CERTAIN IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1866

page_text: LETTERS PATENT to John Charles Pearce, of the Bowling Iron Works,
near Bradford, in the County of York, Engineer, for the Invention of
"CERTAIN IMPROVEMENTS IN STEAM ENGINES AND BOILERS."
Sealed the 16th October 1866, and dated the 28th April 1866.
PROVISIONAL SPECIFICATION left by the said John Charles Pearce.
at the Office of the Commissioners of Patents, with his Petition, on the
28th April 1866.
I, JOHN CHARLES PEARCE, of the Bowling Iron Works, near Bradford, in
the County of York, Engineer, do hereby declare the nature of the said
Invention for "CERTAIN IMPROVEMENTS IN STEAM ENGINES AND BOILERS," to be
as follows:
My Invention consists, firstly, in the means of increasing the power and
general efficiency of existing or other steam engines by improvements in the
application of additional or auxiliary cylinders fixed either vertically or hori-
zontally, or in any other convenient position, in close proximity to the crank..
In applying my Invention to a stationary beam engine of ordinary construction.
I prefer fixing the auxiliary cylinder in a vertical position on either side of the
crank as may be found most convenient, with the piston rod working through the
bottom of the cylinder, and connected to a lever or beam working upon a contre
or gudgeon situated at a suitable distance below the crank; a connecting rock

page_text: The
power
ascends from this lever or beam to the crank and takes hold of the crank pin,
which requires to be lengthened for the
of the auxiliary
purpose.
cylinder is thus communicated to the crank shaft without causing any strain
upon the other or original parts of the engine. In certain cases where the
boiler pressure is limited, and where the load upon the original or principal
engine is already very considerable, I use the exhaust steam from the original
cylinder to supply the auxiliary cylinder, the steam being thus made to do duty
a second time before it is condensed. In other cases where there is ample
boiler pressure and sufficient capacity of original cylinder, I supply steam direct
from the boiler to the auxiliary cylinder which steam is afterwards expanded
into the original or principal cylinder, while in other cases the fresh steam
supplied to the auxiliary cylinder is exhausted at once into the original
condenser.
Secondly, in the application of high and low pressure or compound auxiliary
cylinders arranged to communicate power to the crank of an existing or other
engine in a manner similar to that above described in the case of a single
auxiliary cylinder. The steam for the supply of these high and low pressure
or compound auxiliaries is taken direct from the boiler first to the high-
pressure cylinder, from which it is expanded into the low-pressure cylinder and
also into the original cylinder, or it may be exhausted from the low-pressure
auxiliary cylinder into the condenser without first passing into the original
cylinder.
Thirdly, in the application of an air pump and condensing apparatus to be
used in connection with an auxiliary cylinder in cases where the original air
pump is not sufficient for the auxiliary and original cylinders. This additional
air pump is worked direct from the lever or beam of the auxiliary cylinder.
Fourthly, in the use and combination of these improved arrangements of
cylinder, lever, or beam, connecting rod, and air pump, in connection with a
crank and fly wheel to produce rotatory motion independently of any other
engine, that is to combine them so as to constitute an independent engine with
cylinder or cylinders either vertical or horizontal, simple ar compound,
condensing or non-condensing.
Fifthly, in the construction of metallic pistons in which I make the wearing
or outer ring in two parts depthwise, each part being cut through in one
point to allow it to expand or open out. A series of angular-shaped pieces
of metal in combination with suitable springs are made to press on the inner
surfaces of each part of the wearing ring so as to produce the horizontal and
vertical pressures necessary to keep the wearing ring in steam-tight contact
with the piston flanches and inner surface of the steam cylinder.

