Improvements in Engines Worked by Motive Fluid, such as Steam, suitable for Driving Pumps.
Year: 1899

page_text: Date of Application, 2nd May, 1899 - Accepted, 17th June, 1899
COMPLETE SPECIFICATION.
Improvements in Engines Worked by Motive Fluid, such as Steam,
suitable for Driving Pumps.
I, JOHN PERCY HALL, of Carville, Lawrie Park Road, Sydenham, in the County
of Kent, 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 of improvements in engines worked by motive fluid, such as
stean, suitable for driving pumps has reference more especially to improved
means whereby distribution of motive fluid to the working cylinders of such
engines is effected and controlled. In describing the invention I will assume
steam to be the motive fluid employed. For distributing it I provide a balanced
piston valve such as presently described that is itself actuated by steam regulated
by a supplementary valve (hereinafter called for distinction an impulse valve) to
which the required motion is imparted from the engine piston rod by suitable
means such as a lever and rods. The distributing valve is constructed with four
pistons or rings and works in a cylinder formed with the necessary ports and
adapted to receive at its ends the steam whereby the valve is moved,
the movement being controlled by means of a cataract device coul-
prising a piston connected to the valve and working in a cylinder
charged with air, oil, water or other fluid and having a communication
between its ends. Steam is admitted to the cylinder of the engine through the
space between the two inner pistons or rings of the valve and the exhaust steam
from the two ends of the cylinder passes through the spaces between the said
inner pistons or rings and the outermost pistons or rings, on the outer ends of
which steam regulated by the impulse valve acts.
In the case of a compound steam engine with two or more cylinders, each
cylinder is provided with a steam distributing valve and the impulse valve so
regulates the steam as to actuate one of these steam valves, the other steam valve
or valves having motion communicated to it or them from the first mentioned
valve by means of one or more levers and rods.
The steam which has served to actuate the steam distributing valve is caused by
the impulse valve to pass to and form part of the steam supply for the low pres-
sure or secondary cylinder.
The accompanying drawings illustrate a steam pump having high and low pres-
sure steam cylinders arranged tandemwise and provided with valves according to
this invention.
Fig 1 is an elevation of the steam pump;
Fig. 2 a vertical section on the line A, B, Fig. 1;
"
Fig. 3 is a part elevation of the engine with the valve case removed and show-
ing steam passages to cylinders;
Figs. 4 and 5 are plan views; in the latter figure the high pressure cylinder is
removed so that the disposition of the steam passages leading thereto may be
readily seen.

page_text: Figs. 6 and 7 are respectively a side elevation and an end elevation of the
casing of the main distributing valves; Fig. 8 is a section on the line C, D Fig. 7,
showing one main distributing valve in section, the other in elevation; and
Fig. 9 shows a section of the valve, casing on the line E,,F Fig. 6.
1 is the high pressure cylinder, 2 the low pressure cylinder and 3 the pump
cylinder; the said cylinders are respectively fitted with pistons 4, 5 and 6, fixed
to the common piston rod 7 as usual. Steam passes to and from the top of the
cylinder 1 through a passage and to and from the bottom of the said cylinder
through the passage 9; also to and from the top of the cylinder 2 through the
passage 10 and to and from the bottom of the said cylinder through the passage 11.
Valves 12 and 13 which are arranged side by side and preferably horizontally
in cylindrical valve casings 14 and 15, distribute steam to and from the cylinders 1
and 2 respectively.
The valve 12 is formed in one casting, or otherwise,, with four pistons or
rings 12ª, 12, 12° and 12d and the valve 13 is similarly formed with four. pistons
or rings 13, 13b, 13° and 13d. Steam enters the valve casing 14 between the
pistons 12 and 12° through the inlet 14" and passes therefrom to the cylinder 1
alternately through ports 14 and 14° which communicate with the passages 8
and 9 respectively. From the two ends of the cylinder 1 steam passes respectively
through the port 14b to the space between the pistons 12 and 12b and through
the port 14° to the space between the pistons 12 and 12d; from these spaces the
steam passes through ports 14, 14° and an inlet passage 15" to the valve casing. 15
between the pistons 13 and 13° and thence alternately to the opposite ends of the
cylinder 2 through ports 15b and 15° which communicate with the passages 10
and 11 respectively. The steam subsequently exhausts through these passages
and ports to the spaces between the pistons 13 and 13 and 13" and 13b alternately
and thence through ports 15d and 15° to the exhaust passage 16.
The valves 12 and 13 are actuated by means of steam. regulated by an impulse
valve 17, preferably of the piston valve form, working in a valve chest 17 fitted to
the outside of the valve casings 14 and 15; the piston valve 17 is hollow so that
steam can pass through it. Steam is led to the space between the piston valve
rings or pistons through the part 17" from the steam space between the pistons 12b
and 12 of the valve 12; the movement of the impulse valve places the port 17
in communication with the opposite ends of the valve casing 14 alternately
through the ports 17b and the passage 17° and through the port 17d and the pas-
sage 17° respectively, that end of the casing 14 which is cut off from the steam
supply being placed in communication with steam space of the valve 13
of the low pressure cylinder 2 through the valve chest 17* and the
port 18. The impulse valve 17 is worked by means of lever 19
pivoted to a bracket 20 and having one arm connected to the piston or pump
rod 7 by a link 21 and its other arm bifurcated and pivoted to રી sleeve
encircling the valve spindle 22 between a pair of tappets 22ª fixed thereto. The
valve spindle 23 of the valve 12 is connected to the valve spindle 24 of the
valve 13 by a lever 25 fulcrumed at 20 so that motion of the valve 12 in one
direction will impart a like extent of motion but in the opposite direction to the
valve 13 and the steam thus distributed to both steam cylinders in the manner
required to work the pump. In order that the valves 12 and 13 may travel to and
fro at the required speed of travel for the control of the action of the steam on
the pistons of the steam cylinders, that is to say, so as to ensure the requisite
admission," cut off," "release," and "compression" of the steam, a cataract
device is fitted either to the steam actuated valve 12, or to the valve 13, connected
thereto, as may be preferred. The device comprises a cylinder. 27, which, in
the example shown, is secured to the cover of the valve casing 14 and is fitted
with a piston 28 that is fixed to an extension of the valve spindle 23 so as to
move with the valve 12; the cylinder 27 is filled, or partly filled with air, oil,
water, or other fluid and its two ends are in communication through a passage 29,
the size of which is such that the time required to force the contents of the
66
:

