Improvements in Rotary Engines.
Year: 1888

page_text: Date of Application, 2nd July, 1888
Complete Specification Left, 2nd Apr., 1889-Accepted, 2nd July, 1889
PROVISIONAL SPECIFICATION.
Improvements in Rotary Engines.
A communication from JOHN HAMSON VENABLES, engineer, JOSEPH HUGHES,
engineer, and SAMUEL COXON, gentleman, all of the city of Toronto, in the
County of York, in the Province of Ontario, Canada.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. do hereby declare the nature of this invention to be as follows :-
The object of the invention is to design a reversible rotary engine in which the
steam may be cut off at any desired point of the revolution, and the expansive power
of the steam utilized; and it consists, essentially, first, of a steam engine cut-off
valve or valves connected to the steam port or ports leading to the rotary engine, the
said cut-off valve or valves being operated from the driving shaft of the engine;
secondly of two steam cylinders connected together and opening into each other, and
having steam and exhaust ports, a cam-shaped piston being carried within one
cylinder on a suitably journalled shaft, and a cam carried by a suitable spindle
journalled in the other cylinder, pressure being directed against the latter cam to
hold it against the surface of the revolving cam-shaped piston; thirdly, of a piston
fixed to a shaft and fitted against the inner circumference of a cylinder, a steam-
port entering said cylinder, and a cam carried on a spindle suitably journalled in a.
cylinder connected to and forming part of the other cylinder so that the inner
circumference of one cylinder intersects and extends into the circle of the inner
circumference of the other cylinder, the said cylinder being provided with an
exhaust port; fourthly of a cam-shaped piston carried on a shaft within a cylinder
against the inner surface of which it fits, said cylinder being provided with steam-
ports immediately opposite to each other, a two-winged cam fitting a cylinder
connected to and forming part of the other cylinder so that the circle of the
inner circumference of one cylinder intersects and extends into the circle of the
inner circumference of the other cylinder, said cam being carried on a spindle, and
said cylinder being provided with exhaust ports entering it immediately opposite to
each other, a curved bridge connecting together the two wings of the cam, and
fitting against a block, the whole being arranged in connection with steam pipes.
nated thin and day of July 1888
W. P. THOMPSON & BOULT,
A cente
COMPLETE SPECIFICATION.
Improvements in Rotary Engines.
A communication from JOHN HAMSON VENABLES, engineer, JOSEPH HUGHES,
engineer, and SAMUEL COXON, gentleman, all of the city of Toronto, in the
County of York, in the Province of Ontario, Canada.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. 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 :—
The object of the invention is to design a reversible rotary engine in which the
steam may be cut off at any desired point of the revolution and the expansive power
of the steam utilized; and it consists, essentially, of a steam-engine cut-off valve or
valves connected to the steam port or ports leading to the rotary engine, the said

page_text: cut-off valve or valves being operated from the driving shaft of the engine; the
whole constructed and oporating substantially as hereinaftor more particularly
explained.
Fig. 1 is a perspective outside view of the improved rotary engine.
Fig. 2 is a sectional side view showing the interior construction of the rotary-
engine cylinder.
For the purpose of illustrating this invention I have chosen an ordinary link-
motion valve-gear but it will of course be understood that any class of valve or valves
may be applied.
In the drawing A represents the main steam pipe leading from the boiler and
connecting with the valve-chest B. (is the steam port leading from the valve-
chiest B to one side of the cylinder D; and E is a similar steam-port lending from
the valve-chest B and entering the other side of the cylinder D immediately opposite
to the point where the port (enters.
Fis a link supported on the spindle of the valve and connected to the driving
shaft G by the rods H and eccentries as shown. Two eccentrics and two rods aro
shown although this engine will operate with one eccentric and one rod for the
reason which will be explained farther on.
Each of the steam ports C and E is provided with a cut-off valve operated by
the lovers J which levers are connected to the link F as indicated in figura 1.
It is of course not necessary to connect the levers which operate the cut-off valves
with the link as the link and the valves may each be operated by an independent
lever.
K is a cylinder connected to and forming part of the cylinder 1 so that the circle
of the inner circumference of one cylinder intersects and extends into the circle of
the inner circumference of the other cylinder; consequently the piston which follows
the inner circumference of one cylinder will extend into the other cylinder when
passing the space connecting the two cylinders.
I is a cam-shaped piston fixed to the driving shaft G and formed so that its greatest
diameter extends to and is fitted against the inner circumference of the cylinder D.
M is a two winged cam fixed to a spindle N suitably journalled in the cylinder K
and living fixed to its outer end a handle O. The outer circumference of this two-
winged cam M fits the inner circumference of the cylinder K and the two wings aro
connected together by a curved bridge P which fits against the block Qoxtending into
and forming part of the cylinder K.
Adjustable plates operated by springs or steam may be placed at the points of
contact between the piston L and the cylinder D and the two-winged cam M and its
cylinder K and between the bridge P and its block Q; but as there is no appreciable
friction at these points the wear will be very slight. Each end of the cylinders D
and K is closed by a cover R securely bolted to flanges formed on the said cylinders.
Adjustable plates operated by springs or steam are placed on the inner surface of
each cover to press against and form steam-tight joints with the piston L, cam M
and curved bridge P.
As adjustable packing of the description used is employed in other rotary engines
it is not necessary to illustrate its construction in this specification.
There are two exhaust ports S extending from the cylinder K opposite each other
as shown and each exhaust port S is provided with a cut-off valve operated by a
handle T.
Two steam pipes U extend into the cylinder K on either side of the block Q.
These steam pipes U are either provided with cut-off valves or are so connected to
the steam ports (and E that stoam will be only admitted through one of them at a
time.
Having described the general construction of this improved rotary engine, I shall
now explain briefly its oporation.
It will be noticed on reference to Figure 2 that the portion of the cam-shaped
pistou L which fits against the circumference of the cylinder D has just passed the

