IMPROVE- MENTS IN ROTARY STEAM ENGINES AND PUMPS
Year: 1872

page_text: LETTERS PATENT to Cyrus Avery, of Tunkhannock, Pennsylvania,
United States of America, now of Little Cross Street, Islington, in
the County of Middlesex, Engineer, for the Invention of "IMPROVE-
MENTS IN ROTARY STEAM ENGINES AND PUMPS."
Sealed the 3rd September 1872, and dated the 8th March 1872.
PROVISIONAL SPECIFICATION left by the said Cyrus Avery at the
Office of the Commissioners of Patents, with his Petition, on the
8th March 1872.
I, CYRUS AVERY, of Tunkhannock, Pennsylvania, United States of
America, now of Little Cross Street, Islington, in the County of Middle-
sex, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN ROTARY STEAM Engines and Pumps,” to be as follows:-
My said Invention relates to a rotary engine whose action is produced
by the force of steam ejected from the piston upon an abutment in a
circular passage or channel wherein the piston moves. The said abut-
ment is so constructed and arranged in the passage that it is operated

page_text: to move across and away from the path of the piston by the piston itself
or by a cam arranged outside the case or drum in which the piston is
enclosed. The area of the said channel or passage is uniform at all
parts, and the admission and exhaust apertures are so arranged in com-
bination with the piston and abutment that the full pressure of the
steam on the piston is maintained nearly throughout its entire revolu-
tion. The case or drum in which the piston is enclosed is made of cast
iron or other suitable metal. The said case is made in two parts, one
of which forms a cover and is removeable. The channel in which the
piston works is formed half in the cover and half in the back part of
the said case; this back part consists of a central fixed portion and
an annular piece in which the channel is formed, and which is made
adjustable on the said fixed portion. The piston is formed on or attached
to a disc which is fixed on the central shaft or axis. The said disc is
preferably constructed of two thin plates rivetted or screwed together.
At one side of the disc there is an aperture which extends between the
two plates to the piston and communicates with another aperture
through the rear of the said piston. The inlet aperture for the steam is
preferably made in the cover and communicates with a long slot or
groove formed in the inner surface of the same. As the aperture in the
disc passes over this slot steam is admitted to the piston, but when it
passes away from the said slot the steam is cut off.
I place a valve in
this slot to divide it into two portions, and by opening or closing this
valve the steam is admitted for a longer or shorter time. The disc fills
the central portion of the case,
the piston channel or passage being at
the periphery of the said case. On each part of the case I form a recess
to receive one part of the abutment and its connections. This abutment
is preferably made in two parts which when the channel is closed meet
at the centre thereof. When the channel is opened to allow the piston
to pass each half of the said abutment is withdrawn into one of the
recesses. To effect the adjustment of the abutment I use the following
contrivances -I connect each part of the abutment to levers which
I make the forward
have antifriction rollers projecting into the channel.
side of the piston wedge shaped or inclined on both sides. As the piston
approaches the abutment the inclines act on the rollers of the first levers
and open the abutment, then as the piston leaves the abutment the said
inclines immediately pass over the rollers of the second levers and close
the abutment, the opening and closing being almost instantaneous, so
that no space or steam will. be wasted. In some instances - instead of

page_text: making the piston act on the abutment I may operate the same by
means of cams placed outside the case and connected to the abutment
by rods passing through stuffing boxes in the recesses. The exhaust
aperture is arranged slightly in front of the abutment. The annular part
of the case in which one-half of the piston channel is formed is made
adjustable by means of screws so that the two parts of the channel may
be drawn more closely together as the piston becomes worn. The central
shaft or axis extends through one side of the case, and its projecting
end is supported in suitable bearings. The shaft carries a fly wheel and
may be provided with belt pulleys or gear wheels.
To adapt my Invention for use as a pump the only change required
will be to lengthen the slot of the admission aperture so that the water
or other liquid will be admitted to the piston throughout the entire
revolution of the piston.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Cyrus Avery in the Great Seal Patent Office on
the 6th September 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CYRUS
AVERY, of Tunkhannock, Pennsylvania, United States of America, now of
› Little Cross Street, Islington, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of March, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
5 and grant unto me, the said Cyrus Avery, Her special licence that I,
the said Cyrus Avery, my executors, administrators, and assigns, or such
others as I, the said Cyrus Avery, 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
O 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 STEAM ENGINES AND
PUMPS," upon the condition (amongst others) that I, the said Cyrus Avery,
my executors or administrators, by an instrument in writing under my,

page_text: or their, or one of their hands and seals, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Cyrus Avery, 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 Drawing
forming a part of this Specification:—
My said Invention relates to a rotary engine which may also be
used as a pump, and is so constructed that its action is produced by the
force of steam ejected from the piston upon an abutment in a circular
The said abutment is
passage or channel wherein the piston moves.
so constructed and arranged in the passage that it is operated to move
across and away from the path of the piston by the piston itself, or by
a cam arranged outside the case or drum in which the piston is enclosed.
The area of the said channel or passage is uniform at all parts, and
the admission and exhaust apertures are so arranged in combination
with the piston and abutment that the full pressure of the steam on the
piston is maintained nearly throughout its entire revolution.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a plan of my improved rotary engine; Figure 2 is a front
elevation of the said engine; Figure 3 is a similar elevation with the
cover and other parts removed; Figure 4 is a side elevation of the said
engine; Figure 5 is a vertical section of the same on the line x, x,
Figure 1; Figure 6 shews portions of the said engine detached. Like
letters indicate the same parts throughout the Drawing.
The case or drum a in which the piston is enclosed is constructed of
cast iron or other suitable metal. The said case is made in two parts
a, a; the part a² forms a cover and is removable; the channel a³ in
which the piston 6 works is half in the cover and half in the back part
or body a¹ of the said case. Inside the cover I fit an annular piece c
in which one half of the channel is formed, and which is made adjust-
able in the said cover to compensate for the wear of the said channel
or of the piston. This adjustment is effected by means of the bolts c¹,
which are screwed through the cover and bear upon the said annular
•

