IMPROVEMENTS IN. STEAM BOILERS
Year: 1869

page_text: LETTERS PATENT to Alexander Chaplin, of Lavender Hill, in the
County of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN.
STEAM BOILERS."
Sealed the 28th June 1870, and dated the 31st December 1869.
PROVISIONAL SPECIFICATION left by the said Alexander Chaplin at
the Office of the Commissioners of Patents, with his Petition, on.
the 31st December 1869.
I, ALEXANDER CHAPLIN, of Lavender Hill, in the County of Surrey,.
Engineer, do hereby declare the nature of the said Invention for "Im-.
PROVEMENTS IN STEAM BOILERS," to be as follows:-
This Invention has for its object by an improved construction to
render steam boilers of moderate size capable of easy cleaning and
repairs, whilst being economical in first cost, and capable of being con-
veniently made of better proportions than boilers of a similar class as
hitherto constructed.
The Invention consists in making the boiler in upper and lower parts
which can be easily separated; the lower part is a water casing sur-

page_text: rounding and forming the fire-box, and consists of two shells of a
cylindrical, conical, or other convenient form rivetted or welded upon
rings at the top and bottom; the upper part is of a cylindrical or other
convenient form with a dome-shaped top or steam space, whilst its bottom
forms the roof of the fire-box. It is formed with a single central vertical
flue tube, or with several tubes of sizes inversely proportioned to their
number. When there is a single central flue tube water tubes with
closed bottom ends may in some cases be fixed in the bottom of the
upper part so as to project down into the fire-box. The two parts of the
boiler are fixed together by bolts entered into the upper ring of the
bottom part, being screwed up inside the upper part, access to which is
got by a man-hole door. All or any convenient number of the bolts
may be made tubular to form communications for water and steam
between the two parts of the boiler, or if the joint between the two parts
is made steam-tight (which is not necessary otherwise), holes may be
left without bolts to provide the necessary communications, the bolts may
either be fixed in the ring and receive nuts inside the upper part of the
boiler, or they may be headed screw bolts screwed from the upper part
down into the ring. In either case the point of the bolt is made slightly
shorter than to project through the nut or ring so that the thread will
be kept always covered and so provented from rusting.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Chaplin in the Great Seal Patent Office
on the 29th June 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
CHAPLIN, of Lavender Hill, in the County of Surrey, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of December, in tho
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Chaplin, Her special licence
that I, the said Alexander Chaplin, my executors, administrators, and
assigns, or such others as I, the said Alexander Chaplin, my executors,
administrators, and assigns, should at any time agree with, and no

page_text: 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 BOILERS," upon the condition (amongst others) that I, the said
Alexander Chaplin, 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 Alexander Chaplin, 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 in writing, and on reference being
had to the accompanying Sheet of Drawings, that is to say :-
My said Invention has for its object by an improved construction to
render steam boilers of moderate size capable of being easily cleaned and
repaired and made of better proportions at a smaller first cost than boilers
of a similar class as hitherto constructed.
My Invention consists in making the boiler in upper and lower parts
which can be easily separated, the lower part being a water casing
surrounding and forming the sides of the fire-box, whilst the upper
part is of a cylindrical or other convenient form with a dome-shaped
or flat top or steam space, its bottom forming the crown of the
fire-box.
And in order that my said Invention and the manner of performing
the same may be properly understood, I have hereunto appended a Sheet
of explanatory Drawings to be herein-after referred to representing three
modifications of boiler embodying my improvements; the same reference
numerals are used to mark the same or like parts wherever they arc
repeated.
Figure 1 is a vertical section of one modification of my improved
boilers in which the lower or fire-box part is a cylindrical water casing 1
consisting of inner and outer shells rivetted, or as I prefer it welded on
upper and lower rings 2, 3. The upper part 4 is of a plain cylindrical
form with a dome-shaped top 5, whilst its bottom 6 forms the crown

page_text: of the fire-box 1; a single large flue tube 7 passes up centrally through
the upper part 4; the upper part 4 is fixed and connected to the fire-
box part 1 by a number of screw bolts 8 fixed into the upper ring 2
and projecting up through the bottom plate 6 of the upper part inside
which the nuts are screwed upon them. All or some of the screw bolts 8
are made tubular, as shown on an enlarged scale in Figure 2, for the
passage of the water. The feed water is led into the fire-box part 1 so
that there is a continual flow of the water from that part upwards into
the upper part 4 of the boiler, but if it is wished a circulation of the
water from the upper to the lower part and back again may be obtained
by having one or more of the tubular bolts 8 elongated, as shown at 9.
Instead of the screw bolts 8 being arranged as described they may consist
of headed tubular screw bolts screwed from the upper part down into the
ring 2, and in either case the point of the bolt is made short enough not
to project through the nut or ring so that the thread will be kept always
covered and thus prevented from rusting. Pendent tubes 10 are placed
at intervals round the outside of the bottom plate 6 of the upper part
to act as mud collectors, and each of them is fitted with a blow-off cock
as shown at 13 at its lower end; one or more of which cocks being
connected to the lower part of the water space in the casing 1 a strong
circulation of water may thus be established, all tendency to priming
prevented, and the steaming power of the boiler greatly increased.
Figure 3 is an elevation showing the upper part 4 as separated from
the lower part 1, also the application of a number of pendent water
tubes 11 with closed bottom ends, these tubes being screwed into or
otherwise fixed in the bottom plate 6 of the upper part to increase the
heating surface.
Figure 4 is a vertical section of a modification in which whilst the
fire-box part 1 is of a conical form the upper part 4 is comparatively
longer, and is traversed by a number of vertical flue tubes 12, which I
prefer to be of the kind successfully used by me for many years with a
contraction near the middle of each, as shown. The joint between the
upper and fire-box parts 4, 1, is only a smoke joint and not a steam
joint. There is no tendency to separate, and it can be readily made tight
by making the faces true and fair or by interposing a joint ring of lead.
In the latter case if the water should become too low this lead would be
melted and by allowing an escape of smoke would show that something
was wrong.

page_text: Having thus particularly described my said Invention and the manner
in which the same is to 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, the constructing of vertical steam boilers in "separating"
parts and substantially in the improved manner herein-before described.
In witness, I, the said Alexander Chaplin, have hereunto set my
hand and seal, this Twenty-eighth day of June, in the year of
our Lord One thousand eight hundred and seventy.
Witness,
BRISTOW HUNT,
Solicitor and Patent Agent,
1, Serle Street,
Lincoln's Inn.
ALEX. CHAPLIN. (L.S.)