IMPROVE- MENTS IN THE CONSTRUCTION OF TRAMWAY ENGINES DRIVEN BY COMPRESSED AIR to be as
Year: 1884

page_text: I ROBERT WILSON of 18 Exchange Street Manchester in the County of
Lancaster Engineer do hereby declare the nature of my invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF TRAMWAY ENGINES DRIVEN BY COMPRESSED AIR
to be as follows:
"
The object of this invention is to construct tramway engines to be driven by
compressed air in such a way that the power of the compressed air shall be
maintained at a normal pressure throughout the journey.
The objection to the use of compressed air for the purpose of driving tramway
engines has hitherto been that when a certain amount of air has been compressed
into a receiver at a given pressure the said compressed air when used to drive the
engine would become gradually attenuated at each stroke of the Engine until
finally the pressure would be reduced below that necessary to drive the engine, and
it is to obviate this difficulty that my present invention is designed.
I propose to drive the train way engine direct by means of a compressed air
Engine of any known construction and actuated by air compressed into a receiver
carried by the Engine, and in order to maintain this air at the pressure required
I mount a gas Engine upon the same frame and I employ such gas engine to work
a pump or pumps for compressing the air into the receiver so as to maintain the
pressure therein up to the normal standard required for driving the atmospheric
Engine.
The receiver may be fitted with a pressure valve so regulated and arranged that
as soon as the pressure rises above the required standard the valve shall open. and
allow the air to expand into and cool the water in the tanks provided for circulation
through the jackets of the gas Engine, and air compressing portion.
The com-
pressed air in the receiver can also be employed to work an atmospheric brake
which may be put in action either by the governor or by the driver.

page_text: The gas Engine will be driven by means of compressed gas according to the
Specification of an invention for which I have made application for Letters Patent
bearing even date herewith and the other adjuncts will also be constructed and
arranged in a similar manner: the principal feature of difference in the present
modification of my invention being that I propose to substitute a compressed air
engine to drive the main axle direct, instead of the combined. bevil wheel and
friction cone gearing described in the Specification above referred to, the gas
engine being used mainly in the present instance to compress the air and to
maintain the pressure of the compressed air in the receiver up to the standard
required.

page_text: COMPLETE SPECIFICATION.
1931
"
I ROBERT WILSON of 18 Exchange Street Manchester in the County of
Lancaster Engineer do hereby declare the nature of my invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF TRAMWAY ENGINES DRIVEN BY COMPRESSED AIR
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
The object of this invention is to construct tramway Engines to be driven by
compressed air in such a way that the power of the compressed air shall be
maintained at a normal pressure throughout the journey.
The objection to the use of compressed air for the purpose of driving tramway
engines has hitherto been that when a certain amount of air has been compressed
into a receiver at a given pressure the said compressed air when used to drive the
engine would become gradually attenuated at each stroke of the engine until finally
the pressure would be reduced below that necessary to drive the Engine, and it is
to obviate this difficulty that my present invention is designed.
The nature of my invention and in what manner the same is to be performed will
be readily understood on reference to the two sheets of drawings hereto annexed
and the following explanation thereof.
In Sheet 1. of the drawings Fig. 1. is a side elevation and Fig. 2 a half end view
of so much of a tramway engine as is necessary to illustrate my invention; and in
Sheet 2 Fig. 3. is a plan view of the saine.
I propose to drive the tramway Engine direct by means of a compressed air
engine of any known construction and actuated by air, compressed into a
receiver a, a carried by the tramway Engine, and in order to maintain this air at
the pressure required I mount a gas Engine b, b upon the same and I employ such
gas Engine to work a pump or pumps c, c for compressing the air into the receiver a, a,
so as to maintain the pressure therein up to the normal standard required for
driving the atmospheric Engine.
The receiver a, a may be fitted with a pressure valve so regulated and arranged
that as soon as the pressure rises above the required standard the valve shall open
and allow the air to expand into and cool the water in the tanks d, d provided
for circulation through the jackets of the gas Engine b, b and air compressing
portion.
The compressed air in the receiver a, a can also be employed to work an
atmospheric brake which may be put in action either by the governor or by
the driver as described in the Specification of Letters Patent No 12776 dated
September 25th 1884.
The gas Engine will be driven by means of gas stored by compression into a
reservoir, according to the said Specification and the other adjuncts will also
be constructed and arranged in a similar manner, the principal feature of difference
in the present modification of my invention being that I propose to substitute a
compressed air engine (the cylinders of which are shown at e, e) to drive the main

page_text: axle direct instead of the combined bevil wheel and friction cone gearing, described
in the Specification above referred to, the gas Engine being used mainly in the
present instance to compress the air and to maintain the pressure of the compressed
air in the receiver a, a up to the standard required.
The arrangement of the stopping, starting and reversing gear, and the air brake
are indicated by centre lines ff on Fig. 1.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
In the construction of tramway Engines driven by compressed air, the com-
bination with a compressed air receiver of a pump or pumps carried by the
tramway engine and actunted by a gas Engine for the purpose of maintaining the
compressed air at a normal pressure throughout the journey substantially as
hereinbefore described and illustrated by the drawings annexed.