An Improved Vertical Simple or Compound Balanced Duplex Pumping Engine.
Year: 1887

page_text: Date of Application, 2nd July, 1887.
Specification Accepted, 23rd Aug., 1887.
An Improved Vertical Simple or Compound Balanced Duplex
Pumping Engine.
I, EZRA EDWARD CLARK, of the City of Northampton in the county of Hampshire,
in the State of Massachusetts, one of the United States of America, Hydraulic and
Mechanical 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:-
My invention relates to improvements in Vertical Compound Balanced Duplex
Pumping-Engines, of which the following is a specification.
Pumping-engines have heretofore been made in which the steam is allowed to
expand into a second cylinder, and thereby form what is known as a "compound
engine," and in other instances the pump has been duplex, so that the valve of one
engine is moved by a connection to the piston-rod of the other engine.
In my present improvements I connect the pistons of the respective steam-cylinders
to the plungers of the pumps, so that the action is direct, and I make use of steam-
cylinders of different sizes, so as to expand the steam from the smaller cylinder into
the larger, and I place these cylinders and piston-rods vertically and connect them in
pairs, so that the weights of the plungers, pistons, and connections are balanced, and
two pairs of engines are arranged adjacent to each other, so that the valve of one
engine is moved by a connection to the other engine, and I construct the parts in such
a manner that they are very compact and simple, and the moving parts are arranged
so as to balance each other in their weight and lessen the resistance to the steam-
engine.
In the drawings, Fig. 1 is a vertical section through the pumping-cylinders and
steam-cylinders of one engine. Fig. 2 is an elevation, partly in section, at right
angles to Fig. 1. The bearings for some of the shafts are omitted in Figs. 1 and 2,
for greater clearness. Fig. 3 is a sectional plan at the line xx, and Fig. 4 is a
sectional plan below the line Y Y.
The pumping-cylinders A A' B B' are provided with the hollow plunger a a¹b b¹
and the inlet and discharge valves, and the suction and delivery pipes are of ordinary
character, and will vary according to the circumstances of use, and hence do not
require further description.

page_text: Upon the respective plungers are columns or rods C, connecting the plungers to
the respective cross-heads D D1 D2 D3, and these cross-heads receive the lower ends
of the piston-rods E E E E³, that pass up through the stuffing boxes or glands of
the respective steam-cylinders to the respective pistons.
The engines are arranged in pairs, the pumps A A' being driven by the engine
cylinders G G¹, and the pumps B B¹ by the engine-cylinders H H', and as these
pairs of engines and pumps are similarly made it is only necessary to describe in
detail one pair and the connections.
Between the pumping-cylinders and the steam-cylinders there are suitable
colums, K, and the intermediate frame, L, that supports the bearings of the equalizing
levers and the valve-gear.
Mis a walking-beam supported in suitable bearings upon the frame L, and at the
ends there are connecting-rods NO, that extend down into the hollow-plungers a a¹,
and they are jointed to said plungers by the pins 2, 2. The piston of the cylinder Gi
being larger and heavier than the piston of the cylinder G, the plunger a of the
pump A is to be weighted at A³ sufficiently to counterpoise the parts, not only of the
engines, but of the connections to the valves as hereinafter described.
The walking-beam M' and connecting-rods N'O' act in connection with the engine-
pistons H Hand plungers of the second engine, and pump in the same manner
as before described in connection with the first engine and pump. P P represent the
steam-supply pipes to the valve-chest QQ of the engine-cylinders G and H, and
R represents the valve to the cylinder H, the valve to the cylinder G being similar.
4 and 5 represent the valve-rods to the respective valves. These valves may be of
any suitable character; but I prefer and use piston valves, which act to admit steam
through the respective ports to the high-pressure cylinder, (G or H).
Upon reference to Fig. 3, it will be seen that the respective steam-cylinders occupy
quadrilateral positions, and that the steam-valves R are between the cylinders Hand G,
and that the low-pressure valve-chests S and S¹ are between the respective cylinders G
and G and H and H', and that the exhaust-pipe T is central between the respective
cylinders, and is connected laterally to the low-pressure valve-chests S S¹.
The valve between each pair of steam-cylinders is similar to that shown in Fig. 1.
I will, however, describe the same with reference to the cylinders G G¹. I prefer to
make use of piston-valves in the low-pressure valve-chests, and the valve U is provided
with a rod, C. The ports 7 and 8 are at the upper and lower portions of the transfer-
valve chest and connect directly the cylinders G G₁, and the intermediate ports, 9
and 10, are the exhaust ports.
Upon reference to Fig. 1, it will be understood that when the piston-valve U is
drawn down the port 7 is opened, so that high-pressure exhaust-steam rushes directly
into the cylinder G', and that when the valve U is raised the port 8 is open for a similar
object. In consequence of the respective piston and cross-heads being connected by
the walking-beam M, the piston on the rod E will be at the top of the cylinder G
when the piston on the rod E' is at the bottom of the cylinder G¹, and the reverse;
hence the pistons will always be moving in opposite directions, and the high-pressure
exhaust-stream from G will act directly against the piston in the cylinder G¹ when
nearest to the head, and as the steam passes out of the cylinder G it goes into and
expands within the larger cylinder, G.
In Fig. 1 the parts are represented as at rest, the cylinder G being full of high-
pressure steam beneath the piston, so that as soon as the low-pressure valve is raised
by the movement of the other pair of engines, H H', the steam will rush through the
port 8 and lift the piston in the cylinder G₁, and as the valve U is raised the port 9
is opened for the exhaust to pass out from the upper part of the cylinder G. Similar
movements take place when the strokes are in the other directions.
Upon reference to Fig. 4 the respective connection for the valve-rods will be
that
apparent. The crank-pins for the valve-rods 5 and 6 are upon crank-arms a³ a*,
stand in opposite directions from the rock-shaft 15, and this shaft 15 has an arin, 16,
and a connecting-rod, 17, to the walking-beam M', so that the valves of the engine G G
will receive their proper movements from the engine H H', and the valve-rods 4 and 12

