Improvements in or connected with Electro-motors, more especially applicable to the Propulsion of Vehicles.
Year: 1893

page_text: Date of Application, 20th Apr., 1893
Complete Specification Left, 19th Jan., 1894-Accepted, 24h Feb., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by MAXIME JOHANNET and G. DUPONT, both of
30, Rue de Bécon, Courbevoie, France, Engineers.]
Improvements in or connected with Electro-motors, more especially
applicable to the Propulsion of Vehicles.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a special mode of transmitting force, whereby two
shafts can be driven at any speeds by connecting one of them to the armature and
the other to the field magnets of one and the same electro-motor, the said field
magnets being made revoluble. The invention has more particularly in view the
driving of the axles of tramcars in which a single electro-motor drives the two
shafts of a bogie, but this is only one application of the invention, which, by the
intervention of well known means of transmission, can be so adapted as to drive
two shafts having any relative positions with respect to each other. It is even
possible to arrange the armature and field magnets of the electro-motor in such a
manner as to drive a single shaft.
In the following description it will be assumed that the invention is to be
employed for the electric propulsion of a tramcar.
When secondary batteries or accumulators are employed as the source of electric
energy for the propulsion of tramcars, experience has shown that the car with
50 seats (the most generally adopted for convenience of service) can never, to be
in good working condition, weigh less than about 16 tons, including the passengers.
With a weight so considerable for a vehicle intended to run on ordinary roads,
the distribution of the load upon the axles must be carefully considered. The
most simple plan consists in the employment of two axles charged with 8 tons each,
a weight which is excessive for tramway rails. Moreover, it is necessary to
increase the stability of the car so that the points of support may be as far apart
as possible which increases considerably the resistance of the vehicle on curves.
To remedy this inconvenience radial axles have been tried. Now, theory has
demonstrated and experience has confirmed that good results cannot be obtained
without a third axle, à director of the other two, and this directing axle should be
charged with about two tons, the weight necessary to ensure its hold on the way.
Under these conditions each of the outer axles will still have to support the
excessive weight of six tons and further the two tons carried by the third axle will
be lost on account of adhesion (which will limit the number of accessible inclines)
unless a third electro-motor be employed, an impracticable solution, as it would
increase beyond measure the complication of the mechanism.
These difficulties are overcome by means of a special arrangement which
constitutes a very important part of this invention.
The means employed consist in distributing the total load over four axles each
carrying say four tons (a very suitable weight), making the adhesion of the four
axles similar and rendering them all driving axles.
For this purpose the frame of the car is mounted on two bogies composed of a
truck with two driving axles very close together, and provided with spaces for the
reception of the secondary batteries or accumulators.
To render the axles of the bogies driving axles without requiring for each bogie
two electro-motors, one of the axles is driven by means of the armature and the

page_text: other by the reaction of the field magnets as already stated. It is in this arrange-
ment that the essential character of the invention resides.
If in an electro motor the field magnets are mounted so that they can turn on
the shaft of the armature when the current is switched on to the motor, the
armature and field magnets will commence to turn in opposite directions to each
other. To obtain this result when the motor is employed to actuate the two axles
of a bogie, the armature is geared up to one of the axles by means of suitable
gearing, and the field magnets are similarly geared up to the other axle by
analogous means, precautions being taken, in each case, to ensure that the rotation
of the two axles shall be in the same direction.
For the purpose of enabling the secondary batteries or accumulators to be
conveniently re-charged, they toust be arranged so as to be independent of the car,
and therefore be carried by the bogie frames, and moreover, in order that the
plates may be kept in good condition, the batteries must not be subjected to
unnecessary jar, but be carried with as much resiliency as possible.
To this end the bogie frame may rest upon the axle boxes through the
intervention of spiral springs, while the car frame may rest upon the axles through
the intervention of adjustable legs or supports carrying, at their upper ends,
friction rollers, and at their lower ends plate springs connected to and beneath the
axle boxes, by any suitable means. Other and independent springs may also be
provided for simply supporting the bogie frame and batteries.