page_text: And, lastly, in a new method of making the hoops or rings for strengthening
the circular flues and fire-boxes of steam boilers. In making these hoops or
rings I take solid or annular blocks of wrought iron or ingots of cast steel,
which I forge by means of a steam hammer or otherwise to a suitable diameter
and section, and afterwards finish to the required diameter and T-shaped or
other section by rolling them in an ordinary circular rolling mill, such as is
now commonly used for rolling solid or weldless tyres for railway wheels.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Charles Pearce in the Great Seal Patent Office on
the 27th October 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN CHARLES
PEARCE, of the Bowling Iron Works, near Bradford, in the County of York,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of April, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Charles Pearce, Her special licence that I, the said John
Charles Pearce, my executors, administrators, and assigns, or such others as
I, the said John Charles Pearce, my executors, administrators, and assigns,
should at any time agree 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 "CERTAIN
IMPROVEMENTS IN STEAM ENGINES AND BOILERS," upon. the condition (amongst
others) that I, the said John Charles Pearce, 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 Charles Pearce, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings annexed, that is to say :-
My Invention consists, firstly, in the means of increasing the power and

page_text: general efficiency of steam engines by the application of auxiliary cylinders
with improved connections for communicating the power to the crank.
Secondly, in the application of high and low pressure or compound auxiliary
cylinders.
Thirdly, in the application of an air pump and condenser in connection with
my improved auxiliary arrangements.
Fourthly, in the combination of my improved cylinder and connecting
arrangements with a crank and fly wheel to produce rotatory motion, that is,
to combine them so as to constitute an independent engine.
Fifthly, in the construction of metallic pistons.
And, sixthly, in the construction and application of solid weldless hoops
and rings for strengthening the flues and fire-boxes or other parts of steam
boilers.
And in order that my Invention may be more readily understood I will
proceed to describe the Drawings annexed.
Figs. 1 and 2, Sheet No. 1 of the accompanying Drawings, are side and
end elevations of a stationary steam engine of ordinary construction to which
one of my improved auxiliary arrangements is applied. The original cylinder,
beam, connecting rod, crank, and condenser are respectively shown at A, B,
C, D, and E. The auxiliary cylinder, shewn at F, is fixed to the box
girdler G, which is firmly bolted to the ashlar foundation and fastened at one
end into the side wall of the engine house. The piston rod H works through
a stuffing box formed in the box girder or cylinder bottom, and terminates in
a suitable cross head I, which is connected by means of the parallel motion
links J with the end gudgeon of the lever K. The gudgeon at the opposite
end of this lever is supported by the pedestals L, L, attached to a strong
cross bearer M. The lever K and the crank D are connected together by
the connecting rod N, which takes hold of an extension of the crank pin, as
shewn at O, Fig. 2. The power of the auxiliary cylinder is by these means
communicated to the crank and fly wheel shaft without causing the slightest
additional strain in any other parts of the original engine. It will be observed
that this arrangement admits of an auxiliary cylinder of any required capacity,
it may be less, equal to, or greater than that of the original cylinder; it also
admits of the auxiliary being employed as an independent condensing cylinder
receiving steam direct from the boiler and exhausting into the original con-
denser; or it may be compounded with the original cylinder in two different
ways; for example, one method of compounding is that represented in the
Drawings already explained, where the capacity of the auxiliary cylinder is
about two and a half times greater than that of the original one; in this case

page_text: the steam is first supplied to the original cylinder, wherein it effects one
stroke of the piston, and is then exhausted or allowed to escape by way of
the pipe P into the valve chest Q, where the valve being already partially
open it is admitted into the auxiliary cylinder, and by its expansive force
there effects another stroke, on the completion of which the eduction valve
opens and allows the expanded volume of steam to escape through one of the
cells R of the box girder G and down the exhausting pipe S to the condenser
E. In the second method of compounding, the capacity of the auxiliary
cylinder is made about one-third, or two-fifths (more or less) that of the
original cylinder; the steam being first supplied to the auxiliary, wherein it
performs the high-pressure stroke, and is then expanded into the original
cylinder to perform the second or low-pressure stroke before being condensed,
the exhausting pipe S being omitted and the original one shewn in dotted
lines at T retained. The situation occupied by the auxiliary cylinder between
the crank and the entablature pillar, as shewn at F, is preferable, inasmuch
as it is very convenient for the steam and exhausting pipe connections with
the original cylinder and condenser, but I have frequently found it more con-
venient in other respects to place it on the opposite side of the crank, as
represented in dotted lines at U, the connecting lever being arranged
accordingly. The valvular arrangement of the auxiliary cylinder may be of
any approved construction; I generally prefer a common slide with double
exhausting passages. The motion for working the valve is readily obtained
from an eccentric V on the fly wheel shaft.
In Fig. 1, Sheet No. 2, I have shewn one of my improved compound
auxiliary cylinder arrangements as applied to an ordinary beam engine. The
connecting rod, crank, and condenser of the original engine are shewn at
C, D, and E, F and F being the high and low pressure auxiliary cylinders;
II and H, the piston rods; J and J2, the parallel motion links; K, the con-
necting lever working in fixed pedestals at L; and N, the connecting rod.
I have also shewn in the same Drawing one of my improved methods of
applying an additional air pump d and condenser e, the motion of the air
pump bucket being communicated from the main working beam by the pump
The compound action of the steam in this instance will be readily
understood, and is as follows:-Steam from the boiler is first supplied to the
small or high pressure cylinder F, in which it effects a struke of the smaller
piston, it is then expanded into the large or low-pressure cylinder F³, and
there effects the return stroke of the larger piston, and is finally discharged
through a passage in the box girder G and exhaust pipe S to the condenser e.
In certain cases where the original air pump and condenser are of ample
rod r.

