IMPROVEMENTS ASBESTOS PACKED COCKS AND THE PROCESS OF PACKING THE SAME
Year: 1883

page_text: LETTERS PATENT to John Dewrance of 158 Great Dover Street Lambeth
in the County of Surrey Engineer for an Invention of IMPROVEMENTS
ASBESTOS PACKED COCKS AND THE PROCESS OF PACKING THE SAME
IN
PROVISIONAL SPECIFICATION left by the said John Dewrance at the Office
of the Commissioners of Patents on the 6th September 1883.
JOHN DEWRANCE of 158 Great Dover Street [Lambeth] in the County of Surrey
Engineer IMPROVEMENTS IN ASBESTOS PACKED COCKS AND THE PROCESS OF
PACKING THE SAME
This invention has for its object certain improvements in Asbestos packed cocks
and the process of packing the same.
In asbestos packed cocks the asbestos fibre is caulked into grooves formed
either in the body or plug and running parallel with the axis of the plug.
It has however been found necessary to protect the packing from the current of
steam or other fluid because it is liable to be blown out and this is at present
effected by making the distance between the edge of the waterway and the
grooves a little greater than the width of the waterway so that the current of
steam or other fluid is cut off while the packing is exposed in turning the cock.
This arrangement however increases the diameter of the cock.
In order to avoid the necessity for this protection I treat asbestos in the
following way.
The asbestos is thoroughly dried and the fibres separated as much as possible
and saturated with a solution of the best india rubber or gutta percha mixed with
sufficient sulphur to cause it to vulcanize when exposed to heat or it may be
mixed with any other material that has a tendency to harden it.
The asbestos when dry is packed into the grooves of the cock in the usual way
and the cock is heated to a sufficient temperature to vulcanize the india rubber so
D

page_text: as to thoroughly cement the fibres of the asbestos together and prevent them being
blown out by the current of steam or other fluid the grooves can then he placed as
near to the edge of the waterway in the body or the plug as is convenient which
considerably reduces the size of the cock.
Where the cocks are not subjected to heat it may not be necessary to vulcanize
the India rubber.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Dewrance in the Patent Office on the 4th March 1884.
JOHN DEWRANCE of 158 Great Dover Street Lambeth in the County of Surrey
Engineer 'IMPROVEMENTS IN ASBESTOS PACKED COCKS AND THE PROCESS OF
PACKING THE SAME
"
This Invention has for its object certain improvements in asbestos Packed Cocks
and the process of packing the same.
In Asbestos packed Cocks the asbestos fibre is caulked into the grooves formed
either in the body or plug and running parallel with the axis of the plug.
It has however been found necessary to protect the packing from the current of
steam or other fluid because it is liable to be blown out and this is at present
effected by making the distance between the edge of the water way and the
grooves a little greater than the width of the water way so that the current of
steam or other fluid is cut off while the packing is exposed in turning the plug
This arrangement however increases the diameter of the Cock.
In order to avoid the necessity for this protection I treat Asbestos in tho
following way;-
The Asbestos is thoroughly dried and the fibres separated as much as possible
and saturated with a solution of the best india rubber or gutta percha mixed with
sufficient sulphur to cause it to vulcanize when exposed to heat or it may be mixed
with any other material that has a tendency to harden indiarubber
This asbestos when dry is packed into the grooves of the cock in the usual way
and the cock is heated to a sufficient temperature to vulcanize the india rubber so
as to thoroughly cement the fibres of the asbestos together and prevent them being
blown out by the current of steam or other fluid: the grooves can then be placed
as near to the edge of the water way in the body or the plug as is convenient,
which considerably reduces the size of the cock.
Figure 1. of the accompanying drawings is a sectional elevation and Figure 2 is
a sectional plan Figure 3 front elevation and Figure 4 a top plan of a cock
constructed according to this Invention. A is the shell or body, B the plug, C the
gland and D a loose ferrule which forms a circular cavity for the packing in the
bottom of the shell. EE are the grooves which join the ring of packing in
the bottom of the shell to the ring of packing on the upper end of the plug.
It may sometimes be advantageous that all the packing in the cock should be
coated with india rubber in the way described but packing treated in this way is
necessary for the grooves of a cock constructed in this way because these grooves

page_text: E E are so close to the water way that the packing would be blown out when
uncovered by the plug.
Having now described my invention and the manner of carrying the same into
effect I would have it understood that what I claim as my Invention is; the
coating of the fibres of Asbestos with india rubber mixed with material for
vulcanizing substantially as described so that when the asbestos is caulked into the
grooves of cocks the influence of heat shall vulcanize the rubber and cement
the fibres of the asbestos and prevent them being blown out by the current of
steam or other fluid passing through the cock.
Secondly The cementation of the fibres of asbestos in the grooves of cocks
substantially as described.
In witness whereof I the said John Dewrance have hereunto set my hand and
seal this fourth day of March in the year of our Lord One thousand eight
hundred and eighty four.
JOHN DEWRANCE (L.S.)