IMPROVEMENTS IN SAFETY VALVES
Year: 1855

page_text: LETTERS PATENT to William Hartley, of Bury, in the County of Lancaster,
Engineer, for the Invention of "IMPROVEMENTS IN SAFETY VALVES."
Sealed the 25th April 1856, and dated the 29th October 1855.
PROVISIONAL SPECIFICATION left by the said William Hartley at the
Office of the Commissioners of Patents, with his Petition, on the 29th
October 1855..
I, WILLIAM HARTLEY, of Bury, in the County of Lancaster, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN SAPETY
VALVES" to be as follows:-
The first part of my Invention has for its object the effecting a discharge of
steam equal to the bore or area of the valve seat. The valve loaded in any
ordinary manner is provided at its upper portion with a projecting disc or
other part constituting an enlarged surface; when steam begins to escape, it
therefore acts against this increased area, and causes the valve to rise within a
casing which surrounds it. The valve casing I so construct that the rising of
the valve shall open a passage or passages therein of increasing area, and
communicating with the atmosphere. One method I adopt is to construct the
said casing so that its section shall be of a curved or conical form, increasing in
diameter as it extends upwards, by which means the steam may be caused to
act against the valve with an uniform force, and to continue its motion until.

page_text: sufficiently high for a full discharge.
When the pressure of the steam in the
boiler has been reduced below the loaded amount, the valve again closes.
Instead of the above arrangement, I can fit the valve within a cylinder, pro-
viding suitably shaped apertures therein for the discharge of the steami.
Another part of my Invention relates to a method of allowing steam to
escape from the boiler when the water becomes too low. This 1 effect by con-
necting the valve to,a lever, balanced by weights or otherwise. Upon the level
of the water sinking too low, the weight on one side of the lever becomes
neutralized, and the valve is then at comparative liberty to rise, the weight at
the other end only being in operation.
In order to illustrate this I will mention one arrangement I employ. A
valve of any ordinary construction is connected by a rod to a lever situate
within the boiler, and at one end of the said lever is a float, connected thereto
by a chain, which is slack when the water is correct, while at the other end is
a weight, bearing the said lever by means of a stop against the suspension rod,
but only slightly, for the whole is nearly balanced by means of a second weight
situate on the other side of the centre. To the second weight is attached a short
chain, the other end of which is fixed to the boiler top, and the said chain is slack
when the water stands at the desired level; should. it, however, sink too low,
then the chain of the float will become distended, and the float itself will act as
a weight to overcome the balance. The lever will then be caused to turn upon
its centre and distend the chain of the secondly-mentioned weight, and this
being thereby prevented from moving lower, will cease to act as a weight upon
the valve, which will then be at liberty to rise against the pressure of one
weight only. Instead of the chain above mentioned, a fixing may be employed
for the weight to drop upon.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Hartley in the Great Seal Patent Office on the
29th April 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAMS
HARTLEY, of Bury, in the County of Lancaster, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of October, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Hartley, Her especial license that I, the said William Hartley,

page_text: my executors, administrators, and assigns, or such others as I, the said;
William Hartley, my exécutors, 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 "IMPROVEMENTS IN.
SAFETY VALVES," upon the condition, amongst others, that I, the said William
Hartley, by an instrument in writing under my hand and seal, should par-:
ticularly 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 William Hartley, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement and accompanying Drawings (that is to say):
:-
The first part of my Invention has for its object the effecting a discharge of
steam equal to the bore or area of the valve seat, and another part thereof
relates to a method of allowing steam to escape from the boiler when the water
becomes too low.
Figs. 1 and 2 of the accompanying Drawings are sectional views, shewing
the improvements in combination; it is not, however, necessary that they
should be used together.
The shell of the boiler is shewn at a, upon which is mounted a pipe b,
carrying the valve seat c, and provided with a passage d for the escape of
steam; the valve is shewn at e mounted upon a spindle f, which passes through
a guide piece ; the part which rests upon the seat. is a portion of a sphere
according to the Drawing, but it may be flat, or of any other usual form.
Above this part is a flange h, situate within a cup-formed part i, which increases
in diameter as it rises from the seat. Suppose the valve to be loaded by an
ordinary interior dead weight by external levers or by other usual apparatus,
it will, upon being lifted by undue pressure, allow the steam to exert its force
against the flange h, by which means an additional surface will be gained for
assisting a continual rising of the valve; and as the form of the cup i affords
an increasing area for the passage of steam, this upward motion will continue
until the valve is sufficiently high for a full discharge; this position is shewn
at Fig. 2, which also represents a stop k in contact with the guide piece g.
I would here observe that I am aware that in all ordinary arrangements of
valves an additional area for the action of the steam must exist immediately

