A Method of and Apparatus for Controlling Power-operated Steering Gear.
Year: 1891

page_text: Date of Application, 4th Mar., 1891
Complete Specification Left, 29th Dec., 1891-Accepted, 4th Mar., 1892
PROVISIONAL SPECIFICATION.
A Method of and Apparatus for Controlling Power-operated
Steering Gear.
I, WALTER BASSETT BASSET of 110, Westminster Bridge Road, Engineer, do
hereby declare the nature of this invention to be as follows :-
My invention relates to a method of, and apparatus for, automatically controlling
the operation of the steam or hydraulic steering gear of a navigable vessel in such
manner that the vessel will be rendered self-steering upon any given course without
preventing such occasional deviations from the course set as may be necessary for
the safe navigation of the vessel.
The invention consists essentially in the combination, with the mariner's compass,
of photo-electric cells or photo-electric resistances, or of magnetically or mechani-
cally controlled circuit resistance regulating devices and of oppositely-acting sets
of electro-magnetic mechanism adapted to act directly or indirectly upon the
controlling valve of an auxiliary engine whereby the valve of the steam or hydraulic
steering gear is operated, the photo electric cells resistances or circuit regulating
devices being adjustable according to the course to be steered and being so influenced
by the position of the compass card that so long as the true course is steered the
electro-magnetic valve-operating mechanism will be in equilibrium, but as soon as
a deviation from the course occurs, the influence of the electro-magnetic mechanism
will prevail in one direction and the controlling valve of the auxiliary engine will
be so moved as to start the steering engine in the direction required to give the
vessel such helm as will bring her back to her compass course.
In one method of carrying out the invention, one half of the compass card or of
a disc moving therewith is rendered opaque and is adapted to partially screen a
pair of selenium cells acting either as electric generators or as resistances (each in
the latter case being in the circuit of a battery) and of a solenoid or electro-
magnet, the two solenoids or magnets influencing in opposite directions the same
core or armature.
The cells or resistances are partially exposed to parallelised rays of light
emanating from a natural or artificial source, and when the cells or resistances are
so adjusted in azimuth that the areas thus exposed are equal, their resistances are
equal and the oppositely-acting electro-magnetic mechanisms are in equilibrium.
When, however, deviation from the compass course occurs, the cells or resistances
become unequally exposed the one being covered and the other uncovered, so that
their electrical resistances will vary inversely and will differ in proportion to the
difference of area exposed to the light, the consequence being that the influence of
the one solenoid or magnet will prevail over the other and the steering gear will
be operated accordingly as above mentioned.
Instead of photo-electric cells or resistances, the compass may magnetically
influence an armature or may mechanically operate contact or other devices whereby
the electrical resistances of the two circuits will be varied inversely so as to produce
the same effect.
Dated this 4th day of March 1891.

page_text: COMPLETE SPECIFICATION.
A Method of and Apparatus for Controlling Power-operated
Steering Gear.
I, WALTER BASSETT BASSET of 110, Westminster Bridge Road London
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 :-
My invention relates to a method of, and apparatus for, controlling the power-
operated steering gear of a navigable vessel in such manner that the vessel will be
automatically steered upon any given course from which however such occasional
deviations may be made as may be necessary for the safe navigation of the
vessel.
The invention consists essentially in the combination, with a magnetic compass,
of electro receptive devices such as electric resistances or electric circuit regulating
devices, susceptible of being influenced by radiant energy, and of oppositely-acting
sets of electro-magnetic mechanism adapted to act upon and to control directly or
indirectly the power-operated steering gear the electric resistances or regulating
devices being adjustable in azimuth according to the course to be steered and the
extent to which they are influenced being so dependent on their position with regard
to the compass card that so long as the true course is steered the electro-magnetic
mechanism will be in equilibrium but when a deviation from the course occurs, this
equilibrium will be disturbed and the steering engine will be actuated in the
direction required to give the vessel such helm as will bring her back to the
compass course. For the purpose of magnetically regulating the influence of
the radiant energy upon the electric resistances or circuit regulating devices, the
compass card is so made as to partially intercept and partially give passage to such
energy and the resistances whose conductive values are equal are so arranged with
regard to the compass card that they will be normally exposed to the said influence
to equal extents but will be screened to unequal extents upon any deviation from
their normal relation to the compass card occurring whereby their conductive
values will be rendered unequal. The resistances are respectively in the circuits of
solenoids or electro-magnets influencing in opposite directions an armature lever
common to both and connected with the controlling device of the steering gear, the
efforts of these two electro-magnetic devices balancing one another under normal
conditions. The source from which the radiant energy emanates may either be
natural or artificial, preferably the latter for the sake of constancy and being
preferably light-rays which may or may not be parallelised by suitable means and
the resistances are preferably composed of selenium as being the conducting medium
most susceptible to the action of light and heat rays. I am not however limited
to the use of this material, copper coils or other conductors being similarly susceptible
of influence though in a lesser degree. They are arranged symmetrically and
diametrically with regard to the compass card and the latter is preferably made
one-half of opaque or non-conducting material and the other half translucent or
open so as to normally screen and expose one-half of each resistance. When how-
ever deviation from the compass course occurs the areas of the resistances exposed
and consequently their conductive values will vary inversely, the consequence being
that the electro-magnetic balance will be disturbed and the influence of the one
solenoid or magnet will prevail over that of the other whereby the steering gear
will be operated accordingly...
I will now proceed to describe the invention in detail with reference to the
accompanying drawings, forming part of this Specification, wherein
Figure 1 is a vertical section showing the resistances and their connections as
applied in combination with a magnetic compass,
Figure 2 is a plan of the compass-card,

