IMPROVEMENTS IN MEANS AND APPARATUS FOR EFFECTING AERIAL LOCOMOTION
Year: 1868

page_text: LETTERS PATENT to Matthew Piers Watt Boulton, of Tew Park, in
the County of Oxford, Gentleman, and John Imray, of 190, West-
minster Bridge Road, in the County of Surrey, Engineer, for the
Invention of "IMPROVEMENTS IN MEANS AND APPARATUS FOR EFFECTING
AERIAL LOCOMOTION"
Sealed the 18th September 1868, and dated the 24th March 1868. .
PROVISIONAL SPECIFICATION left by the said Matthew Piers Watt
Boulton and John Imray at the Office of the Commissioners of
Patents, with their Petition, on the 24th March 1868.
We, MATTHEW PIERS WATT BOULTON, of Tew Park, in the County of
Oxford, Gentleman, and JoшN IMRAY, of 190, Westminster Bridge Road,
in the County of Surrey, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MEANS AND APPARATUS FOR EPPECTING
AERIAL LOCOMOTION," to be as follows:-
Our Invention relates to propulsion and support of bodies moving
through the air and to apparatus for generating and applying motive
power for this purpose.

page_text: Some parts of the improvements are applicable to propulsion effected
by the movement of wings, while other parts are applicable generally for
aerial propulsion.
The chief objects contemplated in the case where wings are used are
to actuate them directly from pistons without the intervention of
rotating parts; to apply the engine power to them only in their down
stroke, their up stroke being effected by gravity acting in conjunction
with resistance of air; and to apply the moving force in the form of
tension so as to secure lightness of construction whether the propulsion
be effected by wings or otherwise; to obtain the motive power from the
combustion of aeriform mixtures by means of apparatus specially
arranged for vaporising the inflammable liquid, and for cooling the parts
heated by the combustion.
For aerial propulsion by means of wings we employ the following
construction: Two extended surfaces or wings are mounted on axes, or
on flexible joints parallel to the longitudinal centre line of the moving
body or vessel, so that one wing extends on either side, and that both
can oscillate freely up and down. A lever or arm projects downwards
from the axis of each wing perpendicular or nearly so to the general
surface of the wing. The lower extremity of this arm is connected by
ties to various points in the surface of the wing, so that when force is
applied to the arm to move the wing downwards, or when pressure is
applied to the under surface of the wing causing it to move upwards,
the strain is conveyed through the ties in the form of tension. Each
of the arms is connected directly to a piston moving to and fro in a
cylinder, so that when the piston is moved by pressure in the one direction
it causes the wing with which it is connected to strike downwards, and
when the pressure on the piston is relieved the air pressing on the under
surface of the wing so as to raise it moves the piston in the opposite
.direction. The two pistons are fitted in one cylinder open at both ends,
so that they approach each other in the one stroke, and recede from each
other in the other stroke. In the middle of the cylinder a charging
piston or plunger is made to slide in a cylinder or space transversely to
the working cylinder by levers and rods connecting it with the working
pistons or the wing arms on which they act. When the working pistons
'are at the extremity of their stroke towards one another the charging
piston or plunger is withdrawn and a charge of inflammable gas or
vapor mingled with air is admitted to the space which was occupied by

page_text: it.
This charge is ignited by electricity or by the indraught of a flame
kept constantly burning, or by other convenient means. The expansion
caused by the ignition forces the two pistons outwards and thus causes
the down stroke of the wings, which being resisted by the air raises the
car or vessel to which the wings are attached. The pistons having
completed their out stroke, during which the charging piston or plunger is
moved inwards, a slide or valve is opened so as to permit the products
of combustion to issue from the cylinder and so to relieve the pistons of
pressure. The vessel then descending by gravity the under surface
of the wing is pressed on by the air and they are thus caused to rise
relatively to the vessel and to move the pistons inwards; a fresh charge
is then introduced into the cylinder and the action is repeated. The two
working pistons instead of being fitted into one cylinder may work in
separate cylinders each closed at one end. Also the charging piston or
plunger instead of working transversely to them may work parallel with
them; or there may be two such charging pistons or plungers working
at the sides of the main cylinders or in the space between them; or the
working pistons may be hollow and fitted themselves with charging
plungers; or the charge of inflammable mixture may be introduced
into the main cylinder in the following manner so as to avoid loss of
time and contain greater continuity of action:-A secondary cylinder is
fitted with pistons of short stroke acting in the same manner as those in
the main cylinder and connected with them or with the wing arms on
which they operate. A charge of inflammable mixture is introduced
in the secondary cylinder before the return or complete inward stroke
of the main pistons. When they have completed this stroke the charge
in the secondary cylinder is ignited, and its pistons moving outwards
begin the down stroke of the wings, and also move the two main pistons
outwards through a space which is supplied with a charge of the
inflammable mixture. This charge being ignited continues and com-
pletes the stroke of the wings, and during the movement of the main
pistons the secondary pistons receive the movement necessary to clear
their cylinder of the products of combustion by a return stroke and to
separate them by a space for receiving the inflammable mixture. This
movement may be imparted to them either from the main pistons or
from separate apparatus suitably timed.

