IMPROVEMENTS IN PRINTING TELEGRAPHS AND IN THE CODES OF SIGNALS EMPLOYED THEREWITH
Year: 1874

page_text: •
PROVISIONAL SPECIFICATION left by John Henry Johnson at the
Office of the Commissioners of Patents, with his Petition, on the
5th September 1874.-A communication from abroad by Louis
Victor Mimault, of Paris, in the Republic of France.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN PRINTING TELEGRAPHS AND IN THE CODES OF
SIGNALS EMPLOYED THEREWITH," a communication to me from abroad by
Louis Victor.Mimault, of Paris, in the Republic of France, to be as
follows:-
This Invention relates partly to the system of printing telegraph, for
which Letters Patent were granted to me on behalf of the said Louis
Victor Mimault, March 10th 1874, No. 870, but is also partly appli-
cable to other descriptions of printing.telegraphs.
One part of the said former Invention consisted in the employment
for the formation of letters, figures, or signs of elementary signals,
obtained by the aid of simultaneous or successive emissions of a current,
each having, according to its relative position or the order of its

page_text: emission, the numerical value of one of the first five numbers or terms
of geometrical progression. Now according to the present Invention it
is proposed to employ any suitable number other than five, as described
in the Provisional Specification of the said former Invention of the first
terms of geometrical progression, and any required number of wires.
When six terms, 1, 2, 4, 8, 16, and 32, and six line wires for example,
are employed, the multiplier used with the apparatus described in the
said former Provisional Specification may be dispensed with.
In the case of apparatus in which a single line wire only is employed,
the letters, figures, or signs are represented by elementary signals,
obtained by the aid of any suitable number of successive emissions of a
current, each having assigned to it, according to the order of its emission,
the numerical value of one of the first numbers or terms of geome-
trical progression, the first 6 numbers or terms of which admit of
obtaining 63 different signs. The codes or alphabets employed, according
to this Invention, are formed of parallel elementary strokes, dots, or
signals, arranged on one, two, or more longitudinal or transverse parallel
lines in such a manner as to obtain, according to the greater or less
number of these lines, signals presenting forms which approximate
more or less to the shape of the letters of the alphabet, or of the figures
or signs used in telegraphy. The arrangement in two parallel lines
of the elementary strokes, dots, or signals, which print each sign is par-
ticularly suitable as it has the advantage of contributing to the rapidity
of the transmission, whilst at the same time it admits of the dimen-
sions of the strip or riband on which the messages are printed being
reduced; the forms and arrangements which may be selected for repre-
senting the letters of the alphabet render the same moreover sufficiently
legible.
Another part of this Invention relates to printing telegraphs in which
a single wire is employed, but is also partly applicable to other descrip-
tions of printing telegraphs, and consists in arranging the apparatus in
„such a manner as to obtain any desired number of transmissions simul-
taneously in the same direction, either with or without synchronism
between the transmitting and receiving apparatus. In the latter case
"this result is obtained by printing the despatches in duplicate, so that
*one at least will be always intact on one or other of the two strips
tam mihands of nenon which woncizes them however much the receiving

page_text: rr
apparatus.
In carrying out this part of the Invention as applied for effecting a
double transmission, for example, the apparatus consists of,—
1st. Two keyboards, each containing, say, six keys for transmitting
along the line separate marks or traces or combinations of from, say,
two to six marks or traces.
2nd. Two double receiving apparatus, the strips or ribands of which
receive the two dispatches transmitted.
3rd. Clockwork for obtaining and regulating the motions of the
various parts of the manipulators and receiving apparatus.
-
. The following are the arrangements which admit of the synchronism
of the transmitting and receiving apparatus being dispensed with, viz*. :
The dispatch may be received on a rotating cylinder, over which the
strip or riband of paper is drawn in an inclined or oblique direction, the
marks or traces being produced either by a style or point to which
motion is imparted, or by forming the signs on the cylinder itself. Or
two despatches may be received in duplicate on two rotating cylinders,
so that by cutting in an inclined or oblique direction a rectangule out of
the strip or riband of paper, a despatch completely intact may be obtained.
The despatch may also be received in duplicate on a single strip or riband
of paper, such strip or riband being conducted over a printing helix or
spiral having one or more turns as desired. It is obvious that in the
event of one station being in arrear or advance of the other, the strokes
transmitted rise or fall, as the case may be, on the two strips or ribands
of paper. The apparatus is however so arranged that if one of the two
despatches should leave the strip or riband on which it is being printed
it is resumed immediately on the other strip or riband.. As moreover
the two dispatches transmitted in duplicate are disposed in the reverse
direction on the two strips or ribands, that which is across the two
strips or ribands is always integrally reproduced in the centre of one of
them ; so that a despatch printed intact may always be cut out of each
strip or riband.
.
The transmitting apparatus is composed, as before stated, of a key-
board provided with, say, six keys, so that for the double transmission
4 boyhoods of any six kava encli pre emploved, such káve core.

