Improvements in Torpedoes.
Year: 1888

page_text: Date of Application, 16th Nov., 1888
Complete Specification Left, 6th Sept., 1889-Accepted, 12th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Torpedoes.
I, THORSTEN NORDENFELT, of 53 Parliament Street in the City of Westminster,
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates more especially to means for controlling torpedoes by
electricity so as to regulate their movement, direction and depth. The torpedo is
connected to the shore or controlling station by a cable containing insulated
conductors, and this is paid out from the torpedo as it passes through the water.
The torpedo is driven by means of an electro motor which is supplied with current
from batteries contained within it. The motor actuates a propeller at the stern of the
torpedo. The direction of the torpedo is controlled by a rudder which is operated by
gear which I will presently describe.
Another rudder controls the distance of the torpedo from the surface and similar
gear is provided in connection with this rudder. The rudder gear is as follows:-
The propeller shaft by means of a worm wheel gives motion to an axis upon which
are two spirals. The rudder lines terminate in hooks in close proximity to the
spirals, and these hooks are operated by electro magnets. The hook when operated
on by its electro magnet engages with its spiral first where the spiral is at its
smallest diameter, and by the rotation of the spiral, the hook is caused gradually to
mount to the larger diameter of the spiral, and in this way the rudder line con-
nected with the hook is pulled upon, and the rudder is pulled over from its midship
position to its greatest inclination. Thus when the armature is attracted the hook
engages and mounts the spiral and when the inagnet ceases to attract, the hook
leaves the spiral and returns to its original position. The hooks are coupled together,
so that one only can operate at a time.
The magnets receive their current from batteries in the torpedo, and their circuits
are closed by a polarized relay brought into action by a current sent through one of
the cable cores.
A positive current causes one of the electro magnets to operate, and
the corresponding hook to engage with its spiral. A negative current in like manner
operates the other electro magnet and hook. So by transmitting positive and
negative currents through the cable the torpedo is steered to port and to starboard.
For the vertical rudder which controls the distance of the torpedo from the surface
of the water the controlling current is not transmitted through the cable but is
derived from a governor which the torpedo carries. The construction of this governor
is as follows:-
.
AU tube containing liquid is closed at one end by a membrane which is exposed
to the presence of the external water. The other end of the U tube is connected
with a chamber in which air is enclosed. In the U tube there is a float and this
float (following the liquid) rises and falls in the tube as the pressure on the membrane
varies in consequence of the torpedo ascending or descending in the water. The
float is connected with a lever, and this lever consequently is turned through a con-
siderable angle when a small change takes place in the depth of immersion of the
torpedo. The lever carries upon it two tubes curved like the glass of a spirit level,
but with the curvature downwards in place of upwards. These tubes are similar the
one to the other. Sealed into the ends of each tube are platinum strips or wires
extending from the ends towards the centre of the tube where (when the position is
horizontal) a globule of mercury lies: There is also a wire sealed into the top of the
tube and dipping into this mercury. The strips at the ends of the tube are
connected with the two poles of a battery but so long as the tube is horizontal, the
circuit is broken in the tube, but when the tube is inclined the mercury globule
establishes metallic connection between the strip at the lower end of the tube and

page_text: the central wire: thus, this wire is connected with the battery, and the pole to
which it is connected is either the positive or negative pole according to the
direction in which the tube is inclined. As already stated the lever carries two of
these tubes, and the two wires passing through the centre of the tubes are thus
connected with the battery in one way or the other according to the direction in 5
which the lever is inclined. When the torpedo is above its proper level the battery
connected is in one direction; when it is below its level the connections are the
other way. In addition to these tubes there are also two other similar tubes which
are operated by the same lever by means of springs: they incline always in the
opposite direction to the first mentioned tubes, and stops are applied which confine
their movements to a very small angle of inclination to the axis of the torpedo.
