IMPROVEMENTS IN RAILWAY BRAKE APPARATUS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 7th April 1881. A communication
from abroad by Emil Schrabetz, of Vienna, Austria, Civil Engineer.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent.
Agents, Southampton Buildings, London. "IMPROVEMENTS IN RAILWAY BRAKE
APPARATUS." [A communication from abroad by Emil Schrabetz, of Vienna,
Austria, Civil Engineer.]
This Invention relates to improved brake-apparatus for railway vehicles.
According to my Invention I employ gravity to produce the requisite pressure
by means of a weight applied to each vehicle.
The effect of this weight is counteracted when the brake is not in use by
compressed air, the weight being raised by means of an ordinary cylinder with a
piston or diaphragm, or by means of bellows or other suitable device.
The compressed air is produced on one part (or in several parts) of the train, and
transmitted by means of a pipe to the discharging cylinders of the vehicles to be
braked. The weight may also be counterbalanced by any gaseous or aeriform
body instead of by air, the compression or tension being obtained either
mechanically or by caloric power; or the gas may be chemically produced and
simultaneously receive the necessary tension. The said arrangements may be
combined, and the same effect may, be obtained by a vacuum. Liquid bodies may
also be employed instead of air or gases.
The said substances having substantially the same effect, I shall only describe a
brake worked by compressed atmospheric air, which will be sufficient to enable
any practical man to apply my Invention, though using any of the bodies or
substances aforesaid.
Valves are dispensed with in the conduit-pipe, and distributing cocks are
necessary only at the point or points from which the mechanism is to be worked.
My arrangement differs in essential features from other pneumatic brakes, the
compressed air being discharged not only from the conduit-pipe but from all the
cylinders, and the compressed air is never, either directly or indirectly, employed for
exercising a pressure upon the brake-blocks.
All the arrangements I employ for producing, accumulating, and conducting the
compressed air serve a purpose quite different from that which they are made to
serve in brakes wherein such arrangements have been hitherto employed.
This improved brake apparatus comprises two specially distinctive parts, viz., the
mechanical and the pneumatic.
In the operation of the mechanical part of the brake, that is to say, in working
the said weight, three requirements have to be kept in view, viz., a rapid movement
of the brake-blocks towards the wheels. The production of a mechanical

page_text: combination capable of greatly increasing the power actually applied, the
employment of this combination for producing a relatively high pressure of the
brake.
When the brake is to be relieved, the operations take place in an inverted
order.
The lever carries a suitable weight, and is fixed directly on the piston rod of
the discharging cylinder, which is suspended by means of a ball and socket joint;
or the said lever may be fixed to the piston rod of a fixed cylinder by means of
a chain or wire-rope passing over a pulley.
When the air escapes from the discharging cylinder the action of the weight is
transferred by means of combined levers (one, the brake lever, and. the other, the
lever carrying the weight) to the brake-shaft and through it to the brake-blocks.
The effect of the weight is proportionally counteracted when air pressure is
maintained in the cylinder, so that any desired degree of pressure of the brake
may be obtained, and is limited only by the dimensions of the levers and the
weight. But when the highest pressure for which the cylinder is adapted is
produced therein, the lever is raised, and consequently a regulating lever pushes
back a link piece connecting the brake-lever and the pivotted lever carrying the
weight, thus disengaging the brake-lever. Meanwhile the regulating lever has
reached a rib or projection on the brake-lever, and lifting it removes the brake-
blocks from the wheels.
As the weight follows the vertical vibrations of the carriage, the pressure of the
brake must continually vary, and consequently the effect be augmented. Springs
may be fixed on the extremity of the lever carrying the weight in order to regulate
this effect.
The connecting piece is continually drawn towards the brake-lever by the
weight of the link connected therewith; but in order to overcome the effects of the
jolts of the railway vehicles, the continuous contact of these parts is also secured
by a spring. The tendency of the brake-lever to take the lowest position can be
assisted by a helical spring.
