Improvements in and connected with Steam Engines.
Year: 1897

page_text: Improvements in and connected with Steam Engines.
I, PIERRE MARCHAND, of 74, Rue Pierre Legrand, Lille, in the Republic of
France, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to steam engines capable of working without expan-
sion or with a fixed or variable expansion, and particularly suited for driving
direct-acting pumps.
In order that this invention may be clearly understood I will describe by way
of example a type of a triple-expansion engine, with three tandem-cylinders
constructed in conformity with my system and capable of having either a fixed
or a variable expansion.
I will first describe this engine as working with a fixed expansion. The
principle of this improved system lies in the storage of a portion of the exhaust
steam from the admission cylinder and in its distribution to the expansion
cylinders at the proper time.
The direct-admission cylinder, the first expansion cylinder, and the second
expansion cylinder are arranged tandem like and their pistons have one common
piston rod.
Side by side with the direct admission cylinder and the first expansion cylinder
reservoirs are arranged, formed by cylinders, the volume of which can be rendered
variable or even reduced to nil, by the play of one or two pistons so displaced
as to produce a space.
In the hollow cylindrical space two pistons can be so displaced that, owing
to their movement, the volume of this hollow is formed, then increased to a
maximum and subsequently reduced in order to be finally annulled; these pis-
tons recede from one another during the time that steam is exhausted from the
admission cylinder and approach each other during the time when the space
formed between them, communicates with the subsequent expansion cylinder.
The approachment of these pistons is effected by means of springs or by other
reacting means and mechanisms of any suitable system', 'the action of which can
be regulated according to requirements.
The three cylinders are provided with slide valves of a known type, distributing
in the usual manner the steam arriving in the valve chests.
The admission cylinder is provided with the following parts.
Into both ends of the cylinder is inserted a controlling mechanism constructed
as follows.
A cylindrical piece is perforated so as to form two channels capable of being
set in communication by the movement or play of a slide valve, moving in a
cavity; this slide valve is traversed by a screw threaded rod which can be operated
from the exterior and which from the opposite side can protrude against the
bottom of the cylinder into the interior of the latter.

page_text: · One of the channels communicates with the steam generator by the aid of a
pipe provided with any suitable valve, the other channel communicates by a
pipe with a cylinder, the function of which will be hereinafter explained.
Another channel connected to the reservoir by a pipe can communicate with
the second channel by a channel when a groove provided in the slide valve
places this latter channel and a branch conduit of the second channel into com-
imunication. The slide valve is actuated by a spring which has the tendency to
push it to the side of the interior of the direct admission cylinder.
The ordinary slide-valve of the cylinder receives its movement through a
piece or lug of a double piston which is displaced in a cylinder forming in reality
two cylinders, in each of which moves one piston end; each of these cylinders
communicates through a pipe with the second channel of the corresponding
mechanism; on the other hand, each pipe communicates with the corresponding
portion of the cylinder, by a channel, The piston is perforated longitudinally
so as to form a channel in the interior of which a rod can move, which latter
terminates at each end in a double seat-valve capable of intercepting the steam
passing into the longitudinal channel of the piston.
The exhaust from the direct admission cylinder can on the one hand com-
municate with the valve chest of the first expansion cylinder and on the other
hand with the reservoir by means of clack valves which open toward the interior
of this latter; the reservoir and the other exhaust portion open into a simple
valve chest through the medium of two orifices and of a double auxiliary-slide
valve; this double slide valve only acts at certain moments of the piston stroke,
as will be seen from the description of the operation; for attaining this object
any appropriate mechanical devices may be employed; for instance the rod of
the slide valve carries a cross bar sliding under friction upon a portion of the
rod of the double slide valve above mentioned and displacing itself between
two abutments, the rod of the double slide valve is on the other hand connected
to an arm pivoted to the frame of the engine and its movement is produced by
its striking against a piece or projection mounted on the piston rod at each
forward and backward stroke of the said rod.
The auxiliary slide valve of the first expansion cylinder, which is like the
direct-admission cylinder, provided with a reservoir of a variable volume, is
controlled by its main slide valve in the same manner as in the case of the
direct-admission cylinder.
