IMPROVEMENTS IN COCKS
Year: 1876

page_text: LETTERS PATENT to John Dewrance, of 176, Great Dover Street, Borough,
in the County of Surrey, and James Mallinson, of Welwyn, in the County of
Herts, for the Invention of "IMPROVEMENTS IN COCKS."
Sealed the 2nd February 1877, and dated the 22nd November 1876.
PROVISIONAL. SPECIFICATION left by the said John Dewrance and James
Mallinson at the Office of the Commissioners of Patents on the 22nd November
1876.
JOHN DEWRANCE, of 176, Great Dover Street, Borough, in the County of Surrey,
and JAMES MALLINSON, of Welwyn, in the County of Herts. "IMPROVEMENTS IN
Cocks."
The object of this Invention is to improve the construction of cocks the tightness
of which is wholly dependent on the introduction of packing, and in nowise upon
the fit of the metallic parts.
The packing is applied in grooves formed in the shell or body (two on either
side) at right angles to the direction of the flow of the fluid, which grooves open
into spaces running around the shell one above and the other below the waterway.
Into this shell is placed a taper plug, and the taper is in the opposite direction from
that which is usual, the handle or instrument by which the plug is turned being
applied at the smaller end of the plug. This arrangement is more convenient for
applying the packing than if the taper were in the contrary direction. The packing
after being well rammed into the grooves is compressed by means of glands screwed
or bolted to both ends of the shell; these glands compress the packing especially at
the ends of the plug, and the packing, together with the gland, prevents the plug.
from being forced into rubbing contact with the shell. The glands also hold the
plug in position. With cocks thus made tight by compressed packing we employ
plugs plated with nickel or other metal not readily corroded, and by reason of such
plated plugs working against non-metallic bearings they do not become scored or cut
as they would be if they worked against metal surfaces.

page_text: We also employ asbestos as the packing, though hemp or other packing may be
used, as described in the Specification of a former Patent granted to one of us.
To adjust the working of the larger sizes we sometimes insert in the bottom
gland a regulating screw and lock nut, the plug being supported on the end of the
screw, this allows of the plug being eased off its bearings without slackening the
gland.
In cases where the handle is of a piece with the plug we form the handle to spring
from the larger end of the plug, and we make one of the glands to overlap this end
of the plug so as to hold the plug in position.
In order to prevent the current of steam, water, or other fluid rushing against
the packing when the cocks are partly open, we make the distance between the
edge of the waterway and the edge of the recess in the shell equal to or greater than
the width of waterway; by this means the current is entirely cut off while the way
in the plug is passing the packing upon the cock being shut.
Sometimes to reduce the enlargement of size this arrangement entails we make
the plug with a stop and to work backwards and forwards a little over a quarter of
a revolution; we also provide for the opening and shutting of the cocks a toothed
rack or wheel fitted on the plug and a worm mounted on the shell, then by means
of a wheel or lever the plug may be turned as slowly as desired. This arrangement
is more applicable to the larger sizes.
We also make cocks or the plugs of cocks of stone or other such like ware for
acids or purposes where metals would speedily decay.
We also construct steam and other cocks with piston-like valves, consisting of a.
ring of compressible packing, by preference asbestos, held between two metal discs.
This valve by a screw or other appliance can be forced into a cylindrical seat so as
to close the waterway or passage through it. When the valve is home one of the
metal discs of the piston valve comes against a flange within the seating and the
further action of the screw or equivalent appliance causes the two discs of the piston
valve to approach each other and compresses the packing between them.
To protect the packing when the valve is withdrawn from its seat a cylindrical
shield is provided; it is able to slide on the valve stem and a spring presses it
forward.
In the operation of closing the cock the shield first comes against the upper part
of the valve seat, and being stopped by it the valve travels out of the shield and
into the cylindrical seating. Similarly in opening the cock the valve leaves the
seating and enters the shield before the latter passes out of contact with the valve
Beat.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Dewrance and James Mallinson in the Great Seal Patent Office
on the 22nd May 1877.
JOHN DEWRANCE, of 176, Great Dover Street, Borough, in the County of Surrey,
and JAMES MALLINSON, of Welwyn, in the County of Herts. "IMPROVEMENTS IN
Cocks."
The object of our Invention is to improve the construction of cocks, the tightness
of which is wholly dependent on the introduction of packing, and in nowise upon
the fit of the metallic parts.
Figure 1 is a vertical section, and Figure 2 is a horizontal section of a cock con-
structed according to our Invention. a is the shell; b is the plug; and c, c, aro
glands. The packing is applied in grooves a¹, a¹, formed in the shell at right angles
to the direction of the flow of the fluid, and these grooves open into spaces a³, a²,

