IMPROVEMENTS IN TELEPHONE SWITCHES
Year: 1880

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
TELEPHONE SWITCHES." A communication from abroad by Ernest Marx, Frank
A. Klemm, and Julius Kayser, all of New York, United States of America,
and Louis Davis, of Montreal, Canada.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 13th April 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN TELEPHONE SWITCHES." A communication from
abroad by Ernest Marx, Frank A. Klemm, and Julius Kayser, all of New York,
United States of America, and Louis Davis, of Montreal, Canada.
This Invention relates to certain improvements in the construction of telephone
switches. It has for its objects simplicity and economy in construction and absolute
positiveness in operation, and with these ends in view the Invention consists of a
stationary hanger post in combination with a vibratory bell crank lever and flat
spring so arranged in relation to the main line wire bell telephone and transmitter
wire and local battery that the presence of the telephone in position will positively
connect the bell with the main line and open the local circuit, and its removal for
use will cut out the bell, close the local battery circuit, and put the telephone and
transmitter on the line, as will be hereinafter more fully explained.
In carrying out this Invention a switch board is employed, to the front of which
is secured a metallic hanger post, which is secured in a horizontal position by a
thread or otherwise to a metallic plate fastened to the rear side of the board, and
to which is pivotted or hinged a bell crank lever capable of vibration. The upper
end of the vertical arm of this lever is furnished with contact points, one on each
side, designed to come in contact with the bell and telephone connections respectively,
as will be presently explained.
A flat metal spring is provided, which is rigidly secured at its lower end to the
board by screws with its upper end bifurcated to straddle and bear against the
lever above the pivotted point, thus tending to hold one of the contact points
against the telephone wire connection. A short metal spring is also provided,
which is secured to the board by screws, from which a wire extends to the signall

page_text: bell, and a similar spring is secured in like manner, and from which extends the
wire which connects the telephone and transmitter.
The main line wire is connected with the lower end of the flat metal spring, and
two local battery wires are respectively connected with a spring plate secured to
the board and a lateral arm extending from the lover. From this construction it
will be observed that when the handle of the telephone is placed upon the hanger
(the space between it and the lower side of the horizontal arm of the lever being
less than the thickness of the handle) the horizontal arm of the lever is pressed
upwardly, causing it to vibrate on the pivot, and thus carrying the upper end of
the vertical arm in contact with the signal bell connection and out of contact with 1
the telephone and transmitter connection, and at the same time opens the local
battery circuit by lifting the lateral arm out of contact with the spring plate or
connection, so that the main line then travels through the flat metal spring, the
lever and the short metal spring connection to the bell and when the telephone is
removed from the post or hanger the power of the flat metal spring causes the 1
upper end of the lever to come in contact with the telephone and transmitter
connection, thus putting them on the line, and at the same time disconnecting the
bell and closing the local battery circuit in an obvious manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 12th
October 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN TELEPHONE SWITCHES.' A communication from
abroad by Ernest Marx, Frank A. Klemm, and Julius Kayser, all of New York,
United States America, and Louis Davis, of Montreal, Canada.
The said Invention relates to certain improvements in the construction of
telephone switches, and has for its objects simplicity and economy in construction
and absolute positiveness in operation, and with these ends in view the Invention
consists of a stationary hanger post in combination with a vibratory bell crank
lever and flat spring so arranged in relation to the main line wire bell telephone
and transmitter wire and local battery that the presence of the telephone in position
will positively connect the bell with the main line and open the local circuit, and
its removal for use will cut out the bell, close the local battery circuit, and put the
telephone and transmitter on the line, as will be bereinafter more fully explained.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of
reference indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a rear view of the improved
apparatus; Figure 2 is a central vertical section taken along the line 1, 2, Figure 1;
and Figure 3 is a cross section taken along the line 3, 4, Figure 1.
A represents the switch board, to the front of which is secured a metallic hanger
post B, which is secured in a horizontal position by a screw thread or otherwise
to a metallic plate C fastened to the rear side of the board, and to which is
pivotted or hinged at 1 a bell crank lever D capable of vibration, as shewn by
dotted lines in Figure 2.
The upper end of the vertical arm of this lever is furnished with contact points
a, b, one on each side, designed to come in contact with the bell and telephone
connections respectively, as will be presently explained.
E is a flat metal spring rigidly secured at its lower end to the board by screws
c, d, with its upper end bifurcated to straddle and bear against the lever D above
the pivotted point, and thus tend to hold one of the contact points b against the
telephone wire connection.
F is a short metal spring secured to the board by screws e, e, from which a wire G
extends to the signal bell. H is a similar spring secured in like manner, and from
which extends the wire I which connects the telephone and transmitter.
K is the main line wire connecting with the lower end of the flat metal spring E.
L, L', are the local battery wires connecting respectively with a spring plate M
secured to the board, and a lateral arm N extending from the lever D.
From this construction it will be observed that when the handle of the telephone
is placed upon the hanger B (the space between it and the lower side of the
horizontal arm of the lever D being less than the thickness of the handle) the
horizontal arm of the lever D is pressed upwardly, causing it to vibrate on the
pivot 1, and thus carrying the upper end of the vertical arm into contact with
the signal bell connection F and out of contact with the telephone and transmitter
connection H, and at the same time opening the local battery circuit by lifting the
arm N out of contact with the connection M, so that the main line then travels
through the spring E, lever D, and connection F to the bell. When, on the other
band, the telephone is removed from the post or hanger B the power of the spring E
causes the upper end of the lever D to come in contact with the telephone and
transmitter connection H, thus putting them on the line, and at the same time
disconnecting the bell and closing the local battery circuit in an obvious manner.

page_text: Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
First. In combination with the permanent hanger B the vibrating bell crank
lever D and actuating spring E, to which is connected the main lino wire K,
substantially as and for the purpose herein before described.
Second. In combination with the hanger B, lever D, and actuating spring E,
arranged as herein set forth, the connections F, H, M, and lateral arın N, substantially
as and for the purpose herein before described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and scal, this Twelfth day of October, Ono
thousand eight hundred and eighty.