IMPROVEMENTS IN STEAM ENGINES
Year: 1862

page_text: LETTERS PATENT to Edward Humphrys, of Deptford, in the County of
Kent, Engineer, for the Invention of "IMPROVEMENTS IN STEAM ENGINES."
Sealed the 3rd February: 1868, and dated the 8th August 1862.
PROVISIONAL SPECIFICATION left by the said Edward Humphrys
at the Office of the Commissioners of Patents, with his Petition, on the
8th August 1862.
I, EDWARD HUMPHRYS, of Deptford, in the County of Kent, Engineer,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN STEAM
ENGINES," to be as follows:-
This Invention has for its object improvements in steam engines, and relates
to that description of steam engines, in which two cylinders, a small one, into
which the steam first enters, and a larger one in which it is subsequently
allowed to expand are employed, and in which the pistons of the cylinders are
connected together by a piston rod, passing through the cover or partition
which separates the small from the large cylinder. The improvements consist
in applying a trunk to the large piston, and a suitable connecting rod as in
ordinary trunk engines, to transmit the power from the two pistons to a crank
on a shaft or axis.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Humphrys in the Great Seal Patent Office on
the 7th February 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
HUMPHRYS, of Deptford, in the County of Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of August, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Edward Humphrys, Her special licence that I, the said
Edward Humphrys, my executors, administrators, and assigns, or such
others as I, the said Edward Humphrys, 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, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the 'Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN STEAM ENGINES," upon the condition (amongst
others) that I, the said Edward Humphrys, 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 Inven-
tion, 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.
NOW KNOW YE, that I, the said Edward Humphrys, 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, that is to say :-
This Invention has for its object improvements in steam engines, and
relates to that description of steam engines in which two cylinders, à small
one into which the steam first enters, and a larger one in which it is subsequently
allowed to expand, are employed, and in which the pistons of the cylinders are
connected together by a piston rod passing through the cover or partition
which separates the small from the large cylinder. The improvements consist
in applying a trunk to the large piston, and a suitable connecting rod, as in
ordinary trunk engines, to transmit the power from the two pistons to a crank
on a shaft or axis.
And in order that my said Invention may be most fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side view, partly in section, and Figure 2 is a plan, also partly
in section, of a steam engine constructed according to my Invention. a, is the
small cylinder to which the steam is first admitted, and b, is its piston; c, is
the larger cylinder into which the steam is expanded after it has worked in
the cylinder a, and d is the piston of the larger cylinder. Through the
pistons and d a piston rod passes, at one end of it the bearing is formed for
the pin of the connecting rod e, and at the other is a nut to secure it on the
further side of the smaller piston; f is a tube which surrounds the piston rod
and keeps the two pistons at a proper distance apart; g is a stuffing box, by
preference with metallic packing, it is formed between the two cylinders a
and c, and the piston rod with the tube f work through it, the joint being
steam-tight or nearly so. a¹ is the moveable end cover of the cylinder a
and cand care the moveable covers of the cylinder c. a*, a*, and c*, c*,
are steam spaces, with which it is preferred to surround the steam cylinders
to prevent condensation. d' is a trunk formed on the piston d, it works
steam-tight through a large stuffing box in the cover c³, and the connecting
rod e passes down within it. h is the cranked axle to which the connecting
rod communicates the motion of the pistons, and i is a frame bolted to the
end of tho cylinder c, for supporting one of the bearings of the axle h, the
other bearing or bearings may be carried in any convenient manner. The
valves and other parts of the engine which are not shewn in the Drawings
be of ordinary construction.
may
I would remark that I do not confine myself to the details of the arrange-
ment shewn in the Drawings, which may be varied without departing from
my Invention.
In witness whereof, 1, the said Edward Humphrys, have hereunto set my
hand and seal, this Seventh day of February, in the year of our
Lord One thousand eight hundred and sixty-three.
EDW. HUMPHRYS. (LS.)