page_text: cylinder from one. end to the other therethrough will be such that movement' of
the valves will be retarded by said device, which acts as a brake, to the required
extent.
Sometimes steam valves constructed and arranged as hereinbefore described may
Such an
be worked by means of an independent steam actuating cylinder.
arrangement is indicated diagrammatically in Fig. 10; 30 is the actuating
cylinder which is fitted with a piston 31 the rod 32 of which is connected to a
lever 33 acting on the steam valve or valves; and the slide or impulse valve 17 of
the actuating cylinder is worked from the piston rod of the pump by means of
lever and rods as in the arrangement shown. The valves are so arranged that at
the point at which it is intended that the steam supply to the steam cylinders of
the pump should be cut off, the piston rod of the pump works the slide or impulse
valve 17 of the actuating cylinder, the piston of which then moves the steam
valves by means of the lever 33, and cuts off the steam; the continued motion of
the valve admitting steam to the other side of the pistons for the return stroke.
In connection with this independent steam actuating cylinder, a cataract device
as previously described is provided the piston thereof being attached to an exten-
sion of the piston rod 32. In a compound tandem engine such as illustrated the
actuating cylinder 30 with its cataract cylinder 27 may be bolted to the low pres-
sure cylinder and the piston rod carried up and connected to an arm of the lever
which couples the steam valves.
Although the herein before described valves and gear have been designed chiefly
for compound or more expansive engine pumps and especially for the compound
tandem for illustrated, my invention is applicable to other forms of steam
engines, for instance, to steam pumps of the double cylinder or duplex form.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I wish it to be under-
stood that I do not claim broadly for distributing steam in engines suitable for
driving pumps the use of steam actuated piston valves the motion of which is con-
trolled by means of a valve operated by the motion of the piston rod but I declare
that what I claim is;-
1. An engine of the kind herein referred to, wherein distribution of motive fluid
is effected by means of a balanced piston valve constructed with four rings or
pistons and itself actuated by motive fluid under control of an impulse valve
worked from the engine piston rod the arrangement being such that motive fluid
passes to the cylinder between the two inner rings or pistons of the said distribut-
ing valve and exhausts from each end of the cylinder between one of the outer
rings or pistons and the inner one adjacent to it substantially as described.
2. A compound engine of the kind herein referred to, wherein distribution of
motive fluid to two cylinders is effected by two main distributing valves each con-
structed with four rings or pistons, as mentioned in the preceding claim, one of
said distributing valves being actuated by motive fluid under control of an impulse
valve worked from the engine piston and the second distributing valve being
operated by mechanical means from the first, substantially as described.
3. In a compound engine of the kind herein referred to, distributing the steam
to and from the respective cylinders by means of an arrangement of valves such
as indicated in Claim 2 the motive fluid for actuating the valves being permitted
by the impulse valve to act on the ends of the distributing valve of the high
pressure cylinder and, after having so acted, to pass to the motive fluid supply
of the low pressure cylinder, substantially as described.
4. In an engine of the kind herein referred to, so arranging a cataract device in
connection with a fluid worked distributing valve of the type indicated in such
manner as to determine the speed of travel of the distributing valve or valves sub-
stantially as described.
5. In an engine of the kind referred to, the hereinabove described and illustrated

page_text: combined arrangement of parts whereby the distribution of motive fluid to the
engine is effected, the speed of travel of the distributing valve or valves being
determined in the manner set forth.
Dated this 2nd day of May 1999.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.