Improvements in Reducing Valves for Steam, Water, Air, or Gases.
Year: 1890

page_text: Date of Application, 11th Aug., 1890
Complete Specification Left, 11th May, 1891-Accepted, 18th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in Reducing Valves for Steam, Water, Air, or Gases.
I CHARLES STUART of Bletchley Iron Works Fenny Stratford, Bucks
Mechanical Engineer do hereby declare the nature of this invention to be as
follows:-
In carrying this invention into practice I construct a suitable shell or casing
having an inlet and outlet passage formed thereon, the former to admit fluids or
liquids of a higher pressure than that which it is intended to escape by the latter.
This shell or casing has fitted to it a cylinder into which is fitted a working piston,
at the back end and pressing against same is a column of mercury, of a height
equal to the desired pressure of fluid when escaping, through the outlet passage to
the front end of this piston is fixed a toothed rack arranged to work or gear into
a toothed pinion wheel fixed to a valve, called herein the admission valve," and
such valve shuts into a suitable seating, to this valve is also fixed a spindle having
a square threaded screw with two or more threads, and of any desired pitch formed
upon its periphery, and fitted to screw in and out of a female nut, which is also
fitted to the shell or casing before mentioned.
The pressure of the column of mercury now acting upon the back end of the
piston within the cylinder, the said piston with rack is moved forward this rack
being in gear with the pinion on the valve and spindle produces a rotative motion
to the latter causing it to unscrew itself out of the nut and thereby open the
admission valve from its seat thus admitting the high pressed fluid or liquid
against the front end of the piston this pressure will re-act against the pressure due
to the column of mercury and by its superior force push the piston back into the
cylinder the rack will also reverse the action of the screwed valve spindle and thus
tend to fully close the valve upon its seat until the uniform and desired pressure is
obtained and equal to a pressure due to the height of the column of mercury
pressing against the piston such action will continue intermittently until both
pressures become of equal force or until the column of mercury balances the
reduced pressure of supply of the fluid or liquid.
CHARLES STUART.
COMPLETE SPECIFICATION.
Improvements in Reducing Valves for Steam, Water, Air, or Gases.
I, CHARLES STUART, of 3, Cursitor Street, Chancery Lane, in the County of
London, Mechanical Engineer, 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 :-
My invention relates to reducing valves for regulating the pressure of fluids
such as steam, water, air or gas.
According to my invention adapt the shell or casing of the valve to receive a
piston against one face of which presses a column of mercury or a spring, the
other face receiving the pressure of the fluid entering the valve casing. The said
piston carries a rack which gears with a pinion fitted to the valve, the spindle of
which is provided with a screw thread working in a nut formed in the valve casing,
whereby the pressure of the column of mercury causes the valve to open whilst
that of the fluid tends to close the valve.
To enable my invention to be fully understood 1 will describe how it can be
carried into practice by reference to the accompanying drawings, in which:-
Figure 1 is a plan of a reducing valve constructed according to my invention.

page_text: Figure 2 is a section on the straight-line A-B of Figure 1, and,
Figure 3 is a section on the crooked line CD of Figure 2.
The shell or casing of the valve comprises an inlet a, an outlet b, the valve
chamber G the valve-seating d, the nnt e, a cylinder fand a tube g, all as hereinafter
more fully described.
is the piston adapted to work in the cylinder f; is the column of mercury
enclosed within a tubej adjustably inserted in the tube y forming part of the valve-
casing, the mercury entering the cylinder and pressing against one face of the
piston as clearly shewn in Figure 3, whilst the Huid entering the inlet a under
pressure, on its way to the outlet, presses against the other face of the piston;
is the rack carried by the piston h.
I is the pinion in which the rack gears, the said pinion being fixed to the valve m
and rotating in the valve chamber c; is the valve-spindle and is the screw
thread with which it is provided, the latter working in the nut e.
The height of the column of mercury is calculated to give a pressure equal to
that at which it is desired the fluid shall pass out of the valve-outlet and this
height can be regulated by raising or lowering the mercury tube j in the tube
the mercury tube being then secured in position by means of a stuffing box and
clamp p.
The action is as follows:-
-
g
The pressure of the column of mercury upon the piston moves the latter
forward with the rack; the said rack through the medium of the pinion causes
the valve m and its screw-threaded spindle to rotate and consequently the valve m
is moved away from its seat d, thereby admitting the fluid entering the valve casing
at a at a higher pressure than it is intended it shall leave. The fluid now pressing
against the piston with greater pressure than that exerted by the column of
mercury will force it backwards in the cylinder fand the rack k through the medium
of the screw-thread and mut e will cause a reverse movement of the valve to that
hereinbefore described, that is to say, it will tend to close itself and these two
movements of the valve in reverse directions will continue alternately until the
pressure of the fluid upon the piston equals that of the column of mercury upon
the piston or until the pressure of the fluid supply is reduced to that of the column
of mercury upon the piston.
It will be obvious that instead of employing a column of mercury the required
effect could be produced by the pressure of a spring upon the piston h.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. A reducing valve for regulating the pressure of fluids in which the pressure of
a column of mercury or of a spring acting upon a piston is employed to regulate
the opening of the valve and thereby reduce the pressure at which the fluid enters
the valve, substantially as herein before described.
2. In a reducing valve for regulating the pressure of fluids, the combination with
a piston adapted to rotate the valve having its spindle provided with a screw-thread
working in a nut, of a column of mercury (or a spring) arranged to act upon the
said piston in the manner and for the purposes set forth and substantially as hercin-
before described and illustrated in the accompanying drawings.
3. The improved reducing valve for regulating the pressure of fluids as herein-
before described and illustrated in the accompanying drawings.
Dated the 11th day of May 1891.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.