IMPROVEMENTS IN TELEPHONES
Year: 1881

page_text: LETTERS PATENT to Friedrich Hermann Felix Engel; Civil Engineer and
Patent Agent, in the City of Hamburg, Germany, for an Invention of
"IMPROVEMENTS IN TELEPHONES." A communication from Johann Heinrick
Königslieb, of Hamburg, in the German Empire.
PROVISIONAL SPECIFICATION left by the said Friedrich Hermann Felix
Engel at the Office of the Commissioners of Patents on the 22nd January
1881.
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hamburg, Germany. "IMPROVEMENTS IN TELEPHONES." A communi-
cation from Johann Heinrick Königslieb, of Hamburg, in the German Empire.
This Invention relates to certain improvements in telephones, and has for its
purpose to increase the power of transmitting sounds, words, and so forth, by such
instruments, and also to render more distinct or clear the transmitted words or
sounds.
Instead of constructing that part of the casing of a telephone which is below the
diaphragm of the instrument massive a thin walled wooden or other box is placed
underneath the diaphragm, and a second casing of wood or other convenient
material is placed beneath, and some distance apart from this box, which casing
forms a resonance board or sounding board. The magnet may be passed from
below through the bottoms of both box and casing into the free space under the
diaphragm, or it may be introduced into the resonance casing through the upright
circumference sideways, and the ends of the magnet, which must in this case be
bent at angles, will be introduced through the bottom of the box into the free
space between box and diaphragm.
The casing forming the resonance board may be furnished with one or more
sound-holes.
By the application of the above described box and casing the transmitting
qualities of telephones of different constructions are greatly improved.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Friedrich Hermann Felix Engel in the Great Seal Patent Office on
the 22nd July 1881.
FRIEDRICH HERMANN FELIX ENGEL, Civil Engineer and Patent Agent, in the
City of Hamburg, Germany. "IMPROVEMENTS IN TELEPHONES." A communi-
cation from Johann Heinrich Konigslieb, of Hamburg, in the German Empire.
This Invention relates to certain improvements in telephones, and has for its
purpose to increase the power of transmitting sounds, words, and so forth, by such
instruments, and also to render more distinct or clear the transmitted words or
sounds.
Instead of constructing that part of the casing of a telephone which is below the
diaphragm of the instrument massive a thin walled wooden or other box is placed
underneath the diaphragm, and a second casing of wood or other convenient
material is placed beneath; and some distance apart from this box, which casing
forms a resonance board or sounding-board. The magnet may be. passed from
below through the bottoms of both box and casing into the free space under the
diaphragm, or it may be introduced into the resonance casing through the upright
circumference sideways, and the ends of the magnet, which must in this case be
bent at angles, will be introduced through the bottom of the box into the free space
between box and diaphragm.
The casing forming the resonance-board may be furnished with one or more
sound-holes.
By the application of the above described box and casing the transmitting
qualities of telephones of different constructions are greatly improved.
The accompanying Sheet of Drawings explains one mode of carrying out this
Invention, and represents a sectional elevation of a telephone of otherwise known
construction furnished with the improvements.
A is the thin walled wooden box forming part of the casing or body of the
instrument placed underneath the metal diaphragm plate m; B is the resonance
or resounding-box surrounding the above box A, and is furnished with sound holes 8,
of which one or more may be applied; R is the magnet reaching with its ends into
box A, as will be readily understood from the Drawing.
Having now described the nature and particulars of the said Invention,
I claim,
The application of a thin-walled casing underneath the membrane of telephones,
which casing is surrounded or enclosed by a resounding box, substantially for the
purpose and in the manner as herein described.
In witness whereof, I, the said Friedrich Hermann Felix Engel, have hereunto
set my hand and seal, this Seventeenth day of July, One thousand eight
hundred and eighty one.