IMPROVEMENTS IN SAFETY VALVES
Year: 1879

page_text: LETTERS PATENT to Thomas Lee, of Nottingham, in the County of Nottingham,
Engineer, and John Ward Jones, of Holloway, in the County of Middlesex,
for the Invention of "IMPROVEMENTS IN SAFETY VALVES."
Sealed the 22nd August 1879, and dated the 10th June 1879.
PROVISIONAL SPECIFICATION left by the said Thomas Lec and John Ward
Jones at the Office of the Commissioners of Patents on the 10th June 1879.
THOMAS LEE, of Nottingham, in the County of Nottingham, Engineer, and JOHN
WARD JONES, of Holloway, in the County of Middlesex. "IMPROVEMENTS IN
SAFETY VALVES."
This Invention has for its object improvements in safety valves which are so
arranged and constructed as to be capable of adjustment, so that the steam or other
fluid under pressure will escape at any pressure determined, upon the valve being
previously adjusted to act at that pressure, and securely locked in position to
prevent it from being tampered with or altered without proper authority.
For this purpose according to our improvements a safety valve is formed with a
cylindrical chamber containing a coiled spring or springs for putting pressure upon
the valve. The coiled spring (which may either be compressed or clongated) is
acted upon by the lower end of a cylindrical slide or socket mounted within the
upper casing of the valve, the interior of the cylindrical slide being formed advan-
tageously with a hand screw thread, into which a corresponding screw enters.
A projection upon the cylindrical slide passes through a slot in the casing, and thus
prevents the slide from revolving when the adjusting screw therein is turned round,
which causes the slide to act as a travelling nut upon its screw. The projection
upon the cylindrical slide carries a pointer, which indicates the pressure (at which
the valve is set to act) upon a scale or index on the outer casing.
Near the upper end of the adjusting screw which actuates the cylindrical slide

page_text: a toothed disc is mounted, and enclosed within a box formed by a cap screwed on
to the top of the casing, by which the screw is prevented from rising when the
screw is turned to set the slide and spring at any desired pressure. A toothed
eccentric on an axis mounted on one side of the cap and casing of the valve is
arranged to interlock by means of a key with the teeth of the disc upon the
adjusting screw, and thus prevent it from being turned until the teeth of the
eccentric are disengaged from the disc by means of the key employed for that
purpose; or the adjusting screw may be fixed in position by other suitable means.
A hand wheel or lever is mounted upon the upper end of the adjusting screw to
set the valve to any desired pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Lee and John Ward Jones in the Great Seal Patent
Office on the 10th December 1879.
THOMAS LEE, of Nottingham, in the County of Nottingham, Engineer, and JOHN
WARD JONES, of Holloway, in the County of Middlesex.
"IMPROVEMENTS IN
SAFETY VALVES."
This Invention has for its object improvements in safety valves, which are so
arranged and constructed as to be capable of adjustment, so that the steain or
other fluid under pressure will escape at any pressure determined upon, the valve
being previously adjusted to act at that pressure, and securely locked in position to
prevent it from being tampered with or altered without proper authority.
And in order that our said Invention may be clearly understood and readily
practiced, we will proceed to describe the Drawings hereto annexed.
Figure 1 shows a section; Figure 2, an elevation; Figure 3, cross section
at A, B; and Figures 4 and 5, cross sections at C, D, and E, F, of our improved
safety valve.
According to our improvements, a safety valve is formed with a cylindrical
chamber a containing a coiled spring or springs 6 for putting pressure upon the
valve c.
The coiled spring (which may either be compressed or clongated) is acted
upon by the lower end of a cylindrical slide or socket d, mounted within the upper
casing e of the valve, the interior of the cylindrical slide a being formed advan-
tageously with a left hand screw thread, into which a corresponding screw fenters.
A projection upon the cylindrical slide & passes through a slot in the casing e,
and thus prevents the slide d from revolving when the adjusting screw f therein
is turned round, which causes the slido d to act as a travelling nut upon its screw f.
The projection & upon the cylindrical slide carries a pointer d, which indicates the
pressure (at which the valve is set to act) upon a scale or index d³ on the outer
casing e.
Near the upper end of the adjusting screw f which actuates the cylindrical
slide d, a toothed disc f' is formed or mounted, and enclosed within a box formed
by a cap g screwed on to the top of the casing e, by which the screw f is prevented
from rising when the screw is turned to set the slide d and spring b at any desired
pressure. A toothed eccentric /* on an axis mounted on one side of the cap g
and casing e of the valve is arranged to interlock by means of a key f³, with the
teeth of the disc f' upon the adjusting screw f, and thus prevent it from being
turned until the teeth of the eccentric fi are disengaged from the disc f¹, by
means of the key f³ employed for that purpose; or the adjusting screw may be
fixed in position by other suitable means.
A hand wheel or lever h is mounted upon the upper end of the adjusting screw,
to set the valve to any desired pressure.
f
In order that the safety valve may be tried from time to time by the attendant
to ascertain whether it is "sticking," or in proper action to blow off stean, a lever
(not shown in the Drawings) is arranged in combination with the valve, so as to
lift the cylinder a and with it the valve c, as is well understood with reference to
other safety valves. For this purpose the safety valve need not be unlocked, as the
attendant is not supposed to be in possession of the key.
Safety valves thus arranged and constructed do not require a dome or cover.
Having thus described the nature of our improvements and the manner of
performing or carrying the same into practice, we would remark that we do not
claim any of the parts separately which are well known and in common use, nor do

page_text: we confine ourselves to the exact details herein before described, but what we claim
is, the improved arrangement and construction of safety valves whereby the valve c
can be adjusted to act at any given pressure, and be locked by the cam f² or its
equivalent, acting on the thread of the screw f by which the pressure is put on to
the spring b, substantially in the manner and for the purpose hereinbefore described 5
and represented in the Drawings annexed.
In witness whereof, I, the said John Ward Jones, have hereunto set my hand
and seal, this Sixth day of December, in the year of our Lord One thousand
eight hundred and seventy nine.
J. W. JONES. (L.S.)
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