IMPROVEMENTS IN STEAM-ENGINES
Year: 1883

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine, Lake
& Co, Patent Agents, Southampton Buildings, London for an Invention of
"IMPROVEMENTS IN STEAM-ENGINES" communicated to him from abroad by
Thomas W. Porter of Chelsea, Massachusetts, United States of America
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 28th December 1883.
"
WILLIAM ROBERT LAKE, of the firm of Haseltine Lake and Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN STEAM-ENGINES [a com-
munication to him from abroad by Thomas W. Porter of Chelsea, Massachusetts,
United States of America]
This invention relates to steam engines of that class in which both a high and a
low pressure cylinder are employed, and in which the steam first exerts its force in
the high-pressure cylinder, after which it passes into, and acts expansively in, the
low-pressure cylinder; from whence it passes into the condenser, or is exhausted
into the open air.
The said invention consists essentially in so connecting the exhaust ports of the
high-pressure cylinder by suitable conduits and valvular devices, with the low-
pressure cylinder and the condenser, or escape pipe, that, as soon as the steain
escaping, at each stroke, from the high-pressure cylinder, shall have produced an
equilibrium of pressure in the two cylinders, it will then during the rest of the
stroke, be exhausted into the condenser or pass out through the escape pipe, without
passing into the low-pressure cylinder; thereby relieving the high-pressure cylinder
of back pressure, and also giving it the benefit of the vacuum in the condenser, if
the same be employed.
In carrying the said invention into practice I provide a receiver into which the
steam passes, on its way from the high-pressure cylinder to the low-pressure
cylinder, and which performs the function of a steam chest to the low-pressure
cylinder. An auxiliary receiver is arranged between the high-pressure cylinder
and the main receiver, the passage between which is closed and opened by a valve

page_text: which is actuated by a rod connected with an excentric on the crank-shaft. The
said auxiliary receiver also communicates with the condenser through a port which
is closed and opened by a second valve actuated by a rod connected with an
excentric on a rock-shaft; the said rod for convenience moving in a hollow portion
of the first rod. The steam, as it passes through the said port, enters a small
chamber whence it passes into the condenser through a passage.
The practical operation of an engine embodying this invention is as follows, that
is to say, the piston of the high-pressure cylinder being supposed to be at, or nearly
at, the extreme point of the return stroke where steam will be admitted through a
second port, the slide valve is then moved by its rod to open the said second port,
and close the third port, allowing the exhaust steam to pass by way of the cavity
in the slide valve, in the usual manner, into the exhaust pipe whence it flows into
the auxiliary receiver, thence through the passage into the main receiver and the
low pressure cylinder, as admitted by its valvular devices. After lapse of sufficient
time for the flow of steam from the high-pressure cylinder to produce an equilibrium
or pressure therein and in the main receiver the first valve is closed and the second
valve is opened by the means stated; whereby the flow of steam into the receiver
ceases, and it is exhausted directly into the condenser thereby relieving the high
pressure piston from the back pressure which would equal that existing in the
receiver and the low pressure cylinder; and also giving it the benefit of the
vacuum in the condenser. The steam thus admitted into the receiver from
the high pressure cylinder before the first valve closes, enters the low pressure
cylinder alternately through its ports, controlled by a slide-valve, and after acting
on the low pressure piston, passes through an exhaust pipe into the condenser, all
in the usual manner.
Instead of the auxiliary receiver, the steam from the high pressure exhaust may
pass directly into the main receiver, but when arranged as described, the first valve
is more conveniently arranged to be held to its seat by steam pressure, and the same
is true with reference to the small chamber through which the steam passes to the
condenser. If desired, the receivers may be altogether dispensed with in a well
known manner, the steam from the high pressure cylinder passing directly into the
low pressure cylinder. It will be obvious that instead of exhausting from each
cylinder into the same condenser a separate condenser may be employed for each,
and the valves, air pump and other devices usually employed in connection with a
steam condenser may be of the ordinary construction and operation. Instead of a
condenser the steam from both cylinders which would pass directly therefrom into
the condenser when a condenser was employed, with these improvements, may be
exhausted directly into the open air; whereby the condenser and air pump would
be dispensed with.
All the parts and devices described may be of any known kind or construction,
and may be changed or varied as desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Patent Office on the 27th June
1884.
"
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN STEAM-ENGINES
A com-
munication to me from abroad by Thomas W Porter, of Chelsea, Massachusetts,
United States of America.
This invention relates to that class of steam engines in which both a high and a
low pressure cylinder are employed, and in which the steam first exerts its force
in the high pressure cylinder, after which it passes into and acts expansively in the
low pressure cylinder, from whence it passes into the condenser or is exhausted into
the open air.
The said invention consists essentially in so connecting the exhaust ports of the
high pressure cylinder, by suitable conduits and valvular devices, with the low
pressure cylinder and the condenser or escape pipe, that as soon as the steam
escaping at each stroke from the high pressure cylinder shall have produced an
equilibrium of pressure in the two cylinders, it will then, during the rest of the
stroke, be exhausted into the condenser, or pass into the escape pipe, without passing
into the low pressure cylinder; thereby relieving the high pressure cylinder of back
pressure, and also giving it the benefit of the vacuum in the condenser, if the same
be employed.
The accompanying drawing shows in side elevation an inverted engine embodying
my invention; certain of the parts being shown in section, or in part broken away,
in order to show clearly the interior parts, and their connections.
In the said drawing A indicates the bed plate, and B, B the cylinder supporting
standards secured to said bed.
C indicates the crank shaft, journalled in pillow-blocks D secured on said bed,
and E the crank of the high pressure cylinder I whose piston J is, by the piston
rod K, the connecting rod G and any suitable cross head; connected with said
crank.
Steam is admitted at a into the steam chest P of the high pressure cylinder I
from whence it is admitted into the said cylinder alternately at top and bottom
through ports e, e, and escapes through the exhaust port f by the action of the
valve b, actuated by the rod c and eccentric d, in the usual manner.
The steam escaping from the cylinder I through the port f, passes around the
said cylinder, as indicated by dotted lines, to the chamber R, which communicates
with the steam chest S of the low pressure cylinder L, through the port hand
conduit and with auxiliary chamber Y (through which the conduit i, passes), by
ports u, v; the said ports h, u and being respectively opened and closed by the
valve g, which is actuated through the rod n by the eccentric p. The said valve
is formed as shown whereby when its (central) passage is coincident with either
of the said ports, it closes the other two. The steam entering the chest S through
the conduit is controlled by the valve j actuated by rod and eccentric m, which
valve allows the steam to alternately enter the cylinder L through steam
ports k, k, and to escape by the exhaust port s, and pipes T, V, to the
condenser X.
The piston M in the cylinder L is shown as at half stroke in the ascent; and the
piston J in the cylinder I, is shown as turning the lower dead-centre and as ready
to take steam below the piston and exhaust the steam above it. The steam
exhausted from the cylinder I passes, as stated, into the chamber R, and from
thence into the steam chest S, through the port h and passage i, and from the said
steam chest into the cylinder L, until an equilibrium of pressure is attained in both
the said cylinders, when the valve g_will close the port h, thereby shutting
communication between the cylinders. The said valve will also be moved to allow