page_text: of the respective valves of the engine H H' are connected to arms B2 B3, that extend
in opposite directions from the rock-shaft 20, and this shaft 20 has an arm, 21, and a
connecting-rod, 22, to the walking-beam M of the engine G G¹. The rock-shafts 15
and 20 are supported in suitable bearings on the frame L. By these arrangements
it will be understood that when the engine G G¹ is in motion the engine H H is
quiescent, but the engine G Gis moving the valves of the engine H H³, and said
valves admit steam to the engine H H before the engine G G¹ completes its strokes ;
hence the engine H H starts before the engine G G¹ stops. In like manner the
valves of the engine H H stop at the same time the engine G G¹ stops; but the
valves of the engine G G₁ commence to move at the same time that the engine H Hi
starts, and they are moved fully when the engine H H' stops. By this arrangement
the two compound engines work in harmony, the action of the steam is equalized in
the respective engines, the parts work vertically, and are balanced; hence there is
very little friction or wear. The valves also are balanced both in relation to the
weight of the parts and the pressure of the steam.
If the low-pressure steam-cylinders are dispensed with, the steam may be passed
from the cylinders G H to the atmosphere, or to a condenser, the walking-beams and
double pumps remaining the same, and being balanced.
The vapours in the cylinders G₁ H' are confined between the heads and the pistons
after the pistons pass over and cover the exhaust-ports; hence the pistons are
cushioned, and by the connections to the high-pressure cylinders the pistons of the
cylinders Hand G are simultaneously stopped, so that there is no concussion against
the cylinder-heads.
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 combination, with four vertical pumps, of two pairs of vertical compound
engines, direct connections between the pump-plungers and the engine piston-rods,
valves to the respective compound engines, and connections for moving the valve of
one engine by the piston of the other engine, substantially as set forth.
2. The two vertical compound engines, each having a high-pressure and an
expansion cylinder, in combination with the vertical piston-valves and their valve-
chests, the valve rods, and connections for moving the valves of one engine by tho
piston of the other engine, substantially as set forth.
3. Two vertical pumps and plungers, in combination with a pair of engine-
cylinders, valves, pistons, and rods, walking-beams, and connections at the respective
ends to the plungers, whereby the weights of the respective parts are balanced,
substantially as set forth.
4. Two pairs of vertical pumps and plungers or pistons, in combination with two
compound vertical engines, the piston-rods of which are connected to the pump-
plungers, connecting-rods and walking-beams to balance the respective engines and
pumps, and valves to the separate compound engines and connections from the
valves of one engine to the walking-beam of the other engine, substantially as
set forth.