page_text: by heat. The heat imparted to the cylinder by the combustion of the
mixture within it may be used for this purpose. If this heat is more
than sufficient the superfluous heat may be removed by a current of
air. The current caused by the movement of the body through the air
may be used for this purpose, or a further current may be created by the
issue of the products of combustion as a blast, or by separate jets.
Some of the parts may also be cooled by water, and in. this case in order
to save the weight of a large supply we cause the same water to circulate
and cool it by currents of air created by such blasts or jets. The heat of
the cylinder may also be reduced by causing a certain quantity of air
to enter it as an annular film in contact with its surface.
The vaporization of the hydrocarbon alcohol may be effected in
the following manner-A portion of the hot products of combustion
discharged after performing work in the cylinder is passed through or
in contact with the liquid hydrocarbon or alcohol and thus becomes
mixed with sufficient vapour to charge the cylinder. In this case the
force derived from the combustion in the cylinder is somewhat reduced,
but the weight of vaporizing surface is diminished. Instead of employing
inflammable gas or vapour mixed with air for combustion in the cylinder
the elastic gases resulting from the ignition of explosive substances, such
as gunpowder or gun cotton, may be made to act upon the pistons.
Charges of such substances may be introduced into the cylinder at
suitable intervals and fired by electricity, or by pressure or percussion
on detonating or fulminating matter, or by other convenient means.
Besides the wings we use another extended surface placed at the hinder
part of the vessel somewhat like the tail of a bird. This tail is mounted
on a universal joint so that it may be turned on it axis and moved
horizontally and vertically at will for the purpose of steering, trimming,
and balancing the vessel; and this may also be effected by moving part
of the load so as to shift the centre of gravity. The wings are made to
a certain extent flexible from front to back, and the front part only is
rigidly connected to the pistons that work them. In consequence of this
flexibility the inclination of the wing is changed during the up-and-
down strokes, propulsive effect being obtained in the down stroke, and
the up stroke being assisted by the action of the air.
We prefer to construct the wing in the following manner:-A number
of rods are fixed side by side to the axis or jointed piece on which the
wing has to turn, and to which the lever operated on by the piston is

page_text: also fixed. Of these rods the longest is that which is at the front edge
of the wing, and the others are successively shorter as they are farther
from that edge. Each of these rods is curved backwards so that their
extremities reach a line forming the back edge of the wing at points
separated by suitable intervals. A sheet of light fabric is stretched
under these rods and attached to them by stitching or other suitable
means. The ties previously mentioned connect various points in these
rods with the lever on which the piston operates. It is to be understood
however that such ties may be used with other constructions of wings.
The back edge of the fabric is not rigid. We prefer to strengthen it by
a cord, the inner end of which may be attached to the framing of the
vessel or mechanism at a higher or lower level as may be desired. By
changing this point of attachment the inclination of the surface of the
wing may be to a certain extent varied. The horizontally curved ribs
above described may be also curved vertically, so as to render the under
The ribs
surface of the wing concave and its upper surface convex.
may be made of cane, bamboo, whalebone, or other light but strong and
elastic material, or of tubular or trough-shaped bars of steel; aluminium,
or its compounds with other metals may also be employed; and such
materials may also be used in other parts of the apparatus.
Also for the
sake of lightness, hollow forms may be used generally throughout the
apparatus.
The methods above described for generating inflammable vapour or
fluid to be used in a gas engine and for cooling the cylinder or cylinders
of the engine & parts connected with it may be also used in a gas
engine of any form employed to work a rotary propeller or apparatus
instead of wings. When this mode of propulsion is employed in coin-
bination with a plane or extended surface so disposed as to obtain
upward support from the action of the air upon it, we prefer to employ
two propellers revolving in opposite directions so as to prevent tendency
to rotate. We also prefer to place the propelling apparatus in front of
the plane or extended surface, so that the back current of air from it
acts on the surface and thus increases the upward support.
We prefer
that the surface thus acted on should be somewhat concave on the under
side. Instead of one surface several surfaces may be used. The vessel
may be raised or lowered, trimmed and steered by varying the inclination
of the surface or surfaces, or of some of them.
shaves decoribed may haved wither be

