IMPROVEMENTS IN STEAM BOILERS
Year: 1873

page_text: LETTERS PATENT to George Hermann Babcock, of Plainfield, Union
County, in the State of New Jersey, and Stephen Wilcox, of
Brooklyn, King's County, in the State of New York, both in the
United States of America, for the Invention of "IMPROVEMENTS IN
STEAM BOILERS,"
COMPLETE SPECIFICATION filed by the said George Hermann Babcock
and Stephen Wilcox at the Office of the Commissioners of Patents,
with their Petition and Declaration, on the 27th March 1873, pursuant
to the 9th Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, We, GEORGE
HERMANN BABCOCK, of Plainfield, Union County, in the State of New
Jersey, and STEPHEN WILCOX, of Brooklyn, King's County, in the State
of New York, both in the United States of America, send greeting.
WHEREAS we are in possession of an Invention for "IMPROVEMENTS
IN STEAM BOILERS," and have petitioned Her Majesty to grant unto us,
our executors, administrators, and assigns, Her Royal Letters Patent for

page_text: the same, and have made solemn Declaration that we are the first and
true Inventors thereof.
NOW KNOW YE, that we, the said George Hermann Babcock and
Stephen Wilcox, do hereby declare the following Complete Specifi-
cation, under our hands and seals, fully describes. and ascertains the
nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to
say :-
.
The Invention applies to that class of boilers which exposes the water
in inclined tubes, and induces an active circulation of water through the
tubes. We have devised an improved mode of construction of the parts
at the ends of the tubes, and improvements in the connection of the work
at the back and lower ends of the inclined series of tubes to the larger
vessels or separating chamber above in which the steam separates from
the water..
The following is a description of what we consider the best means of
carrying out the Invention.
Figure 1 is a side elevation partly in section; Figure 2 is an end
elevation partly in section; Figures 3 & 4 represent certain portions on
a larger scale. Similar letters of reference. indicate like parts, in all the.
Figures.
A is a large vessel of boiler iron or other suitable material, in which a
considerable body of water is retained, and in which a large surface is
allowed for the separation of the steam therefrom; B, B, are inclined
tubes which form the main heating surface of the boiler; C is the
furnace or fire-place. The hot products of combustion rising therefrom
are caused to cross the series of tubes circulating actively between the
space between them several times. These parts with the bridges or
partitions which compel the gases to thus move, and the masonry of the
wall which surrounds and encloses the whole may be of the long known
and well approved constructions.
We have successfully constructed a great number of this class of
boilers. The present Invention is the result of long continued
endeavours to increase their operation. Instead of threading the ends

page_text: -
of the tubes B, & screwing each into a separate small cast-iron
chamber, and then bolting the several chambers together by a bolt
extending up and down to form a series, we adopt a plan which equally
allows the boiler to be made in sections, and overcomes many objections
previously obtained. We stagger the tubes, or fix them in holes
arranged zig-zig, and form a single chamber for the ends of a whole
series, that is to say, the whole number of tubes in our present boiler
is divided, as in our previous boilers, into sections, each section including
a series of tubes arranged vertically or nearly vertically over each other,
and capable of being applied and removed in a mass, so that we can
form these tubes into sections in the shop, and aggregate together a
greater or less number of sections as may be required to constitute any
given boiler. We make a single casting for each end of each section.
In order to give a sufficient strength, we produce these castings of steel,
using therefor in their manufacture all the care and skill necessary for
the production of sound and perfect castings, the holes for the tubes
being cored a little less than the proper size and then bored properly to
receive the tubes. D¹, D³, represent these peculiarly crooked castings
adapted to recieve the staggered tubes to match together in series as
shown; D is the casting at the back and lower end, and D2 the
casting at the forward and upper end.
We provide hand holes d with tight fitting covers E, arranging a
hand hole opposite the end of each tube. We employ tubes with soft
iron ends without threading, the same as are used in the best class of
tubular boilers, and set them in place in the castings D¹, D³, by
expanding them by an expanding tool, the connection when finished
being of the same character as the junction of the tube ends to the
tube sheets in ordinary boilers; our small castings, being of steel of
proper thickness allow the strain due to this mode of fastening. This
construction avoids the necessity for making the great number of tight
fitting joints heretofore necessary between the separate castings, one of
which was joined to the end of each tube separately. It avoids also the
necessity for the strong compressing bolt which previously extended up
and down through the series of sections at each end.; it allows the end
castings to be crooked so that the tubes may be perfectly staggered as
shown, and it diminishes the weight of the structure and increases the
water and steam capacity with the given volume of boiler; it increases
the freedom of the circulation of the water and the steam.
We

