IMPROVEMENTS IN ENGINES FOR PUMPING AND ANALOGOUS PURPOSES
Year: 1874

page_text: LETTERS PATENT to John Fielding, of the City of Gloucester,
Engineer, for the Invention of "IMPROVEMENTS IN ENGINES FOR PUMPING
AND ANALOGOUS PURPOSES."
Sealed the 28th April 1874, and dated the 4th March 1874.
PROVISIONAL SPECIFICATION left by the said John Ficlding at the
Office of the Commissioners of Patents, with his Petition, on the
4th March 1874.
I, JOHN FIELDING, of the City of Gloucester, Engineer, do hereby.
declare the nature of the said Invention for "IMPROVEMENTS IN ENGINES
FOR PUMPING AND ANALOGOUS PURPOSES," to be as follows:-
This Invention relates more especially to those direct acting engines
having no rotating crank shaft or fly wheel and which are used for
pumping water or other fluids, and for blowing or exhausting air.
The object is to enable the engines to be worked expansively without
necessitating heavy masses to be put into motion for the purpose of
absorbing surplus energy during the first part and of giving it out-

page_text: during the last part of the stroke, with the end of obtaining an
approximately constant pressure on the pump piston throughout the
whole of the stroke, whilst having a varying pressure on the steam
piston resulting from the expansion of the steam after the supply has
been cut off, and also for the purpose of obtaining a great pressure at
the end of the stroke in the pump with a pressure on the driving
piston. These results are attained by the employment of two separate
pistons working in the same cylinder coupled by suitable rods and levers
outside the cylinder. Each of these two pistons is connected with a
pump plunger in cases where two single-acting pumps are employed,
but should one double-acting pump be found preferable then the two
steam pistons are suitably connected to two similarly arranged water
pistons working in one pump barrel.
The levers and rods are so arranged that during the carlier part of the
stroke when the pressure of steam is greatest the advance of the water
piston or plunger is greater than that of the steam piston, and as the
steam piston approaches the middle and end of the stroke, and the
pressure of steam in the cylinder is consequently diminished, from the
supply having been cut off, the motion of the water piston or plunger,
in relation to that of the steam piston, becomes gradually diminished,
and to such a degree that à practically constant pressure and velocity is
maintained upon the water piston, thus preventing any undue shock
upon the pump, pump valves, or pipes. The levers may be proportioned
to suit various degrees of expansion.
My Invention further consists in arranging relief valves in the steam
pistons for the purpose of opening a communication between the
exhausting end (for the time being) of the cylinder and the space
between the pistons, to prevent any accumulation of pressure taking
place arising from leakages past the piston packing, the same arrange-
ment being employed in the case of double-acting pumps to open a
communication between the drawing or vacuum side (for the time being)
of the pistons and the space between them for the same purpose.
The third and last part of this Invention relates more particularly to
those engines whose steam passages enter the cylinder at such a distance
from the ends that the pistons will cover them before reaching the end
of the cylinder, thus shutting up a certain amount of steam between the
piston and cylinder cover which upon compression will form a cushion

page_text: and prevent any violent contact between them, and consists in the use of
a small clack or valve arranged in such a manner that the steam shut
up between the piston and cylinder cover cannot escape, but that the
steam for the next stroke will open the valve by its pressure and obtain
access to the interior of the cylinder, causing the piston to be gradually
and slowly started till it has moved sufficiently to open the main steam
passage.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Fielding in the Great Scal Patent Office
on the 4th September 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
FIELDING, of the City of Gloucester, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of March, in the year
of our Lord One thousand cight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc.
cessors, give and grant unto me, the said John Fielding, Her special
licence that I, the said John Fielding, my executors, administrators,
and assigns, or such others as I, the said John Fielding, my executors,
administrators, 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 ENGINES FOR PUMPING AND ANALOGOUS PURPOSES," upon the condition
(amongst others) that I, the said John Fielding, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and scals, 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.
✅NOW KNOW YE, that I, the said John Fielding, do hereby declare

page_text: performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention relates more especially to those direct acting engines
having no rotating crank shaft or fly wheel, and which are used for
pumping water or other fluids and for blowing or exhausting air.
The object is to enable the engines to be worked expansively (without
necessitating heavy masses to be put into motion) for the purpose of
absorbing surplus energy during the first part and of giving it out during
the last part of the stroke, with the end of obtaining an approximately
constant pressure on the pump piston throughout the whole of the stroke,
whilst having a varying pressure on the steam piston resulting from
the expansion of the steam after the supply has been cut off, and also for
the purpose of obtaining a great pressure at the end of the stroke in
pumps, such as are required for compressing air with a regular pressure
on the driving piston such as water pressure. These results are attained
by the employment of levers outside the cylinder coupled by means of
rods to two separate pistons working inside the same cylinder. Each of
these two pistons is connected with a pump plunger in cases where two
single-acting pumps are employed, but should one double-acting pump
be found preferable then the two steam pistons are suitably connected to
two similarly arranged water pistons working in one pump barrel.
The levers and rods are so arranged that during the earlier part of
the stroke when the pressure of steam is greatest the advance of the
water piston or plunger is greater than that of the steam piston, and as
the steam piston approaches the middle and end of the stroke, and the
pressure of steam in the cylinder is consequently diminished, from the
supply having been cut off, the motion of the water piston or plunger
in relation to that of the steam piston becomes gradually diminished,
and to such a degree that a practically constant pressure and velocity is
maintained upon the water piston, thus preventing any undue shock
upon the pump, pump valves, or pipes. The levers may be proportioned
to suit various degrees of expansion.
The manner of carrying my Invention into effect will be clearly
understood by reference to the following description and the annexed
Drawings.
'
Figure 1 represents in sectional elevation, Figure 2 in side elevation,
and Figure 3 in plan a double ended cylinder A with two pistons B, O,

