Improvements in Double Acting Fluid Pressure Motors, such as Steam Engines and the like.
Year: 1899

page_text: Improvements in Double Acting Fluid Pressure Motors, such as Steam
Engines and the like.
We, WILLIAM CHILTON, of Turvey, Bedfordshire, England, Engineer, and
DAVID JOHNSTONE MACDONALD, of South St. Roque's Works, Dundee, in the
County of Forfar, Scotland, Engineer, do hereby declare the nature of this inven-
tion to be as follows:
-
This invention relates to improvements in double acting fluid pressure motors,
such as steam engines and the like, the object being to improve the working and
simplify the construction of double acting engines with the view of increasing
their mechanical and thermal efficiency.
The improvements relate to all of the following types of engines:-
Simple high pressure engines with one or more cylinders working on one or
more cranks; compound engines and multiple expansion engines with two or
more cylinders working on two or more cranks; compound and multiple expansion
engines with one or more sets of tandem cylinders working on one or more
sets of cranks. It is to be understood that where two or more than two cranks
are used they may be placed at any desired angle, the one to the other.
In order to clearly show how our invention may be carried out, we will first
describe our improvements as adapted to a vertical tandem compound engine with
the cylinders arranged tandemwise, the high pressure above the low pressure,
and the two pistons connected, somewhat in the usual way by means of piston
rods, crosshead and connecting rod, to the crank pin which is situated below the
cylinders.
The cylinders are made with central valves, arranged concentrically with such
cylinders, and the valves reciprocate vertically. The cylinders themselves are
preferably formed like simple cylindrical pipes with flanges at the top and bottom.
Starting our description with the top high pressure cylinder: It is formed as
previously described like a cylindrical pipe with top and bottom flanges. The
piston is of annular form, the outer cylindrical surface working, as usual, against
the inner surface of the cylinder. The inner cylindrical surface of the piston
on the other hand works on the outer surface of the cylindrical valve liner which
is placed concentrically with the cylinder. The cylinder and the valve liner are
therefore like two pipes of different diameters parallel to and concentric with one
another, and the annular piston works inside of the one and outside of the other.
The cylinder is bored out on the inside, the valve liner is turned round both on
the inside and on the outside surfaces. The steam distribution valves reciprocate
up and down inside of the valve liner. The top cylindrical cover is made with a
steam space on the top and has a hole in the centre which fits the outside of the
valve liner in such a way as to be steam tight. It also, in the usual way, is

page_text: bolted down to the flange on the top of the cylinder. From this it will be seen
that the liner passes up through the cylinder cover. Near the top of the cylinder
cover a series of ports is formed in the valve liner, and these ports communicate
with the annular space between the outer surface of the cylindrical valve liner and
the inner surface of the cylinder. Such ports are so placed that when the annular
piston is at the top of its stroke they are not entirely covered by it, and steam
passing through these ports can act on the upper side of the piston.
A short distance above this first series of ports there is another set which com-
municates with the steam space, formed as previously described, in the top of the
cylinder cover. This steam space, in the case of the high pressure cylinder, is
supplied with steam from the boiler. An annular piston valve is arranged over
these ports in such a manner that in reciprocating it distributes the steam to the
top part of the high pressure cylinder. This piston valve is in shape like an
ordinary hollow piston valve turned at each end to fit the liner and having an
annular space between the two ends which, for the sake of perspicuity will be
termed the waist" of the valve. Such valve may be made with packing rings,
if desirable. The valve is made sufficiently large in diameter to allow the exhaust
steam to pass through its centre. The steam from the boiler passes through the
steam space in the top of the cylinder cover described above, from thence it
passes through the top set of ports in the liner into the annular space contained
by the waist of the piston valve and the valve liner, and from this space it is
passed through the bottom set of ports into the top of the high pressure cylinder.
This is done while the valve moves, say downwards. When the valve is carried
upwards by the valve gear, the lap portion of the valve uncovers the bottom set
of ports on the lower side, allowing the steam after having done its work, to
exhaust. The bottom high pressure cylinder cover also forms the top cover of
the low pressure cylinder and is made with two spaces, one above the other,
instead of with only one, as in the case of the top high pressure cylinder cover.
