Improvements in Apparatus for Electric Lighting of Railway Trains.
Year: 1892

page_text: Date of Application, 1st Jan., 1892
Complete Specification Left, 1st Oct., 1892-Accepted, 5th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Electric Lighting of Railway
Trains.
We, EDWARD JOHN HOUGHTON, of Camden, Underhill Road, Dulwich, S.E.
Electrical Engineer, and WILLIAM WHITE, of 58, Bread Street, in the City of
London, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
In the system of lighting trains by electricity to which this invention relates a
dynamo is placed in the guards van and driven by a belt from an axle of the van;
brush bolders are attached to the dynamo in such a manner that they are free to
travel round the commutator. A centrifugal governor working with the dynamo
causes the brush holders to move forwards as the speed of the dynamo increases
and to more backwards as the speed diminishes, thus altering the lead of the brushes
to suit the speed.
The brushes, made preferably of layers of copper wire gauze, are pressed by
springs against the commutator and by their friction are with their holders carried
round a portion of the commutator sufficiently far to be in suitable position for
running in either direction, and this movement of the brushes reverses the polarity
of the field of the dynamo by means of a switch and thus ensures a similarity of
current in whichever direction the dynamo armature revolves.
A high resistance solenoid is connected to the terminals of the dynamo and to a
contact operated by the governor. The governor at a prearranged speed closes the
solenoid circuit, whereupon the core of the solenoid closes. the dynamo and
accumulator circuit causing the former to charge the latter.
In the circuit of the lamps is a regulator consisting of a solenoid with an iron
core having attached to it some resistance wire wound in the form of a spiral
conical bed spring and arranged in such a manner that when the solenoid is excited
the core lets more or less resistance into the lamp circuit when the dynamo is
acting, taking the resistance out when the dynamo ceases to charge.
Dated this 1st day of January 1892.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Electric Lighting of Railway
Trains.
We, EDWARD JOHN HOUGHTON of Camden, Underhill Road, Dulwich, S.E.
Electrical Engineer, and WILLIAM WHITE of 58 Bread Street, in the City of
London, Electrical Engineer, 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 :-
In the system of lighting trains by electricity to which this invention relates, a
dynamo is placed in the guard's van or other convenient part of the train and
driven by a belt or otherwise from an axle of the van; brush holders are
attached to the dynamo in such a manner that they are free to travel round the
commutator.
A centrifugal governor working with the dynamo causes the brush holder's to
move forwards as the speed of the dynamo increases and to move backwards as the
speed diminishes, thus altering the lead of the brushes to suit the speed.

