IMPROVEMENTS IN STEAM PUMPING ENGINES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by John Wolstenholme and Edward
Holt at the Office of the Commissioners of Patents, with their
Petition, on the 29th December 1870.
WC, JOHN WOLSTENHOLME, of Radcliffe Bridge, in the County of
Lancaster, Engineer, and EDWARD HOLT, of the same Place, Machanist,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN STEAM PUMPING ENGINES," to be as follows:-
Our Invention relates to steam pumps or pumping engines in which
the movements of the valves employed to regulate the admission and
emission of the steam to and from the steam cylinders of the said
engines are effected and controlled without the employment of rotating
crank shafts, and principally to such pumps or pumping engines, or
steam fire engines as are self-contained, and as are ordinarily styled
portable pumps. In such engines it is of importance that the move-
ments of the aforesaid valves shall be fully controlled by and be in
unison with the movements of the piston of the steam cylinder.
When constructing a steam pump in manner according with our said
Invention we prefer to make the valve box of a cylindrical form inter-

page_text: "
nally, and to bore the said valve box to receive the valve or valves
which is or are made of a cylindrical form, and are fitted to slide to
and fro to some extent within the said valve box in a steam-tight or
nearly steam-tight manner. The said valve box is fitted at each end
with a cover, and the said covers are suitably formed to limit the extent
of movement of the valve, the steam confined between the said valve
and each cover acting as a " cushion to prevent the valve from
striking the said cover. The said valve box is in communication
through steam ports with each end of the steam cylinder, and is pro-
vided with suitable exit ports, through which the exhaust steam flows
when leaving the said valve box. A port or passage is made or formed
at a distance from each end of the steam cylinder, the said distance
being such that on the piston approaching either end of the cylinder
it will pass beyond the said port, or the side of the piston on which the
steam is acting will partly uncover the said port, and a portion of the
propelling steam will flow through the said port and through a pipe
or passage and will enter the valve box at such a point in the said box
as that the said steam shall act upon the piston valve or one of the
piston valves, and shall move the said valve or valves into a position
suitable to cause the direction of motion of the main piston to be
reversed. At the time when the steam is flowing through the said
port into the valve box as aforesaid, the port near the other end of
the cylinder will also be uncovered, but the passage through which the
last-named port communicates with the valve box is at the time covered
by the valve or by one of the valves, the said valve or valves being so
formed, and the passages through which the steam flows to move the
said valve or valves are so situated as that one of the said passages
and one of the exit ports for the exhaust steam are covered, and the
other passage and other exit port are uncovered by each movement
of the said valve or valves. The said valve or each valve may be packed
by means of a metal ring or portion of a ring, or by other suitable
means.