Improvements in Rotary Steam and similar Engines.
Year: 1898

page_text: Date of Application, 25th Nov., 1898-Accepted, 21st Jan., 1899
COMPLETE SPECIFICATION.
Improvements in Rotary Steam and similar Engines.
I, DAVID MORELL, of 29, Wilhelmshoher Allee, Cassel, in the German Empire,
Engineer, do hereby declare the nature of this invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention relates to rotary steam and similar engines, and its object is to
improve their efficiency.
In the improved engine a plurality of rotary pistons and casings is employed,
and the steam passes from one to the next succeeding one, expanding successively
as it does so. The full power of the steam or other fluid is thus more nearly utilised.
Any single casing and its pistons may be employed as a single engine.
Any convenient number of pistons and casings may be employed but the com-
pound engine illustrated by the accompanying drawings is provided with five.
Referring to the drawings Figure 1 represents the improved engine in front
view.
Figure 2 shows it in plan.
Figure 3 illustrates a casing in partial section.
Figures 4 and 5 are representations of one of the pistons respectively in longi-
tudinal and cross section.
Figure 6 is a view in elevation of the same piston.
Figure 7 shows the engine diagrammatically with its connections.
Figures 8 and 9 are similar views of a pair of pistons within their casing but
occupying slightly different relative positions.
Figure 10 illustrates the construction of one form of piston.
Figure 11 is a cross section of the piston along the line A-B, Figure 10.
Figure 12 shows a cross section of the piston taken along the line C-D,
Figure 10.
Two rotary pistons a and a¹ are contained within each casing A and are secured
to the shafts 6, 6. See Figures 1, 2, and 3. The two shafts in each casing are
geared together by the wheels c, c', so that the vanes or projections of one piston
always engage with corresponding recesses in the other piston. The peripheries
of the pistons are always in contact, the outer surface of one or other of the
vanes on one piston being always in contact with the hub or lower surface k of
one or other of the recesses in the other piston. See Figures 8 and 9.
These vanes may be variously constructed so as to ensure tight contact with
In the form illustrated
the opposing surface with which they come into contact.
by Figures 3 to 6 the vanes A¹ are provided with a number of separate metallic
plates which are forced outwards by means of the spring or springs f. Some
of the plates may be divided in their length or be recessed or otherwise formed to
engage with a spring or springs f' which force them outwards and ensure a tight
contact against the sides of the casing. See Figure 4.
In engines of large size the construction illustrated in Figures 8 to 12 may be
adopted. The vane A¹ consists of a casting or the like and is adapted to fit within

page_text: a longitudinal recess in the hub k where it may be secured by the bolts or the
like The vane is also further secured by a plate or block which is placed
within it and fastened to the hub by the screws which pass through the vane.
h are separate spring controlled plates contained within the vanes and formed at
their ends with projections which come over the ends of the plate a² as shown in
Figure 11.
As before, f is the spring by means of which the plates h2 are forced
outwards against the inner surface of the casing. The ends of the plates 2 are
formed with suitable recesses into which fit, on each side of the piston, rings i
concentric with the piston. The recesses in the ends of the plates are larger than
the thickness of the rings so that a limited movement is allowed to the plates.
Additional smaller but similar plates are placed upon the surface of the hub
within the spaces between two vanes and are also engaged by the ring i.
The spring controlled plates are of such a size that, when the piston is out of its
casing, they project slightly above the surfaces within which they are fitted when
they have reached the limit of their outward movement. They are pressed inwards
against their springs when the piston is in its working position.
The arrangement of the compound engine is illustrated in Figures 1 and 2,
the desired number of casings A being secured to a suitable bed plate or founda-
tion. The shafts 6 of the upper pistons are coupled together and the shafts b¹ of
the lower pistons are geared to them by means of the wheels c and c¹. The steam
or the like enters the first casing, that on the left in Figures 1 and 2, by means
of the pipe or port d, and moves one or other of the pistons round, say the
one. When this rotation has continued for a little time the vane of the lower
upper
piston which was against the surface of the hub of the upper one, leaves it, and
steam is now free to enter the space between two vanes on the lower piston, one
of the vanes of the upper piston coming against the hub of the lower piston. The
two pistons are thus alternately worked the one which is not under active pressure
being driven round by the other through the gear wheels.
While the steam is exerting an active pressure upon one piston, the steam con-
tained within the space between two vanes on the other, say the upper one, is
carried round to the port e and pipe el, Figures 2 and 3, whence part of it escapes
and is carried by the pipe el to the inlet g of the second casing A, Figure 1, where
it performs its work at a reduced pressure, and partly passes through a
to the third casing at a still lower pressure, and so on throughout the series of
pipe h
casings.
A second set of pipes and ports is provided for the passage of the steam which
has not already escaped through those already described. The upper part of the
first casing has a port m through which the steam passes which has not escaped
through e, and is carried by a pipe m¹ to the inlet of the third casing. The surplus
steam in the second casing is carried by a similar pipe m¹ to the fourth casing,
and so cn through the series. The lower pistons are provided with a similar set of
ports and pipes o and o¹. In the last casing all the pipes lead to the inlet, and
the steam escapes through the outlet.
Each casing is provided with a similar outlet p opposite the inlet for the escape
of any remaining steam or water of condensation.
The course of the steam is approximately as follows, the upper parts of the cas-
ings only being referred to. Steam enters the first casing under a pressure of,
say, six atmospheres. When the steam contained between two vanes in the first
piston is brought into communication with the first escape port it is placed in com-
munication with a space of equal size contained between two vanes in the piston
of the second casing, and is thus consequently reduced in pressure to about one
half, that is about three atmospheres. The steam contained within two vanes on
the second piston, after doing its work, is placed in communication with a similar
space upon the third piston, into which space also opens the superfluous steam
from the first cylinder, m² and h¹ being the pipes by which the steam is conveyed.
The space for the steam is thus increased by about one-third and the pressure
consequently falls to about two-thirds or about two atmospheres. The fourth

page_text: casing receives its steam from one space in the third piston and one space in the
second, so that the pressure is again reduced about a third and falls to about one
and a third atmospheres. The final casing receives the steam from three pipes,
that is from the two escape pipes of the fourth casing, and from the superfluous
steam escape pipe of the third casing. The pressure is consequently decreased
about a fourth so that it acts in the last casing under a pressure of but little more
than one atmosphere. The higher the initial steam pressure the higher will be
the efficiency of the engine.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. A rotary steam or similar engine, consisting of a plurality of casings cach
containing two geared pistons formed with vanes and recesses, steam under full
pressure being caused to enter the first casing and operate the two contained
pistons, whence it is conveyed by suitable ports and pipes to the succeeding casings,
all constructed and arranged substantially as and for the purpose herein before
described and as illustrated by the accompanying drawings.
2. In a rotary steam or similar engine, a piston formed with three vanes the
surfaces of both or either the vanes and the hub being formed or provided with
spring controlled plates to form tight joints, constructed and arranged substantially
hereinbefore described and as illustrated by the accompanying drawings.
3. A rotary steam or similar engine, constructed and arranged substantially
as hereinbefore described and as illustrated by the accompanying drawings.
Dated this 24th day of November A.D. 1898.
W. E. HEYS & SON,
Agents for the Applicant.