Year: 1896

page_text: Date of Application, 14th July, 1896
Complete Specification Left, 13th Apr., 1897-Accepted, 15th May, 1897
We, WILLOUGHBY STATHAM SMITH of 13 Courtfield Road, South Kensington,
Telegraphic Engineer, and WILLIAM PUDDICOMBE GRANVILLE, of 36 Oakfield
Road, Stroud Green, both in the County of Middlesex, Electrician, do hereby
declare the nature of this invention to be as follows:-
This invention relates to a relay to be worked with very feeble currents; it is
arranged to respond only to two currents in opposite directions the one following
the other at a short interval. The purpose for which we intend immediately to
apply this relay is to actuate a call bell say from a rock lighthouse to shore. In
such a case it is usually impossible to have a continuous cable connection and a
portion of the circuit has to be between metal plates immersed in the sea and at
some distance apart. Under these circumstances the signal currents are weak and
precautions have to be taken that earth currents do not give rise to false signals,
or arrest the action of the call arrangement. Our improved relay satisfies these
conditions, it is preferably constructed as follows:-In a magnetic field a coil is
suspended, through it currents coming from line pass and cause the deflection of
the coil to one side or the other. The coil carries a metal arm which is the
terminal of a local battery. The deflection of the coil brings the arm against one
or other of two contact springs and so closes a local circuit. In this circuit is an
electro-magnet which attracting its armature liberates a clockwork train and
allows an axis driven thereby and which we will call the clock axis, to make a
complete revolution, which it does say in a quarter of a minute. The clock axis.
by bevilled gearing and a worm turns the torsion head from which the coil is
suspended in such a direction as to tend to remove the contact arm of the coil from
the contact spring. The same local battery current which starts the clockwork
passes through one or other of two electro magnets which determine the position of
a pair of bevelled wheels on the clock axis causing one or other of them to gear
with a similar wheel which is fast with the worm. Hence the direction in which
the torsion head is turned depends on which of the contact springs completes the
local circuit.
If earth currents be the cause of the local circuit being closed, the torsion head
will be turned in this way, and again and again if necessary, until the arm of the
coil remains clear of both of the contact springs between which it plays, thus
automatically setting the instrument to an approximate zero in readiness for the
call signal. In addition to the local circuit already referred to there is a bell
circuit and a gap in this circuit is opened and closed by the movement of a pawl like
lever carrying a contact stud. The tail of this lever rests upon the teeth of a
wheel which is fast with the worm for turning the torsion head. Each time that
the direction of the wheel's movement is reversed the tail of the lever passes over
from one side of the wheel to the other and then the teeth are able to pass with
but little further movement of the lever until the next reversal takes place. During
the passage of the lever from side to side a contact is made and opened again.
The bell however does not necessarily sound when the lever makes contact, were
it to do so it would sound with every reversal of the earth current. To prevent

page_text: this there is another gap in the bell circuit where a metal spring rests on a disc
on the clock axis and this disc is partly of metal and partly of ivory, or other
insulating material. Whilst the clock axis is in the position of rest and for a short
time after starting the spring rests on the ivory, and the circuit is open. In this
interval the pawl like contact lever can pass from side to side of its wheel without
ringing the bell; but if after the start a reversal occurs, which would be from the
signal current, for earth currents do not usually vary in strength in this rapid
fashion, then the pawl lever will at once return again from side to side of its wheel
and as the movement will now take place when the clock axis is at a distance from
the starting point the bell circuit will be complete past both of the gaps and the
bell will sound.
The suspended coil is of sufficient weight to enable it to close its contacts firmly,
it responds to very feeble currents provided they are of some duration.
Dated this 13th day of July 1896.
WILLOUGHBY S. SMITH.
W. P. GRANVILLE.
We, WILLOUGHBY STATHAM SMITH, of 13 Courtfield Road, South Kensington,
Telegraphic Engineer, and WILLIAM PUDDICOMBE GRANVILLE, of 36 Oakfield
Road, Stroud Green, both in the County of Middlesex, Electrician, 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 :-
This invention relates to a relay to be worked with very feeble currents; it is
arranged to respond only to two currents in opposite directions the one following
the other at a short interval. The purpose for which we intend immediately to
apply this relay is to actuate a call bell say from a rock lighthouse to shore. In
such a case it is usually impossible to have a continuous cable connection and a
portion of the circuit has to be between metal plates immersed in the sea and at
some distance apart. Under these circumstances the signal currents are weak and
precautions have to be taken that earth currents do not give rise to false signals,
or arrest the action of the call arrangement. Our improved relay satisfies these
conditions, it is preferably constructed as follows:-In a magnetic field a coil is
suspended, through it currents coming from line pass and cause the deflection of the
coil to one side or the other. The coil carries a metal arm which is the terminal
of a local battery. The deflection of the coil brings the arm against one or other
of two contact springs and so closes a local circuit. In this circuit is an electro-
magnet which attracting its armature liberates a clockwork train and allows an axis
driven thereby and which we will call the clock axis, to make a complete revolution,
which it does say in a quarter of a minute. The clock axis by bevilled gearing and
a worm turns the torsion head from which the coil is suspended in such a direction
as to tend to remove the contact arm of the coil from the contact spring. The
same local battery current which starts the clockwork passes through one or other
of two electro magnets which determine the position of a pair of bevelled wheels
on the clock axis causing one or other of them to gear with a similar wheel which
is fast with the worm. Hence the direction in which the torsion head is turned
depends on which of the contact springs completes the local circuit.
If earth currents be the cause of the local circuit being closed, the torsion head
will be turned in this way, and again and again if necessary until the arm of the

