IMPROVEMENTS IN STEAM ENGINES
Year: 1869

page_text: LETTERS PATENT to George Allibon, of the Rosherville Iron Works,
Northfleet, in the County of Kent, Engineer, for the Invention of
"IMPROVEMENTS IN STEAM ENGINES."
Sealed the 18th January 1870, and dated the 31st July 1869.
PROVISIONAL SPECIFICATION left by the said George Allibon at the
Office of the Commissioners of Patents, with his Petition, on the
31st July 1869.
I, GEORGE ALLIBON, of the Rosherville Iron Works, Northfleet, in the
County of Kent, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STEAM ENGINES," to be as follows:-.
My Invention relates to improvements in compound engines or
combined high and low pressure engines, and I propose to illustrate
their application by describing combined vertical inverted double cylinder
engines suitable for a pair of screw engines.

page_text: This Invention consists in so combining the smaller cylinder with the
cover of the larger cylinder by casting them together, and regulating
the direction of motion and the amount of steam admitted to both the
cylinders of the engine by regulating the slide valve of the smaller
cylinder only, the slide valve of the larger cylinder having a fixed
amount of travel or motion imparted to it by a fixed eccentric, the
steam being admitted throughout the entire length of the stroke.
The two pistons travel in the same direction at the same time, but
instead of fitting the two pistons on to the same piston rod, and having
a single central gland or stuffing box communication between the two
cylinders, I carry the piston rod of the smaller cylinder upwards through
the cylinder cover, and on to its outer end I fit a cross head, and I
connect it to the larger piston by means of two side rods or piston rods
working through glands or stuffing boxes in the open or uncovered
portion of the upper cover of this larger cylinder, and they may work in
suitable guides on the outside of the small cylinder. The steam as
exhausted from each end of the smaller cylinder is by means of a short
connecting pipe admitted to the corresponding side of the piston of the
larger cylinder, where at its reduced pressure, due to the degree of
expansion, it exerts its force upon the larger surface until the end of
the stroke, when the communication with the condenser is opened and
it is admitted thereinto, and the partial vacuum within the condenser is
brought to the aid of the return stroke of the larger piston on the one
side thereof, whilst the steam pressure is acting on the opposite side
to move the piston in the same direction in the way common to all
condensing engines.
Instead of employing any complex arrangements of link motions and
cut-off valve gear for actuating the slide valves in different degrees at
different times for governing the admission of steam to both cylinders,
I employ the double eccentric and an inverted link for operating the
slide valve of each of the high-pressure cylinders, which may be single
ported. The exhaust steam pipe from the larger cylinder is carried
direct to the condenser, which in a pair of combined inverted cylinder
engines having the two valves of the larger cylinders working back to
back, each in its own valve chest, may be conveniently placed between
the unnicht fromna of +1.

