IMPROVEMENTS IN OR CONNECTED WITH SAFETY VALVES
Year: 1883

page_text: LETTERS PATENT to Alexander Turnbull, of Glasgow, in the County of
Lanark, North Britain, Engineer, for an Invention of IMPROVEMENTS IN
OR CONNECTED WITH SAFETY VALVES
»
"
PROVISIONAL SPECIFICATION left by the said Alexander Turnbull at the
Office of the Commissioners of Patents on the 3rd July 1883.
ALEXANDER TURNBULL of Glasgow, in the County of Lanark, North Britain,
Engineer, "IMPROVEMENTS IN OR CONNECTED WITH SAFETY VALVES
"
This Invention relates to the class of safety valves which are loaded by means of
helical steel springs and its object is to prevent the corrosion of the springs which
ordinarily takes place in consequence of steam getting access to them.
In one safety-valve arrangement to which the Invention is applicable the valve
is in the lower compartment of a box or casing containing the spring in an upper
compartment, the outlet for the steam which passes the valve being at the side of
the lower compartment. The spring acts on the valve by means of a spindle which
passes through an orifice in the horizontal partition or diaphragm which divides
the lower compartment from the upper one; and it is to prevent the leakage of
steam through this orifice that the present improvements are applied the object
being effected without interfering with the perfect freedom of the spindle to move
through the orifice or to be turned round.
The spindle is formed with a shoulder which is ordinarily just above the orifice
in the diaphragm and on this shoulder there rests a ring or washer upon which the
bottom of the helical spring bears, the ring rising and falling with the action of
the spring when the valve opens and closes. The Invention is carried out by
interposing between the ring on which the spring bears and the bottom of the
upper compartment an elastic combination having a bottom ring which always
bears closely down on the diaphragm close round the orifice and a top ring which
always bears closely up against the ring on which the spring, bears, these bottom
and top rings being connected by a flexible material and having a helical spring
applied between them to make the upper ring follow the ring on which the spring
E. Davis

page_text: bears whenever the latter rises. The material connecting the top and bottom
rings may be leather or any suitable flexible and impermeable material, but it is
believed that what is known as insertion rubber cloth is to be preferred. In one
modification the flexible connection is made out of two rings of the material, to
which suitable shapes are given by pressure between dies, the parts being fixed
to each other and to the top and bottom rings by screw gripping rings. The
spring between the top and bottom rings may be placed inside or outside of the
flexible connecting material the latter arrangement having the advantage that the
spring cannot be acted on by any steam leaking through the diaphragm orifice
into the space within the flexible connecting material. The combination.of the
rings and flexible material may be placed below the diaphragm or partition and
between it and the top of the valve or a shoulder on the valve spindle.
Where a single spring is applied to two valves the connection of the spring with
the bar or lever which bears on the valves is by this Invention made by means of
a ring which is screwed into an eye formed in the bar or lever, the end of the
spring being hooked into the ring; and the ring is made slightly eccentric in order
that by turning it a little to one side or the other the strain of the spring may be
made to act equally on both valves.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Turnbull in the Patent Office on the 1st January 1884.
ALEXANDER TURNBULL, of Glasgow, in the County of Lanark, North Britain,
Engineer IMPROVEMENTS IN OR CONNECTED WITH SAFETY VALVES
"
My said Invention relates to the class of safety valves which are loaded by
means of helical steel springs and one of its objects is to prevent the corrosion of
the springs which ordinarily takes place in consequence of steam getting access to
them. My Iuvention also comprises simple and convenient means for accurately
adjusting the point or points of action of levers combined with. helical steel
springs.
In one safety-valve arrangement to which my Invention is applicable the valve
is in the lower compartment of a box or casing containing the spring in an upper
compartment; the outlet for the steam which passes the valve being at the side of
the lower compartment. The spring acts on the valve by means of a spindle
which passes through an orifice in the horizontal partition or diaphragm which
divides the lower compartment from the upper one; and it is to prevent the
leakage of steam through this orifice that the first part of my present improvements
is applied the object being effected without interfering with the perfect freedom of
the spindle to move through the orifice or to be turned round.
The valve spindle is formed with a shoulder which is ordinarily just above the .
orifice in the diaphragm, and on this shoulder there rests a ring or washer upon
which the bottom of the helical spring bears, the ring rising and falling with the
action of the spring when the valve opens and closes. My Invention is carried out
by interposing between the ring on which the spring bears and the bottom of the
upper compartment an elastic combination having a bottom ring which always
bears closely down on the diaphragm close round the orifice and a top ring which
always bears closely up against the ring on which the spring bears, these bottom
and top rings being connected by a flexible material and having a helical spring
applied between them to make the upper ring follow the ring on which the spring.
bears whenever the latter rises. The material connecting the top and bottom rings
may be leather or any suitable flexible material, but I believe that what is known
as insertion rubber cloth is to be preferred.
Where a single spring is applied to two valves the connection of the spring with
the bar or lever which bears on the valves is by my Invention made by means of
a ring which is screwed into an eye, formed in the bar or lever, the end of the
spring being hooked into the ring; and the ring is made slightly eccentric in order
that by turning it a little to one side or the other. the strain of the spring may be
made to act equally on both valves. For the same purpose one or both of the.
bearing points of the bar or lever may be fitted eccentrically, or where the lever
between two valves is centered on a pin this pin may have the part or parts by
which the lever. bears on the fixed support eccentric to the part by which it is fixed
in the lever. The eccentricity gives the same capability of adjustinent in the
several cases.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append a sheet of explanatory drawings to
be hereinafter referred to and representing examples of my improved arrangements.
On the accompanying sheet of drawings, figure, 1, is a vertical section of a
safety valve and parts connected therewith including a modification of my spring
protector. Figure, 2, is an enlarged section of the spring protector, and figure, 3,
is a similar view of a second modification. Figures, 4, and 5, are sectional views.

