IMPROVE- MENTS IN ELECTRIC TELEGRAPHS AND IN APPARATUS CONNECTED THEREWITH.
Year: 1878

page_text: LETTERS PATENT to Sir Charles Tilston Bright, of 11, Delahay Street, West-
minster, in the County of Middlesex, Knight, for the Invention of "IMPROVE-
MENTS IN ELECTRIC TELEGRAPHS AND IN APPARATUS CONNECTED THEREWITH.'
"
Sealed the 9th May 1879, and dated the 29th November 1878.
PROVISIONAL SPECIFICATION left by the said Sir Charles Tilston Bright
at the Office of the Commissioners of Patents on the 29th November 1878,
SIR CHARLES TILSTON BRIGHT, of 11, Delahay Street, Westminster, in the
County of Middlesex, Knight. "IMPROVEMENTS IN ELECTRIC TELEGRAPHS AND IN
APPARATUS CONNECTED THEREWITH."
My Invention consists of improvements in type printing electric telegraph
instruments, part of the improvements being applicable to other telegraph
instruments.
In the type printing telegraph instruments hitherto devised the type wheel has
been brought into position by one of two methods, the first of these is by alternate
currents of electricity producing a step by step motion of the type wheel; the
second, by causing a type wheel at the receiving station to rotate synchronously
with the sending apparatus.
In my Invention I cause the letters to be printed by inserting different artificial
resistances into the line circuit at the sending station. At the receiving station I
place one of the coils of a differential relay in circuit with the line and with one
pole of a battery (which I call hereafter the line battery), the other pole of which is
connected to the earth.
The second coil of the differential relay is connected at one of its ends to one
pole of the line battery, and at the other to a shaft or axle carrying a contact-
maker, the function of which will be described hereafter.
The relay actuates two magnets, and its coils are so connected to the line battery
that when the current through one of the coils is stronger than the current through
the other, one or the other of the two magnets is moved against a contact stud,

page_text: whereby a circuit which I call the "motive circuit" is brought into connexion
with a local battery, causing the movement of a shaft upon which a type wheel is
fixed. I cause this shaft to be propelled by the motive force of the local current.
Upon the type wheel shaft, or upon another shaft geared to and moving with it, is
a metallic arm carrying a spring, which (when the shaft is in motion) passes over
and makes contact successively with a series of metallic plates insulated from each
other. This arm is the contact-maker previously referred to as being connected
with one end of the second coil of the differential relay.
To each of the metallic plates is connected one end of a separate resistance coil,
and the other ends of all of the resistance coils are united together, and are connected
to the other pole of the line battery. The coils differ from each other in resistance,
and correspond in each case with one of the resistances at the sending station.
The actual resistance of the line wire is placed permanently in the circuit thus
formed by the line battery and the second coil of the differential relay by means
of an adjustable rheostat..
At the sending station the resistances are inserted by means of a key-board, the
keys of which are marked with the letters and signs required. Upon a resistance
being inserted the relay at the receiving station comes into action, and the type
wheel shaft moves onward until the contact maker brings into the circuit containing
the second differential coil the resistance which corresponds with the resistance put-
into the line circuit at the sending station, whereupon the movement of the type
wheel shaft ceases.
The paper is then impressed against the type by an electro magnet comprised in
.the local circuit.
In this description of my system of selecting different letters or signs by means
of resistances I have referred to the use of a differential relay because its action can
be simply explained without reference to Drawings, but an ordinary relay may be
used by employing what is technically known as a bridge arrangement, which is
well understood by all who are conversant with electricity.
Another part of my Invention consists in automatically transmitting communica-
tions in combination with the foregoing apparatus by perforated paper.
For this purpose I arrange a series of resistance coils, so that the whole of the
resistance, or any part of it, may be placed in circuit. For example, the coils
offering resistance according to the proportions shown by the Figures are arranged
thus 10, 20, 30, 40, 100, 200.
The coils are connected together in series, the ends of each core being joined to
metallic plates, between which, when the apparatus is at rest, contact is made by a
metallic junction piece fixed to one end of a lever. If all the junction pieces rest
on the metallic plates no resistance is added to the circuit, but if all or some of
them are raised the whole or a portion of the resistance is inserted in the
circuit.
The other ends of the levers rest in a line with each other upon a ribbon of paper
which is drawn along by clockwork or by the motive power derived from a battery.
The paper is perforated with holes corresponding to the levers, which have to be
moved in order to insert the resistance requisite for the separate letters.
The levers have studs at their ends, so that upon one of the perforations coming
under the end of a lever the latter drops, and its other end being raised its junction
piece is removed from contact with its resistance coil, which is either the entire
resistance required for the letter, or one of a group of several resistances making
up the amount required.
In a modification of this machine I cause the levers to be moved by electro
magnets instead of being moved directly by the perforations in the paper, which is
in this case drawn over a metallic cylinder. By means of contact springs pressing
upon the paper in the line of the several perforations one (or more) of the levers is
moved as metallic contact is made through the perforations between the springs
and the cylinder.
For making the perforations I employ a similar series of levers actuated by

page_text: electro magnets, and having punches fixed to their ends. The levers are so fixed
upon their axles that the punches are near to each other and in a direct line at
right angles to the direction in which the paper is drawn.
The electro magnets are connected at one end with a battery, and at the other
to the keys of a key board upon which the letters and signs are inscribed. Each
key on being depressed brings into action one or more of the electro-magnets by
which the hole or group of holes necessary for inserting the required resistance (by
the aid of the transmitting machine) is made in the paper.
Several ribbons of paper may be perforated at the same time.
Another part of my Invention consists in causing the type wheel of the printing
apparatus to move to the letter which is to be printed in either direction (instead
of rotating in one direction only as in previous instruments); I effect this by
causing the motion of the two magnets of the differential relay, previously described,
to produce a positive or a negative local current, as the resistance at the sending
station is greater or less than the resistance of the last letter printed, and thereby
to move the type wheel in one or the other direction. By this means I am enabled
to place together the letters which are most frequently used, and thus to avoid the
delay arising from frequently passing over letters which are rarely wanted. All
the parts of my invention which I have described in relation to type printing
instruments are also applicable to letter showing instruments, except that which
refers specially to the type wheel and paper arrangements. Such letter or figure
showing apparatus may be employed with a single wire to show the locality whence
a summons is given, where at present, as, for example, in hotels, a great number of
wires are used.
Another part of my Invention consists in applying my system of transmitting
signals by artificial resistances to the ordinary recording instrument and other
instruments where conventional signs are used to represent letters. In effecting
this I employ at the receiving station the differential relay before described, and
by inserting different resistances, or by withdrawing resistances at the sending
station, I cause signals to be recorded (or to be shown) to the right or to the left,
whereby the various combinations of the code employed are produced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Sir Charles Tilston Bright in the Great Seal Patent Office on the
28th May 1879.
SIR CHARLES TILSTON BRIGHT, of 11, Delahay Street, Westminster, in the
County of Middlesex, Knight. "IMPROVEMENTS IN ELECTRIC TELEGRAPHS AND IN
APPARATUS CONNECTED THEREWITH."
My Invention consists of improvements in type-printing electric telegraphs, part
of which are applicable to other telegraph instruments. I cause the letters of the
alphabet, numerals, and other required signs to be printed by inserting different
artificial resistances into the line circuit at the sending station. At Fig. 1 is shown
a key board at the sending station;, the keys, which should be made of ivory or
wood, so as to be insulated from each other, are marked with the letters of the
alphabet. Each of the keys is fixed upon a metallic spring a, one end of which is
connected to a resistance coil b. The other end of each resistance coil is connected
to earth. Immediately beneath the keys and along the entire key-board there is a
metallic bar c, c, moving on centres d, d; when at rest it is pressed by a spring
against the metallic plate e which is connected to earth. A metallic pin fattached
to the under side of the spring of each key breaks the connection between c and e
when any of the keys is depressed, and contact then being made between f and b
the resistance coil belonging to the key is placed in the circuit. At Fig. 2 the
working parts and connections of the type-printing instrument at the receiving
station are shown; a and b are the coils of a differential relay, and the upper
portion of the Figure represents a local circuit made or broken by the armature
lever c.
The lower portion also shows some of the parts comprised in the upper
portion, and these are indicated by the same letters. Coil is connected to the
line wire and to the pole d of a battery whose other pole e is connected to
earth. Coil a is also connected at one end to d and at the other end to the
adjustable rheostat f, composed of resistance coils which can be adjusted to equal
the resistance of the line circuit, and can be varied to compensate for any
change therein. Where the conditions of the circuit require it I combine con-
densers or accumulators with resistance coils so as to form an artificial line
equivalent in its resistance and inductive capacity to the line to be worked.
The other end of f is connected to an axle g, g, upon which is fixed the type
wheel and also a metallic arm i, i, which when the axle is in motion passes over
and makes contact with a series of metallic plates jjj, to which are connected a
series of resistance coils k, k. Two or more type-wheels may be carried by g, g, so
that two or more duplicates of a message may be printed simultaneously. 1, 1, is an
electromagnet, and m its commutator; n is a local battery by which 1, 1, is worked,
and the axle g, g, rotated thereby when the local circuit is closed by the action of c.
A train of clockwork may be controlled by 1, 1, in place of directly propelling g, g;
o is an electromagnet acting upon the printing pad p. When the instrument is not
at work c is in the position shown in the Figure, but upon a resistance being inserted
at the sending station the local circuit is completed by the motion of c against the
stop q, and g, h, and i rotate until i comes into contact with the particular plate j,
by which the amount of resistance inserted at the sending station is equalled, where-
upon the current passing through a and b being balanced c is separated from q, the
movement of the typewheel ceases and the paper is impressed against h by p. The
above arrangements are applicable to a letter showing instrument, an index hand
and lettered dial taking the place of the typewheel and the appliances for impres-
sing and moving the paper. In place of the key board, shown at Fig. 1, I arrange
the resistance coils in the letter showing instrument around the dial, connection
being made with them in sending by studs or buttons placed above them, and in
receiving by a contact arin rotating over metallic plates similar to ȧ and j, in Fig. 2.
At Fig. 3 the apparatus at the receiving station is shown arranged as a "bridge," in

page_text: which a is an ordinary relay; b, the battery; c, the adjustable rheostat or artificial
line; d, the series of metallic plates and resistance coils represented by j and k in
Fig. 2; and R, R¹, proportional resistances equal to each other. Another part of my
Invention consists in automatically transmitting communications in connexion with
the apparatus previously described by means of perforated paper. At Fig. 4 a series
of metallic plates insulated from each other is shown by a, a. b, b, are levers
which rest at one end on the plates so as to unite them electrically when all the
levers are pressing upon the plates. Resistance coils c, c, are connected together
and with the plates as shown in the Figure. The line wire d is connected to the
first of the plates, the last of which is connected to earth at E; and as the levers,
when at rest, place all the coils c, c, on short circuit, the circuit is then direct from
d through a, a, to earth. If all or any of the levers are raised, the whole or a
portion of the resistance is added to the circuit. The value of the coils is made
such that any part of the total resistance may be inserted by the movement of
different levers; as, for example, supposing the total resistance required for all the
letters to be 1100 units of resistance, the coils would be arranged in a group of 10,
20, 30, 40, 100, 200, 300, 400, as in an ordinary resistance box. The other ends of
the levers rest upon a ribbon of paper e, e, passing over and moved by the cylinder
or roller ff. The paper is perforated with holes corresponding to the levers, so that
upon any perforation coming beneath the end of a lever it sinks into the perforation;
and the other end being lifted places one of the resistance coils in circuit. ff, may
be moved by a battery or by clockwork, as shown in the Figure. Upon the resist-
ance being inserted in the line circuit, the relay at the receiving station is thrown
out of balance, and the action described in reference to Fig. 2 takes place, but when
the automatic system is used, the printing pad p, Fig. 2, moves a contact piece as it
presses the paper against the type, by which the line circuit is broken or is placed
upon short circuit for a very brief interval of time, by which a relay at g, Fig. 4, is
moved, and the electromagnet h (actuated by a local battery, which is connected
with the relay at g) and the escapement i at the end of its armature lever cause
the cylinder f to advance the paper a division, and thus to bring another perforation
or group of perforations under the levers. This process continues in succession as
long as there are perforations in the paper, and as fast as, the balance is obtained at
the receiving station. In a modification of this machine I cause the levers to be
moved by electromagnets instead of being moved directly by the perforations in
the paper, which is drawn over a metallic cylinder. By springs pressing upon the
paper in the line of the several rows of perforations one or more of the levers are
moved by the attraction of armatures fixed to them, and attracted by the electro-
magnets when metallic contact is made through the perforations between the springs
and the cylinder, at which time a local battery is brought into circuit with one or
more of the electromagnets. For making the perforations, a similar series of
electromagnets may be used, with corresponding levers fitted with punches at one
of their ends. The levers are so fixed upon their axles that the punches are near to
and in a line with each other at right angles to the direction in which the paper is
drawn. The electromagnets are connected at one end with a battery, and at the
other to the keys of a keyboard, upon which the letters and signs to be trans-
mitted are inscribed. Each key, on being depressed, brings into action one or more
of the electromagnets, by which the hole or group of holes necessary for inserting
the required resistance in the transmitting machine, shown in Fig. 4, is made in the
paper. In a modification of this machine I cause the holes to be punched by the
direct action of the hand; a machine of this kind is shown in plan at Fig. 5, which
consists of a keyboard, carrying keys inscribed with the letters of the alphabet.
