IMPROVEMENTS IN ROTARY ENGINES
Year: 1873

page_text: LETTERS PATENT to Edward James Greey, of 3, Windsor Road,
Denmark Hill, in the County of Surrey, Civil Engineer, for the
Invention of "IMPROVEMENTS IN ROTARY ENGINES."
PROVISIONAL SPECIFICATION left by the said Edward James Greey
at the Office of the Commissioners of Patents, with his Petition,
on the 5th July 1873.
I, EDWARD JAMES GREEY, of 3, Windsor Road, Denmark Hill, in
the County of Surrey, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN ROTARY ENGINES," to be as
follows:-
This Invention has for its object to construct an efficient rotary
engine which will allow of steam being applied directly to produce a
circular motion without any "dead point," thereby avoiding the
necessity of using cranks or fly wheels, whilst at the same time a more
regular motion and the maximum amount of power capable of being

page_text: exerted by steam under pressure is obtained, economy in steam, and
consequent saving of fuel being thus effected.
The engine is composed of an annular steam-tight chamber in which
is fitted à radial piston carried by a cylindrical boss situated within the
central space and fitting steam-tight against the inner circumference of
the annular chamber; around the inner circumference a slot is also
formed through which passes the connection between the boss and
piston. On one side of the boss is a steam chest and on the opposite
side an exhaust chamber. From the steam chest a passage is formed
from the side of the boss to its circumference just in rear of the radial
piston; just in front of the piston a similar passage is formed through
the boss leading to the exhaust chamber. The shaft which carries the
central boss and piston passes out from the steam and exhaust chambers
through stuffing boxes, and is mounted in suitable bearings. At two or
more points slides are applied at the two opposite sides of the annular
chamber; these are arranged so that they can be withdrawn into recesses
at the sides of the chamber or can be moved up to one another, and be
thus caused to form a partition across the chamber. From the back
of each of the two parts of the partition a rod passes out through a
stuffing box, and these are acted on by circular cams on the main shaft,
there being one such cam on each side of the annular chamber or
cylinder to work the slides at its two opposite sides. As the piston
moves round past each set of slides they are closed together in rear of it
and before the piston again comes round they are again opened to allow
the piston to pass.
The admission of steam to the steam chest is controlled by a valve
actuated from an eccentric on the main shaft, so that the steam may be
used expansively.
In order that the sliding partitions may readily be moved into and
out of the recessed chambers which receive them small passages are
formed from front to rear of the chambers, so that there may always be
an equal pressure upon the front and rear of the partitions and but little
power will then be required to move them in and out.
In order also that the issuing of steam from the steam passage in rear
of the piston may aid in turning the engine shaft, this passage is formed
so that the steam shall issue from it as nearly as may be at a tangent to
the central boss in which the passage is formed..
1

page_text: In order also to prevent leakage of steam past the radial piston this
piston is packed at its sides and ends by packing pieces which are all
pressed outwards by a central spring to cause them to press against the
four sides of the annular chamber; the several packing pieces also fit
one to the other with mortice joints to prevent leakage of steam between
them.
The engine above described is also made capable of being reversed
without the necessity for link motion, the method of reversing being
by a two-way cock introducing the steam into the exhaust pipes and
making the exhaust pipes steam pipes for the time being.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward James Greey in the Great Seal Patent
Office on the 5th January 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
JAMES GREEY, of 3, Windsor Road, Denmark Hill, in the County of
Surrey, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of July, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Edward James Greey, Her special
license that I, the said Edward James Grecy, my executors, ad-
ministrators, and assigns, or such others as I, the said Edward
James Greey, 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 ROTARY ENGINES," upon the condition (amongst
others) that I, the said Edward James Greey, my executors or adminis-
trators, by an instrument in writing, under my, or their, or one of
their hands and seals, should particularly describe and ascertain the