page_text: capacity I omit the additional condensing apparatus and extend the exhaust-
ing pipe of the auxiliary cylinders to the original condenser E, as shewn by
the dotted lines S, S. The auxiliary cylinders may be made of any desired
cupacity, and their relative proportions adapted to the available steam pressure;
I have generally found the proportions of two and a half and three to one to
answer well in practice.
Fig. 2, Sheet No. 2, shews another of my improved auxiliary arrange-
ments, wherein D is the original crank, and E the original condenser; F
and F, the auxiliary cylinders on opposite sides of the crank; H and H, the
piston rods; J and J2, the parallel motion links; K, the connecting lever
on beam; L, the connecting rod; and S, the exhausting pipe communicating
with the original condenser. It will be seen that this arrangement admits
of the cylinders being constructed of any required capacity and proportions
suitable for being compounded together or with the original cylinder, or used
separately, as before described.
Fig. 3 of the same Sheet shews another modification of my improvements,
also applied as an auxiliary to a beam engine, the cylinder F in this
instance being fixed horizontally beneath the crank, to which the power is
transmitted through the lever K and connecting rod L nearly at right angles
with the original connecting rod C. In this instance no communication is
supposed to exist between the original and auxiliary cylinders, the latter being
provided with a separate air pump and condenser, shewn at a and e. It will
however be obvious that in many cases a separate condensing apparatus would
be unnecessary, as the auxiliary cylinder could be readily made to exhaust into
the original condenser by the application of an exhausting pipe, as shewn in
dotted lines at S, S, S. It will also be observed that this arrangement affords
ample facility for compounding with the original cylinder. When employed to
compound, the exhausting pipe S, S. S, instead of being connected with the
original condenser E, must be carried forward to the valve chest W of the
original cylinder, as shown by dotted lines at 9.
In all the preceding examples the auxiliary cylinders are shewn as working
in connection with the crank of the original engine, both connecting rods in
fact being coupled to the same crank pin; but I have often found it equally
convenient, and in some cases more advantageous, to apply the auxiliary
cylinder in connection with a crank on the opposite or outer end of the fly-
wheel shaft. The power of a vertical auxiliary is thus more readily applied
at right angles with that of the original engine.
.
Figs. 4 and 5 are respectively side and end elevations of an independent hori-
zontal compound cylinder engine constructed in accordance with my
Invention.