The actuation of this main slide valve of the first expansion cylinder is effected
by a device suitably arranged on the rod of the main slide valve of the direct
admission cylinder. In like manner the main slide of the first expansion
cylinder controls, in its turn, the main slide valve of the second expansion
cylinder, this latter cylinder has no reservoir of a variable volume and is there-
fore not provided with auxiliary slides.
The working of the engine is as follows:
Let us suppose the piston to be at the termination of its course toward the
right; it has moved the rod and consequently the slide valve of the controlling
mechanism or the orifice of the steam inlet is uncovered and the steam filling
the free space lying between the cover and the piston, will form a cushion, while,
the piston ring or collar closes the exhaust orifice on this side. The piston
arriving at the end of its stroke pushes the above mentioned rod still further
forward; the orifice of the second channel is then uncovered and the steam is
admitted behind the double piston; the latter drives the valve which places
itself into a space provided upon the face of the double piston; the communica-
tion between the two faces of this latter is then intercepted, it is pushed toward
the left, carrying with it the whole device of the distributing slides. Before
arriving at the end of its stroke, it stops the orifice of the channel acting as a
discharge or waste-cock; at this moment the left hand valve closes the orifice
of the pipe on this side; while the piston terminates its stroke the valve dis-
engages or clears the opening in which it was located, so that, while the com-

page_text: munication between the two piston faces is restored, the latter is prevented from
bearing against the bottom.
The auxiliary slide-valve then opens communication between the exhaust of
the cylinder and the valve chest of the first expansion cylinder intercepting the
communication between this latter and the reservoir of the direct admission
cylinder. This reservoir is then filled with exhaust steam from the admission
cylinder owing to the action of the clack valves which open under the force of
the steam.
The engine then works toward the left; as the pressure decreases in the
valve chest of the first expansion cylinder, the clack valves close under the pres-
sure of the steam confined in the reservoir which, then, is isolated from the whole
operating device.
At the moment required for receiving the transmitted movement as described
and which movement is suitably regulated, the rod of the double slide valve
will be actuated and this latter while being displaced toward the left
cuts off"
the communication between the valve chest of the first expansion cylinder and
the exhaust from the direct admission cylinder placing this latter into com-
munication with the condenser, or with the admission to a second expansion
cylinder in the case of double expansion.
At this moment, the double slide valve opens with its part the communication
between the reservoir and the valve chest communicating with the valve chest
of the first expansion cylinder which is then supplied with steam from this
reservoir. The steam remains at the pressure determined by the counter pres-
sure from the springs or other means of reaction, until the reservoir has been
emptied; its volume is then nil or nearly nil and the steam continues to expand
until the end of the stroke is reached. This reaction of the volume of the
reservoir to nil has for its object to suppress as much as possible the noxious
spaces and consequently to increase the medium pressure of expansion, whereby
the thermic efficiency of the machine is increased.
When the driving pistons have nearly reached the end of the stroke, the piston
ring or collar stops the exhaust channel at this side; at the same time the pis-
ton drives the rod of the slide valve of the controlling device which is thus
actuated; the steam is admitted to the double piston and the same phenomena
are repeated.
As soon as the piston ceases to drive the rod the slide valve returned by the
spring closes the first and second channels and uncovers the auxiliary channel
thus placing the face of the double piston into communication with the reser-
voir; this double piston is then ready to receive the inverse impulse.
If a quadruple or other expansion is required, the expansion cylinders would
be provided with steam chests or reservoirs similar to that already described
excepting the last cylinder, which would not receive any. In the case of a
double expansion, only the direct-admission cylinder would receive a reservoir
or chest.
The system which I have described may be simplified while retaining. the
fundamental arrangement; that is to say the feeding of the expansion cylinders
from reservoirs of a variable volume.
The clack valves and the double slide valve with all the appertaining con-
nections may also be omitted. The springs or other means of reaction to the
pistons of the reservoirs or chests are adjusted to the final expansion pressure
of the expansion cylinders supplied from these reservoirs; the efforts or working
effects then are constant during the whole duration of the stroke; but the
thermic efficiency will be reduced.
