Improvements in Direct-acting Duplex Engines.
Year: 1891

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by CHARLES CAMPBELL WORTHINGTON; of
Irvington, Westchester County, State of New York, United States of
America, Mechanical Engineer.]
Improvements in Direct-acting Duplex Engines.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of Middlesex, 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 relates to direct-acting duplex engines, and especially to that class
of engines known as the Worthington Duplex Pumping Engine, which are described
and shown in many prior British Letters Patent, of which special reference is made
to the Patents of C. C. Worthington 2342 of 1884, and H. E. Newton 15770 of
1885, 6368 of 1886, and 6545 of 1889 (communications from said C. C. Worthington),
the object of the invention being to increase the economy of such engines, while
preserving the duplex. arrangement, by providing a simple and compact arrange-
ment of triple expansion cylinders and receivers, which will permit of a uniform and
constant action on both sides of the engine.
To that end, the invention consists generally of a duplex engine having two high
pressure steam eylinders, arranged one on each side, and exhausting into a common
receiver,. from which an intermediate steam cylinder placed on one side is supplied,
the intermediate cylinder in turn exhausting into another receiver, from which a
low pressure steam cylinder placed at the other side of the engine is supplied.
The invention consists further in providing the induction pipes of the two high
pressure steam cylinders, of the construction constituting the general invention,
with separate throttles, by which the steam admitted to the high-pressure cylinders
may be adjusted so as to secure an equal and constant effort on both sides of the
engine; and in the arrangement of cut-off valves in the intermediate and low
pressure cylinders so as to prevent a sudden accession of pressure therein at the end
of the stroke, due to the exhaust of the cylinders on the other side of the engine
into their respective receivers.
As the invention rests chiefly in the general construction and arrangement of
the engine, a full understanding of the same can best be given by an illustration
and a somewhat detailed description of an engine embodying the invention; and
such description will now be given, reference being had to the accompanying
drawings, forming a part of this Specification, in which
Fig. 1 is a front elevation, partly in section, of a vertical duplex pumping engine
embodying these improvements.
Fig. 2 is a side elevation of the same."
Fig. 3 is an elevation of the steam end of the engine, taken on the side opposite
that of Fig. 2.
Fig. 4 is a front elevation of the steam end of the engine.
Fig. 5 is a plan view.
Fig: 6 is a diagram, shewing the arrangement of the cylinders and valves.
Fig. 7 is a central vertical section of the high pressure cylinders and tanks.
Fig. 8 is an elevation of the other tank.
Fig. 9 is a horizontal section taken on the line 9-9 of Figure 8.
Fig. 10 is a horizontal section taken on the line 10-10 of Figures 7 and 11,
shewing the construction and position of the lower tank.
Fig. 11 is a vertical section taken on the line 11-11 of Figure 10.
Referring to said drawings, it will be seen that the steam end of the engine

page_text: consists of two high pressure steam cylinders, A, B, an intermediate cylinder C,
and low-pressure steam cylinder D, these four cylinders being arranged in pairs,
the high pressure cylinder A and intermediate cylinder C forming one side of the
engine, and having the common piston rod E, and the other high pressure cylinder B
and low pressure cylinder D, forming the other side of the engine, and having the
common piston rod F. Between the cylinder A, B, is mounted a tank G, and
between the cylinders A, B, and the cylinders C, D, is the tank H, which tanks
form the receivers, and will be more particularly described hereafter.
The water end of the engine, or pump proper, consists of two water cylinders K, L,
having plungers which are connected directly with the piston rods E F, at the
opposite sides of the engine. These water cylinders are of the usual construction,
being provided with suction and force chambers, which communicate respectively
with the suction main M and force main N, as usual.
Between the water cylinders K L and the steam cylinders C, D, the piston
rods E, F are connected to cross heads 10, sliding in fixed guides 11, and acted
upon by the piston rods of two pairs of oscillating compensating cylinders 12,
having pistons which act in opposition to the main piston rods during the first part
of the stroke of the engine, and in conjunction therewith during the last part of the
stroke, the construction and arrangement of these cylinders being substantially the
same as those of the Patents above referred to. These cross heads 10 are provided
also with transverse arms 13, which are connected at their inner end to the crank
arms 14 on the shafts 15, these shafts being provided with crank arms 16, from
which rods 17 extend to the cranks of the induction and eduction or exhaust valves
of the engine, each piston rod, through this construction, operating the induction
and exhaust valves of the other side of the engine. The arms 13 are connected at
their outer ends by links to the crank arms 18 on shafts 19, which operate the cut-
off valves of the engine through rods 20, the cut-off valves for each side of the
engine being operated by the piston rod of its own side. The arrangement and
construction of these parts is that of the Patent 6545 of 1889 above referred to.
