Improvements in Duplex Pumps Worked by Steam or other Fluid.
Year: 1889

page_text: Date of Application, 8th Mar., 1889
Complete Specification Left, 8th Jan,, 1890-Accepted, 8th Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in Duplex Pumps Worked by Steam or other Fluid.
I, CLEMENT EDWIN OWENS of 22 Whitefriars Street in the City of London
Engineer, do hereby declare the nature of this invention to be as follows:-
In duplex pumps worked by steam (or other fluid) as hitherto constructed the
cylinders of the two pumps have both been supplied with high pressure steam. This
is a very wasteful arrangement, inasmuch as the steam, after doing its work at high
pressure, is exhausted into the atmosphere. In some cases these duplex pumps
have been compounded, that is to say each pump has had a high pressure cylinder
and a low pressure cylinder, the steam exhausting into the low pressure cylinder after
doing its work in the high pressure cylinder, so that there is not the waste above
referred to. But as these compound duplex pumps have had four cylinders there is
of necessity multiplication and combination of parts.
Now according to my invention I construct a duplex compound fluid pressure
pump with one high pressure cylinder and one low pressure cylinder, the two
cylinders being placed side by side and operating upon the pumps in precisely the
same way as the two high pressure cylinders, such as have hitherto been used side by
side have operated, and the piston rod of each cylinder actuating the slide valve or
other valve of the other cylinder in the manner which is usual in duplex pumps.
In order to start the pump I arrange so that the steam is admitted to the high
pressure cylinder at full pressure and simultaneously to the low pressure cylinder at
a reduced pressure obtained by means of any ordinary reducing valve, after which
the direct supply to the low pressure cylinder is cut off. This direct supply to the
low pressure cylinder in the first instance enables the pump to be started even in
cases where the inlet to both ends of the high pressure cylinder happens to be closed
owing to the position of the valve.
With my arrangement I obtain double the power with the same volume of steam,
because the second cylinder is worked by the exhaust steam from the first cylinder
instead of by a separate volume of high pressure steam as in duplex steam pumps
hitherto constructed.
The sectional area of the low pressure cylinder should be approximately one-half of
that of the high pressure cylinder, so that about equal power is obtained by each
cylinder.
Instead of employing two cylinders I sometimes employ four cylinders, two for
each pump, and work these four cylinders with quadruple expansion as will be well
understood.
Soun uay Ur
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Duplex Pumps Worked by Steam or other Fluid.
I, CLEMENT EDWIN OWENS of 22 Whitefriars Street in the City of London,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
In duplex pumps worked by steam (or other fluid) as hitherto constructed the
cylinders of the two pumps have both been supplied with high pressure steam. This
is a very wasteful arrangement inasmuch as the steam after doing its work at high
pressure is exhausted into the atmosphere. In some cases these duplex pumps have

