IMPROVEMENTS IN ROTARY ENGINES
Year: 1881

page_text: LETTERS PATENT to John Patten, of the City and County of San Francisco, in
the State of California, one of the United States of America, Engineer,
for an Invention of IMPROVEMENTS IN ROTARY ENGINES."
PROVISIONAL SPECIFICATION left by the said John Patten at the Office
of the Commissioners of Patents on the 22nd November 1881.
JOHN PATTEN, of the City and County of San Francisco, in the State of
California, one of the United States of America, Engineer. "IMPROVEMENTS IN
ROTARY ENGINES."
My Invention relates to a rotary engine in which the chamber of the cylinder is
divided diagonally by a rotating disk and transversely by one or more pistons.
which bisect the disk and move through it from side to side as the two revolve
together, so that the disk divides the chamber into two separate compartments, into
and from each of which steam or other working fluid is supplied and exhausted
independently of the other, while it acts against the same piston or pistons in both
of the compartments, all as hereinafter more fully described.
In constructing a rotary engine in accordance with my Invention and provided
with valve gear for working steam expansively.
I make the interior rim of the case or shell of the engine cylinder concave, the
sides being convex, thus enclosing a chamber, the form of which is best illustrated
by the solid which remains after boring a conical portion out of the opposite sides
of a solid sphere. The engine shaft passes through openings in the centre of each
side of the case, and the pistons and diagonal disk are connected therewith.
A disk is placed diagonally across the interior of the chamber so as to divide it
into two equal compartiments, one on each side of the disk. The position of this
disk is such that it presses close against the flaring wall of one compartment on one
side of the centre, and close against the wall of the other compartment on the
opposite side, while its rim or periphery fits close against the interior rim of the
chamber, thus dividing the main chamber into two crescent shaped compartments
which face in opposite directions. The disk will then form one side of both the
compartments.
A circular opening is made in the centre of the disk in which a portion of a

page_text: hollow sphere is secured so that the disk forms an equatorial flange surrounding the
sphere and the two move together as one. A hole or opening is inade in the sphere
on each side of the disk in a line at right angles to the plane of the disk, and the
disk and its sphere are supported in position by a tubular block on each side, the
edge of which fits against the edge of the opening in the sphere.
These blocks are adjustable by means of screws, so that they can be set towards
or from the sphere. These blocks are stationary while the sphere rotates between
them, the bearing for the edges of the sphere being against the edges of the
blocks. The axis of the disk will then be diagonal to the line of the engine shaft.
The exterior face of the sphere on each side of the disk will fit against the
circular opening in the centre of the case or shell, and the intermediate portion will
form the bottom of the chambers. The engine shaft passes through both the afore-
said tubular blocks and the sphere, but as above stated it passes axially through
the cylinder.
The disk and the sphere will then rotate together in a plane diagonal to a
vertical plane drawn at right angles across the engine shaft. The edges of the
radial slots in the disk are rounded and a packing is introduced between them and
the piston on each side, so that the angle of piston with relation to the disk can
change as it traverses across the disk, and at the same time keep a tight joint.
The pistons are connected together by a bar plate or rod which is secured to the
engine shaft at its middle in any convenient way. This bar plate or rod passes
vertically across the opening in the centre of the engine, and its ends pass through
the sphere while the pistons are attached to its extremities and stand transversely
across the cylinder.
Each piston fits in a radial slot in the disk, in which it can move easily and
freely, so that when the pistons are driven they will move laterally through the
slot from side to side as the disk travels across the plane of the pistons, thus
projecting the pistons gradually from one side of the disk to the other
The openings in the sphere through which the ends of the bar, plate, or rod
pass, are slotted on opposite sides of the shaft in a plane with the pistons so that
the piston and disk can move laterally with relation to each other, and the bar,
plate, or rod carries a covering plate which moves against the interior face of the
sphere and covers the opening.
The packings are placed in grooves in the wall of the cylinder opposite the points
of closest contact between the faces of the disk and the angular face or wall of the
chamber, and these packings are pressed outward against the faces of the disk by
springs.
