IMPROVEMENTS IN RELAYS OR TELEGRAPHIC RECEIVING INSTRUMENTS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I JAMES SANFORD LAMAR, of Augusta, in the County of Richmond and State
of Georgia, one of the United States of America, Gentleman, do hereby declare
the nature of my Invention for IMPROVEMENTS IN RELAYS OR TELEGRAPHIC
RECEIVING INSTRUMENTS and in what manner the same is to be performed to
bo particularly described and ascertained in and by the following statement :—
23
This Invention has relation to relays or telegraphic receiving instruments and it
consists essentially in a vibratory steel magnet acting by its own attraction upon
the core of an electro-magnet to break circuit and by means of the mutual repulsion
between said electro-magnet and said steel magnet to make circuit; in the device
of of a steel magnet so pivoted that it may freely oscillate between stops, and so
adjusted and arranged that one of its poles shall embrace within the field of its own
magnetism the soft iron core of an electro magnet so connected with its battery or
other source of electrical supply that the magnetism of its core produced by the
electrical current shall cause the steel magnet to be repelled the successive attractions
and repulsions between the two magnets causing the steel magnet to oscillate
between said stops so as to produce telegraphic signals; in the device of a metallic
projection or arm rigidly connected at an angle with a steel magnet which is caused
to oscillate by the successive attractions and repulsions between said steel magnet
and an electro magnet, said arm being furnished with a point of platinum or other
metal adjusted to make and break electrical connections or to produce telegraphic
signals; in the combination with an oscillating steel magnet operating with an
electro magnet to make and break circuit of a receptacle containing mercury, with
which a metallic point connected to said steel magnet is made successively to make
and break circuit; in the combination with an oscillating steel magnet operating
with an electro magnet to make and break circuit of a mercury chamber, a metallic
point in connection with the steel magnet and a governing screw, working in a
passage of the mercury chamber to adjust the height of the mercury with reference
to the operation of said metallic point, and in the general combination with an
adjustable electro-magnet connected with the main circuit, of a vibratory steel
magnet having an arm in the line of the local circuit and a pole in attractive
relation with the core of the electro-magnet, a mercury chamber and an adjusting
device to regulate the height of the mercury in the chamber all as hereinafter set
forth.

page_text: In the accompanying Drawings Fig. 1, illustrates a sectional elevation of the
apparatus and Fig. 2 a top plan view thereof.
A designates the base of the instrument and B an electro-magnet, which is
preferably made adjustable, C represents a thumb screw working in a bearing D
and adapted to move the electro-magnet when turned F F indicate binding-posts
for the line wires a, a, with which the electro-magnet is in circuit, G represents
the soft iron core of the electro magnet, H represents a steel magnet having a
pivot b seated in bearings o which are preferably made adjustable by employing
screws for the purpose. The steel magnet is provided with a rigid arm K which
extends at an angle with the magnet and said arm is provided with a downwardly
extending point of platinum or other metal as indicated at d. The steel magnet
is designed to extend downward its end e being near the end g of the soft iron core
of the electro-magnet..
L represents a block of iron having the horizontal chamber h formed with an
aperture at . The end of this chamber is closed by means of a neatly fitting
screw . A threaded perforation m extends to the chamber h at a distance from
the aperture k and in this perforation is placed a governing screw n. The point d
of the arm of the steel magnet is designed to extend downward into the aperturo />
and in the chamber h is placed sufficient mercury to fill the horizontal portion
of said chamber. The height of the surface of mercury in the aperture k is
regulated by means of the screws and n, the latter being employed for the
nice adjustment required.
Adjustable stops & and t are employed to limit the movements of vibration of the
steel magnet. N N represent binding posts for the wires of a local battery.
From one of these posts the local circuit, extends by a brass standard S to the
pivot bearings of the magnet H and, when the point d, of the magnet is in contact
with the mercury the circuit extends through the magnet arm and mercury and
down by a brass standard S¹ to the other binding post. When the point d of the
steel magnet is not in contact with the mercury the local circuit is open.
In this relay, the polarity of the end g of the soft iron core of the electro magnet
is to be similar to that of the end of the steel magnet, and therefore the binding
posts F F are to be so connected with the wire of the main line that the current
passing through the coil of the electro magnet shall produce in its core at g the
same polarity as that of the steel magnet at e.
The electro-magnet is to be adjusted by means of the thumb-screw, until the
steel magnet is freely drawn by its own magnetism towards the end g of said
core. This movement of the magnet H will lift its arm and move the point & out
of connection with the mercury opening the local circuit. When the main circuit
is closed the end g of the core of the electro magnet and the end e of the steel
magnet having the same polarity, the end e will be driven by magnetic repulsion
away from g vibrating the steel magnet outward and bringing the point & of the
magnet arm down into the mercury and closing the local circuit. When however
the main circuit is open the end g of the core of the electro-magnet having no
polarity the magnetism of the steel magnet H will cause it to be drawn toward
said end g thus lifting the point d from the mercury and opening the local circuit.
The arm K of the steel magnet is not designed to be perfectly counterbalanced, but
should have a slight excess of weight which is readily lifted by the permanent
magnet, when the main circuit is open, and, when the current is introduced, this
excess of weight assists the repulsive effort of the electro magnet in throwing off
the steel magnet.
This relay is designed to effect a great saving of battery power. It does not
require adjustment, to preserve uniformity of action, notwithstanding variations in
the strength of the line current. The margin of admissible variation ranges from
the feeblest current that will do the work, up to a current of any degree of
strength below that which would reverse the polarity of the steel magnet.
The device utilizes the principle that two magnetic poles of the same name will
mutually repel, although one of them may be too feeble to manifest any useful

page_text: attraction for soft iron. Its capacity is designed to be sufficient to operate a local
battery in ocean telegraphy thereby facilitating and expediting, the reception of
cable messages.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is:-
1. In a telegraphic relay, the combination with an electro magnet, of a vibratory
steel magnet, acting by its own attraction upon the core of the electro-magnet to
break circuit, and by means of the mutual repulsion between said electro magnet
and said steel magnet to make circuit substantially as specified..
2. In a telegraphic receiving instrument the combination with an electro
magnet of a vibratory steel magnet having a metallic projection or arm rigidly
connected at an angle with said steel magnet and having a point of platinum, or
other metal adjusted to make and break electrical connections when operated
by the successivo repulsions and attractions between said steel magnet and the
electro-magnet substantially as specified.
3. In a telegraphic receiving instrument the combination with an oscillating
steel magnet operating with an electro-magnet to make and break circuit, of a
receptacle containing mercury with which a metallic point connected to said steel
magnet is made to make and break circuit, substantially as specified.
4. In a telegraphic receiving instrument the combination with an oscillating
steel magnet operating with an electro-magnet to make and break circuit, of a
mercury chamber, a metallic point in connection with the steel magnet. and a
governing screw working in a passage of the mercury chamber to adjust the
height of the mercury with reference to the operation of said metallic point
substantially as specified.
5. An automatic magnetic telegraphic relay substantially as specified.