The shaft occupying the whole width of the vehicle should be very strong,
because the pressure of the brake may be equal to the weight of the carriage.
I may also arrange brake-rods directly upon the brake-lever, and this arrange-
ment offers the advantage of the shaft serving only as an axle; the said shaft may
in this case be thinner.
In this modified arrangement, and for the purpose of making the lever of the
weight pass the axle and brake-rods, the said lever and the discharging cylinder
are arranged sidewise.
The fixed revolving axle in this case serves to render uniform the movement of
the lever carrying the weight and the regulating lever.
The lever carrying the weight can be arranged above and below the brake-lever.
The cylinders may be arranged, as above described, or a vertical fixed cylinder
may be used, in which case the piston-rod may move the lever carrying the weight;
or the cylinder may be connected with the lever carrying the weight, and the piston-
rod may be suspended by means of a ball and socket joint so that the cylinder is
utilized as an acting weight. According to a further modification of my Invention
the disengaging of the piece connecting the brake-lever and the lever carrying the
weight is operated by the collar of the piston-rod pressing against the regulating
lever. A further advance of the piston-rod causes a second collar upon the same to
press against the arm of the brake-lever, thus lifting it, and consequently releasing
the brake-blocks.
According to another construction I unite the brake-lever and the lever of the
weight in the joint or bolt, and the pivot or axle is not fixed but only inserted.
The collar of the piston-rod relieves the support, and afterwards the second collar
raises the brake-lever and its appendages.
In another arrangement the axle is capable of longitudinal movement, and the
lever carrying the weight is placed on the axle. This axle is pressed by a spring

page_text: into such a position that the brake-lever and the lever carrying the weight are in
the same plane. In this case the regulating lever turns on an axle.
The regu-
lating support is firmly connected with the lever carrying the weight; when
the piston-rod moves outward, a boss throws the regulating-lever aside; the
disengagement is now effected and the second collar raises the brake-lever.
The axle may also be fixed, and the lever carrying the weight acted upon by a
spring will, in this case, be movable, or the said lever may be fixed and the
brake-block may move, or I may combine some features of the above described
arrangements in one construction. I may, in some cases, dispense with the two
links which connect the two levers, and the regulating lever may raise one of the
links bearing against the piece connecting the two levers, which, owing to its
form, is thrown aside when the said link is raised as stated.
One of the links may be guided in a channel, and on its extremity carry a pullet.
The regulating lever is, in this case, furnished with a wedge-shaped boss, and
throws the piece connecting the two levers aside by means of the aforesaid link.
A further modification consists in connecting one of the links with a crank-lever,
the axle of which is fixed on the brake lever. The regulating lever bears against
the crank-lever and throws the piece connecting the two levers aside.
These arrangements may also be applied in different combinations to the
brake-lever and the lever carrying the weight, and in a similar manner the piece
connecting the two levers can be so arranged as not to vibrate in the plane of the
levers, but to be thrown out sidewise.
In order to increase the power a third lever may be applied to the lever which
carries the weight. The arrangement of the brake-lever and the lever carrying the
weight remains substantially the same.
For the purpose of facilitating the readjustment of worn brake-blocks, and
chiefly for regulating all the brake-blocks from one point, the brake-lever may be
composed of two pieces.
The brake-lever, properly so called, moves freely upon the brake-shaft, but a
second auxiliary lever is firmly connected with the shaft and is directly attached
to the brake-rods, in which case the last named lever may move freely upon the
shaft. Both levers are so connected that an angular motion between them is
possible. In constructing this arrangement, it will be convenient to double one of
the levers. When the brake rods are not fixed on the auxiliary lever the latter is
firmly connected with the shaft, furnished at its extremities with the usual
contrivances for receiving the brake-rods.
The movable connection of the brake-lever and the auxiliary lever is effected by
set screws.
When horizontal discharging cylinders with pistons are used the piston may
be turned from time to time in order to obtain its uniform wearing and lubrication.
For this purpose a toothed wheel is fastened on the piston-rod outside the cylinder,
and upon the rod I provide a revolving piece with a shank running in a slot.
