CERTAIN IMPROVEMENTS IN STEAM ENGINES, WHICH MAY IN WHOLE OR IN PART BE APPLICABLE TO PUMPS AND OTHER MACHINES NOT WORKED BY STEAM POWER
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
URWIN, of Ashford, in the County of Kent, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Eleventh day of
January, One thousand eight hundred and forty-nine, in the twelfth year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
mc, the said Robert Urwin, my exors, adñiors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Robert
Urwin, my exors, adñiors, and assigns, or such others as I, the said
Robert Urwin, my exors, adññors, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, ny
Invention of "CERTAIN IMPROVEMENTS IN STEAM ENGINES, WHICH MAY IN WHOLE
OR IN PART BE APPLICABLE TO PUMPS AND OTHER MACHINES NOT WORKED BY STEAM
POWER;" in which said Letters Patent is contained a proviso that I, the said
Robert Urwin, shall cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, to be inrolled in Her said Majesty's High
Court of Chancery within six calendar months next and immediately after
the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Robert Urwin, hereby declare that the nature of my said Invention, and
in what manner the same is to be performed, are fully described and ascer-
tained in and by the present Specification thereof, reference being had to the
Drawings hereunto annexed (that is to say):-
:-
Firstly, whereas in the ordinary condensing or low-pressure steam engine the
motion of the piston is produced either by steam of low pressure (say from
five to ten lbs. per square inch), or by means of the pressure of the atmosphere
alone, acting on one side of the piston against a vacuum of more or less
completeness produced on the other by the condensation of steam, and several
attempts have been made to encrease the efficiency of such engines by
encreasing the pressure of the steam (say to fifteen lbs. and upwards), but
without the proportional advantage anticipated; and whereas in the ordinary
non-condensing or high-pressure engine the motion of the piston is produced
solely by the pressure of steam (that is to say, by an inflow of steam of high
pressure on one side of the piston acting against an outflow of used steam of
less and constantly diminishing pressure on the other side, in which case the
force exerted on the inflow side is of necessity proportional to the velocity and
completeness with which the clearance of the steam from the other or exhaust
side is effected; and whereas both sorts of engine fall short of developing
the full motive force due to the quantities of steam consumed by them
respectively, owing to the slowness or imperfection of the methods employed to
get rid of the air or steam on the exhaust sides of the piston.
Now, the first of my improvements in steam engines consists of a method or
system of effecting the clearance or exhaustion, whereby I am enabled to
combine in one engine the advantages peculiar to both the condensing and
non-condensing or low-pressure and high-pressure engines, and to obtain from
given quantities of steam, within given times, a greater amount of work or
duty than I believe has been ever before obtained from like quantities in
the like times, and this without the aid of the ordinary air pump. Figures 1
to 10, both inclusive, shew the manner in which this improved mode of
clearance or exhaustion is applied to an engine suitable for locomotive
purposes. Figure 1 is a vertical section of the cylinder and piston and their
immediate appendages, taken on the lines a, b, c, of Figure 2, which is a cross
section on the line d, c. Figures 8, 4, 5, 6, 7, and 8, are plans of the piston
on the lines respectively marked f, g, h, i, k, l, m, n, o, p, and 7, r. Figure 9
is a sectional elevation of a locomotive carriage, with a pair of such engines
fitted to it; and Figure 10, a plan on the line s, t, of Figure 9. A is the
cylinder, which is longer in proportion to the stroke than usual, and instead

page_text: of being entire in the sides from top to bottom, as usual, is made with an
opening B at the middle all round, with the exception of four connecting
pieces or ribs v, v (sec Figure 2). C is the piston, the constructive
details of which are clearly shewn in the sectional plans of it given in
Figures 3, 4, 5, 6, 7, and 8. It is made of such a depth in proportion
to the length of the cylinder, that when the piston has reached the end of
its stroke in either direction the top or under part of it (as the case may be)
shall just have passed clear of the middle opening B, so as to allow the steam
which was previously behind the piston to escape through that opening. To
enable the steam to pass off all at once and in one mass (as it were), and
without the least delay or obstruction, the piston is rounded off at the top and
bottom edges, as shewn, so that the instant the part of the piston which is
square or flush with the sides of the cylinder passes the top or bottom edge of
the opening B (as the case inay be) the entire opening is thrown open to the
steam. D is a jacket or casing which surrounds the middle opening B of the
cylinder and terminates in a valve box E at one side, which is kept closed
against the atmosphere by a spring stalk valve E, but yields readily to any
pressure exceeding the weight of the valve. From this jacket or casing the
steam which rushes into it through the opening B may be either allowed to
pass into the open air or conducted into the chimney of the locomotive to act
as a blast. F, F, are two ports, one at the top and the other at the bottom
of the cylinder, which serve alternately as inflow and outflow passages for the
steam to and from the cylinder, in the same way as in ordinary engines. Gis
the exhaust passage, which leads to a small condenser H (shewn in Figure 10).
K is a slide valve box, which differs in no respect in its details from ordinary
slide valve boxes. The operation of the engine is as follows:-Let us suppose
the parts to be in the position represented in Figure 1, that is to say, the
piston at the bottom of the cylinder, the communication just about to open
between the upper part of the cylinder A and the exhaust passage G, and
the atmosphere shut out by the stalk valve E. Steam of a high pressure,
say fifty or sixty lbs. per square inch, is then admitted beneath the piston
through the port F, which drives up the piston against such vacuum as
there may be on the other side to the upper end of the cylinder. As the
under side of the piston passes clear of the middle opening B, the steam
which was beneath it rushes out into the jacket or casing D, forces up the
stalk valve E, and escapes into the atmosphere, or is conducted to the chimney,
as the case may be, whereby the under part of the cylinder is almost entirely
cleared of steam preparatory to the return stroke; steam of the same high

