Improvements in Piston Valves.
Year: 1890

page_text: Date of Application, 7th Oct., 1890
Complete Specification Left, 7th July, 1891-Accepted, 8th Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in Piston Valves.
I, HENRY CARLISLE Eagle Foundry, Sheffield, in the County of York,
Manufacturer, do hereby declare the nature of my invention to be as follows:-
This invention relates to an improvements in the construction of spring piston-
valves, and more particularly to the rings of such pistons, the object being to prevent
the steam gaining access to the spring space at the back of the rings.
It is specially applicable to, and useful in combination with, the improved
piston described in the Specification of Patent No. 2155 dated the 25th of Jan.
1884, but it may be applied to piston valves having rings, and other forms of
springs.
In the improved piston above named, vertical and lateral pressures are given to
the two split rings, by a peculiarly constructed spring placed inside the rings, and
the slight play between the central faces of the rings to allow free action provides
also a space sufficient for high pressure steam to find a passage through into the
spring chamber, which in this, and other like pistons of somewhat similar construction,
is detrimental to their perfect action.
To overcome this defect propose to make an alteration in the said rings and to
enclose them in an outside single ring of peculiar construction.
I make the outside ring of sufficient width to enclose the two ordinary rings, and
pass beyond them, upon the piston block and cover; and centrally upon and round
its internal face I form an annular projection or collar, having inclined top and
bottom faces, and this annular projection or collar fits between the opposite edges of
the top and bottom rings, which are correspondingly reduced in width and tapered
to admit the said collar.
The ring is divided by a vertical or diagonal cut to render it clastic.
ROBT. F. DRURY, Fel. Inst. P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant
COMPLETE SPECIFICATION.
Improvements in Piston Valves.
1, HENRY CARLISLE Eagle Foundry, Sheffield in the County of York,
Manufacturer, 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 improvement in the construction of spring piston
valves, and more particularly to the rings of such piston valves, the object
being to prevent the steam gaining access to the spring space at the back of the
rings.
It is specially applicable to, and useful in combination with the improved piston
described in the Specification of Patent No. 2155 dated the 25th day of January
1884 but it may be applied to piston valves having rings and springs of other
construction.
The invention is illustrated in the annexed sheet of drawings, in which like letters
refer to like parts in any of the figures.
Fig. 1, is a sectional elevation of the outside ring showing the annular collar.
Fig. 2, plan of outside ring.
Fig. 3, section of outside and inner rings.

page_text: In the improved piston described in the before mentioned Patent, vertical and
lateral pressures are given to the two split rings A and B, shown in Fig. 3, of the
annexed drawings by a peculiarly constructed spring placed within the said rings,
this spring C, is indicated by a section cut through where it has an ordinary spiral
or coiled form, and the slight play between the central faces of the rings in the
piston before mentioned, while allowing free action, which is necessary, also
provides a sufficient space for high pressure steam to find a passage through into
the spring chamber, which in this, and in other like pistons of analogous construction,
is detrimental to their perfect action.
To overcome this defect I use the following device which is shown in the
drawings, and will be readily understood.
I make an outside ring OR, of the desired diameter, and of sufficient width to
enclose the two rings A and B, and to have a margin beyond them, as seen in
Fig. 3, to pass upon the periphery of the piston block and cover plate.
In the centre of the internal face of the outside ring OK, I make an annular
projection or collar D, having its top and bottom faces E, inclined, or tapering
inwards, and make the central faces or edges of the rings A and B, with a
corresponding incline or taper, to fit against and move upon the faces E, as the
spring C, expands or contracts, and thus although the rings A, and B, in action
approach and separate there is no passage for steam.
The outside ring is divided by a vertical or diagonal cut to render it clastic.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed or carried into effect, I
declare that what I claim is :-
A piston valve having an outside ring of greater breadth than the two inner
rings, and provided with an internal annular collar having its top and bottom faces
inclined, against which the inclined edges of the inner rings bear, substantially as
hereinbefore described and shown.
ROBT. F. DRURY, Fel. Inst. P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.