IMPROVEMENTS IN ELECTRO-MAGNETIC ENGINES
Year: 1875

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Ohancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN ELECTRO-MAGNETIC ENGINES."-A communication
from abroad by Charles A. Hussey, of the City, County, and
State of New York. United States of America.
COMPLETE SPECIFICATION filed by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition and Declaration, on the 3rd June 1875, pursuant to the
9th Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
ELECTRO-MAGNETIC ENGINES," and have petitioned Her Majesty to grant
unto me, my executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that it has

page_text: been communicated to me from abroad by Charles A. Hussey, of the
City, County, and State of New York, United States of America.
NOW KNOW YE, that I, the said Alexander Melville Clark, do
hereby declare that the following Complete Specification, under my
hand and seal, fully describes and ascertains the nature of the said In-
vention, and in what manner the same is to be performed in and by
the following statement, reference being had to the accompanying Sheet
of Drawings, and to the letters and figures marked thercon (that is to
say) :-
This Invention relates to an improved electro-magnetic engine for
running sewing machines and other light machinery, by which the
induction currents of the magnets and sparks at the commutator
are entirely avoided, and a more perfect utilization of the battery
current is produced.
The Invention consists of a circular supporting frame carrying two
stationary magnets with radial arms and T shaped pole ends, which
are placed by a commutator of the revolving shaft in connection with
the poles of the battery, so that the currents in the magnets are
alternately reversed to act with continuous force on a central revolving
magnet of similar shape, but double T shaped pole ends, connected
directly to the battery.
The commutator revolves with the central magnet, and is made of
positive and negative sections with separating insulating layer or band
for reversing, by the alternating contact with the adjustable current
transmitting contact wheels, the polarity of the stationary magnets.
This Invention is illustrated in the accompanying Drawing, in which
Figure 1 represents a side clevation of the improved electro-magnetic
engine; Figure 2, a vertical detail section of the commutator and
adjustable reversing contact wheels; Figure 3, a vertical transverse
section of the engine on the line c, c, Figure 1; Figure 4, a plan view, a
and Figure 5. a horizontal section of the same on line X, X, Figure 1,
showing distribution of electric current.
Similar letters of reference indicate corresponding parts.
A represents the supporting ring-shaped frame of the outer stationary
magnets B, which are secured therein by suitable set screws a, their a
circular core section being centrally perforated to form the bearings for
the driving shaft C of the engine. Each magnet B is constructed with

page_text: a suitable but even number of radially extending arms of which eight
are shown in the Drawing. The arms are provided with widening
ends B of T shape (at right angles thereto) which face towards the
inside.
The relative position of the stationary magnets is arranged in such a
manner that the arms and T ends of the same are alternating, that is,
that the T ends of one magnet are opposite the intermediate spaces
between two adjoining T ends of the other magnet. The distance
between the outer extremities of two adjoining T ends is somewhat
less than the face width of the same. Lateral brace rods 6 stiffen the
ring frame and the stationary magnets, whose base part is secured
to a suitable support by fastening, screw bolts, or otherwise. The
arms of the magnets are wound with coils of insulated wire in the
usual manner.
A third magnet D is keyed centrally between the outer magnets to
shaft C, and constructed with a corresponding number of radial arms
and coils. The outer pole ends D' are placed at right angles to the
arms, and widened symmetrically from the centre in the shape of a
double T with face width equal to those of the outer pole ends B',
so as to lap across the distance from one pole end to the adjoining
one of the outer magnets. The pole ends D' of the interior maguets.
pass closely to the alternating pole ends B of the outer magnets to be
alternately acted upon by the same.
A commutator E is applied to. oue of the projecting ends of shaft C,
and formed of two outer sections E' that are separated by a narrow:
meandering insulating layer or band d, as shown clearly in the plan
view, Figure 4. The cylindrical commutator E has front and rear.
extensions or limbs of smaller diameter which serve to form the con-.
nection with the battery wires by revolving contact pulleys e and
supporting posts f, while the outer divided circumference of the
commutator forms contact with four revolving wheels that turn
on shafts g' attached to a supporting frame 9' which is connected
adjustably by slot and clamp screw' h with a supporting post ' of
the outer post f. The battery current may however be conveyed
to the commutator through the shaft, and the contact wheels of the
limbs be dispensed with. The adjustable frame g³ is insulated from
the lower carrying post / so that no current can pass from one to
the other. Each of the outer contact wheels g is connected by suitable

