IMPROVEMENTS IN APPARATUS FOR GENERATING AND ECONOMISING STEAM
Year: 1856

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
"IMPROVEMENTS IN APPARATUS FOR GENERATING AND ECONOMISING STEAM.”
Sealed the 18th July 1856, and dated the 22nd May 1856.
PROVISIONAL SPECIFICATION left by the said John Charles Pearce at.
the Office of the Commissioners of Patents, with his Petition, on the
22nd May 1856.
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 In-
vention for "IMPROVEMENTS IN APPARATUS FOR GENERATING AND ECONOMISING
STEAM," to be as follows:-
My Invention relates to improvements to be used in the construction of.
steam boilers and furnaces so as to secure superior strength and general
efficiency. Lemploy T-ribbed and other sections of iron which, being bent into
rings, hocps, or other suitable forms, are rivetted to the edges of the adjoining
plates, or to the edges of each other, as the case may require, for giving
additional strength to the fire-boxes, flues, and other parts of such boilers. In
some cases I produce increased stiffness by simply turning up the edges of
ordinary boiler plate parallel with the rivet holes; this method of strengthening
requires the rivet holes to be punched farther from the edges of the plate than
the distance necessary to form the lap joint. In order to secure within the
Price d

page_text: body of an ordinary cylindrical boiler ample breath of fire grate and flue,
preserving at the same time sufficient space above for water and steam, I
make the transverse section of the internal flue somewhat resembling the
letter D, with its straight side upwards; and in order to prevent collapse or
giving way under pressure, I form the top into a series of undulations shewing
in the longitudinal section a wave line running from end to end of boiler; or,
I secure the necessary stiffness by composing the top of the furnace-flue of a
series of curved plates with their convex sides downwards. I also apply these
methods of strengthening the tops of flues and furnaces to a novel form of
steam boiler, in which I omit the lower part of the cylindrical body, and unite
the lowermost edges of the flue sides to the corresponding edges of the plates
composing the sides of the boiler-body, thus forming a broad passage with
parallel straight sides and open bottom extending from end to end of the
boiler. At the mouth or entrance of this passage or flue the furnace is situated,
which, for the purpose of more effectually consuming the smok, is provided
with two sets of grate bars, an upper set and a lower set, arranged so that the
fuel from the former is deposited upon the latter in a partially consumed state.
These bars may be constructed so as to be easily moved .n a vertical direction
for regulating the admission of air to the furnace, and also for the convenience
of the stoker in clearing the fire.
In order to get rid of the very objectionable friction, and the consequent loss
of steam experienced in the working of slide valves, I make use of a loose
adjustable plate, which is kept in close contact with the back of the valve by
means of adjusting screws. The valve is a simple frame, its front and back
faces being perfectly parallel, and of similar form and dimensions. In the
adjustable plate, on that side next the valve, compensating recesses are formed
opposite and similar to the steam passages. Steam from the boiler is conveyed
to the interior of the valve instead of into the valve-box, as is usually the case,
where it acts with its full pressure upon the adjustable plate; tending to force
it off the valve, and thus holding it firm against the adjusting screws, while
the valve is at liberty to slide easily in either direction, as required, in opening
and shutting the steam passages.
In the construction of metallic packing for pistons, I form grooves or
channels around the interior of the packing-rings for the reception of other
rings; which possessing considerable elasticity act as springs in forcing the
outer rings against the surface of the cylinder in which the piston works. The
compound packing, consisting of outer and inner rings, as here described,
is accurately fitted between the flanches, or into suitable grooves formed
around the piston. The outer or packing-riugs are cut through in one or
:

