Improvements in the Construction and Application of Screws or Spirals.
Year: 1890

page_text: Date of Application, 16th Apr., 1890-Accepted, 14th June, 1890
COMPLETE SPECIFICATION.
Improvements in the Construction and Application of Screws or
Spirals.
We AUGUSTE DESGOFFE and LÉONIDAS A DE GIORGIO, both of Odessa Russia Civil
Engineers do hereby declare the nature of the said invention for "IMPROVEMENTS IN
THE CONSTRUCTION AND APPLICATION OF SCREWS OR SPIRALS and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement, and 5 sheets of accompanying drawings, representing the appli-
cation of the invention to motors, regulators, receivers and projectiles to be as
follows:-
The object of this invention is to make use of the mechanical effects naturally pro-
duced by the inverse movements of helicoidal, concentric, or parallel surfaces, whose
juxtaposed projections (but not in contact with one another) are arranged in opposite
directions on each of the antispiral faces.
Experience has shown that the inclination of the projections, or spirals on their
axis of rotation, if they are concentric, or in a plane with their point of attachment,
should be 17° 40' for producing the maximum of effective power.
These mechanical effects may arise either from motion communicated to the anti-
spirals, by transmission from some source, or from some impelling substance entering
the spirals, and imparting to them a transmissable movement. Four series of
apparatus may be classed under this head viz.: motors, regulators, receivers, and
projectiles, 1st motors-The antispirals become motors when their spirals are sub-
mitted to the action of pressure of some sort, arising either from a fall of water,
steam or explosive and expansive gas, or some detonating substance, or hot air which
would communicate to the motors a transmissable motion.
Taking as example a steam engine Fig. 1, Sheet 1, which consists, First of the
cylindrical case A, closed at both ends by two lids fixed on the frame of the machine,
and containing internally the spirals a, a, traced at its upper part from right to left,
at a fixed inclination, and taking a left and right direction at the lower part b, b, at
an equal angle. Secondly of a cylinder B, keyed to the movable axis D, supported
by the plumber blocks F. G, pivotting at C, concentrically with the fixed case A, this
cylinder is furnished externally with spirals a' a', 61 61, traced on the whole surface,
in respectively opposite directions, opposed to that of the spirals of the case; that is
to say, that on each of the upper and lower surfaces of the movable cylinder, the
spirals cross with those that are juxtaposed to them inside the case, without in any
way hindering the mobility of the cylinder by any contact. Thirdly of an endless
screw, (the angle or inclination of whose threads or worm is invariably 17° 40')
keyed on the axis D, gearing with the wheel K, mounted on the shaft L, allowing for
the reduction (with the least possible loss of force) of the number of revolutions of
the machine, conformable with the requirements of transmission. Fourthly of a
frame H, on which the case, and its base are fixed, as well as the plumber blocks and
bearings of the axis of the movable cylinder, and transmitting shaft. Fifthly of a
regulator P, hereafter described in Fig. 3.
.
Action of the apparatus-The steam enters by the tube M, situated in the centre,
either lengthways, or horizontally in the cylindrical case A, penetrates the anti-
spirals a a, b b, a' a, b, to which it communicates its pressure, which acting on the
peripherically opposed inclinations is conveyed by the rotary motion of the movable
part B, at the two upper ends of which it escapes and passing through the
openings 0 0', on the central rib of the movable cylinder, (which serves as conduit
to it,) or by a special conduit connected to the cylinder A, meets at the exit N, with
the steam escaping from the lower spirals of the same cylinder B.
Observations The equilibrium of the weight of the movable parts, as well as the

page_text: effects produced by them, may be directed either to the wheel of an endless screw
serving to transmit motion either to the tool, or the machine directly connected to the
extended part of the axis D, so as to reduce friction to its lowest degree, by increasing
the diameter of the antispirals at their upper part, in such a manner as to overcome
resistance.
The steam surrounding the movable cylinder circulating all round its periphery,
keeps it constantly centred on its blocks, moreover the stean escaping from the anti-
spirals at a very low pressure, only requires a very slight locking of the joints, and
stuffing boxes, and assists in lubricating the metallic parts in contact, without heating
them, thus preventing wear of the blocks.
The form of the compensated machine is double, by reason of the compensating
arrangement here before described.
