IMPROVEMENTS IN CONTINUOUS RAILWAY BRAKES
Year: 1877

page_text: LETTERS PATENT to Francis Busfeild Armstrong, of the India Office, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN CONTINUOUS
RAILWAY BRAKES." A communication from abroad by John Arthur Armstrong,
of Simlalı, Punjaub, in the Indian Empire, Captain, Royal Engineers.
Sealed the 24th May 1878. and dated the 6th December 1877
PROVISIONAL SPECIFICATION left by the said Francis Busfeild Armstrong
at the Office of the Commissioners of Patents on the 6th December 1877.
FRANCIS BUSFEILD ARMSTRONG, of the India Office, in the County of Middlesex.
"IMPROVEMENTS IN CONTINUOUS RAILWAY BRAKES." (A communication from abroad
by John Arthur Armstrong, of Simlah, Punjaub, in the Indian Empire, Captain,
Royal Engineers.)
According to this Invention the brakes fitted to any vehicles are actuated by
means of suitable compressers or pumps connected to a continuous tube, in which
a vacuum, more or less perfect, is maintained by any suitable exhausting appliance,
this vacuum acting on the suction or supply valves (or their equivalents) of the
said compressers or pumps, preventing their drawing and coming into action, whilst
the destruction of the vacuum in the continuous tube allows the compressers or
pumps to draw and put on the brakes.
For the purpose of this Invention an air pump is actuated from a crank or
eccentric on a carriage axle or other revolving part of the train. The hollow
plunger of the air pump is fitted with a sliding block and spiral spring to prevent
undue compression (or a relief valve would answer the same purpose, but waste air
from the continuous tube). There is a compressing cylinder on each side of a
carriage for actuating the brakes on all wheels.
The space between the air pump suction and delivery valves is connected to the
compressing cylinder, a valve being between. The space below the suction valve
of the air pump is connected with a box fitted with a flexible diaphragm or
equivalent elastic or receding appliance exposed to the atmospheric pressure, so that
[Price Bd7

page_text: disturbances of pressure in the continuous tube can serve to actuate a relief cock or
valve fitted on the compresser or brake cylinder, and actuated by the diaphragm.
There is a regulator cock or valve for shutting off to the branch pipe leading to the
continuous tube.
The action is as follows:-Supposing the last-named cock is open and that there
is a vacuum in the continuous tube, then the outer air acting on the diaphragm will
tend to collapse it or force it in, whereby the relief cock on the brake cylinder will
be opened, thereby allowing the escape of any residue or leakage in the cylinder;
as there is a vacuum below the suction valve, the air pump will not be able to draw,
and the brakes will fall off by gravity or other means. But on the admission of
air at any point, or by disruption of the tube connections, the pump at once comes
into action, the relief cock is closed, and the compressing cylinder puts on the
brakes.
A single vehicle is complete in itself for breaking in, shunting, and other cases,
for by closing the regulator cock, which by suitable connection may be made to 1
open the relief valve or cock, the apparatus is rendered inoperative; but on
admitting air through the same, the brakes are put on by the motion of the
carriages themselves; also so long as the regulator cock is open, any accidental
motion, due to gravitations, wind, collisions, or other causes, will at once check
itself.
The continuous tubes may be charged with pressure (instead of a vacuum being
therein) to close the valves of the compressers.
A vacuum may be used in the brake cylinders as a means of actuation from the
pump or exhaustor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Francis Busfeild Armstrong in the Great Seal Patent Office on the 6th
June 1878.
FRANCIS BUSFEILD ARMSTRONG, of the India Office, in the County of Middlesex.
"IMPROVEMENTS IN CONTINUOUS RAILWAY BRAKES." (A communication from abroad
by John Arthur Armstrong, of Simlah, Punjaub, in the Indian Empire, Captain,
Royal Engineers.)
