Improvements relating to the Transmission of Signals Through Submarine Telegraph Cables.
Year: 1894

page_text: Date of Application, 7th June, 1894
Complete Specification Left, 15th Jan., 1895-Accepted, 16th Feb., 1895
:
PROVISIONAL SCENTICAIN.
Improvements relating to the Transmission of Signals Through
Submarine Telegraph Cables.
I, ALEXANDER MUIRHEAD, of No. 2 Princes Street, in the City of Westminster,
Doctor of Science, Electrical Engineer, do hereby declare the nature of this
nvention to be as follows:-
My invention relates to improvements in the mode of automatically making and
breaking the contacts between line, earth, and battery in the transmission of electric
impulses or currents ou submarine cables.
According to my invention the two contact-making levers of the automatic
transmitter used by me are each constructed in two parts working on separate axes.
The upper part of each lever at the end which enters the perforations of the
punched paper strip used in connection with the instrument is terminated preferably
by a steel nose shaped like the tooth of a ratchet wheel, that is to say flat at one
edge and curved or rounded off at the other. These noses may, in some cases,
instead of being formed in one with the levers, be hinged thereon.
On either side of, and on the same spindle as, the spur wheel which carries along
the paper strip are fixed two rollers having as many grooves in them, with alternate
edges rounded off, as there are spurs or teeth in the spur wheel. These rollers
serve to keep the paper strip taut as it passes underneath them and they assist the
paper in driving or pushing the noses of the levers out of the perforations as the
paper strip is carried along by the central row of spurs in the spur wheel.
i
In addition to these grooved rollers I employ another wheel mounted on the same
axis having the same number of similar grooves cut in it into which a lever
constantly rises and falls. The grooves are so shaped that the lever which plays
in them comes into contact with the upper arms of the hereinbefore mentioned
compound contact levers directly after one or other of the noses has entered a
perforation in the paper strip and thus assists the paper in driving the levers out.
The grooves are also so shaped that the lever falls suddenly into them at the moment
when the perforations in the paper strip are fairly opposite the noses of the upper
may dispense with
arms or levers of the compound contact levers. Sometimes I
the grooved wheels at the side of the spur wheel and depend solely on the single
grooved wheel last described for controlling or regulating the movements of the
upper arms of the contact levers.
The lower arms of the contact levers are arranged to bear on the upper arms at
one end and to play between limiting stops at the other end against which they are
kept firmly applied by means of roller or jockey springs.
A combination of grooved wheel with lever of similar construction to that above
described is fixed in proximity to the lower arms of the contact levers so that a pin
at one end of the lever is brought into contact with the lower arms at the end of
every space in the punched paper strip. 1 find it advantageous to give this
grooved wheel an intermittent motion; accordingly it is by preference actuated or
turned by means of a Geneva stop wheel arrangement consisting of a wheel having
a single tooth mounted on the same shaft as that which drives the spur. wheel
engaging in the notches of another wheel on the same shaft as the said grooved
wheel. The object of giving intermittent motion to the grooved wheel is to give
more certainty to the movements of the lever. which rides on it...For every
5 revolution of the driving wheel the grooved wheel is thus advanced through the

page_text: distance of one notch in the Geneva stop wheel corresponding with the period of
one space in the paper strip.
In order to transmit "curbing". currents into the cable by means of the above
mechanism I sometimes employ a revolving commutator mounted on the same shaft
as the driving wheel of the mechanism. The spring or roller contact which rests
on the commutator wheel and the two separate and insulated metallic surfaces of
such commutator wheel are joined up electrically to one of the two limiting stops
between which the lower arms of the contact levers play in such manner that
during every revolution of the commutator wheel the battery is reversed. The
instant of reversal of the battery is determined by the position of the spring or
roller on the commutator wheel. A tangent screw or similar device is employed
to move the spring or roller contact laterally on the commutator wheel. Or I may
sometimes substitute for the commutator wheel a lever working between two spring
contacts and limiting stops actuated by means of an adjustable cam mounted on the
same shaft as the driving wheel of the mechanism.