The adjustment of the pistons is such that when they are opposite the abutments
their entire width projects on the opposite side of the disk so that they pass the
packings readily.
The steam ports through which steam is admitted to drive the engine connects
with the interior of the cylinder just in front of the packings, while the exhaust
ports connect with it just behind the packings.
The arrangement of the ports will vary according to the character of the motive
agent; for instance, in a water wheel pump or blower the port for admitting the
fluid into the cylinder is enlarged so that it extends from the packing one fourth of
the distance around the cylinder, and the exhaust port is also enlarged to the same
proportion; consequently while making one half of the revolution the pressure
against the piston on one side is equal to the pressure on the other side, so that
each piston is only working one half of the time. This by no means impairs the
operation of the machine, for while the piston is passing the port on one side of the
disk it is working on the opposite side.
The operation will therefore be as follows:-
Assuming that the two pistons have just passed the packing and are taking
steam behind them, while the steam in front of thein is working expansively
against the next piston, which has a larger area exposed to pressure, and the steam
in front of the next piston is exhausting behind the packing.

page_text: Owing to the conical form of the sides of the cylinder and the diagonal position
of the disk, the chamber on each side is in the form of a crescent. The disk forms
one side of each chamber, and is carried around in its diagonal plane by the pistons
as they move in a vertical plane. The diagonal inclination or angle of the disk
is just equal to the width of the pistons, so that every time the disk and pistons
make a complete revolution each piston moves laterally through the slot in the
disk and back again.
Now when steam is admitted behind the pistons the pistons have just commenced
to move through the slot in the disk, and the full pressure of the steam is exerted
As the
against that portion which projects through the disk on the steam side.
pistons move farther away from the steam ports they gradually present larger
surfaces until they pass the opposite side of the engine, after which the space in
front of them gradually contracts in size towards the exhaust ports until the pistons
again pass the abutments.
When working the engine solely by the pressure of the steam, the steam acts
against each piston on one side of the disk from the time it passes the packings
until it passes half way round the cylinder, at which point the steam is cut off by
the next piston passing between it and the abutment, after which the steam exhausts
during the balance of its stroke, but during this latter part of the stroke the piston
gradually moves through the disk and takes steam in the opposite chamber, so that
each piston is being driven by live steam on one side of the disk, while it is either
exhausting or working expansively on the opposite side.
In working the steam expansively it is cut off when the piston has moved
through a portion of its stroke only, that is, before it reaches the point where the
following piston commences to take steam behind it.
The steam then works
expansively until the piston has moved three fourths of the distance around the
cylinder, when it commences to exhaust through the preliminary exhaust port,
which is connected with the main exhaust by a port or passage.
This saine arrangement will form an excellent water wheel or air compressor.
For the latter purpose it is especially useful, as its arrangement is such that it will
compress air in proportion to the power employed to drive it.
For compressing air the port through which the air is admitted into the cylinder
is arranged in the same way, but the exit port through which the air is forced must
be just in front of the packing; when the air is to be compressed to a very high
tension I will place a check valve over the egress port to prevent the air re-entering
into the machine again.
For a steam engine the exhaust port can be the same as the ingress port to the
compressor or water wheel pump and blower, but the ingress port through which the
steam will be admitted into the engine to drive the machine will be constructed like
the egress port to the air compressor; when the ports are so arranged it is obvious
that by having two pistons directly opposite each other, as soon as one makes one
half of a revolution the other passes the port and cuts off the steam, consequently
the steam is worked under full pressure one half the way around.
Then it works expansively one quarter farther. It is then exhausted, and the
With
action of the piston is dormant during the remaining portion of the stroke.
this arrangement two volumes of steam is expanded to three volumes, and then
exhausted.
As it is sometimes desirable to produce a more economical engine by expanding
the steam more than this, and as it is also very essential for a handy engine to be
reversible to accomplish these objects, I arrange ports in the cylinder case on each
side of the packings, which can be used either for ingress or egress, according to
which way the engine is to revolve, and other ports connecting with the interior
of the cylinder, these latter extending, say, one fourth of the way round from the
packings. I also arrange a D valve so as to cover one of each of the above men-
tioned ports, making them both exhaust ports at the same time, and while it is in
this position the other end covers the other port, which connects with the interior
of the cylinder, and makes it lie dormant.

