AN IMPROVED APPARATUS FOR PREVENTING EXPLOSION IN STEAM BOILERS
Year: 1858

page_text: LETTERS PATENT to Rudolph Bodmer, of 2, Thavies Inn, Holborn, in
the City of London, for the Invention of "AN IMPROVED APPARATUS FOR
PREVENTING EXPLOSION IN STEAM BOILERS."-A communication.
Sealed the 15th March 1859, and dated the 24th September 1858.
PROVISIONAL SPECIFICATION left by the said Rudolph Bodmer at the
Office of the Commissioners of Patents, with his Petition, on the
24th September 1858.
I, RUDOLPH BODMER, of 2, Thavies Inn, Holborn, in the City of London,
do hereby declare the nature of the said Invention for "AN IMPROVED
APPARATUS FOR PREVENTING EXPLOSION IN STEAM BOILERS," (a communication
from a foreigner residing abroad,) to be as follows:-
This Invention consists of a self-acting apparatus, by which the fire under
the boiler is extinguished as soon as the water from evaporation or other
causes goes down below a certain level; and the manner in which the same is
to be performed and carried into effect will be seen by reference to the
annexed Diagram, which represents one modification of this Invention.
In the annexed sectional Diagram, A is a tube or pipe, one end of which

page_text: passes down into the water in the boiler to a point which is intended to be the
lowest level of the water at any
a
time, and the other end of which
passes through a collar or stuffing
box into the box or case a, a, a, a.
This box a, a, a, a, is perfectly
steam-tight, and is placed in any
convenient position above the
boiler. The upper end of the
pipe B is screwed into the lower a
side of the box a, a, a, a, where
it is closed by the vibrating arm
G pressed down by a small spring,
which forms a valve opening in-
wards to the interior of the box
The other extremity of the tube B is carried under the boiler into
the fire-place.
Now, supposing the boiler to be filled with water to a proper level, the
lower extremity of the pipe A will be considerably below the surface, and
as soon as the steam is generated, water will be forced up the pipe A, and
into the box a, a, a, a, where it is arrested by the valve formed by the arm G
on the top of the pipe B. In this position the apparatus remains stationary
as long as the water in the boiler remains at its proper level, but as soon as
the water in the boiler gets too low and leaves the end of the pipe A free, the
water in the pipe flows out, and steam rushes into its place. At this period
the superior temperature of the steam expands the pipe A, which by its
elongation presses against the vibrating arm G, and opens the valve formed on
the top of the pipe B. The steam filling the box a, a, a, a, proceeds forward
down the pipe B and under the boiler to the fire, which is thereby extinguished,
and all further chance of explosion avoided.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Rudolph Bodmer in the Great Seal Patent Office on the
24th March 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RUDOLPH
BODMER, of 2, Thavies Inn, Holborn, in the City of London, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of September, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Rudolph Bodmer, Her special licence that I, the said Rudolph
Bodmer, my executors, administrators, and assigns, or such others as I,
the said Rudolph Bodmer, 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 "AN IMPROVED
APPARATUS FOR PREVENTING EXPLOSION IN STEAM BOILERS," (a communication,)
upon the condition (amongst others) that I, the said Rudolph Bodmer, 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 Rudolph Bodmer, 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 fol-
lowing statement (that is to say) :-
My Invention consists in the adaptation and arrangement of a tube, made
of copper or other suitable metal or material, and of sufficient length to give
the requisite amount of expansion necessary to actuate a depressing lever when
the escape valve requires to be opened. The construction of my improved
apparatus will be understood by reference to the accompanying Drawing, in
which Fig. 1 represents a sectional view of my improved apparatus, Figs. 2
and 3 are side views of the general arrangement, and Fig. 4 an enlarged
section, shewing the moving parts of the apparatus.
In these Figures A is the expanding copper tube; B, the common or
ordinary tube inside of the boiler; C, the box; D, iron pillar; E, outlet of
steam; F, ordinary tap or valve; G, continuation of tube with bell-shaped
5 vessel; H, valve inside the bell-shaped vessel; I, the lever; J, J, the nuts
and screw for adjustment; K, spiral spring; L, the whistle; and M, a pipe.
In these Figures the expanding tube A is screwed into an ordinary tap
placed on and screwed to the boiler. To the under side of the tap or valve

page_text: (and inside the boiler) I attach a piece of ordinary or common tubing B,
which is continued down to the point near the flue at which it is determined
to limit the fall of the water before the danger signal is to be brought into
operation. Over the copper tube A, on the outside of the boiler, I place a
hollow iron pillar D, with longitudinal openings to allow the free circulation
of air around the copper tube A. This pillar serves as a protection to the
tube A, and also as a support for a box C, having a railway whistle mounted
on the top, and an outlet opening E on one side; this box is bolted to the iron
pillar D, and within it is mounted an inverted bell-shaped vessel, having a
tube G, which descends through a stuffing box, and is connected to the copper
expansion tube A by means of a screw joint and nuts, the stuffing box
allowing the tube G to move freely therein as the expansion and contraction
of the copper tube A varies. At the bottom of the bell-shaped vessel on the
tube G, there is placed a valve H, having the face of its seating on the under
side; and this valve H is provided with a spiral spring K on the upper side,
which has a tendency to keep the valve shut against its seating. A little
higher on the box a bar or perforated disc carries a pin, upon which is
mounted a lever I, having its longest end resting on the valve H, whilst the
shortest end is brought into contact with the edge of the bell-shaped vessel
on G. When the water in the boiler is higher than the bottom end of the
pipe B, the copper tube A will be either partially or wholly filled with water
forced up by the pressure of the steam, and the valve H being kept in contact
with its seating by the spiral spring K, the orifice will be closed; but so soon
as the water falls below the bottom of the pipe B, the water in the tube A
will flow back into the boiler, and the steam will take its place. This steam
will instantly heat the copper tube A and cause it to expand or elongate; and
by this means the edge of the bell-shaped vessel on G will press up the short
end of the lever I, and cause it to press down the valve H, thereby allowing
the steam to escape. This rush of steam sounds the whistle L (or danger
signal), and at the same time passing through the outlet E, a portion of the
steam is conveyed to the fire by the pipe M, for the purpose of extinguishing
it: At Figs. 2 and 3 the openings in the iron pillar D are seen for the
purpose of allowing a free circulation of air to keep the tube A cool, whilst
the water remains at a suitable height to ensure safety, and it also shews the
contrivance I have adopted for preventing the apparatus from being tampered
with, namely, a door secured by lock and key at X.
Having thus described the nature of my Invention, and the manner of
carrying the same into effect; I would have it understood that I make no claim

page_text: to any of the parts separately; but what I do claim as of my Invention is, the
combination of the whole of the parts forming an improved apparatus for
preventing explosions in steam boilers, which acts by giving a danger signal,
and extinguishing the fire when the water becomes too low in a steam boiler,
as herein-before described.
In witness whereof, I, the said Rudolph Bodmer, have hereunto set my
hand and seal, this Eighteenth day of March, in the year of our Lord
One thousand eight hundred and fifty-nine.
RUDOLPH BODMER. (L.8.)