Improvements in or relating to Multiple Telegraphic Apparatus.
Year: 1894

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to Multiple Telegraphic Apparatus.
J, ALFRED Piedfort, Professor of Science, Pensionnat St. Pierre, Calais,
France, 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 :-
1
This invention relates to a system of telegraphy enabling over 100 messages to
be sent over one and the same wire at one and the same time, and in the same
direction or in opposite directions, in such manner that each message shall reach its
destination without delay or interruption from any of the others, and shall in no
way be confounded or mingled therewith.
To this end each ordinary telegraph key or instrument is arranged so as to launch
over the line wire, at each manipulation of the handle, an intermittent current
corresponding to a determinate number of vibrations per minute but differing for
each operator. Thus, though all the operators, send their messages simultaneously
on the same wire, and these are mixed up together, so to say, they are separately
sifted out into the exact number of the messages sent by the operators, so soon as
they arrive at the receiving instruments of the telegraph system; and they
distribute themselves by a self-acting selection and register themselves auto-
matically on the several optic receivers for which they were destined.
The principle of my system of multiple telegraphy is based upon the laws of
resonance discovered by Helmholtz.
The figures on the accompanying drawing illustrate apparatus for carrying into
execution this system of multiple telegraphy ;-
Figs. 1 and show in side elevation and in plan as seen from above, my improved
mechanical transmitter.
Figure 2 shows a modification of the arrangement of the transforming
cylinder.
Figs. 3 and 4 show in plan and side elevation an arrangement of my optical
receiver, wherein a lens is fixed upon the vibrating diaphragm and moves between
two fringed or striped screens.
Figure 4 is a sectional elevation of the optical receiver in which the lens is
fixed while the vibrating diaphragm is provided with a fringed screen.
Fig. 4 shows the two fringed screens placed opposite each other.
Fig. 5 is a side elevation (partly in section) of an optical receiver, placed in a
camera, working by the direct passage of the luminous rays, previously collected
together in conduits, through openings in a screen, fixed upon the vibrating
diaphragm, behind which a radioscope is arranged.
Figure 6 is a diagram showing the connection of a series of minor stations with a
chief telegraph office capable of transmitting up to 20 messages simultaneously over
the same line-wire x.
Throughout the drawings like reference letters indicate like parts.
The mechanical transmitter, illustrated in Figures 1 and 2, consists of a table a,
upon which is screwed a base plate a rigidly supporting the parts a³ a³ of the
framework of a clock-movement actuated by a weight Q, which sets the traus-
forming cylinder R in continuous rotation. This transformer consists of a metal
cylinder or drum on the periphery of which are mounted rings rl of copper, or
other metal which is a good conductor of electricity, in which are inlaid, at equal
intervals small blocks of ivory or other material which is a non-conductor of
electricity. The cylinder is provided with as many metal rings as there are

page_text: -
ininor telegraphic stations placed in communication with the mechanical transmitter
at the chief office.
In the example here shown the transmitter is supposed to be provided with
10 metal rings r, corresponding to 10 minor stations; and it allows any number of
messages to be despatched and received simultaneously, up to 20.
and
Each metal ring is provided with a different number of ivory blocks
with a separate brush r. Each of these brushes is connected by a special. wire to
the joint-pivot of a key M which when depressed upon a contact m is connected
with an electric battery P, so as to transmit, over the telegraph line, an electric
current which is rendered intermittent or undulatory by reason of its passing
through one of the metal rings 1, in consequence of the interruptions in the electric
current resulting from the passage of the non-conducting blocks beneath the
.brushes r.
with a
The frame a of the clock-work movement is connected by the terminal
battery P. All the brushes are carried by a pair of small standards b and by a
hinged bearer or° frame b. The insulation of the brushes r from the metallic
portions of the clock-work movement may be effected by an ebonite plate b².
The shaft of the transforming cylinder R is connected with the shaft d of the
clockwork movement by means of the two discs and joint d'. The rotation of the
shaft d is effected by the descent of the weight Q acting upon a wheel-train E of
the Hughes type. The endless chain o of this winding train passes under a pulley
or wheel e¹ upon the spindle of which is suspended a small weight q, and thence
over the pulleys e over the chain wheel 2, round the suspended wheel I and over
one of the chain wheels (c) of the winding train E, passing thence to the pulley e',-
as above described. The wheel I is provided with a shell or pulley-frame from
which the weight Q is hung. The chain wheel 2 actuated by the descent of the
weight sets in motion the train of toothed wheels and pinions 10, 9, 8, 7, 6, 5, 4, 3,
of the clockwork movement and thereby the shafts d and h on which respectively
are keyed the transforming drum R and the Hughes regulator H.
