IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
and Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS." A communication
from abroad by Benjamin Thompson and Charles Selden, both of Toledo,
Ohio, United States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 13th February 18S0.
58
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. IMPROVEMENTS IN ELECTRIC TELEGRAPH
APPARATUS." A communication from abroad by Benjamin Thompson and Charles
Selden, both of Toledo, Ohio, United States of America.
This Invention relates, first, to means for the sending of telegrams by induced
currents of opposite polarities, one polarity being required to close a reading magnet,
and the other polarity required to open the reading magnet; and this part of the
said Invention consists in a peculiar arrangement of apparatus, substantially as
described and as shown in Figure 1.
The said Invention relates, secondly, to the application of a condenser to multiple
telegraphs, by which means the static charge of the line may be completely
neutralized, and the reversals of battery from distant station, when working
multiple telegraphs, are bridged over on the home relays; and this part of the
said Invention consists in the peculiar arrangement of the condenser in combination
with resistance coils, as shown in Figure 2.
In the accompanying Drawing,-
Figure 1 shows an arrangement of a tolegraph apparatus for sending telegrams
by induced currents of opposite polarities, and
Figure 2 shows particularly the application of a condenser for neutralizing the
static charge of the line.
B is a relay or magnet, differentially wound, resting upon a vertical pivot E;
a, a', are permanent magnets adjustable by screws c, c; D is a bar attached to
magnet B and having the usual points.
K is a key which when closed throws local battery K' through local magnet K³,
attracting armature of pole-changer F, which through the positions of points
[Price Gd.l

page_text: M, M², N, N', O, and P serves to reverse the polarity of local battery G through
the primary coil I of induction coil H.
L is a secondary coil of two wires wound in the same direction around primary
coil of induction coil H, one terminal being to earth, and the other connecting by
wire Q, Q', to line through relay B¹.
R, h, c, o, is a rheostat used for neutralizing the effect of currents passing to the
line from induction coil H.
-
When the operator at key K makes rapid dots the pole-changer F reverses the
direction of battery G through primary coil I to earth, which charges the induction
coil H in opposite directions, and causes + (plus) and (minus) currents to
inductively pass to line. When the operator has the said key open battery G
charges the iron core of induction coil H; now let the operator close his key
and the iron core will discharge one polarity and take up an opposite polarity
in charge, and by induction will pass a current to the line which by its direction
will cause relay B to respond and close its local points, and record a signal on the
sounder or reading magnet, and if the key be opened an inductive current will
flow to line of an opposite polarity, and causo relay B to move in a direction that
will open its local points and cause sounder to open, relay B being so adjusted that
it will stay where placed, that is to say, its points will remain closed until the
sending of a current which will cause it to fall back and open its local points.
The currents sent by induction being momentary the relay is so adjusted that it
will remain open or closed, governed by reversals only, the currents being of long
enough duration to cause the relay to respond in one direction or the other.
The currents in passing to line are neutralized on the home relay by the adjust-
ment of the rheostat, as in the usual well known method.
The induction magnet H is wound with two coils of wire so connected that the
incoming currents will have no effect upon the core. It will be seen by reference
to Figure 1 of the Drawing that incoming currents pass through the two coils in
an opposite direction, and thus have a neutral effect on the induction magnet H.
By this device two messages may be sent, one in ench direction, upon the
same wire by the differential winding of magnets, and the use of rheostats and
other parts.
The second part of the said Invention, which is illustrated in Figure 2 of the
Drawing, comprises the following devices -L, B, is a local battery; M, B, a main
battery; D, a duplex transmitter; R, h, c, o¹, a set of resistance-coils; H', a
differential relay; C, a condenser in a shunt of the main line around the relay ;
R', R3, R³, arc resistanco coils; and L', the main line grounded and marked "carth
at the receiving end; K', a Morse key.
When the operator at key K' closes his key, transmitter D becomes charged by
local battery L, B, and places main battery M, B, to lino through points a of
transmitter. The current in passing to line is rendered neutral on the differential
relay H' by the adjustment of rheostat marked R, h, e, o', which is so balanced
that it shall offer about the same opposition or resistance to the current from main
battery M, B, as the line L' does to the distant end of the line. Thus the outgoing
current from the main battery is rendered neutral on the relay H. The current to
the line passes in the opposite direction to the current to the rheostat. Now let
the operator at key K' withdraw the main battery from the line by opening his key,
and it will be found that the line to distant end being charged by the current sent
into it, seeks to discharge itself the moment the operator withdraws the charging
current and in discharging itself requiros time. This is what is known as the
"static charge" of the line. Now the condenser C being also charged at the time
that the main line receives its charge, also discharges itself instantaneously with
the line through the saine coil of relay H', but as the condenser discharges a current
of an opposite polarity to that which the line discharges, and is adjusted to meet
the static charge of the line, the static action on relay H¹ is neutralized.
In charging the main line a small resistance coil R' is placed in the same to
assist in charging the condenser C; but this is not found necessary when the

page_text: relay H is of a high resistance, or when working quadruply where the resistance
of a second relay is sufficient to charge the condenser C. The resistance R² is
inserted between the condenser and the line for the purpose of fully adjusting the
condenser to meet the static charge, and the coils R2 may be of any required
resistances; or a series of condensers may be placed alongside of the one shown in
the Drawing, and also a series of resistances may be placed at R², that is, cach
condenser so used may be furnished with a separate resistance coil.
By charging the line with the main battery a minus current is sent out, conse-
quently the condenser C, plate No. 1, becomes charged with a minus current, and
plate No. 2, by induction, receives a plus charge; so that when the line discharges
it meets the charge from the condenser C, the line being minus and the condenser
plus; and while the line and the condenser C have a charge of the same intensity,
but of an opposite polarity, the effect on relay H' is neutralized. During reversals
of the battery from a distant station when working quadruple or other multiple
telegraphs, let distant end place battery to line when the condenser C, plato No. 2,
receives a charge of the same polarity as battery placed to line. Now let distant
station reverse battery, the plate No. 2 of condenser C discharges through home-
relays and maintains signals until the reverse battery power has time to follow
correctly. This condenser nicthod is found to be superior for neutralizing the
static chargo to that now in use, wherein the condenser is placed in the rheostat-
circuit, that is, the condenser is placed around the rheostat in such a way that
while the line discharges itself the condenser simultaneously discharges, but through
a different coil of wire wrapped around the relay H', and in an opposite direction,
while it is of the same polarity, so that the difference between the arrangement
now in use and that above described may be readily understood by those skilled in
the science.
Having thus fully described the said Invention as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it under-
stood that I claim,-
First. The relay B in a multiple telegraph, substantially as described with
reference to Figure 1 of the Drawing, and for the purpose set forth.
Second. The induction coil H in a multiple telegraph, substantially as described
with reference to Figure 1 of the Drawing, and for the purpose set forth.
Third. The combination of the parts K, K¹, K², F, G, H, and B in an electric
telegraph, substantially as described with reference to Figuro 1 of the Drawing,
and for the purpose set forth.
Fourth. The application of the condenser C in a shunt of the main line around
the relay or relays in combination with resistances R¹ and R' in a multiple
telegraph, substantially as described with reference to Figuro 2 of the Drawing,
and for the purpose set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Thirteenth day of February, in the year of our Lord
One thousand eight hundred and eighty.
W. ROBT. LAKE. (L.S.)