IMPROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS, AND IN VALVES FOR OTHER PURPOSES." PROVISIONAL SPECIFIC
Year: 1876

page_text: LETTERS PATENT to David Hunter, of No. 82, South Street, Greenwich, in
the County of Kent, and David Hill, of No. 32, Bridge Street, in the said
Greenwich, both Engineers, for the Invention of "IMPROVEMENTS IN SAFETY
VALVES FOR STEAM BOILERS, AND IN VALVES FOR OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said David Hunter and David
Hill at the Office of the Commissioners of Patents on the 8th September
1876.
DAVID HUNTER, of No. 82, South Street, Greenwich, in the County of Kent, and
DAVID HILL, of No. 32, Bridge Street, in the said Greenwich, both Engineers.
"IMPROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS, AND IN VALVES FOR OTHER
PURPOSES."
The object of the Invention is to reduce as much as possible the ability to
sticking of the parts of the valve to its seat, and to facilitate the passage
through it.
We form the passage through the seat to be closed by the valve of an annular
form, the parts being connected by connecting pieces or bridges. The valve is also
formed annular to correspond with its seat, and the surfaces in contact are formed
flat in place of being conical or spherical, by which, whilst a better fit of the parts
is maintainable, increased freedom of action is secured
The valve is bridged over, and is formed with a pin or spindle, the lower part of
which serves as a guide, whilst the upper portion of it is acted upon by the lever,
or otherwise depending on the purpose to which the valve is applied.
We also form or apply a saucer, or such like surface, on the seat around the
outer edge of the valve for steam to act on, and sound an alarm as it escapes when
the valve is applied as a safety valve.
By removing the tendency of the valve to sticking the weight or pressure on the
valve may be reduced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters, Patent filed
by the said David Hunter and David Hill in the Great Seal Patent Office on
the 7th March 1877.
DAVID HUNTER, of No. 82, South Street, Greenwich, in the County of Kent, and
DAVID HILL, of No. 32, Bridge Street, in the said Greenwich, both Engineers.
"IMPROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS, AND IN VALVES FOR OTHER
PURPOSES."
The object of the Invention is to reduce as much as possible the liability to
sticking of the parts of the valve to its seat, and to facilitate the passage
through it.
We form the passage through the seat to be closed by the valve of an annular
form, the parts being connected by connecting pieces or bridges. The valve is also
formed annular to correspond with its seat, and the surfaces in contact are formed
flat in place of being conical or spherical, by which, whilst a better fit of the parts
is maintainable, increased freedom of action is secured.
The valve is bridged over, and is formed with a pin or spindle, the lower part of
which serves as a guide, whilst the upper portion of it is acted upon by the lever,
or otherwise depending on the purpose to which the valve is applied.
We also form or apply a saucer, or such like surface, on the seat around the
outer edge of the valve for steam to act on, and sound an alarm as it escapes when
the valve is applied as a safety valve.
By removing the tendency of the valve to sticking the weight or pressure on the
valve may be reduced.
Figure 1 shows by sectional view; Figure 2, by external side view; and
Figure 3, by plan view, an arrangement of valve with its seating according to our
Invention.
Figure 4 shows by plan view the valve seating separately.
Figures 5 and 6 show an upper side view and an under side view of the valve
separately.
In each of the views the same letters indicate corresponding parts.
A is the seat, which is formed in two parts a, a, so as to leave an annular
space C between them, and these parts a, a¹, are held together for their correct
relation by means of the pieces or bridges d, d, d, d; B is the valve of a ring form,
and such that the bearing surfaces thereof b, b', may rest over the edges of the parts
a, a¹, of the seat next the annular space c; c are the bridge pieces of the valve B, by
which it is connected to the central pin or spindle f, which, by moving in the
opening formed for it in the part a of the seat, serves to guide the valve in its
motion, and keep it in correct relation to the seat. The upper end of this spindle f
also serves to receive the pressure of the weighted or spring lever g.
It will be seen that the surfaces of the valve in contact with its seat for closing
the passage through the valve are flat for the reason stated above.
h, h, represents an inverted cup or saucer-like shield, which may be applied over
the valve and around the outer edge of the seat when such valve is used as a
safety valve for a steam boiler for steam as it escapes to act on and thereby sound
an alarm.
The valve shown is one adapted to a steam boiler, but it will be evident to
persons acquainted with such class of apparatus that the arrangements are equally
applicable to hydraulic and other purposes.
Having thus described our Invention, we would have it understood that we do
not confine ourselves to the precise arrangement of parts, as shown and described,

page_text: as in some cases the respective surfaces a¹, b¹, may be at a lower or other level
than the surfaces at a, b; but what we claim is, the forming of safety valves for
steam boilers and valves for other purposes of the character described, with the
surfaces thereof in contact flat, and also the application to such valves of a shield h,
substantially as described.
In witness whereof, we, the said David Hunter and David Hill, have hereunto
set our hands and seals, this Sixth day of March, in the year of our Lord
One thousand eight hundred and seventy-seven.
Witness to the signatures of the said
David Hunter and David Hill,
ALFRED GEORGE BROOKES,
62, Chancery Lane,
London
DAVID HUNTER. (L.S.)
(L.S.)
DAVID HILL.