Improvements in Regulators for Electric Car Motors.
Year: 1898

page_text: Date of Application, 15th Dec., 1898
Complete Specification Left, 11th Sept., 1899-Accepted, 14th Oct., 1899
(Communicated from abroad by HIRAM STEVENS MAXIM, of 80, Madison Avenue,
New York, United States of America, Chevalier of the Legion of Honour,
Civil and Mechanical Engineer.)
Improvements in Regulators for Electric Car Motors.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
It is frequently necessary in electric railroad systems to couple together two
or more cars, and in such cases it is usual to depend upon the motors of the
forward car only, as the drawing force, the remaining cars of the train being
simply trailing cars. This imposes an abnormally great load upon the hauling
motors, unless the latter are of a capacity greater than is usually required for
propelling a single car, and even in such cases the number of cars in a train
that can be practically managed in this way i8 very limited.
It has hence been recognized as desirable to propel each car independently
by its own motor or motors, but this involves the careful regulation of the
electric current supplied to each individual motor of the train in order that
each may perform its proper share of the work. Various means have been pro-
posed for controlling all the motors of the train from one point, usually on the
first car of the train, but this plan does not insure such action of the several
motors that no one of them performs more or less than its proper amount of
work.
The object of my invention is to provide automatic means of regulating the
motors on the several electrically propelled cars of a train, so that each shall do
only so much work as may be necessary to prevent its car from getting ahead or
lagging behind, and so pushing or pulling the cars immediately in advance or
in rear thereof.
For this purpose I employ an inextensible rod, bar, or other suitable form of
connection extending from car to car throughout the train, and with reference
to which each car has a normally determined position. I also provide means
whereby any departure of a car from this normal relative position will set in
operation devices which will supply more current to the car-motor if its motion
is retarded, or less current if its motion is accelerated.
In carrying my invention into practice each of the cars may be provided with
a rod supported in suitable guides and provided at its ends with means whereby
it may be coupled to similar rods on other cars, so that when a number of cars
are made up into a train the several sections of rod will form the aforesaid
inextensible bar. Under each car is a cylinder through which the rod section
extends, and on said rod within the cylinder is a piston. This piston has a
normal tendency to occupy a given position in the cylinder, usually a central
position, by the action of springs interposed between the heads of the cylinder

page_text: and the opposite sides of the piston, and the cylinder is preferably filled with a
fluid which acts to prevent sudden movements of the piston.
To permit the flow of fluid from one side of the piston to the other, I preferably
make the bore of the cylinder at the centre slightly greater than the piston,
but gradually reduce the diameter towards the ends, so that as the piston
approaches the limits of its travel the resistance to its movement will be increased
by the diminution of the clearance space between the circumference of the
piston and the wall of the cylinder.
At a convenient point of each of the aforesaid rod sections, and preferably
under the controller box on the platform of the car, are teeth which engage
with a pivoted segmental rack, so that by the forward or rearward movement of
the rod the said segmental rack will be correspondingly turned about its pivot.
This movement of the rack is utilized to turn a stem that extends up through
the controller box and carries a contact arm that travels over the controller
points. The movement of this stem by the rod sections may however be effected
in other ways.
The above parts are so arranged that when the piston moves from its normal
position in a forward direction in the cylinder, or in the direction of motion of
the car, current will be directed into the motor of the car, so that the propelling
effect of the motor will be increased in proportion to such forward movement.
And conversely, as the piston moves backward towards its normal position, the
current will be reduced until the normal position of the piston is again reached
when the current will again be shut off from the driving motor.
In applying this apparatus to the control of a train of cars, the forward car
does not require a controller rod, but is operated by the usual hand switch or
controller. A short rod may however be fixed to the rear of the car for coupling
thereto the rod of the next car.
When the forward car is started, it pulls on the rods under the cars to the rear,
and as the latter are stationary, the pistons are slowly drawn forward and current
sent through the several car motors. As the rear cars under the propelling
effect of these motors are driven forward, the pistons return more or less to their
normal positions and the propelling effect is thereby regulated in exact accor-
dance with the speed of the forward car. It is desirable to use a sufficient
number of contact points in each controller to ensure that a movement of the
pistons backward from their normal positions, will gradually reverse the motors
so that should the forward car come suddenly to a stop, or the speed of the rear
cars be too great, the forward movement of the latter will be positively asserted.
With such an arrangement it follows that if the direction of movement of
the forward car be reversed, the motors on all the cars of the train will also be
reversed, and in general, that the work which each motor performs will be in
proportion to the load on or resistance of its car.
Dated this 15th day of December 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: 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:
It is frequently necessary in electric railway systems to couple together two
or more cars, and in such cases it is usual to depend upon the motor or motors
of the forward car only, for the tractive force, the remaining vehicles of the
train being simply trailing cars. This arrangement imposes an abnormally great
load upon the motors of the forward car, unless the motors are of a capacity
greater than that usually required for propelling a single car, and even in such
cases the number of cars in a train that can be practically managed in this
way is very limited.
It has hence been recognized as desirable to propel each car independently
by its own motor or motors, but this manner of driving a train requires the care-
ful regulation of the electric current supplied to each individual motor of the
train in order that each may perform its proper share of the work. Various
methods have been proposed for controlling all of the motors of the train from
one position, usually on the first car of the train, but no effectual means have
been provided for ensuring such regulation of the several motors that each of
them performs at all times its proper amount of work.
The object of my invention is to provide a method of automatically controlling
or regulating the motors on the independently propelled cars of an electric
train, so that each shall perform only so much work as may be necessary to
prevent its car from getting ahead of or lagging behind its proper position,
and consequently pushing or pulling the cars immediately in advance or in rear
thereof.
For this purpose I employ an inextensible but movable rod, bar, or the like
which extends from car to car throughout the train, and with reference to
which each car has a normally determined position. I also provide means
whereby any departure of a car from this normal position will set in operation
devices which will increase or diminish the supply of current to the car-motor,
to accelerate or retard it as much as may be necessary to restore the said car to
such position.
In order that my said invention may be clearly understood and readily carried
into effect I will proceed to describe the same more fully with reference to the
accompanying drawings, in which:-
Figure 1 represents a train of cars provided with my improved regulators.
Figure 2 is an enlarged sectional view of one of the said regulators.
A, A, A, are the cars, each provided with one or more propelling motors B,
to which current is led from an overhead conductor by a trolley arm C as is well
understood. It is assumed, for the purpose of the present case, that the cars
are in all material respects of ordinary construction, and that each is provided
with the usual controller D.
Under each car extends a rod E which is supported in suitable guides F, and
provided at its ends with means whereby it may be coupled to similar rods on
other cars, as shown, so that when a number of cars are made up into a train,
the rods E will form an inextensible continuous bar passing from end to end
of the train.
Under each car is secured a cylinder G, through which the rod E extends,
and on said rod within the cylinder is a piston H. The piston has a normal
tendency to occupy a given position in the cylinder, (usually midway between
its ends) owing to the action of two stout springs K, interposed between the ends
of the cylinder and the sides of the piston, and the cylinder is filled with water
or other fluid L.
To permit the flow of this fluid from one side of the piston to the other, and to
prevent sudden movement of the said piston, I preferably make the bore of the
cylinder at the middle slightly greater than the piston, but gradually reduce
the diameter towards the ends, so that as the piston approaches the limit of its

