IMPROVEMENTS IN DYNAMO OR MAGNETO ELECTRIC MACHINES
Year: 1883

page_text: LETTERS PATENT to Henry Harris Lake of the firm of Haseltine Lake
"
& Co, Patent Agents Southampton Buildings London for an Invention of
"IMPROVEMENTS IN DYNAMO OR MAGNETO ELECTRIC MACHINES Communi-
cated to him from abroad by Herman R. Boissier of the City and State of
New York, United States of America
PROVISIONAL SPECIFICATION left by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 22nd January 1883.
HENRY HARRIS LAKE, of the firm of Haseltine Lake and Co. Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN DYNAMO OR MAGNETO
ELECTRIC MACHINES [A communication to him from abroad by Herman
R. Boissier of the City and State of New York, United States of America]
"
My invention relates particularly;
First To the commutator brushes and brush-holders, and
Second;
generator.
The object of the first part of the said invention is to provide a brush-holder
of such construction that the brush may be readily adjusted therein, and yet be
held firmly and securely in the desired position, and to so protect the clamping
devices and the brush that they may be handled without danger of accidental
shocks, to which end it consists in the features more particularly hereinafter
described.
To a shunt circuit around the armature or inductive portion of the
In carrying this part of the said invention into effect, the brush-holder is made
as a frame with open sides within which a follower is arranged to travel, it being
adapted to press and hold the brush upon the bottom of the frame. Upon the
sides of the follower two projections rise in which are pivotted a rod carrying an
excentric, shaped on its two sides and lower end as a parallelogram, while the
upper end is formed into a refused curve. Upon the under side of the upper part
of the brush-holder is a spring. The rod upon which the excentric is mounted is
prolonged beyond the carrier and terminates in a knob, preferably rubber coated,
or otherwise insulated.

page_text: When this rod is turned so that the longer sides of the excentric are parallel to
the brush the follower is so loosened that the brush may be freely moved therein.
When it is adjusted, a quarter turn of the rod brings the excentric so that the
lower end presses the follower down upon the brush, holding it securely, the upper
end taking against the spring, which, fitting slightly into the refused curve
mentioned, holds the excentric against accidental displacement.
The outer end of the brush which is preferably composed of several strips or
wires, is covered with rubber or other good insulator, so that it may be handled
without danger of shock.
It is well known that whenever an electric circuit is broken, a high tension reflex
current is generated at the moment of breaking, termed ordinarily the extra
current, which gives rise to sparks at the point of breakage and oftentimes also
at any comparatively weak insulated points, whereas in the case of dynamo-
machines, two or more portions of the circuit may be in contiguity.
"
"
Such sparks are in the one instance destructive of the contact points at the place
of breakage, and in the second instance of the insulation, creating crosses
leading primarily to weakening and eventually to destruction of the organization in
which it occurs.
These evils are especially liable to occur in dynamo-electric machines supplying
current to several electric lamps or other translating devices of comparatively high
resistance.
The object of the second part of the said invention therefore is to prevent, to a
great extent, such injurious currents, and to prevent any spark from the extra
current, if such there still may be, obviating the dangers to contact points and
armatures before noted.
This I accomplish by controlling the main circuit without even breaking it,
forming a shunt thereto between the poles of the generator, which closed, shall
simply afford a path of a resistance infinitesimal almost, in comparison to that of
the main circuit, so that while the latter remains constantly closed the shunt takes
therefrom practically all the current.
The mechanism which is proposed to be used therefor may be described simply
as two springs or resilient pieces, one connected to either commutator brush and
tending normally to contact with each other, their length being such that they
overlap ordinarily they are prevented from contacting by an excentric of
insulating material mounted upon one and adapted in one position to force them
apart, so that the only circuit is through the consumption circuit, while in the other
position the excentric permits the springs to contact and form a short circuit for
the armature, cutting out practically the consumption circuit.
Referring to the first part of the said invention, the frame of the brush-holder is
provided with a projection or lug for attachment to the machine. This frame is
composed of a bottom, sides, and top. Within a rectangular opening thus formed
plays the follower upon the sides of which lugs are formed, furnishing a support
and pivots for a rod which is prolonged, and terminated in an india-rubber or
insulated knob. Upon this rod, and between the lugs or supports, is secured an
excentric formed with two long parallel sides and a base at right angles thereto,
while the top is formed as a refused curve, that is having two slightly elevated
curves with a concavity between them.
Upon the under part of the top of the brush-frame is secured a spring.
When the rod is turned so that the excentric is in a certain position the follower
is raised up so that the brush may be inserted or moved to any desirable position.
When the brush is adjusted, the rod is given a one fourth turn which brings the
excentric into a certain position, the upper part taking against the spring, the
lower end pressing the follower down firmly, so as to grip the brush in position.