page_text: Two ports, extending through the D valve correspond with the ports in the
cylinder case, and when one of these ports in the D valve is directly over one of
the ports in the cylinder case, allowing the steam to pass from the steam chest to
the cylinder, the other port in the D valve is dormant
For an ordinary engine, where the steam is expanded from two to three volumes, 5
the D valve is the only one used, and it remains stationary while the machine is
revolving in one direction, but must be moved so as to make one of its ports
correspond with one of the ports in the cylinder case for reversing the engine.
When it is desired to expand the steam farther than it can be expanded in the
above manner I use an additional valve, which is handled in the usual, manner by 1
an eccentric.
For a reversible engine I may use an ordinary link motion.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Patten in the Great Seal Patent Office on the 4th May
1882.
JOHN PATTEN, of the City and County of San Francisco, in the State of
California, one of the United States of America, Engineer. "IMPROVEMENTS IN
ROTARY ENGINES."
My Invention relates to a rotary engine in which the chamber of the cylinder is
divided diagonally by a rotating disk, and transversely by one or more pistons
which bisect the disk and move through it from side to side as the two revolve
together, so that the disk divides the chamber into two separate compartments,
into and from each of which steam or other working fluid is supplied and exhausted
independently of the other, while it acts against the same piston or pistons in both
of the compartments, all as hereinafter more fully described.
Referring to the accompanying Drawings, in which Figure 1 is an elevation of a
rotary engine constructed in accordance with my Invention, and provided with
valve gear for working steam expansively; Figure 2 is an enlarged sectional view.
It is drawn to a scale double the size of Fig. 1, and it is a section taken transversely
through the outer case or cylinder, and through the centre of the near steam chest
and valves that are shown at the left hand side of Fig. 1; the inclined disk and
piston project from the case and are not in section; and the steam chest on the left
hand side in this view has its front side broken away to disclose the valve;
Figure 3 is a horizontal section through the case or cylinder and the steam chest,
the shaft, the diagonal disk, and pistons not being in section; Figure 4 is a
detail view of the piston; Figure 5 shows the disk and spherical hub.
Letter A represents the case or shell of the engine cylinder. The interior rim
of the shell is concave while the sides are convex, thus enclosing a chamber the
form of which is best illustrated by the solid which remains after boring a conical
portion out of the opposite sides of a solid sphere; B is the engine shaft which
passes through openings in the centre of each side of the case, and with which
the pistons and diagonal disk are connected.
C is a disk which is placed diagonally across the interior of the chamber so as
to divide it into two equal compartments, one on each side of the disk. The
position of this disk it will be noticed is such that it presses close against the
flaring wall of one compartment on one side of the centre and close against the wall
of the other compartiment on the opposite side, while its rim or periphery fits close
against the interior rim of the chamber, thus dividing the main chamber into two
crescent shaped compartments, which face in opposite directions. The disk will
then form one side of both the compartments.
A circular opening is made in the centre of the disk in which a portion of a
hollow sphere D is secured, so that the disk forms an equatorial flange surrounding
the sphere, and the two move together as one. A hole or opening F is made in
the sphere on each side of the disk in a line at right angles to the plane of the
disk, and the disk and its sphere are supported in position by a tubular block E
on each side, the edge of which fits against the edge of the opening in the
sphere.
These blocks are adjustable by means of screws f, f, so that they can be set
towards or from the sphere. These blocks are stationary while the sphere rotates
between them, the bearing for the edges of the sphere being against the edges of
the blocks. The axis of the disk will then be diagonal to the line of the engine-
shaft B.

page_text: The exterior face of the sphere on each side of the disk will fit against the
circular opening on the centre of the case or shell A, and the intermediate portion
will form the bottom of the chambers. The engine-shaft passes through both the
tubular blocks E, E, and the sphere, but as above stated it passes axially through
the cylinder.
