IMPROVE- MENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1883

page_text: LETTERS PATENT to William Phillips Thompson, Fel Inst PA of the Liverpool
"
and London Agency for Foreign Patent Solicitors 6 Lord Street Liverpool
in the county of Lancaster Civil Engineer for an Invention of "IMPROVE-
MENTS IN DYNAMO-ELECTRIC MACHINES a communication to him from
Joseph. A. I Craig a person resident at the city of Montreal in the district
of Montreal and province of Quebec in the dominion of Canada
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 1st February 1883.
WILLIAM PHILLIPS THOMPSON Fel. Inst. P.A. of the Liverpool and London
Agency for Foreign Patent Solicitors, 6. Lord Street Liverpool, in the County of
Lancaster, Civil Engineer, "IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
"
a communication to me from Joseph A. Craig a person resident at the city of
Montreal in the district of Montreal and province of Quebec in the dominion of
Canada
This invention has for its object to increase the efficiency of dynamo-electric
machines by reducing the magnetic friction between the armature and the field and
thus economize power; and also to lessen the cost of the apparatus while greatly
increasing the electrical force, and at the same time produce a machine which can
be easily taken apart for repairs and readily put together without disturbing more
than a few parts at one time.
The improvements consist firstly in an improved construction of armature which
is made up of an annular core of pasteboard or other non-magnetic material upon
which is wound a coil of iron wire (or alternate layers of wire and sheet iron if
found preferable) in such manner as to envelope said non-magnetic core on all
sides; transversely or across the ring thus formed, insulated wire is wound to form
the bobbins, which bobbins are electrically connected with each other and with the
commutator in a suitable manner, and this bobbin ring is held between two
perforated end plates or discs mounted firmly on a central shaft, and the different
bobbins are separated at the periphery by bars of wood or other non-magnetic
Price Gidl

page_text: material. These bars are affixed at either end to the rims of the end plates or discs,
and serve the double purpose of preventing "short circuiting" when the armature
is revolved very close to the poles of the field magnets, and of holding the core and
bobbins firmly in their proper place.
By this construction of armature, thorough ventilation is ensured as the same
will be hollow and the perforated end discs will allow of the free passage of air
through the interior, in this manner preventing that heating of the parts, which is
found so detrimental in machines of the old type.
The invention consists secondly in a field magnet or series of same, constructed
of a core of iron wire, or alternate layers of wire and sheet iron, wound in curved
or elongated form continuously around or through separate polar extensions which
partially encircle the revolving armature, said core being covered with insulated
wire wound transversely on same, the positive and negative fields being separated
from each other by blocks or division plates, but the helices being electrically
connected in the usual or any approved manner.
A modification of this part of the invention consists in providing the field
magnet thus formed, with a non-magnetic core similar to that described for the
armature; and the invention may be still further modified by substituting for the
wire core and separate pole pieces, a series of sheet metal plates stamped to
the configuration required and afterwards piled together and wound with insulated
wire; or alternate plates and coils of wire, may be used with like effect.
This part of the invention enables the builder to rapidly construct the field
magnets at small cost, and produce a symmetrical and compact machine.
The improvements embody thirdly, a duplex commutator made up of two sets of
metal strips placed end to end with relation to each other, each separate strip being
insulated from each other at sides and ends, and the strips in each set being
connected alternately with the différent sections of the commutator plate or disc
(and thus forming connection with the bobbin wires) by means of metal connecting
strips constructed with steps and projecting ends and arranged between the
commutator strips and the central shaft but insulated from the latter.
By using two brushes or collectors, two currents may be taken from a commutator
of this Construction, one current being thus taken if desired from one half of the
commutator along the line, and another sent again to the field magnets; or two
line currents for different purposes may be utilized or one brush in connection
with both halves of the duplex commutator will carry off the current in one
direction as at present.
If desired two or more rings of bobbins may be used in constructing the
armature, and placed one inside the other in magnetic contact, and the wires from
these extra bobbins can be connected with the improved commutator, and a double
current in this way produced to good advantage
The armature, magnets, and commutator above described, may be used separately
with machines of different constructions, but the power of the dynamo-electric
machine is greatly increased and its general efficiency advanced by their conjoined.
use, especially in the combination of the armature and field-magnets.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Phillips Thompson in the Great seal Patent Office on
the 1st August 1883.