page_text: contact springs i to the base of frame A, and thence by connecting
wires to the coils or the arms of the outer magnets, two of the contact
wheels forming the circuit with the coils of one, the two remaining
with the coils of the other magnet B, as shown in Figure 3 and 5.
The coils of the central magnet D are placed into direct circuit
with the battery wires by posts 1, contact rollers A, and fixed insulating
cylinders of shaft C, an uninterrupted current being thus supplied
to the coils of the revolving inner magnet as long as the battery circuit
is closed.
When the battery wires are applied to the clamp screws of the
engine the current is split, forming a direct circuit in the coils of
the revolving magnet, and an indirect and more circuitous one through
the commutator to the coils of the outer stationary magnets.
The revolving commutator. being divided by the insulating band
into alternating positive and negative sections, forms rapidly changing
alternating contact with the revolving wheels. The number of alter-
nating commutator sections corresponds with the number of magnet
arms so as to produce at each passage of the respective pair of contact
wheels over the dividing insulating band the reversing of the current
in the coils of the outer magnets, and consequently the reversal of the
polarity of the pole ends of the same. The effect of the reversal of
polarity on the pole ends of the revolving central magnets is the
continuous attraction and repulsion of the pole ends without any
induction currents and neutral points. The positive pole end of the
revolving magnet is attracted at one side by the negativo pole end :
of one of the outer magnets, and at the opposite end at the same
time repulsed by the reversal of the current in the pole of the opposite
magnet.
When one side of a positive pole end of the central electro-magnet
faces fully the negative pole of an outer magnet, the other face fills up
the intermediate space between the pole ends of the opposite magnet,
being then attracted by the negative polarity of the adjoining pole end,
and by the simultaneous reversal of the polarity of the other magnet
repulsed at the opposite side, so that the position of the central pole is
changed to face the pole of the latter magnet and lap over the inter-
mediate space between the poles of the former magnet. The reversal of
polarity by the change of the direction of the current produces in this
position of the pole the effect already described, which is exactly the same,

page_text: but with opposite polarities, as regards the negative poles of the central
magnet, so that throughout the same, by the alternating attraction and
repulsion by the co-operating pole ends of the stationary magnets, the
central magnet is rapidly revolved.
The formation of induced currents is prevented by the lapping over
of the T shaped pole ends across the space between two adjoining
pole ends of the outer magnets, as the adjoining pole end begins to
assert its influence before the other pole end is entirely passed. But
even in case induction currents should be formed they would servo,
by reversing the current in the side poles, to assist instead of detract
from the magnetic force by being in the same direction as the primary
current so as to be fully utilized. The neutral points, formed by the
full facing of the inner and outer pole ends at the moment of the
reversing of the current by the commutator, are overcome by the action
of the alternating pole ends of the opposite magnets. As the magnets
are parallel to each other they are entirely within the magnetic field,
by which the speed of the revolving magnet is accelerated, which is
not the case in electro-magnetic engines in which the magnets are
out of the magnetic field, so as to interfere in some degree with each
other. The non-formation of induced currents avoid sparks or heating
of the commutator, which has hitherto been one of the most objectionable

page_text: As the main parts of the engine may be cast, and as no very
extensive devices are employed, the engine may be furnished at very
reasonable price, being on account of the complete utilization of the
current, more economical and advantageous than the electro-magnetic
engines at present in usc.
Having described the nature of the Invention, and the manner of
performing the same, I declare that what I claim as new and desire to
secure by Letters Patent is,-
5
1st. An electro-magnetic engine composed of outer stationary electro-
magnets with radial arms and T shaped ends having alternately reversed 1
polarities, and of a central revolving electro-magnet of corresponding
shape and double T shaped ends having a constant current and polarity,
substantially in the manner and for the purpose set forth.
.
2nd. The combination of the stationary electro-magnets with the
revolving commutator and the adjustable insulated contact wheel for 1
reversing the direction of the current and polarity of the outer magnets,
substantially as described.
3rd. A commutator for reversing the current in the stationary
magnets, being divided by a thin curved or angular insulating layer
or band into sections of alternating polarity, substantially as shown and 2
described.
4tli. In electro-magnetic engines the stationary magnets having radial
arms with T shaped ends, being arranged in alternating position so that
the pole ends of one face the intermediate space between the pole ends
of the other, for the purpose set forth.
5th. The outer stationary magnets having widening pole ends of T
shape at right angles to the arms, substantially as described.
6th. The central revolving magnet provided with widening pole ends
of double T shape at right angles to the radial arms of the same, as set`
forth.
7th. The stationary and revolving magnets having radial arms and
widening pole ends whose face width is somewhat larger than the
distance between two adjoining pole extremities so as to lap on the
pole ends across the intermediate space, substantially as described.
2!
30

page_text: 8th. In electro-magnetic engines the combination of the outer
stationary electro-magnets with the central revolving magnet in such
a manner that their pole ends face cach other and pass parallel
alongside of each other in the same magnetic fields, substantially
in the manner specified.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Third day of June, in
the year of our Lord One thousand eight hundred and seventy-
five.