IMPROVEMENTS IN COCKS."
Year: 1877

page_text: LETTERS PATENT to John Dewrance, of 176, Great Dover Street, Borough,
in the County of Surrey, for the Invention of "IMPROVEMENTS IN COCKS."
PROVISIONAL SPECIFICATION left by the said John Dewrance at the
Office of the Commissioners of Patents on the 23rd October 1877.
JOHN DEWRANCE, of 176, Great Dover Street, Borough, in the County of
Surrey. " IMPROVEMENTS IN COCKS."
This Invention relates especially to cocks which are kept tight by means of
packing and not by the accurate fitting of metallic surfaces. I construct such cocks
with a cylindrical or parallel plug, and the shell of the cock I make with a cor-
responding cavity, which is closed at one end and open at the other, to admit the
plug. Near the open end the cavity is enlarged and adapted to receive a gland to
compress the packing.
The packing which I employ is composed of asbestos; it is placed around the plug
in the enlarged part of the cavity, also in grooves formed in the shell parallel to the
axis of the plug, and on either side of and at some distance from the waterway, and
also between the end of the plug and the bottom of the cavity in the shell. The
packing in the grooves is continuous with the packing at the end of the plug, and
with that around it, near its outer end, upon which the pressure of the gland is
immediately exerted.
The gland also bears upon a shoulder on the plug, forcing it down and compelling
it to compress the packing resting upon the bottom of the cavity in the shell."
To reduce the area of the rubbing surface at the inner end of the plug I some-
times form a cylindrical cavity within it, and a corresponding projecting then
made upon the bottom of the cavity in the shell to enter the hole in the plug, and
thus the packing at the end of the plug is confined to a comparatively narrow
ring.
I sometimes turn down the plug to form a shoulder where the packing comes
into contact with it, and I employ a gland, which is drawn up by side bolts. I

