IMPROVEMENTS IN STEAM FIRE ENGINES AND PUMPING APPARATUS
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Edward Field at the Office of the
Commissioners of Patents, with his Petition, on the 10th May
1869.
I, EDWARD FIELD, of Chandos Chambers, Adelphi, in the City of
Westminster, Consulting Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN STEAM FIRE ENGINES AND
PUMPING APPARATUS," to be as follows:-
My Invention has for its object improvements in steam fire engines
and other pumping apparatus, and one part thereof consists in actuating
the valves which regulate the admission and emission. of steam to and
from the main steam cylinders of steam pumping engines. by means of
tongues or levers actuated by curved or inclined surfaces in or in
connection with the main pistons.
Another part of my Invention consists in regulating the admission
and emission of steam to and from the respective sides of the small
pistons by which the steam valves of the main cylinders are carried over
their dead points in pumping engines having no fly wheels, such, for
instance, as those of the class designed by me, and well known as

page_text: Merryweather and Sons' direct-acting steam fire engines, by allowing
the rods of the main slide valves a certain amount of longitudinal
movement or play independently and in advance of their valves, by
which method the separate valves heretofore usually employed for
regulating the admission and emission of steam to and from the
respective sides of the aforesaid small pistons are dispensed with. For
the purpose of feeding the boilers of steam pumping engines I arrange
the piston rods of the main pumps to serve as cylinders working on
fixed hollow plungers, and so to draw and force the feed water through
suitable valves into the boilers.
My Invention also relates to pumps whose valves are (by preference)
made of elastic material or provided with elastic or resilient faces,
bearing surfaces, or seats, and this part of my Invention consists in
arranging and combining the suction and delivery valves or closing
faces in pairs consisting of one suction valve or face, and one delivery
valve or face having their areas, connections, seats, or relative positions
differentially proportioned or arranged, and connecting such pairs
together, so that when the pumps are at rest the whole of the valves
may be closed or nearly so, but that when at work the pressure of the
entering fluid upon the back of one suction valve, will force it tightly
against its seat and simultaneously open its fellow delivery valve, while
at the same time the other delivery valve will be firmly closed and its
fellow suction valve will be opened, the ways for the passage of the
fluid being afforded by the resilient action of the valves themselves or
of their elastic faces, bearing surfaces, or scats, as the case may be. In
some cases valves of other descriptions may be arranged and combined
in pairs, and with their areas, connections, seats, or relative positions
differentially proportioned or arranged according to this part of my
Invention. Or otherwise in some pumps instead of connecting the
valves together as described the suction valves may be combined in
pairs independently of the delivery valves, and the delivery valves com-
bined in separate pairs so that the pressure of the fluid in opening one
valve of a pair will have the effect of pressing its fellow valve against
its seat.
In portable fire engines or pumping apparatus I prefer to arrange and
combine the several working parts with straight frames, and to employ
the under part or parts of the valve chamber or chambers of the pump
or pumps as a portion or portions of the fore carriage, by which method

page_text: the steam cylinders and pumps can be brought nearer together than in
most other engines of this class, so as to render the engine more compact
and to simplify and cheapen its construction.