page_text: the steam to pass out through the port u, or v, as its eccentric may be moving, into
the chamber Y, whence it will pass through the pipe V, either into the condenser X,
or be exhausted through pipe t, according as valve W may at the time be
arranged.
By thus shutting off the flow of steam from the high pressure cylinder to the
low pressure cylinder L, at each exhaust from the former, as soon as an equilibrium
of pressure in the two is established, and then exhausting the steam remaining in
the high pressure cylinder into the condenser, or through exhaust pipe t, the back
pressure upon the piston in the high pressure cylinder, equal to the pressure in the
low pressure cylinder, is obviated; and besides, if the exhaust steam remaining in
the high pressure cylinder at the time of such shutting off between the cylinders,
is then exhausted into the condenser, the high pressure cylinder obtains the benefit
of the vacuum in the condenser.
It will be obvious that divers changes may be made in the various devices and
details without departing from the nature of this invention
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 In a compound or double cylinder engine, wherein the same steam acts
first in the high and then in the low pressure cylinder; the combination with the
said cylinders and the condenser, of suitable conduits and valvular devices, whereby
the steam passing from the high pressure cylinder will, without passing through
the said low pressure cylinder, be diverted into the condenser at or near the point
or time when the pressure of such exhaust steam has produced an equilibrium of
pressure in the two cylinders, substantially as specified
Second. In a compound or double cylinder engine, the combination with the high
and low pressure cylinders, and a condenser having suitable conduits and valvular
devices by which the steam, as it is exhausted from the high pressure cylinder,
enters and operates in the low pressure cylinder, of a conduit and automatically
actuated valvular devices, whereby when the piston in the high pressure cylinder
is at or near the ends of its stroke, and after the exhaust therefrom has produced
an equal pressure, or nearly so, in the two cylinders, the remaining exhaust steam
in the said high pressure cylinder will be conducted to the condenser without
passing through the low pressure cylinder, substantially as specified.
Third. In a compound engine, the combination with the high pressure cylinder I,
the low pressure cylinder L, the condenser X, and its exhaust pipe T arranged to
connect with the said condenser, of the chamber R having a passage f to conduct
thereto the exhaust steam from the cylinder I; the chamber Y through which passes
the passage i having the port h, communicating with the steam chest S, the
ports, connecting the chamber R with the chamber Y, and a valve g, to
successively open and close the said ports; a pipe V leading to the said condenser ;
and automatic devices connected with and arranged to actuate the said valve g, so
that at or near the point or time when the exhaust steam passing from cylinder I
through the passage i shall have produced an equilibrium of pressure in the two
cylinders, the said valve g will close the port and allow the steam to escape
through the ports u, v to chamber Y, and thence through the pipe V, substantially
as specified.
In witness whereof I the said William Robert Lake, have hereunto set my hand
and seal this twenty seventh day of June in the year of our Lord One thousand
eight hundred and eighty four.