IMPROVEMENTS IN OBTAINING, INCREASING, AND EMPLOYING CURRENTS OF ELECTRICITY, AND IN APPARATUS THEDEROD
Year: 1880

page_text: LETTERS PATENT to Thomas Slater, of Westbourne Park, in the County of
Middlesex, Civil Engineer, for an Invention of "IMPROVEMENTS IN OBTAINING,
INCREASING, AND EMPLOYING CURRENTS OF ELECTRICITY, AND IN APPARATUS
THEDEROD "
PROVISIONAL SPECIFICATION left by the said Thomas Slater at the Office
of the Commissioners of Patents on the 3rd June 1880.
THOMAS SLATER, of Westbourne Park, in the County of Middlesex, Civil
Engineer. "IMPROVEMENTS IN OBTAINING, INCREASING, AND EMPLOYING CURRENTS
OF ELECTRICITY, AND IN APPARATUS THErefor.'
This Invention relates to improvements in obtaining, increasing, and employing
currents of electricity.
According to my Invention I use a revolving armature or armatures in close
proximity to the poles of a permanent or a series of permanent magnets in place
thereof electro magnets. The fixed magnets, whether permanent or electro, are
placed with opposite poles 180° apart from the axis of the revolving electro
magnet or magnets.
The
If the
The fixed magnets, when electro magnets, have a constant unbroken current
passing through them at the time the revolving electro magnet (or magnets) is at
work, and only these revolving magnets (or magnet) have the current that passes
through them cut off and reversed once in every 180° of their revolution.
poles of the fixed magnet or magnets rest upon a plate of soft iron of about half an
inch thick, and the magnets bridge over or under, or both, the revolving armature
or armatures. I also use a compound armature divided into two or more lengths,.
and each part thereof revolves simultaneously on the same axis or centre.
compound armature is of two lengths the current of electricity is arranged to enter
and leave the same having opposite polarity, i.e., if one part of the magnet has S.
polarity that of the other on the same side of axis will have N. polarity. This is
effected by either winding on the wire of each part of the compound magnet
differently or by reversing the poles of the fixed or permanent magnets at the place
of their attraction when doing work. Each part of the compound armature may be
the same or of different diameters, but greater power is obtained therefrom when
the diameter of one part is two, three, or more times larger, and its length propor-
tionately shorter than that of the other part of the armature. This enlarged part
of the armature may have a primary and a secondary coil of wire wound thereon,
one coil receiving the current from a galvanic battery or from a dynamo electro or
magneto electro machine, and the other coil receiving its current from the permanent
fixed magnets of its own machine.
°

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Slater in the Great Seal Patent Office on the 3rd
December 1880.
THOMAS SLATER, of Westbourne Park, in the County of Middlesex, Civil
Engineer. "IMPROVEMENTS IN OBTAINING, INCREASING, AND EMPLOYING CURRENTS
OF ELECTRICITY, AND IN APPARATUS THEREFOR."
This Invention relates to improvements in obtaining, increasing, and employing
currents of electricity, and in apparatus therefor.
And in order that my Invention may be clearly understood and readily carried
into effect, I will proceed to describe same with the aid of the accompanying
Drawings, reference being had to the letters and Figures marked thereon, and in
which Figure 1 is a side elevation of a dynamo-electric machine constructed according
to my Invention, and Figure 2 an end elevation thereof, but with plate E and
standard G removed; Figures 3 and 4 are sectional views of modified forms of the
revolving armature; Figure 5 is a side elevation of a modified and simplified form of
dynamo-electric machine. In the Drawings I have shown only electro-magnets
applied for the fixed magnets, but it is evident these may be replaced by permanent
magnets, their poles resting on a plate of soft iron.
A, A, are the fixed electro magnets having their like poles a, a, opposed and
separated by a strip B of non magnetic material. Each magnet surrounds one
half the circumference of the revolving armature C, and the poles are each brought
to a line (as shown) where opposed to the revolving armature. The form of the
core of these magnets is clearly shewn in the Drawings, the wire being wound
thereon in the direction of the axis of the revolving armature.
These fixed magnets
are supported by pillars D or by any other suitable means.
The revolving armature C is in like manner composed of two similar electro-
magnets with their like poles c, c, opposed and separated by a strip of non magnetic
material. The wire is wound on in the direction of the axis, as in the fixed
magnets. On the ends of the ring are fixed two plates E, and these carry the
shaft F for imparting rotary motion to the armature; G are the standards and
bearings for shaft F, and H is the driving pulley. For small machines I prefer
making the cores of the armature magnets of the sectional form shewn at Figure 3,
and for large machines of the sectional form shewn at Figure 6. The current is of
course made to enter each half of the revolving armature in the same direction,
leaving at the opposite poles. The fixed magnets (when electro-magnets) have a
constant unbroken current passing through them, whilst the revolving armature has
The
the currents passing it cut off and reversed once in about every 180°.
commutator or collector and the connecting up are all as well understood at
present.
In large machines and where the fixed magnets are fed by a separate battery
or other source of electricity I prefer to wind these coils with iron wire. In such
case the resistance of the fixed magnets may be thirteen to fifteen times that of
revolving armature.
Sometimes I employ a compound armature composed of two or more lengths on
the same axle, and all revolving together. The currents are arranged to enter and
leave these sections so that all will have a corresponding current.
This is effected by either winding on the wire of each part of the compound
magnet differently, or by reversing the poles of the fixed or permanent magnets at
the place of their attraction when doing work. Each part of the compound
armature may be the same or of different diameters, but greater power is obtained
therefrom when the diameter of one part is two, three, or more times larger, aud

page_text: its length proportionately shorter than that of the other part of the armature, the
current passing from the smaller to the larger.
This enlarged part of the armature may have a primary and a secondary coil of
wire wound thereon, one coil receiving the current from a galvanic battery or from
a dynamo-electro or magneto-electro machine, and the other coil receiving its
current from the permanent or fixed magnets of its own machine.
I claim as my Invention, to be secured by the herein before in part recited Letters
Patent,―
1. The form and construction of armatures hereinbefore described and illustrated
in the accompanying Drawings.
2. For dynamo electric machines the form and construction of fixed magnets
hereinbefore described and illustrated at Figures 1 and 2 of the accompanying
Drawings.
In witness whereof, I, the said Thomas Slater, have hereunto set my hand
and seal, the Third day of December, in the year of our Lord One thousand
eight hundred and eighty.
THOMAS SLATER. (L.S.)