When the torpedo is required to descend the fore ends of these tubes are raised or
inclined upwards relatively to the axis of the torpedo and vice versa. The battery
circuit may be traced from one pair of tubes to the relay which controls the rudder,
and from the relay by the other pair of tubes to the other battery poles. The tubes 1
operate as pole changers:-one tube of each pair (viz. :-the tube mounted directly
upon the lover and which moves through a large angle) when the torpedo passes the
line of mean immersion; the other when the axis of the torpedo is inclined at such
an angle to the horizontal plane, that it is desirable to check it by the use of the
rudder.
The action of the apparatus is as follows:-
2
If the torpedo is too near to the surface, the tubes, which are directly actuated by
the lever, at once oporate decisively to transmit a current suitable to cause the torpedo
to be steered downwards, and the torpedo is steered downwards, unless indeed the
axis is already sufficiently inclined in this direction, in which case the second tube 2
intercepts or reverses the current, the inclination of the torpedo itself then being
such as to neutralize that of the second set of tubes and to cause the mercury globules,
which they contain to roll to their reverse ends. When the torpedo is too deeply
immersed the action is in all respects similar but in the reverso direction. When
the torpedo is nearly at the proper depth, the sets of tubos assume a horizontal
position or rather a position parallel to the axis of the torpedo and then for so long
as it remains on an even keel, the rudder is inoperative, but if it inclines upwards or
downwards it is checked by the rudder.
•
The starting and stopping of the torpedo is effected in the following manner :-
The axis which carries the steering spirals has a pinion upon it and a wheel having 3
teeth a part of the way around it, can be made to gear with the pinion. The wheel
is carried upon an axis to which an end wise movement can be given by means of an
electro magnet and spring. When the magnet attracts its armature the teeth of the
wheel come into gear with the pinion. When the attraction ceases the wheel passes
out of gear. The axis is cranked and a spring connected with the crank brings it 4
back to its starting point as soon as the wheel passes out of gear. The axis at its
upper end carries a contact arm passing over a series of contacts in order that at
starting only a part of the battery power may be applied to the motor, and the power
is increased step by step until the whole battery is on. This arrangement is necessary
because if the full power were applied to the motor at rest injury would be done to 4
it, it can only take full power when it is already in rapid movement.
An electric current passing through the cable operates a relay and this closos the
circuit of the electro magnet. It draws down the axis and brings the contact arm
which it carries on to a stationary contact stud. At the same time the wheel is
brought into gear and the axis commences to revolve slowly. The contact arm can i
turn upon the axis through a small angle but it is connected by a spring to an arm
rigidly fixed upon the axis. The friction between the contact arm and the stud keeps
the arm upon the stud whilst the axis rotates until the fixed arm comes up to the
contact arm and pushes it off the contact stud. Then by the operation of the spring
the contact arm is caused to jump forward to another stud through which increased
battery power flows to the motor. So the contact arm passes from stud to stud
until the crank upon the axis has passed the centre and the teeth of the wheel have

page_text: run past the pinion then the spring in connection with the axis turns it with a jump
until the fixed arm is brought against a stop and the contact arm rests upon the
last of the contact studs of the series. The motor will then be working with full
battery power applied.
When in consequence of no current passing in the cable the electro magnet releases
the axis the fixed arm upon it escapes over the stop and the spring brings the axis
back to its original position. The motor circuit is then open.
A similar arrangement may be applied in torpedoes driven by compressed air to
control the air valve so that the engines may start gradually otherwise there is a risk
of the torpedo plunging when it is started which may in some circumstances cause
the loss of the torpedo or in others an irregular movement continuing for a considerable
time.
4000
COMPLETE SPECIFICATION.
Improvements in Torpedoes.
I, THORSTEN NORDENFELT, of 53 Parliament Street, in the City of Westminster,
Civil Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement
--
The
This invention relates more especially to means for controlling torpedoes by
electricity so as to regulate their movement, direction and depth. The torpedo is
connected to the shore or controlling station by a cable containing insulated con-
ductors, and this is paid out from the torpedo as it passes through the water.
torpedo is driven by means of an electro motor which is supplied with current from
batteries contained within it. The motor actuates a propeller at the stern of the
torpedo. The direction of the torpedo is controlled by a rudder which is operated by
gear which I will presently describe.
