Receiving Apparatus for High-speed Telegraphy.
Year: 1899

page_text: Date of Application, 9th Oct., 1899
Complete Specification Left, 9th July, 1900-Accepted, 6th Oct., 1900
Date of Application, EN OUL, TO
Complete Specification Left, 9th July, 1900-Accepted, 6th Oct., 1900
PROVISIONAL SPECIFICATION.
Receiving Apparatus for High-speed Telegraphy.
We, SIEMENS BROTILERS & Co. LIMITED, of 12, Queen Anne's Gate, West-
minster, S.W., Electrical Engineers, do hereby declare the nature of this inven-
tion (as communicated to us from abroad by Siemens & Halske Aktien Gessell-
schaft, of Markgrafenstrasse 94, Berlin, S.W., Electrical Engineers), to be as
follows:-
This invention relates to a receiving apparatus for automatic high speed
telegraphy wherein, for facilitating rapid working the movement of mechanical
devices is as much as possible obviated, and in particular the mechanical print-
ing of letters or other symbols is done away with.
For the production of the various symbols electric currents of varying intensity
are employed which currents act either directly or through the medium of coils
electromagnets and mirrors upon a cathode ray or a ray of light so as to deflect
it to varying degrees, the said ray being employed according as it is deflected
to a different degree to photograph different letters &c. consecutively side by side
upon successive points of a continuously travelling sensitised paper band, which
is then treated in the known manner for fixing the letters.
We will describe the invention with reference to the accompanying dia-
of carry-
grammatic drawing which shews by way of example two different ways
ing it into effect. Referring to Fig.. 1, a is a lamp from which a ray of light is
projected through the system of lenses bc to a mirror d. This mirror is pivoted
to a support e and is subject to the influence of a telephone membrane f with
which it is connected by a suitable device. The membrane is actuated in the
known manner by an electromagnet g.
The coil of the electromagnet g is traversed by the rapid telegraphy currents
and constitutes together with the telephone membrane and the mirror d the
actual telegraph receiving instrument.
The angle to which the mirror d is deflected from its zero position is dependent
upon the intensity of the telegraphing currents. According to the extent of
the deflections of the mirror, the impinging ray of light is reflected on to one
or other of the mirrors hh &c. and from these it is again reflected on to one
of the mirrors i &c. which are so arranged that the ray of light is reflected
from any one of them to one and the same fixed point & past which a band of
sensitised paper is made to travel continuously. On the mirrors hh &c. are
marked letters or other telegraphic symbols so that the image of these is reflected
on to the mirrors ii &c. and thence to the point on the paper band on which
it is then fixed in a visible manner by any known photographic process. The
number of the mirrors corresponds to the numbers of letters &c. employed in
signalling.
A suitable transmitting instrument for telegraphing by means of currents of
varying intensity, is shewn at Fig. 2 in longitudinal section and at Fig. 2* in
plan. It consists of a set of levers m corresponding in number to that of the