The engine is provided also with the usual balancing pistons 21 connected to the
respective piston rods E F, and working in the cylinders 22,-this construction being
common in this class of engines, and requiring no further description.
Returning to the steam end of the cylinder, a detailed description of the con-
struction in which the present invention is embodied will be given. The high
pressure cylinders A, B, receive their supply of steam from steam pipe 23, provided
with a throttle 24, and communicating with the cylinders A. B by means of
induction pipes 25, communicating with steam chests 26, 27, at the opposite ends of
the cylinders. The induction pipes 25 are each provided with a throttle 28, by
which the amount of steam entering the respective cylinders A. B may be inde-
pendently regulated, for a purpose which will be hereafter described. The
cylinders A B are provided with the usual exhaust pipes 29, communicating with
opposite ends of the cylinders, and exhaust into the tank G, placed between
the two cylinders A. B, as previously described, the exhausts for the cylinders A. B
entering the tank at opposite sides.
This tank G, as shewn in Figures 7, 8; and 9, is provided with a port at each
side, through which the exhaust pipes 29 communicate with the tank, and with a
series of re-heater tubes 30, through which steam is introduced by means of a feed
pipe 31, the steam after passing through the tubes escaping through a drain pipe 32.
The feed and drain ports are located in a chamber formed at the base of the tank,
this chamber communicating with the re-heater tubes, and being provided with a
central perforated partition 33, to secure the slow circulation of the re-heating
steam through the tank. The feed and drain pipes are controlled by cocks 34.
The tank G is also provided with a nozzle 35, communicating with the induction
pipe 36, by which steam is supplied from tank G to the intermediate cylinder C
through the steam chests 37 at opposite ends of the cylinder.
The cylinder C exhausts into the tank H through the exhaust pipe 38, com-
municating with opposite ends of the cylinder. This tank H, as shewn in Figures 7, 10,

page_text: and 11, is provided at opposite sides with ports communicating with the exhaust
pipe 38 of the intermediate cylinder C, and with the induction pipe 39 of the low
pressure cylinder D. The tank is provided also with a series of re-heater tubes 40,
and receives steam through the feed pipe 41, the steam after passing through the
tank escaping through the drain pipe 42, the chamber with which these pipes con-
nect being located at the base of the tank, and divided by a partition 43, and the
pipes being controlled by cocks 44, all as in tank G.
The tanks G H. may be arranged in any desired manner, but will preferably be
positioned as shewn, the tank H being placed above, and forming the heads of the
intermediate and low pressure cylinders C, D, and providing also a support for the
tank G, which is mounted directly above and upon it and between the high pressure
cylinders A. B, this construction affording a compact and convenient arrangement
of tanks, and one enabling the induction and exhaust pipes forming the means of
communication between the tanks and the cylinders to be placed so as to form a
direct and short connection, without interfering with other parts of the engine.
The induction pipe 39 from the tank H communicates with the low pressure
cylinder D through the steam chests 45 at the opposite ends of the cylinder. The
low pressure cylinder D exhausts through a pipe 46 communicating with a condenser
or the open air, according to the type of engine.
The valve apparatus may be of any suitable construction, but preferably is of
the form shewn, which however forms no part of the present invention, but is
substantially the same as that of Patent 6545 of 1889 above referred to. As the
construction and operation of these valves is the same as that of the Patent above
referred to, a brief, general description of these parts will suffice, and as the general
construction of the valves of all the cylinders is the same, the same reference letters
will be used for the different cylinders.
Referring now particularly to Figs. 6 and 7, each of the cylinders is provided at
its opposite ends with induction ports 1 and exhaust ports 2, the exhaust ports
being placed, as is usual, somewhat nearer the middle of the cylinder than the induc-
tion ports, in order to provide a cushion or dash for the piston. The induction
and exhaust ports are controlled by a pair of oscillating induction and exhaust
valves a. b, located in cavities 3 in the valve chest at the opposite ends of the
cylinders. These valve chests also contain cavities 4 outside the induction and
exhaust valves, which communicate with the induction pipes for the respective
cylinders by means of the ports 5, and with the cavities of the induction and exhaust
valves by one or more ports 6, which are controlled by one or more cut-off valves c d
at opposite ends of the cylinder. These cut-off valves c d oscillate in the
cavities 4, and preferably are of the gridiron form, as shewn, this form, together
with the plurality of ports, securing a quick cut-off, as described in the Patent
above referred. The induction and exhaust valves a bare provided with stems
and crank arms, and are operated by rods 17 connected to the respective piston
rods, as previously described, the induction and exhaust valves for each side of
the engine being operated by the piston rod for the opposite side, and the cut-off
valves are similarly connected to the operating rods 20, the cut-off valves at
each side of the engine being operated by the piston rod for its own side, all as in
Patent No. 6545 of 1889.
