Year: 1886

page_text: I HENRY EDWARD NEWTON of the Office for Patents 6 Bream's Buildings,
Chancery Lane in the County of Middlesex, Civil 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:-
The présent invention relates generally to that class of engines which are
provided with one or more compensating or auxiliary cylinders and pistons, which
are supplied with a suitable motor fluid, and are arranged to act in opposition to
the main piston or pistons during the first part of the stroke of the latter, and in
conjunction therewith during the last part of the stroke,-thereby permitting the
admission of the steam to the main.cylinder or cylinders to be cut off before the
stroke is completed without reducing the power of the engine at the end of
the stroke. One form of such an engine is shown and described in English Letters
Patent No 2342 of 1884.
The present invention consists principally in the employment of an accumulator
for producing the required pressure upon the piston or pistons of the compensating
cylinder or cylinders.
Another feature of the invention consists in deriving the pressure in the
compensating cylinder or cylinders from the pressure in the force main, and trans-
mitting it to the cylinder or cylinders through a volume of air or other elastic gas.
The invention also includes a governor apparatus which is arranged to control
the pressure upon the piston or pistons of the compensating cylinder or cylinders
in such manner as to prevent the engine from being subjected to a shock or strain
at the end of the stroke, and from operating violently and being damaged in case
it is attempted to start or run it with no load, or with less than its full load, or in
case it is suddenly relieved of the whole, or a large part of its load, as by the
breaking of a piston or plunger rod, or the force main.
As a full understanding of the invention can be best imparted by a detailed
description of the organization and operation of the engine, all further preliminary
description will be omitted, and a full description given, reference being had to the
accompanying drawings, in which :-
Fig. 1 is a side elevation of a duplex pumping engine embodying the present
invention, the parts being shown in the position they will occupy when the pistons
of the main steam cylinders are at the middle of their strokes.
Fio 2 is a ton view of the coma

page_text: Fig. 3 is an enlarged sectional elevation taken upon the line X X of figs. 1, 2
and 5, looking toward the water end of the engine.
Fig. 4 is a similar view taken upon the line Z Z of the same figures.
Fig. 5 is an enlarged side elevation, partly in section, showing particularly the
accumulator and the governor valve for controlling the pressure in the compensating
cylinders of one side of the engine.
Fig. 6 is an enlarged view of a portion of figure 5.
Fig. 7 is a similar view showing the parts in a different position; and
Fig. 8 is a view similar to fig. 5, showing an accumulator of a different form, and
also showing one way of deriving the pressure for the compensating cylinders
from the force main, and transmitting it to the cylinders through a body of air or
other elastic gas.
Referring particularly to figs. 1 and 2, it is to be understood that the steam end
of the engine, or what may be termed the engine proper, is of a common form,
consisting of two steam cylinders A. B,-one for each side of the engine, which
are provided with the usual steam chests a b, into which the steam is admitted
from the boiler through the usual induction pipe 90.-After performing its work in
the cylinders, the steam is exhausted through the usual exhaust pipe 91 into a
condenser, or into the open air. The steam chests a bare provided with ordinary
slide valves (not shown), the rods 24, 25 of which are provided with the usual
connections 92-93, by which the valve of each side of the engine is operated from
the piston rod of the other, in the manner common in duplex engines.
The water end of the engine, or what may be termed the pump proper, is also
of a common form, consisting of two water-cylinders C D, the plungers or pistons
of which are connected directly to the piston rods 26-27 of the steam cylinders in
the manner common in this class of engines. The water cylinders CD are provided
with the usual suction and force chambers E F, the former of which is connected
to the suction main 98, and the latter to the force main 99. The force main 99 is
provided with the usual air compression chamber 97, to equalize the flow of the
water discharged from the pump.
The organization thus briefly outlined is, as before stated, common, and will be
readily understood by those familiar with this class of engines.
Referring now more particularly to figs. 3, 4, and 5, it will be seen that the
piston rods 26-27 are provided, between the steam and water cylinders, with
heads or bearings 28-29, to which are pivoted the piston rods 30-31 of two pairs
of oscillating compensating cylinders 32-33, which are supplied with a suitable
motor fluid, and are arranged so that their pistons 34-35 act in opposition to the
main steam pistons during the first part of the stroke of the latter, and in con-
junction therewith during the last part of the stroke, in substantially the manner
described in my former letters patent hereinbefore referred to.-The cylinders 32-33
are arranged to oscillate upon trunnions 20, which are mounted in bearings 23
supported upon the tie-rods 22, which connect the steam and water cylinders, or in
any other suitable manner.
it is to be remarked that the compensating cylinders, instead of being located
between the steam and water cylinders, may be located at the outer end of the
water cylinders, or at the outer end of the steam cylinders. In such case, the main
piston rods will be extended through the water cylinders, or the steam cylinders, as
the case may be; or, in fact, the compensating cylinders may be located in any
other convenient position. It is also to be remarked that one compensating
cylinder may be employed for each of the main piston rods, instead of two, and also
that the compensating cylinders or or cylinder may be arranged to act on the main
piston rod in any of the ways shown in my letters patent before referred to, or in
any other suitable way.
