A NEW OR IMPROVED HORIZONTAL COMPOUND ENGINE
Year: 1875

page_text: LETTERS PATENT to James Thompson, of the Borough and County
of Newcastle-upon-Tyne, Engine Smith, for the Invention of "A
NEW OR IMPROVED HORIZONTAL COMPOUND ENGINE."
PROVISIONAL SPECIFICATION left by the said James Thompson at the
Office of the Commissioners of Patents, with his Petition, on the
24th November 1875.
I, JAMES THOMPSON, of the Borough and County of Newcastle-upon-
Tyne, Engine Smith, do hereby declare the nature of the said Invention
for "A NEW OR IMPROVED HORIZONTAL COMPOUND ENGINE," to be as
follows:-
The main object of my Invention is to render the ordinary compound
marine engines capable of being worked horizontally, thereby deriving
the advantages possessed by the class of engines known as horizontal
land engines; or, conversely, adapting horizontal engines to work with
high and low pressure steam, as is the case in compound engines, and

page_text: thus conferring on both classes the advantages and conveniences
possessed by the other.
-
The means I adopt to carry out the first part of my Invention, that is
to say, to render the compound marine engine capable of being worked
horizontally, which I believe has never before been done, is as follows :-
From the crank of the propeller shaft rises a vertical connecting rod
attached by a pin to one arm of a bell-crank lever, the other arm being
fastened in a like manner to the piston rod of a piston working horizon-
tally to and fro within the low-pressure cylinder.
The high-pressure cylinder lies immediately below the low-pressure
cylinder, the piston of the former working horizontally to and fro and
united by a horizontal connecting rod to a beam lever (slightly out of
horizontal) to which it gives motion. The other arm of this lever is
connected by a link and pin to the aforesaid arm of the bell-crank lever,
to which the vertical connecting rod rising from the crank of the pro-
peller shaft is also connected, this being the point where the efforts of
the two cylinders are concentred. The fulcrums of the bell-crank and
beam levers are supported in a suitable cast-iron frame, to which also
the cylinders are secured. The difference of travel between the crank
lever and the beam lever (consequent upon the difference of stroke of
their respective pistons, the stroke of the low pressure being twice that
of the high-pressure piston) is compensated for by the before-mentioned
link that unites one arm of the beam lever to the bell-crank or top of
the vertical connecting rod, as before described, thus a uniform upward
and downward motion is by means of the two pistons conveyed to this
rod, which necessarily imparts a rotary motion to the propeller shaft by
aid of the crank.

page_text: (2). Opens the lower port of the same cylinder, and permits the par-
tially exhausted steam of a previous supply to enter the low-pressure
cylinder, and act upon the under side of the piston therein.
(3). Opens the upper port of the last-mentioned cylinder, and allows
the exhausted steam to escape into the exhaust pipe.
Another motion of the eccentric rod reverses the order of things as is
usually arranged in the ordinary slide valve.
The exhaust pipe is surrounded by a jacket of cold water flowing by
the means of a small pump or by gravitation in the same direction as
the exhaust steam; this pipe terminates in an open mouth within the
jacket of cold water. The water flowing onward takes with it the con-
densed or exhausted steam.
The next part of my Invention, namely, adapting the horizontal land
engine to work with high and low pressure steam may be described in
the same words as those employed in describing the first part, substi-
tuting "main shaft of the engine" for the "propeller shaft."
My method of condensing the exhaust steam renders this class of
engine specially adaptable for street traffic.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Thompson in the Great Seal Patent Office
on the 23rd May 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
THOMPSON, of the Borough and County of Newcastle-upon-Tyne, Engine
Smith, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of November, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Thompson, Her special licence,
that I, the said James Thompson, my executors, administrators, and
assigns, or such others as I, the said James Thompson, my exccutors,
administrators, and assigns, should at any time agree with, and no

page_text: 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 “▲ New or In-
PROVED HORIZONTAL COMPOUND ENGINE," upon the condition (amongst others)
that I, the said James Thompson, 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 1
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said James Thompson, 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 in writing, reference being had to the accom-
panying Drawing and to the letters and figures marked thercon (that is
to say) :—
The main object of my Invention is to render the ordinary compound
marine engines capable of being worked horizontally, thereby deriving
the advantages possessed by the class of engines known as horizontal
land engines; or conversely, adapting horizontal engines to work with
high and low pressure steam, as is the case in compound engines, thus
conferring on both classes the advantages and conveniences possessed by
the other.
The means I adopt to carry out my Invention is as follows:-From
the crank of the propeller shaft or driving shaft of the engine, according
as it is used for marine or land purposes, rises a vertical connecting rod
attached by a pin to one arm of a bell-crank lever, the other arm of the
said lever being fastened in a like manner to the rod of a trunk piston
working horizontally (or nearly so) to and fro within the low-pressure
cylinder.
Immediately below the low-pressure cylinder is the high-pressure
cylinder, the piston of which works horizontally to and fro, and united
by horizontal connecting rods to the lower arm of a side lever in dupli- 3
cate, to which a rocking motion is given. The upper arm of this lever is
connected by a link, also in duplicate, to that arm of the aforesaid bell-