page_text: themselves in conjunction with the balloons or receptacles of various forms
containing light fluids which provide the whole or part of the support
required. In this case we supply the waste and maintain the heat of
the supporting fluid by admitting hot products of combustion to the
receptacles containing it after they have operated in the engine. In
order that the products of combustion may be of a light nature and so
afford greater supporting power we sometimes prefer to use inflammable
substances, such as alcohol containing a large proportion of hydrogen so
that a considerable amount of aqueous vapour is generated by their
combustion. In such cases the engine power would be used to raise
and lower the vessel as well as to propel it.
For starting aerial vessels the following apparatus may be employed:
-Legs are provided which are capable of being lowered so as to
support the vessel at some height from the ground. At the moment
of starting these are suddenly drawn up so that the vessel is free to
fall, and the engine power acts on it while falling.
These legs may
be jointed so that they can be drawn up into a small compass.
Jointed legs may also be applied for the purpose of starting in the
following manner :-A powerful spring is arranged so as to unfold the
legs to their full length on being released, and thus the vessel is pro-
jected upwards and the engine power acts on it while rising. As
additional power is desirable at starting this may be provided by means
of rockets or similar instruments which eject jets of aeriform fluid
as to urge the body in the direction desired. Vessels may also be
employed from which water is ejected by the pressure of gas or aeriform
fluid suddenly created within the vessels by the ignition of inflammable
compounds or by other suitable means.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Matthew Piers Watt Boulton and John Imray in
the Great Seal Patent Office on the 22nd September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, MATTHEW
PIERS WATT BOULTON, of Tew Park, in the County of Oxford, Gentleman,
and JouN IMRAY, of 190, Westminster Bridge Road, in the County of
Surrey, Engineer, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of March, in the year.
of our Lord One thousand eight hundred and sixty-eight, in the thirty..
first year of Her reign, did, for Herself, Her heirs and successors, give.
and grant unto us, the said Matthew Piers Watt Boulton and John
Imray, Her special licence that we, the said Matthew Piers Watt
Boulton and John Imray, our executors, administrators, and assigns, or
such others as we, the said Matthew Piers Watt Boulton and John
Imray, our executors, administrators, and assigns, should at any time.
agree with, and no others, from time to time and at all times there-.
after 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 Inven
tion for "IMPROVEMENTS IN MEANS AND APPARATUS FOR EFFECTING AERIAL
LOCOMOTION," upon the condition (amongst others) that we, the said
Matthew Piers Watt Boulton and John Imray, our executors or adminis-
trators, by an instrument in writing under our, or their, or one of their
bands and seal, 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 we, the said Matthew Piers Watt Boulton and
John Imray, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, that is to
say:
Our Invention relates to the propulsion and support of bodies moving
through the air and to apparatus for generating and applying motive
power for this purpose.
Some parts of the improvements are applicable to propulsion effected
by the movement of wings, while other parts are applicable generally
for aerial propulsion.
The chief objects contemplated in the case where wings are used are
to actuate them directly from pistons without the intervention of
rotating parts; to apply the engine power to them only in their down
stroke, their up stroke being effected by gravity acting in conjunction
with resistance of air; to apply the moving force in the form of tension

