Year: 1888

page_text: 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 this invention to be as follows:-
Our invention relates to stop-cocks which have a taper plug made fluid tight in the
socket by fibrous or other suitable substance or coinpound of sufficient hardness and
stability not to abrade or disintegrate and properly prepared and applied to prevent
scoring or cutting of the parts of the cock by the turning of the plug in the barrel
or socket.
We apply the said fibrous or other suitable packing substance or compound to the plug,
that is to say, we insert the said packing in straight and circular grooves or rebates
surrounding the water-apertures of the plug.
The said packing can be advantageously formed of vulcanite, ebonite or the like,
or of vulcanizable compounds of asbestos or of other fibrous material, or of the
substance known as "vulcanized fibre," or of other suitable substances hardened or
otherwise treated so that, when applied to the plug as above set forth, it will be
sufficiently hard and incompressible to form a smooth and close surface which will
fit and seat itself in the barrel or socket and will resist compression and ensure a
durable fluid-tight fit upon its taper metal seat without excessive friction.
Our invention affords great facility for applying the packing in the grooves in
such a manner as to ensure an accurate fitting of the plug in the socket. Also for
interchangeability, as we are enabled to adopt a very convenient method of repairing
cocks that from long use or accident have become imperfect, that is to say, we use
a mould or die which is a fac-simile of the socket, and we make the packing on the
plug fit the said die as if it were the socket of the cock in which the said plug is to
be used. The barrels of the cocks are preferably made to standard sizes and are
marked with numbers or otherwise distinguished, and the moulds or dies are marked
to correspond so that they can always be identified as appertaining to particular cocks.
Therefore, if at any time a cock becomes leaky or otherwise defective, a new plug

page_text: already packed can be substituted for the old one, and, being made to a standard size,
will accurately fit the barrel of the said cock and can be applied thereto with little
trouble or cost without removing the said barrel from its place, or packing the barrel
in its position.
Our improved cock requires no packing other than that in the plug applied as
above described. Moreover it enables us to dispense with the gland or stuffing box
usually employed in packed cocks as hitherto constructed, the plug being merely
held to its metallic seat by a cover or other suitable device or by a screw-nut at the
small end of the plug. Or we may apply our invention to what are termed inverted
plug cocks; and in no case is this improved cock rendered tight by the compression
of packing or the contact of metallic parts, the packing requiring merely to be held
to its seat without compression of any kind or the application of any force greater
than that required to keep the plug from being blown or raised from its conical
seat.
This invention allows the cock to be constructed with a barrel or socket of
comparatively small diameter and weight.
1 11. 0
1
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicants.

page_text: Improvements in and relating to Stop-cocks.
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 this invention 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 which have a taper plug constructed with a
bearing surface which, though not so hard as the metal whereof the cock is formed,
has sufficient hardness and stability to permit it to be accurately fitted to, or seated
in the barrel or socket, and to he fluid-tight therein without compression, and which
will be free from liability to abrade or disintegrate and will not score or cut the
surface of the barrel or socket.
In the specification of our former Letters l'atent dated June 9th 1887, No. 8312,
we have described a stop-cock which has a bearing surface formed by packing
placed in grooves in the barrel or socket, and we mentioned the properties or qualities
which we require in our packing material and the manner in which we fit the barrel
or socket of a stop-cock therewith to form a bearing surface for the plug so that the
latter shall be fluid-tight in the barrel without compression. Inasmuch as the
bearing surface formed by this packing has a degree of hardness intermediate
between that of the metal and that formed by fibrous or soft packing such as is ordinarily
used in packed cocks, it may be termed a semi-hard hearing surface. According
to our present invention, we use packing forming a semi-hard bearing surface, but
we apply the same to the plug instead of to the barrel, that is to say, the packing
substance or compound is attached to and forms part of the plug.
The said packing is fixed in straight and annular grooves or rebates surrounding
the fluid-apertures of the plug as shown in the accompanying drawings, in which
Figure 1 is a side view of a plug constructed according to our present inven-
tion, and
Figures 2, 3, 4, 5, 6, 7 and 8 are vertical sections of stop-cocks fitted with our
improved plugs.
Like letters indicate corresponding parts throughout the drawings.
A is the barrel, and B the plug. B₁ is the packing forming the bearing surface of
the plug.
It is not practicable or necessary for us to name all of the substances which may be
used in or for the manufacture or preparation of our packing material. The qualities
or properties which we require may be imparted to various substances or compounds
not having any other similarity or relation to each other than their fitness for our
purpose.
We have found that the said packing can be advantageously formed of, or partly
of, vulcanite, ebonite or the like, or of vulcanizable compounds of asbestos or of other
fibrous material, or of the substance known as "vulcanized fibre," or of other suitable
substance hardened or otherwise treated so that, when applied to or forming part of

