IMPROVEMENTS IN SLIDE VALVES
Year: 1869

page_text: LETTERS PATENT to Enoch Hill, of Longton, in the County of
Stafford, Engineer, for the Invention of "IMPROVEMENTS IN SLIDE
VALVES."
Sealed the 9th November 1869, and dated the 22nd September 1869.
PROVISIONAL SPECIFICATION left by the said Enoch Hill at the
Office of the Commissioners of Patents, with his Petition, on the
22nd September 1869.
I, ENOCH HILL, of Longton, in the County of Stafford, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
SLIDE VALVES," to be as follows:-
The improvements consist in making valves hollow for the purposes of
admitting steam therein and through, whereby a considerable area of
the valve is saved from being exposed to the pressure of steam used,
also in making valves of a (downward) tapering form (in section)
working in a tapering slide made to receive them; the object of the
improvements being to obtain a more perfect equilibrium and to

page_text: reduce friction, thereby saving power and wear and tear, and also to
render the starting, stopping, and general management of the engine
to which they may be applied more easy than heretofore.
The improvements may be carried into effect by making the various
parts of metal properly and truly fitted, the steam inlet pipe supplying
the valve being made so as to allow the steam to enter the hollow valve
through ports on both sides thereof simultaneously. The valve may be
formed (as viewed in cross section) with the top and bottom shaped to
segments of concentric circles, and the sides radiating or tapering to the
centre, from which such segments are struck, or to any other convenient
centre.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Enoch Hill in the Great Seal Patent Office on the
18th November 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ENOCH
HILL, of Longton, in the County of Stafford, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of September, 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 Enoch Hill, Her special
licence that I, the said Enoch Hill, my executors, administrators, and
assigns, or such others as I, the said Enoch Hill, my executors, adminis-
trators, 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 "IMPROVEMENTS IN SLIDE VALVES,"
upon the condition (amongst others) that I, the said Enoch Hill,
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 Enoch Hill, 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:-
The improvements consist in making valves hollow for the purposes of
admitting steam therein and through, whereby a considerable area of the
valve is saved from being exposed to the pressure of steam used, also
in making valves of a (downward) tapering form (in section) working in
a tapering slide made to receive them, the object of the improvements
being to obtain a more perfect equilibrium and to reduce friction,
thereby saving power and wear and tear, and also to render the starting,
stopping, and general management of the engine to which they may
be applied more easy than heretofore.
The improvements may be carried into effect by making the various
parts of metal properly and truly fitted, the steam inlet pipe supplying
the valve being made so as to allow the steam to enter the hollow valve
through ports on both sides thereof simultaneously. The valve may be
formed (as viewed in cross section) with the top and bottom shaped to
segments of concentric circles, and the sides radiating or tapering to the
centre from which such segments are struck, or to any other convenient
centre.
The accompanying Drawing is intended to illustrate a convenient
mode of performing the Invention, but it is to be understood that I do
not limit myself to the actual arrangement there designed, as it is
obvious that it may be varied considerably without departing from the
spirit or nature of the improvements above described.
Figure 1 shows a sectional end view of a cylinder having a hollow
valve a and seating 6 made according to my improvements. The
widening out of the bottom of the valve seat is intended for the purpose
of making it more easy to fit and plane, as it leaves no more surface to
plane than that over which the valves work. The flanges c, c, on the
top of valve are intended to prevent the valve from falling too tight into
the seating, and also to save as chipping pieces when it is desired to
lower the valve in its seating, and thus regulate it and make it steam-
tight after wear. Figure 2 is a sectional plan taken at A, A, Figure 1,
and shows the ports in the valves open for steam opposite the ports in
the seating, and so arranged that the steam passes into the valve from

page_text: both sides when supplied through the steam branch, being carried to the
opposite side by means of a belt d running round the under side of the
cylinder. Thus while the steam is passing into the valves by the two
ports on each side it is passing out through the other two into the
cylinder. The valve marked e is shown open for exhaust, but is moved
back in action so as to open the ports leading from the cylinder into the
valve chamber, thereby allowing the steam to pass from the cylinder into
the valve chamber and escape through a branch in the end of the valve
chamber or otherwise escape. The Figures 3, 4, and 5 are end view,
sectional plan, and side elevation respectively of the hollow valve.
In witness whereof, I, the said Enoch Hill, have hereunto set my
hand and seal, this Eighth day of November, in the year of our
Lord One thousand eight hundred and sixty-nine.
Signed, sealed, and delivered by the
above-named Enoch Hill, in the
presence of
JAMES BONNER,
46, Stafford Street,
Longton,
Staffordshire.
ENOCH HILL. (L.S.)