Improvements in Taps and Valves.
Year: 1894

page_text: Date of Application, 12th Oct., 1894
Complete Specification Left, 11th July, 1895-Accepted, 24th Aug.,
1895
PROVISIONAL SPECIFICATION.
Improvements in Taps and Valves.
I FREDERICK COBHAM of Clovelly Duppas Hill Lane, Croydon, Surrey,
Buyer, do hereby declare the nature of this invention to be as follows:-
This invention relates to an improved screw down valve particularly suited for
high pressure, the valve, contrary to the usual arrangement being adapted to be
closed with and by the pressure instead of against it so that the greater the
pressure on the back of the valve the less the liability to leakage which is in fact
practically impossible.
The screw spindle by which the valve is operated acts only to remove the valve
from its seat so that the liability of the rotation of the spindle when screwed down
being communicated to the valve and so causing the rubber or other valve face to
be ground away against its seat, is entirely avoided since pressure of the screw
spindle against the valve stem can only occur when the valve is being removed
from its seat and not when it is being applied against it as usual.
The screw spindle works in the usual collar and nut in the cap of the casing
and its inner end is made tubular to receive the valve stem which projects at front
and back of the valve disc, the latter being faced with a washer of rubber, leather,
or other suitable material. The valve closes in the upward direction against a
shoulder or seat in the valve casing, the chamber in which the valve is contained
communicating with the inlet, and the chamber above the valve seat with the
outlet of the tap. A spring may be applied at the back of the valve to supplement
the pressure of the water and raise the valve to its seat in closing if the water
pressure is insufficient.
لبحو
1004
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
I, FREDERICK COBHAM, of Clovelly, Duppas Hill Lane, Croydon, Surrey,
Buyer, 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 screw-down valve particularly suited for
high pressure, the valve being adapted to be closed gradually and without shock
by the pressure of the water instead of against it as usual, so that the greater the
pressure on the back of the valve the less the liability to leakage. Furthermore,
the valve cannot be rotated by the screw spindle whilst being closed so that the
rubber or other valve face cannot thereby be ground away against its seat, as
usually happens in ordinary screw-down valves.
Reference is to be bad to the accompanying drawings, forming part of this
Specification, wherein have represented a central longitudinal section of the
improved screw-down valve.

page_text: The screw-down spindle A by which the valve is opened passes through the usual
gland and packing and its enlarged lower end a is screw-threaded and works in a
corresponding socket.b.formed in the cap B of the casing, the screw threads being
preferably left-handed so that the rotation of the spindle A to the right will have
the effect of permitting the valve to close. The valve C is provided with an
upwardly projecting stem c which is received and guided in a socket or bore in the
lower end of the spindle A and the valve is also furnished with a downwardly
projecting continuation c', of the stem which is received and guided in a socket
formed in a screw cap D closing the valve chamber E at bottom. The valve
closes in the upward direction against a seat f formed around the orifice f¹, in a
diaphragm F separating the chamber E which communicates with the inlet from
the chamber G above which communicates with the discharge nozzle. The valve C
is formed by a metal disc 2 in one with the valve stem c, c', faced with an annular
washer 3 of rubber or leather surrounding a boss 4 or enlargement of the stem c.
the washer being held in place by the inwardly curved flange of a ring or ferrule 5
screwing on to the disc 2. The enlargement or boss 4 projects above the face of
the valve so that as the valve is being allowed to close the boss first rises into the
aperture, which it nearly fills, the boss thus serving both to ensure the valve
being guided accurately to its seat and also by partially checking the flow of water
through the orifice f¹, before the valve closes entirely ensures that the valve shall
close against its seat gently and without shock in the event of the valve not
responding immediately to the valve-closing movement of the spindle A. A spring
might be applied below the valve to supplement the water pressure in the event of
the latter being insufficient to ensure the closing of the valve.
.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
:-
1. The herein described improvement in screw-down valves consisting essentially
in the valve closed by the pressure and guided by upward and downward extensions
of its stem and by a boss serving also to partially close the aperture before the
valve reaches its seat, substantially as specified.
2. The combination, with the valve adapted to be closed by the pressure and
provided with a guide stem and with a boss fitting in the aperture of the valve
seat,, as described, of a screw spindle for opening the valve as specified.
3. The improved screw-down valve substantially as herein described.
Dated this 11th day of July 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.