page_text: to work in the same direction within it alternately under pressure of,
say, steam through the passages D, D. Both of these pistons aro
hollow, and one B has a pump plunger or ram E projecting from it, the
plunger working to and fro in the pump barrel F to draw, say, water
into it, say, through the passage G, and to expel it through the passage H,
these passages being provided with valves to ensure the proper inlet and
outlet in the desired direction. The other piston C has a hollow extension
or tube I attached or formed in a piece with it to which another pump
plunger J is secured to draw into and expel water from its barrel K,
the engine working the pumping mechanism from both ends. The
piston B has also a rod projecting from the end opposite to that of the
plunger or ram E, which rod terminates in a cross head L whose
blocks M slide in straps N, N.
cross pin V
R, R, S, S,
The head P of the plunger J is slotted for the cross head L to move
in, and has blocks which slide in the same straps N, N, to partake of a
movement corresponding to that of the blocks of the cross head L.
Both cross heads have rods R, R, S, S, attached, and these lead to
separate arms T, T, U, U, of quadrants centred upon a
arranged at the under portion of the cylinder A. The rods
are of different lengths, as pairs, so that when the action of the steam
forces, say the left hand piston (as in Figure 1) along its course tho
quadrant takes the piston on the right in the same direction and at a
greater speed for a certain distance, because of the different angles at
starting of the quadrant arms T, T, U, U, and then its speed diminishes
again gradually until the end of the stroke, by which time the quadrant
arms have taken up a position diametrically opposite to the vertical
line to that which they occupied before the pistons B, C, being then
ready for a reverse travel to act upon the plungers of the two pumps
in a similar manner to that just explained.
Figure 4 represents in sectional elevation a cylinder A in which both
plungers E, J, are actuated from one end of the cylinder only. In this
case the pump barrels H, K, are in one casting with separate inlets and
outlets for the ingress and egress of the water in a similar manner to
that described with reference to Figures 1, 2, and 3, the only difference
being that the rod of the plunger E passes through the plunger J which
is provided with a stuffing box as also the partition W to keep the parts
water-tight.
Figure 5 shows a similar view to Figure 4 but with two plungers E, J,

page_text: working in the same barrel K. In this case the two plungers act
relatively through their connection with bars or rods R, S, as in
Figures 2 and 3, for both the forward and the backward strokes under
the action of pressure in the cylinder A.
My Invention further consists in arranging relief valves in the steam
pistons for the purpose of opening a communication between the
exhausting end (for the time being) of the cylinder and the space
between the pistons to prevent any accumulation of pressure taking
place arising from leakages past the piston packing, the same arrange-
ment being employed in the case of double-acting pumps to open a com-
munication between the drawing in or vacuum side (for the time being)
of the pistons and the space between them for the same purpose. This
will be understood by reference to Figure 6 in which portions of the
two steam pistons B, C, are shown in a cylinder A, and with relief
valves X, Y, in the pistons B, C, which valves as they respectively reach
the end of the stroke strike against the cylinder ends or against tappets
thereon, whereby they become shot in, so to speak, and open a passage
through one of the pistons for any steam or water to pass through it
from the space between the pistons to the exhausting end (for the time
being) of the cylinder and thus prevent any accumulation of pressure
that might occur through leakages past the piston packing.
The third and last part of my Invention relates more particularly to
those engines whose steam passages enter the cylinders at such a distance
from the ends that the pistons cover them before reaching the end of the
cylinder, thus shutting up a certain amount of steam between the piston
and cylinder cover, which upon compression forms a cushion and
prevent any violent contact between them, and consists in the use of a
small clack or valve arranged in such a manner that the steam shut up
between the piston and cylinder cover cannot escape, but that the steam
for the next stroke opens the valve by its pressure and obtains access to 3
the interior of the cylinder, causing the piston to be gradually and slowly.
started till it has moved sufficiently to open the main steam passage.
This portion of my Invention is clearly shown in Figure 7 where A is
the cylinder; B, the piston, shown in the position it occupies when
covering the steam port or passage D, in which steam has next to pass, 3
to act upon the back of the piston to push it forward; a is the valve in
the bend of the passage and closing the aperture by the pressure of the
cushion of steam in the space b, which cushion of steam is boxed in