The function and operation of the valves of the high pressure cylinders A. B
differ in no respect from that of the Patent just referred to, and need but a brief
description.
As the piston E of the cylinder A completes its stroke away from the water
cylinders, the valves a b will be in such a position as to close the induction port at
one end of the cylinder, and open the exhaust port at the other end of the cylinder,
and at the same time, through the cross-heads 10 and the connections which
have been described, the movement of the induction and exhaust valves of the
cylinder B has been completed, so as to start the piston of that cylinder, and cause
it to make a stroke in the same direction. As the piston of the cylinder B, makes
its stroke, it will, through the piston rod F, cross head 10, and connections previously

page_text: described, oscillate valves ab of the cylinder A, and, as the piston rod arrives at
the middle of its stroke, the valves of the cylinder A will arrive in their mid position,
in which they close the induction and exhaust ports of the cylinder, and the continued
movement of the piston rod F will immediately commence to open the induction
port at one end of the cylinder A. and the exhaust port at the other end, and, as
the piston of cylinder B completes its stroke, the valves of cylinder A will arrive
in such a position as to completely open the induction port 1 in front of the piston
of cylinder A and the exhaust port 2 behind it. The piston of cylinder A will
then commence its stroke, and as it arrives at the middle or about the middle of the
stroke, it will, through the piston rod E and cross-head 10 and the connections
previously described, operate the cut-off valves c. d to close the port 6, and cut off
the further admission of live steam in front of the piston, and, at the same time,
open the port 6 at the opposite end of the cylinder, to prevent the admission of
live steam for the next stroke.
The main and cut-off valves of the intermediate and low pressure cylinders C, D,
are operated through the same connections as the valves of the high pressure
cylinders A B, and generally in the same manner as those of the low pressure
cylinders in the Patent above referred to. The cut-off valves, however, in the
engine embodying the present invention, perform an important function, differing
from that of the cut-off valves of the Patent above referred to. The cut-off valves
of the high pressure cylinders A. B in this engine, and of the low pressure cylinders
of the Patent, perform simply the function of cutting off the steam at or about
the middle of the stroke of the piston, in order that the steam may be used
expansively during the latter part of the stroke, this being a feature common in
high duty engines.
As the supply of steam is uniform, however, the continuous admission of steam
throughout the stroke, would not interfere with the steady and uniform action of
the engine.
In the present case, however, in which the high pressure cylinder B exhausts
into the tank G towards the end of the stroke of the piston of the intermediate
cylinder C, a sudden accession of pressure would be caused in the cylinder c,
thus producing a sudden increase in the force operating the piston, and disturbing
the equal and uniform action of the engine. In the same way, the exhaust of
the intermediate cylinder C into the tank H, towards the end of the stroke
of the piston of low pressure cylinder D, would produce a sudden accession
of pressure in the latter cylinder, and a disturbance in the action of the engine.
The cut-off valves cd, at opposite ends of the cylinders C. D, operate to
prevent this sudden accession of pressure, these valves being so timed in their
action, as shewn in Fig. 6, as to operate to cut off the supply of steam from the
respective tanks G. H. at the proper time to prevent the exhaust from the tanks G H
from affecting the steam supply of the respective cylinders CD. An equal and
uniform action of the engine at every point of the stroke is thus secured, each of
the cylinders CD being compelled to receive its entire supply of steam from its
tank, prior to the exhaust of the cylinder on the opposite side of the engine which
communicates with the tank.
It is necessary in this class of engines, that the two sides of the engine should
have a regular and uniform movement at all times, and that the total effective
power on the two sides of the engine should be equal and constant, any varia-
tion in the power on one side, relatively to that of the other side, causing a
disturbance in the action of the engine, and preventing the attainment of the greatest
economy in its operation.
It is apparent that, in the construction shewn and described, the admission of
the same amount of steam to each of the high pressure cylinders A B, may produce
an inequality in the action of the engine, due to the fact that the effective power in
cylinder D, in combination with that in cylinder B, will not, under certain condi-
tions, be equal to that of the combined effective power in the cylinders A and C.
This is especially the case in starting the engine, the steam from cylinders A, B

page_text: passing to cylinder C through the tank and exhaust pipe, so as to produce in
cylinder C a pressure prior to the accession to pressure in cylinder D. The
combined pressure upon the pistons in the cylinders A. C will therefore be in excess
of that upon the opposite side of the engine, the steam acting upon the
cylinder B with a pressure equal to that upon the piston of cylinder A; and it
will be some time before an equality of power will be established in the cylinders
on opposite sides, during which time the action of the engine is not uniform and
steady.
In the same way, in case of any change of water pressure, by which an excess or
deficiency of pressure in cylinder D is produced, the balance between the two sides
of the engine will be destroyed, and the action rendered uneven.
