IMPROVEMENTS IN ROTATORY STEAM ENGINES
Year: 1852

page_text: LETTERS PATENT to Charles Harford, of Down Place, near
Windsor, in the County of Berks, Esquire, for the Invention of
"IMPROVEMENTS IN ROTATORY STEAM ENGINES."
Sealed the 19th January 1853, and dated the 25th November 1852.
PROVISIONAL SPECIFICATION left by the said Charles Harford
at the Office of the Commissioners of Patents, with his Petition,
on the 25th November 1852.
I, CHARLES HARFORD, of Down Place, near Windsor, in the
County of Berks, Esquire, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN ROTATORY ENGINES" to be as
follows:-
This Invention relates principally to rotatory engines of the class
patented by Mr. Elijah Galloway, in the year 1846, and consists of
an improved arrangement for admitting the steam to such engines.
By this Invention the steam is admitted to the engine from the
interior of a revolving trunnion through a series of radiating ports
formed in the cylinder ends, a metallic ring being contained within
such trunnion, portions of the ring being cut away at the places
corresponding to the radial ports where the steam is to be admitted.

page_text: This ring is expanded outwards, by means of two plates, which are
cut away at certain places corresponding to the openings in the
ring; the edges of these plates are conical, and made to fit into the
ring, which is bevelled to correspond with them; by this arrangement,
the admission of the steam will cause the cylinder, piston, and shaft
to be slightly moved in the direction of their axis, thereby opening
all the ports in the cover of the induction end of the cylinder,
and simultaneously closing all those ports on the eduction end of
the cylinder, except those in connection with that part of the
cylinder where the piston is in contact. Those chambers not in
contact with the piston are filled with high pressure steam, thereby
acting as a spring or elastic cushion for keeping the piston firm up
against the working side of the cylinder.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said Charles Harford in the Great Seal
Patent Office on the 25th May 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
CHARLES HARFORD, of Down Place, near Windsor, in the County of
Berks, Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Twenty-fifth day of November, in the
year of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said Charles Harford, Her special
license that I, the said Charles Harford, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Harford,
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 ROTATORY STEAM ENGINES," upon the condition

page_text: (amongst others) that I, the said Charles Horford, by an in-
strument in writing under my hand and seal, 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 Charles Harford, 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 accompanying Drawings, and to the letters and figures
marked thereon (that is to say):
My said Invention relates to that class of rotatory engines for
which Letters Patent were granted to Elijah Galloway in the year
One thousand eight hundred and forty-six, my essential improve-
ments having reference to a superior arrangement for admitting the
steam to such engines. According to these improvements, I admit
the actuating steam to the engine from the interior of a revolving
trunnion, and through a series of radial ports or thoroughfares
formed in the cylinder ends, an annular piece of metal being
fitted within such trunnion, with portions of this ring cut away at
the localitics corresponding with the radial ports for the steam to
pass through. This internal ring is capable of lateral expansion by
the longitudinal pressure of two disc-plates, the circumferential
edges of which are bevilled off or conical, and made to fit into
the ring, the latter being also bevilled to correspond. By this
contrivance, the pressure of the actuating steam is made to move
the cylinder, piston, and shaft slightly in the direction of the
engine's axis whenever the steam is let on; and this action opens
all the induction ports, and simultaneously closes all the exhaust
ports, with the exception of those in connexion with that part of
the cylinder with which the piston is in contact. Such of the
chambers as are not in contact with the piston are filled with high
pressure steam, to act as a spring or elastic equipoise for retaining

page_text: the piston firm up against the working side of the cylinder. Figure
1, on my Sheet of Drawings, is a longitudinal section of my
improved engine. Figure 2, is an end elevation, at right angles to
Figure 1, but with the front end cover plate removed, portions of
the details being shewn in section. Figure 3, is a vertical section
through the plane of one of the end plates, shewing the steam ways
therein. Figure 4, is an external end elevation of one of the casings
of the trunnions. Figure 5, is an end elevation of one of the ex-
panding trunnion rings. Figure 6, is a corresponding side view of
the same. Figure 7, is an end or face elevation of one of the
bevilled set up or expanding discs; and Figure 8, is a corresponding
view at right angles thereto. The entire engine is carried upon
the open rectangular framing A, cast hollow to serve as steam and
exhaust ways. On this, as a foundation, are bolted down the two
fixed casings F, containing the bearings for the trunnion centre,
and annular casing F; B, is a pedestal or stay, to support the shaft
D, having an external stuffing box C, through which the main
first motion or engine shaft D, is passed. Each pedestal has cast
upon it a circular disc, set eccentrically as regards the axial line
of the main shaft, and having a ring of bolts E, set round its
periphery, and entered into the edge of the external annular casing
F, which forms the outer shell of the main stuffing box for the
revolving trunnion of the engine. Inside this piece F, is a brass
gland G, capable of being set up by a set screw H, to act upon the
stuffing box packing at I, between the inside of the outer shell F,
and the exterior of the hollow revolving trunnion J. This forms
the main stuffing box, the bottom end as it were being produced by
a shoulder in the shell F, at which part are inserted three pieces of
brass K, arranged in a triangle, as a bearing surface for the trun-
nion. The trunnion J, is cast in one piece with the end disc plate
L, of the engine, and the details being exactly the same on each
side of the engine, the central portion of the steam chamber or
cylinder M, is bolted up between these two end discs; the working
steam chamber being thus made up of these three details, connected
by annular flanges and bolts N. The inner face end of the pedestal

