Improvements in Steam and other Fluid-pressure Engines.
Year: 1889

page_text: Date of Application, 9th May, 1889
Complete Specification Left, 8th Mar, 1890-Accepted, 12th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in Steam and other Fluid-pressure Engines.
I, SAMUEL ROBINSON of 35 Hugon Road, Fulham, in the County of Middlesex,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows
-1
This invention has reference to steam or other fluid pressure engines where more
than one cylinder is employed to constitute one engine. It applies to engines of the
high pressure compound type and to those of the low pressure triple expansive
type
In my engines the ordinary construction of coupled double acting steam engines is
departed from. High pressure and double acting engines as ordinarily constructed
are subjected to the resistance of the atmospheric pressure four times each revolution
and this requires the steam passages to be emptied and refilled with steam four times
in the revolution also; this steam cannot affect directly or indirectly the power of
the engine, although it has to pass through the engine; it is a waste of power,
approximately 5th the developed power of the engine. Further, the useful energy left
in the steam at the point of exhaustion is with most engines worth 3rds more than the
With
power attained by the present constructed double-acting high pressure engines.
iny invention, however, it becomes impossible for the resistance of the atmosphere to
affect the piston impelled by the initial pressure, either when the piston is in com-
munication with the boiler or after it is cut off by the valve, to complete the inner
or outer stroke by expansion. My invention also renders it unnecessary for the
steam passages conducting the initial steam to the piston, to be emptied at all when
the engine is in operation. As regards the useful energy left in the steam at the
point of exhaustion I will explain how and why my invention will lead to a con-
siderable economy in the useful steam that is discharged into the air and wasted or
otherwise conducted to an additional cylinder generally called the compound cylinder
and differing in capacity from the high pressure cylinder in the proportion generally
of about 4 to 1. This difference in the capacities of the cylinders is based on false
premises and is not consistent with the properties of steam, and it cannot materially
economize the steam discharged into the larger cylinder to do work a second time;
1st because the more the volume of steam is allowed to increase the weaker it
becomes; 2ndly because the compound piston and the high pressure pistons are in
communication causing action and reaction to exist, and as the high pressure is
unquestionably the foundation for the low pressure piston, the high pressure pistons
are retarded in proportion to the difference in the areas of the high and low pressure
pistons respectively; and 3rdly because the increased piston surface of the compound
piston entails an increase of resistance from the back pressure of the atmosphere and
absorbs a great portion of the power gained by the high pressure compound type of
engine. Probably better results are attamed by the low pressure triple expansive
type of engine, but an engine constructed according to my invention will give far
better results, and can be employed as a triple expansive condensing engine.
The principle upon which iny engine is constructed may be explained by the
following
-
With the ordinary high pressure double acting engine there are only four chambers
which receive the pressure from the boiler, and it is requisite that two of these should
be empty and exposed to the air while the steam on the opposite side is impelling the
piston. The ordinary compound engine has six chambers; one of these is exposed
to the atmosphere, three are in communication at the same time, and two are receiving
the live steam from the boiler, but the respective cylinders differ in their capacity.
If the cylinders were the same size, and the valves, the steam passages, and steain

page_text: connections were to remain as they are at present, there would be no advantage
derived by high pressure compound engines. My engine, on the contrary, is con-
structed with three cylinders of equal capacity, having six chambers. The valves,
steam passages, and connections are such that it is impossible for any pressure, no
matter how great, that may be admitted to three selected chambers to drive the engine,
and yet, if a fourth chamber is communicated with from the three chambers, the
piston in the fourth chamber will impel the engine with the maximum power of an
ordinary single acting engine with the resistance of the atmospheric pressure against
one piston only. There is thus an independent foundation for the steam to do its
work upon instead of the piston being retarded in its work from the live steam from
the boilers as is the case with the ordinary high and low pressure compound type of
engine. The stem should not be allowed to increase in volume more than can
possibly be avoided, as this is neither necessary nor beneficial, providing the initial
steam is working independently of the steam which has performed its work on the
inner or outer stroke, and is discharged into other chambers to do its work a second
time as it does in my engine. Now while in my engine the second steam, which 1
term the retained steam, is in communication with four chambers only, the fifth
chamber is open to the atmosphere; consequently the sixth chamber is empty; there-
fore the atmospheric pressure can affect neither the piston in the sixth chamber nor
the steam in the four chambers, it follows, therefore, that the live steam from the boiler
is impelling the piston in the sixth chamber unmolested by the atmospheric pressure
resistance. The second or retained steam is impelling the engine in unison with
the live steam from the boiler on an independent foundation at a constant force,
because the steam retuned will not fall materially in pressure during the stroke
The retained steam is in communication even in this instance on one side of the
piston that has the initial steam acting on it, but it is differently situated to what it
is in the compound engine, that is to say the cylinders I employ are, as I have already
stated, of the same capacity; the reaction that would occur with the ordinary com-
pound arrangement being counterbalanced My arrangement effects or causes an
equilibrium to take place and obviates the loss of power from the reaction inevitable
-with the ordinary compound engine. Engines constructed according to my invention
are very suitable for locomotive purposes. The saving in fuel effected will be very
large.
