IMPROVEMENTS IN ROAD LOCOMOTIVE ENGINES
Year: 1878

page_text: LETTERS PATENT to Thomas Aveling, of Rochester, in the County of Kent,
Engineer, for the Invention of " IMPROVEMENTS IN ROAD LOCOMOTIVE
ENGINES
""
Sealed the 25th June 1878, and dated the 15th January 1878.
PROVISIONAL SPECIFICATION left by the said Thomas Aveling at the Office
of the Commissioners of Patents on the 15th January 1878.
THOMAS AVELING, of Rochester, in the County of Kent, Engineer.
MENTS IN ROAD LOCOMOTIVE ENGINES,"
"IMPROVE-
The chief object of this Invention is to enable road locomotives of eight horse
power and upwards to be used on railways, the usual gauge of which is less than
the gauge required for the road wheels of engines of such capacity.
Hitherto it has been the practice to place the driving gear between the
boiler and the running wheels, and this necessitated a great width of gauge.
To provide for a narrower gauge without altering the dimensions of the boiler, I
propose to rearrange the gearing and to key all the gear wheels firmly on their
shafts, and thereby to avoid the inconvenience due to the use of pinions sliding on
feathers. I moreover render unnecessary the use of overhanging bearings, except in
the case of the driving spur wheel and pinion.
The crank shaft I fit with two pinions of equal pitch, which are intended
respectively to take into a spur wheel made fast to a sleeve that is free to slide on
a dead counter shaft made fast to the horn plates. Between these pinions is a space
that allows of the spur wheel being thrown out of gear by being brought into line
therewith. This is done when the engine is required to be used as a stationary"
engine for driving machinery.
On the sleeve which carries the spur wheel are also mounted two pinions of
different pitch, and on a second counter shaft also mounted in the horse plates are
mounted two wheels which are intended respectively to gear into the pinions on the
sleeve, according to the speed required to be imparted to the driving axle. All this

page_text: gearing lies within the horn plates, and cousequently permits of the carrying wheels
being brought closer together.
On the end of the second counter shaft externally of the horn plate is fitted a
spur wheel which transmits motion to the driving axle, on which the carrying
wheels are mounted.
By shifting the sleeve on the fixed counter shaft to the right or left, its pinions
will be thrown into or out of gear with one or other of the pinions of the second
counter shaft, and thus the motion of the crank shaft as it is transmitted to the
driving axle will be reduced to a greater or less extent as desired.
It will be understood that when the engine is required to run upon a railway, it
must be provided with flanged wheels which are to be removed and replaced
by the ordinary wheels when the engine is again transferred to the common
road.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Aveling in the Great Seal Patent Office on the 15th July
1878.
THOMAS AVELING, of Rochester, in the County of Kent, Engineer. "IMPROVE-
MENTS IN ROAD LOCOMOTIVE ENGINES."
The chief object of this Invention is to enable road locomotive engines of, say,
six horse power and upwards to be used on railways, the usual gauge of which
is less than the gauge required for the road wheels of engines of such capacity.
Hitherto it has been the practice to place the driving gear (or the greater portion
thereof) between the boiler and the driving wheels, which necessitated a great width
of gauge.
To provide for a narrower gauge without altering the dimensions of the boiler, I
propose to rearrange the gearing for working with two speeds, and to bring the
same within the width of the boiler, and also to key all the gear wheels firmly on
their shafts, and thereby to avoid the inconvenience due to the use of pinions sliding
on feathers.
I moreover render unnecessary the use of overhanging bearings, except in the case
of the driving spur pinion.
In the accompanying Drawing,
Fig. 1 shews in side elevation a road locomotive engine fitted with gearing
according to my Invention; Fig. 2 is an end elevation of the same; and Fig. 3 is a
plan or top view of the engine.
In these Figures, A is the boiler, and B, B, are the horn plates standing up above
the boiler for receiving the shafting which carries the driving gear; C, C, are the
driving wheels; D, D, the front wheels; E is the steam cylinder set above the
smoke box; and F, the crank shaft which receives rotary motion from the piston
rod of the engine as usual. This shaft is fitted with two pinions f, f, of equal

page_text: made fast to
diameter, which are intended respectively to take into a spur wheel
a sleeve G that is free to slide under the action of a hand lever g* (as shewn in the
Drawing at Fig. 4) on a dead countershaft G¹ made fast to the horn plates B, B.
Between the pinions f, f¹, is a space that allows of the spur wheel g being
thrown out of gear by being brought into line therewith. This is done when the
engine is required to be used as a stationary engine for driving machinery.
On the sleeve G which carries the spur wheel are also mounted two pinions g', g³,
of different diameter, and on a second countershaft H having its bearings in the
horn plates are mounted two wheels h, h³, which are intended respectively to gear
into the pinions g¹, 9%, on the sleeve G, according to the speed required to be
imparted to the driving axle. All this gearing lies within the horn plates, and
consequently permits of the driving wheels being brought closer together.
On the end of the second countershaft H externally of the horn plate is fitted a
spur pinion which gears into a spur wheel I on the axle of the driving wheels C,
and thereby transmits motion to the driving wheels.
By reference to Fig. 3, it will be seen that the gearing is in the position for
imparting a slow travelling motion to the engine, that is to say, the pinion f on the
crank shaft is in gear with the spur wheel g on the sleeve shaft, and the pinion g¹ of
that shaft is in gear with the spur wheel h of the countershaft H. When however
it is required to apply a quicker speed, this may be effected by shifting the sleeve G
on the first countershaft so as to bring the pinion g³ into gear with the spur wheel h¹
of the second countershaft H, and at the same time shifting the wheel g out of gear
with the pinion f, and into gear with the pinion f¹ on the crank shaft F. This
arrangement allows of the pinions f, f, and g', and the wheels h and h¹ being
shrouded or flanged on one side, as shewn in the Drawing.
It will be understood that when the engine is required to run upon a railway it
must be provided with flanged running wheels, which are to be removed and replaced
by the ordinary wheels when the engine is again transferred to the common
road.
Having now set forth the nature of my Invention of "Improvements in Road
Locomotive Engines," and explained the manner of carrying the same into effect, I
wish it to be understood that under the above in part recited Letters Patent, I claim,
the arrangement of driving gear for transmitting motion from the crank shaft to
the spur wheel on the driving axle, whereby I am enabled to diminish the width of the
engine and to dispense with the use of pinions sliding on feathers, as and for the
purpose herein set forth.
In witness whereof, I, the said Thomas Aveling, have hereunto set my hand
and seal, the Fifteenth day of July, in the year of our Lord One thousand
eight hundred and seventy-eight.
THO³. AVELING. (L.S.)