The compensating cylinders and pistons are, as before stated, arranged to act in
opposition to the main steam pistons during the first part of the stroke, and in
conjunction therewith during the last part of the stroke, thereby permitting the
steam to be cut off from the main cylinders before the end of the stroke, without

page_text: interfering with the proper operation of the engine. The engine shown in the
present case, is, therefore, provided with cut off mechanisms 89, by which the
steam is cut off from the main cylinders A B when their pistons have arrived at
the proper point in their strokes, after which their pistons complete their strokes
by the expansive force of the steam in the cylinders, aided by the power exerted
by, the pistons of the compensating cylinders. These cut off mechanisms are of the
form shown and described in the specification of Letters Patatent N° 2342 of
1884 before referred to, and need not, therefore, be herein described in detail. It is
to be remarked, however, that any other form of cut-off mechanism may be used
if preferred.
The motor fluid which acts upon the piston or pistons of the compensating
cylinder or cylinders may, as set forth in iny letters patent before referred to, be
steam, air or other gas, or it may be a liquid, but it has been found in practice
that in those cases where steam, air, or other gas is employed, as the motor fluid,
it is desirable that a liquid packing should be interposed between the motor fluid
and the piston or pistons of the compensating cylinder or cylinders, which liquid
packing will fill the cylinder or cylinders, and transmit the pressure of the motor
fluid to the piston or pistons. The advantages of this liquid packing are fully set
forth the specification of English Letters Patent N° 15770 of 1885. It has also be
found in practice that in order to develop the desired amount of power in the
compensating cylinder or cylinders, and yet avoid making it or them of an
inconveniently large size, it is sometimes necessary that the pressure upon the
piston or pistons of the compensating cylinder or cylinders should be greater than
exists in the boiler or other source from which it is most convenient and desirablė
to derive the pressure for the motor fluid.
To overcome this difficulty, I provide the engine with an accumulator, which is
interposed between the compensating cylinder or cylinders and the source from
which the pressure on the motor fluid is derived, and by which the pressure is
accumulated or concentrated upon a smaller area, thereby increasing the pressure
in the compensating cylinder or cylinders to any desired extent.
Other advantages are also gained by the employment of this accumulator, which
will be hereinafter referred to.
In one
Two applications of the accumulator are illustrated in the present case.
(see figs. 1 to 5), the pressure in the compensating cylinders is derived directly
from the pressure of the column of water in the force main, while in the other (see
fig. 8), the pressure is derived indirectly from the same source, but directly from
the pressure of the air in the air chamber 97.
Referring now to figs. 1 to 5, the first of these applications of the accumulator,
and its connections with the compensating cylinders and the force main, will be
described. The inside trunnions of the compensating cylinders are provided with
tubular extensions 19 (see fig. 4), which communicate with a vertical pipe 50
having a vertical partition or diaphragm 18, by which it is divided into two
compartments or ducts 16-17, the tubular extensions 19 of the trunnions of the
cylinders 32 communicating with the duct 16, and those of the cylinders 33 with
the duct 17. It is to be remarked, however, that instead of using the single pipe 50,
which is divided to form the two ducts 16-17, two separate pipes may be employed,
one for each of the pairs of compensating cylinders. The tubular extensions 19
are provided with pipes 21 (see fig. 4), which communicate with the ends of their
respective cylinders behind the pistons 34-35. The ends of the tubular exten-
sions 19 enter stufting boxes formed on the sides of the pipe 50, which serve to
form tight connections between the oscillating cylinders, trunnions and tubular
extensions and the stationary pipe. The ducts or pipes 16-17 are provided with
branch pipes 14-15, which communicate with the chamber or cylinder 51 (see
fig. 5) of the accumulator, which is of a capacity at least equal to the combined
displacement of the pistons of the compensating cylinders, and which, together
with the connections just described, are filled with water, oil, or other liquid, which
also fills. the compensating cylinders behind their pistons. The upper end of the

page_text: cylinder 51 is provided with an opening through which passes the smaller end of a
differential plunger 52, the larger end of which works in à cylinder 53, which is
located above the cylinder 51, and is provided at a point above the end of the
plunger with a pipe 54, which communicates with the force main 99, and through
which the water from the main enters and fills the cylinder 53, and communicates
the pressure of the main directly to the larger end of the plunger 52.
