Improvements in and connected with the Electric Lighting of Trains and other Vehicles.
Year: 1894

page_text: Date of Application, 17th Mar., 1894
Complete Specification Left, 17th Jan., 1895-Accepted, 16th Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Electric Lighting of Trains
and other Vehicles.
We, EDWIN JAMES PRESTON of the Firm of J. Stone & Co. of Deptford in
the County of Kent, Engineers, and ARTHUR BERNARD GILL of Shirley House,
Grove Park, Lee, in the county aforesaid in the employ of the said firm do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to enable one or more railway or other carriages
to be electrically lighted in such manner that as regards the lighting such carriage
or carriages is or are independent of the rest.
The invention consists in providing a suitably sized dynamo for lighting the
entire carriage (or carriages in the case of two or more such carriages which will
then have suitable electrical connections) and the dynamo aforesaid is preferably
suspended from the under frame or other convenient part of the carriage in such
manner as to be capable of swinging or moving on a fulcrum. The dynamo receives
its motion from one of the axles of the carriage by means, for instance, of a strap
and pulleys or of friction gearing. Or instead of pivoting the dynamo it may be
fixedly mounted and the driving mechanism may be so arranged, that it can swing,
or in some other convenient manner slacken the tension of the belt and thereby
limit the grip of same on the pulley and consequently by the slip of the belt
diminish the speed at which the dynamo is driven or in some other way cause the
speed of revolution of the dynamo to be reduced or regulated in comparison with
the speed of its motor, when the speed at which the train is travelling is too great
for the efficient working of the electric lighting system. The dynamo when pivoted
is provided with a counterweight or its equivalent so that its centre of gravity may
be varied at desire. By arranging the sizes of the driving and driven pulleys and
the belt the dynamo can be so regulated as to never exceed the speed required and
this without any undue strain or wear. It is of importance that the brushes on the
dynamo be so arranged that the armature may run in both directions and it has
been found that brushes made of carbon are exceptionally suitable, but other forms
of brushes may be used. The carbons are held in a suitable holder provided with
spring and screw adjustments and catches to hold the brushes off when required.
By properly proportioning the winding and the amount of iron in the dynamo the
lead of the brushes may be so fixed that no adjustment is necessary in whichever
direction the armature may be running.
In order that the current may always flow in the same direction a contact board
provided with a contact arn: controlled by a centrifugal or other governor is used
in such manner that the contact arm is mounted so that it follows the direction of
motion of the dynamo shaft until it is arrested by a contact and on the speed of the
shaft increasing the governor causes it to slide up the shaft and make the desired
contacts. Or instead hereof the contacts may be made magnetically and dependent
on the direction of motion of the contact arm. By this means the contact arm is
moved into the proper contacts whichever way the dynamo is moving. The current
is taken from the contact board to the lamp and accumulator circuits. When the
carriage is at a standstill the lamps are lighted from the accumulators only, but
when in motion the contacts are so arranged that the lamps are also in circuit with

page_text: the dynamo. In some cases it may be necessary to insert an automatic resistance
for keeping the lamps at a certain degree of brightness.
Dated this 17th day of March 1894.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
Improvements in and connected with the Electric Lighting of Trains
and other Vehicles.
We, EDWIN JAMES PRESTON of the Firm of J. Stone & Co. of Deptford in
the County of Kent Engineers and ARTHUR BERNARD GILL of Shirley House,
Grove Park, Lee in the county aforesaid, in the employ of the said firm 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 :--
One object of this invention is to enable one or more railway or other carriages
to be electrically lighted in such manner that as regards the lighting such carriage
or carriages or are independent of the rest. For this purpose we provide a
suitably sized dynamo for lighting the entire carriage (or carriages in the case of
two or more such carriages which will then have suitable electrical connections) and
the dynamo aforesaid is suspended preferably from the under frame or other
convenient part of the carriage in such manner as to be capable of swinging or
moving ou a fulerum. Or the dynamo may be suspended in a driving strap from a
carriage axle. The dynamo receives its motion from one of the axles of the
carriage by means, for instance, of a strap and pulleys or of friction gear. Or
instead of pivoting the dynamo it may be fixedly mounted, and the driving
nechanism (whether by friction of pulleys against each other or by belt driving)
may be so arranged that it can swing or in some other convenient manner vary the
driving force the object in all cases being to limit the grip and consequently by the
slip of the pulley (or belt) the speed at which the dynamo is driven is not unduly
increased, when the speed at which the train is travelling is too great for the
efficient working of the electric lighting system. The dynamo when pivoted is
provided with a counter-weight or its equivalent so that its centre of gravity may
be varied at desire. By arranging the sizes of the driving and driven pulleys and
the belt the dynamo can be so regulated as to never exceed the speed required and
this without any undue strain or wear. It is of importance that the brushes on the
dynamo be so arranged that the armature may run in both directions and it has
been found that brushes made of carbon are exceptionally suitable but other forms
of brushes may be used. The carbons are held radially to the shaft in a suitable
holder provided with spring and screw adjustments and catches to hold the brushes
off when required.
In order that the current may always flow in the same direction a contact board
is provided and a contact arm controlled by a centrifugal governor is used in such
manner that the contact arm follows the direction of motion of the dynamo shaft
until it is arrested by a stop opposite to a contact and when the speed of the shaft
increases the governor causes it to slide on the shaft and make the desired contacts.
By this means the contact arm is moved into the proper contacts whichever way
the dynamo is moving. The current is taken from the contact board to the lamp
and accumulator circuits. When the carriage is at a standstill the lamps are
lighted from the accumulators only, but when in motion the contacts are so arranged
that the lamps are also in circuit with the dynamo. In some cases it may be
necessary to insert an automatic resistance for keeping the lamps at a certain degree
of brightness.