The system may be advantageously employed on board ship, for the various
kinds of pumps used there. These machines apart from the fact that they
occupy little space, would offer great simplicity owing to the suppression of
movements; the same is the case by reason of the great regularity of stresses.

page_text: The organic efficiency would be still superior to that of pumps at present
employed.
In order greatly obɣiate this reduction of the thermic efficiency, the engine
may be simplified by omitting the clack valves and a portion of the auxiliary
double slide valve but still having an auxiliary slide valve and its return motion
or mechanism.
At a certain moment of the slide the intermediate expansion cylinder, is
isolated the steam will continue to expand therein as in an ordinary cylinder
after the admission, while the exhaust from the said cylinder to the third cylinder
continues; the exhaust from the direct admission cylinder is then completed
in this third cylinder. In like manner, in the case of a triple, quadruple or
other expansion, one or more cylinders are isolated and complete the evacuation
of the preceding into one of the following or to the condenser but then, in this
latter case, a certain quantity of steam is lost.
In this manner the final action or working effect upon the piston of the direct
admission cylinder will be considerably increased; and it is possible to increase
even more the initial working effects upon the other pistons by raising the
initial pressures, which can be done by suitably adjusting the springs or other
means reactory to the pistons of the reservoirs.
The system still very economical may be advantageously employed for work
which requires great economisation of fuel.
With engines working with variable expansion it will be constructed the same
to suit the minimum feed; to the admission cylinders small reservoirs are con-
nected which may be isolated from the admission cylinder by means of cocks;
the volume of introduced steam is thus increased, which amounts to the same as
if the period of introduction into ordinary engines be increased. The total
volume of these reservoirs will be so calculated as to ensure an effect capable
of the maximum efficiency. The supplementary work is in fact ensured by the
increase of the medium expansion pressure, which increase results from the
greatest volume of steam required to expand.
These reservoirs of which several are arranged at each side of the cylinder
will, on placing one or several into operation, allow of fixing the intermediate
efforts or effects corresponding to likewise intermediate supplies.
In case where the advantage of the expansion is not desired to be utilized,
the engine may be constructed with the one single admission cylinder operating
at full pressure this cylinder then only comprises the slide valve actuated by
the double piston.
My device offers the following advantages.
On examining the phases of the operation, it is seen that the maximum
length of stroke can be utilized by appropriately regulating, for the various
rates of speed, the action or impulse of the rod of the controlling device; the
steam cushion is thus obtained in a perfectly reliable manner; the starting of
the double piston is ensured by the maximum opening at the time when the
impulse commences--of the steam inlet on this double piston and by the position
of this steam inlet upon the top and bottom.
But to these analogous advantages, although superior to those already known
in existing engines of the direct-action type, associates itself one which is of
a high value: namely that of being able to apply expansion, while nevertheless
having a constant effort (working effect) or nearly constant effect during the
whole duration of the stroke, while at the same time, by a decrease of the initial
efforts, the changes of direction of the liquid vein in the clack valves take place
more slowly.
This regularity in the efforts is very important inasmuch as the abrupt actions
and concussions so greatly injurious to the stability of the apparatus are avoided;
at the same time the changes of direction taking place in a slower manner are
advantageous inasmuch as they increase the practical efficiency.
Moreover, owing to the faculty of employing, at will, a variable expansion,

page_text: this engine meets all requirements industrial as well as domestic, for drawing
or raising water. Moreover the saving resulting from the omission of all the
mechanisms ordinarily employed in connection therewith, must be taken into
consideration.
Having thus fully described my invention I declare that I do not limit myself
to any detail parts of the particular arrangement or construction; it is under
this consideration that I have represented a type of triple-expansion engine with
three cylinders placed endwise; I reserve the right to construct cylinders with
pistonless reservoirs having a fixed volume, in which case the reservoir may
form a steam jacket.
Finally, this engine, whatever may be the number of cylinders employed, is
not solely designed for the working of pumps but may be arranged and used for
all suitable purposes; the same may be driven either by steam or by another
fluid, such as compressed air, for example.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
I, PIERRE MARCHAND, of 74, Rue Pierre Legrand, Lille, in the Republic of
France, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
-
•
This invention relates to steam engines capable of working expansively or
with a fixed or variable expansion, and particularly suited for driving direct-
acting pumps.
