Improvements in Apparatus for the Automatic Transmission of Signals through Telegraph Lines and Cables.
Year: 1894

page_text: Date of Application, 11th June, 1894
Complete Specification Left. 11th Mar., 1895-Accepted, 13th Apr., 1895 -
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for the Automatic Transmission of
Signals through Telegraph Lines and Cables.
We, ALEXANDER MUIRHEAD, of No. 2 Princes Street, in the City of
Westminster, Doctor of Science, Electrical Engineer, and ANGUS FRASER, of
No. 11 Old Broad Street, in the City of London, Telegraph Engineer, do hereby
declare the nature of this invention to be as follows:-
Our invention relates to apparatus for the automatic transmission of signals
through submarine telegraph cables or other telegraphic circuits and comprises
the provision of means whereby the signalling and curbing currents sent into the
cable are made and broken at perfectly definite instants.
In the instruments known as automatic transmitters a strip of paper provided
with a central row of holes on either side of which perforations are punched
corresponding in position to the dot and dash system of the Morse code is caused
to pass between a jockey wheel and a revolving spur wheel the spurs or teeth of
which, by reason of their engagement with the line of central holes, operate to
carry the perforated strip along. The spur wheel is actuated by clockwork or other
suitable motive power and the jockey wheel has two grooves ou its periphery,
located one on each side of the teeth of the spur wheel, under which the side
perforations in the paper strip pass.
According to our invention two upright steel rods are made to play against the
paper strip by means of levers. These levers may each be formed with a sleeve or
boss, one of such sleeves fitting loosely over a fixed pin while the other fits similarly
over its neighbour each working concentrically on the same point. A spring
attached to each lever operates to pull it so that it presses the rod towards the
paper strip in a line with its side perforations. On each lever a pin is fixed which
plays against one end of a rocking beam. The opposite end of this rocking beam
terminates in a knife edge. A spring carrying a roller or jockey wheel is adjusted
to press on this latter end serving to keep a contact arm carried by the beam firmly
against one of two limiting stops between which it plays. These two rocking beams
are respectively connected to line and earth while the limiting stops between which
their contact arms play form the battery contacts.
Sometimes instead of employing the springs carrying roller or jockey wheels we
may substitute a short rod or strip inserted between the end of each rocking beam
and the spring which secures the beam and its contact arm in one position or the
other in such manner as to firmly press the contact arms on their limiting stops.
In this case the ends of the rocking beams are modified in shape so as to receive
the short rod or strip.
Another method of causing the rocking beams to make contact is to make the
contacts by means of external flat springs in such manner that the contact point
carried by such bean makes rubbing contact with the said exterual springs, the
resultant friction causing the beam to remain in the position in which it is placed
by the action of the instrument.
In connection with the above described mechanism is an axle which geared to
revolve once for every advance of the spur wheel that is to say, with a spur wheel
having ten teeth the said axle is caused to revolve at ten times the rate of the spur
wheel. This axle carries a series of cams or two or more eccentrics. One cam or
its equivalent is formed so as to permit the levers which carry the upright steel

page_text: rods to rise and let the steel rods play against the paper. If at that instant a
perforation is opposite one of the said rods the lever is allowed to rise sufficiently
to push over the rocking beam which is opposed to it, throwing its arm on to a
limiting stop where it is held by one of the spring jockey wheels or its equivalent
until at the end of the revolution of the axle another cam or its equivalent comes
into play and resets it in its normal position.
When it is required to transmit curbing currents into the cable a pole changing
device, consisting of two contact levers or springs resting on contacts which are
changed in such manner as to reverse. the connections, employed actuated by
another cam or its equivalent mounted preferably on the same axle as the two cams
hereinbefore mentioned. This other cam may be made adjustable by being formed
in two parts one of which is movable radially on the axle or interchangeable cams
may be employed, having different time durations so that the current sent into the
cable may be reversed to form a curb at any instant during the revolution of the
axle, that is to say during one space of the perforated paper strip.
When a more gradual adjustment of the amount of curbing is required the
curbing cam may be shaped to lift the reversing arm of the pole changer gradually and
the contact other than that attached to the reversing arm is mounted on an adjustable
slide piece.
As a pole changing device we may employ a revolving commutator wheel with
spring contacts resting on its surface. One pair of the contact springs may be fixed
while the other may be adjustable radially around the commutator. In this case: it
may be necessary to mount the commutator on a separate axis geared to a speed
different to that of the cam axis.
The governor we prefer to use in connection with the motive power of the
transmitter is one having a revolving friction disc provided with an axial sleeve
sliding on a long bearing and brought up by the centrifugal action of a pair of
weights attached to a circular steel spring to bear against a fixed adjustable stop.
Dated this 11th day of June 1891
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicants.
Improvements in Apparatus for the Automatic Transmission of
Signals through Telegraph Lines and Cables.
We, ALEXANDER MUIRHEAD, of No. 2 Princes Street, in the City of
Westminster, Doctor of Science, Electrical Engineer, and ANGUS FRASER, of
No. 11 Old Broad Street, in the City of London, Telegraph 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:-
Our invention relates to apparatus for the automatic transmission of signals.
through submarine telegraph cables or other telegraphic circuits and comprises the.
provision of means whereby the signalling and curbing currents sent into the cable
are made and broken at perfectly definite instants.
In the accompanying drawings-
Figure 1 is a side elevation of our apparatus ;
Figure 2 is a partial plan thereof.
Figure 3 is a like elevation with the side plate a with its attachments removed

