IMPROVEMENTS IN STEAM ENGINES
Year: 1875

page_text: LETTERS PATENT to Emile Boire, of the Firm Baudet et Boire, of
Lille (Nord), France, Engineers, for the Invention of "IMPROVEMENTS
IN STEAM ENGINES."
Sealed the 31st August 1875, and dated the 19th March 1875.

page_text: This combination of parts for distributing the steam is much varied;
in all the modifications the distributors have a curved face having the
form of a cock cylindrical or nearly so, or have valves equilibrated or
not. These distributors do not remain long steam-tight, besides, the
action of the springs or counterweights is transmitted to them by
arrangements of levers which produce a certain amount of complication.
Numerous inconveniences thus result which are overcome by employing
the arrangement which I now proceed to describe.
My improved arrangement or system for distributing the steam com-
prises the employment of ordinary plane slide valves, and of counter
slides or distributors, which are likewise plane and are operated by
catches or clicks under the command of the regulator, and returned by
the action of steam contained in the distributing box.
The cylinder of the engine is provided with ports which put it in
communication with the steam chest or with the exhaust as the case
may be.
According to one arrangement I employ two steam chests, one for
cach end of the cylinder, and two exhaust outlets, but one steam chest
and one exhaust outlet may be made to answer the purpose if preferred.
The steam chests are in communication with the generator, and in them
work the slide valves and the distributors. The slide valves have a
plane face and are moved by an excentric to which they are connected
by a rod. Ports are formed in the slide valves to allow of the intro-
duction of steam, and the body of these valves is hollowed out to
allow of the escape of the steam. The distributors work against the
slide valves to open or close their ports, and they are carried by rod
pistons which work in a cylinder; the rods are furnished with segments
to prevent the leakage of steam, and a packing at the outer end of the
cylinder will stop any leakage which tends to escape. The section of
these rod pistons is sufficient to enable the steam which acts upon them
to return the distributors with every desirable rapidity and precision.
Air pistons are carried by these rod pistons and work in a double air
cylinder, rigidly attached to the excentric rod so as to move therewith.
Fixed abutments in the interior of or outside the steam chests limit the
movement of the distributors. Moveable catches or clicks are fitted
upon axes upon the double air cylinder, so that these catches follow the
movement of the excentric rod. When the catches are in contact with

page_text: the rod pistons they communicate to them the movement of the
excentric. A moveable arm connected by levers with the regulator is
employed to release the catches.
The action is as follows:-When the machinc is in work the following
takes place. If the piston of the steam cylinder is moving, for example,
to the left the excentric rod will be moving in the opposite direction.
The port of the slide valve at the right is uncovered by the corresponding
distributor, the movement of the slide valve will open the port at that
end of the steam cylinder, and will put the cylinder in communication
with the steam chest. During this time the relative movement of the
distributor and of the slide valve is nil, as they both move in the same
direction with the same speed. The right-hand catch meets the
movable arm and will turn around its axis, its release from the rod
piston will be effected, and the pressure upon this piston of the steam in
the chest will return the distributor quickly a sufficient distance to
cause it to cover the port of the slide valve. It is to prevent the con-
cussion of this quick return of the distributor that I use the air cylinder.
The air contained in it is driven back and escapes by small holes formed
for the purpose, a resistance being thus produced which forms a spring
and diminishes the concussion. The air cylinder also serves as a guide
for the movements of the rod pistons. After the return movement
caused by the distributor, the air piston of this distributor will be at the
bottom of the air cylinder, and this cylinder will impart to the dis-
tributor the same movement as that of the slide valve, so that the
relative movement of the slide valve and of the distributor in its new
position will again be nil. As soon as the release of the catch has been
effected, all communication between the engine cylinder and the steam
chest ceases, and the steam introduced into the cylinder expands therein
causing the piston to make a stroke. During this time the slide valve
continues its movement, returns to put its hollowed portion in communi-
cation with the cylinder, and the steam introduced into the latter
escapes freely into a condenser or into the atmosphere. During all this
period the relative movement of the distributor and of the slide valve
continues to be nil, but before the slide valve finishes its entire movement
the distributor meets the fixed abutment and is held while the slide
valve finishes its stroke. During this period the port in the slide valve
is uncovered, the catch again put into communication by means of a
spring or of its own weight with the rod piston, and the whole is ready
to recommence a fresh movement of the steam piston.

page_text: It will readily be understood that the arrangement just described for
distributing the steam in the cylinder of an engine may be modified
with regard to the relative position of the different parts. For example,
the two steam chests may, as before mentioned, be made in one, and in
this case the two slide valves will be combined in onc, so that a single
escape outlet situated between the two valve ports would suffice for the
exhaustion of the steam.
It will also be understood that the slide valves and the distributors
might move in different media, so that the cylinder would be provided
with different ports for the admission and escape of the steam.
An examination of the action of this mode of distribution shews that
the pressure exerted in one of the two rod pistons of the distributors is
nearly always equilibrated by the pressure of the steam on the other
rod piston, so whatever be the section of these rod pistons the power
absorbed by their movement will always be very slight and very much
less than that which is absorbed in stretching the springs or displacing
the counterweights usually employed. Considered in this point of view
my arrangement has a further advantage over other arrangements.
My combination of slide valves having a plane face and of catches
can if required be submitted to the action of springs and counterweights;
for instance, levers and counterweights may be substituted for the
action of steam on the rod pistons for returning the distributors; or
instead of the counterweights springs may be used; the fixed abut-
ments will in this case be placed outside the steam chest.
The mode of distributing the steam herein-before described may be
applied to all cylinder engines, whether the cylinders be inclined,
vertical, or horizontal.
In engines arranged for this mode of distribution, and in other engines
where the distribution is controlled by the regulator, it is desirable to
have means of being assured at any instant of the duration of the
admission of steam. This duration being in direct ratio with the steam
pressure and the amount of resistances to be overcome, it is well to
know when necessary if the variation of the resistances is due to normal
or to abnormal causes.
In order to provide for this I 'attach to the engine an apparatus com-
posed of, 1st, a manometer to indicate the pressure of the steam in the

page_text: steam chests; 2nd, a manometer to indicate the pressure or the depression
of the condenser; 3rd; an indicator which shews the regularity of working
of the machine. This indicator is put in motion by one of the operating
shafts of the regulator, the movement of the indicator is therefore in
relation with that of the engine; 4th, a graduated sector, which shows
at any instant the degree of admission of steam and the corresponding
horse-power.
In applying this apparatus to my system of distribution for example,
the moveable arm of the regulator moves through the intermediation of
a rod a hand, which indicates on the graduated sector (the graduations of
which correspond with the different positions of the regulator) the degree
of admission of steam and the horse-power of the engine. One of the
manometers is in communication with the condenser and the other with
the steam chests, while the indicator receives its movement from the
regulator shaft, as before mentioned. The indications given by this
apparatus are very important to shew the working of the machine, and
oven to shew the action of the general plant of the factory.
As the indications may at any moment be more important for the
manager than for the engineman they may be transmitted by means of
electric wires and electro-magnets to similar apparatus situated at any
required place and distance. The manometers or the indicator may if
desired be dispensed with.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Emile Boire in the Great Seal Patent Office
on the 2nd September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EMILE
BOIRE, of the Firm Baudet et Boire, of Lille (Nord), France, Engineers,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of March, in the year of our
Lord One thousand eight hundred and seventy-five, in the thirty-eighth
year of Her reign, did for Herself, Her heirs and successors, give and
grant unto me, the said Emile Boire, Her special licence that I,
the said Emile Boire, my executors, administrators, and assigns, or

page_text: such others as I, the said Emile Boire, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN STEAM ENGINES,"
upon the condition (amongst others) that I, the said Emile Boire, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Emile Boire, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being had to the accom-
panying Drawings, that is to say :-
-