To utilize the expansion of the steam it is necessary to arrange the threads or worm
of the antispirals, so that the openings for the passage of the steam, which are very
contracted at the entrance, constantly cross throughout the whole length of the
- antispirals, which are calculated up to the exit orifice in proportion to the steam's
expansion.
The greater the pressure of the steam at the orifice of its entry, the quicker should
be the progression of the orifices of passage, for a similar length of antispirals, or this
length should be increased so much more, if the same progressive crossing of the
spirals is to be preserved.
The threads on the screw, and counter screw, which superpose one another, should
he equal, and of the same inclination, to produce the maximum effect, nevertheless as
the threads of the counterscrew are of rather larger diameter than those of the screw,
a reduction can be made in the depth of the spirals of the counterscrew, in proportion
to this difference of diameter.
The antispirals may consist of any number of threads, this number depends on the
power and consumption of steam for a machine of a certain diameter. The form to
be given to the spirals of the screws, and counterscrews, may vary according to the
motive substance, or matter employed for driving; but in the application of steam,
the forms adopted are shown by the Figs. 1.
The depth of the spirals as compared to their breadth may also vary; however the
depth we prefer is the breadth.
The dimensions of the spirals should be in proportion to the fluidity of the body
actuating the motor, and to its speed of flow. Too deep threads would give passage
to too great a quantity of motive power, a part of which would escape without being
submitted to the continuous contact resulting from the intercrossing of the spirals on
the screw, and counterscrew, and would only produce feeble results, whilst threads
not sufficiently hollow, forming canals in the antispirals insufficiently marked for the
density of the body or matter running through them, could only result in separating
the veins of matter intended to intercross, during their passage through the anti-
spirals.
The dimensions of the threads of the antispiral motors, may be regular when they
are connected with a transmitter of force, from which they take but a small portion
of the power, such for example as air, water, or gas, counters, and indicators of
pressure, expansion, propelling and explosive forces, and so forth.
The power of the antispiral motors inay be doubled, tripled, or qurdrupled, without
altering their number of rotations, or their diameter, by lengthening the apparatus,
so that by lengthening the axis D, (Fig. 1) one or more cylinders may be added, in
this case the distribution of steam for cach couple of antispirals, is as above described
that is to say, that to the case as many tubes are added for the admission of steam, as
there are couples keyed on the axis, the exit of the steam acting at the lower part of
the apparatus, after having passed through the steam evacuation conduits; the power
of the antispiral motors may also be doubled, tripled, and so forth, without modifying
their rotary speed, nor in increasing either the diameter, or length, by applying inside
the movable cylinder (shown in section and elevation by Figs. 2 and 2) spirals of
the same thread and direction as those that are outside the said cylinder, then by

page_text: placing inside a second fixed counter screw, always of the same thread, but in an
opposite direction; that is to say, similar to that of the first counter screw, then in
causing the steam to enter the movable cylinder by openings ad hoc, a double force
and double consumption of steam will be obtained, and as the threads of the two
antispirals are equal, their peripherical speed will be the same, without increasing the
size of the machine, but this first addition of a second inner antispiral, concentric
with the first, may be repeated as often as desired, by fixing spirals to the concave
part of the second counter screw, and in adding to the same movable piece of the
first screw, a second screw, of the same thread as the first, taking care to make a
series of openings for the distribution of steam, on the second counter screw.
This second screw may also have internal spirals, covering those of a third fixed
counter screw, which forms a fourth antispiral, acting conjointly with the three others,
which surround it.
In this case each antispiral, whatever number of spirals it may have, takes the steam
from the centre, and ejects it expanded at the two ends, uniting at a common orifice
or steam exit.
This arrangement although complicated in explanation, is very simple in practice,
and its execution effected by unerring means, admits of the construction of machines
of great power and very small consumption, and dimensions, and is very light in
weight.
As example a machine of 20 horse power with four double concentric antispirals,
can be contained in a case of 0 m. 19 c., in diameter, and 0 m. 40 c. in length.
The condensation of the steam leaving the antispirals, can be effected inside the
apparatus itself, or the steam escaping without artificial condensation under
100 degrees, is so dispersed throughout the periphery of the said cylinders, that
the least refrigeration entering through the upper lid Fig. 1, immediately con-
denses it.
This condensation can also be produced by any other condensing apparatus, placed
in any other position than that above described, at the same time the steam can
escape by one or more conduits, made either in the upper and lower lids of the motor,
or lengthways outside the cylinder.
