Year: 1887

page_text: Date of Application, 3rd June, 1887
Complete Left, 2nd Mar., 1888
Complete Accepted, 27th Apr., 1888
I, GEORGE ALFRED DE PENNING of 13 European Asylum Lane, Calcutta in the
Empire of India, do hereby declare the nature of this invention to be as follows:-
To appreciate the value and advantages of a good rotary steam engine having the
above qualifications we must first clearly show the inability of cylinder steam engines
to attain the desired requirements of great power and speed combined.
The cylinder engines now constructed, although they are excellent and beautiful.
works of mechanism, so much so that they may be said to be perfect in their way, are
yet quito unsuited to the purposes of locomotion and marine propulsion from having
insufficient power combined with want of speed, arising from inherent defects
inseparable from their very form and construction.
The defects and disadvantages clearly are:-
1. The indirect application of power, for the piston works the axle or shaft by the
intervention of a crank.
33
2. Loss of power in working the crank from the restraint of the slides, this
necessarily absorbs part of the generated force.
3. Loss from bad leverage, for the piston works from the centre or pivot against
the arm or lever of the crank, particularly when the crank is at right angles to the
piston rod, or at the best of its stroke; this loss of power is further increased in the
actual work, since the driving wheel or screw propeller has generally more than three
times the leverage or radius of the crank.
4. The existence of the dead points prevents all possibility of cylinder engines ever
attaining very great speed as to give a very rapid rate of motion to the shaft, for a
loss of time must necessarily occur from every stoppage of the piston to reverse its
stroke. Even in compound engines, where the movement is carried on by the second
cylinder, the stoppage of each piston undoubtedly occurs, and although this is
apparently compensated as to be rendered imperceptible from the movement being
regular; yet these momentary stoppages (which are distinctly heard and felt as
beats) must indisputably occur and detract from the possibility of great speed or very
rapid motion.
5. The piston of each cylinder of compound engines though completing a full

page_text: revolution of the crank does, in fact, but half the effective work, for at the dead points
and for an eighth of the circle of revolution on each side, the power of the piston is
barely effective for any force or work. It is only when the crank is at right angles
with the piston, and to an eighth on each side thereof, that it does its best, but against
great leverage, so that the actual power of a compound engine of two cylinders, is, as
if it were worked by only one cylinder acting fully all round the crank."
6. High and low pressure steam engines of even triple or three cylinders (which
are considered the best,) have the disadvantage or loss from the reaction of steam in
the first and second cylinders. In fact to gain some power or advantage over the
reaction it is found absolutely necessary to use very high pressure stea:n.
These inherent defects of cylinder steam engines decidedly result in a large
expenditure or waste of steam, which we find increases where a combination of force
with great speed is required as in the case of our fast or best steam vessels, where the
large or extravagant consumption of fuel is quite out of proportion to the small
advantage of speed gained.
These evident and series defects of cylinder steam engines being inherent or
inseparable from their very form or construction naturally tend to make us desire and
seek for some improved form wherein these defects may be avoided; in fact we sec
the necessity of a good rotary steam engine wherein the difficulties hitherto presented
or met with, have been overcome or remedied.
Fig. 1 of the drawings attached reprosents the interior of the improved rotary steam
engine with the covering plate unscrewed and removed, M, N, O, may be called the
cylinder thereof; it is cast in three pieces, and joined at X, Y, Z, the top or apex of
cupolas or semi cylindrical attachments or parts of the larger cylinder. The
parts M, N, O, of the cylinder are first well fitted together and then turned true to its
centre S, while the cupolas are also turned true to their respective centres U, V, W,
their junctions are then rounded off; the cylinder being securely fastened to the sole
plate.
Within the cylinder is a cast iron drum D, R, turned on its exterior surface true to
its centre S; this drum revolves or rotates fastened to the shaft S, being carried
round by the pistons or standards P, and Q, working within the annular space between
the drum and the cylinder.
The pistons may be cast with the drum or made separately of wrought iron and
firmly affixed thereto. The pistons should revolvo freely within the cylinder, and so
may be made an or of an inch less or shorter so as not to touch the cylinder; this
would prevent all accidents from jars and shocks.
On both sides of the pistons a plate of steel is attached at foot by bolts or rivets so
as not to be in the way. These steel plates stand forward a little from the pistons and
are bent or curved at the top as represented; these steel plates nearly touch the
cylinder, the one on the steam side when acted upon by its force in bending toward
the piston fills up the space between the piston and cylinder while the curved or bent
tops by expanding from the force of the steam, act as metallic packing and so perfectly
close up all possible escape of the steam past the piston, and thus makes it steam tight,
acting in fact in the same manner as the leather collars of hydraulic rams.
size or thickness, these steel plate should be proportionate to the force of the steam
used.
In
Within each of the three cupolas, three arms or abutments revolve with their
axles U, V, W. These abutments when fixed in position as those of V, and W, take
the place of the ends of a cylinder for steam to act or abut upon while it works the
piston, the steam abutting on the arms H and G, while it acts on the piston Q. These
arms are made similar to the pistons and furnished with steel plates on both sides,
The arm C, is shown loosened and moving out of its position to allow of the piston P
to pass, while A would come into position and be there fixed by a strong spring catch.
SV to S V are the steam and exhaust ports; these may have slide valves worked
over them, either to admit steam, or to open a communication with the vacuum box
and condenser, or to cut off the connection with both, to retain the steam in the
blocked compartment between V and U to work the second engine expansivoly.

