IMPROVEMENTS IN TELEPHONES
Year: 1879

page_text: LETTERS PATENT to John Imray, of No. 28, Southampton Buildings, in the
"
County of Middlesex, for the Invention of "IMPROVEMENTS IN TELEPHONES."
A communication. from abroad by Joshua Franklin Bailey, of New York,
United States of America.
Sealed the 30th January 1880, and dated the 6th December 1879.
COMPLETE SPECIFICATION filed by the said John Imray at the Office of
the Commissioners of Patents on the 6th December 1879.
JOHN IMRAY, of No. 28, Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN TELEPHONES." A communication from abroad by Joshua
Franklin Bailey, of New York, United States of America.
This Invention relates to the construction of telephones and their connections, as
shewn by the accompanying Drawings. Fig. 1 is a section on the line 1-1 of
Fig. 3, and Fig. 2 is a section on the line 2-2 of Fig. 3, which is a plan of one
form of telephone according to this Invention. A is a permanent magnet of horse-
shoe form, having one of its limbs bent so as nearly to cross the gap between it and
the other limb; B is an electromagnet fixed on the bent limb, and C is the
diaphragm secured in a case D of non-conducting material, such as is not liable to
have its form altered by change of temperature or humidity. The conducting
wires F covered with insulating material are passed through holes in the free limb
of the magnet A, and are secured at their ends by the contact screws E Fig. 4
represents in section a telephone of similar kind somewhat modified in its con-
structive details; Fig. 5 is a section of a modified form of telephone. A permanent
horseshoe magnet H carries on one of its limbs the core of two electromagnet
coils 13 and 14, which has thus certain polarity induced on it; the other limb of
the magnet is in connection with the diaphragms d, d, which thus have the
opposite polarity induced on them. The coils 13 and 14 may form part of the
principal line.
Fig. 6 is a section of a union for connecting lengths of telephonic wire. a is a
socket screwed at the mouth to receive a gland b, in which is inserted the helical
wire e cased in insulating material f. The wire is held in b by a screw c, the
thread of which engages with a few convolutions of the helical wire. By
screwing up the gland b the screw head c is pressed against the bottom of the
socket a, completing electrical connection. Fig. 7 is a perspective view of a double
telephone for speaking and hearing.

page_text: 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 correspondent, I
claim,-
First. The construction of telephone in which a permanent magnet of horse form
has one of its limbs extending across the gap between the limbs, and carrying an
electromagnet and a diaphragm with its casing, substantially as herein described.
Second. The construction of telephone, herein described with reference to Figs. 1,
2, and 3 of the accompanying Drawings.
Third. The modified construction of telephone, herein described with reference to
Fig. 4 of the accompanying Drawings.
Fourth. The construction of telephone, herein described with reference to Fig. 5
of the accompanying Drawings.
Fifth. The combination of two telephones, as shewn at Fig. 7 of the accompanying
Drawings.
Sixth. The union for connecting telephonic wires, herein described with reference
to Fig. 6 of the accompanying Drawings.
In witness whereof, I, the said John, Imray, have hereunto set my hand and
seal, this Sixth day of December, in the year of our Lord One thousand
oight hundred and seventy nino.
TATTY TIST