CERTAIN IMPROVE- MENTS IN STEAM ENGINES
Year: 1848

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LAWES COLE, of Lucas Street, in the County of Middlesex, 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 dato at Westminster, the Twenty-second day of
March, One thousand eight hundred and forty-eight, in the eleventh year of
Her reign, did, for Herself. Her heirs and successors, give and grant unto me,
the said John Lawes Cole, my exors, adññiors, and assigns, Her especial license,
full power, sole privilege and authority, that I, tho said John Lawes Cole, my
exors, admors, and assigns, or such others as I, the said John Lawes Cole, my
exors, adiñors, 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, my Invention of "CERTAIN IMPROVE-
MENTS IN STEAM ENGINES;" in which said Letters Patent is contained a proviso
that I, the said John Lawes Cole, 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 scal, 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

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
John Lawes Cole, hereby declare that the nature of the said improvements, and
in what manner the same are to be performed, are
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, my improvements, have relation to high-pressure and expansion
double cylinder beam engines, and consist in an improved arrangement of the
parts thereof, whereby a great reduction is effected; both in the space occupied
by them and in the first cost. Instead of placing the cylinders side by side, I
place the large or expansion cylinder immediately underneath the small or high- 1
pressure cylinder, and connect, the two by a stuffing box through which one
piston rod, common to both cylinders, works.
5
Figure 1 of the Drawings annexed -is-a-side elevation, and Figure 2 a
plan of an engine thus constructed. A is the small or high-pressure
cylinder, and C its slide case. B, the 'large or expansion cylinder, and 1
D its slide case. N, the connecting stuffing box, a plan, elevation, and
section of which are given separately in Figures 3, 3, and 3. A' is the piston
rod; B¹ the
space for the packing and O, O; two packing glands. 'D' is a
flange which fits the interior of the small cylinder, and E¹ a flange which fits
the interior of the large cylinder. E, E, E, are passages, through which the
steam passes from the small to the large cylinder, and in which also the slide
rod of the large cylinder works. F'is the eccentric pin. G the way shaft of the
small cylinder. H, the way shaft of the large cylinder, to which motion is
communicated by the rod I. J is the eduction pipe from the large cylinder to
K, the condenser, in the centre of which is placed the air pump. L'is' the hot s
well; and M the injection pipe.
From this description it will be seen that little more is necessary to
convert an ordinary high-pressure beam engine into one on this improved plan,
than the addition of the extra large cylinder, which is accomplished without
any increase whatever in the ground area occupied; while the expence of that
addition is as nothing compared with the immense saving in fuel to be realized
by working the steam on the high-pressure and expansion systemi combined.
The stuffing box N may be dispensed with by having two piston rods to the
large piston passing through stuffing boxes in the cover of the large cylinder,
one on each side of the small cylinder, as represented in Figure 4. A is the
piston of the large cylinder, and B the piston of the small cylinder. The piston
rods C, C, of the large cylinder, and the piston rod D of the small cylinder, aro
all connected to the same cross head."
.
་
Secondly, my Invention has relation to double-cylinder engines of the direct-

page_text: -acting class, and consists in the following now, arrangement, in which the
cylinders are placed side by side, but the other, parts are so disposed as greatly.
to improve the engine in point of general compactness and concentration. The,
details of this arrangement are shewn. in plan in Figure 5, and in elevation in
Figure 5. A is the small high-pressure, cylinder, and D its piston rod;
B, the large or expansion -cylinder, and C its piston rod. The piston rods of
both pistons are connected to the same cross head E; from the centre of which
the connecting rod; F passes down-between the two cylinders directly to the
crank pin H on the crank shaft G, the two cylinders being raised sufficiently.
from the bed plate to allow the crank shaft to pass underneath the small or
high-pressure cylinder. The cross, head and piston rods are not kept perpen-
dicular by guides as usual,, which are on many accounts objectionable, but by:
means of the shafts I, I, the levers J, J, J, J, and the rods K, K, K, K,
which are maintained in their relative positions by the rod L. This rod L is
attached at one end to an arm a, on the lower side of the shaft I, and at the
other end to an arm'b, on the upper side of the shaft I', thereby causing the
levers J and röds. K. to move in unison; M and N are levers for working the
air and hot and cold water pumps. By the arrangement just described, the
power developed from the two cylinders, although of very unequal amount, is
equalized and transmitted to the connecting rod without producing any strain
or torsion upon the other parts of the framing.
Thirdly, my Invention: consists of a double-acting air pump. for steam
engines of the improved construction represented in Figure 6. In this pump
I use a slide valve similar to'a steam-engine slide, in place of the usual clack
valve in the piston, only that, instead of the slide having the lead forward as
in the steam engine, it travels behind, the piston, the exhaust of the steam
engine forming the induction for the air pump, and the steam ports the
delivery. A is the cylinder or barrel; B, the piston; C,. C, the slide valves ;
F, the induction port, and D, the delivery, in which is placed the valve G.
A pump of this description can be, driven at any speed without that noise from
the valves which is the inseparable accompaniment of the clack valve.
Figure 6, shews the relative positions of the eccentric, pin H (for working the
valves), and the.crank pin. I:...
....
&...
Fourthly, my Invention consists of the improvement in steam expansion
slide valves, represented. in Figure 7. A;' A, are the steam ports into the
cylinder; B, B, the exhaust ports leading to the atmosphere or to the condenser;
C, C, the slide valves, which are of the common D construction, with the
exception of having: moveable laps.d; d,, which cut off the steam; E, E; are
rods by which the laps.d, d, are connected,, and the length, of which may be

