IM- PROVEMENTS IN CONTINUOUS BRAKES FOR RAILWAY TRAINS AND ANALOGOUS PURPOSES
Year: 1879

page_text: LETTERS PATENT to Alexander Cunningham Boothby, of Kirkcaldy, in the
County of Fife, North Britain, Civil Engineer, for the Invention of "IM-
PROVEMENTS IN CONTINUOUS BRAKES FOR RAILWAY TRAINS AND ANALOGOUS
PURPOSES."
PROVISIONAL SPECIFICATION left by the said Alexander Cunningham
Boothby at the Office of the Commissioners of Patents on the 12th April
1879.
ALEXANDER CUNNINGHAM BOOTHBY, of Kirkcaldy, in the County of Fife,
North Britain, Civil Engineer. "IMPROVEMENTS IN CONTINUOUS BRAKES FOR
RAILWAY TRAINS AND ANALOGOUS PURPOSES."
This Invention, which relates to improvements in the operating of the brake
blocks for retarding or stopping the motion of railway trains, and which may be
used for other analogous purposes, consists in the direct application of electricity
to the brake blocks when iron or steel brake blocks are used, or to the shoes which
carry the brake blocks when wooden brake blocks are used.
The direct application of electricity to the brake blocks or to the brake shoes
converts them when so applied into electro-magnets, so that when the electric cur-
rent is applied to them they being suspended in the neighbourhood of the revolving
wheels are attracted to and press upon the tyres of the said wheels with a retarding
force proportional to the strength of the current used.
For the purpose of operating either the whole or any desired number of brake
blocks throughout a train according to this Invention conducting wires are led
throughout the train, and connected at their ends to complete the circuit, a Gramme
machine or other generator of electricity is used, which is by preference driven
independently of the driving power of the train.
For the purpose of ensuring at all times and at any part of a train the making
of the circuit in the event of a part of the train breaking away the positive and
negative wires in each carriage are connected together by a platinum wire or other
substance offering great electrical resistance.
When the train is in its normal con-
dition of complete working order the platinum wires or their equivalents prevent
Prins 677