page_text: The steam cylinders F and F (high and low pressure) are here placed side
by side with a space between them for the connecting rod. The pistons,
each having the same length of stroke, are coupled to the pins c, c, on opposite
sides of the connecting lever K, as shewn in Fig. 5. The connecting rod L
is coupled at one end to the same centre of the lever K as and at a point
between the two piston rods, as shewn at m, Fig. 5, and at the other end to
the pin O in the crank plate, which plate is fixed upon the fly wheel shaft.
The valve chest Q situated beneath the cylinders, to which it is fixed, contains
a double-acting slide valve communicating with a double set of passages for
high and low pressure cylinders. The motion for working the valve is com-
municated from the fly wheel shaft by an eccentric and rod a to the rocking
shaft and lever y. Placing the valve beneath the cylinders has the im-
portant advantage of preventing the accumulation of water inside the cylinders,
thus dispensing with the pipes and stop-cocks usually employed for that pur-
purpose. The air pump and condenser are shown at a and e, motion to the
pump bucket being given by the lever arm n.
A very compact and economical engine of any required power, adapted to a
great variety of purposes, may be constructed as last described. The arrange-
ment admits of several modifications; for instance, a single cylinder may be
employed instead of a double one; slides and slide blocks substituted for the
hollow piston rods; the valve chest placed on the side or top of cylinder
instead of beneath it; the air pump and condenser omitted, and the exhaust
steam blown away.
My improvements in pistons are shewn in Figs. 1 to 7, Sheet No. 3. Fig. 1
shews a piston half in section and half in elevation; and Fig. 2 is a plan of
the same with one half of the cover ring removed for the purpose of shewing
the interior. The same reference letters apply to the same parts in all the
Figures.
a is the piston body; b, the cover ring; c, the screws for fixing cover ring;
d, d, the two packing rings, each being cut through as shewn at e.
My improvements consist in imparting to the packing rings the requisite
lateral and vertical pressure to keep them in steam-tight contact with the
inner surfaces of the cylinder and piston flanches. I employ a series of springs
and angular-shaped blocks of metal, three of the latter to one of the former.
Figs. 3 and 4 shew on an enlarged scale one of the springs 9 and centre
block h screwed to it by the pin J; this pin also fits into a suitable hole in
the piston body and keeps the spring in its proper position. A small projec-
tion n on each bevel face of the block h fits into a corresponding groove or
recess o in the slanting face of each side block m, shewn in Figs. 5 and 6..

page_text: The springs and blocks are shewn in position in Figs. 1 and 2, and are pre-
vented from getting asunder or out of position by means of the pin ends and
block projections already described. The springs g, with their ends abutting
against the piston body, as shewn in Fig. 2, exert a certain amount of radi-
ating or outward lateral pressure. The action of the slanting faces of the
centre block upon the corresponding faces of the side blocks m, as shewn in
section, Fig. 1, converts the simple lateral force exerted by the springs into a
compound of lateral and vertical pressure against the inner surfaces of the
packing rings, thus keeping their outer or wearing faces in close or steam-
tight contact with the cylinder and piston flanches. Fig. 7 is an enlarged
section of the packing rings and angular blocks in connection with a different
form of (namely, helical) spring, the ends of which fit loosely into suitable
recesses in the piston body and centre block, as shewn.
In the Specification of a Patent granted to me for "Improvements in
Apparatus for Generating and Economising Steam," bearing date the Twenty-
second day of May One thousand eight hundred and fifty-six, I have described
certain methods of strengthening the flues and fire-boxes or other parts of
steam boilers by the employment of hoops and rings made from straight bars
of iron of T-shape, ribbed, or other section. My present improvements in
steam boilers consist, firstly, in making the said hoops and rings circular from
the commencement, thereby dispensing with the operations of bending and
welding, as practised heretofore; and, secondly, in constructing the flues,
fire-boxes, or other parts of such boilers wholly or partially of my improved
weldless hoops and rings, which are readily produced as follows:-A pile of
iron, being thoroughly welded, is taken from the furnace and forged by means
of a steam hammer into a circular block or slab, as shewn in Figs. 8 and 9,
Sheet No. 3. The slab being sufficiently heated is again brought under the
hammer, when a few blows with the aid of a short punch or drift suffice to
punch or drive out the central portion of the block. The perforation thus
made is gradually widened by driving in the taper punch or drift first from
one side of the slab and then the other until the hole has attained the desired
size. A sound annular bloom suitable for making a hoop or ring of any
desired section, as shown in Figs. 10 and 11, is thus produced. The weight
of the bloom must be in accordance with that of the finished hoop or ring for
which it is intended, due regard being had to the loss or waste caused by the
subsequent operations. The bloom being again heated and placed upon a
suitable mandrill is submitted to further hammering, principally edgeways,
and slightly sideways, until its internal diameter is sufficiently increased and
its cross section made to approximate roughly that required in the finished

