CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1853

page_text: LETTERS PATENT to John Griffiths, of Stepaside, Saunderfoot,
near Tenby, in the County of Pembroke, South Wales, Engineer,
for the Invention of "CERTAIN IMPROVEMENTS IN STEAM ENGINES."
Sealed the 12th December 1853, and dated the 2nd August 1853.
PROVISIONAL SPECIFICATION left by the said John Griffiths
at the Office of the Commissioners of Patents, with his Petition,
on the 2nd August 1853.
I, JOHN GRIFFITHS, of Stepaside, Saunderfoot, near Tenby, in the
County of Pembroke, South Wales, Engineer, do hereby declare the
nature of the said Invention for "CERTAIN IMPROVEMENTS IN STEAM
ENGINES" to be as follows:-
My improvements consist in letting off the elastic pressure of steam
out of the cylinder before the steam is let into the condensor; by this
means an engine can be worked to sixty pounds pressure (or more or
less) to the inch; and by letting out the first elastic steam the remainder
will be let into the condensor at a low pressure.
Secondly, in pumping engines the steam is taken from the boiler; for
the descending part of the stroke the steam is first let out into a

page_text: receiver, and for the returning part of the stroke it is supplied with the
steam from the receiver (but at a much lower pressure than the steam
in the boiler), so that the engine will have the advantage of the pressure
of the atmosphere during both the descending and ascending parts of
the stroke, whereas it is only supplied with steam from the boiler for
one part; this mode of working may be applied to a rotary engine by
a counter balance on the fly wheel, as the power will be greater at that
part of the stroke when the steam is taken from the boiler than when
taken from the receiver.
Thirdly, in marine or other engines where two are connected, so that
one may be supplied with steam from the boilers, and the other from
the receiver; but the cylinder of the second should be larger than the
first (to have the same power) in order to derive the greatest advan-
tage from the atmosphere; by this means there will be two engines
working condensively with the same steam.
The accompanying sketch represents the valves, &c. for working a
pumping engine. A, is the steam valve for letting the steam into the
cylinder from the boilers. B, is the bottom valve for letting the steam
out of the cylinder into the condensor, so that when the piston comes
near to the bottom of the cylinder the two valves shut, leaving a
vacuum below the piston and a pressure of steam on the top side; at
the very instant the piston is at the end of its stroke the valve G, is
open to let out the steam into the receiver H, (which is fixed on the
boilers so as to be always warm that the steam may not condense,)
passing through the valve D, which is a self-acting valve with a lever
attached to it); this lever has a spiral spring to resist the action of the
steam which opens it. When the piston is intended to return, the
valves E, and F, are opened to admit the remainder of the steam into
the condensor; as soon as the valve E, is opened, the valve D, will
shut of itself, and the steam returns through the valve F, from the
receiver H, to supply the returning part of the stroke.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Griffiths in the Great Seal Patent Office,
on the 1st February 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JOHN GRIFFITHS, of Stepaside, Saunderfoot, near Tenby, in the County
of Pembroke, South Wales, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of August, in the year of
our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Griffiths, Her special licence
that I, the said John Griffiths, my executors, administrators, and
assigns, or such others as I, the said John Griffiths, my executors;
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exer-
cise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
CERTAIN IMPROVEMENTS IN STEAM ENGINES," upon the condition
(amongst others) that I, the said John Griffiths, by an instrument in
writing under my hand and seal; should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and imme
diately after the date of the said Letters Patent.
65
NOW KNOW YE, that I, the said John Griffiths, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement (that is to say):
My Invention consists in conveying a portion of the off steam of high
pressure engines into a receiver to be again used, and the remainder to
the condensor, whereby a better vacuum is obtained, and the steam is
more advantageously applied than heretofore; and in order that my