Another rudder controls the distance of the torpedo from the surface and similar
gear is provided in connection with this rudder. The rudder gear is as follows:-
The propeller shaft by means of a worm wheel gives motion to an axis upon
which are two spirals. The rudder lines terminate in hooks in close proximity to
the spirals, and these hooks are operated by electro magnets. The hook when
operated on by its electro-magnet engages with its spiral first where the spiral is at
its smallest diameter and by the rotation of the spiral, the hook is caused gradually
to mount to the larger diameter of the spiral and in this way the rudder line
connected with the hook is pulled upon and the rudder is pulled over from its mid-
ship position to its greatest inclination. Thus when the armature is attracted the
book engages and mounts the spiral and when the magnet ceases to attract the
hook leaves the spiral and returns to its original position. The hooks are coupled
together, so that one only can operate at a time.
The magnets receive their current from batteries in the torpedo, and their circuits
are closed by a polarized relay brought into action by a current sent through one of
the cable cores. A positive current causes one of the electro-magnets to operate,
and the corresponding hook to engage with its spiral. A negative current in like
manner operates the other electro magnet and hook. So by transmitting positive
and negative currents through the cable the torpedo is steered to port and to star-
board. For the vertical rudder which controls the distance of the torpedo from the
surface of the water the controlling current is not transmitted through the cable but
is derived from a governor which the torpedo carries. The construction of this
governor is as follows:-
--
AU tube containing liquid is closed at one end by a membrane which is exposed
to the presence of the external water. The other end of the U tube is connected
with a chamber in which air is enclosed. In the U tube there is a float and this

page_text: float (following the liquid) rises and falls in the tube as the pressure on the
membrane varies in consequence of the torpedo ascending or descending in the water.
The float is connected with a lever, and this lever consequently is turned through a
small angle when the torpedo deviates from its normal depth of immersion. The
lever carries upon it two tubes curved like the glass of a spirit level, but with the
curvature downwards in place of upwards. These tubes are similar the one to
the other. Sealed into the ends of each tube are platinum strips or wires extending
from the ends towards the centre of the tube where (when the position is horizontal)
a globule of mercury lies. There is also a central wire or strip sealed into the tube
and in contact with this mercury. The strips at the ends of the tube are connected
with the two poles of a battery but so long as the tube is horizontal, the circuit is
broken in the tube, but when the tube is inclined the mercury globule establishes
metallic connection between the strip at the lower end of the tube and the central
wire or strip: thus, this wire or strip is connected with the battery, and the pole to
which it is connected is either the positive or negative pole according to the
direction in which the tube is inclined. As already stated the lover carries two of
these tubes, and the two wires passing through the centre of the tubes are thus con-
nected, with the battery in one way or the other according to the direction in which
the lever is inclined. When the torpedo is above its proper level the battery is
connected in one direction, when it is below its level the connections are the other
way. This however only occurs if the torpedo is approximately on a level keel.
It will be soon that if the torpedo is already directed decisively in the direction it
is required to go, it is not adviseable that it should also be steered in this direction
and this is avoided by permitting the lever to incline only through a small angle so
that when the reverse inclination of the torpedo itself is at all considerable it
neutralises or overcomes that of the lever within it and the mercury globule
gravitates towards the lower end of the torpedo notwithstanding the movement of
the lever under the control of the governor.
To obtain this result I originally employed a double apparatus (described in my
provisional specification) but this I find to be unnecessary.
Instead of a mercury globule 1 an employ a solid weight free to move under the
influence of gravity.