The valve liner at the bottom end has two sets of ports, one above the other, like
those at the top end of the high pressure cylinder. In this case however the
top set communicates with the bottom end of the high pressure cylinder and the
bottom set with the upper one of the two spaces in the bottom high pressure
cylinder cover. The steam is distributed by means of a circular valve similar to
the one working at the top end of the valve liner. The steam in this case also
passes trom the top space in the bottom high pressure cylinder cover through the
bottom set of ports into the waist of the bottom valve, and is passed into the
bottom end of the high pressure cylinder, say during the upward travel of the
valve, while during the downward travel the steam is exhausted over the top
lap of the valve. Steam is supplied from the boiler to the top space in the bottom
high pressure cylinder cover as well as to the steam space in the top high
pressure cylinder cover, and these two spaces communicate with one another by
means of a pipe or passage. This pipe may either be separate from the cylinder,
or it may be formed as a separate passage cast on, or otherwise made in any
convenient manner. The exhaust steam from both the top end and the bottom
end of the high pressure cylinder passes downwards and through the centre of
the bottom valve. Now, the exhaust steam of the high pressure cylinder, in pass-
ing downwards, passes into the bottom of one of the two spaces of the bottom high
pressure cylinder cover.
The low pressure cylinder is made very much in the same way as the high
pressure cylinder. The top cover of the low pressure cylinder is formed, as
already described, in one with the bottom cover of the high pressure cylinder.
There is also a bottom cover to the low pressure cylinder which is made with
two spaces, one above the other. The lower space in the top low pressure cylinder
cover communicates with the top space of the bottom low pressure cylinder cover
by means of a pipe, which may be either a separate pipe, or a passage cast on
the cylinder, as described above in the case of the high pressure cylinder, It
will be understood therefore that the exhaust steam from the high pressure

page_text: cylinder can find its way into the lower space of the top low pressure cylinder
cover and from thence through the pipe or passage into the top space of the
bottom low pressure cylinder cover.
In the case of tandem compound cylinders, the valve liner inside the low
pressure cylinder has preferably only one set of ports at the top end, but has
iwo sets of ports, one above the other, like those in the high pressure liner, at
the bottom end. The ports at the top of the low pressure valve liner com-
municate with the top part of the low pressure piston, and the top part of the
low pressure distribution valve is preferably unlike the valves of the high pressure
cylinder, and is made more like a piston, and in moving downwards uncovers the
top ports of the low pressure cylinder and allows the steam which has been
exhausted from the high pressure cylinder to enter the top end of the low
pressure cylinder. On the upward travel it allows the steam from the top end
of the low pressure cylinder to be exhausted on the under side of this piston valve
into the interior of the low pressure valve liner. The bottom part of the low
pressure valve is made like the valves of the high pressure cylinder. A portion
of the exhaust steam from the high pressure cylinder finds its way into the upper
one of the two spaces formed in the bottom low pressure cylinder cover: from
this space it passes through the bottom set of the two sets of ports into the
annular waist of the valve. During the upward travel of the valve, the steam
passes from this annular waist through the upper set of ports into the bottom of
the low pressure cylinder, and during the downward travel of the valve the steam
is exhausted over the top lap of such valve. Here again it will be understood
that the exhaust steam of both ends of the low pressure cylinder has to pass
through the centre of the bottom part of the low pressure valve. After finally
passing through the centre of this valve the final exhaust steam finds its way to
the lower one of the spaces formed in the bottom low pressure cylinder cover,
and from this space it is taken either to the atmosphere or to the condenser. In
some cases the passage of the steam through the valves may be arranged to take
place in the reverse way to that described above.
Two piston rods connect the low pressure piston to the cross-head, and two rods
also connect the high pressure piston to the low pressure piston. The cross-head
I prefer to use is circular in form. This cross-head carries the cross-head pin
which is connected to the crank pin by means of a connecting rod of the usual type.
The steam distribution valves are driven in the usual way by eccentrics and
gear, or by levers and links from the connecting rod.
Having described a tandem compound engine working on one crank we will
now show how different combinations of cylinders can be arranged to form engines
of the various types already referred to.
Two, three, or more sets of tandem compound engines, as described above, may
be arranged side by side working on two or more crank pins.
