Improvements in Brakes for Railway and similar Vehicles.
Year: 1893

page_text: Date of Application, 6th June, 1893
Complete Specification Left, 6th Mar., 1894-Accepted, 7th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in Brakes for Railway and similar Vehicles.
I, JOHN SOMERVILLE HIGHFIELD, of Rhiwlas Colwyn Bay, North Wales
Student do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in the construction and in the method of
operating the brakes for railway and other vehicles and more particularly it
relates to continuous brakes such as those which work and are controlled by gas
and fluid pressure.
According to my invention I employ electricity in connection with such brakes
chiefly for controlling the admission or emission of the gas or fluid & thereby the
action of the brakes, the electricity being generally employed to energise a solenoid
or solenoids or other electro-magnet or magnets such magnets controlling the action
and position of a gas or fluid pressure valve or valves which determine the period
and rate of action of the admission of the gas or fluid into the brake cylinders or
its emission. The valve or valves so controlled form part of my invention and are
so made as to be specially suitable for action by means of electric attachments and
so as to make some of the more complicated valves now used unnecessary and so as
to secure simultaneity of action of any number of brakes. The valve generally
consists of a piston whose position in a cylinder is controlled by an electro magnet
connected directly or indirectly thereto, the cylinder containing ports which are in
communication with a main reservoir with a brake cylinder and with an exhaust.
I may describe the invention with reference to an ordinary railway train.
Situated on the locomotive or other convenient place is a cylinder of suitable
size called the main reservoir connected by suitable pipes and couplings to pipes
running under each vehicle of which the train is composed, the whole length of the
pipe or pipes thus formed running from end to end of the train such pipe or pipes
being called the train pipe or pipes. Under each vehicle is placed one or more
vessels or receivers called the carriage reservoir or reservoirs. Each reservoir and
preferably only one is used to each vehicle, is connected through a valve opening
to this reservoir by a pipe to the train pipe.
From each carriage reservoir connection is made by a branch pipe, through an
electrically actuated valve, to a brake cylinder in which usually are two opposite
pistons whose rods are coupled to levers which are arranged to move the brake
blocks.
Along the length of the train are laid electric mains connected by flexible
or jointed couplings between the carriages and to these current is supplied by
secondary batteries or other suitable generator or source.
On the locomotive is
placed a driver's switch, connected in series with the mains and generator or source,
which enables the driver to cut the current off entirely or to place any required
resistance in the circuit. From the electric mains branches are arranged under
each carriage to a suitably designed magnet or solenoid which by attracting or
releasing an iron core or armature controls the piston valve.
To work the brake the main reservoir is charged with for instance compressed
air which flows from this reservoir through the train pipe thence it passes into the
carriage reservoirs. If no current is flowing in the mains owing to the driver's
switch being open, the solenoids are unexcited and by the pressure of the air above
them the piston valves are opened so as to admit air from the carriage reservoirs
to the brake cylinders, forcing out the brake pistons and thus applying the
brakes.
To release the brakes the driver closes his switch so as to send a current through
the mains thence through the solenoids which are excited and so enabled to move

page_text: the iron cores or armatures connected to the piston valves; these are moved so
that the passages from the carriage reservoirs to the brake cylinders are closed and
ways opened from the brake cylinders to exhaust ports in the piston valves; air is
thus released from the brake cylinders and the brakes are withdrawn from the
wheels generally by suitable springs. To make graduated stops the driver
decreases the current in the mains by putting in an artificial resistance by means
of his switch, this weakens the pull of the solenoids and enables the valves to admit
air into the brake cylinders, the amount admitted depending on the resistance the
driver puts into the electric circuit. As the brakes are applied by cutting off the
current, in case of rupture of the train the brakes will go on automatically. In
some cases I may arrange the whole of the apparatus described so that the brakes
are put on by completing instead of by breaking the electric circuit.
Dated this Fifth day of June 1893.