page_text: coil remains clear of both of the contact springs between which it plays, thus
automatically setting the instrument to an approximate zero in readiness for the
call signal. In addition to the local circuit already referred to there is a bell
circuit and a gap in this circuit is opened and closed by the movement of a pawl like
lever carrying a contact stud. The tail of this lever rests upon the teeth of a
wheel which is fast with the worm for turning the torsion head. Each time that
the direction of the wheel's movement is reversed the tail of the lever passes over
from one side of the wheel to the other and then the teeth are able to pass with but
little further movement of the lever until the next reversal takes place. During
the passage of the lever from side to side a contact is made and opened again.
The bell however does not necessarily sound when the lever makes contact, were it
to do so it would sound with every reversal of the earth current. To prevent this
there is another gap in the bell circuit where a metal spring rests on a dise on the
clock axis and this dise is partly of metal and partly of ivory, or other insulating
material. Whilst the clock axis is in the position of rest and for a short time after
starting the spring rests on the ivory and the circuit is open. In this interval the
pawl like contact lever can pass from side to side of its wheel without ringing the
bell; but if after the start a reversal occurs, which would be from the signal
current, for earth currents do not usually vary in strength in this rapid fashion,
then the pawl lever will at once return again from side to side of its wheel and as
the movement will now take place when the clock axis is at a distance from the
starting point the bell eirenit will be complete past both of the gaps and the hell
will sound.
The suspended coil is of sufficient weight to enable it to close its contacts firmly,
it responds to very feeble currents provided they are of some duration.
In order that our invention may be fully understood we will proceed to describe
the drawings annexed,
DESCRIPTION OF THE DRAWINGS.
Figure is a front view, Figure 2 is a side view and Figure 3 is a plan of an
instrument in accordance with our invention.
a a are two strong permanent ring magnets the like pole of one magnet being
immediately above the like pole of the other and b is a soft iron ring between the
two; in this ring the permanent magnets induce strong polarity. At the points
where the poles are situate the ring is encircled by coils cc mounted upon a
beam e' which is suspended by a fine wire from a torsion head d.
Figure 4 shows diagrammatically the method of suspension. A wire extends
from beneath the beam to a plug which is pressed downwards by a light
spring so that the suspension wire is kept at a constant tension. Or the
suspension may be arranged as indicated in Figure 44 in which a silk thread is
used for suspension and a helical wire for torsion. The suspension or torsion wire
also forms part of the line circuit which may be traced from the torsion head d
through the coils c c in series and down to the plug c whence the connection to line
is suitably made. The line circuit is appropriately insulated from the other two
circuits which traverse the instrument. From the arrangement of the magnets and
coils it follows that any feeble current passing in the line circuit causes the beam c¹
to move to the one side or the other. The beam has upon it an armn which
projects upwards and terminates between the two contact springs el e. The arin e
and the contact springs e' e form parts of a local battery circuit the arm being
connected by a fine spiral wire c'. The circuit may be traced as is shown diagram-
matically in Figure 5 from the arm e through one or other of the springs el eand
one or other of the electro magnets if to another electro magnet g. Thus signal
or other currents passing in the line círcuit, a part of which is shown by Figure 4
are repeated in the second circuit shown by Figure 5. The armature of the
magnet g is carried on a detent lever g' which engages with a stud on the periphery
of a wheel h. This wheel is on an axis idriven by a clock train i which is regulated