The above described mechanical arrangements can be used for receiving, and utilizing
the pressure produced by a charge, in such a manner, that (with a column of water) a
hydraulic motor can be produced.
In this application the dimensions of the orifices of entry, and exit, as well as the
threads of the antispirals, and their number, may vary, for the density of the water,
and the adherence of its molecules being greater than those of the steam, or of an
expansive or gaseous body, the spirals may be larger without detriment to the
capacity of the vein running through them, moreover the suppression of expansion
allows of a special progression of the threads, whose capacity should correspond
to the degree of slackening to be effected, whilst the water runs through the anti-
spirals.
The speed of rotation in these machines being due to the height of their charge,
their diameter and thread may be arranged in combination, as required, either for
producing the number of revolutions necessary for the best use of this charge, or to
employ with equal profit large deliveries or supplies, with a small fall, or a small
delivery with a great fall.
The antispiral motors whether actuated by hydraulic, steam or other motive power,
or substance, may be horizontal, vertical, or inclined, with simple or double anti-
spirals, compensating or not the pressure exercised on the section of the movable
parts, with double, triple, or quadruple concentric screws, acting in the same
direction.
The outer case may itself be made movable, and the cylinder fixed, or the screw
and counter screw may be movable. They may also consist of two movable plates,
whose plain surfaces juxtaposed Fig. 2bs., bear helicoidal spirals inversely arranged,
in this arrangement the motive power would penetrate the centre.
It should be observed that these motors are not restricted to the use of any

page_text: distributing apparatus, that their working parts are not subjected to any friction,
either of their projections or spirals, that the furniture of the blocks requires no
locking, and that the expansion of the gas acts naturally in its course between the
threads of the apparatus, whose dimensions are very small, and their weight equally
so, in addition the facility of mounting and dismounting them is beyond comparison
with motors at present in use.
The antispiral motors are intended for use in aerostatice, drying, ventilation,
suction, blowers, fire engine pumps, and so forth, for tramway locomotives, nautical
use, agricultural and electrical purposes, tools, saw mills, and all industrial
machinery.
}
As hydraulic motors whether in substitution of turbins, or wheels, or as motors in
works, or in domestic usage.
As gas motors, hot air engines, compressed air machines, or for use with very
expansive substances.
In most of these applications it is well to regulate the introduction of the substance
acting on the antispiral motors, so as to keep the movable parts at the determined
number of revolutions, notwithstanding the variations of pressure of the generators,
or the irregularities in the mode of utilizing the working. Experiments on these
subjects have led to a novel application of the antispiral system, which we here
describe under the title of "The antispiral regulator." Like many other appliances
for regulating, the speed of motors, the orifice of entry of the vis viva, is regulated
according to the pressure of the generator, and the employment of the effects
produced by it in various ways, so as to keep the motor working in the most
advantageous manner, but the points where this regulator differs from others, are
the physical and mechanical means we employ to effect a spontaniety of its action,
correlatively with the working of the motor.
We have attained this result in a complete manner, by freeing our regulator from
the use of all flexible intermediaries, or the employment of all elastic, or centrifugal
force, which we have replaced by water or some liquid which being by nature
incompressible, transmits the pressure received, directly on the butterfly valve,
or steam admitting valve, with a force determined by the number of revolutions which
the main shaft of the motor communicates to an antispiral, sunk in the liquid
contained by the regulator.
On a shaft A, Fig. 3 Sheet 2, of the regulator shown in section, and side view, and
mounted on the motor as shown Fig. 1, or receiving motion from a driving shaft of
some motor or other, a screw B, is fixed to its end composed of right handed convex
threads, turning freely without contact with the projections of the concave threads
traced in opposite directions, or left handed, inside the box C, which envelopes the
screw and forms an antispiral.
This box bears four ears or lugs, in which two rods F. G. pass, and serve as guides
to the spiral springs which surround them; at the same time forming a means of
closing the lids on the box, by locking the bolts, besides which they paralyze by
their passage through the corresponding fixed ears H. J of the support K, any
rotary motion of the box C, which moves freely in a direction parallel to the axis,
under the impulse that the antispiral transmits to it in motion, by means of the liquid
driven to the lid D, hermetically closing one of its ends, whilst the other com-
municates with the free air supply reservoir M, also containing liquid, which a simple
joint and stuffing box L prevents running down the axis.
