IMPROVEMENTS IN COMPOUND FLUID PRESSURE ENGINES
Year: 1884

page_text: I, ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents, 6 Bream's
Buildings Chancery Lane in the County of Middlesex, Patent Agent do hereby
declare the nature of my invention for IMPROVEMENTS IN COMPOUND FLUID
PRESSURE ENGINES, to be as follows:-
Engines actuated by the double, triple or multiple expansion of the motive
power fluid, and having two, three or more working cylinders or groups of
cylinders cannot, as at present constructed and arranged, work under the most
suitable conditions as to regularity and economy, when the power required to be
developed, is less than a certain fraction of the maximum power of which they
are capable.
The object of the present invention is to provide means whereby one or more of
the cylinders in the series may be readily cut off from such series when and so soon
as the engine power requires to be considerably reduced, and the engine, through the
remaining cylinder or cylinders, continue to work with all the economy and
regularity desirable.
In applying the invention by way of example to a compound engine actuated
by successive expansion of the steam in three cylinders the following arrangement
is adopted.
The first cylinder which receives steam direct from the boiler and the second
cylinder which receives its steam from the first cylinder, are arranged so that their
piston rods act upon the driving shaft one end of which serves to transmit the
power and the other end of which is fitted with a clutch adapted to engage with
or be disconnected from a second shaft arranged in line with the main shaft. The
piston rod of the third cylinder acts upon this second shaft and this cylinder
receives its steam from the second cylinder with which it is thus connected when
required for use.
On the other hand when this connection is severed the exhaust steam from
the second cylinder passes to the condenser by a pipe specially adapted for the
purnose

page_text: When the engine is working at full power or under conditions which assure its
regular and economical working, the two driving shafts are united and the three
cylinders operate in the usual manner, the steain passing successively from one to
the other of the cylinders before escaping.
When on the other hand that fraction of the maximum power which it is desired
to obtain becomes so small that by reason of the large size of the third cylinder the
action ceases to be regular and economical, the two shafts are disconnected, the
steam connection between cylinders two and three severed, and communication
between the second cylinder and the condenser opened. The third cylinder situate
at the end of the main shaft remote from that whence the power is given off ceases
to act, and the engine continues to run as a two-cylinder compound engine with a
regularity and economy which would not have been attainable with the three
cylinders.
It is evident that the above arrangement is applicable to all engines of triple,
quadruple or multiple expansion, of whatever type. It is especially valuable for
those, such as marine engines and certain workshop engines which are frequently
required to develop powers far below their maximum capacity.
NEWTON & SON,
Agents for the Applicant.
Improvements in Compound Fluid Pressure Engines.
I ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents, 6 Bream's
Buildings Chancery Lane in the County of Middlesex, Patent Agent do hereby
declare the nature of the invention for IMPROVEMENTS IN COMPOUND FLUID
PRESSURE ENGINES and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
Engines actuated by the double, triple or multiple expansion of the motive power
fluid, and having two, three or more working cylinders, or groups of cylinders,
cannot, as at present constructed and arranged, work under the most suitable
conditions as to regularity and economy when the power required to be developed
is less than a certain fraction of the maximum power of which they are capable.
The object of the present invention is to provide means whereby one or more of
the cylinders in the series may be readily cut off from such series when and so soon
as the engine power requires to be considerably reduced, and the engine through
the remaining cylinder or cylinders may nevertheless continue to work with all the
economy and regularity desirable.