page_text: by a connection with a small propellor screw mounted on the vertical axis and
contained in the box which is charged with oil. This regulator so controls the
clock work that the wheel when liberated makes one revolution in ten seconds or
thereabout before it is again stopped by the detent lever g'. So it will be seen that
when the contact arm is brought by any current passing in the line circuit against
either of the springs el e the clockwork is started and if the contact is of short
duration and is not repeated the clockwork will run for ten seconds and then
stop.
kk are a pair of bevelled wheels mounted on a sleeve which can slide along the
clock axis but which rotates with the axis. f3 is an armature lever with its
fulerum at it is jointed to the sleeve which carries the pair of bevelled wheels kk.
The armature lever is drawn to one side or the other by the attraction of one or
other of the magnets ff and so one or other of the bevelled wheels k k is brought
into position to drive the bevelled wheel . On the axis of the wheel a worm
is cut and this engages with worm teeth on the torsion head d. So it results that
when the arm c comes against one of the contact springs ee the torsion head is
immediately operated upon and is slowly turned in such a direction as to tend to
remove the arm from the spring with which it is in contact. The action is repeated
as often as may be necessary so that the arm is brought to stand normally
between the two springs el e in contact with neither of them.
Figure 6 shows diagrammatically a third circuit with which the instrument is
provided it contains an electric trembling bell. The circuit passes through a
small wheel m which is on the clock axis i and through a contact spring m which
presses on the wheel m. When the clock train is at rest no current can pass in the
bell circuit because the contact spring m¹ then rests on a small piece of ivory m²
which is inlaid in the periphery of the wheel. But for most of the time during
which the clock train is in motion metallic contact is established between the
wheel m and the spring m¹. The bell circuit is continued through a portion of the
instrument which is best seen in Figure 7 where n is a toothed wheel which is fast
on the axis of the worm land o is a pawl like lever engaging with these teeth, it
does not interfere with the revolution of the wheel n in either direction but it is
carried by the wheel from side to side according to the direction in which the wheel
itself revolves. The lever o carries an ivory disc o and from it a metal pin o
slightly projects; this pin is in metallic connection with the wheel m in fact they
are both in metallic connection with the upper platform of the instrument. p is a
contact spring which rests on the periphery of the disc o and with it the pin o
comes into contact as it is moved from side to side. When the lever o commences
to move as soon as the clockwork is started the pin o² is already past the contact
spring p before the contact spring m leaves the ivory m² and makes metallic
contact; consequently under such circumstances the bell does not ring, but if
the lever o commences to move at a later period the bell circuit is completed and
the bell sounds. Thus the lever o with the parts in connection there with acts as a
switch closing and opening contacts as required. So it will be seen that to ring
the bell two currents of different sign following each other at a short interval, are
required. is a spring which by pressing against inclines in the diac o' serves to
ensure the engagement of the lever o with the teeth of the wheel n. The parts
marked are of vulcanite or other insulating material; it has not been deemed
necessary in every case to indicate the insulation of the parts for it is obvious where
insulation is needed.
To prevent sparking at the contacts each of the electro-magnets is shunted
through a resistance equal to about ten times that of the wire with which the
magnet is wound.
The details of this apparatus may be varied; thus any suitable form of
galvanometer may be employed to carry the contact arm c; it is not essential that
the motor employed should be clockwork although clockwork is the most
convenient; nor is it necessary that a bell should be used, some other form of
signalling instrument may be substituted.

page_text: Having now particularly described and ascertained the nature of our said inven--
tion and in what mauner the same is to be performed, we declare that what we
claim is :-
1. A relay substantially as described responding to two currents in opposite-
directions the one following the other at a short interval.
2. A relay in which there are three circuits, a line circuit, a starting and
reversing circuit, and a bell or signal circuit; the line circuit including a
galvanometer or appliance which repeats into the starting and reversing circuit;:
the starting and reversing circuit including appliances for bringing into action and
reversing a clockwork or motor, and the bell or signal cir uit containing appliances
operated upon by the clockwork or motor, namely a circuit closer which soon after-
the commencement of a run closes a gap in the bell or signal circuit and opens it
again as the run terminates; and a switch which is moved by the clockwork or
motor for a short time after a reversal has taken place and which switch in its.
movement closes and afterwards opens again another gap in the bell or signal
circuit; the whole so arranged that a bell is rung or a signal given on the arrival
by the line circuit of a reversing current whilst the clockwork or motor is in
action.
3. The combination substantially as described of a torsion galvanometer the.
contact arm c moved by the galvanometer, the contacts e¹ and e² through which
the contact arm closes a local circuit, the clockwork or motor liberated by the
closing of the local circuit, the axis i driven by the clockwork or motor, and the
torsion head d geared with the axis i through clectrically controlled reversing gear
which determines the direction of rotation of the torsion head in accordance with.
the position of the contact arm; the whole so arranged that the torsion is.
automatically adjusted until the contact arm leaves the contacts e¹ and e² and
stands between them in readiness to be brought by the galvanometer into contact.
with either.
4. In a relay operating on reversal of the line current, the circuit closer consisting
of the toothed wheel n the lever o engaging with the wheel when it reverses its.
direction of movement and electrical contacts o2 and p which the lever brings..
together and separates in passing across the wheel n.
5. A. relay substantially as described and illustrated by the annexed drawings.
Dated this 29th day of March 1897
WILLOUGHBY S. SMITH..
W. P. GRANVILLE.