In some instruments made according to this invention cach contact-making lever
is constructed of one arm only, that is to say in one piece, and carrying loosely
jointed to it at the end next to the spur wheel an upright steel rod which is kept
pressed against the paper strip and, being loosely jointed to the contact arm, is free
to move forward and out of the paper strip after entering a perforation. The other
ends of the contact levers work in a grooved wheel of similar construction to that
lastly described to which intermittent motion is imparted and also between limiting
stops against which they are kept pressed by a jockey roller spring. Or sometimes,
as in the case of the compound levers above described, a lever working in the
grooved roller regulates the movements of the single arm contact levers.
Sometimes instead of the latter mechanism I may attach armatures to the
contact levers and place an electromagnet beneath them joining the coils of the
electromagnet to the roller or spring contact of a revolving commutator and to a
local battery in such manner that at the commencement of every revolution of the
driving wheel of the mechanism, that is to say at the beginning of every space in
the paper strip, a current is set up in the coils of the electromagnets the result
being that the armatures of both contact levers are attracted and whenever a
perforation in the paper strip comes opposite one or other of the upright steel rods
connected to the levers the corresponding lever is drawn into contact with the
opposite limiting stops. The duration of the current in the coils of the electro-
magnet is regulated by varying the position of the spring or roller contact on the
revolving commutator. On the cessation of the current the levers are withdrawn
by means of springs. Jockey or roller springs are applied to the contact levers, as
before, to keep them firmly pressed against the limiting stops on one side or the
other.
Instead of attaching armatures to the contact levers I sometimes, in a simpler
form of the apparatus made according to this invention, make use of one armature
only and attach thereto a pin bent into such a position as to intercept the levers
from falling into the perforations of the paper strip except when the armature is
attracted. By this arrangement the instant at which a contact lever can enter a
perforation and the duration of the contacts are controlled by the movement of the
pin attached to the armature of the local electromagnet.
Whenever it is required to reverse the battery or to send "curbing" currents
into the cable during the period of a contact or revolution of the driving wheel of
the mechanism another electromagnet with armature is employed so joined up to a
spring or roller contact mounted in a line with the former spring contact on the
revolving commutator wheel that at the beginning of every revolution of the latter
a current is set up in the coils of the electromagnets whose duration is dependent on
the position of the spring on the commutator wheel. The armature of this second
electromagnet is connected to the front limiting stops of the first electromagnet, the
back limiting stops being connected to the middle of a split line battery. The two
ends of the split battery are connected to the limiting stops of the armature of the

page_text: second electromagnet respectively. The metallic surfaces of the commutator wheel
are constructed or designed so that at the end of every revolution of the wheel the
spring contacts are insulated from the remainder of the circuit in order to allow
the armatures of the first electromagnet time to return to the back limiting stops
thus earthing the cable before being again attracted on the passage of the successive
perforations in the paper strip.
Sometimes instead of the commutator wheel with the two spring or roller contacts
I employ an arrangement of levers playing between spring contacts and limiting
stops and actuated by au adjustable cam mounted on the same shaft as the driving
wheel of the mechanism in a similar manner to that described above to effect the
same purpose.
Sometimes in the above mechanism I may with advantage give intermittent
motion to the spur wheel which drives the perforated paper strip by means of the
Geneva stop wheel arrangement above described. When ench intermittent motion
is given to the paper strip the combination of grooved wheels and levers or the
electrical equivalent may be dispensed with.
Dated this 7th day of June 1894
A. F. SPOONER.
124, Chancery Lane, W.C., Agent for the Applicant.
Improvements relating to the Transmission of Signals Through
Submarine Telegraph Cables.
I, ALEXANDER MUIRHEAD, of Princes Street, in the City of Westminster,
Doctor of Science, Electrical 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 improvements in the mode of automatically making and
breaking the contacts between line, earth, and battery in the transmission of
electric impulses of currents through submarine cables.