the
To further explain the operation of my engine I will call the three cylinders A,
B, and C for distinction. Assuming the engine to be working forward, the boiler
pressure in cylinder A will impel the piston therein on the outer stroke at the end of
the cylinder farthest from the crank shaft. On the return stroke the boiler pressure
will impel the piston in cylinder B also at the end farthest from the crank shaft. A
and B are the outside cylinders and they each receive the boiler pressure at one end
only and at the particular ends mentioned Cylinder C does not receive the boiler
pressure except on starting. The piston of cylinder C is impelled by the steam which
is discharged from cylinders A and B and conducted into the valve box of C in a
Similar way to that in which the boiler pressure enters the valve boxes of A and B.
The valve box of C is constantly filled with steam when the engine is in operation
owing to the manner in which the steam connections are arranged, that is to say,
ends of cylinders A and B nearest the crank shaft are permanently connected with
the valve box of C. Thus there is sufficient steam at the disposal of cylinder (
retained, to maintain a constant force throughout the stroke to and fro on the piston
of cylinder C. The valve that controls the said steam in the valve box of C is
similar to an ordinary slide valve, that is to say the valve admits the steam alternately
and will also exhaust at each end precisely as in an ordinary high pressure steam
engine. But with the valves of cylinders A and B it is not so; when the high
pressure steam has forced the piston of A half its stroke the valve cuts the steam off
from the boiler and allows the steam to expand to the end of the stroke, or as desired
in the ordinary manner, when it has completed the stroke, the steam passes over the
valve face and unites with the retained steam and is on both sides of the same piston
communicating with the permanent connection before mentioned with the valve box

page_text: of C and remains so during the return stroke. When on the return stroke cylinder B
receives the boiler pressure, the steam is controlled by the valve similar to the valve
of cylinder A; the only difference is that the boiler pressure is admitted in the
opposite direction and produces an equilibrium alternately and causes the steam to
commingle in the four chainbers also alternately. This as I have already pointed
out, constitutes an independent founuation for the steam to work upon after it has
performed the first stroke from the boiler pressure and first expansion Of course
the steam will increase in volume during the first stroke by expanding after it is cut
off from the boiler But when it is doing its work a second time in the fourth
chamber the steam in the four chambers will not materially change in bulk or pressure
during the one stroke. The entire volume of steam in the four chambers is not
discharged each stroke, but only one cylinder full of steam is, and only one cylinder
is filled each stroke. The steam passages are kept filled with steam by forming
an equilibrium; thus about 25th of the steam is saved and the steam is made to
do its work a second time without retarding the initial pressure. The power 13
more equally distributed on the crank shaft than in ordinary engines For stationary
purposes the pistons of cylinders A and B are attached to two separate crank pins
opposite each other, and the crank of cylinder (is set approximately at right angles
to the two last named cranks on the same shaft. The valve motion is reversible and
operated by the connecting rod by a pin passing through the straps of the rod,
which moves to and fro a sliding bai, passing through a box arranged on the axle
so as to oscillate the axle and give motion to the valve spindle
Dated this 11th day of February 1889
SAMUEL ROBINSON.
COMPLETE SPECIFICATION.
Improvements in Steam and other Fluid-pressure Engines.
I, SAMUEL ROBINSON of 35 Hugon Road, Fulham in the County of Middlesex
Mechanical Engineer, 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 .-
--
This invention has reference to steam or other fluid pressure engines where more
than one cylinder is employed to constitute one engine
In my engines the ordinary constinction of coupled double acting steam engines 1
departed from. High pressure and double acting engines as ordinatly constructed
are subjected to the resistance of the atmospheric pressure four times each revolution
ind this requires the steam passages to be emptied and refilled with steam four times
in the revolution; also this steam cannot affect directly or indirectly the power of the
engine, although it has to pass through the engine, it is a waste of power, approxi-
mately one-twentieth the developed power of the engine.
