An Improved Rotary Engine.
Year: 1891

page_text: Date of Application, 14th May, 1891
Complete Specification Left, 30th July, 1891-Accepted, 5th Sept., 1891
PROVISIONAL
SPECIFICATION.
An Improved Rotary Engine.
I, GEORGE GATTON MELIUISH HARDINGILAM, of 191, Fleet Street, in the
City of London, Civil Engineer and Patent Agent, do hereby declare the nature
of this invention (a communication to me from Alexander Cleland, M.A., of
159, Queen Street, Melbourne, in the Colony of Victoria, Presbyterian Minister,)
to be as follows:-
My invention has for its object the construction of a rotary engine for producing
motive power and capable of being propelled at high speed by steam, by com-
pressed air, by water under pressure, or, when slightly modified, by the explosive
force of gas, and which possesses increased simplicity and efficiency as compared
with other known engines of the same kind.
Intan engine constructed according to my invention, a cylindrical piston hollow
at each end works within an outer cast iron cylindrical case; the hollow spaces
being divided by a vertical perforated diaphragm. One end of the case is closed
by a brass disc having a hollow cylindrical shank projecting outwardly and forming
a bush for the shaft. The outer end of the shaft is provided with a driving rigger
or toothed gear: the inner end is connected to one arm of an U-shaped crank; the
other arm of the U-shaped crank. being furnished with a crank-pin which passes
through the centre of the vertical diaphragm. The throw of the crank may be
adjusted by forcing outwards, with the aid of a set-screw, a wedge which is fitted
between the arms of the crank, or by a set-screw passing through one arm of the
crank and bearing against the other arm. The throw of the crank is altered in
order to maintain contact between the exterior of the cylindrical piston and the
internal surface of the case. A male screw-thread cut on the end of the hollow
cylindrical shank engages with a female screw-thread cut in the interior of a
hollow boss on one of the cast iron cylinder-covers; the end of the shank being
hexagonal and projecting from the boss when the cylinder-cover is bolted to the
case. By these means, the brass disc can be adjusted in the case to take up wear
caused by the working of the piston, and to ensure the steam-tight fitting of the
said piston the wear circumferentially being compensated for by the adjustment of
the crank as previously explained. The vertical diaphragm has several perforations
sufficient to allow the free passage of steam from the inlet end of the case to the
other end, so that, within the piston, there may be no residual pressure. Attached
rigidly to the piston and extending across from end to end thereof, a radial blade or
abutment is placed; this blade being slightly longer than the stroke of the piston
and its end passing into a recess cut in the case. The lower part of the recess is
maile wider than the upper part to allow the blade to oscillate as it rises and falls
with the moving piston. The effect of placing the blade radially is to cause the
circumference of the piston to bear against the interior of the case throughout its
movement. An inlet pipe is fitted centrally to the cylinder-cover which is opposite
the brass disc to admit steam to the interior of the hollow piston. In the same
cylinder-cover, an arc-shaped groove, having a radius equal to that of the piston, is
cut for the admission of steam from the interior of the piston to the space behind
it. The main shaft of the engine has a collar turned upon it to work against the
brass disc. The steam pressing outwards makes the joints.steam tight. The. cut-
off is regulated by the length of the aforesaid arc. The end of the piston.com-
pletely closes the groove against the passage of steam before each movement of the
piston begins. The exhaust-port may be cut in the same cylinder-cover as, and
may form a prolongation of, the cut-off groove; the port going through the
cylinder-cover to the exhaust pipe. The exhaust may, however, be arranged in

page_text: any other suitable manner.
The exhaust port is entirely covered by the flat piston
rim at the end of the stroke, and begins to be freed by the said piston rim to open
the exhaust when the line of contact between the piston and the case has passed
the recess in which the radial blade works. By so delaying the exhaust, the steam
in the recess is saved from being exhausted. At the same time, the ends of the
arc-shaped cut-off groove are opened; one to the live steam in the interior of the
piston and the other to the cylinder behind the piston.
The internal mechanism is oiled by means of an oil-duct connected with an
ordinary oil-cup; the duct traversing the inlet pipe and projecting into the interior
of the piston. Oil may, when the piston is in its lowest position, be dropped from
the end of the duct into a cup fixed on the bearing for the crank pin in the vertical
diaphragm. The oiling of these parts may, however, be performed in any known
manner. The brass bearing of the shaft is oiled by admitting oil from an oil-cup,
through a vertical passage in the iron boss, to an annular oil-passage in the disc,
whence radial perforations lead to the shaft. To allow for the brass disc being
moved forward at intervals, the amular passage is made sufficiently wide.
Dated this 14th day of May 1891
COMPLETE SPECIFICATION.
An Improved Rotary Engine.
1, GEORGE GATTON MELIUISH HARDINGHAM, of 191, Fleet Street, in the
City of London, Civil Engineer and Patent Agent, do hereby declare the nature
of this invention (a communication to me from Alexander Cleland, M.A., of
159, Queen Street, Melbourne, in the Colony of Victoria, Presbyterian Minister,)
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention has for its object the construction of a rotary engine for producing
motive power and capable of being propelled at high speed by steam, by compressed
air, by water under pressure, or, when slightly modified, by the explosive force of
gas or vapour mixed with air, and which possesses increased simplicity and efficiency
as compared with other known engines of the same kind.
In the accompanying drawings,
Fig. 1 is a vertical section of my improved rotary engine taken on the line A B
in Fig. 2.
Fig. 2 is a transverse vertical section on the line C D in Fig. 1.
Fig. 3 is a horizontal section through the cylinder, showing the oblique recess
for the blade or abutment on the piston.
The
In an engine constructed according to this invention, a cylindrical piston b,
hollow at each end, works within an outer cast iron cylindrical case a; the hollow
spaces being divided by a vertical perforated diaphragm. One end of the case is
closed by a brass disc i having a hollow cylindrical shank projecting outwardly
and forming a bush for the shaft. p. The outer end of the shaft is provided with a
driving rigger or toothed gear: the inner end is connected to one arm of an
U-shaped crank; the other arm of the U-shaped crank being furnished with a
crank-pin h, which passes through the centre of the vertical diaphragm c.
throw of the crank n may be adjusted by forcing outwards, with the aid of a set-
screw a, a wedge w which is fitted between the arms of the crank n, or by a set-
screw passing through one arm of the crank and bearing against the other arm.
The throw of the crank is altered in order to maintain contact between the exterior
of the cylindrical piston and the internal surface of the case a. A male screw-
thread cut on the end of the hollow cylindrical shank engages with a female
screw-thread cut in the interior of a hollow boss a² on one of the cast iron cylinder-
covers; the end of the shank at o being hexagonal and projecting from the boss.
By these means, the brass disc i can be adjusted in the case to take up wear caused