By reason of this arrangement, it results, according to the well known law of
hydrostatics, that the pressure in the cylinder 51, and upon the pistons of the
compensating cylinders, is, to the pressure in the force main, as the area of
the larger end of the plunger is to the area of its smaller end. By this means, the
pressure in the compensating cylinders is increased above the pressure which exists
in the force main, and it will readily be seen that by properly proportioning the
relative areas of the two ends of the plunger, any desired degree of pressure can
be obtained in the compensating cylinders. It will, of course, be seen that if the
pressure in the main should be greater than is desired in the compensating
cylinders, the pressure can be reduced by simply reversing the relative areas of the
ends of the plunger.
The lower end of the cylinder 53, which rests upon the cylinder 51, is provided
with one or more openings, as 36, through which air is allowed to pass freely into
and out of the cylinder below the enlarged part of the plunger, so as to prevent the
plunger from being cushioned. The openings 36 also serve to allow any liquid
which may leak past the plunger to escape into a trough 37 formed upon the
upper end of the cylinder 51, from which trough it flows through a spout 38 to a
drain pipe 39. The pipe 54 is provided with a valve or gate 55, by which, when
desired, communication between the cylinder 53 and the main 99 may be shut
off, and the pipe is also provided with a small branch pipe 56, which communicates
with a drain pipe 39, and is provided with a cock or valve 57, by which, when the
gate 55 is closed, the liquid can be drawn out of the cylinder 53.-The plunger 52
will preferably be provided with a small rod, as 58, which passes through a
stuffing box in the upper end of the cylinder 53, and extends by the side of a
stationary scale, as 59, so as to indicate the position of the plunger 52, and enable
the engineer to determine when the cylinder 51 contains the proper quantity of
liquid.
In the second application of the accumulator illustrated, viz: that shown in
fig. 8, the general organization of the engine is substantially the same as that
already described. The cylinder 51, and the smaller end of the plunger 52, are,
however, as shown, much smaller in proportion to the cylinder 53 and the larger
end of the plunger. The accumulation of the pressure in the cylinder 51 is, there-
fore, much greater, and as a consequence the compensating cylinders 32-33 are of
correspondingly reduced diameter. The cylinders 51-53 are in this case entirely
independent of each other, and are supported upon vertical rods 49. The con-
nections for conducting the liquid from the cylinder 51 to the compensating
cylinders are the same as already described.
The pipe 54, however, instead of communicating directly with the force main 99,
extends upward through the air chamber 97, and terminates at a point near its
top, so that the pressure of the column of water in the force main, instead of being
transmitted directly to the plunger 52 through the column of water in the pipe 54,
is transmitted indirectly to the plunger through the body of air in the chamber 97,
and in the pipe 54 and cylinder 53.
In order to keep the larger end of the plunger 52 properly packed and lubricated
in the cylinder 53, the cylinder is provided with a small pipe 48, which com-
municates with the main 99, and is provided with a cock 47, through which a small
amount of water can be allowed to enter the cylinder above the plunger.
The proper amount of air can be maintained in the chamber 97 by means of a
small air compression pump, as 46, which communicates with the chamber of
a pipe 45. This pump, as herein shewn, is operated from an arm 41 extending
from one of the trunnions 20 of the compensating cylinders, and connected by. a

page_text: rod 42 to an arm 43, which is pivoted on a stud extending from the side of the
water cylinder C, and is connected to the plunger rod 44 of the pump. By this
means, the pump 46 is caused to make two strokes to each stroke of the engine,
the advantages of which are fully set forth in the specification of English Letters
Patent No 16858 of 1884. The pump 46 will need to be operated only occasionally,
and at other times it will be disconnected from the engine.-Instead of using the
compressor 46, the proper amount of air can be supplied to the chamber 97 in any
other suitable manner. The chamber 97 is provided with an ordinary glass gauge,
as 60, by which it can be determined when the chamber contains the proper
quantity of air. The pipe 54 is provided with an ordinary three-way cock 55, by
which communication with the air chamber can be cut of from the cylinder 53,
and communication opened between the atmosphere and the cylinder.
The operation of the accumulator when arranged in either of the ways described
is as follows: for the purpose of this description it will be assumed that the engine
is in operation, and that the normal or ordinary pressure exists in the main 99, and
also that the piston of the cylinder A is commencing its stroke toward the water
cylinders. During the first half of the stroke, the liquid will be forced out of the
compensating cylinders 32, and through the pipes 21, duct 16, and pipe 14, into
the cylinder 51, where it will act upon the smaller end of the plunger 52, and raise
the plunger against the pressure of the water in the main 99. During the last
half of the stroke, the operation will be reversed, and the plunger 52, acted upon
by the pressure from the force main in the cylinder 53, will force the liquid out of
the cylinder 51 back into the cylinders 32, thus giving back the power which was.
expended in raising the plunger. As the piston of the cylinder A approaches the
end of its stroke, the connections 93 will operate the valve of the cylinder B só
as to start the piston of that cylinder upon its stroke in the same direction.