page_text: effected by wings or otherwise; to obtain the motive power from the
combustion of aeriform mixtures by means of apparatus specially
arranged for vaporizing the inflammable liquid, and for cooling the
parts heated by combustion,
For aerial propulsion by means of wings we employ the following
construction-Two extended surfaces or wings are mounted on axes
or on flexible joints parallel to the longitudinal centre line of the
moving body or vessel, so that one wing extends on either side, and
that both can oscillate freely up and down. A lever or arm projects
downwards from the axis of each wing perpendicular or nearly so to
the general surface of the wing. The lower extremity of this arm is
connected by ties to various points in the surface of the wing, so that
when force is applied to the arm to move the wing downwards or when
pressure is applied to the under surface of the wing, causing it to
move upwards, the strain is conveyed through the ties in the form of
tension. Each of the arms is connected directly to a piston moving
to and fro in a cylinder, so that when the piston is moved by pressure
in the one direction it causes the wing with which it is connected
to strike downwards, and when the pressure on the piston is relieved
air pressing on the under surface of the wing so as to raise it moves
the piston in the opposite direction. The two pistons are fitted in one
cylinder, open at both ends, so that they approach each other in the
one stroke, and recede from each other in the other stroke. In the
middle of the cylinder a charging piston or plunger is made to slide in
a cylinder or space transversely to the working cylinder by levers and
rods connecting it with the working pistons or the wing arms onl
which they act. When the working pistons are at the extremity of
their stroke towards one another the charging piston or plunger is
withdrawn, and a charge of inflammable gas or vapour mingled with
air is admitted to the space which was occupied by it. This charge
is ignited by electricity or by the indraught of a flame kept constantly
burning, or by other convenient means. The expansion caused by
the ignition forces the two pistons outwards, and thus causes the
down stroke of the wings, which being resisted by the air raises the
car or vessel to which the wings are attached. The pistons having
completed their out stroke, during which the charging piston or plunger
is moved inwards, a slide or valve is opened so as to permit the products

page_text: a
of combustion to issue from the cylinder, and so to relieve the pistons
of pressure. The vessel then descending by gravity, the under surface
of the wings is pressed on by the air, and they are thus caused to
rise relatively to the vessel, and to move the pistons inwards;
fresh charge is then introduced into the cylinder, and the action is
repeated. The two working pistons instead of being fitted into one
cylinder may work in separate cylinders, each closed at one end. Also
the charging piston or plunger instead of working transversely to them
may work parallel with them; or there may be two such charging
pistons or plungers working at the sides of the main cylinders or in
the space between them; or the working pistons may be hollow and
fitted themselves with charging plungers; or the charge of inflammable
mixture may be introduced into the main cylinder in the following
manner, so as to avoid loss of time and obtain greater continuity of
action-A secondary cylinder is fitted with pistons of short stroke
acting in the same manner as those in the main cylinder, and connected
with them or with the wing arms on which they operate. A charge of
inflammable mixture is introduced into the secondary cylinder before
the return or complete inward stroke of the main pistons. When they
have completed this stroke the charge in the secondary cylinder is
ignited, and its pistons moving outwards begin the down stroke of the
wings, and also move the two main pistons outwards through a space
which is supplied with a charge of the inflammable mixture. This
charge being ignited continues and completes the stroke of the wings,
and during the movement of the main pistons the secondary pistons
receive the movement necessary to clear their cylinder of the products
of combustion by a return stroke, and to separate them by a space for
receiving the inflammable mixture. This movement may be imparted
to them either from the main pistons or from separate apparatus
suitably timed.
We prefer to generate the inflammable gas or vapour used in the
cylinder from some substances such as hydrocarbons or alcohol
vaporized by heat. The heat imparted to the cylinder by the com-
bustion of the mixture within it may be used for this purpose. If
this heat is more than sufficient the superfluous heat may be removed
by a current of air. The current caused by the movement of the body
through the air may be used for this purpose, or a farther current may
be created by the issue of the products of combustion as a blast or by
B

