IMPROVEMENTS IN STOP-COCKS
Year: 1885

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We, JOHN ADDY HOPKINSON, and JOSEPH HOPKINSON, both of the firm of
J. Hopkinson & Co, of Huddersfield, in the County of York, Engineers, do hereby
declare the nature of our invention for "IMPROVEMENTS IN STOP-COCKS and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
Our invention relates to stop-cocks in which the plug is made tight in the body
or socket by the aid of fibrous or soft packing, such as jute, hemp, asbestos, and, in
some instances, india-rubber or a compound of the same; and the said invention
consists chiefly in a peculiar construction and arrangement of the plug in com-
bination with such packing for the purpose specified.
We are aware that fibrous or other soft and pliable substances have already been
applied as packing for cocks, taps and valves of various kinds, but we are not
aware of their having been used in such an efficient and advantageous manner as
that which we adopt. In one form of cock for which Letters Patent were granted
to James Mallinson February 28th, A.D. 1874, such packing has been applied in an
annular space around the plug and above and below the same in a large mass, but
this arrangement is objectionable because of the large contact or bearing surface of
the packing and its liability to deteriorate so that it fails to prevent leakage and at
the same time prevents the free turning of the plug. In other cocks, those, for
instance, for which Letters Patent were granted to John Dewrance, October 23rd,
A.D. 1877, and to Dewrance and Wall, February 23rd, A.D. 1881, the packing has
been applied in grooves or channels formed in the socket parallel to the axis of the
plug between the entrance and exit apertures, and at the top and bottom of the
plug, so that there are longitudinal and transverse packing surfaces, which enclose
the said apertures, and which are supposed to separate or isolate one from the other
of the said apertures and thus prevent the passage of the fluid around the plug.
One objectionable feature in these cocks is the. use of large packing-glands at the
upper end of the plug. Moreover, at a date many years earlier than the earliest of
the dates above mentioned, stop-cocks or taps with fibrous or non-metallic packing
placed in grooves in the barrel parallel to the axis of the plug and in grooves
surrounding the same were well known.
But, although the use of soft or fibrous packing for preventing leakage between
the plug and barrel of stop-cocks has been so long known, its use for this purpose
has not hitherto been, in all cases, completely satisfactory. The manner in which
such cocks have usually been constructed has prevented the full realization of the
advantages which might have been derived from the use of such packing, or has
given rise to, or been attended by, disadvantages which have partially neutralized
its good qualities.
In devising our improved stop-cocks, we have sought to provide against the
defects attendant upon, and difficulties experienced in, the use of fibrous, soft, or
flexible packing, and, although, as above stated, the application of this kind of

page_text: packing in grooves or channels formed in the cock-barrel has been so long known,
yet we have adopted this method of its application in our improved cocks as herein
specified, and, by our improvements, we obtain all the advantages derivable from
soft or fibrous packing, without the disadvantages heretofore attending the
employment of the same. Our improved stop-cocks may be constructed of any
required dimensions and may be used for any purposes for which stop-cocks are
required.
Our invention is illustrated in the accompanying drawing, in which
Figure 1 is a longitudinal sectional side elevation of a stop-cock such as we
use for water-gauges.
Figure 2 is a longitudinal section on a plane at right angles to Figure 1.
Figures 3 and 4 are similar views of another cock which may be used for steam,
water or gas pipes.
Figure 5 is a longitudinal central section showing a slight modification of our
invention.
.
Like letters indicate the same parts throughout the drawing.
a is the barrel, shell, or socket, is the plug,
is the hole or aperture through
the same, c c are the fluid ways or passages in the barrel or shell.
We use either a cylindrical plug or one that is slightly taper or conical as
shown in Figures 1 and 3, or, in some instances, we make the plug partly
cylindrical and partly taper, as shown in Figure 5.
It will be seen that the said plug differs from that of an ordinary cock in respect
of the flange, head or collar 62 at one end, and also in respect of its inverted
position. It is by the use of this novel form and arrangement in combination
with asbestos or other fibrous or soft packing at d, e, and e¹ that we obtain the
results which are the object of our invention.
"
We have shown the flange or head of the plug with the surface that bears on the
packing flat or perpendicular to the axis of the plug, but this surface may be
curved or bevelled, and we wish it understood that we consider any form of
enlargement or protuberance of the plug, which will act to compress the packing at
this end of the plug sufficiently for the purpose of our invention, to be an equivalent
for the flange shown in the drawing.
The packing is arranged in the following manner, that is to say, in the barrel,
cavity or socket surrounding the plug we form grooves d at the sides of the fluid
passages c, c and extending beyond the same at their upper and lower ends. These
grooves terminate in chambers or recesses e, e¹ formed in the two ends of the barrel
or body of the cock, as clearly shown in Figure 1.
It will be seen that the packing surface is all within the space between the two
ends of the plug, and that there is no packing in contact with the surface of either
end of the plug, and that the use of packing at these parts is unnecessary, as,
without having it at the ends, we completely enclose or surround the fluid ways or
passages with the packing.
We provide for adjusting the packing, during the use of the cock, by the
following means, that is to say, we place over the soft packing at e a metal ring or
gland f. Over this ring f we place a washer g, and outside of this washer we fit,
on the screw-threaded part of the plug-spindle or stem, a nut h.
-P
In Figure 3, f¹, g₁ are keys or feathers fixed or formed on the ring or gland f
and the washer g, and fitting into grooves a¹, b³ in the barrel a and the stem or
spindle of the plug b. These keys or feathers prevent the turning of the ring or
gland with the said plug, and ensure the turning of the washer g therewith.
It will be seen that, in respect of the endwise compression of the packing, the
same may be said to be "self-contained "in relation to the plug, that is to say, the
endwise pressure is exerted only between the parts of the plug and not between
the plug and the barrel or its adjuncts. It is obvious that, by tightening the said
nut upon the said stem, the plug will be drawn upward in its socket or barrel, or the
ring will be forced downward. Now, inasmuch as the collar or head 62 of the plug,
and the ring fare in contact with the fibrous packing at e and e', the adjustment or