page_text: more places, but I prefer the inner or spring rings cut only in one place; both
inner and outer rings are put together so as to break joint. In some cases I
employ other springs, for the purpose of pressing the packing rings against
the flanches or sides of the grooves in which they are placed.
By these improvements I am enabled to produce metallic packing applicable
to piston bodies of any construction, which from its superior elasticity and
lightness is calculated to effect considerable economy in the use of steam.
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
18th November 1856.
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-second day of May, in the year of our Lord One
thousand eight hundred and fifty-six, in the nineteenth 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 lawfullymight 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 APPARATUS FOR
GENERATING AND ECONOMISING STEAM," upon the condition (amongst others) that
I, the said John Charles Pearce, my executors or administrators, by an instru-
ment 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 perforined, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and im-
mediately 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 per-
formed, to be particularly described and ascertained in and by the following
statement :-
The first part of my Invention relates to improvements in the construction

page_text: of steam boilers, furnaces, and flues, in order to secure superior strength and
general efficiency. I employ T-shaped, ribbed, and other sections of iron, as
shewn in Figures 1 and 2 of the accompanying Drawings, which, being bent
into rings,hoops, or otherwise suitably formed, are rivetted to the edges of the
adjoining plates,or to the edges of each other,as the case may require, to give
the necessary strength to the fire-boxes and flues, or other parts of such boilers.
In some cases I produce great additional stiffness by simply bending the edges
of the ordinary boiler-plate parallel with the rivet holes, as shewn in Figure 3.
These turned-up edges of the plates, and also the ribs shewn in Figures
1 and 2, should never be exposed to the direct action of the fire, but arranged
so as to be in contact with the water inside the boiler, where they will be found
very convenient for the attachment of stays and tie rods.
In order to secure within an ordinary cylindrical boiler of limited diameter
ample area of fire-grate and upper flue surface, preserving at the same time
sufficient space for water and steam, I make the transverse section of the
internal flue of a D-shape, with the straight side upwards, and to avoid collapse
or giving way under pressure, I employ the methods of strengthening the
plates herein-before described; or I form the top of the furnace flue into a
series of undulations shewing, in the longitudinal section a wave line running
from end to end; or I secure the necessary strength by composing the top of
the furnace flue of a series of curved plates with their convex sides placed
downwards.
Figure 4 is a transverse section, and Figure 5 a longitudinal section, of a
cylindrical boiler constructed in accordance with these improvements. Instead
of cutting away the upper edges of the flue sides to correspond with the unda-
lations of the roof, I prefer making them straight, as shewn at a, a, Figure 4,
and by the dotted line a, a, Figure 5. In the Drawing this boiler is shewn to
be set in brick-work, with side and bottom flues for the passage of heat in the
ordinary way; but in some cases I combine my improvements with a series of
small tubular flues extending from a suitable distance beyond the fire-bridge
to the end of the boiler; these tubes being surrounded with water and pre-
senting a large internal surface for the absorption of heat enable me to
dispense with the external brick flues.
I also apply these methods of forming and strengthening the tops of flues
and furnaces to a novel construction of boiler, in which I omit the lowermost
part of the cylindrical body, and unite the lowermost edges of the flue sides to
the corresponding edges of the plates composing the sides of the boiler, thus
forming abroad passage with parallel straight sides and open bottom extending
from end to end of the boiler.