page_text: Figure 1 on the accompanying drawing is a side view of a dynamo suspended to
the underframe of a railway carriage. Figure 2 is a plan of same shewing also the
electrical connections to the secondary batteries and the lamps;
Figure 3 is an end view of the switch and commutator arrangement, Figure 4 a
vertical longitudinal section of same and Figure 5 a plan view.
The dynamo W is suspended from the underframe X at the fulcrum point X' or
any other suitable point and is driven by strap from a carriage axle Y. The
tension and adhesion of the strap are such that any tendency to increase the speed
of rotation of the dynamo beyond its normal and proper speed is diminished by the
slipping of the strap. The dynamo may be provided with a counter-weight or
with a shifting fulcrum of suspension so that its centre of gravity may be varied at
desire in order to regulate the tension of the strap as required. The proportion of
the driven pulley and the width of the strap should be such as not to permit an
undue speed of the dynamo. Hence when the speed reaches a certain determined
degree the strap begins to slip and whatever the further increase of speed of
rotation of the train wheel may be the dynamo remains practically constant.
Figure 6 shows in end view an arrangement of driving the dynamo by friction
pulley Z on a train axle Y and friction pulley W on the dynamo shaft W.
Figure 7 shows an arrangement in which the dynamo is not suspended but fixed,
and an additional intermediate friction pulley W is used which is mounted on one
end of a double armed lever V having its fulcrum V' in a bracket fixed to the
carriage frame.
In order that the current may always flow in the same direction whichever way
the train runs a contact switch is provided. A is a double armed insulated contact
lever which is capable of rocking on the boss of a cam disc H which latter is free
to slide on the dynamo shaft W₁. This lever A is provided with insulated switch
plugs B B which are capable of being inserted in one set or other of the
contacts C+ C C° C and C³ these contacts being fixed on the insulating switch-
board base K mounted on the framing of the dynamo. The lever A will by
reason of friction with the cam boss follow the direction of rotation of the dynamo
shaft W¹ until it is arrested by stops opposite to one set of contacts C or the
other, whereupon as the speed increases the plugs B are pushed into the said
contacts by the operation of the governor as will be presently described.
On the dynamo shaft is fixed the head D of a centrifugal governor which as an
example may be of the form shown its two arms D¹ being jointed to the head D
and provided with an endless coiled spring D' which partially counteracts the
centrifugal effort of the balls or weights D³ the other ends D of the levers D
act against the cam disc H which slides on the shaft W and transmits a corre-
sponding sliding motion to the lever A. Or instead of the cam disc H we may
use other forms of sliding sleeve operating in connection with the governor and the
lever A.
E Figures 2, 3 and 5 is a lever used for introducing a resistance between the
lamps and the dynamo when the dynamo is running at its normal speed: it is
mounted on the bracket E' on the base K. One forked end of this lever engages
with the flange F on the boss of the lever A and the other end carries an insulated
contact piece which by coming between the contacts G and G' Figure 3 serves to
short circuit the resistance L inserted between the secondary batteries M and the
lamps N when the dynamo is not working or working at a low speed. Or the
resistance L may be made variable by subdividing it and causing the contact
piece at the end of the lever E to slide over suitable contacts connected with such
resistances. Or we may substitute for the lever E a sliding bar which operates
the necessary resistances directly.
As soon as the normal or desired speed has been attained and the switch
plugs B B inserted, the lever E is actuated by the governor so that the short
circuit is broken and the current to the lamps then passes through resistance L.
The arms Dx of the governor at the same time act against the conical arm H and
push it and therewith also the contact arm A in such manner as to overcome the

