IMPROVEMENTS IN ROTATORY STEAM ENGINES
Year: 1872

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN ROTATORY STEAM ENGINES."-A communication
from abroad by Hugo Füngling, Civil Engineer, and Adolf Möller,
Manufacturer, both of the City of Hanover, Kingdom of Prussia,
and German Empire.
ealed the 30th August 1872, and dated the 11th April 1872.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 11th April 1872.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ROTATORY STEAM ENGINES," a communica-
tion to me from abroad by Hugo Füngling, Civil Engineer, and Adolf
Möller, Manufacturer, both of the City of Hanover, Kingdom of Prussia;
and German Empire, to be as follows:-

page_text: specially applicable by reason of its compactness and the small number
of its working parts as a locomotive engine or traction engine, also for
propelling vessels, and more particularly for all purposes where small
power is required. This improved rotatory engine consists of a stationary
inner cylinder and a revolving outer cylinder, the latter being provided
with two or more internal projections acting as pistons, and the former
with three or more sliding radial diaphragms actuated by cam grooves in
the inner faces of the sides of the rotating cylinder, such diaphragms
containing inlet and outlet steam ports in communication
with corre-
sponding passages in a central fixed shaft which supports in suitable
bearings the said inner or stationary cylinder. Against each end of this
central shaft or support works a slide valve in the form of a rotating disc,
the said disc having two or more openings therein, according to the
number of pistons or stops employed, which communicate in succession
with the different steam passages as the valve rotates so as to enable the
steam to operate against both the pistons simultaneously in two of the
three chambers formed by the three radial diaphragms, whilst from the
third chamber the steam escapes through the exhaust passages into the
central shaft, and out through the opposite end thereof to that by which
it entered.
The rotatory valves are worked by spur gearing from the rotatory
cylinder, and between each of them and the end of the shaft there is
introduced a variable expansion valve consisting of a disc, with steam
ports therein capable of circular adjustment by a screw and worm
wheel.
As both ends of the engine are similarly constructed and fitted it is
simply requisite to reverse the steam inlet and exhaust valves to reverse
the engine. When the reversing action is not required, as for stationary
engine purposes, for example, then the exhaust passages in the dia-
phragms may all lead into one common thoroughfare in the exhaust end
of the central shaft.
In some cases, moreover, in lieu of causing the outer cylinder to
rotate and taking the power therefrom, as from a pulley, by a strap or
belt, or by gearing, as preferred, the outer cylinder may be arranged to
be stationary whilst the inner one rotates, the power being then taken off
from the central shaft in any well known manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 11th October 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of April, in the year of
our Lord One thousand eight hundred and seventy-two, in the 35th
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special
license that I, the said John Henry Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or 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," a communication to me from
abroad by Hugo Füngling, Civil Engineer, and Adolf Möller, Manu-
facturer, both of the City of Hanover, Kingdom of Prussia, and German
Empire, upon the condition (amongst others) that I, the said John
Henry Johnson, my executors or administrators, by an instrument in
writing under my hand and seal, should particularly describe and ascer-
tain 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 John Henry Johnson, 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, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon,
that is to say :—

page_text: of rotatory steam engine capable of being worked expansively, which
is specially applicable, by reason of its compactness and the small
number of its working parts, as a locomotive engine or traction engine,
also for propelling vessels, and more particularly for all purposes where
small power is required. This improved rotatory engine consists of a
stationary inner cylinder and a revolving outer cylinder, the latter being
provided with two or more internal projections acting as pistons, and the
former with three or more sliding radial diaphragms actuated by cam
grooves in the inner faces of the sides of the rotating cylinder, such
diaphragms containing inlet and outlet steam ports in communication
with corresponding passages in a central fixed shaft which supports in
suitable bearings the said inner or stationary cylinder. Against each
end of this central shaft or support works a slide valve in the form of a
rotating disc, the said disc having two or more springs therein, according
to the number of pistons or stops employed, which communicate in
succession with the different steam passages as the valve rotates, so as to
enable the steam to operate against both the pistons simultaneously in
two of the three chambers formed by the three radial diaphragms, whilst
from the third chamber the steam escapes through the exhaust passages
into the central shaft, and out through the opposite end thereof to that
by which it entered.
The rotatory valves are worked by spur gearing from the rotatory
cylinder, and between each of them and the end of the shaft there is
introduced a variable expansion valve consisting of a disc, with steam
ports therein capable of circular adjustment by a screw and worm
wheel.
As both ends of the engine are similarly constructed and fitted it is
simply requisite to reverse the steam inlet and exhaust valves to reverse
the engine. When the reversing action is not required, as for stationary
engine purposes for example, then the exhaust passages in the dia-
phragms may all lead into one common thoroughfare in the exhaust end
of the central shaft.
In some cases, moreover, in lieu of causing the outer cylinder to rotate
and taking the power therefrom, as from a pulley, by a strap or belt, or
by gearing, as preferred, the outer cylinder may be arranged to be
stationary whilst the inner one rotates, the power being then taken off
from the central shaft in any well-known manner.