The starting and stopping of the torpedo is effected in the following manner :-
The axis which carries the steering spirals has a pinion upon it and a wheel having
teeth a part of the way around it, can be made to gear with the pinion. The wheel
is carried upon an axis to which an endwise movement can be given by means of an
electro magnet and spring. When the magnet attracts its armature the teeth of the
wheel come into gear with the pinion. When the attraction ceases the wheel passes
out of gear. The axis is cranked and a spring connected with the crank brings it
back to its starting point as soon as the wheel passes out of gear. The axis at its
upper end carries a contact arm passing over a series of contacts in order that at
starting only a part of the battery power may be applied to the motor, and the
power is increased step by step until the whole battery is on. This arrangement is
necessary because if the full power were applied to the motor at rest injury would
be done to it, it can only take full power when it is already in rapid movement.
An electric current passing through the cable operates a relay and this closes the
circuit of the electro magnet. It draws down the axis and brings the contact arm
which it carries on to a stationary contact stud. At the same time the wheel is
brought into gear and the axis commences to revolve slowly: The contact arm
can turn upon the axis through a small angle but it is connected by a spring to an
arm rigidly fixed upon the axis. The friction between the contact arm and the stud
keeps the arm upon the stud whilst the axis rotates nntil the fixed arm comes up to
the contact arm and pushes it off the contact stud. Then by the operation of the
spring the contact arm is caused to jump forward to another stud through which
increased battery power flows to the motor. So the contact arm passes from stud
to stud until the crank upon the axis has passed the centre and the teeth of the
wheel have run past the pinion then the spring in connection with the axis turns it

page_text: upon the last of the contact studs of the series. The motor will then be working
with full battery power applied.
When in consequence of no current passing in the cable the electro magnet releases
the axis the fixed arm upon it escapes over the stop and the spring brings the axis
back to its original position. The motor circuit is then open.
A similar arrangement may be applied in torpedoes driven by compressed air to
control the air valve so that the ongines may start gradually otherwise there is risk to
the torpodo and gear.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal and vertical section showing diagrammatically a torpedo
to which my controlling gear is applied.
Figure 2 is an elevation and Figure 3 is a plan partly in section of mechanism for
operating the vertical rudder and for controlling the propelling motor.
Figure 4 is a vertical section of mechanism which governs that shown by the
preceding figures in all that concerns its action upon the vertical rudder.
Figure 5 shows a modification of part of the apparatus shown by Figure 4.
In Figure 1a is the body of the torpedo, within which is contained the batteries
from which the power is derived for propelling, steering and working the controlling
mechanism. Also the motor by which the propellor 6 and other parts are driven.
Also the reel from which the electric cable is paid out as the torpedo advances. Also
the relays which respond to currents transmitted from the shore or distant station,
through the electric cable to the torpedo. Also the charge of explosive and the
firing apparatus with which the torpedo attacks the object against which it is
directed. These parts however being well understood are not represented in the
drawings. c indicates the position of the steering rudder and d that of the rudder
which directs the torpedo up or down in the water. Ate and may be placed
the two portions of the controlling gear shown by the Figures 2, 3 and 4 and at g
may be the relays. is a fin or spine upon the torpedo which stands above water
and is sufficiently visible to enable the torpedo to be accurately directed from a
distant station; this fin or spine folds down to allow the torpedo to pass beneath
obstacles.
m m
In Figures 2 and 3 i is a shaft driven by the motor and having upon it a worm i ;
this gears with and drives continuously a wheel j and on the axis of this wheel are
two spirals. Two spirals are provided for each of the two rudders c and d
that is to say there are four spirals in all but two only are shown as the apparatus
for working the rudder c differs in no respect from that employed for working the
rudder although the former is controlled by currents transmitted from the distant
station and passing through the cable and the latter by currents supplied automatically
by the apparatus shown by Figure 4. kkaro two hooks which are attached to the
tiller lines. Each hook & passes through a stirrup in which rollers are mounted so
that the hook can move endwise through the stirrup with but little friction.
are two powerful electro magnets; the coil m' is contained in an iron case and the
armature m² which carries a core piece m entering the coil moves to and fro within
the case as it is attracted when the magnet is rendered active and drawn back by the
spring n attached to the stirrup when the magnet becomes passive. The magnets
circuits are closed by a polarised relay which responds to currents transmitted to it from
the distant station or from the apparatus shown by Figure 4 as the case may be.
