Improvements in Direct-acting Pumping Engines.
Year: 1894

page_text: Date of Application, 14th Dec., 1894
Complete Specification Left, 23rd Aug., 1895-Accepted, 7th Dec., 1895
PROVISIONAL SPECIFICATION.
Improvements in Direct-acting Pumping Engines.
I, JAMES PATTERSON of West Lodge, Walker, in the County of Northumber-
land, Engineer, do hereby declare the nature of this invention to be as follows:-
This invention hus reference to an improved arrangement according to which the
admission and exhaust of motive fluid (hereinafter referred to as steam) to and
from the respective ends of the motor cylinder of a pumping engine of the kind
commonly known as a direct acting pump in which the piston of the motor cylinder
is coupled by a piston rod direct to the piston of the pump cylinder, is effected by
a distributing valve operated by the piston of an auxiliary motor cylinder con-
trolled by an independent distributing valve and by a cataract device, and the
motion of the main valve required for cutting off the admission of steam to the
main cylinder and cushioning the exhaust is obtained from the pump rod. My
arrangement is such that when the pump has been started and before the main
distributing valve has been sufficiently operated by the pump rod to cut off steam
from the main steam cylinder, the auxiliary valve will be caused to admit steam to
one end of the auxiliary cylinder and exhaust steam from the other end but the
auxiliary piston will be prevented by the cataract device from again moving the
main distributing device until the pump piston has reached the end of its stroke.
The cataract device comprises a cylinder fitted with a piston connected by a rod
to the auxiliary piston and having its ends in communication with the respective
ends of the pump cylinder. The connections between the cataract cylinder and
the pump cylinder are so made that when the auxiliary distributing valve opens
the steam port on one side of the auxiliary piston, then the opposite side of the
cataract piston is in communication with the pressure side, for the time being, of
the pump cylinder, so that the pressure on the cataract piston will prevent the
auxiliary piston from moving, thereby enabling the auxiliary valve to be designed
with a very considerable lead without liability of reversing the motion of the
pump piston before it reaches the end of its stroke. When the end of the stroke
is reached the pump stops and the pressure is removed from the cataract cylinder
whereupon the auxiliary piston moves and reverses the motion of the main
distributing valve and pump.
An arrangement of valves and valve gear according to this invention is as
follows:-
The main and auxiliary distributing valves are arranged to work in the same
steam chest of the motor cylinder which I will assume is arranged above the pump
cylinder. The auxiliary valve is of the ordinary D type admitting steam over the
ends and exhausting in the centre. It is operated by a spindle and in turn operates
the main valve but there is a space left between the two valves in the direction of
their motion so that the valve spindle can move the auxiliary valve to a limited
extent, at each reversal of the direction of motion, before moving the main valve.
The main valve is constructed of a well known type so that when moved upward it
will admit steam to the top steam port of the main motor cylinder and open the
exhaust from the bottom steam port, and vice versa.
1.
The valve spindle is operated by a link from a lever one end of which is attached
by suitable, means to the main piston rod and the other end to the auxiliary -piston

page_text: rod. This latter rod is attached at its upper end to the auxiliary piston and at its
lower end to the cataract piston.
The upper and lower ends of the cataract cylinder are connected to the upper
and lower ends respectively of the pump cylinder by pipes which may be provided
with regulating cocks or valves and the ports into the cataract cylinder may be so
arranged as to cushion the cataract piston at each end of its stroke.
The operation of this arrangement is as follows:-
Assuming the auxiliary piston to be moved to the upper end of its stroke, the
main valve will admit steam to the upper side of the main piston and open the
exhaust to the under side (thereby causing the main piston to move downwards)
until the main valve is brought to its central position when it will stop. Owing to
the lost motion between the main and auxiliary valves, before the main valve has
arrived at its central position, the auxiliary valve will have crossed its central
position so as to place the top end of the auxiliary cylinder in communication with
the steam chest and the lower end in communication with the exhaust thereby
tending to make the auxiliary piston move downwards, but as the pump piston is at
the time moving downwards, the water below the same is under pressure which is
communicated to the lower side of the cataract piston with sufficient force to
counteract the tendency of the auxiliary piston to move downward. When the
pump piston reaches the lower end of its stroke the pressure in the cataract
cylinder ceases and the auxiliary piston is allowed to move downward which it
immediately does so as to place the lower end of the main cylinder in communi-
cation with the steam chest and the upper end in communication with the exhaust.