Further the useful energy
left in the steam at the point of exhaustion is with most engines worth two-third's
more than the power attained by the present constructed double acting high pressure
engines With my invention, however, it becomes impossible for the resistance of the
atmosphere to affect the piston impelled by the initial pressure, either when the
piston is in communication with the boiler or after it is cut off by the valve to
complete the inner or outer stroke by expansion
My invention also renders it unnecessary for the steam passages conducting the
initial steam to the piston to be emptied at all when the engine is in operation. As
regards the useful energy left in the steam at the point of exhaustion I will explain
how and why my invention will lead to a considerable economy in the useful steam
that is discharged into the air and wasted, or otherwise conducted to an additional
cylinder generally called the compound or low pressure cylinder and differing in
capacity from the high pressure cylinder in the proportion generally of about four to
This difference in the capacities of the cylinders is based on false premises and
is not consistent with the properties of steam, and it cannot materially economize the
steam discharged into the larger cylinder to do work a second time,-First, because
one

page_text: the more the volume of steam is allowed to increase the weaker it becomes, Secondly
because the compound or low pressure piston and the high pressure piston are in
communication causing action and reaction to exist, and as the high pressure is
unquestionably the foundation for the low pressure piston the high pressure pistons
are retarded in proportion to the difference in the areas of the high and low pressure
pistons respectively; and Thirdly, because the increased piston surface of the low
pressure piston entails an increase of resistance from the back pressure of the atmo-
sphere and absorbs a great portion of the power gained by the high pressure compound
type of engine. Probably better results are attained by the low pressure triple
expansive type of engine, but an engine constructed according to my invention will
give far better results.
The principle upon which my engine is constructed may be explained by the
following: With the ordinary high pressure double acting engine there are only four
chambers which receive the pressure from the boiler, and it is requisite that two of
these should be empty and exposed to the air while the steam on the opposite side is
impelling the piston. The ordinary compound engine has six chambers; one of these
is exposed to the atmosphere, three are in communication at the same time and two
are receiving the live steam from the boiler, but the respective cylinders differ in their
capacity. If the cylinders were the same size and the valves, the steam passages, and
steam connections, were to remain as they are at present, there would be no advantage
derived by high pressure compound engines My engine on the contrary is con-
structed with three cylinders of equal capacity, having six chambers. The valves
steam passages and connections are such that it is impossible for any pressure no
inatter how great that may be admitted to three selected chambers to drive the engine.
and yet if a fourth chamber is communicated with from the three chambers the piston
in the fourth chamber will impel the engine with the maximum power of an ordinary
single acting engine, with the resistance of the atmospheric pressure against one
piston only. There is thus an independent foundation for the steam to do its work
upon instead of the piston being retarded in its work from the live steam from the
boilers, as is the case with the ordinary high and low pressure compound type of
engine. The steam should not be allowed to increase in volume more than can
possibly be avoided as this is neither necessary nor beneficial, providing the initial
steam is working independently of the steam which has performed its work on the
inner or outer stroke and is discharged into other chambers to do its work a second
time as it does in my engine. Now while in my engine the second steam which I
term the retained steam is in communication with fou chambers only the fifth
chamber is open to the atmosphere, consequently the sixth chamber is empty, there-
fore the atmospheric pressure cannot affect the piston in the sixtli chamber; it follows
therefore that the live steam from the boiler admitted to the sixth chamber will impel
the piston in the sixth chamber unmolested by the atmospheric pressure resistance
The second or retained steam will impel the engine in unison with the live steam
from the boiler on an independent foundation at a constant force, because the steami
retained will not fall materially in pressure during the stroke The retained steam is
in communication even in this instance on one side of the piston that has the initial
steam acting on it, but it is differently situated to what it is in the compound engine,
that is to say the cylinders I employ are as I have already stated of the same capacity,
the reaction that would occur with the ordinary compound arrangement being
counterbalanced. My arrangement effects or causes an equilibrium to take place and
obviates the loss of power from the reaction inevitable with the ordinary compound
engine. Engines constructed according to my invention are very suitable for
locomotive purposes
The saving in fuel effected will be very large
To further explain the operation of my engine I will call the three cylinders A, B
and for distinction. Assuming the engine to be working forward the boiler
pressure in cylinder A will impel the piston therein on the outer stroke at the end of
the cylinder farthest from the crank shatt On the return stroke the boiler pressure
will impel the piston in cylinder B also at the end farthest from the crank shaft.