page_text: Figures 6 and 7 are respectively a transverse section and a longitudinal
section of one of these boilers. The furnace situated beneath the front end,
as shewn in Figure 7, is provided with two sets of grate bars, an upper set aud
a lower set, arranged so that the fuel from the former is deposited upon the
latter in a partially consumed state. These bars are constructed so as to be
easily moved in a vertical direction by means of the handle b and the double
lever c upon the shaft d, which cause the adjacent ends of each set of bars to
move simultaneously in opposite directions, so that the two grates can be
readily set to form one even inclining surface or two distinct surfaces of various
inclination, as shewn by the dotted lines at e, e. This arrangement of the
grate bars enables the stoker to regulate the admission of atmospheric air to
the body of the fire in order to promote more perfect combustion of the fuel
and gases; it also facilitates the operation of cleansing the fire.
The second part of my Invention relates to the arrangement and construc-
tion of slide valves suitable for steam engines and a variety of other useful
purposes. In order to get rid of the very objectionable friction, and the con-
sequent loss of steam experienced in the working of slide valves, I employ a
loose adjustable plate, kept in close contact with the back of the valve by
means of adjusting screws passing through the valve case. The valve is a
simple frame, its front and back faces being perfectly parallel, and of similar
form and dimensions. In the adjustable plate, on its side next the valve.
compensating recesses are form d opposite and similar to the steam ports.
Steam from the boiler is conveyed to the interior of the valve instead of into
the valve-box, as is usually the case, where it acts with full pressure upon the
adjustable plate, tending to force it off the valve, and thus holding it firm
against the djusting screws, while the valve is at liberty to slide easily in
either direction, as required in opening and shutting the steam ports.
In Figures S and 9 on the Second Sheet of the accompanying Drawings,
I have shewn a longitudinal section and a cross section of one of my improved
valves applied to an ordinary steam engine cylinder, adapted to either vertical
or horizontal position. is the adjustable plate, fitting loosely into the valve-
box sideways, and kept in position end ways by the projections b, b. c,, are
the adjusting screws provided with lock nuts, and tapped through the valve
case for keeping the plate a in close contact with the valve. Steam is con-
veyed through the branch pipe e, Figure 9, and central port f, Figure Sinto
the interior of the valve, where it exerts its full pressure upon the plate a,
thereby forcibly holding it against the ends of the screws c,c, while the valve
is at liberty to slide freely between the parallel surfaces of theadjustable plate
and cylinder face. The motion of the valve is regulated by the rod g passing

page_text: through the stuffing box h. By reference to the Drawing, Figure 8, it will be
seen that, when the valve is at half stroke, the two thoroughfares s, sl, will be
closed on the steam sides, in which position the valve will be perfectly balanced
as regards the pressure of the steam within it; and in order to preserve the
balance in all other parts of the stroke, the compensating recesses are formed
in the adjustable plate, as shewn at n, n, n², but more distinctly at n, n', n²,
Figure 10, which is a face view of that side of the plate in contact with the
valve. On opening the thoroughfare to admit steam to the cylinder, the valve
will assume the position sewn in Figure 8, when that portion of its face over
the thoroughfare, as seen at s, will be exposed to the steam pressure; but there
being always a corresponding area of the opposite face of the valve exposed to
a similar pressure within the recess n, the balance of the valve will remain
undisturbed. And on closing the thoroughfare to prevent further admission of
steam to the cylinder, the equilibrium of pressure of the steam within the
ports, and the corresponding recess n will be preserved by means of the small
passages through the valve face, shewn by the dotted lines, but more dis-
tinctly by the small circles a, a, in the face view of the valve, Figure 15, so
that the balance of pressure upon the valve is still perfectly maintained. The
motion of the stean into and out of the cylinder is indicated by the arrows,
The branch pipes for the ingress and egress of steam are shewn ate and m,
Figure 9; the latter, it will be observed, being in immediate communication
with the interior of the valve case, may be formed in the valve case itself
thereby dispensing with the side passage p.
In some cases I employ two of my improved valves connected together by,
a rod for one cylinder, as shewn in Figures 11 and 12; and I prefer this
arrangement for long cylinders, as it enables me to avoid an objectionable
length of steam passage. In the upper part of Figure 11,which is a vertical
section of valve case and part of cylinder, I have shewn the nozle plate, or
valve face plate, as it is sometimes called, as a separate casting, fixed to an
ordinary branch upon the cylinder, but in the lower part of the section I have
shewn this plate as cast in one piece with the cylinder. The steam pipe is
attached by a branch or otherwise to any convenient part of the face plate, as
ate, and steam is conveyed therefrom to the valves by means of the passager, r,
at the back of the plate. The exhausting branch is situated at m, and the
other letters of reference apply to parts corresponding with those already
described in Figures 8 and 9.
Figures 13 and 14 are longitudinal and transverse sections of one of my
improved valve, adapted to a compound or double cylinder engine, for using
the steam twice over. a is the adjustable plate; c, c, the adjusting screws;

