Improvements in Apparatus for Electrically Actuating and Controlling Ships' Rudders or Other Mechanism.
Year: 1897

page_text: Date of Application, 5th Aug., 1897-Accepted, 2nd Oct., 1897
COMPLETE
SPECIFICATION.
Improvements in Apparatus for Electrically Actuating and
Controlling Ships' Rudders or Other Mechanism.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, do hereby
declare the nature of this invention (which has been communicated to me from
abroad by Société Sautter, Harlé and Compagnie, of 26 Avenue de Suffren, l'aris,
France,) and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
The use of electro-motors for directly actuating ships' rudders has been re-
peatedly proposed but its use has not up to the present been carried out in a
practical manner.
People have contented themselves with electrically governing the steam engine
which actuates the rudder; a mixed system which has certain advantages viz., in
obviating mechanical transmission which is liable to all sorts of damage, but it
is not a general solution of the problem.
According to this invention the rudder is directly actuated by means of an
electro-motor without the intervention of a steam engine and its servo motor.
On the one hand there is thus obtained the advantage of a possibility of
transmitting from any spot in the ship by the employment of electric wiring and
on the other hand the use of steam piping and all the inconveniences resulting
from the use of a steam engine placed at such a distance from its boilers is
avoided.
The conditions necessary in electrically actuating rudders are as follows:-
1. Complete control over the movement of the electro motor which actuates the
rudder.
2. Immediate stoppage, as soon as the rudder has taken the position it should
occupy.
3. The automatic return of the rudder into its proper position when it has
been shifted by the influence of the movements of the ship or of the sea.
These conditions are completely realized by the arrangements forming the
subject of this invention which depend upon the combination of a small auxiliary-
motor with a main motor and of a rheostat commutator whose motion depends
upon both motors at the same time.
DESCRIPTION OF THE ARRANGEMENT.
This system comprises
A transmitter A provided with a number of contacts corresponding to the
different positions it is wished to cause the rudder to assume and an insulated
lever, moved by the operator, which places the positive pole in communication with
any one of the contacts.
Also a receiver B provided with contacts corresponding to those of the trans-
mitter the contact rod of which is mechanically connected by means of the screw J
the wheels HF and F to the principal motor M which actuates the rudder.
Also the auxiliary electro motor M' fed by means of an arrangement of com-
mutators and electro magnetic relays R1 R2 or of any other electrically or
mechanically actuated commutators, which auxiliary motor actuates the rheostat E
This by sv
A transmitter A provided with a number of contacts corresponding to the
different positions it is wished to cause the rudder to assume and an insulated
lever, moved by the operator, which places the positive pole in communication with
any one of the contacts.
Also a receiver B provided with contacts corresponding to those of the trans-
mitter the contact rod of which is mechanically connected by means of the screw J
the wheels HF and F to the principal motor M which actuates the rudder.
Also the auxiliary electro motor M' fed by means of an arrangement of com-
mutators and electro magnetic relays R¹ R2 or of any other electrically or
mechanically actuated commutators, which auxiliary motor actuates the rheostat E
...0.1