page_text: condenser) upon which the engine cylinders may be mounted, and so be.
utilized as a framing.
The manual power required to start, reverse, or stop these engines is
reduced to a minimum by having to operate upon the small slide valvo
of the smaller and high-pressure cylinder only instead of upon the large
slide valve of the larger cylinder or the slide valves of both cylinders.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Allibon in the Great Seal Patent Office on
the 31st January 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
ALLIBON, of the Rosherville Iron Works, Northfleet, in the County of
Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of July, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said George Allibon, Her special licence that I,
the said George Allibon, my executors, administrators, and assigns, or
such others as I, the said George Allibon, 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 George Allibon,
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 George Allibon, do hereby declare
the nature of my said. Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the
following statement:-
My Invention relates to improvements in compound engines or com-
bined high and low pressure engines, and I propose to illustrate their
application by describing combined vertical inverted double cylinder
engines.
This Invention consists in combining the smaller cylinder with the
cover of the larger cylinder, as herein-after described, and in regulating
the direction of motion and the amount of steam admitted to both the
cylinders of the engine by means of the slide valve of the smaller
cylinder only through the eccentrics and inverted link motion, as
described, the slide valve of the larger cylinder having a fixed amount
of travel or motion imparted to it by a fixed eccentric, independently of
the eccentrics and link motion employed for working the small slide
valve, the steam being admitted thereto and following the larger piston
throughout the entire length of the stroke.
In engines constructed according to the present Invention the two
pistons travel in the same direction at the same time, but instead of
fitting the two pistons on to one and the same piston rod, and having a
single central gland or stuffing box communication between the two
cylinders, as heretofore commonly done, I carry the piston rod of the
'smaller cylinder upwards through that cylinder cover, and on to its outer
end I fix a cross head, and I connect it to the larger piston by means
of two side rods or piston rods working through glands or stuffing boxes
in the open or uncovered (annular) portion of the upper cover of the
larger cylinder, and they may also work in suitable guides mounted
upon or fixed to the outside of the small cylinder. The steam as it is
exhausted from each end of the smaller cylinder is, by means of a short
connecting pipe admitted to the corresponding side of the piston of the
larger cylinder, where at its reduced pressure, due to the degree of
expansion, it exerts its force upon the larger surface of the piston during
its stroke, when the communication with the condenser is opened and
the attenuated steam is admitted thereinto, and the more or less perfect
vacuum within the condenser is brought to the aid of the return stroke
of the larger piston on the one side thereof, whilst the steam pressure is
acting on the opposite side to move the piston in the same direction in
the way common to all condensing-engines.
Instead of employing any complex arrangements of link motions and

page_text: cut-off valve gear for actuating the slide valves in different degrees at
different times for governing the admission of steam to both cylinders,
I employ the double eccentric and an inverted link for operating the
slide valve of each of the high-pressure cylinders, which may be single
ported. The exhaust steam pipe from the larger cylinder is carried
direct to the condenser, which in a pair of combined inverted cylinder
engines having the two valves of the larger cylinders working back to
back, each in its own valve chest, may be conveniently placed between
the upright frames of the engines and at the back thereof; or each
engine may have a separate condenser (whether an injection or a surface
condenser) upon which the engine cylinders may be mounted, and so
utilize it as a framing.
The manual power required to start, reverse, or stop these engines is
reduced to a minimum by having to operate upon the small slide valve
of the smaller and high-pressure cylinder only, instead of upon the large
slide valve of the larger cylinder or the slide valves of both cylinders.
Thus the steam as exhausted from the smaller cylinder is admitted to
the larger cylinder throughout or nearly throughout the whole of the
stroke of the piston by means of a slide valve having a fixed or definite
travel, and is not subject to being changed, nor is it operated by hand.
The high-pressure steam is however admitted to the smaller cylinder,
under regulation as to volume and time, by means of the double eccentric,
and inverted link motion, as herein-after described, the amount of "cut-
off;" or the degree of expansion in the smaller cylinder, being regulated
by changing the relation of the slide valve rod connection to the position
of the slot link.
In vertical inverted cylinder engines suitable for screw-propelled ships,
as herein-before stated, the smaller cylinder would be uppermost, its
piston rod would work through its top cover, and by means of a cross
head fitted thereon, each end of which has a side rod, which is also a
piston rod, connecting the larger piston, into one side of which it enters,
and on the opposite side the other side rod or piston rod connected to
the other end of the cross head similarly enters, so that the lower portions
of each of the two side rods or piston rods enter the larger cylinder at
each down stroke. Thus it will be seen that all the piston glands are
thus accessible, and there is no direct passage way or communication
either by glands or other similar opening by which the vacuum can be
impaired or destroyed by the leakage of steam from the smaller cylinder.

page_text: All the steam admission and exhaust passages are short, and the slide
valve chests of the two cylinders of each engine are brought close
together, so that the loss of effective pressure and steam heat is reduced
to a minimum.
In some cases I prefer to cast the small cylinder and the upper end or
cover of the large cylinder together, as such cover would only be of a
flat ring-like or annular shape, representing the difference between the
outside diameter of the small cylinder and that of the flange of the large
cylinder; but in other cases, particularly for or in constructing large
engines, the small cylinder and the cover of the large cylinder may be
cast separately, and the lower end of the small cylinder may be recessed
into and be seated in and upon a central opening in the large cylinder
cover, and the bottom end of the small cylinder may project within the
large cylinder, and by means of a flange ring around the small cylinder
at a convenient distance from the bottom thereof it may be firmly seated
and secured. Instead also of a single piston rod from the large piston.
I prefer in constructing large engines to employ two piston rods, which
passing through suitable glands in the bottom cover or end of the large
cylinder are connected together by means of a cross head, and the upper
end of the connecting rod is connected to the cross head pin, or other-
wise in the usual manner, whilst the lower end of the connecting rod is
connected to and works upon the crank pin. When the large piston has
two piston rods instead of a single or central piston rod they may either
be in the same line with and be enlarged continuations of the side rods
from the cross head to the smaller piston, or the two large piston rods
may be placed at right angles with and to the side rods, as before
described. Thus in some cases I find it convenient to carry the two
side rods through the large piston and cylinder on to a lower cross head,
thereby making a complete double piston rod engine, whereby the con-
necting rod end, or the upper end of the connecting rod, can be brought
up close to the cylinder bottom, and the bottom of the high-pressure
cylinder be recessed into the large cylinder by dishing or recessing the
large piston, and thus greater compactness and reduction in the heighth
of the engine over all is effected.
In the accompanying two Sheets of Drawings I have illustrated the
application of my Invention in each of the two examples given to
inverted cylinder engines, the small cylinder being shewn above, and
the large cylinder below, but the position of the engine may be

page_text: reversed, the small cylinder being below, and the large cylinder above,
the connecting rod and crank being also above; or, the cylinders may:
be laid horizontally, according to the purpose for. which the engines may;
be required, and to adapt them to the space, and other conditions of the
particular application, and in selecting the inverted cylinder type of
screw engine, for illustrating the application of this Invention, I have.
thought it desirable to limit myself thereto, rather than increase the
number of illustrative diagrams or figures in the Drawings accompanying
the Specification.
In Sheet 1, I have shewn a pair of engines complete, Figure 1 being a
front elevation, one half thereof being a vertical sectional view taken
through the centre of the cylinders; Figure 2 is a side or end elevation;
Figure 3 is a vertical section of Figure 2, and Figure 4 is a plan view
of Figures 1, 2, and 3, in which the high and low pressure cylinders
are shewn and the slide valves and valve gearing or apparatus for
admitting the high-pressure steam to the small cylinder to the requisite
extent during the travel of the small piston, and for admitting the steam
exhausted from each end of the small cylinder into the large cylinder,
where it is expanded and acts upon the increased piston area, and are
all shewn in the several relations of their parts. The mode of operating
the slide valves of the small cylinders, and of varying the degree of
expansion, and of changing the forward to a backward movement, and
reversing the engines, as shewn in Figures 1 and 2 more particularly, as
is also the position of the condensing apparatus and its connections with
the larger cylinders.
In Sheet 2, Figures 5 and 6 show modifications in the details, chiefly
but not exclusively as to the arrangement and disposition of the piston
rods for transmitting the motion to the crank, and which'in engines of
large size we prefer to employ, as being convenient and enabling
increased compactness and a reduction in the total heighth to be effected
in the manner herein-before described; Figure 5 is an elevation
shewing the two side rods from the cross head of the small piston rod
as upward continuations of the two larger piston rods of the large piston,
and Figure 6 is a vertical sectional view of Figure 5, in which the
recessing down of the small cylinder bottom within the large cylinder
and the recessing of the upper side of the large piston to receive the
small cylinder bottom, the recessing of the under side of the cover of the
large cylinder to receive the piston rod nuts projecting above the top

