Improvements in Duplex Pumping Engines.
Year: 1896

page_text: Date of Application, 26th Oct., 1896
Complete Specification Left, 23rd July, 1897-Accepted, 28th Aug., 1897
PROVISIONAL SPECIFICATION.
Improvements in Duplex Pumping Engines.
We PHILIP FRANCIS ODDIE and GUSTAV HESSE both of 125 and 130 Larkhall Lane,
Clapham in the County of Surrey, Engineers do hereby declare the nature of this
invention to be as follows:-
This invention has reference to improvements in Duplex Pumping Engines to
simplify their operation, add to their efficiency, and effect economy of Steam.
In a former Specification numbered 23044-1895 we described a duplex pumping
engine in which each piston is formed with an inclined groove or guide adapted to
effect the operation of the valve controlling the supply of steam to the companion or
duplicate cylinder and an arrangement of expansion valves working on the back of or
through the main valves operated by the same groove or guide formed on the
pistons.
In the present invention we make use of substantially the same arrangement and
action of main and expansion valves but instead of forming the inclined groove on
the pistons, it is formed on or in separate rods or bars which are located in the valve
chest. One end of each of these bars is continued through suitable stuffing boxes
and is rigidly in connection with projecting arms fixed on each piston rod.
Each bar is free to reciprocate within the valve chest in a line parallel with the
notion of the pistons and lateral movement being prevented by suitable guides
preferably fixed on the valve chest covers.
The valves for the admission and emission of steam are formed with inclined
parts corresponding with and engaging in the inclined portion on the bars.
When the pistons reciprocate within their respective cylinders each bar or rod
reciprocates also imparting to the main and expansion valves a reduced motion in a
line at right angles to the line of motion of the pistons.
The connection between the projecting arms on the piston rods and the extending
ends of the bars is made by means of adjustable collars or nuts or other suitable
arrangements so as to provide a certain amount of lost motion or slack between the
travel of the pistons and that of the bar or rod.
Dated the 26th October 190c
PHILIP FRANCIS ODDIE.
PHILIP FRANCIS ODDIE,
6. HESSE,
Improvements in Duplex, Pumping Engines.
We PHILIP FRANCIS ODDIE, and GUSTAV HESSE both of 125 and 130 Larkhall Lane,
Clapham, in the County of Surrey, Engineers, do hereby delare 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:-
.

page_text: This invention has reference to improvements in Duplex Pumping Engines-to
simplify their operation, add to their efficiency, and effect economy of steam.
In a former Specification of Letters Patent granted to both of us, No. 23044 of
December 2, 1895, we described a duplex pumping engine in which each piston is
formed with an inclined curved groove or guide adapted to effect the operation of the
valve controlling the supply of steam to the companion or duplicate cylinder and an
arrangement of expansion valves working on the back of or through, the main valves
operated by the same groove or guide forined on the pistons and controlling admission
of steam to its own cylinder.
In the present invention we make use of substantially the same arrangement and
action of inain and expansion valves but instead of forming the inclined curved groove
on the pistons, it is formed on or in, separate rods or bars which are located in the
valve chest.
One end of each of these bars is continued through suitable stuffing boxes and is in
connection with projecting arms rigidly fixed on each piston rod.
Each bar is free to reciprocate within the valve chest in a line parallel with the
motion of the pistons, any lateral movement being prevented by suitable guides
preferably fixed on the valve chest covers. The valves for the admission and emission
of steam are formed with inclined parts corresponding with and engaging in the
inclined portion on the bars.
When the pistons reciprocate within their respective cylinders each bar or rod
reciprocates also imparting to the main and expansion valves a reduced motion in a
line at right angles to the line of inotion of the pistons.
The connection between the projecting arms on the piston rods and the extending
ends of the bars is made by means of adjustable collars or nuts or other suitable
arrangement so as to provide a certain amount of lost motion or slack between the
travel of the pistons and that of the bar or rod. Or the extending ends of the bars
may be rigidly fixed to the projecting arms on the piston rods-in which case the
lost motion is provided for within the inclined parts themselves, by making them
somewhat smaller in diameter than the diameter of the corresponding inclined ways,
or inclines, on the bars in which they engage.