This Invention refers to the actuation of the brakes by compression of air or
vapour, the pumps or compressors for this purpose being driven by the vehicle's
own motion. These pumps or compressers draw their supply of air or vapour from
a continuous tube, which acts as their suction or supply tube, and which continuous
tube by suitable appliances can at pleasure be maintained in a state of exhaustion,
more or less, or under pressure, and by this means regulate the action of the pumps
or compressors which actuate the brakes as may be desired. A supplementary or
relief valve worked by the variation of the pressure in the continuous tube is
also used to assist the control of the admission of pressure to actuate the brakes.
In describing the Invention it will be convenient to divide it into two parts,
viz., the continuous tube with its connections and appliances for regulating its
exhaustion; and the appliances on each vehicle in connection with the aforesaid
continuous tube, by which the vehicle's own motion is caused to actuate the
brakes.
The continuous tube is shown at c, c, c, on Figures 1, 2, and of the Drawings,
and is of sufficient size with reference to the number of compressors to freely
supply them.
The tube may be duplicated and placed in any convenient position.
I would here remark that the scale of the apparatus shown in Figures 1, 2, and 3
of the accompanying Drawings is much exaggerated for the sake of clearly illus-
trating the Invention.
The tubes C may be connected between vehicles with ordinary suction hose and
connections, as shown at Q, Figure 1, or the other methods shewn in the Drawings
may be used; these are founded on the properties of a coiled or spiral pipe to lengthen
and bear considerable flexion without injury. It here takes the shape of a helical
cage of wires or bands with a suitable swelled or bellied form for stiffness, as shown
in the coupling at Figures 2 and 3, and this may form a matrix as shown at R,
Figure 4, which is a sectional detail of a peculiar pipe coupling. On these wires or
bands R the outer sheath or hose of suitable material is laid; or the cage may
carry a hose within it as shown at T, Figures 2 and 3; or the hose may be laid
between two such cages.
The joints may be made as shown at Figure 4 for a single coupling, or at Figure 5,
which represents a double coupling. In both cases the coupling consists of an
arrangement of sleeves or collars a working on spiral grooves, screws, or bayonet
slots, these collars a being fitted with handles g and projecting studs and con-
necting links d, which are held down by the springs e to make the joint. The
handles g are turned so that the links d can be shot over the studs f, which they
engage with, and on turning round the handles g the elastic washers b at the
mouths of the connections can be brought up into close contact, and so make an
air-tight joint.
The continuous tube C may be closed by cocks or valves, or by a cap as shown
at U, Figures 2 and 3.
The continuous tube may be exhausted by any form of pump, or ejector, or
exhauster.
In Figure 1 is shown an ordinary double acting air pump A driven by a direct-
acting steam cylinder; this donkey engine is supplied with steam from the
boiler.
The main regulator shown in Figure 1, and to an enlarged scale at Figure 6, is

page_text: designed to govern the pressure or exhaustion in the continuous tube by a species
of reducing or air valve F, and at the same time correspondingly regulate the
supply of steam to work the exhaustor by an equilibrium or throttle valve E. This
is effected by the main lever D, on which is a stud working in the slotted lever i, k,
which carries the air valve F and the main balance at i. At k there is a smaller
balance of a strength sufficient when the lever is in the dotted position marked
open" with the stud fulcrum near to the balance at i to open the air valve F, and
the main balance at i is arranged so that when the lever is in the position "exhaust,"
it will have strength sufficient to balance the desired degree of vacuum pulling on F.
Intermediate positions of the lever give intermediate degrees of exhaustion or
tt
pressure.
To regulate the action of the pump or ejector, a similar arrangement is used;
the piston m or equivalent arrangement is jointed or coupled to the equilibrium
valve E on the steam pipe, and the pressure on the piston is balanced by the balance
at p; when the main lever D is in the position "open" the small spring n suffices
to close the valvo E, and whon in the position "exhaust" the balance at p is
adjusted to carry the same (or a trifle lower) unit pressure on mas is on F for a
corresponding position of the lever; hence the balance at 2 will keep the equi-
librium valve E open, and permit the exhaustor to work until the vacuum in the
continuous tube is able to lift the piston m and close the valve for any position of
the main lover, and by theso means an entire control of the state of the vacuum or
pressure in the continuous tube is effected.