page_text: sponding to the first six members of geometrical progression 1, 2, 4, 8;
16, and 32, which admits of 63 different combinations being obtained.
A catch bolt or bar is provided in connection with the keys, which bolt
or bar is controlled by an eccentric or cam to which motion is imparted
by the clockwork. This clockwork also effects the rotation of a disc
which produces the successive distribution of the current by means of a
species of pawl bearing or rubbing against a series of pins or rods
disposed on such disc, and the parts are so combined that the catch bolt
or bar will prevent the depression of the keys at any other time than
when the current is able to pass into the disc and proceed to the receiving
apparatus.
A certain number of the pins or rods carried on the disc are con-
stantly cut off whilst the others communicate with the keys in series of
three, corresponding to the three keys of half a keyboard in the arrange-
ment of telegraph for double transmission, which has been selected as
an example. One peculiar feature of this system of disc is that the
contact of the frictional pawl, with one pin or rod, cannot cease until
such pawl has commenced its contact with the following pin or rod, by
which means any break or interruption in the current is prevented
when it is required to produce a sign of a length corresponding to, say,
two or three of the conducting pins or rods of the disc. The number
and arrangement of the frictional pawls and of the pins or rods may be
varied as required to suit the codes or combinations of codes which it
is desired to transmit simultaneously. If desired a keyboard containing,
say for example, forty-eight keys each, corresponding to a letter, figure, or
telegraphic sign may be employed. In this case the keys are arranged
in a similar manner to that described in the Provisional Specification of
the said former Invention, but in lieu of using springs it is proposed to
employ levers which are raised by the act of contact therewith of a
series of projections formed on a vertical bar attached to the key, which
has the effect of releasing certain other levers so as to bring the latter
into communication with the battery. By this, means the combinations
of elementary contacts necessary for the production of the signals will
be automatically obtained.
The arrangements of the keyboards herein-before described may be
applied to both modifications, either separately or in combination.
In order to impart motion to the printing helix or spiral and the strip
or riband of paper, it is proposed to employ an arrangement of clock-

page_text: work somewhat similar to that adopted in the printing telegraph con-
structed on what is known as Morse's systems, and such motion is trans-
mitted by means of bevel and other gearing from the shaft carrying
the eccentric or cam herein-before referred to to the respective shafts
carrying the printing helices or spirals and the feeding rollers between
which the paper is conducted. The motion of the paper may be arrested
by turning down one of the rollers on a pivot, springs being employed
for the purpose of maintaining such roller in position when in operation.
The strip or riband of paper is caused to pass above or beneath
transverse rods secured to uprights which are connected with plates
forming part of the armature, so that the action of the paper in concert
therewith is insured.
The paper is also conducted over a cross piece formed with two sharp
or bevilled edges, leaving an intervening groove which the paper slightly
enters, so as to receive a clear mark or trace of the requisite thickness by
its contact with the helix or spiral.
A number of despatches composed with different codes or alphabets
may be transmitted simultaneously by the same apparatus by the employ-
ment in substitution for a single helix or spiral of a number of segments
of helices or spirals, the one covering or extending to a certain extent
beyond the other, so as to prevent any solution of continuity in the
passage of the current; and this arrangement may be adopted in other
cases if found desirable. Double connecting segments corresponding to
the two extreme transmissions of an entire helix or spiral, or two single
connecting segments projecting or extending beyond the semi-helices or
semi-spirals of each transmission may be used if desired.
The principle of employing the terms of geometrical progression may
also be applied in imparting motion to a wheel of types by means of
arrangements based on the use of apparatus operating either succes-
sively or simultaneously.