IMPROVEMENTS IN SAFETY VALVES OF STEAM BOILERS
Year: 1858

page_text: LETTERS PATENT to William Parsons, of Pratt Street, Lambeth, Manu-
facturing Engineer, for the Invention of "IMPROVEMENTS IN SAFETY VALVES
OF STEAM BOILERS."
Sealed the 25th February 1859, and dated the 8th September 1858.
PROVISIONAL SPECIFICATION left by the said William Parsons at the
Office of the Commissioners of Patents, with his Petition, on the 8th
September 1858.
I, WILLIAM PARSONS, of Pratt Street, Lambeth, Manufacturing Engineer,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN SAFETY
VALVES OF STEAM BOILERS," to be as follows:-
This Invention has for its object improvements in safety valves of steam
boilers. For these purposes the valve employed is by preference of a spherical
form on its under side, where it rests on a corresponding hollow seat.
Through the valve a tube is fixed which descends into the boiler, and at its
lower end a hollow float is placed, which is allowed to slide up and down a
short distance upon the tube in order that it may be the means of acting on a
rod within the tube, and by it on a whistle at the upper part or end of the
tube, when the water sinks below the proper level in the boiler. Provision is
made for the rod moving down a certain distance, by the descent of the float
before it acts on the valve. The tube of the valve is suitably weighted
according to the pressure desired. Over the valve is fixed a hood or inverted
vessel, up into which the steam rises when the valve begins to open, and by
acting on the interior, tends to lift the valve. The hollow standard on which
the seat of the safety valve is formed admits of the tube to which the valve is
fixed moving or swinging therein, so that as the ebullition of the water acts on
the float and causes it to move, the safety valve is also caused constantly to
move in its seat, by which it is prevented sticking.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Parsons in the Great Seal Patent Office on the
8th March 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
PARSONS, of Pratt Street, Lambeth, Manufacturing Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of September, 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 William Parsons, Her special licence that I, the said William
Parsons, my executors, administrators, and assigns, or such others as I,
the said William Parsons, 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 "IMPROVE-
MENTS IN SAFETY VALVES OF STEAM BOILERS," upon the condition (amongst
others) that I, the said William Parsons, my executors or administrators,
by an instrument 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 immediately after the date of the said Letters Patent.
}
NOW KNOW YE, that I, the said William Parsons, do hereby declare
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 fol-
lowing statement thereof, that is to say:-
This Invention has for its object improvements in safety valves of steam
boilers. For these purposes the valve employed is by preference of a spherical
form on its under side, where it rests on a corresponding hollow seat. Through
the valve a tube is fixed which descends into the boiler, and at its lower end a
hollow float is placed, which is allowed to slide up and down a short distance
upon the tube in order that it may be the means of acting on a rod within the
tube, and by it on a whistle at the upper part or end of the tube. When the
water sinks below the proper level in the boiler, provision is made for the rod
moving down a certain distance, by the descent of the float before it acts on
the valve. The tube of the valve is suitably weighted according to the pressure
desired; over the valve is fixed a hood or inverted vessel, up into which the

page_text: steam rises when the valve begins to open, and by acting on the interior, tends
to lift the valve. The hollow standard on which the seat of the safety valve is
formed, admits of the tube to which the valve is fixed moving or swinging
therein, so that as the ebullition of the water acts on the float, and causes it
to move, the safety valve is also caused constantly to move in its seat, by
which it is prevented sticking.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWING.
Figure 1 is a side view of apparatus constructed according to my Invention;
Figure 2 is a vertical section thereof; a shows the upper part of a steam boiler
to which the apparatus is applied; 6 is a safety valve which is by preference
spherical on its under surface, and it has a corresponding bearing or seat as
shown; c is a tube to which the valve b is fixed, and on the lower end of the
tube c is a float d which can slide freely on the end of the tube. Through
each side of the tube c is a slot e, and f is a rod which is fixed at its lower end
to the float, whilst at its upper end it is arranged to act on the valve / of the
steam whistle i. The steam passes to the whistle through the holes j, j, in the
tube c, and the whistle will be sounded when the float descends so as to cause
the valve to descend also; k, k, are weights with which the safety valve is
weighted; is a hood over the valve b. It will be seen that in this arrange-
ment, the agitation of the water in the boiler tends to keep the valve in
constant motion and prevent its becoming fast in its seat.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that what I claim is the
combination herein described.
In witness whereof, I, the said William Parsons, have hereunto set
my hand and seal, this Eighth day of March, in the year of our Lord
One thousand eight hundred and fifty-nine.
Witness,
S. CARPMAEL.
WILLIAM PARSONS. (L.S.)