page_text: piece. If found more convenient this annular piece with its adjusting
screws may be placed in the part a¹ of the case instead of in the
cover a². The piston 6 is formed on or attached to a disc d; which is
fixed on the central shaft or axis e. The said disc is preferably con-
structed of thin plates rivetted or screwed together. Through the plate
forming one side of the disc d there is an aperture f, which by cutting
through the inner plates of the disc is extended between the two outer
plates thereof to the piston b, and opens through the rear of the said
piston. The disc d occupies the central portion of the case a or that
portion between the axis and the piston passage or channel which is at
the periphery of the said case. The steam is admitted through the inlet
pipe g and valve h, which are preferably connected with the cover a³.
The said valve is shewn detached in Figure 6. It is fitted in a circular
box or recess h¹ formed in the said cover. The said valve has a series of
holes 1, 2, 3, 4, and the back of the valve box has similar holes 5, 6, 7, 8.
By turning the said valve on its axis one or more of its holes .may be
brought in line with one or more of the holes in the bottom of the
cover, and more or less steam is thus admitted as required, that is to
say, by turning the valve so that the hole 1 comes opposite the hole 5,
I only open one aperture for the admission of the steam, but by turning
the said valve till the hole 1 comes opposite the hole 6, the hole 2 will
be brought opposite the hole 5 and two admission apertures will be
opened. By turning the said valve still further upon its axis I can
bring the other holes opposite each other, and thereby open three or
four admission apertures as will be readily understood by observation
of the Drawing. The spindle h² of the valve h is extended through a
stuffing box i and provided with a hand wheel j, whereby the turning
of the valve is conveniently effected. The said spindle is also furnished
with a pointer k, and on the front of the cover is a dial over which
the said pointer moves. By means of this pointer the correct adjust-
ment of the valve to open one, two, or more holes is readily and
accurately accomplished. Or instead of using the above device I may
form a long slot in the cover in such a position that the aperture fin
the dise passes over this slot, steam being then admitted to the piston,
but when it leaves the said slot the steam is cut off. I place a valve
in this slot to divide it into two portions, and by opening or closing this
valve the steam is admitted for a longer or shorter time. With either
of these contrivances the steam is only admitted once during each
revolution of the piston, and is thereby used very advantageously. The

page_text: abutment / may be made in two parts, which when the channel is closed
meet at the centre thereof, and when the channel is opened to allow
the piston to pass each half of the said abutment is withdrawn into a
.recess. To effect this adjustment of the abutment I may use the
following contrivances:-Each part of the abutment is connected to
levers which have antifriction rollers projecting into the channel. I
make the forward side of the piston wedge shaped or inclined on both
sides. As the piston approaches the abutment the inclines act on the
rollers of the first levers and open the abutment, then as the piston
leaves the abutment the said inclines immediately pass over the rollers
of the second levers and close the abutment, the opening and closing
. being almost instantaneous so that no space or steam will be wasted.
I prefer however to operate the abutment by means of cams placed
outside the case a, and have therefore devised the arrangement shewn in
the Drawing, in which the abutment consists of one piece / fitted to
move vertically into and out of the path of the piston. For the reception
of this abutment I form above the piston passage a recess or chamber m.
The abutment is secured to the rod which works through a stuffing
box m¹ in the top of the chamber m. To the upper end of the abutment
rod is attached the elbowed rod n, this rod extends down at the back
of the case, and is provided at its lower end with an antifriction roller
which works in the cam groove o in the fly wheel p; the latter is fast
on the shaft e to which the disc d is also made fast. The said shaft is
supported in a bearing formed in the centre of the case a, and by
another bearing 9 supported on the top of the framer as shewn.
belt pulley ¹ on a toothed gear wheel is also fixed on the said shaft.
The exhaust aperture s is preferably made through the top of the
case or drum a, the exhaust pipe s¹ being extended into any convenient
position.
A
To make the engine reversable I provide the case with two exhaust
apertures and fit the same with valves whereby I can open one and close
the other aperture; the piston must also be provided with means whereby
the steam may be ejected from either side. By these contrivances and

page_text: liquid will be admitted to the piston throughout the entire revolution of
the piston.
Having thus fully described my said Invention, and the manner of
performing the same, I wish it understood that I claim,―
First. A rotary engine with its parts so constructed that the steam or
other fluid is admitted at or near the axis of the piston and discharged
from the same against an abutment which closes the piston passage, as
herein set forth.
Second. A rotary engine with its parts so constructed, combined, and
operating that the steam or other fluid is admitted to the piston only
once during each revolution of the same, and the pressure thereon is
maintained throughout nearly its entire revolution.
Third. The sliding abutment and the mechanism for actuating it
constructed and operating in combination with the piston and the
contrivances for admitting the steam to the same, as herein set forth.
In witness whereof, I, the said Cyrus Avery, have hereunto set
my hand and seal, this Third day of September, in the year of our
Lord One thousand eight hundred and seventy-two.
CYRUS AVERY. (L.S.)
) Witness,
CHAS. J. GOOCH,
Clerk to Messrs. Haseltine, Lake, & Co.,
Southampton Buildings,
London.