page_text: running around the shell one above and the other below the waterways. The plug b
is taper in the opposite direction from that which is usual in plug taps, the handle
or instrument by which the plug is turned being applied at the sinaller end of the
plug. This arrangement is more convenient for applying the packing than if the
taper were in the contrary direction. We employ asbestos as the packing, although
hemp or other packing may be used, as is stated in the Specification of a former
Patent granted to one of us. The packing after being well rammed into the grooves
and spaces is compressed by means of the glands c, c. These glands compress the
packing, especially at the ends of the plug, and the packing together with the form
of the gland prevents the plug from being forced into rubbing contact with the shell.
In order to prevent the current of steam, water, or other fluid rushing against the
packing when the cocks are partly opened we make the distance between the edge
of the waterway and the edge of the recess in the shell a little greater than the
width of the waterway. By this means the current is entirely cut off while the
way in the plug is passing the packing. These wide marginal spaces between
the waterway and the packing grooves are in the Drawing marked a³.
Figure 3 is a vertical section of another cock constructed according to our
Invention.
Figure 4 is a horizontal section; Figure 5 is an end elevation; and Figure 6 is a
plan of the same.
In this cock, in order to reduce the enlargement of size which the provision of the
wide marginal spaces ³ entails, we make the plug with a stop and to work back-
wards and forwards a little over a quarter of a revolution. The stop upon the plug
is marked b¹ and there is a corresponding stop or shoulder e¹ upon the gland.
It will be observed that in this cock the wide marginal space a³ is on one side
only of the waterway, so that for a given width of waterway the cock is of smaller
diameter than when the plug is allowed to turn both ways or all round.
We also provide for the opening and closing of the cocks a toothed quadrant d
fitted on the plug, and a worm e mounted on an axis, carried by the shell and
actuated by a hand wheel or lever. By these means the plug may be turned as
slowly as may be desired, and the shock which results from the sudden closing
of cocks upon water pipes is avoided.
To adjust the working of the larger sizes of cocks we sometimes insert into the
bottom gland a regulating screw c with a lock nut. The plug is supported upon the
end of the screw, and as this is adjustable. the plug can be eased off its bearing
without slackening the gland. We sometimes introduce an india-rubber ring on
the lower gland at as an extra security against leakage. It will be observed
that in this cock the glands are applied with bolts, and in Figures 1 and 2
they are shown screwed into their places; they may be made either way.
We do not in all cases employ four grooves to receive the packing, thus
Figure 7 is a vertical section, and Figure 8 is a horizontal section of a cock in
which there are but two such grooves, the delivery being downwards through
the plug. It will also be observed that in this cock the taper of the plug is
in the opposite direction from that shown in the preceding Figures. This is
sometimes convenient where as in the Figure the handle is formed of a piece with
the plug.
Having thus described the nature of our said Invention and the manner of
performing the same, we would have it understood that we claim,―
First. The construction of cocks substantially as described in respect to Figures 1
and 2, of which construction it is an essential peculiarity that marginal spaces a³
should be provided at the sides of the waterway, so that the packing may never be
exposed to the current of the fluid.
Second. The construction of packed cocks with marginal spaces a³, but on one
Bide only, and with stops to limit the rotation of the plug, substantially as described
in respect to the Figures 3, 4, 5, and 6.

page_text: Third. The construction of packed cocks, substantially as described and represented
in the Drawings hereunto annexed.
In witness whereof, I, the said John Dewrance, have hereunto set my
hand and seal, this Seventeenth day of May, in the year of our Lord
One thousand eight hundred and seventy-seven.
JOHN DEWRANCE. (L.S.)