Year: 1888

page_text: We, WILLIAM PURCELL O'NEILL of Longford Railway Station Ireland Engineer
and FRANCIS O'NEILL of Ard Brugh Dalkey County Dublin Mechanical Engineer do
hereby declare the nature of the said invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
According to our invention we construct a complete engine which can_readily_be
fitted to an existing tram car thus making it into a locomotive tram car.
The engine
is so constructed that only a small motor power is required for driving and so that
nevertheless in the case of starting and of ascending inclines great extra power shall
be available thus conforming to the conditions obtaining in horse power traction
viz. extra store of power when starting a normal speed on a level track and a reduced
speed when ascending inclines. For the purpose of our invention we employ a
petroleum engine or other motor which actuates an air compressing pump, the com-
pressed air passing to a receiver and thence to a double acting cylinder which by
connecting rod transmits motion to a crank, on one of the tram car axles. Or we
may use two single acting cylinders each transmitting motion to its cranked tramcar
axle. In connection with the compressor we provide a vaponr producer having for
instance a moving endless belt or screen which absorbs water or other vapour pro-
ducing liquid whereby the air before entering the compressor is moistened or saturated.
with moisture by which means the loss of power owing to the rise of temperature in
the compressor is greatly reduced. Between the receiver and the cylinder or cylinders
we provide a reducing valve capable of adjustment from the engine platform or from
either platform of the tramcar for the purpose of allowing the air under pressure to
enter the cylinder at the desired rate so that the air can so to say adjust itself to the
work it has to do, the air working expansively or at a low pressure in the cylinder
when going down an incline at a higher pressure on a level and at a still higher
pressure when starting or going up an inclino. We also provide a centrifugal pump
and water supply for cooling the cylinder of the petroleum engine if such be
used.
We shall now describe in detail the construction and arrangement of the aforesaid
parts in connection with drawings hereto annexed of which Figure 1 is a side view of

page_text: an ordinary tramcar with our invention applied thereto and Figure 2 a plan shewing
the working parts. Figure 3 is a front view and Figure 4 a sectional side view of
the motor cylinder and the air compressor actuated thereby. Figure 5 is a sectional
side view and Figure 6 a sectional front view of the vapour box. Figure 7 is a
sectional elevation of the compressed air receiver. Figure 8 is a plan section through
the cylinder and Figure 9 a back end view of same. Figure 10 is a sido view of the
cylinder with valve gear and other working parts and Figure 11 a plan of same partly
in section.
As will be seen from Figures 1 and 2 the engine A is mounted on one of the end
platforms of the car but so that the starting reversing and stopping same can be
effected from either platform by the handles o. Other handles necessary for working
the tramcar may also be arranged to be worked from either platform. From the
motor cylinder crank shaft is worked the air compressor b which receives supply of
moistened or saturated air from the vapour box c and air compressor 6 discharges into
the receiver by the supply pipe g. h is the pipe for supplying compressed air to the
cylinder k and i the regulating or reducing valvo on the pipe h. d is the centrifugal
water pump which draws its water for cooling the cylinder 6 of the petroleum engine
from the water tank e and returns it thereto.
f
The arrangement of motor engine, centrifugal cooling pump, air compressor
centrifugal pump and vapour box will be understood from Figures 3, 4, 5 and 6. The
centrifugal pump d is on the same bed plate as the compressor pump c and is driven
by strap and pulleys d¹ d² from the petroleum engine shaft a'. The air to be
compressed enters the vapour box c by the inlet c¹ and passes off to the suction pipe
S of the compressor by the outlet c and during this passage it traverses the endless
apron or screen of hair cloth or fine gauze. This endless band passes round two
rollers c and c faced with vulcanite rubber, the upper roller c touching against the
interior top of the box, the lower roller c working in water or other vapour producing
liquid and both rollers and apron fitting well against the sides of the box. The upper
roller is worked by pulleys and strap from the pump shaft a¹. As the air passes
through this box it becomes well moistened or saturated and in this condition it is
drawn into the compressor which is double acting and may have its valves arranged
as shewn in Figure 4 the suction valves 61 being faced with leather, gutta percha
or the like and working against V face seatings and the secondary delivery valves b*
being connected by a light spindle thus making the closing of one synchronous
with the opening of the other. The moist or saturated compressed air from the
compressor bis passed to the pipe g and into the receiver f. This latter is shewn
separately in Figure 7. The air enters it by the valve f which by preference is of the
same type as the suction valves 6' Figure 4 it is also provided with a safety valve,
not shewn on drawings for blowing off when the maximum pressure is exceeded.
In the delivery pipe_h_from the receiver f to the working cylinder k Figure 2
is provided a reducing or regulating valve which by preference_can be actuated
from either platform and adjusted to wire draw the air or allow it to flow to the
cylinder kat a suitable pressure according to the work which has to be done, so
that the cylinder k works with full pressure when the tram car is starting or
ascending a steep incline with lower pressure when running on a level, and with
still lower pressure when descending a gradient, the speed being of course inversely
slower the higher the pressure used, but the size of the receiver may be such as to
afford a material reserve or store of pressure which is available especially on
starting.
The cylinder k Figures 8, 9, 10 and 11 has a hollow cylindrical slide valve m which
is thus balanced entailing little friction and requiring little power to work it. A very
fine hole m may be provided for preventing accumulation of water or pressure around
the central part of the valve. The cylinder k is by preference provided with liquid
stuffing box k¹ and so also the slide valve chest as shown at m² in addition to the
ordinary packed stuffing boxes. The cylinder valve gear n is shown in Figures
10 and 11 as of the ordinary link motion type. p is an endless chain which passes
round the pulleys p¹ and p² on the tramcar axles for coupling them for the purpose of

page_text: increasing the adhesion of the wheels. And in the case of two single acting cylinders
also keeps the cranks in their respective positions as to one another. When we use
two cylinders k one for each axle of the vehicle we may use similar valve gear and
bring the pressure supply pipe and exhaust pipe from each cylinder to a common
three way cock or valve by which means the exhaust can be changed to the
supply and vice versa thus providing a means of reversing.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed We declare that what
We claim is :-
First. In a tramway locomotive worked by compressed air, the application of
means for moistening or saturating the air supplied to the air compressor and
means for adjusting the compressed air supply to the working cylinder according
to the work required substantially as set forth.
Second. The construction of the apparatus for saturating the air with moisture
substantially as described and shewn.
Third. The construction of the compressed air receiver substantially as described
and shewn.
Fourth. The construction of the air compressor substantially as described and
shewn.
Fifth. The combination in a tram car locomotive of a petroleum or other motor,
an air compressor worked therefrom and supplied with moist or saturated air, a
receiver for the compressed air fitted with back pressure valve and safety valve,
a pipe from the air compressor to a cylinder or cylinders which take on to the
tramcar axle or axles, and a valve, in such pipe for reducing and regulating the
working pressure in the cylinder or cylinders according to requirements substan-
tially as set forth.
Sixth. The general construction and combination of parts forming the engine or
machinery for propelling tram cars substantially as described and shewn.
Dated this 29th day of March 1888.
WILLIAM PURCELL O'NEILL.
FRANCIS O'NEILL.
By Jensen & Son,
.77, Chancery Lane, London, W.C.,
Patent Agents.