JOHN SOMERVILLE HIGHFIELD.
COMPLETE SPECIFICATION.
Improvements in Brakes for Railway and similar Vehicles.
I, JOHN SOMERVILLE HIGHFIELD of Rhiwlas, Colwyn Bay, North Wales
Student, 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:-
My invention consists in devices by means of which I employ electricity in
connection with those forms of brakes which are controlled by gas or fluid pressure,
and my invention is employed chiefly for controlling the action of a gas or fluid
pressure valve or valves by means of a solenoid or solenoids or other suitable
electro magnet. The valve so controlled is used for determining the period and
rate of action of the admission or emission of the gas or fluid into the brake
cylinders and also the action of the brakes. The valve or valves so controlled
form part of my invention, and are so made as to be specially suitable for
performing their required functions by means of electric attachments. The valve
generally consists of a piston whose position in a cylinder is controlled by an
electro magnet and admits of several modifications by which it may be adapted to
any desired brake system. These different forms of my valve may be described
by reference to the drawings hereunto.
Fig. 1. II. III. Sheet I. show three views of the valve as adapted to those
brake systems which use gas or fluid under pressure to transmit the energy from
some point on the train to the brake blocks. This valve consists essentially of a
cylinder E (see Figs. I. II. III. & IV. Sheets 1. & 11.) in which are made
ports G. H. L. N. Ports H. L. are connected by a passage K from which a
pipe M leads into the brake cylinder. Piston D connected to a piston rod C
slides in the cylinder E and serves to close or open the ports H. N. H acting as
the direct admission port of the gas or fluid to the brake cylinder and N as an
exhaust by which the gas or fluid is released therefrom. The piston D is caused
to move in the cylinder by an electro maguet or solenoid A which attracts an
armature B connected to the piston rod. There is one position of the piston in
which the ports H. & N. are both closed and the piston is kept in this position
by the pressure at one end of the piston balancing the pressure at the other end and
the pull of the solenoid; this balancing of the piston giving the means by which
the rate of admission of the gas or fluid and hence the strength of the stops is
regulated, the piston D closing the admission port H automatically as the pressure
increases in the brake cylinder. The port G. is connected to the supply of gas or
fluid when the pressure system is used. The port N is connected to the ejector or
pump through the train pipe when the vacuum system is used.

page_text: Fig. IV Sheet 1 is a diagrammatic view of the valve or connections as adapted
to an air pressure continuous brake.
In Fig. I, A. represents an electro magnet which by attracting the armature B
in this case fitted directly to the piston rod C which passes through stuffing
boxes S, S controls the position of the piston D in the cylinder E.
F. is an
admission pipe for the gas or fluid under pressure, which communicates with a flat
section port G. H is a port leading from the cylinder into a passage K which
communicates with a port L leading into the other end of the cylinder and an
outlet pipe M. N is a port opening to air and acts as an exhaust.
Stops are fitted at O. P. to restrain the play of the piston within suitable
limits.
The valve and its immediate attachments are connected up with the various
parts of the whole brake working apparatus as follows. On the locomotive or
other suitable position on the train is a secondary battery or other source or supply
of electricity A', connected to this passing first through a variable resistance B¹.
Under the control of the driver are electric leads C' D' which extend from end to
end of the train and are connected by suitable flexible or jointed couplings
between the vehicles of which the train is composed. The windings of the
solenoids or electro magnets are connected either in parallel across the mains as
shown in Fig. IV where A is the electromagnet or in some cases may be connected
all in series in which case the couplings at the extreme end of the train must be
connected together. E' is a main reservoir situated on the locomotive and charged
with air under pressure and from it the air is conducted along the length of the
train by the train pipe F and from the train pipe small reservoirs G¹ (of which
one is shown) situated. under each vehicle are charged through a non-return
valve H. The pipe F' (Fig. IV) of the valve is connected to this small reservoir
and the pipe M is connected to the brake cylinder in which usually move two
opposite pistons whose rods by suitable levers apply the blocks to the wheels.
