Year: 1899

page_text: ARTHUR HENRY BARKER, 14, Cromwell Street, Hull, Engineer, do hereby declare
the nature of this invention to be as follows:-
The object of this invention is to provide a perfectly balanced engine which,
whether worked by steam, compressed air, or other motive power, with two
cylinders only, preferably single-acting, will work at all speeds without any
vibration and which with two single acting cylinders will give two impulses per
revolution whether worked simple or compound.
The engine consists of two cylinders with pistons and connecting rods, at least
one of which has a piston rod. The cylinders work from diametrically opposite
sides on the same crank shaft. The crank shaft has three crank pins the two
outer of which have collinear axes which seen in end view are diametrically
opposite to the axis of the central crank pin. The two outer crank pins are worked
by two parallel connecting rods which receive their motion preferably from the
opposite ends of one crosshead pin passing through the crosshead attached to one
of the pistons. These two rods may, if desired, be connected together in one rod
with a fork deep enough to embrace the two cranks. The central crank pin is
worked by one rod driven by the other piston whether through a piston rod and
crosshead or not. In a single acting engine constructed on this principle the two
outer rods are kept by the steam pressure in constant thrust or tension, preferably
tension. The inner rod is kept in constant tension or thrust, preferably thrust,
so that with single acting cylinders there are two impulses per revolution. In all
cases one set of rods on the one side of the crank shaft are in tension at the same
time as the others are in compression.
The crank shaft is so made that its centre of gravity lies in the axis of rotation
and its axis of rotation is a principal axis so that it will revolve alone at all speeds
without vibration. The two pistons have preferably the same stroke and the
following statements as to weights etc. have reference to pistons having equal
strokes :-
The total weight of the purely reciprocating parts on the one side of the crank
shaft is exactly equal to that of those on the other side.
The weight of each of the two outer rods is equal to half that of the central rod.
All connecting rods are of the same length centre to centre. The centre of
gravity of each rod is at the same distance from the centre of its cross-head and
crank pins. The moment of inertia of each of the smaller rods is half that of the
larger.
In the case of engines the pistons of which have unequal strokes the weight of
any part is inversely as its stroke. The length of the connecting rod must, how-
ever, be proportional to the stroke and its moment of inertia must in all cases be
such that the moment of inertia of the single rod is exactly double of that of the
double rod. The centre of gravity of each rod must divide the length of the rod
centre to centre in the same proportion,

page_text: The valves are preferably of the piston type admitting steam to the middle
of the valve and have preferably two diameters with the larger diameter away
from the eccentric so that each eccentric rod is in constant tension. The valves
work in the same line and have preferably the same stroke and the same weight.
The three eccentrics, preferably cast in one piece, are made on the same principle
as was described in the case of the crank pins, the two outer ones working one
valve through a deeply forked rod, and the inner one working the other valve.
The valves however may be of any other type. The valves are set so as to keep
the connecting rods working the cranks in constant tension and thrust respectively,
in spite of the inertia of the moving parts. This end may be attained, if desired
by the introduction of an air cushion after the manner of the Willans engine.
The engine may be worked simple or compound or two or more of the engines
may be combined in one without departing from the spirit of this invention.
Dated this 27th day of March 1899.
ARTHUR HENRY BARKER, of 14, Cromwell Street, in the City of Hull, Engineer,
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
The object of this invention is to provide a perfectly balanced engine, which,
whether worked by steam or other motive power, with two cylinders only, will
work at all speeds without any vibration, and which gives two impulses per
revolution with two single acting cylinders, whether worked simple or compound.
The engine consists of two cylinders with pistons and connecting rods, at least
one of which has a piston rod. The cylinders work from diametrically opposite
sides on the same crank shaft. The crank shaft has three crank pins. the two
outer of which have co-linear axes, and which seen in end view are diametrically
opposite to the axis of the central crank pin. The two outer crank pins are
worked by two parallel connecting rods, which receive their motion preferably
from the opposite ends of one crosshead pin, passing through the crosshead
attached to one of the pistons. These two rods may, if desired, be connected
together into one rod, with a fork deep enough to embrace the two cranks. The
central crank pin is worked by one connecting rod, driven by the other piston;
whether through a piston rod and crosshead or not. Either piston may have a
trailing piston rod.
In a single acting engine constructed on this principle, the two outer rods are
kept by the steam pressure in constant thrust or tension, preferably tension. The
inner rod is kept in constant tension or thrust, preferably thrust; so that with
single acting cylinders there are two impulses per revolution. In all cases one set
of rods on one side of the crank shaft are in tension at the same time that the
others are in compression. The crank shaft is so made, that its centre of gravity
lies in the axis of rotation, and its axis of rotation is a principal axis, so that it
will revolve alone at all speeds without vibration. The two pistons have prefer-
ably the same stroke, and the following statements as to the weight, dimensions
and moments have reference to pistons having equal stroke.
The total weights of the reciprocating parts on the one side of the crank shaft
are exactly equal to that of those on the other side. The weight of each of the
two outer rods is equal to half that of the central rod. All connecting rods are

