IMPROVEMENTS IN ROTATORY OR REVOLVING ENGINES, AND IN APPARATUS CONNECTED WITH STEAM ENGINES AND IN PROPELLING VESSELS
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
Earl of DUNDONALD, of Regent's Park, in the County of Middlesex, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Nineteenth day of January, in the sixth year. of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Earl of Dundonald, Her especial licence, full power, sole privilege
and authority, that I, the said Thomas Earl of Dundonald, my exors, admors,
and assigns, or such others as I, the said Thomas Earl of Dundonald, my
exors, admiors, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick upon Tweed, and also in the Isles of Gersey,
Guernsey, Alderney, Sark, and Man, and, in all Her Majesty's Colonies and
Plantations abroad, my Invention of "IMPROVEMENTS IN ROTATORY OR REVOLVING
ENGINES, AND IN APPARATUS CONNECTED WITH STEAM ENGINES AND IN PROPELLING
VESSELS;" in which said Letters Patent is contained a proviso that I, the said
Thomas Earl of Dundonald, shall cause a particular description of the nature
of my said Invention, and in what manner the same is to be performed, to be
inrolled in Her said Majesty's High Court of Chancery next and immediately
after the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
I

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Earl of Dundonald, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, reference
being had to the Drawings hereunto annexed, and to the figures and letters
marked thereon (that is to say):-
My Invention relates, first, to improvements in packing certain parts of
rotatory or revolving steam engines.
Secondly, my Invention relates to improvements in the construction of
apparatus for generating steam for steam engines.
Thirdly, my Invention relates to the construction of apparatus for propelling
vessels.
And, fourthly, my Invention relates to a mode of causing air put in motion
by paddle wheels to be conducted from the paddle boxes through suitable
channels or passages into the engine room or other parts of steam vessels.
And in order that my Invention may be most fully understood, I will
proceed to describe the Drawings hereunto annexed.
....
DESCRIPTION OF THE DRAWINGS.
Figure 1 represents a transverse section of a rotatory steam engine, con-
structed with improvements. according to the first part of my Invention;
Figure 2 shews part of a longitudinal section; Figure 3 shews an end view of
one of the steam stops separately; and Figure 4 shews part of a plan of one
of the steam stops. In each of these Figures the same letters are used to
indicate similar parts. a, a, is the external cylinder, within which the piston
revolves, such piston 6 consisting of a cylinder affixed on the axis c, such axis
not being in the centre of the cylinder b, whereby one part of the cylinder b
at all times touches the cylinder a, a, leaving a lunate space between the inner
cylinder 6 and the cylinder a, a, as is shown in the Drawing. I would,
however, remark, that although I prefer that the piston 6 should be a cylinder,
as shewn, yet that is not absolutely necessary, as the same may be more or
less flattened, and produce an elliptical or other figure; but I believe that all
departures from a cylindrical figure is injurious to the well working of an
engine of this description. At each end of the piston and on the axis c is
affixed a cover or end e, which is concentric with the cylinder a, a, the object
being to pack the peripheries of such end covers, in place of applying packing
between the ends of the piston band the end covers of the cylinder a, a, as was
formerly my practice when making similar engines according to my former
atents. At each end of the cylinder a, a, is affixed a cover f, as is shown.

page_text: 9, 9, is an annular space for packing, which I prefer to be of metal, pressed on
by springs, in like manner to packing pistons of steam engines, as heretofore
practised. The annular space g, g, is shewn to be formed in the peripheries of
the ends e, e, and the packing placed therein works against the inner surfaces
of the covers f, f, of the cylinder a, a; but it will be evident that the annular
space may be formed in the covers f. f, and the packings press against a plain
surface of each end e. By this arrangement the end covers e, e, will not rub
against the inner surfaces of the covers f, f, of the cylinder a, a, and the pack-
ing employed at g, g, will be worn equally, which could not be the case with
the packing when the ends of the piston were packed and worked against the
end covers ff, of the cylinder a, a. The steam stops h, h, are packed at the
parts i, i, by packing placed in grooves, running from end to end of the knuckle
joints on which they move, as will readily be understood on examining the
Drawing. I have not thought it necessary to shew more of a steam engine,
as the steam slides and other necessary parts will readily be applied by an
engineer, and by referring to my former Specification the distinct character of
my present improvements will be better understood; and such will also be the
case in respect of the construction of those parts of this description of engines
which are not shewn in the present Drawings.
I will now proceed to describe the second part of my Invention. Figure 5
shews a section of apparatus for generating steam for steam engines con-
structed according to this part of my Invention, and the apparatus is composed.
partly of tubes or hollow surfaces, the interior of which are open to the
water spaces of the boiler with which the tubes are combined; such boiler or
outer vessel may be varied in shape so long as there be a chamber, as hereafter.
described, between the furnace or fire-place and the chimney. k, k, is a steam
boiler, which may be of a square or cylindrical section, or other convenient
figure; is the fire-place; m, m, m, m, is a rectangular chamber, there
being a number of tubes or hollow surfaces in an upright position, through
which the water flows, in consequence of the water therein becoming hotter
than other parts of the boiler. The heat of the fire passes into the chamber m
at n, over the bridge o, at the end of the furnace or fire-place, and the passage
from the chamber m into the flue or chimney is situated as low as possible.
in order that the greater heat of the vapours may be retained in the chamber
m, m; for it will readily be understood that the more highly heated vapours or
products of combustion will occupy the upper part of the chamber m, m,
and the draft into the chimney will only carry off the cooler parts of the
vapours from the chamber m, the more highly heated vapours being com-
paratively in a quiescent state at the upper part of the chamber m; and it is
P