From the shape of the top, the spring bears upon the top and holds it positively.
and firmly against accidental displacement.
The free end of the brush is covered with india-rubber or other good insulator;

page_text: the rod being protected at its end by the knob and the brush by its coating, all
danger of shock while adjusting or changing the brushes is avoided.
The devices described enable the brush to be rapidly and easily put in position
or adjusted, the minimum of manipulation being required to loosen or to tighten
the brush.
While I have here described the preferable means for carrying my invention into
effect it is obvious that it may be varied in many ways without departing from the
principle thereof.
For example the form of the excentric might be varied in many ways, or the rod
controlling it might be mounted in bearings independent of the follower, and many
other changes might be made.
Referring now to the second part of the said invention I will here describe the
same in connection with any dynamo or magneto electric machine, the field of force
magnets having poles or polar extensions within which rotates the inductive coil or
coils or armature. Upon the commutator or collector take brushes springs or
collectors supported in frames. From one set of the brushes and one frame a wire
leads to one magnet, while from the other brushes and frame another wire leads to
the other magnet. From the first magnet a wire leads away and to any distance
and through any kind or number of translating devices, from which a wire leads to
the other magnet a complete circuit being formed containing no switch or other
device for interrupting the circuit, unless some circuit-breaking or circuit
transferring-device be located at the translating devices for the purposes of such
devices.
The frames are, however, connected by a short circuit which forms a shunt to the
main circuit just described, and which does contain a circuit controlling device.
This short circuit comprises two parts, each part being a piece of rather stiff spring
metal of good electrical conductivity, one piece being in electrical contact with the
one frame and set of collectors, while the other is in electrical contact with the
other frame and collectors. They are arranged to normally overlap each other at
their free ends, and springing against each other by their own resilience, to form
good electrical contact.
In one of these parts is cut a slot and upon its outer side are formed two
bracelets or legs forming bearings for a rod having a thumb-piece. Upon this rod
and within the slot is excentrically mounted an excentric cam or block of insulating
material. The cam or block being excentrically mounted is, when the rod is turned
in one position, entirely above the inner end of one of the parts so that both parts
impinge. When the rod is turned a quarter way around, the cam projects upon the
inner side and forces the two parts apart
It is evident that the spirit of this invention does not depend upon any particular
form of circuit controller between the frames and collectors but only that there
shall be between them a short circuit containing some kind of circuit-controller
and forming a shunt to the main circuit.
It is also evident that in the switch or circuit controller and associated devices,
many modifications may be made, for instance the two parts, instead of being of
springy material and hence self-resilient may have applied to them external
springs; that the cam or excentric may be applied to either part, that instead of
working through a slot in one, it may work upon the side of one, or be hollowed
to embrace and work upon both sides.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Harris Lake in the Great Seal Patent Office on the
20th July 1883.
HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co, Patent Agents
Southampton Buildings, London, ** IMPROVEMENTS IN DYNAMO OR MAGNETO
ELECTRIC MACHINES A communication to me from abroad by Herman R. Boissier,
of the city and State of New York, United States of America,
"
This invention relates to dynamo or magneto electric machines, and comprises
improvements in the commutator-brushes and brush-holders; and a shunt circuit
around the armature or inductive portion of the generator.
The object of one part of the said invention is to provide a brush holder of such
construction that the brush may be readily adjusted therein, and yet be held firmly
and securely in the desired position, and to so protect the clamping devices and the
brush that they may be handled without danger of accidental shocks, to which end
it consists essentially in the novel features hereinafter described.
According to this part of the said invention the brush-holder is made as a fraine
with open sides, within which a follower is arranged to travel, it being adapted
to press and hold the brush upon the bottom of the frame. Upon the sides of the
follower two projections rise in which are pivotted a rod carrying an excentric,
shaped on its two sides and lower end as a parallelogram while the upper end is
formed into a curve.
Upon the under side of the upper part of the brush holder is a spring.
The rod upon which the excentric is mounted is prolonged beyond the carrier
and terminates in a knob, preferably india-rubber coated or otherwise insulated.
When this rod is turned so that the longer sides of the excentric are parallel to
the brush, the follower is so loosened that the brush may be freely moved therein.
When it is adjusted, a quarter turn of the rod brings the excentric so that the
lower end presses the follower down upon the brush, holding it securely, the upper
end bearing against the spring which, fitting slightly into the said curve, holds the
excentric against accidental displacement.
The outer end of the brush, which is preferably composed of several strips or
wires, is covered with india-rubber or other good insulator, so that it may be
handled without danger of shock.
