Improvements in Compound Steam Engines.
Year: 1894

page_text: Date of Application, 11th Aug., 1894
Complete Specification Left, 30th Apr., 1895-Accepted, 1st June, 1895
PROVISIONAL SPECIFICATION.
Improvements in Compound Steam Engines.
I, THOMAS GETHING CLAYTON, The Grange, Normanton near Derby in the
County of Derby, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention consists in making a steam cylinder of such a form as will give a
very great difference of area on one side of the piston to what it does on the other,
the one side of the piston being at least twice the superficial area of the other side
or even greater if desired.
The form or the area of the smaller or high pressure side of the piston is that of
an annular ring, whilst that of the larger or low pressure side of the piston
embraces the whole area of the circle of the cylinder.
My improvements also consist in a novel design of slide valve having passages
through it so arranged as to conduct the steam from the smaller or high pressure
end of the cylinder, after the steam has done its work there to the larger or lov
pressure end of the cylinder in order that the steam may there operate expansively.
The valve may be either of the piston form or a rotary one, or may be similar in
shape to an ordinary flat slide valve. The steam at high pressure is first admitted
by this valve to that side of the piston forming the annular ring, and when the
piston has completed its stroke the same steam is then passed through a passage in
the valve from the smaller side to the larger side of the piston having twice or
thrice as much area, and where it then and there acting upon the increased
surface of the piston gives it its return stroke. As soon as this is accomplished a
third passage opens through which the steam escapes into the atmosphere or into a
condenser, before the high pressure steam is again admitted to the smaller side of
the piston. By this arrangement a single steam cylinder is made to work upon the
compound principle and thus effect a considerable economy in the steam utilized.
Dated this 11th day of August 1894.
I, THOMAS GETHING CLAYTON, of The Grange, Normanton near Derby, in the
County of Derby, Civil 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 :-
My invention consists in making a steam cylinder of such a form as will give
a very great difference of area on the two sides of the piston, the one side of the
piston having at least twice the superficial area, of the other side, or even greater
if desired.

page_text: The form or the area of the smaller or high pressure side of the piston is that of
an annular ring, whilst that of the larger or low pressure side of the piston embraces
the whole area of the circle of the cylinder.
My improvements also consist in a novel design of slide valve having passages
through it so arranged as to conduct the steam from the smaller or high pressure
end of the cylinder, after the steam has done its work there, to the larger or low
pressure end of the cylinder in order that the steam may there operate expansively.
Upon the accompanying drawings illustrating my invention-
Figure 1 is a vertical section of a cylinder and valve constructed according to
my invention the valve being arranged in the forin of a piston slide-valve,
Figure 2 being a side elevation and part section of a cylinder and valve of
cylindrical form.
Figure 3 is a section of Figure 2 on line 1-2.
As will be seen on the drawings the valve G may be either of the piston form as
shewn on Figure 1, or a rotary one as shewn on Figures 2 and 3.
The
In the arrangement shewn on Figure 1, A is the cylinder having two diameters A A',
and B is the piston also having two diameters B B'; the connecting rod C from
the piston to the crank is attached to the piston B by means of a pin D.
outside casing E for the slide valve G, is provided with a suitable lining F, a steam
inlet a, and ports cand e communicating respectively with the spaces on the
smaller, and on the larger side of the piston B. G is the piston slide valve
operated from the eccentric by the rod H and provided with an inner passage d and
outer passage for conveying steam into and out of the cylinder A, and from one
side to the other of the piston B at different periods of the stroke.
In operation the steam at high pressure being admitted through the inlet a fills
the space or passage b around the piston slide valve G and from thence passes
through the port c into that part of the cylinder A which forms with one side of the
piston B an annular space. The port c is so arranged as to be partly open before
the piston B begins to ascend or commences its upward stroke, as is usual in steam
engines, and by the time the steam has forced the piston nearly the length of
its stroke, the valve G has travelled to such a position that the steam from the
passage is cut off from the port c, and the passage d in the valve is brought
over both ports c and e, thus establishing communication between the two ends of
the cylinder A. Consequently the steam returns from the annular space on
one side of piston B, through the port e and passes through the passage d in
the valve G and the port e into the cylinder on that side of the piston B having
the larger diameter and area. Upon the piston commencing its return or
downward stroke the steam follows it expanding until the return stroke is nearly
completed, when the valve G having travelled back to its first position leaves the
port-hole e uncovered and open to the space within the valve-box, whereupon the
steain which has performed its double duty escapes through an exhaust, or may be
conveyed by a suitable pipe to a condenser.
When employ a cylindrical or rotary form of valve I adopt the arrangement
illustrated on Figures 2 and 3, on which A is the cylinder, B the piston and G the
rotary valve operating within the casing E, and provided at each end with
suitable glands L. The valve G is traversed by the passages band & arranged
in such a manner in relation to the steam inlet a and ports cand e formed in
the casing E, that steam entering at the inlet a before the piston B commences
its upward stroke, passes through the passage b and port c-to which it is at this
moment opposite-into the high pressure end, A', of the cylinder. When the
piston has nearly reached the end of its up-stroke, the valve G is turned to
such a position as to bring the passage d opposite the two ports c and e,-the
passage being then closed at both ends,-whereupon the steam passes from the
high-pressure end A' of the cylinder through the port e and passage d to the low-
pressure end A by the port e and acts expansively in driving the piston downwards.
When the latter has completed its return stroke the valve G is in a position with
the passage d opposite to an outlet f formed in the casing E, and escapes to the

page_text: atmosphere, or it may be conveyed if desired by a suitably arranged pipe to a
condenser.
The valve G in this case is operated by the rod H and a lever K so as to
partially rotate in alternate directions as the piston makes its up or down stroke.
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. In compound steam engines having a differential piston, the combination of
the cylinder A, piston B and valve G having steam passages b and d, substantially
as arranged for the purposes and as described and illustrated upon Figures 1, 2
and 3 of the accompanying drawings.
Dated this Thintinth
of Annil 1905
Dated this Thirtieth day of April
il 1905
For the Applicant,
GEDGE & FEENY,
Agents.