A HIGH-PRESSURE STEAM ENGINE
Year: 1858

page_text: LETTERS PATENT to Thomas Tertius Chellingworth, of West Bromwich,
in the County of Stafford, Civil and Mechanical Engineer, for the
Invention of "A HIGH-PRESSURE STEAM ENGINE,"
PROVISIONAL SPECIFICATION left by the said Thomas Tertius Chelling-
worth at the Office of the Commissioners of Patents, with his Petition,
on the 8th July 1858.
I, THOMAS TERTIUS CHELLING WORTHI, of West Bromwich, in the County of
Stafford, Civil and Mechanical Engineer, do hereby declare the nature of
the said Invention for "A HIGH-PRESSURE STEAM ENGINE," to be as follows:-
My Invention consists, first,in the arrangement of the steam ports,eduction
port, and slide valve of steam engines, in such a manner that the steam, having
been cut off after the completion of a portion of the stroke, is expanded the
For this purpose,
remaining portion and the whole of the return stroke.
I place the openings of the steam ports in the face on which the slide valve
works side by side or next each other, and the eduction port underneath or
outside, or next after them, instead of between them, as in the ordinary
manner. The piston is attached to a hollow trunk, one end open to the
atmosphere. The steam is first admitted on the small area round the trunk,
cut off at about or of its stroke, as most convenient, and expanded to
The two steam ports are then brought into commu-
the end of the stroke.
071

page_text: nication with each other, and the steam allowed to act on the large area,
expanding the whole of the return stroke, and then passes through the educ-
tion port into the atmosphere, while fresh steam is admitted on to the small
area at the commencement of a fresh stroke. By these arrangements trunk
engines are adapted for being effectively worked by high-pressure steam.
My Invention further consists in fixing the trunk to the piston by a conical
bolt, with an eye at one end, to which is attached the connecting rod for
working the crank, and forming and arranging the stuffing-box, through which
the trunk works, so that it may project inside the cylinder instead of outside,
as is usual, while a corresponding recess is cast in the piston, so that they
may fit into each other with only a very small space between them.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Tertius Chellingworth in the Great Seal Patent
Office on the 7th January 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
TERTIUS CHELLINGWORTH, of West Bromwich, in the County of Stafford,
Civil and Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of July, in the year of our Lord One
thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Tertius Chellingworth, Her special licence that I, the said
Thomas Tertius Chellingworth, my executors, administrators, and assigns,
or such others as I, the said Thomas Tertius Chellingworth, 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 ex-
pressed, should and lawfully might make use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "A HIGH-PRESSURE STEAM ENGINE," upon the con-
dition (amongst others) that I, the said Thomas Tertius Chellingworth, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, 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 immediately after the date of the said
Letters Patent.

page_text: NOW KNOW YE, that I, the said Thomas Tertius Chellingworth, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to say:-
My Invention consists, first, in the arrangement of the steam ports,eduction
port, and slide valve of steam engines in such manner that the steam having
been cut off after the completion of a portion of the stroke, is expanded the
remaining portion and the whole of the return stroke.
For this purpose,
I place the openings of the steam ports (in the face on which the slide valve
works) side by side or next each other, and I place the eduction port under-
neath outside, or next after them instead of between them, as in the
ordinary manner. The piston is attached to a hollow trunk, one end open to
the atmosphere. The steam is first admitted on the small area round the
trunk, cut off at about or of its stroke as most convenient, and expanded
to the end of the stroke. The two steam ports are then brought into
communication with each other, and the steam is allowed to act on the large
area, expanding the whole of the return stroke, and then passes through the
eduction port into the atmosphere, while fresh steam is admitted to the small
area at the commencement of a fresh stroke. By these arrangements trunk
engines are adapted for being effectively worked by high-pressure steam.
a
. My Invention further consists in fixing the trunk to the piston by
conical bolt with an eye at one end, to which is attached the connecting
rod for working the crauk; and also in forming and arranging the stuffing
box through which the trunk works so that it may project inside the
cylinder instead of outside, as is usual, while a corresponding recess is cast
in the piston so that they may fit into each other with only a very small
space between them.
I now proceed with reference to the accompanying Drawings to describe
the manner in which my Invention may be carried into effect.
Figure 1 is a vertical section of a high-pressure non-condensing stationary
steam engine constructed according to my Invention; Figure 2 is a vertical
section of the valve and ports detached; Figure 3 is a front elevation of the
engine; and Figure 4 an elevation, shewing valve rod, excentric arrange-
ments, and feed pump, &c., with the frame of engine removed.
A trunk and piston are employed, constructed as shewn. A is the trunk;
B is the piston, having a larger area on the one side than on the other. The
trunk A is secured to the piston B bya conical bolt C, at theupper end of which
is forged an eye or jaw D for attaching the connecting rod Ę for actuating the

