Improvements in Valve Seats.
Year: 1892

page_text: Date of Application, 1st Jan., 1892
Complete Specification Left, 23rd Sept., 1892-Accepted, 29th Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements in Valve Seats.
We, GEORGE COCKBURN, and ALLAN WATSON BAIRD, of 28 St. Andrew's
Drive, Pollokshields, in the County of Renfrew, 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 construct valve seats for ordinary disk
valves in an improved manner and so as to keep tight, when closed, notwith-
standing variations in the temperature or pressure of steam or other fluid acting
on them.
In carrying out our invention we form the contact face or seat surface upon a
ring of brass or other suitable metal which is fitted or driven tightly into the cast
iron or other plate or frame forming part of the valve box. The ring constituting
the valve seat is either of a tapered section or is made with a projecting rim or
flange to retain it in the valve opening; but as otherwise ordinarily constructed
the seat surface however true it may be when the parts are cold is apt to become
uneven when heated by steam and in consequence to be leaky when closed. The
uneveness is believed to be due to expansion caused by heat combined with
the grip of the frame in which the seat ring is tightly fitted. The invention
consists in forming a groove on the inside or outside or on both inside and outside
on the seat ring so as to reduce the thickness of the ring to a small extent at and
near the part at which, in the ordinary construction, the grip of the frame acts
on the seat ring nearest to the seat surface.
This improved construction is found to answer the purpose and it is believed
that owing to the reduction of the thickness at the part indicated the expansion
therefrom upwards or towards the seat surface is rendered uniform all round.
Dated this Thirty-first day of December 1891.
EDMUND HUNT,
Applicants' Agent.
COMPLETE SPECIFICATION.
Improvements in Valve Seats.
We, GEORGE COCKBURN, and ALLAN WATSON BAIRD, of 28 St. Andrew's
Drive, Pollokshields, in the County of Renfrew, 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 construct valve seats for ordinary disk
valves in an improved manner, and so as to keep tight when closed, notwith-
standing variations in the temperature or pressure of steam or other fluid acting
on them.
In carrying out our invention we form the contact face or seat surface upon a
ring of brass or other suitable metal which is fitted or driven tightly into the cast
iron or other plate or frame forming part of the valve box. The ring constituting
the valve seat is either of a tapered section or is made with a projecting rim or
flange to retain it in the valve opening; but as otherwise ordinarily constructed,
the seat surface, however true it may be when the parts are cold, is apt to become
uneven when heated by steam, and in consequence to be leaky when closed. The
uneveness is believed to be due to expansion caused by heat combined with the
grip of the frame in which the seat ring tightly fitted. The invention consists

page_text: in forming a groove on the inside, or outside, or on both inside and outside, on the
seat ring, so as to reduce the thickness of the ring to a small extent at and near
the part at which, in the ordinary construction, the grip of the frame acts on the
seat ring nearest to the seat surface.
And in order that our said invention and the manner of performing the same
may be properly understood, we hereunto append a sheet of explanatory drawings
to be hereinafter referred to and representing some examples of the application
of our improvements.
Figure 1, of the drawings is a vertical section showing the internal' parts of a
stop, or regulator, or safety valve; and
Figure, 2, is a similar view of a reducing valve.
Figures, 3, 4, and 5, are enlarged sections showing in each case a seat piece and
part of the frame or valve box in which the seat piece is fitted.
In these drawings the same reference letters are used to mark the same or like
parts wherever they are repeated.
In the example shown in Figure, 1, the valve, A, is arranged to open upwards,
whilst in that shown in Figure, 2; the valve, A, is arranged to open downwards
and is inverted as is also the seat piece, B. The seat piece, B, as showing in
Figures, 1 to 4, is made with a flange or slightly projecting rim, C, which retains
the seat piece in place in the frame or part, D, through which the passage to be
controlled by the valve is formed. In Figure, 5, the seat piece, B, is shown as of
a tapering form. In all cases the groove, E, the application of which constitutes
our invention is formed at the part of the seat piece, B, at or opposite the corner
of the part, D. We prefer to make the groove, E, in the inner surface of the seat
piece as shown in Figures, 1, 2, 3, and 5; it may however be formed in the outer
part as shown in Figure, 4; or there may be grooves both internally and
externally.
The improved construction herein described and delineated is found to answer
the purpose; and we believe that owing to the reduction of the thickness at the
part indicated, the expansion therefrom towards the seat surface is rendered
uniform all round.
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
claim is
The constructing of valve seats of the kind herein described and delineated with
a groove or reduction of thickness at or opposite the part where the seat piece is
gripped near the seat surface substantially as and for the purposes herein before
described.
Dated this Twenty-second day of September 1892.
EDMUND HUNT,
Applicants' Agent.