page_text: B, has bolted to it a brass disc O, cut out on one side, to admit the
main shaft, as shewn in my detailed Figures. A similar disc is also
set up against the end face of the steam piston, and the two con-
tiguous circumferential edges of these discs are bevelled or shaped
conically, to correspond to an expanding brass ring Q. This ring
is cut away on its lower side, as at R, to afford the necessary steam
ways, whilst its upper solid side blocks up the upper ports S,
leading to the steain chamber. Unlike Galloway's engine, this
engine is contrived so that both its cylinder and piston shall
revolve. In other respects, the internal cells T, of the chamber,
and the corresponding rounded projections U, of the piston, are
arranged precisely the same as in Galloway's engine. In this
instance there are six cells, and consequently six radial ports in
connection with them; each of the radial ports opens at the entrance
end into the interior of the trunnion J, outside the ring Q, and after
radiating outwards in the line of the disc's plane, the port terminates
in a bend at V, in correspondence with a thoroughfare W, in the
steam chamber, terminated by a central division X. From this
thoroughfare, a lateral branch, as at Y, forms the communication
between it and each cell of the chainber, the only difference, as
regards the two opposite sides of the engine, being, that these lateral
ports are set in reverse directions on the sides of the prominences
forming the cells. In this way steam may be admitted from either
side, accordingly as the engine is to revolve in one direction or the
other, the ports being steam and exhaust ways by turns. The
arrows on the right of Figure 1, indicate the direction of the passage
of the working steam from the boiler, when the engine is revolving
in the direction pointed out in Figure 2, and similarly the arrows on
the left of Figure 1, point out the exhaust course of the used steam.
The boiler is in connection with the base frame A, and the hollow
in such frame conducts the influx working steam up through the
port Z, and thence into the open outer end of the trunnion J. Here
its pressure, acting upon the area of the trunnion, and the end of the
piston a, causes them to move slightly in the direction of their axes.
This movement necessarily removes the expanding wedge pressure

page_text: from the ring piece Q, so as to leave a space all round it for the
passage of the working steam. The steam then passes round about
this ring Q, and enters the cells of the working chamber succes-
sively. This causes a peculiar differential eccentric revolution of
both the piston and its chamber, owing to the steam pressure in the
constantly widening or expanding cells b, as the prominences U,
work through them. Whilst this is going on, the steam from each
cell is successively exhausted, as each thoroughfare comes round to
the cut out portion of the brass ring Q, on that side; for the steam
pressure from the opposite side, which has slackened the ring Q,
has correspondingly expanded the ring Q, by. the lateral wedge
action of the discs O, P, so that the upper solid side of the ring is
pressed against the converging ends of the steam ports, leaving only.
those open for exhaustion where the ring is cut away for the pur-
pose. Hence the escape steam passes off through. the trunnion on
that side, to the thoroughfare in the base frame. Whilst the engine
is working the upper ports and cells, as T, are all kept full of the
steam at the high working pressure, so as to balance and resist the
working strain from beneath.
.
Having now described, and particularly ascertained the nature of
my said Invention, and the manner in which the same is or may be
used or carried into effect, I would observe, in conclusion, that I do
not confine or restrict myself to the precise details or arrangements
which I have had occasion to describe or refer to, as many varia-
tions may be made therefrom without deviating from the principles
or main features of any Invention; but what I consider to be novel
and original, and therefore claim as the Invention secured to me
by the herein-before in part recited Letters Patent, is,-
-
First, the general arrangement and construction of rotatory
engines as herein-before described.
Second, the system or mode as herein-before described of con-
structing rotatory engines of the internal toothed cellular class,
wherein both cylinder or steam chamber and piston revolve in the
same direction.
Third, the system or mode of supporting and retaining in position

page_text: the revolving trunnion by means of three bearing surfaces arranged
in a triangle as herein-before described.
Fourth, the system or mode of governing and regulating the steam
and exhaust ways of rotatory engines by means of expanding wedge
or cone rings.
Fifth, the application and use of the working steam pressure for
shutting up and opening the steam and exhaust passages by means
of expanding rings.
Sixth, the system or mode of balancing rotatory engines, and
keeping the working surfaces up to their bearings, by filling the
non-working cells with high pressure or direct steam.
In witness whereof, I, the said Charles Harford, have hereunto
set my hand and seal, the Twenty-fourth day of May,
One thousand eight hundred and fifty-three.
CHARLES HARFORD,
Down Place.
(L.S.)