page_text: Figs. 19 and 20 show respectively by a plan view and a cross section a modification
whereby the lost motion is provided for by means contained within the inclined parts
themselves by making the inclined driving pieces i and which engage with the
corresponding inclined slots &, & in the sliding blocks d', d', referred to-somewhat
smaller in diameter than the diameter of said slots, thereby securing the desired
effect whilst avoiding the production of noise, or disagreeable effect.
The rod d is fixed to the arm c by means of a set screw or other suitable
arrangement so that the position of the rod can be easily adjusted and ready
means therefore provided of setting the valves in their corrrect position.
a is the steam piston and a' the piston rod. b is the valve chest with cover b. cis
an arm rigidly attached to the piston rod a and conveying reciprocating motion to
rod d, connected to a bar or block d, de d, see Figs. 1 and 6, are adjustable collars
on the rod d by regulating which the travel of the block can be varied. e is a main
steam valve, and fan expansion valve. g, g, are steam inlet passages communicating
with the ends of their respective cylinders, and h, h, are exhaust passages, see
Figs. 2 and 7.
Referring to Figs. 3, 4, 5, 11, 15 and 16, e, el, are the main steam valves,,, are
the expansion valves, and i, il are inclined driving pieces which engage with
corresponding inclined slots k, in the sliding blocks d', d see Figs. 6, 14 and 17.
Suitable guides Fig. 7, are formed in the valve chest cover to prevent lateral
movement of the bars d', d.
As shown in Fig. 1 lost motion is obtained to the desired extent by allowing the
fixed arin e on the piston rod al, to travel between the adjustable nuts d², d³, on the
sliding rod d.
In some cases it may be preferable to have the lost motion take place in the valve.
chest, as shown in Figs. 8, 9 and 12. In this arrangement the outer end of the rod d
is attached to the arm c by means of a screw thread d formed on the rod d the
inner end of the said rod being provided with a screw thread d' and nnt d', the pitch
of this thread being double that of d'. A hand wheel d may be provided at the
outer end of the rod d for convenience of turning the same to regulate the travel and
cut off of the valves. The guide piece i, see Figs. 11 and 18, has a stem which passes
through the expansion and main valves and serves to fix them together. I is a pump
cylinder and m the water piston.
As shown, two steam pumps are placed side by side, and the arrangement is such
that ench piston, while actuating the main slide valve for the other, has also control
over its own steam admission by means of a cut off valve, working on the back of the
main valve.
In addition to the economy secured by the absence of short strokes, and the
expansive working of the steam, this improved pump can be run smoothly and quietly
without shock or jar of the water column, at considerably greater speeds than those
hitherto attainable with the ordinary duplex pump. This advantage is due to the
action of the cut off valves, which cause the pistons to "slow down" towards and
pause at the end of the stroke. This allows the pump valves ample time to seat
themselves quietly before the return stroke.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what we
claim is
1. In a duplex pumping engine having two steam cylinders, each cylinder having
a main valve and to each main valve an expansion valve formed in one with such main
valve connecting each said expansion valve so as to cause them to control the
admission of the steam to the main valve of the opposite steam cylinder, substantially
as set forth.
2. In a duplex pumping engine, steam cylinders, main valves thereto
each main valve having in one with it an expansion valve in combination
with blocks provided with inclines and suitable connecting mechanism to move said
valves, substantially as set forth.

page_text: 3. In a duplex pumping engine, mounting the valve passages to each cylinder in a
line at right angles to the line of travel of the pistons in said cylinders, substantially
as and for the purpose set forth.
4. In a duplex pumping engine, pump mechanism, piston roda, pistons, cylinders
and valve passages and to each cylinder a main valve having mounted on it an
expansion valve provided with an inclined part in combination with blocks and
connecting mechanism actuated by the piston rods; each said block being provided
with an inclined part adapted to engage with and move the corresponding inclined
part formed on its corresponding expansion valve, substantially as set forth."
5. In a duplex pumping engine cylinder having its valve passage at right angles
to the line of travel of its piston, a inain valve mounted thereon, an expansion valve
formed in one with said main valve and with an inclined guide part on said expansion
valve in combination with a correspondingly provided block seated thereon and
actuated by a connection piece from an arm operated by one of the piston rods of the
engine and means for adjusting and regulating the extent of travel of the block and
consequently the travel of the valves and the amount of steam supplied to the engine,
substantially as set forth.
6. In a duplex pumping engine, a combined main valve and expansion valve of a
duplex pumping engine, an inclined part thereto, a block mounted on said valve and
having a correspondingly inclined part, engaging with the valve incline, means to
move said block, and an adjusting and regulating device to adjust the movement
relatively of the inclined parts to the extent of movement required to the valve, to
admit the amount of steam required to operate the engine, substantially as
described.
7. In a duplex pumping engine, a sliding inclined faced block actuated by
connections from the piston rod of the engine, and means to regulate the extent of
throw of said block in combination with a combined main valve and expansion
valve for each cylinder of a duplex pumping engine, substantially as set forth.
8. In a duplex pumping engine, a sliding block having an inclined face, a
correspondingly formed part of an expansion valve engaging with said block and
means to impart to said block, adjustably, and to a reduced extent the motion of the
piston rod of a duplex pumping engine, substantially as described.
9. In a duplex pumping engine the construction or arrangement and use of parts
for attaining the lost motion for effecting the operation of the valve controlling the
supply of stean, in the type of engine and after the manner set forth, by making the
driving pieces somewhat smaller in diameter than the diameter of inclined slots in
the sliding blocks those driving blocks engage, substantially as and for the purpose
set forth and illustrated with reference to Figs. 19 and 20.
Dated the 17th day of July 1907
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, Agents for the Applicants.