In order that this invention may be clearly understood I will describe by way
of example a type of a triple-expansion engine, with three tandem-cylinders
constructed in conformity with my system and capable of having either a fixed
or a variable expansion.
In the accompanying drawing
Figure represents a longitudinal section of the arrangement of the three
cylinders of this engine.
Figure 2 is a section on the line 2-2 of the direct admission cylinder and its
constituent parts.
Figure 3 is a section on the line 3₁-3, 3-3 of Figure 2;
Figure 4 is a plan representing the whole of this cylinder-arrangement and
its reservoir, the slide box and the slide valves being omitted;
Figure 5 is a section on the line 5-5 of Figure 4.
Figure 6 is a partial section on line 6-6 of Figure 4;
Figure 7 is a longitudinal section of a portion of the admission cylinder.
Figure 8 is a section on the line 8-8 of Figure 7.
Figure 9 is a section, similar to Figure 2, of a direct-admission cylinder and
its constituent parts, but with certain modifications
Figure 10 is a similar section but provided with other modifications.
Figure 11 is a section representing the whole arrangement of a cylinder and
its reservoir, similar to Figure 2, the reservoir being however in this instance
of a fixed volume; and
Figure 12 is a reproduction of diagrams.

page_text: I will first describe this engine as working with a fixed expansion.
The principle of this improved system lies in the storage of a portion of the
exhaust steam from the admission cylinder and in its distribution to the expan-
sion cylinder at the proper time.
The direct-admission cylinders A the first expansion cylinders A¹ and the
second expansion cylinder A are arranged tandem like or in line and their
pistons B, B1 B2 have a common piston rod C.
Side by side with the direct-admission cylinder A and the first expansion
cylinder A¹ are arranged, reservoirs, formed by cylinders, the volume of which
can be rendered variable or even reduced to nil, by the play of one
pistons so displaced as to produce a space.
or two
In the drawing only the reservoir of the direct-admission cylinder has been
represented, that of the first expansion-cylinder being identical. In the hollow
cylindrical space or reservoir D two pistons E can be so displaced that, owing to
their movement, the volume of this space can be increased to a maximum or
reduced and if necessary finally annulled; these pistons recede from one or
another during the time that steam is exhausted from the admission cylinder
and approach each other during the time when the space D formed between
them, communicates with the following expansion cylinder. The approach of
these pistons is effected by means of springs e or by other reacting means and
mechanisms of any suitable system, the action of which can be regulated accord-
ing to requirements.
The three cylinders A A¹ As are provided with slide valves F F¹ F2 of a known
type, distributing in the usual manner the steam arriving in the valve chests.
The admission cylinder A is provided with the following parts.
Into both ends of the cylinder is inserted a controlling mechanism G con-
structed as follows. This mechanism, Figure 7, is formed by a cylindrical piece
perforated so as to form two channels g and g¹, capable of being set in com-
munication by the movement or play of a slide valve g², moving in a cavity g';
this slide valve is traversed by a screw threaded rod g which can be operated
from the exterior and which from the opposite side can protrude against the
bottom of the cylinder into the interior of the latter.
The channel g communicates with the steam generator by the aid of a pipe H
provided with a stop valve of any suitable kind; the other channel g com-
municates by a pipe I with a cylinder J, the function of which will be herein-
after explained.
Another channel 96 connected to the reservoir D by a pipe g7 can communicate
with the channel g₁ by a channel when a groove provided in the slide
valve places this channel 9 and a branch conduit g¹ of the channel g¹ into
communication. The slide valve g² is actuated by a spring 9 which has the
tendency to push it to the side of the interior of the cylinder A.
