AN IMPROVED SAFETY VALVE FOR KITCHEN BOILERS
Year: 1882

page_text: LETTERS PATENT to John Williams of 115 Chancery Lane in the City of
"
London hot water engineer for an Invention of AN IMPROVED SAFETY VALVE
FOR KITCHEN BOILERS
PROVISIONAL SPECIFICATION left by the said John Williams at the Office
of the Commissioners of Patents on the 20th December 1882.
"
JOHN WILLIAMS of 115 Chancery Lane in the city of London-Hot-water
Engineer "AN IMPROVED SAFETY VALVE FOR KITCHEN BOILERS
"
My Invention has for its object to prevent, the explosion of kitchen boilers and
the consequent loss of life and destruction of property which so frequently occur
under the present arrangements of this class of boilers.
My Invention is applicable to every description of kitchen boiler but more
particularly to that class in which the boiler is combined with an overhead tank
connected to the boiler by two pipes through one of which on the fire being lighted
the steam and hot water riso from the boiler to the tank whilst the. cold water
descends from the latter, through the other pipe to the boiler A regular circulation
of water is thus set up and so long as the pipes are clear the surplus steam finds a
free escape from the boiler and tank, the two open columns of water forming natural
safety valves as it were, to the boiler i
"
- But if, as is often the case, the circulating pipes become choked with corrosion,
or in times of frost with ice or from any other cause the steam formed in the boiler
is prevented from escaping and gradually, increasing in pressure exceeds at last
the strength of the boiler and an explosion of the latter inevitably results,
Now my invention consists in the application and use to a kitchen boiler of a
specially arranged safety valve which is enclosed on its seating in a casing and
formed on its upper side with a central stem or, spindle which is guided by and
projects through a hole in the top of the casing On the top of this spindle is placed
or fixed a spherical or other suitably shaped weight proportioned to the strength
of the boiler and so arranged that its centre of gravity. coincides as nearly as
possible with the centre line of the valve spindle-Around and through the wall of
the casing are holes for the escape of the steam
}
By this invention the levers, hinges or springs common to the ordinary forms of
safety valves are dispensed with and the valve acting entirely on the dead weight
principle is unaffected by temperature thereby ensuring certainty of action and
instant relief to the boiler directly the pressure of the steam exceeds a certain
limit-hence the danger of the boiler exploding through accident or inattention is
entirely obviated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Williams in the Great Seal Patent Office on the 19th June
1883.
JOHN WILLIAMS of 115 Chancery Lane in the City of London Hot water
Engineer "AN IMPROVED SAFETY VALVE FOR KITCHEN BOILERS
ور
My Invention has for its object to preventi the explosion of kitchen boilers and
the consequent loss of life and destruction of property which so frequently occur
under the present arrangements of this class of boilers
My invention is applicable to every description of kitchen boiler but more
particularly to that class in which the boiler is combined with an overhead tank
connected to the boiler by two pipes through one of which on the fire being lighted
the steam and hot water rise from the boiler to the tank whilst the cold water
descends from the latter through the other pipe to the boiler-A regular circulation
of water is thus set up and so long as the pipes are clear the surplus steam finds a
free escape from the boiler, and tank the two open columns of water forming natural
safety valves, as it were, to the boiler
But if, as is often the case the circulating pipes become choked with corrosion or
in times of frost, with ice or from any other cause. the steam formed in the boiler
is prevented from escaping and gradually increasing in pressure exceeds at last
the strength of the boiler and an explosion of the latter inevitably takes place..
'
Now my invention consists in the application and use to a kitchen boiler of a
specially arranged safety valve which is enclosed on its seating in a casing and
formed on its upper side with a central stem or spindle which is guided by and
projects through a hole in the top of the casing-On the top of this spindle is placed
or fixed a spherical or other suitably shaped weight proportioned to the strength of
the boiler and so arranged that its centre of gravity coincides as nearly as possible
with the centre line of the valve spindle-Around and through the wall of the
casing are holes for the escape of the steam
And in order that my said Invention may be, well understood I shall now
proceed more particularly to describe. the same and for that purpose shall refer to
the accompanying sheet of drawings like letters of, reference indicating corre-
sponding parts in the respective figures
Figure 1 represents a vertical section of one form of my invention and
figures 2 and 3 a similar section, and elevation respectively of a modified
arrangement thereof
In figure 1-a represents a safety, valve enclosed on its seating b in a casing cand
having on its upper side a central stem or spindle d which is enlarged at a suitable.
distance from the valve a so, as to form thereat a circular plate or disc e sliding
freely in, and guided by, the casing c-Above this enlarged portion e, the spindle d
is extended and projects through a guide hole in the top or cover f of the casing c
On the top of the spindle d is placed (or fixed) a spherical (or other suitably shaped.)
weight properly proportioned to, the pressure required on the valve a and boiler
to which such valve is applied-The weight g is so arranged that its centre of
gravity coincides as nearly as possible with the centre line of the valve a and its
spindle dAround and through the wall of the casing c are arranged any, desired
number of holes.h for the escape of the steam from the boiler
By this arrangement the levers, hinges or springs common to the ordinary system
of safety valves are dispensed with and the valve a acting entirely on the dead
weight principle is unaffected by temperature thereby ensuring certainty of action,
and instant relief to the boiler directly the pressure of steam therein exceeds a

page_text: certain limit and hence the danger of the boiler exploding through accident or
inattention is entirely obviated
In figures 2 and 3 in lieu of making the weight g¹ spherical as in figure 1-I
may make it of a hollow cup or bell shape working over (or not) the top or cover f
of the casing c and resting at the bottom of its hollowed portion on a shoulder i of
the valve spindle d which projects through the weight g' as shewn-Around the
mouth or bottom of the weight gl is a flange j which may carry (or not) two or
more adjustable weights as desired-The other parts of this arrangement being
similar to those described in figure 1. need no further description
I may apply my Invention where suitable to any class of boiler kitchen or
otherwise
Having now described and particularly ascertained the nature of my said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider novel and original and
therefore claim as the invention secured to me by the herein before in part recited
Letters patent is :-
The application and use to kitchen boilers, of a specially arranged safety valve
and spindle in combination with a casing and a weight (or weights) substantially
as and for the purpose hereinbefore described and illustrated by the accompanying
drawing
In witness whereof I the said John Williams have hereunto set my hand
and seal this eighth day of May in the year of Our Lord One thousand
night hundred and sights throa
JOHN WILLIAMS (L.S.)