page_text: separate jets. Some of the parts may also be cooled by water, and in
this case in order to save the weight of a large supply we cause the
same water to circulate and cool it by currents of air created by such
blast or jets. The heat of the cylinder may also be reduced by causing
a certain quantity of air to enter it as an annular film in contact
with its surface.
The vaporization of the hydrocarbon may be effected in the following
manuer A portion of the hot products of combustion discharged after
performing work in the cylinder is passed through or in contact with
the liquid hydrocarbon, and thus becomes mixed with sufficient vapour
to charge the cylinder. In this case the force derived from the
combustion in the cylinder is somewhat reduced, but the weight of
vaporizing surface is diminished. Instead of employing inflammable
gas or vapour mixed with air for combustion in the cylinder the elastic
gases resulting from the ignition of explosive substances, such as gun-
powder or gun cotton, may be made to act upon the pistons. Charges
of such substances may be introduced into the cylinder at suitable
intervals, and fired by electricity, or by pressure or percussion on
detonating or fulminating matter, or by other convenient means. Besides
the wings we use another extended surface placed at the hinder part of
the vessel somewhat like the tail of a bird. This tail is mounted on a
universal joint, so that it may be turned on its axis and moved
horizontally and vertically at will for the purpose of steering, trimming,
and balancing the vessel; and this may also be effected by moving
part of the load so as to shift the centre of gravity. The wings are
made to a certain extent flexible from front to back, and the front
part only is rigidly connected to the pistons that work them. In
consequence of this flexibility the inclination of the wing is changed
during the up and down strokes, propulsive effect being obtained in
the down stroke, and the up stroke being assisted by the action of
the air.
We prefer to construct the wing in the following manner:-A
number of rods are fixed side by side to the axis or jointed piece
on which the wing has to turn, and to which the lever operated on by
the piston is also fixed. Of these rods the longest is that which is at
the front edge of the wing, and the others are successively shorter as they
are farther from that edge. Each of these rods is curved backwards
so that their extremities reach a line forming the back edge of the wing

page_text: at points separated by suitable intervals. A sheet of light fabric is
stretched under these rods and attached to them by stitching or other
suitable means. The ties previously mentioned connect various points
in these rods with the lever on which the piston operates. It is to
be understood, however, that such ties may be used with other con-
structions of wings. The back edge of the fabric is not rigid. We
prefer to strengthen it by a cord, the inner end of which may be attached
to the framing of the vessel or mechanism at a higher or lower level, as
may be desired. By changing this point of attachment the inclination
of the surface of the wing may be to a certain extent varied. The
horizontally curved ribs above described may be also curved vertically
so as to render the under surface of the wing concave, and its upper
surface convex. The ribs may be made of cane, bamboo, whalebone, or
other light but strong and elastic material, or of tubular or trough-
shaped bars of steel; aluminium or its compounds with other metals
may also be employed; and such materials may also be used in other
parts of the apparatus. Also for the sake of lightness hollow forms
may be used generally throughout the apparatus.
The methods above described for generating inflammable vapour or
fluid to be used in a gas engine, and for cooling the cylinder or cylinders
of the engine and parts connected with it may be used in a gas engine
of any form employed to work a rotary propeller or apparatus instead
of wings. When this mode of propulsion is employed in combination
with a plane or extended surface so disposed as to obtain upward support
from the action of the air upon it, we prefer to employ two propellers
revolving in opposite directions so as to prevent tendency to rotate.
We also prefer to place the propelling apparatus in front of the plane
or extended surface so that the back current of air from it acts on the
surface and thus increases the upward support. We prefer that the
surface thus acted on should be somewhat concave on the other side.
Instead of one surface several surfaces may be used. The vessel may be
raised or lowered, trimmed, and steered by varying the inclination of the
surface or surfaces or of some of them.
The various forms of apparatus above described may be used either
by themselves in conjunction with balloons or receptacles of various
forms containing light fluids which provide the whole or part of the
support required. In this case we supply the waste and maintain the
heat of the supporting fluid by admitting hot products of combustion to

page_text: the receptacles containing it after they have operated in the engine. In
order that the products of combustion may be of a light nature, and so
afford greater supporting power, we sometimes prefer to use inflammable
substances, such as alcohol, containing a large proportion of hydrogen,
so that a considerable amount of aqueous vapour is generated by their
combustion. In such cases the engine power would be used to raise
and lower the vessel as well as to propel it.
For starting aerial vessels the following apparatus may be employed :—
Legs are provided which are capable of being lowered so as to support
the vessel at some height from the ground. At the moment of starting
these are suddenly drawn up so that the vessel is free to fall, and the
engine power acts on it while falling. These legs may be jointed so
that they can be drawn up into a small compass.
Jointed legs may also be applied for the purpose of starting in the
following manner:-A powerful spring is arranged so as to unfold the
legs to their full length on being released, and thus the vessel is
projected upwards and the engine power acts on it while rising. As
additional power is desirable at starting this may be provided by means
of rockets or similar instruments which eject jets of aeriform fluid so as
to urge the body in the direction desired. Vessels may also be employed
from which water is ejected by the pressure of gas or aeriform fluid
suddenly created within the vessels by the ignition of inflammable
compounds or by other suitable means

