Improvements in or relating to Brake-apparatus for Railway and like Vehicles.
Year: 1895

page_text: Date of Application, 23rd Aug., 1895-Accepted, 13th June, 1896
COMPLETE SPECIFICATION.
Improvements in or relating to Brake-apparatus for Railway and
like Vehicles.
We, LEOPOLDO ROVIDA, C.E. of 9 Corso Dogali, Genoa, and GIOVANNI
ONETO, Tradesman, of 30 Via Demarini Sampierdarena, both in the Kingdom of
Italy, 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 :-
•
This invention relates to the utilization of the momentum of a train or vehicle
by means of a hydraulic brake applied to the locomotives or other vehicles of
railways and tramways.
In the accompanying drawings
Fig. 1 is a side elevation, partly in section and
Fig. 2 a plan of a part of our improved brake apparatus ;
Fig. 3 is a view of the parts H, L and G of Fig. 1 as seen at right angles
to the position in which they are shown in the said Fig. 1, and in a smaller
scale;
Fig. 4 is a vertical section of a reservoir and heater hereinafter referred to;
Fig. 5 is a plan view of the apparatus shown in Fig. 4;
Fig. 6 is an elevation, partly in section of a brake cylinder, such as is fitted on
the vehicle;
Fig. 7 is view, half in section, and half in elevation of special valves for
counteracting the effects of breakage in the system of pipes and apparatus ;
Fig. 8 shows two views at right angles to each other (one being a central
longitudinal section), of a coupling by which the brake pipes of different carriages
are connected.
Fig. 9 is a central vertical section of a whistle arranged in the tank P.
Fig. 10 is a vertical section of a valve by means of which a false discharge may be
effected;
Fig. 11 is a vertical section of the cylinder in which N is the piston pressed by
a coiled spring;
Fig. 12 is an elevation of the cylinder of the brake with pipes and valves V', and
Figure 13 is a plan view of the same;
Figure 14 is an elevation of the operating lever.
Figure 15 is an elevation of the reservoir P, heater R, pipes and valves, and
Figure 16 is a plan view of the same.
This brake is constituted by a system of force-pumps, with which is combined
a system of levers arranged to press the brake blocks against the periphery of the
wheel rim.
E (Fig. 1) is an eccentric secured to one of the axles A of say a locomotive and
of which the ring or strap F carries an arm F which by means of the joint-pin G.
sets the suspended sector L in swinging motion on the pivots H H, attached to the
frame of the vehicle..
This sector is formed of two parallel arcs, side by side, between which as
guides, may reciprocate the slide C jointed to the connecting-rod B, which
transmits the liorizontal to and fro movement of the eccentric-arm F to the pump-
pistons 1. 2. of the pumps 3, 4, respectively.
The pumps, 34, communicate by means of the horizontal: pipe K (Fig. 2) with

page_text: the reservoir P (Figs. 4 and 5) and with a cylinder N (Fig. 11) with a spring-
controlled piston. This piston and the cylinder N form an equalizer like an air-
vessel.
To the reservoir P is annexed a heater R (Fig. 4) whereof the functions will
hereafter be described.
A system of balanced levers, 3, 4, y, 6 counterpoised by the weight P₁, serves to
transmit to the vertical rod 6 a vertical movement, for adjusting it relatively to the
arc Land is manipulated by the lever handle 6 placed within the engine-driver's
reach, and drawn to and fro against a notched quadrant 7 suitably fixed for
instance on the foot plate.
The reservoir P is fitted with a safety valve v serving to put the reservoir itself
into communication with the water in the boiler.
The tube, thus connecting the reservoir with the boiler, is not shown at all; but
it carries a manometer or pressure-gauge, showing the exact pressure at any given
moment.
If, to the locomotive and tender, any other carriages have been attached, one or
several of the latter require to be fitted with brakes, therefore we fix on the under-
side of each individual carriage, a cylinder 8 provided with 2 pistons (Figs. 6, 12,
and 13) operating, by their rods, a lever-system analogous to those placed on the
locomotive.