When one of the hooks k is drawn inwards it first catches on one of the pro-
jections jxjx at the root of the spiral; so the hook is pulled forward until it can
engage with the spiral and then it continues to mount the spiral until the rudder is
pulled hard over; unless the attraction of the magnet (as will usually be the case)
should cease sooner and then the hook is at once withdrawn by the spring n and the

page_text: rudder is released without having been put hard over. o is a bent lever having its
fulcrum at o'; it is intended to render it impossible for both hooks & to simultaneously
engage; when one stirrup is advanced by the pull of the magnet it places the lever o
in a position to oppose the advance of the other stirrup.
For controlling the passage of current to the propelling motor the axis of the
spirals and of the wheelj carries a spur pinion . p is a cranked axis which is able
to slide longitudinally as well as to turn in its boaring, it carries the toothed wheel 7.
p' is an armature on the end of the axis p it is attracted by an electro magnet so long
as the propelling motor is at work. The magnet receives the current from a relay
which responds to a current transmitted through the cable. When the armature pl
is drawn down the wheel 7 passes into gear with the pinion ³ and is then slowly
rotated; at first against the resistance of a spring p³ connected with the crank.
is
The teeth do not extend entirely around the wheel 9 so that under the influence
of the pinion the rotation is never completed but whenever the electro magnet
allows the axis to rise (under the influence of a spring) the spring p³ immediately,
brings the axis p back to its original position. The axis p carries a contact arm
forming part of the circuit by which the propelling current passes to the motor; this
arm is in two parts and the part is fast upon the axis p and the part
loose but connected with the part by a spring and also by a link which only
allows the part to lag for a certain distance behind the part 1. s¹² s³ &c. are
contact pieces ranged around the axis p. When the part of the arm is in contact
with either of them the circuit for the motor is complete but the current when
passing by the piece s is supplied by a smaller number of cells and so is moderated.
When passing by the piece the number of cells is greater and by the piece ³
still more and so on.
When the armature p' is first attracted the parts 72 and are brought together
and remain so until the part 7 travels on so far as to draw the part off the part s¹
and then jumps suddenly forward to the parts and makes contact with it and so
on. This passing from contact to contact may take place without the batter
circuit being at any time entirely open. Finally the part comes to the stop ***
which it does not pass and the pinion ja passes out of gear before the part pl
commences to pull upon it. When the magnet ceases to attract the arm passes over
the top of the stop x and the circuit is opened.
In Figure 4 t is a siphon closed at one end by the diaphragm t¹ and charged with a
liquid preferably somewhat viscid so that its movements may not be too rapid and the
liquid is further restrained by a stop at 2 in which is a small perforation. On the
surface of the liquid is a float u. w is a box charged with air under pressure. Until
the torpedo is sunk to its proper depth the diaphragm t¹ is deflected upwards by the
pressure in the box w and the float u falls to its lowest position as the drawing
shows it. The upper surface of the diaphragm is exposed to the pressure of the
outer water which enters by the pipe . At a certain prearranged depth the
pressure of the water will force down the diaphragm and the float u will rise;
but as will be seen the movement of the float is closely limited by stops. The
float is connected by a rod with a small lever frame pivoted at y. The frame carries
two small glass tubes closed at the ends and marked zz; on the bottom of each
there is a platinum strip marked 1 and inserted through the ends are other strips
marked respectively 2 and 3. The strips 1, 1 are connected one with the terminal
marked and the other with the terminal marked and so with a small battery
which works a polarised relay sending currents to the steering magnets.