The electro-motor itself may be mounted within a rigid frame supported by
bearings upon the axles of the bogie, a suitable spring being provided between
one or more of the bearings and the frame so that the motor is freely and flexibly
carried between the axles.
The secondary batteries or accumulators may be so arranged in the bogie frames
as to be readily removed therefrom when it is necessary to re-charge them, the
car being brought over a pit arranged between the rails, within which works a
The batteries can thus be disconnected from the car and deposited onto the
lift, and be readily lowered into the pit where they may be recharged and be
brought up again for connection to the car.
lift.
Although the motor is more especially applicable to the axles of tram cars and
other vehicles, it may be equally well employed for driving any other axles or
shafts.
Dated this 00h 1
זי
1000
COMPLETE SPECIFICATION.
Improvements in or connected with Electro-motors, more especially
applicable to the Propulsion of Vehicles.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being had to the accom-
panying drawings and to the letters and figures marked thereon, that is to say :-
This invention relates to improvements in or connected with electro motors,
more especially applicable to the propulsion of vehicles, and has reference to an
improved mode of, or means for transmitting force, whereby two shafts can be
driven at any speed by connecting one of them to the armature, and the other
to the field magnets, of one and the same electro-motor, the said field
magnets being rendered revoluble. The invention has more particularly in view
the driving of the axles of self-propelling vehicles of tramways, in which a single
electro-motor drives two shafts or axles of a bogie; but this is only one of the
applications of the invention which, by the intervention of well known means of
transmission, can be so adapted as to drive two shafts having any relative positions

page_text: the one to the other. It will be readily understood that the armature and field
magnets of the single electro-motor may even be caused to add their effects for
driving a single shaft.
In the following description it will be assumed that the invention is to be
employed for the electric propulsion of a tramcar.
When secondary batteries or accumulators are employed as the source of electric
energy for the propulsion of self-moving tramcars, experience has shown that a
car with fifty seats (that most generally adopted for convenience of service), can
scarcely, to be in good condition for working, weigh less than about 16 (French)
tons, including passengers.
In view of so considerable a weight for a vehicle intended to run on ordinary
tram lines, the distribution of the load upon the axles must be carefully considered.
The most simple plan consists in the employment of two axles, each charged with
8 tons, which is an excessive weight for tram rails. Moreover, it is necessary,
in order to increase the stability of the car, to place its points of support as far
apart, as possible, which considerably increases the resistance of the vehicle on
curves.
To remedy this inconvenience, radial axles have been tried, but theory has
shown, and experience has confirmed that good results cannot be obtained without
a third axle, a director of the other two, this directing axle being charged with
about two tons, the weight necessary to ensure its hold upon the line.
Under these conditions, each of the two other axles will still have to support the
excessive weight of 6 tons, and further, the two tons carried by the third axle will
be for adhesion (which will limit the number of accessible inclines) unless a third
electro-motor be employed, an impracticable solution, as it would unnecessarily
increase the complication of the mechanism.
These difficulties are overcome by means of a special arrangment which constitutes
a very important part of this invention. The means employed consists in dis-
tributing the total load over four axles, each axle thus carrying 4 tons (a very suitable
weight); and in causing these four axles to contribute to the adhesion by
rendering them all driving axles.
For this purpose, the body of the car is mounted on two bogies, each consisting
of a truck having two driving axles arranged very near together. This arrange-
ment, as well as other details of the invention will be readily understood on reference
to the annexed drawings which represent, by way of example, the various parts of
the vehicle to which the invention relates.
In these drawings:-
:-
Fig. 1 is a plan of one of the bogies, the armature and field magnets being shown
in horizontal axial section.
Fig: 2 is a section of the same on line A, B, of Fig. 1.
Fig. 3 is a transverse section of the armature and field magnets taken on the
line C, D, of Fig. 1, and showing the relative position of the axles and driving
shafts.
Fig. 4 is a view of the end of the bogie as seen from the left of Fig. 1.
Fig. 5 is a view of the end of the bogie, but as seen from the right of Fig. 1.
