Invention consists in so arranging the plates that their rivetted
joints shall not run parallel with the axis of the boiler but be placed obliquely
thereto; or the rivetted joints may be placed so as to be neither parallel to
the axes of the boiler, nor in a plane perpendicular to the said axis, but
generally oblique to the direction of the greatest-strains. This I effect by
disposing the plates in a helical or cork screw form around the axis of the
boiler, the joints of the plates although at right angles to one another, or nearly
so, being all oblique to the direction of the greatest strains; or, whilst dis-
posing the plates in the usual manner, I so place the rivetted joints which
cross those running round the boiler in a plane perpendicular to the axis, that
they do not run parallel to the axis of the boiler, but in a direction oblique
thereto.
By placing the rivitted joints obliquely to-the strain, it is distributed
amongst a greater number of rivets or along a greater length of jointing
than in boilers of the ordinary, construction, and the boiler is made stronger
thereby.
The application of my said Invention to ships;-boats, and other vessels and
things, consists of a similar oblique arrangement.of the rivetted joints; by which
the greatest strain is distributed over a greater number of rivitszor a greater
length of jointing than by the ordinary method, and their strength is increased
thereby.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edwin Thomas Wright in the Great Seal Patent Office on
the 13th September 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWIN
THOMAS WRIGHT, of Wolverhampton, in the County of Stafford, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria; by Her Letters
Patent, bearing date the Fifteenth day of March, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Herself; Her heirs 'and successors; give 'and grant unto me,
the said Edwin Thomas Wright, Her special licence that I, the said Edwin
Thomas Wright, my executors, administrators, and assigns," or such others
as 1, the said Edwin Thomas Wright, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and

page_text: 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
"AN IMPROVEMENT OR IMPROVEMENTS IN THE MANUFACTURE OF STEAM ENGINE
BOILERS, IRON SHIPS, AND BOATS, AND SUCH OTHER VESSELS, AND THINGS AS ARE OR
MAY, BE MADE BY RIVETTING TOGETHER METAL PLATES," upon the condition.
(amongst others) that I, the said Edwin Thomas Wright, 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 date of the said Letters.
Patent!
:
NOW KNOW YE, that I, the said Edwin Thomas Wright, do hereby.
declare the nature of the said Invention; and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:
My said Invention consists of the methods herein-after described, and
illustrated in the 'accompanying Drawing, of forming and arranging the
rivetted joints' in the manufacture of articles-composed of plates of metal
rivetted together, such as steam engine boilers, irón: ships, boats, and vessels.
In the ordinary manufacture of cylindrical steam boilers, the plates of which
the said boilers are made are so arranged that the rivetted joints.run in lines
parallel to the axis of the boiler, and also in planes perpendicular to the
said axis; or in other words, the joints run in the direction of the length
of the boiler; and at right angles to the same; running round the shortest:
diameter of the boiler. The joints: thús running parallel to the axis of the
boiler, or the longitudinal joints,.it..is well known are subjected to a greater:
strain than those crossing them at right angles and running round in' planes:
perpendicular to the axis, and consequently the said longitudinal jointing is the:
weakest, and the part of the boiler first to give way 'under 'great pressure...
4.1
My said Invention consists in so arranging the rivettéd joints of cylindrical!
boilers, and other articles of similar manufacture, that they. shall not run
parallel to the axis of the boiler, but shall run in a line oblique thereto; 'the
lines of plates being made to run round the axis of the boiler in a helical or▸
corkscrew direction, and the joints either at right angles to one another, or
varying from a right angle, being oblique to the direction of the greatest strain.
By thus placing the lines of rivetted jointing oblique to the direction, of
greatest strain, any given amount of such greatest or lateral strain is resisted:

page_text: by a greater length of jointing, and consequently greater number of rivets, than
when such line of jointing is situated parallel to the axis of the boiler, whilst
the whole length of jointing and number of rivets in the boiler is not increased,
or is increased only to an inconsiderable extent.
Or, whilst disposing the plates in the usual manner, I so form and place the
rivetted joints which cross those running around the boiler in a plane per-
pendicular to the axis that they do not run parallel to the axis of the boiler or
cylinder, but in a direction oblique thereto. The amount of increased strength
of joint will appear on referring to Figure 1 of the accompanying Drawing.
The dotted line a, b, will represent a given length of lateral strain, say one
yard. This amount of lateral strain, instead of being resisted by only one yard,
or an equivalent length of jointing, it will be perceived is resisted by a length
of jointing represented by the two lines a, c, and c, b, together equal to 1,414
yards.
The methods by which I prefer to carry my Invention into effect are illus-
trated in the accompanying Drawing, Figure 1 representing in side and end
elevations a cylindrical boiler with hemispherical ends, constructed in the
manner invented by me. The oblique position of the joints and the arrange-
ment of the plates in the form of helices are so clearly indicated in the
Drawing that I do not consider a further description of the same necessary.
Figure 2 represents, in side and end elevations, a cylindrical boiler with flat
ends, which said boiler is constructed in the manner invented by me, and
differs from that represented in Figure only in having flat instead of hemi-
spherical ends.
Figure 3 represents, in side and end elevations, a cylindrical boiler, also con-
structed in the manner invented by me. In this boiler the plates are disposed
in the usual manner; but the said plates are not rectangular, but of a lozenge
shape, or have ends which although parallel to one another are not at right
angles to their sides. This method of construction will be so readily under-
stood by an inspection of the Drawing that I do not think a further description
of the same necessary. I do not consider the mode of construction shewn
in Figure 3 to be so desirable for boilers as that shewn in Figures 1 and 2,
because the length of jointing in the boiler is increased.
The application of my said Invention to iron ships and other vessels and things
consists of an oblique arrangement of the rivetted joints, similar to that herein-
before described, and illustrated in the accompanying Drawing, by means of
which the greatest strains are distributed over a greater number of rivets or a
greater length of jointing than by the ordinary method of construction, and the
strength of the structure is thereby increased.

page_text: Having now described the nature of my said Invention, and the manner of
carrying the same into effect, I wish it to be understood that I do not limit
myself to the precise details herein described and represented, as the same may
be varied without departing from the nature of my said Invention; but I
claim as my Invention the method herein described, and illustrated in the
accompanying Drawing, of manufacturing steam engine boilers, iron ships,
and boats, and such other vessels and things as are or may be made by
rivetting together metal plates, that is to say, so joining and arranging the
plates of which the said boilers and other articles are made, that the line of
rivetted joints shall run in a direction oblique to the axis of the boiler or other
vessel, and oblique to the direction of the greatest strain.
In witness whereof, I, the said Edwin Thomas Wright, have hereunto
set my hand and seal, this Twelfth day of September, in the year of
our Lord One thousand eight hundred and fifty.
5
Witness,
GEORGE SHAW.
EDWIN THOMAS WRIGHT. (L.S.)