page_text: Figure 3 is a part sectional elevation of the electro-magnetic mechanism in circuit
with such resistances, and
Figures 4 and 5 are detail views of two slightly different modes of making the
selenium resistances.
Figure 6 is a plan of the contact rings hereafter referred to.
The same letters of reference denote like parts in all the figures.
The compass card A is constructed of the usual aluminium frame one-half of
which is covered by black paper whilst the other half is open. B'B' are the
resistances arranged immediately below the card symmetrically at diametrically-
opposite sides of its axis, the resistances being preferably in the form of sectors
radial to said axis. They are carried by a disc of vulcanite B supported upon the
central post which supports the compass pivot a so as to be always maintained in a
horizontal plane the disc being adjustable circularly. Below the disc and carried
by the inner member of the gimbal frame are pairs of contact rings C₁ C₁ C'C' (also
shown in plan in Figure 6) upon which bear pairs of contact rollers b¹¹ª
carried by springs in electric connection the one pair with the terminals of the one
and the other pair with those of the other resistance. The rings are insulated and
to binding posts c', c¹, c², c³ (Figure 6) attached to their under-sides are connected
the conducting wires d' d' d²d which are respectively connected with what may be
distinguished, by the effect they produce on the helm, as the port and starboard
solenoids or electro-magnets hereafter described. The compass card A carries a
U-shaped contact piece between whose arms is situated a contact e carried by the
vulcanite disc B the latter being in electrical connection through a contact
roller e and its spring with a contact ring e the U shaped contact piece being
connected through the aluminium ring and a wire f' running to the hub of the
frame of the compass card with the steel dab or socket a' by which it is poised on
the pivot a and through the latter and the inner and outer members of the
gimbal frame to which and to the binding post of the ring e² the two wires of an
electric bell circuit are connected so that the two members of the double or
bifurcated contact being at an angular distance of, say, two points apart the bell
circuit will be completed whenever the ship deviates to the extent of a point either
way from the course set. The compass card is enclosed by a binnacle in the top of
which immediately over the compass is mounted an oil lamp or an incandescent
electric lamp the rays from which are preferably parallelised and thrown down-
wards by a reflector through a lens or directly on to the compass card and so much
of the resistances as may be exposed beneath it. In Figure 1 the contacts e, fare
for convenience shown at the N point of the compass card whereas their proper
position is that shown in Figure 2 so that the contacts shall counterbalance the
semi-disc of paper. Referring now to Figure 3 which illustrates the electro-
magnetic apparatus as applied to operate a hydraulic piston by which the controlling
valve of a hydraulic steering gear is operated, GG are two solenoids respectively
connected with the circuits d' d. H is a three-armed lever centred at h and
carrying the solenoid cores g¹ g², the third arm being connected with the hydraulic
valve. I are springs connected by adjusting screws to the arms of the
lever H so as to act thereon in opposite directions and to an abutment i³ common
to both and formed by a nut adjustable along a screw so that the tension of the
springs may be varied simultaneously and equally or independently and unequally
according as it is desired to diminish the sensitiveness of the mechanism or to
compensate for unequal resistance of the two solenoids or that the mechanism
shall have a normal tendency to give the ship a certain amount of port or star-
board helm as may be required. The two solenoids and their corresponding
resistances are preferably placed in parallel in the circuits connected to one
battery so that they normally counteract each other. In the example here illus-
trated the third arm of the lever H (which is weighted so that the lever is in
neutral or indifferent equilibrium) is coupled by a jointed link to a tubular valve K
provided with an annular series of ports k and working within a corresponding
valve seat in the boss of a piston L which works within a cylinder M and has two