The
strips 2, 2 are both connected with one end of the winding on the relay bobbin and
the strips 3, 3 with the other end. 4 is a mercury globule, there is one in each of
the tubes z; it gravitates to the lower end. So in the one tube the strip 1 is
electrically connected with the strip 2 and in the other tube the strip 1 is connected
with the strip 3. A current then passes through the relay and the steering takes
place as already described. When, either in consequence of the torpedo itself
inclining or of the lever being moved by the float, the mercury globules gravitate
to the other ends of the tubes the connections are reversed and, as a consequence,

page_text: the rudder is put over the other way. A is a collapsible air tight bag contained in
the box w; it is connected by a pipe B on which is a stop cock with a vessel D
in which highly compressed air is contained. The stop cock C can be opened by
means of the electro-magnet E, the same attracting its armature F which is con-
nected with an arm on the plug of the cock C. When the magnet becomes passive
the spring G closes the cock. The magnet E receives its current from a relay and
the relay responds to a current transmitted to it through the cable. On the opening
of the cock the bag A becomes inflated and the pressure in the box w is thereby
increased; the increased pressure depresses the liquid in the siphon t, the float u
falls and the torpedo is then steered downwards. In this way the torpedo can be
made to descend at pleasure to pass beneath an obstacle or for other purpose. The
action of the magnet is but momentary and the bag after being inflated soon collapses
again, the air leaking out from it by a vent H.
In the modification shown by Figure 5 the glass tubes z zare dispensed with; the
float u transmits movement in a horizontal direction to a piece I which is supported
by links 11' and this carries the contacts 2 and 3, 3 which correspond to the contacts
similarly numbered in Figure 4. Contact 2 is insulated from contact 3 and is
connected with one end of the winding upon the relay bobbin. The contacts 3, 3
are both connected with the other end of the winding. The contacts 1, 1 are small
inasses of metal mounted on springs; they are electrically connected in pairs, and
the pairs are connected by an insulating bar K. The part carrying all the
contacts 1, 1 is suspended by fine wires so that it can swing but only in one plane
and the suspending wires serve also to connect one pair of contacts 1, 1 with the
positive pole of a small battery and the other pair with the negative pole. When the
torpedo inclines contacts 1 and 2 come together on the one side and contacts 1 and 3
on the other, the contacts 1, 1 falling to the lower contacts. The contacts 1, 1
being mounted each on a separate light spring they make good electric connections.
The result is the same when the torpedo being on a level keel the contacts 3, 3 are
shifted sideways by the operation of the float u. The piece I is further controlled by
a pair of light springs which tend to bring it to a central position.
In torpedoes which are propelled by compressed air I employ the apparatus shown
by Figures 2 and 3 both to steer them and also to control the admission of air to the
engines.
The electric contact arm is of course dispensed with and the plug of the air
cock is engaged with the axis p but not in such a way as to prevent the free
longitudinal movement of the latter. So the air is gradually admitted to the ongines
when the armature p' is attracted and is suddenly shut off as soon as the attraction
ceases.
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. A torpedo with steering gear substantially as described in which an axis with a
spiral or other surface upon it is kept in slow rotation and in which hooks or instru-
ments connected with the rudder are, by electric apparatus controlled from a distant
station, made to engage with the said spiral or other surfaces when the rudder is
required to operate as herein set forth.
2. A torpedo in which the depth at which it travels is controlled substantially as
described by electric currents transmitted by mercury globules or other masses free
to gravitate between contacts dependent for their position both on the inclination
which the torpedo assumes and on the pressure of the external water as herein set
forth.
3. A torpedo propelled by electricity in which the propelling current is gradually
applied to the propelling motor substantially as described by a contact maker which
by electric apparatus controlled from a distant station is brought into gear with a
rotating axis and is then moved by it progressively from contact to contact until the
full current is applied as herein set forth.

page_text: 4. A torpedo in which the propelling fluid is gradually applied to the propelling
engine substantially as described by an instrument which hy electric apparatus con-
trolled from a distant station is brought into gear with a rotating axis and is then
moved by it progressively until by degrees a full supply of the propelling fluid is
given to the propelling engine as herein set forth.
5. Torpedo gear substantially as represented by the Figures 2, 3, 4 and 5 of the
annexed drawings.
Dated this 4th day of September 1889.