IMPROVEMENTS IN ELECTRIC TELEGRAPHS AND IN APPARATUS CONNECTED THEREWITH
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by Julius Lent at the Office
of the Commissioners of Patents, with his Petition, on the
31st March 1868.
I, JULIUS LENT, of Berlin, in the Kingdom of Prussia, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
ELECTRIC TELEGRAPHS AND IN APPARATUS CONNECTED THEREWITH," to be as
follows:-
The most improved construction and arrangement of this improved
express telegraph consists of three keyboards to one apparatus in con-
nection with a round disc of ivory, the path of rotating spring contacts
called the "sled." The ivory disc has one group of contact points and
two groups of contact surfaces arranged in three concentric circles
which groups are equal one to another each filling up a third of a circle,
and each group of contact points or surfaces corresponds with one
keyboard. For the sake of simplicity one keyboard will for the present
be considered and described, but it must be understood that the use of
a single system is by no means excluded, but then the contact points
and surfaces must be arranged on the entire circle of the disc of the
rotating spring contact. The framework of the key mechanism consists
of two vertical frames at each end connected together at the top and

page_text: bottom by horizontal tie frames and a table or slab at the top, the two
vertical frames at each end being maintained at their proper distance
apart by eight stay bolts. To each pair of vertical frames are bolted
nine stationary shafts on which are hinged hangers carrying forty-nine
small flat bars, which are grouped in eight series containing six flat
bars with a single bar below them. To the said flat bars are fixed
tappets formed of pins projecting on both sides, which tappets are fixed
in the flat bars in certain positions, in accordance with a pre-arranged
diagram or plan representing different positions of dots. corresponding
with the different letters and marks on the keys of the keyboard. The
ends of the bars on the right-hand side are provided with insulating
shoes of wood to which thin steel wires are fastened by Screws. To the
bottom horizontal tie frames of the framework are fixed 61 rods, each
forming the axis of a wire grid composed of 12 vertical steel wires
and 4 cross pieces, the 61 wire grids being parallel with each other
when the apparatus is at rest, and each of the 8 series of flat bars pass
through 6 corresponding interspaces of the wire grids and the single
bar between one interspace. The upper tie frames of the framework
'carry 61 small shafts in 2. series alternating one above another, each
shaft supporting a lever with 2 arms entering holes in the upper
cross pieces of the corresponding wire grids, and the other arms
gearing into cyes in vertical key pins which are placed in holes in
horizontal plates at the top of the framework and encircled by spiral
springs. Each key has an incline and notch, and the incline pushes
when the pin is descending a stopping apparatus from the right to the
left side. The stopping apparatus consists of two parallel bars with
projecting pins provided with springs which push the bars from the left
to the right side when the inclined part of the key pin has completed
its descent, and when the projecting pins enter the notches return
movements of the parts are prevented. The heads of the key pins, are
not touched directly by the operator, but he presses upon the upper keys
in the keyboard which transfers the pressure to the key pins. The
keyboard mechanism contains 61 keys on which are letters, numbers,
and marks, and by the pressure. upon a key the corresponding key pin
and one arm of the two-armed lever are depressed, and the other arm
moving the wire grid by its upper cross piece and turning it a little on
its axis. The steel wires of the grid act on the tappets in the small
flat bars so as to push the corresponding flat bars from the left to the
right side, it being understood that the tappets agree with the letters;