page_text: letters &c. to be transmitted, all mounted side by side on the same axis, and
carrying at one end pins which slide through corresponding holes in a table o
over which travels a paper band that has been previously perforated in the
known manner according to the message to be transmitted.
Near the other end of each lever is mounted a contact piece j, these contact pieces
being connected together in series by resistances of equal value, the end resistance
being connected to earth. These contact pieces carry contact springs with
which the end of the corresponding lever comes into momentary contact on
moving downward. If on the paper band travelling over the table, a perforation
passes over the pin n of one of the levers m the lever, being thus momentarily
free to be forced up by its spring, its tail is moved downward so as to make
contact with the spring 9 and thus close the circuit of the battery which is passed
through the axis of the lever m, the current being of greater or less strength
according to the greater or smaller number of resistances through which it has
to pass before going to earth. Thus currents of different strength will be
transmitted through the conductors to the receiver g. The separate current
impulses thus transmitted are only of very short duration and the resulting
deflection of the mirror will consequently only be momentary, so that only at
the moment of the reversal of the motion of the ray of light on the mirror carry-
ing the intended letter, can a clear photographic image thereof be obtained, the
passage of the ray over the other mirrors being much too rapid to produce a photo-
graphic impression.
In the same way that a light ray is employed in the manner above described
for projecting the image of a letter &c. on to a sensitized band of paper, a cathode
ray can also be employed the deflections of which are effected under the direct
influence of the electromagnet whose coil is traversed by signalling currents of
varying strength. An arrangement for this purpose is shewn at Fig. 3 of the
drawings. is a Wheatstone transmitter for automatic rapid telegraphy. The
current passing through this apparatus is led through conductor to the receiver
where it passes through the coil of electromagnet 2. In front of this electro-
magnet is situated the cathode tube v, excited in any suitable known manner.
Of the cathode rays emitted from the cathode wa group passes through a
hole in the metal disc and falls on the fluorescent screen y where it will be
visible as a spot of light. The zero position of the cathode ray is caused by
the action of the adjusting magnet ul to fall upon the lower part of the fluorescent
screen in the position h, and it is deflected by to the several points h¹ h¹ &c.
Each of these deflections indicates a letter &c. The points of light are projected
through a lens upon a mirror 2 &c. and from these they are reflected through
a hole in a diaphragm on to the travelling sensitised band. On the mirrors are
marked letters of oqaque material the images of which are fixed on the photo-
graphic paper, by instantaneous photography as the duration of each current im-
pulse is exceedingly short. The projection of the different points of light upon the
single point where the letters &c. are to be photographed can be effected by other
known optical means such for instance by prisms or separate lenses of fluorescent
letters may be provided at the points 2 which become luminous under the
cathode rays, and are projected on to the photographic paper.
If instead of acting on the cathode rays by a single electromagnet u, two or
more such, arranged at an angle to each other and acted upon by
different telegraphing currents each of which can be varied at the sending station
both as to intensity and direction, combined magnetic fields are produced which
effect the deflection of the cathode rays in several directions.
In this way the cathode ray can be deflected into different positions surround-
ing the zero position and in each of these positions they can project a different
letter to the uncovered spot of the travelling band of photographic paper. This
last described arrangement can also be employed when using a ray of light as
first described there being provided in place of a single receiving coil two or
more such, through which currents of different direction or different strength

page_text: are passed, and which act conjointly upon the mirror d so that the ray of light
is deflected in different directions.
This might for example be effected if in the arrangement at Fig. 1 there were
provided two electromagnets each being excited by a separate current and
arranged to act in such manner that the one causes the mirror to be deflected
in a plane at right angles to that in which it is deflected by the other.
With reference to the arrangement shown in Fig. 1 special means may be
provided in combination with the receiving coil which will prevent the ray of
light, when deflected from passing over several of the signs in a row before
arriving at the letter &c. which is intended to be projected, so that the ray of
light will be projected exclusively on to the letter corresponding to the strength
of current transmitted.
Hated thi. 04.
Ontahan 1800
Receiving Apparatus for High-speed Telegraphy.
We, SIEMENS BROTHERS & Co. LIMITED, of 12, Queen Anne's Gate, West-
minster, S.W., Electrical Engineers, do hereby declare the nature of this inven-
tion (as communicated to us from abroad by Siemens & Halske Aktien Gessell-
schaft, of Markgrafenstrasse 94, Berlin, S.W., Electrical Engineers), and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to a receiving apparatus for automatic high speed
telegraphy wherein for facilitating rapid working the movement. of mechanical
devices is as much as possible obviated, and in particular the mechanical print-
ing of letters or other symbols is done away with.
For high speed telegraphing the application of a ray of light deflected by
the telegraph current and indicating by the amount or direction of its deflection,
on a travelling strip of photographic paper Morse signals or a zig-zag line
translatable into Morse signals, is known.
According to the present invention a ray of light is employed for producing
photographic impressions of letterpress symbols, which ray is deflected to a vary-
ing extent or at varying intervals by the telegraph current in consequence of
the varying lapse of time between the separate electrical impulses. In this
manner it is caused to impinge successively on letterpress symbols suitably
arranged in the apparatus and to project their image to the same point past which
a strip of photographic paper travels.
In the diagrammatic drawing accompanying our Provisional Specification is
shown a form of this invention in which telegraph currents of varying intensity
deflect a ray of light, through the intermediary of coils or electromagnets and
mirrors, through a varying angle. These different degrees of deflection are
utilised by causing the ray to impinge upon different letter-press symbols and to
project their images to a point where they are photographically registered on a
travelling strip.
Referring to Fig. 1. a is a lamp from which a ray of light is projected through
the system of lenses bc to the mirror d. This mirror is pivotted to a support e
and subject to the influence of a telephone membrane f with which it is
connected by a suitable device. The membrane is actuated in the known manner
by an electromagnet g.
The coil of the electromagnet' g is traversed by the rapid telegraph currents