IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1884

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for IMPROVEMENTS IN
DYNAMO-ELECTRIC MACHINES, a communication to me from abroad by Elisha
Barton Cutten of Kingsbridge in the City, County and State of New York, United
States of America, Gentleman to be as follows:-
The object of this invention is to obtain a sufficiently strong field magnet with
less iron and wire and consequently a lower resistance, and a smaller percentage of
power than is now used.
The invention consists in a dynamo-electric machine constructed with the parts
of the field magnet that receive the wire, tapered from the pole pieces to the yoke,
as will be hereinafter more fully described.
In this machine, the arms of the electro-magnet, which are connected at their
upper ends by an iron yoke firmly bolted to them, are made with their inner or
adjacent sides vertical, and with their edges and outer sides inclined or tapered.
The pole pieces are connected at each end by a piece of non-magnetic metal,
which serves as a bearing for the armature, which is of the well known Siemens
type.
Upon the bases of the pole pieces are formed small ears of iron to receive the
bolts that secure the machine to its wooden base, and which project a little below
the bases of the said pole pieces, so as to elevate the machine a little above its base,
to allow the heat generated in the machine to escape fully by radiation.
The pole pieces are made heavy and the arms of the field magnet are tapered so
that the upper portions surrounded by the coils will have about one half the
circumference of the lower portions. With this construction the resistance will be
decreased without decreasing the number of turns of wire and without a propor-
tional decrease in the strength of the field.

page_text: 1
COMPLETE SPECIFICATION.
I, ALEXANDER MELVILLE CLARK, of, the firm of A. M. and Win. Clark," of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for IMPROVEMENTS IN
DYNAMO-ELECTRIC MACHINES (a communication to me from abroad by Elisha
Barton Cutten, of Kingsbridge, in the City, County and State of New York,
United States of America) and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
The object of this invention is to obtain a sufficiently strong field magnet with
less iron and wire and consequently a lower resistance and a smaller percentage of
power than is now used.
The invention consists in a Dynamo-Electric Machine constructed with the parts
of the field magnet that receive the wire tapered from the pole pieces to the yoke
as will be hereinafter more fully described.
Reference is to be had to the accompanying drawings, forming part of this
specification in which similar letters of reference denote corresponding parts in all
the figures.
1
Figure 1 is a side elevation partly in section of a machine embodying the
improvement.
:
Figure 2 is an end elevation of the same partly in section-Figure 3 is a sectional
plan view of one half of the field magnet taken through the line X X figure 2-
Figure 4 is a plan view of one half of the field magnet the connecting yoke and
the wire being removed.
↓
A, are the arms of the electric magnet, which are connected at their upper ends
by an iron yokė B; firmly bolted to them-The arms A. are made with their inner
or adjacent sides, vertical, and with their edges and outer sides inclined or tapered
as shown in figures 2, 3 and 4.
3
The pole pieces C are connected at each end by a piece of non magnetic metal D
which serves as a bearing for the armature E-The armature E is of the Siemens
type and is too well known to require a description.
:
Upon the bases of 'the pole pieces C are formed small ears F of iron to receive
'the bolts that secure the machine to its wooden base G and which project a little
below the bases of the said pole pieces C to elevate the machine à little above its
base G to allow the heat generated in the machine to escape fully by radiation.
-20
The pole pieces C are made heavy and the arms A. of the field magnet are
tapered so that the upper portions surrounded by the coils H will have about one
half the circumference. of the lower portions With this construction the resistance
will be decreased without decreasing the number of turns of wire and without a
proportional decrease in the strength of the field.
Having now. particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
a
The electro magnet arms A having the inner side perpendicular, the outer
inclined and the upper ends connected by a yoke bolted to each one of them in

page_text: combination with the pole pieces O having non-magnetic connections D and the
armatúre E provided witli bearings in said connections D whereby the resistance
will be decreased without a corresponding decrease in the wire turns or the
strength of the field as described.