A similar regulator in whole or part is shown at O, Figure 2, fitted to a brake
van, and if desired an exhaustor driven by the vehicle or by hand may be added
so as to give the brakesman entire control over a train or section of a train.
Special brake actuators can be fitted to the passenger or other vehicles, as shown
at P, Figure 3, provided with suitable valves, frangible diaphragms, and the tell-
tales as desired.
A steam jet may be used to assist in the rapid admission of air, or to aid in
lubrication.
The brake action and appliances are shown in Figures 1, 2, and 3, and to a
larger scale at Figures 7 and 8. G is a pump or compressor to draw the air or
vapour from the continuous tube C, and to compress it to the required degree, these
compressers or pumps may be driven direct from cccentrics as at M, Figures 1 and 2,
or by friction gear as shown at N, Figure 3, to regulate the speed and force required.
The compressed air or vapour acts on a piston plunger or diaphragm H, by which
the vehicle brakes are actuated; when necessary, a relief or safety valve I is added
to prevent undue pressure.
The suction valve V of the compresser may be regulated by means of a spring,
as shown at Figure 8, so as to require any desired degree of air in the continuous
tube before it will lift and allow the compresser to draw and work.
Below the suction valve V of the compresser, and in connection with the con-
tinuous tube C is fitted an air box with flexible diaphragm K (or a piston arrange-
ment may be used), which is connected by suitable means, say by a lever W, as here
shown, to the pet cock or valve L, so that when there is exhaustion in the continuous
tube C, the valve or cock L is kept open, but it closes itself when air is admitted
to the continuous tube; its use is to obviate pressure in the brake cylinder
arising from a residue of air in the compresser or small leakage, and it also enables
the compresser to assist in maintaining an imperfect vacuum by the escape so
provided. I propose to use this method only as a check on the other, but as have
already said it could be used in another way so that the compressers draw air from
without under the command of this arrangement, either below the suction valve to
cut off the supply, or to divert it from the brake compressers.
This apparatus may also be arranged so as to cut off the compresser entirely from
the brake cylinder by suitable valves, three-way cock or slides, and thus form a
complete supplementary check on the action of the brake.
A suitable cock or valve J, Figures 3 and 8, is placed on the branch C¹ from the

page_text: continuous tube C below the connection with the air box K actuating the check
valve L by means of the cock or hand regulator J. The brake of a vehicle can be
entirely cut off from the rest of the train, and it also gives the means of applying
the brakes by hand in shunting, or when separate, an arm and stud 8 is so arranged
that when the hand regulator J is closed, it will open the cock L, and thus permit
air to escape without putting on the brakes, but on opening the hand regulator any
movement of the vehicle enables the compresser to draw air and put on the
brake.
Water jackets may be used to the compressers, if found necessary to prevent
> heating.
The action of the apparatus is as follows:-Supposing the cock J is open, and
that there is a vacuum in the continuous tube C, then the outer air acting on the
diaphragm K will tend to collapse it or force it in, whereby the relief cock or
valve L on the brake cylinder H will be opened, thereby allowing the escape of any
residue or leakage in the cylinder H; as there is a vacuum below the suction
valve V the air pump G will not be able to draw, and the brakes will fall by
gravity or other means. But on the admission of air to the continuous tube Cat
any point of same (or say, by disruption of the tube connections) the pump G at
once comes into action, drawing air from the continuous tube C, and forcing and
compressing it against the piston H, so that this latter puts on the brakes; the
diaphragm K is at the same time forced out and closes the relief cock L.