page_text: altered at pleasure by means of the nuts F, F, one end of the nut being formed
with a right and the other with a left-handed thread upon it. The rate of
expansion can be altered when the engine is in motion by turning the nuts F, F,
which are left outside the jackets for the purpose.
And, fifthly, my Invention consists in certain improved safety valves, pos-
sessing the common characteristic of affording double the usual security against
explosion. An external elevation of one of these valves is given in Figure 8,
a transverse section of it in Figure 9, on the line a, b, of Figure 8, and a plan
in Figure 10. A, A, is a basement to which the valve box B, B, is bolted by
means of the flanges C, C; the basement itself is secured by its lower flanges
D; D, to the steam boiler or other vessel upon which it is to be used. The
valve box consists of two concentric cylinders, E and F, which are joined
together at top by an intervening ring of metal G, or the concentric rings may
be cast in one piece, as represented in Figure 9. The inner cylinder E forms
internally the case and seat for the valve H; I is the weighted lever belonging
to this valve; K is a second valve or piston of an annular form, which is fitted
and ground into the space left between the two concentric cylinders E and F.
At bottom the piston has a bridge L, which projects some distance downward:
below its lower surface, but leaves the piston free play to move up and down
within certain limits between the cylinders E and F. M is a cross head, to
which there are attached on its lower side two guides N, N, which pass down
through apertures, made in the top of the valve box or case and rest at their
lower ends upon the top side of the annular piston K. Again, the cross head
at top is connected by two links O, O, to a weighted lever P; the weights
on the levers I and P are so proportioned to the area of the valve H, and
the annular piston K, that the pressure on the latter shall be somewhat in '
excess over that on the former. When these conditions have been observed,
should the valve H or its spindle by any chance get stiff or furred up, and
consequently cease to act, the increased pressure of steam in the boiler, which
is the necessary result, exerting itself upon the lower side of the piston K, will
cause it to rise till the bridge L comes into contact with a projecting stud Q,
on the lower end of the valve H, and lifts that valve for the escape of steam.
Figure 11 is an external elevation of a valve, similar to that which has been
just described, only differing in the manner in which the weights are applied
to the valve and the piston. A is the basement of the valve; B, the valve
box; C, the cross head, which carries a weight D, equal to the load of the
annular piston; E is the weight or load of the valve, which is suspended from
the lower end of its spindle, and occupies a place inside the boiler. It will.
be seen by reference to the Drawing that there is a sufficient space left between:

page_text: the top of the valve I, and the lower side of the cross head C, to allow of the
valve rising for the escape of steam, without its interfering in any way with the
piston. Should the valve, however, get fast in its seat, then an increased pressure
beyond what the safety valve is loaded to sustain causes the annular piston to
rise till the bridge on its lower side comes in contact with the bottom of the
safety valve, as before described, and causes the valve to rise. A plan of the
annular piston employed in this valve is given separately in Figure 12, shewing
the manner in which the valve spindle passes through the bridge. Figure 13
is a section of the valve and valve box.
A compound safety valve, constructed on the same principle as the pre-
ceding, but varying in the details, is represented in Figures 14,-15, and
16, Figure 14 being a side elevation, Figure 15 a back elevation, and
Figure 16 a plan. A is the valve box; B, the safety valve, which is similar
to the common safety valve; C, its weighted lever. D is a cylinder which
is cast in one. piece with the valve box: it is truly bored out inside,, and
I has a piston, E, fitted to it, F. is a hole in the seat, plate communicating
with the boiler, and G, another hole in the top of the cylinder communi-
cating with the external atmosphere. H is a valve which is fitted into the
piston E, and opens inwards; it is kept in its place by the force of the steam,
but when the pressure in the boiler gets too high it overcomes the load placed
on the piston by the weighted lever M, through the intervention of the guide
rods I, I, and the piston is forced up until the cross pin K of the valve H
comes in contact with the seat plate D', when the valve is prevented from
following the piston any further. Should the piston still continue to rise above
that point the valve H is opened, and the steam is free to escape.
And having now described the nature of my said Invention. in the several
parts thereof, and in what manner the same is to be performed, I declare that
the improvements which I claim as constituting the said Invention are as
follows:-
First, I claim the high-pressure and expansion double cylinder beam engine
first herein-before described, in so far as regards the placing of the one cylinder
above the other, and such other parts, or modifications of parts, as are necessary
to the said change of position.
Second, I claim the direct acting double cylinder engine secondly herein-
before described, in so far as regards the passing of the connecting rod down
between the two cylinders, and the system of leverage by which the parallelism
of the piston rods is maintained without the use of guides, and the amount of
power given off by each piston is equalized, as herein-before described.
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