page_text: steam-port C. The valve in this steam port is assumed to be open and the exhaust-
port on the same side is closed while the steam port E is closed and the exhaust-
port on the same side open. The steam-pipe U on the right-hand side of Fig. 2 is
open and the steam pipe U on the opposite side of the block Q is closed. The
pressure of the steam admitted through the open steam-pipe U acting against the back
of the wing of the cam M which presses against the cami-shaped piston L holds the
said wing against the said piston with sufficient force to form a steam-tight joint
between the two and the steam admitted through the open steam port C forces the
cam-shaped piston L to travel in the direction indicated by arrow until it passes the
point where the circles of the cylinders D and K intersect each other when the steam
will escape through the open exhaust port S and the piston L must then continue
to travel by the force of its own momentum until it once more reaches the open
steam-port.
By adopting a cut-off valve operated by eccentrics as described, the steam may be
cut off from the open steam-port at any desired point, when of course the expansive
force of the steam will be utilised for propelling the revolving piston L.
In order to reverse the engine it is merely necessary to shift the link F, turn the
two-winged cam M so as to bring the opposite cam into contact with the piston L
close the ports which were previously open and open those which were previously
closed, when the piston L will be caused to immediately revolve in the opposite
direction.
As the steam ports C and E enter the cylinder K exactly opposite to each other
the relative position of the piston L to each steam-port will be the same consequently
a single eccentric will be sufficient to operate the valve to propel the piston in either
direction.
It will be understood that two cylinders may be coupled together and arranged so
that the piston of one will be taking steam during the period that the piston of the
other cylinder is passing over the dead centre.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondents I declare that what I claim is
-
1. A steam engine cut-off valve or valves connected to the steam port or ports
leading to the rotary engine the said cut-off valve or valves being operated from the
driving shaft of the engine the whole constructed and operating substantially as and
for the purpose specified.
2. Two steam cylinders connected together and opening into each other as described
and having steam and exhaust ports as specified in combination with a cam-shaped
piston carried within one cylinder on a suitably-journalled shaft and of a cam carried
by a suitable spindle journalled in the other cylinder pressure being directed against
the latter cam to hold it against the surface of the revolving cam-shaped piston
substantially as and for the purpose specified.
3. The piston L fixed to the shaft G and fitted against the inner circumference of
the cylinder Da steam port E entering the said cylinder in combination with a cam
carried on a spindle suitably journalled in the cylinder K and of an exhaust port S
in the said cylinder K substantially as and for the purpose specified.
4. A cam-shaped piston L carried on the shaft G within the cylinder D against
the inner surface of which it fits the steam ports E entering the cylinder D
immediately opposite to each other as shown in combination with the two winged
cam M fitting the cylinder K and carried on the spindle N the exhaust ports S
entering the cylinder K immediately opposite to each other the curved bridge P
connecting together the two wings of the cam M and fitting against the block Q
and the steam pipes U arranged substantially as and for the purpose specified.
Dated this 2nd day of April 1889.