Improvements in Electric Tramcars and Locomotives.
Year: 1889

page_text: Date of Application, 21st June, 1889
Complete Specification Left, 21st Mar., 1890-Accepted, 26th Apr,, 1890
Improvements in Electric Tramcars and Locomotives.
I, JOHN SMITH RAWORTH, of 112, Belvedere Road, Lambeth, in the County of
Surrey, Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to electric tramcars and locomotives. In carrying it out I
may use one or two motors according to the power required.
In a self propelled tramcar for use on easy gradients I propose to employ a single
motor geared to one axle, and for heavy gradients, especially with electric locomotives
designed to draw one or more cars I propose to use two or more motors, one geared
to each axle.
Either chain or toothed gearing or a combination of the two may be used and I
propose to introduce into the train of gear either on the dynamo shaft or intermediate
shaft or on the axle an electro-magnetic coupling constructed in accordance with the
Specification of the Patent granted to me and to Henry M. Sayers in the year 1887
No. 11091.
When a current is sent through the coupling the armature of the dynamo will be
in connection with the axle and revolves at a speed proportionate to the speed of the
axle but when no current traverses the coupling the armature will be free from the
gearing and may revolve at any speed while the axle is stationary.
It follows that when the car or locomotive stops, the armature or armatures may
continue to revolve so that their momentum may be available to start the car when
desired.
I also propose to use two sets of gearing and two sets of magnetic couplings on
lines with heavy gradients one set of gearing being arranged for slow speed and the
other for high speed; either set of gearing may be used as desired by sending a
current through the corresponding magnetic coupling.
1 arrange the motors when two or more are used (by preference) in series and I
place in series with them a resistance capable of absorbing for a short time the total
available current.
I regulate the current to the motor or motors and to the magnetic couplings by a
barrel provided with raised strips or partial rings which make contact with springs
or studs in connection with the resistances and with the magnetic couplings.
Rotary motion may be communicated to the barrel by hand wheels or handles at
each end of the car or locomotive through suitable gearings.
The same barrel also carries an insulated raised strip which may be used to put
the above mentioned resistances in parallel with the field magnets of the motor or
motors, to act as a shunt thereto, the objects being to reduce the strength of the
fields when running at a high speed on the level or down hill so that the counter
electromotive force of the motor or motors may be reduced below that of the generating
dynamo or accumulators.
The action of the regulating barrel is as follows:-
First, it makes contact with the resistance all in series and turns the current
through the slow speed magnetic clutch.
Second, it reduces the resistance gradually to nothing.
Third, it introduces all the resistances and substitutes the high speed clutch for
the slow speed clutch.
Fourth, it cuts out all the resistances.
Fifth, it introduces resistance gradually as a shunt to the field of the motor.
With this arrangement I require only one set of resistances which are applied
necessarily during and by rotation of the regulating barrel as described above first

page_text: in series with the armature and field of the motor and afterwards in parallel as a
shunt to the fields, the same resistances being used for both purposes.
The regulating barrel is insulated from its arbor and consists of three principal
pieces which are insulated from each other but are mechanically connected and all
bound together on the same arbor.
The principal part of the barrel is a cylinder with raised portions which make
contact with the springs or studs in connection with the resistances for the purpose
of putting, these in series with the motor as described above. This cylinder has a
recess in its surface in which is fixed an insulated raised piece which makes contact
with one end of the field circuit and with the springs or studs connected with the
resistances for the purpose of shunting a portion of the current in the field.
The third part consists of a short cylinder fixed at one end but insulated from the
main cylinder; it has raised pieces or partial rings formed on its surface which make
contact with special springs or studs in connection respectively with each of the
magnetic couplings, so that either coupling may be brought into action according to
the position of the barrel.
I also use a small permanent resistance as a shunt or bye-pass to the couplings, so
that at all times, whether the couplings be in circuit or not, there may be a path for
the current from the motor to earth or to the return conductor.
At each end of the car I fix a pillar in which is a vertical shaft surmounted by a
hand wheel. which acts upon the regulating barrel through suitable gearing.
A spring is arranged in connection with the barrel or gearing which tends to
bring back the barrel to its initial position, i.e. with all resistance in series and
circuit broken.