page_text: crank. The piston B is dished out on the top side in order to lighten it, and
the stuffing box or cylinder cover W, through which the trunk works, is
made to project inside the cylinder so as nearly to fit the piston, leaving only
a very small space between them. F is the bed or base plate, cast with a
circular recess of the same diameter as the cylinder, forming a steam box;
between this plate F and the cylinder a plate G of copper or other metal is
fixed. His a pipe at one side of the base plate leading into the recess or
steam box, and having in it a valve or regulator I worked by a wheel and
screw J; another pipe or steam way K cast in the base plate leads from the
steam box to the valve box L, and is provided with a throttle valve worked
by the governors in the usual manner.
My improved arrangement of the steam and eduction ports is exemplifiedin
Figures 1 and 2. M and N are the steam ports; O the exhaust or eduction
port; V is the exhaust pipe leading into the atmosphere; P is the slide valvė
worked by valve rod R. I arrange the ports and valve as follows:-Thesteam
ports M. and N are placed next each other, and the eduction or exhaust port O
is placed beneath or next after them, as shewn in the Drawing, instead of
placing the exhaust between the steam ports as is usual, and the slide valve P
is so arranged that the steam port M is alone open at any time to the steam
chest, the steam port N being at all times covered by the slide valve; Qis the
feed pump fixed in a direct line with the valve rod R, so that both the pump
and slide valve may be worked by the same rod and by one excentric S having
a wrought-iron bow T, T, as shewn in the section, Figure 4; w³, w¹, are bolts
for tightening the brass in eye D, having oil cups x, x, at top, and passage y
down their centres for oil to pass through for lubricating; z, z, hexagons for
applying spanner. In Figure 1, valve P is shewn in the position in which
port M is open for passage of steam, and port O open to the exhaust; and in
Figure 2 steam is passing from M to N, and exhaust closed. The working of
the engine is as follows:-Steam is admitted into the steam box cast in the
bed plate F, through the valve I in the pipe H, and thence through the pipe K
into the valve box. The engine being at, say, the top stroke, the steam passes
through the port M on to the annular space on the top of the piston roundthe
trunk, the actual pressure of the steam makes the down or first half of the
double stroke to within or of the bottom of the cylinder, when the com-
munication with the boiler is cut off, and the steam expands the remaining
or stroke as may be ; during the return stroke the steam that has previously
made the down stroke passes along the steam ports M and N, through the
slide valve P, see the Diagram, Figure 2, and expands the whole of the return
stroke, the pressure of the steam acting on the unbalanced portion of the

page_text: piston open to the atmosphere. During the return stroke the steam which
is reduced in pressure by expansion, being in contact with the copper or
other metal plate G, absorbs the heat proceeding from the high-pressure
steam contained in the box in the base plate F, which not only prevents
condensation but also causes a partial re-evaporation of the expanding steam
and a corresponding increase of pressure. When the steam is acting on the
top of the piston, the steam which had previously made the double stroke
passes into the atmosphere through the exhaust pipe V, Figure 1.
In order to start the engine at any part of the double stroke, I employ a
small valve U, opening a communication between the valve box and the
upper steam port; when this valve is opened to start the engine, if the
engine is working in the direction of the down stroke, as shewn in Figure 1
of the Drawings, it will only give a slight increase to the area of the steam
port, but if the engine should be in the direction of making the up stroke,
and the steam cut off from the boiler, as in Figure 2, the steam will be
admitted simultaneously to both sides of the piston, which has the same
effect as if the steam were expanding from the top to the bottom; this
valve is to be closed when the engine has fairly started, but may be left open
while the engine is-at work, as its effect will only be to cause the steam to
be worked less expansively.
According, therefore, to my improved arrangement and construction of
steam engine, the steam may be employed to make the double stroke, or
entire revolution of the crank, the same steam which makes the first portion
of the stroke also making the return stroke, and by my arrangement of parts
simplicity of construction is obtained.
Of course,each of my improvements as herein-after claimed, firstly, secondly,
and thirdly, may be employed singly or they may be employed combined in
one and the same engine, and instead of fitting the cylinder as shown, it may
be horizontal or oblique, and it may be attached to a beam; and indeed, I
wish it to be understood that I do not confine myself to the precise forms or
details represented in and described in refereuce to the Drawings, as the
same may be varied, provided that the general character of my improvements
be retained, and although the Drawing represents a stationary engine my
Invention may also be applied to portable locomotive and marine engines.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I déclare that I claim,-
First, the mode of arranging and combining the steam ports and eduction
or exhaust port and the slide valve substantially as described, the steam ports
being next each other or nearest together, and the eduction port beyond,

page_text: below, or outside them instead of between them, with the valve arranged and
operating in the manner and for the purpose herein-before explained.
Second, the mode of connecting the trunk and piston by bolt and eye,
substantially as described.
Third, the combined arrangement of the cylinder stuffing box and the
piston, substantially as described, that is to say, constructing the stuffing box
so as to project within the cylinder and the piston so as nearly to fit the
stuffing box, but leaving a small space between,all as herein-before described.
Fourth,the general arrangement and combination of parts of steam engine,
as herein-before described, and represented in the accompanying Drawings.
In witness whereof, I, the said Thomas Tertius Chellingworth, have
hereunto set my hand and seal, this Fifth day of January, in the
year of our Lord One thousand eight hundred and fifty-nine.
Witness,
THOMAS TERTIUS CHELLINGWORTH. (L.S.)
WILLIAM WILLIAMS.