page_text: Fig. 2 of the drawings represents a side view of a fourth part of the engine over
the shaft S. S. the cylinder being supposed to be removed, showing only the bolt holes
of the opposite part of the cupola of the cylinder at the top X. P represents the
piston and A the arm above (the other arms not being shown) T, and T, the side plates
fixed to and revolving with the drun, and G, and G, the outer covering case attached
or bolted to the cylinder.
The steam from the boiler is caused first to enter a steam box, and is thence supplied
to the engine at SV, being cut off by the revolving plate within the box when
required as shown by the slit a in Fig. 3, from its having past the port or steam
pipe E, and the steam is supplied again by the slit b, at the pipe s¹ as the piston in
Fig. 1 passes the arms A and C, other slits in the same plate supply the other steam
pipes to when necessary as the piston or pistons go round; the length of the slit
regulating the quantity of the steam supplied. The box is fixed, while the plate
revolves with the shaft, so that the supply of steam may be accurately regulated
thereby, or we may say with mathematical precision.
A vacuum box attached thereto, and connected with the condenser, acts in the same
way to draw off or exhaust the steam from the back or opposite side of the piston.
Over the steam and vacuum boxes ordinary slide valves are placed; these may be
moved by a lever or a screw, and on changing position would at once reverse the
engines, as the steam weld at once go to the back of the piston, while the vacuum
would act in front or on the opposite side of the piston. Where the steam and
vacuum boxes are used, the s valves on the cylinder may be dispensed with.
On piston P passing the arms A, C the high pressure steam in the annular com-
partment between the arms V and U could be utilised to work a second Engine or its
piston P P within the case G G and G G the double letters indicating the second
Engine. The steam first enters into a second box between the two engines, and then
passes into the second engine, while the high pressure steam left in the next compart-
ment of the first engine would in turn be utilised. In the same manner a third
engine (not represented) may be worked with the steam left in and from the locked
compartment of the second engine. And where low pressure steam is used, the third
engine may be worked by atmospheric pressure.
C, C, Fig. 2, is a revolving shaft passing through the centres of the upper cupola
whereon the arms are fixed, a plate R B fixed thereto carries three strong spring slide
bolts each of which in turn fixes each of the abutment arms of the cupola to the fixed
frame of the engine at W. (not shown). These arms are in turn released by a second
revolving plate W. B. carrying an inclined surface to raise the bolt and then causes
the next arm to be turned round by friction, and then to be fastened in its turn.
Steam may be let in between the covering plate and the drum, piston and abutment
arms to keep the engine hot so as to prevent condensation.
The drawings shew the principle of the engine as well as the method or means of
working the same. In constructing or making it however, the proportions may bo
altered or varied if necessary and the parts may also be modified or added to
without departing from the principle or the manner of using or working the
same.
The advantages of this rotary engine are clear
1st. Direct action in turning the axle or shaft, without the intervention of a
crank.
2nd. The great gain of leverage, the force of steam being applied at the full distance
of the piston from the centre, pivot or shaft.
3rd. No reaction from steam when passing from the first to the second and from
the second to the third cylinder.
4th. Perfect and immediate reversing power without possibility of harm to the
engine, as it acts equally as well either way.
5th. Equal great power, as each piston does equal full work all round the cylinder
or shaft, there being no dead points.
6th. Little friction, as the rounded steel plate packing must necessarily work very
smooth. The wear would be small and equal, and so in no way deteriorate the engine.

page_text: 7th. The advantage of the cylinder being cast in three pieces, the chances of
breakage and from all possible shrinking defects is thereby greatly lessened, besides a
very large size and powerful engine may thus easily and certainly be made or
obtained and this has been a great difficulty with cylinder engines.
8th. Great speed or rate of motion, as the movement is continuous and in one
direction round the shaft. In fact with these rotary steam engines we may reasonably
expect a gain of over four fold velocity greater than the maximum speed acquired by
the best constructed cylinder engines, and this with equal power or exerting force;
so that by applying these rotary steam engines to the new form of vessels herewith
referred to, we will certainly gain the therein mentioned rate of speed.
Dated this 3rd day of June 1887.
ABEL & IMRAY,
Agents for the Applicant.