In the accompanying drawings,
Figures 1, 5, 9, 13 and 17, are side elevations of various forms of transmitting
instruments. Figure 2 is a plan and Figures 3 and 4 sectional elevations of
Figure 1; Figures 6 and are part plans and Figure 8 a sectional elevation of
Figure 5; Figure 10 is a plan of the platform, Figure 12 a full plan and Figure 11
a sectional elevation of Figure 9; Figure 16 is a part plan, Figure 14 a sectional
elevation through the line 1-2 and Figure 15 a sectional elevation through the
line 3-4 of Figure 13; Figure 19 is a sectional elevation and Figure 20 a plan of
Figure 17; and Figures 21, 22 and 23 are diagrammatic illustrations all hereinafter
more particularly referred to.
According to this invention the two contact-making levers of the automatic
transmitter used by me are each constructed in two parts L1, L2 see Figures 1, 9
and 17 working on separate axles as shown or independently on the same axle.
The upper part L' of each lever, at the end which enters the perforations of the
punched paper strip used in connection with the instrument, may, in some cases,
terminate in a steel nose shaped like the tooth of a ratchet wheel, that is to say
flat at one edge and curved or rounded off at the other, or instead of being formed
in one piece with the contact levers they may be hinged or loosely jointed thereon,
or they may be replaced by vertical rods, R, see Figures 1, 5, 9, 13 and 17 as in
the well known Wheatstone transmitter.
When the upper part L' of the levers terminate in a steel nose I employ, on
either side of, and either on the same axle as the spur wheel which carries along
the paper strip, or on an axle suitably geared thereto, two rollers having as many

page_text: =
grooves in them, with alternate edges rounded off,--that is to say shaped like the
teeth of a ratchet wheel-as there are spurs or teeth in the spur wheel. These
rollers serve to keep the paper strip taut as it passes underneath them and they
assist the paper in driving or pushing the noses of the levers out of the perforations
as the paper strip is carried along by the central row of spurs in the spur wheel.
In addition to these grooved rollers or cam wheels 1 employ another cam
wheel G (see Figure 3) mounted on the same axle as the spur wheel and having
the same number of similarly shaped teeth or grooves in which a pivotted lever or
pawl L³ with a pin p' projecting from it constantly rises and falls. The grooves of
the wheel G are so shaped that the pin p comes into contact with the upper
arms L', Figure 1, directly after one or other of the noses or rods R has entered a
perforation in the paper strip. The grooves of the said wheel G¹ are also so
shaped that the lever or pawl L³ falls suddenly into them at the moment when the
perforations in the paper strip are fairly opposite the noses or ends of the rods R.
Sometimes I may dispense with the grooved rollers or cam wheels at the side of
the spur wheel and rely solely on the cam wheel G' with its pawl L³ and attached
pin, last described, for controlling or regulating the movements of the upper
arms L, of the contact-making levers. Both the levers L', L' are crank shaped
and the lower arme L2 are arranged to bear on the upper arms L' at the one end
and to play between the limiting stops a, y at the other end, against which they
are kept firmly applied by means of roller or jockey springs j.
A combination of a grooved wheel or cam wheel G2, Figure 3, with a pivotted
bar or lever L of similar construction to that above described is fixed in proximity
to the lower arms L2 of the contact levers so that a pin 2, Figures 1 and 3, at one
end of the bar L is brought into contact with the lower arms L2 at the end of
every space in the punched paper strip. I find it advantageous to give this cam
wheel G an intermittent motion; accordingly it is by preference actuated or
turned by means of a Geneva stop wheel arrangement consisting of a wheel G³,
Figure 4, having a single tooth engaging in the notches of another wheel G* on
the same shaft as the said grooved wheel or cam wheel G². The object of giving
intermittent motion to the cam wheel G2, Figure 3, is to give more certainty to the
movements of the lever or pawl L which rides on it. For every revolution of the
driving wheel G³, Figure 4, the cam wheel G2, Figure 3, is thus advanced through
the distance of one notch in the Geneva stop wheel G, Figure 4, corresponding
with the period of one space in the paper strip.
In order to simplify the construction of the mechanism hereinbefore described
1 may dispense with the Geneva stop wheel movement and employ in some instru-
ments made according to this invention in place of the cam wheels G¹ and G²
single grooved wheels or plain cams G, G' (see Figures 11 and 12) mounted on
an axle geared to that of the spur-wheel s so as to revolve once on the passage o'
every tooth or spur of the spur wheel, that is to say on the passage of every space
in the perforated paper strip. On these cams G6, G7, ride the pivotted levers or
pawls L L carrying the pins p² respectively which come into contact with the
contact-making levers L L respectively during every revolution of the said
cams G G The cam G8 with lever L³ and pin p' and the cam G' with lever L
and pin regulate the movements of the levers Land L' respectively. The
position of the pins p', p² relatively to the levers L', L2 is accurately adjusted by
means of the screws w, w which are also useful to correct for any alteration of
distance between the ends of the levers L³, L' and the cams G, G on which the
levers rest, through wear and tear of the parts.
In some transmitters made according to this invention the two cams G and G'
are combined into one single compound cam which acts through one lever separately
upon the upper and lower arms L and L2, of the contact levers.
In order to transmit "curbing" currents into the cable in conjunction with the
above mechanism I sometimes employ a revolving commutator S, Figure 23;
mounted on the same shaft as the cams G6 and G' (see Figure 12). The spring or
roller ccntact bar L which rests on the commutator wheel S and the two separate

page_text: and insulated metallic surfaces of such commutator wheel marked Z and C in
Figure 23 are joined up electrically to a split battery as shown and the two
limiting stops y between which the lower arms L2 of the contact levers play in
such manner that during every revolution of the commutator wheel the polarity of
the line battery is reversed. The instant of reversal of the battery is determined
A tangent
by the position of the spring or roller on the commutator wheel.
screw T such as shown in Figures 2, 7 and 12 or similar device is employed.to
move the spring or roller contact bar laterally on the commutator wheel. Or I
may sometimes substitute for the commutator wheel a lever L, Figure 4, working
between two spring contacts g' g² and limiting stops K1, K2 actuated by means of
a graduated cam S, Figure 2, the position of the lever L' on the cam S being
adjusted by means of the tangent screw T. The limiting stops K1, K2 are con-
nected electrically to the two poles of the line battery respectively and the
springs go to the limiting stops a, y, Figure 1, between which the levers L2 play.
By employing a split battery the spring contacts g', g² may be dispensed with and.
the simpler arrangement, shown in Figures 8, 11, 19 and 22, adopted in which the
lever L itself plays between the two limiting stops K' and K². These stops are
connected electrically to the poles of the split battery respectively, the middle of
the battery and the lever L being connected to the limiting stops x, y between
which the contact levers L2 play respectively. Figure 22 illustrates diagram-
matically the electrical connections between the revolving cam S, the lever L³, the
L² the two contact-making levers
contact levers L2 and the split battery B¹, B².
of the transmitter are connected to line and earth respectively. S is the revolving.
cylindrical cam along whose length the lever L³ is adjustable for the purpose of.
varying the relative lengths of primary and secondary or "curbing" contacts.
Kis connected to the end B₁, and K2 to the end B2 of the split battery B₁ B².
The contact point L' of the lever L° is mounted on a spring in order to give a
When the transmitter is at work the line
slight rubbing on the limiting stop K².
and earth levers L2, L2 are kept pressed against the limiting stops or y by the
jockey springs. The revolving cam S puts the lever L³ into contact first with K¹
then with K2 sending signalling and "curbing " currents alternately to line through
the contacts Kand K2 respectively. The position of the wire z on the,
battery B B2 can be altered to get any relative powers of the primary and the
eurbing" currents. In this figure the battery is shewn divided into two equal
parts by the wire z so that the "curbing" current arises from the same number of
cells as the primary current. This arrangement is found to answer well on most
cable circuits.
In some instruments made according to this invention each contact-making lever
is constructed of one arm only see L, Figures 5 and 13, that is to say in one piece,.
carrying loosely jointed to it at the end next to the spur wheel an upright steel
rod R which is kept just clear.of the paper strip by the action of the spring V in.
Figure 5 and by the cam S in Figures 14 and 16. The rods, R, are free to move
forward after entering a perforation. The other ends of the, contact levers work
in some cases in a cam wheel of similar construction to that above described to
which intermittent motion is imparted and also between limiting stops against
which they are kept pressed by a jockey roller spring. Or sometimes as in
a lever with pin p
the case of the compound levers above described
Figures 14, 15 and 16 working on a graduated cam S is employed to regulate the
movements of the single arm contact levers. This lever I is attached to an
O arm L which works on the axle 5. The lever L is capable of movement laterally
along the face of the cam while the mechanism is in operation, by means of the
ɛaddle-piece 6 riding on the axle 5 and passing over and moved by the tangent
screw T in order to adjust the duration of contact between the levers Land
battery to suit the varying conditions of the line.
5
Sometimes instead of the latter mechanism I may attach armatures A, Figures 5
and-6, to the contact levers L and place an electromagnet M beneath them joining
⚫ the coils of the electromagnet to the roller or spring contact of a revolving..

page_text: commutator S and to a local battery in such manner that at the commencement of
every revolution of the cam, S, that is to say at the beginning of every space in the
paper strip, a current is set up in the coils of the electromagnets M the result being
that the armatures A of both contact-making levers L are attracted and whenever
a perforation in the paper strip comes opposite one or other of the upright steel
rods R connected to the levers L the corresponding lever is drawn into contact with
the opposite limiting stops . The duration of the current in the coils of the
electro-magnet M is regulated by varying the position of the spring or roller
contact L (see Figure 7) on the revolving commutator or the graduated cam S,
and this can be done without stopping the transmitter. On the cessation of the
current, the levers are withdrawn by means of springs V. Jockey or roller springs j
are applied to the contact-making levers L as before, to keep them firmly pressed
against the limiting stops x, y on one side or the other.
Instead of attaching armatures to the contact levers themselves I sometimes, in
another and simpler form of the apparatus made according to this invention, make
use of only one armature and attach thereto a pin bent into such a position as to
intercept the levers from falling into the perforations of the paper strip except when
the armature is attracted. By this arrangement the instant at which a contact
lever can enter a perforation and the duration of the contacts are controlled by the
movement of the pin attached to the armature of the local electro-magnet.
In the latter case when the contact levers are constructed in two parts L', L²
(see Figures 17 19 and 20) as above described, instead of employing another electro-
magnet to regulate the movements of the upper levers L', I prefer to effect the
regulation by means of a lever L³ and cam C7, Figures 19 and 20, mounted on the
same axis as the graduated cam S, the lower levers L2 being controlled by means
of the local electro-magnet M, Figures 19 and 20, with armature A and pin p²
projecting from it as before. The cam on which the lever L³, Figure 19, works is
adjusted relatively to the spur-wheel s', Figure 17, so that the upright rods R
attached to the upper levers L' can only enter the perforations in the paper strip at
the instant when such perforations are opposite the ends of the rods R. The coils
of the electromagnet M are so joined up in this case with the local battery through
the contact bar L, Figure 20, and K' that at the end of every revolution of the
revolving commutater or cam-wheel S a current flows through them for an instant
attracting the armature A and bringing the pin p² into contact with the levers L³,
the result being a resettal of the levers L² after every deflection on the passage of
a perforation in the paper strip.
•
Whenever it is required to reverse the signalling battery or to send "curbing "
currents into the cable during the period of a contact or revolution of the
commutator wheel another electromagnet is in some cases employed and so joined
up to a spring or roller contact mounted in a line with the former spring contact on
the revolving commutator wheel that at a certain interval after the beginning of
every revolution of the latter a current is set up in the coils of the electromagnet
whose duration is dependent on the position of the spring on the commutator wheel.
The armature of this second electromagnet is connected to the front limiting stops
of the first electromagnet, the back limiting stops being connected to the middle of
a split line battery. The two ends of the split battery are connected to the limiting
stops of the armature of the second electromagnet respectively. The metallic
surfaces of the commutator wheel are constructed or designed so that at the end of
every revolution of the wheel the spring contacts are insulated from the remainder
of the circuit in order to allow the armatures of the first electromagnet time
to return to the back limiting stops, thus earthing the cable before being again
attracted on the passage of successive perforations in the paper strip.