page_text: hoop or ring. Some of these rough sections are shewn in Figs. 12, 13, 14,
and 15. The forging or bloom is then again reheated and finally submitted to
the action of a circular rolling mill, such as is now commonly employed for
rolling solid weldless tyres for railway wheels, and is rolled out to the exact
diameter and section required. Some of these finished sections are shewn in
Figs. 16, 17, 18, and 19.
In making hoops and rings of malleable cast steel the process is much sim-
plified. The steel ingots being cast in suitable moulds assume at once the
rough proportions as shown in Figs. 16, 17, 18 and 19, or any other required
section, thus dispensing entirely, or nearly so, with the hammering process
necessary in the case of malleable iron as before described. Cast steel ingots
of mild quality properly annealed require no hammering, the circular rolling
process being of itself quite sufficient for their completion.
Fig 20. is a longitudinal section shewing the application of one of my
improved weldless hoops to the flue or fire-box of a steam boiler. P, P, are
portions of the two adjacent plates about two inches apart, and r is the
strengthening hoop of -section, rivetted on each side to the plates by the
rivets S, S.
Fig. 21, also a longitudinal section, illustrates the application of another
hoop or ring of a different section, the reference letters in this case being the
same as in the preceding one.
Fig. 22 shews, also in longitudinal section, a portion of a flue or fire-box
composed entirely of my improved weldless rings of double-flanch section,
made of any convenient width. In this case it will be observed there are no
rivets exposed to the action of the fire within the flue, they being all outside
and consequently surrounded with water.
Weldless hoops and rings of any diameter and form of section applicable to
different parts of steam boilers, as, for instance, the flat hoops required for butt
joints of boiler shells, various sections of angle iron rings, and so forth, may
be readily produced in the same way as above described.
It would be useless here to attempt any explanation as to the utility and
importance of my improvements in relation to flues and fire-boxes as herein-
before described, the object being to give to such parts of steam boilers
great additional strength or power to resist collapse, whereby the safety and
durability of such boilers are materially increased.
Having thus described my Invention, and the manner in which the same
may be performed or carried into practical operation, I desire it to be under-
stood that I do not confine myself to the precise details or arrangements herein

page_text: specified, provided the peculiar character of my said Invention be retained;
but what I claim is,―
First, the application of an auxiliary cylinder to any existing or other steam
engine, as described in reference to Figs. 1 and 2, Sheet No. 1.
Second, the application of compound auxiliary cylinders, as described in
reference to Figs. 1 and 2, Sheet No. 2.
Third, the application of simple and compound horizontal auxiliary cylinders,
as described in reference to Fig. 3, Sheet No. 2.
Fourth, the application of an addition air pump and condenser, as described
in reference' to Figs. 1 and 3, Sheet No. 2.
Fifth, the application of any of my improved arrangements of cylinders,
levers, and connecting rods in the construction of an independent engine,
whether the same be vertical or horizontal, one example of such application
being that described in reference to Figs. 4 and 5, Sheet No. 2.
Sixth, the improvements in metallic pistons, as described in reference to
Figs. 1 to 7 inclusive, Sheet No. 3.
Seventh, the manufacture of solid or weldless hoops and rings for
strengthening the flues and fire-boxes or other parts of steam boilers, whether
the same be made of malleable iron or malleable cast steel, as described in
reference to the Figs. 8 to 19 inclusive, Sheet No. 3.
And, eighth, the construction of flues, fire-boxes, and other parts of steam
boilers, either wholly or partially of my improved solid or weldless hoops or
rings of malleable iron or malleable cast steel, as described in reference to
Figs. 20, 21, and 22, Sheet No. 3.
In witness whereof, I, the said John Charles Pearce, have hereunto
set my hand and seal, this Twenty-fourth day of October, in the year
of our Lord One thousand eight hundred and sixty-six.
JOHN CHARLES PEARCE. (L.8.)