Fig. 6 is a plan of the framing and the means employed for the suspension of the
bogie, the motor mechanism being removed.
Fig. 7 is a longitudinal elevation of the bogie frame and of the suspension
apparatus.
Fig. 8 shows the bogie half in face or end view (that portion on the left of the
figure), and half in transverse section (that portion to the right of the figure).
Fig. 9 is a general view of a car mounted upon its two bugies. The two bogies
being identical, it will be sufficient to describe one of them.
In order to render the axles 1 and 2, motor, or driving, axles, without having to
employ two electro motors or receiving dynamos; one of the axles, 1, is driven by
means of the armature, and the other by the reaction of the field magnets, as before
stated. It is in this arrangement that the essential character of the invention
"

page_text: resides. If, in an electro-motor, the field magnets are so mounted as to be free to
turn on the shaft of the armnature, when the current is switched on to the motor,
the armature and field magnets will commence to turn in opposite directions to each
other.
To obtain this result, when the motor is employed to actuate the two axles of a
bogie, the armature 3 (Figs. 1 to 5) is geared up to one of the axles 1, by means of
gearing 4, 5, or by any other suitable means of transmission, such as chains, belts,
etc. The field magnets 6 are likewise geared up to the other axle 2 by analogous
means, for example by the gearing 7, 8, 9, 10, provision being made in each case to
ensure the same direction of rotation for the two axles which are being driven, in
this way, by a single electro motor. It is important to note that under these
conditions the working speed of the electro motor which is equal to the relative
speed of the armature, with respect to the field magnete, is, in this case, the sum of
their absolute speeds. Therefore, if we adopt as the ratio of two successive
gearings, as shown in Figs. 1 and 2, and if we suppose that the axle 1 makes
100 revolutions per minute, the armature 3 will make 300 revolutions in one
direction, whilst the field magnets 6 will revolve in the opposite direction with a
speed of 900 revolutions. The relative speed between these two parts will
therefore be 1200 revolutions per minute, and in this way there will be produced
a light electro-motor working under very reasonable conditions of speed, as regards
centrifugal force and other causes giving rise to serious annoyance in the case of
portable electro-motors running at high speeds. Furthermore, the motion takes
effect upon two axles situated very near together and forming bogies which readily
take the curves so that less resistance is produced at these parts of the line, while
the total weight of the vehicle is caused to contribute to the adhesion.
Figs. 6 to 9 show the particular arrangement employed for the distribution of
the loads.
For the purpose of maintenance, the battery of accumulators must be rendered
completely independent of the body of the car, and therefore be supported by the
truck, and moreover, in order to keep the plates of the batteries in good condition,
the batteries should be suspended as elastically as possible.
To this end, each of the trucks or bogies is constructed with two parallel
cheeks 11 and 12 forming guard plates which are connected together by four cross
pieces 13, 13, 13, 13, and constituting a rigid framing. This framing rests upon
the axle boxes 14 through the medium of four spiral springs 15, 15, 15, 15, and
carries two boxes or cases 16, 16, located in spaces for their reception, and each
containing one quarter of the total battery of accumulators.
The body of the car with its passengers rests upon the axles through the
intervention of two adjustable legs or rods 17, 17, which carry, at their upper ends,
friction rollers 23 for permitting the radial displacement of the bogies on curves,
and these legs rest upon two plate springs 18, 18, fixed under the axle boxes. The
said body thus bears upon four springs entirely independent of the spiral springs
abovementioned, which latter have only to support the bogie frames and the
accumulators. The electro motor or dynamo is mounted within a rigid frame 19
(Figs. 1 to 4), which is supported on one of the axles 1, of the bogie by two
bearings 20, 20, and on the other axle 2, by a third bearing 21 provided with an
intermediate spring 22, so that the motor is, in reality, freely and elastically
suspended between the axles.
The following calculation will at once show the advantage of this system of
suspension over that now in use.
Let it be supposed that the total weight of the vehicle is composed of the
following elements, the weights being expressed in French tons each of 1000 kilos.