page_text: of the main motor by means of an epicycloidal train of conical gearing D put in
motion by means of the pinion G connected to the main motor M.
The current passing through the transmitter A and the receiver B has simply
the function of causing the working of the relays R1 and R2 that is to say of
opening or closing the circuit of the armature of the motor M¹.
The excitation of the motors M and M is independent, it is taken in derivation
from the source itself and is not shown in the drawings.
WORKING OF THE APPARATUS.
When the lever A¹ of the transmitter A is moved from its position of rest, as is
the case in the figure, the current from the positive pole of the source passes by
one of the contacts to the contact 2 of the received B; from this contact
it passes into the contact rod C and from thence by the conductors 3, 4 to the
relay R whose armature it actuates; it then returns to the negative pole of the
source by the conductors 5, 6. The armature of the relay R being attracted.
causes the closing of the corresponding commutator, the current coming from the
source then traverses the armrature of the auxiliary motor M¹ by 7, 8, 9, 10, 11,
12, 13, 14 and 6 and puts it in motion. The motor carries with it in its
turn the epicycloidal train and consequently the axis K of the contact com-
mutator E.
As soon as the handle of this latter has quitted its position of rest, the current
of the source is admitted by 15, 16, 17, 18, 19, to traverse the armature of the
principal motor M, and puts it consequently in motion and with it the rudder
itself; the motor M carries with it at the same time by means of F F H J the
contact rod C and tends to bring the insulated contact e of this rod in front of the
current inlet contact b².
If this coincidence is produced the incoming current is interrupted, the relay R
releases its armature, the current of the auxiliary motor M' is broken, the motor
stops and the differential train D is only moved by the wheel G itself actuated by
the principal motor.
But as the effect of the wheel G upon the differential train consists in causing
the axis K to rotate in a direction contrary to the motion given to it by the
motor Mit results that when the motor M stops, the motion of the motor M
continuing brings the lever of the commutator back, and causes the different
sections of the rheostat to come successively back into circuit and interrupts the
current when the lever comes upon the zero contact; and the main motor itself
then stops.
The movement of the principal motor therefore essentially depends upon the
movement of the auxially motor.
24
If the latter quickens and surpasses the speed of the former, the differential
train carries with it the axis K and the lever of the rheostat E in the direction
for an increase of speed by placing a more or less greater portion of the rheostat
out of circuit, if on the contrary the movement of M slows the axis K is given
movement in the contrary direction and gradually puts back into circuit the
resistance for diminishing the speed of M. Equilibrium always therefore tends to
be established between the speeds of the two motors and the movement of the
rudder stops exactly at the time when the contact rod C brings its insulated
contact in front of the contact corresponding to the angle of the rudder it is
wished to obtain.
The mechanical transmission of the main motor to the rudder is calculated in
such a manner that each position of the contact opposite one of the contacts b²,
corresponds to the angle of the rudder indicated upon the contact of the operator.
Absolute control therefore is obtained by this system; when the rudder has
come into the position, indicated by the operator it stops of itself.
If indeed it be assumed that the motor M continues its movement, the contact c
will go past the current inlet contact 78, the supply current will be sent into the
electro magnet of the relay R2 and the armature M¹ will rotate in the opposite

page_text: direction, it will then carry with it in the opposite direction the lever of the
rheostat E, and will change the movement of the main motor and thus bring it
back to zero.
Control of the main motor and the rudder is therefore obtained by this
arrangement.
When the sea or other effect carries the rudder away from the position it should
be in and with it the armature M, the screw J and the rod C, the auxiliary motor M¹
will be put into action for correcting the effect produced and will compel the
main motor, and the rudder itself to again take exactly the position assigned to it.
The instantaneous stoppage of the rudder is produced by short circuiting the
armature M by means of the relay commutator according to an arrangement
already known.
Any other arrangement of commutator which permits this effect to be produced
be used.
may
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. Apparatus for controlling electric motors applicable to actuating ships
rudders or other mechanism whose movements should be controlled consisting of
the combination with a transmitter of receiving contacts, commutators with electro
magnetic relays or any commutator which produces the opening and closing of the
circuit of the armature of an auxiliary electro motor as also the reversal of its
current, this auxiliary motor controlling in its turn, by the intervention of a
differential epicycloidal train with conical gearing, the rheostat commutator which
directs the current of the main motor, the main motor acting by mechanical
transmission on the one hand upon the differential train, and on the other hand
upon the contact rod of the receiver.
2. The combination of an auxiliary motor with the main motor and with a
differential epicycloidal train with conical gearing calculated in such a manner
that the movement of the small motor always corrects the deviations of the main
motor by forcing it to come back when it has passed the position it should occupy,
the speed of the main motor itself remaining constant when equilibrium is
established between the motion communicated to the differential train by this
motor and the motion produced by the auxiliary motor.
3. The combination of the preceding parts with an arrangement of commutators
with magnetic relays or any other arrangement of commutators which cause
instantaneous arrest of the auxiliary motor by short circuiting its armature and
consequently the arrest of the main motor.
1907