The upward stroke of the pump is exactly similar to that just described for the
downward stroke.
Instead of placing the main and auxiliary valves in the same steam chest, they
may be placed in separate steam chests and the steam to each may be independently
regulated. The valve spindle may receive its motion from any part of the afore-
said lever and not necessarily from a point between the pump rod end and the point
of attachment to the auxiliary piston rod. For instance the point of attachment of
the lever to the auxiliary piston rod may be between the pump rod end of the lever
and the poiut of attachment of the lever to the link connected to the valve spindle.
In this case the main and auxiliary valve must be so constructed as to be of the
opposite nature to those hereinbefore described that is to say, the main valve must
admit steam over the ends as in the ordinary type, and the auxiliary valve
must be similar to the main valve used in the herein previously described
arrangement.
The main distributing valve may be made in two parts one of which receives a
motion identical with that of the auxiliary valve and may be formed in one piece
therewith, the other part receiving a motion which corresponds with the motion
given to the main distributing valve in those arrangements in which the main and
auxiliary valves are independent.
In one arrangement of this kind the two valves are arranged as first herein
described, the two parts of the main valve being preferably of different sizes. In
this case the form and motion of the smaller part is identical with that of the main
valve bereinbefore described, but there is no lost motion between the auxiliary
valve and the larger part of the main valve which is formed with sufficient lap on
the steam and exhaust edges to cover the ports in its valve face when the smaller
part is in its central position. As the auxiliary valve and larger part of the main
valve have the same motion they may be cast together and work on the same valve
face with appropriate ports leading to their respective cylinders.
By the use of two steam cylinders the pump may be arranged as a compound.
one. To, effect this the cylinders may be placed in line, tandem fashion. The
smaller or high pressure cylinder is provided with valves and valve gear as herein-
before described for the single cylinder arrangement, and exhausts into the steam
chest of the larger or low pressure cylinder. The valve for this latter cylinder: is

page_text: driven by the same valve spindle as that used to drive the valves of the high
pressure cylinder, and is designed in a similar way but is preferably made without
lap, in which case there will be the same lost motion between the valve spindle and
the valve as there is in the similar case in the high pressure cylinder.
Dated this 14th day of December 1894.
Improvements in Direct-acting Pumping Engines.
I, JAMES PATTERSON, of West Lodge, Walker, in the County of
Northumberland, 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 :-
.
This invention has reference to an improved arrangement for controlling the
admission and exhaust of motive fluid to and from the respective ends of the motor
cylinder of a pumping engine of the kind commonly known as a direct acting
pump-in which the piston of the motor cylinder is coupled by a piston rod direct
to the piston of the pump cylinder-and the admission and exhaust of the motive
fluid (hereinafter referred to as steam) is effected by a distributing valve operated
by the piston of an auxiliary motor cylinder controlled by an independent
distributing valve and by a cataract device, and the motion of the main valve
required for cutting off the admission of steam to the main cylinder and cushioning
the exhaust is obtained from the pump rod. My arrangement is such that when
the pump has been started, and before the main distributing valve has been
sufficiently operated by the pump rod to cut off steam from the main steam cylinder,
the auxiliary valve will be caused to admit steam to one end of the auxiliary
cylinder and exhaust steam from the other end, but the auxiliary piston will be
prevented by the cataract device from again moving the main distributing valve
until the pump piston has reached the end of its stroke. The cataract device
comprises a cylinder fitted with a piston (or its equivalent such as a pair of
plungers or a diaphragm) connected by a rod to the auxiliary pistou and having
its ends in cominunication with the respective ends of the pump cylinder. The
connections between the cataract cylinder and the pump cylinder are so made that
when the auxiliary distributing valve opens the steam port on one side of the
auxiliary piston, then the opposite side of the cataract piston is in communication
with the pressure end, for the time being, of the pump cylinder, so that the pressure
on the cataract piston will prevent the auxiliary piston from moving, thereby
enabling the auxiliary valve to be designed with a very considerable lead without
liability of reversing the motion of the pump piston before it reaches the end of
its stroke. When the end of the stroke is reached, the pump stops and the
pressure is removed from the cataract cylinder, whereupon the auxiliary piston
moves and operates the main distributing valve and reverses the pump.