page_text: in applying the invention by way of example to a compound engine actuated by
successive expansion of the steam in three cylinders the following arrangement is
adopted which will be understood on reference to the accompanying Drawing in
which
Fig: 1 is a front elevation of a three cylinder engine.
Fig: 2 is a side elevation of the same.
Fig: 3 is a plan view of the same; and
Fig: 4 is a detail view of one form of clutch connection or coupling suitable for
the purposes of this invention.
The first cylinder A which receives the steam direct from the boiler, and the
second cylinder B which takes its steam from the first cylinder, are arranged so
that their piston rods act upon the main driving crank shaft M one end of which
serves to transmit the power, and the other end of which is fitted with a clutch N
(see the detail view Fig. 4) adapted to engage with, or be disconnected, from a second
crank shaft M' arranged in line with the main shaft. The third cylinder C acts
through its piston rod upon this second shaft M¹ and receives its steam from the
second cylinder with which it is brought into connection by opening the cock or
valve a when required for use.
When, on the contrary, the third cylinder is not required for use, this connection
between the second and third cylinders is closed or cut off, and the exhaust steam
from the second cylinder passes by the valve or cock 6 and the pipes t t¹ t³ to the
condensers D.
When the engine is working at full power, or under conditions such that its
working is regular and economical the two driving shafts are coupled, and the
three cylinders operate in the usual manner, that is to say the steam passes
successively through the three cylinders A, B and C, before escaping to the
condenser. The cocks or valves a and c are open, the cock or valve b is closed, and
the clutch N is in gear.
When on the other hand that fraction of the maximum power which it is desired
to obtain from the engine becomes so small that by reason of the large size of the
third cylinder the action of the engine ceases to be regular and economical, the
two shafts are disconnected, by throwing the clutch N out of gear, and communi-
cation between the second and third cylinders is cut off by closing the cock or
valve a and is opened between the second cylinder and the condenser by opening
the cock or valve b and closing the cock or valve c. Thereupon the third cylinder
situated on the side remote from the transmission of the power, ceases to act, and
the engine continues to run as a two cylinder engine with a regularity and
economy which would not have been attainable with the three cylinders under the
same conditions as to steam pressure and work to be done.
The economy effected by the adoption of this arrangement is, for the engine
above described by way of example, about 30 per centum, when working at about
one-fifth (th) of its maximum power, under which conditions the distribution of
the work over the several pistons still remains normal.
It is evident that the above arrangement is applicable to all engines of triple,
quadruple or multiple expansion of whatever type. It is especially valuable for
those, such as marine engines, and certain workshop engines, which are frequently
required to develop powers far below their maximum capacity.
I am aware that it is usual to build up crank shafts of lengths connected by
flanges and bolts, and that in the Specification of Mess Richardson and Tweed,
N° 11973 AD 1884 it has been proposed to arrange the valves and pipe con-
nections of triple expansion marine engines whose cylinders work on separate
cranks in such a manner that in the event of the failure of any one or other of
the said cylinders the steam may be admitted to the remaining sound cylinders
only, but in carrying out that invention an ordinary or built up crank shaft is
employed and considerable time and labour are consequently required to effect the
disconnection of the engine or engines to be thrown out of work; whereas in the
present invention that portion of the crank shaft corresponding to the cylinder or

page_text: cylinders cut off by the valves or cocks a, b, and c is or are uncoupled from the
main crank shaft by means of simple clutch mechanism.
The present invention affords means for instantly and temporarily adapting the
.capacity of the engine to the work in hand; the object in view being to secure
greater economy in fuel and regularity in working rather than to make provision
against the accidental disablement of a cylinder and the means employed in carrying
out this object being essentially different from those above referred to.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to mo
by my Foreign Correspondents I declare that what I claim is
1. The combination with the cylinders of compound engines operated by the
double, triple or multiple expansion of the steam or fluid successively within the
said cylinders, of a divided shaft or shafts such as M, M a clutch N or its equivalent
for coupling and uncoupling the parts of the said divided shaft or shafts and valves
or cocks such as a b and c for opening or closing communication between two or
more of the said cylinders and the condenser or condensers, substantially as and for
the purpose set forth.
2. A compound engine having two three or more cylinders arranged to act upon
a divided crank shaft and provided with a clutch such as N or its equivalent for
readily coupling or uncoupling the parts of said shaft; and a valve or its equivalent
for opening or closing fluid communication between two or more of the said
cylinders, for the purpose of throwing out of action one or more of such cylinders
and disconnecting that part of the shaft on which it or they operate when the power
required to be developed by the engine falls considerably below the maximum
capacity of the engine as set forth.
"
100K