page_text: resistance of the spring O so that the switch plugs B B are pushed into one set
of contacts C and complete the circuit of the dynamo with the secondary batteries
on the one side and with the lamps on the other. To prevent the oil or other
lubricant from escaping while the dynamo is not running the aforesaid flange F
may actuate a lever or other mechanism in connection with a cock or valve for
controlling the supply of oil to the various bearings.
The current from the dynamo when the parts are in the position shown in
Figure 3 leaves the brush P passes to the contact piece C+ and through the
contact plug B on the rocking bar A to the contact C2 and thence through the
field magnets to the contact Co the contact plug B' and the contact C-to
the brush P¹. When the speed necessary to charge the accumulator has been
attained the plugs B B are pushed so far along the shaft as to connect C+ to C¹,
thereby allowing the current to pass to the accumulator or to that and the lamp
circuit also, returning through the contact C° and thence to the brush P¹. When
the train carriage axle or other driver runs in the opposite direction the arm A is
swung round so as to come opposite the other contacts the governor then pressing
the plugs B B into said contacts. The current is then reversed and goes from
the brush P¹ to the contact C+ in the manner above described.
The field magnets may be wound with two windings and the supply of current
regulated by a switch in such manner that when both batteries and lamps require
current the two windings are joined to assist each other whereas if only the
batteries or the lamps have to be supplied the windings do not assist each other.
Or instead of the second winding we may use a resistance in the magnet coils
or in the main circuits.
In some cases it is found advantageous that the dynamo should produce more
electrical energy than is required for the lamps in the carriage when alight.
To utilize this we insert between the dynamo and the accumulator a resistance
through which the current passes when the lamps are out, but which when the
lamps are alight is reduced or short circuited thus allowing the dynamo to
supply current to the lamps and the accumulator.
Figure 8 is a diagram showing a convenient mode of attaining this result, and
Figure 9 a mode of applying it to a carriage. D is the dynamo, Z the accumulator
and SB the switch box. When the sliding bar contact maker Q Q is in the
position shown in Fig. 8 the current passes from the dynamo D to the point A,
through the resistance R to the point B and thence to the side of the
accumulator. A and B are also connected to contacts A' and B'. The
accumulator and the resistance are adapted to absorb the surplus current.
When the sliding bar Q1 is shifted so as to make contact with A and C the
current flows to circuit No. 1 and also short circuits the resistance R thereby
allowing the dynamo to produce useful work. By shifting the sliding bar Q
still further on to the contact C¹ the current flows to circuit No. 2.
Instead of allowing the main current to pass through the resistance Ra
resistance may be actuated in the magnet circuit or a differential winding may
be actuated by the sliding switch.
The sliding bar Q' is held up against the contacts by a suitable spring on the
back. In Figure 9 the conductors D and E lead respectively from the positive
side of the accumulator and dynamo and the negative side of same.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
1. The mode of suspending the dynamo from a fulcrum, the dynamo being
driven by a strap and pulley or by friction gear so proportioned that when a
certain predetermined speed has been attained the strap slips and no further
increase of speed and output of the dynamo takes place substantially as set forth.
2. For the automatic reversing of the current in a dynamo when the direction
of its rotation is reversed the application and use of a rocking lever mounted

page_text: freely on the dynamo shaft and provided with suitable contact plugs so arranged
that the switch lever by its friction with the shaft is reversed when the motion
of the train is reversed and the contact plugs are by a centrifugal or other suitable
governor inserted in new contacts, substantially as set forth.
3. For the automatic reversing of the current in a dynamo when the direction
of its rotation is reversed the application and use of a centrifugal governor on
the dynamo shaft and of a sleeve operating therewith and capable of sliding on
the latter and connected to a switch lever such as named in the second claim all
so arranged that the centrifugal force of the governor acting on the cam inserts.
the plugs into the contacts against the effort of a spring substantially as set forth.
4. In combination with the switch lever and the governor the application and
use of a lever or sliding bar which engages with the switch arm boss or with
the governor and inserts resistance in the lamp circuits when the dynamo has
attained its normal speed substantially as set forth.
5. The construction of apparatus for reversing and controlling the current shown
in the drawings 1 to 5..
6. The application and use of the sliding bar switch described and shown for
controlling the current substantially as set forth.
Dated this 17th day of January 1895.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.