Referring to Fig. I, suppose the driver's switch B¹ to be open circuited so that
no current passes through the electro-magnet A and suppose the piston D to be at
the extreme left of its travel, then the pressure of the air entering from the
carriage reservoir G' through the pipe F and the port G acting on the piston D
forces it to the right thereby opening the port H, the air passes through this port
along the passage K and through the pipe M whence it passes into the brake
cylinder K and by forcing out the pistons L' M' applies the brakes by suitable
levers attached to the piston rods. In this case with the electro-magnet entirely
demagnetised the full pressure of the air would be utilized in the brake cylinder.
To release the brakes the driver places his switch so as to send a sufficient current.
through the magnet or solenoid A to enable it to draw the piston D hard to the
left, this shuts the port H and opens the exhaust port N, the air flows from the
brake cylinder through the pipe M along the passage K through the port L and
out at the exhaust N, the brakes being withdrawn from the wheels usually by
springs.
If instead the driver reduce the current through the solenoid A by putting
resistance in the circuit by means of the switch B₁, the pull of the solenoid will
be diminished and if the reduction be sufficient, the pressure of the air on the
piston D will force it to the left, air will be admitted through the ports G, H_the
passage K and the pipe M to the brake cylinder and also through the port L to
the back of the piston D thus tending to force the piston D to the left again.
The solenoid A still exerts a pull on the piston D tending to draw it to the left
and this pull together with the pressure of the air acting through the port L on
the back of the piston D will-when this pressure attains a sufficient value through
air entering (through the ports G H) the brake cylinder and (through the port L)
the back or right hand end of the cylinder E-force the piston D to the left
against the pressure of the air acting on the left hand end of the piston: thus the
port H is closed and the air cut off from the brake cylinder. The amount to
which the pressure must rise in the brake cylinder and the right hand end of the

page_text: cylinder E before the piston D is driven to the left and the supply of air
through H thereby cut off, depends on the amount by which the pull of the
solenoid has been weakened, the less the pull of the solenoid the greater the
pressure of air in the brake cylinder and hence the greater the force used to
apply the brakes, the greater the pull of the solenoid the less the pressure of air
in the brake cylinder and hence the less the force used to apply the brakes.
So long
as the driver keeps his switch in the position he has moved it to, to apply the
brakes with something less than their full force, as above, the piston D (the
pressure in the carriage reservoir remaining constant) will remain in such a
position as to close both the ports H. N. kept in equilibrium by the full pressure
of the air in the carriage reservoir G and the combined action of the pressure in
the brake cylinder and the pull of the solenoid. Thus it will be seen that the
driver can by suitably adjusting his switch allow air under any desired pressure to
enter the brake cylinders and thus graduate the brake power with great accuracy.
Switches to open the electric circuit may be placed anywhere on the train when
the magnets are all connected in series which generally will be found to be the
most suitable method of connecting up, so that with this arrangement the guard or
other person may apply the brakes. Also in case of rupture of the train at any
point the electric current would be broken and the brakes automatically applied.
In some cases it may be found practicable to apply only one insulated lead along
the train and to use the frames of the vehicles to make an earth return.
this arrangement the brakes are off when the current is on but the same valve
may be used with a slightly different arrangement of carriage reservoir to work so
that the brakes are put on by switching on the current.
With
Fig. IV. Sheet II shows this arrangement where the air passes through the
valve E and the pipe M into the brake cylinder K' directly, and into the carriage
reservoir G¹ through the valve H', the current being off the air pressure keeps the
piston D (see Sheet I. Fig. 1) continually to the right consequently the pressure is
the same at both sides of the piston L' and the brakes are kept off by springs or
other means, if however the driver switch on the current at B' the piston D is
drawn to the left and the air escapes through the pipe M and the exhaust N (see
Sheet I, Fig. I,) from the under side of the piston L' the superior pressure of the
air above the piston L' kept in by the non-return valve H₁ forces down the piston
and applies the brakes; this arrangement is automatic as a break in the train-pipe
immediately releases the pressure below the piston L' and so applies the brakes.
