A New or Improved Stop Valve.
Year: 1889

page_text: Date of Application, 17th Oct., 1889
Complete Specification Left, 29th Mar., 1890-Accepted. 5th July, 1890
PROVISIONAL SPECIFICATION.
A New or Improved Stop Valve.
I, JAMES ROBINSON of Penryn in the County of Cornwall, Engineer do hereby
declare the nature of this invention to be as follows:-
This Invention relates to a novel construction of stop valves differing from the
ordinary stop valve in the following manner: The body of the valve is composed of
two circular or cup shaped castings one fitting into the other in an inverted position.
A suitable circular chamber is formed partly in each casting in such a manner that
by forcing the inner casting upwards, by screwing or other means, the said chamber
is reduced in size. The chamber is filled with a ring of asbestos or other suitable
material.
A circular opening is formed between the two circular or cup shaped castings to
permit the metallic face of the valve seat to come into close contact with the said
asbestos within the said chamber. The face of the valve seat is made of a suitable
form to fit into the aforesaid opening between the two circular or cup shaped
castings.
1000
COMPLETE SPECIFICATION.
A New or Improved Stop Valve.
I, JAMES ROBINSON of Penryn in the County of Cornwall 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:-
This Invention relates to an improved construction of stop valve which is applicable
to stop valves for steam, gas, compressed air, water or other fluids. Such improved
construction is illustrated in the accompanying drawing which shews a view partly in
section and partly in elevation of my improved stop valve. The letters of reference
occurring in the following description of my invention refer to corresponding letters
upon such drawing. My invention consists in making the valve of two castings A. B
which fit into each other and are of any convenient shape. The outer casting forms
the valve body and the inner casting a loose valve centre. A recess a is formed on
the inside of the top of the valve body wherein the crown b of the valve centre fits.
The thickness of metal surrounding the recess a is reduced on its under surface so as
to form a bevelled face a¹ which terminates in a deep rim a². A second bevelled
face b¹ is formed on the outside of the valve centre immediately below the crown b.
These two bevelled faces are made at contrary angles to each other so that when the
two castings are fitted together a packing chamber c is formed round the valve centre.
This chamber is filled with asbestos or any other suitable elastic packing which
packing is indicated by dots in the accompanying drawing. The size of the packing
chamber is regulated by the degree of approximation existing between the valve body
and the valve centre and such chamber may be readily made either smaller or larger
by operating the valve spindle and so slackening or increasing the pressure on the
valve centre. On reference to the drawing it will be seen that when the valve body
and valve centre are fitted together a groove d is formed round the valve centre into
which the metallic face of the valve seat e fits. By this means such face is brought
into immediate contact with the asbestos or other packing, (which is partially forced
out from the packing chamber by the compression of the valve centre against the
valve body) thus rendering the valve thoroughly air tight. The rim a² on the valve

page_text: body extends below the packing chamber and forms a guard which prevents the
steam or other fluid cutting through the asbestos or other packing. The hole in the
crown of the valve centre is not threaded so that when the centre is fitted on
the central stud vit is free to move up and down thereon. The loose valve centre
may be mounted on two or more such central studs; or in the case of large valves
the ordinary arrangement of a small central valve to facilitate opening the larger
valve may be employed. Such loose valve centre projects below the packing chamber
and serves as a guide whereby to adjust the valve in its proper position when it is
closed. A bevelled metallic face b² similar to that on an ordinary stop valve is formed
on the under surface of the valve centre so that in the event of the asbestos or other
'packing in the chamber c becoming displaced my improved stop valve will act
temporarily in the same way as an ordinary stop valve. The valve spindle V is
attached in any convenient manner.
I would here observe that I do not confine myself to the precise details of con-
'struction hereinbefore described as the same admit of various minor modifications
without departing from the principle of my invention which is to construct a stop
valve with a loose centre which together with the valve body forms an adjustable
'packing chamber and a groove wherein the face of the valve seating fits whereby I
provide a simple and ready means of applying and fixing asbestos or other suitable
material to the faces of stop valves in such a manner as to resist the cutting or wear-
ing action of the steam or other fluid.
The advantages of my invention may be summarised as follows:-1° The asbestos
or other packing being brought into direct contact with the face of the valve seating
is held firmly in position thereby, thus keeping the valve perfectly tight under any
pressure and temperature. 2° There is no liability to leakage through unequal
expansion and contraction. 3° The asbestos or other packing is protected by the
guard against the wearing action of the steam or other fluid. 4° No grinding in or
re-facing is required as the valve can be renewed in a few minutes by inserting fresh
..packing. 5° Owing to its combined efficiency, utility and simplicity, and the facility
with which it can be renewed my improved stop valve is particularly adapted for
´use for marine and other steam engines.
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.
A stop valve consisting of two castings fitting into each other one of which forms
the valve body and is furnished with a suitable guard and the other a loose valve
centre and which valve body and centre when fitted together form an adjustable
packing chamber and also a groove wherein the face of the valve seating fits all
substantially as hereinbefore described and shewn.
Dated this 20th day of March 1890
ELT & Co.,
33, Southampton Buildings, Holborn, London, Agents for Applicant.