page_text: d, the slide, with division plate, for separating the steam of the respective
cylinders; the main steam passage; 8, 8, the thoroughfares of the high
pressure cylinder; and 2,3, the thoroughfares of the low pressure cylinder ;
c, the steam pipe, and m, the exhaust pipe. On reference to Figure 13 it
will be seen that the upward motion of the valve allows the steam from the
low-pressure cylinder to escape through the ports into the exhausting pipem,
at the same time steam is conveyed into the opposite end of the same cylinder
out of the high-pressure cylinder by way of the ports, 3, and also at the
same time fresh steam is supplied to the opposite end of the high-pressure
cylinder from the central passage f through the port 8. In like manner it
will be seen that the reverse motion of the valve produces a corresponding
opening of the ports on the return stroke of the engine.
The third part of my Invention relates to improvements in the construction
of metallic packing for pistons, by means of which I effect considerable
economy in the use of steam. In the construction of my improved packing, I
form a groove or a series of grooves around the inner surface of the packing
ring for the reception of other rings possessing considerable elasticity, which
act as springs to force the packing or outer ring against the surface of the
cylinder in which the piston works. Figure 19 is a transverse section of my
improved packing. is the outer packing or wearing ring; and b, b, b, the
inner spring rings. The number and form of section of the spring rings may
be varied at will. I sometimes employ 4 or 5 such rings, and at other times
only 1 or 2, as shewn in Figure 20. I prefer the packing or outer ring of
uniform section, being of the exact diameter of the cylinder, and cut through
in a slanting direction to admit of expansion when worn, as shewn at c,
Figure 16. The spring rings may also be of uniform section, but they must
be of considerably larger diameter than the interior of the packing, so as to
insare sufficient elasticity to force the latter against the surface of the cylinder.
These rings, when released from the packing, assume the form shewn in
Figure 17. In the construction of large pistons it is sometimes preferable to
make the spring rings of tapering section in order to obtain more uniform
elasticity, as shewn in Figure 18. In putting therings together it is necessary
to force the ends of the packing apart sideways for the purpose of getting in
the springs, as shewn in Figure 21, and care should be taken to dispose the
joints at equal distances from each other, so that any inequality in the elasticity
of one ring may be counteracted by the others, in order to preserve the correct
circular form of the outer ring. When the packing is complete, ready for
being placed in the piston, the united elasticity of the inner rings causes the
joint of the outer ring to open considerably, as shewn at Figure 22. The

page_text: packing thus described is accurately fitted between the flanches of the piston
in the usual manner, as shewn at d, Figure 16, which is a half section and a
half elevation of a complete piston. To prevent the escape of steam through the
bevel joint of the packing ring, narrow strips of brass are accurately fitted into
snitable recesses so as to cover the ioints,as shewn at 8,8, Figures 16, 19,and20.
Having thus described my Invention, and the man ner in which the same
may be performed or carried into practical operation, I desire it to be under-
stood that do not confine myself to the precise details or arrangements herein
specified, provided the peculiar character of my said Invention be retained;
but what I do claim is,-
First, the modes of strengthening fire boxes, flues, and other parts of steam
boilers by means of ribs formed upon the plates, as before described.
Second, the bending or flanching the edges of the plates for giving additional
strength, as before described.
Third, the construction of fire boxes and flues with undulating roofs or
otherwise, as before described.
Fourth, the construction of furnaces with two sets of bars and apparatus for
moving the same, as before described.
Fifth, the general construction and arrangement of balanced slide valves, as
before described.
Sixth, the employment of one or more adjustable plates, provided with com-
pensating recesses and adjusting screws, to act as before described.
And, seventh, the construction of metallic packing for pistons, as before
described.
In witness whereof, I, the said John Charles Pearce, have hereunto set
my hand and seal, this Seventeenth day of November, One thousand
eight hundred and fifty-six.
JOHN CHARLES PEARCE (L.S.)