Improvements in or relating to Direct Acting Pumps.
Year: 1899

page_text: Date of Application, 4th Dec.,
1899
Complete Specification Left, 4th Sept., 1900-Accepted, 20th Oct., 190G
PROVISIONAL DORT
Improvements in or relating to Direct Acting Pumps.
communication from abroad by WILLIAM HENRY MARTIN, of Schelde Engine
Works, Flushing, in the Kingdom of Holland, Engineer.
I, ROBERT ALEXANDER SLOAN, of the Firm of Sloan & Lloyd Barnes, of 34,
Castle Street, Liverpool, in the County of Lancaster, Patent Agent, do hereby
leclare the nature of this invention to be as follows:-
-
This invention has reference to pumps of the type known as Duplex pumps,
the object being to render the working of such pumps more economical in steam
consumption, especially where high pressure steam is used.
In this invention, I arrange, say, two steam cylinders, one high pressure and
one low pressure, side by side, each cylinder actuating one pump in the usual
way. The slide valves of each cylinder are actuated through valve gear, by the
other cylinder.
Steam is first admitted to the high pressure cylinder, where after doing its
work it exhausts to the low pressure casing, and then performs duty in the
larger low pressure cylinder before finally exhausting in the ordinary way of
compound engines. To enable this arrangement to work effectively where steam
special type to prevent
of high pressure is used, the slide valves are made of a
leakage, as otherwise effective and economical working of these compound pumps
cannot be obtained.
Perfectly balanced steam admission valves, working in a loose bridle preventing
the access of steam pressure to the back of the valve, are used, and these are so
constructed that the advantage of the flat-slide steam tightness is combined with
the balanced action of a piston valve.
I also provide
an arrangement whereby triple expansion can be obtained
instead of compound, in pumps of this type. I effect this by placing two of the
cylinders tandem-wise so that one of the pump buckets is actuated by two
cylinders placed co-axially, and the other pump bucket by one cylinder.
The valve motion would be of the usual type, and the steam would do work
in the three cylinders consecutively.
Quadruple expansion can be similarly obtained by employing a fourth steam
cylinder.
or 1899.
SLOAN & LLOYD BARN 17,
Chartered Patent Agents, 34, Castle Street, Liverpool.

page_text: A communication from abroad by WILLIAM HENRY MARTIN, of Schelde Engine
Works, Flushing, in the Kingdom of Holland, Engineer.
I, ROBERT ALEXANDER SLOAN, of the Firm of Sloan & Lloyd Barnes, of 34,
Castle Street, Liverpool, in the County of Lancaster, Patent Agent, 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:
This invention has reference to pumps of the type known as Duplex pumps,
the object being to render the working of such pumps more economical in steam
consumption, especially where high pressure steam is used.
In this invention I arrange, say, two steam cylinders, one high pressure. and
one low pressure, side by side, each cylinder actuating one pump in the usual
way. The slide valves of each cylinder are actuated through valve gear, by the
other cylinder.
I have illustrated my invention in the accompanying drawings in which Fig. I
is an end elevation, partly in section; Fig. II a side elevation, and Fig. III a
plan, in section on the line X, X, of Fig. I.
The two pumps are of the usual construction, and are placed side by side
as shown in Fig. II, and each pump is operated by its own steam cylinder.
Referring first to the right hand pump of Fig. II, the steam cylinder for which
is shown in section in Fig. I-a is the pump casing, b the suction, c the
delivery, the pump rod, e the piston rod connecting the pump rod to the
steam piston working in the cylinder g. h is the valve casing, the valve
and a bridle which is pressed onto the port face by an abutment on the valve
casing door which presses on a spring on the bridle. The bridle j is held
against movement by the wing pieces which fit in the abutments m carried
from the casing walls. It will be seen that the bridle j relieves the valve i
from the steam pressure which would otherwise act on the back of the valve
and press it with considerable force on the port face. The valve spindle n of
the valve is.operated by a lever keyed to one end of the weigh shaft p, to the
other end of which is keyed a lever q to which motion is given by the operating
block fixed to the pump rod and piston rod or the other pump. A hand lever s
is provided by means of which the valves may be operated to start the pumps,
and a starting valve is also provided to allow the steam to pass from the high
pressure to the low pressure casing.
(Fig. II) is the steam inlet, (Fig III) is the intermediate casing, and y is
the exhaust.
The parts of the high pressure cylinder and the left hand pump operated
thereby are indicated by capital letters corresponding to the small letters used
in referring to the right hand pump and the low pressure cylinder.
The action of the apparatus is as follows:
Steam is admitted to the high pressure casing by the inlet and is distributed
by the valve I to the high pressure cylinder: the ports leading to the cylinder
are similar to those shown in the sectional view, Fig. I, that is to say there are
a pair of outer ports x, x, by which steam enters the cylinder from the casing
and a pair of inner ports z. z, by which the exhaust leaves the cylinder and passes
through the central exhaust passage to the intermediate chamber w (see Fig. III).
thence it passes to the low pressure casing where it is distributed by the valve i
to the low pressure cylinder. The object of the separate steam ports x, x, and

page_text: 5
exhaust ports, 2, is to give the necessary compression at the end or the su
which, with the arrangement of ports shown, will result in consequence of the
port being closed by the slide valve i and the port z by the piston f when the
latter is near the end of its stroke.
It will be seen that by the construction adopted I am enabled (a) to distribute
the steam to the two cylinders in succession (b) to provide for the cushioning
or compression at the end of the stroke which is necessary with compound
cylinders, and (c) to relieve the pressure on the valve face which would, with high
pressure steam. be very considerable with the ordinary construction.
I also provide an arrangement whereby triple expansion can be obtained
instead of compound, in pumps of this type. I effect this by placing two of the
cvlinder's tandemwise so that one of the pumn buckets is actuated by two cylinders
placed co-axially. and the other pump bucket by one cylinder.
The valve motion would be of the same type, and the steam would do work
in the three cylinders consecutively.
Quadruple expansion can be similarly obtained by employing a fourth steam
cylinder.
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. The improved duplex pump which consists of a pair of pumps operated
respectively by cylinders through which the steam expands in succession being
distributed by balanced valves operating and actuated substantially as described
and illustrated.
2. The improved duplex pump substantially as described and illustrated in
the drawings.
1000
SLOAN & LLOYD BARNES,
Chartered Patent Agents, 34, Castle Street, Liverpool.