It is desirable, therefore, that some means should be furnished whereby the
effective power upon the opposite sides of the engine may be equalized at the
starting of the engine, and adjusted readily at all times. For this purpose, there
is provided the induction pipes 25, with throttles 28, by which the amount of steam
entering each of the cylinders A B may be readily adjusted, so that the effective
power upon the two sides of the engine shall be uniform, and any variation therein
quickly corrected.
The operation of these throttles will be readily understood. In starting the
engine, both throttles will be used, and more or less steam be admitted to the
respective cylinders A. B until a uniform action of the engine is secured, it being
apparent that an excess of steam will first be required in cylinder B to balance the
excess of power on the other side of the engine, due to the power exerted upon
the piston of cylinder C, and that this excess of steam will be gradually reduced
as the cylinder D receives its supply from tank H, until the supply of steam to
cylinder B is equal or nearly equal that of cylinder A. Similarly, in case of any
unevenness in the action of the engine after starting, due to any excess or deficiency
of pressure in cylinder D, the amount of steam admitted to cylinders A, B, may
readily be adjusted by the throttles, so as to compensate therefor.
The improvements have been illustrated in connection with a vertical high duty
engine. For a vertical low duty engine, the same general arrangements will
evidently pertain, the only difference being in the absence of the high duty
attachment, involving a change in the proportioning of the size of the steam
cylinders and tanks, and the omission of the cut-off valves upon the high pres-
sure cylinders, these valves being retained, however, on the intermediate & low
pressure cylinders, for the purpose previously described.
It is evident that the same general arrangement may be applied to a horizontal
high or low duty engine. In the latter case, the tanks may be arranged in any
desired position, but will preferably be constructed to form a portion of the
foundation upon which the intermediate and low pressure cylinders rest, thus
economising in space, and affording means for a convenient and short connection
between the tanks and the cylinders.
Having now particularly described and ascertained the nature of the said
invention, (as communicated to me from abroad) and in what manner the same is
to be performed, I declare that what I claim is :-
1. In a duplex engine, the combination with two high pressure cylinders, of an
intermediate and low pressure cylinder, each forming, with one of the high pressure
cylinders, a side of the engine, and two receivers, through one of which the
exhaust from both high pressure cylinders passes to the intermediate cylinder, and
through the other of which the exhaust from the intermediate cylinder passes to
the low pressure cylinder, substantially as described.
2. In a duplex engine, the combination with two high pressure cylinders, of an
intermediate and low pressure cylinder, each forming, with one of the high pressure
cylinders, a side of the engine, two receivers, through one of which the exhaust
from both high pressure cylinders passes to the intermediate cylinder, and through
the other of which the exhaust from the intermediate cylinder passes to the low

page_text: pressure cylinder, and cut-off valves controlling the supply from the receivers to
the intermediate and low pressure cylinders, substantially as described.
3. In a duplex engine, the combination with two high pressure cylinders, of an
intermediate and low pressure cylinder, each forming, with one of the high pressure
cylinders, a side of the engine; two receivers, through one of which the exhaust
from both high pressure cylinders passes to the intermediate cylinder, and through
the other of which the exhaust from the intermediate cylinder passes to the low
pressure cylinder, and cut-off valves operated late in the strokes of the intermediate
and low pressure cylinders, to prevent the sudden accession of pressure from the
exhaust of the cylinder on the opposite side of the engine, substantially as
described.
4. In a duplex engine, the combination with two high pressure cylinders, of an
intermediate and low pressure cylinder, each forming, with one of the high
pressure cylinders, a side of the engine; two receivers, through one of which the
exhaust from both high pressure cylinders passes to the intermediate cylinder, and
through the other of which the exhaust from the intermediate cylinder passes to
the low pressure cylinder, and valves for controlling the amount of steam admitted
to each of the high pressure cylinders, substantially as described.
5. In a duplex engine, the combination with the high pressure cylinders, at
opposite sides of the engine, of a receiver through which the exhaust passes to a
cylinder on one side of the engine only, substantially as described.
6. In a duplex engine, the combination with the high pressure cylinders, at
opposite sides of the engine, of a receiver placed between the cylinders, through
which the exhaust from both cylinders passes to a cylinder on one side of the
engine only, substantially as described.
7. In a duplex engine having two cylinders at each side, the combination with
the cylinders of two receivers, through one of which the exhaust from one cylinder
on each side passes to a third cylinder on one side, and through the other of which
the exhaust from the third cylinder passes to the fourth cylinder on the opposite
side, substantially as described.
8. In a vertical duplex engine, the combination with two cylinders at each side
of the engine, of two receivers, through which the exhaust passes, the lower
receiver. being placed above, and forming the head of the lower pair of cylinders,
and the upper receiver being supported upon the lower receiver, and between the
upper pair of cylinders, substantially as described.
Dated this 13th day of January 1891.
NEWTON & SON,
Agents for, the Applicant.