The ordinary slide-valve F of the cylinder receives its movement through a
piece or lug of a double piston j¹ which is displaced in a cylinder J forming in
reality two cylinders, in each of which moves one piston end j¹; each of these
cylinders communicates through a pipe I with the channel g' of the corresponding
mechanism G; on the other hand, each pipe I communicates with the corre-
sponding portion of the cylinder J, by a channel i. The piston j¹ is perforated
longitudinally so as to form a channel, in the interior of which a rod can
move, which latter terminates at each end in a double seat-valve 3 capable of
intercepting the steam passing into the longitudinal channel of the piston j¹.
The exhaust from the cylinder A can on the one hand communicate with the
valve chest of the first expansion cylinder A¹ and on the other hand with the
reservoir D by means of clack valves M which open toward the interior of this
latter; the reservoir D and the other exhaust portion open into a ingle valve
chest through the medium of two orifices and of a double auzinary slide valve n n¹;
this double slide valve only acts at certain moments of the piston stroke, as will
be seen from the description of the operation; for attaining this object any

page_text: appropriate mechanical devices may be employed; I have represented one of them
in Figure 4; the rod k of the slide valve F carries a cross bar k¹ sliding under
friction upon a portion of the rod n² of the double slide valve n n' and displacing
itself between two abutments ³ ³; the rod n³ is on the other hand connected to
an arm pivoted to the frame of the engine 5 and its movement is produced
by its striking against a piece or projection c mounted on the piston rod C of
the pistons at each forward and backward stroke of the said rod.
The auxiliary slide valve of the first expansion cylinder A¹, which is, like
the direct-admission cylinders, provided with a reservoir of a variable volume,
is controlled by its main slide valve in the same manner as in the case of the
direct admission cylinder.
The actuation of this main slide valve of the first expansion cylinder is effected
by a device suitably arranged on the rod k of the main slide valve of the cylinder A.
In like manner the main slide F¹ of the cylinder A¹ controls, in its turn, the
main slide valve F2 of the cylinder A3, this latter cylinder has no reservoir of a
variable volume and is therefore not provided with auxiliary slides.
The operation of the engine is as follows:
Let us suppose the piston B to be at the termination of its course toward the
right; it has moved the rod g and consequently the slide valve g² of the controlling
mechanism or device G, the orifice of the steam inlet g is uncovered and the
steam filling the free space, lying between the cover and the piston, will form a
cushion while the piston ring or collar closes the exhaust orifice on this side.
The piston B arriving at the end of its stroke pushes the above mentioned rod g
still further forward; the orifice of the channel g¹ is then uncovered and the
steam is admitted behind the double piston j; the latter drives the valve j³
which places itself into a space provided upon the face of the double piston j¹;
the communication between the two faces of this latter is then intercepted, it
is pushed toward the left, carrying with it the whole device of the distributing
slides. Before arriving at the end of its stroke, it stops the orifice of the channel
acting as a discharge or waste-cock; at this moment the left hand valve closes
the orifice of the pipe I on this side; while the piston j terminates its stroke,
the valve disengages or clears the opening in which it was located, so that,
while the communication between the two piston faces is restored, the latter is
prevented from bearing against the bottom.
The auxiliary slide-valve n n¹ then occupies the position indicated in Figures 5
and 6, opening the communication between the exhaust of the cylinder and the
slide box valve chest N¹ of the expansion cylinder A' and intercepting the com-
munication between this latter and the reservoir D of the cylinder A. This
reservoir is then filled with exhaust steam from the admission cylinder A owing
to the action of the clack valves M which open under the force of the steam.
The engine then works toward the left; as the pressure decreases in the valve
chest of the first expansion cylinder A¹, the clack valves M close under the
pressure of the steam confined in the reservoir which, then, is isolated from the
whole operating device.
At the moment required for receiving the transmitted movement as described
and which movement, is suitably regulated, the rod of the double slide valve n n¹
will be actuated and this latter while being displaced toward the left cuts off
the communication between the valve chest of the first expansion cylinder A¹
and the exhaust from the direct admission cylinder A, placing this latter into
communication with the condenser, or with the admission to a second expansion
cylinder in the case of double expansion.
