IMPROVEMENTS IN STEAM ENGINES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by James Strang Thomson at the
Office of the Commissioners of Patents, with his Petition, on the 13th
July 1859. A communication from abroad by Henry Blandy and
Frederick T. L. Blandy, of Zanesville, United States.
I, JAMES STRANG THOMSON, of Kilmarnock, in the County of Ayr, North
Britain, Manufacturer, do hereby declare the nature of the said Invention
of "IMPROVEMENTS IN STEAM ENGINES," (being a communication from abroad
by Henry Blandy and Frederick T. L. Blandy, of Zanesville, United States,)
to be as follows, that is to say :-
This Invention relates to the arrangement and construction of steam engines,
more especially of the portable class, such as are used for agricultural
purposes and by contractors and others, but the improvements are also appli-
cable to a greater or less extent to other steam engines, the objects being the
securing superior working efficiency and durability of the parts. According to
one modification under which these improvements are carried out in practice,
a horizontal cylindrical tubular boiler is set upon end pedestals with feet
which rest upon the ground as a base, the supports being both at the fire-box
and smoke-box end. To the upper side of the boiler there is bolted by broad
flanges a hollow or tubular and continuous bed plate extending from end to end
of the boiler, and answering as the entire support of the engine, suitable
flanges being formed upon it for the reception of the working steam cylinder
or cylinders. The cylinder is bolted on at the fire-box end, and the piston rod

page_text: directly actuates the crank shaft, which is disposed horizontally in bearings over
the other or smoke box end of the boiler, one such bearing being on the bed
plate and the other on the boiler. This continuous hollow bed plate may or
may not be used as a heater for heating the boiler feed water. When so
used, the water from the source of supply is forced or drawn by the pump
through it into the boiler. The waste steam escapes from the working slide
valve into a pipe in the interior of the hollow bed plate, when it is used for the
double purpose of beating the feed water and generating a furnace blast, or it
is discharged directly into the water in the hollow bed plate, when used solely
for heating purposes. In this way the hollow bed plate is turned to econo
mical account, and it keeps all the working parts of the engine quite free from
and independent of the boiler.
Both the inside and outside fire-boxes of the engine are oval in transverse
section, and they are so formed as to be almost entirely self-supporting. The
inside box is entirely covered or surrounded with water, and the lower sido of
both is quite open so as to secure a large extent of grate surface. The upper
portion of the external fire-box is cylindrical, whilst its sides are brought in to
the narrower width of the fire-grate by easy curves. The curvature of the
top of the inside fire-box is flat or oval, and its curvature downwards corre-
sponds to that of the outside box, leaving a water space between the two all
round, the open bottom exposed to the fire-grate being the only portion where
there is no water space. The slide valve is worked by an eccentric on the
main shaft operating a slotted lever or link motion.