page_text: the valve is lifted, and corresponding to the amount of seating; nevertheless,
such additional surface lías never, to my knowledge, been applied in addition
to the necessary seating, and for the purpose of my Invention, and I consider
it therefore as one feature of my improvements; nevertheless, another part
thereof, and which consists in so enclosing the valve that it may be caused to
open an increasing area for the passage of steam, may be used without the
said additional surface; this I will illustrate by reference to Fig. 3, which also
shews a modification of the cup i. In this instance, an ordinary valvea is
situate within a chamber 6, which is provided with apertures c'for the escape
of steam; these are of triangular form with curved sides, increasing in
diameter as they rise from the valve, and therefore affording increasing areas
as the valve is forced upward, the effect being the same as' if the cup i were.
employed.
I will now proceed to describe. the second part of my Invention. To the.
valve spindle, or to that of any ordinary valve, is connected a rod 1, the "lower
end of which is connected with a lever m; this lever is provided' at 'one end.
with an eye n, through which the rod o of a float p passes, the said rod having
an enlarged part 9 at its upper end, which will not pass through the eye n..
The other end of the lever m carries. a weight r, which is 'nearly counter-
balanced by a second weight s, the former slightly preponderating, so as to
cause a stop piece t on the lever m to bear lightly against the rod l. 'The
link by which the weight. s is hung extends upward at u, and there passes
through a fork v attached to a stationary part, through which, however, it is
prevented from passing by a stop piece w. So long as the water remains at a
certain level or above it the several parts will remain as shewn at Fig. 1'; but
upon its sinking below a determined point, the piece q will arrive in contact
with the lever m, and the float p will then act as a weight, and will overcome
the balance of the lever m; the consequence of this will be the arrival of the
stop win contact with the fork v, by which the weights and levers m will
become suspended, and as the water lowers the float p causes the lever m to
turn upon the centre a, and overbalances the weight r; hence, the weights,
lever, and float all become suspended, thereby leaving the valve to the free
action of the steam.
Fig. 4 represents, in section, a'modification of the second part of my Inven-
tion. In this instance the weights is dispensed with, and the lever m is nearly
balanced by the float p at one end and the weight at the other, the
latter slightly preponderating, and causing a stop t to bear against the rod ;
upon the water becoming too low, the float p will sink therewith, and
cause the lever to turn upon its centre a, until the upper end of a slot y

page_text: shall have arrived in contact with a fixed pin ; the weight of the float will
then cease to act upon the valve, and it will be free to rise.
Fig. 5 represents another modification of this part of my improvements.
In this instance the lever m is so formed that the weight of metal on either
side of the pin x constitutes a balance or nearly so; the rod of the float p
passes through the lever, as in Figs. 1 and 2, and upon sinking with the water
becomes suspended thereon, the pin w arriving in contact with the fixture v,
and the valve will then be free to rise.
Having thus described and ascertained the nature of my said Invention,
and the manner in which. the same is to be performed, I desire it to be under-
stood that I claim, as secured to me under the above in part recited Letters
Patent,―
Firstly, the application to a safety valve of a projecting disc or flange, as
illustrated at Figs. 1 and 2, for the purpose above set forth.
Secondly, placing the valve within a cup-formed or other chamber, which
will afford an increasing area for the escape of steam as the said valve rises
from its seat.
Thirdly, loading safety valves by means of balanced or nearly balanced
levers, the whole load or part thereof being neutralized by the sinking of the
water below a determined level.
In witness whereof, I, the said William Hartley, have hereunto set my
hand and seal, the Twenty-eighth day of April, in the year of our Lord
One thousand eight hundred and fifty-six.
WM HARTI TV
WM HARTI TV
(L.S.)