When the car is at work the barrel is turned by the hand wheel into any suitable
position corresponding to the load and speed required, and is retained in that position
by a magnetic clutch formed in the head of the pillar and acting on the hand wheel
or on a suitable plate or disc in connection therewith.
The driver can release this clutch by pressing a short-circuit switch with his foot,
or it will be automatically released by the cutting off of the current by the main
switch which is operated by the putting on of the brake or by the driver.
The main switch is fitted with a spring which tends to open the circuit and at any
time on releasing a trigger by hand or putting on the brake the switch will fly back
and cut off the current from the motor and from all the magnetic couplings and
clutch.
The direction of driving is reversed by a commutator which reverses the direction
of the current in the fields, but does not affect the current in the armature.
Dated this 21st day of June A.D. 1889.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electric Tramcars and Locomotives.
I, JOHN SMITH RAWORTH, of 112 Belvedere Road, Lambeth, in the County of
Surrey, Engineer, do hereby declare the nature of this invention and in what 4
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
My invention relates to electric tramcars and locomotives. In carrying it out I
may use one or two motors according to the power required.
In a self propelled tramcar for use on easy gradients I propose to employ a single 50
motor geared to one axle, and for heavy gradients, especially with electric
locomotives designed to draw one or more cars I propose to use two or more motors,
and geared to each axle.

page_text: Either chain or toothed gearing or a combination of the two may be used, and I
propose to introduce into the train of gearing either on the dynamo shaft or inter-
inediate shaft, or on the axle, an electro-magnetic coupling constructed in accordance
with the Specification of the Patent granted to me and to Henry M. Sayers dated
August 13th 1887, No. 11091.
When a current is sent through the coupling the armature of the dynamo will be
placed in connection with the axle, and revolves at a speed proportionate to the speed
of the axle, but when no current traverses the coupling the armature will be dis-
connected from the axle and may revolve at any suitable speed while the axle is
stationary.
It follows that when the car or locomotive stops, the armature or armatures may
continue to revolve so that their momentum may be available to start the car when
desired.
I also propose to use two sets of gearing and two sets of magnetic couplings on
lines with heavy gradients one set of gearing being arranged for slow speed and the
other for high speed; either set of gearing may be used as desired by sending a
current through the corresponding magnetic coupling.
I arrange the motors, when two or more are used, (by preference) in series and
I place in series with them a resistance capable of absorbing for a short time the total
available current.
:
:
I regulate the current to the motor or motors and to the magnetic couplings
by a barrel provided with raised strips or partial rings which make contact
with springs or studs in connection with the resistances and with the magnetic
couplings.
Rotary motion may be communicated to the barrel by hand wheels or handles, at
each end of the car or locomotive through suitable gearing.
The same barrel also carries an insulated raised strip which may be used to put
the above mentioned resistances in parallel with the field magnets of the motor or
motors, to act as a shunt thereto, the objects being to reduce the strength of the
fields when running at a high speed on the level or down hill so that the counter-
electro-motive force of the motor or motors may be reduced below that of the
generating dynamo or accumulators.
The action of the regulating barrel is as follows:
First, it makes contact with the resistances, all in series, and passes the current
through the slow speed magnetic coupling.
Second, it reduces the resistance gradually to nothing.
Third, it introduces all the resistances and substitutes the high speed coupling for
the slow speed coupling.
Fourth, it cuts out all the resistances.
Fifth, it introduces resistance gradually as a shunt to the field of the motor.
With this arrangement I require only one set of resistances which are applied
necessarily during and by rotation of the regulating barrel as described above,
first in series with the armature and field of the motor and afterwards in parallel
as a shunt to the fields, the same resistance reing used for both purposes.
The regulating barrel is insulated from its arbor and consists of three principal
pieces which are insulated from each other but are mechanically connected and all
bound together on the same arbor.
The principal part of the barrel is a cylinder with raised portions which make
contact with the springs or studs in connection with the resistance for the purpose of
putting these in series with the motor as described above. This cylinder has a recess
in its surface in which is fixed an insulated raised piece which makes contact with
one end of the field circuit and with the springs or studs connected with the
resistances for the purpose of shunting a portion of the current in the field.
