Improvements in Steam Engines.
Year: 1889

page_text: Late of Application, 9th Oct., 1889-Accepted, 9th Nov., 1889
COMPLETE SPECIFICATION.
Improvements in Steam Engines.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., the General
Patent Office, No. 4, South Street, Finsbury, in the county of London, Patent
Agents, do hereby declare the nature of this invention (a communication from
abroad by Baron (. Adolphe de Landsée, of 6, Boulevard de Strasbourg, Paris, in
the republic of France, Civil Engineer,) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
This invention consists in an engine having two cylinders of equal diameter, coupled
at a right angle and arranged in such a manner as to allow of both working at high
pressure or one only at high pressure and the other at low pressure by receiving or
admitting the exhaust steam from the first cylinder similarly to the action in the
small and large cylinders of a compound engine.
The advantage of this system is considerable as it increases the power of the engine
to an extent hitherto unknown and, consequently, allows of considerably varying the
work produced, whilst realising an economy when working with the minimum of
power by the utilization of the expansion at the maximum. Economical working
exists also in ordinary compound engines but the engine is limited to it and, besides
the construction being costly and difficult of application for the purposes of conversion,
there exists the inconvenience that at the moment when great power is required the
engine cannot exceed the maximum resulting from the more powerful introduction,
that is to say, the ordinary compound engine works regularly and uniformly but it is
absolutely incompatible with the requirements with very variable service, such for
example, as that of locomotives, for which, on the contrary, this arrangement gives
superior results.
I have already stated that the two cylinders of this improved engine are of equal
diameter and they are so made by reason of the fact that the expansive force of the
steam issuing from the cylinder at high pressure forces before it the piston of the
cylinder at low pressure, which, being of the same diameter, can thus transform
the maximum of its expansive force into work without losing the major part of it, as
is the case in the compound engine, properly so called, in which the large and small
cylinders are usually in the proportion of 1 to 4 as regards diameter and consequently
of 1 to 4 in capacity.
The transfer of a volume into one about four times larger deprives, without advan-
tage, the steam of its principal agent.
The compression of the steam by its passage from one cylinder into the other (these
cylinders being of equal diameter according to this invention) does not prejudice the
economical working properly so called nor the expansion of the steam in the cylinder
it low pressure.
The axiom that water becomes converted into steam in vacuum, and
again changes to water under the effect of the decrease of the vacuum without 10-
ucing any external work fully applies and with reason to this new kind of engine
because the steam coming from the boiler brings along a certain quantity of war r,
notable condensation having taken place during its admission into the cylinder.
The expansion consequently gives place to vapourization so that during tlie com
pression the greater part of the steam is subjected to the above mentioned law and
returns to the condition of water without producing negative work during its passage
from one cylinder into the other except, be it understood, in cases where in conse- :
quence of the presence of two small ports or orifices a contraction would perceptibly
influence the above described results.
Supposing an admission of 50 per cent. the expansion of steam which is produced
luring the economical or compound working in the cylinder at low pressure is only