During this stroke, the operation just described will be repeated in connection
with the compensating cylinders 33, and as the piston of the cylinder B approaches
the end of its stroke, the connections 92 will operate the valve of the cylinder A,
BO as to start the piston of that cylinder upon its return stroke, and so the
operation will continue to be repeated.
In addition to its function of accumulating or concentrating pressure in the
It sometimes
cylinder 51, the accumulator is important in another respect.
happens, owing to a change in the character or amount of the work which the
engine is to perform, that it is desirable to cause the compensating cylinder or
cylinders to develop a greater or less amount of power without changing the
pressure at the source from which the pressure in the cylinder or cylinders is
derived. When the pressure in the compensating cylinder or cylinders is com-
municated directly to it or them, from the source at which it is derived, such change
can only be effected by changing the diameter of the cylinder or cylinders, but by
the use of the accumulator, this change can be effected by simply changing the area
of the smaller end of the plunger 52, which can be readily and cheaply done.
It will readily be seen, that so far as concentrating or accumulating the pressure
in the cylinder 51 is concerned, and also so far as changing the pressure in the
compensating cylinder or cylinders is concerned, the operation of the accumulator
will be the same, whether the pressure upon the larger end of the plunger 52 is
derived from the force main, as shown in the present case, or from any other source,
as the steam boiler, or a tank containing air or other gas under pressure, or a stand
pipe containing a column of liquid, or even a weight or spring arranged upon or
to act upon the plunger. In any of these cases, the pressure upon the u.per end
of the plunger is, in effect, nothing more than so much weight placed upon the
plunger, and it is, therefore, to be understood that my invention embraces the com-
bination of the accumulator with one or more of the compensating cylinders,
regardless of the source from which the pressure upon the plunger of the accumulator
is derived.
There are, however, several important advantages gained by having the pressure
in the compensating cylinder or cylinders derived either directly or indirectly from

page_text: the force main. By this means the power developed by the compensating cylinder
or cylinders is controlled by, and conforms to the pressure in the main; or, in other
words, conforms to the load upon the engine. This is a feature of particular
importance, as there are many cases in which the full pressure in the main, or, in
other words, the full load upon the engine, is not attained until it has been
operating for some time or has acquired a considerable degree of speed. This is
the case in raising liquids when, for any reason, the force main has become empty
or partly empty while the engine is at rest. It is also the case in pumping through
a long line of pipe, when the pressure in the pipe, and, as a consequence, the load
upon the engine, is due to the friction of the fluid, depending on its velocity, and
not to the height of the column.
In these and other like cases, if the compensating cylinder or cylinders is or are
allowed to develop its or their full power when the engine is started and when the
load is light, it will cause the engine to act violently, and be liable to occasion
damage, but by having the pressure in the compensating cylinder or cylinders
derived from the pressure in the main, the power developed by the former gradually
increases as the pressure in the latter increases, so that all violent action of the
engine is avoided.
In pumping against a heavy pressure, there is also some danger that the force
main may burst, and thus suddenly relieve the engine of all, or a large portion of
its load. In this case also, the compensating cylinder or cylinders will at once
cease to develop any power, and the danger of damage from the sudden acceleration
of the speed of the engine, which would otherwise ensue, is avoided.
The results just stated will be the same, whether the pressure in the compensating
cylinder or cylinders is derived directly from the force main, as shewn in figs. 1 to 5,
or indirectly, as shewn in fig. 8. When, however, the pressure is derived directly
from the main, the flow of the liquid into and out of the cylinder 51, and the
consequent reciprocating movement of the plunger 52, will cause pulsations in the
main, owing to the non-compressibility of the liquid in the main, which, in some
cases, will be objectionable, but these pulsations will be wholly or nearly wholly
avoided when the pressure is derived indirectly from the main through the air in
the chamber 97, as shown in fig. 8, because these pulsations will be absorbed by
the elasticity of the air in the chamber 97, and will not be communicated, excepting
perhaps in a slight degree, to the water column.
It will readily be seen that, although it is most convenient to utilize the air in
the chamber 97 for transmitting the pressure in the main to the compensating
cylinder or cylinders, a special air chamber may be provided for containing the air
for that purpose, such chamber being located in any convenient position, and made
to communicate with the main and the cylinder 53. It will also be seen-that the
advantage due to transmitting the pressure in the main to the compensating
cylinder or cylinders indirectly through a body of air or other elastic fluid, will
be the same in those cases where no accumulator is employed.