The third part consists of a short cylinder fixed at one end but insulated from the
main cylinder; it has raised pieces or partial rings formed on its surface which make
contact with special springs or studs in connection respectively with each of the

page_text: magnetic couplings, so that either coupling may be brought into action according to
the position of the barrel.
I also use a small permanent resistance as a shunt or bye-pass to the couplings,
so that at all times, whether the couplings be in circuit or not, there may be a path
for the current from the motor to earth or to the return conductor.
At each end of the car I fix a pillar in which is a vertical shaft surmounted by
a hand wheel which acts upon the regulating barrel through suitable gearing.
A spring is arranged in connection with the barrel or gearing in such a manner
that it tends to bring back the barrel to its initial position, i.e, with all resistances in
series and with the circuit broken.
When the car is at work the barrel is turned by the hand wheel into any suitable
position corresponding to the load and speed required and is retained in that
position by a magnetic clutch formed in the head of the pillar and acting on the hand
wheel or on a suitable plate or disc in connection therewith.
The driver can release this clutch by pressing a short-circuit switch with his foot,
or it will be automatically released by the cutting off of the current by the
main switch which is operated by the putting on of the brake or by the driver.
The main switch is fitted with a spring which tends to open the circuit and at any
time on releasing a trigger by hand or putting on the brake the switch will fly back
and cut off the current from the motor and from all the magnetic couplings and
clutch.
The direction of driving is reversed by a switch which reverses the direction of the
current in the fields but does not affect the current in the armature.
The accompanying drawing illustrates diagrammatically in plan the general arrange-
ment of the mechanism and connections for an electric tramcar or locomotive
according to this invention.
A is the main switch and B one of the electro motors the power from which is
conveyed by a pitch chain from a pinion F on the armature shaft to a chain wheel G
loosely mounted on a counter shaft G. Hand K are magnetic couplings by which
either of two pinions L and N can be gripped or held to the wheel G and be com-
pelled to revolve with it, and by suitably proportioning the toothed wheels M and
and the pinions L and N that gear therewith two different powers can be obtained;
if proportioned as in the diagram, the wheels N and when transmitting power will
enable the locomotive to exert a heavy pull when hill climbing, although the speed
over the track will be reduced, while the motor speed can be maintained constant.
PP is one of the driving axles of the locomotive, and to it the wheels M and O are
secured. D is one of the regulating pillars carrying at theupper end a handwheel which
by suitable gearing is connected with a regulating barrel Q. An electro magnetic
clutch, not shewn but contained within the pillar D serves to lock the regulating gear
but this clutch can be thrown out of circuit by a switch E when it is desired to move
the regulating barrel.
The regulating barrel, which is shewn in the drawing developed or laid out flat,
carries conducting strips or pieces R, S, T, U, V, the portions of the surface of the
barrel that are below the contact pieces being indicated by diagonal lines. The various
contact tongues 1, 2-17, 18 are shewn above the drum and are so arranged that the
contact pieces R, S, T, U, and V when passing under these tongues will make contact
with them while the lower shaded surfaces will always be clear of the tongues. The
contact pieces R, S, and Tare in electrical connection with each other, while the contact
pieces U, U and V are insulated from the rest of the barrel. The contact tongues 5
to 16 are connected with a set of resistances W as shewn while tongue 5 is also con-
nected with one end of a separate resistance X, the other end of which goes to earth
through the wheels of the locomotive.
C is the reversing switch by which the polarity of the electro magnets of the
motor or motors can be reversed for the purpose of reversing the motion of the
armature and connected gearing.