page_text: pressure as before is then admitted by the port F¹above the piston (now at the
top of the cylinder), and simultaneously therewith a communication is opened
between the under part of the cylinder and the exhaust passage G, so that any
small portion of steam which may have been left in the under part of the
cylinder may be drawn off to the condenser II, and there condensed, and the
vacuum rendered as perfect as it practically may be. And so the reciprocating
action of the piston is kept up as long as steam is supplied to the cylinder, the
clearance of the cylinder from steam on the exhaust side of the piston at each
stroke being effected with a celerity and completeness never, to the best of my
knowledge, heretofore accomplished. The proportions which the areas of the
steam ports F and F, and the middle opening B, should bear to those of the
cylinder or piston, will vary with the speed at which it is desired to work the
piston. I find in practice that the following proportions answer well for high
velocities, namely, to allow, for every twenty circular inches in the piston, onc
square inch for the steam ports, and three square inches for the middle opening.
And in order that the engine may always have passed the centre, and the steam
have made its escape through the opening B into the jacket or casing D,
before the communication is opened between the exhaust side of the piston
and the small condenser H, care must be taken that whatever lap is given to
the outside of the slide the same lap shall be given on the inside, together with
twice the lead which the engine is intended to have. When the stroke of the
piston is longer than usual I would also recommend the employment of a slide,
with a middle bridge to fill the ports. Where there are two engines worked
in connection, as in the locomotive represented in Figures 9 and 10, and it is
desired to convey the bulk of the used steam into the chimney, in order to
encrease the draught, the two valve boxes E, E, in which the jackets or
casings D, D, terminate, are made to open into one common discharge
pipe M, which is carried upwards into the throat of the chimney. The
smaller portion of the steam which passes off through the two exhaust pas-
sages G, G, is conveyed by a common receiving pipe N, (see Figure 10), to the
condenser H, which is kept partly filled with cold water from the tender.. The
heated water which accumulates in the condenser is transferred to the boiler
by the pumps P, P, or should more accumulate there than is needed for the
boiler, the feed pipes are coupled together above the stop clacks, and the sur-
plus conveyed back to the tender. Should it be deemed advisable to encrease
the temperature of the water in the condenser previous to its being pumped
into the boiler, this may be effected by screwing down or giving less range to
the springs of the valve boxes E, E, which will necessarily cause a larger

page_text: portion of steam to be left in the cylinder on the exhaust side of the piston at
each stroke. In no case is the aid of the ordinary air pump requisite to work
an engine of the improved construction just described.
Secondly, my Invention has for its object to reduce the consumption of fuel
in marine and stationary engines, and also to obviate the rapid wear of tube
and boiler surfaces, arising from the employment of impure or salt water, and
the deposits and incrustations resulting therefrom, and I accomplish this by
providing the boilers with a supply of warm distilled water, in the manner
exemplified in Figures 11 and 12. Figure 11 is a vertical section of one of a
pair of marine engines, with the additional apparatus necessary for carrying
this part of my Invention into effect, and Figure 12 is a plan of the same.
The engine is represented as being of the improved kind herein-before described,
but I desire it may be understood that I do not limit myself to the use of any
particular sort of engine in combination with the system of condensation and
distillation which I am now about to describe. C is the middle opening in
the cylinder through which the great bulk of the steam is, as before explained,
discharged at each stroke of the piston into the jacket or casing D, and valve
box E. I is a pipe by which the steam is conveyed from the valve box E
into a covered cistern K, which is kept about half filled with cold water, and
where the steam being of high pressure (say as before fifty lbs. or sixty lbs.
per square inch), and consequently of a temperature much higher than the
boiling point of water, converts a considerable portion of the cold water with
which it comes into contact into vapour. K is a shield for breaking the force
of the steam as it rushes into the cistern K; I is a bent pipe, by which the
steam and vapour in K. are carried over into a condensing vessel R, which is
set in a casing S, filled with cold water, and closed in at top from the atmo-
sphere; I' is a pipe by which the casing S obtains its supply of cold water from
the river or sea, outside of the vessel; and U, another pipe, with cock v
attached to it, by which the first cistern K is fed from the casing S, as required.
The condensed water which collects in R is transferred while still in a warm
state by a pump V, and connecting pipe W, to the boiler. Any steam or
which may happen occasionally to remain uncondensed at the top of
the receiver R is let off into the atmosphere by a pipe X. By the preceding
arrangement all the steain which passes through the cylinder, with the excep-
tion of the small residual portion which goes off through the exhaust pas-
sages G, G, to the condenser H (as explained under the first head of this
Specification), is in effect worked over and over again, and any short coming
in quantity which may arise from imperfect condensation, or leakage, is more
than made up for by the portion of the cold water in K, which is evaporated
vapour