It is often desirable, even when the engine is running at its normal speed, and
under its ordinary working conditions, that the pressure upon the piston or pistons
of the compensating cylinder or cylinders should be reduced, or entirely removed,
just at the end of the stroke of the engine, as otherwise the shock occasioned by
arresting these pistons, while they are subjected to their full working pressure, and
at the time when, by reason of their position, they are exerting their maximum
power upon the main piston rod, is straining to the engine.
In order to avoid this strain upon the engine, the compensating cylinders for
each side of the engine are provided with a governor or cut-off valve or cock,
which operates to regulate the flow of the liquid to the cylinders, and to greatly
reduce or entirely cut it off just at the end of the stroke of the main steam piston,
and thus deprive the compensating cylinders of all, or nearly all their power at that
time. For this purpose, the pipes 14-15, which connect the ducts 16-17 with
the cylinder 51, are provided with enlargements 40 (see fig. 7), which form cham-
bers for a pair of piston valves 9, which reciprocate in bearings 8 formed in the

page_text: chambers 40, and are provided with rods 7, which pass through stuffing boxes in
the tops of the chambers, and are connected to heads 6, which move in guides 13,
and are connected to levers 12, which are fulcrummed to links 11, pivoted upon
the pipes 14-15, and are connected by rods 10 with crank arms
extending from
the trunnions 20 of two of the cylinders 32-33. The valves 9 are so connected to
the rods 7 (see figs. 5, 6, and 7), that they are capable of a small amount of motion
independent of the rods, the purpose of which will be made clear when the operation
of these valves is explained.
This operation is as follows: As either of the main steam pistons moves in
either direction from the middle of its stroke, thereby oscillating its pair of
compensating cylinders, and allowing the liquid in the cylinder 51 to flow out
through the pipe 14 or 15, as the case may be, and into the compensating cylinders
behind their pistons, the arm 5 will be rocked, thereby rocking the lever 12, and
permitting the valve 9 of that side of the engine to move downward toward its
seat. As the main piston approaches the end of its stroke, the valve 9 will fall
below its guide S, and commence to close the pipe 14 or 15, as the case may be,
and cut off the flow of the liquid to its pair of compensating cylinders, and this
movement will continue until the main piston arrives at the end of its stroke, at
which time the valve 9 will have nearly or quite reached its seat, as shown in
fig. 7, and consequently have cut off all, or nearly all flow of the liquid to the
compensating cylinders, and deprived them of all or nearly all power. As the
main piston starts upon its return stroke, and the liquid in the compensating
cylinders is forced back into the cylinder 51, the valve 9 will be raised from its
seat in advance of the movement of the rod 7, as shewn by dotted lines in fig. 7,
so as to offer no obstruction to the flow of the liquid. As the main piston arrives
at the middle of its return stroke, the parts will be restored to the position shown
in fig. 6, and as it makes the last half of its return stroke, the arm 5 will be rocked
in the opposite direction, and the operation just described will be repeated.
By reason of these governor valves, the whole or nearly the whole pressure is
removed from the pistons of the compensating cylinders just at the end of the
stroke of the engine, thus relieving the engine of the strain which might result
from arresting these pistons when subjected to full pressure.
It will also be seen that these governor valves operate to control the rate at
which the liquid is permitted to enter the compensating cylinders. This latter is
a feature of great importance, because it allows the compensating cylinders to
develop their full power only when the engine is operating at its normal speed, and
thus prevents the engine from acting violently in case it is suddenly relieved of its
load in such manner as not to affect the pressure in the force main, as by the
breaking of a piston rod. This finction of the governor valves is of especial
importance in those cases where the pressure in the compensating cylinder or
cylinders is not derived from the pressure in the main, as in such case the power
developed by the compensating cylinder or cylinders does not vary to conform to
variations in the pressure in the main.
The rods 10 are made adjustable in length, and the arms 5 and levers 12 are
slotted, as shown, so that the extent of the movement of the valves 9, and their
time of closing, can be regulated to conform to the different running conditions of
the engine.
It is to be understood that any other form of valve which will perform the same
function may be substituted for the valves 9, without departing from the substance
of the invention, or that a rotary valve or cock combined with a check valve may
be used in place of each of the valves 9.-In such case, the rotary valve or cock
will be operated to regulate the flow of the liquid into the compensating cylinder
or cylinders, while the check valve will operate to permit the liquid to flow freely
out of the cylinder or cylinders. Such an arrangement is, therefore, to be under-
stood as the equivalent of that shown.