The disk and its sphere will then rotate together in a plane diagonal to a vertical
plane drawn at right angles across the engine shaft. The edges of the radial slots
in the disk are rounded, and a packing is introduced between them and the piston
on each side, so that the angle of piston with relation to the disk can change
as it traverses across the disk, and at the same time keep a tight joint.
The pistons G, G, are connected together by a bar, plate, or rod H, H, which is
secured to the engine shaft B at its middle in any convenient way. This bar.
plate, or rod H passes vertically across the opening in the centre of the engine,
and its ends pass through the sphere D, while the pistons G, G, are attached to its
extremities and stand transversely across the cylinder.
Each piston fits in a radial slot in the disk C, in which it can move easily and
freely, so that when the pistons are driven they move laterally through the
alot from side to side as the disk travels across the plane of the pistons, thus
projecting the pistons gradually from one side of the disk to the other."
The openings in the sphere D through which the ends of the bar, plate, or
rod H, H, pass, are slotted on opposite sides of the shaft at K in a plane with the
pistons, so that the piston and disk can move latterally with relation to each other,
and the bar, plate, or rod H carries a covering plate J which moves against the
interior face of the sphere and covers the opening.
L, L, are the packings which are placed in grooves in the wall of the cylinder
opposite the points of closest contact between the faces of the disk and the
angular face or wall of the chamber, and these packings are pressed outward
against the faces of the disk by springs shown in Figures 2 and 3.
The adjustment of the pistons is such that when they are opposite the abutments
their entire width projects on the opposite side of the disk, so that they pass the
packings readily.
The steam ports m, m¹, through which steam is admitted to drive the engine,
connects with the interior of the cylinder just in front of the packings, while the
exhaust ports connect with it just behind the packings.
The arrangement of the ports will vary according to the character of the motive
agent, for instance, in a water wheel pump or blower the port for admitting the
fluid into the cylinder is enlarged, so that it extends from the packing one fourth
of the distance around the cylinder, and the exhaust port is also enlarged to the
same proportion, consequently while making one half of the revolution, the pressure
against the piston on one side is equal to the pressure on the other side, so that
each piston is only working one half of the time. This by no means impairs the
operation of the machine, for while the piston is passing the port on one side of
the disc it is working on the opposite side.
The operation will therefore be as follows, referring to Figure 2 for the
preliminary position of parts.
As represented in this Figure the two pistons have just passed the packing and
are taking steam behind them, while the steam in frout of them is working
expansively against the next piston, which has a larger area exposed to pressure,
and the steam in front of the next piston is exhausting behind the packing.
Owing to the conical form of the sides of the cylinder and the diagonal position
of the disk, the chamber on each side is in the form of a crescent. The disk forms
one side of each chamber and is carried around in its diagonal plane by the
pistons as they move in a vertical plane. The diagonal inclination or angle of the
disk is just equal to the width of the pistons, so that every time the disk and
pistons make a complete revolution each piston moves laterally through the slot in
the disk and back again.
Now when steam is admitted behind the pistons, as represented at Figure 2, the

page_text: pistons have just commenced to move through the slot in the disk, and the full
pressure of the steam is exerted against that portion which projects through the
disk on the steam side. As the pistons move farther away from the steam ports
they gradually present larger surfaces until they pass the opposite side of the
engine, after which the space in front of them gradually contracts in size towards
the exhaust ports until the pistons again pass the abutments.
When working the engine solely by the pressure of the steam, the steam acts
against each piston on one side of the disk from the time it passes the packings
until it passes half way round the cylinder, at which point the steam is cut off by
the next piston passing between it and the abutment, after which the steam
exhausts during the balance of its stroke, but during this latter part of the stroke
the piston gradually moves through the disk and takes steam in the opposite
chamber, so that each piston is being driven by live steam on one side of the
disk while it is either exhausting or working expansively on the opposite side.
In working the steam expansively it is cut off when the piston has moved
through a portion of its stroke only, that is, before it reaches the point where the
following piston commences to take steam behind it. The steam then works
expansively until the piston has moved three fourths of the distance around the
cylinder when it commences to exhaust through the preliminary exhaust port
which is connected with the main exhaust by a port or passage.
This same arrangement will form an excellent water wheel or air compressor.