page_text: by coming in contact with the high-pressure steam, and which of necessity
must pass off in a fresh state, whether the water is fresh or salt. The water
of condensation too is constantly supplied in a warm state to the boiler, re-
quiring but little additional heat to raise it to a state of ebullition. The salt,
or other impurities, which are precipitated to the bottom of the cistern K, are
drawn off from time to time through a flush trap door, not seen in the Draw-
ings. The small condenser II, which serves in this, as in the locomotive engine
first herein-before described, to complete the exhaustion of the steam cylinder
after the escape of the bulk of the steam through the middle opening C, is
represented separately in Figure 18. H is the condenser; N, the common
receiving pipe, into which the exhaust passages G, G, empty themselves; H', a
pipe by which water is allowed to flow from the outside of the ship into the
condenser H; Y, a pump by which the water in the condenser, when it
becomes heated, is pumped overboard; and Z, a float valve attached to the
condenser end of the pipe N, by which, on the engine being stopped, any up-
flow of cold water through that pipe into the cylinders is prevented. As the
supply of steam from the condensing apparatus will always be more than suffi-
cient for the wants of the boiler, a portion of it may be led off through a
pipe E attached to the valve box E into the chimney, in order to accele-
rate the draught of the furnace or furnaces, the pipe E¹ being provided with
a cock, by which it may be shut or opened at pleasure..
And, thirdly, my Invention consists in the application of the method or
system of clearance or exhaustion, described under the first head of this
Specification, to pumps and other machines for raising and forcing water and
other fluids in the manner variously exemplified in Figures 14 to 20, both
inclusive, of the Drawings hereunto annexed. Figure 14 is a longitudinal
section of a single acting force pump, on this plan of construction, and Figure
15 a plan on the line m, m. A, is the pump barrel; and B, the ram. C is a
bush, which is fitted into a place made for it in the body of the barrel, at
about the middle of its length (forming in effect a middle piece to the barrel),
and has four openings through it F, F, F, F; an external clevation of this
bush, detached from the rest of the pump, is given in Figure 16. D is a
jacket or casing which surrounds the bush C, with its four openings F, F, F, F,
and communicates at one side with the water supply pipe E. G is the outlet
discharge pipe, and H, a ball clack valve attached to it, which acts as a stop
clack. The mode of operation will be obvious. On drawing up the ram B,
the space between the bottom of it and the ball clack valve H is more or less
exhausted of air, but as soon as the ram begins to pass clear of the openings
F, F, F, F, in the bush C, the water rushes in from all sides into the