page_text: In the instruments known as automatic transmitters a strip of paper provided
with a central row of holes on either side of which perforations are punched
corresponding in position to the dot and dash system of the Morse code is caused
to pass between a jockey wheel A and a spur wheel B the spurs or teeth of which,
by reason of their engagement with the line of central holes, operate to carry the
perforated strip along. The spur wheel is actuated by clockwork or other suitable
motive power and the jockey wheel has two grooves on its periphery, located one
on each side of the teeth of the spur wheel, under which the side perforations in the
paper strip pass.
According to our invention two upright steel rods C are made to play against
the paper strip by means of levers D, D to which they are attached. These levers
may each be formed with a sleeve or boss E, one of such sleeves fitting loosely over
a fixed pin while the other fits similarly over its neighbour each working con-
centrically on the same point and each of them is provided with a spur das more
clearly shown in Figure 5. A spring G attached to each lever operates to pull it
so that it presses the rod C towards the paper strip in a line with its side perfora-
tione. On the levers are pins H which play against the one end of the rocking
beams 1. These beams rock about the axis J and they are each formed at one end
with a spur I* while the other end terminates in the knife edge K of a blade K¹
attached to the beam 1 as shown and adjustable by a screw K². A spring L which
is adjustably fixed by screws L' carrying a roller or jockey wheel L' is arranged to
press on the edge K and serves to keep a contact arm M carried by the beam I
firmly against one of two limiting stops N', N' between which it plays. The
contact arm M is 'securely pinned to the insulating block O which forms part of the
rocking beam and connection is made with the terminals of the instrument through
the spring P. The two rocking beams are respectively connected to line and earth
through their springs P while the limiting stops between which their contact arms
play form the battery contacts.
In lieu of the springs L carrying roller or jockey wheels L we may employ two
Hat external springs to each rocking beam as shown at L, L in Figure 8 which.
may be adjusted by set screws LL. The end K of the rocking beams in this
case make rubbing contact with the springs, the resultant friction causing the
beams to remain in the position in which they are placed by the action of the
instrument.
In connection with the above described mechanism is an axle Q which is geared
to revolve once for the advance of each tooth of the spur wheel B that is to say
with a spur wheel having ten teeth the said axle is caused to revolve at ten times.
the rate of the spur wheel. Carried on this axle are cams or eccentrics R, S. One
cam S is formed and timed so as to permit the levers D which carry the upright
steel rods C to rise and let such rods play against the paper strip: If at that.
instant a perforation is opposite one of the said rods the corresponding lever is allowed:
to rise sufficiently to cant the rocking beam I which is opposed to it, throwing its
arm M on to the limiting stop N' where it is held by the spring L until at a later
period or at the end of the revolution of the axle the cam R, which is shaped and
timed to effect the purpose, comes into play and resets the beam I in its normal
position against the limiting stop N'. The cam S is more clearly shown in elevation
in Figure 5.
When it is required to transmit curbing currents into the cable we sometimes
employ a pole changing device consisting of two contact levers or springs resting
on contacts which are changed in such manner as to reverse the connections, and
actuated by another cam or its equivalent mounted preferably on the same axle as
the two cams hereinbefore mentioned. This other cam may be made adjustable by
being formed in two parts one of which is movable radially on the axle or inter-
changeable cams may be employed having different time durations so that the
current sent into the cable may be reversed at any instant during the revolution of
the axle, that is to say, during one space of the perforated paper strip.
When a more gradual adjustment of the amount of curbing is required the last

page_text: mentioned cam may be shaped to lift the reversing arm of the pole changer
gradually and the contact other than that attached to the reversing arm is mounted
on an adjustable slide piece.
.
Instead of the above described pole changing device we prefer to employ the
apparatus shown in Figures 6 and 7 which consists of a revolving commutator
ring T in two insulated metallic segments with spring contacts T₁, T resting on its
surface. The contact springs T' are fixed while the other pair T' are mounted and
adjustable radially around the axis of the commutator. In the example illustrated
the commutator ring is intended to be mounted on a separate axis geared to that of
the cams R, S so as to revolve once for every two revolutions of the latter. One
pair of springs is connected to the two poles of the battery and the other pair to
the limiting stops N¹ N2 respectively.
The governor we prefer to use in connection with the motive power of the
transmitter is one having a revolving friction disc U provided with an axial
sleeve V sliding along, and keyed to, the rotatory bearing and brought up by the
centrifugal action of a pair of weights W attached to a circular steel spring ✗ to
bear against a fixed stop Y adjustable by the set screw Z.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :--
1. In apparatus for the automatic transmission of telegraphic signals, the com-
bination of levers such as D pivoted as described and carrying rods such as C
adapted to impinge upon, and pass through the perforations of, the paper strip,
with rocking beams such as I normally resting on the said levers or pins attached
thereto, but capable of being held over by spring devices such as described, and a
series of cams on one axis the one governing the motion of the levers D and the
other replacing the rocking beams I substantially as set forth.
"
2. The combination, with apparatus for the automatic transmission of telegraphic
signals such as claimed in the preceding claim, of a pole changing or "curbing
device consisting of a commutator ring in two insulated metallic segments, and two
pairs of spring contacts bearing thereon the one pair fixed and the other pair
adjustable radially substantially as set forth.
3. An apparatus for automatic transmission of telegraphic signals having in
combination levers such as D, rocking beams such as I, a pole changing or curbing
device such as shown in Figures 6 and 7 and a governor consisting of a friction disc
adapted to be brought up by the centrifugal action of a pair of weights to bear
against a fixed adjustable stop substantially as set forth.
4. The arrangement and combination of parts constituting our improved
apparatus for the automatic transmission of telegraphic signals substantially as
set forth.
Dated this 11th day of March 1895.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicants.