IMPROVEMENTS. IN STEAM ENGINES
Year: 1882

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine Lake
and Co., Patent Agents, Southampton Buildings, London. for an invention of
"IMPROVEMENTS. IN STEAM ENGINES A communication from abroad by
"
PROVISIONAL SPECIFICATION left by the said William Robert Lake at'
the Office of the Commissioners of Patents on the 27th March 1882.
WILLIAM ROBERT LAKE of the firm of Haseltine, Lake, & Co Patent Agents
Southampton Buildings London "IMPROVEMENTS IN STEAM-ENGINES
A com-
nunication from abroad by Emmanuel Denis Farcot of Paris France Engineer
The chief object of the said invention is to simplify the construction of steam-
engines in which the steam is successively expanded by means of cylinders of
different diameters into which the steam passes successively, at the same time
diminishing in pressure. These engines present the advantage from a practical
point of view, of utilizing the expansion of the steam without causing any violent
shocks or strains upon the moving parts of the engine. The main feature in
engines made according to the said invention is that the cylinders of different
diameters are directly in a line with one another and have no division nor stuffing-
box between them. Each of the cylinders is therefore single acting.
I will describe the said invention as applied to an engine in which the larger
cylinder is placed above the smaller one, and which is worked by a single slide-
valve and has only one piston rod and one stuffing-box. The said piston-rod is
common to both pistons, and the framework of the engine is hollow and forms a
reservoir in communication with the steam exhaust or the condenser. The steam
is distributed to both pistons by a single slide-valve the engine being provided
with suitable steam supply pipes and exhaust passages. The space between the
two pistons is constantly in communication with the said reservoir and steam
exhaust.
One object of the said improvements is to construct an engine which shall
economize steam and have the smallest possible number of working parts; the

page_text: '
engine is arranged in such a manner as to work at a great speed without requiring
frequent repairs, and without much wear of the working parts even when running
night and day, either, for example, to give motion to ventilators or to centrifugal
pumps.
The
The steam acts during one stroke upon one of the faces of the small piston and
during the following stroke upon one of the faces of the large piston expanding
according to the different capacities of the cylinders. The two pistons are secured
to the same rod without the employment of any stuffing-box between them, and
this is an important point in working the engine without leakage of steam.
variations in the volume of the steam contained in the chamber formed between
the two pistons may be reduced as much as desired; it is only necessary to make
this chamber communicate with a side reservoir which may be formed by the
hollow frame of the machine; a reservoir may thus be constituted of ten times
greater capacity than the chamber formed between the two pistons and the pressure
in it will then be nearly constant. The exhaust may be made to communicate with
this chamber; but the water which accumulates by condensation in the said
hollow frame forming the reservoir must be drained off from time to time.
A condenser may be used with this engine as well as with ordinary double
acting engines; the variations in volume between the two pistons will then not
affect the working of the engine. If desired a steam-jacket may be provided.
around the cylinder.
The slide-valve is preferably worked by the following means, that is to say, an
excentric is fixed upon the crank-shaft, and the excentric-rod is connected to a
sliding-piece which works in a suitable guide, the rod of the slide-valve being also
connected to the said sliding-piece, thereby causing the slide-valve to have a
strictly, rectilinear movement.
I provide means whereby the two pistons may be fitted upon the piston-rod.
The latter is divided into two parts at the point where the small piston is fixed
upon it, each part terminating in a cone; these two conical parts are held with
their ends nearly touching each other, by the pressure of two rings forming the
smaller piston, which are secured together by bolts or screws. I also provide a
supplementary column which serves to augment the rigidity of the whole structure,
and which can easily be fixed in place or removed to allow of repairs to the engine
being more easily effected.

page_text: Figure 4 a section on the line P, Q, Figure 2 and,
Figure 5 a section on the line R, S, Figure 2, of a single-acting engine with
superposed cylinders working by means of a single slide-valve, and having only
one piston, rod and stuffing box.
Figure 6 represents a vertical section of a modified form of my improved
engine.
A is the smaller steam-cylinder, and B is the larger cylinder placed above the
smaller one.
C is a rod common to both pistons and passing through the stuffing
box D. The framework E of the engine is hollow and forin's a reservoir in
communication with the steam exhaust, or the condenser. The steam is distributed
to both pistons by a single slide-valve F, being admitted through the ports G and
exhausted through the port H. The space I between the two pistons is
constantly in communication with the said reservoir and steam exhaust.
One object of the said improvements is to construct an engine which shall
economize steam and have the smallest possible number of working parts; the
engine is arranged in such a manner as to work at a great speed without requiring
frequent repairs, and without much wear of the working parts, even when running
night and day, for example, to give motion to ventilators or to centrifugal pumps.
In Figure 6 is represented an engine especially adapted for this purpose. In
this engine a supplementary column X augments the strength by giving increased
rigidity to all the parts.
The
The steam acts during one stroke, upon one of the faces of the smaller piston,
and during the following stroke, upon one of the faces of the larger piston,
according to the different capacities of the cylinders. The two pistons are secured
to the same rod without the employment of any stuffing-box between them, and
this is an important point in working the engine without leakage of steam.
variations in the volume of the steam contained between the two pistons may be
reduced as much as desired; it is only necessary to make the chamber between the
two pistons communicate with a side reservoir which may be formed by the
hollow frame of the engine as shown in the drawing; a reservoir may thus be

page_text: constituted of ten times greater capacity than tho chamber formed between the
two pistons, and the pressure in it will then be nearly constant. The exhaust may
be made to communicate with this chamber; but the water which accumulates
by condensation in the said hollow frame forming the reservoir must be drained
off from time to time.
A condenser may be used with this engine as well as with ordinary double-
acting engines; the variations in volume between the two pistons will, then, not
affect the working of the engine. If desired a steam jacket K may be provided
around the cylinder.
The slide-valve is preferably arranged as shown in Figures 2 and 5. The
distribution is effected by a slide with a double plate and a variable expansion
valve and gear. By this arrangement obtain the advantages of a compound
engine with separate cylinders, or a double acting engine with a single cylinder
An excentric L is fixed upon the crankshaft O, and the excentric rod N is
connected to a sliding piece P which works in a suitable guide Q, the rod R of the
slide-valve F being also connected to the said sliding-piece, thereby causing the
slide-valve to have a strictly rectilinear movement. The supplementary column X
which serves to augment the rigidity of the whole structure, can easily be fixed in
place or removed to allow of repairs to the engine being more easily effected..
Having thus fully described the said invention as communicated to me by my
foreign Correspondent, and the manner of performing the same, I wish it understood
that I Claim,
First, The improved engine having two cylinders of different diameters, and two
pistons fixed on the same rod without an intermediate stuffing box, each cylinder
being single-acting, substantially as set forth.
Second. The slide-valve for admitting steam above and below the two pistons
in such a manner as to obtain the advantages of a compound engine with separate
cylinders, or a double acting engine with a single cylinder, substantially as set
forth.
Third. The side reservoir communicating with the chamber formed, between the
two pistons and arranged in such a manner as to reduce the variations of volume
produced during the working of the pistons, substantially as set forth.
Fourth. The framework constructed and arranged to serve as an expansion
reservoir, substantially as set forth.
Fifth. The lateral framework forming an expansion-reservoir while permitting
free access to the parts of the engine, as set forth.
Sixth. The supplementary column for augmenting the rigidity of the whole
structure, and capable of being removed to permit access for repairs, as set forth.
Seventh. The intermediate sliding piece for guiding the distributing slide valve,
constructed and arranged as set forth.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Twenty seventh day of September in the year of our,
Lord One thousand eight hundred and eighty two.