IMPROVEMENTS IN ELECTRIC TELEGRAPHS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Sydney Pitt at the Office of the
Commissioners of Patents on the 8th March 1882. A communication from
abroad by Henry Christopher Mance of Kurrachee in the Empire of India.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN ELECTRIC
TELEGRAPHS [A communication from abroad by Henry Christopher Mance of
Kurrachee in the Empire of India.]
"
The object of the invention is to improve the arrangements for translation of
signals automatically between two cables or between a cable and land line when
relays of an extremely sensitive or unstable character are employed. Although
designed more especially to meet the requirements of the Brown Allan relay
my system can be worked in connection with other relays and telegraph
apparatus.
I join up four Morse sounders or recorders with clockworks suitable for double
current cable translation in such manner that notwithstanding the unstability of
the relays at the translation office and the possibility of their coming to rest with
the local circuits sometimes open and at other times closed the distant station on
the left is not cut off in the translation apparatus or prevented from replying
when the distant station on the right ceases sending and vice versa.
As is customary in translation arrangements I place the right hand line under
the control of the left hand instrument or set of instruments. I use Morse or
Sounder apparatus with clockworks either continuously running or self starting.
In connection with the clock work is a lever called the translating switch, or back
lever. This lever is in connection with line and so arranged that as required it
will fall or suddenly change from one contact to another either at the up or down
movement of the printing arm as may be arranged and remain in that position
until the printing arm finally comes to rest in its original position, when the back
lever actuated by the clockwork or by any other equivalent mechanism, slowly
returns to its normal position. The back lever when acted on or liberated from
its normal position is placed in connection with the printing arm of a companion
or duplicate instrument (four instruments or their equivalent being used instead of
two). The positive currents are transmitted from one instrument and negative
currents from the other the batteries being connected to the stops which limit the
31

page_text: downward play of the printing or sounding arms and the connections are so
arranged that the translation current of one instrument can only find its way to
line through the back lever of the companion instrument.
It is necessary
therefore that both back levers shall be acted on at short intervals in order
that the line shall be kept constantly in connection with the printing arms as
should either back lever regain its normal position it breaks connection with the
battery connected to the companion instrument and reconnects the line to its relay.
If the relay is not furnished with local contact points on both sides of the
tongue or armature so that currents can be sent alternately through the coils of
the two printing arms with every right or left movement the local current set in
action whenever the relay closes can be made to actuate the tongue of an auxiliary
relay provided with double local contacts and a second local battery can be used
in connection with this auxiliary relay to attract the printing arms alternately the
dots and dashes being signalled by the depressions of one printing arm and the
spaces by the other. The back levers in each pair of instruments are connected
electrically with the opposite line and in their normal position they both rest
against stops which are in connection with the relay of the opposite set of instru-
ments. In the method I arrange by preference that each back lever shall
fall when the printing arm is depressed and rise three or four seconds after the
printing arm has come to rest in the up position. The additional contacts herein-
after described are also used in connection with this method.
The following is a modification in which only two Morse recorders or sounders
are required at the translation station. These instruments should be fitted with
my additional contacts. This method is intended to meet the requirements of a
relay the local circuit of which always closes after signalling ceases thus causing
the printing or sounding arm to remain permanently attracted. The starting and
back levers in the apparatus are so arranged that the clockwork of the instruments
instead of running continuously with the back lever down when the printing arm
is permanently depressed, stops after a few seconds the back lever at the same time
rising to the relay stop or contact notwithstanding the permanent current and thus
enables the distant station to reply. If the local circuit of one of the relays used
always remains open when at rest an ordinary translation instrument in which
the back lever action is not reversed could be used on that side. In this method
the back levers immediately they are acted on by the printing arm place themselves
in connection with their own printing arms which transmit to line both positive
and negative currents in the usual manner.
I also connect a cable and land line by translation with two recorders or sounders
in such a manner that it is immaterial whether the local circuit of the relay
connected to the cable remains open or closed after signalling ceases the distant
station on the land line being in either case able to reply.
In this method the recorder worked by the land line relay may be of any double
current submarine translation pattern with the addition of the arrangement
hereinbefore described for additional contacts.
The instrument worked by the cable relay must be connected in the following
manner. If the cable local circuit usually closes when at rest the starting gear
should be arranged for the translation lever to rise slowly and connect itself to the
opposite relay when the printing arm remains down. The back lever is as usual
connected to the opposite line. The stop which limits the up play of the back
lever is connected to the opposite relay. The stop which limits the down play of
the back lever is connected directly to the printing arm of its own instrument
in the usual way. The stop which limits the up play of the printing arm is connected
to the opposite relay. The stop which limits the down play of the printing arm
is connected to the land line working battery.
Or the same results can be obtained in another way. The right hand or land
line apparatus to be as described in the last case and the instrument on the cable
side to be connected as follows, back lever as usual to opposite line. Back lever top
stop and printing arm bottom stop to be permanently connected to the land line