Instead of the commutator wheel arrangement as above described I
may prefer
to employ the graduated cam S with the levers L' and L joined up electrically as
shown in Figure 21. The spring F holds the armature A with its pin p away from
contact with the signalling levers L' when no current flows through the coils of the
lectromagnet M. When the transmitter is running, the upright bars K complete

page_text: successively two circuits with the local battery B first the one through the coils of
the electromaguet N and then that through the coils of the electromagnet M..
During every revolution of the adjustable graduated cam S the first electromagnet
attracts the lever attached to the armature D and keeps the contacts over to one
side thus reversing the battery until the end of each revolution; the secoud
electromagnet M alter an interval depending on the position of the lever L on the
graduated cam S draws the pin p against that lever L' which happens to be
deflected on the passage of a perforation in the paper and knocks it back on to the
limiting stop y
Sometimes in the above mechanism may with advantage give intermitten
motion to the spur wheel which drives the perforated paper strip by means of the
Geneva stop wheel arrangement above described. When such intermittent motion,
is given to the paper strip the combination of grooved wheels and levers above
described or the electrical equivalent may be dispensed with. In this case the
contact levers may become springs or brushes of wire pressing constantly on the
perforated band of paper and falling through the perforation into a wire brush
or cushion or revolving contact wheel beneath as in the well-known Bain
transmitter.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In automatic transmitters the combination of contact-making levers formed in
two parts working either on separate axles or independently on the same axle, with
one or more cams controlling the movements of each part separately.
2. In automatic transmitters the combination of a lever or pawl with a grooved
wheel or cam for the purpose of regulating or controlling the movements of the
contact-making levers.
3. In automatic transmitters the combination, with the contact-making levers, of
a graduated cam and a lever adjustable thereon for the purpose of controlling the
movements of the contact-making levers whereby the relative durations of the
battery and earth contacts may be varied without stopping the mechanism.
4. In automatic transmitters. the combination of an electromagnet with an
adjustable revolving commutator or an adjustable graduated cam and a local
battery for the purpose of controlling the movements of the contact-making levers
whereby the relative durations of the battery and earth contacts may be varied
without stopping the mechanism.
5. In automatic transmitters the combination of a Geneva stop wheel arrangement
or its equivalent with the cams or grooved wheels which regulate or control the
movements of the contact-making levers for the purpose of imparting intermittent
notion to such cams or grooved wheels.
6. In automatic transmitters the adjustable revolving commutator or the
graduated cam constructed as herein described with reference to Figures 7, 8, 11,
12, 19, 20 and 22 or the equivalent device of an adjustable cam actuating a lever
which works between two spring contacts and limiting stops as described with
reference to Figure 4 for the purpose of reversing the battery or transmitting
"curbing" currents.
7. In automatic transmitters the combination of the adjustable revolving
commutator or the adjustable graduated cam arrangement constructed as herein
described with a split battery for the purpose of transmitting curbing
) currents.
'
"
8. In automatic transmitters the combination of the two cams for regulating the
movements of the compound contact-making levers with the adjustable revolving
commutator or graduated cam or the equivalent device of an adjustable cam
actuating a lever which works between two spring contacts and limiting stops as
described with reference to Figure 4 for the purpose of reversing the battery or
transmitting "curbing" currents.

page_text: 9. In automatic transmitters the combination of an adjustable revolving
commutator or cam wheel on which roller or spring contacts rest with two local
electromagnets for the purpose of controlling or regulating the movements of the
contact-making levers.
10. In automatic transmitters the combination of a cam wheel and a single local
electromagnet with an adjustable revolving commutator or adjustable graduated cam
arrangement on which roller or spring contacts rest for the purpose of controlling
or regulating the movements of the contact-making levers and, when it is required
to transmit "curbing" currents, with an extra roller or spring contact on the said
revolving commutator or cam.
11. In automatic transmitters the method of transmitting "curbing " currents by
means of a local electromagnet in connection with an adjustable revolving
commutator or cam wheel as herein described with reference to Figure 21.
Dated this 15th day of January 1895.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicant.