IMPROVEMENTS IN MAGNETO OR DYNAMO ELECTRIC MACHINES
Year: 1882

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine Lako
& Co Patent Agents, Southampton Buildings, London, for an invention
of "IMPROVEMENTS IN MAGNETO OR DYNAMO ELECTRIC MACHINES". A. com-
munication from abroad by Edward Weston, of Newark, New Jersey,
United States of America,
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 3rd April 1882.
WILLIAM ROBERT LAKE of the firm of Haseltine Lake & Co Patent Agents,
Southampton Buildings London "IMPROVEMENTS IN MAGNETO OR DYNAMO
ELECTRIC MACHINES A communication from abroad by Edward Weston, of
Newark, New Jersey, United States of America,
"
This invention relates to that class of electrical generators which have an
armature wound with a number of coils, the ends of which are united to form an
endless wire, and from which loops are taken off from the junctions of the originally
separate sections of wire on the said armature and united to the separate insulated
segments of the commutator.
Great difficulty is experienced in these machines in avoiding "short circuiting"
of the adjacent commutator-strips, and the consequent destruction of the insulation
of the coils included in the circuit between the adjacent segments. This arises
notwithstanding the fact that all the strips on one side of a line, bisecting the
commutator diametrically, are of opposite polarity only to those on the other side,
for there is a difference of potential between any two adjacent strips on either side
of this line, and a consequent tendency for a current to pass from one strip to the
adjacent strip having a lower potential, thus forming a branch, or derived circuit
through which a portion of the current that should pass to the main circuit will
flow. The liability of thus short-circuiting and injuring by the effects of heat, the
coils included in the circuit between any two given adjacent commutator segments,
is reduced by increasing the number of sections of wire on the armature, and
correspondingly increasing the number of commutator segments. In this manner
it is possible to so far increase the number of sections as to avoid the flow of a
current of such strength as to heat any section to a degree sufficient to destroy the
insulating material. This is, however, in practice both expensive and troublesome,

page_text: and does not obviate the loss of useful effect which arises from cutting out that
portion of the otherwise effective wire included between the two adjacent strips
which have been short circuited.
The present invention is directed to overcoming these difficulties, and is designed
to render the machines constructed substantially as above described, more reliable
and efficient, and easier of management.
To this end the said invention consists essentially in winding the armature with
two or more independent endless wires and so connecting them by loops to the
commutator segments as to avoid having any two adjacent strips of the commutator
connected to loops from adjacent coils on the armature.
In practice, two wires for the armature will generally be found sufficient to avoid
short circuiting the coils. In this case the armature may be wound in sections, as
customary heretofore, but in connecting them together it is necessary to connect
alternate sections, instead of adjacent sections, and to lead the loops, or ends, so
formed, to alternate strips of the commutator. When this is done with the first
series of alternate coils, the second, or intermediate series, may be connected in the
same manner to the remaining commutator segments.
It is well known that the cylindrical and ring armatures as at present employed,
are wound with a number of independent coils or bobbins. An armature has
heretofore been made in which these coils are connected end to end to form a single
continuous wire, the connections in this case being made by the loops or joined ends
passing to the commutator segments.
In carrying this invention into practice the coils are wound in the sections; the
direction of winding and method of taking off the loop being similar to, that
heretofore employed by the communicator of this invention. Upright arms are
connected with the commutator segments and arranged to receive at their ends, the
loops or ends taken from the armature coils. One set of loops are connected with
alternate uprights and commutator segments while the other loops are connected in
a similar manner to the intervening segments. From this construction it will be
seen that the brushes as they slide from one pair of segments of the commutator
will come on another pair of segments, with which there is no tendency to short
circuit.
The same results are obtained in the case of a ring armature; the loops or ends.
are taken from the wires where they are brought over from one coil to the next to
form two continuous conductors:
It will be observed in this case, as in the former, that the set of wires forming.
the loops from one conductor are connected to alternate strips, while the wires
forming the loops from the other conductor, are attached to the intervening
segments.
It will thus be seen that by this mode of winding and connecting the coils to the
commutator strips or segments, should any two adjacent strips of the commutator
be accidentally connected, as by particles of metal from the brushes bridging the
space between the separate strips, no injury can result to the machine nor is there
any loss of useful effect.
In fact it now becomes necessary to connect the alternate strips in order to short
circuit any section of the coils on the armature-this can only occur in practice by
connecting or bridging over two of the insulating spaces and so connecting three
of the commutator strips. It is also evident that winding an increased number. of
coils, will still further reduce the liability to injury or loss of energy.
I have above described my invention as embodied in the most practical and
effective form of which I am at present aware. As above stated this method of
winding may be varied by winding each coil in independent sections, in the several
recesses or grooves, instead of having the wires side by side throughout their whole
length. In either case, however, the result is the same.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
3rd October 1882.
}
WILLIAM ROBERT LAKE; of the firm of Haseltine, Lake, & Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN MAGNETO OR DYNAMO
ELECTRIC MACHINES A communication from abroad by Edward Weston, of
Newark, New Jersey, United States of America,
دو
This Invention relates to that class of electric generators which have an
armature wound with a number of coils, the ends of which are united to form an
endless wire, and from which loops are taken off at the junctions of the originally
separate sections of wire on the said armature and are united to the separate
insulated segments of the commutator.
Great difficulty is experienced in these machines in avoiding "short circuiting"
of the adjacent commutator strips and the consequent destruction of the insulation
of the coils included in the circuit between the adjacent segments. This difficulty
arises, notwithstanding the fact that all of the strips on one side of a line bisecting
the commutator diametrically are of opposite polarity only to those on the other
side of such line; for there is a difference of potential between any two adjacent
strips on either side of this line and a consequent tendency for a current to pass
from one strip to the adjacent strip having a lower potential, thus forming a
branch, or derived circuit through which will flow a portion of the current that
should pass to the main circuit. The liability to thus short circuit and injure (by
the effects of heat) the coils included in the circuit between any two given adjacent
commutator segments is reduced by increasing the number of sections of wire on
the armature and correspondingly increasing the number of commutator segments.
In this manner it is possible to so far increase the number of sections as to avoid
the flow of a current of such strength as to heat any section to a sufficiently high
degree to destroy the insulating material. This increase in the number of sections
is, however, in practice, both expensive and inconvenient, and does not obviate
the loss of useful effect due to the cutting out of that portion of the otherwise
effective wire included between the two adjacent strips which have been short
circuited. The present invention is designed to overcome these difficulties and to
render the machines constructed substantially as above described more reliable,
efficient and manageable than heretofore.
For this purpose the armature is wound with two or more independent endless
wires which are so connected by loops to the commutator segments as to avoid
having any two adjacent strips of the commutator connected to loops from adjacent
coils of the same wire on the armature. In practice, two wires for the armature
will generally be found sufficient to avoid short circuiting the coils. In this case,
the armature may be wound in sections as heretofore, but in connecting them it
is necessary to connect alternate sections, instead of adjacent sections, and to lead
the loops so formed, to alternate strips of the commutator. When this is done
with the first series of alternate coils, the second, or intermediate series may be
connected in the same manner to the remaining commutator segments.
In the accompanying drawing are illustrated two armatures constructed
according to the said invention,
Figure 1 represents in perspective the end of a cylindrical armature with its
commutator attached showing the method of winding and the connections as above
Specified.
1.

page_text: Figure 2 is. a side view shewing a circular or ring armature embodying the
above specified manner of winding according to the said invention.
Figure 3 is a diagram illustrating the winding of the coils on the armature.
It is well known that cylindrical and ring armatures as at present employed.
are wound with a number of independent coils or bobbins. An armature has
heretofore been made in which these coils are connected end to end to form a single
continuous wire, the connections in this case being made by the loops or joined
ends passing to the commutator segments. An armature of substantially this
construction is illustrated in the drawing,
In Figure, 1, A, A, represent the sections of a cylindrical armature.
In these sections are wound the wire coils represented by the white and black
lines, the direction of winding and the method of taking off the loops B, C, being
similar to that herein before referred to.
The arms D of the commutator segments E are arranged to receive at their ends
the loops or ends taken from the armature coils. As shown in the drawing, the
loops shown in black are connected with alternate arms and commutator segments
while the other loops, that is to say, those shown in white, are connected in a
similar manner to the intervening segments. It will be obvious that in the
machine provided with this armature, the brushes, as they are left by one pair of
segments of the commutator, will bear upon another pair of segments with which
there is no tendency to short circuit.
The same results are obtained with a ring armature, as shown in Figures 2 and 3
in which A, A, represent the several sections or bobbins. In this armature the
loops or ends B, C, are taken from the wires where they are brought over from one
coil to the next to form two continuous conductors. It will be observed that in
this armature, as in that shewn in Figure 1, the set of wires shown in black and
forming the loops from one conductor are connected to alternate strips, while the
wires shown in white forming the loops from the other conductor are attached to
the intervening segments. In Figure 3 the conductors are indicated the one by an
unbroken or full line and the other by a dotted line line; C, B, being the points of
their attachment to the commutator.
It will be seen that in an armature embodying this mode of winding the coils
and connecting them to the commutator strips or segments, should any two
adjacent strips of the commutator be accidentally connected, for instance, by
particles of metal from the brushes bridging the space between the separate strips,
no injury can result to the machine nor will there be any loss of its useful effect.
In order to short circuit any section of the said coils it would be necessary to
connect alternate strips; this connection could only occur in practice by bridging
over two of the insulating spaces and so connecting three of the commutator
strips. And it is obvious that winding an increased number of coils upon the
armature will still further reduce the liability of the machine to injury or loss of
energy.
I have described this Invention as embodied in the most practical and effective
form of which I am at present aware. As above stated the method of winding
shown may be varied by winding each coil in independent sections in the several
recesses or grooves, instead of having the wires side by side throughout their whole
length. In either case, however, the result will be practically or substantially the
same.
Having thus fully described the said Invention and shewn in what manner the
same may be conveniently and advantageously carried into practice I wish it
understood that I do not restrict myself to any precise form of armature, or machine
to which the same is or may be applied, but I claim, in or for a magneto or
dynamo electric machine :-
First. An armature wound with two or more independent continuous conductors,
the adjacent sections of which are connected to alternate segments of the
commutator, substantially as, and for the purpose, set forth.

page_text: Second. A cylindrical or annular armature core having grooves or recesses for
the reception of the coils, and two or more independent continuous conductors
wound therein, in combination with a commutator to whose segments the said coils
are alternately connected, substantially as, and for the purpose, set forth.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Third day of October in the year of our Lord One
thousand eight hundred and eighty two.
W.ROB. LAKE. (L.S.)