page_text: causing it to strike downwards.
This pressure causes them to
The arms and wings are represented in
Fig. 1 at the middle of their stroke, the dotted lines indicating the
extreme positions of the wings. e is a horizontal cylinder in which the
power for moving the wings is generated, as will hereafter be described.
This cylinder e is fixed to the framing of the vessel, and is fitted with two
pistons or plungers f, f. Each of these pistons is connected to the one
of the arms d, d, which is on the side of the vessel opposite to it, that
is to say, is connected to d¹ and f¹ to d. The connection may
be effected in the manner represented in Fig. 2. Each piston rod
terminates in a crosshead from which side rods extend on either side
of the cylinder to the extremities of the respective arms; the arms
may be double or forked to receive the side rods. As the side rods
are subjected to tension only they may be flexible as cords or straps.
The action of the apparatus is as follows:-By means to be more
particularly described hereafter fluid pressure is produced in the
cylinder e between the two pistons.
move outwards from the middle of the cylinder with a force which
being communicated through the side rods, levers, and ties to the wings
causes them to strike downwards. This down stroke being effected
with considerable velocity the reaction of the air against the descending
wings bears the vessel upwards.
When the down stroke has been
completed the pressure of the fluid in e between the pistons being
reduced to that of the atmosphere or nearly so, and the fluid being
allowed to issue from the cylinder, the car descends by gravity, but
the wings offering greater resistance to the air are caused to rise
relatively to the car. They thus draw the pistons inwards towards
the middle of the cylinder. When it is desirable to effect this up stroke
of the wings more rapidly they are fitted with springs which are
strained by the out stroke of the pistons, and by their clasticity assist
the in stroke, when the fluid pressure within the cylinder is reduced.
The wings have attained the extremity of their up stroke when the
pistons have met in the middle of the cylinder e a fresh charge of
elastic fluid is introduced between the pistons and the action is repeated.
The cylinder e may be constructed in various ways. Fig. 3 represents
a longitudinal section of the middle part of the cylinder according to
one construction. e, e, is the cylinder; f, f', the two pistons; g is
a plunger or piston fitted to slide, in a space transversely to the
cylinder e, e. The rod g of this plunger works through a stuffing box,

page_text: and is connected by a pin working in a slotted hole, or it may be by
jointed links, to a lever h which is mounted so as to vibrate freely on a
pin or axis m supported on a bracket projecting from the cylinder; the
lever has a pin h¹ projecting on its side. i is a bent lever mounted
on the axis m with an arm i which carries a pall k fitted to engage
with the pin h. The lever i is connected by a rod 7 to the crosshead
or one of the side rods of the piston 1, so that as the piston j' moves
to and fro in the cylinder the lever and arm ¹ are caused to vibrate,
as indicated by the dotted lines. is a pin fixed to the bracket of the
axis m, so that as the arm with its pall attains the upper extremity
of its stroke the pin bears against the tail of the pall; n is a slide
moved to and fro by stops on one of the side rods of the piston f¹ so
as to cover and uncover alteruately a passage from the interior of the
cylinder e; 0, 0, are valves for admitting air and inflammable gas or
vapour respectively. Although for the sake of distinctness these valves
are represented as separate and at some distance from each other, they
may be combined with any of the apparatus commonly used for mixing
the air and inflammable fluid admitted to the cylinder of a gas
engine. p is a passage fitted with a valve through the body of the
plunger ..
The action of the apparatus is as follows:-When the pistons f, f¹,
are at the extremity of their out stroke, the lever i being drawn to the
right extreme of its stroke, the arm with its pall is at the lowest
extremity of its stroke, and the lever hand plunger g are also at the
lowest extremity of their stroke, the pall being engaged with the
pin h¹.
Also the slide n is in the position represented, leaving a clear
passage out of the interior of the cylinder e. As the pistons move
inwards towards the middle of the cylinder, the lever i being connected
by the rod to the piston f¹ is moved towards the left, raising the arm i
and pall . The pall being engaged on the pin h', the lever and the
plunger are also raised. As the plunger g rises, the passage p being
closed by its valve, air and inflammable gas or vapour enter by the
valves o, o, to the space below the plunger g; at the same time the
contents of the cylinder e and of the space above the plunger g escape
by the passage in the slide n. When the plunger is just reaching
the top of its stroke and the pistons f, f, approaching closely to it the
slide is moved so as to close the port, and the tail of the pallis
pressed against the fixed pin This causes the pall to disengage
itself from the pin , and thus the lever hand plunger g are left free
q

