Improvements in and relating to Electric Motors.
Year: 1894

page_text: Date of Application, 11th Sept., 1894-Accepted, 17th Nov., 1894
"
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Motors.
We, JOHN SAMUEL LOSCH, a citizen of the United States of America,
residing at Summit Station, in the County of Schuylkill and State of Pennsylvania,
Machinist, and JOHN HUY PHILLIPS, Builder, JOSEPH WINFIELD MOYER,
Lwyer, and JOHN HARRISON WILLIAMS, Merchant, also citizens of the United
States of America, all residing at Pottsville, in the County of Schuylkill and
State of Pennsylvania aforesaid, one of the United States of America, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
Our invention relates to electric motors of that class in which series of radial
armatures carried by a revolving shaft are caused to rotate in the field produced by
a series of electro magnets, the said electro-magnets being energized in succession
through the action of a commutator carried by the armature-shaft in such manner
that a series of impulses shall be exerted upon the radial armature in the direction.
of rotation of the shaft, and the arrangement of the parts being such that the
total number of impulses so acting upon the armature during one revolution shall
be equal to the number of field-coils multiplied by the number of armature-sections.
The invention is mainly directed to the novel arrangement of the commutator
with relation to a series of brushes bearing thereon and connected to the field-coils,
by means of which the active or effective point of the magnetic field is caused to
rotate in the same direction as the armature and at a rate of speed greatly in
excess of the same, by which construction a series of impulses is exerted upon the
armature greatly in excess of the number of field-coils, and the speed of rotation
and efficiency of the machine as regards power are greatly increased.
•
The invention consists, therefore, in the details of construction and combination
of parts by means of which the results above outlined are obtained, and which will
be more fully developed in the following description, in which connection it will be
understood that while we have shown and described what we deem to be the best
and most efficient manner of carrying the invention into practical operation, many
modifications might be devised in which the mechanical construction might be
changed to embody the same ideas in a varying form, and that such modifications
would be substantially the equivalent of the invention shown.
Referring now to the drawings which accompany the Specification-
Figure is an elevation of the machine from the front or commutator end;
Figure 2 is a vertical cross section through the field and armature, illustrating
the manner of supporting the field-coils and the construction of the armature.
Figure 3 is a side elevation of the machine.
Figure 4 is a vertical longitudinal section on the line 5-5 of Figures 1 and 2.
Figure 5 is a diagram illustrating the winding and connections of the machine.
Figure 6 is a detail of the commutator.
Figure 7 is a modified form of brush-holder and connections.
Figure 8 is a detail view of one of the brushes.
Figure 9 is a detail view, showing the plan of the commutator, with the leading-in
brush and one of the distributing brushes in position.
The machine consists, as usual in machines of this class, of a field, A, an
armature, B, mounted to revolve therein, and a commutator, C.

page_text: As shown in Figures and 2, the field consists of a series of six electro-
magnets b, 'b, &c., mounted at equal distances upon a shell or casing D in such
manner as to project radially therefrom. These magnets are of the double or
horseshoe type, and their poles are arranged to enter openings d in the shell or
casing D, the poles, when in position, being in operative relation to the armature,
which rotates within the casing. The magnets are secured in position by screws E,
which pass through the magnet-yokes a and are seated in an annular rib F formed
on the outer surface of the casing D. Each pair of magnets is wound in such
manner as to produce consequent poles to influence the armature-section, and the
free ends or terminals of their coils are brought out and secured to a series of
binding-posts G, G, mounted in and insulated from an annular rib or flauge H
formed on the end of the casing D, these binding posts being connected to the
commutator-brushes and the outgoing main, as will be hereinafter described.
At each end of the casing and extending across the same is secured a bracket I,
provided with a bearing i adapted to receive a shaft J. Between the brackets
and upon the shaft is secured a hub K of non-magnetic material, to which is secured
a series of seven soft-iron bars L extending longitudinally inside the shell D from
end to end thereof, in such position as to revolve in close proximity to the
inwardly-projecting poles of the magnets b b.
It will be noted in connection herewith that the arrangement of seven armature-
sections in connection with six field-magnets results in a condition in which one
of the armature-sections is continually in a position of greatest efficiency in relation
to one of the coils, and that this point of greatest efficiency travels around the
ring in the direction of rotation of the armature at a much higher speed than
the speed of rotation of the armature, the speed at which such effective point
travels being dependent on the numerical relation of the armature-sections to the
field-coils. In order to utilize this point of greatest efficiency, the effective
magnetic field is caused to rotate in time therewith by a special arrangement of
commutator and connections, the field being always slightly in advance of the
armature, and therefore exerting a direct longitudinal pull thereon.
Referring to Figures 1 and 6 of the drawings, which illustrate more particularly
the construction of the commutator and the arrangement of its connections, the
commutator C consists of a cylindrical shell c of conducting material, mounted
upon the shaft, from which it is insulated by a fiber sleeve c', and upon which it
is secured by a nut . The forward end of the conducting-shell is continuous
and forms a contact surface upon which rests a brush M, by which the current
enters the machine. At its rear end the shell c is divided into a series of
distributing-sections equal in number to the number of armature-sections, in
this case, seven, separated by insulating spaces e, or by blocks of insulating
material therein, the fractional portion of the circumference of said shell occupied
by each of the distributing-sections being represented by the product obtained in
multiplying the number of field-magnets by the number of armature-sections.
The commutator at its divided or distributing point has resting upon it, at equal
distances around its circumference, a series of brushes N, one for each field-coil by
means of which current is transmitted to the field coils in succession as the
commutator is revolved. The brushes N are mounted, preferably, as shown in
Figure 1, each being secured to an arm O pivoted upon an insulated pin P mounted
upon a ring secured upon the front bracket of the machine. Each pin P is
surrounded by a spiral spring p, one end of which is secured thereto, the free end
resting upon the back of the brush and exerting a pressure upon the same, by which
a good contact with the surface of the commutator is insured.
To each of the brushes a connection R is fastened, the other end of which is
secured to one of the binding-posts G, forming a terminal of the field-coil. The
other ends of the feed-coils are connected, as shown, by wires S leading to a
common binding-post T, mounted upon the base of the machine, to which the
outgoing main is secured. We may, and preferably do, interpose a switch in eitber