In conclusion, it is to be remarked that parts of the invention may be used
without the whole. The accumulator may be used without the governor valves,
-

page_text: and in such case, the cylinder 51 can be made to communicate with the com-
pensating cylinder or cylinders in any convenient manner. The accumulator may
also be used in connection with a governor valve or cock such as described in the
specification of Letters Patent No 15,770 of 1885. So, also, the the governor valves
shown in the present case may be used without the accumulator, that is to say,
when the pressure of the motor fluid is transmitted directly to the compensating
cylinder or cylinders, as described in the specification of the Letters Patent
NOB 2342 of 1884 and 15770 of 1885.
The duplex engine shown in the present case has been selected for the purpose
of illustration, because it is thought the invention is most useful in connection
with the engines of this type. The invention is, however, applicable to any
engine in which a compensating cylinder or cylinders is or are used.
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 me by my Foreign Correspondent I declare that what I claim is :-
1. The combination with a main cylinder or cylinders and piston or pistons, and
a compensating cylinder or cylinders, and piston or pistons arranged to act in
opposition to the main piston or pistons during the first part of the stroke, and in
conjunction therewith during the last part of the stroke, of an accumulator
arranged between the compensating cylinder or cylinders, and the source from
which the pressure in said cylinder or cylinders is derived, substantially as
described.
2. The combination with the main cylinders and pistons forming the two sides
of a duplex engine, and having connections by which the valve or valves of each
side is or are operated by the other side, and a compensating cylinder or cylinders
and piston or pistons for each side of the engine, which is or are arranged to act in
opposition to the main piston or pistons during the first part of the stroke, and in
conjunction therewith during the last part of the stroke, of an accumulator
arranged between the compensating cylinders and the source from which the
pressure in said cylinders is derived, substantially as described.
3. The combination with a main cylinder or cylinders and piston or pistons, and
a compensating cylinder or cylinders, and piston or pistons arranged to act in
opposition to the main piston or pistons during the first part of the stroke, and in
conjunction therewith during the last part of the stroke, of an accumulator con-
sisting of two cylinders of different diameters, and a differential plunger arranged
between the compensating cylinder or cylinders and the source from which the
pressure in said cylinder or cylinders is derived, substantially as described.
4. The combination with the main cylinders and pistons forming the two sides
of a duplex engine, and having connections by which the valve or valves of each
side is or are operated by the other side, and a compensating cylinder or cylinders
and piston or pistons for each side of the engine, which is or are arranged to act in
opposition to the main piston or pistons during the first part of the stroke, and in
conjunction therewith. during the last part of the stroke, of an accumulator con-
sisting of two cylinders of different diameters, and a differential plunger arranged
between the compensating cylinders and the source from which the pressure in
said cylinders is derived, substantially as described.
5. The combination with the main cylinder or cylinders and piston or pistons
of a pumping engine, and a compensating cylinder or cylinders and piston or
pistons arranged to act in opposition to the main piston or pistons during the first
part of the stroke, and in conjunction therewith during the last part of the stroke,
the pressure in said compensating cylinder or cylinders being derived from the
force main, of an accumulator arranged between the compensating cylinder or
cylinders and the force inain, substantially as described.
6. The combination with the main cylinders and pistons forming the two sides
of a duplex pumping engine, and having connections by which the valve or valves
of each side is or are operated by the other side, and a compensating cylinder or

page_text: cylinders and piston or pistons for each side of the engine, which is or are
arranged to act in opposition to the main piston or pistons during the first part of
the stroke, and in conjunction therewith during the last part of the stroke, the
pressure in said compensating cylinders being derived from the force main, of an
accumulator arranged between the compensating cylinders and the force main,
substantially as described.
7. The combination with the main cylinder or cylinders and piston or pistons of
a pumping engine, and a compensating cylinder or cylinders and piston or pistons
arranged to act in opposition to the main piston or pistons during the first part of
the stroke, and in conjunction therewith during the last part of the stroke, the
pressure in said compensating cylinder or cylinders being derived indirectly from
the force main through a body of air or other gas which is subjected to the pressure
in the main, of an accumulator arranged between the compensating cylinder or
cylinders and the force main, substantially as described.
8. The combination with the main cylinders and pistons forming the two sides
of a duplex pumping engine, and having connections by which the valve or valves
of each side is or are operated by the other side, and a compensating cylinder or
cylinders and piston or pistons for each side of the engine, which is or are arranged
to act in opposition to the main piston or pistons during the first part of the struke,
and in conjunction therewith during the last part of the stroke, the pressure in
said compensating cylinders being derived indirectly from the force main through
a body of air or other gas which is subjected to the pressure in the main, of an
accumulator arranged between the compensating cylinders and the force main,
substantially as described.