The lid D, communicates either directly with the steam admission valve, or with
the lever of the butterfly valve; when the motor is at work, the screw B, makes by
its axis, either the same number of turns as the main shaft, or a greater or less
number of revolutions. From that time the liquid contained between the spirals of
the screw, and counter screw, urged by the rotary motion of the screw, and forced
towards the lid with a pressure in proportion to the number of turns, and when
this pressure acting throughout the surface of the lid is sufficient to overcome
either the weight of the case of the regulator (if it is not in equilibrium) or the
resistance of tension of the regulating springs, the said box rises parallel to the

page_text: axis, at a height in proportion to this pressure, and to the elasticity of the spiral
springs overcome, or the lifting of additional weight previously calculated, so that
the rising of the box does not begin to be effected till the normal speed of the
motor exceeds that assigned to it, and it is this rising which operates most directly
on the butterfly valve of the steam entry orifice, by masking a section of its
aperture, which instantly reduces the speed of the motor. It should be observed
that as soon as the number of turns diminishes consequent on the partial closing
of the steam admission orifice, the action of the antispiral on the box diminishes,
and the box either by its weight, or by the continuous additional pressure it is
subjected to, causes it to instantly reoccupy its normal position, due to the simple
fact that the liquid contained in the box being noncompressible, and devoid of
elasticity, becomes a direct transmitter of pressure which it receives from the anti-
spiral, that is to say, from the driving shaft of the motor. This regulator whose
dimensions may be very small, may be placed in any position, horizontal, vertical,
or inclined, the top upwards, or downwards, without altering either its principle or
action, it can also pass alternately from one to the other of these positions, and be
submitted to trepidations, oscillations, or pitching effects, and still preserve its precision
of motion. It can also be applied for regulating the speed of all existing motors, as
well as to fixed, or movable engines, locomotives, ships engines, aerostats, dynamos,
hydraulic motors, and so on. They are placed either on the extended portion of the
driving shaft, or any other part or place, connecting it to them by any suitable
means, with or without multiplying or reducing the number of turns.
In all cases the force employed for working this regulator is as slight as desired,
and its use does not require any particular care or watching.
3rd. Antispiral Receivers-The antispiral receivers transform motion imparted to
them in a practical manner thus :-
1st. The antispiral pump consists of a screw A Fig. 4, Sheet 3, on which spirals
are traced from right to left, having a very limited number of threads turning freely,
with a slight play, the counter screw B, of which envelopes it concentrically, with
similar spirals but left to right handed, it pivots at G, and receives rotary motion
from the multiplier D D', the teeth of which lift the worm of the endless screw, at an
angle which permits of counterbalancing the effect of the column of water lifted by
the antispiral on the screw. This apparatus set in motion forces the sheet of water
into which it plunges to a height h, depending on the speed v. marked at the circum-
ference, and expressed by the formula 2. g. h. The saine is the case if the body of
the pump is placed 6 or 8 metres above the level of the water, with which it is
connected by a suction tube, terminating in a retention valve, after having been
first primed. A pump is thus constructed which with a very small diameter gives
a considerable delivery at a great height, the whole of which may be placed either
vertically, horizontally, or inclined, the rotary motion of the screw being communi-
cated to it either from a direct motor placed on the axis, or by belting, gearing,
friction, endless screw, or any other means of transmission.
This pump can be placed outside a well, the water to be raised from which, is
under 8 metres high, or placed inside deeper wells, in this case it is worked by
lengthening the axis of the screw, which communicates with a motor placed outside,
or directed to the bottom of the well.
If the diameter of the well is restricted, or consists of tubes of small diameter, on
the axis many screws and counterscrews can be mounted, the spaces between each,
being at heights corresponding with the elevating power of each, the whole being set
in motion inside the wells or tubes, in this case the lower pump furnishes the water
to the one preceding it, which in turn passes it to the next, an I so on till the mouth
of the tube is reached. In this manner the height of the water supplied by each
antispiral, is restricted to the normal and regular action of the elements constituting
this chain the rotary speed of whose screws may be very moderate notwithstanding
their small diameter, and the total height of elevation which may be considerable.