A and B are the outside cylinders and they each receive the boiler pressure at one end

page_text: only and at the particular end mentioned Cylinder C does not receive the boiler
pressure except on starting. The piston of cylinder C is impelled by the steam
which is discharged from the cylinders A and B and conducted into the valve
box. The ends of cylinders A and B nearest the crank shaft are permanently
connected. Thus there is sufficient steam at the disposal of cylinder C retained,
to maintain a constant force throughout the stroke to and fro on the piston of
cylinder C. The retained steam is admitted to the two ends of cylinder C
alternately, and it also exhausts at each end as in an ordinary high pressure steam
engine But with the cylinders A and B it is not so, when the high pressure
steam has forced the piston of A half its stroke the valve cuts the steam off from
the boiler and allows the steam to expand to the end of the stroke, or as desired
in the ordinary manner. When it has completed the stroke the steam passes
over the valve face and unites with the retained steam which is therefore now on
both sides of the same piston communicating with the permanent connection
before mentioned between A and B and remains so during the return stroke.
When on the return stroke cylinder B receives the boiler pressure the steam is
Similarly controlled by the valve; the only difference is that the boiler pressure
is admitted in the opposite direction; an equilibrium is produced alternately and the
steam is caused to commungle in the four chambers also alternately.
This as I have already pointed out constitutes an independent foundation for
the steam to work upon after it has performed the first stroke from the boiler
pressure and first expansion.
Of course the steam will increase in volume during the first stroke by expanding
after it is cut off from the boiler But when it is doing its work a second time
in the fourth chamber the steam in the four chambers will not materially change
in bulk or in pressure during the one stroke. The entire volume of steam in the
four chambers is not discharged each stroke but only one cylinder full of steam
12. and only one cylinder is filled each stroke The steam passages are kept filled w th
steam by forming an equilibrium; thus about one-twentieth of the steam is saved
and the steam is made to do its work a second time without retarding the initial
pressure. The power is more equally distributed on the crank shaft than in
ordinary engines. For stationary purposes the pistons of cylinders A and B are
worked from two separate crank pins opposite each other and the crank of
cylinder C is set approximately at right angles to the two last named cranks on
the same shaft.
The annexed drawings represent an engine constructed according to my invention.
Figure 1 is a plan, Figure 2 an elevation as seen from the end where the cranks are
situated. Figure 3 is a transverse section partly on the line a-a, partly on the
line and partly on the line c-c of Figure 1 Figure 4 is a longitudinal section
on the line 1-1 of Figure 1. Figure 5 is a plan view of the valve seat showing the
ports and the passages communicating therewith Figures 6, 7, 8 and 9 are sections
respectively through the lines 2-2, 3-3, 4-4, and 5-5 of Figure 5
A, B and C are respectively the three cylinders all of the same capacity and
herein before referred to by those distinguishing letters D is the crank shaft, E, F
and G are the cranks for working the pistons of A, B and C respectively. The
cranks and F that work the pistons of A and B are opposite each other and the
crank G that works the piston of C is set at right angles to the cranks E and F.
H is the valve for controlling the supply of live steam to the cylinders A and B
alternately, for controlling the passage of what I have hereinbefore termed the
retained steam from the cylinders A and B to the two ends of cylinder Calternately
and for controlling the exhaust from the two ends of cylinder Calternately. The
valve rod I is operated by ordinary link motion or otherwise All the ports under the
control of the valve aro formed in one seat It is obvious, however, that instead of
the one valve H as shown and a single seat in wluch all the requisite ports are formed
there may be several valves, say for example one to each cylinder, ai ranged to open
and close the requisite communications at the proper times as will be well understood.
