Improvements in Steam Engines.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Steam Engines.
I, JOHN ROBERT BIRD of 10 Morrison Street in the City of Glasgow,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates to steam engines of the type in which two three or more
single acting cylinders are disposed radially around the crank shaft and it consists
essentially in the construction and arrangement of the steam distributing valve by
which steam is admitted to the several cylinders in rotation and through which it
is exhausted into a crank chamber, the exhaust steam serving as a carrier for the
lubricant for the crank pin bearings.
In the accompanying drawings
Figures 1 and 2 are vertical sections at right angles to each other of a modifi-
cation of the improved engine having three cylinders,
Figure 3 is an end view of the crank chamber or central part of the engines
the cover of the valve casing being removed to show the valve and steam ports,
and
Figure 4 is a sectional elevation of a modification of the engine having two.
cylinders.
As represented in these drawings the engine consists of a central crank chamber A
round the circumference of which are formed two three or more faces B B corre-
sponding to the number of cylinders employed to which are attached the
cylinders C C. One side A¹ of this chamber A is cast in a piece with the shell
and has formed in it passages a a a for steam admission and exhaust ports a¹. The
other side A' is bolted on and is provided with a packing gland D through which
passes the crank shaft E.
The end e of the crank shaft which passes through the solid side A' of the crank
chamber A has a stud e¹ formed on it eccentric to the centre of the shaft for
actuating the valve F.
The valve F is by preference circular in form and fitted to turn freely on the
driving stud but it may be formed with angular sides and fixed so that it cannot
turn round on the stud e.g. a square stud on the end of the crank shaft may fit in
a square hole in the valve, or it may be circular and similarly fitted to prevent it
turning round.
The valve F which is placed within a valve casing G is formed with an annular
recess F¹ serving to open the steam passages a to the exhaust ports a' whilst its
ring face serves both to cover and uncover the steam admission passages a to the
several cylinders and to close communication between the steam ports and the
exhaust ports unless during the period of exhaust. As shewn at Figure 4 the valve
may have a tail A³ formed on it working in a slot H in the cover to impart to it
an oscillating motion.
The cylinders C C are fitted with trunk pistons I and are attached to the crank
pin J by connecting rods K. The crank ends k of the connecting rods bear only
on a portion of the circumference of the crank pin and are held in position by
means of two glands fitting loosely into grooves formed in the rod ends.
Steam is admitted to the valve chamber by an inlet and port L and to the
cylinders by the valve uncovering in rotation the ports a which communicate with
the steam passages leading to the cylinders. The exhaust steam is carried through
openings a' into the crank chamber A and from thence by a pipe M to the
atmosphere or condenser.
The object of carrying the exhaust steam through the crank chamber is to.

page_text: provide for the more efficient lubrication of the crank pin and connecting rod joints
as all the oil or grease admitted along with the steam will collect there.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. A steam engine constructed and furnished with steam distributing valve and
crank chamber substantially as described with reference to the annexed drawings.
2. In a steam engine of the class set forth a rotating or oscillating steam
distributing valve constructed and arranged to operate substantially as described.
Dated this Twentieth day of June 1893.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.