IMPROVE. MENTS IN SAFETY VALVES
Year: 1858

page_text: LETTERS PATENT to Robert Illingworth, of Blackburn, in the County of
Lancaster, Engineer and Draughtsman, for the Invention of ." IMPROVE.
MENTS IN SAFETY VALVES."
Sealed the 1st November 1858, and dated the 1st May 1858.
PROVISIONAL SPECIFICATION left by the said Robert Illingworth at
the Office of the Commissioners of Patents, with his Petition, on the 1st
May 1858.
I, ROBERT ILLINGWORTH, of Blackburn, in the County of Lancaster,
Engineer, and Draughtsman, dó hereby declare the nature of the said
Invention for: "IMPROVEMENTS IN SAFETY VALVES," to be as follows:-
My said Invention consists of a compound safety valve for the prevention of
boiler explosions from excessive pressure, or deficiency of water, to accomplish
which I employ a hollow equilibrium valve placed in a suitable chamber, so
that when the steam escapes in consequence of its being above the working
pressure it may pass from the upper seating of the valve to the exterior, and
from the lower seating through the hollow or centre of the valve, both dis-
charging into the atmosphere; and if the pressure of the steam should still
encrease to a certain degree above the working pressure, it will disturb the
equilibrium, inasmuch as the volume of steam discharged by the lower seating
is too great to escape up the hollow or centre of the valve, and thereby opens
the valve to its full discharging power.
I also employ, in connection with the aforesaid hollow equilibrium valve,
"two valves placed at the lower part of the chamber, one larger valve having a
double discharge, and furnished with a facing constituting a seating for a
[Pride 8d.1

page_text: smaller one, the latter being attached to a lever, one end of which is connected
to a float and the other to a balance weight. When the float sinks from a
slight deficiency of water, the smaller valve is brought downwards and allows
steam to escape by a tube passing through the hollow or interior of the
equilibrium valve, and also through the chamber into the atmosphere, thereby
giving distinct notice of the slight deficiency, a whistle or other signal being
employed when desired. When there is still a greater deficiency, or when the
water descends to a dangerous level, the smaller valve pulls down the larger
one, and allows steam to escape to the under side of the hollow equilibrium
valve in a larger volume than can escape up the interior, thereby disturbing the
equilibrium, and causing the valve to rise from the seatings, and thus prevent
explosion by giving ample space for the full discharge of the steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Illingworth in the Great Seal Patent Office on the
1st November 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
ILLINGWORTH, of Blackburn, in the County of Lancaster, Engineer and
Draughtsman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of May, 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 Robert Illingworth, Her special licence that I, the said Robert
Illingworth, my executors, administrators, and assigns, ar such others as I,
the said Robert Illingworth, 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
"IMPROVEMENTS IN SAFETY VALVES," upon the condition (amongst others) that
I, the said Robert Illingworth, 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 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 imme-
diately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Robert Illingworth, 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, that is to say:-
It consists of a hollow cylindro-domical shaped seating. having a circular
opening at its top, round which is placed a face or seat; its base is
formed so as to present an annular opening, and in the upper edge of the
inner wall is another face. Within and partly upon this seating is placed a
hollow equilibrium valve, having faces at its top and bottom which rest upon
the corresponding faces of the before mentioned seating. This valve is loaded
by a weight, which may either be arranged so as to press vertically on its
upper surface, or may be suspended from its bottom; in this latter case the
inner walls of the bottom part of the seating are prolonged downwards beyond
the outer. Placed over the whole is a dome or other suitably formed steam
chamber, having apertures communicating with the external atmosphere.
When applied, the seating is either fixed upon and over an opening in the
boiler, or upon a proper base or stool fixed thereon; the steam passing from
the latter through the annular opening in the bottom of the seating acts upon
the equilibrium valve. If then the elasticity of the steam exceeds the load
upon the valve, the latter will be raised from its seats, and the steam passing
through the opening at the lower face will escape through the hollow centre
of the valve into the steam chamber, while at the same time it will also be
escaping past the upper one direct into the said chamber, and from thence
into the atmosphere. Should the elasticity of the steam increase to such an
extent over. the load upon the valve, that the area of escape through the
hollow interior is too small, then from the increased pressure the equili-
brium of the valve being further disturbed, it will be urged still higher, thus
enlarging the opening of discharge at both top and bottom faces, and con-
tinuing so to act in proportion to the pressure until the valve reaches its
highest limit, gradually closing and falling to its seat again as the steam
returns to its normal pressure.
In combination with this steam safety valve I arrange my water-indicating
valve, but so constructed as to act quite independently of the former, and may
be applied to steam boilers quite separately. This consists of a valve having,
when used in combination with the said safety valve, its seat in the bottom inner
face of the equilibrium valve seating, and opening into a tube which passes
through the centre of the said seating, the hollow centre of the equilibrium
valve, and the steam chamber into the atmosphere or elsewhere as may be
arranged. The under side of this valve is fixed into the end of a spindle, the