At this moment, the double slide valve n n opens with its part n the com-
munication between the reservoir D and the valve chest N* communicating
with the valve chest N¹ of the expansion cylinder A' which is then supplied with
steam from this reservoir. The steam remains at the pressure determined by
the counter pressure from the springs or other means of reaction, until the
reservoir has been emptied; its volume is then nil or nearly nil and the steam

page_text: continues to expand until the end of the stroke is reached. This reduction of
the volume of the reservoir to nil has for its object to suppress as much as possible
the noxious spaces and consequently to increase the medium pressure of expan-
sion, whereby the thermic efficiency of the machine is increased.
When the driving pistons have nearly reached the end of the stroke, the
piston ring or collar stops the exhaust channel at this side; at the same time
this piston drives the rod g of the slide valve which is thus actuated; the
steami is admitted to the double piston and the same phenomena are repeated.
As soon as the piston ceases to drive the rod g, the slide valve g² returned by
the spring closes the channels and gl and uncovers the auxiliary channel gi
thus placing the face of the double piston j¹ into communication with the reser-
voir D; this double piston is then ready to receive the inverse impulse.
If a quadruple, or other expansion is required, the expansion cylinders would
be provided with steam chests, or reservoirs, similar to 1) excepting the last
cylinder, which would not receive any. In the case of a double expansion,
only the direct admission cylinders would receive a reservoir or chest.
The system which I have described may be simplified while retaining the
fundamental arrangement that is to say the feeding of the expansion cylinders
from reservoirs of a variable volume.
The clack valves M and the double slide valve n n¹ with all the appertaining
connections (Figure 10) may also be omitted. The springs or other means of
reaction to the pistons E of the reservoirs or chests are adjusted to the final
expansion pressure of the expansion cylinders supplied from these reservoirs;
the efforts or working effects then are constant during the whole duration of the
stroke; but the thermic efficiency will be reduced.
The system may be advantageously employed on board ship for the various
kinds of pumps used there. These engines apart from the fact that they occupy
little space would offer great simplicity owing to the suppression of movements;
the same is the case by reason of the great regularity of stresses. The organic
efficiency would be still superior to that of pumps at present employed.
In order to greatly obviate this reduction of the thermic efficiency, the engine
may be simplified by omitting the clack valves M. and a portion n¹ of the auxiliary
double slide valves n n¹; but still leaving an auxiliary slide valve and its
return motion or mechanism.
At a certain moment of the stroke the intermediate expansion cylinder is
isolated, the steam will continue to expand therein as in an ordinary cylinder
after the admission, while the exhaust from the said cylinder to the third cylinder
continues; the exhaust from the direct admission cylinder is then completed
in this third cylinder. In like manner, in the case of a triple, quadruple or
other expansion, one or more cylinders are isolated and completes the evacuation
of the preceding into one of the following or to the condenser but then, in this
latter case, a certain quantity of steam is lost.
In this manner the final action or working effect upon the piston of the direct-
admission cylinder will be considerably increased; and it is possible to increase
even more the initial working effects upon the other pistons by raising the
initial pressures, which can be done by suitably adjusting the springs or other
means reactory to the pistons of the reservoirs.
The system still very economical may be advantageously employed for work
which requires great economisation of fuel.
Figure 12 shows indicator diagrams representing the pressures and efforts or
effects; these diagrams have been studied with regard to the particular case of
three cylinders placed end to end; it is found that the line representing the
total effect deviates only slightly from the horizontal line.
To obtain with engines a machine working with variable expansion, such
engine will be constructed to suit the minimum feed; to the admission cylinders
small reservoirs such as P P are connected which may be isolated from the
admission cylinder by means of cocks; the volume of introduced steam is thus

page_text: increased, which amounts to the same as of the period of introduction into
ordinary engines be increased. The total volume of these reservoirs will be so
calculated as to ensure an effect capable of the maximum efficiency. The supple-
mentary work is in fact ensured by the increase of the medium expansion pres-
sure, which increase results from the greatest volume of steam required to
expand.
These reservoirs P of which several are arranged at each side of the cylinder
will, on placing one or several into operation, allow of fixing the intermediate
efforts or effects corresponding to likewise intermediate supplies.
In case where the advantage of the expansion is not desired to be utilized,
the engine may be constructed with the one single admission cylinder operating
at full pressure, this cylinder then only comprises the slide valve actuated by
the double piston.