Hence the result is, that if the antispiral was continued throughout the height of
the tube, the water would be lifted with a very moderate rotary speed, as no

page_text: -
matter what the height of elevation, the speed required at the circumference of the
pump will then only be the square root of the product of 2g (g being the
gravity 9 m. 81) by the pitch of the screw. To avoid all strain on the pivots of
the pump the antispiral may be placed so as to balance the column of water, by
placing the suction pipe lengthways in the centre of the antispiral Fig. 5 Sheet 4,
which then consists of two spirals on the same cylinder, but whose threads placed
back to back, propel the water towards two evacuation tubes, placed at the ends, so
forming two pumps acting in opposite directions on the same axis, one of the pumps
may have the spirals more open in proportion to the excess of charge they may
have under certain circumstances to bear, and overcome, by reaction.
The water drawn at A Fig. 5, is forced at B B¹, if the apparatus is placed hori-
zontally, the equilibrium of the column forced is naturally established on the two
extreme faces of the double screw, without the supports of its axis having anything
more to hear than its own weight. But if the apparatus is placed vertically and
works by the transmission of a certain weight, the water penetrating at A Fig. 6, is
projected at BB', by the action of the antispirals C, and D, the first of which is of
larger diameter than the second, so that the pressure of water acting on a larger
surface balances the pump and the weight of the movable part D. C. and of the
transmission F. In both cases the total delivery of the apparatus may be double that
of an antispiral pump with a single screw of the same diameter. Instead of using a
double escapement tube, one may be done away with, by passing the forced water by
one of the antispirals through the central movable screw, which may be hollow for
the purpose.
Equilibrium of the column of water may also be established by the use of two
screws A, B, Fig. 7, one made outside a cylinder F, the other inside the same
cylinder, and both concentric with two fixed counter screws C, D, the first placed in
the centre of the apparatus, the second serving as outer case to it. If the two
Screws A, B, have their threads arranged in the same propelling direction, their
forcing action operating through the same evacuating pipe will add (without any
compensation) to the weight of the column of water or metal of these screws, and
of the transmission, but if the two screws A, D, have their threads arranged so
as to propel in opposite directions, the evacuation of the water being effected by
two conduits placed one above, the other below the apparatus, the compensating
effects are produced in causing the threads of the screw which propel the water
at the lower end, to be larger than those of the screw projecting the water at the
upper part.
A simple antispiral pump placed vertically, and drawing the water at its upper
part, whilst forcing it at its lower end, is also a compensating pump, if the weight of
the screw and transmission is equal to the effort of suction of the column raised, the
equilibrium is completed by forcing it at a calculated height, this compensation may
also be perfected by either increasing the diameter of the axle of the screw at the
part where there is an excess of pressure, or by adopting some kind of socket joint,
offering a sufficient surface to this pressure to effect equilibrium.
Pumps constructed on these principles are useful for raising all liquids, substances,
wine, spirits, beer, cold or hot oils, varnishes and so forth, or for mixing liquids with
or without pressure, fatty matters, acids, churning butter, clarifying petroleum, or for
use as pneumatic or hydraulic pumps, fire engine pumps, irrigating and watering,
draining, mining, ships pumps, and in any and all purposes where pumps can be
advantageously employed.
In adapting the antispiral pumps to these various applications, modifications are
required in some cases, thus in certain instances the counter screws may be made
movable, and the screws may be fixed, or the screws and counter screws may both be
animated with an inverse motion, which with an equal diameter allows of an increase
in delivery.
2. Antispiral elevators-Fig. 8 Sheet 5 represents an antispiral elevator, whose
movable screw A, placed vertically, consists of a certain number of threads, and turns
freely on its pivot B, between the spirals of the counter screw, which placed in

page_text: opposite directions, are made inside the fixed case G. Rotary motion is given to the
screw by the mechanism placed beneath the reservoir D, if the mattor to be raised is
fibrous, granular and so on, at the lower end of the screw a collector is situated,
serving to place it in the lower end of the antispiral, whence it is forcibly lifted to
the upper end of the antispiral, without any further resistance than its own weight,
and its friction against the inside of the apparatus, this friction is very slight if the
threads of the antispiral are regular in pitch, but crossing each other in proportion to
the differences occurring between the entry threads F, of the substances, and those of
the exit threads, as the quantity of matter engaged in the antispiral should reduce in
volume in proportion to the contents of the threads between which it passes, it,
will also be subjected to change of form, the effect of compression or the separation
of the aqueous parts, it may contain, and to the expulsion of these parts if the sides of
the case are suitably perforated.