page_text: I, GEORGE ALFRED DE PENNING of 13 European Asylum Lane, Calcutta in the
Empire of India 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 :-
To appreciate the value and advantages of a good rotary steam engine we must
first clearly show the inability of cylinder steam engines to attain the desired require-
ments of great power and speed combined.
The cylinder engines now constructed although they are excellent and beautiful
works of mechanism, so much so that they may be said to be perfect in their way,
are yet quite unsuited to the purposes of locomotion and marine propulsion from having
insufficient power combined with want of speed, arising from inherent defects
inseparable from their very form and construction.
The defects and disadvantages clearly are:
1. The indirect application of power, for the piston works the axle or shaft by the
intervention of a crank.
2. Loss of power in working the crank from the restraint of the slides, this
necessarily absorbs part of the generated force.
3. Loss from bad leverage, for the piston works from the centre or pivot against the
arm or lover of the crank, particularly when the crank is at right angles to the piston
rod or at the best of its stroke; this loss of power is further increased in the actual
work since the driving wheel or scrow propeller has generally more than three times
the leverage or radius of the crank.
4. The existence of the dead points prevents all possibility of cylinder engines ever
attaining a very great speed so as to give a very rapid rate of motion to the shaft,
for a loss of time must necessarily occur from every stoppage of the piston to reverse
its stroke. Even in compound engines, where the movement is carried on by the
second cylinder, the stoppage of each piston undoubtedly occurs and although this is
apparently compensated as to be rendered imperceptible from the movement being
regular; yet these momentary stoppages (which are distinctly heard and felt as
beats) must indisputably occur and detract from the possibility of great speed or very.
rapid motion.
The piston of each cylinder of compound engines though completing a full revolu-
tion of the crank does in fact, but half the effective work, for at the dead points and
for an eighth of the circle of revolution on each side the power of the piston is barely
effective for any force or work. It is only when the crank is at right angles with the
piston, and to an eighth on each side thereof, that it does its best but against great
leverage, so that the actual power of a compound engine of two cylinders, is, as if it
were worked by only one cylinder acting fully all round the crank.

page_text: 6. High and low pressure steam engines of even triple or three cylinders (which
are considered the best) have the disadvantage or loss from the reaction of steam in
the first and second cylinders. In fact to gain some power or advantage over the
reaction it is found absolutely necessary to use very high pressure steam.
These inherent defects of cylinder steam engines decidedly result in a large expendi-.
ture or waste of steam, which we find increases where a combination of force with
great speed is required as in the case of our fast or best steam vessels, where the large
or extravagant consumption of fuel is quite out of proportion to the small advantage
of speed gained.
These evident and serious defects of cylinder steam engines being inherent or
inseparable from their very form or construction naturally tend to make us desire
and seek for some improved form wherein these defects may be avoided; in fact we
see the necessity of a good rotary steam engine wherein the difficulties hitherto
presented or met with, have been overcome or remedied.
Referring to the drawings accompanying my Provisional Specification Fig. 1
represents the interior of the improved rotary steam engine with the covering plate
unscrewed and removed, M, N, O may be called the cylinder thereof; it is cast in
three pieces, and joined at X, Y, Z, the top or apex of cupolas or semi-cylindrical
attachments or parts of the larger cylinder. The parts M, N, O, of the cylinder aro
first well fitted together and then turned true to its centre S, while the cupolas_are
also turned true to their respective centres U, V, W, their junctions are then
rounded off; the cylinder being securely fastened to the sole plate.
Within the cylinder is a cast iron drum D R, turned on its exterior surface true to
its centro S; this drum revolves or rotates fastened to the shaft S, being carried
round by the pistons or standards P and Q, working within the annular space between
the drum and the cylinder.
The pistons may be cast with the drum or made separately of wrought iron and
firmly affixed thereto. The pistons should revolve freely within the cylinder, and so
may be made an or of an inch less or shorter so as not to touch the cylinder; this
would prevent all accidents from jars and shocks.
On both sides of the pistons a plate of steel is attached at foot by bolts or rivets so
as not to be in the way. These steel plates stand forward a little from the pistons and
are bent or curved at the top as represented, these steel plates nearly touch the
cylinder, the one on the steam side when acted upon by its force in bending toward
the piston fills up the space between the piston and cylinder while the curved or bent
tops by expanding from the force of the steam; act as metallic packing and so
perfectly close up all possible escape of the steam past the piston and thus makes it steam
tight, acting in fact in the same manner as the leather collars of hydraulic rams.
In size or thickness, these steel plates should be proportionate to the force of the
steam used.
Within each of the three cupolas three arms or abutments revolve with their
axles U, V, W. These abutments when fixed in position as those of V and W take
the place of the ends of a cylinder for steam to act or abut upon while it works the
piston, the steam abutting on the arms H and G, while it acts on the piston Q. These
arms are made similar to the pistons and furnished with steel plates on both sides.
The arm C, is shown loosened and moving out of its position to allow the piston P to
pass, while A would como into position and be there fixed by a strong spring catch.
SV to S V are the steam and exhaust ports, these may have slide valves worked
over them; either to admit steam, or to open a communication with the vacuum box
and condenser, or to cut off the connection with both, to retain the steam in the
blocked compartment between V and U to work the second engine expansively.
Fig. 2 of the drawings represents a sido view of a fourth part of the engine over
the shaft S S, the cylinder being supposed to be removed shewing only the bolt holes
of the opposite part of the cupola of the cylinder at the top X. P represents tho
piston and A the arm above (the other arms not being shewn), T and T the side plates
fixed to and revolving. with the drum, and G and G¹, the outer covering case
attached or bolted to the cylinder.