page_text: been compounded, that is to say each pump has had a high pressure cylinder and
a low pressure cylinder, the steam exhausting into the low pressure cylinder after
doing its work in the high pressure cylinder, so that there is not the waste above
referred to. But as these compound duplex pumps have had four cylinders, there is
of necessity multiplication and combination of parts.
Now according to my invention I construct a duplex compound fluid pressure pump
with one high pressure cylinder and one low pressure cylinder, the two cylinders
being placed side by side and operating upon the pumps in precisely the same way as
the two high pressure cylinders, such as have hitherto been used side by side,
have operated, and the piston rod of each cylinder actuating the slide valve or other
valve of the other cylinder in the manner which is usual in duplex pumps.
In order to start the pump I arrange so that the steam is admitted to the high
pressure cylinder at full pressure and simultaneously to the low pressure cylinder
at a reduced pressure which may be obtained by means of a suitable reducing valve,
after which the direct supply to the low pressure cylinder is cut off. This direct
supply to the low pressure cylinder in the first instance enables the pump to be
started even in cases where the inlet to both ends of the high pressure cylinder
happens to be closed owing to the position of the valve.
With my arrangement obtain double the power with the same volume of steam,
because the second cylinder is worked by the exhaust steam from the first cylinder
instead of by a separate volume of high pressure steam as in duplex steam pumps
hitherto constructed.
The sectional area of the high pressure cylinder should be approximately one third
to one half of that of the low pressure cylinder so that about equal power is obtained
by each cylinder, but the proportion should be regulated according to the pressure of
the steam employed.
--
Figures 1, 2 and 3 of the annexed drawings represent so much of a duplex pump as
is necessary to illustrato my invention. Figure 1 is a plan, Figure 2 a longitudinal
elevation with the cylinders and valves in section on the line 1- 1 and Figure 3a
transverse section on the line 2 - - 2. a is the high pressure cylinder and the low
pressure cylinder, these two cylinders being placed side by side and operating upon
the pumps (not shown) in precisely the same way as the two high pressure cylinders
such as have hitherto been used side by side have operated. c is the rod of the piston
of cylinder a and of the piston or plunger of the corresponding pump barrel and dis
the rod of the piston of cylinder and of the piston or plunger of its corresponding
pump barrel.
e and fare respectively the slide valves of the two cylinders. The
piston rods c, actuate the valves and e respectively in the manner which is usual
in duplex pumps, that is to say a link g fitting at its lower end into a fork h in
the piston rod so as to receive an oscillating movement therefrom is connected
at its upper end to a shaft i to which it imparts rocking motion, and this rocking
shaft has a tongue or projection which takes into the rod k of the valve f; while on
the other hand a link fitting at its lower end into a fork m on the piston rod d,
imparts similar rocking motion to a shaft n which has a tongue or projection which
takes into the rod p of the valve e.
The steam is admitted at full pressure to the high pressure cylinder a by the pipe v
fitted with a valve ic and exhausts therefrom into the chamber q and thence to the
box of the slide valve of the low pressure cylinder b; from the low pressure
cylinder the steam exhausts at r into the atmosphere or into a condenser. In order
to ensure that the pump shall start, even if owing to the position of the valve the
inlet to both ends of the high pressure cylinder happens to be closed, 1 arrange for
the high pressure steam to be admitted in the first instance to the low pressure
cylinder as well as to the high pressure cylinder, for which purpose I provide a
branch steam pipes leading to the low pressure cylinder; this pipe is fitted with a
valve t by which it is closed after the pump has been started and this pipe may also be
fitted with a suitable reducing valve so as to reduce the steam pressure.
uu are tie rods between the steam cylinders and the pump barrels.
Instead of employing two cylinders I sometimes employ four cylinders, two for

page_text: 4.
each pump, and work these four cylinders with quadruple expansion as will be well
understood. This arrangement is illustrated in Figures 4, 5 and 6, Figure 4 being a
plan, Figure 5 a section on the line 3-3 and Figure 6 a section on the line 4 -
In line with the high pressure cylinder a is a cylinder x, the pistons of these two
cylinders being on the same rod c and working the same pump piston or plunger.
Similarly in line with the low pressure cylinder b is a cylinder y the pistons of these
two cylinders being likewise on the same rod d and working the same pump piston
or plunger. The valves of the cylinders a and move together and the valves of the
cylinders b and y movo together. The steam from cylinder a exhausts into cylinder b
as in the arrangement shown in Figures 1, 2 and 3, but instead of the cylinder b
exhausting into the atmosphere it exhausts into a channel leading down the outside
of the cylinder to a pipe ¹ which conducts the exhaust to a channel leading up the
outside of cylinder a to the valve box of this cylinder. The cylinder
exhausts into
the channel ' and thence to the valve box of cylinder y which in its turn exhausts
at into the atmosphere or into a condenser.
In starting this four cylinder arrangement the cylinders a and y should be supplied
with steam of a higher pressure than they receive in normal working; this can be
effected by connecting pipes from the main steam supply and valves as will be readily
understood.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. A duplex compound fluid pressure pump constructed substantially as herein-
before described with a high pressure cylinder and a low pressure cylinder, these two
cylinders being placed side by side and operating the pumps in the same way as the
two high pressure cylinders such as have hitherto been used side by side in duplex
fluid pressure pumps have operated, and the piston rod of each cylinder actuating the
valve of the other cylinder in the manner which is usual in duplex pumps.
2. The duplex compound fluid pressure pump constructed and working as shown in
Figures 1, 2 and 3 and hereinbefore described.
3. A duplex compound fluid pressure pump with four cylinders arranged substan-
tially as hereinbefore described and shown in Figures 4, 5 and 6, and worked with
quadruple expansion as set forth.
Dated this 8th day of January 1890
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.