Improvements in Spring-loaded Safety or Relief Valves.
Year: 1890

page_text: Date of Application, 15th Mar., 1890
Complete Specification Left, 12th Dec., 1890-Accepted, 24th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Spring-loaded Safety or Relief Valves.
We, GEORGE WEIR, and JAMES WEIR, of Holm Foundry, Cathcart, in the County
of Lanark, North Britain, Engineers, do hereby declare the nature of this invention to
be as follows, that is to say :-
Our said invention has for its object to insure the equal pressure upon all parts of
the surface of contact of a safety or relief valve with its seat, when the valve is
directly loaded by a helical spring. The helical spring is applied between a disk or
plato which bears on the valve through a spindle or other part, and a stationary disk
or plate which is adjustable so as to compress the spring to the necessary extent. The
invention consists in connecting the two disks between which the spring is held, by
universal joints, one disk to the valve or valve spindle, and the other to the adjustable
stationary part. In each case the joint is by preference made by forming spherical
contact surfaces at the bearing parts, that is, a convex spherical surface on one part
fitting a concave spherical surface on the other part. With this construction,
although the spring may act unequally at different parts, the resulting strain or
pressure on the valve is central and therefore acts equally all round the valve. A
spindle for turning the valve on its seat may extend through the spring and through
central holes in the spherical parts.
Dated this Fourteenth day of March 1890
EDMUND HUNT,
Applicants' Agent.
COMPLETE SPECIFICATION.
Improvements in Spring-loaded Safety or Relief Valves.
We, GEORGE WEIR, and JAMES WEIR, of Holm Foundry, Cathcart, in the County
of Lanark, North Britain, Engineers, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, that is to say :-
Our said invention has for its object to insure the equal pressure upon all parts of
the surface of contact of a valve with its seat, when the valve is directly loaded by a
helical spring. The helical spring is applied between a disk or plate which is
adjustable, in most cases, so as to compress the spring to the necessary extent. The
invention consists in connecting the two disks between which the spring is held, by
universal joints,-one disk to the valve or valve spindle, and the other to the stationary
part. In each case the joint is by preference made by forming spherical contact
surfaces at the bearing parts;-that is, a convex spherical surface on one part fitting
a concave spherical surface on the other part. With this construction, although the
spring may act unequally at different parts of it, the resulting strain or pressure on
the valve is central and therefore acts equally all round the valve.
Examples of safety or relief valves as made with our improvements are shown on
an accompanying sheet of explanatory drawings. Figures, 1, and 2, are vertical
sections of two modifications; and Figure, 3, is a sectional elevation of a valve spindle
and other parts showing an alternative mode of arranging the spherical bearing parts.
In these drawings the same reference letters are used to mark the same or like parts
wherever they are repeated.
In the modification shown in Figure, 1, the valve, A, is held down on its seat, B,
by a spindle, C, connected to it by a loosely-fitting cross key, D. The spindle, C, has
formed on it a convex spherical coller, E, which fits and has a slight play in a concave
spherical bearing surface formed in the lower disk, F, between which and an upper
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page_text: disk, G, the helical spring, H, is placed. The upper disk, G, is formed with a concave
spherical recess which fits on a convex spherical surface, J, formed on the lower end
of a tubular piece, K, screwed into the top of the valve box, L. The valve spindle, C,
extends up through the piece, K, and is represented as being secured with an ordinary
arrangement of locking key, M, passed through slots in the spindle and in a small
screwed-in cover, N.
In the modification shown in Figure, 2, the parts to which our invention relates are
the same as shown in Figure, 1, but the upper convex spherical surface, J, is formed
on the cover, P, which is screwed upon the outside of the otherwise opentopped valve
'box, L.
The spherical part, E, on the spindle, C, may be concave as shown in Figure, 3,
instead of convex as shown in Figures, 1, and 2, the spherical part on the lower
disk, F, being made convex instead of concave. And similarly the spherical surface
on the upper disk, G, may be convex instead of concave, the part it bears on being
made concave instead of convex.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
olaim is :-
In a spring-loaded safety or relief valve introducing a universal joint between the
valve spindle and the spring and between the spring and the stationary part against
which it bears substantially as hereinbefore described.
Dated this Eleventh day of December 1890
EDMUND HUNT,
Applicants' Agent.