page_text: 35 per cent. and is effected under such favourable conditions that the compression of
about which takes place at this moment in the cylinder of high pressure is as
will be hereafter described, of too small importance to be taken into consideration. In
fact the piston of this cylinder being at this moment at one of the dead points its
crank will have to describe an angle equal to that corresponding to 35 per cent. of the
expansion of the cylinder at low pressure but, in consequence of the influence of the
obliquity of the motor-connecting-rod, the distance really traversed can only be esti-
mated at about 7 per cent. The piston of the high pressure cylinder having before it
at the moment of its departure from the dead point a volume of a cylinder of
100 per cent. plus the volume of steam from the pipe forming the communication
between the two cylinders which would be similar, that is to say, 100 per cent. There
is thus a total volume of 200 per cent. which, during the expansion, undergoes a
diminution of 7 per cent. which gives rises to a compression of 200 or about 30
which is an amount too insignificant to be prejudicial to this expansion.
In the accompanying drawing,
Figure 1 is a longitudinal section of a steam engine constructed according to this
.invention, the section being taken on the line 1, 2 figure 2.
Figure 2 is a plan of the engine with one of the cylinders in section.
Figure 3 is a partial plan taken through the axis of the steam chest.
Similar letters in all the figures indicate similar parts.
A is a right-hand cylinder of a steam engine provided at its two ends with dis-
charge valves, not shown in the drawing, and opening at the register pressure of the
boiler.
A is the left-hand cylinder of the engine of the same dimensions as the right-hand
cylinder. B is the steam chest for distributing the steam coming from the boiler.
b, 61, 62, 63 are the inlet ports and C is the regulating valve, c is a bronze slide valve
working in the chest B, d is the rod of the slide valve c. E' is the inlet pipe of the
steam coming from the boiler. e is the discharge pipe for the steam from the
cylinder A. e is the discharge for the steam from the cylinder A'. f is the steam
inlet pipe of the cylinder A and f¹ is the steam inlet pipe of the cylinder A'. F FI
is a pipe for discharging the steam into the atmosphere or into the condenser, g, gl are
levers, rod, h¹ counterweighted lever, H large lever with handle, i quadrant, K
reversing lever of the engine.
The parts being thus arranged it will be understood that by placing the reversing
lever K, figure 1, in the position I or II' allowing the engine to work either in one
direction or in the other and by opening the regulating valve C the steam coming
from the boiler will pass through the pipe E into the chest B.
I. Suppose that at this moment there was a necessity for using steam at high
pressure coming from the boiler into the two cylinders the large lever H, the
levers h', g', g, d as well as the slide valve C would be left in the position indicated
at I, figure 1 in the drawing. The steam finding a free passage would pass through
the port through the pipe e into the right-hand cylinder A and would accomplish
its work and escape through the pipe by passing through the ports 63 and 63
into the outlet pipe F and would be delivered either into the air or into the
condenser.
b
The left-hand cylinder A¹ receives the steam at high pressure from the boiler
through the port 61 of the chest B and through the pipe e'; when its work has been
effected in the cylinder A¹ the steam escapes through the pipes f¹' and F¹ into the air
or into the condenser.
Thus, at this moment, the engine is working at a constant speed while admitting
steam at high pressure into both cylinders and its maximum power can then eventually
be put in action.
II. By placing the lever H, figure 1, instantaneously in the position indicated in
the drawing at II the levers h¹ by pulling hand g¹ and g will move the slide valve c.
in the direction of the arrow and the movement will be stopped by the stopper t ; at
this moment the port of the chest B is put in communication with the port 611
whilst the port 111 is entirely closed by the slide valve c; it follows that the steam

page_text: at high pressure coming from the boiler only passes through the port 6 (6¹ being
covered by the slide valve c); it then passes through the pipe e (the total capacity
of which will be equal to one volume of a cylinder) into the cylinder A (which I call,
in this case, the high pressure cylinder), performs its work therein and escapes
through the pipef and passes beneath the slide valve c through the port 6". It then
leaves through b', passes into the pipe e¹ which conducts it into the cylinder A¹
(low pressure,) performs its work and passes off through the pipe f' then through F
(figure 3) and is discharged into the air or into the condenser.
The engine in this latter case works at a constant speed with a simple admission of
steam at high pressure into the right-hand cylinder A. After having performed its
work the steam is admitted (without having given rise to a compression prejudicial to
the working) into the left-hand cylinder A where it works at low pressure and then
escapes therefrom in the usual way. It is this latter working which constitutes the
basis of the economical principle of this construction of engine.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
(1) A new kind of steam engine having two coupled cylinders of equal diameter
with cranks keyed at right angles allowing, by means of distributing mechanism,
of causing both to act at high pressure or at a constant speed, or to expand in
the second cylinder the steam which has previously been employed in the first
cylinder according to the resistance to be overcome, of uniting, at will the discharge
of one of the cylinders to the inlet of the second cylinder in order to work as a
compound engine.
(2) The improved steam engine hereinbefore described with reference to the
accompanying drawing.
n
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.