Beneath the keys and at right angles to them are eight steel plates a, a, at the ends
of which are the punches b, b. The plates are free to move in slides in their bear-
ings c, c, but are held back at a, a, by springs d, d. Under each key is a steel
roller, and in each plate a series of cam-shaped teeth are cut, corresponding to the
letters on the keys, where the punch at the end of the plate is required. At Fig. 6,
a side view of a key and section of the plates is shown, and at Fig 7 a front view

page_text: of one of the keys, and part of a plate in front view, e being the steel roller,
and f f f plates in which there are teeth for punching holes. The paper g, g,
Fig. 5, is drawn in by clockwork in front of the punches, and the depression
of each key punches out the holes appertaining to its letter or sign; the
clock work is released to give the requisite forward motion by the pressure of each
key releasing a detent by means of a bar common to all the keys, which it is not
necessary to show. In another part of my Invention I cause the type-wheel of the
printing apparatus to move in either direction to bring the letter which is to be
printed to the impressing pad, instead of rotating in one direction only as in previous
instruments. The letters which occur most frequently, such as E, I, T, A, N, O, S,
are grouped together on the type-wheel, and thus the loss of time arising from con-
stantly passing over rarely wanted letters, such as Z, is avoided. Fig. 8 is an
instrument of this kind in plan; the central horizontal wheel a, a, is driven by a
train of clockwork, which is not shown, below the frame upon which the printing
apparatus is fixed. b, b, are two friction wheels which move the shaft c, c, in either
direction according as the magnet d is moved to one side or the other by the elec-
tromagnets e, e. fis the type wheel on c, c. d is brought to a central position
when the relay is balanced by the armature at the other end of the electromagnets.
The electromagnet g actuates the armature lever h, h, by which the paper is impressed
against the type wheel, and which also advances the paper a space when each letter
is printed by moving a ratchet wheel on the roller i. j is a wheel on c, c, having
pins fixed into it corresponding to the spaces between the letters on the type-wheel,
and a shaped arm projecting from h, h, which is not seen in the Figure, is inserted_
between two of the pins whenever a letter is printed, so as to adjust the centre of
the letter immediately above the centre of the impressing pad. k, k, is the series of
resistance coils, and the rotating contact arm fixed to c, which is represented by i
in Fig. 2. The arrangements of the circuits either at Fig. 2 or Fig. 3 may be used
with this instrument, but the relay whether differential or single is required to
make contact on both sides as the balance at the last letter printed is in favor of
the line circuit or of the artificial circuit. The system of moving the type-wheel to
either side is of special advantage where great speed is required as in automatic
sending, as three times the number of letters may be printed from the same number
of revolutions, but where sending by manipulating the keyboard is sufficiently fast
an instrument in which the type-wheel inoves in one direction only will suffice.
Fig. 9 shows a front view of such an instrument, which is represented as being
driven by an electro-motor below the frame upon which the printing apparatus is
fixed, instead of by clockwork as described in Fig. 8. The letters refer to the same
parts as the letters in Fig. 8. Another part of my Invention consists in applying
my system of transmitting signals by artificial resistances to the ordinary recording
or visual, or acoustic instruments, and the method whereby I effect this is shown at
Fig. 10, where A is the relay or other instrument to be worked at the receiving
station; b, the battery; C, the adjustable rheostat or artificial line (which in addi-
tion to the resistance of the line includes that of M, to be referred to hereafter); and
R, R', the proportional equal resistances in the bridge; e, f, and g, h, are two lever
keys at the sending station, insulated from each other and moving on centres at e
and g.
When at rest both keys are pressed by springs beneath them against the
plates or stops i and j. k and lare similar plates against which the keys are stopped
when either of them is depressed. M, N, are two resistances, the magnitude of
which is proportional to the resistance of the circuit to be worked; o and o repre-
sent the line wire. When both keys are at rest N is placed on short circuit through
9, 3, and the current then passes through o, M, k, g, and j to earth at E, and as the
resistance of M is included in C an electrical balance is maintained at A. On
depressing fit is stopped by k, and M being thereby placed on short circuit at e, k,
the current flows through e, k, g, j, to E. The balance being now disturbed the
magnet or other moving part of A moves to one side, coming back to its place of
rest when fis allowed to return to its former position. When his depressed N is
brought into the circuit by contact being broken at j, g, and the current flows

page_text: through o, M, k, g, and N to earth at E. The balance at A is now disturbed, but
the motion of its moving part takes place on the opposite side, for in the depression
off the resistance of the line circuit balanced by C was reduced by the withdrawal
of M, while by the depression of the resistance of N is added to the circuit. The
apparatus for sending or receiving can be changed by a switch at either station, and
condensers may be used with or without resistance coils at M, N. This method of
signalling allows of a negative current being continually used, while right and left
movements of the receiving instruments are obtained therefrom.
Having thus described the nature of my said Invention, and the best means I
am acquainted with for carrying the same into effect, I wish it to be understood
that what I claim is,-Firstly. The system of telegraphing by means of varying
resistances as described. Secondly. The different apparatus described in connexion
therewith.
In witness whereof, I, the said Sir Charles Tilston Bright, have hereto set my
hand and seal, this Twenty sixth day of May, in the year of our Lord One
thousand eight hundred and seventy nine.
CHARLES T. BRIGHT. (L.S.)