page_text: 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 Edward James Greey, 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 :-
This Invention has for its object to construct an efficient rotary
engine which will allow of steam being applied directly to produce a
circular motion without any "dead point," thereby avoiding the
necessity of using cranks or fly wheels except when high expansion is
used, whilst at the same time a more regular motion and the maximum
amount of power capable of being exerted by steam under pressure is
obtained, economy in steam and consequent saving of fuel being thus
effected.
The engine is composed of an annular steam-tight chamber in which
is fitted a radial piston carried by a cylindrical boss situated within the
central space and fitting steam-tight against the inner circumference of
the annular chamber; around the inner circumference a slot is also
formed through which passes the connection between the boss and
piston. On one side of the boss is a steam chest and on the opposite
side an exhaust chamber. From the steam chest a passage is formed
from the side of the boss to its circumference just in rear of the radial
piston; just in front of the piston a similar passage is formed through
the boss leading to the exhaust chamber. The shaft which carries the
central boss and piston passes out from the steam and exhaust chambers
through stuffing boxes and is mounted is suitable bearings. At two or
more points slides are applied at the two opposite sides of the annular
chamber; these are arranged so that they can be withdrawn into recesses
at the sides of the chamber or can be moved up to one another, and be
thus caused to form a partition across the chamber. From the back of
each of the two parts of the partition a rod passes out through a stuffing
box, and these are acted on by circular cams on the main shaft, there
being one such cam on each side of the annular chamber or cylinder to
work the slides at its two opposite sides. As the piston moves round
past each set of slides they are closed together in rear of it, and beforo

page_text: the piston again comes round they are again opened to allow the piston
to pass.
The admission of steam to the steam chest is controlled by a valve
actuated from an eccentric on the main shaft, so that the steam may be
used expansively.
In order that the sliding partitions may readily be moved into and
out of the recessed chambers which receive them, small passages are
formed from front to rear of the chambers so that there may always be
an equal pressure upon the front and rear of the partitions and but
little power will then be required to move them in and out.
In order also that the issuing of steam from the steam passage in rear
of the piston may aid in turning the engine shaft this passage is formed
so that the steam shall issue from it as nearly as may be at a tangent to
the central boss in which the passage is formed.
In order also to prevent leakage of steam past the radial piston this
piston is packed at its sides and ends by packing pieces which are all
pressed outwards by springs to cause them to press against the four sides
of the annular chamber, the several packing pieces also fit one to the
other with mortice joints to prevent leakage of steam between them.
The engine above described may also be made capable of being reversed
without the necessity for link motion, the method of reversing being by
a two-way cock introducing the steam into the exhaust pipes and making
the exhaust pipes steam pipes for the time being.
Rotary engines such as above desscribed may be constructed at
much less cost than engines as now ordinarily constructed.
In the Drawings hereunto annexed I have shewn a rotary engine
constructed as above described.
Figure 1, Sheet 1, shews a side view partly in section of the engine;
Figure 2, Sheet, 2, shews a plan view partly in section of the same.
Figure 3 shews a vertical section, and Figure 4 a horizontal section
taken through the centre of one pair of the slides.
Figures 5 shew separate views of the central boss and piston arm.
A is the annular steam chamber; B, the piston fitted therein and
carried by the central boss C on the shaft D; this shaft passes out

page_text: through stuffing boxes carried by the ends of the chamber A. The
ends of the boss C and the stuffing boxes are so formed as to leave
between them a chamber at each end of the boss, one marked E for
steam, the other for the exhaust. Both ends of the boss are surrounded
with packing rings F which bear against the inner circumference of the
steam and exhaust chambers respectively to make a tight joint. The
piston arm B is also caused to fit steam-tight within the annular steam
chamber A by packing pieces fitted within it and pressed outwards by
springs to cause them to bear against the four sides of the annular
chamber, and as before stated the several packings are also fitted one to
the other with mortice joints to prevent leakage of steam between
them.
From the steam chest E a passage G is formed through the boss to its
circumference just in rear of the radial piston B, and this passage
is as
shewn at Figures 5 so formed that the steam shall issue from it as nearly
as may be at a tangent to the boss, and so aid in turning the shaft; this
is more especially of importance when working the engine with water.
Just in front of the radial piston a similar passage is formed through
the boss and leading to the exhaust chamber. H, H, are two pair of
slides each of which can be caused to form a partition across the
chamber A. The two slides of each pair can be withdrawn into
recesses I, I, at the sides of the chamber or can be moved up to one
another to form a partition across the chamber A.
From the back of each slide a rod passes out through a stuffing
box K at the back of the recess I, and is attached to a block L which
can be moved to and fro along guides M as shewn ; N, N, are cams on
the main shaft which act upon pins or tumblers capable of pivoting in
the blocks as shown at Figure 4*, and cause the blocks to move to and
fro and so alternately to withdraw the slides into the recesses I, and
move them up to one another to form a partition across the chamber A.
A steam-tight joint is formed between the ends of the slides where they
meet together in the manner shewn at Figure 3.
In order that the slides may readily be moved into and out of the
recesses I small passages I* are formed from the front to the rear of the
recesses, so that there may always be an equal pressure upon the front
and rear of the slides, and the cams are so formed as to keep each pair of
slides entirely closed during a half revolution of the main shaft D.

page_text: The admission of steam to the steam chest E is controlled by a slide
valve O in the valve box P. The valve rod Q is connected by a link to
an arm on a shaft R to which a rocking motion is imparted by a con-
necting rod S from an arm on the shaft T; this shaft has a rocking
motion imparted to it by an eccentric U on the main shaft D as shewn,
but other arrangements of valve gear may be adopted.
The action of the engine is as follows :― -When the radial piston has
travelled round past one pair of slides these slides are closed behind it, and
when the piston has moved through about one quarter of a revolution and
the slides in rear of it have been completely closed steam is admitted in
rear of the piston, the slide valve O being opened the valve is then
again caused quickly to close, and the radial piston is then carried round
by the expansion of the steam in rear of it, the slides up to which it is
moving being drawn back by the cams N to allow it to pass, and when
the piston has moved past these slides they again commence to close,
and when the piston has moved about one quarter of a revolution past.
them they have been completely shut, and the other pair of slides
commence to open at the same time steam is again admitted to the
space in rear of the piston and so on continuously; thus a constant
pressure is maintained against the back of the piston whilst the space in
front of the piston is always open to the exhaust. The steam is caused.
to act more or less expansively in the engine, according as the slide valve
is allowed to remain open for a greater or less length of time. As
before stated the engine might be made capable of being reversed by
simply shutting off the supply of steam to the steam chest and
admitting it to what was previously the exhaust chamber, suitable
modifications being then made in the valve gear.
Having thus described the nature of my Invention and the manner of
performing the same, I would have it understood that I do not confine
myself to the precise details of construction herein described, and also
that in place of each of the slides or partitions being made in two parts
to be withdrawn into recesses at the two sides or ends of the annular
steam chamber each partition might although not so advantageously be
in one piece and be made to move in and out of a recess at one or other
side of the annular steam chamber.
I would also state that the engine may be worked with air or with

page_text: What I claim as my improvements in rotary engines is,―
ритр.
1. The combined arrangement of rotary engine, substantially as
described.
2. The combined arrangement of annular chamber, radial piston
carried by a central shaft, and two or more slides or partitions which can
be moved across the annular chamber, substantially as described.
3. Admitting steam or other fluid under pressure to and carrying it
off from the annular steam chamber through the central boss which
carries the radial piston, substantially as herein described.
4. Forming each of the partitions as herein described in two parts to
be moved towards and from each other.
5. Employing cams on the main shaft to move the partitions to and
fro as herein described.
6. The tangential passages in the boss of piston aiding the piston in
its progress both in the entrance side and escape side.
In witness whereof, I, the said Edward James Greey, have here- a
unto set my hand and seal, this Third day of January, in the
year of our Lord One thousand eight hundred and seventy-
four.