page_text: numbers, and marks on the keys of the board. When a key has
been pressed down it and all the other moved parts remain
stationary by the effect of the stopping apparatus until by means
which will be hereafter described a releasing rod has been pulled
down and at the same time one arm of the two armed lever has been
pushed from the left to the right hand side, by which means the key
pin is released and all the parts return to their original positions.
The working of the releasing rod is regulated by the following con-
trivance One arm of a two-armed lever gears into the groove of a
cam fixed to the main shaft carrying the sled, the other arm of the
lever being jointed to the releasing rod. The cam groove is so formed
that at one part of the rotation of the rotating sled a short up-and-
down movement is given to the lever, but while the sled passes the
contact points the lever is arrested and no letter of the keyboard can
be given. As soon as the rotating spring contact points the cam groove
quickly moves the lever for enabling the depressed key and the other
parts of the mechanism to return to their original positions, and as
the lever is now free any of the keys can be again depressed. By the
depression of a key, and the consequent motion of the before described
parts are effected, the contacts which are necessary for producing a Morse
letter under the rotating sled. The steel wires which are screwed in the
insulating heads of the flat bars are curved in a hooked manner and enter
slits in the contact springs, which springs are the ends of 49 insulated
and conducting wires fixed by screws to a vertical board. The other
ends of these insulated wires are the contact points and contact surfaces
which are arranged in concentric circles, and are touched by the springs
of the rotating sled during its revolution. By the movement of the flat
bars the contact springs are in or out of contact with the conducting
studs of the battery, and thereby establish or break the conducting
connection of the lines with the batteries. The upper 24 contact springs,
which are arranged in 4 series of 6, are when not acted upon out of
contact with their corresponding conducting studs, and the circuits are
only conducting when the spring studs are joined by the motion of the
flat bars. The other 25 contact springs arranged in 4 series of 6, and
a single one at the bottom, are when not acted upon in contact with their
corresponding conducting studs, and this contact is broken by the motion
of the flat bars. The upper 12 contact springs can communicate with
the positive pole of a battery, but the other 37 contact springs com-
municate only with the negative pole of a battery. The upper part

page_text: of the main shaft, to which the rotating sled is fixed, is insulated from
its lower part and also from the releasing rod, and the clockwork or
motion power which turns the sled, and the said upper part of the shaft
is in continual spring contact with the line, and the contact faces of the
sled springs are in conducting junction with the upper conducting part
of the shaft. The contact points are in the exterior concentric circle
of the ivory disc, and the sled is turned around by mechanical power
with uniform velocity from left to right, and its exterior contact spring
rides on the ivory disc and touches one after the other at equal intervals
the 24 points which project a little above the surface of the disc. The
contact points communicate with the upper 24 contact springs, of which
12 as before mentioned are in connexion with the positive pole of a
battery, and the other 12 with the negative pole of another battery. The
I contact of the odd numbers up to 23 can only communicate with the
positive pole, and the contact of the even numbers up to 24 only with
the negative pole of a battery.
The construction of the rotating sled and of the part of the apparatus
in which the conducting wires are joined will now be explained. The
bottom of the shaft of the rotating sled works in a footstep, and the
upper part in a collar. The upper end of the shaft is insulated by an
ivory piece from the under part and also from the mechanism in con-
junction with it. The sled is fixed by a fore lock and a screw on
the shaft, it has 3 rotating contact springs, the 2 interior of which run
on 2 circles of contact surfaces. The path of the third is the scries of
the contact points; the springs are so curved and shaped that they
slide continually on the surface of the ivory disc and touch with their
edges of aluminiun bronze the contact surfaces and points which
project a little from the surface of the disc. The contact points and
surfaces of platina are in circular recesses for the purpose of preventing
the contact springs from chipping or breaking the contact points and
surfaces. The exterior spring is provided with 2 screws, one intended
to regulate the tension of the spring, the screw abutting against an
insulated ivory plate; when the contact spring is going down the other
screw falls upon a conducting platinum plate insulated from the other
parts of the rotating mechanism by the before-mentioned ivory plate
to which a conducting wire is screwed. The sinking of the contact
spring is effected by the removal of a slide in the ivory disc, the operator
causing the spring to enter the open groove. The other end of the