page_text: the plug as above set forth, it will be sufficiently hard and otherwise of a nature or
quality to form a durable, smooth and close surface, which, when properly placed in
the barrel or socket, will, without compression or force tending to reduce the volume
of the packing substance (and therefore without excessive friction), fit fluid-tight
upon its taper metal seat. And, so long as the packing substance or compound
possesses these properties, we do not limit ourselves in respect of the materials of
which it is manufactured or prepared, or exclude any materials which can be used in
the construction of the plug as above described, so that the said plug will have a
bearing surface which will be fluid-tight in the barrel as herein specified.
Our invention obviates the difficulty which has heretofore existed in applying
packing to stop-cocks in such a manner as to ensure an accurate fitting of the plug in
the barrel or socket. The insertion of the packing material into grooves in the barrel
has always been attended with difficulty, but its application to the grooves in the plug
is a very simple and easy matter. Moreover by the said invention we provide for
interchangeability, that is to say, the exchange or substitution of one plug for another
plug in any stop-cock. We are thereby enabled to very readily, conveniently and
cheaply repair cocks that from long use or accident have become imperfect. For this
purpose we adopt the following method of constructing the plugs, viz.We use a
mould or die which, in respect of its interior surface, is a fuc-simile of the barrel or
socket of the stop-cock in which the plug is to be used. We make the grooved part
or body of the plug of metal or other suitable material and form the semi-hard bearing
surface thereon, so that it will fit the said die in all respects exactly as it will have to
fit the barrel or socket of the said stop-cock. And it is obvious that we can thus
manufacture any number of stop-cocks with barrels identically the same, so that any
plug made in the corresponding die or mould will fit either of the said barrels. The cocks
can be made to standard sizes and numbered or otherwise distinguished and the moulds
or dies can be correspondingly numbered or distinguished, so that any die or mould
can be readily identified as appertaining to its particular size or gauge of cocks.
Therefore, if at any time a stop-cock which has been manufactured by us and sent to
any part of the world becomes leaky or otherwise defective, a new plug made to the
same standard size in the die or mould, and therefore accurately fitting the barrel of
the said cock, can be applied thereto with very little trouble or expense. And it is
especially important that the plug can be exchanged or renewed without having to
disconnect the stop-cock and remove it from its place and without having to repack
the barrel. This is an advantage which is impracticable and unattainable with stop-
cocks as hitherto manufactured. Another advantage afforded by our invention is that
it allows a stop-cock to be constructed with a barrel or socket of comparatively small
diameter and weight.
Our improved stop-cock requires no packing for ensuring fluid-tightness other than
that applied to the plug as above described and as shown in Figure 1. Therefore we
can dispense with the gland or stuffing-box usually employed in packed stop-cocks as
hitherto constructed; the plug being merely held to its metallic seat by a cover a as
shown in Figures 2, 3 or 4; or by a screw-nut at the small end of the plug as in
Figure 5. Or we may apply our invention to what are termed inverted plug cocks as
in Figures 6 and 7, the plug being held to its seat by a screw-nut b. In some
instances, we construct our stop-cocks with a compound lid or cover, that is to say,
a cover a¹ provided with a gland a² as in Figure 8. We prefer that a ring c of suitable
packing material should be inserted between the plug B and the cover to prevent
metallic contact between these parts and thus facilitate the rotation of the plug in the
barrel or socket.
Our improvements are applicable to plug-cocks whether made of metal, porcelain or
other material.
We wish it understood that we do not claim generally or irrespectively of our within
described improvements the application of fibrous materials or compounds or other
substances to the plug of a stop-cock. Nor do we make any claim relative to the
making of a plug fluid-tight in the barrel or socket by compression, as in cocks
which have loose packing material squeezed or rammed into grooves or slots or placed

page_text: in a cavity or space around the plug. Our principle of construction, as hereinbefore stated,
entirely obviates the necessity for any compression or squeezing of the packing material
to ensure fluid-tightness and our invention is thereby clearly distinguishable from those
stop-cocks which depend for their fluid-tightness upon the maintenance of a stress or
pressure upon the packing material. That is to say, the bearing surface of our plugs,
though formed of fibrous or other substance which is soft relatively to the metal or
other surface on which it works, is made fluid-tight by being so accurately and closely
fitted to the same as to prevent the passage of fluid between the two surfaces and not
in any wise by being kept by compression in a sufficiently dense or compact condition
to prevent the passage of the fluid between the surfaces of the plug and barrel.
In no case do we consider it necessary to provide for the application of any force or
restraint greater than that required to keep the plug from being blown or raised from
its taper or conical seat.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we wish it understood that
we claim :-
First. A plug constructed partly of a substance or compound forming a bearing
surface such as we have herein specified, to be fitted in the barrel or socket of a stop-
cock so that without compression it will be fluid-tight therein.
Second. The herein described method of providing for the interchangeability or
renewal of the plugs of stop-cocks.
Third. A stop-cock provided with our improved plug and constructed substantially
as described with reference to Figure 2, 3, 4, 5, 6, 7, or 8 of the accompanying
drawings.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicants.