IMPROVEMENTS IN PRINTING TELEGRAPHS
Year: 1885

page_text: "
I WILLIAM HENRY DAVIES Managing Director of the Exchange Telegraph
Company Limited of 17 and 18 Cornhill in the City of London do hereby declare
the nature of my invention for "IMPROVEMENTS IN PRINTING TELEGRAPHS
(a communication to me from abroad by George B. Scott of Brooklyn, New York,
one of the United States of America, Telegraph Engineer) to be as follows:-
This invention has for its object improvements in printing telegraphs and it
applies to a printer in which the step by step rotation of the type wheels is
controlled by short electrical impulses alternately of positive and negative polarity.
These impulses pass in a coil of which the axis is vertical. An iron core passes
up through this coil and is free to vibrate within it about pivots at its lower end.
At its upper end the core carries an escapement which as the core oscillates operates
against pallets on the opposite sides of the escapement wheel. Adjustable stops
opposite its ends limit the movement of the escapement.
At the upper end of the core immediately beneath the escapement are two pole
pieces one on either side-they are fixed upon a permanent horse shoe magnet,
The magnet is placed between two capstan headed adjusting screws passing through
attachments on the frame. These screws spring the magnet poles together and so
adjust the position of the pole pieces.
The coil above mentioned or the escapement magnet whatever it may be for
controlling the rotation of the type wheels is in the same circuit with a neutral
electro magnet which is only brought into action to effect printing upon a
prolongation of one of the short impulses employed to rotate the type wheels.
The controlling of the rotation of the type wheels, and the taking of impressions
upon a strip of paper, are effected solely by electrical currents transmitted over one
main line.
To determine however, from which of the two type wheels an impression shall
be taken, a second, and independent main line, burdened with no other condition
of operation is employed.
The second line includes at each instrument preferably, a neutral electro magnet
which serves to shift the press pad from one side to the other under either type
wheel at the will of the transmitting operator.

page_text: This second main line is normally opened and remains so at all times during the
printing of figures, and the armature lever of the electro magnet therein is normally
held in such a position by a retracting spring, as to retain the press pad under the
letter wheel while no current is flowing over said line, but when it is desired to
print a figure instead of a letter, a current is transmitted over the second main
line at the same time that the type wheels are being rotated to a position to print.
Thus, while the type wheels are being rotated, the press pad is shifted under the
figure wheel by the attraction of the armature of the electro magnet in the second
line, and upon a prolongation of a current on the first line, the impression of a
figure will be taken.
The transmitter consists of a rotating axis carrying a wheel which in rotating
makes and breaks the circuit through one of the line wires.
Two contact springs operate in conjunction with this wheel, they come into
action alternately and transmit positive and negative impulses alternately along
the line wire.
The axis also carries an arm which can be arrested in the course of its rotation
by finger keys operating through the intervention of electro-magnets or otherwise.
The arm can be stopped on any impulse which thus is prolonged into a current
of sufficient duration to cause the printing magnet to operate. There are two sets
of keys, one set for letters and the other for figures; they operate similarly so far
as concerns arresting the movement of the revolving arm but the keys of the latter
set operate also by means of a relay magnet or otherwise to close the circuit
through the second line wire and -thus at the receiving end cause the impression to
be taken from the figure wheel as already explained.
Date : 0.13
T
1007

page_text: Improvements in Printing Telegraphs.
I, WILLIAM HENRY DAVIES Managing Director of the Exchange Telegraph
Company Limited, of 17 and 18 Cornhill in the City of London (a communication
to me from abroad by George B. Scott of Brooklyn, New York, one of the United
States of America 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:-
This invention has for its object improvements in printing telegraphs and it
applies to a printer in which the step by step rotation of the type wheels is
controlled by short electrical impulses alternately of positive and negative polarity.
These impulses pass in a coil of which the axis is vertical. An iron core passes
up through this coil and is free to vibrate within it about pivots at its lower end.
At its upper end the core carries an escapement which as the core oscillates operates
against pallets on the opposite sides of the escapement wheel. Adjustable stops.
opposite its ends limit the movement of the escapement.
At the upper end of the core immediately beneath the escapement are two pole
pieces one on either side-they are fixed upon a permanent horse shoe magnet.
The magnet is placed between two capstan headed adjusting screws passing through
attachments on the frame. These screws spring the magnet poles together and so
adjust the position of the pole pieces.
The coil above mentioned or the escapement magnet whatever it may be for
controlling the rotation of the type wheels is in the same circuit with a neutral
electro magnet which is only brought into action to effect printing upon a
prolongation of one of the short impulses employed to rotate the type wheels.
The controlling of the rotation of the type wheels, and the taking of impressions
upon a strip of paper, are effected solely by electrical currents transmitted over one
main line.
To determine however from which of the two type wheels an impression shall
be taken, a second and independent main line burdened with no other condition of
operation is employed.
The second line includes at each instrument preferably, a neutral electro magnet
which serves to shift the press pad from one side to the other under either type
wheel at the will of the transmitting operator.
This second main line is normally opened and remains so at all times during the
printing of figures, and the armature lever of the electro magnet therein is normally
held in such a position by a retracting spring, as to retain the press pad under the
letter wheel while no current is flowing over said line, but when it is desired to
print a figure instead of a letter, a current is transmitted over the second main,
line at the same time that the type wheels are being rotated to a position to print.
Thus, while the type wheels are being rotated, the press pad is shifted under the
figure wheel by the attraction of the armature of the electro magnet in the second
line, and upon a prolongation of a current on the first line, the impression of a
figure will be taken.

page_text: The transmitter consists of a rotating axis carrying a wheel which in rotating
makes and breaks the circuit through one of the line wires.
Two contact springs operate in conjunction with this wheel, they come into
action alternately and transmit positive and negative impulses alternately along
the line wiro.
The axis also carries an arm which can be arrested in the course of its rotation
by finger keys operating through the intervention of electro magnets or otherwise.
The arm can be stopped on any impulse which thus is prolonged into a current
of sufficient duration to cause the printing magnet to operate. There are two sets
of keys, one set for letters and the other for figures; they operate similarly so far
as concerns arresting the movement of the revolving arm but the keys of the latter
set operate also by means of a relay magnet or otherwise to close the circuit
through the second line wire and thus at the receiving end cause the impression
to be taken from the figure wheel as already explained.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.
Figure 1 is a front view of the escapement apparatus of a receiving instrument
arranged in accordance with my invention. Figure 2 is a side view of portions of
the said escapement apparatus.
Figure 3 is a perspective view of another part of a receiving instrument to
which my invention relates.
Figure 4 is a diagram of the transmitter.
In respect to Figures 1 and 2 B is one of the brass side-plates forming a part of
the frame of a printing telegraph instrument; r is a bracket plate having a right
angular extension s fastened to the base plate B by means of screws u. To the
lower side of the extensions, is rigidly fastened a permanent electric horse-shoe
magnet a, by a rivet or screw t. The permanent magnet rests with its inner face
next to the base plate B but is rigidly connected there with only by the rivet t.
The upper and free ends of the limbs of the horse shoe magnet a are respectively
provided with pole pieces b c. The arms of the permanent magnet are flexible and
elastic and their pole pieces are respectively adjusted by set screws fg by means of
which varying pressure may be applied and the arms of the permanent magnets
bent to a greater or less degree as may be required.
The adjusting set screws f g are respectively mounted in screw brackets de
which are also fastened by screws to the base plate B.
m is an electro magnet having an axial opening mounted upon a shelf h. This
shelf his provided with two arms extending backward therefrom over the ends of
which and parallel with the plate B is secured a plate i. The plate and the
plate h form bearings for the journal j which supports the armature / pivoted
thereon. To the upper end of the armature k escapement pallets are attached.
The amplitude of the movement of the pallets is limited by adjustable set
screws respectively mounted in brackets no which are also secured to the
base plate B.
w is the escapement wheel, it is mounted upon the type wheel
shaft and the end of the said shaft near the escapement wheel is mounted in a
bracket which is also secured to the base plate B.
In Figure 3 T T are type wheels respectively provided upon their peripheries
with letters and figures. These type wheels are subjected to a constant tendency
to rotation through a pinion N¹ and a clock motor connected therewith by a spur
wheel N*. Upon the same shaft with the type wheels is an escapement
wheel w whose step by step rotation is controlled by the escapement pallets
actuated by an electro magnet whose coils are in the circuit L with those of
magnet M for controlling the operation of the press lever.
The press lever W.is pivoted upon a shaft Z and connected to the armature A
to which is attached a tail piece and a retracting spring 71; t¹ is an adjustable stop

