IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1862

page_text: LETTERS PATENT to John Elder, of Glasgow, in the County of Lanark,
North Britain, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES AND BOILERS."
Sealed the 24th October 1862, and dated the 25th April 1862.
PROVISIONAL SPECIFICATION left by the said John Elder at the Office
of the Commissioners of Patents, with his Petition, on the 25th April
1862.
1, JOHN ELDER, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention of "IMPROVE-
MENTS IN STEAM ENGINES AND BOILERS," to be as follows, that is to say:-
This Invention relates to improvements in steam engines of the class known
as "Randolph Elder and Company's Patent combined cylinder engines,"
and to improvements in steam boilers suitable therefor.
An improvement in the engines consists in constructing and arranging the
valves, ports, and passages between each low-pressure cylinder and the high-
pressure cylinder, so that when the valve is admitting steam from the latter
to the former, only a comparatively small amount of admission opening (one
port for example) is uncovered, whilst the same travel of the valve in the
opposite direction will put a comparatively large amount of opening (two or
more ports for example) in communication with the exhaust. Supposing the
passage from one end of the low-pressure cylinder is formed with two ports,
the valvo slides only so far as to uncover one port for the fult, waist t.c

page_text: other port is then prevented from communicating with the exhaust through
the hollow of the valve by a plate or covering piece formed upon the valve for
that
purpose. With this arrangement the travel of the valve may be reduced
to a minimum, as also the loss of steam by clearance, the valve and valve
chamber being shaped so that the former as it were fills up the latter when
cutting off the entrance of steam.
A second improvement relates to the modification of valve gearing in use
with this class of engines, wherein the eccentrics mounted on a separate shaft,
are reversed by the action of spiral feathers on such shaft on moving it
longitudinally. The improvement consists in mounting the eccentric which
works the valve of the high-pressure cylinder upon an elongated tubular
boss set on the feathered shaft, and this boss has an external cylindrical
surface disposed obliquely to the shaft, the eccentric being bored to corre-
spond. Rack teeth are formed round a part of the boss to permit of its being
moved longitudinally by a pinion, and the longitudinal adjustment causes
the amount of eccentricity of the eccentric to be altered. The arrangement
permits of an easy and accurate adjustment of the cut-off.
A third improvement relates to the working of four cylinders when
arranged to act in pairs on cranks at different angles. Hitherto two of such
cylinders have received steam directly from the boiler, the other two receiving
the steam which has already acted in the first two. According to the present
improvement, however, but which is designed only for steam of very high
original pressure, the steam from the boiler works in one cylinder, and then
in a second, from which it is made to pass into a chamber wherein it may or
may not be superheated. From this chamber it is next made to pass into and
work in the third cylinder, and finally works in the fourth one, from which it
passes to the condenser.
A fourth improvement relates to the general design or arrangement of the
parts of four-cylinder engines combined with surface condensers. In this
improved design four inverted cylinders are arranged in a line with two high-
pressure cylinders, one at each end, and two low-pressure cylinders in the
middle. There are two surface condensers disposed transversely and centrally,
one beneath the adjacent parts of two of the cylinders, and the other beneath
the adjacent parts of the other two cylinders, the condenser casings forming
the supports of the cylinders. The condenser tubes are disposed horizontally
and transversely, being accessible from either side, whilst below the tubes
the condensers are arched for the passage of the main shaft. The air pumps
and circulating pumps may be attached against the sides of the condensers,
and be worked by rods passing through stuffing boxes to the steam pistons, or

page_text: they may be placed to the side, and be worked by levers connected to tho
piston rod slide blocks.
In a modification of this general design three cylinders only are used, one
a high-pressure one, the steam from which next works in an intermediate one,
and, lastly, in the third or low-pressure cylinder. The surface condenser,
arranged much as in the other modification, is placed beneath the adjacent
parts of the second or intermediate, and third or low-pressure cylinders.
The improvements in steam boilers are applicable to the class of boiler in
which the fire gases act directly upon a series of tubes containing the water,
and they consist in arranging the tubing and other parts, and in applying appa-
ratus in such a way that the water may circulate through the tubing in a
downward direction opposite to the direction of the fire gases.
The object is to prevent the formation of steam in those parts of the tubing
directly exposed to the fire, and for this purpose the details are, according to
one modification, arranged to give as high a column of water as possible or
convenient in each case, so that as the water in descending becomes hotter, it is
also pressed upon by a greater superincumbent weight, and its expansion into
steam is restrained until it escapes into a vessel at the side. This vessel is
provided for the disengagement of the steam, and is arranged not to be acted
upon by tho hotter firo gases; the water just acted upon by the fire enters it at
the bottom, whilst that part which does not flash into steam again enters the
upper end of the system of tubing. The apparatus for effecting the circulation
of the steam may consist of a screw or other fan, or a pump, and may be situated
at any convenient part of the circuit. At the communication between the system
of tubing and the vessel provided for the disengagement of the steam there
may
bo arranged a valve, loaded to such a degree as to keep the water in the
tubing under a pressure sufficient to prevent its expansion into steam whilst
in the parts directly acted on by the fire, and in this case the position or
height of the parts, and the direction of the currents relatively to that of the
firo gases, may be varied according to circumstances or convenience.

