Improvements in Stop-cocks or Valves.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in Stop-cocks or Valves.
We WILLIAM HITCHCOCK SPENCER and JOHN MILLER RALSTON both of Hitchin in
the County of Herts, Engineers do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement :-
This invention for improvements in stop cocks or valves relates to full way stop
valves of the sluice or sliding type and has for its object to construct a stop valve in
such manner that, while the fluid is allowed to pass through with little obstruction
when the valve is open, the said valve will be firmly pressed or jammed on its
seats when closed and can be readily opened; and consists in forming the valve of
two separate discs which are pressed outward against their faces or seats when the
passage is being closed by means of a double cam or eccentric placed between them
and to which a limited rotary motion is imparted as the valve approaches the extent of
its travel by means of inclined guides in the casing or valve box engaging with
projections on the said cam or eccentric.
In the accompanying two sheets of drawings
Fig. 1 is a vertical section through the passages of a full way stop valve constructed
according to our invention.
Fig 2 is a horizontal section of the same shewing the valves relieved of the cam
pressure, and
Fig. 3 is a similar view but showing the valves shut with the cam moved to
position to press the valves against their seats.
g
An outer casing or box a with through passages b and flanges c is fitted with faces
or seats d on which two valves e slide for the purpose of closing the passages b.
Studs on the backs of the valves ffit into suitable apertures in a hollow screw box
raised and lowered at pleasure by means of the screw h and bear against the surface of
a cam or eccentric i situated in the screw box and formed with two lugs k working
in grooves or channels on the walls of the valve box. These channels are through
the greater part of their length parallel with the actuating screw but are inclined at
their lower extremities so that, as the valves are traversed downwards to close the
passages b, the cam i through the lugs k is caused to rotate through a limited angle
and so press the said valves firmly upon their seats d as will be clearly seen.
The actuating screw engages with the screw box at m and passes through the
cami and bottom of the box 9, its upper end passing through a stuffing box n and
gland o in the cover p secured by the bolts 7 to the casing a and being surmounted
by the hand wheel all as clearly shewn. Motion of the screw in the direction of its
length is prevented by the collars which bears on its upper side against the bottom of
the cover and on its under side against a collar plate t lying on the recessed ledge u
in the casing a.
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 :-
1. In a full way stop valve, automatically pressing the valves upon their seats
when the passages are covered by means of a cam or eccentric guided in channels in
the casing aud actuated by means of a screw substantially as described.
2. The arrangement and construction of full way stop valves substantially as
described with reference to the drawings.
Dated this 30th day of December 1889.