Improvements relating to Motor Tram Cars and other Motor Cars running on Rails.
Year: 1896

page_text: Date of Application, 24th July, 1896
Complete Specification Left, 13th Mar., 1897-Accepted, 24th Aug., 1897
[Communicated from abroad by MAXIME JOHANNET and G. DuroNT, both of 113
Boulevard Menilmontant, Paris, France, Engineers.]
Improvements relating to Motor Tram Cars and other Motor Cars
running on Rails.
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 has reference to improvements relating to tram and motor cars
running on rails. For propelling such vehicles, a petroleum engine is according to
this Invention, used in conjunction with dynamo electric machines, whereby the
inconveniences inherent in the several modes of traction heretofore used are
obviated.
Owing to the use of electricity as an intermediary agent, the difficulty of starting
is overcome, a defect which is almost invariably to be found in motors driven by
heavy petroleuin; while all the advantages of the several modes of traction arc
retained, there being for instance no danger of fire, no reservoirs subjected to great
pressures, no necessity for returning to the stations for frequent recharging, and an
absolute independence obtained for the carriages or vehicles.
In carrying out the said Invention, the movable field magnets of a dynamo-electric
machine are provided on the fly-wheel of a petroleum engine, which is always in
motion, and the armature of this dynamo is connected to one of the axles of the
vehicle. When the vehicle is at rest no current is produced, the external circuit of
the dynamo being open. If this circuit is closed upon a high resistance, a weak
current will be produced, which necessitates an increase in the tangential force
produced by the petroleum engine. Owing to the reaction of the points of support,
the armature of the generator is, at this moment, impelled by the field magnets
and tends to tuin in the same direction; it is prevented therefrom by the resistance
offered by the rails to the movement of the carriage. If the electric resistance of
the external circuit is diminished, the intensity produced by the generator increases,
and, with it, the tangential force, which increases appreciably as its square.
Therefore, a moinent will occur when this force being greater than the resistance to
the rolling motion, the starting will take place. At this moment, the arinature of
the dynamo commences to turn in the same direction as the field magnets; the
relative speed of the field magnet with regard to the armature diminishes, and
consequently the absolute speed of the dynamo. The electro motive force then
diminishes, and, with it, the intensity produced, and consequently the force. But
this has no disadvantage, as the normal driving force when in motion is much less
considerable than the force required at starting. Accordingly, there will he a
tendency to the establishment of a state of equilibrium between the absolute speed of
the dynamo, (and consequently of the field magnet) and the force, during the rolling
movement, so that the work performed in moving the vehicle will be in constant
ratio to the work done by the petroleum engine. In the foregoing, it is supposed

page_text: that the resistance of the external circuit may be varied, for instance, by means of a
rheostat. It is clear that this mode of application would not be advantageous,
because of the necessity for expending energy to move the vehicle, and to heat the
rheostat.
The present system or arrangement is rendered economic by sending the current,
produced by the generator, into an appropriate receiver, the field magnet of which is
secured upon the second axle of the vehicle. By interposing a rheostat, the speed of
the vehicle can be varied, and the starting gradiated.
The means or mechanisin comprises a four cylinder petroleum engine actuating a
shaft having two cranks; two dynamos, the armatures of which are respectively
connected to the front axle and to the rear axle of the vehicle, and the field magnets
of which dynamos may be set in motion by the shaft of the petrolenin engine. For
this purpose, they are connected with the latter by means of a suitable coupling
device, so that the field magnets in front are stopped when those at the rear turn,
and vice versa, with this peculiarity, that the rotation of the field magnets at the rear
always takes place in the opposite direction to that of the field magnets in front.
To enable the field magnets in front, or at the rear, to he set in action, a friction
coupling is employed and is actuated by a Lemoine break which utilizes the existing
movement for effecting the sudden stoppage, engagement taking place at the same
time as the other end is liberated.
In the like arrangement for driving in a forward direction, a wheel at one end of
the coupling turns in one direction, while a second wheel, at the other end of the
coupling, remains stationary. If a backward movement is to be effected, a lever is
moved from front to rear, so that the break immediately acts by reason of the
direction of the movement of that part of the coupling which is connected to the
first of the aforesaid wheels, and a transverse bar is caused to turn thereby liberating
the second wheel which begins to turn, whereas the first wheel becomes stationary.
At the same time, the transverse bar causes a toothed pawl to move towards the first
wheel, which pawl prevents any movement to the rear, by reason of the magnetic
attraction and the possible reversal of the brake. This pawl is raised from the side of
the movable wheel simply to obviate any noise, for it is designed to prevent any
return of the first wheel to the rear, and it might, except for their inconvenience,
always remain in contact. The same arrangement exists on the side of the second
wheel, the pawl of which approaches the same by reason of the position of the
transverse bar.
Changes of speed are obtained in two ways, that is to say, by varying the admission
to the petroleum engine, or by varying the resistance of a rheostat interposed
between the two dynamos.
1004
COMPLETE SPECIFICATION.
Improvements relating to Motor Tram Cars and other Motor Cars
running on Rails.
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
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
accompanying drawings and to the letters and figures marked thereon, that is
to say-
This Invention has reference to improvements relating to motor tram cars and
other motor cars running on rails, a compound system of traction by petroleum