Instead of arranging the high and low pressure cylinders one above the other
to form a tandem engine, we can arrange them side by side, the high pressure
piston being connected to one crank and the low pressure cylinder to a second
crank, thus forming what is usually called a twin compound side by side engine.
In this case the valves of the low pressure cylinder may be made similar to those
of the high pressure cylinder, or as those already described for the low
pressure cylinder in the tandem engine. The cylinders are connected by the
necessary steam pipes or passages in any convenient way. In the case of the
tandem engine we can place a third cylinder above the other two and thus form
a triple expansion tandem engine.
Again, we can arrange the cylinders in a three crank triple engine as follows:
The high pressure cylinder may be placed above the intermediate pressure cylin-
ler and these two tandem cylinders may be connected to one of the cranks, as
lescribed in the case of the tandem engine. At the same time we may place a
low pressure cylinder above each of the other cranks, these two low pressure
cylinders being preferably of the same size. Such an arrangement would form a

page_text: triple expansion engine having four cylinders; riz.: one high pressure cylinder,
one intermediate pressure cylinder and two low pressure cylinders.
When describing the construction of the cylinders, covers and liners, we have
indicated that they are separate castings which are bolted together after being
machined. Instead of constructing them in this way we can make them as
follows: In any cylinder, whether high or low pressure, the cylinder proper, the
bottom cover and the valve liner may be cast in one piece; or the cylinder and
the bottom cover may be in one pièce and the valve liner in another; or the
valve liner and the bottom cover may be in one piece and the cylinder in another.
Also the covers, whether top or bottom, may be made separately, or in one or
more pieces. The cylinders may or may not be jacketted.
Although we have described several arrangements of cylinders and their appur-
tenances to show that they readily lend themselves to various useful combinations,
yet we do not intend to limit ourselves wholly to these, nor even to the exact
methods referred to as it is obvious that such combinations and methods may be
altered in various ways without departing from the nature and purpose of our
invention.
Datad this 14h luv of Mu 1900
GEO. C. DOUGLAS & Co.,
41, Reform Street, Dundee, Agents for Applicants.
Improvements in Double Acting Fluid Pressure Motors, such as Steam
Engines and the like.
We, WILLIAM CHILTON, of Turvey, Bedfordshire, England, Engineer, and
DAVID JOHNSTONE MACDONALD, of South St. Roque's Works, Dundee, in the
County of Forfar, Scotland, Engineer, do hereby declare the nature of this inven
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:--
This invention relates to improvements in double acting fluid pressure motors,
such as steam engines and the like, the object being to improve the working and
simplify the construction of double acting engines with the view of increasing
their mechanical and thermal efficiency.
The improvements relate to all of the following types of engines,
Simple high pressure engines with one or more cylinders working on one or
more cranks; compound engines and multiple expansion engines with two or
more cylinders working on two or more cranks; compound and multiple expan-
sion engines with one or more sets of tandem cylinders working on one or more
sets of cranks. It is to be understood that when two or more than two cranks
are used they may be placed at any desired angle, the one to the other.
And in order that our said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, we have hereunto
appended four explanatory sheets of drawings in which the same reference
numerals are used to indicate corresponding parts in all the figures where shown.
that is to say:
Figure 1, (Sheet 1) is a vertical section showing the general arrangement of
cylinders of a vertical tandem compound engine.
Figure 2, (Sheet 2) is a vertical section. of same in a plane at right angles to
that shown in Figure 1, and Figure 3, (Sheet 2) is a half cross-section at B B.
(Figure 2).
Figure 4, (Sheet 3) is a vertical section at C, C (Figure 6), showing the general

page_text: arrangement of a vertical compound engine with the cylinders arranged side by
side.
Figure 5, (Sheet 3) is a cross-section at A.A. (Figure 4) of same and
Figure 6, (Sheet 4) is a vertical part sectional elevation on the line D.D.
(Figure 4).
In order to clearly show how our invention may be carried out, we will first
describe our improvement as adapted to a vertical tandem compound engine with
the cylinders arranged tandemwise, the high pressure above the low pressure,
and the two pistons connected, somewhat in the usual way by means of piston
rods, crosshead and connecting rod to the crank pin which is situated below the
cylinders and is not shown in these particular drawings, viz.: Figures 1, 2, and 3.
