IMPROVEMENTS IN MOTOR ENGINES WORKED BY STEAM OR OTHER ELASTIC FLUID PRESSURE."
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the Office
of the Commissioners of Patents on the 5th September 1876. A commu-
nication from abroad by Carl Beissel, of Cologne, in the German Empire.
CHARLES DENTON ABEL, of No. 20, Southampton Buildings, Chancery Lane, in
the County of Middlesex IMPROVEMENTS IN MOTOR ENGINES WORKED BY STEAM
OR OTHER ELASTIC FLUID PRESSURE."
This Invention has reference to an improved construction of motor engines,
wherein four cylinders with their pistons are arranged radially round one central
ciank, the piston rods being all connected to the said crank, so that the pistons of
each of the cylinders, being made to perform then instrokes consecutively and in
oider, effect the rotation of the crank and its shaft The cylinders are arranged
at 90° apart round the crank shaft, so that two and two are diametrically opposite
each other; they are single acting, the steam or other fluid pressure acting only on
the outer sides of the pistons to cause them to perform their instrokes In two of
the cylinders the steam acts with full pressure throughout the stroke, while the
other two, which are of larger diameter and diametrically opposite the first two,
are supplied with steam from these, the steam being made to act expansively
therein.
The proper distribution of the steam to the several cylinders to produce the above
described mode of action is effected by a rotary valve, which is rotated by the crank
shaft, and is of the following construction:-The valve is of conical form fitting in
a conical chamber, into the sides of which open passages communicating with the
outer ends of each of the cylinders. The valve is hollow and its interior is divided
by diaphragms at right angles to its axis into four separate compartments; of these
the innermost one communicates by side openings, firstly, with an annular channel
in the casing, through which steam is introduced from the boiler, and secondly,
with the steam passages of the two high-pressure cylinders. The next compart-
ment has two apertures communicating respectively with the one high-pressure
cylinder, and with its opposite low-pressure cylinder; the third compartment has
two apertures communicating respectively with the other high-pressure cylinder
and its opposite low-pressure one, and the fourth compartment has three apertures
by which it communicates respectively with each of the two low-pressure cylinders,
and with an exhaust passage leading from the valve casing to a condenser or whe-
ever required.

page_text: Assuming the piston of the one high-pressure cylinder to be at the end of its
out stroke, while that of its opposite low-pressure cylinder is at the end of its
instroke, the piston of the other high-pressure cylinder will be at about half out-.
stroke, and that of its opposite low-pressure cylinder will be at about half instroke.
The rotary valve will now be in such a position that steam will be about to pass
from the innermost compartment of the valve to the first high-pressure cylinder to
cause it to perform its instroko, while the opposite low-pressure cylinder will just
have been made to communicate with the outer compartment of the valve, so as to
allow the steam which had previously entered it from the opposite high-pressure
cylinder and had acted expansively therein to escape to the exhaust. At the same
time the second high-pressure cylinder, and its low-pressure cylinder will both be
in communication with the third compartment of the valve, so as to allow the
steam to pass from the former into the latter
When the piston of the first high-pressure cylinder has performed about half its
instroke, the second one will be at the end of its outstroke, and the valve will
begin to admit steam to it; at the same time the second low-pressure cylinder will
be at the end of its instroke, and the valve will establish its communication with
the exhaust. The valve is rotated by means of a disc, which can slide upon
its spindle, and which has a semicircular slot into which fits an extension of the
crank pin.
For reversing the engine the disc is slid back on the valve spindle by a lever, so
as to disengage it from the crank pin, and the valve is turned 180° degrees by hand,
whereupon the disc is slid forward so as to cause the crank pin to enter the other
end of the slot. The four cylinders are formed in one with or fixed to a central
casting inside, which is the engine crank, and which is fixed to the end of a base
plate carrying the bearings of the engine shaft.