IMPROVEMENTS IN THE MEANS OR APPARATUS EMPLOYED FOR THE PREVENTION OF BOILER Ex- PLOSIONS
Year: 1873

page_text: LETTERS PATENT to John Crosby Hargreaves, of Hunslet, near Leeds,
in the County of York, for the Invention of "IMPROVEMENTS IN THE
MEANS OR APPARATUS EMPLOYED FOR THE PREVENTION OF BOILER Ex-
PLOSIONS."
PROVISIONAL SPECIFICATION left by the said John Crosby Hargreaves
at the Office of the Commissioners of Patents, with his Petition,
on the 9th May 1873.
I, JOHN CROSBY HARGREAVES, of Hunslet, near Leeds, in the County
of York, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN THE MEANS OR APPARATUS EMPLOYED FOR THE PREVENTION OF
BOILER EXPLOSIONS," to be as follows:-
:-

page_text: The object of my Invention is the provention of steam boiler
explosions which as is well known generally arise from one or two
causes, either excess of steam pressure or deficiency in the water
supply.
My improved apparatus is applicable to any class of boilers, and is as
hereafter described.
I affix over the furnace or furnaces a chamber connected with the
front end and back of each furnace by means of suitable pipes or tubes.
The chamber which I make of brass or other suitable material is fitted
with, by preference, two ball valves instead of one conical valve; to these
valves is connected a lever or levers of the first order, having its or their
fulcrum on a projection extending from the valve chamber or chambers.
The lever or levers is or are hung or supported on V" of a similar con-
struction to those usually provided for the scale beam of a weighing
machine instead of those shewn and described in the Specification of
the herein-before mentioned Patent.
The remaining parts not herein explained are of a similar description
to those described in the Specification of the hercin-before mentioned
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said
John Crosby Hargreaves in the Great Seal Patent Office on the
11th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JoпN
CROSBY HARGREAVES, of Hunslet, near Leeds, in the County of York,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of May, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Crosby Hargreaves, Her special
licence that I, the said John Crosby Hargreaves, my exécutors, adminis-
trators, and assigns, or such others as I, the said John Crosby Har-
greaves, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter

page_text: 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 THE MEANS OR APPARATUS EMPLOYED FOR THE PREVENTION OF
BOILER EXPLOSIONS," upon the condition (amongst others) that I, the said
John Crosby Hargreaves, 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 In-
vention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office on or before the
Eleventh day of November, One thousand eight hundred and seventy-
three.
NOW KNOW YE, that I, the said John Crosby Hargreaves, 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, reference being had to the accom-
panying Drawings and to the letters of reference marked thereon, that
is to say :-
My improvements have reference to an Invention for which Letters
Patent were granted to Edwin Bray and myself in the year 1866,
No. 1197.
The object of my Invention is the prevention of steam boiler
explosions which as is well known generally arise from one or two
causes, either excess of steam pressure or deficiency in the water
supply.
My improved apparatus is applicable to any class of boilers and is as
hereafter described.
I affix over the furnace or furnaces a chamber connected with the
front end and back of each furnace by means of suitable pipes or tubes.
The chamber which I make of brass or other suitable material is fitted
with, by preference, two ball valves instead of one conical valve; to these
valves is connected a lever or levers of the first order, having its or their
fulcrum on a projection extending from the valve chamber or chambers.
The lever or levers are hung or supported on V" of a similar con-
struction to those usually provided for the scale beam of a weighing
machine, instead of those shown and described in the Specification of the
herein-before mentioned Patent.

page_text: The remaining parts not herein explained are of a similar description
to those described in the Specification of the herein-before mentioned
Patent.
In order that my Invention may be more completely understood
reference is given to the accompanying Sheet of Drawings in which
Figure 1 is an end elevation, and Figure 2 a cross section of my
apparatus.
Figures 3, 4, 5, 6, 7, and 8 shew different modes of applying tho
same.
My apparatus is applicable to any class of boilers and is as hereafter
described. a is a chamber or chambers which I make of brass or
other suitable material, provided with two openings into which are fitted
the valves b and c which, by preference, I make of a ball shape as shown;
to these valves is connected a lever or levers d of the first order, and
having its or their fulcrum on a projection e extending from the valve
chamber or chambers a.. The lever or levers d are hung or supported
on V's of a similar construction to those usually provided for the scale
beam of a weighing machine, instead of those shewn and described in
the Specification of the herein-before mentioned Patent.
The lever is provided with a float h at one end, of ordinary con-
struction, and a counterbalance weight i at the other; this lever g is
also suspended on the projection e and supported on V's j. By means
of this lever the motion imparted to the float by the reduction of water
in the boiler is transmitted to the lover & through the rod ď.
The various modes of applying this valve arrangement are clearly
shown at Figures 3, 4, 5, 6, 7, and 8.
Figures 3 and 4 shew the application of my Invention to single
flued Cornish boilers; Figures 5 and 6, to double flued Cornish boilers;
Figures 7 and 8, to boilers with external flues.
The herein described apparatus is placed within the boiler and may be
connected to the front and back of each furnace, as shewn at Figure 7,
by suitable pipes or tubes. Instead of being connected at the back and
front one pipe or tube only may be passed into each furnace, as shewn
at Figures 5 and 6. It will be readily understood that as the water
lowers in the boiler the float h is carried with it, actuating thereby the
lever & through the rod d', whereby the valve c is first lifted from its

page_text: seat, allowing a quantity of steam to pass into the chamber or chambers
from thence through the tubes or pipes on to the fire, whereby an alarm
is given at once to the attendant; should his attention not be drawn by
this the water will continue to lower in the boiler and the lever or
levers d continue to rise until the valve is opened, when a much larger
quantity of steam is thrown into the fire which immediately extin-
guishes it, preventing collapsing of tubes or flues or further danger
arising from shortness of water.
Having now described the nature of my said Invention and the
manner in which the same may be performed, I would remark in con-
clusion that I do not limit myself to the exact limits, details, and
configuration of parts I have explained and shewn, as the same may of
course be varied or modified without in any way departing from the
nature of my Invention. But what I do claim and desire to be secured
to me by Letters Patent are,—
Firstly. The application of a ball valve or valves b and c in com-
bination with a chamber a, substantially as and for the purposes herein
set forth.
Secondly. The arrangement and combination of various parts forming
the apparatus, substantially as and for purposes herein set forth.
In witness whereof, I, the said John Crosby Hargreaves, have here-
unto set my hand and seal, this Eighth day of November, in
JOHN CROSBY HARGREAVES. (L.S.)