page_text: from the main shaft, and from the sled frame the conducting pin is
connected by a wire from one earth plate, and it can be easily understood
in what manner the contact surfaces and points are in conducting
connection by well insulated wires with the contact springs which
communicate with the conducting studs of the battery. The apparatus
is fixed to standards, and a cast-iron plate through which passes the
main shaft receives its revolving motion from some machine by means
of gearing.
The electric current of a sending and a receiving station is the
following-On the transmitting station from the earth plate the
current passes through the one or the other battery to the conducting
studs through the contact springs, through the conducting wires, through
the contact points and surfaces, through the rotating contact springs,
through the sled frame to the main shaft, through a spring contact, and
through a wire, and through the writing apparatus to the line, then
through the writing apparatus of the receiving station, through the
spring contact to the shaft, through the sled frame, through the contact
screw of the downlet contact spring, through the platinum plate to the
insulated wire, and through the conducting pin and wire to the carth
plate. The express telegraph being used as before described by an
operator working on one keyboard the contact 49 is continually in
conducting connection with the battery, the operator must in this case
when receiving a despatch press a white key provided for the purpose,
drawn out the small slide of the disc, and put the outer rotating contact
spring in the breach left open by the removal of the slide. The joining
of the writing apparatus is arranged so that the writing instrument at
the sending and receiving station records not only the despatch going
off but its arrival; this effects a control for the right recording on the
sending station, and makes it possible for the operator to signalize when
the despatch is incorrect. For this purpose the operator turns the sled
a little by hand, by which a constant current instantly passes into the
wire paralyzing all opposite currents coming from the sending station.
The operator on the sending station having remarked the effect stops
working and prepares by drawing out the slide, and at the same time
depressing a white key for receiving the required question and explant-
tion. The express telegraph can be used as before described, or two or
more keyboards may be united to one apparatus worked by one operator,

page_text: or the arrangement of the keyboards belonging to one rotating contact
mechanism can be made, so that each keyboard can be worked by one
operator. The operator working with 1, 2, or 3 keyboards takes from
each keyboard the letters of the despatch one after the other, and the
arresting contrivances of the keyboards work in equal times one after
the other. For making use of the arrangement with three keyboards
and three operators the three keyboards must be separated; in this case
it is necessary to give the three keyboards with arresting contrivances
a radial position to the main shaft which carries the sled, the pro-
portional and alternating activity of the arresting contrivance being
retained. Let us suppose that at the receiving station there is a
polarized ink writer, and for arresting the paper strip an electro-magnet
of which the armature is not attracted by a quick succession of
instantaneous currents, but only as soon as a constant negative current
passes into the line, in which case there will be recorded alternately on
the strip the letters of the 3 despatches. The reading of these letters
would be difficult without some contrivance, and for this reason a new
combination of writing apparatus has been established, and by this
apparatus the 3 despatches transmitted at the same time are recorded
are recorded in the usual Morse letters on 3 separate paper strips.
The apparatus contains 3 polarized ink writers, and 4 horizontal
polarized electro-magnets are in the circuit of the line so that
all make by the same currents the same motions, and the lever of
one polarized electro-magnet serves as a circuit changer. In the state
of rest which is effected by a negative current, the lever changes
the circuit so that the current passes not only the coils of the 4
polarized electro-magnets, but the coils of a vertical electro-magnet
of which the armature is attracted only by constant negative currents,
when the levers of the 4 electro-magnets are in a state of rest and
a constant negative current passes it runs through the coils of the
horizontal polarized electro-magnets without any effect, but it passes
through the coils of the vertical electro-magnet and produces a motion of
the armature.
This has two different effects, first are attracted by the vertical
electro-magnet 3 levers of the horizontal magnets, the other arms of
which are pressed against the 3 reels of paper strips and arrests
them; and, secondly, an escapement lever is put in motion. To the
axis of an escapement wheel are fastened two discs cach with a groove

page_text: on the periphery, one disc holds with its groove the. ends of 3 writing
levers lengthened and curved for this purpose, and the second disc holds
with its groove the ends of the levers which arrest the paper strips. The
2 discs are so notched that one writing lever and one arresting lever can
leave the grooves, whilst the two other writing and arresting levers are
arrested in their motion.
The employment of the heretofore described recording apparatus is
not to be regarded as indispensable for making use of the transmitting
instrument, and it is naturally permitted to separate the letters of
the despatches at the same time transmitted, and to compose the letters
to the single despatches by the help of the operators of the receiving
station with or without application of mechanical contrivance.