Improvements in Internal Combustion Motors for Use in the Propulsion of Automobile Vehicles and Water Craft, and for General Purposes.
Year: 1896

page_text: Date of Application, 5th June, 1895
Complete Specification Left, 2nd Sent.. 1895-Accepted, 24th Apr., 1897
PROVISIONAL SPECIFICATION.
Improvements in Internal Combustion Motors for Use in the
Propulsion of Automobile Vehicles and Water Craft, and for
General Purposes.
I, JOHN WILLIAM HUNTER of Eastdown Works, Dermnody Road, Lewisham, in
the County of Kent, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention has for its object the construction of a motor which shall be as free
as possible from shock and vibration when in action, so as to render it suitable for use
in situations where a rigid foundation is not available. I accomplish this by so
arranging the various parts of the mechanism that the momentum associated with the
movement of some of them, under the influence of the explosive charge, shall be
balanced and compensated by that due to other parts similarly acted on, and by
compactness and general lightness of design. The manner in which these improvements
are carried out is as follows:-Instead of the cylinder having one end rigidly closed,
and a free moving piston acting on a crank through the medium of a connecting-rod
com:non to gas engines and other prime movers of the same class, I construct a
cylinder consisting substantially of a tube open at both ends, and fitted with two
pistons moving always in opposite directions when in action. The explosive charge is
drawn in between these two pistons, and on the charge being fired both pistons are
propelled outwards at the same time, and the force thus developed is communicated to
a revolving shaft by means of connecting-rods, rocking levers, and cranks, and further
applied by any means which may be most convenient.
The type of motor adopted is based upon what is commonly known as the
"Otto cycle,
"which embraces 1st drawing in the charge; 2nd compression;
3rd firing; 4th exhaust, thus giving an impulse in one cylinder to every second
revolution of the crank or cranks acted on by the pistons; but any other cycle may be
adopted. This is the simplest form of motor constructed in the manner set forth, but
the usual type will be fitted with two cylinders, each having two pistons arranged as
previously described, and so adjusted that the cranks will receive one impulse in each
revolution of the crank shaft; but any larger number of cylinders may be employed.
This motor may be worked by gas, petroleum, spirit, or any product capable of forming
an explosive mixture, and is fitted with the usual valves, cams, vaporizers, (if required)
and other parts necessary to the working of motors of this class. The result of such
an arrangement of parts is that, 1st. The engine or motor, being balanced and
compensated throughout both as regards its impulses and moving parts, can be run at
a high rate of speed without undue vibration; 2nd. The explosive force of the charge,
acting on both pistons at the same time, is taken up much more quickly than in the
ordinary type of gas or oil engine, the result being a great reduction of heat waste and
consequent higher efficiency, whilst at the same time the expansive force of the
exploded charge is more fully utilized. 3rd. A reduction in the number of parts is
effected, as the four pistons (in the case of a two cylinder engine) may be operated by
two sets of valves, and in the case of a petroleum engine only one vaporizer need be
employed. 4th. Compactness of design and light weight in relation to the power of
the engine.
Tune 1806