page_text: other extremity of which is attached to a lever suspended so as to vibrate within
the boiler. Surrounding the said valve and its spindle is another tube, which is
prolonged within the boiler to a depth a little beyond the high-water level.
One extremity of the fore-mentioned lever has a float attached to it, the other
has a corresponding balance weight. The action of this combination is as
follows: When the water in the boiler is within the limits of proper supply,
the adjustment of the lever through the balance weight and float is such that
the water valve is kept close to its seat by the action of the steam alone, the
axis of the lever being then horizontal. If, however, from a deficiency the
level of the water within the boiler should fall, the float on the extremity of
the lever sinking will cause the latter to vibrate, so as to depress the spindle
of the water valve, and thus detach the latter from its seat, permitting the
steam to escape through the tube within the steam chamber to the exterior of
the boiler, where it may be caused to produce some signal so as to indicate
the said deficiency: Furthermore, should the said deficiency not be remedied,
.but continue to increase so as to become dangerous, then as the opening of
the valve enlarges, in proportion as the water diminishes, this opening will be
sufficient to discharge all the steam off, and prevent all danger from explosion.
On the other hand, should the level of the water in the boiler get too high,
that is, should the supply of water be too great, then the balance weight on
the extremity of the lever becomes acted upon by the water pressing upon its
under surface, and the equilibrium of the lever is disturbed, the float end pre-
ponderating, the spindle and with it the valve becomes depressed, and the steam
acting upon the water forces it up the inner tube past the open valve through
the outer pipe to the exterior of the boiler, where it can be arranged so as to
indicate by signal to the attendant the alteration requisite to the pumps, and
thus prevent the injurious effects of "priming."
In order more fully to illustrate my Invention, and render the above
description clearly intelligible, the accompanying Drawings are appended to
this Specification, it being understood, however, that all the dimensions, sizes,
and even the forms of the different parts, may be varied, modified, and altered
to suit the particular circumstances of the case to which the Invention is
applied.

page_text: Figure 2 is a similar elevation of the steam safety valve wholly detached
from the water-indicating valve; in this Figure the steam valve is shewn with
the weight or load placed directly upon its upper surface, hence the con-
struction is somewhat modified; nevertheless, although in this arrangement
the form is much simplified by the disposition of the load, yet from the
difficulty of keeping the motion of the valve, or rather of the centre of gravity of
the valve, and its load in a straight vertical direction, I prefer from its more
regular action the form and arrangement shewn in Figure 1.
Figure 3 is a sectional elevation, shewing the self-acting water-indicating
valve as applied by itself, and distinct from the steam safety valve.
The same letters indicate the same or similar parts in each of the different
Figures, where a, a, is the seating of the steam valve; in Figure 1 the bottom
inner walls of this seating are prolonged downwards, in order to receive within
them the load or weight of the valve, which in this arrangement is suspended
freely from it. a, a, is the base or stool on which the seating a, a, is fixed;
in Figure 2 this base is omitted as unnecessary. b, b, is the hollow equilibrium
valve, with its faces y, y, y, y, resting on the corresponding seats x, x, x, x;
c, c, is the steam chamber; d, d, the load or weight upon the valve; in
Figure 1, as before mentioned, it is suspended freely, or on a socket joint, so
as to vibrate in any plane. g, g, are openings in the steam chamber c, com-
The
municating with the external atmosphere; B, B, the boiler plates.
steam rising in the direction of the arrows enters the seating a, a, and acting
upon the valve b, pases between the faces at x, x, x, x, part issuing up the
hollow interior of the valve, and part at the top face of the valve, into the
steam chamber c, passing from thence to the atmosphere through the openings
g, g, the open spaces between the faces of the valve and the seats increasing
in proportion as the pressure of the steam exceeds the load upon the valve.
The steam chamber c is fixed to the seating, and a lock n prevents its
removal and obviates the possibility of tampering with the load upon the
valve. In the lower face of the seating is placed i, the water valve, with its
spindle attached to the lever m, which latter is suspended by and vibrates on
the rod, having the balance weight hung to its one extremity, and the float
on the other. The tube or pipe K passes down a little below the high-water
mark, and the tube K¹, which is a continuation of it from the upper seat of the
When the lever stands as shewn in the
5 valve to the exterior of the boiler.
Drawings, then the valve i is held close to its seat by the steam acting against
its under side; should, however, the water fall below the level indicated, then
the float sinks, depressing the extremity of the lever to which it is hung, thus
acting upon the spindle ; and the valve i, withdrawing the latter from its seat

page_text: and allowing the steam to escape from the tube K through the pipe K¹ to the
exterior of the boiler, so as to attract the notice of the attendant, at the same
time discharging the steam, and thus avoiding the possibility of an explosion.
Should the water rise to the line indicating the high-water mark, the balance
weight through its immersion destroys the equilibrium of the lever m, the float
again sinking opens the valve i, and the steam pressing upon the surface of
the water ejects it through the pipes K and K' to the outside of the boiler, so
as to give warning as before.
Having now described my Invention and how the same is constructed and
acts, I wish it understood that what I claim as new, and wish secured by the
before in part recited Letters Patent, are,-
First, the construction and arrangement of the seating a and the valve b, so
as to produce the mode of action before described, that is to say, to regulate
the area of escape or discharge in proportion to the elasticity of the steam,
and whenever that elasticity becomes dangerous, to give the greatest area of
discharge.
Second, the combination of the seating a, the valve b, with its weight or
load d, and the chamber c, so as to form a self-acting steam safety valve,
substantially as described in the Specification and illustrated in Figures 1 and
2 of the Drawings.
Third, the construction and arrangement of the various parts forming the
self-acting water-indicating valve, and so contrived as to act either by itself or
in combination with the before described self-acting steam safety valve, sub-
stantially as described in the Specification and illustrated in Figures 1 and 3
of the Drawings appended thereto.
In witness whereof, I, the said Robert Illingworth, have hereunto set niy
hand and seal, this Twenty-eighth day of October, in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness,
THOMAS J. BAckhouse.
ROBERT ILLINGWORTH. (L.S.)