The advantages which are believed to appertain to this brake, and which are
stated here in order further to elucidate its action are as follows:-
1. That the brake is not necessarily dependent for its working on its connections
with any other vehicle of source of action; the brake is self-contained as far as each
vehicle is concerned.
2. That when combined in a series of vehicles the brake is held in a state of
tension with duplicate safe guards to its action
continuous tube at once releases the brakes to do their work.
The simple admission of air to the
3. That the controlling medium being simply a tube connecting the brakes
(without any reservoirs, accumulators, or their equivalents, supplied through the
means of the continuous tube with motive power from without) requires but small
power and time to work it, thus giving quick control.
4. That the continuous tube being subject to a vacuumn, the joints and connections
are subjected to a low pressure, and pressure from without is favorable to closing
small leakages, hence simple connections may be used with small risk of leakage.
5. That as long as a partial vacuum is maintained in the continuous tube, each
brake apparatus will act as an exhaustor to assist in preserving the action and over-
coming leakage.
6. That the motive power to apply the brakes is taken from the "vis viva," which
has to be overcome, thus economizing work, instead of as in most continuous brakes
being supplied with motive power by an independent engine.
7. That any practical degree of pressure can be used in working the brakes, the
apparatus may hence be rendered small and compact, although the continuous tubes
re only subject to a low pressure.
8. That the power to work the brakes being practically unlimited, a considerable
margin of play or clearance can be given to the brake compressors, so as to obviate
he necessity of complicated methods of taking up the wear of brake blocks which
re required when a limited amount of force has to be transmitted and stored
hrough the continuous tube.
9. That the skidding of the wheels prevents an increase of pressure on the brake
locks, and forms a self-acting adjustment to keep the brakes at the most efficient
egree of retarding action.
10. That the brake is self-acting or automatic in case of disruption of the vehicles
n all sections of a train.
11. That the brake can be put in action by guards, passengers. or at any maint

page_text: it is desirable to give the power of doing so, by a connection to admit air to the
continuous tube.
12. That vehicles with this brake can be hand shunted and braked by the aid of
the band regulator as may be desired.
13. That vehicles on a siding or standing cannot get away by wind, gravitation,
or other causes if the hand brake regulator be left open.
14. That the brake action of each vehicle can be cut off separately in a train
without interfering with the action of others.
15. That the proper connections and working are ensured at all times, and any
defect enforces attention by stopping the train.
16. That by the command of the degree of exhaustion given by the main
regulator, and small differences in the action of the suction valves of the compressors,
the brakes may be taken on and off by degrees as well as be nearly instantaneous
in their action.
17. The parts of the brakes may be duplicates, and they are few and simple;
there are no reservoirs to take up space, and the fitting to existing stock is easy.
All the parts may be constructed of durable materials, and the packing of glands
easily got at. A very small amount of power is taken from the locomotive boiler;
it is hence expected that the cost of construction, repairs, and maintenance should
be low.
And having thus described and ascortained the nature of this Invention, I declare
that I claim,-
Firstly. Actuating railway brakes by compression of air or vapour by means of
pumps or compressors worked by the motion of the vehicle itself, and drawing from
a continuous tube or tubes, the fluid in which can be maintained in any required
tension, and thus regulate the action of the said pumps or compressers, all sub-
stantially as set forth.
Secondly. In a system as set forth in the first claim putting on the brakes by an
alteration in the tension of the fluid in the continuous tube or tubes.
Thirdly. The combination of the pump or compresser G and suction valve V with
a diaphragm or piston K and valve L, all operating as and for the purpose set
forth.
Fourthly. The appliances for regulating the tension of the fluid in continuous
tube or tubes in a system as set forth in the first claim.
In witness whereof, I, the said Francis Busfeild Armstrong, have hereunto set
my hand and seal, this Third day of June, One thousand eight hundred and
seventy-eight
FRANCIS BUSFEILD ARMSTRONG. (L.S.)
MONTAGU STANLEY HALL.
ALFRED BENGER.
} Witnesses.