IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY VALVES."
Year: 1872

page_text: LETTERS PATENT to George William Hawksley and Matthew Wild,
both of Brightside Boiler Works, Sheffield, in the County of York,
for the Invention of ""IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY
VALVES."
PROVISIONAL SPECÍFICATION left by the said George William
Hawksley and Matthew Wild at the Office of the Commissioners
of Patents, with their Petition, on the 30th October 1872.
We, GEORGE WILLIAM HAWKSLEY and MATTHEW WILD, both of
Brightside Boiler Works, Sheffield, in the County of York, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF SAFETY VALVES," to be as follows:-
Our Invention relates to that class of safety valves for steam boilers,
known as "dead weight valves," and consists principally in providing
such valves with internal and external annular escaping lips, whereby a
very much larger area for escapement is available in a given diameter
of valve than is obtained in any of the ordinary valves of this class, and
consequently a greater amount of steam can escape in a given time.
They also require less dead weight.

page_text: The valve seating is constructed with an annular opening near its
outer circumference, and also a central opening. The valve is formed
with an outer ring over the annular opening, and an inner one over the
central opening, leaving an annular space between the two for the
escape of steam. The annular openings in both the seating and valve
are of course not perfect, but are intersected at suitable intervals by
connecting ribs or webs joining the inner and outer rings. A rod is
screwed into the centre of the valve, and to the lower end of this rod
the dead weight is attached. The upper end of this rod projects above
the valve, and is formed with a neck terminating with a collar at the
top. A fork or clip at the lower end of a screwed rod embraces this
neck, and the latter rod passes out through a brass bush in the top of
the valve casing, the screwed part of the rod passing through the
screwed boss of a hand wheel. From this it will be seen that the valve
is free to rise and fall independently of the forked rod, whilst whenever
it may be desirable, the engineer by turning the hand wheel can raise
the valve so as to test whether it is in proper working order. Above the
hand wheel is a fixed nut or collar on the rod, so that it is not possible
for him to screw down the valve.
If it be preferred to have the dead weight outside the boiler the
weight may be made in an annular form, and suspended outside the
pipe leading to the valve.
The safety valve first described may also be made to indicate low
water, and to release the boiler from pressure when the water. falls.
below the proper working level by connecting the rod which supports
the dead weight to a balance beam, to one end of which the ordinary
stone float is attached, so that if the level of the water becomes, too low,
the falling of the float raises the valve and allows the steam to escape.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George William Hawksley and Matthew Wild in 30
the Great Seal Patent Office on the 30th April 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
WILLIAM HAWKSLEY and MATTHEW WILD, both of Brightside Boiler
Works, Sheffield, in the County of York, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of October, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said George William Hawksley and Matthew Wild,
Her special license that we, the said George William Hawksley and
Matthew Wild, our executors, administrators, and assigns, or such others
as we, the said George William Hawksley and Matthew Wild, our
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 THE CONSTRUCTION OF SAFETY VALVES," upon the condition (amongst others)
that we, the said George William Hawksley and Matthew Wild, by an
instrument in writing under our 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
immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said George William Hawksley and
Matthew Wild, do hereby declare that 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 and
accompanying Drawings (that is to say) :-
Our Invention relates to that class of safety valves for steam boilers,
known as tr
'dead weight valves," and consists principally in providing
such valves with internal and external annular escaping lips, whereby
a very much larger area for escapement is available in a given diameter
of valve than is obtained in any of the ordinary valves of this class, and
consequently a greater amount of steam can escape in a given time.
They also require less dead weight.
Such being the nature and object of our said Invention we will now
proceed to describe more in detail the manner in which the same is to be
or may be performed or carried into practical effect, and in order that the
same may be clearly understood we have annexed hereunto a Sheet of
Drawings illustrative thereof, and have marked the same with figures and

page_text: letters of reference corresponding with those in the following explanation
thereof:
Fig. 1 in the annexed Drawing is a section showing one modification
of our improved safety valve adapted so as to act either by the increased
pressure of the steam or by the fall in the level of the water.
a, a, is the valve seating which (see also enlarged detached view,
Fig. 2) is constructed with an annular opening b, b, near its outer
circumference, and also with a central opening c, c; d, d, is the valve
(see also enlarged detached view, Fig. 3) which is formed with an outer
ring over the annular opening b, b, and an inner one over the central
opening, an annular space e, e, being left between the two for the escape
of the steam. It will be evident that the employment of this annular
opening e, e, in the valve provides the latter with internal as well as
external escaping lips, and allows of the escape of a much larger volume
of steam in a shorter time through a given diameter of valve than would
be possible if the steam escaped round the external circumference of the
valve only. The annular spaces 6 and e are intersected at suitable
intervals by connecting ribs f, f, joining the inner and outer rings. A
rod g, g, is screwed into the centre of the valve, and to the lower end of
this rod the dead weight h, h, is attached. The upper end of this rod g, g,
projects above the valve, and is formed with a neck terminating with a
collar at the top. A fork or clip i, i, at the lower end of a screwed
rod k, k, embraces this neck, and the latter rod passes out through a
brass bush 1, 1, in the top of the valve casing m, m, the screwed part of
the rod passing through the screwed boss of a hand wheel n, n. From
this it will be seen that the valve is free to rise and fall independently
of the forked rod k, k, whilst, whenever it may be desirable, the engineer
by turning the hand wheel n, n, can raise the valve so as to test whether
it is in proper working order. Above the hand wheel n, n, is a fixed
nut or collar o, o, on the rod so that it is not possible for him to screw
down the valve.
In order to indicate low water and to release the boiler from pressure
when the water in the same falls below the proper working level, we
connect the rod g, g, (which supports the dead weight) by means of a
nut and washer p, p, to a balance beam q, q, one end of which supports
a balance weight r, r, and to the other end the ordinary stone float 8, 8,
is attached; t, t, being the fixed fulcrum of the beam, so that if the
level of the water in the boiler becomes too low, the falling of the

page_text: at the lower end of the short tube w, w, an internal shoulder x, x, of
which bears upon the valve d, d. In this case the valve is merely in
the form of a ring (as shewn in detached view, Fig. 5), and when it lifts
the steam escapes both through the central opening and also round the
outer circumference through the openings z, 2.
Fig. 6 is a plan view of the valve seating, showing the use of a ring
of small holes or perforations, instead of the annular space b, b, described.
This seating has no central opening.
о
Fig. 7 is a section showing a further modification wherein the internal
and external dead weights are combined, each acting independently of
the other.
Having now described the nature and object of our said Invention,
together with the manner in which the same is to be performed
or carried into practical effect, we wish it to be understood that
we do not desire to limit ourselves to the precise details of con-
struction above-described and exhibited in the annexed Drawings, but
what we consider as novel and desire to claim as our Invention is, the
use of an internal annular or central opening in a valve of this descrip-
tion, whereby two or more escaping lips are provided for the exit of the
steam, substantially as herein-before described.
In witness whereof, we, the said George William Hawksley and
Matthew Wild, have hereunto set our hands and seals, this
Twenty-eighth day of April, A.D. 1873.
GEORGE WILLIAM HAWKSLEY. (L.S.)
MATTHEW WILD.
(L.S.)