The guard or driver may control the brakes by opening suitable cocks which release
the pressure in the train pipe. The valve used in this way graduates the strength
of the application of the brakes exactly as described above.
The valve may also be adapted for use on those brake systems which employ
atmospheric pressure to apply the brakes and in which a vacuum is maintained
in the train-pipe. The pipe F communicates through the port N with the cylinder
(Sheet II, Figs. II & III) and the port G is open to atmosphere. The current
being on, the port H is closed and a vacuum is maintained at both sides of the
piston as shown in Sheet III Fig. IV by a pump or ejector situated on the
locomotive or other suitable place exhausting the air from the train-pipe and
through the valve E from the cylinders G' K. If now the current be cut off
or sufficiently weakened the atmospheric pressure acting through the port (+
(Sheet II Fig. 11) on the piston D forces it back, and opens the port H thus
admitting air through the passage K to the back of the piston and through the
pipe M to the under side of the piston L, a non-return valve H preserving the
vacuum on the top side of piston. The air pressure forces up the piston Li and
by suitable levers attached to the piston rod the brakes are applied. Graduation
is effected as described for the valve illustrated on Sheet 1, Fig. I, the power
The brakes
of application depending on the amount of reduction of the current.
are applied automatically by either a rupture of train-pipe or electric leads, an I
may be applied by the guard or other person if a switch is put in the electric
circuit in the brake van or a cock fitted to the train-pipe by which air may be

page_text: admitted thereto. In this valve a stuffing box is not used at T Sheet II, Fig. II.
In this arrangement the brakes are off when the current is on. Another modifi-
cation of the general principle of this invention works with vacuum systems, but
the brakes are put on by switching on the current. The cylinder E in this valve
has two different bores (Sheet III Figs. I, II, III) in which slide two pistons V
&D fitted on to a common rod C, the end of which passes through a gland W and
is attached to the armature of an electro-magnet as before. A port S joins the
port M to an opening Z into the back of the cylinder. The pipe F is connected
to the train-pipe from which the air is withdrawn by a pump or ejector thus
creating a vacuum behind the piston V, this is forced back by the air entering at G
and thus the port M is opened so that the air is also exhausted through L and M
from the reservoir G¹ and brake cylinder K' as shown (Sheet III Fig. IV) thus
taking the brakes off. To apply the brakes the driver switches on the current by
his switch B' this enables the solenoid or magnet to draw the piston V and D to
the right against the atmospheric pressure acting through G on the superior area
of the piston V over the piston D. The port H is opened and M closed, air
enters Ġ and through H, Kand M below the piston L' and the brakes are applied
with more or less force according to the strength of the current, graduation being
effected by the air entering through L and driving back the piston D so as to
close the port H and cut off further supplies of air. A. break in the train-pipe
admits air to the lower side of the piston L' thus applying the brakes
automatically.
The form of solenoid or electro magnet which will give the best results is shown
in detail on Sheet II Figs. I, & II but other forms might be employed either
connected directly or indirectly to the piston rod. The driver's variable distance
switch is designed so as to give sufficient range to control the strength of the current
through a wide range and so suit the one generator or source of electricity for
trains of widely varying lengths.
Having now particularly described and ascertained the nature of
my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
I. Controlling the application and release of fluid pressure brakes for vehicles
by the action of the combination of electro-magnet ported valve case and piston
valve substantially as herein described and shown.
II. The combination and arrangement of electro magnet, piston valve, valve
case and ports for the purpose and substantially as herein described and shown.
Dated this Fifth day of March 1894
J. S. HIGHFIELD.