page_text: for limiting the retracted position of the press lever. The press lever W under the
type wheels is provided with a bracket v to which is attached an arm t* at
right angles thereto and parallel with the arm W. A spindle & having a press
roller q rigidly attached thereto is loosely journalled in the arm t* and lever W
thereby enabling the said press roller to be laterally shifted to one side or the
other immediately under either type wheel.
N is an electro magnet whose coils are included in a second main line L¹; i* is
an armature attached to an armature lever j* which is pivoted at h*. The forked
arm g* is rigidly attached to jx and carries at its pendulous or free end 7* two
prongs pressing respectively against the opposite disc faces of the press roller q*.
The lever gx is provided with an arm * which is connected by means of a
retracting spring p* to the fixed post o*. When no current is passing over the
line L' under the influence of the retracting spring p*, the lever g* holds the press
roller q* to the right or directly under the letter type wheel; on the other hand if
a current is flowing over the line L' armature i* is attracted and lever gx holds
the press roller to the left or under the figure type wheel.
Instead of the prongs of the lever g* for operating press roller q* the free end
of g* could be connected to spindle g¹ by any ordinary joint which would permit
the said arm to give the press roller a to and fro movement.
In the transmitter shown in Figure 4 C is a circuit reversing wheel whose
periphery is provided with conducting and non-conducting spaces with which two
conducting brushes a° and 6° respectively connected to the copper pole of battery Bº.
and zinc pole of battery B¹ make frictional contact. The conducting and non-
conducting spaces are of equal length and the free ends of the brushes a° 6° rest'
upon the periphery of the said wheel at a distance apart equal to one space thus
enabling a current to alternately flow from a copper and a zinc pole. The wheel C
has a metallic hub ho and a contact brush co connected with the main line L. P is
a base board carrying a circular series of electro magnets which correspond with
the characters upon each type wheel for arresting the rotating arm A° which is
rigidly connected with the circuit breaking wheel C by means of the shaft S. The
shaft S is geared with a constantly moving motor and its rotation is continuous as
long as the arm A° is not arrested by any one of the circular range of electro
magnets mo. When however the armature of an electro magnet m° is projected
into the path of A° the circuit breaking wheel C is arrested and a prolonged
positive or negative current is transmitted to line according as the spring aº or 6°.
happens to be in contact with a conducting portion of the said wheel.
F F¹ are two circular rings of conducting material insulated from each other
carrying finger keys, which respectively represent the letters of the alphabet upon
the periphery of one type wheel, and numerals and various other characters upon
the periphery of the other type wheel; is a series of anvils or stops forming
electrical contacts for the letter keys, and y is a series of anvils or stops forming
electrical contacts for the figure keys.
If the letter A on one type wheel is abreast of the figure 1 on the other type
wheel and B is abreast of figure 2 &c, it is obvious that the depression of the finger
key A should cause the arm A° to be arrested in the same position as would the
numeral key representing figure 1 and likewise that letter key B and figure key 2,
should arrest the arm A in the same position.
To accomplish this result the anvils of the letter key A and of figure key 1 are
connected together at the point 15 and thence proceed by a common wire through
one of the electro magnets m° to point 11, battery B° B¹ and point 10, to the key
frames F F by branches e° f°. In like manner the letter and figure keys are
connected in pairs to the other electro magnets mo. By depressing the letter key A
a local circuit will thus be completed through one of the electro magnets mo, and a
local circuit through the same electro magnet will also be completed by the
depression of the figure key 1 thereby causing the arm A to be arrested in the
same position whether the letter key A or the figure key 1 is depressed. In
the branch fleading from the point 10 to the frame F' is an electro magnet D;

page_text: upon the depression of a figure key therefore the armature E is attracted by the
electro magnet D and closes a second main line connected with a battery G and
the earth E. The line will obviously be closed in advance of the arresting arm A
thus upon the depression of a figure key before a cessation of the short impulses for
rotating the type wheel to any desired position for printing, a current is directed
from the line and the press roller of the receiving instrument is laterally shifted
under the figure type wheel. Whereupon after the type wheels have been set an
impression will be taken from the figure wheel. Instead of employing the electro
magnet D and local circuits to control the same the figure keys may be directly
used to close and break the main line L; and both the letter and figure keys may
be used to arrest rotary arm A° without the intervention of electro magnets m and
local circuits.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. The combination consisting of the flexible magnet a fixed at one point and
having suitable pole pieces; the adjusting screws ƒ and g and the armature k
substantially as described.
2. The combination consisting of the electro magnet m, axial armature lever k
and flexible electro magnet a with suitable pole pieces and adjustments substantially
as described.
3. The combination consisting of the electro magnet m, axial armature lever k
escapement pallets escapement wheel w and limiting stops p q substantially as
described.
4. In a printing telegraph, the combination of a printing electro magnet and an
escapement electro magnet on the same main line and also an electro magnet on
another main line which when the circuit is open allows one type wheel to print
and when closed causes the second type wheel to print substantially as described.
5. The combination substantially as described of a transmitter which directs
short electrical impulses over a main line and when arrested prolongs one of the
said impulses for the purpose of printing; and two series of arresting figure keys
the said finger keys of one series also causing the closing of a second main
circuit and thereby bringing another type wheel of the receiving instrument into
operation.
6. My improvements in printing telegraphs substantially as described.