Improvements in Electric Locomotives.
Year: 1890

page_text: Date of Application, 30th May, 1890-Accepted, 5th July, 1890
COURIE DI DUIFICATION.
Improvements in Electric Locomotives.
I, EDWARD DUMMER, of 82 Water Street, Boston, Massachussets, United States of
America, Mechanical Engineer, 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
-
My invention relates to locomotives propelled by electricity, that is, to wheeled
vehicles which embody or support electric motors for the propulsion thereof.
It has heretofore been the practice to locate the electric motor on the axle, frame, or
body of the vehicle, so that there will be rotation of the axle in bearings supporting
the motor, as to the whole or the heavier portion thereof, and also supporting such
pulleys and belts or chains, gearing &c. as are employed between the driving wheels
or their axles and the motor-shaft. This method has certain objectionable features,
and is accompanied by certain serious difficulties. The weight of the motor and
motive mechanism-which in a powerful locomotive must be very great-causes a
proportional degree of friction at the supporting bearings on the axle. There should
be springs between the axle and load to prevent very damaging jolts or jars. While
belts or chains between the motor and axle permit the use of such springs and the
consequent vertical motion of axle with reference to the load, they cause considerable
friction, are constantly stretching and are otherwise objectionable. When gearing is
employed there can be no springs between the motor-shaft and the axle but the motor
must ride "dead" on the axle in order that the elements of the gearing may be main-
tained in proper relative position.
My invention is free from such objection and difficulties. According to it the motor―
or the heavier part thereof is not supported by bearings in which the axle revolves,
and hence there is no corresponding friction, and when gearing is employed the
elements thereof may be in true working position with reference to each other without
the detrimental results above referred to.
My invention consists, fundamentally, in an electric locomotive so constructed as to
embody one or more field magnets connected with the driving wheel or wheels to
revolve therewith. Each of the magnets may be magnetized constantly, and thus be
supported as one body with the wheel or wheels directly by the rails of a railway.
The invention also consists in the combination of gearing when gearing is required→
and other parts of the motor and motive mechanism with the driving-wheel or wheels
and frame of the locomotive as hereinafter described.
In the drawings forming part of this specification-
Figure 1 is a side view of a locomotive embodying my invention, in which gearing
is employed.
Figure 2 is a plan view of the same.
Figure 3 is a vertical longitudinal section in the direction of lines 1, 1, in
Figure 2.
Figure 4 illustrates a modification, being a plan view of a locomotive embodying
my invention, in which gearing is not employed.
Figure 5 is a vertical longitudinal section taken in the direction of lines 2, 2,
in Figure 4.
The frame A may be of any construction suitable for the vehicle. I have shown
four ordinary truck-wheels, B, between which and the frame intervene springs a of
any desirable form. There may be a greater or less number of these truck wheels,
and they may be a part of one or more pivoted trucks, as is well understood in the
art. If four driving-wheels were employed-or two driving-wheels one forward of
the other, as might be the case with a hanging vehicle in telpherage-the truck wheels
might be dispensed with, as is customary. The two driving wheels C on the same