page_text: esteem especially important the fact that it allows tubes to be removed
and replaced without disturbing the neighbouring tubes..
In our former arrangement when a tube from any cause became
defective, it was necessary to separate the tubes, and if the defective
tube was in a central section, to seperate the several sections. Then
having removed the tube with the small casting at each end from its
neighbours, the tube was unscrewed from the casting and a new tube
set in it, or preferably a new tube with new castings was introduced in
its place, and the whole operation must be repeated in the reverse order,
that is to say, all tubes in that section must be again bolted together
steam-tight, and the section must be restored to its place, and the whole
again.secured.
Our improved construction greatly reduces the labor of such an
exchange. The end castings will rarely if ever require renewal. It is
the tubes alone which fail. When the tube is found to be leaky or
becomes warped or otherwise defective, the hand holes d adjacent to the
ends thereof, are opened by simply removing the two covers E, E, one at:
each end of that tube, and a proper tool being introduced the tube is
cut out and a new one is inserted and made tight by an expanding tool.
used first. The other tubes in the section and the other sections are not
disturbed in the least.
The front castings D2 are united to the main vessel A by horizontal
bolts g as shown. To connect the back castings D₁ to the main vessel A,
we provide connections peculiarly adapted to allow for the slight
imperfections and inequalities liable to occur in such work.
The main length of these several connections are wrought iron. They
may be in the form of thin wrought iron tubes tightly set in castings at
each end. The employment of wrought iron for the main body of these
connections allows a high degree of elasticity; the castings at the lower
ends serves simply as flanges to bolt to the casting D¹ below; the
castings at the upper end serve to present faces, the plane of which is
parallel to the axis of the wrought iron connections. They match on
corresponding faces formed on the main vessel A, and the faces being
truly finished they will form tight connections whether they match
together at exactly the proper level, or a little above or below.
Referring to Figure 1, these peculiar wrought iron connections with
cast ends thus faced, are represented by I, I', I². I is the main wrought

page_text: iron portion, I the lower flange, and I the upper casting which
presents the face in an upright plane; J is a horizontal bolt adapted
to hold the casting A' tightly against the adjacent face of the main
vessel A. The inner end of the bolt should take hold of a vertical
cross-bar with a long hole, or be otherwise adapted to allow it to stand
at different levels. This mode of construction allows the joint to be
fitted tightly and perfectly whether the work is matched together, so
that all the several castings I shall come at exactly the same level, or
they should vary considerably. It is represented in the Figure as a
little below the best position; it may go still lower, or it may go a half
inch higher more or less without involving any want of tightness.
Having thus described the nature of our Invention, and the manner
of performing the same, what we claim is,-
First. A sectional boiler having inclined tubes in sections joined to a
separating vessel A, presenting a large surface for the separating
of the steam from the water, and having the ends of the sections
formed each of a single casting or connecting piece with a hand hole
opposite to each tube, which will allow the insertion of a new tube when
required, the tubes being connected and arranged substantially as
herein set forth.
Second. The sinuous pipes D1, D2, in combination with a series of
tubes B, B, fixed therein, and with hand holes d to allow of access to
the interior of the tubes, and of the removal and insertion of the same,
and adapted when placed side by side to produce a staggered position of
the tubes B, all substantially as and for the purpose herein set forth.
In witness whereof, we, the said George Hermann Babcock and
Stephen Wilcox, have hereunto set our hands and seals, this
Eleventh day of March One thousand eight hundred and
seventy-three.
GEORGE HERMANN BABCOCK. (L.S.)
STEPHEN WILCOX.
(L.S:)