page_text: travel, the resistance to its movement will be increased by the diminution of the
clearance space surrounding the piston. It will be obvious that any other
device may be employed for increasing the resistance to the movement of the
piston as it approaches the limit of its travel.
At a convenient point on each of the rods E, and preferably under the con-
troller box D on the platform of the car, teeth are formed to gear with a pivoted
segmental rack M, so that by the forward or rearward movement of the rod the
said segmental rack will be correspondingly turned about its pivot. This move-
ment of the rack turns a stem or spindle N that extends up through the con-
troller box and carries a contact arm that travels over the controller points P.
The aforesaid parts are so arranged that when the piston H moves forwardly
from its normal position (or in the direction of motion of the car) electric
current will be directed into the motor of the car, so that the propelling effect
of the motor will be increased in proportion to such forward movement, and
conversely, when the piston moves backwardly toward its normal position the
current will be reduced until in the normal position of the piston it will again
be shut off from the motor.
When the forward car is started it pulls on the rods E and as the cars are then
stationary, the pistons are slowly drawn forward in their cylinders and electric
current is sent through the several car motors. As the rear cars under the pro-
pelling effect of their motors are driven forward, the pistons return more or
less to their normal positions and the propelling effect is thereby regulated in
exact accordance with the speed of the forward car. It is desirable that the
stroke of the piston and the number of contact points in the controller shall
be such as to ensure that the reversal of the motors will be gradual, so that should
the forward car come suddenly to a stop or the speed of the rear cars be too great,
the reversal will be effected without violent shock or blow.
With such an arrangement it follows that if the movement of the forward car
be reversed, the motors on all the cars of the train will also be reversed, and in
general, that the work which each motor performs will be in proportion to the
load on, or resistance of its car.
By the use of this apparatus each car in a train is caused to run at a speed
regulated in accordance with that of the forward car, and each motor is caused to
do such an amount of work that the relative positions of the cars are maintained
without the use of the usual draw-bars: The rods E, it will be observed, are
not intended to serve the purpose of couplings or drawbars from one car to
another, (although they may if desired do so), but merely as a rigid or inexten-
sible connection extending back from the forward car and with reference to
which each car of the train tends to preserve a certain position. Any tendency
of a car to recede from such position is corrected by the additional electric current
which its displacement throws into the motor, and conversely, any advance move-
ment of a car with respect to such position tends to cut off or reduce such
current.
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 in connection with electric car motors, is:-
1. The herein described method of automatically controlling or regulating
the motors on the independently propelled cars of an electric train, for the pur-
pose specified.
2. A regulator comprising an inextensible rod or bar normally maintained
in a definite position relatively to the cars and so connected to the circuit
controllers that any displacement of the aforesaid rod or bar relatively to a car
will cause the current supplied to the motor of such car to be varied accordingly,
for the purpose specified.
3. The combination with the aforesaid rod or bar of a piston and cylinder,
substantially as and for the purpose specified.

page_text: 4. The regulator having its parts constructed, arranged and operating sub-
stantially as described with reference to the accompanying drawings for the
purpose specified.
Dated this 11th day of September 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.