page_text: movement of the plug or the ring as aforesaid cannot take place without causing,
or tending to cause, endwise compression and consequent lateral expansion of one
or both of the packing rings e, e².
The tendency of the nut to draw the plug upward in its socket would be resisted
only by the packing at el, and its tendency to force the ring f downward or, inward
would be resisted only by the packing at e, were it not for the arrangement of this
packing at e and el in combination with the packing in the grooves at d. But,
with this arrangement as shown, the pressure in either direction will to some extent
affect, and be resisted by, the whole of the packing, that is to say, the action of the
out, when the same is tightened upon the plug-spindle, will tend to cause the
end wise compression and consequent lateral expansion of the packing at every part
of the same.
Moreover, as the stress produced by the tightening of the nut is thus
felt throughout the whole extent of the packing, it is obvious that the softest or
least compressed parts, that is to say, the parts which are most in need of com-
pression, will first yield to the stress and adapt themselves to the surface of the
plug, and, therefore, there will be an even or uniform contact throughout the entire
area of the packing, so that the joint will be everywhere perfectly tight without
excessive pressure and friction upon the plug. Moreover the gland or ring f, as
shown in the drawing, does not exert its pressure upon a hard or rigid surface, the
said gland or ring having its "home or bearing upon the soft and elastic substance
of the packing and acting to adjust the same as above described.
"
In some instances, we make the plug, as shown in Figure 5, with a flange, head
or enlargement b at one end as above described and make the intermediate
portion of the plug cylindrical and the other end taper or conical as at 65,
and we arrange the packing e at this end to bear against this taper or conical
portion. Or we may vary the form of the plug in other respects without materially
affecting its utility for the purpose of our invention so long as we retain the flange,
head or enlargement on one end thereof as aforesaid.
Being aware, as above stated, of the knowledge already.existing of the use of
soft or fibrous materials and the manner of their application for making the plugs
of stop-cocks tight in their barrels or sockets, we wish it distinctly understood that
we make no claim in respect of the use of such materials otherwise than in connec-
tion with our improved devices or arrangements, but we claim the improvements
in and relating to stop-cocks as hereinabove specified, that is to say, we claim
First. The plug provided at one end with a flange, head or enlargement, and at
the other end with means for assisting or facilitating its adjustment when in use,
substantially as, and for the purpose, specified.
Second. The combination of the said plug with a barrel or socket lined or packed
with soft, fibrous, or pliable material, substantially as, and for the purpose,
specified.
Third. A stop-cock provided with a plug so constructed and arranged in com-
bination with soft, fibrous or compressible packing fitted in the barrel or socket
substantially as described, that the action of a nut or other device at one end of
the said plug will effect or tend to effect the adjustment or tightening of the
packing thereupon throughout the entire area of the packed surface, as above set
forth.
Fourth. A stop-cock constructed as shown in either of the figures of the accom-
panying drawing for the purposes specified.
HASELTINE, LAKE & Co.,
For the Applicant.