IMPROVEMENTS IN STEAM ENGINES
Year: 1882

page_text: LETTERS PATENT to James Shanks and James Gordon Lyon, Engineers, of
Arbroath in the County of Forfar North Britain for an Invention of
"IMPROVEMENTS IN STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said James Shanks and James
Gordon Lyon at the Office of the Commissioners of Patents on the 19th August
1882.
JAMES SHANKS and JAMES GORDON LYON Engineers of Arbroath in the County
of Forfar North Britain " IMPROVEMENTS IN STEAM ENGINES"
Our Invention consists in employing two single acting cylinders one port in each
the steam exhausted from the small or high pressure cylinder being used in the
large or low pressure cylinder for the purpose of making the return stroke of the
piston.
In carrying the Invention into effect the cylinders may be arranged end to end
the opposed ends being connected by a casting carrying bearings for the crank
shaft and the pistons being connected together by a connecting piece in the centre
of which is formed a long slot in which is a die or bush piece encircling the crank
pin of the shaft. After steam has been admitted to the high pressure cylinder and
moved the piston thereof forward to make a half revolution of the shaft the steam
from the said cylinder is exhausted into the low pressure cylinder when it forces
the piston thereof in the reverse direction to complete the revolution of the shaft.
An ordinary fly-wheel may be employed to carry the crank over the dead points.
The slide valves also may be of the ordinary construction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Shanks and James Gordon Lyon in the Great Seal Patent
Office on the 19th February 1883.
JAMES SHANKS and JAMES GORDON LYON Engineers of Arbroath in the County
of Forfar North Britain "IMPROVEMENTS IN STEAM ENGINES"
Our Invention has for its object to provide a compact simple and effective
compound engine and consists in employing two single acting cylinders a high
pressure cylinder and a low pressure cylinder with one port in each the steam
from the high pressure cylinder being exhausted into the low pressure cylinder
the said cylinders being placed end to end and the pistons of the said cylinders
being connected together by a connecting piece in which is formed a long slot in
which is a die or bush piece encircling the crank of the shaft which is thus situated
between the two pistons. After steam has been admitted to the high pressure
cylinder and moved the piston thereof to make a portion of a revolution of the
shaft the steam from the said cylinder is exhausted from the said cylinder into
the low pressure cylinder and forces the piston thereof in the reverse direction to
complete the revolution of the shaft. This compact arrangement may also be
applied to double acting cylinders.
And in order that our said Invention may be fully understood we will now
proceed more particularly to describe the same and for that purpose shall refer
to the several figures on the annexed sheet of drawings the same letters of
reference indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawings represents a plan-Figure 2 a horizontal
section and Figure 3 a vertical longitudinal section of an engine constructed
according to our Invention.
A is the high pressure cylinder and B is the low pressure cylinder. The said
cylinders are open at the ends presented to each other and are connected together
by any suitable means as for example by the casting J as shewn which may
completely envelope the space between the two cylinders and be provided with a
lid or cover I and suitable air openings if necessary. In the cylinder A is the
piston A2 and in the cylinder B is the piston B the said pistons being formed with
an extension or connected together by the connecting piece K having in its centre
a long slot C in which is a die or bush piece D capable of sliding in the said slot
and encircling the crank pin E of the crank shaft H. L is the valve of the high
pressure cylinder and M is the valve of the low pressure cylinder both of which
may be actuated by separate eccentrics or from the same eccentric m on the shaft H
connected to both valve rods by a pin m² as clearly shewn in figure 2.
When the
engine is in action the steam first enters the cylinder A by its one port a and the
piston A² is moved forward. The valve L moves back at the same time and opens
communication between the port a and the exhaust passage n from the cylinder A
to the cylinder B so that the steam after acting on the piston A² passes by the said
passage into the cylinder B through the one port thereof and forces the
piston B2 back to complete the revolution of the shaft. The valve M will at the
same time be inoved to open communication between the port b and the exhaust p
from the cylinder B and the valve L will also be moved to admit live steam to the
cylinder A An ordinary fly wheel may be employed to carry the crank over the
dead points.
Figure 4 is a side elevation and Figure 5 is a horizontal section shewing the
before described compact arrangement applied to an engine with double acting
cylinders, A. is the high pressure cylinder and B is the low pressure cylinder. The
said cylinders in this case are of course closed at both ends and are shewn as being

page_text: connected together by a casting J as in figures 1, 2 and 3.-The piston rods are
connected together by the piece K which may in this case be formed in two parts,
one on each of the piston rods and connected together by bolts and distance pieces
as shewn in figure 4, forming between them the slot C, for the crank pin bush or
bearing. The valves are of course duplicated and may be actuated by eccentrics
arranged as shewn in figure 5. One of the connecting bolts of the piece K may be
continued as a piston rod p, with a piston working in a cylinder, P, constituting a
feed pump for supplying water to the boiler.
The other parts which correspond with those shewn in figures 1, 2 and 3, are
marked with the same letters of reference.
Having now described and particularly ascertained the nature of our said
Invention and the manner in which the same is or may be used or carried into
effect, we would observe in conclusion that what we consider to be novel and
original and therefore claim as the Invention secured to us by the herein before in
part recited Letters Patent is :-
First. The herein before described Improvements in Steam Engines, consisting
in the combination of high and low pressure single or double acting cylinders
the low pressure cylinder using the exhaust steam from the high pressure cylinder
and having the crank Shaft situated between the pistons of the said Cylinders
as hereinbefore described and shewn in the accompanying drawings.
Second. In Steam Engines having cylinders arranged as hereinbefore described,
the employment of a piston rod having an extended or connecting piece or
pieces K and a slot C therein for the crank pin bush or bearing as hereinbefore
described and illustrated in the accompanying drawings.
In witness whereof we the said James Shanks and James Gordon Lyon have
to this our Specification set our hands and Seals this seventeenth day of
February One thousand eight hundred and eighty three.
JAMES SHANKS.
(L.S.)
JAS GORDON LYON (1..S.)