page_text: to descend by gravity. By the descent of the plunger g the fluids under
it are forced up through the passage punto the space 7 above the
plunger; the gaseous mixture is then ignited by an electric spark or
otherwise. The expansion caused by the combustion produces a pressure
on the pistons f, f, which causes them to move outwards from the
middle of the cylinder. The outward movement of ft brings back the
lever i towards the right hand and causes the arm to descend until
the pall again engages with the pin k¹; also when the pistons are
just reaching the extreme of their outward stroke the slide n is caused
to move so as again to open the port from the cylinder e; the action is
then repeated. The plunger g is represented in the Figure as fitted to
slide vertically, its descent when left free being in this case effected by
gravity. It might be made to slide horizontally, its outward stroke
being in that case caused by a spring or counterbalance weight.
Fig. 4 represents a longitudinal section of part of the cylinder e
with its pistons constructed in a different manner. e is the cylinder
fitted with a slide n and valves o, o¹, to act as described with reference
to Fig. 3; f, f", are the two pistons which are enclosed within short
cylinders,, in which they can freely slide; a, a, are spiral springs
bearing against each piston and against the bottom of the short cylinder
in which it slides. These springs are conveniently wound round guide
rods projecting from the bottom and passing through the piston, with
collars at the ends to stop the piston from being forced by the springs
beyond a certain distance from the bottom of its enclosing cylinder.
s is a cam-shaped body mounted on an axis passing through a stuffing
box in the side of the cylinder e and capable of being turned round a
quarter of a revolution, as marked by the dotted lines. The axis of 9 is
fixed to a levert outside of the cylinder, which is actuated by a spring
tending always to pull it to the position represented on the Drawing;
t is a pin on this lever; and u is a pall with a notch for engaging the
pin t; is a slotted rod working on a pin on the lever and connected
to the crosshead of the piston for to one of its side rods so as to move
with it. The rod v has a horn ¹ projecting from it so as to bear against
the tail of the pall u.
The action of the apparatus is as follows:-The parts being in the
position represented in the Figure, and the interior space of the
cylinder e between r and being charged with an inflammable
mixture, the mixture is ignited and the pistons with the short

page_text: cylinders, 1, enclosing them are pressed outwards. The rod v moving
in unison with the piston f towards the left draws the levert with it
until the pin t¹ becomes engaged with the pall u, the cam s being thus
turned into the position indicated by the dotted lines. The pistons
approaching the extremity of their out stroke the slide (which is
worked by stops as described in reference to Fig. 3) opens the port
and relieves the pistons of the pressure to which they were subjected
by allowing the fluid to escape from the cylinder. The springs x, x¹,
then cause each of the cylinders 7, 71, to recede inwards from the piston
to which it is fitted as far as the collars on the guide rods permit.
The pistons make their in stroke, during which the slot in the rod v
passes freely along the pin on the levert without moving that lever.
When the pistons are just reaching the extreme of their in stroke, the
cylindrical parts 1, 1, just meeting in the middle of the cylinder, the
slide is moved so as to close the port. The horn bears against the
tail of the pall and disengages it from the pin t¹. The lever t being
thus left free is caused by the spring connected with it to make its
stroke to the right hand. In making this stroke it turns the cams,
which pushes the cylindrical parts 7, 1, away from each other so as
to leave a space in the cylinder between them. Air and inflammable
gas or vapour enters this space and form a charge which is ignited and
the action is repeated.
Having thus described the nature of our Invention, and in what
manner it is to be performed, we would have it understood that we
do not limit ourselves to the details represented on the Drawings.
In witness whereof, I, the said John Imray, have hereunto set my
hand and seal, this Twenty-first day of September, in the year of
our Lord One thousand eight hundred and sixty-eight.
Witness,
JOHN IMRAY. (L.S.)
ALEX. P. WRIGHT,
Secretary to the Inventors' Patent Right Association, Limited,
21, Cockspur Street,
Charing Cross.