page_text: form lugs upon the gland corresponding to the packing grooves formed in the shell
to compress the packing which these grooves contain.
For some descriptions of cocks I place the packing on the plug in place of in the
shell. Packing grooves are then formed in the plug, parallel with its axis, and on
either side of the waterway, and the ends of the plug are roughened, so that when
the plug is turned round within the cavity of the shell it carries the whole of the
packing with it.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Dewrance in the Great Seal Patent Office on the 23rd April
1878.
JOHN DEWRANCE, of 176, Great Dover Street, Borough, in the County of
Surrey. "IMPROVEMENTS IN COCKS."
This Invention relates especially to cocks which are kept tight by means of
packing, and not by the accurate fitting of metallic surfaces. I construct such cocks
with a cylindrical or parallel plug, and the shell of the cock I make with a cor-
responding cavity which is closed at one end and open at the other to admit the
plug. Near the open end the cavity is enlarged, and adapted to receive a gland to
compress the packing.
The packing which I employ is composed of asbestos; it is placed around the plug
in the enlarged part of the cavity, also in grooves formed in the shell parallel to the
axis of the plug and on either side of and at some distance from the waterway, and
also between the end of the plug and the bottom of the cavity in the shell. The
packing in the grooves is continuous with the packing at the end of the plug, and
with that around it near its outer end, upon which the pressure of the gland is
immediately exerted.
The gland also bears upon a shoulder on the plug, forcing it down and compelling
it to compress the packing resting upon the bottom of the cavity in the shell.
To reduce the area of the rubbing surface at the inner end of the plug I some-
times form a cylindrical cavity within it, and a corresponding projection is then
made upon the bottom of the cavity in the shell to enter the hole in the plug,
and thus the packing at the end of the plug is confined to a comparatively narrow
ring.
I sometimes turn down the plug to form a shoulder, where the packing comes
into contact with it, and I employ a gland which is drawn up by side bolts. I form
lugs upon the gland corresponding to the packing grooves formed in the shell to
compress the packing which these grooves contain.
For some descriptions of cocks I place the packing on the plug in place of in the
shell. Packing grooves are then formed in the plug, parallel with its axis, and on
either side of the waterway, and the ends of the plug are roughened, so that when
the plug is turned round within the cavity of the shell it carries the whole of the
packing with it.
In order that my said Invention may be most fully understood and readily carried
into effect, I will proceed to describe the Drawings hereunto annexed.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is an elevation; Figure 2 is a plan; Figure 3 is a vertical section; and
Figure 4 is an horizontal section of a parallel plug asbestos packed cock constructed
according to my Invention.
The cavity in the shell to receive the plug is open at one end only. The packing
is received into a cavity a beneath the plug, also into grooves b, b, formed in
the walls of the plug cavity, and into the enlargement of the plug cavity near
its mouth at c.
I make the plugs of these cocks parallel, so that they can be pressed down
on to the bottom packing, or eased off without tightening or slackening the packing
in the grooves or top space, and so that the plug and shell can never be jammed,
metal to metal, or be so far separated as injuriously to expose the packing. The
plug should fit in its cavity so that at all temperatures to which the cock will be
exposed the plug will just turn freely within the shell.
The packing which I employ is asbestos in a fibrous state, and mixed with sufficient
grease to cause it to cohere when subjected to pressure. The packing is first filled
into the space a, the plug is then inserted and forced down upon the packing; it
remains in its place whilst the grooves b, b, are gradually filled and rammed up
solid, and afterwards the space c is filled. There is just so much packing rammed
into the space c that when it is sufficiently compressed the gland cover d rests upon
the shoulder of the plug, and forcing it down compels it to compress the packing in
the space.a.
A washer e is sometimes used between the gland cover and the shoulder of the
plug to reduce friction.
When a metallic washer is used the bearing surface marked d' is not continuous
around the plug, otherwise from inequality in screwing up the gland there might be
risk of undue pressure upon one side of the plug.
Figures 5, 6, 7, and 8 represent a similar cock, but of larger dimensions. In this
case in order to save space two of the four grooves b, b, are brought close up to the
waterway, and at the same time a stop is applied upon the gland cover, which pre-
vents the plug being turned in such manner as to expose the packing in these
grooves to the fluid flowing through the cock. In this case also in place of the
washer e and the raised bearing surfaces d' on the under side of the gland cover,
packing is inserted between the shoulder of the plug and the under side of the gland
cover.
Figure 9 shows in section, and Figure 10 in plan, another cock in which the
washer is used, but in place of the bearing surfaces on the gland cover two set
screws are inserted. They pass through the cover and are screwed down at the last
to give a light pressure upon the shoulder of the plug in order that it may compress
the packing beneath the plug. In this cock also the cavity a at the bottom of the
plug is shown of an annular form, an arrangement which reduces the amount of
packing at this part.
Figure 11 is a section of a cock in which the shoulder of the plug is so made
that the packing at c rests upon it, and serves to force down the plug on to the
packing at a.
The cavity c, as here shown, is circular, and of such a size that the upper ends of
the grooves b, b, fall within it; the cavity c may however be of the same diameter
as the plug, and then the upper ends of the grooves b, b, will fall without its
circumference, in which case a gland cover is employed, such as is shown at
Figure 12, which is an under side view. The projections d², d³, correspond to
the grooves b, b, these grooves being in this arrangement somewhat enlarged at
their upper ends, so that by the screwing up of the gland the packing is com-
pressed not only in the annular space c, but also in the grooves b, b.
The cock represented in Figure 11 is a three-way cock, a connection at the
bottom being provided communicating with the interior of the plug; with this

page_text: exception, the arrangement of the lower part of the cock is similar to that shown in
Figure 9.
As represented in the Drawing the connecting piece at the bottom of the cock is
made separately and screwed into its place, but this is done only for convenience of
construction, as the packing can be put in entirely from the top, as in the other
arrangements.
Figure 13 is a section on the line 1, 1, in Figure 11.
Figure 14 is an elevation; Figure 15, a plan; Figure 16, a vertical section; and
Figure 17, an horizontal section of a cock with a cylindrical plug, and in which the
plug carries the whole of the packing. The cavity in the shell is without grooves;
but grooves f, f, corresponding to the grooves b, b, of the other arrangements are
formed in the plug; the packing is inserted in the same way as when packing the
cocks, having the grooves in the shell. There are points or projections formed both
upon the under side and on the shoulder of the plug, which serve to attach the
packing to the plug; and when the plug is turned the packing moves with it.
Having thus described the nature of my said Invention and the manner of per-
forming the same, I would have it understood that I claim,―
First. The construction of cocks having the packing surrounding the passages
in such manner that the inner end of the plug abutts on and compresses the
portion of the packing contained in the bottom of the plug cavity, substantially as
described.
Second. The construction of packed cocks, substantially as described, and repre-
sented in the annexed Drawings.
In witness whereof, I, the said John Dewrance, have hereunto set my hand
and seal, this Eighteenth day of April, in the year of our Lord One
thousand eight hundred and seventy-eight.
JOHN DEWRANCE,
(L.S.)