The outside cylinders A and B receive the boiler steam alternately at the end furthest

page_text: from the crank shaft and at that end only, and their respective pistons are alternately
impelled by this boiler steam. The cylinder receives the retained steam from th
cylinders A and B at its two ends alternately and its piston is impelled by this retained
steam in the two directions alternately while the cylinder exhausts alternately at its
two ends Only one volume of steam is admitted to the engine at each stroke, that is
to say into A or B as the case may be, and only one volume is discharged, that is to
say from the one end or the other of cylinder C. The ends of the cylinders A and B
which are nearest the crank shaft are always in communication with each other by the
passage J and these ends are alternately in communication at one time with the other
end of cylinder A and with the one end of cylinder (when the piston of B is being
inipelled by the live steam and at another time with the other end of evlinder B and
with the other end of cylinder C when the piston of A is being impelled by the live
steam. Consequently of the six chambers in the three cylinders there are always
four chambers which are in communication with each other and full of retained steam,
while the fifth chamber is exhausting and the sixth chamber is receiving live steam
from the boiler. As the combined capacity of the four communicating chambers and
their connecting passages does not appreciably vary during the stroke, the retained
steam has an independent foundation to work upon, and it impels the piston. of
cylinder C without appreciably expanding. There is in my engine only one expansion
of steam at each stroke, viz.,-in the chamber of cylinder A or B (as the case may be)
into which the live steam is admitted, the admission being cut off at any desired part
of the stroke
There are five ports K, L, M, N, and O in the seat of the valve H. The valve has
a bridge with three passages P, Q, R in it; the passage P adnuts live steam from
the boiler; the passage transfers the retained steam fiom cylinder A to cylinder B
and uce ver a alternately and also communicates with the permanent passage J
between A and B, and the passage R communicates between the two ends of
cylinder C and the exhaust port In the position of the valve shown in Figure 4 the
end of the cylinder C further from the crank shaft is exhausting through port K,
passage R and port 0; the port L is allowing the retained steam from cylinder B
at the end further from the crank shaft to pass through the passage and port N to
the end of cylinder C nearest to the crank shaft and also through the passage to the
permanent passage J. Lave steam from the boiler is entering by the passage P
and port M into cylinder A at the end furthest from the boiler so as to impel the
piston of A. The crank E of cylinder A is falling below the crank shaft so that this
Crank is pushed while the crank G of cylinder C is being pulled, the two working in
unison On the next or return troke the cylinder B receives the live steam at the
end furthest from the crank shaft, the port L being now in communication with the
passage P while port M receives the retained steam from A and transmits it through
the passage to cylinder C at the end furthest from the crank shaft; the opposite
end of C now exhausts through the ports N and O.
In order to start the engine a starting valve S is opened which allows the full
pressure fluid to enter and fill all the six chambers; the exhaust at the one or the
other end of cylinder C is then opened and the engine will at once start
1 do not limit myself to the employment in my engine of three cylinders and
pistons as it is obvious that more can be employed. Although I have described the
engine as being actuated by steam it can be actuated by other fluid pressure such for
example as compressed air, and although I have stated that the fluid is admitted to
the cylinders A and B at the end furthest from the crank shaft it is obvious that
the engine may be arranged for the fluid to enter these cylinders at the other end
instead.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
:―
1. In a fluid pressure engine, three cylinders of equal capacity to two of which,
whose pistons drive annosita oranla the initial or full proceure And 18 admitted

page_text: alternately and always at the same end, the ends of the three cylinders being so
connected under the control of a valve or valves that there are always four
communicating cylinder chambers full of the fluid hereinbefore termed the retained
fluid, which has already exerted its initial pressure, this fluid being in contact on the
one hand with the piston which for the time being is being impelled by the initial
fluid and on the other hand with the piston of the third cylinder which drives a crank
approximately at right angles to the other cranks, whereby the retained fluid having
what I have called an independent foundation to act upon impels the piston of the
third cylinder without increasing in volume while there is no back pressure or reaction
against the piston on which the initial fluid acts, substantially as set forth.
2 In a Anid pressure engine, three cylinders of equal capacity to two of which,
whose pistons drive opposite cranks, the initial or full pressure fluid is admitted
alternately and always at the samo end, the other ends of these two cylinders being in
permanent cominunication with each other, each of these other ends alternately being
put in communication with the opposite end of its own cylinder, and each of them
alternately being also put into communication with the respective ends of the third
cylinder which never receives the full pressure fluid, and whose piston drives a crank
approxunately at night angles to the other cranks, and the ends of the third cylinder
being alternately put into communication with the exhaust, whereby when the initial
fluid is acting upon its piston there are four cylinder chambers in communication
with each other and full of the fluid herein before termed the retained fluid, which has
already exerted its initial pressure and which fluid without increasing in volume
impels the piston of the third cylinder, substantially as set forth.
3. Constructing fluid pressure engines substantially as hereinbefore described and
represented in the accompanying drawings
Doted the 6th day of Maurh 1000
SAMUEL ROBINSON.