page_text: And in order that the said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings, the
same letters of reference indicating corresponding parts in all the
Figures.
Figure 1 (Sheet 1) of the Drawings is a side elevation of the improved
rotatory engine; Figure 2 is an end view of the same; Figure 3 is a
longitudinal vertical section taken along the line 1, 2, in Figure 4;
Figure 4 is a horizontal section taken along the line 3-4 in Figure 3;
Figure 5 is a transverse section taken along the line 5-6 in Figure 3;
Figure 6 is a transverse section of the engine taken along the line 7, 8,
in Figure 3.
Figure 7 (Sheet 2) is a plan of the engine; and Figure 8 is an end
elevation of the engine, showing parts in cross section taken along the
line 9-10, Figure 3.
a is an inner cylinder with two fixed studs 6', 62, forming a shaft, by
means of which the inner cylinder is steadily supported in the two side
frames or bearings O, O. The two sides of this inner cylinder a are cach
covered with circular discs c, c, (Figure 3), rigidly attached to the said
body, and of the diameter shewn by c¹, c', (Figure 5). In this stationary
inner cylinder a there are placed three radial diaphragms x1, x2, x³,
which are moveable in an outward radial direction, and which are each
provided with two cylindrical prolongations y, y', (Figure 3), and with
two studs z, z¹.
Through each of the above named standard fixed studs 6', 62, lead
through steam conduits h, h', (Figures 3 and 5), which through the
cylindrical prolongations y, y¹, of the diaphragms x1, x2, x³, terminate at
the sides of the latter at i and ¹ (Figure 5).
A second or outer cylinder d, with two covers e, e, rigidly fastened to
it, moves around the above described inner cylinder a, the second cylinder
fitting tightly upon the periphery of the discs c, c, and its two covers
bearing on the two standards or fixed studs b', 6', on or around which
they are centered, the second cylinder being furthermore provided with
two stops ff (Figures 3, 5, and 6), projecting from the inner cylin-
drical surface, these stops f¹, f, constituting the true or proper pistons
of the steam engine. On the inner side of each of the above-mentioned

page_text: two covers e, e, are formed the two cam grooves g, g, Figures 3, 5, and 6.
The studsz, z¹, of the before-mentioned diaphragms x¹, x², x³, which
latter are capable of moving in an outward radial direction, project into
the cam grooves g, g, which revolve along with the covers e, e, and the
cylinder & around the fixed inner cylinder a.
Steam is admitted through the main pipe R¹ (Figure 8) and through
the stop valve V2 into the slide box S² (Figures 3 and 4), whence it passes
through the open slide valve into the steam conduct h¹, and thence
into the diaphragm x'. This diaphragm will (as soon as the piston f¹,
(Figure 5) by the rotation of the cylinder d has arrived at the position
shown in Figure 6, be elevated by means of the can grooves g, g, from
its lowest to its highest position, and the steam passage h³ will com-
municate with the space between the piston f¹ and the diaphragm x¹.
As the steam admitted between the diaphragm x¹ and the moveable
cylinder d and the two immoveable discs c, c, as well as between ƒ¹, a,
and c, c, is unable to escape, it will urge round the piston f¹, and with it
the outer cylinder d in the direction of the arrow.
This operation of the parts will be repeated with each of the three
diaphragms x, x³, x³, as often as one of the two steam pistons f¹ and ƒ³
passes the same. As there are in our system three fixed diaphragms and
two moveable steam pistons, equal to a system of three steam cylinders
with two pistons in each working simultaneously, the above described
method of working the parts will be repeated six times every full revo-
lution, and in such way that two cylinders are working with full steam
or with expanding steam, whilst the third cylinder is preparing for new
work.
In like manner as the steam is admitted through the steam passages h¹
and through the openings when i communicates with the space consti-
tuting the cylinder of the steam engine, so will the steam after having
performed its action escape out of that part of the cylinder which is pre-
paring for new work, through the openings i, Figure 5, into the passages h,
and hence through the steam box S¹ and steam valve V₁ (Figure 3) to
the exhaust pipe R.
When steam is admitted through the steam valve V¹ the engine will
run in the reverse direction.
The rotation of the cylinder d may be used as a motor by means of a
strap and pulley gearing, or a chain with chains wheels.