page_text: by the working of the piston b, and to ensure the steam-tight fitting of the said
piston; the wear circumferentially being compensated for by the adjustment of the
crank as previously explained. The vertical diaphragm c has several perforations g
sufficient to allow the free passage of steam from the inlet end of the case to the
other end, so that, within the piston b, there may be no residual pressure. Attached
rigidly to the piston and extending across from end to end thereof, a radial blade d
or abutment is placed; this blade being slightly longer than the stroke of the
piston and its end passing into a recess e cut in the case. The lower part of the
recess is made wider than the upper part to allow the blade to oscillate as it rises
and falls with the moving piston b. The effect of placing the blade obliquely is to
cause the circumference of the piston to bear against the interior of the case
throughout its movement. An inlet pipe is fitted centrally to the cylinder-
cover to admit steam to the interior of the hollow piston b. In the same
cylinder-cover, an arc-shaped groove k, having a radius equal to that of the piston 1,
is cut for the admission of steam from the interior of the piston 6 to the space
behind it. The main shaft of the engine has a collar turned upon it to work
against the brass disc i. The steam pressing outwards makes the joints steam-
tight. The cut-off is regulated by the length of the aforesaid arc k. The end of
the piston completely closes the groove against the passage of steam before each
movement of the piston begins. The exhaust port may be cut in the same
cylinder-cover as, and may
form a prolongation of, the cut-off groovek; the port going
through the cylinder-cover to the exhaust pipe f¹. The exhaust may, however, be
arranged in any other suitable manner. The exhaust port is entirely covered by
the flat piston rim at the end of the stroke, and begins to be freed by the said piston
rim to open the exhaust when the line of contact between the piston and the
case a has passed the recess e in which the blade d works. By so delaying the
exhaust, the steam in the recess e is saved from being exhausted. At the same
time, the ends of the arc-shaped cut-off are opened; one to the live steam in the
interior of the piston and the other to the cylinder behind the piston.
The internal mechanism is oiled by means of an oil-duct t connected with an
ordinary oil-cupy the duct traversing the inlet pipes and projecting into the
interior of the piston b. Oil may, when the piston is in the lowest position, be
dropped from the end of the duct into a cup u fixed on the bearing for the crank-
pin h. The oiling of these parts may, however, be performed in any known
manner. The brass bearing of the shaft p is oiled by admitting oil from an oil-
cup, through a vertical passage in the iron boss, to an annular oil-passage in the
bearing, whence radial perforations lead to the shaft p. To allow for the brass disc
being moved forward at intervals, the annular passage is made sufficiently wide.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I claim :-
:-
1. In a rotary engine, the combination, with a cylinder provided with an inlet
passages and a suitable exhaust port, of a piston having chambers at its sides
separated by a central perforated diaphragm and provided with a single blade or
abutinent working in a recess in the case, and a crank and crank-pin for actuating
the main shaft, substantially as set forth.
2. In a rotary engine, the combination, with a U-shaped crank provided with a
wedge and screw, of a crank n and crank-pin h, whereby contact is maintained
between the exterior of the piston and the internal surface of the case a, substantially
as set forth.
3. In a rotary engine, a case or cylinder a provided with a cover a³ containing
an inlet passages, an exhaust passage f, an exhaust port f¹, and an arc-shaped
groovek, substantially as described.
4. In a rotary engine, the combination, with a cylinder-cover a³ having a narrow
arc-shaped steam-groove of the same radius as the piston, of a piston having a
flat rim which serves to cut off the steam, substantially as set forth.
5. In a rotary engine, the combination, with a piston having a flat rim and a

page_text: blade or abutment, of a cylinder-cover provided with a narrow arc-shaped groove k
on one side of the blade or abutment, and, on the other side thereof, with a,semi-
crescent-shaped groove or exhaust passage f, which is covered by the rim of the
piston at the end of each stroke, substantially as and-for the purpose-set forth.
6. In a rotary engine, the improved means for lubricating the chambered piston
and its crank-pin, substantially as herein described; the same consisting of the oil-
dict projecting axially from the cylinder-cover into the piston chamber, and an
oil-cup on the crank-pin-bearing located to receive oil from the oil-duct jaforesaid.
Datal this 50th day of July 1801
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.Ċ.