IMPROVEMENTS IN APPARATUS FOR THE PRE- VENTION OF STEAM BOILER EXPLOSIONS
Year: 1866

page_text: LETTERS PATENT to. Edwin Bray, of Leeds, in the County of York,
Engineer, and John Crosby Hargreaves, also of Leeds, in the County
of York, for the Invention of." IMPROVEMENTS IN APPARATUS FOR THE PRE-
VENTION OF STEAM BOILER EXPLOSIONS."
Sealed the 24th October 1866, and dated the 27th April 1866.
PROVISIONAL SPECIFICATION left by the said Edwin Bray and John
Crosby Hargreaves at the Office of the Commissioners of Patents,
with their Petition, on the 27th April 1866.
We, EDWIN BRAY, of Leeds, in the County of York, Engineer, and JOHN
CROSBY HARGREAVES, also of Leeds, in the County of York, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR THE
PREVENTION OF STEAM BOILER EXPLOSIONS," to be as follows:-
., The object of our Invention is the prevention of steam boiler explosions,
which, as is well known, generally arise from one of two causes, either
excessive steam pressure or a deficiency in the water supply.
. Our improved apparatus is applicable to any class of boilers, and consists in
affixing over the furnace a small chamber made of brass or other suitable
material, and fitted with a copical valve (by preference). To this valve is

page_text: connected a lever of the first order, having its fulcrum on a projection ex-
tending from the valve chamber. The end of the longer arm of the lever
may be of a "fork" or "cross" formation, and is so cranked or otherwise
relatively to the seat of the valve that an ordinary water float (having a guide
spindle passing, if desired, into a locked chamber on the top of the boiler)
fitted in the usual manner may fall upon it and depress it, thus opening the
valve and admitting steam into the furnace when the water has become too
low. The fire having been extinguished and the steam exhausted a spring
affixed near to the fulcrum and under the longer arm of the lever restores
the valve to its normal position. In order, however, to meet the exigencies
of those cases where although the water is not too low the steam is at an un-
usually high pressure, still using the apparatus before named, we extend the
shorter arm of the lever and form a hole in the extremity of the same capable of
receiving a connecting rod, depending either from a spring pressure gauge affixed
to the top of the boiler or the lever of an ordinary safety valve. The maximum
steam pressure therefore being decided upon and the gauge or gauges having
been fixed in accordance any excess of pressure elevates the conical valve and
also the safety valve, when the two are connected by means of the connecting
rod before named, the effect being as in the first instance.
It will thus be seen that our first-named arrangement is efficient in case of
a low supply of water, and our united or second arrangement, either in a
similar case or when there is undue pressure of steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
' by the said Edwin Bray and John Crosby Hargreaves in the Great Seal
Patent Office on the 27th October 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, EDWIN
BRAY, of Leeds, in the County of York, Engineer, and JOHN CROSBY
HARGREAVES, also of Leeds, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh 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 us,
the said Edwin Bray and John Crosby Hargreaves, Her special licence that
we, the said Edwin Bray and John Crosby Hargreaves, our executors, adminis-
tatorid, and assigns, or such others as we, the said Edwin Bray and John Crosby
Hargreaves, our executors, administrators, and assigns, should at any time

page_text: 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 "In-
PROVEMENTS IN APPARATUS FOR THE PREVENTION OF STEAM BOILER EXPLOSIONS," upon
the condition (amongst others) that we, the said Edwin Bray and John
Crosby Hargreaves, our executors or administrators, by an instrument in
writing under our or their hands and seals, or under the hand and seal of
one of us or them, 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 Edwin Bray, on behalf of myself and
the said John Crosby Hargreaves, do hereby declare 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, that is to say:-
The object of our Invention is the prevention of steam boiler explosions,
which, as is well known, generally arise from one of two causes, either ex-
cessive steam pressure or a deficiency in the water supply."
Our improved apparatus is applicable to any class of boilers, and consists in
affixing over the furnace a small chamber made of brass or other suitable
material and fitted with a conical valve (by preference). To this valve is
connected a lever of the first order, having its fulcrum on a projection ex-
tending from the valve chamber. The end of the longer arm of the lever
may be of a "fork" or "cross" formation, and is so cranked or otherwise
relatively to the seat of the valve that an ordinary water float (having a guide
spindle passing, if desired, into a locked chamber on the top of the boiler)
fitted in the usual manner may fall upon it and depress it, thus opening the
valve and admitting steam into the furnace when the water has become too
low. The fire having been extinguished and the steam exhausted, a spring
affixed. near to the fulcrum, and under the longer arm of the lever, restores the
valve to its normal position. In order, however, to meet the exigences of
those cases where although the water is not too low the steam is at an' un
asually high pressure, still using the apparatus before named, we extend the
shorter arm of the lever and form a hole in the extremity of the same capable
of receiving a connecting rod, depending either from a spring pressure gauge
affixed to the top of the boiler or the lever of an ordinary safety valve. The
maximum steam pressure therefore being, decided upon and the gauge or