The cylinders 10, and 11, are made with central valves 12, 13, 14, and 15,
arranged concentrically with such cylinders, and the valves reciprocate vertically.
The cylinders themselves are preferably formed like simple cylindrical pipes
with flanges at the top and bottom. Starting our description with the top high
pressure cylinder 10. It is formed as previously described like a cylindrical pipe
with top and bottom flanges. The piston 16, is of annular form, the outer cylin-
drical surface working, as usual, against the inner surface of the cylinder. The
inner cylindrical surface of the piston on the other hand works on the outer
surface of the cylindrical valve liner 17, which is placed concentrically with the
cylinder. The cylinder and the valve liner are therefore like two pipes of
different diameters parallel to and concentric with one another, and the annular
piston works inside of the one and outside of the other. The cylinder is bored
out on the inside, the valve liner is turned round both on the inside and on the
outside surfaces. The steam distribution valve 12, 13, 14, and 15, reciprocate up
and down inside of the valve liner. The top cylinder cover 18, is made with a
steam space on the top and has a hole in the centre which fits the outside of the
valve liner 17, in such a way as to be steam tight. It also, in the usual way, is
bolted down to the flange on the top of the cylinder. We have deemed it unneces-
sary to show such bolting. From this it will be seen that the liner 17, passes up
through the cylinder cover. Near the top of the cylinder cover a series of
ports 19, are formed in the valve liner, and these ports communicate with the
annular space between the outer surface of the cylindrical valve liner and the
inner surface of the cylinder. Such ports are so placed that when the annular
piston 16, is at the top of its stroke they are not entirely covered by it, and
steam passing through these ports can act on the upper side of the piston. A
short distance above this first series of ports there is another set 20, which
communicates with the steam space 18, formed as previously described, in the
top of the cylinder cover. This steam space, in the case of the high pressure
cylinder, is supplied with steam from the boiler by means of the pipe 21.
annular piston valve 12, is arranged over these ports in such a manner that in
reciprocating it distributes the steam to the top part of the high pressure cylinder.
This piston valve is in shape like an ordinary hollow piston valve turned at each
end to fit the liner and having an annular space 22, between the two ends which,
for the sake of perspicuity will be termed the waist of the valve. Such valve
may be made with packing rings if desirable. The valve is made sufficiently
large in diameter to allow the exhaust steam to pass through the centre. The
steam from the boiler passes through the steam space in the top of the cylinder
cover described above, from thence it passes through the top set of ports 20, in
the liner and into the annular space contained by the waist of the piston valve
and the valve liner, and from this space it is passed through the bottom set of
ports 19, into the top of the high pressure cylinder, as indicated by the arrow.
This is done while the valve moves, say downwards. When the valve is carried
upwards by the valve gear, not shown in these figures, riz. 1, 2, or 3, the lap
portion of the valve uncovers the bottom set of ports 19, on the lower side,
allowing the steam after having done its work, to exhaust into the space 23. The
bottom high pressure cylinder cover 24, also forms the top cover of the low
"
An

page_text: pressure cylinder 11, and is made with two spaces 25, and 26, one above the
other, instead of with only one, as in the case of the top high pressure cylinder
cover. The valve liner at the bottom end has two sets of ports 27, and 28, one
above the other, like those at the top end of the high pressure cylinder. In this
case however the top set 27, communicate with the bottom end of the high
pressure cylinder 10, and the bottom set 28, with the upper one 25, of the two
spaces in the bottom high pressure cylinder cover 24. The steam is distributed
by means of a circular valve 13, similar to the one working at the top end of the
valve liner. The steam in this case also passes from the top space 25, in the
bottom high pressure cylinder cover through the bottom set of ports 28, into
the waist of the bottom valve, and is passed through the ports 27, into the
bottom end of the high pressure cylinder, say during the upward travel of the
valve 13, while during the downward travel the steam is exhausted over the top
lap of the valve into the spaces 23, and 26. Steam is supplied from the boiler to
the top space 25, in the bottom high pressure cylinder cover as well as to the
steam space 18, in the top high pressure cylinder cover, and these two spaces, riz.