page_text: WHEREAS IIer most Excellent Majesty Queen Victoria. by Her Letters
Patent, bearing date the Twenty-fifth day of April, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
said John Elder, Her special licence, that I, the said John Elder,
my executors, administrators, and assigns, or such others as I, the said
John Elder, my executors, administrators, and assigns, should at any time
agreo with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
STEAM ENGINES AND BOILERS," upon the condition (amongst others) that I,
the said John Elder, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said John Elder, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
My said Invention relates to improvements in steam engines of the class
known as "Randolph Elder and Company's combined cylinder engines," and
to improvements in steam boilers suitable for the same, and for other kinds of
steam engines. And in order that my said Invention and the manner of
performing the same may be properly understood, I have hereunto appended
five Sheets of explanatory Drawings to be herein-after referred to in par-
ticularly describing my improvements. In the said Drawings the same
reference numerals are used to mark the same or like parts in all the Figures
in which they occur.
A first improvement in the engines consists in constructing and arranging
the valves, ports, and passages between each low-pressure cylinder and the
high-pressure cylinder, so that when the valve is admitting steam from the
latter to the former, only a comparatively small amount of admission opening
(one port for example) is uncovered, whilst the same travel of the valve in
the opposite direction will put a comparatively large amount of opening (two
or more ports for example) in communication with the exhaust passage.

page_text: Figure 1, Sheet 1 of the Drawings, is a longitudinal section showing a
modification of my improved intermediate valve arrangements. The steam
in passing from the high-pressure cylinder 1, to the low-pressure cylinder 2,
leaves the former by ports 4, 4, opening into two intermediate valve chambers,
5, 6. The valves 7, 8, are fixed upon the same spindle 9, which
passes from
one chamber 5, to the other 6, through a gland, and they work upon port
faces, each having an exhaust port 10, and two inlet ports 11, 12, communi-
cating with the low-pressure cylinder 2. One valve 7, is shown as having
uncovered one 12, of the two ports into the cylinder 2, the other port 11,
being covered by a plate 18 crossing the cavity of the valve 7. The other
valvo 8, is necessarily in the opposite position, both ports 11 and 12 being
open to the exhaust 10, whilst the covering plate 13 occupies the space
between the two ports 11, 12. The valves 7, 8, in either direction of their
motion travel only so far as to uncover one port 12, to admit steam across
from the high-pressure cylinder 1 to the low-pressure cylinder 2, whilst the
same travel uncovers the two ports 11, 12, at the opposite end of the
cylinders, to the exhaust. The travel of the valves is thus reduced to a
minimum, and also the loss of steam by clearance, tho valves 7, 8, and valve
chambers 5, 6, being shaped so that the former as it were fill up those ends
of the latter toward which they move in cutting off the steam.
A second improvement relates to the modification of valve gearing in use
with the same class of engines, wherein the eccentrics mounted on a separate
shaft, or on a tubular shaft, are reversed by the action of spiral grooves or
feathers on such shaft on moving it longitudinally.
Figures 2 and 3, Sheet 1 of the Drawings, are vertical sections taken at
right angles to each other, showing a modification of this gearing as arranged
for engines for driving paddle wheels. The valve shaft 14 is driven by means
of a toothed wheel 15, connected to it by a straight groove and feather, so as
to admit of the shaft's movement endways, and the wheel 15 is in gear with
an intermediate wheel 16, which last is driven by means of a wheel fast on
the main shaft, not shown in Figure 3, but indicated by a red circle in Figure 2,
as also in each of the wheels 15, 16. The wheel 15 and the eccentric 17, for
working the low-pressure valves, are mounted on the shaft 14, between
bearings which keep them from being moved endways when the shaft is so
moved, and the eccentric 17 is connected to the shaft by a spiral groove and
feather, in consequence of which the endway movement of the shaft alters
the position of the eccentric relatively to the wheel 15, (and therefore to tho
crank shaft.) For the purpose of moving the valve shaft 14 endways, there
is fitted on it at one end between collars a loose tubular piece 18, formed with

