IMPROVEMENTS IN SAFETY APPARATUS FOR STEAM BOILERS OR STEAM GENERATORS
Year: 1867

page_text: LETTERS PATENT to John William Kenyon and Robert Arthur Armitstead,
both of Manchester, in the County of Lancaster, Engineers, for the
Invention of "IMPROVEMENTS IN SAFETY APPARATUS FOR STEAM BOILERS OR
STEAM GENERATORS."
Sealed the 5th June 1868, and dated the 6th December 1867.
PROVISIONAL SPECIFICATION left by the said John William Kenyon and
Robert Arthur Armitstead at the Office of the Commissioners of
Patents, with their Petition, on the 6th December 1867.
We, JOHN WILLIAM KENYON and ROBERT ARTHUR ARMITSTEAD, both of
Manchester, in the County of Lancaster, Engineers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN SAFETY APPARATUS FOR
STEAM BOILERS OR STEAM GENERATORS," to be as follows:-
Our Invention is deseigned for the purpose of lessening the risk of the
explosion of steam boilers arising from a deficiency of water in the said
boilers, and consists in an improved apparatus intended to discharge a portion
of the water or steam, or of water and steam into the furnace or furnaces at
such times as the "water level" in the boiler is lowered to a dangerous
extent, and our Invention consists, in the first place, in employing the scum-

page_text: ming apparatus for which Letters Patent were granted to the John William
Kenyon of these Presents, bearing date the Third day of January in the
present year, as or in lieu of a float to govern the action of a safety apparatus
for the purpose herein above mentioned, the said safety apparatus being of
any suitable form or description, or it may be the improved apparatus next
immediately to be described. To the bottom of the boiler or the crown of the
furnace, or each crown of the furnaces, or to any other suitable part of
the interior of the boiler we attach a vertical or nearly vertical pipe or tube,
the upper end of which projects above the water into the steam space and is
fitted or formed with a valve seat, the lower end of the said pipe communi-
cating with the interior of the furnace. A valve of suitable form is fitted to
rest upon the valve seat on the upper part of the said tube, the said valve
being fitted or fixed to one end of a pipe of larger size than the one first
mentioned, the said larger pipe being of a suitable length to reach below the
"low-water level" when the valve is placed on its seat; the said valve is
connected with or attached to a lever or to levers fitted with a float or with floats,
or is connected with the scumming apparatus, as herein above mentioned, the
said connection being such that in the event of the water falling to the low
level the fall of the float or of the "scummers" raises the valve off its seat to
a certain extent, and a portion of water is discharged into the furnace. It is
preferred that the upper part of the annular space between the two pipes shall
le occupied by steam when the valve is closed, and to admit of this a small
perforation may be made in the upper part of the outer tube.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John William Kenyon and Robert Arthur Armitstead in
the Great Seal Patent Office on the 5th June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
WILLIAM KENYON and ROBERT ARTHUR ARMITSTEAD, both of Manchester, in
the County of Lancaster, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of December, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirty-first year of Her. reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
John William Kenyon and Robert Arthur Armitstead, Her special license
that we, the said John William Kenyon and Robert Arthur Armitstead, our

page_text: executors, administrators, and assigns, or such others as we, the said John.
William Kenyon and Robert Arthur Armitstead, our executors, adminis-
trators, 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 the Isle of Man, an Invention for " IMPROVEMENTS IN SAFETY APPARATUS
FOR STEAM BOILERS OR STEAM GENERATORS," upon the condition, ainongst
others, that we, the said John William Kenyon and Robert Arthur Armitstead,,
by an instrument in writing under our hands and seals, or under the hand and
seal of one of us, 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 Robert Arthur Armitstead, do
hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement and accompanying Drawings, that is to say :-
'
Our Invention is designed for the purpose of lessening the risk of the
explosion of steam boilers arising from a deficiency of water in the said
boilers, and consists in an improved apparatus intended to discharge a portion,
of the water or steam, or of water and steam, into the furnace or furnaces at
such times as the "water level" in the boiler is lowered to a dangerous extent;
and our Invention consists, in the first place, in employing the scumming
apparatus for which Letters Patent were granted to the said John William
Kenyon of these Presents, bearing date the Third day of January in the year
One thousand eight hundred and sixty-seven, as or in lieu of a float to govern
the action of a safety apparatus for the purpose herein above mentioned, the
said safety apparatus being of any suitable form or description, or it may be
the improved apparatus next immediately to be described. To the bottom of
the boiler or the crown of the furnace, or each crown of the furnaces, or to
any other suitable part of the interior of the boiler we attach a vertical or
nearly vertical pipe or tube, the upper end of which projects above the water
into the steam space, and is fitted or formed with a valve seat, the lower end
of the said pipe communicating with the interior of the furnace. A valve of
suitable form is fitted to rest upon the valve seat on the upper part of the said
tube, the said valve being fitted or fixed to one end of a pipe of larger size
than the one first mentioned; the said larger pipe being of a suitable length