page_text: the peculiar arrangement of the chamber m within a steam boiler, when con-
taining tubes or hollow surfaces, and combined with the mode of arranging
the outlet p into the chimney, so as to leave a considerable space above it (for
the more highly heated vapours to be retained in the chamber m), which
constitutes the peculiar character of this part of my Invention. is an opening
into the chimney at the upper pårt of the chamber m, m, to facilitate the
getting up a draft when first lighting a fire, it being closed at all other times.
y is a steam pipe in connection with the upper part of the boiler, having a
stop-cock; this pipe is drilled with many small holes in the direction towards
the chimney, by which numerous jets of steam can be projected amongst
the tubes, in order to sweep away the dust and ashes when required. I would
remark that it is not necessary that the tubes should be in an upright
position.
Figure 6 shews a longitudinal section of another boiler; the same letters of
reference being used to indicate the same parts, the chief difference being the
horizontal position of the tubes; these differences, as well as the other varia-
tions, will be fully understood by an inspection of the Drawing. The peculiar
construction of the chamber m, and the opening p into the chimney, leaving a
space above it from which the heat cannot get away excepting through the
metal to the water, are in this case similar to that above described. It should
be understood that in the last construction of boiler that the bridge o is only
open below for the flow of water into it, and that the water is prevented passing
away from the bridge o except through the tubes or hollow spaces; and
farther, that the descending bridge or vessel q is open at top only and closed
at bottom, by which there will be a constant circulation of water into the
bridge o through the tubes or hollow surfaces into the compartment or
descending bridge q. In neither construction of boilers I have not thought
it necessary to shew the safety valves, steam pipes, and other usual parts of
steam boilers, as they will be such as heretofore used in steam boilers. .:
I will now describe the third part of my Invention, which relates to that
description of propelling apparatus which consists of oblique vanes affixed to a
revolving shaft placed below the water line at the stern or other convenient
position of a vessel. In constructing this description of propeller it has been
heretofore usual to place such vanes perpendicular to the axis of motion, and I
have discovered that by such mode of using perpendicular vanes for propelling
vessels that the power employed is not so advantageously used as it might be by
causing the vanes to incline to the axis of motion; and although the angle may
be varied, I believe that the vanes, being obliquely fixed on to their axis of motion
at about an angle of forty-five degrees, will be found most advantageous and

page_text: that as the vanes approach a vertical position in respect to their axis of motion,
and become more and more near to being at right angles to the shaft or axis,
they will become less and less beneficial. The effect of this arrangement is,
that the water is thrown off from oblique vanes when inclined to their axis of
motion in a cylindrical figure, whilst the water from similar vanes placed at
right angles to their axis of motion is thrown off in a conical figure. Figure 7
shews part of a shaft with two oblique vanes affixed thereto, and they are
affixed inclining to the axis; Figure 8 is an end view thereof.
I will now describe the fourth part of my Invention, which relates to
causing the air put in motion by the paddle wheels commonly used in pro-
pelling vessels, and such part of my Invention consists in applying passages or
channels from the upper part of the paddle boxes into the engine room or
other part of the vessel under the fire bars of closed ash pits, or the air may
be used for ventilating the engine room.
In carrying out this part of my Invention, the outer sides of the paddle
boxes are to be closed in place of being open. In order to collect the air
and direct its course, I'apply oblique battens or projecting bars to the inside of
the paddle boxes, so that the air driven against them may be guided towards
the vessel, and to these battens I affix angular plates, so that the back edge of
each will be parallel with the float boards as they successively come up; by
which arrangement there will be angular hollow spaces at the upper part of
the paddle boxes, into which the air will be forced by the float boards, and
these spaces open into a channel or passage formed at the inner sides of each
of the paddle boxes, which passages or channels descend into the engine room
and communicate with the ash pits of the furnaces of the boilers; and from
such passages other passages. may be branched to convey the air in other
directions, such as below the floor of the engine room, which may be perforated
with numerous small holes.
Having thus described the nature of my Invention, and the manner in which
the same is to be performed, I would remark that I do not confine myself
to the precise details, provided the peculiar character of either part of my
Invention be retained; but what I claim is,-
First, the mode of constructing and combining the parts e, b, and ƒ of
rotatory or revolving steam engines, whereby packing may be applied, as above
described.
Secondly, I claim the mode of constructing apparatus for generating steam
for steam engines, whereby a series of tubes or other hollow surfaces wherein
water is caused to circulate are exposed to heat in a chamber within a steam

page_text: boiler, the vapours being controlled to pass off at the lower part of such
chamber.
Thirdly, I claim the mode of combining oblique vanes for propelling vessels
in such manner that they are fixed in an inclined position to their axis of
motion.
And, fourthly, I claim the mode of applying suitable apparatus to the paddle
boxes of steam vessels, in order to cause the air put in motion by the paddle
wheels to be conveyed into the engine room or other parts of a vessel.
In witness whereof, I, the said Thomas Earl of Dundonald, have here-
unto set my hand and seal, this Fourteenth day of July, in the year of
our Lord One thousand eight hundred and forty-three..