page_text: rack teeth, with which there gears a pinion on a shaft 19, driven by a small
donkey engine 20. The present improvement in this arrangement of valve
gearing relates to the mounting of the eccentric 21, which works the valves
of the high-pressure cylinders. Such eccentric has hitherto been connected
directly to the valve shaft 14 by a spiral groove and feather, as in the case of
the other eccentric 17; but by the present Invention it is mounted upon an
elongated tubular boss 22, shown in section in Figure 3, but as detached and
in enlarged elevation in Figure 4. This tubular boss 22 is fitted upon the
valve shaft 14 with a spiral groove and feather, so that its position in the
circle relatively to the main cranks may be altered by the endway movement
of the valve shaft simultaneously with that of the eccentric 17. Externally
the tubular boss 22 is formed with a cylindrical surface disposed obliquely to
the shaft 14, and the eccentric is bored with corresponding obliquity to fit on
such oblique part, whilst its proper rectangular position is retained relatively
to the shaft 14. The axis of the oblique piece is in the plane passing through
the axis of the shaft 14, and through the centre or axis of the eccentric 22,
so that an adjustment of the oblique piece through the eccentric varies the
eccentricity or throw of the latter. This endway adjustment of the tubular
piece 22 is effected by means of a pinion 23, tho teeth of which gear with
teeth upon the piece 22, such teeth being cut round the piece to admit of the
latter revolving without getting out of gear. The pinion 28 is fast on a
shaft 24, which may be actuated by a hand wheel or other convenient means
to effect the adjustment when it is wished to vary the throw of the eccentric,
and consequently the period of cut-off. To keep the eccentric 22 in its place,
it is formed with a collar, which is embraced by grooved sleeves 25, formed
upon the brasses of the bearing in which the parallel portion of the tubular
boss 22 turns, and which supports that end of the valve shaft 14.
A third improvement relates to the working of four cylinders when arranged
to act in pairs on cranks at different angles. Hitherto two of such cylinders
have received steam directly from the boiler, the other two receiving the
steam which has already acted in the first two. According to the present
improvement, however, but which is designed only for steam of very high
original pressure, the steam from the boiler works in one cylinder and then
in a second, from which it is made to pass into a chamber wherein it may or
may not be superheated. From this chamber it is next made to pass into
and work in the third cylinder, and finally works in the fourth one, from
which it passes to the condenser. A set of paddle-wheel engines constructed
for carrying out this improvement is represented upon Sheet 2 of the
accompanying Drawings, Figure 5 being a side elevation; Figure 6 a plan,

page_text: '
and Figure 7 a section of two of the cylinders and their valve chambers,
taken at right angles to their axes. The four cylinders, 1, 2, 3, 4³, vary in
size, the steam from the boiler entering number 1, the smallest, and suc-
cessively working in a larger and larger one as it is more expanded. The
two smaller cylinders 1, 2, are disposed at one side, and the two larger ones,
8, 4, on the opposite side; cylinders 1 and 4 working on one crank, and
cylinders 2 and 8 working on a second crank disposed diametrically opposite
to the first. The steam is directed into cylinder 1 by means of a pair of
simple cut-off valves on one spindle at 61, and it passes thence by passages
62 to valve chambers 68, wherein valves of the ordinary kind or of the kind
described under the first head hereof direct the steam into cylinder 2, and out
of that cylinder into an intermediate chamber or reservoir 64. From this
reservoir 64, the steam passes by a pipe 65 to cylinder 8, being directed
thereinto by cut-off valves at 66. Valves at 67, between cylinders 8 and 4,
regulate the transference of the steam to the last and from it to the
condenser 68.
A fourth improvement relates to the general design or arrangement of the
parts of four-cylinder ongines combined with surface condensers. A set of
engines constructed according to this improved design is represented upon
Sheet, 3 of the accompanying Drawings, Figure 8 being a side elevation,
partly in section; Figure 9, an end elevation, partly in section; and Figure 10
a horizontal section. In this arrangement there are four inverted cylinders
placed in a line over the crank shaft 30, the two end cylinders 1 being for
high-pressure steam, and the two middle ones 2 for the low-pressure steam
from the other cylinders 1. There are two surface condensers 31 disposed
transversely and centrally, one beneath the adjacent parts of two 1, 2, of the
cylinders, and the other beneath the adjacent parts of the other two cylinders,
the condenser casings forming the supports of the cylinders. The condenser
tubes are disposed horizontally and transversely, being accessible from one
side in the modification represented, whilst below the tubes the condenser
casings are arched for the passage of the main shaft 30. An air pump 32 is
attached against the side of one condenser 31, and the cold-water circulating
pump 88 is attached against the side of the other condenser, whilst the feed
and bilge pumps 84 are attached against the fore and aft sides of the air
pump; 82 and circulating pump 38. The pumps connected by cross heads are
worked by levers 35 on rocking shafts 86, which shafts are mounted in
bearings against the condenser sides, and are actuated by levers 87 linked to
the slide blocks 38 of the high-pressure piston rods. The arrangement of
the cylinder valves is clearly shown in the sectional plan, Figure 10, the valve

