IMPROVED MEANS AND APPARATUS FOR EFFECTING TELEPHONIC COMMUNICATION
Year: 1879

page_text: LETTERS PATENT to John Imray, of No. 28, Southampton Buildings, in the
County of Middlesex, for the Invention of "IMPROVED MEANS AND APPARATUS
FOR EFFECTING TELEPHONIC COMMUNICATION." A communication from abroad
by Robert Georges Brown and Joshua Franklin Bailey, both of New York,
in the United States of America.
Scaled the 30th January 1880, and dated the 5th December 1879.
COMPLETE SPECIFICATION filed by the said John Imray at the Office of
the Commissioners of Patents on the 5th December 1879.
"Iar-
JOHN IMRAY, of 28, Southampton Buildings, in the County of Middlesex.
PROVED MEANS AND APPARATUS FOR EFFECTING TELEPHONIC COMMUNICATION."
A communication from abroad by Robert Georges Brown and Joshua Franklin
Bailey, both of New York, in the United States of America.
This Invention relates to the construction and arrangement of apparatus for
effecting telephonic communication among a number of persons or subscribers at
two or more stations, the objects aimed at being economy and simplicity in the
first establishment and in the continued working of the apparatus, it being so
arranged that a few attendants can with great promptitude and certainty put any
subscriber at one station in communication with any subscriber at another station,
and stop such communication. The arrangement of apparatus and the mode of
operating with it will be described with reference to the accompanying Drawings
and the figures and letters marked thereon. At each station there is a circular
table, shewn in plan at Fig. 1, Sheet I., having distributed over its surface a number
of interrupters or contact makers and breakers b, each marked by a numeral
or other distinctive mark. This table A occupies a central position in a circular
or polygonal apartment, shewn in plan at Fig. 1, Sheet II., and round the table
are arranged a number of seats or boxes B for subscribers; a perspective view
of one of these boxes is shewn at Fig. 2, Sheet II. D is the seat beside a table
undor which are accommodated suitable batteries and induction coils, and above
which is a tablet C presenting a number of contact makers j. Such being the
general arrangement of the apparatus certain details may now be described as
follows:-The table A is conveniently mounted on a central stem hinged to the
floor, as shewn at Fig. 2, Sheet I., with supporting legs a, a, also hinged to the
floor, so that either leg being folded down the table can be inclined either way, as
indicated by the dotted lines. Each of the interrupters b on the table A is con-

page_text: structed as shewn on Sheet I., in section at Fig. 3, in plan at Fig. 4, and in
sectional plan at Fig. 5. It consists of a plate of copper or brass 6 secured to the
table by bolts c and d. The bolt d is insulated from 6 by being passed through a
bush i of ebonite or other non-conductor, through which a tongue of the bolt head
projects a little beyond the edge of the plate b, as shewn in Fig. 5. To the side of
the plate is fixed a spring e which has a tongue g projecting into a lateral hole of
the plate b, and which has a contact piece to meet the tongue of the bolt d. In the
plate there are two holes o and o¹, into either of which can be inserted a metal
pin 2, shewn at Fig. 7, Sheet I. When it is inserted in the hole o it displaces the
tongue g, and so pushes the spring e out of contact with d, which is in electrical com-
munication with the indicator of one of the telephones. This indicator is con-
structed as shewn at Fig. 3, Sheet II., two indicators being there represented, the
onc closed and the other open. It consists of an electro-magnet g with a spring
armature h, an arm from which acts as a latch to hold a hinged screen i. When
the electromagnet is excited the armature h is attracted, releasing the screen i,
which opening shews a number or other mark distinguishing the subscriber who is
going to operate. The mode of operating will be understood on reference to Fig. 6,
Sheet I., which is a diagram shewing a number of the electrical connections in order
to illustrate their reciprocal action. Assuming that the subscriber No. 21 is going
to operate he calls attention by sending into a line a current by the interrupter b,
No. 21 on the table A, and this at the distant station causes the screen of the
indicator No. 21 to open. The attendant then inserts into the hole of the contact
maker j, No. 21, the pin p, which by means of a wire attached to it communicatos
with the manipulating key m, and thence by a wire with the receiving telephone t,
which is in connection with a battery and induction coil k. By the insertion of the
pin p in the hole of j the circuit for the indicator is broken and that for the
receiving telephone is completed. The attendant then by means of his key m
informs the subscriber that he is ready, whereupon the subscriber telephonically
acquaints the attendant with the number of the other subscriber with whom he
desires to communicate. The attendant then proceeds to complete tho communica-
tion, his operation, say, for permitting No. 3 to communicate with No. 23 being as
follows: He takes one of the insulated conducting wires n having at each end of
it a metal pin p; he puts one of the pins in the hole o¹ of the interrupter 6, No. 3,
and the other into the hole o of the interrupter b, No. 23. He then by his key m
causes the electric bell of No. 23 to sound. No. 23 replies, as above described, and
this reply is heard by the attendant and also by the intending sender, No. 3, as a
beating of their respective receiving telephones. The communication being thus
established the attendant cuts his telephone out of circuit by taking the pin out of
the contact maker j and the subscribers communicate. When they have done they
apprise the attendant by means of their call keys, causing the screen of No. 3
indicator to open, and thereupon the attendant breaks the circuit by removing the
pins 2 from the holes of the interrupters b, Nos. 3 and 23. For enabling the
attendants at different stations to communicate with each other there are central
sets of interrupters on the table A and a separate box E (Fig. 1, Sheet II.), with its
fittings as for a subscriber. When a subscriber at one station desires to communicato
with a subscriber at another station which is not in direct communication with the
former station he communicates with the attendant at the intervening station, and
the attendant by the use of the central interrupters of his table completes the com-
munication with the farther station, and so on from station to station.
Having thus described the nature of the said Invention and in what manner the
same is to be performed, as communicated to me by my foreign correspondents, I
claim,―
First. Arranging on a circular table at a telephonic station a number of inter-
rupters distinguished by special marks, so that an attendant can by inserting in the
holes of any two of these interrupters pins, electrically connected together, establish
telephonic communication between two subscribers, distinguished by marks corre-
sponding to those of the interrupters, substantially as herein described.

page_text: Second. The construction of the interrupter referred to in the preceding claim,
substantially as herein described with reference to Figs. 3, 4, 5, and 7 on Sheet I. of
the accompanying Drawings.
Third. The construction of indicator herein described with reference to Fig. 3 on
Sheet II. of the accompanying Drawings.
In witness whereof, I, the said John Imray, have hereunto set my hand and
seal, this Fifth day of December, in the year of our Lord One thousand
eight hundred and seventy nine.
JOHN IMRAY. (L.S.)