page_text: The rotation of the revolving slide valve r, Figure 8, Sheet 2, which on
account of the working of two steam pistons is of a double construction,
is effected by the spur wheels k¹, k², k³, k'; k¹, k¹, being rigidly fastened
to the covers e, e, of the revolving cylinder d, and transmitting the
rotation of the latter by means of k, k², to the shafts w, w, which by
means of the wheels k³, k³, and k*, k, will cause r, r, to revolve.
The regulation of the expansion is effected by increasing or decreasing
the apertures of the three openings in the discs n, Figures 3, 4, and 6,
which openings communicate with the three steam passages h; the disc n
may be turned by means of a hand wheel and worm and worm wheel,
Figure 6, behind the rotatory valve r. In working with full steam the
apertures in the valve or disc n are entirely opened, as they are also when
situate on what is for the time being the exhaust side of the engine.
The steam will obviously be admitted or exhausted according to the
direction in which the engine is intended to revolve by regulating the
position of the steam valves V₁ and V (Figures 3 and 8).
In stationary engines of the improved construction which may not
require to be reversed, the three steam passages for the exhaust steam
which were necessary in the above described construction may be replaced
by one main passage. In these engines, which rotate in one direction
only, it might be advisable to have the outer body or cylinder d fixed,
and to allow the inner cylinder a to revolve within the former.
3. Perfect absence of any dead centre and counter steam.

page_text: from oblique pressure in piston engines, with crank, connecting rod,
and slide.
5. The engine may in every position be started and regulated from
either side.
The above described construction of rotatory engines may therefore be
advantageously employed in all those cases where engines of uniform
and constant speed in a small compass are desired; as for example,
in the cases of locomotives, traction engines, steam vessels, and especially
for engines of small power in immediate connection with what is known
as a "Field boiler."
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be usde or
carried into effect, I would observe in conclusion that 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 peculiar construction and arrangement of variable expansion
rotatory engine, as herein-before described and illustrated by the Draw-
ings hereunto annexed.
Secondly. The peculiar combination of an inner and an outer con-
centric cylinder, the inner cylinder being provided with three or more
sliding diaphragms worked by cam grooves, and having steam and
exhaust passages therein leading to corresponding passages formed in the
stationary centre or supporting shaft, and the outer cylinder being pro-
vided with two or more internal projections acting as pistons, arranged
and operating in conjunction with the inner cylinder, substantially in
the manner herein-before described.
Thirdly. The peculiar combination of rotatory disc slide valve with
the ends of the stationary supporting shaft of the inner cylinder when
arranged and operating substantially as herein-before described.
Fourthly. The combination with the said rotatory disc slide valve of
a variable expansion valve, substantially as and for the purpose herein-
before described.
Fifthly. The so constructing a rotatory steam engine as that the
steam shall operate simultaneously against two pistons or stops in two of
a series of three chambers formed by three radial sliding diaphragms in

page_text: an inner cylinder whilst the exhaust is taking place from the third
chamber of the series, as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to
this my Specification set my hand and seal, this Tenth day of
October One thousand eight hundred and seventy-two.
J. HENRY JOHNSON. (L.S.)