IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1881

page_text: LETTERS PATENT to Legh Sylvester Powell, of Notting Hill, in the County
of Middlesex, for an Invention of " IMPROVEMENTS IN DYNAMO-ELECTRIC
MACHINES." A communication from abroad by Jean Marie Anatole Gerard
Lescuyer, of Paris, in the Republic of France, Engineer.
PROVISIONAL SPECIFICATION left by the said Legh Sylvester Powell at
the Office of the Commissioners of Patents on the 21st December 1881.
LEGH SYLVESTER POWELL of Notting Hill in the County of Middlesex.
"IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES." [A communication from
abroad by Jean Marie Anatole Gerard Lescuyer of Paris in the Republic of
France Engineer]
This Invention relates to dynamo-electric machines and it consists in certain
improvements in their construction and arrangement as hereinafter described.
In carrying out this Invention the improved dynamo-electric machine is con-
structed with a moveable inducing part formed by a wheel say for example of
brass or gun metal which is keyed upon a shaft mounted in suitable bearings.
A certain number of straight electro-magnets are arranged on the circumference of
this wheel in such a manner as to present alternate north and south poles on each
side of the wheel. These electro-magnets are connected with a collector on the
shaft of the machine communicating through rubbers or brushes with a machine
generating direct or continuous currents.
The induced part is fixed or stationary and consists of two series of oval or
elliptical coils attached to two rings or frames of iron or copper placed on each
side of the inductor.
The wire in these coils is wound between two elliptical plates or cheeks connected
together by two iron connecting bars and a copper bolt which serves to attach the
coils to the rings. The connecting bars nearest to the centre of the machine are
preferably angular in cross section and the bars nearest to the outer extremity of
Daina G71

page_text: the cheeks are preferably circular in section and somewhat thicker than the
angular bars. The wire is wound upon these bars in the space between the
cheeks.
The cheeks facing the inductors or revolving magnets are perforated with a
number of holes; but the cheeks which face the rings or frame are imperforated.
A thin sheet of metal is interposed between each layer of wire in the coils in order
to assist the inducing action and prevent the formation of extra currents. The
currents generated in the coils by the passage of the inducting electro-magnets
are alternate and may be used separately or may be combined by means of a
commutator.
A portion of the currents generated in the machine may be employed for exciting
the induction magnets by the employment of suitable commutators or devices for
controlling the passage of the said currents.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Legh Sylvester Powell in the Great Seal Patent Office on the
20th June 1882.
LEGH SYLVESTER POWELL of Notting Hill in the County of Middlesex.
"IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES." A communication from
abroad by Jean Marie Anatole Gérard-Lescuyer of Paris in the Republic of
France, Engineer.
This Invention relates to dynamo electric machines and it consists in certain
improvements in their construction and arrangement as hereinafter described with
reference to the accompanying Drawing Figure 1 of which represents in elevation
a machine constructed according to the said Invention Figure 2 is an elevation at
right angles to Figure 1 of the same the framing being omitted. The said
improved dynamo electric machine is constructed with a moveable inducing part
formed by a wheel A made of suitable material say for example made of brass or
gun metal which wheel is keyed upon a shaft B mounted in suitable bearings
carried in a framing as shewn in Figure 1. Straight, electro magnets C are
arranged on the circumference of this wheel A in such a manner as to present
alternate north and south poles on each side of the said wheel A. These electro
magnets C are connected with a collector or commutator D on the shaft B
communicating through rubbers or brushes E with a machine generating direct
or continuous currents of electricity.
The induced part of the machine is fixed or stationary and consists of two series
of oval or elliptical coils F attached to two rings or frames G of iron or copper
placed on each side of the inductor A. The wire in each of these coils F is wound
between two elliptical plates or cheeks connected together by two iron connecting
bars a a and a copper bolt b which serves to attach the coils to the rings.
Figure 3 is an enlarged view of one of the coils F with the bars and bolt a a
and b in section and one of the plates removed. The connecting bars a nearest to
the centre of the machine are preferably rectangular or angular in cross section
and the bars a nearest to the outer extremity of the cheeks are. preferably circular
in section and somewhat thicker than the angular bars as shewn clearly in the
said Figure 3. The wire f is wound upon these bars in the space between the
plates or cheeks as is also shewn clearly in the said Figure 3.
The plates or cheeks of the said coils F which face the inductors or revolving
magnets C are perforated with a number of holes as shewn in Figure 2 but the
cheeks or plates of the said coils F which face the rings or frames G are unperforated.
A thin sheet of metal is interposed between each layer of wire in the coils as
shewn by the thick lines in Figure 3 in order to assist the inducing action_and
prevent the formation of extra currents. The currents generated in the coils F by
the passage of the inducting electro magnets C are alternate and may be used
separately or may be combined by means of a commutator.
A portion of the currents generated in the machine may be employed for exciting
the induction magnets by the employment of suitable commutators or devices for
controlling the passage of the said currents.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is:-
First. The general arrangement or combination of parts constituting the dynamo-
electric machine substantially as hereinbefore described and illustrated in the
accompanying Drawings.

page_text: Second. The construction of the induced coils of dynamo-electric machines
substantially as herein before described and illustrated in the accompanying
Drawings and drawn to an enlarged scale in Figure 3 of the said Drawings.
In witness whereof I the said Legh Sylvester Powell have to this my
Specification set my hand and seal this Nineteenth day of June One thousand
eight hundred and eighty two.
LEGH S. POWELL.
(L.S.)