page_text: rods 39 issuing upwards, and being worked by rocking shafts mounted upon
the tops of the cylinders, but not shown in the Drawing. The valve rocking
shafts are themselves actuated by eccentrics 17, 21, upon the valve shaft 14
below, this last being parallel to the crank shaft 30, from which it receives
its motion through the wheels 15, 16, whilst a groove-and-feather arrange-
ment, similar to that herein-before described under the second head of my
improvements, provides for the reversing of the valves. In a slightly modified
arrangement of these engines the air pump and circulating pump may be
placed directly beneath the steam cylinders and be worked by rods passing
through stuffing boxes to the steam pistons, and in this modification access can
be given to the condenser tubes at either or both sides. Crossing passages
are provided between the two condensers 81 and the pumps, one to convey
the circulating water to both, and the other to convey the condensed (fresh)
water from both to the air pumps.
A modification of the general design last described is represented upon
Sheet 4 of the accompanying Drawings, Figure 11 being a longitudinal
vertical section, Figure 12 a transverse vertical section, and Figure 13 a
horizontal section. In this arrangement there are three inverted cylinders,
1, 2, 3; Number 1 receiving the high-pressure steam direct from the boiler,
Number 2 receiving the steam from Number 1, and Number 3 from Number 2,
the cylinders being of successively increasing size to correspond to the suc-
cessively increasing volume of the steam. With equal strokes a convenient
proportion for the diameters of the three cylinders will be that of 18 inches,
30 inches, and 50 inches, but the proportion may be varied according to the
initial pressure intended for the steam and other circumstances, the engines
shown in the Drawing being designed for an initial pressure of about 60
pounds per square inch. Various arrangements of valves may be adopted. In
the modification represented, two simple "cut-off" valves 40 on one rod
regulate the inlet of steam to the high-pressure cylinder 1, from which the
steam passes by ports on the other side into separate valve chambers 41,
between cylinders 1 and 2. Simple "cut-off" valves 42, both on one spindle,
regulate the admission of the steam from the valve chambers 41 into cylinder 2,
and the transference of the steam thence into cylinder 3 is effected by means
of valves 7, 8, and ports of the kind described under the first head of my
improvements. The cranks on the main shaft are disposed so that the crank
of cylinder 2 is 150 degrees of the circle behind that of cyilnder 1, and the
crank of cylinder 3 150 degrees of the circle bebind that of cylinder 2. The
three valves are worked by separate eccentrics, which may be arranged upon
a separate shaft with the spiral groove-and-feather arrangement hercin-before

page_text: described as applied to other modifications (but omitted in this Drawing,
Sheet 4). The relative positions of the cranks may be varied, and if necessary
spaces may be provided in connection with the intermediate valve chambers
to prevent too great a compression of the steam in them. With the described
disposition of the cranks their relation to each other will be different when
backing from what it is when going a-head, and to prevent inconvenience
arising therefrom, the reversing gear is contrived to open a stop-cock in a
pipe forming a communication between the top and bottom of the middle
dylinder 2, whereby this cylinder will for the time being act simply as a reser-
voir between cylinders 1 and 8. A surface condenser 81, arranged much as in'
the modification represented upon Sheet 8 of the Drawings, is placed beneath
the adjacent parts of the intermediate and low-pressure cylinders 2 and 3.
An air pump 32 is placed on one side, and a circulating pump 83 is placed on
the other side, both in a transverse vertical plane passing through the axis of
the low-pressure cylinder 8, and these pumps with the feed and bilge
pumps 84 are worked by levers 85, 87, linked to the slide block $8 of the
low-pressure piston rod (8).
In the several modifications of engines herein-before described, I prefer to
maintain the heat of the cylinders by means of steam jackets, and the spaces
therefor are shown in the several Drawings.
The improvements in steam boilers are applicable to the class of boiler in
which the fire gases act directly upon a series of tubes containing the water,
and they consist in arranging the tubing and other parts and in applying
ápparatus in such a way that the water may circulate through the tubing in a
downward direction opposite to the direction of the fire gases. The object is
to prevent the formation of steam in those parts of the tubing directly exposed
to the fire, and for this purpose the details are, according to one modification,
arranged to give as high a'column of water as possible or convenient in each
case, so that as the water in descending' becomes hotter it is also pressed upon
by a greater superincumbent weight, and its expansion into steam is restrained
until it escapes into a vessel at the side. This vessel is provided for the dis-
engagement of the steam, and is arranged not to be acted upon by the hotter
fire gases; the water just acted upon by the fire enters it at the bottom, whilst
that part which does not flash into steam again enters the upper end of the
system of tubing.
The apparatus for effecting the circulation may consist of a screw or other
fan or a pump, and may be situated at any convenient part of the circuit. A
simple modification of boiler to illustrate this part of my Invention is represented
in vertical section upon Sheet 5 of the accompanying Drawings..