page_text: sets of ports, viz. admission ports 1 1 leading through the piston to opposite sides,
with one or other of which the valve ports may be made to coincide according
as the piston is to be moved in the one or other direction, and exhaust ports m² m²
also leading through the piston to opposite sides, with one or other of which may
be made to coincide exhaust ports n in the valve in communication with an exhaust
passage through the tubular piston rod N. The tubular valve K is connected by a
Hexible tube coupled to it at A¹ with an accumulator or other source of power
whence the motive fluid under pressure is supplied through the valve. The valve
having been moved in either direction to the extent necessary to put the ports &
in communication with the one or other set of ports or 12, the piston is moved
accordingly, the valve then following up the motion of the piston so as to maintain
such communication so long as the lever H continues to be influenced in the same
direction by the solenoids. The piston rod N is connected to the controlling valve
of any ordinary hydraulic or steam steering gear whilst permitting of the steering
gear being controlled by the hand steering wheel for the purpose of steering the
ship independently of the automatic gear when it is necessary that she should
temporarily deviate from her course for the purposes of safe navigation. The piston
may however be of such a diameter as to itself work the rudder without the inter-
vention of any other steering gear.
It will be evident that the automatic steering mechanism of my invention is
equally applicable for controlling electric steering gear should such be used, it
being only necessary to couple the lever H or the hydraulic piston rod N to the
controlling switch or regulator of the electric motor. It will also be evident that
sunlight may be used in the daytime as the source of the radiant energy influencing
the electro-receptive devices under the control of the magnetic compass, the light
rays being admitted and parallelised by passing through a suitable lens or com-
bination of lenses mounted in the top of the binnacle. It will also be evident that
if the line of demarcation between the opaque and open portions of the compass
card be on the diameter coinciding with the north and south points of the card,
as shewn, the direction of the centre line passing through the electro receptive
devices will normally coincide with the magnetic meridian, the adjustment
of the said devices relatively to the "lubber's point" or direction of the
ship's head being such as to cause her to follow the desired course. The line of
demarcation might however be on the diameter extending from the east to west
points of the card, in which case the said devices would be transverse to the
magnetic meridian. Or the electro-receptive devices whose resistance is to be
varied need not be diametrically opposite each other, in which case the line of
demarcation would be on semi-diameters dividing the card into segments respec-
tively greater and less than a semi-circle. In determining the construction and
arrangement, regard should be had to the known laws of electrical induction in
order that the compass needles may be detrimentally influenced to the least possible
extent by the proximity of the electric currents but the arrangement shewn and
described gives good results. In order that a perfect balance of the oppositely
acting electro-magnetic devices may be maintained, it is preferred to use but a
single battery or other source of electricity and to divide the current equally in
the two branches of the parallel circuit suitable permanent resistances being
provided for enabling this division to be accurately made, but it will be obvious
that the two electro-magnetic devices might be influenced by separate batteries of
equal power.
The preferred mode of constructing the electro-receptive devices whose resistance
is to be varied by the influence of radiant energy, is as follows-A plate of
platinised or gilded glass is superimposed upon a lamina of selenium of about one
decimillimetre in thickness whilst the same is in a molten state on a metal plate of
about sixty square centimetres area, the metallised surface of the glass being in
close contact with the selenium and forming one terminal whilst the metal plate
forms the other terminal. The selenium is then to be annealed in order to render
it crystalline in the usual way. The platinized glass must be sufficiently transparent

page_text: to permit of the light acting on the selenium freely. Such platinized glass may be
obtained from Messrs. Siemens of London. The device so constructed should have
a resistance in the light to which it is to be exposed of about five ohms and in
absolute darkness of about thirty ohms and the battery power employed should be
from one to five ampères and from five to ten volts. The greater the intensity of
the light the better, but a light of ten-candle power should give good results.
would observe however that although I have indicated the best proportions with
which I am acquainted I do not in any way limit myself thereto.
I
Or the electro-receptive devices may be made somewhat in the manner of a
condenser, as shewn in Figure 4, of juxtaposed strips of thin brass o alternately
connected to terminal strips p p and separated from each other by intervening
strips of paper or asbestos paper of about one millimetre less width than the brass
strips so as to leave interstitial spaces of that depth between the brass strips into
which melted selenium is run and thoroughly annealed, the selenium forming the
electrically conductive connection between the strips and presenting a large area to
the action of radiant energy.
Or two fine brass or other wires 7 q' respectively connected to the two terminals
may be wound in parallel coils around a sheet of mica or glass (as shewn on an
exaggerated scale in Figure 5) the wires being about two decimillimetres apart and
kept separate by strips of asbestos paper laced alternately under and over them
at the bends, as shewn, the bends of one wire being exposed at the one side and
those of the other wire exposed at the other side and the bends of the one wire
being united at one side and those of the other wire at the other side by solder.
Melted selenium is then run between the parallel wires on the one face of the mica
core to electrically connect them, and annealed as before.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
The herein described method of, and means for, magnetically controlling and
automatically operating the valve or other controlling device of a steering gear,
the said means consisting in the combination, with a magnetic compass, of electro-
receptive devices susceptible of variations of resistance by the influence of radiant
energy and which are more or less screened from such influence by the compass,
and of electro-magnetic mechanism actuating in one or other direction the
controlling valve or other device of the steering gear according as the electro-
receptive devices aforesaid are permitted to be so influenced, substantially as herein
specified.
Dated the 24th day of December 1891.
W. B. BASSET,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.