As the weight Q descends, q ascends, and the fork q¹ may then encounter a lever
which acting upon a sounder or alarm apparatus, warns the operator that the
weight. Qrequires to be wound up again.
For this purpose the treadle p, pivotted on the pin p, is operated, whereby the
rod p' is drawn down, which rod, at its upper end, is hooked on a short length of
chain o which passes over the chain-wheel c, and is hooked on to the end of a
coiled spring p. As the chain wheel c over which the chain o¹ passes, carries a
pawl, engaging with the teeth of a ratchet wheel, the result is that as often as
the chain o¹ is drawn down by the depression of the treadle p the ratchet wheel is
rotated, and as a second pawl c² also engages with the teeth of that wheel, this pawl
causes a step-by-step rotation of the chain wheel over which the chain o passes, so
that the weight Q is thus gradually drawn up. This winding apparatus E is well
known and I simply make use of it without any claim for novelty.
The rotary movement of the transforming drum R is regulated by the Hughes
regulator H connected with the shaft h of the clockwork movement. This
regulator H is also thoroughly well known; I use it similarly without laying
claim to it.
In the arrangement of the transforming drum illustrated in Fig. 2ª the drum
carrying the rings is divided longitudinally into two parts between which is
interposed an ebonite disc or ring or any other substance which is a non-
conductor of electricity. In the example here shown upon each of the two sections
of the drum R are secured two rings, each fitted with a different number of
insulating blocks; each of these two rings r¹p is in contact with a separate
brush r, connected with a battery P. The rings of one of these sections (into
which the cylinder R is divided) are thus connected with the positive pole of the
battery P by the brushes r, while the corresponding rings * of the other section
are connected with the negative pole of the same battery by the other series of
brushes. The rings r correspond contrariwise in each section, so that when a

page_text: conducting part of the ring r¹ of one of the sections passes the brush r, the brush,
which rubs on the corresponding ring of the other section only touches the small
insulating ring of the ring in such manner that the circuit of the battery P
appears to be closed in passing from one brush to the other through the
rings. The circuit only closes for the battery when the transforming
drum R is stationary, but experience has shown that it is not closed when the
drum R rotates at its regular normal speed. The group of the two brushes
is connected to the single key M which is common to both and corresponds
thereto.
These sections of the drum R are put into communication with a battery by the
two brushes y. -
The optical receiver shown in Figs. 3, 4, 44 and 4 is formed of a rectangular
chamber forming a camera N into which light from any source, natural or artificial,
can only penetrate by the orifice z. In front of this orifice, and inside the camera N,
is arranged a plate w¹ fixed on a carriage w which can be moved forwards or.
backwards by means of a milled head to which turns a micrometer screw or by
other equivalent means. In this plate w¹ and just in front of the orifice is placed
a fringed screen n³ like that shown in Fig. 4. In front of the carriage w is
arranged a vibrating receiving device, formed of a magnet ; on the poles of which
are mounted the electro magnet coils i. A vibrating plate n is fixed as regards one
of the poles of the electro magnet ; while it is free to oscillate as regards the other
pole; at this place it is provided with a lens' which is moved in exact unison with
the fringed screen n' attached to the plate w¹.
The light which enters the camera N through the orifice and traverses the
openings or transparent parts of the screen n falls upon the lens which projects
the rays, after they have passed through a tube secured to a fixed screen upon
a movable frame or screen u (Figs. 3, 4 and 48) which may slide along a partition u*
separating the camera into two compartments N and N'. This, screen is
perforated with a number of equidistant and parallel orifices whereof the size is
so calculated that the opaque parts of the screen n' may be exactly reflected in
those orifices after the luminous rays have traversed the lens v, when it is
stationary.
In order to be enabled to place the orifices of the screen u exactly in front of the
solid parts of the screen n', the plate which carries the latter may slide from side
to side in the partition u*; as this plate is constantly drawn in one direction by
coiled springs attached to it at u', it suffices to turn the milled head us and micro-
meter screw u, to push the said plate and bring the orifices correctly into position
in front of the image of the opaque hands of the screen ¹.
Behind the partition u and in front of the screen u is placed a double convex
lens v in front of which and a small distance away is placed a cylindrical lens t in a
vertical rectangular frame.
A radioscope formed of a hollow shell k blown in glass is arranged behind the
lens t in the compartment N' of the camera. This glass shell k is provided with
gudgeons which allow it to rotate around its longitudinal axis when operated by
the milled head in such manner that the thin metal strip placed inside the glass
shell k offers itself vertically in front of the luminous rays which traverse the
screen n. The strip is suspended by a yoke so as to be capable of oscillating
freely without appreciable friction. A considerable metallic surface is placed
behind the metal strip / at its lower part. This metallic surface is connected to
one of the terminals of a relay while the yoke is connected to the other terminal
of the same relay.