page_text: gauges having been fixed in accordance any excess of pressure elevates the
conical valve, and also the safety valve when the two are connected' by.
means of the connecting rod before named, the effect being as in the first
instance.
:
It will thus be seen that our first-named arrangement is efficient in case of
a low. supply of water and our united or second arrangement, either in a
similar case or when there is undue pressure of steam.
And in order that our Invention may be most fully understood we will
proceed to describe the manner in which we prefer to carry our Invention into
practice, reference being had to the Drawing hereunto annexed.
"
DESCRIPTION OF THE DRAWING.
Figures 1 and 2 show longitudinal sections of two boilers (with their
furnaces) having apparatus applied thereto arranged in accordance with our.
Invention for the purpose of preventing them from exploding by excessive.
pressure, of steam. The apparatus being similar in each Figure, as shown
separately on a larger scale at Figure 3, the same letters refer to corresponding
parts in each Figure.
in
1
- a is a tube or, chamber screwed or otherwise fixed into the boiler over
the furnace b, as shown, the tube or chamber a forming a communication
between the interior of the boiler and the furnace or fire space 6 when
the valve c is raised or opened; c³ is a lever connected to the valve c, and
moving on a: fulcrum at c³ carried by the arm or support a³, upon which a
lever d (of the first order) is mounted. To one end of the balance lever & the
water float, d¹, is suspended, a rod d³ being attached to the other end of the
lever, and d. is an adjustable stop or projection capable of being slid and fixed
any desired position on the rod d.. When the water in the boiler descends
below a safe level the descent of the, float with, it causes the stop or projection
d on the rod din rising to come in contact with the slotted or forked end
of the levers c',, so as to raise the valve.c (which is by preference conical) from
its seat, and, thus, cause the steam to be discharged on to the fire in the
furnace to lower and extinguish, it; by which means all danger of explosion
will be rapidly removed... On the admission of a proper supply of water to
the boiler. the, apparatus will at once readjust itself, the valve c assuming its
normal position. I would here remark, that the valve rod c may if desired be
a lever of. the first order, as previously stated, and the water float be arranged
so as to act in its descent, upon, the longer, end of the valve lever, or, a valve
lever c of this character may, be arranged to act upon a conical valve placed
at the lower end of the steam escape tube or chamber a, as shown at Figure 4

page_text: of the Drawing, the mode of acting upon the lever c¹ to open the inverted
valve c corresponding with the arrangement shown and described in reference
to Figures 1, 2, and 3. In order to afford additional protection from the
risk of explosion from excessive pressure we connect the valve lever c¹ by means
of a connecting rod c* with the safety or other valve, as clearly shown in
Figures 4 and 5 of the Drawing; or the valve lever may be connected with
a spring pressure gauge, as previously stated.
Having thus described the nature of our improvements we would remark
that the arrangement and construction of the apparatus herein-before described
may be considerably varied in detail without departing from the true character
of our Invention, which consists in so arranging a safety valve c in combination
with a water float of a steam boiler that in case of excessive pressure the
steam will be discharged direct on to the fire in the furnace to extinguish the
same should the water and float descend below a safe or proper level, as
herein described and shewn in the several Figures of the Drawing hereunto
annexed.
In witness whereof, I, the said Edwin Bray, have hereunto set my hand
and seal, this Twenty-fifth day of October, in the year of our Lord
One thousand eight hundred and sixty-six.
Witness,
J. G. TONGUE,
Patent Agent,
84, Southampton Buildings,
Chancery Lane, W.C.
EDWIN BRAY. (L.S.)