Body and accessories
Passengers
2 motors and their frames
2.5 tons
3.5
"
2.5
"

page_text: This loads will be distributed as follows:-The weight of the body and its
accessories and of the passengers, say 6 tons, will be distributed over four plate
springs, such as 18, to which a span of 1 metre may readily be given. The weight
of the two electro-motors and their frames, say 2.5 tons, will rest upon four fixed
points and upon two spiral springs, such as 22, of about 50 /m play. The weight
of the four pairs of wheels, say 4 tons, will rest directly upon the line at eight
points. And, lastly, the weight of the trucks and of the accumulator boxes or
cases, say 5.5 tons, will be distributed between eight spiral springs, such as 15,
capable of readily having 120 / play. By calculating the weight supported by
the different springs, it is easy to see that :—
the different springs, it is easy to see that :—
Each of the plate springs 18, carries a load of 1.5 tons
0.4
spiral
"
22,
"
"
"
39
.
"
15,
0.7
"
"
">
"
"
"
"
99
Hence each of these springs may be so constructed as to reduce the vibrations to
such an extent as to practically completely deaden them, as there great amplitude
of flexion available for a comparatively feeble load to be supported. Furthermore,
the four accumulator boxes or cases are suspended, still elastically, beneath the
bogie trucks, so that they may, in this manner, possess the advantage of the double
suspension.
With respect to the working, it has been seen that the armature 3 drives,
through the pinion and gear wheels, one of the axles 1, the field magnets 6
actuating the other axle 2, by a double train of pinions and gear wheels 7, 8, 9, 10.
This arrangement may, however, be reversed and the rates of speed, or even the
nature of the parts, be varied.
Each of the axles being in motion drives its bogie through the intervention of
the bearings 20, 20, the axles boxes 14, 14, and the guard plates 11, and 12.
Furthermore, the cheeks 11 and 12 likewise form guard plates in connection with
the cross frame 24 carrying the centre pin or pivot 25, so that the body is carried
by the intervention of the truck 11, 12, cross frame 24, and centre pin or pivot 25.
The body, moreover, ensures connection between the two trucks through the
medium of the same parts. The body rests, as has been stated, by its under frame,
on the adjustable legs 17 by means of the friction wheel supports 23, so that freedom
of inflexion is ensured when passing over curves.
The manipulation of the batteries of accumulators may be effected by bringing
the car over a pit arranged across the line, and in which there is a lift for the
reception of the boxes or cases 16. This lift conveys them to the bottom of the
pit, wherein they may be recharged and afterwards conveyed up again by said lift
and be deposited in their place. The boxes or cases may also be provided with
rollers so as to ensure their complete independence when they are lowered from the
It is owing to the arrangement of the accumulator cases or boxes upon
the trucks or bogies that this simple means of manipulating the batteries can be
employed.
car.
Although I have described the system of driving by electro-motors having
revolving armatures and field magnets, as applied to the propulsion of a self-moving
car, it is evident that these arrangements are capable of a more general and wider
application. Therefore, they may be employed for driving two shafts or two axles
of a railway or other carriage actuated from any source of electric energy, or any
two shafts whether parallel or not, or even a single shaft. The invention is
therefore not limited to the precise construction and arrangement of parts illustrated
by the annexed drawings.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described mode or means whereby any two shafts, or even a single
one, may be readily driven by a single electro-motor. actuated from any suitable

page_text: electric source, by utilizing the rotation of the field magnets as well as that of the
armature.
2 The employment of a single electro-motor in which both the armature and
the field magnets revolve freely, for the purpose of driving the two axles of a
bogie of a self-propelling carriage, substantially as hereinbefore described and
shown by the annexed drawings.
3. The special arrangements adopted for the application of the invention to
tramcars, substantially as herein described and shown in the annexed drawings.
4. The improvements in or connected with electro-motors, more especially
applicable to the propulsion of vehicles, substantially as herein described and shown
with reference to the annexed drawings.
Dated this 19th day of January 1894.