When the vibrating plate n is stationary the light which penetrates into the
camera N by the orifice and which passes through the orifices or transparent
parts of the striped or fringed screen n¹ and are reflected by the lens v' upon the
opaque parts of the screen u, is intercepted by those opaque parts and the light
being unable to penetrate into the dark chamber N' has no effect upon the metal
strip of the radioscope which therefore remains motionless.

page_text: As soon however as a current passes through the electro-magnet
and sets the
plate or diaphragm n in vibration the lens v is displaced and the luminous rays
which pass through the screen n' and fall upon the lens v' traverse the orifices
formed in the screen 1 and are reflected upon the lenses v and t so as to fall upon
and displace the metal strip of the radioscope k in such manner as to set in action
the relay in connection with the wires k¹ k³.
In Fig. 4 I have supposed the lens to be placed upon the movable carriage w
and the fringed or striped screen n¹ secured to the vibrating plate or diaphragm n;
when the plate n does not vibrate its transparent parts are reflected upon the
opaque parts of the screen u but as soon as the diaphragm begins to vibrate
the screen n is displaced and allows the light to pass through the orifices of the
screen u so that it strikes upon the metal strip of the radioscope k so as to set it
in motion and cause the relay to act.
In the optical receiver shown in Fig. 5 the luminous rays which fall upon the
inclined mirror D are directed into the openings or channels formed between a
series of equidistant parallel plates arranged in a rectangular box s. The position
of the plates contained in that box, with relation to the transparent fringes (or
stripes) of the screen n¹ secured to the vibrating plate or diaphragm n may be
regulated by manipulating the milled head f, which raises or lowers the box 8, and
by rotating the screw g' which engages with the helicoidal toothed wheel g so as to
impart a rotary or angular movement to the box s. The milled head euables
the core of the electro-magnetic coil i to be raised or lowered so as to regulate its
action upon the vibrating plate or diaphragm n.
When the latter is vibrating the screen n' permits the light, passing through the
channels in the box s, to enter the dark chamber N and the luminous rays falling
upon the metal strip 1 of the radioscope k set in action a relay connected up with
the terminals 20 and 30.
The superimposed plates arranged in the box may be replaced by tubes
arranged in equidistant parallel rows. In this case, the apertures of the screen n¹
may consist of a series of holes similarly placed in equidistant parallel rows to
correspond.
In the general diagram of my system of multiple telegraphy shown in Fig. 6,
the chief office or station A is provided with a transforming drum R such as
described and shown in Figs. 1 and 2, and supposed to comprise ten rings each
provided with a different number of non-conducting blocks. Corresponding to
each one of these rings ¹ there is a similar ring on the transforming drum R of
one or another of the minor stations B° B'... B³.
All the transforming drums R of the stations A, Bº, B'. . . B³ rotate at the
same speed, whence it follows that the particular intermittent current created by
the rotation of each of the rings of the chief office A, or of the like corre-
sponding ring of the minor stations Bº B¹ B etc., is distinctly and accurately
produced in each case, those for each ring being all exactly the same while differing
from those produced by any or all of the other rings; and consequently it is
possible both to send and to receive messages simultaneously between the central
station A and the subordinate stations B° B¹... B. To each ring r¹ corresponds
a key M, a battery P, and an optical receiver N provided with a vibrating plate or
diaphragm, whereof the number of vibrations per second exactly equals the number
of interruptions in the electric current produced in a given time by the rotation of
the ring which corresponds to it.
The various brushes of the same transforming drum R may be connected with
a single battery, but in this case a resistance coil is placed between each brush r
and the battery P.
At the several points where the batteries P are connected up with the primary
circuit by an induction coil L which has its primary circuit also connected with
the transforming drum R by the terminal y. The secondary circuit of the
induction coil Igoes, on the one hand, to the main line wire ; on the other hand
to one or more optical receivers N according to the number of rings r¹ of the

page_text: station under consideration. The line-wire x on leaving the secondary circuit of.
the induction coil L, conducts the current through the coils of the electro-
magnet of the receiver N, and then is continued to earth. The resistance of each
station B° B' &c. is greater than that of the line-wire a from the chief station A
to the station B' which is the farthest removed therefrom. On the other hand the
insulated stations B° B' &c. have all the same resistance from the chief station A
to earth.