page_text: this latter class, which is preferable, that my mode of distribution
applies.
The arrangements which have hitherto given the most satisfactory
results consist in transmitting the movement of an excentric directly or
indirectly to the steam distributors through the intermediation of catches
or clicks, the release of which can be produced by a very slight power.
In distributions of steam thus effected the steam disibutor uncovers
the inlet port into the cylinder by the displacement which the excentric
imparts to it; then when the volume of steam introduced into the
cylinder is sufficient a suitably placed catch meets an abutment which
produces the release, and causes the action of the excentric on the
distributor to stop. The distributor, submitted to the new action of a
spring or counterweight, is brought back quickly, and closes the port
which it had previously uncovered for the introduction of steam into the
cylinder. When the piston has completed its stroke the steam intro-
duced into the cylinder becomes more or less expanded therein, and
escapes by a port, the opening and closing of which are regulated by a
special distributor. The abutment which produces the release of the
catches, and which consequently limits the time of the introduction of
steam, is submitted to all the oscillations of the governor, therefore if
the catches have such a form that their meeting with this abutment
takes place only when the volume of steam introduced into the cylinder
is in accordance with the amount of the resistances to be overcome one is
assured that the governor will direct the distribution with all desirable
precision.
This combination of parts for distributing the steam is much varied.
In all the modifications the distributors have a curved face having the
form of a cock, cylindrical, or nearly so, or have valves equilibrated or
not. These distributors do not remain long steam-tight; besides, the
action of the springs or counterweights is transmitted to them by
arrangements of levers which produce a certain amount of complication.
Numerous inconveniences thus result, which are overcome by employing
the arrangement which I now proceed to describe with reference to
Figures 1 and 2 of the accompanying Drawings.
My improved arrangement or system for distributing the steam
comprises the employment of ordinary plane slide valves, and of counter
slides or distributors, which are likewise plane, and are operated by

page_text: catches or clicks under the command of the governor, and returned by
the action of steam contained in the distributing box.
C (Figure 2) is the engine cylinder, which may be placed in any
suitable position; c, c, arc ports which put the cylinder in communi-
cation with the steam chest V, or with the exhaust A², A²; V, V, are the
steam chests in communication with the generator, and in them work
the slide valves T, T, and the distributors D, D. The slide valves T, T,
have a plane face, and are moved by the excentric to which they are
connected by the rod E. t, t, are ports formed in the slide valves T, T,
to allow of the introduction of steam, and the body of these valves is
hollowed out, as seen at t¹, t, to allow of the escape of the steam. The
distributors D, D, work against the slide valves T, T, to open or close
their ports t, t; P, P, are rod pistons, on which the distributors D, D,
are mounted. These rods work in a cylinder, and are furnished with
segments to prevent the leakage of steam, and a packing at the outer
end of the cylinder will stop any leakage which tends to escape. The
section of these rod pistons is sufficient to enable the steam which acts
upon them to return the distributors with every desirable rapidity and
precision. A, A, are air pistons carried by these rod pistons; A', A¹, is
a double air cylinder in which the pistons A, A, work. The cylinder A¹
is rigidly attached to the excentric rod E, so as to move therewith; B, B,
are fixed abutments in the interior of the steam chest to limit the move-
ment of the distributors D, D. These abutments may, if required, be
placed outside the steam chests. D', D', are movable catches or clicks
fitted upon axes o, o; these axes are on the double air cylinder, so that
these catches follow the movement of the excentric rod E. When the
catches are in contact with the rod pistons P, P, they communicate to
them the movement of the excentric. B' (Figure 1) is a movable arm
worked by the governor, and which releases the catches D, D; L, L, L,
are levers which connect the arm B' with the governor.
The action is as follows:-When the machine is in work the following
takes place:If the piston of the steam cylinder is moving for example
in the direction of the arrow, the rod E will be moving in the opposite
direction; the port of the slide valve T at the right is uncovered by
the distributor D%; the movement of the slide valve T will open the
port c, and will put the cylinder in communication with the steam
chest V. During this time the relative movement of the distributor 1)
and of the slide valve T is nil, as they both move in the same direction