18 and 25, communicate with one another by means of a pipe or passage 21. This
pipe may either be separate from the cylinder, as shown, or it may be formed as
a separate passage cast on, or otherwise made in any convenient manner. The
exhaust steam from both the top end and the bottom end of the high pressure
cylinder 10, passes downwards and through the centre of the bottom valve 13.
Now, all the exhaust steam of the high pressure cylinder, in passing downwards,
passes into the bottom one 26, of the two spaces of the bottom high pressure
cylinder cover. The low pressure cylinder 11, is made very much in the same
way as the high pressure cylinder 10. The top cover 24, of the low pressure
cylinder is formed, as already described, in one with the bottom cover of the high
pressure cylinder. There is also a bottom cover 29, to the low pressure cylinder
which is made with two spaces riz. 30 and 31, one above the other. The lower
space 26, in the top low pressure cylinder cover communicates with the top
space 30, of the bottom low pressure cylinder cover by means of a pipe 32,
which may be either a separate pipe, as shown, or a passage cast on the cylinder,
as described above in the case of the high pressure cylinder. It is to be under-
stood therefore that the exhaust steam from the high pressure cylinder can find
its way into the lower space 26, of the top low pressure cylinder cover and from
thence through the pipe or passage 32, into the top space 30, of the bottom low
pressure cylinder cover. 333, is the final exhaust pipe and 34, is a closed non-
conducting air space placed between the inlet steam space 30, and exhaust steam
space 31.
In the case of such tandem compound cylinders, the valve liner 37, inside the
low pressure cylinder 11, has preferably only one set of ports 38, at the top end
but has two sets of ports 39, and 40, one above the other, like those in the high
pressure liner, at the bottom end. The ports at the top of the low pressure
valve liner communicate with the top part of the low pressure piston, and the
top part of the low pressure distribution valve 14, is preferably unlike the valves
of the high pressure cylinder, and is made more like a piston, and in moving
downwards uncovers the top ports 38, communicating with the top part of the
low pressure cylinder and allows the steam which has been exhausted from the
high pressure cylinder to enter the top end of the low pressure cylinder. On the
upward travel it allows the steam from the top end of the low pressure cylinder
to be exhausted on the under side of this piston valve into the interior 41, of the
low pressure valve liner. The bottom part of the low pressure valve 15, is made
like the valves of the high pressure cylinder. A portion of the exhaust steam
from the high pressure cylinder finds its way into the upper one 30, of the two
spaces formed in the bottom low pressure cylinder cover: from this space it
passes through the bottom set 40, of the two sets of ports into the annular waist
of the valve 15. During the upward travel of the valve, the steam passes from
this annular waist through the upper set of ports 39, into the bottom of the low

page_text: pressure cylinder 11, and during the downward travel of the valve the steam is
exhausted over the top lap of such valve. Here again it will be understood that
the exhaust steam of both ends of the low pressure cylinder has to pass through
the centre of the bottom part of the low pressure valve. After finally passing
through the centre of this valve the final exhaust steam finds its way to the
lower one 31, of the two working spaces formed in the bottom low pressure
cylinder cover, and from this space it is taken either to the atmosphere or to the
condenser. In some cases the passage of the steam through the valves may be
arranged to take place in the reverse way to that described above.
Two piston rods 36, connect the low pressure piston 42, to the cross-head, and
two rods 35, also connect the high pressure piston 16, to the low pressure piston.
The cross-head we prefer to use is circular in form. This cross-head carries the
cross-head pin which is connected to the crank by means of a connecting rod of
the usual type.
The steam distribution valves are driven in the usual way by eccentrics and
gear, or by levers and links from the connecting rod, or by eccentrics worked
from a flywheel governor, that is to say the cut off of the valve is determined by
the speed of the engines in the usual way.
Having described a tandem compound engine working on one crank we will
now show how the different combinations of cylinders can be arranged to form
engines of the various types already referred to. Two, three, or more sets of
tandem compound engines, as described above, may be arranged side by side,
working on two or more crank pins.