Two tubes U and T (Figs. 12 and 13) each communicate at one end with this
cylinder, and at the other are connected either with safety valves V, arranged the
one in the front part of the carriage and the other behind the latter, or with
cocks (Fig. 12). The joining together of these tubes between the vehicles is
made by means of tubular appendices of rubber, united on one side to the iron
tubes and on the other side to a system of helicoidal attachments or couplings with
rubber packing or mounts (Fig. 8).
The safety-valves V¹, and consequently the upper part of the tubes, must all be
located on one side of each vehicle that is to say, on the same side of the carriage
and of an observer, with his back to the front part of the carriage, (Figs. 12:
and 13).
If we now suppose that a certain number of waggons are coupled on behind to
the locomotive, the brakes perform their function in the following manner;-
In the first place, and before all things, it is necessary to fill with water the
conduits U T, the cylinders and the reservoir P, which is effected by means of an
injector placed on the locomotive, which, by aspiration, forces water from the
tender by a pipe into the reservoir P, and thence into the conduit and cylinder;
the air, which previously filled these vacant spaces escapes through the: cock s,
while the water filling is proceeding (Fig. 4) placed at the summit of P, this cock
being closed when the operation is complete.
These preliminary conditions having been established the brake is ready for
action. To this end, the lever S is manipulated in such manner as, by means of
the fixed fulcrum r and the arm b to depress the slide c to the bottom of the sector
from the position H at the top of the sector (which place it occupies. when the
brake is out of action).
In consequence of this depression of the slide, the pump pistons are made to
traverse a portion (larger or smaller) of their stroke, and thereby inject a part of
the water from the tender, which is in general a little elevated in level above the
pumps, into P and into the cylinder N (Fig. 11) of which the object is to render
more uniform the work of the pumps.
It is evident that the pressure will augment and be transmitted to the brake
pistons which moving forwards operate more or less quickly, the pressing of the
brake blocks against the rim of the wheel-according to the distance that the
pistons are made to travel.
The manometer or gauge indicates constantly the pressure during this manipulation.
of the brake.
To release the brakes, one has recourse to the valve 1 (Figs. 4 and 5) which
"

page_text: permits the water to pass from into the tenuer after which the side is restored
to its original position at H.
Let us suppose that, while the brakes are on, a strong leakage took place,
which might in the absence of special precautionary devices paralyse and destroy
the brake action.
This inconvenience and danger is remedied by the system of valves, shown
in Fig. 7 and also represented in Figs. 12 and 13, and counter-marked V1.
This is composed of a pair of identical valves, placed vertically and suspended
at the opposite extremities of a balance beam with equal arms (in such manner that
the depression of the one closes the other) and en closed in two adjacent cylindrical:
boxes intercommunicating by the upper part.
These valves are maintained at an equal distance from their seats (during the
time that the brakes are on) by two light coiled springs. Supposing, now that a
leakage makes itself manifest; the valves nearest to the point of escape will
immediately be closed, and the brake will continue in action by means of the other.
tube.
If the leak declared itself during the running of the train, it would again occur,
as just described, that as soon as the pumps were set in motion to put the brakes in
operation, the valves above mentioned will close at once.
The general arrangement of the brake allows the engineer to keep an eye upon
the occurrence of any rupture, whether these should take place while the brakes
are on or off. In the former case as soon as the brake shall have ceased to act, if
the level of the point of leakage is lower than the summit of the reservoir P the
water level in P will be lowered and will simultaneously lower a float or glass G of i
the apparatus shown in Fig. 9.
This apparatus is nothing but an indicator or means of warning which at the
opportune moment (ie. when the glass G which is full of water and maintained on.
high by a counterpoise, succeeds in overbalancing that counterpoise by the water
which it contains, and when the water level in P sinks) opens, by the aid of the.
valve R' an admission to the steam from the boiler, which thus penetrates into
a whistle or siren fixed to the end of the tube so as to call attention to the.
defect.