page_text: The brushes made preferably of layers of copper wire gauze, are pressed by
springs against the commutator and by their friction are with their holders, carried
round a portion of the commutator sufficiently far to be in suitable position for
running in either direction, and this movement of the brushes reverses the polarity
of the field of the dynamo by means of a switch and thus ensures a similarity of
current in whichever direction the dynamo armature revolves.
A high resistance solenoid is connected to the terminals of the dynamo. and to
a contact operated by the governor. The governor at a prearranged speed, closes
the solenoid circuit, whereupon the core of the solenoid closes the dynamo and
accumulator circuit causing the former to charge the latter.
In the circuit of the lamps is a regulator consisting of a solenoid with an iron
core having attached to it some resistance wire wound in the form of a spiral
conical bed spring and arranged in such a manner that when the solenoid is excited
the core lets more or less resistance into the lamp circuit when the dynamo is
acting; taking the resistance out when the dynamo ceases to charge.
Figure 1 of the accompanying drawings is a side view and
Figure 2 is a front pair of a pair of commutator brushes and their .mounting
according to this invention.
A indicates the end of the armature shaft of a dynamo electric machine having
fixed on it the commutator C, on which bear the two opposite brushes B B'.
According to this invention each brush B or B₁ consists of a number of layers of
wire gauze contained in a box which can slide within an outer box being
pressed towards the commutator C by a spring 2. Over the layers of wire gauze B
is a plate which can be advanced by a screw advancing the wire gauze as it
becomes worn by its friction on the commutator. The box of each brush is fixed
in a block D and these two blocks are connected together by circular frames dd'
which are mounted on supports E E. The circular frame d is fitted to revolve
on a lip e projecting from the frame E the other circular frame d' has an axial
pin which can revolve in a hole in the upper part of the support E' concentric
with the lip e. On the pin e' is fixed a crank F the pin of which is engaged
within a yoke f¹ fixed on the head of a rod. Within the yoke fare plates f³
adjustable by screws and nuts, the one or the other of these plates bearing on the
crank pin according as the armature of the machine revolves in the one direction
or the other. The rod f2 is free to slide in a tube G in which it is pressed down
by a spring bearing on a collar f' at the lower end of the rod.
From this collar a pin g projects through a slot of the tube G and is connected
to the slide or sliding sleeve of an ordinary centrifugal governor, so that the pin g
is drawn up the farther the greater the speed of the governor, which is driven at
speed proportional to that of the armature of the dynamo. The tube G is pivotted
at g' and has behind it a pin 92 entering a hole in a bar h to which are jointed two
contact springs which with contact plates ³ ³ constitute a switch H for
reversal of current. When the commutator revolves in the direction of the arrow c,
the friction resulting from the pressure of the brushes B B on it causes the brushes
and the framing which carries them to revolve to the inclined position shewn in
Figure 2, determined by the bearing of the crank pin f against the one of the
plates the farther movement being resisted by the spring acting on the rodƒ³.
When the speed of rotation increases, the governor drawing up the pin
the plates allowing the crank pin f to rise and the brushes B B' to turn farther
or acquire more lead.
raises
:
When the direction of rotation of the armature is reversed, the brushes are by
the friction moved over to an inclination in the opposite direction, the tube G
moving on its pivot g' to a position such as is indicated by the dotted line G¹, and.
its pin g acting on the switch H so as to change the circuits to suit the change of
direction of rotation.
Figure 3 of the accompanying drawings is a vertical section partly in elevation
and Figure 4 is a plan of regulating apparatus according to this invention. S is
a solenoid coil forming part of the circuit to which the regulator is applied or it may.

page_text: be in a shunt to the circuit taking a portion of the current. K is an iron core pressed
down by a spring k contained within a tube the lower end of which is screwed through
a nut k so that by screwing the tube more or less downwards the force of the
spring can be adjusted. On a rod R extending up from the core K is fixed an
insulated head r to which is secured the innermost convolution of a wire V bent
into the form of a spiral or volute having a number of convolutions, the outermost
convolution being attached at r to a bed plate P of copper or other good conducting
metal on which some of the convolutions lie. The wire V is of metal, such as
German silver, which is of low conductivity offering considerable resistance to passage
of an electric current. The conductors being attached at W and W₁ the current
passes through the solenoid coil S and also through the wire volute V. When the
electromotive force in the circuit and in the coil S is low, the core K not being strongly
attracted upwards is forced down by the spring k, and most or all of the convolutions
of the wire V then lie upon the bed plate P so that the current passes mostly through
the plate meeting with very little resistance. But when the electro motive force
increases, the core K is attracted upwards lifting a number of the convolutions of V
up from the plate, and the current, having then to pass through all these convolutions,
meets with considerable resistance by which it is regulated. The coil V instead of
merely lying on a plate of good conducting metal, may lie in a layer of mercury
contained in a metal tray. Also the convolutions of V, instead of being such as
to lie on a flat bed plate, may take a conical form, resting on a cone C as shewn
diagrammatically in Figure 5. Or the cone C may be dispensed with, as shewn
diagrammatically in Figure 6, all the convolutions being in contact with each other
except such as are separated by the lifting of the innermost convolution.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed we declare that what we
claim in respect of apparatus for electric lighting of railway trains is :-
1. Mounting wire gauze brushes which are adjustably spring pressed against
the commutator of the dynamo machine, in a framing which can revolve around
the commutator, and which has a crank pin engaged by a spring rod linked to the
sliding sleeve of a centrifugal governor, substantially as aud for the purpose set
forth.
2. In combination with the brush frame and crank above referred to, a switch
for automatic change of circuits when the direction of rotation of the dynamo is
changed, substantially as described.
3. In combination with the lamp circuit of the train and the dynamo machine,
a regulator consisting of a coil arranged in connection with a solenoid whereby
more or less resistance is introduced into the lamp circuit while the dynamo
machine is acting, substantially as described.
Dated this 1st day of October 1892.
ABEL & IMRAY,
Agents for the Applicants.