page_text: of the same length centre to centre, so that the weight of the piston which has no
piston rod, is equal to the combined weights of the other piston, piston rod and
crosshead. The centre of gravity of each of the three connecting rods is at the
same distance from its crosshead and crank pin. The moment of inertia of each
of the smaller rods is half that of the larger. In the case of engines, the pistons
of which have unequal strokes, the weight of the parts is to be made inversely as
their strokes. The length of the connecting rod must however be proportional
to the stroke, and the moment of inertia must in all cases be such, that the
moment of inertia of the single rod is exactly double of that of each of the outer
rods.
The valves are preferably of the piston type, the steam acting in the middle.
In this case each valve has two diameters, preferably with the larger one away
from the eccentric, so that each eccentric rod is in constant tension. The valves
work preferably in the same line, and have preferably the same stroke. The
three eccentrics, preferably cast in one piece, or solid with the crank shaft, are
made preferably on the same principle as described above for the crank pins: the
two outer working one valve through a deeply forked rod, and the inner working
the other valve. The valves are so set as to keep the connecting rods in constant
tension and thrust respectively, in spite of the inertia of the moving parts. This
may be aided if desired, by the introduction of an air cushion.
The engine may be worked compound, in which case the steam from the high
pressure exhausts into the low pressure cylinder. Two or more of these engines
may be combined into one, or each cylinder may receive steam or other power
direct from the generator, without departing from the spirit of this invention,
so as to keep at the same time one set of connecting rods in tension and the other
in compression.
And in order that my invention and the manner in which the same is to be per-
formed may be more readily and clearly understood, I have annexed hereto the
accompanying sheet of drawings illustrating the most preferable form of my
invention, in which Fig. 1 is a diagramatic plan, and Figs. 2 and 3 diagrammatic
mid-sections of an engine constructed in accordance with my invention.
In these views:-
C and c indicate respectively the two cylinders, both single acting, and which
may be arranged to work either simple or compound, in which latter case the
cylinders would be of different diameters.
•
These cylinders are arranged in one line, and diametrically on opposite sides of
the crank shafts, which has three crank pins, s₁, s, and 3, of equal strokes, and
of which the two outer & and s are co-linear and equidistant from the middle
crank pin s. The moment of the weight of the crank pin s, and its webs about
the axis is equal to the combined moment of the weights of the crank pins s̟ and
and their webs.
$1
$3
The piston P of the cylinder C is connected to the two outer cranks s₁ and s₂ by
means of the piston rod R, crosshead X and two connecting rods L, and L.; whilst
the piston p of the cylinder c is connected directly to the mid crank pin s by
means of the connecting rod 1. The length of the connecting rod is the same
as that of each of the connecting rods L, and L. The weight of the connecting
rod is made equal to the combined weight of the two outer rods L, and L.;
whilst the weight of the piston p is made equal to the combined weights of the
piston P, piston rod R and crosshead X.
The steam is admitted only to the back side of the piston p, and only to the
front side of the piston P, so that the connecting rod is always in compression,
and the connecting rods L, and L₂ are always in tension, whether the steam is
driving the piston and exhausting in front of the piston l' as indicated in Fig. 2,
or in front of driving the piston 2 as indicated in Fig. 3.
It will be evident from the drawing, that there are two equally divided impulses
for each revolution of the engine.
I wish it to be understood, that my invention is not limited to the case where

page_text: the connecting rod from the central crank pin is attached to one piston only, and
likewise the two outer crank pins connected to one common piston only, but also
inat either or both the centre crank pin and the two outer crank pins together may
be respectively connected to two pistons on a common piston rod, (i.e. tandem
fashion), so long as the weight of the purely reciprocating parts connected to the
centre crank pin are equal to the combined weights of the purely reciprocating
parts connected to the two outer crank pins.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
• 1. In high speed engines the arrangement of two single acting cylinders working
either simple or compound in line with each other on opposite sides of a crank
shaft having three cranks, the two outer crank pins being co-linear and situated
diametrically opposite the centre crank pin, the outer crank pins being connected
by parallel connecting rods and a common crosshead or a forked connecting rod
to the piston rod of one of the cylinders and the centre crank pin connected by
a connecting rod either directly to the piston of the other cylinder or through the
intervention of a piston rod and in which arrangement the steam is admitted so
as to drive the piston of the one cylinder on the out-stroke only and the piston of
the other on the instroke only substantially as and for the purpose or purposes
set forth.
2. In high speed engines having two single acting cylinders working either
simple or compound the arrangement of the cylinders cranks and connecting rods
in the manner herein set forth for the purpose of respectively retaining the piston
rod and the connecting rod or rods of the one cylinder always in tension or always
in compression whilst the connecting rod, and piston rod if provided, of the other
always in compression or always in tension substantially as and for the purpose
or purposes herein set forth.
3. In high speed engines as claimed in Claims 1 and 2 the combination of
tiree eccentrics valve rods and valve rod links and two piston valves with two
different diameters arranged substantially as and for the purpose or purposes
herein set forth.
4. In high speed engines as claimed in Claims 1 and 2, the modification in which
one or other of or both the single acting cylinders are replaced by two or
more cylinders arranged tandem fashion and so that the joint weight of the
purely reciprocating parts on the one side of the crank shaft is equal to the joint
weight of the purely reciprocating parts on the opposite side of the crank shaft
substantially as herein set forth.
Dated this 28th day of Decemb…” 1800.
J. CLARK JEFFERSON,
30, Park Row, Leeds, Agent for Applicant.