The diaphragm m in rubber or in corrugated or ribbed copper serves to protect!
the interior of the chamber A of this alarm apparatus, and at the same time
permits the movement of the rod T, or spindle which further carries a valve M'
(at the lower part of the apparatus) which has for its object to prevent any excess
of pressure upon the diaphragm while the brake is on.
Supposing the case of an escape during the running of the train; the water in
the reservoir P will sink rapidly and cause the warning to sound. The valve
shown in Fig. 10 placed anywhere along the course of the brake conduit, serves to;
produce an artificial escape, and may be opened by any one of the official train-
attendants or by any one of the travellers; thereby warning the engine driver to
pull up.
Figure 12 shows that wherever may be the point at which the leakage makes
itself manifest, the brake-mechanism is only partially emptied and the brake and
apparatus are still always in a condition to act.
During winter the water might be frozen; but this inconvenience will be prevented
by the provision which we are enabled to make by the employment of the heater R.
(Figs. 4 and 5, already mentioned) which creates a circulation of the water in the
direction indicated by the arrows (Figure 12).
This heater is fed by the steam exhausted from the locomotive cylinders, by
means of the pipe m. branching from the escapement pipe, whereby the waste steam
conducted to the top of the heater leaving it by the outlet pipe m' (Figure 4).
It might happen that while the train was running, a coupling should yield,
break, and come loose; the train would thus be divided into two portions. In that
case to prevent (when running up an ascending gradient) the detached portion from

page_text: running back down the decline with a speed gradually accumulative until it became
dangerous, we use the following apparatus ;-
In the carriage at the tail end of the train (and which may probably in fact be
the guard's van) we place a system of pumps analogous to that on the locomotive;
and the function of setting it in operation is fulfilled by a counterpoise R which is
normally maintained in a vertical position by a spring N¹ (Figure 14).
Whether this weight be permitted to fall out of the perpendicular to one side or
the other, it will carry with it the arm D by the aid of the stud or pivot P fixed
on the arm carrying the counterpoise which slides along the slot or opening in the
arm D and therefore also depressing the rod T which commands the pump rod.
The pumps thus set in action draw the water from a supplementary reservoir
located in this tail carriage and force it into the general brake-conduit.
We can now see in what manner the counterpoise R is caused to fall ;-
Owing to a coupling-fracture we should have an increase of the speed in the
front part of the train and a decrease of speed in the detached part; and
immediately afterwards a strong shock in the direction of the train length between
the wagons, or carriages produced by the sudden tension of the chains.
It is evident that the counterpoise falling, owing to the law of inertia will cause
the brakes to put on, in the detached portion.
The engine-driver's attention being called by the warning signal produced by
the disconnection rupture of the tubes will on his side also pull up as soon as
possible.
The valves nearest to the point of rupture will as has been shown be closed and
the putting on the brakes thus facilitated on both sides.
The safety valve V₁ placed on the locomotive serves to operate the brakes by
means of the water from the boiler, in the case of damage to the pumps-as has
been explained.
1.'
A safety valve placed on the pump-tubes to prevent the steam pressure in the
brake apparatus from exceeding certain limits completes the mechanism.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is;-
1. A hydraulic brake constituted by a system of force pumps combined with a
system of levers pressing the brake-blocks against the periphery of the wheel-rims
substantially as described and as illustrated in the accompanying drawings.
2. A reservoir in communication with the pumps and the boiler of a locomotive
or other motor serving to receive the water transmit it to the conducting tubes and
set the warning device in operation substantially as described and as illustrated in
the accompanying drawings.
3. In a reservoir substantially as described in Claim 2 and shown in Figure 9 a
device provided with a diaphragm and serving to automatically set the brake in
operation substantially as described and as illustrated in the annexed drawings.
4. A special arrangement of mechanism or subsidiary brake applied to railway
carriages and other the like operating at need quite independently of that operated
from the locomotive and tender substantially as described and as illustrated in the
annexed drawings (Figures 12 and 13).
Dated this 23rd day of August 1895.
COULT & WADE,
Agents for the Applicants.