page_text: face of the large piston as well the modes of combining together the
small and large cylinder, the glands and stuffing box arrangements at
the top and the bottom of the large cylinder, by which an effective
guiding of the piston rods is secured without recourse to guides projecting
from the small cylinder, and this guiding is shewn as being further
aided by the cross head working between the guides projecting from the
inner faces of the standards or frames.
In each of the Figures in the two Sheets of Drawings hereunto
annexed the same letters of reference are employed to denote like
or corresponding parts; thus A is the foundation plate or bed plate of
the engine; B, the upright frames; C, the large cylinder; D, the small
cylinder; E, the crank shaft; F, the crank; G, the connecting rod which
is between the cross head fitted on the piston rod end, or on to the
lower ends of the two piston rods; H, the condenser; I, the water circu-
lating pump, where a surface condenser is employed, or a combined air
pump and condensing water pump where an ordinary jet condenser is
employed; J is the exhaust steam pipe connecting each of the large
cylinders with the central condenser. Of the minor parts or details,
a is the piston of the small or high-pressure cylinder; b, the piston of the
large or low-pressure cylinder; c, the piston rod of the small cylinder;
d, the cross head fitted thereonto; e, e, are side rods, the upper ends of
which are attached to the cross head, and their lower ends pass through
stuffing boxes in the upper end or cover of the large cylinder, and enter
thereinto, and they are there securely fitted to the large piston, and thus
form piston rods; f, the piston rod, or piston rods, where there is more
than one, of the large cylinder, to the lower end of which the cross
head is attached, and the connecting rod G is connected therewith; g is
the valve chest containing the slide valve of the small cylinder; and
h, the valve chest of the slide of the large cylinder. These slide
valves g', g¹, are connected by means of a rod or rods; and by the
intervention of a weigh shaft and spanners. When the direction of
motion or travel of the small piston is reversed by the link motion or
gear, the slide of the larger cylinder is correspondingly acted upon or
moved by reason of the movement of the small or high-pressure piston;
the fixed eccentric h', on the crank shaft E being by the change in the
direction of the movement thereof caused to operate the large slide valve,
the power of the engine being employed therefor, and the movement of
the valve being a fixed quantity.

page_text: The link motion and gear for actuating the slide valve of the small
cylinder and apparatus for reversing the engines require but a very small
amount of manual power to operate them, and which can be done with
great rapidity. The starting gear of the engine is worked by means of a
hand wheel in the usual manner and as shewn more clearly in Figures 1
and 2 on Sheet 1.
In Figures 1, 2, and 3, the cross head and the side rods with their
guides, together with the small cylinder (from which the guide snugs
project) are all enclosed within a dome or cover; but such covering in
forms no part of this Invention and may be dispensed with.
The large cylinder should be jacketed around its circumference, and
the hollow or chambered covers at the top and bottom thereof may be so
arranged as to be in free communication with the steam boiler, so that
the temperature of the low-pressure steam may be maintained to an
effective degree.
-
Having now described my Invention, as herein set forth, I wish it to
be understood that I do not intend to claim hereby the mere combining
together of two cylinders, or the combining together of the small high-
pressure and a large low-pressure cylinder, irrespective of the modes and
methods herein described, neither do I intend to claim the use or em-
ployment generally of a cross head and side rods from the ends thereof
for combining the two pistons together, as that has heretofore been done
in several ways.
Moreover I do not intend in any case to use or employ
the cross head on the end of the piston rod of the small cylinder for
transmitting the power obtained by the action of the steam on the areas
of both the large and the small pistons, as that also has been done
heretofore, but what I claim as my Invention is,-
First. The improvements in steam engines herein described.
Secondly. The novel arrangement of parts and mode of working
double cylinder engines as herein described, and as illustrated by Figures
1, 2, 3, and 4 on Sheet 1 of the accompanying Drawings.
Thirdly. The mode or method of combining the high and low pressure
cylinders and their respective pistons, and transmitting their combined
motion to the crank shaft as herein described, and as illustrated on Sheet 2
of the accompanying Drawings.

page_text: Fourthly. The mode or method herein described of regulating the
admission and discharge of steam to compound engines of the kind or
description herein described and illustrated.
In witness whereof, I, the said George Allibon, have hereunto set
my hand and seal, this Twenty-eighth day of January, in the year
of our Lord One thousand eight hundred and seventy.
Witness,
W. H. SMITH,
18, Salisbury Street, Strand,.
W.C.
GEORGE ALLIBON. (L.S.)