WILLIAM PHILLIPS THOMPSON. Fel. Inst. P.A. of the Liverpool and London
Agency for Foreign Patent Solicitors, 6 Lord Street, Liverpool in the county of
Lancaster, Civil Engineer "IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES.
"
A communication to me from Joseph A. I. Craig, a person resident at the city
of Montreal, in the district of Montreal and province of Quebec, in the dominion
of Canada.
This invention has for its object to increase the efficiency of the Machine by
reducing the magnetic friction between the armature and the field, and thus
economize power; and also to lessen the cost of the apparatus while greatly
increasing the electrical force, and at the same time produce a machine which can
be easily taken apart for repairs and readily put together without disturbing more
than a few parts at one time.
For complete comprehension of the several improvements reference must be had
to the accompanying drawings, in which letters similar to those used. in this
description indicate like parts in all the figures, and where:
Fig 1. represents a side view of a dynamo-electric machine embodying the
improved armature, but with field magnets of the ordinary type.
Fig. 2. is a side view partly in section of a machine provided with both improved
armature and field-magnets.
Fig 3. is a detail view (partly in section) of the armature.
Fig 4. a view of part of the bobbin ring showing details of construction.
Figs 5 and 6 are enlarged sectional details of same.
Fig 7. is a side view of a dynamo-electric machine showing wire magnets
arranged in an elongated form, the armature being indicated simply in outline.
Fig. 8 is an end view of Fig 7 and Fig a section of same.
Fig 10 is a detail of modified form of magnet specially suitable for Fig 1, and
Fig 10 is another modification of a field magnet of the same internal construction
as the armature core.
Fig 11 is a vertical section of the improved duplex commutator, and Fig 12 is a
cross section of same.
Fig 13 is a view showing conducting strips of commutator.
The first part of the invention consists in an improved construction of armature A
made up of an annular core a of pasteboard or other non-magnetic material upon
which is wound a coil of iron wire b, (or alternate layers of wire and sheet metal if
found desirable), in such manner as to envelop said non-magnetic core on all sides;
transversely across or around the ring thus formed insulated wire B is wound so as
to form the different bobbins 61, 61, which bobbins are electrically connected with
each other and with the commutator plate in any approved way.
This ring of bobbins is held between two end plates or discs C perforated at c,
and firmly mounted on the central shaft D, and the different bobbins are separated
at the periphery by bars E, E, of wood or other non-magnetic material, which bars
are affixed at either end to the rims of the end plates or discs C, thus serving the
double purpose of preventing "short circuiting" when the armature is revolved
very close to the poles of the field magnets, and of holding the core a, b, and
bobbins b', 6', firmly in their proper places.
By this construction of armature also, thorough ventilation is ensured as the
same will be hollow, and the perforations c in the end discs C will allow of the free
passage of air through the interior, in this manner preventing that heating of the
parts, which is found so detrimental in machines of the old styles.

page_text: This improved armature will be easily understood by reference to Figs 1, 3 and 4
of the drawing.
The second part of the invention relates to the improved construction and
arrangement of the field magnets F, F of a dynamo-electric machine, which are
shown specially in Figs. 2, 7, 8 and 9; they are constructed of a core of soft iron
wire f, wound in a circular eliptical or elongated form (Fig. 2 or Fig. 7) con-
tinuously around or through separate polar extensions G, G, of solid metal, curved
on their inner sides to partially encircle the armature A which revolves between
said poles, and grooved at g, on their outer sides to receive the wire core f,
a plate g¹ being bolted to the poles to keep the wires in place. Around the core
and between suitable flanges or shoulders, to keep the positive and negative fields
separate, the usual insulated wire f¹ is wound to form the helices, which are
electrically connected in the usual manner.