page_text: Invention may be fully understood, and readily carried into effect, I will
proceed to describe the means pursued by me, reference being had to
the annexed Drawing, and the figures and letters marked thereon.
DESCRIPTION OF THE DRAWING.
Figure 1, is a sectional elevation of part of a steam engine to which
the requisite parts are attached for illustrating one mode of applying my
improvements; Figure 2, is a side view; and Figure 3, a plan of the
same. In Figure 1, a, is part of the cylinder of a high pressure engine.
b, is the branch leading to the disjunction valve c; this valve c, closes the
opening of the pipe e, by which the steam is conveyed to the condensor,
and the valve d, which is shewn open in the Drawing, allows the steam
to escape through the pipe f, to a receiver, to be again used in another
cylinder, as will be explained hereafter, or into a pipe to be used for heat-
ing or other purposes. In Figure 2, g, is the crank shaft of the engine,
and g', an excentric for working the valve c, by means of the levers g²,
and g. The valve d, is opened by the off steam when let out of the
cylinder by slide or other valves. The mode of operation is as follows:
When the piston of the cylinder a, is descending, part of the steam
under the piston is allowed to escape through the valve d, and pipe f;
and when the requisite quantity of steam has been thus disposed of, the
valve c, is opened by the excentric g', to admit the remainder to the
condensor; the valve d, is then instantly closed, owing to the steam in
the off pipe f, acting on the top of the valve. Fig. 4, is an elevation,
and Fig. 5, is a plan of a pumping engine to which my improvements
are applied. Fig. 6, represents a sectional elevation on an enlarged
scale of the valves and other parts for working the same. h, is a boiler
of the ordinary construction; and h¹, the pipes for conveying the steam
to the cylinder i. j, is the receiver into which part of the steam from
the cylinder i, is conveyed before the remaining portion is let into the
condensor; this receiver is placed near the boiler, and it is kept warm by
the flue which is carried under it previous to entering the chimney k,
seen in Fig. 5. The high pressure steam on leaving the boiler h,
passes through the valve 1, which is shewn open, and thence through
the steam port m, to the upper end of the cylinder; at the same time

page_text: that the high pressure steam is entering above the piston the valve n, is
open to allow the steam from below the piston to enter the condensor.
When the piston is near the bottom of its stroke, the valves n, and 1,
are closed.
As soon as the piston is at the bottom of its stroke the
valves P, and 1, are opened to allow the steam above the piston to escape
into the receiver, and the valve q, is opened to admit the steam from
the receiver to the underside of the piston. As soon as the steam
above the piston has expanded to the pressure of the steam in the
receiver, the valve o, is opened to admit the remainder to the condensor ;
the valve, then closes, owing to the pressure of the steam in the
receiver acting upon its under surface. By this mode of working the
pressure of the atmosphere is made available during the descent and
ascent of the piston, whereas the steam from the boiler is only applied
at one side of the piston. Z, is a cock for letting steam into the
receiver before the engine is started. When this mode of working is
applied to an engine for communicating rotary motion it will be
requisite to have a counter balance on the fly wheel, as the power is
greater at that part of the stroke during which the steam from the
boiler is acting than at that part acting by the steam from the receiver.
I will now proceed to describe the application of my improvements
to steam engines working with two cylinders. Fig. 7, is a vertical
section of the high pressure cylinder and valves in connection therewith;
the low pressure cylinder is not shewn in the Drawing, but it may be
placed in any convenient position so as to act on the other end of the
beam as is customary in working compound engines of the ordinary
construction, or on a separate beam as in marine engines.
Fig. 8, is
another vertical section taken from the reverse side of the engine.
Fig. 9, is a plan in section and Fig. 10, another elevation partly in
section of the valves. s, is the high pressure cylinder; t, the steam chest ;
, the slide valve; v, the disjuntion valve; and a, the valve for supply-
ing the low pressure cylinder, the area of which should be about double
the area of the high pressure cylinder; w, is the pipe under the valve v,
which conveys the steam to the condensor. The valves v, and æ, may
be worked as shewn in Fig. 2, or in any other convenient manner.
When the high pressure steam has acted on the piston in the cylinder 8,

page_text: part of it is let off through the valve a, into the receiver, from whence
it is taken to act on the piston in the low pressure cylinder, and the
remainder is let into the condensor through the pipe w; the whole of
the steam from the low pressure cylinder is admitted to the condensor;
by this mode of working both the cylinders act like independent con-
densing engines, although only one supply of steam from the boiler is
required.
Another of my improvements consists in working high pressure
engines without a condensor; in this case two cylinders are required;
the first cylinder is supplied with steam from the boiler at, for instance,
sixty pounds per square inch pressure (atmosphere not included); a
portion of this steam, after acting on the piston, is let off into a receiver
similar to j, in Fig. 6, at, for instance, twenty-two pounds per square
inch pressure, the remaining portion of the steam being blown off into
the atmosphere; the second cylinder is supplied with steam from the
receiver, which, after doing its duty, is blown off into the atmosphere.
Another modification of this part of my Invention is effected by using
only one cylinder, and admitting high pressure steam for the down
stroke, and steam from the receiver for the up stroke, or vice versa.
Having now described the nature of my Invention, and the manner
of performing the same, I declare that I claim as my improvements in
steam engines the application of the receiver j, for the purposes herein-
before described; also applying a portion of the off steam of high
pressure engines for heating or other purposes, and condensing the
remainder as described with reference to Figs. 1, 2, and 3.
In witness whereof, I, the said John Griffiths, have hereunto set
my hand and seal, this Twenty-seventh day of January, One
thousand eight hundred and fifty-four.
JOHN GRIFFITHS. (L.S.)