My device offers the following advantages:
On examining the phases of the operation, it is seen that the maximum length
of stroke can be utilized by appropriately regulating, for the various rates of
speed, the action or impulse of the rod g; the steam cushion is thus obtained
in a perfectly reliable manner; the starting of the double piston, is ensured by
the maximum opening at the time when the impulse commences of the steam
inlet on this double piston and by the position of this steam inlet upon the top
and bottom.
But to these analogous advantages, although superior to those already known
in existing engines of the direct-acting type, associates itself one which is of a
high value; namely that of being able to apply expansion, while nevertheless
having a constant effort (working effect) or nearly constant effect during the whole
duration of the stroke, while at the same time by a decrease of the initial efforts
or, the changes of direction of the liquid vein in the clack valves take place
more slowly.
This regularity in the efforts is very important in as much as the abrupt
actions and concussions so greatly injurious to the stability of the apparatus
are avoided; while at the same time the changes of direction taking place in a
slower manner are advantageous in as much as they increase the practical
efficiency.
Moreover, owing to the faculty of employing, at will, a variable expansion,
this engine meets all requirements industrial as well as domestic, for drawing
or raising water. Moreover the saving resulting from the omission of all the
mechanisms ordinarily employed in connection therewith, must be taken into
consideration.
Having thus fully described my invention, I declare that I do not limit myself
to any detail parts of the particular arrangement or construction; it is under
this consideration that I have represented a type of triple-expansion engines
with three cylinders placed endwise; I reserve the right to construct cylinders
with pistonless reservoirs having a fixed volume, such as shown in Figure 11, in
which case the reservoirs may form a steam jacket.
Finally, this engine, whatever may be the number of cylinders employed, is
not solely designed for the working of pumps but may be arranged and used for
all suitable purposes; the same may be driven either by steam or by another
fluid, such as compressed air, for example.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a steam engine the storage, in a reservoir having a fixed or variable volume,
of a portion of the exhaust steam from a direct admission cylinder or from an
expansion cylinder, so as to be enabled to utilize the same at a given moment
in one or more other expansions cylinders, substantially as above described and
specified.

page_text: 2. The use, in combination with a steam cylinder, of a reservoir having a
variable capacity, the volume of which can be reduced to nil at the end of the
stroke this variation of volume being realized by the play of one or two pistons
placed under the action of springs or any other adjustable means of reaction;
this reservoir receiving the steam through the medium of clack valves or without
such valves and distributing the same by the intermediary of a slide valve or
without such and allowing-while duly effecting an expansion-to produce
constant efforts (working effects) or nearly constant efforts during the whole
duration of the stroke; substantially as above described and specified with
reference to the accompanying drawing.
3. In connection with a direct-admission cylinder, the arrangement of separ-
able reservoirs, in a sufficient number, with the object of effecting a variable
expansion; or the arrangement of auxiliary cylinders into which the additional
steam would be admitted in order to be subsequently distributed in the expan-
sion cylinders, so as to increase the medium expansion pressure, substantially
as above described and specified with reference to the accompanying drawings.
4. A double piston serving to actuate the slide valves, comprising a rod
traversing the said piston longitudinally and having valves provided at its
extremities which place themselves into cavities arranged on each end of this piston,
so as to have an initial displacement independent of the double piston, whereby
the steam is enabled to arrive through the ends without being separated while
further the exhaust can be interrupted before the end of the stroke and a com-
munication between the two faces of the double piston be established before
the end of said stroke; substantially as described and specified with reference
to the accompanying drawings.
5. In combination with, the double-piston device forming the subject of the
4th Claim, a slide valve device effecting the distribution of steam of this piston,
this slide valve being connected to a rod driven by the motor piston at each
stroke of the latter, the impulse from this rod, and consequently the operation
of the slide valve being made adjustable to the various rates of speed; substan-
tially as described and specified with reference to the accompanying drawing.
6. A steam engine presenting in its whole construction and its detail parts
the characteristic features, substantially such as described and specified with
reference to the accompanying drawing.
Datod this 29th day of April 1898
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.