Improvements in Stop Valves.
Year: 1898

page_text: Improvements in Stop Valves.
I, JOHN COXON, Marine Engineer, of 14, Eden Street, Sunderland, Durham, do
hereby declare the nature of this invention to be as follows:-
-
This invention for improvements in stop valves, has for its object an improved
construction of valve whereby in the event of the bursting of the steam pipe
the valve is automatically closed, while at the same time its ordinary use is not
interfered with.
According to this invention the stop valve and casing are constructed some-
what in the usual way but two seatings are provided for the valve.
are arranged to act upon the valve both above and below so that it is in a
Springs
balanced position. The upper stem of the valve is hollow and within this stem
the operating rod of the stop valve fits.
The operating rod is screwed down in the ordinary way by means of a hand
wheel and its lower end coming in contact with the bottom of the hollow stem
forces the valve down upon the lower seating, thus preventing the passage of
steam.
On screwing up the operating rod the valve takes up a half way position
allowing steam to pass.
In the event of the bursting of a steam pipe the pressure of steam forces the
valve up against the upper seating, thus closing the valve.
In a modified construction the lower end of the two springs is done away
with, the steam pressure itself being sufficient to force the valve upwards to a
middle position as soon as the operating rod of the valve is screwed up to permit
this. The upper spring may be arranged to act between the valve and a guiding
framing or between a washer upon the valve stem and a valve casing.
Dated this 4th day of T.1. 1000
GEO. H. RAYNER,
37, Chancery Lane, London,
Agent for the Applicant.
I, JOIN COXON, Marine Engineer, of 14, Eden Street, Sunderland, Durham, 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:-
This invention for improvements in stop valves, has for ite alioat

page_text: construction of valve whereby in the event of the bursting of the steam pipe
the valve is automatically closed, while at the same time its ordinary use is not
interfered with.
According to this invention the stop valve and casing are constructed some-
what in the usual way but two seatings are provided for the valve.
The operating rod is screwed down in the ordinary way by means of a hand
wheel and its lower end coming in contact with the valve stem forces the valve
down upon the lower seating, thus preventing the passage of steam.
On screwing up the operating rod the valve takes up a half way position
allowing steam to pass.
In the event of the bursting of a steam pipe the pressure of steam forces the
valve up against the pressure of a spring to the upper seating, thus closing the
valve.
The arrangement is also applicable to the ordinary stop valve, the casing of
which requires to be only slightly altered in order that the invention may be
applied.
In order that the invention may be more clearly understood, reference is had
to the accompanying sheet of drawings in which Fig. 1 is a section through the
- valve showing it in its ordinary closed position, Fig. 2 shows it open and Fig. 3
is a view showing the valve closed by the pressure of the steam in case of the
bursting of a pipe or similar accident."
A is the valve which in its closed position as shown in Fig. 1, is pressed upon
the seating B carried by the lower part of the casing C in the ordinary manner.
The upper end of the stem a is provided with a cap or head, a secured to it by a
pin and this head is slightly recessed to receive the end of the operating rod D
This rod is screwed and is raised and lowered by the hand wheel d in the ordinary
manner.
Within the upper part E of the casing is fitted a strong helical spring F
which encircles the operating rod. The lower end of this spring bears upon the
slide G, which can move vertically, but is prevented from turning by the guide d
formed by ribs in the casing E, the flange of the slide being recessed or notched
to receive the ribs or guiding pieces. The operating rod D is also prevented
from turning by the small pin fitted to the part G and projecting into the
vertical groove in the rod.
The slide G carries the ring H which is screwed into it and is recessed to form
The
a seating for the head a¹ when the valve is opened as shown in Fig. 2.
scating under ordinary circumstances forms a stop for the valve stem when the
valve is opened and the pins retain the slide G in the desired position.
lift of the valve can be regulated by adjusting the part H which is formed with
a small rim allowing it to be screwed into or out of the socket in the slide G.
The
The valve stem a passes through the gland J which supports it and prevents
the escape of steam. Immediately above the valve a second valve seating K is
provided. This seating receives the top of the valve disc when that is forced up
against it so that the steam passage can be closed in two ways either by the valve
in its ordinary closed position or by the upper side meeting the seating K when
the valve is raised beyond its normal open position.
The action of the valve is as follows:--When the operating rod is raised as
shown in Figs. 2 and 3, the steam pressure at the bottom of the valve opens it
and allows steam to pass through the inlet at the bottom of the casing to the
outlet and thence through the steam pipe. When in this position the top of
the valve stem rests in the seating H which retains the valve in a mid-way
position as shown in Fig. 2.
Should however the pressure above the valve he suddenly relieved owing to
the bursting of a steam pipe to which the outlet leads the pressure at the
lower side of the valve forces it up against the spring F until the upper side of
the valve meets the seating K and cuts off all communication with the steam
pipe. Immediately the valve is closed in this manner the full pressure of the

page_text: steam is exerted upon the valve and there is no danger of its opening and
allowing the steam to escape until forced down by the operating rod." As shown
in the upper part of Fig. 3, the sleeve G in this case is forced up by the valve
stem and compresses the spring F.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:―
(1) In a stop valve, the combination with an auxiliary seating against which
the upper side of the valve can bear, of a spring adapted to hear against the
upper end of the valve stem and to retain the valve when opened between the
ordinary and second seating and in the event of a sudden release of pressure at
the upper side of the valve to allow the valve to rise against the second seating,
substantially as described and for the purposes specified.
(2) The improved stop valve formed with two seatings and adapted to close
against the pressure of a spring on a sudden release of pressure, constructed and
operating substantially as described and shown and for the purposes specified.
Dated this 4th dar of duril 1899
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.