IMPROVEMENTS IN APPARATUS FOR INSURING THE CORRECT ACTION OF THE SAFETY VALVES OF STEAM BOILERS
Year: 1858

page_text: LETTERS PATENT to Sydney Smith, of Hyson Green Works, near
Nottingham, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
INSURING THE CORRECT ACTION OF THE SAFETY VALVES OF STEAM BOILERS."
Sealed the 27th April 1858, and dated the 24th February 1858.
PROVISIONAL SPECIFICATION left by the said Sydney Smith at the
Office of the Commissioners of Patents, with his Petition, on the
24th February 1858.
I, SYDNEY SMITH, of Hyson Green Works, near Nottingham, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN APPARATUS FOR
INSURING THE CORRECT ACTION OF THE SAFETY VALVES OF STEAM BOILERS," to be
as follows:
This Invention has for its object improvements in apparatus for insuring the
correct action of the safety valves of steam boilers. For these purposes two
volute spiral springs are used, coupled together at their smaller ends; these
springs are enclosed in a box or case which is pressed on by a screw, by which
the pressure- on the springs within. the box can be regulated, and conse-
quently the pressure on the safety valve. As the box is raised or lowered, by
the screw it gives motion to a rack on the upper end of the box, which takes
into and drives a pinion on the axis of a pointer which will indicate the pressure
in pounds per square inch on the safety valve. The spring box is arranged to
move on standards. The spindle of the safety valve works through the bottom.
of the box, and is pressed on by the springs.
I

page_text: .SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Sydney Smith in the Great Seal Patent Office on the
124th August 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SYDNEY
SMITH, of Hyson Green Works, near Nottingham, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of February, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs, and successors, give and grant unto me, the
said Sydney Smith, Her special licence, that I, the said Sydney Smith, my
executors, administrators, and assigns, or such others as I, the said Sydney
Smith, 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
APPARATUS FOR INSURING THE CORRECT ACTION OF THE SAFETY VALVES OF STEAM
BOILERS," upon the condition (amongst others) that I, the said Sydney
Smith, 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 Sydney Smith, 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 following, statement
thereof, that is to say :-
This Invention has for its object improvements in apparatus for insuring
'the correct action of the safety valves of steam boilers. For these purposes
these-
two wolute spiral springs are used, coupled together at their smaller-ends;
springs are enclosed in a box or case which is pressed on by a screw, by which
the pressure on the springs within the box can be regulated, and consequently
the pressure on the safety valve. As the box is raised or lowered by the screw
it gives motion to a rack on the upper end of the box which takes into and
drives a pinion on the axis of a pointer, which will indicate the pressure in
pounds per square inch on the safety valve. The spring box is arranged to
move on standards. The spindle of the safety valve works through the bottoni
of the box, and is pressed on by the springs.

page_text: And in order that the said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawing hereunto
annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 is a front view; Figure 2 is a vertical section; and Figure 3 is a
transverse section (taken at the line A, A, Figure 1,) of a safety valve having
apparatus arranged according to my Invention combined with it. a, a, is an
iron plate to be bolted on to the boiler, to which the valve is applied, this
plate has fixed in it the valve seat a¹; b, b, are two standards also fixed.
on the plate a, they are connected together at their upper ends by the cross
piece c, through which the screw d passes, and its lower end presses on the
top of the box containing the spring; e, e, is this box, it is furnished with lugs
el, el, which are capable of sliding along the standards; f is the spring con-
tained within the box, and shewn separately at Figure 4; it is fitted into the
socket g; and g', is a spindle descending from the under side of the socket, it
passes through the lower cover of the box e, and rests at its lower end in a
step formed for it on the top of the safety valve h. When the steam within
the boiler has attained a pressure sufficient to deflect the spring f, it will escape
by raising the valve, and the amount of pressure necessary for this purpose
may be regulated by turning the screw d, so as to force down the box e to a
greater or less extent. In order that the pressure on the valve may be
indicated by the apparatus, the rack i is jointed to the top cover of the box e,
it gears with a pinion on the axis j, which is mounted on the cross piece c;
thus, as the box e is forced down by the screw the pointer k on the axis j
traverses along the scale l, which is graduated so as to indicate in pounds per
square inch the pressure on the valve.
In witness whereof, I, the said Sydney Smith, bave hereunto set my hand
and seal, this Twenty-first day of August, in the year of our Lord
One thousand eight hundred and fifty-eight.
0
Witness,
SAML MAPLES,
of the Town of Nottingham, -
Notary Public. (L.S.)
SYDNEY SMITH. (L.S.)