9. The combination with the main cylinder or cylinders and piston or pistons,
of a pumping engine, and a compensating cylinder or cylinders, and piston or
pistons arranged to act in opposition to the main piston or pistons during the first
part of the stroke, and in conjunction therewith during the last part of the stroke,
the pressure in said compensating cylinder or cylinders being derived indirectly
from the force main through the body of air or other gas in the chamber 97, of the
pump, of an accumulator arranged between the compensating cylinder or cylinders
and said chamber, substantially as described.
10. The combination with the main cylinders and pistons forming the two sides
of a duplex pumping engine, and having connections by which the valve or valves
of each side is or are operated by the other side, and a compensating cylinder or
cylinders and piston or pistons for each side of the engine, which is or are arranged
to act in opposition to the main piston or pistons during the first part of the
stroke, and in conjunction therewith during the last part of the stroke, the pressure
in said compensating cylinders being derived indirectly from the force main
through the body of air or other gas in the chamber 97. of the pump, of an
accumulator arranged between the compensating cylinders and said chamber,
substantially as described.
11. The combination with the main cylinder or cylinders and piston or pistons
of a pumping engine and a compensating cylinder or cylinders and piston or
pistons, which is or are arranged to act in opposition to the main piston or pistons
during the first part of the stroke, and in conjunction there with during the Inst
part of the stroke, of connections by which the pressure in the force main is
transmitted indirectly to the compensating cylinder or cylinders through a body of
air or other gas, substantially as described.
12. The combination with the main cylinders and pistons forming the two sides
of a duplex pumping engine, and having connections by which the valve or valves
of each side is or are operated by the other side, and a compensating cylinder or
cylinders and piston or pistons for each side of the engine, which is or are arranged
to act in opposition to the main piston or pistons during the first part of the stroke,
and in conjunction therewith during the last part of the stroke, of connections by
which the pressure in the force main is transmitted indirectly to the compensating
cylinders through a body of air or other gas, substantially as described.

page_text: 13. The combination with the main cylinder or cylinders and. piston or pistons
of a pumping engine and a compensating cylinder or cylinders and piston
or pistons arranged to act in opposition to the main piston or pistons during the
first part of the stroke and in conjunction therewith during the last part of the
stroke, of connections by which the pressure in the force main is transmitted
indirectly to the compensating cylinder or cylinders through the body of air other
gas in the chamber 97 of the pump, substantially as described.
14. The combination with the main cylinders and pistons forming the two sides
of a duplex pumping engine, and having connections by which the valve or valves
of each side is or are operated by the other side, and a compensating cylinder or
cylinders and piston or pistons for each side of the engine, which is or are arranged
to act in opposition to the main piston or pistons during the first part of the stroke
and in conjunction therewith during the last part of the stroke, of connections by
which the pressure in the force main is transmitted indirectly to the compensating
cylinders through the body of air or other gas in the chamber 97 of the pump,
substantially as described.
15. The combination with a main cylinder or cylinders and piston or pistons and
a compensating cylinder or cylinders and piston or pistons arranged to act in
opposition to the main piston or pistons during the first part of the stroke, and in
conjunction therewith during the last part of the stroke, of a governor valve or
valves arranged to gradually reduce or cut off the flow of the motor fluid into the
compensating cylinder or cylinders as the engine approaches the end of its stroke,
substantially as described.
16. The combination with a main cylinder or cylinders and piston or pistons and
a compensating cylinder or cylinders and piston or pistons arranged to act in
opposition to the main piston or pistons during the first part of the stroke, and in
conjunction therewith during the last part of the stroke, of a governor valve or
valves arranged to gradually reduce or cut off the flow of the motor fluid into the
compensating cylinder or cylinders as the engine approaches the end of its stroke,
and to allow it to flow freely out of the cylinder or cylinders as the engine
commences its stroke, substantially as described.
17. The combination with the main cylinders and pistons forming the two sides
of a duplex engine, and having connections by which the valve or valves of each
side of the engine is or are operated by the other side, and a compensating cylinder
or cylinders and piston or pistons for each side of the engine, which is or are
arranged to act in opposition to the main piston or pistons during the first part of
the stroke, and in conjunction therewith during the last part of the stroke, of
governor valves for each side of the engine, which are arranged to gradually reduce
or cut off the flow of the motor fluid into the compensating cylinders as the engine
approaches the ends of its strokes, substantially as described.
18. The combination with the main cylinders and pistons forming the two sides
of a duplex engine, and having connections by which the valve or valves of each
side of the engine is or are operated by the other side, and a compensating cylinder
or cylinders and piston or pistons for each side of the engine, which is or are
arranged to act in opposition to the main piston or pistons during the first part of
the stroke, and in conjunction therewith during the last part of the stroke, of
governor valves for each side of the engine, which are arranged to gradually
reduce or cut off the flow of the motor fluid into the compensating cylinders, as
the engine approaches the ends of its strokes, and allow it to flow freely out of the
cylinders as the engine commences its strokes, substantially as described.