page_text: motors and dynamo electric machines being used for propelling such vehicles, thus
obviating the inconveniences inherent in other modes of traction heretofore used.
This arrangement also permits of driving any two shafts or axles.
By the use of electricity, as an intermediary, I overcome the difficulty experienced
in starting, which is a serious drawback in nearly all petroleum motors, whether
heavy oil (i.e. non-inflammable oil at ordinary temperature) or light oil is being
used, without, however, losing any of their advantages, viz. absence of danger from
fire, absence of reservoirs subjected to high pressures, no necessity to frequently
return to stations for recharging, and complete independence of the vehicles.
In carrying out the Invention, I couple the movable field magnets of an electric
generator (preferably constructed according to the British Patent No 8004 dated
20th April 1893) to a petroleum motor kept constantly revolving, and the armature to
one of the axles of the vehicle.
When the vehicle is stationary, the outer circuit of the generator is broken and no
circuit is then produced.
If this outer circuit be closed upon a high resistance, a weak current is generated,
and the armature of the generator being excited by the field magnets tends to revolve
in the same direction, but is prevented from doing so by the resistance opposed to
the rolling movement of the vehicle. This then requires an increased power from
the petroleum motor. By now diminishing the electrical resistance in the outer
circuit, the power generated by the dynamo increases, which is equal to an increase in
the power of the petroleum motor which increased power will eventually overcone
the resistance of the wheels of the vehicle and thus start the vehicle.
At this moment, the armature of the dynamo begins to revolve in the same
direction as the field magnets, thereby causing a reduction in speed of the magnet
relatively to that of the armature, and consequently also in the absolute speed of the
dynamo.
As the electromotive force decreases, the power generated becomes less and
consequently also the work done by the motor. But this is not of any consequence
seeing that the normal power required for driving the vehicle is considerably less
than that required for starting it. The outcome of this therefore is a tendency to
establish a state of equilibrium between the absolute speed of the dynamo and that
of the armature, and thus the power exerted in driving the vehicle will be in constant
ratio to the work performed by the petroleum motor.
It has been here supposed, for convenience sake that the resistance in the outer
circuit has been varied by means of a rheostat.
It is, however, clear that the application of a rheostat would not be advantageous,
as it would require the expenditure of energy not only to drive the vehicle but also
to heat the rheostat.
This arrangement is, however, rendered economical by sending the current from
the generating dynamo into a suitable receiver or electro-motor having its arinature
coupled to the second axle of the vehicle; a rheostat being interposed so as to enable
the speed of the vehicle to be varied, and the starting to be regulated.
It has been assumed that the armatures of both the generator and the motor are
coupled to the axles of a vehicle, say a tram car, having two axles with the wheels
keyed thereon; but the invention may equally well be applied to auto cars in which
the fore axle is used for steering and has the rear wheels turning loose on their axle
which, in such case, is fixed to the wheel. The armatures would then be coupled
one to each boss of the rear wheels.
In the accompanying drawings:-
Figs. 1, 1, and 2, are diagrammatic views, showing, respectively in elevation
and plan, the general arrangement of motor mechanism constructed according to this
nvention.
Fig. 3 shows a detail, drawn to a larger scale partly in section, of a friction clutch
provided with a double drum or sleeve.
The inner arrows (Figs. 1 and 1"), and those drawn on the toothed wheels or other
arts in Figs. 2 and 3, indicate the direction of movement of the parts when the