page_text: The boiler consists of a hollow cone 50, consisting of a single tube arranged
in close spiral coils, and enclosed in a fire-brick casing, the fire-grate 51 being
at the bottom whilst the fire gases rise directly upwards within the cone. The
coiled tube communicates at its ends with a columnar vessel 52 at the side,
surmounted by a steam dome 53. In the pipe 54, leading from the steam!
dome 58 to the upper or entering end of the conical spiral 50, there is a
small screw propeller 55, the shaft of which passes out through a stuffing box
and is fitted with a pulley 56, so as to be turned by a donkey engine. This
screw is driven in such a direction as to make the water circulate down the
conical spiral 50, and as it gets more heated in descending, its consequently
increasing tendency to expand into steam is counteracted by an increasing
superincumbent column or weight of water; this action may be assisted by
applying internally a differential loaded valve, such as is shown in Figure 15,
which the water must raise to enter the vessel 52, 53, wherein the steam is to
separate from it; and this differential valve will have the effect of keeping the
water in the conical spiral 50 under a pressure sufficient to prevent its expansion
into steam, which expansion will, however, take place upon the heated water
passing through the loaded valve into the steam space. Where the differential
valve is used, the position or height of the parts and the direction of the currents
relatively to that of the fire gases, may be varied according to circumstances or
convenience. The disengagement of steam in the vessel 52, 53, will cause
the water to be elevated above its natural level in that vessel, and a contrivance
is introduced to take advantage of this action, so as to assist the current down
the conical spiral 50. The steam dome 53 is formed with circular pockets or
channels 57, which catch the water thrown up above the natural level, and the
water passes from such channels through lateral openings into an outside
pocket 58, constituting the inlet into the pipe 54. The openings are fitted
with valves 59 to prevent water leaving the steam dome at one opening from
returning to it by a lower one. Water thus finding its way into the outside
pocket 58 is separated from the steam, and the column of water thus made
effective in the conical spiral 50, being more solid, preponderates over the
mixed column in the vessel 52, 53, and assists the current. It may in fact in
some cases be unnecessary to use the propeller 55, after the current is once
started in the proper direction.
Having thus particularly described my said Invention, and the manner in
which the same is or may be performed, I have to state that I do not restrict
myself to the precise details herein described or delineated, but that what I
believe to be novel and original, and claim as the Invention secured to me by
the herein-before in part recited Letters Patent, is,-

page_text: 1, the constructing of steam engine valves so that with a double port a
travel sufficient to uncover only one opening of the port to the inlet steam
uncovers two or more openings to the exhaust, substantially as herein-before
described.
2, the adjusting of the eccentricity of the expansion eccentric, so as to vary
the cut-off by means of an oblique boss capable of being shifted endways on
the shaft, substantially as herein-before described.
8, the general designs or arrangements of engines, severally represented
upon Sheets 2, 8, and 4 of the accompanying Drawings, and herein-before
described.
4, the constructing of "tube" boilers, substantially as herein-before described,
and in particular the causing of the water to flow in a generally downward
direction in the tubes directly acted upon by the fire, and the introducing
internally of a differential loaded valve to prevent the premature formation of
steam in the tubes exposed to the greatest heat.
In witness, whereof, I, the said John Elder, have hereunto set my
hand and seal, this Twenty-second day of October in the year of our
Lord One thousand eight hundred and sixty-two.
20 Witness,
EDMUND HUNT,
Patent Agent,
28, St. Enoch Square,
Glasgow.
JOHN ELDER. (L.B.)