page_text: with the same speed. The right hand catch D¹ meets the arm B¹ and
will turn around its axis o, its release from the rod piston P will be
effected, and the pressure upon this piston of the steam in the chest V
will return the distributor quickly a sufficient distance to cause it to
cover the port of the slide valve T. It is to prevent the concussion of
this quick return of the distributor D that I use the air cylinder A.
The air contained in it is driven back and escapes by small holes a, a,
a resistance which forms a spring and diminishes the concussion being
thus produced. The air cylinder A¹ also serves as a guide for the move-
ments of the rod pistons. After the return movement effected by the
distributor the air piston of this distributor will be at the bottom of the
air cylinder and this cylinder will impart to the distributor the same
movement as that of the slide valve T, so that the relative movement of
the slide valve and of the distributor in its new position will again be
nil. As soon as the release of the catch has been effected, all com-
munication between the engine cylinder and the steam chest V ceases
and the steam introduced into the cylinder expands therein, causing the
piston to make a stroke. During this time the slide valve T continues
its movement, returns to put its hollowed portion in communication
with the cylinder, and the steam introduced into the latter escapes freely
into a condenser or into the atmosphere. During all this period the
relative movement of the distributor D and of the slide valve T continues
to be nil, but before the slide valve finishes its entire movement the
distributor D meets the fixed abutment B, and is held while the slide
valve T finishes its stroke. During this period the port is uncovered,
the catch D¹ is again put into communication with the rod piston, and
the whole is ready to recommence a fresh movement of the steam piston.
The catch D' is brought into communication with the rod piston by
means of a spring or by its own weight.
It will readily be understood that the arrangement just described for
distributing the steam in the cylinder of an engine may be modified with
regard to the relative position of the different parts. For example, the
two steam chests may be made in one, and in this case the two slide
valves T will be combined in one, so that a single exhaust outlet A³
situated between the two ports t, t, would suffice for the exhaustion of
the steam.
It will also be understood that the slide valves T and the dis-
tributors D, D, might move in different media, so that the cylinder

page_text: would be provided with different ports for the admission and escape of
the steam.
An examination of the action of this mode of distribution shews that the
pressure exerted on one of the two rod pistons of the distributors is nearly
always equilibrated by the pressure of the steam on the other rod piston,
so whatever be the section of these rod pistons the power absorbed by
their movement will always be very slight and very much less than that
which is absorbed in stretching the springs or displacing the counter-
weights usually employed. Considered in this point of view my
arrangement has a further advantage over other arrangements.
I claim then as secured to me by the Letters Patent herein-before in
part recited, not only the combination of parts described and shewn for
effecting the distribution of steam, but also all modifications of which
this new combination is susceptible.
I also claim the employment of slide valves having a plane face
combined with catches, clicks, and likewise the employment of the action
of steam as described, in lieu of the springs or counterweights hitherto
employed.
My combination of slide valves having a plane face and of catches
can however if required be submitted to the action of springs and
counterweights; for instance, levers and counterweights may be sub-
stituted for the action of steam on the rod pistons for returning
the distributors, or instead of the counterweights springs may be used.
The fixed abutments will in this case be placed outside the steam
chest.

page_text: which is represented in Figure 3; it is composed of, 1st, a manometer
to indicate the pressure of the steam in the steam chests; 2nd, a mano-
meter to indicate the pressure or the depression of the condenser; 3rd,
an indicator which shews the regularity of working of the machine;
this indicator is put in motion by one of the operating shafts of the
governor; the movement of the indicator is therefore in relation with
that of the engine; 4th, a graduated sector which shews at any instant
the degree of admission of steam and the corresponding horse-power.
A reference to Figure 3 will explain the different indications. In
applying this apparatus to my system of distribution, for example, as
indicated in red in Figure 1, the movable arm of the governor moves
through the intermediation of a rod a hand which indicates on the
graduated sector S (the graduations of which correspond with the
different positions of the governor) the degree of admission of steam and
the horse-power of the engine. The manometer M is in communication
with the condenser and the manometer M' with the steam chests, while the
indicator H receives its movement from the governor shaft. The indica-
tions given by this apparatus are very important to shew the working of
the machine, and even to show the action of the general plant of tho

page_text: I claim the employment of this apparatus for supplying at the same
point and by a simple reading at any instant indications of essential
facts connected with the working of the engine.
In witness whereof I, the said Emile Boirc, have hereunto set
my hand and seal, this Third day of August, One thousand eight
hundred and seventy-five.
Witness,
CHARLES FROSSARD,
23, Boulevard de Strasbourg,
Paris.
E. BOIRE. (L.S.)