CERTAIN IMPROVEMENTS IN THE SLIDE VALVES OF STEAM ENGINES
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MULBERY, of Parkersburgh, Chester County, State of Pensylvania, in the
United States of America, Machinist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourth day of July,
One thousand eight hundred and forty-nine, in the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me;
the said James Mulbery, my exors, aditiors, and assigns, Her especial licence;
full power, sole privilege and authority, that I, the said James Mulbery,
my exors, adñiors, and assigns, and such others as I, the said James Mul-
bery, my exors, admors, or assigns, should at any time agree with, and no
others, from time to time and at all times during the term of
years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, in the Islands of
Guernsey, Jersey, Alderney, Sark, and Man, and also in all Her said Majesty's
Colonies and Plantations abroad, my Invention of "CERTAIN IMPROVEMENTS IN
THE SLIDE VALVES OF STEAM ENGINES;" in which said Letters Patent is con-
tained a proviso that I, the said James Mulbery, should cause a particular
description of the nature of my said Invention, and in what manner the same
is to be performed, by an instrument in writing under my hand and scal, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters

page_text: Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Mulbery, hereby declare that the nature of my said Invention, and
in what manner the same is to be performed, are fully described and ascer-
tained in and by the present Specification thereof, reference being had to the
Drawings hereunto annexed, that is to say:
My said Invention has for its object to render the slide valves of steam
engines, more especially those of locomotive engines, more perfect in their
action, and consists in constructing them in such manner that they shall con-
tinue for a longer time than they now do with their rubbing surfaces in that
complete and steam-tight state in which they generally are when delivered from
the hands of the engine builder. As these valves and the cylinder valve
facings which they rub against are now constructed they soon become deeply
scratched or grooved in the direction parallel to the direction of the motion
of the valve, and in proportion to the inequalities of surface thus produced the
steam passes through the valve without causing any useful effect upon the
piston. It has been commonly supposed that this scratching or grooving is
caused by some hard substances introduced into the valve casing, either along
with the steam or with water which. finds its way through the steam pipes;
but I have ascertained, by frequent and careful observation, that it arises chiefly,
if not solely, from metallic particles detached from the valves and valve facings
themselves. Hitherto it has been the practise to make the openings from the
rubbing surfaces quite sharp, or at right angles with the plane in which the
slides move, the consequence of which is, that the edges of these openings soon
yield, from want of side support, to the pressure and friction to which they are
exposed, and become detached in small portions, which get jammed between
the valve and the facing, and thus produce the injurious effects just adverted
to, and which it is the purpose of my Invention to remedy.
Figure 1 of the Drawings is a plan of the face of a valve constructed
according to my Invention; Figure. 2 is a perspective plan of the cylinder
facing, and Figure 3 a longitudinal section of the valve and valve facing.
A is the valve; B, the facing; C, C, C, the steam and exhaust passages. The
edges or corners a, a, a, a, and b, b, b, which have been hitherto made at right
angles with the rubbing surfaces, are here rounded or flattened off to such an
extent as to be no more liable than other parts of the valve and facing to
abrasion.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that what I claim is, the making

page_text: the corners or edges of the openings in the slide valves of steam engines
rounded or flattened instead of angular as before described.
In witness whereof, I, the said James Mulbery, have hereunto set my
hand and seal, this Fourth day of September, in the year of our Lord
One thousand eight hundred and forty-nine.
Taken and acknowledged by James
Mulbery (party hereto), at Phila-
delphia, in the United States of
America, this Fourth day of Septem-
JAMES (L.S.) MULBERY.