page_text: the incoming or out-going main, by means of which the machine may be cut.
out of circuit. We prefer also, to lead a wire from the brush M to a second.
binding-post V mounted upon the base of the machine adjacent to the post T.
Referring to Figures 7 and 8, which show a modified form of brush-holder and
brush, W is a brush, consisting of a plate, preferably of copper, provided at each
end with projecting lips or flanges w, such flanges forming the contact surfaces,
which rest upon the commutator, and a retaining-rib, which rests, when the brush
is in place, within a slot formed in the brush-holder, whereby the brush is held
more securely in place.
The brushes are secured to the holder by a single bolt, to which a conductor may
be secured. The other end of the brush-holder we prefer to pivotally secure to a
binding post mounted upon and insulated from the casing D, and carrying
connection from the brush direct to the field-coils.
While we have in this case shown and described a machine in which six field-
coils are combined with an armature of seven sections, a commutator with seven
sections and six brushes operating in connection therewith, it is obvious that these
proportions may be changed and varied at will without materially affecting the
resulting machine as regards the principle of operation, and that all such
modifications are comprehended within the scope of this invention.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim, is:
1. In an electric motor, the combination, with a series of field-magnets and a
series of armatures, of a commutator composed of a cylindrical shell, one end of
which is divided into a number of distributing-sections equal to the number of
armatures, the fractional portion of the circumference of the shell occupied by
each of said sections being represented by the product obtained in multiplying
the number of field-magnets by the number of armatures.
2. In a motor of the kind described, the combination of a non-magnetic casing
having a series of openings formed therein, through which the poles of a series of
magnets mounted thereon project, an armature mounted upon a shaft revoluble
within the casing, a commutator provided with a continuous ring through which
current is received, and distributing-sections through which current is distributed
to the coils in series, and brushes bearing upon the distributing-sections and
connected to the field-coils in such manner as to cause a change in location of the
effective point of the magnetic field in response to and at a higher speed than the
revolution of the armature.
3. In a motor of the kind described, the combination of an armature composed of
a series of soft-iron bars, an annular non-magnetic casing surrounding said armature.
and provided with a series of openings, field-magnets mounted upon the casing with
their poles projecting through the openings into operative relation to the armature,.
and means whereby the magnetic field may be caused to rotate in the direction of
armature travel and at a higher speed than the same and the point of highest
efficiency between the field-magnets and armature utilized.
4. In an electric motor, the combination of an armature, an annular non-magnetic
casing surrounding the same, openings in the casing, magnets carried by the yokes
secured to their outer ends and with their inner ends projecting through the
openings in the casing, and bolts passed through the yokes and seated in the casing
by which the magnets are retained in place, substantially as described.
5. In an electric motor, the combination, with a commutator, of a brush provided
with ribbed or flanged ends, whereby a greater wearing surface is provided, and
whereby the brush is more readily retained in position.
6. In an electric motor, the combination, with a commutator-brush ribbed or
flanged at its ends and perforated at its center, of a holder correspondingly grooved
and perforated, a retaining-bolt whereby the brush is retained in position, means.

page_text: for holding the brush in operative relation to the commutator, and a spring whereby
the pressure may be determined, substantially as described.
Dated this 11th day of September 1894.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.