Figs. 1 and 2 of the accompanying drawings are respectively an end elevation
and a central vertical section, partly in elevation, of one example of pumping
engine according to this invention.
1 is the pump cylinder, 2 the main steam or motor cylinder, 3 the auxiliary
steam cylinder, and 4 the cataract cylinder, 1, 2, 3, and 4 being the pistons of
these cylinders respectively. The main and auxiliary distributing valves 5 and 6
are both arranged to work in the steam chest 7 of the motor cylinder 2, which is
shown arranged above the pump cylinder 1. The auxiliary valve 6 is of the

page_text: ordinary D type, admitting steam over the ends and exhausting in the centre. It
is operated by a spindle 8 and in turn operates the main valve 5, but there is a
space left between the two valves in the direction of their motion so that the valve
spindle 8 can move the auxiliary valve 6 to a limited extent, at each reversal of
the direction of motion, before moving the main valve 5. The main valve and its
seat are, as shown, constructed of a well known type so that when the valve is
moved upward, steam will be admitted to the top steam port 9 of the main motor
cylinder and the exhaust port 10 put into communication with the bottom steam
port 11, and that when it is moved downward, steam will be admitted to the bottom
steam port 11 and the exhaust port 10 put into communication with the top steam
port 9. The valve spindle 8 is operated by a link 12 from a lever 13, one end of
which is attached by suitable means, for example by an adjustable collar 14,
link 15, and bracket 16, to the main piston rod 17, whilst its other end is pivotally
connected at 13 to the auxiliary piston rod 18, as for example through-a
bracket 13. The latter rod is attached at its upper end to the auxiliary piston 3*
and at its lower end to the cataract piston 4*.
=
The upper and lower ends of the cataract cylinder 4 are connected to the upper
and lower ends respectively of the pump cylinder 1 by pipes 19 and 20 which may
be provided with regulating cocks or valves 21. The ports 22 into the cataract
cylinder 4 may, as shown, be so arranged as to cushion the cataract piston 4ª at
each end of its stroke.
The operation of this arrangement is as follows:-Assuming the parts to be in
the positions shown in Fig. 2, the main piston 2 is stationary and steam is being
admitted to the underside of the piston 3* through the port 23, the upper port 24
being in communication with the exhaust port 25. The auxiliary piston 3* is just
starting on its upward stroke and during that stroke it will raise the main valve 5
and thereby cause it to admit steam to the upper side of the main piston 2* and
put the exhaust port 10 into communication with the lower steam port 11, thereby
causing the main piston to move downwards until it reaches the bottom of its
stroke and thereby, through its rod 17 and connections, brings the main valve 5 to
its central position. Owing to the lost motion between the main and auxiliary
valves 5 and 6 respectively, before the main valve has arrived at its central
position, the auxiliary valve will have crossed its central position so as to place the
top end of the auxiliary cylinder 3 in communication with the steam chest 7
through the port 24 and the lower end in communication with the exhaust port 25,
thereby tending to make the auxiliary piston 3* move downwards, but as the pump
piston 1 is at this time moving downwards, the water or other fluid below the
same is under pressure, which is communicated to the lower side of the cataract
piston 4 with sufficient force to counteract the tendency of the auxiliary piston 3*
to move downward. When the pump piston 1ª reaches the lower end of its stroke,
the pressure in the cataract cylinder 4 ceases and the auxiliary piston 3* is allowed
to more downward, which it immediately does, pulling down the valves 6 and 5
through the rod 18, link 12 and rod 8, and so placing the lower end of the main
cylinder 2 in communication with the steam chest 7 through the port 11, and the
upper end in communication with the exhaust port 10 through the port 9. The
operation of the engine corresponding to upward stroke of the pump is exactly
similar to that just described for the downward stroke. Although the ordinary
by-pass with throttling device might be added to the apparatus so as if desired to
connect together the two ends of the cataract cylinder 4. I have found in practice
that with ordinary good workmanship there is yet sufficient leakage to allow the
cataract piston 4 at the proper time to commence its descent or ascent as the case
may be without the use of a by-pass.