page_text: to reach below the "low-water level" when the valve is placed on its seat. The
said valve is connected with or attached to a lever or to levers fitted with a float,
or with floats, or is connected with the scumming apparatus, as herein above
mentioned; the said connection being such that in the event of the water falling
to the low level the fall of the float or of the "scummers "raises the valve off
its seat to a certain extent and a portion of water is discharged into the
furnace. It is preferred that the upper part of the annular space between the
two pipes shall be occupied by steam when the valve is closed, and to admit
of this a small perforation may be made in the upper part of the outer tube.
In order that the details of our Invention may be more readily described,
and that this present explanation and description may be easily understood,
we have supplied herewith a Sheet of Drawings having similar letters of
reference marked upon corresponding parts in the various Figures.
Referring to the said Drawings, Fig. 1 is a sectional elevation of one of the
improved safety valves drawn about full size; Fig. 2 is a longitudinal section,
and Fig. 3, a cross section of an ordinary Cornish boiler having the improved
valve fitted thereto, and Fig. 4 is a longitudinal section, and Fig. 5 a cross
section of a cylindrical boiler not having internal flues, and illustrating one
method of employing the improved valve in connection with the scumming
apparatus herein above referred to, the four Figures last referred to being
drawn to a scale of about two inches to a foot.
In Fig. 1b is a portion of the crown of the furnace, that is to say, the
upper part of an internal flue or the lower part of the shell of the boiler, as
the case may be. To the said furnace crown is attached an upright pipe or tube
c constituting a connection between the interior of the boiler and the furnace
for the passage of steam or water when required. The said pipe c has a valve
seat d attached to its upper end, or has a valve seat formed thereon, on which
is seated the valve e, the said valve preventing the discharge of steam or
water into the furnace until such time as the said discharge is required, as
will be herein-after explained; the said valve e is fitted into a cap f, the said
capf being screwed on to one end of a pipe or tube g, or cast or otherwise
formed thereon as may be preferred; the said pipe g being open at its lower
end, and being of a suitable length to reach to the low-water level, or to the
lowest level to which it may be considered that the water can with safety be
allowed to be reduced. In order to ensure the occupation of the upper part
of the tube g by the steam one or more small holes is or are drilled in the
cap f, as shewn at f¹. In Figs. 4 and 5 the form of valve immediately above
described is shewn as connected to one of the herein-before mentioned scum-

page_text: mers; the scummer being shewn at h as floating upon the surface of the
water, so that as the level of the water varies the said scummer rises and
falls. To the upper part of the scummer, or to the connecting pipe i, or to
any other suitable portion of the apparatus the lever k is connected by means
of the link l, so that as the scummer rises and falls the lever rocks on the
fulcrum m attached to the shell or to any convenient part of the boiler; the
opposite end of the lever working in a link n coupled to the top of the valve e,
the said link allowing a suitable amount of ". play" to the end of the lever,
but being so adjusted as to length as that the end of the lever will bear upon
the link on the scummer sinking to a level which may be fixed upon as
approaching the point of danger, and on the level of the water, and by con-
sequence of the scummer continuing to fall, the said lever will raise the
valve e off its seat, and a portion of water will be discharged into the furnace
in the direction of the arrows in Fig. 1. In the event of the discharge con-
tinuing until the lower end of the pipe g is out of the water, it is obvious that
the whole or a portion of the steam will be discharged, and the boiler will
thus be relieved to a greater or a lesser extent. If preferred an amount of
play" may be allowed in the connection between the float and the lever. In
Figs. 2 and 3 the improved valve is shewn as adapted to a boiler in which a
floating scummer is not employed, an ordinary float o being used in lieu
thereof, the action being the same or similar to that of the arrangement last
described. The float o is connected to the lever k, and is partially balanced
by the weight p, the link n coupled to the valve e having a suitable amount
of "play" for the purpose herein-before described, the float o actuating the
lever as the said float rises and falls, as will be easily understood.
Having now described the nature of our said Invention, together with
means for carrying the same into practical effect with the intent to define
more exactly the extent of our said Invention, we wish it to be understood that
we claim as novel,-
First. The application and adapation to floating "boiler scummers" of the
description herein referred to, of the form of valve herein-before described and
illustrated in the attached Drawings, or of any modification thereof, or of any
suitable form of valve which will act in the manner and for the purposes
herein-before described and set forth.
Secondly. The use and employment of the safety valve herein-before
described and illustrated at Fig. 1 in the attached Drawings, or any mero
modification thereof otherwise than in connection with the aforesaid
" summer ог "scummers," the said valve being situated, "fitted," and
19

page_text: arranged in manner as shewn at Figs. 2 and 3 in the attached Drawings, or
in any other suitable manner, the same being a mere modification thereof.
In witness whereof, I, the said Robert Arthur Armitstead, have hereunto
set my hand and seal, this Twenty-ninth day of May, in the year of
our Lord One thousand eight hundred and sixty-eight.
ROBERT ARTHUR ARMITSTEAD. (L.B.).
Signed and sealed by the within-named
Robert Arthur Armitstead, in the
presence of
EDWARD K. DUTTON,
Consulting Engineer and Patent Agent,
Manchester.