The transmission of telegraphic messages takes place as follows, all the trans-
formers R being driven at the same speed each operator depresses the key M for
a shorter or longer period, according as he desires to make points or dashes; he
thus transinits over the line-wire a a current whereof the interruptions are
proportional to the number of non-conducting blocks in the ring which is in
communication with that key. This intermittent current, of greater or less
duration is transmitted to the receiving station which contains the vibrating plate
or diaphragm whereof the number of vibrations is equal to the number of..
interruptions in the current produced by the rotation of the above-mentioned
ring; which station alone can take it in; it sets that diaphragm n in vibration
and thus allows the light to traverse the screen attached to it and fall upon the
metal strip of the radioscope k whereby it closes the circuit of the relay which is
in connection with the wires k¹ and k² of the radioscope.
The ten manipulators M thus send simultaneously messages over the same line-
wire, without their becoming mixed or in any way confused together, for these
messages traverse the line-wire with undulations differing the one from the other
because they severally correspond in number to the different number of the
interruption-blocks inlaid in the several rings r.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is ;-
1. A system of multiple telegraphy comprising a transforming drum fitted with
one or more rings of conducting and non-conducting surfaces caused to rotate with
a uniform and regular movement and transforming the continuous electric current
from any source of electricity into one or more intermittent currents which at each
operation of the key are transmitted to the particular receiver the vibration of
whose plate or diaphragm in a given time exactly corresponds to the musical pitch
of the distinct and separate intermittent current transmitted through the line-wire
by each several ring of the transforming devices in combination with a receiver
provided with a vibrating plate or diaphragm producing luminous eclipses
substantially as described.
2. An improved apparatus for producing intermittent currents comprising a
transforming drum such as R upon which are mounted one or more metallic
rings inlaid at regular intervals with small insulating blocks each such metallic
ring being fitted with a different number of insulating blocks the said transforming
drum communicating by means of a terminal y with a source of electricity and
being actuated by a uniform and regular movement of rotation imparted to it by
means of a clockwork movement driven by a weight wound up by a Hughes
winding apparatus E regulated by a Hughes regulator also of brushes r connected
each with a separate key M the said brushes rubbing separately on the individual
rings and thereby transmitting through the line-wire a distinct and separate
undulatory current corresponding to the number of interruptions in the current
caused by the passage of the insulating blocks beneath the brushes of each
metallic ring when the key corresponding to each brush ŕ is operated substantially
as described and shown in Figures 1 and 2 of the accompanying drawings.
3. In a transformer such as R which is connected by brushes y with a source of
electricity and rotated at a regular and uniform speed the combination of two series
of identical rings placed on two insulated sections of the transforming
cylinder R the said rings being each fitted severally with a different number of

page_text: i
insulating blocks on which bear respectively two series of brushes the one
series of brushes being connected with the positive pole of a battery while the
other series of brushes is connected with its negative pole. when the respective
keys M corresponding to each pair of brushes rubbing on each pair of rings r
upon which the insulating blocks are arranged contrary to one another are operated
for the purpose of obtaining more rapid vibrations of the current on long telegraphic
lines substantially as described and shown in Figure 24 of the accompanying
drawings.
4. A luminous eclipse receiver comprising a camera or dark chamber divided.
into two compartments in one of which is placed an electro-magnet i provided with
a vibrating plate or diaphragm and in the other a radiometric metal strip the.
said vibrating diaphragm n carrying either a lens v or a fringed or striped screen,
such as n¹ arranged opposite to an orifice z formed in the camera in such manner
that the light natural or artificial entering by such orifice and traversing the
fringed or striped screen n¹ may be thrown by the lens upon another and larger
striped or fringed screen such as u behind which are placed lenses vt the said
screen u preventing the access of the light into. the second compartment of the
camera or dark chamber so as to prevent the light falling upon the radiometric
strip except and until the diaphragm n is set in vibration and in proportion to the
amplitude and duration of its vibrations substantially as described and shown in
Figures 3 4 44 and 4B of the accompanying drawings.
5. A luminous eclipse receiver comprising a dark chamber or camera wherein is
placed an electro-magnet i fitted with a vibrating plate or diaphragm n carrying a
striped or perforated screen such as n' in front of which is placed a box s adjustable
in position wherein are arranged equidistant parallel plates or tubes which conduct
the luminous rays falling upon a mirror D in front of the fringed or perforated
screen n the openings formed in which screen n' are arranged in such manner as
to intercept the passage of light into the dark chamber N when the diaphragm n
is not in vibration and to allow of its entrance whenever the diaphragm n is in
vibration proportionally to the amplitude and duration of its vibrations so that the
light may act upon the radiometric strip / connected with the electric circuit of an
ordinary relay or of a recording instrument of any known kind substantially as
described and shown in Figure 5 of the accompanying drawings.
Dated this 5th day of November 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.