When, during the movement of the piston, the shank is moved by the inclined
slot, the piston is turned, but the revolving piece runs freely upon the rod when
the piston recedes.
A modification of this part of my Invention, a toothed hoop disposed on one side
of the piston.
One or two pawls are pressed by springs against the piston and
catch in the indentations when the piston moves, thus producing a partial
revolution of the said piston at each stroke thereof.
It is evident that the brake may be worked by hand. The lever carrying the
weight or the piston-rod is, in this case, to be connected by any suitable means
with the brakesman's van but without hindering the movement of the piston.
A spring may be inserted in some part of the apparatus in order to obtain a
partial effect of the weight. The pneumatic apparatus may be omitted, and the
mechanical part of the system separately employed as a hand-brake. The con-
nection of the air-conduit of the several carriages or vehicles is obtained by a
coupling-hose connected by bayonet-joints. Both lengths of hose are twisted in

page_text: opposite directions before being jointed, so that when they are being put together
the union of the coupling is effected by their own elasticity.
On each hose an elastic perforated hood is fastened. When the coupling is
effected the edges of these hoods are pressed together, thus forming an automatically
closing packing.
The hood may be made of leather, india-rubber, or other elastic substance, and
fastened by means of an elastic washer; or the flange of the hood is secured by an
auxiliary piece.
The air necessary for releasing the brakes is compressed in a reservoir by an
air-pump. The mechanism for setting the brakes in motion is situated between
the reservoir and the main conduit. It consists of a cock connecting the main
circuit either with the reservoir or with the atmosphere. The ways of this cock
are very small. A double-seat valve being automatically regulated by a spring
allows the air to pass from the reservoir to the main-conduit when the pressure in
the latter sinks below a certain point.
The tube enclosing the above spring has a thread on its outside and a cap on
the inside, so that the tension of the spring is regulated by turning the socket,
the spring being attached to a spindle, and a bar of the spindle rests in an
excavation of the cap. The pressure in the reservoir is determined by suitable
means; for instance, the working of the air-pump may be regulated by the pressure
in the reservoir.
The tube enclosing the spring communicates with the main conduit by means of
a hollow valve.
The pressure in the reservoir might be much reduced in consequence of an
extraordinary consumption of air, and it might be desirable to open the valve,
which works only to a certain degree of pressure. In this case the spindle may
cause the lifting of the valve by turning the bar 90°. In this position the said
bar or head falls into two longitudinal slots of the cap, so that the spindle can be
pressed upwards.
The lever which turns the cock carries a handle with a worm, which takes into
a fixed toothed segment. The turning of the worm causes only a small movement
of the cock, and a rapid movement of the lever is possible after disengaging the
worm by means of the handle.
The main-conduit contains a safety-valve, which ejects the air when a certain
pressure is effected. The valve is regulated by a cap and springs. The cap is
screwed into the body of the valve.
The air-pressure existing in the main and reservoir-conduit is indicated by two
pressure gauges.
For the purpose of indicating the action of the brakes at any point of the train,
it is advisable to place at that point a pressure gauge connected with the main
conduit; an acoustic signalling apparatus may also be provided. This apparatus
consists of a chamber connected with the main conduit. A whistle is placed at an
aperture therein. A hollow cylinder divided by a partition wall moves in a pipe.
In the inferior chamber of the hollow cylinder I provide holes. The head of a pin
moves in the upper chamber of the hollow cylinder. The pin has at its upper end
a plug or cone shaped valve, which closes the aforesaid aperture, and is kept out of
the hollow cylinder by means of a spiral spring, but the hollow cylinder is pressed
inwards when compressed air is injected, and the opening is closed by the valve or
plug. The spring being compressed, air is injected into the chamber, and owing to
the expansion of the air accumulated in the latter the whistle sounds.
The apparatus can also be employed as an intercommunicating signal by means
of an arrangement forcing the hollow cylinder into the pipe and keeping it there,
thus removing the valve from the opening.