IMPROVEMENTS IN THE VALVES OF AIR PUMPS FOR STEAM ENGINES."
Year: 1878

page_text: LETTERS PATENT to George Hepburn, of Liverpool, in the County of Lancaster,
Engineer, for the Invention of "IMPROVEMENTS IN THE VALVES OF AIR PUMPS
FOR STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said George Hopburn at the
Office of the Commissioners of Patents on the 3rd September 1878.
GEORGE HEPBURN, of Liverpool, in the County of Lancaster, Engineer. "In-
PROVEMENTS IN THE VALVES OF AIR PUMPS FOR STEAM ENGINES."
The valves of air pumps for steam engines have, as regards part thereof, for a
long period been constructed of a flexible material, mainly of india-rubber; theso
flexible parts or discs, apart from being costly in maintenance, not unfrequently
fail to act.
Now my Invention consists in so constructing air pump valves that they are
durable, efficient, and inexpensive to maintain. For that purpose I construct or form
a disc valve of vulcanite, ebonite, or any other hard compound of caoutchouc, or
of celluloid or other hard composition, and I arrange such disc valve to work or
operate with a to-and-fro or sliding motion on one or more spindles, stems, or
guides.
In carrying the Invention into practice I, by preference, employ a series of disc
valves arranged annularly. Each annular disc-like valve works on a stud, pin, or
bolt, on which it is free to move up and down.
The seatings are made of brass or other suitable metal or material, and the disc
valves rest, when closed, flat on the seatings

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Hepburn in the Great Seal Patent Office on the 3rd March
1879.
GEORGE HEPBURN, of Liverpool, in the County of Lancaster, Engineer. "Iм-
PROVEMENTS IN THE VALVES OF AIR PUMPS FOR STEAM ENGINES."
The valves of air pumps for steam engines have, as regards part thereof, for a
long period been constructed of a flexible material, mainly india-rubber; these
flexible parts or discs, apart from being costly in maintenance, not unfrequently
fail to act.
Now my Invention consists in so constructing air pump valves that they aro
durable, efficient, and inexpensive to maintain. For that purpose I construct or
forin a disc valve of vulcanite, ebonite, or any other hard compound of caoutchouc,
or of celluloid or other hard composition, and I arrange such disc valve to work or
operate with to-and-fro or sliding motion on one or more spindles, stems, or
guides.
In carrying the Invention into practice I, by preference, employ a series of disc
valves arranged annularly. Each annular disc-like valve works on a stud, pin, or
bolt, on which it is free to move up and down.
The seatings are made of brass or other suitable metal or material, and the disc
valves rest, when closed, flat on the seatings.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a plan view, and Fig. 2, a sectional elevation of an air pump piston fitted
with my improved valves.
The disc valves 1, formed of vulcanite, ebonite, or other suitable hard composition,
rest, when closed, on the metal seatings 2, and are free to rise therefrom, when
necessary, by sliding along the studs 3. The studs 3 are secured to the body of
the piston 4, and are provided with guards or stops 5, which prevent the said
valves 1 from rising too far from their seats. In Fig. 2 one valve is shown closed
and the other open.
It will be obvious that the disc valves may be square or of other shape, and that
more than one guide rod or stud may be used for each valve; also that the said
valves may be variously arranged on the piston.
Having now described the nature of the said Invention in such manner that
others will be enabled to carry my improvements into effect, I claim, constructing
the valves of air pumps, substantially in the manner and for the purposes set forth.
In witness whereof, I, the said Georgo Hepburn, have hereunto set my hand
and seal, the First day of March, in the year of our Lord One thousand
eight hundred and seventy-nine.
GEO. HEPBURN. (L.S.)