19. The combination with a main cylinder or cylinders and piston or pistons,
and a compensating cylinder or cylinders and piston or pistons arranged to act
in opposition to the main piston or pistons during the first part of the stroke, and
in conjunction therewith during the last part of the stroke, of an accumulator
arranged between the compensating cylinder or cylinders and the source from which
the pressure in said cylinder or cylinders is derived, and a governor valve or
valves arranged to gradually reduce or cut off the flow of the motor fluid into the

page_text: compensating cylinder or cylinders as the engine approaches the end of its stroke,
substantially as described.
20. The combination with a main cylinder or cylinders and piston or pistons,
and a compensating cylinder or cylinders and piston or pistons arranged to act in
5 opposition to the main piston or pistons during the first part of the stroke, and in
conjunction therewith during the last part of the stroke, of an accumulator
arranged between the compensating cylinder or cylinders and the source from
which the pressure in said cylinder or cylinders is derived, and a governor valve or
valves arranged to gradually reduce or cut off the flow of the motor fluid into the
compensating cylinder or cylinders as the engine approaches the end of its stroke,
and to allow it to flow freely out of the cylinder or cylinders as the engine
commences its stroke, substantially as described.
21. The combination with the main cylinder or cylinders and piston or pistons
of a pumping engine, and a compensating cylinder or cylinders and piston or
pistons arranged to act in opposition to the main piston or pistons during the first
part of the stroke, and in conjunction therewith during the last part of the stroke,
the pressure in the compensating cylinder or cylinders being derived from the force
main either directly or through a body of air or other gas, of a governor valve or
valves arranged to gradually reduce or cut off the flow of the motor fluid into the
compensating cylinder or cylinders as the engine approaches the end of its stroke,
substantially as described.
22. The combination with the main cylinder or cylinders and piston or pistons
of a pumping engine and a compensating cylinder or cylinders and piston or
pistons arranged to act in opposition to the main piston or pistons during the first
part of the stroke, and in conjunction therewith during the last part of the stroke,
the pressure in the compensating cylinder or cylinders being derived from the force
main either directly or through a body of air or other gas, of a governor valve or
valves arranged to gradually reduce or cut off the flow of the motor fluid into the
compensating cylinder or cylinders as the engine approaches the end of its stroke,
and to allow it to flow freely out of the cylinder or cylinders as the engine
commences its stroke, substantially as described.
23. The combination with the main cylinder or cylinders and piston or pistons
of a pumping engine and a compensating cylinder or cylinders and piston or.
pistons arranged to act in opposition to the main piston or pistons during the first
part of the stroke, and in conjunction therewith during the last part of the stroke,
the pressure in the compensating cylinder or cylinders being derived froin the force
main either directly or through a body of air or other gas, of an accumulator
arranged between the compensating cylinder or cylinders and the force main, and a
governor valve or valves arranged to gradually reduce or cut off the flow of the
motor fluid into the compensating cylinder or cylinders as the engine approaches
be end of its stroke, substantially as described.
24. The combination with the main cylinder or cylinders and piston or pistons
f a pumping engine, and a compensating cylinder or cylinders and piston or
istons arranged to act in opposition to the main piston or pistons during the first
art of the stroke, and in conjunction therewith during the last part of the stroke,
he pressure in the compensating cylinder or cylinders being derived from the force
ain either directly or through a body of air or other gas, of an accumulator,
rranged between the compensating cylinder or cylinders and the force main, and
governor valve or valves arranged to gradually reduce or cut off the flow of the
otor fluid into the compensating cylinder or cylinders as the engine approaches
e end of its stroke, and to allow it to flow freely out of the cylinder or cylinders
the engine commences its stroke, substantially as described.
25. The combination with the main cylinder or cylinders and piston or pistons
a pumping engine, and a compensating cylinder or cylinders and piston or
stons arranged to act in opposition to the main piston or pistons during the first
rt of the stroke, and in conjunction there with during the last part of the stroke,
connections by which the pressure in the force main of the pump is transmitted

page_text: indirectly to said compensating cylinder or cylinders through a body of air or
other gas, which is subjected to the pressure in the force main, and means for
supplying air to said body to maintain its volume, substantially as described.
26. In an engine constructed substantially as shewn and described, the com-
bination with the accumulator cylinder 53, of the pipe 54 communicating with the
main, and having the cock or gate 55, substantially as described.
27. The combination with the accumulator cylinder 53, of the pipe 54 communi-
cating with the air chamber 97, and the pipe 48 having the cock 47, through
which a small amount of water can be admitted to the cylinder 53, substantially as
described.