page_text: by virtue of their great resisting power the passage through them of any con-
siderable amount of electricity, but in the event of a portion of the train breaking
away and the normal completion of the circuit thereby being destroyed the
platinum wires or their equivalents for the time make the circuit complete. The
platinum wires or their equivalents are of a size sufficient to prevent their fusion.
In place of using platinum wires for the purpose last herein mentioned a dipping
needle or bar with mercury cups or other well known mechanical means for making
the circuit when a part of the train breaks away may be used.
For the purpose of enabling the guards or the passengers of a train to apply the
brakes independently of the engineman a cord connected to the steam admission
valve of the engine which drives the Gramme or other electrical generator is carried
in such a position throughout the train that it may be pulled either by the guards
or passengers so that the engine driving the said Gramme or equivalent generator
is thereby started and the brakes applied. This cord also starts the engine which
operates the brakes in the event of a portion of the train breaking away.
The brakes on the guards' vans or on the engine and tender may be fitted with
the ordinary hand appliances, either independently of or in combination with the
electrical arrangements for applying the brakes herein-before described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Cunningham Boothby in the Great Seal Patent Office
on the 11th October 1879.
ALEXANDER CUNNINGHAM BOOTHвY, of Kirkcaldy, in the County of Fife,
North Britain, Civil Engineer. IMPROVEMENTS IN CONTINUOUS BRAKES FOR
RAILWAY TRAINS AND ANALOGOUS PURPOSES."
My said Invention relates to improvements in operating the brake blocks for
retarding or stopping the motion of railway trains and for other analogous purposes,
and consists in the direct application of electricity to the brake blocks so that they
are converted into electro-magnets when the brakes are to be applied, they (being
suspended in the neighbourhood of the wheels, the motion of which is to be
arrested) then being attracted to and pressing upon treads of the said wheels with
a retarding force proportional to the strength of the current of electricity
employed.
For the purpose of operating either the whole or any desired number of the
brake blocks throughout a train, according to this Invention, a conducting wire or
wires is or are led throughout the train and connected so as to complete the circuit.
A Gramme machine or other generator of electricity is used to give the electrical
current through the said wire or wires, the said generator being driven by preference
independently of the driving power of the train.
In Figures 1 and 2 of the accompanying Drawing I have represented in end and
side elevation respectively a portion of the lower part of a railway carriage having
thereon a brake block arranged in accordance with my Invention. The brake
block is marked A. The wire or wires B, through which the electrical current is
conveyed, leads or lead from a machine for generating electricity, being continued
in a coil or coils wound around soft iron cores b, the said cores being connected at
back by the soft iron backing c.
The surfaces d of the blocks which bear on the
tread of the wheels are fixed to these cores b with a filling piece e, preferably of
gun metal between them.
When an electrical current is sent through the wires B the coils around the
cores concentrate sufficient electrical force at these parts to convert the brake
blocks into electro-magnets of sufficient power to be attracted to, and bear upon
the tread of the wheels in proximity with which the said brakes are suspended
with the force necessary for retarding or braking the motion of the said wheels.
The machine which generates the electricity may be as before stated a Gramme
machine, or it may be a Siemens machine, or other suitable machine which will give
the necessary strength of current, and it may be placed upon the locomotive and be
worked by a small special engine supplied with steam from the boiler of the loco-
motive, the supply of the said steam being effected by opening a valve upon a steam
admittance pipe communicating with the said special engine. In or on the
carriages, engine, and brake van, or any, either, or all of them are communications
with the said valve by means of which it may be opened to apply the brakes.
These connections may consist of a chain or rope extending throughout the train
and connected to a lever upon the aforesaid valve. This rope or chain is so
situated that it may be readily pulled by the guard or driver, or passengers, or any
or either of them, either directly or by means of rods connected with the said rope
or chain, and terminating in handles in or on the carriages, engine, and brake van,
or one or any of them, so that by pulling any rod the valve may be opened and
electrical machine worked and a current of electricity passed through the wire or
wires (B) so that the brake blocks (A) are converted temporarily into electro-
magnets and come in contact forcibly with the tread of the wheels in whose
proximity they are suspended and retard the motion of the train. The aforesaid
cord or chain also causes the operation of the special engine which drives the
electrical machine in the event of a portion of the train breaking away, so as then

page_text: to apply the brakes by reason of the tension upon it opening the valve of the said
special engine.
The conducting wires are preferably formed into coils at the ends of each carriage,
so that in the event of a brake away these coils become uncoiled sufficiently to
prevent fracture of the wires.
The brakes on the guard's van or on the engine and tender may be fitted with
the ordinary hand appliances either independently of or in combination with the
electrical arrangements for applying the brakes hereinbefore described. The brake
blocks are preferably faced with a bearing face, which can be readily removed and
replaced when worn.
From the foregoing description of the application of my Invention to a railway
train, its application to analogous purposes will be understood without further
description. I do not limit myself to any particular form of brake block nor to any
particular method of operating the machine for producing the electrical current, as
these and other details may be considerably varied without departing from the
nature of my Invention. In Figure 3 I have shewn a slightly modified form of
brake constructed according to my Invention, parts corresponding with those shewn
in Figures 1 and 2 being marked with the same letters of reference. In this
example the cores 6 and wires B are shewn as being protected by a leather
covering f, thus obviating the cost of the metal covering shewn in Figures 1 and 2.
What I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein before in part recited Letters Patent is,-
The hereinbefore described improvements in continuous brakes for railway trains
and for analogous purposes whereby the said brakes are operated by converting the
brake blocks temporarily into electro-magnets by means of a current or currents of
electricity, essentially as herein before described.
In witness whereof, I, the said Alexander Cunningham Boothby, have here-
unto set my hand and seal, this Seventh day of October, in the year of
our Lord One thousand eight hundred and seventy nine.