AN IMPROVED AND ECONOMICAL METHOD OF APPLYING THE PRESSURE OF FLUIDS AS A MOTIVE FORCE
Year: 1878

page_text: LETTERS PATENT to Joseph Fulton Meade, of Eastwood, Newton-Mount-
Kennedy, County Wicklow, Ireland, for the Invention of "AN IMPROVED
AND ECONOMICAL METHOD OF APPLYING THE PRESSURE OF FLUIDS AS A
MOTIVE FORCE."
Sealed the 28th March 1879, and dated the 28th December 1878.
!.
PROVISIONAL SPECIFICATION left by the said Joseph Fulton Meade at the
Office of the Commissioners of Patents on the 28th December 1878.
JOSEPH FULTON MEADE, of Eastwood, Newton-Mount-Kennedy, County Wicklow,
Ireland. "AN IMPROVED AND ECONOMICAL METHOD OF APPLYING THE PRESSURE
OF FLUIDS AS A MOTIVE FORCE."
Th Invention consists of a method of modifying the velocity of fluids (liquid or
aeriform) passing under pressure either from or into a "receiver," so that the
unbalanced pressure on the interior or exterior parts of the receiver opposite the
apertures of efflux or influx, as the case may be, can be used with economy and
advantage as a motive or propelling force.
This result it is proposed to effect by limiting the motion of the fluid to approxi-
mately initial rates of velocity by the agency of a movable perforated disc through
which it must pass, either from or into the receiver to one end of which it is closely
attached.
This disc is mounted so as to be capable of a revolving or of a reciprocating
movement, and when in motion successively shuts and opens apertures communi-
cating with the interior of the receiver, thus causing the flow whether outward or
inward to be intermittent, and its velocity to a proportionate extent to be initial
and not accelerated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joseph Fulton Meade in the Great Seal Patent Office on the
27th June 1879.
JOSEPH FULTON MEADE, of Eastwood, Newton-Mount-Kennedy, County Wicklow,
Ireland. "AN IMPROVED AND ECONOMICAL METHOD OF APPLYING THE PRESSURE
OF FLUIDS AS A MOTIVE FORCE."
The object of this Invention is direct propulsion by the agency of the unbalanced
pressure of air or other fluid. If one side of an open vessel filled with water be
perforated, the inner side opposite the aperture of efflux will be subject to an
unbalanced pressure equivalent to the initial pressure on the jet. If the vessel
when empty be immersed in water above the aperture, there will be an external
pressure on the side opposite the point of influx like in kind, but except where
initial less in effect by the amount of projectile force arrested within the vessel.
It would however under ordinary conditions be impossible to employ with profit
this unbalanced pressure as a motive force, for the velocity of the escaping fluid
would absorb all or nearly all the power expended. But if the velocity of the jet
or current can be limited to a low, that is, an approximately initial rate, an
economical use of the unbalanced pressure may be obtained by the method either
of influx or of efflux. Although hitherto apparently overlooked in practice, all
fluids passing as described from a state of rest reach their maximum velocity
gradually, however rapidly, and up to that point are subject like other matter to
the accelerative action of gravity or pressure modified by their peculiar constitution.
While this may be stated in relation to all fluids, it is here proposed to consider
air as the immediate agent for propulsion, and an explanation of its mode of
application on the influx method will suffice, as the employment of it or of other
fluids whether by influx or efflux will be on the same principle and in essentially
the same manner. In the case then of atmospheric air passing through an orifice
into a vacuum, both its maximum velocity and the law which regulates it are
known. But time as well as pressure is a primary factor, and this velocity is not
attained at once, but by continuous accession, and as will be assumed in one fourth
of a second. As this however supposes that all the force is expended in one direc-
tion and takes no account of retardation from lateral intrusion near the point of
passage, the actual time may be considered greater. But taking it at one fourth of
a second then in accordance with the law of acceleration, it will in one eighth of
a second have attained from a state of rest to one half of its maximum velocity, in
one sixteenth of a second to one fourth, and so on towards zero, the velocity
lessening as the time and the space passed through as the square of the time.