page_text: exhausted space beneath it, and is by the return of the ram forced through the
ball clack valve E to a height proportionate to the force employed. Figure
17 is a longitudinal section of a double acting lift and force pump, on the
same plan as the preceding, but with the jacket or casing in the centre, as in
the case of the steam engine first herein-before described. Figure 18 is a
cross section on the line o, p, of Figure 17. A is the barrel, B, the piston,
which is packed in the manner shewn in Figure 17, and made of such depth,
in proportion to the length of the barrel, that, at the termination of the stroke
either way, the piston shall pass clear of the opening H. E, E, a jacket or
casing, which surrounds the opening H in the barrel; F is the water supply
pipe, which terminates in a cistern or chamber F', which communicates with
the jacket or casing E. G is the delivery pipe; H' and H³, the lower and
upper ports of the barrel which lead to the delivery pipe G; and I' and I³ the
clacks which command these ports. As the pump is represented in the
Drawing, the piston is at the termination of its down stroke and the upper
part of the barrel filled with water ready to be ejected through the upper port
H, and clack valve I"; supposing, therefore, the piston to be now drawn up,
it will first close the middle opening H, and the space between the bottom of
the piston and the clack valve I will be more or less exhausted; but as soon
as the bottom of the piston begins to pass clear of the opening H, the water
will rush in from all sides beneath the piston, while the piston by its continued
ascent will expel the water in the upper part of the barrel through the port H°
and clack valve I. On again depressing the piston, the reverse action will
take place, that is to say, the upper part of the barrel will be exhausted, and
when the top of the piston passes clear of the opening H, water will rush in
through that opening into the exhausted space, while the piston, on completing
its descent, will expel the water in the under part of the barrel through the
port H and clack valve I', and so the pump will go on working continuously,
ejecting a body of water at every stroke, either from the upper or lower port of
the barrel. Should it be desired to obtain a continuous stream of water from
a double acting pump, such as that just described, all that would be necessary
would be to attach a short branch pipe to the delivery pipe at K, and to
mount an air vessel thereon, in the same way as is done in the case of fire
engines. In both of the pumps which have been described, only stop clack
valves are used, but in Figures 19 and 20 a modification is represented, in
which clacks are wholly dispensed with, and the inconveniences attending the
use of such contrivances completely avoided. The pump here shewn is sup-
posed to be applied to a water-closet on board ship, in order to lift the water
required and force away the soil, for which purpose it appears to be par-

page_text: ticularly suitable. Figure 19 is a sectional elevation of the pump, and Figure
20, a cross section on the line v, w. A and B are two barrels. The barrel
A has two openings F1, F, on one side, at about the middle of its length,
which are separated from each other by a partition p. The opening F¹ is
surrounded by a jacket or casing E', into which water is admitted by a pipe
O from the outside of the vessel, whence it is forced into the basin, as after-
wards explained. The opening F is also surrounded with a jacket or casing
E, which receives the soil, and from which it is afterward ejected by the
operation of the pump. A' is the piston of the barrel A, which is made in
proportion to the length of the barrel, of such depth that, whether it is at the
bottom or at the top of the barrel, it shall cover only one of the two apertures
F, F. The barrel B is longer than the other, and fitted with two pistons
B', B, attached to one rod, and intermediately connected together in the
manner shewn. These pistons perform the office of two clack valves, the
upper one alternately opening and closing the top passage H, between the
barrels A and B, through which passage water is forced from the barrel A
(through the barrel B and a recurved pipe T, indicated in the Drawing by
dotted lines) over into the soil pan, which is fitted upon the pipe S, and tho
other one alternately opening and closing the passage L, by which the soil
which has been admitted into the bottom of the barrel A (through the open-
opening F) is discharged into the river or sea. The piston rods of both
barrels are connected to one crank shaft W, and so adjusted in respect to one
another that as often as, by the throw of the crank, the piston A' is raised to
the top of the barrel A, it shall simultaneously open the passage from the soil
pipe S into the barrel A, and force up a supply of water into the basin fitted
on the pipe S, and as often as it is depressed (the piston of the barrel B being
proportionately raised) shall close the passage II and open the passage L, the
soil being discharged at that instant through the pipe M into the sea. The
pistons B and B, in order to answer the preceding conditions, must have a
lap on each side, equal to the depth of the ports or passage ways, and the
proper depth to be given to these ports or passage ways may be found by letting
fall a perpendicular from the chord of 120° of a circle whose diameter is equal
to the stroke of the pump, which perpendicular (the sine of the chord) will be
the depth required. The pistons also must be connected to the crank shaft
at an angle of 60°, and the connecting rods, as also the throw of the cranks,
must be of equal lengths.
And having now described my said Invention in the several parts thereof,
and the manner in which the same is to be performed, I declare that the
improvements which I claim as constituting my said Invention are as follows:-

page_text: First, I claim the method or system of clearing or exhausting the cylinders
of steam engines first herein-before described, that is to say, in so far as
regards the openings all round the cylinder, at about the middle of its length,
the jackets or casings and valve boxes by which these openings are enclosed
from the atmosphere, the depth of piston by which the said openings are kept
closed till the piston has completed its stroke in either direction, and the com-
bination of the above-mentioned contrivances with exhaust passages, but
without the accompaniament of the ordinary air pump.
Second, I claim the method or system of furnishing the boilers of steam
engines with a supply of warm distilled water, as herein-before described.
And, third, I claim the application of the aforesaid method or system of
clearance or exhaustion to pumps and other machines for raising and forcing
water and other fluids, as before exemplified and described.
In witness whereof, I, the said Robert Urwin, have hereunto set my
hand and seal, this Eleventh day of July, in the year of our Lord One
thousand eight hundred and forty-nine.