The antispiral Fig. 8, will lift the matters submitted to its action, to its upper end,
which practically may be a great altitude, and if a smooth cylinder I, is placed in
continuation of the antispiral, the matter may continue to rise in this tube, forced by
that which is constantly propelled by the antispiral part, and will form by its
adherence to the sides of the tube lengthways, a resistence equivalent to the com-
pression desired. The mechanical motor placed at the lower part of the apparatus in
cases where the matter may be led above the first threads of the screw as in Fig. 8
for drying and elevating for raising mud and smoke of towns for pressing rasins,
apples and so forth can be placed at the upper part as in Fig. 9 Sheet 5.
In cases where the screw plunges into the matter to be raised, or is at its level, or
plunges into the substance to be lifted such as grain, sand, mortar or any other
matter, or powder, when used for dredging in rivers, ports, and so forth, sinking
wells, Fig. 10, preparing colours, for paper making etc., then in these applications
the rotary motion of the screw can be communicated to it either by a motor placed
directly on its axis, or by direct transmission. Hitherto we have described
cylindrical antispirals moved concentrically, but if we transform this movement by
giving it a rectilinear direction, the cylindrical form of the antispiral parts are no
longer required, and as cases require we can develope the antispirals into plane forms,
concave or otherwise consisting (Fig. 11 Sheet 5) of a flexible movable part A' A' or
composed of chains connected by hinges long enough to wind round the drums C,
and D Fig. 11. 11ª, and furnished with continuous spirals forming projections
throughout its whole surface, embracing its form whilst preserving the same
inclination of 17° 40′ in the direction of motion or 72° 20′ perpendicularly with the
axis. Then of a fixed sheath B, B' 11. 11° 11° in which it moves vertically with
the necessary play to avoid any friction between the spirals, and those which furnish
the interior of this sheath at a like angle, but in contrary directions to those of the
movable piece A.
The rectilinear movement vertically communicated at the centre by the driving
drum G, will lift the matter which accumulates at F, engages between the oppositely
inclined spirals of the fixed sheath, and of the movable part as far as G where
quitting the antispiral it frees itself and discharges at M 11. The employment of
antispiral elevators with a rectilinear metion can be applied to all the cases above
mentioned, or to any other similar applications. The use of the antispirals Figs. 8, 9
and 10 may vary. According to the speed imparted to the movable screws, they
may be used as separators of bodies of different densities, or fluidity; at low speed
they can only lift solid matter, a slight increase of the speed admits of their raising
semi-fluids, although they are not drawn along with any appreciable force, whilst a
still further increase fits them for performing this object.
Fig. 9 represents an elevator which has a fixed speed, and can be used as a pump,
if its lower part is sunk beneath a body or sheet of water, and forms a substitute for
the archimedian screw, without subjecting the apparatus to the vibrations caused by
the inclined position to which elevators on the archimedian screw principle are
subject, and the work it effects is equal to the volume produced by the screw, with a

page_text: speed at the circumference which may be expressed by 2 gd, d' being the diameter
which for the angle 17° 40' is equal to the pitch of the threads of the antispiral.
Antispiral Projectors.-The object of these projectors is to utilize the force of
percussion of an explosive, on a projectile to the greatest advantage, either by
dispensing with the use of plugs, for which are substituted a series of spirals, or by
some equivalent arrangement. In applying this principle to artillery Fig. 12
Sheet 2 the interior of the cannon is rifled with right handed threads or
spirals, sufficiently close to produce the desired result, and with left handed
spirals 12 12 12b of lesser depth (on the cylindrical part of the projectiles, and at
their bottom) which engage in those of the spirals or threads of the cannon freely,
and with slight play only.
If under these conditions an explosion is produced in rear of the ball, the
explosive force will drive the projectile and gases in the oppositely sloped spirals on
the bore of the cannon, and on the cylindrical part of the projectile, giving a
gyratory motion to the bail, the velocity of which is in proportion to the angle of
inclination of the spirals, and the length of the opposite spirals.
It would appear from this arrangement that a great quantity of gas would be
allowed to uselessly escape round the projectile, but this is an erroneous supposition,
as the escape of gas produced by explosion encounters such a perplexity where the
threads and spirals intersect, and cross each other, on the ball and cannon, that their
speed is greatly slackened, their velocity being given up to assist in the projection
and rotary motion of the projectile. The ball furnished in this manner with spirals
has a trajectory equal to that of an ordinary projectile, and on account of the
increased gyratory motion, has an increased range. Moreover the surrounding gas
keeps the ball in the centre of the rifling of the cannon, and prevents forcing, and
friction against the sides, and utilizes the expansive force to the best advantage.