The principle thus stated is the basis of the presont Invention, and is carried out
in it by causing the motion of the influent air to be so intermittent as to reduce it
to extremely low or approximately initial rates. The highest actual velocity will
be inversely as the number of initial rates of motion included in, say, the one fourth
of a second elapsing between zero and the attainment of the maximum velocity due
to height or pressure, and into that one fourth of a second as will be seen, above
one thousand minimum or initial rates can with facility be introduced. But the
unbalanced pressure remains the same whatever may be the velocity which only
effects economy of power, for the slower the motion of the influent air the less as
a consequence will be the amount of force unprofitably expended. The number of
the apertures of influx in simultaneous action can be indefinitely increased, and
any required amount of unbalanced or propelling force be thus brought into pro-
fitable operation. Intermission of flow and the application of the power economically
obtained thereby are effected thus:-The propellor is a hollow cylinder of which
one end is closed, while the other consists of two vertical plates near but not in
contact, of which the inner one is fixed while the outer is capable of a limited
adjusting movement so as to regulate the interval between them.

page_text: These plates are perforated except for a space round the centre, with holes of,
say, one tenth of an inch in diameter, and are so mounted that their apertures will
accurately correspond under. all circumstances. Between them is interposed a thin
but rigid metal disc in which are cut narrow longitudinal slits, the lines of which
are arranged in relation to the perforations in the plates so as to equalize as nearly
as may be the number continuously left open. This disc is mounted on an axis
and is capable of rapid revolution in close contact with the plates between which
it moves, and the apertures of which communicating with the interior of the
cylinder, it with momentary, alternation opens and shuts. To secure air-tight con-
tact with the plates the inner surfaces of the latter are smoothly coated with india-
rubber, leather, or the like, while at intervals grooves for the reception of lubricants
are provided. The disc as well as the exterior plates having a limited freedom of
horizontal motion, screws working in. external cross-bars and bearing against the
outer face of, the, latter will serve to regulate the elastic pressure on both sides of
the disc as may be found desirable.
When air is employed as the immediate propelling agent, the process will be as
follows:-The disc being put in rapid motion the interior of the cylinder is placed
in free communication with a chamber from which the air is being continuously
drawn by mechanical force; the passages or slots between, the external air and
the rarefied interior of the cylinder are with rapid alternation closed and opened by
the motion of the disc, the influent air, being thus only momentarily subject to the
unbalanced action of gravity, is in its constituent currents restricted to initial as
distinguished from accelerated rates of motion, and in so brief a space of time can
do little more than overcome its own inertia; the unbalanced pressure on the closed
end of the propellor remains meanwhile undiminished, and if duly proportionate to
the load and the disc motion be of the requisite velocity, the cylinder will receive
external air to a very small amount by positive influx, but nearly altogether by
its own advance into the virtually motionless atmosphere in front of it. In pro-
portion as this takes place will the power employed. be utilized, and an approach to
a perfect application be attained." The breadth of the slots or inlets should
be relative to the speed of the disc and the nature of the fluid used, but in
the case of atmospheric air, from one eighth to one tenth of an inch with a minimum
disc velocity of, say, twenty-five miles an hour will profitably use nearly all the
force expended. With disc slots of one tenth of an incb, this velocity will include
about eleven hundred initial motions in one fourth of a second, that is, there will
in that time be set in motion eleven hundred columns of air (or the same column
eleven hundred times), or a body of air equal in transverse area to the collective
transverse areas of the columns, and the inertia of this body of air supplies the
necessary reaction to the simultaneously accruing action on the closed end of the
propeller. An aperture area of one square foot would thus in one fourth of a second
subtend an atmospheric column of one hundred and twenty square yards of base,
the force represented by the motion of which is equivalent to the propelling force
accruing in the same fraction of time, or in other words the accruing working
pressure on the propellor is equal to that which would be produced by the
momentum (or wind) of a column of air of the above dimensions, moving at the
low velocity with which it advances into the cylinder. The great area of resistance
or reactive opposition thus virtually obtained in a limited space will, on considera-
tion be apparent.
The perforated plates and disc are made of substance and material sufficient for
strength and rigidity, the inner plate which will have to sustain considerable
atmospheric pressure being strengthened at the back by bars secured to the body
of the propellor. The disc mounted on an axis passing air tight through the plate
or plates, receives its motion by band, cranks, or otherwise, and is made, capable of
disconnection at will. When circumstances render a varying degree, of. propelling
force desirable two or more, parallel propellers can be worked on the same axis, or
the cylinder can be divided longitudinally into distinct, compartments, each,.com-

page_text: municating independently with the exhaust chamber so as to be put in or out of
action as needed. In marine propulsion a collateral position of the propellers
which will be placed within the ship will serve to facilitate steering, and in other
respects contribute to convenience. The principle of the propellor can be applied
either by influx or efflux, and air, water, or steam can be used on the same method
of retardation of flow, the intermittent action being regulated in relation to the
conditions of each case, the pressure and specific gravity of the fluid employed
determining the proper speed of the disc and breadth of inlets. Where a fluid at
high pressure is used and a proportionate velocity of disc motion not conveniently
attainable, two or more sets of apparatus may be fitted in an equal number of
compartments of the same cylinder so as to graduate the difference of pressure and
thus modify the natural rate of flow. To produce a reverse motion a second pro-
pellor, or what is to effect the same, a double-action one, will be employed. If the
former, the perforated ends of the propellers will face each other and a common
axis for the discs lie between. If the latter, a longer cylinder will be centrally
divided by a vertical diaphragm, each division having its outer end constructed
with plates and disc as described, and having a separate communication with the
vacuum chamber. As motion forward or backward is desired, the corresponding
compartment is put in communication with the chamber, and by the same operation
the other is cut off, and if desirable its disc disconnected from its axis. This change
of direction in the propelling force can be instantaneously effected by cocks or slide
valves and rapid admission of air to the unused compartment be given by a
tap.
It will be seen that, mechanically speaking, this propellor pretends to nothing
but to economise power and improve its mode of application, that it fully recognises
the laws of motion and works on the principle that action and reaction must be equal
and opposite. At each moment of time the accruing propelling force acting on the
driving end of the cylinder has, as already stated, its equivalent reaction in the inertia
or resistance to motion of the external air at the perforated end, where however
pressure or gravitation operates successively on each current for so short a portion
of time as to be able to impart to it only a low velocity. The propelling force is
cumulative, constant, and specific in its action, the influent force intermittent,
initial, and diffused over a large body of air. The collective effect however is the
same in amount, and the one balances the other, the resisting force of the large body
of air moving at a low velocity being equal to the propelling force simultaneously
accruing. The amount of force derivable from a given working area is easily cal-
culable on the basis that an approximately perfect vacuum would supply a pro-
pelling pressure of, say, two thousand pounds to the square foot. But whatever
the degree of exhaustion in the cylinder, the resulting propelling force being direct
in its application will with inconsiderable deductions be effective.
This description being intended to explain clearly the principle of the Invention
and show in its essential features, the mode of its application does not enter into
details of supplemental fittings and arrangements which will vary according to
circumstances. The principle of action is of extensive applicability. It may be
used in the case of fixed engines for producing immediate rotary motion in ship
propulsion, for which it presents special and varied advantages of great value in
land and railway traction where it supercedes the necessity of great wheel
adhesion destructive weight of engines, and low and costly gradients, and lastly,
it supplies a method by which, under certain conditions of weight and weather,
aerial navigation may be brought under definite control, for wherever there is an
atmosphere an adequate propelling force can on this system be produced and con-
veniently applied.
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim,―
The right to the mechanical application of the method of regulating the velocity
of fluids passing through orifices from or into a receiver by causing their flow to

page_text: be intermittent as described, and to use as a motive force the unbalanced pressure
thus economically obtained.
In witness whereof, I, the said Joseph Fulton Meade, have hereunto set my
hand and seal, this Twentieth day of June, One thousand eight hundred
and seventy nine.
JOSEPH FULTON MEADE. (LS.)