AN IMPROVEMENT IN THE SLIDE VALVES OF STEAM ENGINES
Year: 1869

page_text: LETTERS PATENT to James Young, of Houghton-le-Spring, in the
County of Durham, Engineer, for the Invention of "AN IMPROVE.
Ар
"
Sealed the 10th December 1869, and dated the 14th June 1869.
PROVISIONAL SPECIFICATION left by the said James Young at the
Office of the Commissioners of Patents, with his Petition, on the
14th June 1869.
I, JAMES YOUNG, of Houghton-le-Spring, in the County of Durham,
Engineer, do hereby declare the nature of the said Invention for "AN
IMPROVEMENT IN THE SLIDE VALVES OF STEAM ENGINES," to be as follows -
My Invention relates to the side valves of steam engines. As is
well known the pressure of steam at the back of the slide valves in
steam engines subjects such valves to considerable friction when in
motion. This friction absorbs power and causes a useless expenditure
of stores, and subjects the eccentrics, working gear, the faces of the
valves and seats to wear more or less rapidly. Now in order partly
to counteract the pressure of the steam at the back of the slide valve
I form recesses in the face of the valve, or in the valve seat, or

page_text: in both, of suitable form and number. These recesses at certain
times during the movement of the slide valve become charged with
steam, such charges of steam retaining sufficient elastic force as the
valve face passes over the valve seat to partly counterbalance the
pressure of the steam at the back of the valve, and considerably
reduce the friction and wear of such valves. Channels and recesses
have hitherto been formed in the faces of slide valves for the intro-
duction and dissemination of lubricating substances, but such channels
and recesses have occupied an inconsiderable proportion of the slide
surfaces. The recesses formed according to my Invention occupy a
considerable proportion, and not less than one-fourth of the sliding
surfaces, and are so formed and arranged in the slide valve or seat, or
in both surfaces as to retain charges of steam of sufficient elastic force
to appreciably counteract the pressure of the steam at the back of the
slide valve as above explained, such arrangement being peculiarly
adapted to meet the requirement of the modern marine engine, more
especially where high-pressure steam is used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Young in the Great Seal Patent Office
on the 14th December 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
YOUNG, of Houghton-le-Spring, in the County of Durham, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of June, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Young, Her special licence
that I, the said James Young, my executors, administrators, and
assigns, or such others as I, the said James Young, 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 Invention for "AN IMPROVEMENT IN

page_text: THE SLIDE VALVES OF STEAM ENGINES," upon the condition (amongst others)
that I, the said James Young, 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.
NOW KNOW YE, that I, the said James Young, 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 :-
My Invention relates to the slide valves of steam engines. As is well
known the pressure of steam at the back of the slide valves in steam
engines subjects such valves to considerable friction when in motion.
This friction absorbs power and causes a useless expenditure of stores,
and subjects the eccentrics, the working gear, the faces of the valves and
seats to wear more or less rapidly. Now in order partly to counteract
the pressure of the steam at the back of the slide valve I cast or other-
wise form recesses in the face of the slide valve, or in the cylinder faces,
or in both, of suitable form and number. I so form such recesses as to
occupy a considerable proportion of the rubbing surface, say, one-half
and not less than one-fourth of such surfaces. These recesses at certain
times during the movement of the slide valve become charged with
steam, such charges of steam retaining sufficient elastic force as the
slide valve face passes over the cylinder faces to partially counterbalance
the pressure of the steam at the back of the valve, and considerably
reduce the friction and wear of such valves, which are consequently
more durable. With valves formed with recesses according to my
Invention the amount of lubricating material required is also lessened,
the engine works more freely, and the slide valves are more readily
reversed or "handled."
In the Drawing hereunto annexed Figure 1 shews a longitudinal
section of so much of a steam engine cylinder a and a slide valve bas
will enable an engineer to understand and carry my Invention into
practice; and Figure 2 shew a face view of the slide valve b; a', a',
are the ordinary steam passages to the cylinder, and a² is the ordinary
exhaust passage. A number of recesses a³, a³, are formed in the cylinder

page_text: faces and a number of similar recesses b', b¹, and also formed in the slide
valve faces. It will be readily understood that during the movement of
the slide valve the recesses a³, a³, and b', 6', are charged with steam,
which in the further movement of the valve becomes enclosed in such
recesses between the slide valve and the cylinder faces, so as to counter-
act by its expansive force the pressure of the steam at the back of the
slide valve.
Having now described the nature of my Invention, and the manner
of carrying the same into practice, I would have it understood that the
form and arrangement of the recesses a³, a³, and b', b', may be greatly
varied without departing from the nature of my Invention. I would also
remark that I am aware that grooves or channels or a few small holes or
recesses have heretofore been formed in the faces of slide valves and
cylinders, but such channels and recesses have occupied an inconsiderable
proportion of the slide surfaces, and have been so formed for the purpose
of aiding the introduction and disemination of lubricating substances.
The recesses formed according to my Invention occupy a considerable
proportion, and not less than one-fourth of the sliding surfaces, and are
so formed and arranged in the slide valve or cylinder faces, or in both
surfaces, as to retain charges of steam of sufficient clastic force to
appreciably counteract the pressure of the steam at the back of the slide
valve as above explained, such arrangement being peculiarly adapted to
meet the requirement of the modern marine engine, more especially
where high-pressure steam is used, what I claim is, forming recesses in
the faces of slide valves, or in the cylinder faces, or in both of such
surfaces, so that such recesses occupy at least one-fourth of the rubbing
surface, as and for the purposes herein-before described.
In witness whereof, I, the said James Young, have hereunto
set my hand and seal, this 11th day of December, in the year
of our Lord One thousand eight hundred and sixty-nine.