Hence cannons are less exposed to the destructive action of recoil, and the barrels
can be reduced in thickness, whilst permitting of the use of more powerful explosives.
The antispiral projector also utilizes the action of the gases more completely, whilst
overcoming a part of the resistence of the plug. The charge may be reduced with
similar results, whilst the weight of the projectile, and range of the gun, are increased.
If a plug is used it suffices to trace on the rear of the ball, and on the cylindrical
part which connects it with the plug, without altering the rifling, but taking care to
arrange the spirals of the projectile, so that their inclination or pitch, should be at
an increased angle, and in the same direction as that of the rifling of the cannon,
the ball thus submits more rapidly to the gyratory effect of the rifling, and it is made
to profit (on leaving the gun) by the rotary impulsion that the surrounding gases
communicate to it.
The antispiral projector is equally applicable to light or heavy ordnance, rifles,
pistols, revolvers, and fire arms generally.
General Observations.-In all the applications of the principle to the severally
enumerated apparatus, the antispirals of the screws may be of metal, or any suitable
substance, they may be cylindrical, conical, or other form. The spirals of the screws
may be cast with their boss, or fixed by any suitable method to the central part,
which may be conical, or bent in any convenient shape to suit the requirements and
purposes of their employment, and the form of the screw threads. Their pitch,
shape, number, dimensions, and spacing, as well as those of the projections
of the counter screws, may vary in accordance with the use to which the
antispirals are to be put. The spacing or distance apart of the spirals may be
regular throughout the entire antispiral, or their separation may be gradually
increased, or diminished for a part, or the whole of the space they cover, their
inclination with regard to the axis may vary from an angle, to an annular section, as
it approaches the case of the machine, or till it becomes parallel with the axis.
However experience proves that the slope of 17° 40' gives the maximum of
useful work. The spirals of the case may be cast with the case, or fixed to it, they
may be of the same shape as the screws they surround, or they may materially differ

page_text: therefrom, they may assume a continuous helicoidal form, or they may be inter-
mittently so, with annular striations, the whole sunk or projecting on the bottom of
the case, they may be worked on the sheet metal, perforated or solid, separated from
the outer case, or forming a part of it, in each case they may be of a uniform depth,
conical, or varying in form in any part. The case or envelope may be in one piece
or divided lengthways, or diametrically in two or more sections.
It may be hollow, or double, to allow of the circulation of heat, or a refrigerant, as
may be required, the screws and counter screws may be placed horizontally,
vertically, or inclined, to suit the requirements of their application, the threads may
be of any formation gradually increasing, or decreasing in size, according to the
nature of the substances to be submitted to their action, they may be single,
fractional or any number of threads, continuous, or broken, these screws and counter
screws can be secured at one, or more points at each side of the exit, or entry, or
throughout their length.
The mechanism setting them in motion, as well as that for regulating their action,
may be of any form, in fact any mechanical combination in present use for producing
similar movements may be employed, in certain cases the counter screw may be
revolved in contrary or inverse directions or one or other may be fixed, moreover the
screws may be double, triple, and so forth, that is to say, they may be composed of
a tube containing within it a second, or third series of threads, acting on fixed
counter screws.
In all their applications the antispirals (screws and counter screws) may be
grooved or partioned off, throughout the whole, or part of their length, as many
times as is necessary, their threads may be smooth, or formed of notches, or they may
abruptly terminate here and there, in a straight line, or of different formation to suit
the helicoidal divisions, and the use to which the antispirals are to be put.
Having now particularly described and ascertained the nature of our invention,
what we claim is.
The exclusive use of the various novel applications of the antispirals herein
specified, that is to say by utilizing the power they produce, and the regulation of
this power for the purpose of lifting liquid or semi-liquid bodies, compact and solid
matters, and the separation or division of such bodies, and those of different
densities, whilst passing through the antispirals, and to utilize to the best advantage
the explosive force of gases, the whole being effected by the means and for the
purpose herein described, reserving to ourselves the right of modifying the form
and disposition of our apparatus in each and all of their applications, as herein
enuinerated.
Dated this 16th day of Anil 1800
A. C. HENDERSON & Co.,
46, Southampton Buildings, Agents for the Applicants.