page_text: axle may be joined together rigidly by means of the axle in the usual manner. For
this axle are boxes b, between which and the frame are springs c.
1 fix the field-magnets E of the motor rigidly with reference to the driving-wheels.
When gearing is to be employed the field-magnets E are so constructed and arranged
that their poles are in convenient positions to receive armatures F-as many as
desired, two in this case-between them. Each armature is on a shafte which has
bearings, which travel with the driving wheels being supported in fixed relation
there to as by arms g fastened rigidly to the axle D. The coils of field magnets and
armatures, the commutators and brushes i are located with reference to each other
and are to be connected for the passage of electricity in a suitable manner and sub-
stantially as in an ordinary motor and as will be well understood without further
illustration or description herein.
The means for electrical connection with the motor may be such as are well known
for connecting with a rotary body. I prefer to employ two insulated metallic rings j
concentric with the axle D and fastened on the exterior of the field-magnets. An
insulated brush & bears on each ring . With these brushes, the conductors to the
motor and with these rings the conductors to the coils will connect in the usual manner
whether the track-rail system, the conduit, third or middle rail, or overhead wire system
be employed, or a storage battery on the locomotive is used. I prefer the simple
means of gearing shown.
Outside of each driving-wheel is a gear G preferably internal-with which engage
pinions, one on each end of each armature shaft, these shafts e extending through the
driving wheels. Each gear G is held so as to be concentric with the axle of the
driving wheels by having a hub through which the axle D extends. Thus the gears G
conform with the driving-wheels in their vertical movement with reference to the
frame or body of the vehicle, and the pinions and gears maintain exactly their proper
relative positions. Each gear G is prevented from revolving which may be done in a
very simple manner by means of a pin or projection m thereon which extends into a
vertical slot in the frame.
When reduction of speed is not desired and hence no gearing is necessary the
arrangement may be such as is illustrated by Figures 4 and 5, according to which the
armature Fis prevented from revolving being connected by cross-pieces n to rings G
which correspond with respect to position to the gears G and are in like manner held
and supported, the construction of the field-magnets and their relation to the driving-
wheels being substantially the same as when gearing is employed as above set forth.
Electric connection is also made with the motor by means of the rings j and brushes k,
the motor brushes which bear on the armature commutator also revolving with the
driving-wheels; while said commutator is joined to the armature and does not
revolve.
I desire to note again and at this point, that the most important feature of my invention
is such construction by which that part of an electric motor-of the class having field-
magnets which in operation are magnetized constantly in the same sense-which is by
far the heavier part, namely: the field-magnets, will revolve with the driving wheel or
wheels. Thus said magnets and driving wheel or wheels will be as one body which
rolls on the track, so that there need be no bearings for supporting these magnets on
the axle, at which bearings there would be friction.
Since however the majority of "electrically propelled vehicles" are for heavy work
so that not only a reduction of speed is required but also the armature, connections of
armature with the field-magnets, and the gearing are of considerable weight, it is
desirable in most cases to also combine other parts of the motor and parts of the
motive mechanism with the driving-wheels to revolve there with as above described.
The field magnets may be of different known shapes and the arinatures may have
the corresponding relation and be combined with the driving-wheels 'substantially as
above set forth, and whereby my invention would be involved.
The operation and utility of a device embodying my invention are apparent from
the above description. Revolution of the armatures of Figure 1 on their own axes
will cause by means of the pinions and gears, revolution of the driving-wheels and the

page_text: motor therewith. Many examples will occur which demonstrate the fact that a load
may be propelled much easier over a way if it is put in a shape to roll evenly thereon,
than if supported on an axle or the like whereby there are bearings which necessitate
sliding friction.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is,
1. The combination with a vehicle, of an electric motor of which the field-magnet
is fixed to the driving-wheel or wheels, the armature is connected with to react on the
frame or body of the vehicle, and the coils of the field have a constant connection
with the electric circuit, substantially as set forth.
2. The combination of a wheel, an electric motor fixed thereto to revolve therewith,
and a gear which does not revolve, the armature of the motor being on a shaft which
is eccentric to the axis of said wheel, said shaft being provided with a pinion in engage-
ment with said gear, substantially as specified.
3. In an electric locomotive the combination of the frame, driving-wheels, an
electric motor fixed to the driving-wheels, and a gear held by said frame whereby it
cannot revolve, the armature of the motor being on a shaft eccentric to the axle of the
driving-wheels and provided with a pinion which engages with said gear, substantially
as set forth.
4. In an electric locomotive the combination of two driving-wheels on the same
axle, field-magnets fastened rigidly with reference to said wheels, an armature on a
shaft occentric to said axle, a gear concentric with said axle, and a pinion on said shaft
which engages with said gear, substantially as described.
5. The combination of a vehicle, electric motor and electric circuit, in which the
armature of the motor is connected with the frame or body of the vehicle, the field-
magnet of the motor is fixed with reference to the driving-wheel, and the coils of the
field form a constant part of the electric circuit, so that the armature reacts on the
body or frame of the vehicle to cause rotation of the driving-wheel, and the field of
force is constant and rotates with the driving-wheel, substantially as and for the
purposes set forth.
6. In an electric locomotive the combination of two driving-wheels, field magnets
fixed to said wheels and providing several fields of force which rotate with said wheels
being fixed in position with reference thereto, and armatures geared to the frame or
body of the locomotive, substantially as set forth.
Dated this 25th day of April 1890.
EDWARD DUMMER.