The pumping engine shown in Figs. 1 and 2 may be variously modified without
departing from the essence of this invention. For example, instead of placing the
main and auxiliary valyes 5 and 6 in the same steam chest 7, they may be placed
in separate steam chests 77 as shown in Fig. 24 and the steam to each may be

page_text: independently regulated. Also the pistons 3 and 4ª instead of being directly
connected with each other by a rod 18, may be otherwise connected with
each other so long as the movement of the former is controlled by the latter.
Furthermore, the valve spindle 8 may receive its motion from any part of the
lever 13 and not necessarily from a point between the pump rod end and
the point of attachment to the auxiliary piston rod; for instance, the point of
attachment 13 of the lever to the auxiliary piston rod 18, may be located between
the pump rod end of the lever 13 and the point of attachment of this lever to the
link 12 connected to the valve spindle with the engine in other respects constructed
as shown in Figs. 1 and 2. In this case, the main and auxiliary valves must be
so constructed as to be of the opposite nature to those herein before described-that
is to say, the main valve 5 must admit steam over the ends, as in the ordinary
type, and as hereinafter described, and the auxiliary valve 6 must be similar to
the main valve 5 used in the herein previously described arrangement.
The main distributing valve may be made in two parts one of which
receives a motion identical with that of the auxiliary valve 6 and may be formed
in one piece therewith, the other part receiving a motion which corresponds with
the motion given to the main distributing valve in those arrangements in which
the main and auxiliary valves are independent.
Figs. 3 to 10 inclusive iliustrate an engine with an arrangement of valves of
this kind;
Fig. 3 being an end elevation, partly in section, of the engine with the cover of
the steam chest and the valves removed, and
Fig. 4 a vertical central section of the engine;
Fig. 5 a face-view, Fig. 6 a horizontal section, and Fig. 7 a front elevation of
the combined valves ;
Fig. 8 a vertical section of the part hereinafter called 5 of the main valve, and
Figs. 9 and 10 vertical sections taken along the lines x x and y y respectively
of Fig. 7.
In these figures parts corresponding to the marked parts in Figs. 1 and 2 are
marked with corresponding reference characters.
The two parts 5 and 5 of the main valve are preferably, as shown, of different
sizes. The larger part 5* is made in one piece with the auxiliary valve 6, and the
two parts of the main valve and the valve 6 work in the same steam chest 7 and
on the same valve face. The auxiliary valve and the two parts of the main valve
are of the ordinary D type, admitting steam over the ends and exhausting in the
centre. The valves 5 and 6 are operated by the spindle 8 without lost motion
and in turn operate the part 5b; but there is a space 5* (Fig. 7) left between the
parts 5 and 5 in the direction of their motion, so that, at each reversal of the
direction of motion, the spindle gives a certain amount of movement to the part 5*
before the latter begins to move the part 5-in other words there is a certain
amount of lost motion between the part 5 and the part 5. The part 5* is formed
with lap on both the steam and exhaust edges the lap on the steam edges being
such that the part 5* does not give admission to steam before the part 5, and the
lap on the exhaust edges being similarly arranged (see Fig. 5). The valve 6
and the part 5 have no lap on either steam or exhaust edges. The pivot 13" by
which the lever 13 is connected to the auxiliary piston rod 18 is in this case
between the points of connection of the lever with the link 12 and the pump
rod 17. In the example shown, the lever 13 is connected to the bracket 16 of the
rod 17 by a pin 16ª which is capable of rotating in the bracket 16 and in which
the lever 13 is adapted to slide freely in an endways direction. The upper end of
the cataract cylinder 4 is connected by a pipe 19 with the lower end of the pump
cylinder 1, and the lower end of the cataract cylinder is connected by a pipe 20*
with the upper end of the pump cylinder. The valve face on which the
valves 5, 5 and 6 work, is provided, in addition to the ports 9, 10, 11, 23 and 24,
with ports 9, 10, and 11 which communicate internally with the ports 9, 10,
and 11 respectively; the bottom and top auxiliary ports. 23 and 24 in this case

page_text: communicate with the corresponding ends of the auxiliary cylinder 3 through
pipes 23 and 24 respectively. As the central exhaust cavities of the valve 6
and the part 5 communicate with each other the exhaust port 10 serves both for
the part 5 and for the valve 6.