page_text: relay. Back lever bottom stop to printing arm of its own instrument in ordinary
way. Top stop of printing arm to land line working battery. During the non
signal the local circuit is complete instead of broken in the relay and the back
lever falls. During the signal the local circuit is broken. The printing arm rises
and the land line is connected to the land line working battery until the signal
ceases or the back lever has had time to rise and reconnect the land line to its
relay.
I add two contacts to the back lever or other suitable portion of the mechanism
of the recorders and by means of these additional contacts with suitable connecting
wires either establishing such short circuit in the arrangement as may prevent the
relay engaged in signalling being cut off from its line or by preference placing the
local battery of the right hand relay under the control of the left hand instrument
or instruments and the locals of the left hand relay under the control of the right
hand apparatus. By this arrangement the instrument which is engaged in
translating signals cannot be interfered with by any accidental movement of the
tongue of the relay which is at rest.
The connections are so arranged that directly the instrument or instruments on
one side A are commencing to signal and before the opposite relay has been cut off
from its line the locals of the opposite relay (side B) are short circuited by the
lever or levers of A or else connected in closed circuit through the coils of the
printing magnets of B thus keeping the printing arm or arins of B in a fixed
position so long as signalling on the side A continues. No accidental movement of
the tongue of the opposite relay B can cause any movement in the back levers of B
until signalling on the other side A has ceased immediately on which the contacts
separate the short circuit is taken off the local circuit of B and the electro magnets
respond to any movement made by the tongue or armature of the relay B.
The following method of translation with one apparatus or its equivalent on each
side is to be preferred to that herein before described inasmuch as it is immaterial
whether the local circuits of the relays remain open or closed or sometimes one
and sometimes the other. This is effected by using a sounder or recorder
constructed on the following principles. A spring weight or other motive power
actuates a train of clockwork which is always running or which starting when the
instrument commences to signal continues to run during the act of signalling. So
long as signalling continues the translation or back lever or its equivalent remains
in contact with the printing arm and the currents pass out to line. But three or
four seconds after the printing arm has stopped no matter in what position the
translation lever must rise or resume its normal position and cutting off line from
the printing arm reconnect it to its relay.
The following methods for securing that the translation switch shall resume its
normal position when signalling ceases irrespective of the position in which the
printing arm comes to rest can be applied with advantage to instruments in use at
terminal stations to secure the stopping of the clockwork whenever signalling
ceases with the local circuit either open or closed and starting when it recommences.
In terminal or non translation instruments the translation switch may be omitted.
The clockwork being only required to lift or depress a starting lever or levers
in addition to the work of drawing the paper through the machine. My
improvements are capable of application to any of the existing submarine Morse
translating apparatus or inkwriters designed for use in connection with telegraph
circuits.
Instead of using only one set of starting and translation levers or their
equivalent acted on directly or indirectly by the local or line battery or by the
downward movement of the printing arm. Such lever or levers being (under the
influence of the clockwork or other suitable mechanism) so arranged as to replace
the translation switch or its equivalent against the relay contact as soon as the
downward movements of the printing arm cease. I use two sets of levers one of
which is released at every signal and the other at every space between the signals.
One translation switch only is necessary this is common to both brake levers

page_text: and capable of being acted on independently by either. The movement of one
of these levers to its normal position causes the translation switch to connect line
to relay. In whatever position the printing arm comes to rest one of these levers
ceases to be acted on by its respective starting lever and consequently as soon as
permitted by the revolving clockwork or other suitable mechanism employed it drops
into its normal position and in doing so causes the switch to move across to the
relay contact the switch being actuated by a weight or spring or pressure from the
lever. Should the apparatus be self starting each lever or the translation switch
is furnished with a piece which coming into contact with a rapidly revolving
friction disc stops the clockwork at the time the line switch is reconnected to
relay.
So long as the printing arm works in an up and down motion the starting and
brake levers are being continually liberated by their respective catches being struck
by projecting pins from the printing arm or by any other convenient method.
The signals succeed one another too rapidly to allow either set of levers assuming
its normal position until about four seconds after the printing arm comes to rest
either in the up or down position when one of the levers will have been lifted
sufficiently high to be caught by its catch and remain fixed in that position
sufficiently long to allow the brake lever to enter its notch and act on the
translation lever.
Instead of duplicate levers I use a single set of levers and switch, working in
connection with a double knee piece or catch or its equivalent the pieces or catches
acting independently of each other. The same results are obtained as in using
duplicate levers or sets of levers. The knee pieces may be on the same axle but
the movement of one must not affect the other. The upper ends of the pieces are
pressed towards the lever by light springs so as to pass into a slight notch or
shoulder in the extremity of the lever when it is raised by the mechanism to a
sufficient height and thus prevent it falling on the brake lever again until the knee
piece is struck out of its normal position by the movement of the printing arm,
As one knee piece is pressed out by the up movement and the other by the down
movement of the printing arm it will be obvious that a single beat of the armature
or not more than two beats will cause the release of both catches and allow of the
lever falling, starting the apparatus and connecting the opposite line through the
translation switch to the line battery stops which limit the play of the printing
arm. Immediately the lever has fallen the clockwork commences to relift it into
its normal position the same portion of the clockwork which lifts the lever permits
a few seconds later the brake lever to come into play and the latter acts directly
or indirectly on the translation switch. The upper extremities of one of the knee
pieces is slightly longer than the other in order to prevent its return under the
end of the lever before the latter has had time to fall. Should the lever be sup-
ported by the longer of the two knee pieces it will on the displacement of the
latter be probably caught by the shorter as it returns to its normal position but on
this shorter knee piece being in its turn displaced by the next movement of the
armature (or make or break in the local circuit) the lever falls the longer knee
piece being unable to pass underneath the lever until the latter has been relifted
by the clockwork or other mechanism employed to replace the levers in their
normal position.