page_text: vehicle is moving forward; while the outer arrows correspond to the backward
movement.
The arrangement comprises a petroleum motor having 4 cylinders 1, 1 Fig 2,
arranged to act on the shaft 2 through the medium of two cranks. It also comprises
two dynamos 3 and 4, of the Johannet-Dupont type described in the British Patent
hereinbefore referred to, having their armatures 5 and 6 coupled respectively to the
rear axle 7 and the fore axle 8 of the vehicle, while their magnets 9 and 10 are
rotated (when required,) by the shaft 2 of the petroleum motor. For this purpose,
they are connected to the motor by a friction clutch, illustrated at Fig. 3, which, in
the position shewn, leaves the front field magnet. stationary while the rear one is
rotated, or vice versa. Owing to an intermedinte pinion 15 the tnagnets always turn
in the reverse direction, when acting as generators, to that when acting as motors
and thus enable the vehicle to travel either forwant, or backwand, as may he required.
The working of this arrangement will be mulerstood from Fig 3.
The friction clutch, which enables the front, or the rear, field magnets to be started,
is operated by any suitable break so ns to cause a sharp stoppage on the one side,
and the starting on the other side, of the clutch sleeve 11.
The parts shewn in the figure are in the position for moving the vehicle forward.
The wheel 12 revolves in the direction of the inner arrow, while the wheel 13 remains
stationary.
When it is desired to travel backwards, the lever is moved from the forward
position A into the position AR, whereupon the break acts immediately by reason
of the rotary movement of the wheel 12 in connection with the sleeve, and causes the
cross bar 14 to take up the position 14', thereby liberating the wheel 13 which then
revolves in the direction of the outer arrows, while the wheel 12 becomes stationary.
At the same time, the lever 14 causes a retaining pawl 19 to engage the ratchet
wheel 17 connected to the wheel 12 and so prevent the latter from turning rearwardly
through the accidental reversing of the break. The pawl 19, when not retaining the
wheel 12, is kept out of engagement with its ratchet wheel 17 so as to avoid noise,
and it might, except for this inconvenience, always remain in contact, as its only
purpose is to prevent the wheel 12 (when disengaged) from revolving back. The
same arrangement is adopted in connection with the wheel 13 the jawl 18 having
been brought into engagement with its ratchet wheel 16 through the position 14 of
the cross bar.
Alterations in speed are effected in two ways, viz., ordinary or slight alterations are
caused by varying the admission into the cylinders of the petroleum motor, while
quick changes are produced by altering the resistance of a rheostat interposed
between the two dynamos.
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 arrangement for driving two shafts so that they revolve at equal or unequal
speeds, and by means of which the movement of one of the shafts is effected through
its connection with one of the movable elements (say the armature) of a Johannet-
Dupont dyname, the other movable element (field-magnet) being operated by any
suitable motor, such as a petroleum motor, and the current from this dynamo, acting
as generator, being enused to operate another dynamo, acting as a receiver or electro
motor, and so revolving the second shaft, substantially as described.
2. The special application to tramcars and other motor vehicles, of the driving
arrangement forming the subject of the previous claim the two above mentioned
shafts being, in this case, the axles of the tramear, or other motor vehicle,
substantially as described.
3. The use, in combination with the arrangement claimed in Claim 1, of a second
Johannet-Dupont dynamo, as a substitute for the receiving dynamo or motor, and
thereby permitting the backward or forward travel of the vehicle, as described,
4. The means for changing the speed and the brake power either by varying the

page_text: motive power or by employing a rheostat between the two dynamos, viz. the electric
generator and the motor, substantially as herein before described.
5. Utilizing the rotation of the shaft carrying the generator for revolving the
second or corresponding shaft, substantially as herein before described.
Dated this 13th day of March 1897.
ERNEST DE PASS,
78, Fleet Street, London, and 5a, Market Street, Nottingham,
Chartered Patent Agent.