IMPROVEMENTS IN TELEPHONIC TELEGRAPHY AND IN APPARATUS THEREFOR
Year: 1882

page_text: LETTERS PATENT to Charles Ambrose McEvoy and James Mathieson both
of 18 Adam Street Adelphi in the County of Middlesex for an Invention
of IMPROVEMENTS IN TELEPHONIC TELEGRAPHY AND IN APPARATUS
THEREFOR,"
PROVISIONAL SPECIFICATION left by the said Charles Ambrose McEvoy
and James Mathieson at the Office of the Commissioners of Patents on the
16th September 1882.
CHARLES AMBROSE M°Evoy and JAMES MATHIESON both of 18 Adam Street
Adelphi in the County of Middlesex " IMPROVEMENTS IN TELEPHONIC TELEGRAPHY
AND IN APPARATUS THEREFOR "
This invention has for its object improvements in telephonic telegraphy and in
apparatus therefor.
The well known Bell telephone is a very efficient instrument for receiving by
sound ordinary make and break or intermittent current signals; in portable
telegraphs such as are used in military telegraphy it has to some extent been
employed. In such telegraphs the use of batteries is inconvenient. Now our
improved military or portable telegraph has for its transmitter a finger key operating
upon an armature which it causes partially to rotate in front of the poles of a
permanent magnet. The armature has coils upon it, in fact it is arranged very
much as the armature is in a magneto-electric machine. When the key is put
down the movement of the armature induces a current in the coils; this current
passes into the line wire and as the key completes its movement the circuit is
suddenly opened, the resulting sharp current gives rise to a click in the telephone
and signals given by this key according to the Morse code are readily read by
sound.
A spring causes the rapid return of the finger key.
For military and other purposes it is frequently required to read signals passing
in a telegraph wire without making any positive connection with the wire or
injuring the insulating material with which it may be surrounded. For this.
purpose also I employ the Bell telephone; and coupled with it is a case containing
a coil of insulated wire. This case is made water tight so as not to be liable to
injury by exposure and it is provided with hooks by which it can be hung against
the wire through which the messages which it is desired to read are passing.
these signals be make and break or intermittent current signals they will be
repeated by clicks in the telephone and can be read by any operator who is
accustomed to read signals by sound.
.
If

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Ambrose McEvoy and James Mathieson in the Great Seal
Patent Office on the 16th March 1883.
CHARLES AMBROSE McEvoy and JAMES MATHIESON both of 18 Adam Street
Adelphi in the County of Middlesex "IMPROVEMENTS IN TELEPHONIC TELEGRAPHY
AND IN APPARATUS THEREFOR
"3
This invention has for its object improvements in telephonic telegraphy and in
apparatus therefor.
The well known Bell telephone is a very efficient instrument for receiving by
sound ordinary make and break or intermittent current signals; in portable
telegraphs such as are used in military telegraphy it has to some extent been
employed. In such telegraphs the use of batteries is inconvenient. Now our
improved military or portable telegraph has for its transmitter a finger key operating
upon an armature which it causes partially to rotate in front of the poles of a
permanent magnet. The armature has coils upon it, in fact it is arranged very much
as the armature is in a magneto-electric machine. When the key is put down the
movement of the armature induces a current in the coils; this current passes into
the line wire. The resulting sharp current gives rise to a click in the telephone and
signals given by this key according to the Morse code are readily read by sound.
A spring causes the rapid return of the finger key.
For military and other purposes it is frequently required to read signals passing
in a telegraph wire without making any positive connection with the wire or
injuring the insulating material with which it may be surrounded. For this
purpose also we employ the Bell telephone; and coupled with it is a case containing
a coil of insulated wire. This case is made water tight so as not to be liable to
injury by exposure and it is provided with hooks by which it can be hung against
the wire through which the messages which it is desired to read are passing. If
these signals be make and break or intermittent current signals they will be
repeated by clicks in the telephone and can be read by any operator who is
accustomed to read signals by sound.
In order that our said invention may be most fully understood and readily
carried into effect we will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is an elevation partly in section of the key transmitter Figure 2 is a
diagram shewing the entire telegraphic system.
In Figure 1 a is a permanent magnet fixed on a convenient base b. c is an
axis mounted in bearings on the base b. The axis c. carries the bobbins of insulated
wire d, such as are used in a medical magneto machine and the extremities of the
insulated wire are connected in any convenient way with the binding screws e. e,
f is a curved spring tending to hold the bobbins d, in the position in which they
are shown.
The end of the plunger g bears upon a metal hoop which surrounds the upper
bobbin d. and when thrust down causes the bobbins partially to rotate, the
spring yielding to permit them to do so and causing their return immediately
the plunger is allowed to rise.
In Figure 2 a pair of these key transmitters are shewn one at either end of a
telegraphic line h. i, i are ordinary receiving telephones and k. k. are earth plates
or connections. The circuit is complete as will be seen from one earth plate through

page_text: the coils d. of the adjacent key and the receiving telephone i. along the wire to the
instruments at the further station then through these instruments and so again to
earth. Or in some cases it will be more convenient that the circuit should be
metallic throughout. There may be intermediate stations on the line if required.
Each time that any key is depressed a click is heard in each of the telephones -
and another click when the key rises.
-
The keys are worked and the signals read in accordance with the well known
telegraphic code.
Figure 3 shews the apparatus which we provide for military purposes for
reading signals passing in a line wire.
Z is an ebonite case containing a coil of fine insulated copper wire of a resistance
of about 10 to 20 Ohms. m. m. are binding screws to which the ends of the wire
are brought and which couple with it the ordinary receiving telephone n. o is a
hook by which the case is hung upon the telegraph wire. The signals passing
through the wire can then often be read by the sounds heard in the telephone.
Figure 4 shews a further use for the instruments shewn in Figure 3. They form
a ready means for connecting especially for military purposes a transmitting
telephone with any one of a series of receiving telephones as may be desired.
1. 12. 13. are three cases such as already described. and 13. are coupled in the
circuit of the transmitting telephone, as is shewn is in the circuit of a receiving
telephone which may be of any required length. When the case 12 is placed
between and 13. the receiving telephones is in communication with the transmitting
telephone.
Any one of a series of receiving telephones may instantly be put into communi-
cation with the transmitter simply by inserting the corresponding case l³, between
the cases 1. and 13. in the circuit of the transmitter.
Having thus described the nature of our said Invention and the manner of
performing the same we would have it understood that we claim.-
First. Our telephonic telegraphic system substantially as described in respect to
Figures 1 and 2 of the annexed Drawings.
Second. Our apparatus for reading signals passing in a telegraphic wire
substantially as described in respect to Figure 3 of the annexed Drawings.
In witness whereof I the said Charles Ambrose McEvoy have hereunto set
my hand and seal this Sixteenth day of March in the year of our Lord One
thousand eight hundred and eighty three.
KARTTAKE