PROVEMENTS IN ATMOSPHERIC BRAKES FOR RAILWAY AND OTHER CARRIAGES AND VEHICLES.
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Charles Cowdery at the Office of the
Commissioners of Patents on the 28th July 1876.
"IM-
CHARLES COWDERY, of Montgomery, in the County of Montgomery.
PROVEMENTS IN ATMOSPHERIC BRAKES FOR RAILWAY AND OTHER CARRIAGES AND
VEHICLES.".
This Invention relates to certain improvements in the construction and arrange-
ment of that class of railway brakes known as the "atmospheric," that is to say,
where the retarding power of the brake is obtained by atmospheric pressure.
The construction of the mechanical arrangement of this brake is as follows:-
Within the frame which supports the flooring of each carriage is fixed an air pump
which is worked by an eccentric keyed to one of the axles of the carriage. This
eccentric is made with an arm extending laterally from its periphery, the free
extremity of. which is connected by a link to the piston rod of the pump, so that
whenever the wheels are in motion the rotatory movement of the eccentric works
the piston rod of the air pump to and fro.
In the centre of this link is fixed a pin or short rod which extends laterally on
both sides of the link. Above this pin is arranged a lever hung from a bearing
fixed to the under side of the floor of the carriage or other convenient part, one end
of which is made of a duplex or fork like form, this part having notches cut in it so
as to catch or hold the pin before referred to when required. The free end of this
lever is when required acted upon by a second lever, which when brought into
operation depresses the end of the lover, thus causing its other or forked end to be
raisod and so lifted clear of the transverse pin of the link, so that when the brake
is not wanted the forked lever moves to and fro without working the air pump.
Behind the air pump or at any other convenient part is arranged a receiving
cylinder or air reservoir which is fitted with a piston and self-acting valve, so
arranged as to close at each return stroke of the air pump. The air as it is pumped
in is forced through the valve and its pressure drives the piston forward, the rod of
which being connected to the brakes they are actuated in a corresponding manner.
Extending along the centre of the framing is a rod or shaft which carries a heavy
weight fixed to any convenient part of it. This rod has also fixed to it two cains or
levers one of which acts upon another lever which allows the forked lever to fall
and become engaged with the transverse pin of the link and thus put the air pump
at work. The other cam or lever acts upon a second lever which closes a valve in
the receiving cylinder. To take the brakes off the guard or driver has merely to
cause the longitudinal rod to make a quarter of a turn, which is done either by
3J1

page_text: :-
means of a wheel or lever arranged in any convenient position and with a pawl or
catch that takes into a notch to keep the brakes off when they are not required.
The brake system of the several carriages is connected together in the following
manner The longitudinal rod before referred to is fitted at each end with a
universal joint to allow for any difference of level or for any oscillation, and to one
end of the rod a socket is fitted having its extremity formed of a bell or trumpet
shape. The other end of the longitudinal rod is formed of a spigot or wedge like
shape corresponding to the internal figure of the socket at the other end. In this
way the carriages are most readily coupled up, the wedge end of one rod fitting
into the socket end of the next carriage, and thus the several longitudinal rods
form a continuous one throughout.the train. These connections are so made that
the carriages can only be coupled up when the brakes are in a like position on
cach carriage, that is to say, the brakes of the contiguous carriage must accord with
the position of those on the carriage to be coupled up. For use in station yards or
where shunting is required there is fixed to each end of the carriage a small hand
lever by drawing down which causes the brakes to be takon off. If found necessary
in order to avoid the admission of sand or dust into the air pump, the air may be
supplied thereto by means of a tube or pipe carried from the air pump up through
the roof of the carriage and fitted with a cowl that may be turned away from the
engine to prevent the admission of ash or dust. The engine and tender may also
be fitted with this brake so that the engine driver bas also the power of instantly
putting the brake on independently of the guard, and in this way any one of the
guards or the driver may stop the train without signalling to the others, and thus
effect a most important saving of time, and in the event of any part of the train
breaking away the weights being released act at once upon the brakes and bring
them into action. These brakes may also be applied to ordinary road vehicles and
arranged so that the driver may be able to put on the brake when required by his
foot or hand.