IMPROVEMENTS IN TRAMWAY LOCOMOTIVE ENGINES
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Henry Vignoles and John Septimus
Ayton at the Office of the Commissioners of Patents on the 16th January
1879.
HENRY VIGNOLES, of Delahay Street, in the City of Westminster, Civil Engineer,
and JOHN SEPTIMUS AYTON, of Manor Street, Clapham Road, in the County of
Surrey, Engineer. "IMPROVEMENTS IN TRAMWAY LOCOMOTIVE ENGINES."
This Invention relates to the general arrangement of tramway locomotive
engines adapted for use on tramways and underground lines, and in other places
where it is an object to avoid smoke and steam; all working parts including joints
are accessible from the foot plate, whilst should any break down occur, such as
broken connecting rod, cylinder cover, and the like, all that is necessary is to dis-
connect the engine from the frame and boiler by means of certain bolts and remove
them, substituting in their place a duplicato engine which can be readily accom-
plished in about 45 minutes, all that is then necessary being to send the damaged
engine by cart to a contract shop to be repaired, thus avoiding the necessity of
keeping an expensive staff of fitters, smiths, and the like on the premises, at the
same time dispensing with machinery and pits as the cleaning can all be done by
removing the loose panels in the case, but as the lower parts of the engine are
completely protected from the dirt by thin plating, there will not be much
necessity for the latter process. One important advantage to be derived from the
use of our arrangement of engine is, that tramway companies will be enabled to
use their present stables as engine running sheds by merely continuing the tram
rails into them, whilst as regards the running of the engines it will not be necessary
to maintain a large stock of reserve engines lying idle, but merely a sufficient
quantity of duplicate cylinders & cast iron frames costing one twelfth of the
complete engine, which parts can as before stated be placed on the engine in a very
short time, & without letting steam down or drawing the fires.
The fire passes from the fire box through a lower set of tubes into a combustion
chamber at the forward end of the said tubes. This combustion chamber will in
many cases be found to obviate in a great measure the smoke arising from the
burning of coal. The fire then returns through a higher series of tubes into a
smoke box situate under the chimney, whence it passes.
The steam is admitted to the cylinders from a steam dome by means of a
regulating valve, the exhaust steam passing into an exhaust chamber where it
expends all its energy, & thence it passes the conical nozzle into the top row of
tubes drawing with it the products of combustion, & thence discharging itself

page_text: through the petticoat blast into the chimney. This arrangement will in a great
measure if not totally dispense with the shewing of steam. An ordinary parabolic
governor is placed on the top of the combustion chamber & connected to the engine
shaft by means of bevel gearing. This acting through a throttle valve prevents
the driver exceeding a certain speed by cutting off the steam as in an ordinary
stationary engine, & by a suitable index it also registers the speed at which the
engine is running, there is a lock arrangement for protecting the bevel wheels of
the governor, thus proventing the wheels which have been registered by government
engineers from being tampered with.
The motive power is transmitted from a counterbalanced disc on the engine
shaft to the crank pins of the leading wheels by means of a long connecting rod, &
from these to the trailing wheels through a short coupling rod.
The draw bars are connected to the contre of the wheel base, thus converting the
engine into a bogie & reducing to a great extent the friction on curves.
The buffers are merely steel plates kept wido, so that the engine can buff at all
angles.
The break arrangement is worked by the application of the foot or steam power
on a pedal, and the power is transmitted by a system of rods and levers to the
blocks on wheels. An equalizing link is put on the leading hanger so as to ensure
an equal pressure on each block. The tank is situate low down between the frames
& wheels, thus keeping the centres of gravity low and not affecting the balance of
the engine as it becomes lighter.
One man will suffice to drive and stoke this engine, as there is a fire door at
either side of tho boiler and regulator, the reversing handle and break pedal are
easily accessible from one position. Doors are placed in smoke box & combustion
chamber, thus affording easy access to the tubes by removing loose panels in the
case.