The course of the electric current in theapparatus is as follows:-Entering through

page_text: the main switch at A it traverses the armature of the electric motor B and passes on
to the reversing switch C by which it is conveyed to the field magnets and by which
its course round the magnets can be reversed. Finally leaving this switch by the
lead c it passes by or through the electro magnetic clutch of the regulating pillar 1
and so on to the terminal tongue 18. Supposing that the regulating barrel Q has
been rotated sufficiently for the tongues 18, 16 and 4 and 3 to be in contact with the
surfaces R, S and U respectively, the current will pass from 18 to R thence to S
round to 16 whence it traverses the resistances Wand reaches the tongue 4 which
U connects with while a portion of the current passes direct to earth through the
extra resistance X. From the main current passes along to the electro-magnetic
coupling K, after traversing which it passes through the counter-shaft and gearing to
earth by the driving wheels. The current in passing through the coupling K causes
this coupling to become engaged with the wheel G so that the axle P P will be driven
from the motor by the gearing N, O. To allow the motor to start before the electric
coupling K comes into action the tongues 3 and 4 are so arranged that they make
contact with U somewhat after 16 and 18 have made their first contacts on K and S.
at which time the only course for the current is through the resistances W and X
direct to earth.
By further rotation of the regulating barrel, the contact piece S will touch the
tongues in succession towards the left hand side so that when say No. 10 is
touching S the current will pass direct from 18 through R and S to No. 10 the
portion of the total resistance W between 10 and 16 being thereby shunted. Con-
tinuing the rotation of the barrel the whole of the resistance W will be shunted and
then be re-inserted as $ passes beyond the tongues, but the contact between 3 and +
by U will be broken and U will establish contact between 1 and 2 so allowing the
current to pass through the magnetic coupling H which locks the pinion L to the
In this way the gear
wheel G, the pinion № being then loose on the counter-shaft.
for high speeds is thrown into action and by continuing the rotation of the barrel Q.
the contact piece T will gradually cut out the resistances between 16 and 5 in the
same way as did S. The final step in the rotation of the barrel is reached when the
contact piece V comes into action and shunts the fields of the motor thereby
reducing the back E.M.F. and so permitting a strong current to traverse the armature
while the speed is high.
This shunting is effected through the lead c' that connects the reversing switch C
with the tongue 17. The contact piece V will at first make contact between 17
and 16 when this shunt will be through the resistances W and the tongues 2 and 1
to earth through the magnetic clutch H. It will thus be seen that while the whole
of the current passes through the armature, only that portion passing through the
The resistance in the shunt circuit is
tongue 18 excites the fields of the motor.
reduced as required by the contact piece V, the regulating barrel as it is further
rotated, gradually cutting out portions of the resistances W, so that by this means
the fields can be weakened to any extent while the electrical resistance of the motor
is reduced at the time when powerful fields are not required.
The handwheel of the regulating pillar D may be connected to the axis of the
regulating barrel by bevel gear, and a spring, not shewn, may be provided of
sufficient power to bring the regulating barrel back into the starting position, so
that on switching the current past the magnetic clutch in D and thereby releasing
it the barrel will spring round into the starting position. By breaking the circuit
at the main switch A the same action will follow.
The independent switch A is not always necessary as the circuit may be broken
by so arranging the barrel Q, that all or certain of the contact tongues shall be
clear of it when turned further back than the position corresponding to the starting
position.
The contact pieces R, S, T, U & V may be carried by a rotary disc instead of by
described

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
;-
1. In an electric tramcar or locomotive constructed with one or more electro
motors the combination with the motor or with each motor, if more than one.be used,
of two sets of speed gearing one for slow speed and one for higher speed and
two electro magnetic couplings substantially as herein described for the purposes
specified.
2. In an electric tramcar or locomotive constructed with one or more electro
uctors the combination with the motor or motors of a regulating barrel or disc
carrying one or more separately insulated contact pieces for regulating the main
current and the current in the shunt coils of the motor or motors by one barrel or dise
and one set of resistances substantially as herein described.
3. In an electric tramcar or locomotive constructed with one or more electro
motors the combination of (a) two sets of gearing to each motor, one for slow
speed and one for higher speed; (b) two electro magnetic couplings to each motor;
aud (c) a regulating barrel or disc carrying separately insulated contact pieces, one
of which can be used for regulating the field or fields of the motor or motors through
the shunt coils and another for manipulating the electro magnetic couplings sub-
stantially as herein described.
4. In an electric tramcar or locomotive, the combination and arrangement of parts
constructed arranged and operating substantially as herein described and shewn in the
drawing annexed.
Dated 18 Bay of March 103.
JOHN S. RAWORTH.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.