IMPROVEMENTS IN LOCOMOTIVE ENGINES FOR TRAMWAYS, RAILWAYS, AND COMMON ROADS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by John Richardson Wigham at the
Office of the Commissioners of Patents on the 15th December 1880.
"
JOHN RICHARDSON WIGHAM, of Capel street, in the City and County of Dublin,
Ireland. IMPROVEMENTS IN LOCOMOTIVE ENGINES FOR TRAMWAYS, RAILWAYS,
AND COMMON ROADS."
My Invention relates to locomotive engines, more particularly for running on
tramways, but also applicable to railways and common roads, wherein the motive
power is obtained by a motor engine that may either be worked by the combustion
of a mixture of combustible gas or vapour and air inside the working cylinder
commonly known as gas, motor engines," or by steam, compressed air, or other
motive force, or dynamo-electric engines may be employed.
"
According to one part of my present Invention I impart the motion from the
driving shaft of such engines to the driving wheels of the locomotive engine by
means of an arrangement of variable speed pullies, for which Letters Patent,
No. 2441, of 1879, were granted to B. Blackburn and A. B. Blackburn. For this
purpose according to one arrangement, a broad pulley on the engine shaft has an
open strap and a crossed strap, by which it can drive a countershaft alternately
in contrary directions by means of two loose and one fast pulley in a well known
manner. This countershaft carries one of Blackburn's variable speed pullies before
referred to, and a second such pulley is mounted on a second countershaft having
a pinion gearing with a spur wheel on the axle of the road wheels, so that by
rotating the first countershaft in one direction or the other, the road wheels are
made to travel in one direction or the other, while by varying the distance apart of
the conical disc of one of the "Blackburn" speed pullies, the speed imparted to the
road wheels by the second countershaft may be varied, or the motion entirely
stopped or started. For varying the distance of the said conical discs according to
the speed required, I employ by preference the following mechanism :-The first
countershaft has a right and left screw thread cut on part of its length, on each of
which threads is a nut carrying a bevil wheel, which wheels are both in gear with
a planet bevil wheel situated between them on an axis carried by a boss that
revolves with the counter shaft, but can slide longitudinally thereon. Each nut
also carries a friction rim having a break strap so arranged in combination with a
sliding break spindle, that by applying the one or other of the straps, the one or
.T

page_text: other of the nuts can be prevented from revolving, while at the same time it causes
by means of the planet wheel the other nut to revolve at double the speed of the
countershaft in the same direction therewith. Thus according as the one or the other
break strap is tightened, the two nuts, together with the parts connected therewith,
will be made to travel longitudinally upon the countershaft, and the one conical
disc of the "Blackburn " pulley being connected to the said mechanism, it will be
moved to or from the other disc and thus vary the speed imparted to the second
countershaft, or stop or start the motion thereof.
The said break straps may be actuated either by hand or foot, or they may be
connected with a governor of any suitable known construction, whereby the speed
of the locomotive is automatically controlled. The lever actuating the said break
straps may also be connected to the breaks of the road wheels, so that when the
apparatus is moved so as to moderate or stop the motion, the break blocks will
be applied with more or less force to the road wheels. According to another
modification the one "Blackburn" speed pulley together with the before described
controlling mechanism are mounted directly on the engine shaft, and the reversal
of the motion for running forwards or backwards is obtained by the following
arrangement: On the first countershaft carrying the second "Blackburn" pulley
are two pinions on a sleeve revolving with but capable of sliding upon it; on a
second countershaft is, firstly, an ordinary spur wheel, and, secondly, at some
distance therefrom, a disc with an internal spur ring. By sliding the one pinion
in gear with the spur wheel the second countershaft will be rotated in one direction,
imparting such motion to the axle of the road wheels by spur gearing, while on
sliding the second pinion in gear with the internal spur ring, the other pinion being
slid out of gear, the countershaft and consequently the road wheels will be rotated
in the contrary direction.
Whether using one or other of the above mentioned arrangements in order to
facilitate the moving of the locomotive round curves, I may use the well known
mechanical appliance termed “ jack in the box," one bevil wheel of which is
attached to one of the driving wheels which is loose on the axle, and the other to
the axle itself. The planet bevil wheels are fixed between the arms of the spur
wheel on the said axle that is driven by the before mentioned countershaft. In
this arrangement by putting the breaks on one wheel only, the locomotive can be
given a strong impulse to one side or the other, which may be useful in case the
locomotive gets off the rail, or for steering purposes when used on common roads.
When using gas motor engines for driving the locomotive these may be worked
either by ordinary coal gas, in which case a reservoir containing a store of such gas
either at atmospheric or greater pressure may be carried by the vehicle, or I work
them by means of atmospheric air charged with hydrocarbon vapour as described
in the Specification to my Patent, No. 382, of 1878. In this case I provide on the
platform carrying the engine, firstly, a reservoir containing air pumped into it at any
desired pressure; secondly, a carburetting apparatus of known construction into
which the air from the reservoir passes so as to become carburetted, and whence it
passes into a gas holder from which it is supplied to the engine; and, lastly, I
provide apparatus of known construction for generating hydrogen gas, which is
also supplied to the engine for the purpose described in my before mentioned
Specification.
The locomotive engines above described may when employed on tramways,
common roads, or railways, have accommodation for passengers or luggage combined
therewith, or they may be used as traction engines (for driving or pushing other
carriages.