page_text: showing modifications of my adjusting device, and figures, 6, and 7, are sectional
views showing another modification of the adjusting device. In these drawings
the same reference numerals are used to mark the same or like parts wherever they
ate repeated.
As shown in figure, 1, the safety valve, 11, is by means of a spindle, 12, pressed
down by a helical spring, 13, the valve being in a lower compartment 14, having
a lateral outlet, 15, whilst the spring is in an upper compartment 16, separated
from the lower one, 14, by a diaphragm, 17, through an orifice in which the
spindle, 12, passes. The spring, 13, bears down ou a ring or washer, 18, which
'rests on a collar on the spindle, 12, and the protector is interposed between this
ring, 18, and the diaphragm, 17. The protector consists essentially of an upper
In the
ring, 19, connected by flexible material, 20, to a bottom ring, 21.
modification shown in figures, 1 and 2, the flexible material, 20, is in two pieces
fixed together by a pair of screwed clipping rings, 22, at the middle, the upper
and lower edges of the pieces being fixed by screwed clipping rings to the top and
.bottom rings, 19, 21, of the protector. In the modification shown in figure, 3, a
single flexible piece, 20, is used the part between the top and bottom rings, 19, 21,
being of a conical form, whilst it is fixed by means of cylindrical portions clipped
to the rings, 19, 21;. by gland-like rings, 23, 24. The flexible pieces, 20, of either
modification of protector are moulded into the required shape by being pressed
between suitable dies. Between the top and bottom rings, 19, 21, of the protector
there is applied a light helical spring, 25, to make the upper ring, 19, rise and
follow the ring, 18, on which the spring, 13, bears when the valve 11, rises.
this purpose a spring might be applied inside of the protector; but it is by
preference placed outside as shown so as to be itself protected from the steam.
For
In figure, 4, two valves, 26, are shown pressed down by a bar or lever, 27, to
which a helical spring, 28, is applied between the two valves. The upper end of
the spring is hooked into a hole which according to my Invention is made
eccentrically in a ring, 29, fixed by screwing (with a fine thread) into a hole in the
bar or lever, 27. The projecting edge of the ring, 29, is made hexagonal for the
application of a key for turning it, and when it is found that the two valves are
not quite equally acted on a slight turning of the ring, 29, will adjust the effective
centre at which the spring acts on the lever or bar, 27, so as to equalize the action.
In a similar way the points, 30, which bear on the valves, 26, may be made
eccentric relatively to their shanks by which they are fitted to the lever, 27, or to
a piece, 31, jointed to the lever. These adjustable bearing points, 30, may be
used in combination with or instead of the eccentric ring, 29.
In the modification shown in figures, 6, and 7. Two springs 32, subjected to
compression are applied to two valves, 26, in, combination with an, equalizing
lever, 33. This lever, 33, which is made double at its middle has fixed in its two
sides by means of fine screw threads a pin, 34, made with a slightly eccentric
middle part to bear and turn in an eye in a fixed holding bar, 35, and by turning
the pin, 34, a little the effective fulcrum can be adjusted to one side or the other
as may be required, the end or ends of the pin being made hexagonal for the
application of a key.
Having thus particularly described my said Invention and the manner of
performing the same I have to state that I do not restrict myself to the precise
details herein described or delineated but that what I believe to be novel and
original and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is:-
1. In connection with a safety valve directly loaded by a helical steel spring
the application and use of an elastic protector between the bottom of the spring
and the diaphragm or horizontal partition through which the spindle passes down
to the valve the said protector being arranged and operating substantially as
bereinbefore described.
2. In connection with a pair of safety valves loaded by a spring or springs
combined with an equalizing lever or bar, the making of a ring, or pin, or acting

page_text: point, on the position of which the equal action depends, slightly adjustable
substantially in the manner and for the purposes herein before described.
In Witness whereof I, the said Alexander Turnbull, have hereunto set my
hand and seal this twenty-ninth day of December in the year of our Lord One
thousand eight hundred and eighty-three.
Witness-
EDMUND HUNT
Patent Agent.
Glasgow.
ALLA TURNDURD (4.5.7