Year: 1886

page_text: WICKL
We, GEORGE COCKBURN, and ALLAN WATSON BAIRD, of the firm of George
Cockburn, and Company of Sussex Street, Kinning Park, in the County of
Renfrew, North Britain, Engineers, do hereby déclare 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 relates to pressure reducing valves of the kind in which the
valve is connected to a diaphragin the effective pressure on which combined with
the pressures on the opposite sides of the valve determines the position of the
valve; and the object of our Invention is to improve the construction and action
of such arrangements, and to render them suitable for high pressures.
In carrying out our Invention we employ a flexible diaphragm of copper or
other suitable sheet metal, and whilst this diaphragm may consist of a single ply
of the sheet metal we prefer to employ two or more plies of thin metal whereby
great flexibility is obtained with the necessary, strength. We increase the strength
of the diaphragm without diminishing its flexibility by combining with it a series
of segments which are not flexible but are capable of moving with the diaphragm,
these segments being placed on the side of the diaphragm opposite to that on
which the internal pressure acts. And we proportion the valve so that a small
range of movement gives all the variation of opening that is required; and by
these means we obtain a pressure reducing valve of great sensitiveness and acting
quickly and accurately whilst it is not injured by high pressures.
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 two applications of our Invention.
Figure, 1, of the drawings is a vertical section of our improved valve as arranged.
for reducing the pressure of steam or other fluid to a definite amount; and figure, 2,
is a plan as with the cover removed and showing the strengthening segments.
Figure, 3, is a vertical section of our improved valve as arranged for reducing the
pressure of steam or other fluid passing through the apparatus to a pressure having
a certain proportion to the initial pressure. In these drawings the same reference
numerals are used to mark the same or like parts wherever they are repeated.
In the arrangement shown in figures, 1, and 2, the valve, 4, which is of an
ordinary form is arranged to close up against a seat, 5, fixed in an opening in an

page_text: inner part of the casting which separates the inlet, 6, from the outlet, 7; and the
amount of opening is limited by a stop, 8, on the bottom cover. The valve, 4, is
formed with feathers, 9, which guide it by working in the opening of the valve
seat, 5; and it is connected by a short link, 10, to a spindle, 11, which extends up
through a central guide eye in the top cover, 12, and has a helical spring, 13,
applied to its outer end. This spring, 13, is held down and adjusted by a screw
pin, 14, bearing on its upper end and screwed through a top plate, 15, tied to the
cover, 12, by rods, 16. Instead of the spring, 13, a dead weight or a weighted
lever may be applied to the valve spindle, 11.
The diaphragm, 17, which is made with annular corrugations at the part where
the pressure acts on it, has its outer edge fixed in the joint between the top
cover, 12, and the body of the valve box or casting, whilst its inner edge is held
between a collar, 18, formed on the valve spindle, 11, and a ring, 19, which is fixed
by a nut, 20, screwed on the spindle. The ring, 19, is formed with a groove or
rebate round it and a similar groove or rebate is formed round the inner edge
of the cover, 12; and between these two grooves there are placed a series of
metal segments, 21, which lie upon the diaphragm, 17, and which are fitted into
the grooves and in contact with each other with just sufficient looseness to allow
of their inner ends moving freely up and down with the valve spindle. These
Begments strengthen the diaphragm and equalise its action without diminishing its
flexibility.
The steam or other fluid entering by the inlet, 6, presses down on the valve, 9,
tending to open it, and upwards on the diaphragm, 17; and this upward pressure
acting through the spindle, 11, tends to close the valve. The diaphragm, 17, should
be proportioned so that the effective upward pressure on it balances the downward
pressure on the valve. The steam or fluid which has passed the valve, 9, and is in
the outlet, 7, acts upwards on the valve. and has opposed to it the pressure of the
spring, 13, or other load applied to the valve; and the load-being adjusted to the
pressure to which it is intended to reduce the steam or fluid on its passage through
the valve, the valve will open or close with any variation of the pressure so as to
maintain the desired pressure at the outlet, 7, as long as the initial pressure is
sufficient for that purpose, as is well understood.
The arrangement shown in figure, 3, differs from that shown in figure, 1, in being
without any separate spring or load to act on the valve, the diaphragm, 17, being
made of an effective area less than that, of the valve, 9, with which arrangement
the pressure in the outlet, 7, will be proportionally less than that in the inlet, 6, in
a degree corresponding to the differences of the said effective areas.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is:-
The improved construction of pressure reducing valve in which the position of
the valve is regulated by a corrugated metal diaphragm which has combined with
it a series of metal segments substantially in the manner and for the purposes
hereinbefore described.