The operation of the engine in this case, is as follows:
Let it be assumed that the main piston 2 is at the upper end of its stroke and
the auxiliary piston 3ª at the lower end of its stroke. The two parts 5 and 5b of
the main valve are, then admitting steam to the upper end of the cylinder 2
through the ports 9 and 9* and forming communication between the lower end
thereof and the exhaust ports 10 and 10 through the ports 11 and 11*; so that
the piston 2 is forced downwards to the lower end of its stroke and thereby
caused to move the main and auxiliary valves upward until the part 5b reaches its
central position. Owing to the lost motion between the valve 6 and the
part 5b, it is evident that before the part 5b has arrived at its central position,
the valve 6 must have crossed its central position and admitted steam to
the bottom of the auxiliary piston 3 through the port 23 and the pipe 23*
and put the exhaust port 10 into communication with the top thereof
through the port 24 and pipe 24" so tending to make the piston 3* move upward;
but, as the pump piston 1 was at the time moving downward, the water or other
fluid being pumped would be under pressure at its lower end, and this pressure
would be communicated through the pipe 19 to the upper end of the cataract
cylinder 4 and press on the upper side of the piston 4 with sufficient force to
counteract the tendency of the piston 3* to move upwards. When the pump
piston 1 stops with the part 5 in its middle position, the pressure in the cataract
cylinder 4 is removed and the piston 3ª thereby allowed to move upwards, which
it does, and in doing so carries with it both the main valve and the auxiliary
valve and thereby puts the upper end of the cylinder 2 into communication with
the exhaust ports 10 and 10 through the ports 9 and 9 and admit steam to the
lower end of the cylinder 2 through the ports 11 and 11ª. The upward stroke
of the piston 2 then commences: the operation of the engine corresponding
thereto is exactly similar to that just described with reference to the downward
:stroke.
By the use of two steam cylinders, the pump may be arranged as a compound
-one. To effect this the cylinders may be placed in line, tandem fashion as shown
in Figs. 11 and 12 which are similar views to Figs. 3 and 4 respectively. The
smaller or high pressure cylinder 2 is furnished with an auxiliary cylinder 3, it
and the auxiliary cylinder being provided with valves and valve gear as berein-
before described for a single cylinder engine, and it exhausts through the pipe 4*
into the steam chest of the larger or low pressure cylinder 2ª. The valve 5* for
this latter cylinder is driven by the same valve spindle 8 as that used to drive the
valves corresponding to the high pressure cylinder 2, and is designed in a similar
way, but is preferably made without lap, in which case there will be the same
lost motion, as shown, between the valve spindle and the valve, as there is
between the valve spindle and the loose valve or part valve of the high pressure
cylinder.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that I do not
claim broadly the controlling by a cataract of the auxiliary motor that operates
the distributing valve of the pump motor, but what I claim is :-
1. In a direct-acting pumping engine in which the admission and exhaust of
Tmotive fluid to and from the motor cylinder is effected by a vulve operated by an
alixiliary motor controlled by a cataract device connecting the ends of the cataract
cylinder to the ends of the pump cylinder, substantially as herein before described
for the purpose specified.
2. The construction and arrangement as hereinabove described with reference
respectively to and shown in Figs. 1 and 2. in Fig. 2ª in Figs. 3 to 10

page_text: inclusive; and in Figs. 11 and 12 of the drawings annexed of direct acting
pumping engines in which the cataract cylinder is connected with the pump.
cylinder as set forth.
Dend this g2nd der of A vos 1805
JAMES PATTERSON.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.