A modification of this part of the invention, shown in Fig. 10 consists in
providing the field magnet thus formed with a non-magnetic core, similar to that
described for the armature; and the invention may be still further modified by
substituting for the wire core f and separate pole pieces G, a series of sheet metal
plates stamped to the configuration shown in Fig. 10 or approximately thereto,
and afterwards piled together and wound with insulated wire; or alternate plates
and coils of wire may be used with like effect.
This part of the invention enables the builder to rapidly construct the field
magnets at small cost, and while greatly increasing its power will ensure the
production of a compact and symmetrical machine.
The improvements also embody thirdly a duplex commutator K shown in detail
in Figs. 11 and 12. It is made up of two sets of metal strips K, K', placed end to
end with relation to each other, and each separate strip being insulated from its
neighbour at sides and ends.
The strips in each set are magnetically connected alternately with the different
sections m of the commutator plate or disc M (and thus forming connection with
the bobbin wire b¹) by means of metal connecting strips L constructed with steps
and projecting ends and arranged between the commutator strips k, k' and the
central shaft D in magnetic contact, with each of the strips alternately, but
insulated from the shaft by a wooden collar A2 or other suitable means.
By using two brushes, or collectors (not shown) of the ordinary kind, two
currents may be taken from a commutator of the above construction, one current
being taken from one half of the commutator along the line, and another sent
again to the field magnets, or two line currents may be taken off, or one brush
in connection with both halves of the duplex commutator will carry the whole
strength of the current in one direction, as in the ordinary dynamo-electric
machines.
If desired two or more rings of bobbins may be used in constructing the
armature, and placed one inside the other, in magnetic contact or subject to the
inductive influence of the outer ring;-and the wires from these extra bobbins can
be connected to the duplex commutator, and a double current produced in this way,
which may sometimes be used to good advantage.
The improved armature, field magnets and commutator above described may be
used separately in connection with machines of different constructions, but the
power and advantages of the machine are largely increased by the use of the
different parts of this invention conjoined, especially by the combination of
the armature and field magnets constructed and arranged as above described.
Having now described the invention as communicated to me, I wish it to be
understood that what I desire to protect under the Letters Patent is
1st. An armature for a dynamo-electric machine, made up of an annular core of
pasteboard or other non-magnetic material, iron wire wound round same con-
centrically, so as to completely envelop same on all sides, and insulated wire wound
transversely around or across same to form the bobbins, substantially as and for the
purpose described.

page_text: 2nd. In an armature for a dynamo-electric,machine, the combination with the
bobbins b', constructed and arranged substantially as described, and perforated end
discs CC, mounted on the armature shaft and enclosing said bobbins between
them, of bars E E, of wood or other non-magnetic material fastened at the ends to
said discs and passing between the different bobbins, substantially as and for the
purpose specified.
3rd. A field magnet made up of a core of soft iron wire, continuous in its coil,
around which is wound transversely insulated wire to form the helices arranged
in combination with separate polar extensions, substantially as set forth.
4th. A field magnet for a dynamo-electric machine, made up of a core of alternate
layers of wire and sheet iron, around which core is wound transversely insulated
wire to form the helices, arranged in combination with separate polar extension,
substantially as set forth.
5th. In a dynamo-electric machine, a core for a field magnet, and its polar
extensions made up of a number of thin metal plates, each stamped in one piece to
the configuration required for such core, and polar extensions and piled together,
substantially as described and shown in Fig. 10.
6th. A field magnet for a dynamo-electric machine made up of a central core of
pasteboard or other non-magnetic material, iron wire wound on and around same
together with the magnet so as to completely envelop said non-magnetic core on
all sides, and insulated wire wound on same transversely to form the helix,
substantially as shown in Fig 10, and described therein.
7th. A commutator for dynamo-electric machine, made up of two sets of metal
strips K K', placed end to end and each strip being insulated from its neighbour at
sides and ends, and the strips in each set being connected alternately with the
different sections of the commutator plate M, by means of conducting strips L, all
arranged and combined to operate, substantially in the manner and for the purpose
specified.
In witness whereof I the said William Phillips Thompson have hereunto set
my hand and seal this twenty sixth day of July in the year of our Lord
one thousand eight hundred and eighty three.