IMPROVEMENTS IN MAGNETO ELECTRIC SIGNAL APPARATUS
Year: 1880

page_text: LETTERS PATENT to Edward Griffith Brewer, of 33, Chancery Lane, in the
County of Middlesex, for an Invention of "IMPROVEMENTS IN MAGNETO
ELECTRIC SIGNAL APPARATUS." A communication from abroad by Edward
Hibberd Johnson and Thomas Alva Edison, both of Menlo Park, in the State
of New Jersey, United States of America.
PROVISIONAL SPECIFICATION left by the said Edward Griffith. Brewer at
:
the Office of the Commissioners of Patents on the 10th November 1880.
EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN MAGNETO ELECTRIC SIGNAL APPARATUS." (A communication
from abroad by Edward Hibberd Johnson and Thomas Alva Edison, both of Menlo
Park, in the State of New Jersey, United States of America.).
Magneto electric machines, as signal apparatus, are often used in such relation to
other devices that it is desirable that they should be cut out of circuit when not in
use, being thrown into circuit only when in use.
It is also often desirable that they should, without any change at the time of
use, be capable of giving two distinct signals, as for instance, a continuous ring and
an intermittent ring, indicating two distinct wants, or operations, or things.
The accomplishment of both these results in one organization is the object of
this Invention.
In carrying the Invention into effect a shunt circuits is formed around the
magneto machine or generator, connected to the main circuit upon each side of the
generator, a portion of which circuit is a contact spring or lever taking against an
anvil or contact point.
upon
The actuating handle or pulley is attached to a sleeve which is loose the
main driving shaft, but secured thereto by a pin on the shaft taking in a triangular
opening or slot in the side of the sleeve.
Upon the inner end of the sleeve is a disc which takes against a rod whose other
end bears against the contact spring or lever.
The force of the contact spring, or that of a special spring, is used to nominally
hold the rod pushed against the disc, so that the sleeve is as far out on the shaft as
the slot and pin permit, in which condition the spring impinges on the anvil or
Din 1

page_text: contact point, closing the shunt circuit, thus practically cutting the generator out of
circuit.
Upon rotation, the sleeve turns loosely upon the shaft until the outer end of the
slot reaches the pin, when sleeve and shaft turn together. The slot being triangular,
causes the carrying inward of the sleeve and disc, pushing the rod against the
contact lever or spring, causing it to leave the contact point or anvil, breaking
thereby the shunt or short circuit, compelling the current from the generator to
traverse the main circuit.
Upon cessation of use the parts return to their normal position, closing the shunt
or short circuit.
By the arrangement thus described, the first of tho objects noted is
accomplished.
To accomplish the second object the arrangement noted is modified as follows:-
The contact spring referred to is made with a twist about its centre so as to be
capable of motion in either direction.
To it is attached directly the pin which takes against the disc upon the sleeve.
In the inner face of the disc a groove is cut extending partly around the disc,
and whose outer edge normally is out of the path of the pin.
One end of this groove is broadened somewhat by its outer edge being carried
by an easy curve into the path of the pin.
At both ends the descent from the face of the disc to the bottom of the groove is
by an incline, so that the pin may enter or emerge from the groove without jar.
As before stated, the groove extends only partially around the face of the disc,
leaving a "land" of the normal plane of the disc between the ends of the groove.
If the sleeve be turned in the direction of the narrow end of the groove the pin
takes against the face of the disc outside of the groove, and is simply pressed in,
breaking the shunt circuit as before explained, causing a continuous wave of current
to be sent upon the line, and a continuous signal to be made, say, a continuous
ringing of a bell.
If, however, the sleeve be turned in the opposite direction, the pin is hit by the
outer edge of the broadened end of the groove and carried inward slightly, the pin
taking in the groove, leaving the shunt closed so long as the pin is in the groove,
the pin being forced inward, and the shunt consequently broken, only when the pin
passes out of the groove and rides upon the land.
By this means the current is sent upon the line during a part of each revolution
only, with the result that an intermittent signal, or a signal composed of sounds
with intervening pauses is given.
In the bottom of the groove referred to could be made a series of inclined or cam
faces following each other in any desired sequence so that a regular dot and dash
or any other arbitrary signal could be given.
This arrangement permits of two distinct signals being given without change of
apparatus, or any operation on the part of the operator, except the mere change of
direction of rotation.

page_text: "
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Griffith Brewer in the Great Seal Patent Office on the
10th May 1881.
EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN MAGNETO-ELECTRIC SIGNAL APPARATUS." (A communication
from abroad by Edward Hibberd Johnson and Thomas Alva Edison, both of Menlo
Park, in the State of New Jersey, United States of America.)
Magneto-electric machines as signal apparatuses are often used in such relation
to other devices that it is desirable that they should be cut out of circuit when not
in use, being thrown into the circuit only when in uso.
It is also often desirable that they should, without any change at the time of
use, be capable of giving two distinct signals, as, for instance, a continuous ring
and an intermittent ring, indicating two distinct wants, or operations, or things.
The accomplishment of both these results in one organization is tho object of
this Invention.
In carrying the Invention into effect a shunt circuit is formed around the
magneto machine or generator, a portion of which circuit is a contact spring or
lever taking against an anvil or contact point.
The actuating handle or pulley is attached to a sleeve which is loose upon the
main driving shaft, but secured thereto by a pin on the shaft, taking in a triangular
opening or slot in the side of the sleeve.
Upon the inner end of the sleeve is a disc which takes against a rod, whose other
end bears against the contact spring or lever.
The force of the contact spring, or that of a special spring, is used, to normally
hold the rod pushed against the disc, so that the sleeve is as far out on the shaft as
the slot and pin permit, in which condition the spring impinges on the anvil or
contact point, closing the shunt circuit, thus practically cutting tho generator out
of circuit.
Upon rotation the sleeve turns loosely upon the shaft until the outer end of the
slot reaches the pin, when sleeve and shaft turn together; the slot being triangular
causes the carrying inward of the sleeve and disc, pushing the rod against the
contact lever, or spring, causing it to leave the contact point or anvil, breaking
thereby the shunt or short circuit, compelling the current from the generator to
traverse the main circuit.
Upon cessation of use, the parts return to their normal position, closing the shunt
or short circuit.
By the arrangement thus described the first of the objects noted is accomplished.
To accomplish the second object the arrangement noted is modified as follows:-
The contact spring referred to is made with a twist about its centre, so as to be
capable of motion in either direction.
To it is attached directly the pin which takes against the disc upon the sleeve.
In the inner face of the disc a groove is cut extending partly around the disc,
and whose outer edge normally is out of the path of the pin.
One end of this groove is broadened somewhat by its outer edge being carried
by an easy curve into the path of the pin.
At both ends the descent from the face of the disc to the bottom of the groove
is by an incline, so that the pin may enter or emerge from the groove without
jar.
As before stated, the groove extends only partially around the face of the disc,
leaving a "land" of the normal plane of the disc between the ends of the groove.
If the sleeve be turned in the direction of the narrow end of the groove, the pin

page_text: The shaft and sleeve then move together, and us the pin i takes upon the plane
of the disc outside of the groove, the shunt circuit is kept broken and a continuous
current is sent, which may be utilized for a.continuous signal call or other purpose.
If however the sleeve be turned in the direction of arrow 1, Figure 3, the pin i
is caught by the enlarged end 6 of the groove, and remains in the groove during a
part of the rotation.
During such part the shunt is not broken, and no current goes to line.
As the pin rises up out of the groove and passes over the "land" L the shunt is.
broken during the time of its passage over such "land," and a current is sent to
line.
Thus during each revolution of the disc there is a period of current and a period
of no current, so that the signal given is intermittent or broken up.
Figure 5 is a diagram representation of a groove straightened out. In the bottom
of the groove.inclines or cam surfaces o, o, could be inade in such order, sequence,
or relation to each other, as might be desired, so that a definito number, letter,
or other arbitrary signal could be given.
:
While in this arrangement the sleeve is shown as mounted upon the main
driving shaft, it is evident that it need not always be placed thereon, but that it
may be mounted upon any other shaft or on a special shaft driven from the main
driving shaft.
Having now described the nature of the said Invention, and in what manner tho
same is to be performed, I declare that I claim,—
First. The combination with a main circuit and a magneto-electric machine of
a shunt or short circuit around the machine, and means for automatically controlling,
upon the operation of the machine, the shunt or short circuit, substantially as set
forth.
Second. The combination of the driving shaft of a magneto-electric machine, a
sleeve mounted thereon in such manner as to have a determinate longitudinal
movement thereon, and a circuit breaker automatically operated by the longitudinal
movement of the sleeve, substantially as set forth.
Third. The combination with a magneto machine and its main current of a
shunt or short circuit, and means for automatically breaking such short circuit
entirely upon movement in one direction and intermittently breaking it upon
movement in the other direction, substantially as set forth.
Fourth. The combination of the driving shaft of a magneto electric machine, a
sleeve mounted thereon in such manner as to have a determinate longitudinal
movement thereon, and a circuit breaker automatically operated by such sleeve to
break a current entirely during movement in one direction and intermittently
during movement in the other direction, substantially as set forth.
Fifth. The combination with a magneto machine of means, substantially such as
described, for producing different signals upon rotation of the driving shaft in
different directions, substantially as set forth.
In witness whereof, I, tho said Edward Griffith Brewer, have hereunto set my
hand and seal, this Seventh day of May, in the year of our Lord One
E. G. BREWER. (L.S.)