page_text: The steam from the boiler is caused first to enter a steam box Z and is thenco
supplied to the engine at SV (see Fig. 1), being cut off by the slit a in the revolving
plate within the box Z having passed over the ports of the steam pipe as shewn
in Fig. 3 which is a view from inside the box Z. The steam is then supplied by the
slit 6 to ports and pipe E.
As the piston in Fig. 1 passes the arms A and C, other slits in the same plate
supply the other steam pipes to s when necessary as the piston or pistons go round;
the length of the slit regulating the quantity of the steam supplied. The box Z is fixed,
while the plate Y revolves with the shaft, so that the supply of steam may be accurately
regulated thereby, or we may say with mathematical precision.
A vacuum box attached thereto, and connected with the condenser, acts in the same
way to draw off or exhaust the steam from the back or opposite side of the piston.
Over the steam and vacuum boxes ordinary slide valves are placed; these may be
moved by a lever or a screw, and on changing position would at once reverse the
engine, as the steam would at once go to the back of the piston, while the vacuum
would act in front or on the opposite side of the piston.
Where the steam and vacuum boxes are used, the side valves on the cylinder may
be dispensed with.
On piston P passing the arms A, C the high pressure steam in the annular com-
partment between the centres V and U could be utilised to work a second engine or
its piston P P within the case G'G' and G G¹ the double letters indicating the
second engine. The steam first enters into a second box between the two engines,
and then passes into the second engine, while the high pressure steam loft in the next
compartment of the first engine would in turn be utilised.
In the same manner a third engine (not represented) may be worked with the
steam left in and from the locked compartiment of the second engine. And where low
pressure steam is used, the third engine may be worked by atmospheric pressure.
C, C, Fig. 2, is a revolving shaft passing through the centres of the upper cupola
whereon the arms are fixed, a plate RB fixed thereto carries three strong spring slide
bolts each of which in turn fixes each of the abutment arms of the cupola to the fixed
frame of the engine at W. (not shewn). These arms are in turn released by a second
revolving plate W B carrying an inclined surface to raise the bolt and then causes
the next arm to be turned round by friction, and then to be fastened in its turn.
Steam may be let in between the covering plate and the drum, piston, and abutment
arms to keep the engine hot, so as to prevent condensation.
The drawings shew the principle of the engine as well as the method or means of
working the same. In constructing or making it however, the proportions may be
altered or varied if necessary and the parts may also be modified or added to without
departing from the principle or the manner of using or working the same.
The advantages of this rotary engine are clear :-
1st. Direct action in turning the axle or shaft, without the intervention of a crank.
2nd. The great gain of leverage, the force of steam being applied at the full distance
of the piston from the centre pivot or shaft.
3rd. No reaction from steam when passing from the first to the second and from
the second to the third cylinder.
4th. Perfect and immediate reversing power without possibility of harm to the
engine, as it acts equally as well either way.
5th. Equal great power, as each piston does equal full work all round the cylinder
or shaft, there being no dead points.
6th. Little friction, as the rounded steel plate packing must necessarily work very
smooth. The wear would be small and equal, and so in no way deteriorate the
engine.
7th. The advantage of the cylinder being cast in three pieces, the chances of
breakage and from all possible shrinking defects is thereby greatly lessened, besides a
very large size and powerful engine may thus easily and certainly be made or
obtained and this has been a great difficulty with cylinder engines.

page_text: 8th. Great speed or rate of motion, as the movement is continuous and in one
direction round the shaft. In fact with these rotary steam engines we may reasonably
expect a gain of over four fold velocity greater than the maximum speed acquired by
the best constructed cylinder engines, and this with equal power or exerting force;
so that by applying these rotary steam engines to the new form of vessels herewith
referred to, we will certainly gain the therein mentioned rate of speed.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The construction of rotary steam engine herein described and illustrated by the
drawings.
1 1000
ABEL & IMRAY,
Agents for the Applicant.