page_text: :
VOMI DELE STEIFICATION.
Improvements in Internal Combustion Motors for Use in the
Propulsion of Automobile Vehicles and Water Craft, and for
General Purposes.
I, JOHN WILLIAM HUNTER, Eastdown Works, Dermody Road, Lewisham, in the
County of Kent, 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:
My invention has for its object the construction of a motor which shall be as free
as possible from shock and vibration when in action, so as to render it specially suitable
for the propulsion of auto-mobile vehicles and launches, and for use in situations
where a rigid foundation is not available.
I accomplish this by so designing and arranging the various parts of the mechanism
that there shall be no appreciable recoil when the motor is working, and that the
momentuni associated with the movement of some of its parts shall be balanced and
compensated by that due to other parts similarly acted on.
"
The manner in which these improvements are carried out is as follows:-The type
of motor herein described is based on what is commonly known as the "Otto cycle,
but instead of having a cylinder with one end rigidly closed, and a free moving piston
acting directly on a crank by means of a connecting rod, common to gas and other
prime movers of this class, I construct a cylinder consisting substantially of a tube
open at both ends; each cylinder being fitted with two pistons between which the
explosive charge is fired, and connected with the crank shaft by an intermediate
arrangement in the manner hereafter shown, and illustrated by drawings.
I now proceed to describe in detail what I shall designate a typical form of this
invention, as shown in the drawings, this being a double or twin-cylinder engine. The
drawings show the essential details of the invention, Figure 1 being a side view
displaying the general arrangement of parts; Figure 2 being an end view, showing
the manner in which the pistons are connected with, and act on the crank shaft.
A. Cylinder, showing pistons at half stroke.
B. Rocking bar, with arins extending upwards to connect with pistons, and down
to crank, the connections at both ends of the cylinders being the same..
C. Crank shaft, having a double throw crank, the cranks and pistons at opposite
ends of cylinders being connected together and operated as shown.
D. Frame supporting the mechanism.
E. Water jacket.
F. Fly wheel..
It is an essential feature of this motor that whether it be constructed with one
(which is not desirable) or two cylinders, the shaft must have two cranks placed
diametrically opposite to each other, and if a perfect balance is to be maintained they
must have the same throw so that the pistons may have an equal travel, although there
is nothing to prevent a deviation from this position of the cranks if steadiness in
running is not a first consideration. An engine built in this manner has its two
cylinders acting alternately, thus giving an impulse once in every revolution of the
crank shaft. Any number of cylinders having their pistons connected in like manner
with the rocking bar at each end of the cylinders, all acting on one crank, could be
employed; but a much better plan is to duplicate the two cylinder-arrangement, using
a shaft provided with two pairs of cranks set at right angles to each other,
which arrangement will furnish an impulse twice during each revolution of the
crank shaft.
This motor may be worked by gas, petroleum, spirit, or any product capable of
forming an explosive compound, and is fitted with the usual valves &c. necessary to

page_text: the working of a gas or oil engine, and may be fired either by a heated tube or
electrically; but these parts are not described or illustrated, they being such as are
common to motors of this class. The cycle of operations when the engine is working
is as follows in a single cylinder engine:-1, drawing in the charge; 2, compression;
3, firing; 4, exhaust; but any other cycle may be adopted if practicable, and variations
in constructional details may be permitted providing the general principles involved
are adhered to.
It will be seen that in a motor constructed as herein described all the causes
of shock and vibration are eliminated, and a perfect balance is secured without
having recourse to artificial loading. When the piston at one end of a cylinder
makes its outward stroke in one direction, that at the other end of the same cylinder
is making an identical movement in an opposite direction. The cranks, also, being
set diametrically opposite to each other are similarly balanced and compensated, each
receiving the thrust at the same time. Thus a very high speed is rendered possible,
resulting in a motor of light weight and small size in relation to its power, which
weight may be still further reduced if the motor is used in such circumstances as will
permit of the water jacket being dispensed with; whilst many advantages are
incidentally secured which need not be here particularized.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In an internal combustion motor, the use of a cylinder or cylinders consisting
substantially of a tube open at both ends, each cylinder being fitted with two pistons
always moving in opposite directions when in action, between which an explosive
charge is fired under compression or otherwise, combined with a crank shaft in the
manner herein described and illustrated.
2. A motor having two cylinders, or any multiple thereof, each cylinder being fitted
with two pistons, and the pistons of each pair of cylinders acting on a crank shaft
having two cranks diametrically opposite each other by means of connecting rods and
intermediate rocking bars, or by levers, substantially as described.
3. A motor having all its parts and movements balanced and compensated in the
manner described, and illustrated in the accompanying drawings; and operated by an
explosive charge between the two pistons of each cylinder.
4. A motor having one cylinder acting on a double throw crank by means of an
intermediate rocking bar, or by levers, arranged and operating in the manner described
as applied to a two cylinder engine.
Dated this 21st dov of August 1896
J. W. HUNTER.