page_text: crank lever to which the vertical connecting rod rising from the crank
of the propeller shaft is also connected, this being the point where the
efforts of the two cylinders are concentred. The fulcrums of the bell-
crank and side levers are supported in a suitable frame, to which also
the cylinders are secured. The difference of travel between the bell-
crank lever and the side lever (consequent upon the difference of stroke
of their respective pistons, the stroke of the low-pressure piston being,
in some instances, twice that of the high-pressure piston) is compensated
for by the before-mentioned link that unites one arm of the side lever to
the bell-crank lever and to the top of the vertical connecting rod, as
before described, thus a uniform upward and downward. motion is by
means of the two pistons conveyed to this rod, which necessarily
imparts a rotary motion to the propeller shaft by aid of the crank.
The supply of steam and the regulation of the ports in both cylinders
are controlled by a three-way cock which performs the duties of an
ordinary slide valve; this cock is placed between the two cylinders, the
steam pipe leading thereto, and the exhaust pipe conducted therefrom.
It is worked by an eccentric off the propeller shaft, and performs simul-
taneously three distinct offices, namely,-
(1). Opens, what would be termed in a vertical cylinder the lower
port of the high-pressure cylinder, and admits high-pressure steam
thereto.
(2). Opens the upper port of the same cylinder, and permits the par-
tially exhausted steam of a previous supply to enter the low-pressure
cylinder, and act upon the upper side of the piston therein.
(3). Opens the lower port of the last-mentioned cylinder, and allows
the exhausted steam to escape into the exhaust pipe.
Another motion of the eccentric rod reverses the order of things, as is
usually arranged by the ordinary slide valve.
The exhaust pipe is surrounded by a jacket of cold water flowing by
means of a small pump or by gravitation in the same direction as the
exhaust steam; this pipe terminates in an open mouth within the cold
water, which flowing onward carries with it the condensed or exhausted
steam.
I will now proceed to describe my Invention more in detail, reference
being had to the accompanying Drawing, and to the letters and figures

page_text: Figure 1 is an end view of my new or improved horizontal compound
engine showing the duplication of the horizontal connecting rod L (see
Figure 2), the side lever E, and the connecting link L*.
Figure 2 is a side elevation, partly in section, and with one of
the side plates or frame removed, to show more clearly the arrange-
ment.
In both these Figures A. is the high-pressure cylinder; B, the low-
pressure cylinder; a, the steam pipe; and 6, the exhaust pipe leading to
the condenser K; O is a three-way cock actuated by an eccentric & off
the propeller shaft or main shaft D. This cock supplies steam to the
high-pressure cylinder, and conducts therefrom the partially exhausted
steam to the low-pressure cylinder, and from thence to the exhaust
pipe b.
The piston in the high-pressure cylinder is connected to the lower arm
of the side lever E (see Figure 2) by the connecting rod L attached to
the piston rod. The piston in the low-pressure cylinder is suitably con-
nected to the lower arm of the bell-crank lever I, the upper arm of
which is attached to the vertical connecting rod H, and to the link L*,
proceeding from the upper arm of the side lever E; thus the united
efforts of the two pistons are conjoined, and convey by means of
the aforesaid vertical connecting rod a rotary motion to the crank
shaft D.
The upper part of the vertical connecting rod is formed, as shown in
Figure 1, to admit the lower arm of the bell-crank lever to work clear
of it.
The mode of action would be as follows:-Steam from the steam
pipe a, see Figure 2, enters the cylinder A. through the steam port a¹.
and drives forward the piston. therein, causing the partially exhausted
steam of a previous supply to enter the cylinder B by the ports all, a¹¹¹,
and to act upon the trunk piston, driving the same rearward and
expelling the exhaust steam through the port 6* into the exhaust pipe b,
which is surrounded by a jacket of cold water, as already described.
Motion by means of the horizontal connecting rods is communicated to
the side lever and bell-crank lever, which are joined together by the
link L*, and impart an upward and downward motion to the vertical
connecting rod H, causing the crank shaft to revolve, consequently the
eccentric at the proper time places the three-way cock in the position

page_text: shewn by the dotted lines at C, and reverses the order of things as is
usual in slide valves.
In Figure 3, which for convenience is drawn to a reduced scale, I
have shown a diagram of my Invention modified to suit those instances
where it is preferable that the two cylinders should have the same length
of stroke. In this case the low-pressure cylinder B is made of a larger
diameter than the high-pressure cylinder A, and the side lever dispensed
with, substituting therefore a bell-crank lever M, rocking freely on the
cranked shaft D, to which it gives motion by means of the link N
attached to the vertical connecting rod H guided by the radial arm O.
In this arrangement, as in the former, certain portions of the mechanism
would be in duplicate, namely, the bell-crank lever M, the link N, and
the connecting rod P.
Having now particularly described the nature of my said Invention,
together with the manner of carrying the same into effect, I wish it to
be understood that I claim, without limiting myself to these precise
details, the combination and arrangement of parts and mechanism, sub-
stantially as and for the purposes herein-before set forth and specified
and illustrated on the accompanying Drawing, or any mere modification
thereof.
In witness whereof, I, the said James Thompson, have hereunto
set my hand and seal, this Twenty-third day of May, in the
year of our Lord One thousand eight hundred and seventy-
six.