Instead of arranging the high and low pressure cylinders one above the other
to form a tandem engine, we can arrange them side by side, as illustrated by
Figures 4, 5, and 6, the high pressure piston 16, being connected to one crank 4:3,
and the low pressure piston 42, to a second crank 44, thus forming what is usually
called a twin compound side by side engine. In this case the valves 45, and 15,
of the low pressure cylinder 11, may be made similar to those of the high
pressure cylinder 10, or as those already described for the low pressure cylinder
in the tandem engine, riz. 14 and 15. The cylinders are connected by the
necessary steam pipes or passages in any convenient way. For example, and
with reference to Figures 4, 5, and 6, the steam operates the high pressure
piston 16, in a manner similar to that previously described in connection with
the tandem engine exhausting through the centre of the lower valve 13, into the
space 46, from which it is distributed to the top and bottom sides of the low
pressure piston 42, the steam used on the top side of the piston being passed
through the pipe 32. The exhaust steam, as in the case of the tandem engine
passes through the centre of the lower valve 15, into the exhaust space 31.
piston rods 47, and 48, are respectively coupled to their circular cross-heads 49,
and 50. 51, are the eccentrics, 52, the connecting rods, 53, the main bearings, 54,
the flywheel, and 55, the centrifugal governor by means of which the throttle
valve 56 is actuated. As all these parts are commonly used in connection with
ordinary engines we deem it superfluous to enter into their detailed description
and consequently only casually refer to them.
The
In the case of the tandem engine we can place a third cylinder above the other
two and thus form a triple expansion tandem engine.
Again we can arrange the cylinders in a three crank triple engine as follows:-
The high pressure cylinder may be placed above the intermediate pressure
cylinder and these two tandem evlinders may be connected to one of the cranks
as described in the case of the tandem engine. At the same time we may place
a low pressure cylinder above each of the other cranks, these two low pressure
cylinders being preferably of the same size. Such an arrangement would form a
triple expansion engine having four cylinders: riz.: one high pressure cylinder,
one intermediate pressure cylinder and two low pressure cylinders.
When describing the construction of the cylinders, covers and liners, we have
indicated that they are separate castings which are bolted together after being

page_text: or
machined. Instead of constructing them in this way we can make them as
follows: In any cylinder, whether high or low pressure, the cylinder proper,
the bottom cover and the valve liner may be cast in one piece; or the cylinder
and the bottom cover may be in one piece and the valve liner in another:
the valve liner and the bottom cover may be in one piece and the cylinder in
another. Also the covers, whether top or bottom may be made separately, or in
one or more pieces. The cylinders may or may not be jacketed.
Although we have described several arrangements of bylinders and their
appurtenances to show that they readily lend themselves to various useful com-
binations, yet we do not intend to limit ourselves wholly to these, nor even to
the exact methods referred to as it is obvious that such combinations and methods
may be altered in various ways without departing from the nature and purpose
of our invention.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
(1) In a double acting single cylinder steam engine, the combination of a set
of central valves with a cylinder and its covers, substantially as described.
(2) In a double acting steam engine, the combination of one or more sets of
central valves and means for operating the said valves, with two or more cylinders
and their covers, substantially as described.
(3) In a double acting compound steam engine, the combination of central
valves and means for operating the said valves, with two cylinders, placed tandem-
wise, and their covers, substantially as described.
(4) In a double acting multiple expansion steam engine, the combination of
central valves and means for operating the said valves, with two or more cylinders
placed tandemwise, and their covers, substantially as described.
(5) In double acting multiple expansion steam engines, the combination of
central valves and means for operating the said valves, with two, three, or more
sets of tandem compound cylinders, arranged side by side, and working on two
or more crank pins, substantially as described.
(6) In double acting multiple expansion steam engines, the combination of
central valves and means for operating the said valves with a high pressure
cylinder, an intermediate pressure cylinder, placed tandemwise, working on one
crank pin and two low pressure cylinders, each working on its own crank pin,
substantially as described.
(7) In a double acting compound steam engine, the combination of central
valves and means for operating the said valves, with two cylinders placed side
by side and their covers, substantially as described.
(8) The construction, combination, and arrangement of parts, substantially as
described and illustrated on the annexed drawings.
Dated this 97th dor of January 1900
GEO. C. DOUGLAS & Co.,
Chartered Patent Agents,
41, Reform Street, Dundee, Agents for Applicants.
GEO. C. DOUGLAS & Co.,
Chartered Patent Agents,
41, Reform Street, Dundee, Agents for Applicants.