For the latter purpose it is especially useful, as its arrangement is such that it will
compress air in proportion to the power employed to drive it.
For compressing air, the port through which the air is admitted into the cylinder
is arranged in the same way, but the exit port through which the air is forced
must be just in front of the packing; when the air is to be compressed to a very
high tension I will place a check valve over the egress port to prevent the air
re-entering into the machine again.
For a steam engine the exhaust port can be the same as the ingress port to the
compressor, water wheel pump, and blower, but the ingress port through which the
steam will be admitted into the engine to drive the machine will be constructed like
the egress port to the air compressor; when the ports are so arranged it is obvious
that by having two pistons directly opposite each other, as soon as one makes one
half of a revolution the other passes the port and cuts off the steam, consequently
the steam is worked under full pressure one half the way around.
Then it works expansively one quarter farther. It is then exhausted and the
action of the piston is dormant during the remaining portion of the stroke;
with this arrangement two volumes of steam is expanded to three volumes and
then exhausted.
As it is sometimes desirable to produce a more economical engine by expanding
the steam more than this, and as it is also very essential for a handy engine to be
reversible, to accomplish these objects I arrange my valve ports, substantially as
shown on the accompanying Drawings, in which m, m', are ports on each side
of the packings which can be used either for ingress or egress according to which
way the engine is to revolve.
e, el, are ports which connect with the interior of the cylinder and extend one
fourth of the way round from the packings.
The large D valve N is so arranged as to cover the ports m', e', so as to make
them both exhaust ports at the same time, and while it is this position the other
end n covers the port e and makes it lie dormant.
Two ports P, P¹, extend through the valve N, which correspond with the
ports m, m', in the cylinder case; at present the port P is directly over the port m,
thereby allowing the steam to pass from the steam chest to the cylinder and the
port P is dormant.
For an ordinary engine where the steam is expanded from two to three volumes,
the valve N is the only one used, and it remains stationary while the. machine

page_text: is revolving in one direction, but must be moved so as to make the ports P, P¹,
correspond with the port m³ for reversing the engine.
When it is desired to expand the steam farther than it can be expanded in the
above manner, I use an additional valve h which is handled in the usual manner
by an eccentric.
For a reversible engine I use the ordinary link motion which I have represented
in my Drawing for the purpose of showing how it is applied, but on which I make
no claims..
Having now described and ascertained the nature of my said Invention, and in
what manner the same is or may be performed,
I claim as secured to me. by the hereinbefore in part recited Letters Patent,-
Firstly. In a rotary engine the slotted disk Chaving the spherical hub D in
which are the openings F and the elongated openings K, in combination with the
journals E, E, which form central bearings for the slotted diska
Secondly. In a rotary engine the slotted disk C having the spherical hub D
in which are the central openings F and the elongated openings K, in combination
with the journal blocks E and the set screws E¹..
Thirdly. In a rotary engine the sphere D with its conical openings P and
elongated slots or apertures K, having the equatorial ring C in which are the slots
for the pistons G, G, their shaft B, and the journal blocks or bearings E, E, in
combination together.
Fourthly. In a rotary engine the combination with the case or cylinder A of the
shaft B having the pistons rigidly secured thereto, the spherical hub or bearing D
with slotted equatorial ring or disk. C and the bearing blocks E, placed from
journals to the hub of the disk in position diagonal to the plan of rotation of the
pistons.
Fifthly. The combination with the case or cylinder A having double sets of
ingress and egress ports m, l, m³, l', separated by the packing L and valve
mechanism for controlling the said ports of the hollow spherical hub D, provided
with the slotted openings for the arms H, and carrying the slotted disk C, the
journal blocks E having a position in the case diagonally with respect to the
shaft B, and forming journals upon which the disk revolves to hold the disk in
a plane diagonal to the plane of the cylinder, and the shaft B with the pistons
secured to it having a position coincident with the axis of the cylinder.
In witness whereof, I, the said John Patten, have hereunto set my hand and
seal, this Second day of February, in the year of our Lord One thousand
eight hundred and eighty two.
JOHN PATTEN. (L.S.)