Improvements in Appliances for Preventing the Fouling of the Atmosphere in Railway Tunnels from Locomotive Engines.
Year: 1892

page_text: COMPLETE
SPECIFICATION.
Improvements in Appliances for Preventing the Fouling of the
Atmosphere in Railway Tunnels from Locomotive Engines.
We, GEORGE BRAY, of Blackman Lane, Gas Lighting Engineer, and GEORGE
DALTON, of Regents Villas, Headingley, Engineer, both of Leeds, in the County
of York, 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 certain improvements in the invention described in
Patent Specification numbered 10851 and dated 26th July 1888, and has for its object
the operation of the inlet valves into the service pipe and trunk in such a manner
that, the outer atmosphere is cut off earlier than hitherto from the valve before it
begins to open and during the closing of the same, and thus more effectually
extracting the products of combustion as they are emitted from the engine and
thereby prevent the fouling of the atmosphere within the tunnel.
On experimenting with the apparatus constructed as described in the before
named Specification, it was discovered that the volume of air discharged by the
extractor was much in excess of the results of combustion of the fuel consumed,
and the steam formerly emitted from the funnel of the engine, the cause of this
being, that during the opening and closing of the valves communicating with the
service pipe, they are open to the outer atmosphere, thus admitting air, thereby
increasing the volume to be extracted and the pressure within the service pipe and
main trunk; thus militating against the efficiency of the apparatus.
In describing our invention in detail, reference is made to the accompanying
drawings in which
Fig. 1. represents a longitudinal section through a trunk valve with our invention
added thereto, and a portion of the service pipe."
Fig. 2. is a plan of same showing the position occupied between the rails.
Fig. 3. an enlarged sectional detail of our improvement, and
Fig. 4. an enlarged cross section through line a. b.
The connection between the engine and slider or trunk valve T. is effected in
the manner as hitherto by junction pipe J. the service pipe G. being fitted with
valves V. at suitable intervals, opening inwards and provided with springs D to
raise them to their seats when not depressed by the trunk valve T.
Each end of the trunk valve T. is prepared with an inclined plane P. by which
the respective valves Y. are opened by one and allowed to close by the other on
passing over them.
In order to prevent the outside atmosphere entering the service pipe G. during
the opening and closing of the valves V. we extend the side plates of the service
pipe G. some distance at each end, and mount between the plates of the extended
portion, two lids N. and N¹ of such width as to fill the space between the division
plates Z. Z. but free to be operated therein, each lid being supported at one end
by a pin L. and the lid N. in the centre by an arm Q. resting on a bar R. attached
to the division plates, the end of lid N' in the centre is formed with a curved lip S.
which engages with a tongue U. formed on lid N. thus hinging the two lids in the
centre, and by these means forming a chamber W. between the lids and inclined
planes P. by which the rush of air from the outside of the service pipe G. is
prevented.
The lids N. and N fall to the position shown on the drawings by gravity, and
are raised when passing over a valve V. by the spindle of same coming in contact
therewith, the weight of the lids and pressure of the bow spring Y. thereon, not
being sufficient to overcome the resistance of the spiral spring D. on underside of

page_text: valve V. therefore the lids are raised by the valve spindle, and when clear of the
same are lowered by gravity assisted by the bow spring Y. thus leaving a
chamber W. between the lids and inclined plane P.
On the rigid surface of the inclined plane P. arriving over the spindle of a
valve V. the valve is depressed, thus allowing the products of combustion and
exhausted steam to escape into the service pipe G. without drawing air from
the outside atmosphere which is presented passing through the valve V. by the
closed lids N. and N' mounted and operated in the manner as hereinbefore
described.
The valves V. are kept open by a central rib in trunk valve T. as hitherto, and
are closed by springs D. on the valve spindle ascending the inclined plane P. at the
opposite end of the trunk valve T. the outside atmosphere being prevented
entering the chamber W. by the lids N. and N mounted at the hind part of
the apparatus, the products of combustion and exhaust steam are carried from the
service pipe G. through branch pipes B. to a main pipe and extracted as hitherto.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we declare that what we
claim is
A trunk valve T. having an inclined plane P. at each end combined with the
lids N and N arranged substantially in the manner and for the purpose as herein-
'before described.
Dated this 10th day of March 1892.
JOHN WAUGH,
Agent.