It is well known that whenever an electric circuit is broken, a high tension
reflex current is generated at the moment of breaking, termed ordinarily the extra
current, which gives rise to sparks at the point of breakage and oftentimes also at
any comparatively weak insulated points, where as in the case of dynamo machines,
two or more portions of the circuit may be in contiguity.
Such sparks are in the one instance destructive of the contact points at the place
of breakage, and in the second instance of the insulation creating "crosses" leading
primarily to weakening and eventually to destruction of the organization in which
it occurs.
These evils are especially liable to occur in dynamo electric machines supplying
current to several electric lamps or other translating devices of comparatively
high resistance.
The object of another part of the said invention therefore is to prevent to a
great extent such injurious currents and to prevent any spark from the extra
current, if such there still may be, obviating the dangers to contact points and
armatures before noted.
This I accomplish by controlling the main circuit without even breaking it by
forming a shunt thereto between the poles of the generator, which closed shall

page_text: imply afford a path of a resistance infinitesimal almost, in comparison to that of
the main circuit, so that, while the latter remains constantly closed, the shunt
takes therefrom practically all the current.
The mechanism used therefor may be described simply as two springs or resilient
pieces, one connected to either commutator brush and tending normally to make
contact with each other, their length being such that they overlap; ordinarily they
are prevented from making contact by an excentric of insulating material mounted
apon one and adapted in one position to force them apart, so that the only circuit
s through the main circuit, while in the other position, the excentric permits the
springs to make contact and form a short circuit for the armature, practically
cutting out the main circuit.
s through the main circuit, while in the other position, the excentric permits the
springs to make contact and form a short circuit for the armature, practically
cutting out the main circuit.
In the accompanying drawing.
Figure 1 is a side elevation and
Figure 2 is a top view of a brush holder constructed according to this invention.
Figures 3 and 4 are end views showing the excentric in different positions ;
and
Figure 5 is a view showing the preferred form of the excentric
Figures 6 and 7 are diagrams showing the shunt applied to a generator and
circuit; and
Figures 89 and 10 are views drawn to an enlarged scale, of a suitable switch
which may be used therewith.
Referring to Figures 1 to 5 C indicates the frame of the brush holder which is
provided with a projection or lug L for attachment to the machine. This frame C
is composed of a bottom a, sides cc and top b. Within the rectangular opening
thus formed plays the follower D upon the sides of which lugs d are formed,
furnishing a support and pivots for the rod A, which is prolonged, and terminated
in the india-rubber or insulated knob B. Upon this rod, and between the lugs or
supports d, d is secured the excentric e, formed with two long parallel sides and a
base at right angles thereto, while the top is formed with two slightly elevated
curves with a concavity between them.
Upon the under part of the top b of the brush frame is secured the spring .
When the rod A is turned so that the excentric is in the position shown in
Figure 3 the follower is raised so that the brush H may be inserted or moved to
When the
any desirable position between the follower D and the bottom a.
brush H is adjusted, the fourth of a turn is given to the rod a which brings the
excentric e into the position shown in Figure 4, the upper part bearing against
the spring, the lower end pressing the follower down firmly, so as to grip the
brush H in position.
From the shape of the top of the excentric the spring bears upon the said
top xx and holds it positively and firmly against accidental displacement.
As the free end of the brush H is covered with india-rubber or other good
insulator I and the rod A is protected at its end by the knob B all danger of
shock while adjusting or changing the brushes is avoided.
The devices described enable the brush to be rapidly and easily put in position
or adjusted, the minimum of manipulation being required to loosen or to tighten
the brush.
While I have here shown and described the preferable means for carrying this
invention into practice it is obv' us that they may be varied without departing
from the nature of the said inv ation. For example the form of the excentric
might be varied in many ways, or the rod controlling it might be mounted in
bearings independent of the follower.
Referring to Figures 6 to 10 M M indicate the field magnets of a dynamo or
magneto electric machine the said magnets having poles or polar extensions P P¹
within which rotates the inductive coil or coils or armature, upon the
commutator C of which bear brushes, springs or collectors b b¹ supported in the
frames B B¹

page_text: From one set of the brushes b' and the frame B' a wire 1, leads to the magnet M,
while from the brush b and the frame B the wire 2 leads to the magnet M¹.
From the magnet M the wire 3 leads away and to any distance and through any
kind or number of devices, such as lamps L L from which a wire 4, leads to the
magnet M', a complete circuit is thus formed which extends from the commutator
back to the same point and containing no switch or other device for interrupting
the circuit, unless some circuit breaking or circuit transferring devices be located at
the lamps or the like for the purposes of such devices.
The frames B B' are however connected by a short circuit which forms a shunt
to the main circuit just described, and which does contain a circuit controlling
device. This short circuit comprises two parts S S¹ each part being a piece of
rather stiff spring metal of good electrical conductivity, one piece S₁ being in
electrical contact with the frame B¹ and collectors b', while the other is in electrical
contact with the frame B and collectors b. They are arranged to normally overlap
each other at their free ends, and springing against each other by their own
resilience to form good electrical contact as shown in Figures 7 and 8.
In one of these parts S' is cut a slot e and upon its outer side are formed two
legs a a forming bearings for a rod d, having a thumb piece h shown in Figure 10,
but removed from Figures 8 and 9 in order not to obscure the operations of the
parts. Upon this rod d and within the slot e is excentrically mounted an
excentric, cam or block c of insulating material. The cam or block c being
excentrically mounted is, when the rod d is turned in one position, entirely above
the inner end of the part S, so that both parts S and S¹ impinge as in Figures 7
and 8. When the rod d is turned a quarter around, the cam c projects upon the
inner side and forces the two parts S and S¹ apart, as shown in Figures 6 and 9..
The operation is as follows that is to say-When it is desired to use the main
circuit the parts are in the position shown in Figures 6 and 9, when the
connection between S and S₁ is broken there is but one path for the current viz
through the frame B' the brush b', the wire 1, the field magnet M the wire 3, the
lamp or lamps L or the like, the wire 4, the field magnet M³ the frame B and the
brush b.
If now it be desired to break the main-circuit the rod d is turned until the
slot e is clear of the part S, allowing the parts S and S¹ to make contact, when the
second circuit S. S₁ is closed. This, being of comparatively small resistance, takes
practically all the current from the main circuit. If now from this there should
be any extra current, in the main circuit, it circulates therein and the electrical
equilibrium is restored without sparking. At the same time, as the generator here
shown is a dynamo with the coils of the field magnets M M in the main circuit,
they are also short circuited whereby the generation of electricity immediately
diminishes and finally censes.
It is evident that this invention does not depend upon any particular form of
circuit controller between the frame B and the brush 6 and the frame B¹ and the
brush but only upon having between them a short circuit containing some kind
of circuit controller and forming a shunt to the main circuit.
It is also evident that in the switch or circuit controller here shown as
consisting of the parts S S¹ and associated devices, many modifications may be.
made, for instance the two parts S S₁ instead of being of spring material and hence
self resilient may have applied to them external springs; the cam or excentric
may be applied to either part; instead of working through a slot in one, it may
work upon the side of one or be hollowed to embrace and work upon both sides.
Having thus fully described the said invention as communicated to me by my
foreign Correspondent, and the manner of performing the same, I wish it under-
stood that I am aware that a continuity preserving switch or key has been used
with a dynamo-electric machine adapted and arranged to close a circuit around
the armature of the machine just before breaking the main circuit, which latter
current is then to be completely broken, but such an arrangement and combination

page_text: requires a larger number and greater complication of circuit connections and
contact points than the method herein described therefore I claim :-
First In a brush-holder for a dynamo or magneto electric machine, an excentric
for securing the brush therein, substantially as setforth.
Second The combination, in the brush-holder of a dynamo or magneto electric
machine, of a follower and an excentric, substantially as set forth and for the
purpose specified.
Third A brush-holder for a dynamo or magneto electric machine, consisting of a
frame, a follower secured therein, and an excentric for operating the follower,
substantially as set forth.
Fourth A brush-holder for a dynamo or magneto electric machine, consisting
of a frame, a follower secured therein, and an excentric for operating the follower,
mounted upon a rod having its bearings in lugs upon the follower, substantially as
set forth.
Fifth In a brush-holder for a dynamo or magneto electric machine, the
excentric having its top curved substantially as set forth and for the purpose
specified.
Sixth-In a brush-holder for a dynamo or magneto electric machine, the com-
bination, with the excentric, of a spring arranged substantially as set forth and for
the purpose specified.
Seventh In a brush-holder for a dynamo or magneto electric machine, the rod
for manipulating the excentric provided with an insulating knob, substantially as,
and for the purpose, set forth.
Eighth The commutator-brush of a dynamo or magneto electric machine,
provided with an insulating coating or covering at its free end, substantially as
set forth, and for the purpose specified.
Ninth The combination, with the poles or brushes or collectors of a dynamo-
electric machine, of a short circuit (and means for controlling the same) forming a
shunt circuit to the main circuit of such machine, substantially as setforth, and for
the purpose specified.
Tenth The combination, with the poles or brushes or collectors of a dynamo-
electric machine, of a switch formed of the resilient conductors S, S', one of which
is provided with means for forcing their contiguous ends apart, substantially as set
forth.
In witness whereof I the said Henry Harris Lake have hereunto set my
hand and seal this Twentieth day of July in the year of our Lord One thousand
| eight hundred and eighty three.
HENRY H LAKE (L.S.)